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Olimpi EM, Garcia K, Gonthier DJ, De Master KT, Echeverri A, Kremen C, Sciligo AR, Snyder WE, Wilson-Rankin EE, Karp DS. Shifts in species interactions and farming contexts mediate net effects of birds in agroecosystems. Ecol Appl 2020; 30:e02115. [PMID: 32145709 DOI: 10.1002/eap.2115] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 01/07/2020] [Accepted: 01/29/2020] [Indexed: 06/10/2023]
Abstract
Some birds are viewed as pests and vectors of foodborne pathogens in farmlands, yet birds also benefit growers by consuming pests. While many growers seek to prevent birds from accessing their farms, few studies have attempted to quantify the net effects of bird services and disservices, let alone how net effects shift across farm management strategies. We quantified the net effect of birds on crop production across 20 California strawberry (Fragaria × ananassa) farms that varied in local management practices and landscape context. We surveyed farms for berry damage and bird droppings (as potential sources of pathogens) and implemented a large-scale exclusion experiment to quantify the impact of birds on production. We found that birds had only a slightly negative overall impact on strawberry production, reducing economic value by 3.6%. Direct bird damage and intraguild predation contributed equally to this net effect, underscoring the importance of indirect trophic interactions that may be less apparent to growers. In simple landscapes (e.g., low proportions of surrounding seminatural habitat), birds provided pest control in the interiors of farm fields, and costs from bird damage to crops peaked at field edges. In complex landscapes (e.g., high proportions of seminatural habitat), birds were more likely to disrupt pest control by feeding as intraguild predators. Nonetheless, seminatural habitat dampened bird services and disservices, and our models predicted that removing habitat around farm fields would increase costs from bird damage to crops by up to 76%. Fecal contamination of crops was extremely rare (0.01%). However, both fecal contamination and bird damage did increase on farms with higher densities of fencing and wires, where birds often perch. Our results demonstrate that maintaining seminatural habitat around farms may enhance bird diversity and mitigate bird damage without increasing food safety risks. We also show that the net effects of birds depend on farming context and vary in complex ways in relation to locations within a farm, local farm attributes, and the surrounding landscape. This context-specific variation must be considered in order to optimize the management of wild birds in agroecosystems.
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Affiliation(s)
- E M Olimpi
- Department of Wildlife, Fish, and Conservation Biology, University of California, 1088 Academic Surge, 455 Crocker Lane, Davis, California, 95616, USA
| | - K Garcia
- Department of Entomology, University of Kentucky, Lexington, Kentucky, 40546, USA
| | - D J Gonthier
- Department of Entomology, University of Kentucky, Lexington, Kentucky, 40546, USA
| | - K T De Master
- Environmental Science, Policy, and Management, University of California, Mulford Hall, 130 Hilgard Way, Berkeley, California, 94720, USA
| | - A Echeverri
- Institute for Resources, Environment and Sustainability, University of British Columbia, Vancouver Campus, AERL Building, 429-2202 Main Mall, Vancouver, British Columbia, V6T 1Z4, Canada
| | - C Kremen
- Environmental Science, Policy, and Management, University of California, Mulford Hall, 130 Hilgard Way, Berkeley, California, 94720, USA
- Institute for Resources, Environment and Sustainability, University of British Columbia, Vancouver Campus, AERL Building, 429-2202 Main Mall, Vancouver, British Columbia, V6T 1Z4, Canada
- Biodiversity Research Centre, Department of Zoology, University of British Columbia, 2212 Main Mall, Vancouver, British Columbia, V6T 1Z4, Canada
| | - A R Sciligo
- Environmental Science, Policy, and Management, University of California, Mulford Hall, 130 Hilgard Way, Berkeley, California, 94720, USA
| | - W E Snyder
- Department of Entomology, Washington State University, PO Box 646382, Pullman, Washington, 99164, USA
| | - E E Wilson-Rankin
- Department of Entomology, University of California, 165 Entomology Bldg., Citrus Drive, Riverside, California, 92521, USA
| | - D S Karp
- Department of Wildlife, Fish, and Conservation Biology, University of California, 1088 Academic Surge, 455 Crocker Lane, Davis, California, 95616, USA
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Restrepo-Escobar M, Sylva D, Gamboa JG, Echeverri A, Márquez J, Pinto LF. Pulmonary-renal syndrome secondary to cocaine-levamisole-induced vasculitis: A case report. Reumatol Clin (Engl Ed) 2020; 16:239-241. [PMID: 29784435 DOI: 10.1016/j.reuma.2018.02.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 02/14/2018] [Accepted: 02/20/2018] [Indexed: 06/08/2023]
Abstract
Pulmonary-renal syndrome has rarely been reported as the clinical presentation of vasculitis caused by the consumption of cocaine adulterated with levamisole. We report the case of a patient in whom we detected the clinical manifestations and indicate the difficulties that arose in relation to the diagnostic and therapeutic approach.
