3D-Printed Liquid Cell Resonator with Piezoelectric Actuation for In-Line Density-Viscosity Measurements

The in-line monitoring of liquid properties, such as density and viscosity, is a key process in many industrial areas such as agro-food, automotive or biotechnology, requiring real-time automation, low-cost and miniaturization, while maintaining a level of accuracy and resolution comparable to benchtop instruments. In this paper, 3D-printed cuboid-shaped liquid cells featuring a rectangular vibrating plate in one of the sides, actuated by PZT piezoelectric layers, were designed, fabricated and tested. The device was resonantly excited in the 3rd-order roof tile-shaped vibration mode of the plate and validated as a density-viscosity sensor. Furthermore, conditioning circuits were designed to adapt the impedance of the resonator and to cancel parasitic effects. This allowed us to implement a phase-locked loop-based oscillator circuit whose oscillation frequency and voltage amplitude could be calibrated against density and viscosity of the liquid flowing through the cell. To demonstrate the performance, the sensor was calibrated with a set of artificial model solutions of grape must, representing stages of a wine fermentation process. Our results demonstrate the high potential of the low-cost sensor to detect the decrease in sugar and the increase in ethanol concentrations during a grape must fermentation, with a resolution of 10 µg/mL and 3 µPa·s as upper limits for the density and viscosity, respectively.

Bidirectional Linear Motion by Travelling Waves on Legged Piezoelectric Microfabricated Plates

This paper reports the design, fabrication and performance of MEMS-based piezoelectric bidirectional conveyors featuring 3D printed legs, driven by linear travelling waves (TW). The structures consisted of an aluminium–nitride (AlN) piezoelectric film on top of millimetre-sized rectangular thin silicon bridges and two electrode patches. The position and size of the patches were analytically optimised for TW generation in three frequency ranges: 19, 112 and 420 kHz, by the proper combination of two contiguous flexural modes. After fabrication, the generated TW were characterized by means of Laser–Doppler vibrometry to obtain the relevant tables of merit, such as the standing wave ratio and the average amplitude. The experimental results agreed with the simulation, showing the generation of a TW with an amplitude as high as 6 nm/V and a standing wave ratio as low as 1.46 for a device working at 19.3 kHz. The applicability of the fabricated linear actuator device as a conveyor was investigated. Its kinetic performance was studied with sliders of different mass, being able to carry a 35 mg silicon slider, 18 times its weight, with 6 V of continuous sinusoidal excitation and a speed of 0.65 mm/s. A lighter slider, weighting only 3 mg, reached a mean speed of 1.7 mm/s at 6 V. In addition, by applying a burst sinusoidal excitation comprising 10 cycles, the TW generated in the bridge surface was able to move a 23 mg slider in discrete steps of 70 nm, in both directions, which is a promising result for a TW piezoelectric actuator of this size.

A comparison of sexual competitiveness and demographic traits of Anastrepha obliqua (Macquart) (Diptera: Tephritidae) among fruit-associated populations

The control of Anastrepha obliqua includes the sterilization of mass-reared insects grown in isolation in a constantly controlled environment. Through time, laboratory mass-reared colonies may produce flies with lower field performance. To recover the genetic variation and aptitude of mass-reared populations, wild insects are introduced into mass-reared colonies. Our aim in this study was to determine whether the host species from two localities influence the life history traits of A. obliqua. We collected flies as larvae from infested fruits of Spondias purpurea, S. mombin, Mangifera indica cv. 'piña', and M. indica cv. 'coche' from two localities in Chiapas, Mexico. There were significant differences in the mating competitiveness of males collected from mango cv. 'coche' compared with mass-reared males. There were no differences in the mating propensity between flies from the two localities, even in the number of matings, when weight was considered as a covariable. The mass-reared strain showed the earliest age at first oviposition. The locality affected the longevity and oviposition period, and these influenced the birth rate, intrinsic rate of increase, finite rate of population increase, mean generation time, and doubling time. According to the demographic parameters, the population of S. mombin would allow artificial colonization in less time, considering that it has a high reproduction rate starting at an early age. Even in the propensity test, it had the highest number of matings. However, males with greater sexual competitiveness and longevity for colonization corresponded to those collected from S. purpurea.

