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Biomedical subjects

S Islam

Publications and source records attributed to S Islam.

At least 19 recordsLinked to original sources
PubMed1992

Development and evaluation of a rapid, simple, sensitive, monoclonal antibody-based co-agglutination test for direct detection of Vibrio cholerae 01.

Cholera epidemics caused by Vibrio cholerae 01 continue to represent a major public health concern in many developing countries. A rapid and simple test kit for the detection of V. cholerae 01 has been developed. The kit, CholeraScreen is a monoclonal antibody-based, co-agglutination test and is used directly with stool specimens. It does not include culturing the specimen and is performed without the need for sophisticated laboratory equipment. Specificity of the test was demonstrated, using 118 reference cultures, to which cross-reactions were not observed. Preliminary results of field trials carried out in Guatemala and Bangladesh demonstrated that the test is equally sensitive as conventional culture methods in detecting V. cholerae and, in many cases, more sensitive. The CholeraScreen test is simple, specific, and does not require culturing procedures, making it suitable for direct detection of cells of V. cholerae in clinical specimens, even in the field. Also, the test requires less than five minutes to complete.

Agglutination Tests↗
PubMed1992

Exercise testing and training of persons with dysvascular amputation: safety and efficacy of arm ergometry.

Recent studies indicate that most persons with dysvascular amputation also have moderate to severe cardiovascular disease with impairment in functional capacity. This may limit the ability to achieve optimal function with their prosthesis because of inadequate conditioning. We developed an exercise testing and training program using arm ergometry in conjunction with standard rehabilitation for persons with acute dysvascular amputation who were profoundly deconditioned after complicated perioperative courses. The program consisted of daily arm ergometry, performed on an interval basis, at an intensity individually optimized through exercise testing. Twenty-five patients, with a mean age of 63 years, completed the inpatient program with pretest and discharge work performance assessment. There was no significant difference between pretest and discharge assessment of baseline or peak heart rate, systolic blood pressure, diastolic blood pressure, or Borg rating of perceived exertion. Peak systolic blood pressure was elevated at discharge compared to admission testing (p less than .04). Heart rate responses were decreased during the early stages of testing when comparing discharge telemetry to admission findings. The duration of exercise increased from 12.6 minutes to 16.3 minutes (p less than .0004), and the maximum work output increased from 17.1 watts to 23.5 watts (p less than .0004). There was no significant morbidity associated with either arm ergometry testing or the exercise program. We conclude that arm ergometry testing and training is a safe and effective method for improving the efficiency of arm work in the patient with acute dysvascular amputation.

Aged↗
PubMed1992

Mutagenic activity of oxathiolane steroids: structural requirement for the genotoxic activity in Salmonella and E. coli.

Oxathiolanes and disulfonyl derivatives of steroids were tested for mutagenic activity in the Ames tester strains. The test compounds exhibited mutagenic activity without metabolic activation although metabolic activation markedly enhanced their activity. A significant decrease in the survival of the radiation-sensitive mutants recA, lexA and rer of E. coli was observed as compared to their wild-type counterpart in the presence of the test steroid. Structural features which appear to be crucial for the mutagenic activity in these steroidal drugs are: (i) an electron-donating group at position 3, and (ii) a bulky group anchored at the 5th and 6th positions. The test steroids appear to damage DNA which in turn initiates the SOS repair with the concomitant induction of mutation.

Biotransformation↗
PubMed1992

Contrast arthrography in thumb polydactyly with variable morphological patterns.

Contrast arthrography was performed in 20 patients with duplicated thumbs where the interphalangeal, metacarpophalangeal, and carpometacarpal joints were involved. Three groups were apparent, those with no joint alteration, those with joint involvement and separate articular impressions, and those with abnormal duplex joints.

Arthrography↗
PubMed1992

Concerted evolution of the mouse Tcp-10 gene family: implications for the functional basis of t haplotype transmission ratio distortion.

The mouse Tcr locus is defined by its central role in the transmission ratio distortion phenotype characteristic of t haplotypes. A molecular candidate for Tcr has been identified in the form of a gene--Tcp-10b--expressed during spermatogenesis. Tcp-10b is one member of a multigene family present in two to four copies on different homologs of chromosome 17. The coding regions of the Tcp-10 genes present within two inbred strains were compared with those of the tw5 haplotype. The various gene family members are highly conserved relative to each other with a minimum nucleotide identity of 98.6% in all pairwise comparisons. Maximal parsimony analysis indicates that the Tcp-10 gene family has evolved in a concerted manner with the obliteration of nearly all individual gene-specific characteristics. As a consequence, the candidate for the full-length mutant Tcr gene product is distinguished by only a single, highly conservative, amino acid change. The data are consistent with the hypothesis that the effector of mutant Tcr activity is a second, alternatively spliced product that is expressed in a haploid- and allele-specific manner.

