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1.
Cureus ; 15(4): e37750, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37214041

RESUMEN

Non-Hodgkin lymphoma (NHL) of the thyroid is a very rare condition. Swelling of the neck is the usual presentation among patients. Of all thyroid malignancies, only a very small portion accounts for NHL of the thyroid. Here, we present two cases of diffuse large B-cell NHL of the thyroid. Preoperative diagnosis helps in the management of patients with chemotherapy, but in rare cases, surgical removal of the thyroid is done to reduce obstructive symptoms. The diagnosis is usually made based on fine-needle aspiration cytology and biopsy with immunohistochemistry. In these two cases, the patients presented with a history of a rapidly growing mass in the neck for three to four months, but the treatment modalities differed. In one of the cases, the patient received six cycles of chemotherapy, and in the other case, the patient underwent a total thyroidectomy, followed by six cycles of chemotherapy, though chemotherapy is the standard treatment option over surgical removal of the thyroid.

2.
J Hosp Infect ; 103(4): 454-460, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31408690

RESUMEN

BACKGROUND: A cluster of seven cases of skin and wound infections caused by a multiply resistant meticillin-resistant Staphylococcus aureus (MRSA) were detected in a small-town community in South Yorkshire. Initial microbiological investigations showed that all isolates belonged to a spa type observed rarely in England (t1476). AIM: To describe the epidemiology of t1476 MRSA in South Yorkshire. METHODS: Retrospective and prospective case ascertainment was promoted through communication with local microbiology laboratories. Public health investigation included a detailed review of clinical notes for a subset of nine cases. Genomic and phylogenetic analysis was undertaken on t1476 MRSA. FINDINGS: Thirty-two cases of t1476 MRSA infection or colonization were identified between December 2014 and February 2018. Cases were older adults (aged 50-98 years). Healthcare exposures for a subset of nine cases indicated frequent contact with a team of district nurses, with all but one case receiving treatment on the same day as another case prior to their own diagnosis. No cases were admitted to hospital at the time of specimen collection. Despite detailed investigations, no carriers were detected among district nursing staff. A long-term carrier/super-shedder was not found. Phylogenetic analysis indicated that t1476 MRSA cases from South Yorkshire were monophyletic and distant from both MRSA of the same lineage from elsewhere in the UK (N = 15) and from publicly available sequences from Tanzania. CONCLUSION: Genomic and epidemiological analyses indicate community-based transmission of a multiply resistant MRSA clone within South Yorkshire introduced around 2012-2013, prior to the detection of a spatial-temporal cluster associated with a distinct risk group. Surveillance data indicate continued circulation.


Asunto(s)
Infección Hospitalaria/epidemiología , Farmacorresistencia Bacteriana Múltiple , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Tipificación Molecular , Infecciones Cutáneas Estafilocócicas/epidemiología , Secuenciación Completa del Genoma , Infección de Heridas/epidemiología , Anciano , Anciano de 80 o más Años , Análisis por Conglomerados , Servicios de Salud Comunitaria , Infección Hospitalaria/microbiología , Infección Hospitalaria/transmisión , Transmisión de Enfermedad Infecciosa , Inglaterra/epidemiología , Femenino , Humanos , Masculino , Staphylococcus aureus Resistente a Meticilina/clasificación , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/genética , Persona de Mediana Edad , Epidemiología Molecular , Filogenia , Estudios Prospectivos , Estudios Retrospectivos , Infecciones Cutáneas Estafilocócicas/microbiología , Infecciones Cutáneas Estafilocócicas/transmisión , Infección de Heridas/microbiología , Infección de Heridas/transmisión
3.
J Mech Behav Biomed Mater ; 86: 122-130, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29986287

