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G Ahmad

Publications and source records attributed to G Ahmad.

At least 19 recordsLinked to original sources
PubMed2004

Partial purification and characterization of Gigantocotyle explanatum somatic antigens.

Soluble extracts of Gigantocotyle explanatum, isolated from the liver of buffalo Bubalus bubalis were fractionated on Sephadex G-200 columns. Nine major fractions referred to as F1, F2, F3, F4, F5, F6, F7, F8 and F9 were separated. Each fraction was tested by ELISA for antigenicity using sera from G. explanatum-infected field buffaloes. Fractions F1 and F2 were highly antigenic, F3, F4, F6 and F7 were moderately antigenic and F5, F8 and F9 were poorly antigenic. Analyses by SDS-PAGE revealed that each fraction comprised several polypeptide(s) in the molecular weight range of <29 to >205 kDa. Results of Western blotting indicated that not all polypeptides which appeared in the SDS-PAGE were antigenic. The antigenic molecules of each fraction were mostly in the low molecular weight range of <14 to >94 kDa with the polypeptides in the range of >14, 14, 18, 21-25 and 34-36 kDa.

Animals↗
PubMed2001

Analysis of potential antigens of protoscoleces isolated from pulmonary and hepatic hydatid cysts of Bubalus bubalis.

The aqueous soluble proteins of the protoscoleces of Echinococcus granulosus isolated from the pulmonary and hepatic hydatid cysts of Bubalus bubalis were partially purified on Sephadex G-200 column. The isolated fractions were tested for their antigenicity by immunodot using the sera collected from experimentally infected puppies during the prepatent period of infection. Six protein profiles (F1-F6) were recovered from both the isolates but the polypeptide recovery of each fraction of the two isolates were some what different, particularly protein concentration of F5 in the liver isolate was greater than the lung isolate. Contrary to this, the concentration of F1 polypeptides of the lung origin protoscoleces is greater as compared to that of the liver. In addition, some antigenic dissimilarity has also been observed in the two isolates. A weak IgG response against F1, F2 and F6 polypeptides was observed in the 4th day post infection (p.i.) sera. With the age of infection the response against these antigens increased as revealed by the intensity of the spot in immunodot analysis. Our studies show that the differences in the elution profile and antigenic profile of the lung and liver isolates, as revealed by gel filtration and immunodot analysis, might be either due to the influence of the microhabitat or these may be two different strains. Further studies are certainly required in this direction.

Animals↗
PubMed2000

Partial purification and characterization of Gastrothylax crumenifer somatic antigens.

The soluble extracts of Gastrothylax crumenifer isolated from the rumen of buffalo (Bubalus bubalis) were fractionated on a Sephadex G-200 column. A total of eight major fractions (F1, F2, F3, F4, F5, F6, F7, and F8) were separated from the whole homogenate of G. crumenifer, and each of these fractions was tested for their antigenicity by ELISA against rabbit hyperimmune sera. It was observed that F1, F2, F3 and F4 were highly antigenic, F6 and F7 were moderately antigenic and F5 and F8 were poorly antigenic. The individual fractions analysed after SDS-PAGE and Western blotting indicated that the antigenic fractions of G. crumenifer are of low molecular weight, in the range of <14-50kDa, and predominant antigenic components which were evident in most of the Sephadex profiles were of Mr 15, 18, 19, 23-24 and 28-32kDa.

Animals↗
PubMed2000

Analysis of excretory-secretory and somatic antigens of Gastrothylax crumenifer.

