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Biomedical subjects

M Ali

Publications and source records attributed to M Ali.

At least 235 records · Page 13Linked to original sources
PubMed1993

Aqueous extracts of garlic (Allium sativum) inhibit prostaglandin synthesis in the ovine ureter.

The prostaglandins (PGs) synthesized from C14-arachidonic acid by the homogenized sheep ureter were identified as being prostacyclin (PGI2), PGF2 alpha and thromboxane B2 (TXB2). The radioimmunoassay (RIA) estimation of 6-keto-PGF1 alpha, a stable metabolite of PGI2, confirms that it was the major metabolite of arachidonic acid. Aqueous extracts of fresh garlic (5, 12.5, 25 and 50 mg/ml) were shown to inhibit the synthesis of the prostanoids in a dose dependent manner. Fresh garlic extracts (1, 2.5, 5 and 10 mg/ml) also dose dependently inhibited spontaneous rhythmic contractions of the isolated ureter. Boiled garlic (5, 12.5, 25 and 50 mg/ml) had no effect on either ureteral motility or the PG synthesizing capacity of the sheep ureter.

Animals↗
PubMed1993

Maternal nutritional status as a determinant of child health.

To determine the relationship between the nutritional status of the mother and that of the child, 339 children aged 3-36 months and their mothers in two urban hospitals and a community out-patient clinic, were studied. The weight and height of both children and their mothers were measured, and body mass indices (BMI) of the mothers were calculated. Socio-economic status, maternal educational level, and dietary information were recorded in a predesigned questionnaire. The child's nutritional status, as indicated by weight for age (as a percentage of NCHS median), was associated with the body mass index of the mother (P < 0.001), socio-economic status of the family (P < 0.001), and breastfeeding status of the child (P < 0.005) in a multivariate analysis after adjusting for several prognostic factors. The results indicate that maternal nutritional status is a proximate determinant of a child's nutritional status and should be considered in programmes aiming at improving child health.

Bangladesh↗
PubMed1993

Regional blood flow during closed-chest cardiac resuscitation in rats.

Quantitative measurement of regional blood flow during cardiac arrest and resuscitation has been confined to large animals. We report on a rodent model utilizing radioactive microspheres during cardiac arrest and resuscitation for investigation of regional blood flow. Ventricular fibrillation was electrically induced in 10 pentobarbital-anesthetized Sprague-Dawley rats. Resuscitation was attempted by precordial compression followed by external direct current countershock. During precordial compression, cardiac output corresponded to 12% of prearrest flow. Similarly low flows were observed in the myocardium and brain. However, much lower flows were observed in the adrenal glands, kidneys, intra-abdominal viscera, skin, and skeletal muscle. Five of ten animals were successfully resuscitated. During precordial compression, resuscitated animals had significantly higher cardiac output (13.1 +/- 4.1 vs. 8.6 +/- 1.46 ml/min), myocardial blood flow (0.70 +/- 0.24 vs. 0.22 +/- 0.15 ml.min-1.g-1), cerebral blood flow (0.17 +/- 0.04 vs. 0.06 +/- 0.02 ml.min-1.g-1), and adrenal blood flow (1.09 +/- 0.60 vs. 0.27 +/- 0.16 ml.min-1.g-1). Thirty minutes after successful resuscitation, cardiac output and myocardial, cerebral, renal, and adrenal blood flows and blood flow to splanchnic viscera (with the exception of the spleen) had returned to > or = 70% of prearrest flows. These studies confirm the conclusion of earlier investigations in larger animals that visceral blood flow during cardiac arrest and precordial compression is preferentially distributed to the brain and myocardium. Successful cardiac resuscitation is contingent on threshold levels of myocardial blood flow that exceed 0.4 ml.min-1.g-1.

Adrenal Glands↗
PubMed1993

Formation of 2,5-diamino-4-hydroxy-6-(2'-deoxyribosyl)-formamidopyrimidine from 2'-deoxyguanosine in aqueous solution irradiated with 60Co gamma-rays.

