PubMed Health⌕ Search

Biomedical subjects

M M Rahman

Publications and source records attributed to M M Rahman.

At least 55 records · Page 3Linked to original sources
PubMed2001

Prednisolone in Duchenne muscular dystrophy.

This Study was carried out in the department of Neuromedicine, Bangabandbu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. A total of 19 Duchenne muscular dystrophy (DMD) patients were recruited for randomized controlled study to see the effect of prednisolone in the natural course of the disease process. Prednisolone was given in 10 patients (study group) in a dose of 0.75 mg/kg for six months. Vitamin was given in 8 patients (control group) for the same duration. One patient was dropped from the study. Patients were assessed for average muscle strength, timed function test and functional grades (pelvic and pectoral). It was found that at the end of the study, almost all the parameters were improved significantly in the prednisolone treated group (P < 0.05).

Activities of Daily Living↗
PubMed2001

Risk factors for acute respiratory infections among the slum infants of Dhaka city.

A cross-sectional study was conducted in five slums of Dhaka city. The study population was all adult women of reproductive age having an infant aged less than one year with a view to assessing the prevalence of Acute Respiratory Infections (ARIs) among the slum infants and also to identify the factors responsible for it. A total of 1,008 mothers were interviewed. Among them, 927 had children aged 0-12 months. Mothers with live infants (927) were asked if their children had any disease during the two weeks prior to the interview. Respiratory infection was the highest among the prevalent diseases (ARI 72%, diarrhoeal diseases 28%, measles 4% and others 4%). So, an emphasis was given in this regard. Out of 228 ARI cases, percentage of mild (78%) and severe ARI (11%) were present in children aged less than 6 months, whereas moderate ARI (23%) was higher in 6 months and above age groups. The variation was statistically significant between the two age groups (p<0.05). But there was no significant difference in ARI by sex (p>0.05). In logistic analysis, maternal age below 20 years, working mothers, low housing and socio-economic index, no household possession, no access to piped water and infant's age above 6 months appeared to be significant predictors of ARIs. The risk of acquiring ARI was 3.33 times higher in low socio-economic index, 3 times in no access to piped water, 2.39 times in low housing index, 1.9 times in mother's age below 20 years, 1.85 times in infant's age above 6 months, 1.69 times in working mothers. On the other hand, household possessions had protective effects on ARIs. The study provides important information for policy makers regarding the prevention of ARI among the children of the slum dwellers.

Acute Disease↗
PubMed2001

Stroke: seasonal variation and association with hypertension.

A prospective study was contemplated with 155 patients of acute stroke in the Department of Neurology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, from March 1996 to February 1997. The objective of the study was to find out seasonal variation of stroke occurrence. An attempt was also made to find out the association of hypertension with ischaemic and haemorrhagic stroke during summer and winter. The numberofsubjects duringsummer and winterwere 121 and 34, respectively. In summer, out of 121 subjects, 87(71.9%) were ischaemic stroke and 34(28.1%) haemorrhagic stroke, of which 32 were intracerebral haemorrhage (ICH) and 2 subarachnoid haemorrhage (SAH). There were 18 (52.9%) ischaemic stroke and 16(47.06%) haemorrhagic stroke (all ICH) among total 34 subjects during winter. The frequency of ischaemic stroke during summer was significantly greater than that during winter (p<0.05). The frequency of haemorrhagic stroke during winter was significantly greater than that during summer (p<0.05). Temperature was positively correlated to ischaemic stroke (p<0.01) and negatively correlated to haemorrhagic stroke (p<0.1). Hypertension was significantly more associated with haemorrhagic stroke than with ischaemic stroke irrespective of season (p<0.05).

Adult↗
PubMed2000

A sodium channel mutation causing epilepsy in man exhibits subtle defects in fast inactivation and activation in vitro.

