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Chanda J, Wagman J, Chanda B, Kaniki T, Ng’andu M, Muyabe R, Mwenya M, Sakala J, Miller J, Mwaanga G, Simubali L, Mburu MM, Simulundu E, Mungo A, Fraser K, Mwandigha L, Ashton R, Yukich J, Harris AF, Burkot TR, Orange E, Littrell M, Entwistle J. Feeding rates of malaria vectors from a prototype attractive sugar bait station in Western Province, Zambia: results of an entomological validation study. Malar J 2023; 22:70. [PMID: 36855105 PMCID: PMC9974387 DOI: 10.1186/s12936-023-04491-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 02/13/2023] [Indexed: 03/02/2023] Open
Abstract
BACKGROUND Attractive targeted sugar bait (ATSB) stations are a promising new approach to malaria vector control that could compliment current tools by exploiting the natural sugar feeding behaviors of mosquitoes. Recent proof of concept work with a prototype ATSB® Sarabi Bait Station (Westham Co., Hod-Hasharon, Israel) has demonstrated high feeding rates and significant reductions in vector density, human biting rate, and overall entomological inoculation rate for Anopheles gambiae sensu lato (s.l.) in the tropical savannah of western Mali. The study reported here was conducted in the more temperate, rainier region of Western Province, Zambia and was designed to confirm the primary vector species in region and to estimate corresponding rates of feeding from prototype attractive sugar bait (ASB) Sarabi Bait Stations. METHODS The product evaluated was the Sarabi v1.1.1 ASB station, which did not include insecticide but did include 0.8% uranine as a dye allowing for the detection, using UV fluorescence light microscopy, of mosquitoes that have acquired a sugar meal from the ASB. A two-phase, crossover study design was conducted in 10 village-based clusters in Western Province, Zambia. One study arm initially received 2 ASB stations per eligible structure while the other initially received 3. Primary mosquito sampling occurred via indoor and outdoor CDC Miniature UV Light Trap collection from March 01 through April 09, 2021 (Phase 1) and from April 19 to May 28, 2021 (Phase 2). RESULTS The dominant vector in the study area is Anopheles funestus s.l., which was the most abundant species group collected (31% of all Anophelines; 45,038/144,5550), had the highest sporozoite rate (3.16%; 66 positives out of 2,090 tested), and accounted for 94.3% (66/70) of all sporozoite positive specimens. Of those An. funestus specimens further identified to species, 97.2% (2,090/2,150) were An. funestus sensu stricto (s.s.). Anopheles gambiae s.l. (96.8% of which were Anopheles arabiensis) is a likely secondary vector and Anopheles squamosus may play a minor role in transmission. Overall, 21.6% (9,218/42,587) of An. funestus specimens and 10.4% (201/1,940) of An. gambiae specimens collected were positive for uranine, translating into an estimated daily feeding rate of 8.9% [7.7-9.9%] for An. funestus (inter-cluster range of 5.5% to 12.7%) and 3.9% [3.3-4.7%] for An. gambiae (inter-cluster range of 1.0-5.2%). Feeding rates were no different among mosquitoes collected indoors or outdoors, or among mosquitoes from clusters with 2 or 3 ASBs per eligible structure. Similarly, there were no correlations observed between feeding rates and the average number of ASB stations per hectare or with weekly rainfall amounts. CONCLUSIONS Anopheles funestus and An. gambiae vector populations in Western Province, Zambia readily fed from the prototype Sarabi v1.1.1 ASB sugar bait station. Observed feeding rates are in line with those thought to be required for ATSB stations to achieve reductions in malaria transmission when used in combination with conventional control methods (IRS or LLIN). These results supported the decision to implement a large-scale, epidemiological cluster randomized controlled trial of ATSB in Zambia, deploying 2 ATSB stations per eligible structure.
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Affiliation(s)
| | | | | | | | | | | | | | - Jimmy Sakala
- PATH, Lusaka, Zambia ,Present Address: Jhpeigo, Lusaka, Zambia
| | | | | | | | | | | | | | - Keith Fraser
- grid.7445.20000 0001 2113 8111Imperial College London, London, UK
| | - Lazaro Mwandigha
- grid.7445.20000 0001 2113 8111Imperial College London, London, UK ,grid.4991.50000 0004 1936 8948Present Address: University of Oxford, Oxford, UK
| | - Ruth Ashton
- grid.265219.b0000 0001 2217 8588School of Public Health and Tropical Medicine, Tulane University, New Orleans, USA
| | - Joshua Yukich
- grid.265219.b0000 0001 2217 8588School of Public Health and Tropical Medicine, Tulane University, New Orleans, USA
| | | | - Thomas R. Burkot
- grid.1011.10000 0004 0474 1797Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Australia
| | - Erica Orange
- grid.415269.d0000 0000 8940 7771PATH, Seattle, USA
| | - Megan Littrell
- grid.416809.20000 0004 0423 0663PATH, Washington, DC USA
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Eisele TP, Kleinschmidt I, Sarrassat S, terKuile F, Miller J, Chanda J, Silumbe K, Samuels A, Janssen J, Ogwang C, Bradley J, Orange E, Yukich J, Ashton R, Kyomuhangi I, Harris AF, Doumbia S, Toure M, Moumine M, Majambere S, Mburu MM, Mwaanga G, Simubali L, Simulundu E, Bennett A, Slutsker L, Muller G, Ochomo E, Gimnig J, Johnson PCD, Wagman J, Littrell M. Attractive targeted sugar bait phase III trials in Kenya, Mali, and Zambia. Trials 2022; 23:640. [PMID: 35945599 PMCID: PMC9361277 DOI: 10.1186/s13063-022-06555-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 07/16/2022] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) target night-time indoor biting mosquitoes and effectively reduce malaria transmission in rural settings across Africa, but additional vector control tools are needed to interrupt transmission. Attractive targeted sugar baits (ATSBs) attract and kill mosquitoes, including those biting outdoors. Deployment of ATSBs incorporating the insecticide dinotefuran was associated with major reductions in mosquito density and longevity in Mali. The impact of this promising intervention on malaria transmission and morbidity now needs to be determined in a range of transmission settings. METHODS/DESIGN We will conduct three similar stand-alone, open-label, two-arm, cluster-randomized, controlled trials (cRCTs) in Mali, Kenya, and Zambia to determine the impact of ATSB + universal vector control versus universal vector control alone on clinical malaria. The trials will use a "fried-egg" design, with primary outcomes measured in the core area of each cluster to reduce spill-over effects. All household structures in the ATSB clusters will receive two ATSBs, but the impact will be measured in the core of clusters. Restricted randomization will be used. The primary outcome is clinical malaria incidence among children aged 5-14 years in Mali and 1-14 years in Kenya and Zambia. A key secondary outcome is malaria parasite prevalence across all ages. The trials will include 76 clusters (38 per arm) in Mali and 70 (35 per arm) in each of Kenya and Zambia. The trials are powered to detect a 30% reduction in clinical malaria, requiring a total of 3850 person-years of follow-up in Mali, 1260 person-years in Kenya, and 1610 person-years in Zambia. These sample sizes will be ascertained using two seasonal 8-month cohorts in Mali and two 6-month seasonal cohorts in Zambia. In Kenya, which has year-round transmission, four 6-month cohorts will be used (total 24 months of follow-up). The design allows for one interim analysis in Mali and Zambia and two in Kenya. DISCUSSION Strengths of the design include the use of multiple study sites with different transmission patterns and a range of vectors to improve external validity, a large number of clusters within each trial site, restricted randomization, between-cluster separation to minimize contamination between study arms, and an adaptive trial design. Noted threats to internal validity include open-label design, risk of contamination between study arms, risk of imbalance of covariates across study arms, variation in durability of ATSB stations, and potential disruption resulting from the COVID-19 pandemic. TRIAL REGISTRATION Zambia: ClinicalTrials.gov NCT04800055 . Registered on March 15, 2021 Mali: ClinicalTrials.gov NCT04149119 . Registered on November 4, 2019 Kenya: ClinicalTrials.gov NCT05219565 . Registered on February 2, 2022.
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Chanda J, Saili K, Phiri F, Stevenson JC, Mwenda M, Chishimba S, Mulube C, Mambwe B, Lungu C, Earle D, Bennett A, Eisele TP, Kamuliwo M, Steketee RW, Keating J, Miller JM, Sikaala CH. Pyrethroid and Carbamate Resistance in Anopheles funestus Giles along Lake Kariba in Southern Zambia. Am J Trop Med Hyg 2020; 103:90-97. [PMID: 32618244 PMCID: PMC7416976 DOI: 10.4269/ajtmh.19-0664] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Whereas data on insecticide resistance and its underlying mechanisms exist for parts of Zambia, data remain limited in the southern part of the country. This study investigated the status of insecticide resistance, metabolic mechanisms, and parasite infection in Anopheles funestus along Lake Kariba in southern Zambia. Indoor-resting mosquitoes were collected from 20 randomly selected houses within clusters where a mass drug administration trial was conducted and raised to F1 progeny. Non–blood-fed 2- to 5-day-old female An. funestus were exposed to WHO insecticide-impregnated papers with 0.05% deltamethrin, 0.1% bendiocarb, 0.25% pirimiphos-methyl, or 4% dichloro-diphenyl-trichloroethane (DDT). In separate assays, An. funestus were pre-exposed to piperonyl butoxide (PBO) to determine the presence of monooxygenases. Wild-caught An. funestus that had laid eggs for susceptibility assays were screened for circumsporozoite protein of Plasmodium falciparum by ELISA, and sibling species were identified by polymerase chain reaction. Anopheles funestus showed resistance to deltamethrin and bendiocarb but remained susceptible to pirimiphos-methyl and DDT. The pre-exposure of An. funestus to PBO restored full susceptibility to deltamethrin but not to bendiocarb. The overall sporozoite infection rate in An. funestus populations was 5.8%. Detection of pyrethroid and carbamate resistance in An. funestus calls for increased insecticide resistance monitoring to guide planning and selection of effective insecticide resistance management strategies. To prevent the development of resistance and reduce the underlying vectorial capacity of mosquitoes in areas targeted for malaria elimination, an effective integrated vector management strategy is needed.