The excretory/secretory (ES) metabolic products released by Gastrothylax crumenifer (Trematoda: Digenea) during in vitro incubations and the somatic extract of the adult parasite were analysed using polyacrylamide gel electrophoresis (PAGE). Immunogenicity of ES and somatic extracts were evaluated by immunoblotting and ELISA using sera raised against ES and somatic antigens in rabbits. The electropherograms of ES and somatic extracts have been resolved into 38 and 41 polypeptides, respectively. The apparent molecular weights of these polypeptides range from < 29 to > 205 kDa. A total of 14 polypeptides were found to be common to both of the samples. The analysis of immunoblot results revealed 22 and 27 antigenic polypeptides in ES and somatic extracts respectively. Only 11 and 13 antigenic polypeptides were found specific to ES and tissue extract respectively. The molecular weights of these specific polypeptides were calculated to be < 14.4, 16, 20, 25, 33, 42, 119, 125 and > 205 kDa for metabolic products and < 14.4, 25, 30, 35, 78, 84 and > 205 kDa for the tissue extracts, respectively. Analysis of ELISA results revealed that a dilution of up to 1:3200 of the test sera could react with the ES product. Further, when the ES antigens were allowed to react with antisomatic extracts in hyperimmune sera the titre of IgG increased up to a dilution of 1:12800. The potential importance of these antigens in the immunodiagnosis of amphistomiasis is discussed.

Journal Article↗
PubMed2000

Analysis of excretory-secretory and somatic antigens of Gastrothylax crumenifer.

The excretory/secretory (ES) metabolic products released by Gastrothylax crumenifer (Trematoda: Digenea) during in vitro incubations and the somatic extract of the adult parasite were analysed using polyacrylamide gel electro-phoresis (PAGE). Immunogenicity of ES and somatic extracts were evaluated by immunoblotting and ELISA using sera raised against ES and somatic antigens in rabbits. The electropherograms of ES and somatic extracts have been resolved into 38 and 41 polypeptides, respectively. The apparent molecular weights of these polypeptides range from <29 to > 205 kDa. A total of 14 polypeptides were found to be common to both of the samples. The analysis of immunoblot results revealed 22 and 27 antigenic polypeptides in ES and somatic extracts respectively. Only 11 and 13 antigenic polypeptides were found specific to ES and tissue extract respectively. The molecular weights of these specific polypeptides were calculated to be <14.4, 16, 20, 25, 33, 42, 119, 125 and > 205 kDa for metabolic products and <14.4, 25, 30, 35, 78, 84 and > 205 kDa for the tissue extracts, respectively. Analysis of ELISA results revealed that a dilution of up to 1:3200 of the test sera could react with the ES product. Further, when the ES antigens were allowed to react with antisomatic extracts in hyperimmune sera the titre of IgG increased up to a dilution of 1:12800. The potential importance of these antigens in the immunodiagnosis of amphistomiasis is discussed.

Animals↗
PubMed1999

Effects of lead on the male reproductive system in mice.

The effect of environmental lead on the male reproductive system has been a major area of concern for several years. Lead toxicity to the male reproductive system of sexually mature male CF-1 mice was investigated by administering two concentrations of lead (0.25% and 0.5%) via drinking water for 6 wk. The low lead dose significantly reduced the number of sperm within the epididymis, while the high dose reduced both the sperm count and percentage of motile sperm and increased the percentage of abnormal sperm within the epididymis. There was no significant effect on testis weight; however, the high-dose treatment significantly decreased the epididymis and seminal vesicle weights as well as overall body weight gain. Plasma luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone (T) levels were not affected by lead administration indicating that in adult male CF-1 mice, lead targets testicular spermatogenesis and sperm within the epididymis to produce reproductive toxicity rather than acting at other sites within the hypothalamic-pituitary-testicular axis.

Administration, Oral↗
PubMed1999

Cost effectiveness evaluation of the Ministry of Health Malaysia dialysis programme.

