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Biomedical subjects

T Hussain

Publications and source records attributed to T Hussain.

At least 73 records · Page 4Linked to original sources
PubMed1995

Rehabilitation of grade III protein energy malnutrition on out patients basis.

Malnutrition is an important yet preventable and curable cause of morbidity and mortality. One hundred and thirty-five children suffering from grade III Protein Energy Malnutrition (PEM) from a poor urban population of Karachi city were enrolled for rehabilitation by health education and growth monitoring as out patient. Of these, 89% showed satisfactory recovery during a mean follow-up period of 3.2 months. Mainstay of this study was simple health messages adapted according to local cultural practices in native language. This simple strategy can go a long way in prevention and treatment of PEM in all the developing countries.

Child Nutrition Disorders↗
PubMed1994

Regulation of adenosine receptor function by theophylline in rat aorta.

The effect of chronic theophylline treatment on adenosine receptor function was investigated in rat aorta. Male Wistar rats were fed theophylline (1 g/L) in drinking water for 30 days. The relaxation-response curves to various adenosine receptor agonists, nonselective 5'-N-ethylcarboxamidoadenosine (NECA), A2-selective 2-phenylaminoadenosine (CV-1808), and A1-selective N6-(2-endo-norbornyl) adenosine (S-ENBA) were generated in aortic rings from control and treated rats. The relaxation curves to both NECA and CV-1808 (10(-9)-10(-4) M) were significantly attenuated in treated rings (endothelium intact) as compared with control. S-ENBA showed a contraction at a lower concentration (10(-10)-10(-6) M) in treated rings as compared with control. Because S-ENBA is highly A1 selective, it produced relaxation only at 10(-4) M. Similar to that of adenosine analogues, the isoproterenol (ISO 10(-9)-10(-5) M) concentration-relaxation curve was shifted to the right in treated rats. Endothelium removal of the vascular rings decreased the magnitude of relaxation to these agonists and eliminated the difference in relaxation between control and treated groups. The relaxation to acetylcholine (ACh), an endothelium-dependent relaxing agent, was also attenuated in the theophylline-treated group. The relaxation responses to forskolin (10(-11)-10(-8) M) and sodium nitroprusside (SNP 10(-10)-10(-7) M) were unaltered in treated rats. These data suggest an endothelium-dependent downregulation of adenosine receptor function together with beta-adrenoceptor after chronic theophylline treatment.

Acetylcholine↗
PubMed1994

Regulation of G proteins by adenosine receptor agonist in coronary artery.

We have previously reported that prolonged exposure of coronary artery to 2-chloroadenosine (CAD) desensitizes the adenosine receptor without altering the beta-receptor-mediated response (Am. J. Physiol. 264 (Heart Circ. Physiol. 33): H441-H447, 1993). In the present study, alpha-subunits of guanine nucleotide binding proteins, stimulatory (Gs) and inhibitory (Gi), were measured using bacterial toxin-catalyzed ADP ribosylation along with a functional response to Gi protein (through muscarinic receptor activation) in the arteries treated with CAD. Isolated coronary arteries were incubated with and without CAD in culture media. CAD treatment (10(-4) M) resulted in a time-dependent (1, 3, and 7 days) attenuation in the cholera- and pertussis toxin-catalyzed ADP ribosylation of 45- and 41-kDa membrane proteins, respectively. Similarly, the 3-day treatment of the arteries with CAD (10(-8)-10(-4) M) produced a concentration-dependent decrease in cholera toxin-catalyzed ADP ribosylation of 45-kDa protein. Unlike cholera toxin, the alterations in ADP ribosylation of 41-kDa protein catalyzed by pertussis toxin was biphasic, an increase at lower concentration of CAD (10(-8)-10(-6) M) followed by a decrease at higher concentration of CAD (10(-5)-10(-4) M). The contraction-response curve to methacholine, a muscarinic receptor agonist, was significantly shifted to the left in the vascular rings treated with a low concentration of CAD (10(-6) M) while without an effect at high concentration (10(-4) M) of CAD. The data suggest that CAD exposure regulates the alpha-subunits of both Gs and Gi in coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

2-Chloroadenosine↗
PubMed1993

An in vitro pharmacological model of vascular smooth muscle.