Generalized epilepsy with febrile seizures plus (GEFS+) is a benign epileptic syndrome of humans. It is characterized by febrile and afebrile generalized seizures that occur predominantly in childhood and respond well to standard antiepileptic therapy. A mutation in the b1-subunit of the voltage-gated sodium channel, linked to chromosome 19q13 (GEFS+ type 1) has been found in one family. For four other families, linkage was found to chromosome 2q21-33 (GEFS+ type 2) where three genes encoding neuronal sodium channel a-subunits are located (SCN1-3A). Recently, the first two mutations were identified in SCN1A. We introduced one of these mutations, which is highly conserved to SCN1A, into the cDNA of the gene SCN4A encoding the a-subunit of the human skeletal muscle sodium channel (hSkm1). The mutation is located in the S4 voltage sensor of domain IV, predicting substitution of histidine for the fifth of eight arginines (R1460H in hSkm1). Functional studies were performed by expressing the a-subunit alone in the mammalian tsA201 cell line using the whole-cell patch clamp technique. Compared to wild-type (WT), mutant R1460H channels showed small defects in fast inactivation. The time course of inactivation was slightly (1.5-fold) slowed and its voltage dependence reduced, and recovery from inactivation was accelerated 3-fold. However, there was no increase in persistent sodium current as observed for SCN4A mutations causing myotonia or periodic paralysis. The activation time course of R1460H channels was slightly accelerated. Slow inactivation was slightly but significantly stabilized, confirming the importance of this region for slow inactivation. The combination of activation and fast inactivation defects can explain the occurrence of epileptic seizures, but the effects were much more subtle than the inactivation defects described previously for mutations in SCN4A causing disease in skeletal muscle. Hence, with regard to pathological excitability, our results suggest a greater vulnerability of the central nervous system compared to muscle tissue.

Amino Acid Sequence↗
PubMed2000

Laparoscopic cholecystectomy, Calot's triangle, and variations in cystic arterial supply.

BACKGROUND: The extrahepatic biliary tree with the exact anatomic features of the arterial supply observed by laparoscopic means has not been described heretofore. Iatrogenic injuries of the extrahepatic biliary tree and neighboring blood vessels are not rare. Accidents involving vessels or the common bile duct during laparoscopic cholecystectomy, with or without choledocotomy, can be avoided by careful dissection of Calot's triangle and the hepatoduodenal ligament. METHODS: We performed 244 laparoscopic cholecystectomies over a 2-year period between January 1, 1995 and January 1, 1997. RESULTS: In 187 of 244 consecutive cases (76.6%), we found a typical arterial supply anteromedial to the cystic duct, near the sentinel cystic lymph node. In the other cases, there was an atypical arterial supply, and 27 of these cases (11.1%) had no cystic artery in Calot's triangle. A typical blood supply and accessory arteries were observed in 18 cases (7.4%). CONCLUSION: Young surgeons who are not yet familiar with the handling of an anatomically abnormal cystic blood supply need to be more aware of the precise anatomy of the extrahepatic biliary tree.

Bile Ducts, Extrahepatic↗
PubMed2000

Genetic and antigenic variance of foot-and-mouth disease virus type Asia1.

The capsid protein encoding genes of five recent type Asia1 foot-and-mouth disease virus isolates, representative of three genotypes, were sequenced. The deduced amino acid sequences were aligned to each other and to two published sequences. The sequence differences suggested different antigenic properties of the isolates. One isolate was used to generate monoclonal antibodies (mAbs) which were analyzed for neutralizing activity and reactivity with trypsinized virus. Trypsin removes the major antigenic sites located at VP1. The five virus isolates formed three reaction patterns with the mAbs, irrespective of their genotype. Combination of all data allowed to suggest the location of the epitope of each antibody: the VP1 G-H and the VP2 B-C loop, the VP3 B-B knob, and the N-terminus of VP2, respectively, were involved.

Amino Acid Sequence↗
PubMed2000

Emigration and development: the case of a Bangladeshi village.

This article examines the developmental consequences of international labor migration in a Bangladeshi village. The data are from the Hoglakandi, a village 30 km southeast of Dhaka, capital of Bangladesh. A structured questionnaire with both open-ended and closed category questions was used among 50 Singapore returnees, supplemented with additional in-depth interviews. International labor migration has often been seen by many sending countries as a short cut development because of its role in unemployment relief, balance of payments relief, and capital formation of national level. The study argues that the causes and effects of emigration can better be understood only when the process is placed within its local context, since what may prove to be advantageous at the national level may prove to be detrimental to a household or community or vice-versa. It demonstrates how the contribution of labor migration is merely the transformation of labor into a structural component of the international political economy. The Hoglakandi experience reveals that labor migration does not fuel the local economy from an external pipeline of remittances and skill acquisition, rather it drains local resources that retard the development.

Asia↗
PubMed2000

Sunlight-induced propagation of the lysogenic phage encoding cholera toxin.

