Biomedical subjects
Publications and source records attributed to M Ahmad.
Three flavone glycosides have been hoisted from the fresh vegetative part of the medicinal herb Caralluma tuberculata. The chemical and spectroscopic properties are consistent with structures of Luteolin.4'-beta-D-glucopyranosyl-(2-->1)-alpha-L-rhamnopyranoside [1], Kaempferol-7-O-beta-D-glycopyranosyl (2-->1)-alpha-L-rhamnopyranoside [2], Kaempferol- 3-O-beta-D-glycopyraaosyl (6-->l)-alpha-L-rahmnopyranouide (3).
The effects of the crude ethanolic extract of whole plant of Bacopa monnieri have been evaluated on left ventricular contractility, heart rate and coronary flow in isolated rabbit hearth showed cardiac depressive activity in all parameters, like quinidine.
Three anticholesterolemic agents, 2,4-dimethoxy phenacyl nicotinium bromide, 2,5-dimethoxy-phenacyl-nicotinium bromide, and 2,3,6-tribromo 3,5-dimethoxy-phenacyl-nicotinium bromide, were synthesized and their chemical structures were determined by spectroscopic method.
A new combination regimen including chemotherapy and interferon was started in 1986 for the treatment of 24 chronic myelogenous leukaemia patients in chronic phase. Complete cytogenetic remission were noted in 10 patients and 6 of them are in sustained remission. The overall survival was 70% at 40 months. However, a minimal residual disease was detected in the 3 patients tested with the polymerase chain reaction. In addition no correlation was detected between the site of the breakpoint and response to therapy.
Analysis of the chromosomal changes in various neoplasia is being increasingly carried out not only to evaluate its relationship with the prognosis and biological behaviour of the tumour but also for diagnostic purposes in some cases. Leukaemias are one such group of haematological malignancies which have been most extensively studied in this regard. Karyotypic analysis with Giemsa banding technique was carried out in 35 consecutive cases of Acute Lymphoblastic Leukaemia. Eighteen cases were in children (less than 15 years age) and 17 cases were in adults. M.F. ratio was 1.8:1 FAB classification of these cases showed 31 cases of L1 type and 4 cases of L2 type including one case of T-ALL. Fifteen cases (43%) had no karyotypic abnormality, 6 cases (17%) showed pseudodiploidy, one case each having (-20 + 21), t (9:22), (+ 2-6), (-6 + 8), while two cases had 6 q-.13 cases (37%) showed hyperdiploidy with 6 cases showing trisomy 8 alone, one case (+ 8 + 21), one case trisomy 18, one case + 15(r), one case trisomy 21 plus t (9:22) and one case with trisomy 21 only. Two cases showed more complex abnormalities i.e. + 2 + 8, t (13:22) and -11 + MR + Min + Min. There was one (3%) case of hypodiploidy showing monosomy 6. The above findings are in agreement with studies carried out in other countries except t (13:22) which is rather a scarcely reported abnormality.
Radionuclide Tc99m DTPA (Diethylenetriaminepenta Acetic Acid) renal imaging is being used to assist in the evaluation of overall GFR, the intra-renal transit time, the cortical transit time, response to frusimide injection, diagnosis of ATN and rejection in renal transplant cases. A study was conducted at PINSTECH in order to prepare DTPA kit locally and evaluate the labeling efficiency as well as the in vitro and in vivo stability of Tc99m DTPA preparation. The results were comparable with those of imported Renal imaging (pentetate-II Technetium 99m) agent. The shelf life of the kit at room temperature recorded is around 3 months, the labeling efficiency with Tc99m pertechnetate is more than 99% and the fraction of hydrolyzed Tc99m recorded is less than 1%. On clinical trials no artifacts were seen on scintigraphic images.
HLA frequencies on 1231 subjects from within the country, using methods employed by National Institute of Health, USA is reported. Pakistani population appears to be a mixture of an indigenous population with others particularly Orientals and Negroids. Relationship with Caucasians is not convincing.