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Affiliation(s)
- Mauricio Restrepo-Escobar
- Sección de Reumatología, Hospital Pablo Tobón Uribe, Medellín, Colombia; Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia.
| | - Dayana Sylva
- Facultad de Medicina, Universidad Pontificia Bolivariana, Medellín, Colombia
| | - Juan Guillermo Gamboa
- Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia; Sección de Medicina Interna, Hospital Pablo Tobón Uribe, Medellín, Colombia
| | - Andrés Echeverri
- Sección de Reumatología, Hospital Pablo Tobón Uribe, Medellín, Colombia
| | - Javier Márquez
- Sección de Reumatología, Hospital Pablo Tobón Uribe, Medellín, Colombia
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Aragón CC, Nieto-Aristizábal I, Ríos-Serna LJ, Barrera MC, Naranjo-Escobar J, Posso-Osorio I, Lara-Erazo V, Leib P, Moreno-Angarita A, Aguirre-Valencia D, Echeverri A, Cañas CA, Tobón GJ. Pentraxin 3 is useful to differentiate infections from flares in patients with systemic lupus erythematosus who present systemic inflammatory response. Lupus 2019; 28:1279-1280. [DOI: 10.1177/0961203319870240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- C C Aragón
- Grupo de Investigación en Reumatología, Universidad Icesi and Fundación Valle del Lili, Cali, Colombia
| | - I Nieto-Aristizábal
- Grupo de Investigación en Reumatología, Universidad Icesi and Fundación Valle del Lili, Cali, Colombia
| | - L J Ríos-Serna
- Grupo de Investigación en Reumatología, Universidad Icesi and Fundación Valle del Lili, Cali, Colombia
| | - M C Barrera
- Grupo de Investigación en Reumatología, Universidad Icesi and Fundación Valle del Lili, Cali, Colombia
| | - J Naranjo-Escobar
- Grupo de Investigación en Reumatología, Universidad Icesi and Fundación Valle del Lili, Cali, Colombia
| | - I Posso-Osorio
- Grupo de Investigación en Reumatología, Universidad Icesi and Fundación Valle del Lili, Cali, Colombia
| | - V Lara-Erazo
- Grupo de Investigación en Reumatología, Universidad Icesi and Fundación Valle del Lili, Cali, Colombia
- Medical School, Universidad Icesi, Cali, Colombia
| | - P Leib
- Grupo de Investigación en Reumatología, Universidad Icesi and Fundación Valle del Lili, Cali, Colombia
- Medical School, Universidad Icesi, Cali, Colombia
| | - A Moreno-Angarita
- Grupo de Investigación en Reumatología, Universidad Icesi and Fundación Valle del Lili, Cali, Colombia
- Medical School, Universidad Icesi, Cali, Colombia
| | - D Aguirre-Valencia
- Grupo de Investigación en Reumatología, Universidad Icesi and Fundación Valle del Lili, Cali, Colombia
| | - A Echeverri
- Grupo de Investigación en Reumatología, Universidad Icesi and Fundación Valle del Lili, Cali, Colombia
| | - C A Cañas
- Grupo de Investigación en Reumatología, Universidad Icesi and Fundación Valle del Lili, Cali, Colombia
| | - G J Tobón
- Grupo de Investigación en Reumatología, Universidad Icesi and Fundación Valle del Lili, Cali, Colombia
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Echeverri A, Naranjo-Escobar J, Posso-Osorio I, Aguirre-Valencia D, Zambrano D, Castaño GL, Martínez JD, Cañas CA, Tobón GJ. Neutrophil CD64 expression, procalcitonin and presepsin are useful to differentiate infections from flares in SLE patients with SIRS. Lupus 2018. [PMID: 29540108 DOI: 10.1177/0961203318763740] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background/Objective Differentiating systemic lupus erythematosus (SLE) activity from infections in febrile patients is difficult because of similar initial clinical presentation. The aim of this study is to evaluate the usefulness of a number of biomarkers for differentiating infections from activity in SLE patients admitted with systemic inflammatory response (SIRS). Methods Patients with SLE and SIRS admitted to the emergency room were included in this study. Measurements of different markers including procalcitonin, neutrophil CD64 expression and presepsin, were performed. Infection was considered present when positive cultures and/or polymerase chain