In toxigenic Vibrio cholerae, the cholera enterotoxin (CT) is encoded by CTXPhi, a lysogenic bacteriophage. The propagation of this filamentous phage can result in the origination of new toxigenic strains. To understand the nature of possible environmental factors associated with the propagation of CTXPhi, we examined the effects of temperature, pH, salinity, and exposure to direct sunlight on the induction of the CTX prophage and studied the transmission of the phage to potential recipient strains. Exposure of cultures of CTXPhi lysogens to direct sunlight resulted in approximately 10,000-fold increases in phage titers. Variation in temperature, pH, or salinity of the culture did not have a substantial effect on the induction of the prophage, but these factors influenced the stability of CTXPhi particles. Exposure of mixed cultures of CTXPhi lysogens and potential recipient strains to sunlight significantly increased both the in vitro and in vivo (in rabbit ileal loops) transduction of the recipient strains by CTXPhi. Included in these transduction experiments were two environmental nontoxigenic (CTXPhi(-)) strains of V. cholerae O139. These two O139 strains were transduced at high efficiency by CTXPhi, and the phage genome integrated into the O139 host chromosome. The resulting CTXPhi lysogens produced biologically active CT both in vitro and in rabbit ileal loops. This finding suggests a possible mechanism explaining the origination of toxigenic V. cholerae O139 strains from nontoxigenic progenitors. This study indicates that sunlight is a significant inducer of the CTX prophage and suggests that sunlight-induced transmission of CTXPhi may constitute part of a natural mechanism for the origination of new toxigenic strains of V. cholerae.

Animals↗
PubMed2000

Recommendations for water supply in arsenic mitigation: a case study from Bangladesh.

Arsenic problems have been observed in several countries around the world. The challenges of arsenic mitigation are more difficult for developing and poor countries due to resource and other limitations. Bangladesh is experiencing the worst arsenic problem in the world, as about 30 million people are possibly drinking arsenic contaminated water. Lack of knowledge has hampered the mitigation initiatives. This paper presents experience gained during an action research on water supply in arsenic mitigation in rural Singair, Bangladesh. The mitigation has been implemented there through integrated research and development of appropriate water supply options and its use through community participation. Political leaders and women played key roles in the success of the mitigation. More than one option for safe water has been developed and/or identified. The main recommendations include: integration of screening of tubewells and supply of safe water, research on technological and social aspects, community, women and local government participation, education and training of all stakeholders, immediate and appropriate use of the available knowledge, links between intermediate/immediate and long term investment, effective coordination and immediate attention by health, nutrition, agriculture, education, and other programs to this arsenic issue.

Arsenic↗
PubMed2000

Risk factors and gender differentials for death among children hospitalized with diarrhoea in Bangladesh.

To identify risk factors for death among children with diarrhoea, a cohort of 496 children, aged less than 5 years, admitted to the intensive care unit of a diarrhoeal disease hospital in Bangladesh, was studied during November 1992-June 1994. Clinical and laboratory records of children who died and of those who recovered in the hospital were compared. Deaths were significantly higher among those who had altered consciousness, hypoglycaemia, septicaemia, paralytic ileus, toxic colitis, necrotizing enterocolitis, haemolytic-uraemic syndrome, invasive or persistent diarrhoea, dehydration, electrolyte imbalances, and malnutrition. Females experienced a 2-fold higher risk of death than males (p = 0.003). Several indices of severe infections were identified more frequently among females than males. Females with severe infections were less frequently brought to the hospital than their male counterparts. The time lapse between onset of symptoms and hospital admission was significantly higher in females than males. This study suggests initiation of programmes to alleviate social disparity between genders for healthcare in poor communities. The study-results may also help physicians identify either prognostic indicators or risk factors for death among children hospitalized with severe illnesses associated with diarrhoea.

Bangladesh↗
PubMed1999

The structure of the colony migration factor from pathogenic Proteus mirabilis. A capsular polysaccharide that facilitates swarming.

Swarming by Proteus mirabilis is characterized by cycles of rapid and coordinated population migration across surfaces following differentiation of vegetative cells into elongated hyperflagellated swarm cells. It has been shown that surface colony expansion by the swarm cell population is facilitated by a colony migration factor (Cmf), a capsular polysaccharide (CPS) that also contributes to the uropathogenicity of P. mirabilis (Gygi, D., Rahman, M. M., Lai, H.-C., Carlson, R., Guard-Petter, J., and Hughes, C. (1995) Mol. Microbiol. 17, 1167-1175). In this report, the Cmf-CPS was extracted with hot water, precipitated with ethanol, and further purified by gel permeation chromatography. Its structure was established by glycosyl composition and linkage analyses, and by one- and two-dimensional NMR spectroscopy. The Cmf-CPS is composed of the following tetrasaccharide repeating unit. [see text]

Carbohydrate Sequence↗
PubMed1999

Hepatic phosphatidylcholine hydroperoxide content in noncirrhotic, cirrhotic, and antioxidant-treated rats with endotoxemia.