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Affiliation(s)
- Javan Chanda
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Kochelani Saili
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Foustina Phiri
- National Malaria Elimination Centre, Zambia Ministry of Health, Lusaka, Zambia
| | - Jennifer C Stevenson
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.,Macha Research Trust, Choma, Zambia
| | - Mulenga Mwenda
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Sandra Chishimba
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Conceptor Mulube
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Brenda Mambwe
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Christopher Lungu
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Duncan Earle
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Adam Bennett
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, California
| | - Thomas P Eisele
- Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Mulakwa Kamuliwo
- National Malaria Elimination Centre, Zambia Ministry of Health, Lusaka, Zambia
| | | | - Joseph Keating
- Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - John M Miller
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Chadwick H Sikaala
- SADC Malaria Elimination Eight Secretariat, Windhoek, Namibia.,National Malaria Elimination Centre, Zambia Ministry of Health, Lusaka, Zambia
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Kiware SS, Russell TL, Mtema ZJ, Malishee AD, Chaki P, Lwetoijera D, Chanda J, Chinula D, Majambere S, Gimnig JE, Smith TA, Killeen GF. A generic schema and data collection forms applicable to diverse entomological studies of mosquitoes. Source Code Biol Med 2016; 11:4. [PMID: 27022408 PMCID: PMC4809029 DOI: 10.1186/s13029-016-0050-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 03/17/2016] [Indexed: 11/10/2022]
Abstract
BACKGROUND Standardized schemas, databases, and public data repositories are needed for the studies of malaria vectors that encompass a remarkably diverse array of designs and rapidly generate large data volumes, often in resource-limited tropical settings lacking specialized software or informatics support. RESULTS Data from the majority of mosquito studies conformed to a generic schema, with data collection forms recording the experimental design, sorting of collections, details of sample pooling or subdivision, and additional observations. Generically applicable forms with standardized attribute definitions enabled rigorous, consistent data and sample management with generic software and minimal expertise. Forms use now includes 20 experiments, 8 projects, and 15 users at 3 research and control institutes in 3 African countries, resulting in 11 peer-reviewed publications. CONCLUSION We have designed generic data schema that can be used to develop paper or electronic based data collection forms depending on the availability of resources. We have developed paper-based data collection forms that can be used to collect data from majority of entomological studies across multiple study areas using standardized data formats. Data recorded on these forms with standardized formats can be entered and linked with any relational database software. These informatics tools are recommended because they ensure that medical entomologists save time, improve data quality, and data collected and shared across multiple studies is in standardized formats hence increasing research outputs.
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Affiliation(s)
- Samson S Kiware
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania ; Department of Mathematics, Statistics and Computer Science, Marquette University, Milwaukee, WI 53201-1881 USA
| | - Tanya L Russell
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania ; Pacific Malaria Initiative Support Centre, School of Population Health, University of Queensland, Brisbane, 4006 Australia
| | - Zacharia J Mtema
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
| | - Alpha D Malishee
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
| | - Prosper Chaki
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
| | - Dickson Lwetoijera
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania ; Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
| | | | | | - Silas Majambere
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania ; Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
| | - John E Gimnig
- Division of Parasitic Diseases, Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Thomas A Smith
- Department of Public Health and Epidemiology, Swiss Tropical Institute, Socinstrasse 57, Basel, CH 4002 Switzerland
| | - Gerry F Killeen
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania ; Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
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Hamainza B, Sikaala CH, Moonga HB, Chanda J, Chinula D, Mwenda M, Kamuliwo M, Bennett A, Seyoum A, Killeen GF. Incremental impact upon malaria transmission of supplementing pyrethroid-impregnated long-lasting insecticidal nets with indoor residual spraying using pyrethroids or the organophosphate, pirimiphos methyl. Malar J 2016; 15:100. [PMID: 26893012 PMCID: PMC4758014 DOI: 10.1186/s12936-016-1143-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Accepted: 02/04/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Long-lasting, insecticidal nets (LLINs) and indoor residual spraying (IRS) are the most widely accepted and applied malaria vector control methods. However, evidence that incremental impact is achieved when they are combined remains limited and inconsistent. METHODS Fourteen population clusters of approximately 1000 residents each in Zambia's Luangwa and Nyimba districts, which had high pre-existing usage rates (81.7 %) of pyrethroid-impregnated LLINs were quasi-randomly assigned to receive IRS with either of two pyrethroids, namely deltamethrin [Wetable granules (WG)] and lambdacyhalothrin [capsule suspension (CS)], with an emulsifiable concentrate (EC) or CS formulation of the organophosphate pirimiphos methyl (PM), or with no supplementary vector control measure. Diagnostic positivity of patients tested for malaria by community health workers in these clusters was surveyed longitudinally over pre- and post-treatment periods spanning 29 months, over which the treatments were allocated and re-allocated in advance of three sequential rainy seasons. RESULTS Supplementation of LLINs with PM CS offered the greatest initial level of protection against malaria in the first 3 months of application (incremental protective efficacy (IPE) [95 % confidence interval (CI)] = 0.63 [CI 0.57, 0.69], P < 0.001), followed by lambdacyhalothrin (IPE [95 % CI] = 0.31 [0.10, 0.47], P = 0.006) and PM EC (IPE, 0.23 [CI 0.15, 0.31], P < 0.001) and then by deltamethrin (IPE [95 % CI] = 0.19 [-0.01, 0.35], P = 0.064). Neither pyrethroid formulation provided protection beyond 3 months after spraying, but the protection provided by both PM formulations persisted undiminished for longer periods: 6 months for CS and 12 months for EC. The CS formulation of PM provided greater protection than the combined pyrethroid IRS formulations throughout its effective life IPE [95 % CI] = 0.79 [0.75, 0.83] over 6 months. The EC formulation of PM provided incremental protection for the first 3 months (IPE [95 % CI] = 0.23 [0.15, 0.31]) that was approximately equivalent to the two pyrethroid formulations (lambdacyhalothrin, IPE [95 % CI] = 0.31 [0.10, 0.47] and deltamethrin, IPE [95 % CI] = 0.19 [-0.01, 0.35]) but the additional protection provided by the former, apparently lasted an entire year. CONCLUSION Where universal coverage targets for LLIN utilization has been achieved, supplementing LLINs with IRS using pyrethroids may reduce malaria transmission below levels achieved by LLIN use alone, even in settings where pyrethroid resistance occurs in the vector population. However, far greater reduction of transmission can be achieved under such conditions by supplementing LLINs with IRS using non-pyrethroid insecticide classes, such as organophosphates, so this is a viable approach to mitigating and managing pyrethroid resistance.
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Affiliation(s)
- Busiku Hamainza
- National Malaria Control Centre, Ministry of Health, Chainama Hospital, College Grounds, off Great East road, PO Box 32509, Lusaka, Zambia.
- Malaria Elimination Initiative, Global Health Group, University of California, 550 16th St., San Francisco, CA, 94158, USA.
| | - Chadwick H Sikaala
- National Malaria Control Centre, Ministry of Health, Chainama Hospital, College Grounds, off Great East road, PO Box 32509, Lusaka, Zambia.
- Malaria Elimination Initiative, Global Health Group, University of California, 550 16th St., San Francisco, CA, 94158, USA.
| | - Hawela B Moonga
- National Malaria Control Centre, Ministry of Health, Chainama Hospital, College Grounds, off Great East road, PO Box 32509, Lusaka, Zambia.
| | - Javan Chanda
- National Malaria Control Centre, Ministry of Health, Chainama Hospital, College Grounds, off Great East road, PO Box 32509, Lusaka, Zambia.
| | - Dingani Chinula
- National Malaria Control Centre, Ministry of Health, Chainama Hospital, College Grounds, off Great East road, PO Box 32509, Lusaka, Zambia.
| | - Mulenga Mwenda
- National Malaria Control Centre, Ministry of Health, Chainama Hospital, College Grounds, off Great East road, PO Box 32509, Lusaka, Zambia.
| | - Mulakwa Kamuliwo
- National Malaria Control Centre, Ministry of Health, Chainama Hospital, College Grounds, off Great East road, PO Box 32509, Lusaka, Zambia.
| | - Adam Bennett
- Malaria Elimination Initiative, Global Health Group, University of California, 550 16th St., San Francisco, CA, 94158, USA.
| | - Aklilu Seyoum
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
| | - Gerry F Killeen
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
- Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, PO Box 53, Ifakara, Morogoro, United Republic of Tanzania.
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Raman VS, Das A, Stöckelhuber KW, Eshwaran SB, Chanda J, Malanin M, Reuter U, Leuteritz A, Boldt R, Wießner S, Heinrich G. Improvement of mechanical performance of solution styrene butadiene rubber by controlling the concentration and the size of in situ derived sol–gel silica particles. RSC Adv 2016. [DOI: 10.1039/c5ra25423j] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The silica particles generated from alkoxide route are grown onto the styrene butadiene polymer chains and offer a direct rubber to filler interaction. As a result, superior mechanical performance of the elastomeric composites can be realised.
