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Biomedical subjects

M A Haque

Publications and source records attributed to M A Haque.

At least 19 recordsLinked to original sources

Vigilance monitoring for operator safety: A simulation study on highway driving.

INTRODUCTION: Alertness of individuals operating vehicles, aircrafts, and machinery is a pre-requisite for safety of the individual and for avoiding economic losses. In this paper, we present a new technique for determining the alertness level of the operator and elaborate the methodology for the specific case of highway driving METHOD: Our hypothesis is that the time derivative of force exerted by the driver at the vehicle-human interfaces can be used to construct a signature of individual driving styles and to discern different levels of alertness RESULTS: In this study, we present experimental results corroborating this hypothesis and introduce a parameter, 'spikiness index,' for the time series data of the force derivative to quantify driver alertness IMPACT ON INDUSTRY: The low cost, ruggedness, and low-volume data processing requirements of the proposed technique give it a competitive edge over existing predominantly image processing based vigilance monitoring systems.

Accidents, Traffic↗

Wash resistance and bioefficacy of Olyset net--a long-lasting insecticide-treated mosquito net against malaria vectors and nontarget household pests.

During recent years, long-lasting insecticide-treated nets (LLINs) have been developed to overcome the problems of low retreatment rates, washing, and erratic dose of the insecticide resulting in the dilution of efficacy of the conventional insecticide-treated mosquito nets. These nets are treated at factory level with insecticide either incorporated into or coated around fibers. Olyset net, a polyethylene net with 2% permethrin incorporated within fibers, is one type of LLIN. Therefore, these nets were evaluated for their wash resistance and bioefficacy against malaria vectors Anopheles culicifacies Giles and Anopheles fluviatilis James (Diptera: Culicidae) and other nontarget species. Cone bioassay tests produced 100% mortality in these two vector species with 3-min exposure. Results of the bioassays on washed nets showed 100% mortality in An. fluviatilis even after 20 washings, whereas in An. culicifacies 100% mortality up to 11 washings and 80% mortality up to 20 washings were observed. Cone bioassay tests also were performed on nontarget mosquito species Culex quinquefasciatus Say; house fly, Musca domestica L.; American cockroach, Periplaneta americana (L.); head louse, Pediculus humanus capitis De Geer; and bed bug, Cimex lectularius L. with 30-min exposure. Except for bed bugs, 100% mortality was observed in these nontarget species after 24-h recovery period. In bed bugs, only 25% mortality was observed. The density of An. culicifacies and An. fluviatilis was significantly reduced in houses with Olyset nets compared with those with untreated nets or no nets. Thus, it may be concluded that Olyset nets are highly effective against malaria vectors and moderately against other nontarget household insects.

Animals↗

Effectiveness of mosquito nets treated with a tablet formulation of deltamethrin for malaria control in a hyperendemic tribal area of Sundargarh District, Orissa, India.

A village-scale trial on the efficacy of mosquito nets treated with a tablet formulation of deltamethrin (K-OTAB) against malaria in comparison to untreated nets or no net was conducted in Sundargarh District of Orissa, India, which is characterized by perennial transmission with Plasmodium falciparum accounting for more than 80% of malaria cases. Three villages with similar topographical and epidemiological situations were selected and randomly assigned to 3 arms of the study: treated net, untreated net, and no net. Distribution of nets, based on a sleeping pattern survey, was carried out to cover 100% of the population in treated-net and untreated-net villages. Longitudinal and cross-sectional surveys were conducted to measure malaria incidence, prevalence, and splenomegaly. Malaria incidence was reduced by 64.3% in the village with treated nets, 45.2% in the village with plain nets, and 21.4% in the control village without nets. Comparison of malaria incidence data after 1 year of intervention showed significant difference between villages with treated net vs. untreated net (P < 0.05) and treated net vs. no net (P < 0.005). The incidence of clinical attack rate due to P. falciparum was significantly lower in the population using treated nets than in those using untreated nets and no nets. However, no age-specific protective efficacy of treated nets or untreated nets was observed. A significant reduction occurred in spleen rate and parasite rate in children aged 2-9 years using treated nets or untreated nets. An overall significant reduction was found in parasite rate in the total population using treated and untreated nets as compared to nonusers.

Adolescent↗

Morphometry of the intercommissural distances and other structures of the aortic valve of bovine heart.

