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1.
J Biomech Eng ; 145(4)2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36193889

RESUMO

Previous experimental flow studies have demonstrated a delay (∼20%) in transition to turbulence for whole blood compared to a Newtonian analog fluid in both a straight pipe and eccentric stenosis model with ridged walls. The impact of wall compliance on the transition to turbulence of blood compared to Newtonian analog and on wall vibration is unknown. The present study employed flexible walls downstream of an eccentric stenosis model and examined the wall vibration during the transition to turbulence with whole blood and a Newtonian analog. Measurements of tube wall vibration velocity (WVV) were used as an indicator of the turbulence level within the flexible tube. WVV was measured at 5, 10, and 15 diameters downstream of the stenosis using a laser Doppler vibrometer at Reynolds numbers 0, 200, 300, 350, 400, 450, 500, 550, 600, 650, 700, and 750. The root mean squares (RMS) of the measured WVV were utilized as an indirect measure of fluid velocity fluctuations present at that location, and hence, an indicator of transition to turbulence. WVV RMS was near-constant until approximately Reynolds number 400. It increased monotonically with Reynolds number for both whole blood and the Newtonian fluid. No differences in the transition to turbulence were observed between whole blood and the Newtonian fluid, as the WVV RMS curves were remarkably similar in shape. This result suggests that rheology had minimal impact on the WVV downstream of a stenosis for transition to turbulence since the fluids had a similar level of vibration.


Assuntos
Modelos Cardiovasculares , Vibração , Humanos , Constrição Patológica , Estresse Mecânico , Reologia , Velocidade do Fluxo Sanguíneo
2.
J Biomech Eng ; 144(3)2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-34505131

RESUMO

Blood, a multiphase fluid comprised of plasma, blood cells, and platelets, is known to exhibit a shear-thinning behavior at low shear rates and near-Newtonian behavior at higher shear rates. However, less is known about the impact of its multiphase nature on the transition to turbulence. In this study, we experimentally determined the critical Reynolds number at which the flow began to transition to turbulence downstream of eccentric stenosis for whole porcine blood and a Newtonian blood analog (water-glycerin mixture). Velocity profiles for both fluids were measured under steady-state flow conditions using an ultrasound Doppler probe placed 12 diameters downstream of eccentric stenosis. Velocity was recorded at 21 locations along the diameter at 11 different flow rates. Normalized turbulent kinetic energy was used to determine the critical Reynolds number for each fluid. Blood rheology was measured before and after each experiment. Tests were conducted on five samples of each fluid inside a temperature-controlled in vitro flow system. The viscosity at a shear rate of 1000 s-1 was used to define the Reynolds number for each fluid. The mean critical Reynolds numbers for blood and water-glycerin were 470 ± 27.5 and 395 ± 10, respectively, indicating a ∼19% delay in transition to turbulence for whole blood compared to the Newtonian fluid. This finding is consistent with a previous report for steady flow in a straight pipe, suggesting some aspect of blood rheology may serve to suppress, or at least delay, the onset of turbulence in vivo.


Assuntos
Glicerol , Modelos Cardiovasculares , Animais , Velocidade do Fluxo Sanguíneo , Constrição Patológica , Reologia , Estresse Mecânico , Suínos , Água
3.
Magn Reson Med ; 85(3): 1237-1247, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32869349

RESUMO

PURPOSE: The goal of this study was to determine the accuracy of displacement-encoding with stimulated echoes (DENSE) MRI in a tissue motion phantom with displacements representative of those observed in human brain tissue. METHODS: The phantom was comprised of a plastic shaft rotated at a constant speed. The rotational motion was converted to a vertical displacement through a camshaft. The phantom generated repeatable cyclical displacement waveforms with a peak displacement ranging from 92 µm to 1.04 mm at 1-Hz frequency. The surface displacement of the tissue was obtained using a laser Doppler vibrometer (LDV) before and after the DENSE MRI scans to check for repeatability. The accuracy of DENSE MRI displacement was assessed by comparing the laser Doppler vibrometer and DENSE MRI waveforms. RESULTS: Laser Doppler vibrometer measurements of the tissue motion demonstrated excellent cycle-to-cycle repeatability with a maximum root mean square error of 9 µm between the ensemble-averaged displacement waveform and the individual waveforms over 180 cycles. The maximum difference between DENSE MRI and the laser Doppler vibrometer waveforms ranged from 15 to 50 µm. Additionally, the peak-to-peak difference between the 2 waveforms ranged from 1 to 18 µm. CONCLUSION: Using a tissue phantom undergoing cyclical motion, we demonstrated the percent accuracy of DENSE MRI to measure displacement similar to that observed for in vivo cardiac-induced brain tissue.