2'-Deoxyguanosine in aqueous solution (5 x 10(-4) mol/dm3) was irradiated with 60Co gamma-rays under N2O. Products were separated by gel chromatography (Cellulofine GC-15-m) and high performance liquid chromatography (Inertsil ODS-2). 2-Amino-4-hydroxy-5-formamido-6-(2'-deoxyribosyl)-aminopyrimidine was one of the main radiolytic products. The formation of 2,5-diamino-4- hydroxy-6-(2'-deoxyribosyl)-formamidopyrimidine was detected, this compound being verified by measuring its ultraviolet absorption spectrum and analyzing its trimethylsilylated derivative by gas chromato-mass spectrometry. Its yield in terms of 2-amino-4-hydroxy-5-formamido-6-(2'-deoxyribosyl)- aminopyrimidine was 1:3.

Chromatography, Gel↗
PubMed1993

A brief history of Indian alchemy covering pre-Vedic to Vedic and Ayurvedic period (circa 400 B.C.-800 A.D.).

History of Indian alchemy can be traced to pre-Vedic period. The archaeological excavations at Mohenjodaro and Harappa in the Indus valley have brought to light that, the people in ancient India were possessing chemical knowledge as early as in the pre-historic period. In Vedic period single herbs were prescribed. Minerals and animal substances were also prescribed but no compound preparations were in use. Alchemy in India, was started for the preparation of an elixir of life for imparting immortality and later for the transmutation process for converting base metals into gold. Indian alchemy derived its colour and flavour to a large extent from the Tantric cult. Then, during the iatro-chemical period all the previous accumulated alchemical ideas were put into something more practical and tangible. a number of preparations of mercury and other metals were evolved as helpful accessories in medicine. Here a bried history of this Indian alchemy is presented which will give an idea about the development of chemical knowledge in India in its multiple aspects.

Alchemy↗
PubMed1993

[Experimental study of poisoning of goats with Pergularia tomentosa L].

A large number of ruminants are often lost in Niger due to poisoning caused by Pergularia tomentosa L. This plant traditionally used to tan skin was experienced in goats. The symptoms observed, the post-mortem findings and the search for toxic compounds suggest that P. tomentosa contains tannins. In addition, this plant most likely also includes substances with cardiac effects.

Animals↗
PubMed1993

Breast-feeding and the risk of life-threatening rotavirus diarrhea: prevention or postponement?

PURPOSE: To assess the relationship between breast-feeding and the risk of life-threatening rotavirus diarrhea among Bangladeshi infants and children younger than 24 months of age. DESIGN: Case-control study. SETTING: A rural Bangladesh community. PARTICIPANTS: One hundred two cases with clinically severe rotavirus diarrhea detected in a treatment center-based surveillance system during 1985 and 1986, and 2587 controls selected in three surveys of the same community during the same calendar interval. OUTCOMES: Cases and controls were compared for the frequency of antecedent breast-feeding patterns. RESULTS: Compared with other feeding modes, exclusive breast-feeding of infants was associated with significant protection against severe rotavirus diarrhea (relative risk (RR) = 0.10; 95% confidence interval [CI] = 0.03, 0.34). However, during the second year of life, the risk of this outcome was higher in breast-fed than in non-breast-fed children (RR = 2.85; 95% CI = 0.37, 21.71), and no overall protection was associated with breast-feeding during the first 2 years of life (RR = 2.61; 95% CI = 0.62, 11.02). CONCLUSIONS: Although exclusive breast-feeding appeared to protect infants against severe rotavirus diarrhea, breast-feeding per se conferred no overall protection during the first 2 years of life, suggesting that breast-feeding temporarily postponed rather than prevented this outcome. While not detracting from efforts to promote breast-feeding to alleviate the burden of diarrhea due to nonrotaviral enteropathogens, our findings cast doubt on whether such efforts will impact on the problem of severe rotavirus diarrhea.

Bangladesh↗
PubMed1993

DNA diagnosis of fatal fructose intolerance from archival tissue.

Hereditary fructose intolerance is a recessively-transmitted disorder of metabolism caused by deficiency of aldolase B in the liver, intestine and kidney, that responds favourably to an exclusion diet. The occurrence of fatal hepatorenal failure in a 16-year-old girl, who had received infusions of fructose and sorbitol during minor surgery, led us to suspect that she had suffered from hereditary fructose intolerance. Molecular analysis of leucocyte DNA obtained from her brother who had had a long-standing aversion to fruit and sugar, showed two previously unknown mutations in the aldolase B gene. An initiation codon mutation, M-1T, was inherited from the father, whereas Y203X, inherited from the mother, is a nonsense mutation that replaces a tyrosine codon by the ochre termination signal. The only source of genomic DNA from the index case was a fixed fragment of necrotic liver that had been obtained by needle aspiration postmortem and was embedded in paraffin wax. Analysis of aldolase B genes in this sample by procedures based on the polymerase chain reaction (PCR) confirmed the presence of both mutations in the proposita, the diagnosis of hereditary fructose intolerance, and the cause of death.