reaction were obtained. Sensitivity and specificity were calculated for all biomarkers. Results Twenty-seven patients were admitted, 23 women (82.5%), mean age 33.2 years. An infectious disease was confirmed in 12 cases. Markers for SLE activity including anti-DNA titers by IIF ( p = 0.041) and enzyme-linked immunosorbent assay ( p = 0.009) were used for differentiating SLE flares from infection. On the contrary, increased procalcitonin ( p = 0.047), neutrophil CD64 expression by flow cytometry ( p = 0.037) and presepsin ( p = 0.037) levels were observed in infected SLE patients. Conclusions High neutrophil CD64 expression, presepsin and procalcitonin levels are useful to differentiate infections from activity in SLE patients. In most cases, a positive bioscore that includes these three markers demonstrate the presence of an infectious disease.
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Affiliation(s)
- A Echeverri
- 1 Grupo de Investigación en Reumatología, Autoinmunidad y Medicina Traslacional (GIRAT), School of Medicine, Universidad Icesi, and Fundación Valle del Lili, Cali, Colombia
| | - J Naranjo-Escobar
- 1 Grupo de Investigación en Reumatología, Autoinmunidad y Medicina Traslacional (GIRAT), School of Medicine, Universidad Icesi, and Fundación Valle del Lili, Cali, Colombia
| | - I Posso-Osorio
- 1 Grupo de Investigación en Reumatología, Autoinmunidad y Medicina Traslacional (GIRAT), School of Medicine, Universidad Icesi, and Fundación Valle del Lili, Cali, Colombia
| | - D Aguirre-Valencia
- 1 Grupo de Investigación en Reumatología, Autoinmunidad y Medicina Traslacional (GIRAT), School of Medicine, Universidad Icesi, and Fundación Valle del Lili, Cali, Colombia.,2 Universidad Icesi, Medical School, Cali, Colombia
| | - D Zambrano
- 3 Universidad CES, Medical School, Medellin, Colombia
| | - G L Castaño
- 4 Immunology Laboratory, Fundación Valle del Lili, Cali, Colombia
| | - J D Martínez
- 4 Immunology Laboratory, Fundación Valle del Lili, Cali, Colombia
| | - C A Cañas
- 1 Grupo de Investigación en Reumatología, Autoinmunidad y Medicina Traslacional (GIRAT), School of Medicine, Universidad Icesi, and Fundación Valle del Lili, Cali, Colombia
| | - G J Tobón
- 1 Grupo de Investigación en Reumatología, Autoinmunidad y Medicina Traslacional (GIRAT), School of Medicine, Universidad Icesi, and Fundación Valle del Lili, Cali, Colombia.,4 Immunology Laboratory, Fundación Valle del Lili, Cali, Colombia
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Muñoz C, Restrepo-Escobar M, Martínez-Muñoz M, Echeverri A, Márquez J, Pinto LF. Differences between patients with sarcoidosis with and without joint involvement treated for fifteen years in a third level hospital. ACTA ACUST UNITED AC 2018; 16:45-48. [PMID: 29456153 DOI: 10.1016/j.reuma.2018.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 12/21/2017] [Accepted: 01/06/2018] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Sarcoidosis is a complex disease of unknown etiology, with a variable course and highly different forms of presentation. Our objective was to characterize all our patients with sarcoidosis with emphasis on their clinical presentation and to establish differences between patients with sarcoidosis with and without joint involvement. METHODS We reviewed the medical records of all patients with a diagnosis of sarcoidosis who were treated at the outpatient or inpatient services of the Pablo Tobón Uribe Hospital in Medellín, Colombia, from January 2002 to April 2017. RESULTS We identified 22 patients with sarcoidosis. There were joint symptoms in 13 of them. All but one of the patients with sarcoidosis affecting the joints had concomitant skin involvement (92%), which was much less frequent in patients without joint involvement (22%) (odds ratio=4.2; P<.001). CONCLUSIONS Patients with sarcoidosis who have joint involvement have a much higher frequency of concomitant skin involvement. The absence of cutaneous findings in a patient with joint symptoms decreases the likelihood of sarcoidosis.