Assuntos
Algoritmos , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem , Humanos , Movimento (Física) , Imagens de Fantasmas
4.
Acta Virol ; 65(3): 245-253, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34565152

RESUMO

The response of the host immune system should be appropriate to fight against pandemic 2009 H1N1 (pH1N1) influenza A virus without causing damage to its self. T cells play an indispensable role in the fight against the virus, but have the potential to cause host immunopathological changes. A better understanding of the immunoregulation that occurs during pH1N1 infection is necessary for preventing severity of the disease. In this study, we found that a significantly higher percentage of Vδ1+ T cells and increased expression of activation markers in total T cells in patients with moderate pH1N1 infection could lead to its efficient fight against the virus. On the other hand, the percentages of total and CD4+ T cells were decreased along with an increased expression of exhaustion marker-Tim-3 on T cells that might suppress excessive T cell responses in the host. This tuning of T cell responses might be necessary in efficient combat against pH1N1 virus, without aggravating T cell mediated immunopathology in patients with moderate pH1N1-infection. Keywords: pH1N1; T cells; activation; exhaustion; Tim-3.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Influenza Humana , Linfócitos T CD4-Positivos , Humanos , Vírus da Influenza A Subtipo H1N1/genética
5.
Neuroradiology ; 62(11): 1389-1400, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32418026

RESUMO

PURPOSE: While the presence of cerebellar tonsillar descent in radiological images has been used as evidence of Chiari malformation type I (CMI), tonsillar ectopia alone is insufficient to identify individuals with symptomatic CMI. This study sought to identify differences in brain morphology between symptomatic CMI and healthy controls in adult females. METHODS: Two hundred and ten adult females with symptomatic CMI and 90 age- and body mass index-matched asymptomatic female controls were compared using seven brain morphometric measures visible on magnetic resonance images. The CMI and control groups were divided into four subgroups based on the tonsillar position (TP) relative to the foramen magnum: group 1 was made up of healthy controls with normal TP (TP < 0 mm); group 2 was comprised of control individuals with low-lying TP (1-5 mm); group 3 was comprised of symptomatic CMI patients with low-lying TP (1-5 mm); group 4 contained symptomatic CMI patients with severe tonsillar descent (6-13 mm). RESULTS: All morphometrics for symptomatic CMI with severe tonsillar descent were significantly different than those for both control groups. The CMI group with low-lying TP was significantly different for four measures when compared to controls with normal TP. However, only clivus length was statistically different between the CMI and healthy control groups with low-lying TP. CONCLUSION: This study demonstrates that clivus length distinguishes adult female healthy individuals with low-lying tonsils from those with symptomatic CMI. Further investigation is required to understand the importance of a shorter clivus length on CMI symptomatology and pathophysiology.


Assuntos
Malformação de Arnold-Chiari , Fossa Craniana Posterior/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Adulto , Estudos de Casos e Controles , Fossa Craniana Posterior/patologia , Feminino , Humanos
6.
Neuroradiology ; 61(9): 1011-1022, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31119343

RESUMO

PURPOSE: While 84% of patients surgically treated for Chiari malformation type 1 (CM1) demonstrate improved quality of life after posterior fossa decompression surgery, there are many risks associated with this surgery. Surgical planning to identify candidates likely to improve postoperatively may benefit from an improved understanding of morphological changes after decompression surgery. To evaluate these changes, we quantified 59 morphological parameters on 42 CM1 adult female patients before and after CM1 decompression surgery. METHODS: Fifty-nine morphological parameters in the posterior cranial fossa, cranio-cervical, and intracranial regions in the midsagittal plane were evaluated using 42 T1-weighted magnetic resonance images of female CM1 patients before and after surgery, and 42 healthy female controls. Morphological differences before and after surgery were compared through the development of a technique to establish the opisthion location, a key reference point not present after surgery. RESULTS: In addition to the expected reduction of the cranio-caudal dimension of the cerebellum, objective analyses showed a significant increase in the area of the cerebrospinal fluid spaces, posterior (6×) and inferior (2.6×) to the cerebellum (+ 112 ± 102 and + 140 ± 127 mm2, respectively). This increased area was primarily impacted by an average reduction in the occipital bone length of 24.5 ± 7.3 mm following surgery. Based on multiple angles, results demonstrated a 2°-4° anterior rotation of the cerebellum after surgery. CONCLUSION: Our results show that decompression surgery results in significant changes in the cerebellum and cerebrospinal fluid spaces. Further investigation should determine how these morphological changes impact clinical outcomes.