Hepatic phosphatidylcholine hydroperoxide (PCOOH) was studied intensively to delineate its role in the altered pathophysiology of liver failure associated with endotoxemic shock. Endotoxemia was induced by cecal ligation and puncture (CLP) in three models using rats. Model 1 consisted of normal healthy rats; model 2, cirrhotic rats; and model 3, rats treated with catalase and superoxide dismutase (SOD). Samples were taken before CLP, then 12 h and 24 h following CLP. A progressive and significant increase in serum endotoxin was seen in all models; however, a significantly low energy charge (EC) and high PCOOH were seen in models 1 and 2, whereas no change was observed in model 3. The regional blood flow remained unchanged throughout the experiment in models 1 and 3, but not in model 2. An initial increase in alpha-tocopherol was seen in model 1. The survival rate was markedly better in model 3 than in models 1 or 2. The fall in EC corresponded to the increase in serum endotoxin as well as to the increase in tissue PCOOH in models 1 and 2. It was more likely that the elevated lipid peroxidation in model 1 resulted from endotoxemia rather than from tissue hypoperfusion. The early increase in alpha-tocopherol that occurred in models 1 and 2, but not in model 3, indicated the antiradical defense response to oxidative injury. Thus, antioxidant therapy significantly improved the survival rate and tissue adenine nucleotide level in spite of the increased serum endotoxin level.

Adenosine Triphosphate↗
PubMed1999

The degree of hepatic regeneration after partial hepatectomy in rats with peritonitis and the role of lipid peroxidation.

Bile accumulation in the peritoneal cavity after partial hepatectomy reduces hepatic regeneration. In 70% of hepatectomized rats with bile peritonitis, hepatic DNA synthesis showed a delayed initiation and diminished peak level. Because intraperitoneal bile significantly accelerated lipid peroxidation and decreased energy metabolism in the liver remnant, all hepatectomized rats with bile peritonitis died within 7 days. Subcutaneous administration of exogenous combined antioxidants SOD and catalase dramatically reduced lipid peroxidation and improved the survival rate. Although the slightly elevated serum endotoxin level in rats with peritonitis may play a role in the inhibition of hepatic regeneration, the result suggest that intraperitoneal accumulation of bile components may also directly accelerate lipid peroxidation in the liver remnant, inhibiting the hepatic regeneration.

Alanine Transaminase↗
PubMed1999

Genetical and immunological analysis of recent Asian type A and O foot-and-mouth disease virus isolates.

This report extends the knowledge on the epizootical situation of foot-and-mouth disease in Asia. RNA from six samples of type A and five of type O virus, isolated between 1987 and 1997 in Bangladesh, Iran, Malaysia and Turkey, was subjected to reverse transcription-dependent polymerase chain reactions that amplify large parts of the capsid protein VP1 encoding genome region. The amplification products were sequenced, and the sequences aligned to each other and to published sequences. This showed the type O isolates of 1987-1997 from Bangladesh to be of same genotype and closely related to isolates of 1988 and later from Saudi Arabia, 1990 from India, 1996 from Greece and Bulgaria, and 1997 from Iran. Among the analyzed type A isolates, those of 1992 and 1996 from Turkey were of same genotype and related to previously described isolates of 1987 from Iran and of 1992 from Saudi Arabia. The isolate of 1997 from Malaysia was found to be related to isolates from Thailand of 1993 and 1996. The isolates of 1987 from Bangladesh and 1997 from Iran, however, represent different so far not described genotypes. Monoclonal antibodies, raised against the vaccine production strains A22 Iraq, Asial Shamir, O1 Kaufbeuren and O1 Manisa, and the recent type A field isolates Saudi Arabia/92 and Albania/96, were used in an ELISA to compare the reaction patterns of many of the field isolates. The monoclonal antibodies were further characterized for virus-neutralizing activity and binding to trypsinized homologous virus. The failure of neutralizing antibodies in binding to trypsinized homologous as well as to heterologous virus suggested the epitopes to reside at the major antigenic component of the virus, which is the capsid protein VP1. Two non-neutralizing antibodies that bind to trypsin-sensitive epitopes cross-reacted, however, with heterologous virus. This indicates the existence of a trypsin-sensitive antigenic site outside of VP1. In summary, the results obtained by ELISA confirm the observed sequence differences, but indicate further sequence differences at minor antigenic sites that do not reside on VP1.