In order to develop an in vitro model of vascular tissue for pharmacological studies, segments of porcine coronary arteries were incubated in culture media under sterile conditions in cell culture incubator at 37 degrees C with 95% O2 + 5% CO2. After 3 days of incubation, changes in isometric tension were measured in vascular rings and compared with the fresh tissue. KCl (10-75 mM) and prostaglandin F2 alpha (1-20 microM) produced a similar concentration-dependent contraction in the incubated and fresh arteries. The concentration-dependent relaxation curves produced by 2-chloroadenosine (10(-8) to 10(-4) M) and isoproterenol (10(-8) to 10(-5) M) were unaltered in the incubated tissue versus fresh. Similarly, the relaxation responses to forskolin and sodium nitroprusside (10(-8) to 10(-5) M) were unaffected in the incubated arteries. The relaxations produced by substance P (10(-12) to 10(-8) M) and bradykinin (10(-7) M)--the endothelium-dependent agents--were also unaltered in the incubated rings versus fresh. Therefore, we conclude that after the incubation of porcine coronary artery for 3 days, the contraction/relaxation responses to various agonists acting through different mechanisms were unaltered in porcine coronary artery. This in vitro model of vascular smooth muscle provides a potential for pharmacological and toxicological studies.

Animals↗
PubMed1993

Regulation of adenosine receptor system in coronary artery: functional studies and cAMP.

Regulation of the adenosine receptor system was investigated using a new in vitro model of porcine coronary artery after exposure to an adenosine receptor agonist. Isolated coronary arteries were incubated in the absence (control) and presence (treated) of 2-chloroadenosine (CAD) in culture media (pH 7.4) at 37 degrees C with 92.5% O2-7.5% CO2. CAD treatment led to a significant rightward shift in the relaxation responses to the adenosine receptor agonists CAD, 5'-(N-ethylcarboxamido)adenosine, and R-phenylisopropyladenosine. The shift was both concentration and time dependent and was maximum at 100 microM at 3 days. The relaxation responses to isoproterenol and sodium nitroprusside were unaltered under identical conditions. Forskolin-mediated relaxation was also shifted rightward in the treated group. The shift in CAD- and forskolin-mediated relaxation in the treated group was endothelium independent. On the other hand, isoproterenol (10 microM, 3 days) treatment produced a rightward shift in the relaxation response to isoproterenol, while the response to CAD was unaltered. In a separate set of experiments, CAD did not stimulate adenosine 3',5'-cyclic monophosphate (cAMP) accumulation in the treated arteries compared with control. However, NaF and forskolin stimulation of cAMP was markedly decreased in the treated group. Unlike these agonists, isoproterenol stimulation of cAMP was similar in both treated and control groups. The data suggest the desensitization of the adenosine receptor via regulation of stimulatory guanine nucleotide binding proteins without altering the beta-receptor-mediated responses in coronary artery.

2-Chloroadenosine↗
PubMed1992

Study of environmental pollutants in and around the city of Lahore, Pakistan. II. Concentrations of cadmium in blood of different groups of people.

Cadmium concentrations were measured in the whole blood of six different groups of persons living in and around the city of Lahore. The cadmium concentrations in the blood of normal persons of both sexes were distributed log normally. The values were lower among the young and increased gradually to reach a plateau at an average age of 45 years and then decreased. There was a trend of a gradual increase of cadmium blood concentrations with age in male industrial workers and female exposed groups. Cadmium-blood concentrations in cancer patients were significantly lower when compared to the rest of the groups, however no statistical correlation between Cd-blood concentration and age of cancer patients was observed.

Age Factors↗
PubMed1992

Pergolide can induce soluble superoxide dismutase in rat striata.

Pergolide, a dopamine receptor agonist, given daily i.p. for three weeks at 0.04 mg/kg and 0.4 mg/kg, significantly induced soluble (Cu-Zn) superoxide dismutase in the rat striatum, while having no effect on the mitochondrial (Mn) form of the enzyme. Such induction, which can also be effected by (-)-deprenyl, may help to protect against nigrostriatal degeneration.

Animals↗
PubMed1992

Effects of adenosine analogues on ADP ribosylation of GS protein in coronary artery.