Assuntos
Malformação de Arnold-Chiari/cirurgia , Fossa Craniana Posterior/cirurgia , Descompressão Cirúrgica , Adulto , Malformação de Arnold-Chiari/diagnóstico por imagem , Malformação de Arnold-Chiari/patologia , Estudos de Casos e Controles , Fossa Craniana Posterior/diagnóstico por imagem , Fossa Craniana Posterior/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Resultado do Tratamento
7.
J Med Virol ; 90(5): 854-860, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29315655

RESUMO

Human leucocyte antigen (HLA) represents one of the most highly polymorphic systems which plays a central role in the immune response. Genetic polymorphism of HLA in influenza A(H1N1)pdm09 infected population may be an important factor in disease progression and severity that needs further probing. In this study, a total of 110 Influenza like illness patients were recruited from the population of Assam, Northeast India, from which 35 cases infected by A(H1N1)pdm09 viruses and 35 controls were typed for HLA-A, B and DRB1 locus by PCR-SSP method. A total of seven alleles of HLA-A, 16 alleles of HLA-B, and 11 alleles of HLA-DRB1 locus were identified. The most common alleles within each locus in cases were HLA-A*11 (85.71%, P = 0.046), HLA-B*35 (25%, P = 0.0001), and HLA-DRB1*15 (49.35%, P = 0.133) as compared to the controls, HLA-A*11 (40.82%), HLA-B*35 (0.00%), and HLA-DRB1*15 (67.53%). The frequency of HLA-A*11 and HLA-B*35 were significantly higher in cases as compared to the controls. In DRB1 locus, HLA-DRB1*10 was significantly higher in cases (20.78%, P = 0.005) than that of controls (0.00%). Whereas, HLA-DRB1*15 showed a higher frequency in controls than in cases. In addition, HLA-DRB3*01 (P = 0.053), DRB4*01 (P = 1.000), and DRB5*01(P = 0.591) were also identified along with HLA-DRB1 haplotype. From this preliminary study, it is suspected that there may be a role of HLA-A*11, HLA-B*35 and HLA-DRB1*10 in conferring susceptibility to influenza A(H1N1)pdm09 infection in the study population. A larger extended study on HLA polymorphism may explain the association between HLA and influenza A(H1N1)pdm09 infection and provide insights for HLA restricted peptide based vaccines.


Assuntos
Predisposição Genética para Doença , Antígenos HLA-A/genética , Antígenos HLA-B/genética , Cadeias HLA-DRB1/genética , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/imunologia , Influenza Humana/virologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Índia , Vírus da Influenza A Subtipo H1N1/imunologia , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Estudos Prospectivos , Adulto Jovem
8.
Parasite Immunol ; 40(12): e12594, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30276843

RESUMO

Gamma delta (γδ) T cells exhibit potent anti-Plasmodium activity but are also implicated in the immunopathology of malaria. It is currently poorly understood how γδ T cells are affected in human suffering from Plasmodium vivax infection or in symptomless individuals living in an endemic region. We examined both the percentages and expression of markers associated with immune exhaustion in γδ T cells in individuals living in a P. vivax endemic region by flow cytometry. The percentage of γδ T cells in the blood was significantly higher both in acute P. vivax-positive patients and in individuals from an endemic region in comparison with control uninfected adults. The frequency of the expression of the exhaustion markers-Tim-3, Lag-3, CTLA-4 and PD-1 was higher in γδ and total T cells from P. vivax-infected patients than in those populations from control uninfected adults. Individuals from a P. vivax endemic region showed elevated percentages of Tim-3-, Lag-3- and CTLA-4-positive γδ T cells and an increased percentage of Tim-3-positive total T cells. The phenotypic exhaustion of these cells might be a protective mechanism preventing the immunopathology associated with activated T cells and may provide a rationale for targeted manipulation of this process in diseases such as malaria.