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Affiliation(s)
- V. Sankar Raman
- Leibniz-Institut für Polymerforschung Dresden e. V
- 01069 Dresden
- Germany
- Technische Universität Dresden
- Institut für Werkstoffwissenschaft
| | - A. Das
- Leibniz-Institut für Polymerforschung Dresden e. V
- 01069 Dresden
- Germany
- Technical University of Tampere
- 33101 Tampere
| | | | - S. B. Eshwaran
- Leibniz-Institut für Polymerforschung Dresden e. V
- 01069 Dresden
- Germany
- Technische Universität Dresden
- Institut für Werkstoffwissenschaft
| | - J. Chanda
- Leibniz-Institut für Polymerforschung Dresden e. V
- 01069 Dresden
- Germany
- Technische Universität Dresden
- Institut für Werkstoffwissenschaft
| | - M. Malanin
- Leibniz-Institut für Polymerforschung Dresden e. V
- 01069 Dresden
- Germany
| | - U. Reuter
- Leibniz-Institut für Polymerforschung Dresden e. V
- 01069 Dresden
- Germany
| | - A. Leuteritz
- Leibniz-Institut für Polymerforschung Dresden e. V
- 01069 Dresden
- Germany
| | - R. Boldt
- Leibniz-Institut für Polymerforschung Dresden e. V
- 01069 Dresden
- Germany
| | - S. Wießner
- Leibniz-Institut für Polymerforschung Dresden e. V
- 01069 Dresden
- Germany
- Technische Universität Dresden
- Institut für Werkstoffwissenschaft
| | - G. Heinrich
- Leibniz-Institut für Polymerforschung Dresden e. V
- 01069 Dresden
- Germany
- Technische Universität Dresden
- Institut für Werkstoffwissenschaft
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Lobo NF, St Laurent B, Sikaala CH, Hamainza B, Chanda J, Chinula D, Krishnankutty SM, Mueller JD, Deason NA, Hoang QT, Boldt HL, Thumloup J, Stevenson J, Seyoum A, Collins FH. Unexpected diversity of Anopheles species in Eastern Zambia: implications for evaluating vector behavior and interventions using molecular tools. Sci Rep 2015; 5:17952. [PMID: 26648001 PMCID: PMC4673690 DOI: 10.1038/srep17952] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 11/09/2015] [Indexed: 11/21/2022] Open
Abstract
The understanding of malaria vector species in association with their bionomic traits is vital for targeting malaria interventions and measuring effectiveness. Many entomological studies rely on morphological identification of mosquitoes, limiting recognition to visually distinct species/species groups. Anopheles species assignments based on ribosomal DNA ITS2 and mitochondrial DNA COI were compared to morphological identifications from Luangwa and Nyimba districts in Zambia. The comparison of morphological and molecular identifications determined that interpretations of species compositions, insecticide resistance assays, host preference studies, trap efficacy, and Plasmodium infections were incorrect when using morphological identification alone. Morphological identifications recognized eight Anopheles species while 18 distinct sequence groups or species were identified from molecular analyses. Of these 18, seven could not be identified through comparison to published sequences. Twelve of 18 molecularly identified species (including unidentifiable species and species not thought to be vectors) were found by PCR to carry Plasmodium sporozoites - compared to four of eight morphological species. Up to 15% of morphologically identified Anopheles funestus mosquitoes in insecticide resistance tests were found to be other species molecularly. The comprehension of primary and secondary malaria vectors and bionomic characteristics that impact malaria transmission and intervention effectiveness are fundamental in achieving malaria elimination.
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Affiliation(s)
- Neil F Lobo
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA 46556
| | - Brandyce St Laurent
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA 46556
| | - Chadwick H Sikaala
- National Malaria Control Centre, Chainama Hospital College Grounds, Off Great East road, P.O. Box 32509, Lusaka, Zambia
| | - Busiku Hamainza
- National Malaria Control Centre, Chainama Hospital College Grounds, Off Great East road, P.O. Box 32509, Lusaka, Zambia
| | - Javan Chanda
- National Malaria Control Centre, Chainama Hospital College Grounds, Off Great East road, P.O. Box 32509, Lusaka, Zambia
| | - Dingani Chinula
- National Malaria Control Centre, Chainama Hospital College Grounds, Off Great East road, P.O. Box 32509, Lusaka, Zambia
| | | | - Jonathan D Mueller
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA 46556
| | - Nicholas A Deason
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA 46556
| | - Quynh T Hoang
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA 46556
| | - Heather L Boldt
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA 46556
| | - Julie Thumloup
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA 46556
| | - Jennifer Stevenson
- Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.; and Macha Research Trust, Choma, Zambia
| | - Aklilu Seyoum
- Abt Associates, Africa Indoor Residual Spraying Project Ghana office, Accra, Ghana
| | - Frank H Collins
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA 46556
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Thomsen EK, Strode C, Hemmings K, Hughes AJ, Chanda E, Musapa M, Kamuliwo M, Phiri FN, Muzia L, Chanda J, Kandyata A, Chirwa B, Poer K, Hemingway J, Wondji CS, Ranson H, Coleman M. Underpinning sustainable vector control through informed insecticide resistance management. PLoS One 2014; 9:e99822. [PMID: 24932861 PMCID: PMC4059741 DOI: 10.1371/journal.pone.0099822] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 05/19/2014] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND There has been rapid scale-up of malaria vector control in the last ten years. Both of the primary control strategies, long-lasting pyrethroid treated nets and indoor residual spraying, rely on the use of a limited number of insecticides. Insecticide resistance, as measured by bioassay, has rapidly increased in prevalence and has come to the forefront as an issue that needs to be addressed to maintain the sustainability of malaria control and the drive to elimination. Zambia's programme reported high levels of resistance to the insecticides it used in 2010, and, as a result, increased its investment in resistance monitoring to support informed resistance management decisions. METHODOLOGY/PRINCIPAL FINDINGS A country-wide survey on insecticide resistance in Zambian malaria vectors was performed using WHO bioassays to detect resistant phenotypes. Molecular techniques were used to detect target-site mutations and microarray to detect metabolic resistance mechanisms. Anopheles gambiae s.s. was resistant to pyrethroids, DDT and carbamates, with potential organophosphate resistance in one population. The resistant phenotypes were conferred by both target-site and metabolic mechanisms. Anopheles funestus s.s. was largely resistant to pyrethroids and carbamates, with potential resistance to DDT in two locations. The resistant phenotypes were conferred by elevated levels of cytochrome p450s. CONCLUSIONS/SIGNIFICANCE Currently, the Zambia National Malaria Control Centre is using these results to inform their vector control strategy. The methods employed here can serve as a template to all malaria-endemic countries striving to create a sustainable insecticide resistance management plan.
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Affiliation(s)
- Edward K. Thomsen
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Clare Strode
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Kay Hemmings
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Angela J. Hughes
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | | | - Mulenga Musapa
- Zambia Integrated Systems Strengthening Program, Abt Associates, Lusaka, Zambia
| | | | | | - Lucy Muzia
- Zambia Integrated Systems Strengthening Program, Abt Associates, Lusaka, Zambia
| | | | | | - Brian Chirwa
- Zambia Integrated Systems Strengthening Program, Abt Associates, Lusaka, Zambia
| | - Kathleen Poer
- Zambia Integrated Systems Strengthening Program, Abt Associates, Lusaka, Zambia
| | - Janet Hemingway
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Charles S. Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Hilary Ranson
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Michael Coleman
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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Sikaala CH, Chinula D, Chanda J, Hamainza B, Mwenda M, Mukali I, Kamuliwo M, Lobo NF, Seyoum A, Killeen GF. A cost-effective, community-based, mosquito-trapping scheme that captures spatial and temporal heterogeneities of malaria transmission in rural Zambia. Malar J 2014; 13:225. [PMID: 24906704 PMCID: PMC4060139 DOI: 10.1186/1475-2875-13-225] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 05/21/2014] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Monitoring mosquito population dynamics is essential to guide selection and evaluation of malaria vector control interventions but is typically implemented by mobile, centrally-managed teams who can only visit a limited number of locations frequently enough to capture longitudinal trends. Community-based (CB) mosquito trapping schemes for parallel, continuous monitoring of multiple locations are therefore required that are practical, affordable, effective, and reliable. METHODS A CB surveillance scheme, with a monthly sampling and reporting cycle for capturing malaria vectors, using Centers for Disease Control and Prevention light traps (LT) and Ifakara Tent Traps (ITT), were conducted by trained community health workers (CHW) in 14 clusters of households immediately surrounding health facilities in rural south-east Zambia. At the end of the study, a controlled quality assurance (QA) survey was conducted by a centrally supervised expert team using human landing catch (HLC), LT and ITT to evaluate accuracy of the CB trapping data. Active surveillance of malaria parasite infection rates amongst humans was conducted by CHWs in the same clusters to determine the epidemiological relevance of these CB entomological surveys. RESULTS CB-LT and CB-ITT exhibited relative sampling efficiencies of 50 and 7%, respectively, compared with QA surveys using the same traps. However, cost per sampling night was lowest for CB-LT ($13.6), followed closely by CB-ITT ($18.0), both of which were far less expensive than any QA survey (HLC: $138, LT: $289, ITT: $269). Cost per specimen of Anopheles funestus captured was lowest for CB-LT ($5.3), followed by potentially hazardous QA-HLC ($10.5) and then CB-ITT ($28.0), all of which were far more cost-effective than QA-LT ($141) and QA-ITT ($168). Time-trends of malaria diagnostic positivity (DP) followed those of An. funestus density with a one-month lag and the wide range of mean DP across clusters was closely associated with mean densities of An. funestus caught by CB-LT (P < 0.001). CONCLUSIONS CB trapping schemes appear to be far more affordable, epidemiologically relevant and cost-effective than centrally supervised trapping schemes and may well be applicable to enhance intervention trials and even enable routine programmatic monitoring of vector population dynamics on unprecedented national scales.
