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Biomedical subjects

S A Ali

Publications and source records attributed to S A Ali.

At least 73 records · Page 4Linked to original sources
PubMed1997

Induction of IL-2 and IFN-gamma in BALB/c mice immunised with subunit influenza A vaccine in combination with whole cell or acellular DTP vaccine.

Splenocytes from mice immunised with two doses of subunit influenza A/Beijing/353/89 vaccine mixed with whole cell DTP (wDTP), acellular DTP (aDTP) or PBS were collected 7 and 10 days after the second immunisation, and re-stimulated with subunit influenza vaccine or live virus in vitro. Interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) were assayed in supernates from these cultures by an ELISA procedure. Splenocytes from mice given subunit influenza vaccine in wDTP produced greater than two-fold and greater than five-fold responses of IL-2 and IFN-gamma, respectively, compared with splenocytes from mice immunised with subunit vaccine alone. In contrast, the response of splenocytes from mice immunised with subunit vaccine in saline or aDTP was similar, significantly less than for vaccine in wDTP (p < 0.01) and only slightly greater than for controls (p < 0.05). The production of IL-2 and IFN-gamma by these spleen cells was not significantly different on days 7 and 10 post-immunisation. Previous reports have shown that wDTP and aDTP enhance the serum antibody response of mice to influenza vaccine, but wDTP enhanced the response 100-fold greater than aDTP, and induced greater IgG2a and IgG2b subclass antibody responses; this last result indicates a cell-mediated immune response to vaccine. The present studies confirm these earlier findings; furthermore, as the IL-2 and IFN-gamma responses of splenocytes are associated with Th-1 subset T-lymphocyte response, the findings indicate a cytotoxic T-cell response to immunisation. The results indicate that influenza vaccine combined with wDTP induced a cell-mediated response in mice, which could confer a more solid immunity to challenge virus infection.

Adjuvants, Immunologic↗
PubMed1997

Occupational dermatitis in the manufacture of color television tubes.

An outbreak of dermatitis occurred in the Flow Coat sector of a large and modern color television factory. After investigating the working procedures in this area, a risk of contamination of the skin and clothing with ammonium dichromate was found when ammonium dichromate was weighed and mixed with polyvinyl alcohol (PVA). All of the workers involved in this process were clinically examined; 9 of 18 showed dermatitis to the back of the hands and forearms. Three of these workers were transferred from the sector and were cured of their dermatitis. Patch tests were carried out using 40 allergens, including those used in the Flow Coat process. The tests for PVA and for the phosphorescent blue, green, and red pigments gave negative results at the three concentrations tested. A high incidence of sensitization was found; 9 of 18 (50%) of the workers were found to be sensitized to ammonium dichromate, which is used as a fixer. The preventive measures adopted consisted of improving the quality of the personal protective equipment (PPE) and transferring the weighing and mixing of dichromate to the company laboratory. During the next 18 months, there were no new cases of dermatitis in the Flow Coat sector.

Chromates↗
PubMed1997

Skeletal scintigraphy with technetium-99m-tetraphenyl porphyrin sulfonate for the detection and determination of osteomyelitis in an animal model.

UNLABELLED: This article explores the accumulation of 99mTc-tetraphenyl porphyrin sulfonate (TPPS4) at inflammatory sites, especially osteomyelitis, and compares the results with 111In Cl3 and 111In-WBC in an animal model. METHODS: Osteomyelitis was induced in 12 New Zealand white rabbits by injecting staphylococcus aureus in the left tibia. Three weeks later, radiographs confirmed the disease. Two hours later, after injection of 74 MBq 99mTc-TPPS4, scintiphotos of the lower extremities were acquired and repeat scintiphotos were obtained 24 hr after injection of 5.55 MBq 111In Cl3. After these studies, 24- and 48-hr scintiphotos of the lower extremities were acquired after injecting 5.55 MBq 111In-labeled WBC. RESULTS: The left tibia averaged three times the uptake with 99mTc-TPPS4 compared with right tibia; with 111In Cl3 and 111In WBC the ratios are two times. These three radiopharmaceuticals reveal positive images, but the image quality using 99mTc-TPPS4 is better, as would be expected from the more favorable physical characteristics of 99mTc and the higher uptake. CONCLUSION: The traditional combination of three-phase bone and 67Ga-citrate scintigraphy can be replaced by a single injection of 99mTc-TPPS4 with imaging as early as 2 hr. Finally, the use 99mTc-TPPS4 should result in a substantial reduction in radiopharmaceutical cost.

Animals↗
PubMed1997

Leishmanicidal activity of Nystatin (mycostatin): a potent polyene compound.