Assuntos
Malária Vivax/genética , Plasmodium vivax/fisiologia , Linfócitos T/imunologia , Adulto , Antígenos CD/genética , Antígenos CD/imunologia , Biomarcadores/análise , Antígeno CTLA-4/genética , Antígeno CTLA-4/imunologia , Feminino , Citometria de Fluxo , Receptor Celular 2 do Vírus da Hepatite A/genética , Receptor Celular 2 do Vírus da Hepatite A/imunologia , Humanos , Ativação Linfocitária , Contagem de Linfócitos , Malária Vivax/imunologia , Malária Vivax/parasitologia , Masculino , Pessoa de Meia-Idade , Plasmodium vivax/genética , Proteína do Gene 3 de Ativação de Linfócitos
9.
Int J Food Sci Nutr ; 69(4): 494-502, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28918674

RESUMO

In order to investigate whether the angiotensin converting enzyme-inhibitory tomato extract Fruitflow® would lower blood pressure after consumption, we conducted a randomised, double-blinded, placebo-controlled human intervention study, involving 12 pre-hypertensive people in a crossover design. Consuming a single dose of 150 mg Fruitflow® resulted in a significant reduction in 24-hour average blood pressure as well as average wake-period and sleep-period SBP, compared to placebo. Other parameters related to blood pressure, such as 24-hour average mean arterial pressure, pulse pressure, heart rate, central aortic systolic pressure and radial augmentation index were also reduced. In addition, the platelet aggregation response to ADP, measured 24 hours after consuming Fruitflow®, fell significantly compared to baseline, and compared to placebo. This pilot study clearly shows the beneficial effects of Fruitflow® on two important cardiovascular risk factors, high blood pressure and platelet hyperactivity.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Alimento Funcional , Extratos Vegetais/administração & dosagem , Pré-Hipertensão/tratamento farmacológico , Adulto , Anti-Hipertensivos/farmacologia , Ritmo Circadiano , Estudos Cross-Over , Método Duplo-Cego , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto
10.
J Neuroradiol ; 45(1): 23-31, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28826656

RESUMO

PURPOSE: Type I Chiari malformation (CMI) is a radiologically-defined structural dysmorphism of the hindbrain and posterior cranial fossa (PCF). Traditional radiographic identification of CMI relies on the measurement of the cerebellar tonsils in relation to the foramen magnum with or without associated abnormalities of the neuraxis. The primary goal of this retrospective study was to comprehensively assess morphometric parameters above the McRea line in a group of female CMI patients and normal controls. MATERIAL AND METHODS: Twenty-nine morphological measurements were taken on 302 mid-sagittal MR images of adult female CMI patients (n=162) and healthy controls (n=140). All MR images were voluntarily provided by CMI subjects through an online database and control participant images were obtained through the Human Connectome Project and a local hospital system. RESULTS: Analyses were performed on the full dataset of adult female MR images and a restricted dataset of 229 participants that were equated for age, race, and body mass index. Eighteen group differences were identified in the PCF area that we grouped into three clusters; PCF structures heights, clivus angulation, and odontoid process irregularity. Fourteen group differences persisted after equating our CMI and control groups on demographic characteristics. CONCLUSION: PCF structures reliably differ in adult female CMI patients relative to healthy controls. These differences reflect structural abnormalities in the osseous and soft tissue structures of the clivus, odontoid process, and cerebellum. Clinical and pathophysiological implications are discussed.