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Affiliation(s)
- Chadwick H Sikaala
- National Malaria Control Centre, Chainama Hospital College Grounds, Off Great East road, P,O, Box 32509 Lusaka, Zambia.
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Chanda E, Chanda J, Kandyata A, Phiri FN, Muzia L, Haque U, Baboo KS. Efficacy of ACTELLIC 300 CS, pirimiphos methyl, for indoor residual spraying in areas of high vector resistance to pyrethroids and carbamates in Zambia. J Med Entomol 2013; 50:1275-1281. [PMID: 24843932 DOI: 10.1603/me13041] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The selection of insecticide resistance in malaria vectors has the potential to compromise any insecticide-based malaria vector control program. To ensure that transmission-interrupting tools remain effective, and their choice is evidence based, insecticide surveillance and monitoring is essential. This study assessed and compared the residual efficacy of an organophosphate insecticide pirimiphos methyl (ACTELLIC 300 CS, 0-2-diethylamino-6-methylpyrimidin-4-yl 0, 0-dimethylphosphorothioate) at 1 g/m2 and the pyrethroid deltamethrin (K-Othrine WG 250, (S)-alpha-cyano-3-phenoxybenzyl (1R, 3R)-3- (2,2-dibromovinyl)-2,2-dimethylcyclopropane carboxylate) at 20 mg/m2 for indoor residual spraying on cement and mud-rendered walls inside houses. Insecticide susceptibility profiles of local malaria vectors were also assessed using World Health Organization standard protocols. The residual efficacy of ACTELLIC 300 CS on cement and mud walls lasted for 5 mo on both surfaces, with complete mortality of Anopheles gambiae sensu stricto Giles (Kisumu strain) (Diptera: Culicidae) in cone assays. By 8 mo, the average residual effect of ACTELLIC 300 CS remained much better on cement walls than on mud walls but not significantly different from deltamethrin-treated cement walls. Anopheles funestus sensu stricto Giles was resistant to 0.05% deltamethrin and 0.01% bendiocarb but remained completely susceptible to 5% malathion and 4% dichlorodiphenyltrichloroethane. The duplicated P450 genes, CYP6P9a and CYP6P9b, were found to be highly overexpressed in deltamethrin-resistant An. funestus s.s as compared with bendiocarb-resistant individuals. Pirimiphos methyl CS is recommended for intra-domiciliary spraying for malaria control and could replace dichlorodiphenyltrichloroethane within the context of an insecticide resistance management strategy.
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Sikaala CH, Killeen GF, Chanda J, Chinula D, Miller JM, Russell TL, Seyoum A. Evaluation of alternative mosquito sampling methods for malaria vectors in Lowland South--East Zambia. Parasit Vectors 2013; 6:91. [PMID: 23570257 PMCID: PMC3639086 DOI: 10.1186/1756-3305-6-91] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 04/04/2013] [Indexed: 01/05/2023] Open
Abstract
Background Sampling malaria vectors and measuring their biting density is of paramount importance for entomological surveys of malaria transmission. Human landing catch (HLC) has been traditionally regarded as a gold standard method for surveying human exposure to mosquito bites. However, due to the risk of human participant exposure to mosquito-borne parasites and viruses, a variety of alternative, exposure-free trapping methods were compared in lowland, south-east Zambia. Methods Centres for Disease Control and Prevention miniature light trap (CDC-LT), Ifakara Tent Trap model C (ITT-C), resting boxes (RB) and window exit traps (WET) were all compared with HLC using a 3 × 3 Latin Squares design replicated in 4 blocks of 3 houses with long lasting insecticidal nets, half of which were also sprayed with a residual deltamethrin formulation, which was repeated for 10 rounds of 3 nights of rotation each during both the dry and wet seasons. Results The mean catches of HLC indoor, HLC outdoor, CDC-LT, ITT-C, WET, RB indoor and RB outdoor, were 1.687, 1.004, 3.267, 0.088, 0.004, 0.000 and 0.008 for Anopheles quadriannulatus Theobald respectively, and 7.287, 6.784, 10.958, 5.875, 0.296, 0.158 and 0.458, for An. funestus Giles, respectively. Indoor CDC-LT was more efficient in sampling An. quadriannulatus and An. funestus than HLC indoor (Relative rate [95% Confidence Interval] = 1.873 [1.653, 2.122] and 1.532 [1.441, 1.628], respectively, P < 0.001 for both). ITT-C was the only other alternative which had comparable sensitivity (RR = 0.821 [0.765, 0.881], P < 0.001), relative to HLC indoor other than CDC-LT for sampling An. funestus. Conclusions While the two most sensitive exposure-free techniques primarily capture host-seeking mosquitoes, both have substantial disadvantages for routine community-based surveillance applications: the CDC-LT requires regular recharging of batteries while the bulkiness of ITT-C makes it difficult to move between sampling locations. RB placed indoors or outdoors and WET had consistently poor sensitivity so it may be useful to evaluate additional alternative methods, such as pyrethrum spray catches and back packer aspirators, for catching resting mosquitoes.
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Affiliation(s)
- Chadwick H Sikaala
- National Malaria Control Centre, Chainama Hospital College Grounds, Lusaka, Zambia.
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Chanda E, Kandyata A, Chanda J, Phiri FN, Muzia L, Kamuliwo M. The Efficacy of Vectron 20 WP, Etofenprox, for Indoor Residual Spraying in Areas of High Vector Resistance to Pyrethroids and Organochlorines in Zambia. ISRN Prev Med 2012; 2013:371934. [PMID: 24967135 PMCID: PMC4062862 DOI: 10.5402/2013/371934] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 07/15/2012] [Indexed: 11/23/2022]
Abstract
The selection of insecticide resistance in malaria vectors has the potential to compromise any insecticide-based vector control programme. To ensure that the insecticides used for indoor residual spraying and insecticide-treated nets in Zambia remain effective and their choice is evidence based, insecticide resistance surveillance and monitoring are essential. This study assessed and compared the residual efficacy of etofenprox (Vectron 20 WP), an ether pyrethroid, at 0.1 g/m2 with pyrethroids: bifenthrin (Bistar 10 WP) and lambda-cyhalothrin (Icon 10 CS) at 25 mg/m2 for indoor residual spraying. We also assessed the resistance status of etofenprox to local malaria vectors, An. funestus s.s and An. gambiae s.s, using World Health Organization standard protocols. The residual efficacy of Vectron 20 WP on cement, rendered walls of houses lasted for four months with 100% mortality. By the eighth month, the killing effect had reduced to 73.8% compared to 63.3% for bifenthrin and 77.0% for lambda-cyhalothrin. Susceptibility tests using standard World Health Organization assays on An. gambiae s.s showed susceptibility to etofenprox (0.1%) but some resistance was detected to Anopheles funestus s.s. The product is recommended as an ideal insecticide for indoor residual spraying for malaria control in Zambia as part of a resistance management programme in selected areas of the country.
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Affiliation(s)
- Emmanuel Chanda
- National Malaria Control Centre, Ministry of Health, Directorate of Public Health and Research, P.O. Box 32509, Chainama College Grounds, 10101 Lusaka, Zambia
| | - Alister Kandyata
- National Malaria Control Centre, Ministry of Health, Directorate of Public Health and Research, P.O. Box 32509, Chainama College Grounds, 10101 Lusaka, Zambia
| | - Javan Chanda
- National Malaria Control Centre, Ministry of Health, Directorate of Public Health and Research, P.O. Box 32509, Chainama College Grounds, 10101 Lusaka, Zambia
| | - Faustina N Phiri
- National Malaria Control Centre, Ministry of Health, Directorate of Public Health and Research, P.O. Box 32509, Chainama College Grounds, 10101 Lusaka, Zambia
| | - Lucy Muzia
- Zambia Integrated Systems Strengthening Programme, Malaria Control Unit, Plot 1321 Enock Kavu Road, Rhodes Park, P.O. Box 39090, 10101 Lusaka, Zambia
| | - Mulakwa Kamuliwo
- National Malaria Control Centre, Ministry of Health, Directorate of Public Health and Research, P.O. Box 32509, Chainama College Grounds, 10101 Lusaka, Zambia
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Seyoum A, Sikaala CH, Chanda J, Chinula D, Ntamatungiro AJ, Hawela M, Miller JM, Russell TL, Briët OJT, Killeen GF. Human exposure to anopheline mosquitoes occurs primarily indoors, even for users of insecticide-treated nets in Luangwa Valley, South-east Zambia. Parasit Vectors 2012; 5:101. [PMID: 22647493 PMCID: PMC3432592 DOI: 10.1186/1756-3305-5-101] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2012] [Accepted: 05/23/2012] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Current front line malaria vector control methods such as indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs), rely upon the preference of many primary vectors to feed and/or rest inside human habitations where they can be targeted with domestically-applied insecticidal products. We studied the human biting behaviour of the malaria vector Anopheles funestus Giles and the potential malaria vector Anopheles quadriannulatus Theobald in Luangwa valley, south-east Zambia. METHODS Mosquitoes were collected by human landing catch in blocks of houses with either combined use of deltamethrin-based IRS and LLINs or LLINs alone. Human behaviour data were collected to estimate how much exposure to mosquito bites indoors and outdoors occurred at various times of the night for LLIN users and non-users. RESULTS Anopheles funestus and An. quadriannulatus did not show preference to bite either indoors or outdoors: the proportions [95% confidence interval] caught indoors were 0.586 [0.303, 0.821] and 0.624 [0.324, 0.852], respectively. However, the overwhelming majority of both species were caught at times when most people are indoors. The proportion of mosquitoes caught at a time when most people are indoors were 0.981 [0.881, 0.997] and 0.897 [0.731, 0.965], respectively, so the proportion of human exposure to both species occuring indoors was high for individuals lacking LLINs (An. funestus: 0.983 and An. quadriannulatus: 0.970, respectively). While LLIN users were better protected, more than half of their exposure was nevertheless estimated to occur indoors (An. funestus: 0.570 and An. quadriannulatus: 0.584). CONCLUSIONS The proportion of human exposure to both An. funestus and An. quadriannulatus occuring indoors was high in the area and hence both species might be responsive to further peri-domestic measures if these mosquitoes are susceptible to insecticidal products.