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Recombinant macrophage colony-stimulating factor (M-CSF) is a hemopoietic growth factor capable of modulating activities of both immature and mature monocytes. The effect of M-CSF on tumoricidal activity of alveolar macrophages and monocytes from nonsmoking normal volunteers was compared using [3H]thymidine-labeled human tumor cells (SK-MEL-28, melanoma) as targets. A dose-response study (500-5,000 U/ml) of recombinant M-CSF indicated that both alveolar macrophages and blood monocytes demonstrated peak cytotoxicity at 1,000 U/ml. Maximal activity occurred 72-96 h after exposure to 1,000 U/ml of M-CSF. To investigate the mechanisms involved in this cytotoxicity, tumor necrosis factor-alpha (TNF) and interleukin-1-beta (IL-1) were measured in supernatant fluids of 24 h M-CSF-treated cells. No significant increase in either cytokine was detected after M-CSF treatment of alveolar macrophages or monocytes. Superoxide anion production of alveolar macrophages was not enhanced by M-CSF. These data suggest that alveolar macrophages tumoricidal activity is induced by M-CSF and is not dependent on oxidative metabolism or secreted forms of IL-1 or TNF.
Four cases of Wegener's granulomatosis involving lung are reported in which immunomicroscopy demonstrated that the parenchymal and vascular infiltrates were composed primarily of T cells and monocytes. No IgG, IgA, IgM, or C3 was identified in pulmonary vessels or alveolar septa. Ultrastructural studies failed to demonstrate dense deposits in alveolar septal capillaries or interstitium. These findings indicate that a cellular immune mechanism is active in these forms of pulmonary vasculitis and that immune complex deposition does not play a role.
The metabolic fate of isatin hydrazone (Ia), isatin-3-thiosemicarbazone (Ib), isatin-3-semicarbazone (Ic), isatin-3-phenylhydrazone (Id), isatin oxime (Ie) and 3-hydroxy-3-acetonyl oxindole (II) was studied in rabbits. The compounds were administered orally in the dose of 300 mg/kg body wt. Isatin anthranilic acid, tryptophan and nicotinic acid were identified as the major metabolites excreted in urine. The 3-hydroxy-3-acetonyl oxindole (II) gave on additional metabolite, oxindole. The major metabolites were separated and identified unambiguously on thin layer silica gel plate. Metabolic pathways have been proposed to explain the biotransformation of the compounds investigated.
We performed radionuclide scanning after the intravenous injection of human IgG labeled with indium-111 in 128 patients with suspected focal sites of inflammation. Localization of 111In-labeled IgG correlated with clinical findings in 51 infected patients (21 with abdominal or pelvic infections, 11 with intravascular infections, 7 with pulmonary infections, and 12 with skeletal infections). Infecting organisms included gram-positive bacteria, gram-negative bacteria, Pneumocystis carinii, Mycoplasma pneumoniae, and Candida albicans. No focal localization of 111In-labeled IgG was observed in 63 patients without infection. There were five false negative results, and nine results were unusable. Serial scans were carried out in eight patients: continued localization correctly predicted relapse in six, and the absence of localization indicated resolution in two. To determine whether 111In-labeled IgG localization was specific for inflammation, we studied 16 patients with cancer. Focal localization occurred in 13 of these patients (5 with melanomas, 5 with gynecologic cancers, and 1 each with lymphoma, prostate cancer, and malignant fibrous histiocytoma). No localization was seen in patients with renal or colon cancer or metastatic medullary carcinoma of the thyroid. We conclude that 111In-labeled IgG imaging is effective for the detection of focal infection and that serial scans may be useful in assessing therapeutic efficacy. This technique may also be helpful in the evaluation of certain cancers.
The effect of granulocyte-macrophage colony-stimulating factor (GM-CSF), a pluripotent cytokine, on tumoricidal activity of alveolar macrophages and monocytes from nonsmoking normal volunteers was compared using [3H]thymidine-labeled human tumor cells (SK-MEL-28, melanoma) as targets. A dose-response study (500-5000 units/ml) of recombinant GM-CSF indicated dramatic differences between cytotoxicity of alveolar macrophages and blood monocytes. Macrophages exhibited significant (P less than 0.01) tumoricidal activity at all GM-CSF doses tested. In contrast, monocytes showed no significant tumoricidal activity at 500 units/ml and significantly (P less than 0.01) less activity than alveolar macrophages at doses of 1000-5000 units/ml. Maximal activity in alveolar macrophages occurred 72-96 h after exposure to 1000-5000 units/ml GM-CSF. Tumoricidal activity may be related to the state of maturation, because monocytes matured in vitro for 7 days displayed enhanced tumoricidal activity after GM-CSF exposure. Tumor necrosis factor alpha and interleukin 1 beta were measured in supernatant fluids of 24-h GM-CSF-treated cells. No significant increase in either cytokine was detected after GM-CSF treatment of alveolar macrophages. Monocyte interleukin 1 beta secretion was not enhanced by GM-CSF; however, tumor necrosis factor alpha secretion was enhanced in some donors (three of five). Superoxide anion production of alveolar macrophages was not enhanced by GM-CSF. These data suggest that alveolar macrophage tumoricidal activity is induced by GM-CSF and is not dependent on oxidative metabolism or secreted forms of interleukin 1 beta or tumor necrosis factor alpha.
