Search PubMedSearch

Biomedical subjects

M Rahman

Publications and source records attributed to M Rahman.

At least 19 recordsLinked to original sources

Variability of surface-exposed antigens of different strains of Moraxella catarrhalis.

For serological diagnosis of infection with Moraxella (Branhamella) catarrhalis it is important to determine if there is variability of antigenic properties among different strains. Cross-reactions of nine strains were investigated by an immunofluorescence test using sera from immunized rabbits. All titres but one were 1:256 or higher, the highest being 1:4096. Thus a high degree of antigenic similarity was demonstrated among different strains of Moraxella catarrhalis. However, the homologous titres of six sera were 2 to 16 times higher than the titres for other strains indicating strain variations in antigenic properties of some surface components. There was no correlation between lipopolysaccharide type and titre in the immunofluorescence test.

Animals

Effects of petrochemicals and ultraviolet radiation on epidermal IA expression in vitro.

We previously demonstrated that combined treatment of mice with crude oil and longwave ultraviolet radiation (UVA) led to the depletion of IA-positive cells from the epidermis. In the present study, we have developed an in vitro screening assay for combined effects of purified petrochemicals and UVA on epidermal IA and Thy-1 expression. This method involves removal of skin from donor mice prior to treatment with chemicals and UVA (20,000 J/m2), followed by in vitro culture and subsequent immunoperoxidase staining. In this study, a complete correlation was observed in terms of IA-positive cell density among similarly treated cultured skin and live mice. In vivo and in vitro studies both indicated that anthracene but not phenanthrene or benzo[a]pyrene led to significant depletion of both epidermal Langerhans cells and Thy-1-positive dendritic cells when followed by UVA treatment. The in vitro assay developed for this study should prove to be a valuable tool for the screening of a wide variety of chemicals for contact photosensitizing activity.

Animals

Rhesus genotype frequency in Bangladeshi population.

The prevalence of Rhesus genotypes in Bangladesh has been studied and several important findings were observed. This being the initial report, includes a population of 1600 only. By using five Rh antisera (Anti-C, Anti-D, Anti-E, Anti-c and Anti-e) a genotype can be deduced since anti-d is not available. More often only a probable genotype can be suggested after reference to the known chromosome frequencies in the population. By using family studies in conjunction, it may be possible to determine genotype with certainty. The prominent Rhesus genotype was CDe/cDE (R1R2), i.e., 39.75%, Rhesus genotype cde/cde (rr) was found to be only 1.75%. The genotype cdE/cde (r"r) was not detected in the present series of Bangladeshi population. These results have been compared with the English and the Indian Bengalee Hindu Population.

Bangladesh

Glycaemic index of Pakistani staple foods in mixed meals for diabetics.

Glycaemic index of local staple foods was determined. In first phase, the post prandial blood glucose response of isocaloric portion of wheat chapati and gram flour (baisen) chapati, were compared in 11 type II diabetic patients as a part of mixed meal in fasting state, alternately. The glycaemic index of baisen chapati was 39 as compared with wheat chapati. In second phase of the study, 22 type II diabetic patients were given isocaloric portions of wheat chapati and boiled rice as a part of mixed meal alternately. The glycaemic index of rice was 98 as compared with wheat chapati. This study favours the belief that baisen chapati is better and refutes that rice is bad for diabetics. It also upholds that glycaemic index is useful for planning a diabetic diet.

Blood Glucose

Streptomycin and tetracycline resistance plasmids in Staphylococcus hyicus and other staphylococci.

Plasmids associated with resistance to streptomycin, to streptomycin plus chloramphenicol or to tetracycline in Staphylococcus hyicus isolated from the skin of pigs have been compared, by restriction endonuclease digest patterns, with similar staphylococci from human sources and with published DNA base sequences. Several plasmids from Staph. hyicus have proved to have a very similar structure to those described from Staph. aureus but others appeared very dissimilar. This confirms the opinion that staphylococci from animal skin share a pool of plasmids with those from human skin but may also possess some of quite different structure.

Animals

Potential role of hands in the spread of respiratory viral infections: studies with human parainfluenza virus 3 and rhinovirus 14.