Alleles↗
PubMed1992

The vasorelaxant effects of acetate: role of adenosine, glycolysis, lyotropism, and pHi and Cai2+.

The mechanism of acetate vasorelaxation is unknown. In the rat caudal artery, acetate has a vasorelaxant effect and also increases cyclic AMP. Here we evaluate the role of adenosine, of possible glycolysis inhibition by acetate, of the lyotropic properties of acetate and other anions, and of intracellular calcium and pH. Adenosine per se did not relax the caudal artery in the range of 10(-8) to 10(-2) M. Preincubation with adenosine deaminase (ADA, 5.0 U/ml) or with 8-phenyltheophylline (8-PT, 10(-6) to 10(-4) M) increased, rather than blocked the vasorelaxant effect of acetate. Oxypurinol (10(-3) M) or the nucleoside transport inhibitor NBMPR (10(-4) M) had no effect on acetate relaxation. Whereas acetate increased tissue cyclic AMP content, 10(-3) M adenosine or 10(-6) M PIA had no effect. In strips studied under conditions of inhibited glycolysis (no glucose, with 11 mM 2-deoxyglucose, 1.0 mM pyruvate, and 0.5 mM 5-iodoacetate), acetate-induced relaxation, as well as acetate-induced cyclic AMP generation, tended to be reduced but not significantly so. Other anions relaxed vascular strips in relation to their lyotropic number, but only at higher doses, and they did not stimulate cyclic AMP formation. Acetate (10 mM) caused a transient fall in Ca2+i followed by a slight, sustained rise. A concomitant decrease in pHi was seen. DIDS, which blocks the relaxant and cyclic AMP effects of acetate, had no effect on the pHi decrease, but did decrease the rate of pHi recovery.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetates↗
PubMed1992

Anatomical study of preaxial polydactyly in 158 hands.

Preaxial polydactyly is a common congenital hand anomaly. Here in 138 patients with 158 duplicated thumbs, a new classification of this anomaly was done from analysis of radiographs and operation records. Initially all the duplicated thumbs were arranged into from Type I to VII on the basis of radiological extent of bifurcation. Appendage type was noted as a separate entity. Type IV was found the most common and had 53 thumbs (33.6%) involved. But findings on surgery indicated that the exact level of bifurcation varied in each type, and Type VII became three times as frequent as previously noted from x-ray examination at the time of surgery. Radiologically encountered duplications at IP (Type II), MP (Type IV) and CM (Type VI) joints were specifically classified into five groups from A to E on the basis of the structural changes detected on surgery. Details in each group were discussed.

Female↗
PubMed1992

Cholera epidemics in Bangladesh: 1985-1991.

In 1991, a major epidemic of diarrhoea broke out in Bangladesh. To estimate the extent of cholera during diarrhoea epidemics and to focus on the public health issues related to cholera in Bangladesh, we have used the government figures of the 1991 epidemic and data from our own experience of epidemic interventions in nearly 400 rural upazilas (sub-district) between 1985 and 1989 and in 1991. Our data showed that V. cholerae 01 was the most frequently (40%) isolated enteropathogen during the epidemics. The disease is widely distributed in the country. Only 24% of the total 1,648 laboratory confirmed cholera patients were below 5 years of age, and children below 2 years of age accounted for only 10% of the total. Access difficulty to medical care and absence of a reliable surveillance were thought to be the constraints to early detection and appropriate intervention, thus, there were more deaths during the epidemics. We have shown that a high proportion (59%) of cholera patients during their illness in the rural areas were not visited by the government surveillance staff and that most (80%) were treated at home. Access to treatment by qualified physicians was limited to 23% of the patients, whereas a large proportion of the patients were treated by the unqualified rural practitioners (68%), and the others (9%) had no access to any health care providers. Our experience also indicated a higher case fatality ratio (14%) prior to intervention by qualified physicians during epidemics and an overall fatality ratio of 4%, despite the significant reduction (less than 1%) achieved by the intervention. Cholera is highly epidemic in Bangladesh.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Radiographic and neuro-SPECT imaging in an immature third ventricle teratoma: case report.