Adolescent↗
PubMed1992

Production and characterization of a monoclonal antibody to dopamine D2 receptor: comparison with a polyclonal antibody to a different epitope.

A monoclonal antibody (Mab) that recognizes the rat dopamine D2 receptor (DAR) has been generated using DAR specific peptide. The Mab, IgM isotype recognizes five proteins (Mr 220, 145, 95, 66 and 47 kDa) in striatal membrane on Western blot. Preincubation of Mab with free peptide blocked the labeling of all five bands. A polyclonal antibody against peptide from a different region of the DAR, reacted with three out of five proteins (220, 66, and 47 kDa) in these membranes. The DAR antagonist NAPS-biotinyl binds to a 220 kDa protein in striatal membrane on ligand blotts; the labeling can be blocked by the addition of 2 microM sulpride. The 220 kDa Mab reactive protein was less in cerebellum and was absent in the liver. Neither the Mab nor polyclonal antibody inhibited binding of a DAR antagonist, [3H]YM09151-2, to the striatal membranes. These antibodies will enable us to study the structure/function and regulation of the synthesis of DAR protein.

Amino Acid Sequence↗
PubMed1992

Genetic diagnosis of Gaucher's disease.

The inherited disorder Gaucher's disease can be caused by various mutations in the glucocerebrosidase gene. Some mutations may be associated with greater severity, and there is a need for methods of gene analysis that would facilitate screening and diagnosis. We have studied the molecular basis of Gaucher's disease in twelve unrelated patients of diverse ethnic origin by means of the amplification refractory mutation system (ARMS). Primers for the polymerase chain reaction were designed to discriminate between mutant and wild-type alleles of glucocerebrosidase and to allow separation from products of the related pseudogene. The nucleotide 1226 mutation (asparagine 370----serine) and 84GG (an insertional frameshift mutation) were found exclusively in five patients of Ashkenazi Jewish descent (7 and 2 of the 10 disease alleles, respectively). Two point mutations, at nucleotides 1448 (leucine 444----proline) and 1504 (arginine 463----cysteine), were found in 4 and 3 alleles, respectively; they were associated with rapidly progressive disease and neurological involvement in non-Jewish patients. The ARMS procedure for direct detection of common mutations in glucocerebrosidase will facilitate genetic counselling and screening programmes for individuals at risk of Gaucher's disease.

Adolescent↗
PubMed1992

Identification of human, mouse, and rat retinoic acid receptor alpha using monoclonal antibodies.

Monoclonal antibodies that recognize the human, mouse, and rat retinoic acid receptor alpha (RAR alpha) protein have been generated using synthetic peptides. Less well-characterized monoclonal antibodies were also generated against the RAR beta and RAR gamma proteins. Monoclonal antibodies of the IgG1 (R alpha 10) and IgG2a (R alpha 13) isotypes effectively and specifically recognize both the human and mouse RAR alpha protein. Preincubation of the antibodies with the synthetic RAR alpha peptide, but not with the RAR beta or RAR gamma peptides, blocked recognition of the approximately 55 kDa RAR alpha protein on western blots. These monoclonal antibodies also detected differing levels of RAR alpha in various rat tissues. These monoclonal antibodies will serve as powerful reagents to study the structure and regulation of the retinoic acid receptor protein.

Amino Acid Sequence↗
PubMed1992

Identification of a generalised packaging sequence for D-type retroviruses and generation of a D-type retroviral vector.