Assuntos
Malformação de Arnold-Chiari/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Adulto , Pontos de Referência Anatômicos , Estudos de Casos e Controles , Fossa Craniana Posterior/anormalidades , Fossa Craniana Posterior/diagnóstico por imagem , Feminino , Humanos , Estudos Retrospectivos , Rombencéfalo/anormalidades , Rombencéfalo/diagnóstico por imagem
11.
J Med Virol ; 88(11): 1999-2003, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27035572

RESUMO

During August 2013, an outbreak of influenza-like illnesses (ILI) was investigated in Monigong area, near Indo-China border of Arunachal Pradesh, Northeast India. Influenza type A/H3N2 was detected by RT-PCR in 33.3% (8/24) of ILI cases. Sequence analysis of HA and NA genes revealed eight and five amino acid substitutions, respectively in Monigong H3N2 (Mo/H3N2) strains as compared to vaccine strain A/Victoria/361/2011. Four non-synonymous substitutions, three localizing at antigenic sites T144A, A; R158G, B; L173S, D, and one H9Y in close proximity to a potential glycosylation site aa8 in HA1 domain along with the substitution T329N in NA are likely to influence the antigenicity/virulence of Mo/H3N2 viruses. J. Med. Virol. 88:1999-2003, 2016. © 2016 Wiley Periodicals, Inc.


Assuntos
Surtos de Doenças , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Influenza Humana/epidemiologia , Adolescente , Substituição de Aminoácidos , Criança , Pré-Escolar , China/epidemiologia , Feminino , Variação Genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Índia/epidemiologia , Lactente , Recém-Nascido , Vírus da Influenza A Subtipo H3N2/classificação , Vírus da Influenza A Subtipo H3N2/genética , Influenza Humana/virologia , Masculino , Neuraminidase/genética , Filogenia , RNA Viral/genética , Análise de Sequência de DNA , Adulto Jovem
13.
J Biomech Eng ; 138(7)2016 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-27109010

RESUMO

Blood is a complex fluid that, among other things, has been established to behave as a shear thinning, non-Newtonian fluid when exposed to low shear rates (SR). Many hemodynamic investigations use a Newtonian fluid to represent blood when the flow field of study has relatively high SR (>200 s-1). Shear thinning fluids have been shown to exhibit differences in transition to turbulence (TT) compared to that of Newtonian fluids. Incorrect prediction of the transition point in a simulation could result in erroneous hemodynamic force predictions. The goal of the present study was to compare velocity profiles near TT of whole blood and Newtonian blood analogs in a straight rigid pipe with a diameter 6.35 mm under steady flow conditions. Rheology was measured for six samples of whole porcine blood and three samples of a Newtonian fluid, and the results show blood acts as a shear thinning non-Newtonian fluid. Measurements also revealed that blood viscosity at SR = 200 s-1 is significantly larger than at SR = 1000 s-1 (13.8%, p < 0.001). Doppler ultrasound (DUS) was used to measure velocity profiles for blood and Newtonian samples at different flow rates to produce Reynolds numbers (Re) ranging from 1000 to 3300 (based on viscosity at SR = 1000 s-1). Two mathematically defined methods, based on the velocity profile shape change and turbulent kinetic energy (TKE), were used to detect TT. Results show similar parabolic velocity profiles for both blood and the Newtonian fluid for Re < 2200. However, differences were observed between blood and Newtonian fluid velocity profiles for larger Re. The Newtonian fluid had blunt-like velocity profiles starting at Re = 2403 ± 8 which indicated transition. In contrast, blood did not show this velocity profile change until Re = 2871 ± 104. The Newtonian fluid had large velocity fluctuations (root mean square (RMS) > 20%) with a maximum TKE near the pipe center at Re = 2316 ± 34 which indicated transition. In contrast, blood results showed the maximum TKE at Re = 2806 ± 109. Overall, the critical Re was delayed by ∼20% (p < 0.001) for blood compared to the Newtonian fluid. Thus, a Newtonian assumption for blood at flow conditions near transition could lead to large errors in velocity prediction for steady flow in a straight pipe. However, these results are specific to this pipe diameter and not generalizable since SR is highly dependent on pipe diameter. Further research is necessary to understand this relation in different pipe sizes, more complex geometries, and under pulsatile flow conditions.