We report a case of an immature teratoma of the third ventricle, which was preoperatively thought to be a choroid plexus papilloma. The diagnosis was made by biopsy since the radiographic (CT, MRI), angiographic and scintigraphic findings ([99mTc]pertechnetate, 99mTc-DTPA, 99mTc-HMPAO brain SPECT) were nonspecific. Disruption of the blood-brain barrier is the mechanism for radionuclidic and contrast tumoral uptake and is demonstrated by marked contrast enhancement on CT and focal concentration on [99mTc]pertechnetate and 99mTc-DTPA images. No suppression of [99mTc]pertechnetate tumor uptake was observed following the administration of potassium perchlorate. Increased concentration of tumor protein is suggested by the increased signal on the T1-weighted magnetic resonance images and high [99mTc]pertechnetate uptake. The tumor's detection on the 99mTc-HMPAO brain SPECT was due to its intraventricular location. A number of potential mechanisms for brain tumor localization of 99mTc-HMPAO are discussed.

Cerebral Ventricle Neoplasms↗
PubMed1991

Mutagenic activity of certain synthetic steroids: structural requirement for the mutagenic activity in Salmonella and E. coli.

Eight steroids, structurally related to cholesterol, were tested for mutagenic activity in the Ames tester strains. All the test compounds were mutagenic without metabolic activation, although metabolic activation markedly enhanced their activity. A significant decrease in the survival of the radiation-sensitive mutants recA and lexA of Escherichia coli was observed as compared to their wild-type counterpart in the presence of the steroids. The role of recA and lexA genes gains further support from the lambda prophage induction in the lysogen as well as with Salmonella strains triggering the error-prone SOS response. Structural features which appear to be essential for mutagenic activity in these strains of the steroids are (1) reactive thio, sulfonyl or sulfinyl groups at the 6 position and (2) a halogen group at the 3 position of the steroidal nucleus. The mutagenicity appears to involve the formation of H2O2 as well as superoxide and hydroxyl radicals.

Catalase↗
PubMed1991

Mutagenic activity of aziridinyl steroids and their mechanism of action in biological systems.

The aziridinyl derivatives of steroids, structurally related to cholesterol, were tested for their mutagenic activity in the Ames tester strains. The test compounds were mutagenic without metabolic activation, although metabolic activation markedly enhanced their activity. A significant decrease in the survival of SOS defective mutants, recA and lexA of Escherichia coli was observed as compared with their wild-type counterpart in the presence of the steroids. The role of SOS repair genes gains further support from the lambda prophage induction in the lysogen and beta-galactosidase induction in the Mud strains as well as mutagenesis with Ames tester strains. Structural features which appear essential for mutagenic activity in these strains are (i) a reactive N-aminophthalamide group at the (5,6-b) position and (ii) an acetoxy/chlorine group at the third position of the steroidal nucleus. The individual moieties/groups were not mutagenic per se. These steroids appear to generate H2O2 as well as superoxide and hydroxyl radicals in the model biological system.

Aziridines↗
PubMed1991

Effects of an EDTA infusion on the urinary elimination of several elements in healthy subjects.

Ethylene diamine tetraacetate calcium disodium salt (EDTA Ca Na2), 1 g dissolved in 250 ml of 5% w/v glucose solution, was infused intravenously over 1 h into 10 healthy subjects (eight males and two females). Urines were collected over 24 h, the day before and on the day of the EDTA Ca Na2 infusion test. The elements Al, B, Ba, Cu, Fe, Mn, Si, Sr, Zn, Na, K, Ca, Mg, S and P were measured by inductively coupled plasma optical emission spectrometry. Pb was measured by inductively coupled plasma mass spectrometry. The EDTA Ca Na2 infusion increased the 24 h elimination of Al from 9.8 micrograms to 58 micrograms, of Fe from 66 to 121 micrograms, of Mn from 2.9 to 16.5 micrograms, of Pb from 9.8 to 56 micrograms and of Zn from 623 to 8847 micrograms. The ratio of the increase of urinary elimination induced by EDTA Ca Na2 was about 2 for Fe, 5 for Al, Pb and Mn, and 15 for Zn.

Adult↗
PubMed1991

Vasorelaxant effects of short chain fatty acid salts in rat caudal artery.