We determine the cost effectiveness of centre and home haemodialysis (HD), continuous ambulatory peritoneal dialysis (CAPD) and intermittent peritoneal dialysis (IPD) treatment in the Ministry of Health (MOH) programme. The viewpoint taken for this evaluation is that of MOH. Cost categories identified were capital cost, dialysis operational cost, medical cost and general hospital cost. Cost estimates were mostly based on actual resource utilisation. Life years saved were estimated based on Dialysis Registry data on 2480 HD and 732 CAPD patients. Overall, the cost-effectiveness ratio (CER) of centre HD was RM21620/life year saved. Those of home HD, CAPD and IPD were RM23375, RM30469 and RM36016 respectively. Sensitivity analyses did not change the ranking of the CER. We conclude the MOH dialysis programme was cost-effective, and among the various dialysis modalities centre HD was the most cost-effective.

Adult↗
PubMed1999

Outcome assessment of the Ministry of Health Malaysia dialysis programme.

We describe the outcomes on haemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) provided by the Ministry of Health (MOH). The assessment was based on data from the Malaysian Dialysis Registry on 2480 HD and 732 CAPD patients who commenced dialysis between 1980 and 1996. Young patients (age < 40) have remarkable long term survival (life expectancies of 16 years on HD, 18 years on CAPD). Adjusting for background mortality, relative survival of older patients was as good as younger ones. Diabetics did poorly. 52% of HD and 26% of CAPD patients were employed in 1996. 71% of HD patients scored 10(normal) on QL index (a measure of quality of life) while 60% of CAPD patients have similar score. Differences in rehabilitation and QL index scores by age, gender and diabetes were also observed. Outcomes of dialysis in the MOH programme are reassuring.

Adult↗
PubMed1998

Coproantigens: early detection and suitability of an immunodiagnostic method for echinococcosis in dogs.

In the present study immunodiagnostic tests for Echinococcus granulosus-specific coproantigens have been evaluated. The techniques are based on polyclonal antisera collected from dogs experimentally infected with E. granulosus protoscoleces. ELISA, Countercurrent immunoelectrophoresis (CCIEP) and Immunodot were evaluated for their application in coprodiagnosis. The level of coproantigens was detectable on day 7 post-infection and reached a maximum level on day 56 as detected by ELISA. Very high O.D values were obtained when faecal samples of 7-8 weeks post-infection were used. Besides this, immunodot and CCIEP were also tested and the 4th week post-infection samples gave significant reactions. It is evident from the results that ELISA was more sensitive and detected the coproantigens as early as the first week post-infection whereas immunodot and CCIEP detected coproantigens later. The latter methods are rapid, cost-effective and can be used to diagnose suspect cases of echinococcosis under field conditions. Thus, it is suggested that future studies should be aimed at early detection of echinococcosis by a rapid and cost-effective immunodot test.

Animals↗
PubMed1998

The anti-stress activity of a gem-containing Unani formulation against diverse stressors.

Drugs of mineral origin, especially gems, are extensively used in Tibb-e-Unani (Unani Medicine), both as single drugs and as compound formulations. But such drugs have not yet been adequately studied scientifically. Jawahir Mohra (JM) is one such, as yet unstudied, anti-stress Unani preparation, containing a few herbal and animal ingredients also. Therefore in the present study, a modified JM preparation was investigated for its anti-stress activity against physical, chemical and metabolic stimuli. The non-gem complement (NGC) of JM was also studied for action against physical stress. In albino rats stressed by swimming and subsequently tested for motor function by Rota rod (muscle coordination), activity wheel (forced motor activity) and photoactometer (spontaneous motor activity), JM treatment for 7 days produced a striking and significant increase in activity. The NGC also increased the activity significantly which was however less than JM. JM also produced a striking increase in cold swimming endurance and in the latency of post-anoxia convulsions, while pentylentetrazol (PTZ)-induced defecation and urination in an open field arena under continuous stimulation by intense light and sound was significantly decreased. Therefore, the present investigation indicates that the gem-containing Unani compound JM has significant anti-stress activity of a non-specific type against diverse stressors. This could be due to adaptogenic activity of the preparation. The study also shows that the gems in JM contribute significantly to its anti-stress activity.

Adaptation, Physiological↗
PubMed1995

Characterization of human platelet IgG Fc receptor associated with membrane glycoprotein.