RESUMEN

Pre-sintered zirconia is preferred as a restoration material in dental applications due to its excellent strength and fracture toughness. When abrasive processes were used to obtain the required shape of (Y-TZP) yttria-stabilized tetragonal pre-sintered zirconia, it resulted in material strength degradation in the presence of coolant. Therefore, experiments were carried out on pre-sintered zirconia with diamond grinding wheel to evaluate the performance of cooling conditions such as dry, wet and minimum quantity lubrication (MQL). The effects of different environments on the grinding performance were studied based on the temperature distribution, phase transformation, flexural strength, microhardness and edge chipping damage. The Raman spectroscopy and X-ray diffraction analysis were used to estimate the quantity of monoclinic phase in pre-sintered zirconia. The temperature rise of the workpiece material during the grinding experiment was not higher and insufficient to cause the thermal stresses. The microstructural changes induced by grinding under different cooling strategies were associated with the quantitative assessment of monoclinic phase. The flexural strength of ground components was improved in the dry condition compared to the other process due to the absence of the defective layer and the occurrence of Y3+ ions segregation. After grinding, there was a slight decrease in the hardness value by (1-8 HV), which was due to the formation of microcracks in the subsurface layer of the ground surface. In addition, to ensure the presence of microcracks, the edge chipping depth was measured. The damage depth obtained from the wet condition showed a higher value of 30 µm compared to the dry and MQL conditions.


Asunto(s)
Lubrificación , Fenómenos Mecánicos , Circonio , Resistencia Flexional , Propiedades de Superficie , Temperatura
4.
Trop Doct ; 47(2): 170-173, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27838633

RESUMEN

As original tribal ways of living have morphed from a forest dweller existence, dengue is no longer an urban infection but is now also found in rural hilly areas. The spread of dengue is enhanced by the frequent movement of people to endemic areas where there is a vector mosquito presence. The impact of the virus is known to be great in the immunologically naive population. Our study reports on the threat of the dengue virus in these hilly areas.


Asunto(s)
Dengue/epidemiología , Brotes de Enfermedades , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Animales , Anticuerpos Antivirales/sangre , Antígenos Virales/sangre , Virus del Dengue/inmunología , Femenino , Humanos , India/epidemiología , Masculino , Persona de Mediana Edad , Población Rural , Adulto Joven
5.
J Food Prot ; 79(5): 732-40, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-27296419

RESUMEN

An outbreak of listeriosis in England affecting 14 people between 2010 and 2012 and linked to the consumption of pork pies was investigated. All 14 individuals were older than 55 years, 12 were men, and 10 reported the presence of an underlying condition. All were resident in or had visited either of two English regions and were infected with the same strain of Listeria monocytogenes. In interviews with 12 patients, 9 reported eating pork pies, and individuals that consumed pork pies were significantly more likely to be infected with an outbreak strain than were individuals with sporadic cases of listeriosis infections in England from 2010 to 2012. Pork pies were purchased from seven retailers in South Yorkshire or the East Midlands, and the outbreak strain was recovered from pork pies supplied by only the producer in South Yorkshire. The outbreak strain was also recovered from samples of finished product and from environmental samples collected from the manufacturer. The likely source of contamination was environmental sites within the manufacturing environment, and the contamination was associated with the process of adding gelatin to the pies after cooking. Inadequate temperature control and poor hygienic practices at one of the retailers were also identified as possible contributory factors allowing growth of the pathogen. Following improvements in manufacturing practices and implementation of additional control measures at the retailers' premises, L. monocytogenes was not recovered from subsequent food and environmental samples, and the outbreak strain was not detected in further individuals with listeriosis in England.


Asunto(s)
Listeriosis/epidemiología , Carne Roja , Animales , Brotes de Enfermedades , Inglaterra , Contaminación de Alimentos , Microbiología de Alimentos , Humanos , Listeria monocytogenes , Masculino , Porcinos
6.
Parasitol Res ; 115(6): 2353-62, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26969179