A Geometrical Study on the Roof Tile-Shaped Modes in AlN-Based Piezoelectric Microcantilevers as Viscosity⁻Density Sensors

Cantilever resonators based on the roof tile-shaped modes have recently demonstrated their suitability for liquid media monitoring applications. The early studies have shown that certain combinations of dimensions and order of the mode can maximize the Q-factor, what might suggest a competition between two mechanisms of losses with different geometrical dependence. To provide more insight, a comprehensive study of the Q-factor and the resonant frequency of these modes in microcantilever resonators with lengths and widths between 250 and 3000 µm and thicknesses between 10 and 60 µm is presented. These modes can be efficiently excited by a thin piezoelectric AlN film and a properly designed top electrode layout. The electrical and optical characterization of the resonators are performed in liquid media and then their performance is evaluated in terms of quality factor and resonant frequency. A quality factor as high as 140 was measured in isopropanol for a 1000 × 900 × 10 µm³ cantilever oscillating in the 11th order roof tile-shaped mode at 4 MHz; density and viscosity resolutions of 10⁻⁶ g/mL and 10⁻⁴ mPa·s, respectively are estimated for a geometrically optimized cantilever resonating below 1 MHz.

Potential of Piezoelectric MEMS Resonators for Grape Must Fermentation Monitoring

In this study grape must fermentation is monitored using a self-actuating/self-sensing piezoelectric micro-electromechanical system (MEMS) resonator. The sensor element is excited in an advanced roof tile-shaped vibration mode, which ensures high Q-factors in liquids (i.e., Q ~100 in isopropanol), precise resonance frequency analysis, and a fast measurement procedure. Two sets of artificial model solutions are prepared, representing an ordinary and a stuck/sluggish wine fermentation process. The precision and reusability of the sensor are shown using repetitive measurements (10 times), resulting in standard deviations of the measured resonance frequencies of ~0.1%, Q-factor of ~11%, and an electrical conductance peak height of ~12%, respectively. With the applied evaluation procedure, moderate standard deviations of ~1.1% with respect to density values are achieved. Based on these results, the presented sensor concept is capable to distinguish between ordinary and stuck wine fermentation, where the evolution of the wine density associated with the decrease in sugar and the increase in ethanol concentrations during fermentation processes causes a steady increase in the resonance frequency for an ordinary fermentation. Finally, the first test measurements in real grape must are presented, showing a similar trend in the resonance frequency compared to the results of an artificial solutions, thus proving that the presented sensor concept is a reliable and reusable platform for grape must fermentation monitoring.

Psychosocial determinants of HIV testing across stages of change in Spanish population: a cross-sectional national survey

Background

The goal of this research is to study the psychosocial determinants of HIV-testing as a function of the decision or change stage concerning this health behavior. The determinants considered in the major ongoing health models and the stages contemplated in the Precaution Adoption Process Model are analysed.

Methods

A cross-sectional survey was administered to 1,554 people over 16 years of age living in Spain by a computer-assisted telephone interview (CATI). The sample design was randomised, with quotas of sex and age. The survey measured various psychosocial determinants of health behaviors considered in the main cognitive theories, the interviewees' stage of change concerning HIV-testing (lack of awareness, decision not to act, decision to act, action, maintenance, and abandonment), and the signal for the action of getting tested or the perceived barriers to being tested.

Results

Approximately two thirds of the population had not ever had the HIV test. The predominant stage was lack of awareness. The most frequently perceived barriers to testing were related to the health system and to the stigma. We also found that the psychosocial determinants studied differed depending on the respondents' stage of change. Perception of risk, perceived self-efficacy, proximity to people who had been tested, perceived benefits of knowing the diagnosis, and a positive instrumental and emotional attitude were positively associated with the decision and maintenance of testing behavior. However, unrealistic underestimation of the risk of HIV infection, stereotypes about the infection, and the perceived severity of HIV were associated with the decision not to be tested.

Conclusions

There are various sociocognitive and motivational profiles depending on people’s decision stage concerning HIV-testing. Knowing this profile may allow us to design interventions to influence the psychosocial determinants that characterise each stage of change.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4148-4) contains supplementary material, which is available to authorized users.

Selection by mating competitiveness improves the performance of Anastrepha ludens males of the genetic sexing strain Tapachula-7

The sexual performance of Anastrepha ludens males of the Tapachula-7 genetic sexing strain, produced via selection based on mating success, was compared with that of males produced without selection in competition with wild males. Mating competition, development time, survival, mass-rearing quality parameters and pheromone production were compared. The results showed that selection based on mating competitiveness significantly improved the sexual performance of offspring. Development time, survival of larvae, pupae and adults, and weights of larvae and pupae increased with each selection cycle. Differences in the relative quantity of the pheromone compounds (Z)-3-nonenol and anastrephin were observed when comparing the parental males with the F4 and wild males. The implications of this colony management method on the sterile insect technique are discussed.