Assuntos
Artérias/fisiologia , Velocidade do Fluxo Sanguíneo/fisiologia , Pressão Sanguínea/fisiologia , Viscosidade Sanguínea/fisiologia , Modelos Cardiovasculares , Animais , Simulação por Computador , Resistência ao Cisalhamento/fisiologia , Estresse Mecânico , Suínos
14.
J Biomech Eng ; 138(11)2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27598222

RESUMO

Quantification of the tricuspid valve (TV) leaflets mechanical strain is important in order to understand valve pathophysiology and to develop effective treatment strategies. Many of the traditional methods used to dynamically open and close the cardiac valves in vitro via flow simulators require valve dissection. Recent studies, however, have shown that restriction of the atrioventricular valve annuli could significantly change their in vivo deformation. For the first time, the porcine valve leaflets deformation was measured in a passive ex vivo beating heart without isolating and remounting the valve annuli. In particular, the right ventricular apexes of porcine hearts (n = 8) were connected to a pulse-duplicator pump that maintained a pulsatile flow from and to a reservoir connected to the right atrium and the pulmonary arteries. This pump provided a right ventricular pressure (RVP) waveform that closely matched physiological values, leading to opening and closure of the tricuspid and pulmonary valves (PVs). At the midsection of the valve leaflets, the peak areal strain was 9.8 ± 2.0% (mean±standard error). The peak strain was 5.6 ± 1.1% and 4.3 ± 1.0% in the circumferential and radial directions, respectively. Although the right ventricle was beating passively, the leaflet peak areal strains closely matched the values measured in other atrioventricular valves (i.e., the mitral valve (MV)) in vivo. This technique can be used to measure leaflet strains with and without the presence of valve lesions to help develop/evaluate treatment strategies to restore normal valve deformation.


Assuntos
Velocidade do Fluxo Sanguíneo/fisiologia , Modelos Cardiovasculares , Valva Tricúspide/fisiologia , Função Ventricular Direita/fisiologia , Animais , Força Compressiva/fisiologia , Simulação por Computador , Módulo de Elasticidade/fisiologia , Técnicas In Vitro , Estresse Mecânico , Propriedades de Superfície , Suínos , Resistência à Tração/fisiologia
15.
J Assoc Physicians India ; 64(10): 24-28, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27766799

RESUMO

OBJECTIVE: Toxoplasma gondii infection is primarily asymptomatic and one third of world's population is estimated to be infected by this protozoan parasite. This study was carried out to determine the seroprevalence of T. gondii infection among pregnant women from north east India, where data on this important parasitic infection is scanty. METHODS: A total of 1141 serum archival samples collected from antenatal clinic attendees in 2007-09, were screened for T. gondii IgG by ELISA and analyzed with their socio demographic information. RESULTS: The median age of the subjects were 25 years with an overall IgG seroprevalence of 48% (95% CI=45% to 51%). Seroprevalence was significantly associated with geographical location (p=0.000), among Mongoloids compared to Caucasoid (p=0.005), regular employees (p=0.003) or unskilled labors (p=0.04) compared to housewives, high or middle income group (p=0.003) compared to low income group and with increasing gravida (p=0.04). However on logistic regression analysis, only significant association was with geographical location (p=0.000) and occupation (unskilled labor) (p=0.04). Highest prevalence of 66.7% was noted among subjects with history of blood transfusion and lowest among Rh negative blood group (14.3%). CONCLUSIONS: T. gondii infection prevalence is high among pregnant women living in hilly states of northeast India, which warrants a detail investigation on congenital toxoplasmosis as well as its economic impact.


Assuntos
Anticorpos Antiprotozoários/sangue , Imunoglobulina G/sangue , Complicações Infecciosas na Gravidez/sangue , Complicações Infecciosas na Gravidez/epidemiologia , Toxoplasma/imunologia , Toxoplasmose/sangue , Toxoplasmose/epidemiologia , Adolescente , Adulto , Feminino , Humanos , Índia/epidemiologia , Gravidez , Estudos Retrospectivos , Estudos Soroepidemiológicos , Adulto Jovem
16.
Indian J Med Res ; 142(3): 293-300, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26458345