RESUMEN

Community-based integrated vector control (IVC) using polystyrene beads (EPS) and pyrethroid impregnated curtains (PIC) as an adjunct to mass drug administration (MDA) was implemented for lymphatic filariasis elimination, in the filaria endemic villages of Tirukoilur, south India. In all the villages, MDA was carried out by the state health machinery, as part of the national filariasis elimination programme. Thirty-six difficult-to-control villages were grouped as, viz, MDA alone, MDA + EPS and MDA + EPS + PIC arms. Implementation and monitoring of IVC was carried out by the community. After 3 years of IVC, higher reductions in filariometric indices were observed in both the community and vector population. Decline in antigenaemia prevalence was higher in MDA + IVC as compared to MDA alone arm. Vector density dropped significantly (P < 0.05) in both the IVC arms, and nil transmission was observed during post-IVC period. Almost 53.8 and 75.8 % of the cesspits in MDA + EPS and MDA + EPS + PIC arms were closed by the householders, due to the enhanced awareness on vector breeding. The paper presents the key elements of IVC implementation through social mobilization in a LF prevalent area. Thus, community-based IVC strategy can hasten LF elimination, as it reduced the transmission and filariometric indices significantly. Indices were maintained at low level with nil transmission, by the community through IVC tools.


Asunto(s)
Culicidae/efectos de los fármacos , Filariasis Linfática/prevención & control , Filaricidas/administración & dosificación , Insectos Vectores/efectos de los fármacos , Insecticidas/administración & dosificación , Control de Mosquitos/métodos , Albendazol/administración & dosificación , Animales , Brugia Malayi/fisiología , Participación de la Comunidad , Culicidae/parasitología , Dietilcarbamazina/administración & dosificación , Erradicación de la Enfermedad , Filariasis Linfática/epidemiología , Filariasis Linfática/parasitología , Femenino , Humanos , India/epidemiología , Insectos Vectores/parasitología , Microfilarias , Nitrilos/administración & dosificación , Poliestirenos , Prevalencia , Piretrinas/administración & dosificación , Wuchereria bancrofti/fisiología
9.
Trop Biomed ; 29(4): 646-9, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23202612

RESUMEN

The vector mosquitoes of dengue and chikungunya fever, Aedes aegypti and Aedes albopictus have adapted to feed on humans and undergo larval and pupal development in natural and artificial freshwater collections. Although several studies reported, still, much information is required to understand the successful survival of Aedes mosquitoes in small temporary containers. In an investigation conducted in the chikungunya affected areas of Kerala state, India, the presence of Bdelloid rotifer, Philodina in 95% of breeding habitats of Ae. aegypti and Ae. albopictus was recorded. The role of Philodina in the breeding containers was investigated. It was found that while in control the number of Philodina was found increasing in the water sample during the study period of seven days, the number found decreased in the containers with larvae of Aedes. The gut content analysis also confirmed the presence of the rotating wheel, corona of Philodina in some of the specimen suggests its role as major larval food.


Asunto(s)
Aedes/parasitología , Rotíferos/aislamiento & purificación , Animales , Vectores de Enfermedades , Femenino , India , Agua/parasitología
10.
J Vector Borne Dis ; 49(4): 258-61, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23428527

RESUMEN

BACKGROUND & OBJECTIVES: Wolbachia are common intracellular bacteria that are found in arthropods and nematodes. These endosymbionts are transmitted vertically through host eggs and alter host biology in diverse ways, including the induction of reproductive manipulations, such as feminization, parthenogenesis, male killing and sperm-egg incompatibility. Since they can also move horizontally across species boundaries, Wolbachia is gaining importance in recent days as it could be used as a biological control agent to control vector mosquitoes or for paratransgenic approaches. However, the study of Wolbachia requires sophisticated techniques such as PCR and cell culture facilities which cannot be affordable for many laboratories where the diseases transmitted by arthropod vectors are common. Hence, it would be beneficial to develop a simple method to detect the presence of Wolbachia in arthropods. METHOD: In this study, we described a method of staining Wolbachia endobacteria, present in the reproductive tissues of mosquitoes. The reliability of this method was compared with Gram staining and PCR based detection. RESULTS: The microscopic observation of the Gimenez stained smear prepared from the teased ovary of wild caught and Wolbachia (+) Cx. quinquefasciatus revealed the presence of pink coloured pleomorphic cells of Wolbachia ranging from cocci, comma shaped cells to bacillus and chain forms. The ovaries of Wolbachia (-) cured mosquito did not show any cell. Although Gram's staining is a reliable differential staining for the other bacteria, the bacterial cells in the smears from the ovaries of wild caught mosquitoes did not take the stain properly and the cells were not clearly visible. The PCR amplified product from the pooled remains of wild caught and Wolbachia (+) Cx. quinquefasciatus showed clear banding, whereas, no banding was observed for the negative control (distilled water) and Wolbachia (-) Cx. quinquefasciatus. INTERPRETATION & CONCLUSION: The Gimenez staining technique applied, could be used to detect the members of the endobacteria Wolbachia easily, even in a simple laboratory without any special facilities or even in the field condition and for handling large number of samples in a shorter duration.