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Affiliation(s)
- Aklilu Seyoum
- Liverpool School of Tropical Medicine, Vector Group, Pembroke Place, Liverpool, L3 5QA, UK
| | - Chadwick H Sikaala
- Liverpool School of Tropical Medicine, Vector Group, Pembroke Place, Liverpool, L3 5QA, UK
- National Malaria Control Centre, PO Box 32509, Lusaka, Zambia
| | - Javan Chanda
- National Malaria Control Centre, PO Box 32509, Lusaka, Zambia
| | - Dingani Chinula
- National Malaria Control Centre, PO Box 32509, Lusaka, Zambia
| | - Alex J Ntamatungiro
- Ifakara Health Institute, Biomedical and Environmental Thematic Group, Kiko Avenue, PO Box 78373, Dar es Salaam, Tanzania
| | - Moonga Hawela
- National Malaria Control Centre, PO Box 32509, Lusaka, Zambia
| | - John M Miller
- PATH Malaria Control and Evaluation Partnership in Africa (MACEPA), National Malaria Control Centre, Lusaka, Zambia
| | - Tanya L Russell
- Liverpool School of Tropical Medicine, Vector Group, Pembroke Place, Liverpool, L3 5QA, UK
- Ifakara Health Institute, Biomedical and Environmental Thematic Group, Kiko Avenue, PO Box 78373, Dar es Salaam, Tanzania
- James Cook University, Faculty of Medicine, Health and Molecular Sciences, Cairns, Australia
| | - Olivier J T Briët
- Swiss Tropical and Public Health Institute, Department of Public Health and Epidemiology, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Gerry F Killeen
- Liverpool School of Tropical Medicine, Vector Group, Pembroke Place, Liverpool, L3 5QA, UK
- Ifakara Health Institute, Biomedical and Environmental Thematic Group, Kiko Avenue, PO Box 78373, Dar es Salaam, Tanzania
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Abstract
BACKGROUND To reverse preexisting coronary graft spasm, we investigated the vasodilative effect of the average therapeutic plasma concentration of nitroglycerin (NTG) alone and various calcium antagonists in combination with NTG in human arterial and venous conduits. METHODS Vasodilative effects of 2 x 10(-8) mol/L NTG alone and 10(-8) mol/L NTG in combination with 2.2 x 10(-7) mol/L diltiazem, 2.8 x 10(-7) mol/L nifedipine, 10(-7) mol/L verapamil, or 5.6 x 10(-8) mol/L nicardipine were assessed in human radial artery, internal thoracic artery, and saphenous vein segments precontracted with a mixture of ten times the maximum plasma concentrations of endothelin-1 (8.6 x 10(-13) mol/L), angiotensin II (36 x 10(-11) mol/L), 5-hydroxytryptamine (3.4 x 10(-7) mol/L), and norepinephrine (1.7 x 10(-8) mol/L). The studies were done in organ baths. RESULTS The therapeutic concentration of NTG alone or nifedipine, verapamil, diltiazem, or nicardipine in combination with NTG caused equal relaxation in a particular group of vascular segments (average vasodilation: radial artery, 83% to 95% [p = 0.7608 by analysis of variancel; saphenous vein, 47% to 70% [p = 0.3142]; internal thoracic artery, 54% to 79% [p = 0.27831). These combinations were not equally effective when compared between different groups of vascular segments (vasodilation; radial artery > internal thoracic artery > saphenous vein [p < 0.0001 by analysis of variance]). Although not significant, in comparison with NTG alone, NTG in combination with a calcium antagonist caused less vasodilation in any group of vascular segments. CONCLUSIONS Nitroglycerin alone or in combination with nifedipine, verapamil, diltiazem, or nicardipine effectively reverses preexisting vasospasm in coronary artery conduits.
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Affiliation(s)
- J Chanda
- Division of Cardiothoracic Surgery, Albany Medical College, New York 12208, USA
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Affiliation(s)
- C C Canver
- Division of Cardiothoracic Surgery, Albany Medical College, New York 12208, USA.
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Abstract
BACKGROUND Surgical management of patients presenting for coronary artery bypass grafting with significant bilateral carotid artery stenosis has not been well defined. In this study, our preliminary results of coronary artery bypass grafting with concomitant bilateral carotid endarterectomy have been reviewed. METHODS A retrospective nonrandomized chart review was performed in 33 patients with unstable angina and bilateral carotid artery stenosis, more than 70%, undergoing simultaneous coronary artery bypass grafting and bilateral carotid endarterectomy using an eversion technique. RESULTS Concomitant coronary artery bypass grafting with bilateral carotid endarterectomy was performed urgently in 24 (73%) and electively in 9 (27%) patients. The average carotid artery cross-clamp and total perfusion times were 14.7 +/- 4.9 minutes and 123 +/- 29.2 minutes, respectively. The average length of stay in the cardiopulmonary intensive care unit was 4.2 +/- 14.2 days and total hospital stay was 16.2 +/- 20.5 days. Postoperative in-hospital stay was 14.9 +/- 20.3 days. There were no postoperative strokes. Twenty-one (64%) patients were discharged before the tenth postoperative day. Nonfatal postoperative complications occurred in 27% (9 of 33) of patients. The overall 30-day mortality was 6.1% (2 of 33) and that was unrelated to primary cardiac or cerebrovascular events. CONCLUSIONS Favorable outcome supports the justification for performing concomitant coronary artery bypass grafting with bilateral carotid endarterectomies in selected patients.
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Affiliation(s)
- M Dylewski
- Division of Cardiothoracic Surgery, Albany Medical College, New York 12208-3479, USA
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Abstract
BACKGROUND Pharmacologic prophylaxis for prevention of notorious radial artery (RA) spasm is critical because of the increasingly routine use of the RA conduit during coronary bypass. Therefore, we investigated the vasodilatory effect of calcium antagonist in combination with nitroglycerin (NTG) RA segments. METHODS We evaluated the vasodilatory effect of nifedipine alone, verapamil alone, diltiazem alone, NTG alone, and calcium antagonist in combination with in endothelin-1 (ET-1)-, angiotensin II (AII)-, 5-hydroxytryptamine (5-HT)-, and norepinephrine (NE)-precontracted human RA rings mounted in organ baths. RESULTS Nifedipine (10(-5) M) alone, diltiazem (10(-5) M) alone, verapamil (10(-5) M) alone, and NTG (10(-5) M) alone showed maximum vasodilatory effect in either 10(-7) M ET-1-, 10(-7) M AII-, 10(-5) M NE-, or 10(-4) M 5-HT-precontracted RA segments. The 10(-5) M NTG alone-induced vasodilation (88.5% +/- 7.7%) in ET-1-precontracted segments was the highest vasodilation (ANOVA, p = 0.0008) among NTG alone-induced vasodilatory effects in RA. The relaxing effect of any of the calcium antagonists alone varied from 32.7% +/- 13.2% to 76.5% +/- 20.5% in RA precontracted with different vasoconstrictors. Nearly 200% vasodilation was observed with calcium antagonist in combination with NTG in AII-precontracted vessels. Nonetheless, the vasodilatory effect of calcium antagonist in combination with NTG in RA segments precontracted with different vasoconstrictors other than AII was nearly 100%. CONCLUSIONS A calcium antagonist in combination with NTG is more potent than calcium antagonist alone or NTG alone in prevention of human RA vasospasm after coronary bypass.
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Affiliation(s)
- J Chanda
- Division of Cardiothoracic Surgery, Albany Medical College, New York 12208, USA
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Abstract
We report an unusual clinical presentation of Lyme carditis in a previously healthy 20-year-old black woman without any epidemiologic history of Lyme disease, fulminant in nature, involving a heart valve necessitating emergent mitral valve replacement, and requiring further surgical intervention because of the development of pericardial effusion and tamponade. A dilated right ventricle with normal contractility and severe tricuspid regurgitation with increase in the right atrial size diagnosed later remains under close surveillance.
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Affiliation(s)
- C C Canver
- Division of Cardiothoracic Surgery, Albany Medical College, New York 12208, USA.