Amino Acid Sequence↗
PubMed1999

Multiple lysophosphatidic acid acyltransferases in Neisseria meningitidis.

Lysophosphatidic acid (LPA) and phosphatidic acid (PA) are critical phospholipid intermediates in the biosynthesis of cell membranes. In Escherichia coli, LPA acyltransferase (1-acyl-sn-glycerol-3-phosphate acyltransferase; EC 2.3.1.51) catalyses the transfer of an acyl chain from either acyl-coenzyme A or acyl-acyl carrier protein onto LPA to produce PA. While E. coli possesses one essential LPA acyltransferase (PlsC), Neisseria meningitidis possesses at least two LPA acyltransferases. This study describes the identification and characterization of nlaB (neisserial LPA acyltransferase B), the second LPA acyltransferase identified in N. meningitidis. The gene was located downstream of the Tn916 insertion in N. meningitidis mutant 469 and differed in nucleotide and predicted amino acid sequence from the previously characterized neisserial LPA acyltransferase homologue nlaA. NlaB has specific LPA acyltransferase activity, as demonstrated by complementation of an E. coli plsC(Ts) mutant in trans, by decreased levels of LPA acyltransferase activity in nlaB mutants and by lack of complementation of E. coli plsB26,X50, a mutant defective in the first acyltransferase step in phospholipid biosynthesis. Meningococcal nlaA mutants accumulated LPA and demonstrated alterations in membrane phospholipid composition, yet retained LPA acyltransferase activity. In contrast, meningococcal nlaB mutants exhibited decreased LPA acyltransferase activity, but did not accumulate LPA or display any other observable membrane changes. We propose that N. meningitidis possesses at least two LPA acyltransferases to provide for the production of a greater diversity of membrane phospholipids.

1-Acylglycerol-3-Phosphate O-Acyltransferase↗
PubMed1999

The structural heterogeneity of the lipooligosaccharide (LOS) expressed by pathogenic non-typeable Haemophilus influenzae strain NTHi 9274.

Nontypeable Haemophilus influenzae (NTHi) is an important pathogen responsible for otitis media in children and of pneumonitis in adults with depressed resistance. NTHi is acapsular and, therefore, capsular polysaccharide-based vaccines are ineffective for preventing infections by this pathogen. Recently it was found that a detoxified lipooligo-saccharide (LOS) conjugate from NTHi 9274 induced bactericidal antibodies effective against a large number of NTHi isolates, and conferred protection against NTHi otitis media in chinchillas (X.-X.Gu et al., 1996, Infect. Immun.,64, 4047-4053; X. -X.Gu et al., 1997., Infect. Immun.,65, 4488-4493). In this paper we report the chemical character-ization of the LOS from NTHi 9274 LOS. NTHi is capable of expressing a heterogenous population of LOS exhibited by multiple oligosaccharide (OS) epitopes. OSs released from the LOS of NTHi 9274 by mild acid hydrolysis were purified using Bio-Gel P4 gel permeation chromatography. The OSs were characterized by glycosyl composition analysis, glycosyl linkage analysis, nuclear magnetic resonance spectroscopy (NMR), fast atom bombardment mass spectro-metry (FAB-MS), matrix-assisted laser desorption time of flight mass spectro-metry (MALDITOF-MS), and tandem MS/MS. At least 17 different OS molecules were observed. These contained variable glycosyl residues, phosphate (P), and phospho-ethanolamine (PEA) substituents. These molecules contained either three, four, or five hexoses, and all contained four heptosyl residues. The four heptosyl residues consisted of one D,D-Hep and three L,D-Hep. Dephosphorylation of the OSs with aqueous 48% hydrofluoric acid (HF) reduced the number of molecules to about to seven; Hex(1)-(7)Hep(4)Kdo(1). Of these seven, Hex(2)Hep(4)Kdo(1), Hex(3)Hep(4)Kdo(1), and Hex(4)Hep(4)Kdo(1)were the major constituents. Thus, this NTHi LOS preparation is very heterogeneous, and contains structures different from those previously published for Haemophilus influenzae. The tandem MS/MS analysis and glycosyl linkage data suggest that the LOS oligosaccharides have the following structures where Hex is either a Glc or Gal residue.

Antigens, Bacterial↗