Asunto(s)
Culex/microbiología , Reacción en Cadena de la Polimerasa/métodos , Coloración y Etiquetado/métodos , Wolbachia/genética , Wolbachia/aislamiento & purificación , Animales , Culex/clasificación , ADN Bacteriano/análisis , ADN Bacteriano/genética , Filariasis Linfática/transmisión , Femenino , Insectos Vectores/microbiología , Ovario/microbiología
11.
Trop Biomed ; 27(2): 330-6, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20962733

RESUMEN

In 2001, a major dengue outbreak was recorded in Chennai city, with 737 cases (90%) out of a total of 861 cases recorded from Tamil Nadu state. A KAP survey was carried out to assess the community knowledge, attitude and practice on dengue fever (DF), following the major dengue outbreak in 2001. A pre- tested, structured questionnaire was used for data collection. The multistage cluster sampling method was employed and 640 households (HHs) were surveyed. Among the total HHs surveyed, 34.5% of HHs were aware of dengue and only 3.3% of HHs knew that virus is the causative agent for DF. Majority of the HHs (86.5%) practiced water storage and only 3% of them stored water more than 5 days. No control measures were followed to avoid mosquito breeding in the water holding containers by majority of HHs (65%). Sixty percent of HHs did not know the biting behaviour of dengue vector mosquitoes. The survey results indicate that the community knowledge was very poor on dengue, its transmission, vector breeding sources, biting behavior and preventive measures. The lack of basic knowledge of the community on dengue epidemiology and vector bionomics would be also a major cause of increasing trend of dengue in this highly populated urban environment. There is an inevitable need to organize health education programmes about dengue disease to increase community knowledge and also to sensitize the community to participate in integrated vector control programme to resolve the dengue problem.


Asunto(s)
Dengue/epidemiología , Epidemias , Conductas Relacionadas con la Salud , Recolección de Datos , Dengue/prevención & control , Dengue/transmisión , Conocimientos, Actitudes y Práctica en Salud , Humanos , India/epidemiología
13.
J Vector Borne Dis ; 47(1): 26-32, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20231770

RESUMEN

BACKGROUND & OBJECTIVES: Climatic attributes have been associated with relative mosquito abundance and transmission of mosquito borne infections in many parts of the world, especially in warm and tropical climatic regions. The main objectives of this study were to assess the change in seasonal pattern of Japanese encephalitis (JE) vectors, their density, to elucidate whether the lagged climate variables (precipitation, temperature and humidity) are associated with JE vector density, and to determine if temperature and precipitation are similarly important for the rise in the number of potential mosquito vectors for JE virus in the temperate climate of Andhra Pradesh, India. METHODS: Mosquito samples were collected from Kurnool district of Andhra Pradesh using hand catch and light-trap methods during 2002 to 2006. The type and abundance of recovered species were compared to ecological correlates. In each geographic area, temperature and precipitation are the two possible proxy variables for mosquito density, in conjunction with other seasonal factors for JE epidemics. RESULTS: Out of the various mosquito species collected, Culex gelidus and Cx. tritaeniorhynchus were noticed in high numbers. There was considerably high prevalence of Cx. gelidus (68.05%) in urban area than in rural areas whereas, Cx. tritaeniorhynchus (57.51%) was found to be more in rural areas than in the urban area. It is noticed that the factors such as rainfall and temperature were found to be correlated with the per man hour (PMH) density, whereas the humidity was inversely correlated with the PMH. INTERPRETATION & CONCLUSION: The environmental and eco-climatic factors are assisting in enhancing the breeding of these mosquitoes in Kurnool district of Andhra Pradesh, India. Both Cx. tritaeniorhyncus and Cx. gelidus are quite adaptable to these environmental conditions and this necessitates immediate control measures in both rural and urban areas of Kurnool district.