In order to construct vectors based upon D-type, rather than C-type, retroviruses, we have identified a 624-bp fragment of Mason-Pfizer monkey virus (MPMV) which constitutes a packaging sequence for at least two D-type retroviruses. When this fragment was included in an extensively deleted D-type vector genome, the D-type viruses MPMV and SRV-5, but not the C-type viruses MLV-A or MLV-E, rescued the vector RNA from HeLa cells. The recombinant virus stocks have the host range of the rescuing D-type virus as shown by expression of an internal (SV40-puromycin) cassette replacing the retroviral structural genes. The recombinant MPMV was specifically neutralized by anti-MPMV serum and receptor interference was demonstrated when it was plated on cells productively infected with wild type MPMV. When the putative D-type packaging sequence was removed from the vector genome, even though the other sequence elements required for efficient reverse transcription remained, the vector was no longer rescued from HeLa cells. These results complement the recent demonstration of broad specificity of rescue of a C-type vector (carrying only the packaging sequence of Mo-MLV) by several different C-type, but not D-type, viruses. Replacement of the D-type packaging sequence by most of the extended packaging sequence of Mo-MLV prevented the otherwise D-type vector from being rescued by D-type viruses and did not allow it to be rescued by C-type viruses. This was probably because of the incompatibility of the D-type vector sequences with the C-type retroviral proteins involved in viral reverse transcription and integration. Hence, we have localized a packaging sequence that is recognized by D-type, but not by C-type, retroviruses and have constructed a D-type vector which may be useful in gene transfer experiments.

Betaretrovirus↗
PubMed1992

Uridine and cytidine nucleotide synthesis in renal hypertrophy: biochemical differences in response to the growth stimulus of diabetes and unilateral nephrectomy.

The effects of unilateral nephrectomy (UN) and streptozotocin (STZ) diabetes on the activities of enzymes involved in uridine and cytidine synthesis in early renal growth (3-14 days after stimulus to growth) have been compared. Measurements were also made of glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) and of glucose 6-phosphate (G6P), UDP-glucose, and glycogen, in relation to phosphoribosyl pyrophosphate, ribonucleotide, and complex carbohydrate formation. There were striking differences in the activities of CTP synthetase, G6PDH, and 6PGDH in the two conditions, with a three-fold increase in all three enzymes at 3 and 5 days and a two-fold increase above basal values at 14 days of STZ diabetes. The UN group showed no significant change in CTP synthetase at any stage and the activity of G6PDH and 6PGDH only kept pace with renal growth. Changes in routes of uridine synthesis were less marked, with a more rapid rise in carbamoyl-phosphate synthetase (glutamine) and a lesser response of dihydroorotate dehydrogenase in the UN relative to the STZ-diabetic groups. The enzymes of complex II and of uracil phosphoribosyltransferase showed essentially similar patterns during renal hypertrophy in UN and STZ diabetes. The parallel increase in CTP synthetase, G6PDH, and 6PGDH in the kidney in diabetes, also known to increase in growth situations in hepatomas and in renal tumors, is discussed in relation to hormone signals involved in renal growth. The importance of the concentration of CTP, and thus of CTP synthetase, in the CTP-cytidyltransferase reaction, an enzyme with a high Km for CTP, makes the present observation of the striking increase in CTP synthetase in STZ diabetes of particular interest in relation to phosphatidylcholine formation and hormone signal transduction.

Animals↗
PubMed1992

Histopathological evidence of protective action of garlic against collagen and arachidonic acid toxicity in rabbits.

Soluble rat tail tendon collagen produced respiratory distress, agitation, convulsions and finally death in rabbits when infused intravenously (i.v.) in lethal doses. Similar observations were noted when a lethal dose of arachidonic acid (unsaturated essential fatty acid) was infused. These agents caused thrombocytopenia, indicative of in vivo platelet aggregation, hypotension and increased levels of thromboxane (TX) B2 (a stable metabolite of TXA2) in the plasma. Histopathological examination of lung, heart and liver tissue indicated that the lungs and livers of treated animals were adversely affected, while heart tissues appeared to be normal. Histopathological examination of lung and liver tissues of animals pretreated with garlic, then treated with a lethal dose of collagen or arachidonic acid showed a significant reduction in the damage observed compared to animals not pretreated with garlic.

Animals↗
PubMed1992

Modification of liver and serum enzymes by paraquat treatment in rabbits.

Paraquat (PQ) is known to cause progressive interstitial fibrosis in the lungs. Previous investigations have indicated that PQ acts by lipid peroxidation of the membrane. However, there are few reports on the action of PQ on hepatic enzymes. This work was carried out to investigate the modulation of various hepatic enzymes by PQ in rabbits. Paraquat was administered at a dose of 3, 6 or 12 mg/kg b. wt/day intraperitoneally to male rabbits for different periods of time. Administration of paraquat resulted in a significant decrease in plasma activities of transaminase enzymes, alkaline phosphatase and liver transketolase. No significant change was found in the activities of plasma and hepatic lactate dehydrogenase and alkaline phosphatase. A marked increase in blood glucose was noticed 48 hours after paraquat administration.

Alanine Transaminase↗