Effect of Three Entomopathogenic Fungi on Three Species of Stingless Bees (Hymenoptera: Apidae) Under Laboratory Conditions

Development of alternative strategies for pest control with reduced effect on beneficial organisms is a priority given the increasing global loss of biodiversity. Biological control with entomopathogenic fungi arises as a viable option to control insect pests. However, few studies have focused on the consequences of using these organisms on pollinators other than the honey bee ( Apis mellifera L.) or bumble bees ( Bombus spp). We evaluated the pathogenicity of commercial formulations of three widely used entomopathogenic fungi, Metarhizium anisopliae (Metschnikoff) Sorokin, Beauveria bassiana Vuillemin, and Isaria fumosorosea (Wize), to three species of stingless bees: Tetragonisca angustula Latreille, Scaptotrigona mexicana Guérin-Meneville, and Melipona beecheii Bennett. Bioassays consisted of exposing groups of bees to the recommended field concentration of each fungus using a microspray tower under laboratory conditions. Susceptibility to fungi varied greatly among species . Isaria fumosorosea (strain Ifu-lu 01) and the two formulations of B. bassiana (Bea-TNK and BotanicGard) caused <30.3% mortality in all bee species. Metarhizium anisopliae (Meta-TNK and strain Ma-lu 01) was highly active against T. angustula (94.2% mortality) and moderately active against M. beecheii (53.0% mortality) and S. mexicana (38.9% mortality). Though our laboratory-derived results suggest a moderate to high impact of these entomopathogenic fungi on stingless bees, further field studies are required to support this finding.

Emerging therapy in arthritis: Modulation of markers of the inflammatory process

The induction of tolerance has been proposed as a therapeutic strategy for arthritis aiming to decrease progression of the pathology, probably by promoting suppressor mechanisms of the autoimmune response. This work aimed to confirm whether the treatment with vitamin D3 could synergize oral tolerance induced by hydrolyzed collagen peptides, in our experimental model of antigen induced arthritis in New Zealand rabbits. Clinical observation of the phenomenon indicates that simultaneous treatment with hydrolyzed collagen peptides and vitamin D3 was beneficial when compared with no treatment, for arthritic animals, and for arthritic animals that received treatment with only hydrolyzed collagen peptides or vitamin D3. Treatment with hydrolyzed collagen peptides caused diminished proinflammatory cytokine levels, an effect synergized significantly by the simultaneous treatment with vitamin D3. The anatomical-pathological studies of the animals that received both treatments simultaneously showed synovial tissues without lymphocytic and plasma cell infiltrates, and without vascular proliferation. Some of the synovial tissue of the animals of these groups showed a slight decrease in Galectin-3 expression. We propose that simultaneous oral treatment with vitamin D3 and hydrolyzed collagen peptides could increase the immunoregulatory effect on the process of previously triggered arthritis. We used articular cartilage hydrolysate and not collagen II because peptides best expose antigenic determinants that could induce oral tolerance. Oral tolerance may be considered in the design of novel alternative therapies for autoimmune disease and we have herein presented novel evidence that the simultaneous treatment with vitamin D3 may synergize this beneficial effect.

Efficacy and community effectiveness of larvivorous fish for dengue vector control

OBJECTIVE

To evaluate the efficacy and community effectiveness of larvivorous fish for the control of dengue vectors and dengue transmission, when used as a single agent or in combination with other vector control methods.

METHOD

Comprehensive literature search of published and grey literature using PubMed, EMBASE (DMDI), Web of Science, WHOLIS, WILEY, LILACS, GIFT, Cochrane Library, ELDIS, New York Academy of Medicine Grey Literature Report and Google. All results were checked for duplicates and examined for eligibility. Methodological quality of the studies was assessed using RoBANS.

RESULTS

Thirteen articles were considered eligible for inclusion. Incorporating a wide range of interventions and outcome measures, three were efficacy studies and 10 assessed community effectiveness. None of the studies were randomised or cluster-randomised controlled trials. All three efficacy studies and seven community effectiveness studies investigated fish as a single agent. All efficacy studies reported elimination of Aedes larvae from treated containers, while community effectiveness studies reported reductions in immature vector stages, two of which also detected a continuous decline over 2 years. An impact on adult mosquitoes was shown in only two community effectiveness studies. Reductions in dengue cases following intervention were reported in two studies, but it was not possible to attribute this to the intervention.

CONCLUSION

While the use of larvivorous fish as a single agent or in combination with other control measures could lead to reductions in immature vector stages, considerable limitations in all the studies restricted any conclusions with respect to the evaluation of community effectiveness. Evidence for the community effectiveness of larvivorous fish as a single agent remains minimal and cluster-randomised controlled studies that include the assessment of impact on dengue are recommended.

Community effectiveness of copepods for dengue vector control: systematic review

OBJECTIVE

Vector control remains the only available method for primary prevention of dengue. Several interventions exist for dengue vector control, with limited evidence of their efficacy and community effectiveness. This systematic review compiles and analyses the existing global evidence for community effectiveness of copepods for dengue vector control.

METHODS

The systematic review follows the PRISMA statement, searching six relevant databases. Applying all inclusion and exclusion criteria, 11 articles were included.