Acetate relaxes rat caudal artery and increases tissue adenosine 3',5'-cyclic monophosphate (cAMP) levels. The present study's purpose was to determine whether related ultrashort chain (volatile) fatty acids, propionate (C3), butyrate (C4), and octanoate (C8) would do so as well. It was found that butyrate and propionate had very similar vasorelaxant profiles to acetate; they relaxed caudal artery strips precontracted with KCl, phenylephrine, arginine vasopressin, and prostaglandin F2 alpha. The vasorelaxation was endothelium independent, was not blocked by indomethacin, and was associated with a rise in tissue cAMP levels but not in guanosine 3',5'-cyclic monophosphate (cGMP) levels. The mean effective concentration for butyrate (0.8 mM) was lower than that for acetate (2.0 mM) or propionate (1.9 mM). Propionate-mediated relaxation was blocked by the stilbene inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). Vasorelaxant effects of octanoate were also not dependent on endothelium and were not affected by indomethacin. Maximal vasorelaxant effect of octanoate was greater than that of acetate, propionate, or butyrate; vasorelaxant effect of octanoate was only slightly attenuated by DIDS and was associated with only a minimal effect on tissue cAMP levels. Results suggest that vasodilatory effects of acetate generalize to propionate and butyrate, but that vasorelaxant effects of octanoate may be occurring via a separate mechanism.

Animals↗
PubMed1991

Thyroid autocrine factors: regulation of secretion of insulin-like growth factor binding proteins from sheep thyroid cells by autocrine basic fibroblast growth factor.

The mRNA for basic fibroblast growth factor has been detected in primary cultures of sheep thyroid cells. RNA species of 2.0 kb, 3.3 kb and 7.2 kb have been identified. The effects of this autocrine factor on the production of insulin-like growth factor binding proteins (IGFBPs) have been examined. bFGF enhanced the secretion of IGFBP-2 and, like epidermal growth factor (EGF) and the tumour promoting phorbol ester (TPA), induced the appearance of IGFBP-3. We conclude that bFGF is synthesized by sheep thyroid cells and has autocrine potential since it can regulate the secretion of other thyroid autocrine factors which, in turn, may regulate thyroid growth and function.

Animals↗
PubMed1991

Triphalangism in thumb polydactyly: an anatomic study on surgically resected thumbs.

Surgically resected thumbs in preaxial polydactyly were submitted to anatomic dissection to detect a triphalangeal thumb. Radiologically, two particular categories of thumbs with duplication at the metacarpophalangeal joint were seen. The surgically excised thumbs of either the radial or the ulnar member were preserved for dissection. Depending on the number of phalanges as well as on osteocartilaginous structures, the thumbs were classified into three groups. In the first group, the thumbs consisted of three phalanges but had absent joint formation between the phalanges and metacarpal. The second group consisted of three phalanges with two well-formed joints between them. The third group of thumbs also had three phalanges but had only one interphalangeal joint between them. In all three groups, morphologic features and clinical criteria are discussed.

Humans↗
PubMed1991

Arm ergometry exercise testing in patients with dysvascular amputations.

The purpose of this study was to test the agreement between the heart rate (HR) response and rating of perceived exertion (RPE) on an arm ergometry graded exercise test (GXT) in deconditioned persons with acute dysvascular amputations before and after an inpatient rehabilitation program. Twenty-six men were studied at admission, and 11 were retested after completion of the program. After obtaining resting measurements of HR and systolic and diastolic blood pressures, each patient performed the GXT using an arm ergometer. Patients maintained a cranking rate of 50rpm, which was monitored electronically. The workloads started with a warm-up period of 0 watts (stage 1) and increased by increments of 5 watts. Each stage lasted three minutes-2.5 minutes of exercise and 30 seconds of rest. The RPE was taken five seconds before the end of each exercise stage. During the rest period, HR and blood pressures were recorded. Scatter plots and linear regression analyses revealed no statistically significant relationship, either at early stages of GXT or at peak work, between HR and RPE. The results suggest that RPE cannot be used reliably as a surrogate for direct pulse measurement in exercise training of persons with acute dysvascular amputations.

Aged↗
PubMed1990

Effect of breast cyst fluid on oestrogen 17-oxidoreductase activity in MCF-7 breast cancer cells.

Breast cyst fluid (BCF) was found to stimulate oestrogen 17-oxidoreductase activity in the reductive direction, i.e., conversion of oestrone (E1) to oestradiol (E2), in MCF-7 breast cancer cells. Dialysis of BCF revealed that this property of BCF was present in both dialysed BCF and dialysate, implying that both high and low mol. wt. substances were responsible for stimulating E1 to E2 conversion. Gel filtration of dialysed BCF revealed that the high mol. wt. substances responsible for the stimulation of E1 to E2 conversion had mol. wts. of approximately 11 kD and 68 kD. This property of BCF would serve to increase the concentration of E2, a steroid which may play a role in mammary carcinogenesis.

Body Fluids↗