Asunto(s)
Clima , Culex/clasificación , Culex/crecimiento & desarrollo , Vectores de Enfermedades , Animales , Encefalitis Japonesa/prevención & control , Encefalitis Japonesa/transmisión , Humanos , India , Dinámica Poblacional , Estaciones del Año
14.
J Commun Dis ; 42(2): 157-9, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22471176

RESUMEN

The prevalence of protozoan, Ascogregarina sp. had been determined in the container breeding mosquitoes, Aedes albopictus. Since, the cyst of Ascogregarina might play role in the maintenance of the Chik virus during silent period, the presence of Ascogregarina has gained importance in recent days. The prevalence was found to be 71.62.


Asunto(s)
Aedes/parasitología , Infecciones por Alphavirus/transmisión , Apicomplexa/aislamiento & purificación , Insectos Vectores/parasitología , Aedes/virología , Infecciones por Alphavirus/epidemiología , Animales , Cruzamiento , Fiebre Chikungunya , India/epidemiología , Prevalencia
15.
Tropical Biomedicine ; : 330-6, 2010.
Artículo en Inglés | WPRIM (Pacífico Occidental) | ID: wpr-630028

RESUMEN

In 2001, a major dengue outbreak was recorded in Chennai city, with 737 cases (90%) out of a total of 861 cases recorded from Tamil Nadu state. A KAP survey was carried out to assess the community knowledge, attitude and practice on dengue fever (DF), following the major dengue outbreak in 2001. A pre- tested, structured questionnaire was used for data collection. The multistage cluster sampling method was employed and 640 households (HHs) were surveyed. Among the total HHs surveyed, 34.5% of HHs were aware of dengue and only 3.3% of HHs knew that virus is the causative agent for DF. Majority of the HHs (86.5%) practiced water storage and only 3% of them stored water more than 5 days. No control measures were followed to avoid mosquito breeding in the water holding containers by majority of HHs (65%). Sixty percent of HHs did not know the biting behaviour of dengue vector mosquitoes. The survey results indicate that the community knowledge was very poor on dengue, its transmission, vector breeding sources, biting behavior and preventive measures. The lack of basic knowledge of the community on dengue epidemiology and vector bionomics would be also a major cause of increasing trend of dengue in this highly populated urban environment. There is an inevitable need to organize health education programmes about dengue disease to increase community knowledge and also to sensitize the community to participate in integrated vector control programme to resolve the dengue problem.

16.
Indian J Med Res ; 129(3): 311-5, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19491425

RESUMEN

BACKGROUND & OBJECTIVE: The first chikungunya outbreak occurred in Kerala during 2006 affecting 14 districts, followed by another during May 2007 affecting almost whole of the State. Four of the worst affected districts viz, Pathanamthitta, Idukki, Kottayam and Thrissur were surveyed during 2007 to understand the magnitude of the problem of chikungunya fever, particularly clinical signs and symptoms. METHODS: A total of 1265 persons from 310 houses were surveyed door-to-door in 20 different localities representing four affected districts. The history and examination findings from 354 clinically diagnosed chikungunya cases were recorded. The symptoms recorded were fever, headache, myalgia, arthralgia, itch/rash, oedema, eye congestion, eye pain, oral ulcers, distaste, nausea, vomiting and haemorrhage. RESULTS: The major symptoms were fever (100%), headache (97.5%), arthralgia (99.4%) and myalgia (99.4%). A significant difference was observed in oedema, distaste, nausea and headache among different age groups and these symptoms were reported to be lower (12.2-89.8%) in younger age group than in older age group (90.4-100%). No genderwise difference was observed for any of the symptoms. In clinically diagnosed chikungunya cases higher age group (>35 years) found with higher rate of severity with symptoms of oedema, distaste, nausea and headache when compared with lower age group (1-35 yr). INTERPRETATION & CONCLUSION: Chikungunya invaded Kerala State for the first time in 2006 and continues to be a major vector borne disease in the State. The clinical symptoms in affected cases highlighted high fever, sever myalgia and prolonged arthralgia, with occasional history of skin itch/rash (petechiae).