RESULTS

There is evidence that cyclopoid copepods (Mesocyclops spp.) could potentially be an effective vector control option, as shown in five community effectiveness studies in Vietnam. This includes long-term effectiveness for larval and adult control of Ae. aegypti, as well as dengue incidence. However, this success has so far not been replicated elsewhere (six studies, three community effectiveness studies--Costa Rica, Mexico and USA, and three studies analysing both efficacy and community effectiveness--Honduras, Laos and USA), probably due to community participation, environmental and/or biological factors. Judging by the quality of existing studies, there is a lack of good study design, data quality and appropriate statistics.

CONCLUSION

There is limited evidence for the use of cyclopoid copepods as a single intervention. There are very few studies, and more are needed in other communities and environments. Clear best practice guidelines for the methodology of entomological studies should be developed.

[Factors determining irregular attendance to follow-up visits among human immunodeficiency virus patients: results of the hospital survey of patients infected with human immunodeficiency virus]

INTRODUCTION

To describe the occurrence of non-regular attendance to follow-up visits among HIV patients and to analyze the determining factors.

METHODS

One-day survey carried out annually (2002-2012) in public hospitals. Epidemiological, clinical and behavioral data are collected in all HIV-infected inpatients and outpatients receiving HIV-related care on the day of the survey. "Non-regular attendance to a follow-up visit" was defined as sporadic attendance to the medical appointments, according to the judgment of the attending physician. Descriptive and bivariate analyses were performed, and factors associated to non-regular attendance to follow-up visits were estimated using logistic regression.

RESULTS

A total of 7,304 subjects were included, of whom 13.7% did not attend medical appointments regularly. Factors directly associated with non-regular attendance were: age between 25-49 years; birth in Sub-Saharan Africa or Latin-America; low educational level; being homeless or in prison; living alone or in closed institutions; being unemployed or retired; being an intravenous drug user; not using a condom at last sexual encounter, and injecting drugs in the last 30 days. Conversely, HIV diagnosis within the last year and being men who have sex with men were factors inversely associated with non-regular attendance to follow-up visits.

CONCLUSION

In spite of health care beings free of charge for everyone in Spain, social factors can act as barriers to regular attendance to medical appointments, which, in turn, can endanger treatment effectiveness in some population groups. This should be taken into account when planning HIV policies in Spain.

A low-cost, sustainable, second generation system for surveillance of people living with HIV in Spain: 10-year trends in behavioural and clinical indicators, 2002 to 2011

A second-generation surveillance system of people infected with human immunodeficiency virus (HIV) has been implemented in Spain. Behavioural and clinical data were collected between 2002 and 2011 through an annual one-day, cross-sectional survey in public hospitals, including all in- and outpatients receiving HIVrelated care on the survey day. Mean age increased over time (from 38.7 years in 2002 to 43.8 years in 2011) and 68.4% of the 7,205 subjects were male. The proportion of migrants increased from 6.1% to 15.9%, while people who inject or used to inject drugs (PWID and Ex-PWID) decreased and men who have sex with men (MSM) and heterosexuals increased. Unprotected intercourse at last sex increased among MSM and PWID/Ex-PWID. Patients receiving antiretroviral treatment increased significantly from 76.0% to 88.2% as did those with CD4 T-cell counts ≥350 (from 48.2% to 66.9%) and viral copies <200 (from 47.0% to 85.2%). HIV-infected people with hepatitis C virus RNA decreased from 36.0% in 2004 to 29.9% in 2011, while those with HBsAg remained stable at around 4.4%. Implementation of a low-cost, sustainable system for second-generation surveillance in people living with HIV is feasible. In Spain, the information obtained has helped to define and refine public health policy and document treatment effectiveness.

Evolution of HIV-related stigma in Spain between 2008 and 2012

To analyze the temporal evolution of HIV-related stigma in Spain between 2008 and 2012. We interviewed a representative sample of the Spanish population (N = 1619) through computer-assisted telephone interviews. The survey measures diverse facets of stigma and other-related variables. We compared the data of the 2012 survey with the result of the survey carried out in 2008. The degree of discomfort concerning people with HIV decreased significantly in 2012. Avoidance intention, negative feelings, the number of people who agreed with the implementation of harsh discriminatory policies, and the number of people who blame people with HIV were also lower in 2012. However, there are still misconceptions about HIV transmission. Attitudes of the Spanish population toward people with HIV have improved in the last four years. However, some attitudes and beliefs still need to be changed.