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Affiliation(s)
- Carolina Muñoz
- Sección de Reumatología, Departamento de Medicina Interna, Hospital Pablo Tobón Uribe, Medellín, Colombia
| | - Mauricio Restrepo-Escobar
- Sección de Reumatología, Departamento de Medicina Interna, Hospital Pablo Tobón Uribe, Medellín, Colombia; Departamento de Medicina Interna, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia.
| | | | - Andrés Echeverri
- Sección de Reumatología, Departamento de Medicina Interna, Hospital Pablo Tobón Uribe, Medellín, Colombia
| | - Javier Márquez
- Sección de Reumatología, Departamento de Medicina Interna, Hospital Pablo Tobón Uribe, Medellín, Colombia
| | - Luis Fernando Pinto
- Sección de Reumatología, Departamento de Medicina Interna, Hospital Pablo Tobón Uribe, Medellín, Colombia
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Tabares CJ, Montoya AF, Arboleda L, Echeverri A, Restrepo LF, Olivera-Angel M. Efecto de la pluviosidad y el brillo solar sobre la producción y características del semen en el pez Brycon henni (Pisces: Characidae). REV BIOL TROP 2014. [DOI: 10.15517/rbt.v54i1.13992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Tabares CJ, Montoya AF, Arboleda L, Echeverri A, Restrepo LF, Olivera-Angel M. [Effect of pluviosity and sun shine on sperm production and seminal characteristics of the fish Brycon henni (Pisces: Characidae)]. REV BIOL TROP 2006; 54:179-187. [PMID: 18457186] [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: 05/26/2023] Open
Abstract
Effect of pluviosity and sun shine on sperm production and seminal characteristics of the fish Brycon henni (Pisces: Characidae). In Colombia the fish Brycon henni is a protected endemic species. It inhabits water bodies in coffee producing areas (700-1900 ma.s.l.; 4 degrees 35'56" N - 74 degrees 04'51" W; 18-28 degrees C). Insufficient knowledge of its basic biology and behavior prevent the commercial culture of this promising fish. We studied the production and sperm physiology of captive males. Along a year 20 samples were taken from each of 10 males. The sample was obtained by abdominal cefalo-caudal massage and transported to the laboratory at 4 degrees C. Except for September and October (maximum rainfall), sperm was always obtained in at least 50% of the males. Color, osmolality and pH were similar in all the samples. Volume, concentration, viability, motility and activation time were variable: sunshine had a positive effect on volume (Spearman p < 0.05) and on sperm concentration (Spearman p < 0.05) while pluviosity had a negative effect on volume and viability. The proportion of ions (Na, K, Mg, Ca) was constant along the year; Na being 10-fold higher than K and 100-fold higher than Mg and Ca; however the absolute concentration of all ions was slightly higher in April and in July (with no apparent relation with the other variables analyzed).
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Gage JR, Breen EC, Echeverri A, Magpantay L, Kishimoto T, Miles S, Martínez-Maza O. Human herpesvirus 8-encoded interleukin 6 activates HIV-1 in the U1 monocytic cell line. AIDS 1999; 13:1851-5. [PMID: 10513642 DOI: 10.1097/00002030-199910010-00006] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Human herpesvirus 8 (HHV-8) encodes a viral interleukin 6 (vIL-6) which is structurally and functionally similar to human interleukin 6 (hIL-6). Since hIL-6 has been shown to upregulate the expression of HIV-1, the objectives of this study were to examine the ability of vIL-6 to upregulate HIV-1, and to determine the interactions of this virokine (viral cytokine) with the components of the interleukin 6 (IL-6) receptor complex. DESIGN AND METHODS Recombinant HHV-8 vIL-6 (rvIL-6) was assayed for bioactivity in the IL-6-dependent cell line MH60.BSF2. HIV-1 p24 production by the U1 monocytic and ACH-2 T-cell lines, which are chronically infected with HIV-1, was used to assess the ability of vIL-6 to affect HIV-1 expression. hIL-6 and vIL-6 receptor utilization was determined by quantifying HIV-1 p24 production after neutralization of components of the IL-6 receptor complex, CD126'IL-6R' and CD130'gp130', on U1 cells with blocking antibodies. RESULTS HHV-8 rvIL-6 was seen to have IL-6-like bioactivity in MH60.BSF2 cells, and readily upregulated HIV-1 p24 production in U1 monocytic cells, but not in ACH-2 T cells. The vIL-6 appeared to utilize the IL-6-specific component of the IL-6 signaling complex, CD126'IL-6R', in U1 cells. CONCLUSIONS HHV-8 vIL-6 clearly has the potential to upregulate HIV-1 expression in monocytic cells, and therefore may play a role in AIDS pathogenesis in individuals infected with both viruses.