The morphometry of the intercommissural distances and their relation with other structures of the aortic valve of bovine heart was carried out. A total of 32 apparently healthy bovine hearts of indigenous cattle of both sexes (50% male and 50% female), 2-4 years of age, weighing 500 to 800 gms were used in this study. The external intercommissural distances were higher in all cusps of the valve compared to the internal intercommissural distances. The internal intercommissural distance was larger in the RC sinus in case of male animals followed by that of the LC and NC sinus. The mean external intercommissural distances were 34.67+/-3.40, 34.40+/-3.64 and 34.97+/-4.37 mm and the internal intercommissural distances were 21.60+/-4.21, 21.20+/-4.70 and 20.67+/-4.06 mm for LC, RC and NC respectively. Analyzing the internal intercommissural distance, value in the LC sinus was higher followed by the RC and the NC but this variation was non-significant. In regard to the position of the coronary ostia, there were two coronary ostia, the right coronary ostium present in the RC sinus and the left coronary ostium in the LC sinus respectively and the right coronary ostium was supracommissural in position in bovine heart. Data about the morphometrical analysis of intercommissural distances and the position of the coronary ostia of the aortic valve facilitate the knowledge of manufacturing bovine tissue valve as well as those might be involved in valve replacement in human.

Animals↗

Village-scale evaluation of mosquito nets treated with a tablet formulation of deltamethrin against malaria vectors.

A field trial was carried out in the Sundargarh district of Orissa, India on the efficacy of mosquito nets treated with a tablet formulation of deltamethrin (K-O TAB) against malaria vectors. Treated nets were used in one village, and in the two control villages, one used untreated nets and the other used indoor spraying with DDT, without nets. In this area the primary malaria vectors are Anopheles culicifacies Giles sensu lato (Diptera: Culicidae) and An. fluviatilis James s.l., which are both endophagic and endophilic, and fully susceptible to deltamethrin. Treatment of a 10-m(2) mosquito net with one of the tablets gave a deltamethrin deposit of 25 mg/m(2). Bioassays repeated on domestically used nets over 7 months showed persistence of almost 100% mortality of An. fluviatilis, whereas An. culicifacies showed a decline from 100% to 71% mortality over this period, after which the nets were re-treated and bioassays were not continued. The sum of collections of mosquitoes resting in village houses and those in exit traps and dead on floor sheets showed a reduction in the numbers of the two vector species due to the treated nets, compared with untreated or no nets, but no reduction in other anophelines or Culex species. Large proportions of the collections of the vector and non-vector anophelines were dead on the floor sheets, but among Culex, mortality was delayed. Treated and untreated nets reduced the proportion of anophelines that had blood-fed; the treated nets did so more effectively than the untreated in the case of An. culicifacies and of Culex mosquitoes. In rooms with treated nets a larger proportion of the total collections [dead + live] were in the exit traps, which can be attributed to the excito-repellent effect of deltamethrin. It is easier to pack and handle tablets of insecticide than liquid concentrate and the use of one tablet per net may be preferable to making up a large volume of diluted insecticide and dipping many nets at a time.

Animals↗

Deformation mechanisms in free-standing nanoscale thin films: a quantitative in situ transmission electron microscope study.

We have added force and displacement measurement capabilities in the transmission electron microscope (TEM) for in situ quantitative tensile experimentation on nanoscale specimens. Employing the technique, we measured the stress-strain response of several nanoscale free-standing aluminum and gold films subjected to several loading and unloading cycles. We observed low elastic modulus, nonlinear elasticity, lack of work hardening, and macroscopically brittle nature in these metals when their average grain size is 50 nm or less. Direct in situ TEM observation of the absence of dislocations in these films even at high stresses points to a grain-boundary-based mechanism as a dominant contributing factor in nanoscale metal deformation. When grain size is larger, the same metals regain their macroscopic behavior. Addition of quantitative capability makes the TEM a versatile tool for new fundamental investigations on materials and structures at the nanoscale.

Journal Article↗

Role of fine needle aspiration cytology in the diagnosis of pulmonary lesions.