Transformer-4 version 2.0.1, a free multi-platform software to quickly reformat genotype matrices of any marker type, and archive them in the Demiurge information system

Transformer-4 version 2.0.1 (T4) is a multi-platform freeware programmed in java that can transform a genotype matrix in Excel or XML format into the input formats of one or several of the most commonly used population genetic software, for any possible combination of the populations that the matrix contains. T4 also allows the users to (i) draw allozyme gel interpretations for any number of diploid individuals, and then generate a genotype matrix ready to be used by T4; and (ii) produce basic reports about the data in the matrices. Furthermore, T4 is the only way to optionally submit 'genetic diversity digests' for publication in the Demiurge online information system (http://www.demiurge-project.org). Each such digest undergoes peer-review, and it consists of a geo-referenced data matrix in the tfm4 format plus any ancillary document or hyperlink that the digest authors see fit to include. The complementarity between T4 and Demiurge facilitates a free, safe, permanent, and standardized data archival and analysis system for researchers, and may also be a convenient resource for scientific journals, public administrations, or higher educators. T4 and its converters are freely available (at, respectively, http://www.demiurge-project.org/download_t4 and http://www.demiurge-project.org/converterstore) upon registration in the Demiurge information system (http://demiurge-project.org/register). Users have to click on the link provided on an account validation email, and accept Demiurge's terms of use (see http://www.demiurge-project.org/termsofuse). A thorough user's guide is available within T4. A 3-min promotional video about T4 and Demiurge can be seen at http://vimeo.com/29828406.

Hybrid matrix grafts to favor tissue regeneration in rabbit femur bone lesions

At present, typical approaches employed to repair fractures and other bone lesions tend to use matrix grafts to promote tissue regeneration. These grafts act as templates, which promote cellular adhesion, growth and proliferation, osteoconduction, and even osteoinduction, which commonly results in de novo osteogenesis. The present work aimed to study the bone-repairing ability of hybrid matrixes (HM) prepared with polyvinyl alcohol (PVA) and bioactive glass in an experimental rabbit model. The HM were prepared by combining 30% bioactive glass (nominal composition of 58% SiO2 -33 % CaO - 9% P2O5) and 70% PVA. New Zealand rabbits were randomly divided into the control group (C group) and two groups with bone lesions, in which one received a matrix implant HM (Implant group), while the other did not (no Implant group). Clinical monitoring showed no altered parameters from either the Implant or the no Implant groups as compared to the control group, for the variables of diet grades, day and night temperatures and hemograms. In the Implant group, radiologic and tomographic studies showed implanted areas with clean edges in femoral non-articular direction, and radio-dense images that suggest incipient integration. Minimum signs of phlogosis could be observed, whereas no signs of rejection at this imaging level could be identified. Histological analysis showed evidence of osteo-integration, with the formation of a trabecular bone within the implant. Together, these results show that implants of hybrid matrixes of bioactive glass are capable of promoting bone regeneration.

The impact of silent vascular brain burden in cognitive impairment in Parkinson's disease

BACKGROUND AND PURPOSE

White matter hyperintensities (WMHs) detected by magnetic resonance imaging (MRI) of the brain are associated with dementia and cognitive impairment in the general population and in Alzheimer's disease. Their effect in cognitive decline and dementia associated with Parkinson's disease (PD) is still unclear.

METHODS

We studied the relationship between WMHs and cognitive state in 111 patients with PD classified as cognitively normal (n = 39), with a mild cognitive impairment (MCI) (n = 46) or dementia (n = 26), in a cross-sectional and follow-up study. Cognitive state was evaluated with a comprehensive neuropsychological battery, and WMHs were identified in FLAIR and T2-weighted MRI. The burden of WMHs was rated using the Scheltens scale.

RESULTS

No differences in WMHs were found between the three groups in the cross-sectional study. A negative correlation was observed between semantic fluency and the subscore for WMHs in the frontal lobe. Of the 36 non-demented patients re-evaluated after a mean follow-up of 30 months, three patients converted into MCI and 5 into dementia. Progression of periventricular WMHs was associated with an increased conversion to dementia. A marginal association between the increase in total WMHs burden and worsening in the Mini Mental State Examination was encountered.

CONCLUSIONS

White matter hyperintensities do not influence the cognitive status of patients with PD. Frontal WMHs have a negative impact on semantic fluency. Brain vascular burden may have an effect on cognitive impairment in patients with PD as WMHs increase overtime might increase the risk of conversion to dementia. This finding needs further confirmation in larger prospective studies.

Effect of temperature on pupa development and sexual maturity of laboratory Anastrepha obliqua adults

The effect of four temperatures (18, 20, 25 and 30°C) on pupa development and sexual maturity of Anastrepha obliqua adults was investigated under laboratory conditions. The results showed that the duration of the pupal stage decreased with an increase in temperature (29, 25, 13 and 12 days, respectively), and maintaining the pupae at 18°C and 20°C results in a low percentage of pupation, pupa weight loss and lesser flying ability. However, it significantly favored sexual behavior, a higher proportion of sexual calls and matings. While enhanced pupa development was observed at a temperature of 30°C, adults had low sexual efficiency, as well as a lower proportion of calls and matings. Gas chromatography-mass spectrometry (GC-MS) analysis of male volatiles showed that the amount of (Z,E)-α-farnesene did not vary among males from pupae reared at different temperatures; however, less (E,E)-α-farnesene was emitted by males obtain from pupa reared at 30°C. Male flies kept at 30°C during their larval stage had more (Z)-3-nonenol and, also, an unknown compound was detected. The fecundity of the females was higher at low temperatures. Regarding fertility, no significant differences were found between temperatures. The optimal temperature on pupa development was 25°C when males displayed ideal attributes for rearing purposes.