The coupling of adenosine receptor(s) to G proteins was investigated in bovine coronary artery smooth muscle membranes. Western blotting of membrane proteins with specific antisera confirmed the presence of 45- and 52-kDa proteins as alpha-subunits of stimulatory (Gs) protein. Cholera toxin (CT) also ADP ribosylated 45- and 52-kDa proteins. Guanosine 5'-O-(3-thiotriphosphate) (10 nM to 10 microM) stimulated the CT-induced ribosylation, suggesting that the ribosylation can be modulated by the activation of G proteins. 2-Chloroadenosine and (R)-phenylisopropyladenosine produced a concentration (10(-7) to 10(-4) M)-dependent increase in CT-induced ribosylation. These responses were completely blocked by adenosine receptor antagonist 8-sulfophenyltheophylline (10 microM). 5'-(N-ethylcarboxamido)adenosine (NECA) alone or in the presence of 8-cyclopentyl-1,3-dipropylxanthine (50 nM) did not affect the ribosylation. Furthermore, NECA did not counter the effects of 2-chloroadenosine and isoproterenol on CT-induced ribosylation. The data provide evidence for the adenosine receptor(s) coupling to Gs proteins and further suggest a different site or mechanism for the action of NECA in bovine coronary artery.

2-Chloroadenosine↗
PubMed1992

Incidence of Aeromonas isolated from diarrhoeal children and study of some virulence factors in the isolates.

Stool samples from 305 children with diarrhoea and equal number of age and sex matched non-diarrhoeal control children, less than 5 years of age, were examined during the period from Sept 1988 to April 1989. Aeromonas spp. were isolated from 37 (12.1%) diarrhoeal and 05 (1.6%) control cases. Out of 37 diarrhoeal isolates 13 (35.1%) were A. hydrophila, 19 (51.1%) A. sobria and 05 (13.5%) A. caviae. All the isolated strains were tested for haem agglutination property and haemolysin production. Seventeen diarrhoeal and 05 control isolates were tested for cytotoxin production in He La cell line and enterotoxin production in rat ileal loop model and suckling mouse model. Chinese hamster ovary cell (CHO) assay and Gm-1 ELISA methods were also employed. Cytotoxin production was found in 82.5% of diarrhoeal and 40% of control isolates. Haemagglutination was found in 62.1% of Aeromonas isolated from diarrhoeal children and 20% from control children. Enterotoxin production was detected in 58.8% diarrhoeal and none of the control isolates by either of the methods. Of the virulence factors enterotoxin production was found to correlate well with enteropathogenicity but haemolysin, cytotoxin and haemagglutinin did not.

Aeromonas↗
PubMed1991

(-)-Deprenyl can induce soluble superoxide dismutase in rat striata.

(-)-Deprenyl (0.25 or 2 mg/kg) or saline was injected daily into male Wistar rats for 3 weeks. The striata were dissected out and soluble and particulate superoxide dismutase activity measured. (-)-Deprenyl at 2 mg/kg induced a significant increase in the soluble but not the particulate form of the enzyme. The possibility that this action contributes to the ability of (-)-deprenyl to retard nigral degeneration in man and prolong life in rats is discussed.

Animals↗
PubMed1991

Effect of supplementary feeding of pregnant women on birth weight of the new born.

A supplementary food mix was prepared from roasted peanut, chickpea and sugar. The effect of this food mix on birth weight was tested on a group of rural women of low socioeconomic group in few villages in Peshawar District of NWFP. A 100 g supplementary food mix providing 16.7 g protein and 520 K.Cal of energy was given daily to a group of mothers in their third trimester, until the time of delivery. Another group of pregnant women acted as control. The results indicaed a high maternal weight gain in the supplemented group. Moreover the birth weight, length, head and chest circumference of the new born in the supplemented group was also significantly higher as compared to control group.

Adult↗
PubMed1991

G proteins subserve relaxations mediated by adenosine receptors in human coronary artery.

The coupling of the human coronary adenosine receptor to a G protein was investigated in vitro. Hearts were obtained from accidental death victims and the left anterior descending coronary artery (LAD) was taken for experimentation. Cholera toxin (CT) and pertussis toxin (PT) ADP-ribosylated proteins with Mr of 45, 49 (CT), and 41 (PT) kDa. Both processes were sensitive to GTP gamma S. In LAD rings contracted with KCl, adenosine (ADO) and its analogs 5'-N-ethylcarboxamidoadenosine (NECA) and 2-chloroadenosine (CAD) produced concentration-dependent relaxation. These concentration-response curves were shifted to the right significantly in the presence of the competitive ADO receptor antagonist, 8-phenyltheophylline (8-PT), indicating the involvement of ADO receptors. Treatment with NaF/AlCl3, which uncouples G protein-mediated responses, caused significant attenuation of the relaxation responses to ADO, NECA, and CAD. When the rings were incubated with CT, there was an attenuation of the relaxations produced by ADO, CAD, NECA, and isoproterenol (ISOP). Incubation with PT resulted in significant inhibition of the relaxations induced by ADO, NECA, and CAD. The results provide evidence for the presence of CT- and PT-sensitive G protein(s) subserving the relaxing adenosine receptors in human coronary artery.