Fine needle aspiration cytology (FNAC) is a rapid, reliable and cost-effective method in the diagnosis of lung lesions. Cells are collected from the lesions usually under fluoroscopic or CT-guidance for cytological examination. Due to lack of these highly sophisticated radiologic imaging techniques in our institute we performed this test under X-Ray film guidance. This study was carried out in 59 patients, who underwent FNAC of lung lesions in the department of Pathology, Mymensingh Medical College, Bangladesh to find out the specimen adequacy and frequency of both benign and malignant lesions of the lungs in our areas. Out of 59 cases 54 were males and 5 were females with age ranged from 20 to 82 years. Adequate samples were obtained in 50 (84.75%) cases of which 35 (70%) were malignant, 10 (20%) were benign and 5 (10%) were suspicious for malignancy. Malignant lesions comprised of squamous cell carcinoma in 20 (57.14%), adenocarcinoma in 1(2.86%), large cell carcinoma in 8 (22.86%) and small cell carcinoma in 6 (17.14%) cases. All the benign lesions were inflammatory in nature, which included abscess in 6 (60%), tuberculosis in 3 (30%) and chronic non-specific inflammation in 1 (10%) case. Majority of the malignant lung lesions were encountered in the 6th decade of life. As the method is simple, rapid, cost-effective and without major complications, so it can be practiced in any centres in our country where specialised radiologists and pathologists are available.

Adult↗

Ultrasound guided fine needle aspiration cytology for diagnosis of mass lesions of liver.

The therapeutic and prognostic evaluation of malignant neoplasia of liver depends mostly on morphologic diagnosis. Ultrasound guided fine needle aspiration cytology (FNAC) of liver has been proved to be a rapid, reliable and cost-effective method for cytological diagnosis of hepatic mass lesions. This study was undertaken to find out the frequency of different benign and malignant space occupying lesions (SOL) of liver from patients attending for FNAC in Mymensingh. Ultrasound guided FNAC was performed on 108 patients with hepatic mass lesions from September 2, 2001 to August 19, 2003. There were 67 (62.0%) males and 41 (37.96%) females with a mean age 53 year (SD +/- 14) ranging from 2 to 83 years. Samples were adequate in 101 (93.5%) and inadequate in 7 (6.5%). Out of 101 adequate samples only one was benign (liver abscess) and 100 were malignant. Of the malignant lesions hepatoblastoma was in 1 (1%), hepatocellular carcinomas in 8 (8%), metastatic adenocarcinomas in 73 (73%) and unclassified malignancies were in 18 (18%). Most of the hepatocellular carcinomas occurred in males (7 in 8). The frequency of metastatic adenocarcinoma was more in males (39 vs. 34) but the difference is not significant (p > 0.05). Ultrasound guided FNAC of liver is a rapid, reliable and cost-effective diagnostic method. It can be practice in any centres where ultrasound facility and specialist pathologists are available.

Adenocarcinoma↗

Histopathological types of malignant lesions of esophagus and stomach.

Upper part of gastrointestinal tract is common site of malignancy. Histological types of malignancy of esophagus and stomach may vary in different countries and also in different regions in the same countries. To find out the frequencies of different histological malignancies in Mymensingh region of Bangladesh, we analyzed the histopathological reports of 259 biopsy specimens examined in one pathology laboratory in Mymensingh town during the period from 6th January 2002 to 29th April 2004. Endoscopic biopsies were 234 (90.35%) and surgical biopsy specimens were 25 (9.35%). Male patients were 193 (72.52%) and female patients were 66 (25.48%). Specimens of esophagus were 73 (28.19%) and of stomach were 186 (71.81%). Out of 69 (94.53%) adequate samples of esophagus 46 (74.19%) were squamous cell carcinoma and 16 (25.81%) were adenocarcinoma. Adequate samples of stomach were 177 (95.16%) in which malignancies were found in 119 (67.23%). All the malignant tumor of stomach were in adenocarcinoma of which 82 (68.91%) were intestinal type, 17 (14.29%) were diffuse type and 20 (16.81%) mixed type. Intestinal type of gastric adenocarcinoma was found to be significantly associated with male patients (p < 0.005). From the present study it is suggested that in the Mymensingh region the common form of malignant lesion of esophagus may be squamous cell carcinoma followed by adenocarcinoma. Adenocarcinoma is the most common type of gastric malignancy of which intestinal type is more common

Adult↗

A case report on Klinefelter syndrome.

An 18 year old boy presented with small genitalia, failure of eruption of secondary sex hairs, female like voice with eunachoid body habitus, bilateral gynecomastia, infantile external genitalia, small testes and poorly developed musculature. He was diagnosed as a case of 47XXY Klinefelter syndrome on the basis of hormone assay and karyotyping. He has given androgen replacement therapy with the aim to relieve symptoms of androgen deficiency, to reproduce physiological levels of plasma testosterone and to prevent long term consequences of androgen deficiency.