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Abstract
BACKGROUND We determined the efficacy of long-term therapy with milrinone alone or in combination with inotropic agents in status 1 heart transplant candidates as a pharmacological support until heart transplantation. METHODS Hemodynamic and biochemical variables were recorded in 29 status 1 men with symptoms of severe congestive heart failure, who received continuous intravenous milrinone alone (group 1, n = 21) or in combination with inotropic agents (group 2, n = 8) while awaiting heart transplantation. RESULTS Symptomatic relief was noted in all patients of both groups without any preoperative deaths. One patient (4.8%) of group 1 died on the second day and 1 patient of group 2 died 16.4 months after transplantation. Although pulmonary capillary wedge pressure (group 1, p = 0.021; group 2, p = 0.0002), mean pulmonary artery pressure (group 1, p = 0.051; group 2, p = 0.004), and pulmonary vascular resistance (group 1, p = 0.0026; group 2, p = 0.056) were reduced by 1 hour after the onset of treatment and maintained unchanged until transplantation, the changes in mean pulmonary artery pressure in group 1 and pulmonary vascular resistance in group 2 were statistically insignificant except in the posttransplantation period. CONCLUSIONS Long-term therapy with milrinone in combination with inotropic agents is safe and effective when only milrinone infusion is inadequate for pharmacologic support in status 1 candidates.
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Affiliation(s)
- C C Canver
- Division of Cardiothoracic Surgery, Albany Medical College, New York 12208-3479, USA.
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Canver CC, Chanda J. Transit-lime Ultrasound Flowmetry in CABG. Surg Technol Int 2000; 9:227-230. [PMID: 21136409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Intraoperative measurement of flow allows functional evaluation of coronary bypass grafts and may be predictive of a patient's immediate and late outcome after myocardial revascularization as it permits early detection of technical errors. Many different methods have been used to assess the quality of the anastomosis intraoperatively. Angiography is considered the gold standard technique to which all other methods should be compared. However, it is invasive, costly, time consuming, and not always readily accessible in the operating room.
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Affiliation(s)
- C C Canver
- Director, The Heart Institute, Sheridan-Alley Professor & Head, Division of Cardiothoracic Surgery, Albany Medical College, Albany, NY
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Abstract
Inhibitory effect of heparin coupling on calcification of bioprosthetic vascular grafts of different origin was studied. Heparin-bonded (Hep) and 0.625% glutaraldehyde-cross-linked (GA) segments of porcine thoracic aorta (AO), pulmonary artery (PA), jugular vein (JV) and rabbit aorta (RA) were implanted subcutaneously in weanling rats for 5 months. Heparin bonding is ineffective in prevention of calcification of JV (Hep: Ca, 159 +/- 32.26 mg g-1; GA: Ca, 193.55 +/- 17.81; p = 0.075) and RA (Hep: Ca, 150.17 +/- 14.78; GA: Ca, 192.12 +/- 26.61; p = 0.015). Calcium content of heparin-coupled PA and AO was significantly less when compared with their GA-treated counterparts. Calcification inhibition was achieved to a greater extent in heparin-bonded PA (Hep: Ca = 22.62 +/- 5.72, GA: Ca = 115.99 +/- 21.91, p < 0.0001) than in the AO coupled to heparin (Hep: Ca = 63.77 +/- 22.75, GA: Ca = 150.40 +/- 35.21, p < 0.0001). Elastin fibers were the predominant site of calcification in all explanted vascular grafts. Heparin-bonded porcine pulmonary artery is seemed to be the best among all vascular bioprostheses in this study.
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Affiliation(s)
- J Chanda
- Department of Cardiovascular Surgery, Akita University School of Medicine, Japan.
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Shibata Y, Sato M, Chanda J, Sato S, Fujiwara R. Isolated tricuspid regurgitation due to atypical morphology of anterior-posterior leaflets in an adult: a case report and review of the literature. J Cardiovasc Surg (Torino) 1999; 40:527-30. [PMID: 10532210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
A 73-year-old woman with congenital isolated organic tricuspid regurgitation was reported. She had neither the history of chest trauma nor rheumatic fever nor the evidence of infective endocarditis. The patient was successfully treated with a bioprosthetic valve replacement in tricuspid position. Operative findings revealed hypoplastic anterior leaflet and relatively large posterior leaflet. Structural anomaly of the valve, coaptation disorder due to the thickened valve leaflets, as well as enlarged valve ring and the occurrence of atrial fibrillation was thought to be the causes of massive regurgitation.
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Affiliation(s)
- Y Shibata
- Department of Cardiovascular Surgery, Yurikumiai General Hospital, Honjo, Japan
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Iijima K, Chanda J. Apico-aortic shunt: an alternate to the aorto-aortic shunt. Am J Surg 1999; 177:528-9. [PMID: 10414715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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Chanda J, Kuribayashi R, Kondoh K, Goto Y, Sekine S. Should the surgical technique of the left ventricular volume reduction be modified? J Thorac Cardiovasc Surg 1998; 116:880-1. [PMID: 9806400 DOI: 10.1016/s0022-5223(98)00428-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Shibata Y, Abe T, Sekine S, Chanda J. Supraannular aortic root enlargement in patients with small aortic annulus: efficacy and safety. Ann Thorac Cardiovasc Surg 1998; 4:262-5. [PMID: 9828283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
BACKGROUND To accommodate optimal sized aortic valve, our experiences with supraan-nular aortic root enlargement (SAE) in 20 patients with small aortic annulus have been described. METHODS From June 1981 to April 1996, aortic valve replacement with a St. Jude Medical (SJM) valve had been performed in 46 patients with aortic stenosis consecutively. After August 1993, we employed SAE in patients to insert 23 mm or larger aortic prostheses (SAE group, n = 20; control group, n = 26). Patients were followed-up for a period of 1.7 to 8.3 years. RESULTS There were no intra- or postoperative complications. The pressure gradient across the prosthesis was greater than 30 mmHg in 4 patients of the control group and in 1 patient of the SAE group. Only in nineteen patients (73%) of the control group, 23 mm or larger sized valves could be implanted by a conventional technique. By contrast, with SAE, 23 mm or larger sized SJM prostheses were possible to implant in 19 out of 20 patients (95%). CONCLUSION To avoid valve-patient mismatch, SAE of aortic root is safe and effective.
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Affiliation(s)
- Y Shibata
- Department of Cardiovascular Surgery, Akita University School of Medicine, Akita
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Kondoh K, Abe T, Sekine S, Goto Y, Iijima K, Chanda J, Matsukawa M. [A case of infective thoracic aortic aneurysm ruptured to the lung]. Kyobu Geka 1998; 51:869-71. [PMID: 9757643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We report a successful surgical treatment of an infective thoracic aortic aneurysm ruptured to the left lung. A 63-year-old man who had been suffering from fever and cough showed twice of hemoptysis. Chest CT revealed a descending thoracic aortic aneurysm ruptured to the left lung. A semiemergent operation was performed. At operation, aneurysm of descending thoracic aorta was found adherent to the left lung. Aneurysmectomy with left pneumonectomy was carried out. The postoperative course of the patient was uneventful. Conceivably, in order to avoid massive intraoperative bleeding during division of dense adhesion and postoperative graft infection, concomitant lung resection is necessary.
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Affiliation(s)
- K Kondoh
- Department of Cardiovascular Surgery, Akita University School of Medicine, Japan
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Abstract
Efficacy of different chemical treatments on calcification of vascular graft in vitro and in vivo was studied. Culture medium-filled rat aortas were separately treated in 0.2% glutaraldehyde and epoxy compound, and photooxidized in 0.01% methylene blue for a shorter period (group 1). Another group of rat aortas were separately treated in the same chemicals for a longer period (group 2). All fresh and treated aortas of both groups were cultured for 21 days in an organ culture medium and implanted (except for group 1) in weanling rats for five months. Histology and immunohistochemistry revealed that differently treated aortas of group 1 grow and calcify, and the smooth muscle cells between elastin fibers are the primary site of calcium deposition. In contrast, differently treated aortas of group 2 neither grew, nor did calcify in the medium except the epoxy compound cross-linked aorta of group 2 which did not grow but did calcify. Untreated aorta did not calcify. All fresh and differently treated aortic homografts calcified severely in rats. Our whole arterial segment-calcification system would be useful for analyzing the molecular and cellular mechanisms of both bioprosthetic and atherosclerotic calcification of vascular graft. New anticalcification technique is the only hope for better outcome of future vascular bioprostheses.
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Affiliation(s)
- J Chanda
- Department of Cardiovascular Surgery, Akita University School of Medicine, Japan.
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Abstract
BACKGROUND The inhibitory effect of short-term photooxidation on medial and neointimal proliferation of human saphenous vein was investigated. METHODS Culture medium-filled surgically prepared saphenous vein segments were photooxidized in 0.01% methylene blue solution for 5 minutes. Photooxidized and nonphotooxidized saphenous veins were checked for viability of endothelial cells by culturing vein segments for 21 days followed by histologic and immunohistochemical studies. RESULTS Endothelial cells of saphenous vein segments remained unaffected after photooxidation. Both the intima and media of nonphotooxidized veins became highly cellular and thickened because of the proliferation and migration of smooth muscle cells. Like precultured fresh saphenous vein, intimal (0.031+/-0.017 mm; p=0.0067) and medial thicknesses (0.702+/-0.123 mm; p < 0.0001) and proliferating cell nuclear antigen-positive cell count (14+/-8/mm2; p=0.0005) of cultured photooxidized veins were significantly less than those of cultured nonphotooxidized veins (intimal thickness, 0.059+/-0.041 mm; medial thickness, 0.997+/-0.228 mm; proliferating cell nuclear antigen positive cell count, 34+/-16/mm2. CONCLUSIONS Methylene blue-induced short-term photooxidation is effective in inhibition of intimal and medial thickening of saphenous vein.