RESUMO

BACKGROUND & OBJECTIVES: Elevated blood pressure (BP) in the young predicts serious cardiovascular events in the adults. High prevalence of adult hypertension reported from Assam, North East (NE) India may be linked with elevated blood pressure in the childhood. The present study was an attempt to describe the distribution of BP and correlates of hypertension in children aged 5-14 yr. METHODS: A total of 10,003 school children from 99 schools of Dibrugarh district, Assam, NE India, were surveyed by stratified random cluster method. Blood pressure, demographic and anthropometric information were recorded. Blood pressure was categorized in to normal, prehypertension, stage I and stage II hypertension. RESULTS: Girls had significantly higher (104.2 ± 12.0 vs. 103.2 ± 11.6 mm Hg, p0 <0.001) mean systolic blood pressure (SBP) than boys. Both SBP and diastolic blood pressure (DBP) revealed significant correlation with age, height, weight and BMI in overall and in gender specific analysis. Hypertension was found in 7.6 per cent school children (Boys: 7.3%, Girls: 7.8%). In multivariable analysis older age (OR 3.3, 95% CI: 2.82-3.91), children from tea garden community (OR 1.3, 95% CI: 1.08-1.55) and other community (OR 1.4, 95% CI: 1.18-1.73) and overweight (OR 1.5, 95% CI: 1.1-2.1) were independently associated with hypertension. INTERPRETATION & CONCLUSIONS: Mean blood pressure in the young school children of 5-14 yr was high. A programme comprising screening, early detection and health promotion through school health programmes may help prevent future complications of hypertension.


Assuntos
Pressão Sanguínea , Hipertensão/epidemiologia , Sobrepeso/epidemiologia , Pré-Hipertensão/epidemiologia , Adolescente , Índice de Massa Corporal , Peso Corporal , Criança , Pré-Escolar , Feminino , Humanos , Índia , Masculino
17.
Glia ; 62(8): 1345-60, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24807189

RESUMO

Microglia, the resident immune cells of the central nervous system, exist in either a "resting" state associated with physiological tissue surveillance or an "activated" state in neuroinflammation. We recently showed that ATP is the primary chemoattractor to tissue damage in vivo and elicits opposite effects on the motility of activated microglia in vitro through activation of adenosine A2A receptors. However, whether systemic inflammation affects microglial responses to tissue damage in vivo remains largely unknown. Using in vivo two-photon imaging of mice, we show that injection of lipopolysaccharide (LPS) at levels that can produce both clear neuroinflammation and some features of sepsis significantly reduced the rate of microglial response to laser-induced ablation injury in vivo. Under proinflammatory conditions, microglial processes initially retracted from the ablation site, but subsequently moved toward and engulfed the damaged area. Analyzing the process dynamics in 3D cultures of primary microglia indicated that only A2A , but not A1 or A3 receptors, mediate process retraction in LPS-activated microglia. The A2A receptor antagonists caffeine and preladenant reduced adenosine-mediated process retraction in activated microglia in vitro. Finally, administration of preladenant before induction of laser ablation in vivo accelerated the microglial response to injury following systemic inflammation. The regulation of rapid microglial responses to sites of injury by A2A receptors could have implications for their ability to respond to the neuronal death occurring under conditions of neuroinflammation in neurodegenerative disorders.


Assuntos
Córtex Cerebral/lesões , Inflamação/fisiopatologia , Microglia/fisiologia , Neuroimunomodulação/fisiologia , Animais , Técnicas de Cultura de Células , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/patologia , Córtex Cerebral/fisiopatologia , Feminino , Fatores Imunológicos/farmacologia , Inflamação/tratamento farmacológico , Inflamação/patologia , Lasers/efeitos adversos , Lipopolissacarídeos , Masculino , Camundongos Transgênicos , Microglia/efeitos dos fármacos , Microglia/patologia , Neuroimunomodulação/efeitos dos fármacos , Pirimidinas/farmacologia , Receptor A1 de Adenosina/metabolismo , Receptor A2A de Adenosina/metabolismo , Receptor A3 de Adenosina/metabolismo , Sepse/tratamento farmacológico , Sepse/patologia , Sepse/fisiopatologia , Triazóis/farmacologia
18.
Eur J Nutr ; 53(8): 1699-706, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24573416