The susceptibility of promastigote of Leishmania major to Nystatin in vitro was examined. L. major (MHOM/PK/88/DESTO) promastigote were cultured in medium 199 supplemented with 10% heat inactivated foetal bovine serum and 2% urine. The growth of the promastigote was monitored in the absence and presence of the experimental compound (Nystatin) for upto 5 days post-inoculation. The EC50 value (the concentration of drug necessary to inhibit the growth rate of cells to 50% of the control value) obtained for Nystatin against the promastigote of L. major was less than 9.76 iu ml. Certain polyene compounds like Amphotericin-B and Nystatin (mycostatin) are familiar for their fungicidal activity. Amphotericin-B is used since long as antileishmanial drug as well. Results obtained suggest that Nystatin has a very good anti leishmanial activity in vitro. The mode of action proposed for this drug is same as for Amphotericin-B as both of these polyene compounds interact with the various sterols present on the surface of the parasite, thus unusual gaps and pores are formed on the surface that results in the leakage of the ions. This leakage finally leads to the destruction of the parasite.

Amphotericin B↗
PubMed1996

Investigation of the effect of BB-94 (batimastat) on the colonization potential of human lymphoma cells in SCID mice.

We have assessed the effectiveness of the metalloproteinase inhibitor BB-94 (batimastat) in reducing the colonization potential of the human Burkitt lymphoma Namalwa cell line. In this study Namalwa cells were injected intraperitoneally into SCID mice and their spread to the spleen, liver and lung studied over a 3 week period. The human cells were detected in the mouse tissues by polymerase chain reaction (PCR) amplification of a human alu repeat sequence. Comparison of BB-94-treated animals with an untreated control group provided no evidence for a significant reduction in the colonization of mouse tissues by the human lymphoma cells in the presence of the drug. Tumour growth, after subcutaneous injection of the Namalwa cells into SCID mice, was similarly unaffected by BB-94. The significance of these results is discussed.

Animals↗
PubMed1996

High-yield production of functionally active human serum transferrin using a baculovirus expression system, and its structural characterization.

Recently, there has been much interest in expressing recombinant human serum transferrin (HST) and mutants thereof for structural and functional studies. We have developed a baculovirus expression system for the rapid and efficient production of large quantities of HST (> 20 mg/l). Like native HST, the recombinant protein can bind two ferric ions in the presence of bicarbonate, and is actively taken up by receptor-mediated endocytosis. Secondary structure calculations from CD measurements indicate a content of 42% alpha-helix and 28% beta-sheet. This is the first reported use of a non-mammalian expression system to produce functional HST, and will provide a practical tool to allow expression of a wide range of HST variants for mutagenesis studies.

Animals↗
PubMed1996

Clinical-epidemiologic study of alopecia areata.

BACKGROUND: Alopecia areata is a common disease and may be associated with autoimmune disease, atopy, Down syndrome, emotional stress, and foci of sepsis. METHODS: Seven cases of alopecia areata were diagnosed among workers in the Water and Effluent Treatment Sector (WETS) of a paper factory, representing a 0.6% incidence, when the value for the population at large is 0.1%. Three of these workers are assigned to the WETS on a permanent basis and four provide maintenance services. One of the latter patients had alopecia areata that fully regressed. Because biologic treatment of water and effluents involves saprophytic bacteria and fungi as well as chemical substances such as acrylamide, a clinical examination and laboratory tests were performed on all workers assigned permanently to the WETS (N = 9) and on 25% of the workers, selected at random providing services to the sector (N = 14). RESULTS: There was no association between alopecia areata and atopy, dermatophytosis, or bacteria isolated. Toxicologic evaluation revealed an acrylamide-like substance in 7 workers with alopecia areata, with a statistically significant correlation. Measures were taken at the workplace to decrease worker contact with the mists (probably containing acrylamide) in the pulp-pressing room; no other cases of alopecia areata had been detected 1 year after the study. CONCLUSIONS: A survey of the literature did not show reports of alopecia areata as an occupational dermatosis, but our conclusion is, that this dermatosis could be due to the professional activities of the workers at the paper factory studied.

Adult↗
PubMed1996

Analysis of the colonization of unirradiated and irradiated SCID mice by human lymphoma and non-malignant lymphoid cells.

We have evaluated the severe combined immunodeficient (SCID) mouse as an in-vivo model for the study of non-Hodgkin's lymphomas (NHL). Characterization of the immune system of the animals in our SCID mouse colony was carried out to assess the numbers of lymphoid cells present, to determine natural killer (NK) cell activity as a function of age and to examine the histology of the lymphoid organs. In this study four human NHL established cell lines (Daudi, Namalwa, U937, MC116), lymphoma cells from four fresh NHL biopsies and normal peripheral blood mononuclear cells (PBMC) and bone marrow cells were investigated, after intraperitoneal injection into the mice. The presence of the human NHL cells in the peritoneum and spleen was assessed by FACS analysis. The colonization potential was investigated in a range of tissues by polymerase chain reaction (PCR) amplification of human repetitive sequences. These studies revealed clear differences in the abilities of the NHL cell types to colonize the SCID mice. Namalwa, Daudi and U937 cells demonstrated the highest efficiency of colonization and readily formed tumours, whereas MC116, the NHL biopsy cell populations and the non-malignant lymphoid cells showed little ability to survive and colonize other tissues in the SCID mice. Whole body irradiation of the SCID mice appeared to improve the survival of human PBMC, NHL biopsy cells and MC116 cells in the peritoneum, but had little effect on their colonization potential. The significance of these studies is discussed.