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Affiliation(s)
- J R Gage
- Department of Obstetrics and Gynecology, Osaka University, Japan
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Abstract
BACKGROUND Pulmonary dirofilariasis is a rare entity caused by Dirofilaria immitis, the dog heartworm that is transmitted to humans by mosquitos. This filarial nematode enters the subcutaneous tissue, travels to the right ventricle where it dies, and then embolizes the pulmonary vasculature, causing a small pulmonary infarction, which subsequently appears as a solitary nodule. Although these nodules are usually identified incidentally by chest radiography in asymptomatic patients, the lesion is generally presumed to be neoplastic. Diagnosis is made by surgical excision. METHODS We reviewed the pathology reports at Memorial Medical Center, Savannah, GA since 1990. RESULTS There have been approximately 150 cases reported in the literature worldwide. We found 4 patients with pulmonary dirofilariasis diagnosed at our hospital since 1992. A review of the pathogenesis of the disease and clinical manifestations, diagnosis, and treatment of this entity are presented. CONCLUSIONS Pulmonary dirofilariasis is a benign condition, transmitted by mosquitos to humans that results in peripheral pulmonary nodules. Awareness of this entity is important in the differential diagnosis of pulmonary coin lesions.
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Affiliation(s)
- A Echeverri
- Department of Surgery, Memorial Medical Center, Savannah, Georgia, USA
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Martínez-Maza O, Widney D, van der Meijden M, Knox R, Echeverri A, Breen EC, Magpantay L, Miles SA. Immune dysfunction and the pathogenesis of AIDS-associated non-Hodgkin's lymphoma. Mem Inst Oswaldo Cruz 1998; 93:373-81. [PMID: 9698872 DOI: 10.1590/s0074-02761998000300019] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Much has been learned about how HIV-induced immune dysfunction contributes to B cell hyperactivation, and potentially, to the pathogenesis of AIDS-lymphoma. However, further studies are needed to fully understand how HIV infection and immune dysfunction promote B cell hyperactivation and the development/growth of AIDS-lymphoma. In particular, studies are needed to define the role of HHV8 vIL6, IL6 receptor-expression, and lymphocyte surface stimulatory molecules, in promoting B cell hyperactivation or lymphoma cell growth.
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Affiliation(s)
- O Martínez-Maza
- Department of Microbiology, UCLA School of Medicine 90095-1747, USA
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Echeverri A, Flexon PB. Electrophysiologic nerve stimulation for identifying the recurrent laryngeal nerve in thyroid surgery: review of 70 consecutive thyroid surgeries. Am Surg 1998; 64:328-33. [PMID: 9544143] [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: 02/07/2023]
Abstract
To describe a simple technique for identifying the recurrent laryngeal nerve (RLN) with a nerve stimulator to prevent damage to the nerve during thyroid surgery. A retrospective review of 70 thyroidectomies performed from October 1989 to January 1995 by one surgeon using electrophysiologic nerve stimulation to identify the RLN was conducted. The technique is described. Outpatient flexible fiberoptic laryngoscopy was performed preoperatively and postoperatively in all patients. From 70 thyroidectomies, 80 RLNs were identified to be at risk for injury. Five patients had transient unilateral vocal cord paresis postoperatively. No RLN transection or permanent vocal cord paralysis occurred. This is the first large series of patients undergoing the use of electrophysiologic nerve stimulation for identifying the RLN during thyroid surgery. We found the technique to be useful and safe for identifying the RLN. We present this technique as a less costly and time-consuming alternative to intraoperative RLN monitoring.