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Affiliation(s)
- J Chanda
- Department of Cardiovascular Surgery, Akita University School of Medicine, Japan
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Chanda J, Kuribayashi R, Abe T. Refined alpha aminooleic acid and experimental calcification in bioprostheses. Ann Thorac Surg 1998; 65:888. [PMID: 9527246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Chanda J, Kuribayashi R, Abe T. Role of lipid in calcification of porcine pulmonary and aortic valves. J Thorac Cardiovasc Surg 1998; 115:259-61. [PMID: 9451081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Chanda J, Kuribayashi R, Abe T. Batista operation for dilated cardiomyopathy: a physiologic concept. J Thorac Cardiovasc Surg 1998; 115:261-2. [PMID: 9451082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Chanda J, Kuribayashi R, Abe T. Pathogenesis of calcification of native and bioprosthetic valves is different. Circulation 1997; 96:3790-2. [PMID: 9396495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Chanda J, Kuribayashi R, Abe T. Antimineralization effect of ethanol and experimental model of accelerated calcification study in heart valve bioprostheses. Circulation 1997; 96:3792-3. [PMID: 9396496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Chanda J, Kuribayashi R, Abe T. Nitric oxide in homograft vein function. Ann Thorac Surg 1997; 64:1524-5. [PMID: 9386754 DOI: 10.1016/s0003-4975(97)00770-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Chanda J, Kuribayashi R, Abe T. Valved conduit in the descending thoracic aorta in juvenile sheep: a useful, cost-effective model for accelerated calcification study in systemic circulation. Biomaterials 1997; 18:1317-21. [PMID: 9307222 DOI: 10.1016/s0142-9612(97)00065-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
To evaluate the efficacy of any new anticalcificant in bioprostheses, a cost-effective and easy circulatory model is proposed. Calcification of 0.625% glutaraldehyde-treated porcine aortic valved conduits implanted in the descending thoracic aorta in 11 juvenile sheep for 5 months was compared with that of leaflets of glutaraldehyde-treated porcine aortic valve implanted subcutaneously in 3-week-old male Wistar rats for the same period. Cusps of valved conduits (Ca, 205.41 +/- 16.24 mg g(-1)) in sheep and aortic valve leaflets in rats (Ca, 235.21 +/- 45.25 mg g(-1)) (P = 0.0299) were severely calcified. Morphological characteristics of calcification of all explants were virtually identical. This model provides a model for testing calcification that lies between the subcutaneous weanling rat model and orthotopic whole valve replacement on the left side of the heart. It is less costly and easier to perform than the latter, but does provide exposure to the bloodstream under pressure, which the rat model does not.
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Affiliation(s)
- J Chanda
- Department of Cardiovascular Surgery, Akita University School of Medicine, Japan
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Abstract
BACKGROUND The problem of calcification in porcine aortic (AVs) and pulmonary (PVs) valves and its relationship to glutaraldehyde (GA) is of current interest. We proposed an anticalcification treatment to develop noncalcifying porcine AVs and PVs. METHODS Porcine AVs and PVs were cross-linked in GA. Partially degraded heparin was coupled to the GA-treated AVs and PVs through intermediate surface-bound substrate containing amino groups. Control AVs and PVs were cross-linked in 0.625% GA but had no heparin coupling. All specimens were implanted subdermally in 3-week-old rats for 5 months for calcification studies. RESULTS Control AVs (Ca, 233.69 +/- 42.61 mg/g) and PVs (Ca, 181.48 +/- 4.06 mg/g) were severely calcified. Coupling of partially degraded heparin revealed complete prevention of calcification in GA-treated AVs (Ca, 0.73 +/- 0.27) and PVs (Ca, 1.125 +/- 0.22 mg/g) implanted subcutaneously in weanling rats for 5 months. CONCLUSIONS The proposed anticalcification treatment is effective in preventing calcification of GA-treated AVs and PVs implanted subcutaneously in weanling rats for 5 months.
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Affiliation(s)
- J Chanda
- Department of Cardiovascular Surgery, Akita University School of Medicine, Japan.
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Abstract
Calcific degeneration is the main cause of failure of glutaraldehyde-treated xenograft heart valve substitutes implanted in humans. Coupling of heparin through an intermediate surface-bound substrate containing amino groups showed complete prevention of calcification of glutaraldehyde-treated porcine pericardium implanted subdermally in weanling rats for 5 months (heparin bonded pericardium: calcium, 0.625 +/- 0.24 mg g(-1); glutaraldehyde-only-treated pericardium: calcium, 228.32 +/- 37.39 mg g(-1); P < 0.0001). Conceivably, inactivation of unpaired aldehyde moieties present in bioprostheses after exposure to glutaraldehyde by amino compounds followed by blocking the potential binding sites of the graft with a surface modifying agent like heparin would be the key steps in the prevention of calcification and degeneration of glutaraldehyde-treated biological tissue grafts.
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Affiliation(s)
- J Chanda
- Department of Cardiovascular Surgery, Akita University School of Medicine, Japan
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Abstract
OBJECTIVE An ideal valved conduit to repair complex congenital heart defects is yet to be developed. In this study we have evaluated the merits of our newly developed calcification-free biologic valve incorporated in a compatible conduit of biologic origin in an animal model. METHODS Porcine aortic valves and main pulmonary arteries were cross-linked in glutaraldehyde, followed by coupling to partially degraded heparin through an intermediate surface-bound substrate containing amino groups. Because commercially available valves are treated only with glutaraldehyde, control aortic valves and main pulmonary arteries were cross-linked in 0.625% glutaraldehyde. Valved conduits were fabricated from main pulmonary arteries, which were sewn to the aortic and ventricular ends of aortic valves. Valved conduits were examined for calcification and other pathologic changes after being implanted in the descending thoracic aorta in juvenile sheep for 5 months. RESULTS Severe calcification was noticed in all layers of cusps (calcium, 231.86 +/- 17.90 mg/gm) and aortic wall (calcium, 123.24 +/- 24.72 mg/gm) of aortic valves and main pulmonary arteries (calcium, 135.43 +/- 26.63 mg/gm) of valved conduits treated with 0.625% glutaraldehyde. Cusps (calcium, 1.28 +/- 0.22 mg/gm) of the aortic valve of heparin-bonded conduits did not calcify at all. Only sparse calcific deposits were noticed in the medial layer of the aortic wall (calcium, 25.90 +/- 22.79 mg/gm) of aortic valves and main pulmonary arteries (calcium, 9.64 +/- 10.79 mg/gm) of the valved conduits coupled to heparin. CONCLUSION Heparin coupling is effective in preventing calcification of glutaraldehyde cross-linked valved conduits implanted in the systemic circulation of juvenile sheep.
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Affiliation(s)
- J Chanda
- Department of Cardiovascular Surgery, Akita University School of Medicine, Japan
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Kuribayashi R, Chanda J, Abe T. Apico-aortic shunt: a support technique during surgery on the descending thoracic aorta. J Cardiovasc Surg (Torino) 1997; 38:271-6. [PMID: 9219477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
To find out whether apico-aortic shunt may become an alternative support technique during surgery on the descending thoracic aorta, performance between apico-aortic shunt and aorto-aortic shunt was compared. In 5 sheep weighing 20-25 kg, apico-aortic shunt and aorto-aortic shunt were instituted with covalently bonded heparin coated polyvinyl tube (internal diameter 5 mm). After clamping the descending thoracic aorta, apico-aortic shunt and aorto-aortic shunt were opened for 30 minutes each. Proximal pressure was elevated to 200 mmHg and distal pressure was fallen to 55 mmHg after clamping the descending thoracic aorta. Opening of apico-aortic shunt and aorto-aortic shunt decreased proximal pressure to 178 +/- 14.8 and 173 +/- 12.0 mmHg, respectively (p = 0.57), and raised distal pressure to 82.4 +/- 7.8 and 90.0 +/- 3.5 mmHg, respectively (p = 0.83). The baseline blood flow of the descending thoracic aorta was 1.4-1.5 l/min. Apico-aortic shunt and aorto-aortic shunt were 0.76 +/- 0.16 and 0.80 +/- 0.22 l/min, respectively (p = 0.67). Blood gas tension, pH and BE measurement showed no significant change and difference between apico-aortic shunt and aorto-aortic shunt, and before and after clamping the descending thoracic aorta. Using apico-aortic shunt, interposition of bioprosthetic valved conduit in the descending thoracic aorta in 10 sheep was successfully performed without paraplegia and any other complications. We concluded that apico-aortic shunt may become an alternative support technique during surgery on the descending thoracic aorta in some specific situations.
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Affiliation(s)
- R Kuribayashi
- Department of Cardiovascular Surgery, Akita University School of Medicine, Japan
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Chanda J, Kuribayashi R, Abe T, Sekine S, Shibata Y, Yamagishi I. Is the dog a useful model for accelerated calcification study of cardiovascular bioprostheses? Artif Organs 1997; 21:391-5. [PMID: 9129770 DOI: 10.1111/j.1525-1594.1997.tb00735.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Chitosan posttreatment has been shown to be effective in prevention of calcification of the glutaraldehyde treated bovine pericardium when implanted subdermally in rats for 12 weeks. The efficacy of chitosan posttreatment in complete calcium mitigation of the glutaraldehyde treated porcine aortic valves implanted in the right side of the heart in dogs was well-documented in our previous study. In this study, an attempt has been made to evaluate the merit of the chitosan posttreatment in prevention of calcification of the glutaraldehyde (GA) treated porcine aortic valved conduits in the systemic circulation in dogs for a period of 5 months. Eleven mongrel dogs underwent left thoracotomy. Porcine aortic valved conduits treated with 0.625% GA (n = 5) and GA-chitosan (n = 6) were implanted in the descending thoracic aortas of the dogs for 5 months. Gross histological observations showed no calcification in either the 0.625% GA treated or in the GA-chitosan treated valved conduits at 5 months. This was confirmed by results of quantitative analyses for calcium in each explant. There was no significant difference in calcium content between the GA only (Ca, 0.43 +/- 0.26 mg/g) and GA-chitosan treated (Ca, 0.51 +/- 0.19 mg/g; p = 0.5959) valved conduits. This study suggests that the dog is not a suitable model for evaluating the efficacy of a calcium mitigating agent in bioprostheses implanted in systemic circulation.