The effects of ultrasonic instrumentation on the preparation shape of curved simulated canals were investigated. Measurements of the displacement amplitudes of the files were made to examine the possible relationship between displacement amplitude and the cutting ability of the file. Twenty-five simulated canals in clear resin blocks were instrumented using a Cavi-Endo unit at a power setting of 1 with differing times of instrumentation and with water as irrigant. Another group of 25 canals received similar treatment but were instrumented with an Enac unit at a power setting of 1. The canal shape and the incidence of elbow formation were evaluated using various measurements taken from photographic prints of the canals. All canals exhibited unequal removal along the canal with more removal occurring coronally. The Enac group exhibited a higher incidence of elbows which occurred further apically than those in the Cavi-Endo group. There was no significant difference between groups in the amount of apical canal enlargement. Coronally, the Enac appeared to cut significantly better. The Enac also caused significantly greater apical deviation and change in width. In both units more elbows were formed following instrumentation, with less flexible files having smaller displacement amplitudes.
Forty teeth with severely curved canals were divided into two groups and the root canals were prepared either ultrasonically or with hand instruments. Canal shapes were compared qualitatively and quantitatively using subtraction macroradiography; this allowed the pre- and postinstrumented canal shapes to be viewed on the same print. The times to carry out instrumentation and the incidence of elbows were recorded. In addition, the following measurements were taken from the radiographs using a digitizer: apical and coronal areas, distance of elbow from canal curvature, change in width at elbow and 0.5 mm apical to it, and apical transport width. Subjective evaluation revealed that no difference was apparent between the methods as to the places where the dentin was removed; both instruments exhibited unequal dentin removal along the canal length with more removal occurring coronally. The quantitative results indicated an absence of differences in the following: the time of instrumentation, the incidence of elbows, the distance of elbow from the point of curvature, the change in width at the region of the elbow, and the apical transport width. These findings indicated that ultrasonic files behaved similarly to hand instruments when used in a filing action.
The validity of using simulated root canals in resin blocks for evaluating the effects of ultrasonic root canal instrumentation was examined. Curved canals in resin blocks and in natural teeth were ultrasonically instrumented using the Cavi-Endo unit at power setting 1. Canal shapes were compared qualitatively and quantitatively from photographs and subtraction macroradiographs of simulated canals and teeth, respectively. The following measurements were taken: apical and coronal areas, changes in width at the elbow and at 0.5 mm apical to the elbow, and apical transport width. Qualitatively, there did not appear to be any differences in the manner of removal of material along the length of the canal in both test models. Quantitatively, there was a similarity in the following: areas of canal walls removed, the incidence of elbows, the change in width at the region of the elbow, and the apical transport width. The lack of differences showed that the ultrasonic file cut in a similar fashion in both test models and indicated that simulated canals are valid models for evaluating the effects of ultrasonic instrumentation.
Analysis of the major biochemical components of Taenia hydatigena cysticerci collected from goats and pigs showed marked differences, particularly in glycogen, protein, lipid and DNA levels. Differences were also detected in the levels of cholesterol, triglycerides, free fatty acids and phospholipids. Furthermore, the profile of phospholipid fractions revealed quantitative differences between the two species. It is concluded that the cysticerci of goat and pig origin probably represent two different strains and possibly follow the same pattern of speciation as reported in the related taeniid, Echinococcus granulosus.
The thyroid scintigraphs of 207 patients were examined with a view to investigate the anatomical origin of the pyramidal lobe (PL) and in order to determine the incidence of its scintigraphic detection. The PL was visualized in 41% of the cases studied with a greater incidence among the females as compared to the males. It was established that the likelihood of the PL arising from the isthmus of the thyroid or its lobes was about the same. Further, it was observed that the isthmal PL was usually located in the mid-line rather than laterally, in which case it was more often deviated to the left than to the right. The scintigraphic visualization of the PL was seen to increase with the size of the gland but in large goitres it was difficult to detect. It evolves that although at times, there might be a discrepancy between the apparent and the actual location of the PL due to the presence of overlying tissue, in a majority of cases, the scintigraphic appearances do in fact reflect the true picture.