Adenosine↗
PubMed1990

Study of environmental pollutants in and around the city of Lahore. I. Determination of lead in blood of various population groups.

Lead concentrations in 102 blood samples collected from seven different population groups living in and around the city of Lahore were determined. Gender differences in blood lead were statistically insignificant for normal males and normal females and also for male and female cancer patients. The differences between exposed male industrial workers and exposed females were statistically significant (P = 0.05). No correlation was observed between age and blood lead for normal males and cancer patients of both sexes. Blood lead levels in the male groups were generally higher than in the corresponding female groups. Much higher blood lead concentrations for cancer patients of both sexes, i.e. 69.63 microgram dl-1 for males and 52.41 microgram dl-1 for females, were observed.

Age Factors↗
PubMed1990

Special properties associated with virulence of urinary Escherichia coli.

Escherichia coli (E. coli) isolated from 53 urine and 26 stool samples of patients with urinary tract infection (UTI) and 50 stool samples of normal individuals were studied to see their hemolytic, hemagglutinating and 'O' antigenic properties which might be related to virulence of the organism. Significantly higher number of E. coli isolated from urine of UTI patients were found to possess hemolytic, hemagglutinating properties and more frequently belonged to certain "O" antigenic groups either singly or in combination as compared to those isolated from stool of both UTI patients and normal individuals. Hemagglutinating property appeared to be most frequently associated with UTI.

Escherichia coli↗
PubMed1990

Evaluation of co-agglutination (COA), counter immunoelectrophoresis (CIE), culture and direct microscopic (Dm) examination of cere-brospinal fluid (CSF) for detection of meningitis caused by common bacterial pathogens.

Cerebrospinal fluid from 260 children clinically diagnosed as meningitis were examined by Dm, culture, COA and CIE test. Dm revealed the presence of bacteria in 41 (15.8%) whereas culture showed growth of organism in 52 (20%) cases. COA and CIE test were done for the detection of antigen of H. influenzae, S. pneumoniae and N. meningitidis. Among the 3 methods viz. culture, COA and CIE test which were used for the detection of the above three organisms COA detected the maximum numbers (23.5%). COA test could detect antigen in both culture positive and culture negative CSF samples. COA test detected 100% of pneumococcal, 88.5% of H. influenzae and 66.7% of N. meningitidis antigens from CSF. Diagnosis by CIE in detecting H. influenzae and N. meningitidis antigens is inferior to culture and COA, whereas in detecting pneumococcal antigens CIE is superior to culture. So COA is a valuable, cheap, rapid and sensitive method for the diagnosis of meningitis caused by the above three organisms and when used along with culture 100% of cases can be diagnosed.

Agglutination Tests↗
PubMed1989

Glutathione peroxidase and catalase in liver, kidney, testis and brain regions of rats following cadmium exposure and subsequent withdrawal.

Intraperitoneal administration of 0.4 mg/kg Cadmium (Cd) daily for 45 days was found to inhibit the activities of glutathione peroxidase and catalase in liver, kidney, testis and various brain regions at different time intervals. The magnitude of inhibition was increased with the period of exposure. Cd produced significant inhibition of glutathione peroxidase at 15 days in liver, kidney and cerebellum only; however, the enzyme activity was found to be decreased in all the tissues, except corpus striatum, at 30 and 45 days of exposure. Hippocampal glutathione peroxidase remained unaltered throughout the experiment. Catalase was found to be inhibited in all the tissues at different time intervals. The withdrawal of Cd treatment for 15 days after 45 days of exposure did not show significant recovery in the activity of both enzymes of different organs, except kidney and testis where partial and full recoveries respectively were observed. Since these two enzymes constitute an important part of cellular defence mechanism against oxidation, their widespread persistent inhibition may be of great significance in view of the recent reports showing the possible involvement of oxidative stress in the mechanism of Cd toxicity.

Animals↗