Human platelets express IgG Fc receptors (Fc gamma R). Previously we reported that circulating immune complexes (CIC) inhibited fibrinogen binding to platelet glycoprotein IIb/IIIa complex (GPIIb/IIIa) and that isolated Fc gamma R were recognized by monoclonal antibodies (mAb's) to GPIIb and GPIIIa (J.Lab. Clin. Med. 117:209-217, 1991). In this study, we further characterized the properties of the Fc gamma R and the activity associated with GPIIb/IIIa. Binding of Fc portion of human IgG (Fc) to the platelet Fc gamma R associated with GPIIb/IIIa complex, unlike fibrinogen receptor, did not require divalent cations. The Fc gamma R bound to immobilized immune complex were recognized by mAb's to GPIIb, GPIIIa, GPIIb/IIIa. Preincubation of platelet extract with fibrinogen inhibited the binding of heat-aggregated IgG (HAG) to the extract. Flow cytometry of whole platelets revealed inhibition of mAb binding to GPIIb/IIIa, when platelets were incubated with Fc fragments or HAG. Using platelet extract coated to microtiter plates, similar findings were noted with Fc and HAG. The dissociation of GPIIb/IIIa complex by incubating platelet extract at 37 degrees C in the presence of EDTA caused a marked decrease in the binding of GPIIb and GPIIIa to the immobilized immune complex. Activation of intact platelets with ADP resulted in an increased binding of HAG to the platelets, indicating that an augmented Fc gamma R activity is associated with the activation of GPIIb/IIIa. These results suggest a close relationship of the Fc gamma R activity to the fibrinogen binding site (GPIIb/IIIa complex).

Adenosine Diphosphate↗
PubMed1995

Human platelet Fc receptors: binding kinetics of Fc derivatives to the receptors.

Human platelets are known to carry Fc receptors (Fc R), but the binding characteristics between ligands and Fc gamma R has not been well elucidated. In this study, we investigated the binding kinetics of IgG Fc fragments (Fc) to Fc R, the association and dissociation characteristics of the ligands to and from Fc gamma R using enzymatically modified Fc fragment derivatives. Approximately 60 minutes and 90 minutes were needed at 37 degrees C and 22 degrees C, respectively, for complete saturation of the Fc binding sites with horseradish peroxidase-conjugated Fc (HPO-Fc). Heat aggregated IgG (HAG) had a greater affinity for the Fc gamma R than Fc monomers. Additional binding of HAG was observed even after the binding sites were saturated with Fc monomers. This could be explained by different binding sites available only for immune complexes or by the partial dissociation of binding sites saturated with Fc by HAG. Further, we noted partial dissociation of HPO-Fc, when HAG was added after saturation of the binding sites with HPO-Fc. In a subsequent experiment, we compared the relative affinities of chemically or enzymatically modified Fc derivatives for Fc gamma R. HAG, which was used as a model for CIC, had a greater affinity for platelet Fc gamma R than IgG monomer and Fc derivatives. Pepsin-digestion of Fc caused a total loss of its affinity for the Fc gamma R, whereas b-mercaptoethanol-treated Fc fragments demonstrated substantial binding to the Fc gamma R. These results indicate that the pepsin digestion affects the Fc portion and causes a disruption in the area of the Fc which is essential for the recognition by the platelet Fc gamma R. On the other hand, cleavage of disulfide bridges by beta-mercaptoethanol resulted in a marked increase in affinity for the Fc gamma R. On the other hand, enzymatic cleavage of the carbohydrate moieties of Fc did not alter the affinity of Fc fragments for the Fc gamma R, indicating that the carbohydrates play an insignificant role or are not involved in their binding to the Fc gamma R.

Binding Sites↗
PubMed1993

Urinary erythrocyte morphology as a diagnostic aid in haematuria.