Retinal nerve fiber layer atrophy is associated with physical and cognitive disability in multiple sclerosis

Background

Studying axonal loss in the retina is a promising biomarker for multiple sclerosis (MS). Our aim was to compare optical coherence tomography (OCT) and Heidelberg retinal tomography (HRT) techniques to measure the thickness of the retinal nerve fiber layer (RNFL) in patients with MS, and to explore the relationship between changes in the RNFL thickness with physical and cognitive disability. We studied 52 patients with MS and 18 proportionally matched controls by performing neurological examination, neuropsychological evaluation using the Brief Repetitive Battery-Neuropsychology and RNFL thickness measurement using OCT and HRT.

Results

We found that both OCT and HRT could define a reduction in the thickness of the RNFL in patients with MS compared with controls, although both measurements were weakly correlated, suggesting that they might measure different aspects of the tissue changes in MS. The degree of RNFL atrophy was correlated with cognitive disability, mainly with the symbol digit modality test ( r = 0.754, P < 0.001). Moreover, temporal quadrant RNFL atrophy measured with OCT was associated with physical disability.

Conclusion

In summary, both OCT and HRT are able to detect thinning of the RNFL, but OCT seems to be the most sensitive technique to identify changes associated with MS evolution.

Treatment of Bolivian Mucosal Leishmaniasis with Miltefosine

BACKGROUND

Although mucosal leishmaniasis is a prominent disease, it has been studied only to a limited extent. It is classically treated with parenteral antimony or, as a last resort, amphotericin B.

METHODS

We treated Bolivian mucosal leishmaniasis due to Leishmania braziliensis with the oral agent miltefosine, 2.5 mg/kg/day for 28 days, and followed-up for 12 months.

RESULTS

Seventy-two patients were evaluable. The cure rate for the 36 patients who had "mild" disease (i.e., affecting nasal skin and nasal mucosa) was 83%. The cure rate for the 36 patients who had more extensive disease (involving the palate, pharynx, and larynx) was 58%. Patients refused to be randomized to parenteral agents, but the cure rate for an almost contemporary group who was receiving amphotericin B (45 mg/kg over 90 days) was 7 (50%) of 14.

CONCLUSIONS

In this unrandomized trial, oral miltefosine was at least as effective as heroic doses of parenteral amphotericin B. The cure rate for miltefosine was approximately equivalent to historical cure rates using parenteral pentavalent antimony for mild and extensive disease in neighboring Peru. Although gastrointestinal side reactions do occur with miltefosine, its toxicity profile is superior to that of antimony and far superior to that of amphotericin B--in part because of the inherent attractiveness of oral versus parenteral agents. Our results suggest that miltefosine should be the treatment of choice for mucosal disease in North and South America.

[SPECT and PET in neurology]

Both single photon emission computed tomography (SPECT) and positron emission tomography (PET) are helpful in the practice of neurology. Ictal SPECT is useful to determine the origin of focal seizures in the pre-surgical evaluation. In some centers, it is used to predict the likelihood of massive cerebral swelling after stroke and of cerebral infarction after a subarachnoid hemorrhage. It has also been used to study dopaminergic function in parkinsonian syndromes and in the evaluation of dementia. Given its higher resolution and some other factors, PET is more useful in the evaluation of brain tumors, dementia and the parkinsonian syndromes. It is also useful in the presurgical evaluation of epilepsy.

Comparison of generic to branded pentavalent antimony for treatment of new world cutaneous leishmaniasis

The cost of generic pentavalent antimony (generic stibogluconate) is approximately one-sixth that of branded pentavalent antimony (stibogluconate in the form of Pentostam or meglumine antimoniate in the form of Glucantime. We compared generic stibogluconate to Pentostam and Glucantime for the treatment of cutaneous leishmaniasis patients in Bolivia and Colombia. For all 114 patients, the per-protocol cure rates were 83-91% and the intent-to-treat cure rates were 75-83%. The highest values were in the generic stibogluconate group. The incidence of pancreatic enzyme abnormalities was 48-88% and the incidence of liver enzyme abnormalities was 48-87%. The lowest incidences were in the generic stibogluconate group. The efficacy and tolerance of inexpensive generic stibogluconate appears comparable to branded formulations for the treatment of cutaneous leishmaniasis in these endemic regions.