Adolescent↗

A case of molluscum contagiosum.

Molluscum contagiosum is a benign contagious disease caused by a poxvirus. The virus proliferates within keratinocytes and forms intracytoplasmic Molluscum bodies. Though it is a common clinical condition, histologically is not yet reported from this region of Mymensingh. We received a skin biopsy specimen in a pathology laboratory for histological examination. The Haematoxylin and Eosin stained sections revealed typical intracytoplasmic Molluscum bodies in keratinocytes. The lesions were in the trunk, which is a common site for Molluscum Contagiosum (MC). As the diagnosis of Molluscum contagiosum is easy by histological examination, every patient suspected to be this disease is recommended to be examined histologically to exclude other similar types of lesions.

Adult↗

Advances in treatment and prevention of hepatorenal syndrome.

Hepatorenal syndrome (HRS) remains one of the major therapeutic challenges in clinical medicine today. The pathogenesis is complex, but the final common pathway seems to be that sinusoidal portal hypertension, in the presence of severe hepatic decompensation, leads to splanchnic and systemic vasodilatation and decreased effective arterial blood volume. Renal vasoconstriction increases concomitantly, renal haemodynamics worsens, and renal failure occurs. About 15 years ago it was shown that the renal failure is potentially reversible after liver transplantation. This potential reversibility together with increased understanding of the pathogenesis has led to successful preliminary attempts to reverse HRS nonsurgically with combinations of splanchnic vasoconstrictors and colloid volume expansion, insertion of trans-jugular intrahepatic portovenous shunt radiologically, and improved forms of dialysis. The aim of this chapter is to discuss the advances in the therapy of patients with HRS

Hepatorenal Syndrome↗

Evaluation of fine needle aspiration cytology (FNAC) of lymph node in Mymensingh.

Fine needle aspiration cytology (FNAC) is widely accepted as the accurate, sensitive, specific and cost-effective procedure in the diagnosis of lymphadenopathy. The purpose of the study was to evaluate the results of FNAC of lymph nodes in our institutions comparing with results of histopathology. We performed 117 FNAC of lymph node in a period between November 2001 to April 2002, of which, histological results were available in 81 (69.23%). Cervical lymph nodes were 102 (87.18%) and axillary lymph nodes were 15 (12.82%). Male to female ratio of the patients was 1:0.65. Patients' age ranged from 3-80 years with a median age of 23 years. FNAC diagnosis was found to be as follows: granulomatous inflammation 46 (40.35%), reactive hyperplasia 31 (27.19%), metastatic carcinoma 20 (17.54%), Non-Hodgkin's lymphoma 6(5.26%), tubercular lymphadenitis 4(3.51%), acute non-specific lymphadenitis 3(2.63%), Hodgkin's lymphoma 3(2.63%) and chronic non-specific lymphadenitis 1(0.88%). Out of 81 cases of FNAC 71(87.65%) were consisted with histopathological diagnosis of granulomatous lymphadenitis. In the malignancy of lymph node sensitivity and specificity of FNAC were 82.76% and 97.92%, respectively. So, the investigators reasonably conclude that before resort to surgical intervention FNAC may be a helpful procedure in the diagnosis of both neoplastic and non-neoplastic lesion of lymph nodes.

Adolescent↗

Epidemiological characteristics of sixty five cases of Kala-azar attending to a laboratory in Mymensingh.

To find out the epidemiological characteristics of the patients with Kala-azar attending to a pathology laboratory at Mymensingh we studied retrospectively in a total of 65 patients. These patients were suspected to be Kala-azar as they were suffering from usually chronic fever, anaemia and splenomegaly. They were referred for serological detection of anti-k39 Leishmanial antibody by Immunochromatographic test (ICT) method. ICT positive cases were included for study. Majority cases were suffering from fever of more than 3 months (40%). Out of 65 patients 43 (66.15%) were males and 22 (33.85%) were females with a M:F ratio 2:1. Patients of 10 or less then 10 years of age were 17 (26.15%), in 11-20 years 23 (35.38%), in 21-30 years 13 (20.00%), in 31-40 years 5 (7.69%), in 41-50 years (6.15%) and in more than 50 years 3 (4.62%). Distribution of patients in different districts were: Mymensingh 54 (83.08%), Tangail 5 (7.69%), Jamalpur (4.62%), Netrokona 1 (1.54%) and Kishorgonj 1 (1.54%). In Mymensingh district patients were distributed as following Upazilla:Trishal 22 (40.74%), Fulbaria 11 (20.37%), Mymensingh Sadar 7 (12.96%), Gaforgaon 7 (12.96%),Bhaluka 5 (9.96%), Fulpur 1 (1.85%) and Nandail 1 (1.85%). Patients were found to scattered among different Unions of the affected Upazillas. The details addresses of the Kala-azar patients are recorded in authors computer databases. This may help in the further study regarding pathogenesis, reservoir and vectors of Leishmania in endemic areas. It may also helps in the community based study of Kala-azar. Present study supports that Kala-azar is still prevailing in the south-western region of greater Mymensingh in Bangladesh of which males and the adolescents are more affected.