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Affiliation(s)
- A Echeverri
- Department of Surgical Education, Memorial Medical Center, Savannah, Georgia, USA
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Abstract
The poliovirus-encoded, membrane associated polypeptide 2C is required for viral replication. We have previously established that, while the 2C protein lacks a defined membrane binding domain, the N-terminal region containing a putative amphipathic helix plays an important role in membrane binding both in vivo and in vitro. In order to determine whether the N-terminal region is sufficient for membrane binding, we have made fusion constructs between this region of 2C (amino acids 1-72 and 1-88) and a soluble protein, chloramphenicol acetyltransferase (CAT). The ability of CAT and the fusion polypeptides to bind to membranes was examined by in vitro translation in the presence of microsomal membrane. While CAT was found in the soluble fraction, both 2C/CAT fusion constructs (1-72/CAT and 1-88/CAT) were membrane associated, suggesting that the N-terminal region of 2C was sufficient to impart membrane binding. To confirm these results in vivo, CAT, 1-72/CAT, and 1-88/CAT were expressed in HeLa cells and their localization was examined using indirect immunofluorescence. Results presented here demonstrate that, while CAT is expressed throughout the cell, 1-72/CAT and 1-88/CAT constructs are capable of localizing to the endoplasmic reticulum (ER) area in transfected cells in the absence of other poliovirus proteins. These results suggest that the first 72 amino acids of 2C contain a membrane binding domain that is capable of targeting soluble proteins to the ER region of the cell.
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Affiliation(s)
- A Echeverri
- Department of Microbiology and Immunology, The University of California, Los Angeles, School of Medicine, 90095, USA
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13
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Abstract
The poliovirus-encoded, membrane-associated polypeptide 2C is believed to be required for initiation and elongation of RNA synthesis. We have expressed and purified recombinant, histidine-tagged 2C and examined its ability to bind to the first 100 nucleotides of the poliovirus 5' untranslated region of the positive strand and its complementary 3'-terminal negative-strand RNA sequences. Results presented here demonstrate that the 2C polypeptide specifically binds to the 3'-terminal sequences of poliovirus negative-strand RNA. Since this region is believed to form a stable cloverleaf structure, a number of mutations were constructed to examine which nucleotides and/or structures within the cloverleaf are essential for 2C binding. Binding of 2C to the 3'-terminal cloverleaf of the negative-strand RNA is greatly affected when the conserved sequence, UGUUUU, in stem a of the cloverleaf is altered. Mutational studies suggest that interaction of 2C with the 3'-terminal cloverleaf of negative-strand RNA is facilitated when the sequence UGUUUU is present in the context of a double-stranded structure. The implication of 2C binding to negative-strand RNA in viral replication is discussed.
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Affiliation(s)
- R Banerjee
- Department of Microbiology and Immunology and Jonsson Comprehensive Cancer Center, UCLA School of Medicine, University of California Los Angeles, 90095-1747, USA
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Abstract
We report a retrospective review of 127 low friction arthroplasties carried out for the failure of a previous hip operation. After an average follow-up of 10.4 years, 20% of cases required further revision, over half of them for deep infection. We estimated from the radiographic appearances that eventual failure by loosening was probable in 58% on the femoral side and 56% on the acetabular side of the arthroplasties.
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Affiliation(s)
- A Echeverri
- Centre for Hip Surgery, Wrightington, Lancashire, England
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Abstract
Twelve adults with confirmed pulmonary tuberculosis who failed to respond to repeated skin tests with 250 TU of second-strength purified protein derivative of tuberculin were studied using in vivo and in vitro tests of cell-mediated immunity. All but 2 of the patients failed to respond to skin tests with candidin and histoplasmin, and only one could be sensitized with topical applications of dinitrochlorobenzene. The blastogenic response of peripheral blood lymphocytes from these anergic patients, when cultured in the presence of phytohemagglutinin, pokeweed mitogen, and purified protein derivative, was significantly less than that of lymphocytes from tuberculin-positive control patients. During the course of therapy with isoniazid and streptomycin, 6 of the anergic patients converted spontaneously and reacted positively to purified protein derivative. This skin-test conversion was accompanied by a significant increase in the blastogenic response of lymphocytes from the converted patients when cultured with purified protein derivate. Tuberculin anergy in these 12 patients was not associated with progessive, disseminated disease. All patients responded successfully to the primary chemotherapeutic regimen.
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