Miltefosine for New World Cutaneous Leishmaniasis

The oral agent miltefosine has demonstrated a >95% cure rate in Indian visceral leishmaniasis. We performed a large, placebo-controlled study of miltefosine therapy (2.5 mg/kg per day orally for 28 days) against cutaneous leishmaniasis in Colombia and Guatemala. In regions in Colombia where Leishmania vianna panamensis is common, the per-protocol cure rates for miltefosine and placebo were 91% (40 of 44 patients) and 38% (9 of 24). These values are similar to historic values for the antimony standard of care and placebo. In regions in Guatemala where L. v. braziliensis and L. mexicana mexicana are common, the per-protocol cure rates were 53% (20 of 38) for miltefosine and 21% (4 of 19) for placebo. The miltefosine rate was lower than historic antimony cure rates of >90%. Miltefosine was well tolerated. Miltefosine is a useful oral agent against cutaneous leishmaniasis due to L. v. panamensis in Colombia but not against leishmaniasis due to L. v. braziliensis in Guatemala.

Treatment of American cutaneous leishmaniasis with miltefosine, an oral agent

There is no recognized oral treatment for American cutaneous leishmaniasis. A rising-dose, open-label phase I/II trial of the oral agent miltefosine against Colombian cutaneous leishmaniasis was conducted. Seventy-two male Colombian soldiers (mean weight, 67 kg) received miltefosine at 50-100 mg/day for 3 weeks (for 32 evaluable patients) or at 133-150 mg/day for 3-4 weeks (for 32 evaluable patients). The per-protocol cure rate for 50-100 mg/day was 21 (66%) of 32 patients. The per-protocol cure rate for 133-150 mg/day was 30 (94%) of 32 patients (P =.01, by use of Fisher's exact test). The historic per-protocol cure rate for standard injections of antimony is 93%. "Motion sickness" that did not interfere with normal duties was experienced by 40% of patients and was dose related. Vomiting and diarrhea were reported on approximately 2% of treatment days. In this uncontrolled study of oral miltefosine for treatment of patients with American cutaneous leishmaniasis, a dosage of approximately 2.25 mg/kg/day for 3-4 weeks was effective and tolerated.

Plasmodium vivax clinically resistant to chloroquine in Colombia

Chloroquine-resistant Plasmodium vivax has been the subject of numerous case reports and prospective studies from Oceania and Asia. In contrast, only case reports exist from the Americas. We performed a prospective study with 28-day follow-up of clinical responses to chloroquine in 2 P. vivax-endemic regions of Colombia. Three (11%) of 27 patients failed to respond to treatment with the standard regimen of chloroquine (1,500 mg of base over 3 days). One patient demonstrated RI resistance on Day 26; one patient demonstrated RI resistance due to recrudescence of blood stages on Day 11; and one patient demonstrated RII resistance of blood stages by never displaying clearing of peripheral parasitemia. All patients were successfully treated with primaquine, which has some blood stage efficacy against P. vivax, combined with a second course of chloroquine. Clinical resistance of P. vivax to chloroquine is present in Colombia and should be monitored in the Americas.

Differential staining of DNA strand breaks in dried comet assay slides

The comet assay involves embedding cells in agarose on microscope slides. After lysis and electrophoresis, staining is usually performed with a fluorescent DNA-binding dye and observation is carried out on fresh wet slides through an epifluorescence microscope. We present here a simple alternative for preservation of the agarose comet slides and a fluorescent staining that allows fine differential analysis of DNA strand breaks under confocal microscopy. Lymphocytes were processed according to previous published methods. Slides were quickly dehydrated in a hot oven at 50C for 20 min. Once the agarose layer was dried and reduced to a thin film, slides were treated with RNase. Image analysis showed higher tail length, total area, and tail moment. Using confocal microscopic optical sectioning, a thickness of approximately 180 microm for wet slides and 12 microm for dehydrated gels was calculated. Acridine orange, used for DNA differential staining, allowed quantitation of metachromasia and orthochromasia with confocal scanning microscopy. Differences between alkaline and neutral comet assay with AO were clear-cut and, in principle, a metachromatic index can be calculated. (J Histochem Cytochem 49:921-922, 2001)

[Growth, mortality and exploitation rate of Priacanthus arenatus (Perciformes: Priacanthidae), in the trawl fisheries of northeast Venezuela]

We analyzed growth, mortality and exploitation rate of Priacanhus arenatus, captured by the shrimp trawling fishery (1989-1996), in northeastern Venezuela. The growth coefficient (K) and the asymptotic length (L8) were estimated by length-frequency data using the Battacharya method and other routines of the FISAT program. Total mortality (Z) and exploitation (E) rates were obtained by length-converted catch curve analysis, based on length-frequency data, and the Berverton and Holt's yield per recruit model, respectively. The mean growth parameters L and K were estimated as 474.7 mm and 0.69 year(-1), respectively. Mean total mortality was 4.03 and the exploitation rate range was 0.70-0.80. Results indicated that the population is overexploited.