Animals↗
PubMed1996

Mammoscintigraphy with technetium-99m-sestamibi in suspected breast cancer.

UNLABELLED: Our goal was to determine the clinical usefulness of 99mTc-sestamibi to identify breast cancer in patients prior to biopsy. METHODS: We studied 66 patients who received 20 mCi 99mTc-sestamibi intravenously. Lateral and anterior planar images were gathered within 30 min of the injection. Only focal increased uptake was interpreted as positive. Confirmatory pathologic diagnoses were obtained within 2 mo. The prevalence of breast cancer in our sample was 54%. RESULTS: We report an overall sensitivity of 83% and specificity of 93% for the diagnosis of breast cancer. In palpable lesions, the sensitivity was of 94% with a specificity of 91%, while in nonpalpable abnormalities the sensitivity was of 64% with a 100% specificity. Six patients with a malignancy had negative scans, four of these lesions were nonpalpable. Only two of 31 patients with benign lesions had an abnormal scan. CONCLUSION: Mammoscintigraphy with 99mTc-sestamibi has high specificity and adequate sensitivity for the noninvasive diagnosis of breast carcinomas.

Adult↗
PubMed1996

Pediatric gastric emptying: value of right lateral and upright positioning.

UNLABELLED: Gastroesophageal reflux and gastric emptying are usually assessed simultaneously with a 1-hr procedure. After ingestion of radiolabeled formula sequential images are gathered when the infant is in the supine position. This position is adequate for gastroesophageal reflux assessment, but delays gastric emptying. METHODS: We studied 48 children, 1 wk to 2 yr of age, who presented with vomiting or failure to thrive. They received 99mTc-sulphur colloid in formula. After completing 1 hr supine imaging we obtained additional abdominal views after changing the position of the infant to right lateral for 30 min, and upright for another 30 min. RESULTS: The percent of gastric emptying at 60 min in the supine position was 35% +/- 19%. After 90 min, in the right lateral decubitus, the percent gastric emptying was 60% +/- 25%. At 120 min, after an upright period, the gastric emptying was 73% +/- 20%. In the supine position 19 of 48 patients showed significant emptying (defined as > 40% emptying). This increased to 41 of 48 normal studies considering the right lateral position and to 45 of 48 normal studies considering the infant upright position. CONCLUSION: Many patients with delayed gastric emptying show significant emptying just by changing position. We routinely complement gastric emptying studies with delayed views in the right lateral and upright position.

Child, Preschool↗
PubMed1996

Effect of histaminergic drugs on integumental melanophores of adult Bufo melanostictus.

Histamine and 2-methyl histamine caused dose-dependent aggregation of melanophores in toad B. melanostictus. The effects were effectively antagonised by mepyramine, a specific H1 histamine receptor antagonist, and metiamide a specific H2 receptor antagonist. On the other, hand 4-methyl histamine, a specific H2 receptor agonist dispersed the melanophores. The results suggest that adult Bufo melanophores have H1 histamine receptors which mediate melanophore aggregation, however, dispersion of melanophores may be controlled by undifferentiated histamine receptors of H2 type.

Animals↗
PubMed1995

Oxygen transport proteins: I. Structure and organization of hemocyanin from scorpion (Buthus sindicus).

Scorpions are regarded as the oldest terrestrial arthropods. Scorpion Buthus sindicus (Buthidae) is commonly found in Pakistan and the Mediterranean region. The hemolymph of most arthropods contains large multisubunit, extracellular metalloprotein commonly known as hemocyanin which performs the important function of oxygen transport. The literature available to date shows that no attempt has been made to study hemocyanins or hemolymph proteins from this species. This communication presents the isolation, characterization and partial structural studies on hemocyanin from scorpion Buthus sindicus. (1) The hemolymph was collected by cardiac puncture, centrifuged and subjected to polyacrylamide gel electrophoresis and isoelectric focussing. (2) Crude hemolymph was subjected to gel filtration and high performance ion-exchange chromatography. (3) Purified hemocyanin subunits Bsin 1, 2 and 3 have been analysed for their amino acid composition and N-terminal sequence. The sequence homology was determined by comparison with other arthropod hemocyanin. The results are discussed.

Animals↗
PubMed1995

Mediastinal scintigraphy for parathyroid localization in hyperparathyroidism.

Two cases are reported demonstrating that mediastinal scintigraphy for hyperparathyroidism should be routinely performed along with scintigraphy of the neck region. Because of the relative cost-benefit ratio, consideration should also be given to performing the procedure before the initial surgery. For the most accurate diagnosis and favorable outcome, our cases suggest that scintigraphic physiologic results should be correlated with anatomic results of conventional radiography.

Adenoma↗