Asunto(s)
Infecciones por Alphavirus/epidemiología , Infecciones por Alphavirus/transmisión , Virus Chikungunya , Culicidae/virología , Brotes de Enfermedades/estadística & datos numéricos , Adolescente , Adulto , Infecciones por Alphavirus/diagnóstico , Animales , Niño , Preescolar , Femenino , Humanos , India/epidemiología , Lactante , Masculino , Persona de Mediana Edad , Adulto Joven
17.
J Med Entomol ; 46(3): 633-9, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19496437

RESUMEN

A 4-yr (2002-2006) entomological study was carried out in Kurnool district, Andhra Pradesh state, south India, to identify the mosquito vectors of Japanese encephalitis virus (family Flaviviridae, genus Flavivirus, JEV). In total, 37,139 female mosquitoes belonging five genera and 18 species resting on vegetation were collected in villages and periurban areas at dusk. Mosquito species composition and pattern of JEV infection in mosquitoes varied in periurban and rural areas. In periurban area, Culex gelidus Theobald was abundant, making up 49.7% of total catch followed by Culex tritaeniorhynchus Giles (44.5%). In rural area, Cx. tritaeniorhynchus was predominant, making up 78.9% of total catch followed by Culex quinquefasciatus Say (10.8%), Anopheles subpictus Grassi (7.1%), and Cx. gelidus (1.1%). In light trap collections, Cx. gelidus and Cx. tritaeniorhynchus predominated in periurban and rural areas, respectively. Of 50,145 mosquitoes screened JEV isolations were made only from Cx. gelidus and Cx. tritaeniorhynchus. Based on high abundance and frequent JEV isolation, Cx. tritaeniorhynchus was found to be the principal vector in both areas, whereas Cx. gelidus plays a secondary vector role in periurban areas only.


Asunto(s)
Anopheles/virología , Culex/virología , Virus de la Encefalitis Japonesa (Especie)/aislamiento & purificación , Insectos Vectores/virología , Animales , Biodiversidad , Encefalitis Japonesa/transmisión , Encefalitis Japonesa/virología , India , Densidad de Población , Estaciones del Año , Factores de Tiempo
18.
J Med Entomol ; 45(5): 927-32, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18826037

RESUMEN

Identification of blood meals of vector mosquitoes is an important tool in the epidemiological investigations of vector-borne diseases. The blood meals of three mosquito species involved in the transmission of Japanese encephalitis virus (JEV) from the Kuttanadu area, Kerala, were determined using the agarose gel diffusion technique. A total of 4959 blood smears belonging to Culex (Culex) tritaeniorhynchus Giles (3273), Cx. (Culex) gelidus Theobald (64), Mansonia (Mnd.) indiana Edwards (735) ,and Ma. (Mnd.) uniformis (Theobald) (887) were tested. Cx. tritaeniorhynchus had predominantly fed on bovids (46.4%), and a good proportion (29%) had fed on more than one host. Cx. tritaeniorhynchus was highly zoophagic, and human feeding accounted for only 1.5% of those individuals successfully tested. Cx. gelidus showed bovid feeding at 36% and pig feeding at 12.5%. The test results showed 42.3% Ma. indiana and 12.2% Ma. uniformis had fed on humans. Multiple feeding was observed in Ma. indiana and Ma. uniformis, and most of the double feedings were from bovids and ovids (7.9 and 20.1%, respectively). Pig feeding accounted for 4.8% of the feedings by Cx. tritaeniorhynchus, 5.3% of Ma. indiana, and 6.4% of Ma. uniformis. This study is significant because of the role played by these mosquitoes in the transmission of JEV in the Kuttanadu area of Kerala, India.