[Cooper, cadmium and lead in the fish Cyprinodon dearborni, in the sediments and in the water of two lagoons in Venezuela]

The concentration of copper, cadmium and lead in superficial sediment, water and the fish Cyprinodon dearborni was determined in two coastal lagoons of Sucre State, Venezuela. Chacopata lagoon is hyper saline while Los Patos lagoon is hypo saline and receives significant wastewater from Cumaná city. Water, sediment and fish samples were collected in February 1998. In the laboratory, samples underwent acid digestion and were analyzed by atomic absorption spectophotometry. The mean values of the metals in C. dearborni from the Chacopata lagoon were: 159.26 +/- 210.68 microg/g for Cu, 44.71 +/- 45.58 microg/g for Cd, and 9.31 +/- 23.34 microg/g for Pb, while for Los Patos lagoon the mean values were: 64.88 +/- 16.30, 19.48 +/- 5.81 and 22.85 +/- 20.00, respectively. In the water column, the metal concentration ranges were: 2.3-11.6, 3.9-5.4 and 21-32 mg/l for copper, cadmium and lead, respectively. These results suggest that metal levels in sediment, water column and organisms in both lagoons do not differ, except for lead, even though only Los Patos receives waste water.

Toxicity of Bacillus thuringiensis beta-exotoxin to three species of fruit flies (Diptera: Tephritidae)

The current study describes toxic effects of the Bacillus thuringiensis beta-exotoxin toward 3rd instars of 3 fruit fly species: Anastrepha ludens (Loew), A. obliqua (Macquart), and A. serpentina (Wiedemann). The beta-exotoxin was highly toxic to all 3 species tested, with LC50 values calculated as 0.641, 0.512, and 0.408 microgram/cm2 of filter paper used to expose the larvae, for A. ludens, A. obliqua, and A. serpentina, respectively. Exposure to beta-exotoxin was associated with an increase in the incidence of deformed pupae. The adult survivors from beta-exotoxin treatments showed no negative effects in terms of their longevity, fecundity, or egg eclosion (fertility). We conclude that the beta-exotoxin may have potential as a control agent for fruit fly pests.

Double-blind, randomized, placebo-controlled assessment of chloroquine/primaquine prophylaxis for malaria in nonimmune Colombian soldiers

To improve upon the efficacy of primaquine prophylaxis for malaria (94%, Plasmodium falciparum malaria; 85%, Plasmodium vivax malaria), we administered chloroquine (300 mg weekly) in combination with primaquine (30 mg daily) to nonimmune Colombian soldiers during 16 weeks of patrol in a region of endemicity and for a further 1 week in base camp. The occurrence of symptomatic parasitemia was determined during those 17 weeks and during a further 3 weeks in base camp. The protective efficacy for the chloroquine/primaquine treatment group of 100 subjects, compared with that for the placebo treatment group of 51 subjects, was 88% (95% confidence interval [CI], 76-94) against all types of malaria, 89% (95% CI, 61-97) against P. falciparum malaria, and 88% (95% CI, 58-93) against P. vivax malaria. Two chloroquine/primaquine recipients had severe gastrointestinal distress. Comparison of these data with data from a previous study indicates that the addition of chloroquine did not increase the prophylactic efficacy of primaquine.

Safety Evaluation of Transgenic Tilapia with Accelerated Growth

Recent advances in modern marine biotechnology have permitted the generation of new strains of economically important fish species through the transfer of growth hormone genes. These transgenic fish strains show improved growth performance and therefore constitute a better alternative for aquaculture programs. Recently, we have obtained a transgenic tilapia line with accelerated growth. However, before introducing this line into Cuban aquaculture, environmental and food safety assessment was required by national authorities. Experiments were performed to evaluate the behavior of transgenic tilapia in comparison to wild tilapia as a way to assess the environmental impact of introducing transgenic tilapia into Cuban aquaculture. Studies were also conducted to evaluate, according to the principle of substantial equivalence, the safety of consuming transgenic tilapia as food. Behavior studies showed that transgenic tilapia had a lower feeding motivation and dominance status than controls. Food safety assessment indicated that tilapia growth hormone has no biological activity when administered to nonhuman primates. Furthermore, no effects were detected in human healthy volunteers after the consumption of transgenic tilapia. These results showed, at least under the conditions found in Cuba, no environmental implications for the introduction of this transgenic tilapia line and the safety in the consumption of tiGH-transgenic tilapia as an alternative feeding source for humans. These results support the culture and consumption of these transgenic tilapia.