RESUMO

PURPOSE: To investigate the presence of anti-angiotensin converting enzyme (ACE) factors in aqueous extract of tomato. METHODS: The bio-guided fractionation of the aqueous extract of tomato produced a sugar-free, heat-stable fraction with molecular mass <1,000 Da from tomatoes. The sugar-free tomato extract (TE) was tested for its anti-ACE activity using human plasma and rabbit lung pure ACE. In addition, its effect on human platelet aggregation induced by ADP, collagen or arachidonic acid was determined. The mechanism of platelet inhibitory action of TE was investigated by measuring platelet factor 4 (PF4) release and cAMP synthesis by platelets. RESULTS: Typically, 100 g tomatoes produced 72.2 ± 4.7 mg of TE. This extract inhibited both platelet aggregation and plasma ACE activity in a dose-dependent manner. It inhibited platelet aggregation in response to ADP, collagen or arachidonic acid, and inhibitory action was mediated in part by reducing platelet PF4 release and by stimulating cAMP synthesis. The IC50 value of TE for ADP-induced platelet aggregation was 0.4 ± 0.02 mg/ml, whereas the IC50 value for ACE enzyme inhibition was 1.40 ± 0.04 mg/ml. Both the TE and commercially available sugar-free TE, Fruitflow(®)-2 had similar amount of catechin, and also had equal inhibitory potencies against platelet aggregation and plasma ACE activity. CONCLUSION: Together these data indicate that aqueous extract of tomatoes contain anti-ACE factors in addition to previously described anti-platelet factors.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Peptidil Dipeptidase A/sangue , Extratos Vegetais/farmacologia , Solanum lycopersicum/química , Animais , Ácido Araquidônico/metabolismo , Colágeno/metabolismo , AMP Cíclico/metabolismo , Hidroxibenzoatos/análise , Hidroxibenzoatos/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/farmacologia , Coelhos
19.
Platelets ; 25(8): 567-75, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24219176

RESUMO

Previous human studies suggest that supplementation with kiwifruits lowers several cardiovascular risk factors such as platelet hyperactivity, blood pressure and plasma lipids. The cardiovascular health benefit of fruit and vegetables is usually attributed to the complex mixture of phytochemicals therein; however, kiwifruit's cardioprotective factors are not well studied. In this study, we investigated the effects of kiwifruit extract on human blood platelet aggregation and plasma angiotensin-converting enzyme (ACE) activity. A sugar-free, heat-stable aqueous extract with molecular mass less than 1000 Da was prepared from kiwifruits. Typically, 100 g kiwifruits produced 66.3 ± 5.8 mg (1.2 ± 0.1 mg CE) of sugar-free kiwifruit extract (KFE). KFE inhibited both human platelet aggregation and plasma ACE activity in a dose-dependent manner. KFE inhibited platelet aggregation in response to ADP, collagen and arachidonic acid, and inhibitory action was mediated in part by reducing TxA2 synthesis. The IC50 for ADP-induced platelet aggregation was 1.6 ± 0.2 mg/ml (29.0 ± 3.0 µg CE/ml), whereas IC50 for serum ACE was 0.6 ± 0.1 mg/ml (11.0 ± 1.2 µg CE/ml). Consuming 500 mg of KFE (9.0 mg CE) in 10 g margarine inhibited ex vivo platelet aggregation by 12.7%, 2 h after consumption by healthy volunteers (n = 9). All these data indicate that kiwifruit contains very potent antiplatelet and anti-ACE components. Consuming kiwifruits might be beneficial as both preventive and therapeutic regime in cardiovascular disease.


Assuntos
Actinidia/química , Frutas/química , Peptidil Dipeptidase A/química , Extratos Vegetais/uso terapêutico , Agregação Plaquetária/efeitos dos fármacos , Humanos , Fatores de Risco
20.
Indian J Pathol Microbiol ; 67(1): 133-139, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38358202

RESUMO

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) responsible for the current pandemic has resulted in over 5 million deaths globally. More than a year has passed, still SARS-CoV-2 panic the public life. Virus isolation is of paramount importance for development of vaccines, in-vitro screening of antiviral compounds, pathogenesis studies, etc., Many cell lines were studied for amplification and replication of SARS-CoV-2 and Vero cells were found to be ideal cell lines for isolation. In May 2020, ICMR-Regional Medical Research Centre, NE region, India, successfully established the SARS-CoV-2 culture system in Vero CCL-81 cell lines. Phylogenetic analyses of the whole genome sequences of the SARS-CoV-2 isolate (EPI_ISL_2501532 | 2020-05-19) showed monophyletic clade G and lineage B.1.1.


Assuntos
COVID-19 , Animais , Chlorocebus aethiops , Humanos , SARS-CoV-2/genética , Células Vero , Filogenia , Pandemias/prevenção & controle
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