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Affiliation(s)
- J Chanda
- Department of Cardiovascular Surgery, Akita University School of Medicine, Japan.
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Shibata Y, Abe T, Kuribayashi R, Sekine S, Seki K, Yamagishi I, Chanda J. Surgical treatment of isolated secundum atrial septal defect in patients more than 50 years old. Ann Thorac Surg 1996; 62:1096-9. [PMID: 8823095 DOI: 10.1016/0003-4975(96)00395-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Arrhythmia-related thromboembolic accidents continue to occur in patients even after closure of secundum atrial septal defect. Older age is usually not a contraindication to the repair of an atrial septal defect. To assess the importance of the type of management in elderly patients with atrial septal defect our clinical experience is reviewed. METHODS Between 1974 and 1994, 49 patients 50 years of age or older (average, 57.4 years) underwent surgical closure of secundum atrial septal defect. All patients have been followed up for 2 to 21 years (mean, 9.7 years). RESULTS There were no operative deaths. Functional classes in most of the patients were improved after operation. There were two cerebrovascular thromboembolic accidents with one permanent neurologic dysfunction, hemiparesis, and one septal dehiscence in the early postoperative period. One patient (2%) died of renal failure 6 years after operation, late arrhythmias developed in 3 patients (6%), 3 patients had a late stroke (6%), and 1 patient was not available for follow-up. CONCLUSIONS Long-term operative results are satisfactory and beneficial to the quality of life in elderly patients. Because there is no safe and effective nonsurgical alternative to surgical closure, atrial septal defect repair in elderly patients without severe pulmonary vascular disease should not be delayed once the diagnosis had been made.
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Affiliation(s)
- Y Shibata
- Department of Cardiovascular Surgery, Akita University School of Medicine, Japan
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Kuribayashi R, Chanda J, Abe T. Efficacy of the chitosan posttreatment in calcification prevention of the glutaraldehyde-treated porcine aortic noncoronary cusp implanted in the right ventricular outflow tract in dogs. Artif Organs 1996; 20:761-6. [PMID: 8828765 DOI: 10.1111/j.1525-1594.1996.tb04537.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Calcific tissue failure results in poor performance of the bioprosthetic heart valve. Chitosan post-treatment has been shown to be effective in calcification prevention of the glutaraldehyde-treated bovine pericardium when implanted subdermally in rats for 12 weeks. The present study investigated the effectiveness of the chitosan posttreatment in prevention of calcification of the glutaraldehyde-treated porcine aortic noncoronary cusp 5 months after implantation in the right ventricular outflow tract (RVOT) in mongrel dogs. Either 0.625% glutaraldehyde-treated (Group 1, n = 6) or glutaraldehyde-chitosan-treated (Group 2, n = 6) porcine aortic noncoronary cusp with the aortic wall was sewn to the RVOT. Gross histological observations showed moderate calcification of the glutaraldehyde-treated cusps, but no calcification was noticed in the glutaraldehyde-chitosan-treated grafts at 5 months. This was confirmed by results of quantitative analyses for calcium in half of each explanted cusp with aortic wall. The calcium content of the 0.625% glutaraldehyde-treated cusps (Ca, 40.6 +/- 24.9 mg/g dry wt) was significantly (p < 0.01) higher than that of glutaraldehyde-chitosan-treated cusps (Ca, 1.3 +/- 0.29 mg/g dry wt). These findings suggest that chitosan post-treatment is effective in complete calcium mitigation of the glutaraldehyde-treated porcine aortic noncoronary cusps implanted in the RVOT in dogs.
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Affiliation(s)
- R Kuribayashi
- Department of Cardiovascular Surgery, Akita University School of Medicine, Japan
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Abstract
The efficacy of chitosan post-treatment of glutaraldehyde-treated porcine pericardial substitute for the prevention of postoperative epicardial reaction and adhesion formation in mongrel dogs has been assessed. Glutaraldehyde (0.625%)-treated porcine pericardium showed moderate to dense adhesions to the heart and other underlying organs with moderate to severe epicardial reaction. None to minimal epicardial reaction without adhesion was observed in glutaraldehyde-treated porcine pericardium post-treated with chitosan at 5 months. Presumably, chitosan post-treatment prevents the slow release of residual glutaraldehyde and reduces the toxicity of the glutaraldehyde-treated implants, minimizing the chance of adhesion formation and epicardial reaction.
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Affiliation(s)
- J Chanda
- Department of Cardiovascular Surgery, Akita University School of Medicine, Japan
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Abstract
To eliminate highly antigenic substances, bovine pericardium was washed in 5% sodium chloride (NaCl) for 24 hours, followed by incubation in trypsin for 40 minutes. To achieve adequate fixation, NaCl-trypsin-treated pericardium was preserved in glutaraldehyde (GA) solution with gradually increasing concentrations from 0.1% to 0.25%. To inactivate the free aldehyde groups and residual GA on the surface of the implant, NaCl-trypsin-GA-treated pericardial samples were posttreated separately with 1% lysine, 8% monosodium glutamate, and 4% chitosan. Fresh (untreated) and 0.1%, 0.2%, and 0.625% GA-treated and NaCl-trypsin-GA-treated pericardial specimens were prepared for comparative study. All samples were implanted subdermally in rats for 2, 4, 8, and 12 weeks for calcification studies. Morphologic and chemical analyses showed mild calcification in fresh pericardia (Ca, 10.5 +/- 1.25 micrograms/mg, von Kossa +) and in glutamate-posttreated pericardia (Ca, 11.5 +/- 3.45 micrograms/mg, von Kossa +). Calcium was practically undetectable in chitosan-posttreated implants (Ca, 1.1 +/- 0.27 micrograms/mg, von Kossa 0), whereas severe calcification was noticed in the rest of the samples (mean Ca greater than 200.0 micrograms/mg, von Kossa ) at 12 weeks. This study suggests that posttreatment with an amino compound such as chitosan would prevent the calcification of GA-treated bioprostheses at an early implantation stage, but elimination of antigenic factors and adequate GA fixation would prevent tissue degeneration, thus enabling the prosthesis to function over a long period.
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Affiliation(s)
- J Chanda
- Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
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Abstract
In this study an attempt was made to find an optimum method of chemical treatment to prevent the calcification of bioprosthetic heart valves. Bovine pericardium was washed in a 5% sodium chloride solution followed by trypsin (Tr) treatment and was kept in 0.1% glutaraldehyde (GA) with a gradual increase in concentration up to 0.25% GA and finally posttreated with a 4% chitosan (Ch) solution. Fresh, 0.2% GA, 0.625% GA, and sodium chloride-Tr-GA treated pericardial samples were taken for comparative study. Tensile testing showed comparable strength and elongation at the breaking point for all groups. The thermal shrinkage studies indicated merit of the proposed treatment (5% sodium chloride-trypsin-glutaraldehyde treated pericardia with chitosan and without chitosan posttreatment). Collagenase assay showed that all differently treated (GA) materials were equally resistant to collagenase. All samples were implanted subcutaneously in rats for 2, 4, 8, or 12 weeks for calcification study. Morphological and mineral analyses showed complete prevention of calcification in sodium chloride-trypsin-GA-chitosan treated pericardium (Ca was 1.1 +/- 0.27 mg/g, von Kossa 0) at the 12th week of implantation.
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Affiliation(s)
- J Chanda
- Department of Thoracic and Cardiovascular Surgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
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Abstract
An attempt has been made to compare the role of different amino compounds in prevention of calcification of glutaraldehyde (GA)-treated pericardium implanted subcutaneously in the rat for 12 weeks. GA pretreated pericardial samples were postfixed separately with glycine, albumin, gentamicin, glycine + gentamicin, and albumin + gentamicin. Severe calcification was noticed in animals undergoing albumin or gentamicin postfixation. Mild calcification was observed in glycine and albumin + gentamicin postfixed materials whereas calcium was undetectable either chemically or morphologically in GA-pretreated pericardium postfixed with glycine + gentamicin (0.32 +/- 0.13.mg/g calcium, dry wt; von Kossa 0) at the 12th week of implantation in the rat.
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Affiliation(s)
- J Chanda
- Department of Cardiovascular Surgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
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Abstract
The aim of the present study was to develop a chemical treatment to eliminate highly antigenic substances, to standardize the glutaraldehyde fixation procedure, to determine the dominant factors contributing to the calcification process and to understand the role of macromolecules like chitosan in the prevention of calcification of bioprosthetic heart valves. Bovine pericardium treated with 5% sodium chloride-trypsin-glutaraldehyde (GA)-chitosan did not calcify at 12 wk in the rat (calcium, 1.1 +/- 0.27 mg/g; von Kossa, 0). Slow release of residual GA from the bioprosthesis and free aldehyde groups on that are still considered the dominant factors for enhancing calcification of GA-treated bioprostheses.
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Affiliation(s)
- J Chanda
- Department of Thoracic and Cardiovascular Surgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
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