Hands often become contaminated with respiratory viruses, either directly or through contact with contaminated surfaces. Spread of such viruses could then occur by touching the nasal mucosa or the conjunctivae. In this quantitative study, we compared the survival of mucin-suspended human parainfluenza virus 3 (HPIV-3) and rhinovirus 14 (RV-14) and the transfer of the viruses to and from the fingers of adult volunteers. When each finger pad was contaminated with 10 microliters of either HPIV-3 (1.3 x 10(5) to 5.5 x 10(5) PFU) or RV-14 (2.1 x 10(4) to 1.1 x 10(5) PFU), less than 1.0% of HPIV-3 and 37.8% of RV-14 remained viable after 1 h; after 3 h, nearly 16% of RV-14 could still be detected, whereas HPIV-3 became undetectable. Tests on the potential spread of viruses from contaminated hands or surfaces were conducted 20 min after contamination of the donor surface by pressing together donor and recipient surfaces for 5 s. Transfer of HPIV-3 from finger to finger or finger to metal disk could not be detected, but 1.5% of infectious HPIV-3 was transferred from disk to finger. Irrespective of the type of donor or recipient surface, 0.7 to 0.9% of RV-14 was transferred. The relatively rapid loss of HPIV-3 infectivity on hands suggests that their role in the direct spread of parainfluenza viruses is limited. However, the findings of this study further reinforce the view that hands can be vehicles for rhinovirus colds. These results also suggest a role for nonporous environmental surfaces in the contamination of hands with respiratory viruses.

Adult

[Chemostimulation and catecholamine content of the rat adrenal medulla].

Unanaesthetized rats whose arterial chemoreceptors were stimulated by an one hour acute exposition to hypoxic gaseous mixtures with various carbon dioxide concentrations, presented depletion of the catecholamines content of their adrenal glands only when hypocapnia or increased pH was present (non compensated hypoxia). Moreover, exposition to simultaneous hypoxia and hypercapnia increased the epinephrine stock of the adrenal glands. No changes were found in the myocardium amine content in the same conditions. When anaesthetized rats were treated by iv injection of almitrine bismesylate, a peripheral chemoreceptors stimulating drug, adrenal catecholamines content was insignificantly reduced. In the myocardium, the amines remained at control levels. The most powerful factor related to catecholamines depletion in the adrenals seems to be the hypocapnia or the alkalosis induced by the hyperventilation provoked by glomic stimulation. No indication has been found in favor of an effective adrenergic stimulation caused directly by chemoreceptors stimulation.

Adrenal Medulla

Diversity of staphylococci exhibiting high-level resistance to mupirocin.

Plasmids mediating high-level resistance to mupirocin (MIC greater than 1000 mg/L) in staphylococci from various sources were studied by restriction endonuclease cleavage. Several patterns were obtained but six plasmids isolated from various Staphylococcus aureus and S. epidermidis strains were indistinguishable. The diversity and spread of these plasmids is illustrated.

Coagulase

A Bangladeshi family with three sisters 'Bombay' or Oh phenotype.

Three sisters in a same family (MIAH FAMILY) are of 'Bombay' phenotype. These being the first known female examples of 'Bombay' blood group have been detected in Bangladesh. As predicted by current theory their red cells are Le(a+b-) and their saliva do not contain any of the antigens A, B and H except Lea substance. Family studies showed that individuals with 'Bombay' or Oh phenotype may have A or B gene which are not expressed. This very particular type of blood is one of the rarest in any other parts of world except in India. Due to the presence of anti-H antibody in the plasma of Oh phenotype, when considering such patients for transfusion only blood of identical Bombay type can be safely transfused.

ABO Blood-Group System

Pseudo-leptospires in blood culture.

Spiral filaments seen in the blood cultures of two patients with fever and jaundice were initially thought to be leptospires; these were later proved to be artefacts. An investigation was carried out to exclude the possibility of laboratory contamination of the culture media and to find out how these objects were produced. The significance of the findings is discussed in relation to the possibility of a mistaken diagnosis in routine laboratories which have a limited experience of leptospires.

Blood

Quality of specimens and sputum culture results: a retrospective study.

A retrospective study of laboratory reports of sputums examined in the first 3 months of 1977 and of 1978 showed some interesting findings, which were similar in these 2 years. Analysis of the findings demonstrated that information from a proportion of sputum cultures were not helpful to the clinicians. Probable causes of such unhelpful results and some ways to overcome these problems were discussed, along with reviews of relevant literature. A conclusion drawn at the end of the discussion was that, under present circumstances, it was not expected that sputum cultures would produce totally reliable aetiological agents, unless attempts were made to obtain a better quality of specimen, e.g. those obtained by transtracheal or bronchoscopic aspirations.

Bacteria

Free-sporing Cl. welchii in ordinary laboratory media and conditions.

A strain of Clostridium welchii produced spores in ordinary blood agar plates. Investigations confirmed that it was the character of this particular strain and that the laboratory media were not inducing sporulation. During a period of 12 months a total of 100 strains of Cl. welchii were studied. None of them produced spores in ordinary laboratory media and conditions when examined microscopically.

Clostridium perfringens