Asunto(s)
Culicidae/fisiología , Culicidae/virología , Virus de la Encefalitis Japonesa (Especie)/fisiología , Conducta Alimentaria/fisiología , Insectos Vectores/virología , Animales , Encefalitis Japonesa/epidemiología , India/epidemiología
19.
Indian J Med Res ; 127(4): 395-7, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18577796

RESUMEN

BACKGROUND & OBJECTIVE: Dengue viruses are spread and maintained in an Aedes aegypti-human- Ae. aegypti cycle in urban areas of the tropics. Dengue viruses are also maintained in nature by vertical transmission by Ae. aegypti. A study was undertaken in Chennai, a known endemic city in south India, to comprehend the natural vertical transmission dynamics in Ae. aegypti and to assess its epidemiological importance. METHODS: Ae. aegypti males collected in resting and landing collections were tested for dengue virus infection by antigen-capture enzyme-linked immunosorbent assay (ELISA) and further examined by insect bioassay, Toxorhynchites splendens inoculation-indirect immunofluorescence technique (Toxo-IFA) using serotype-specific monoclonal antibodies (Mabs), if found positive by ELISA. RESULTS: Of the 509 pools of Ae. aegypti males (n=5408) screened, 15 pools, collected in April, June- July, November-December in 2003 and March, May in 2004, were found positive for dengue virus infection and the minimum infection rate (MIR) among adult males was high in June 2003 (28.0/ 1000). Three positive pools could be serotyped as dengue-2 (2 pools) and dengue-3 (1 pool). INTERPRETATION & CONCLUSION: Dengue virus isolations from wild caught males of Ae. aegypti indicate the occurrence of transovarial transmission. Vertical transmission was mainly observed in summer months when dengue infections in humans were low suggesting that dengue viruses adopt a novel strategy of surviving adverse climatic conditions.


Asunto(s)
Aedes/virología , Virus del Dengue/aislamiento & purificación , Dengue/epidemiología , Dengue/transmisión , Animales , Enfermedades Endémicas , Humanos , India/epidemiología , Transmisión Vertical de Enfermedad Infecciosa , Masculino , Estaciones del Año
20.
J Theor Biol ; 252(1): 15-23, 2008 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-18343410

RESUMEN

In this article we investigate all possible three-dimensional structures for sialyl Lewis(a) (SLe(a)) in aqueous solution and we predict without a priori experimental information its conformation when bound to SelectinE by using a combination of long molecular dynamics (MD) simulations. Based on 10ns MD studies, three structures differing in glycosidic conformations are proposed for SLe(a) in aqueous solution. Based on a 4ns MD study of the SLe(a)-SelectinE complex with initial structures derived from our prediction tools, we find that, fucose and N-acetyl neuraminic acid are in close contact with SelectinE and therefore expect interactions of the protein with these two sugar rings to be significantly more important than in the case of galactose and N-acetyl glucosamine. Our predictions indicate that the N-acetyl glucosamine of SLe(a) is positioned primarily in the aqueous phase. In order to be able to interact with SLe(a) the side chains of amino acid residues Lys99 and Lys111 in SelectinE appear to undergo large conformational changes when contrasted with the positions of these residues in the X-ray crystal structure. Furthermore, amino acid residues Arg97, Glu98 and Lys99 are acting as a holding arm to position the NeuNAc of SLe(a) in the binding pocket.


Asunto(s)
Selectina E/química , Gangliósidos/química , Modelos Moleculares , Antígeno CA-19-9 , Conformación de Carbohidratos , Enlace de Hidrógeno , Unión Proteica , Agua
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