Adolescent↗

Cysteinylation of MHC class II ligands: peptide endocytosis and reduction within APC influences T cell recognition.

Peptides bind cell surface MHC class II proteins to yield complexes capable of activating CD4(+) T cells. By contrast, protein Ags require internalization and processing by APC before functional presentation. Here, T cell recognition of a short peptide in the context of class II proteins occurred only after delivery of this ligand to mature endosomal/lysosomal compartments within APC. Functional and biochemical studies revealed that a central cysteine within the peptide was cysteinylated, perturbing T cell recognition of this epitope. Internalization and processing of the modified epitope by APC, was required to restore T cell recognition. Peptide cysteinylation and reduction could occur rapidly and reversibly before MHC binding. Cysteinylation did not disrupt peptide binding to class II molecules, rather the modified peptide displayed an enhanced affinity for MHC at neutral pH. However, once the peptide was bound to class II proteins, oxidation or reduction of cysteine residues was severely limited. Cysteinylation has been shown to radically influence T cell responses to MHC class I ligands. The ability of professional APC to reductively cleave this peptide modification presumably evolved to circumvent a similar problem in MHC class II ligand recognition.

Alanine↗

Investigation of the nonlinearity in the heart rate dynamics.

This paper presents the application of a neural network to predict human heart rate. Electrocardiograms were measured from 5 healthy adult human subjects and 5 data sets were constructed calculating instantaneous heart rate from the measured signal. The nonlinear radial basis function neural network was applied to have a one step ahead prediction of the 1000 point heart rate. The results of the prediction are compared to that obtained by a linear autoregressive model. The results show that the neural network performs better than the autoregressive model in predicting heart rate for 2 data sets while for the other 3 data sets the performance of the two models is statistically similar. This indicates that the heart rate may be controlled nonlinearly by the autonomic nervous system.

Adult↗

Vairimorpha imperfecta n.sp., a microsporidian exhibiting an abortive octosporous sporogony in Plutella xylostella L. (Lepidoptera: Yponomeutidae).

The microsporidian genus Nosema is characterized by development in direct control with host cell cytoplasm, diplokaryotic nuclei throughout development and disporous sporogony. The genus Vairimorpha exhibits the same features plus an octoporous sporogony producing uninucleate spores in a sporophorous vesicle. A microsporidium from diamondback moth, Plutella xylostella, falls between Nosema and Vairimorpha in that it initiates but fails to complete the octosporous sequence in this host. The name Vairimorpha imperfecta n.sp. is proposed. Merogony is mainly by formation of buds from multinucleate meronts, the buds remaining attached in chains. Diplokaryotic spores measure 4.3 x 2.0 microns (fresh) and have 15.5 coils of the polar tube in 1 rank. The octosporous sporogony is aborted owing to irregular formation of nuclear spindles, incomplete cytoplasmic fission and bizarre deposition of electron-dense episporontal secretions. Phylogenetic analyses of the sequences of the small subunit rRNA genes of V. imperfecta and of several Nosema and Vairimorpha spp. place V. imperfecta in a clade with Nosema spp. from Lepidoptera rather than in the clade containing the more typical species of Vairimorpha. It is suggested that the ancestors of the Vairimorpha/Nosema complex of species exhibited both disporous and octosporous sporogonies, as does the type species of Vairimorpha, Vairimorpha necatrix. It would follow that true Nosema spp. have lost the ability to express an octosporous sequence and that V. imperfecta is in the process of losing it. It is proposed that the genera Nosema and Vairimorpha be placed in the same family Nosematidae Labbé 1899, rather than in separate families and orders as at present.

Animals↗