The value of urinary erythrocyte morphology in diagnosing glomerular and nonglomerular haematuria was studied using phase contrast microscopy in 105 patients with significant haematuria. Fifty-eight (93.6%) out of 62 patients with glomerulonephritis had dysmorphic erythrocytes and 40 (93.1%) out of the 43 patients with nonglomerular disease had isomorphic erythrocytes in the urine. A mixed picture of glomerular and nonglomerular haematuria was seen in 5 patients. The sensitivity was 93.6%, the specificity was 97.7% and the positive predictive value was 98.3% for glomerulonephritis in patients with dysmorphic haematuria. The positive predictive value for a nonglomerular source of bleeding was 96.7% with isomorphic haematuria. It is concluded that phase contrast microscopic examination of erythrocytes in urine is a simple, inexpensive and noninvasive technique that reliably distinguishes between glomerular and nonglomerular bleeding in patients.

Erythrocyte Count↗
PubMed1990

Cerebral ornithine decarboxylase levels following gestational exposure to cocaine.

The pre- and postnatal developmental course of cerebral ornithine decarboxylase (ODC) has been studied in infant rats after treatment of pregnant dams with cocaine. Levels of cocaine attained in brains and serum of embryos were not initially increased over corresponding maternal values, but were more persistent. However, cocaine was not longer detectable in these tissues 4 days after administration. The cerebral ODC level of treated pups was initially depressed and subsequently elevated relative to control values. These changes were apparent at times when cocaine was not detected in the developing brain. Results indicate that a transient exposure to cocaine in utero may lead to prolonged developmental abnormality.

Aging↗
PubMed1989

Effects of gestational exposure to phencyclidine: distribution and neurochemical alterations in maternal and fetal brain.

Phencyclidine is a widely used drug of abuse and is known to produce a wide variety of psychoactive effects. PCP abuse by pregnant women has been reported to result in the birth of infants exhibiting irritability, jitteriness and hyperactivity with high pitched cries. The present study was designed to evaluate the distribution of PCP in the maternal and fetal brain and the neurochemical effects produced by gestational exposure. Pregnant Sprague-Dawley rats were treated sc with 5 mg/kg PCP on 3 consecutive days (GD 9-11, 12-14, 15-16, or 18-20). On gestational day (GD) 21 all rats were killed by decapitation and maternal and fetal blood was collected for PCP analysis. Brains were dissected from dams and fetuses for PCP and neurochemical analyses. On GD 21 after exposure on GD 18-20, the fetal: maternal ratio of brain PCP concentrations was 11:1. PCP exposure on GD 12-14, 15-17, and 18-20 significantly decreased fetal brain PCP binding sites on GD 21, whereas maternal values were unchanged. Fetal dopaminergic and muscarinic cholinergic receptor binding and neurotransmitter concentrations were unaffected by prenatal PCP exposure. These data demonstrated that maternal PCP exposure resulted in prolonged exposure of the developing CNS and also indicated that gestational exposure to PCP decreased high affinity binding sites of PCP in term fetal brain.

Animals↗
PubMed1988

Gestational exposure to phencyclidine (PCP) in rats decreases PCP binding sites in term fetal brain.

Pregnant Sprague-Dawley rats were treated with 5 mg/kg body weight of phencyclidine (PCP) injected at 1 ml/kg subcutaneously on three consecutive days at four different stages of gestation. Within 10-30 min after treatment, dams showed some lack of motor coordination and became lethargic. On gestational day 21, all rats were killed by decapitation and brains were dissected and stored from mother and fetus for neurochemical analysis. PCP, dopamine and muscarinic cholinergic receptor binding was measured in membranes prepared from maternal and fetal whole brain. Neurotransmitter concentrations were also measured in the fetal brain homogenates. There was a significant decrease in PCP binding sites in fetal but not maternal brains after maternal PCP injection at gestational days 12-14, 15-17 and 18-20, but not at 9-11 days. Dopamine and muscarinic cholinergic receptor binding was not significantly altered in fetal or maternal brain when compared with vehicle control animals. The whole brain dopamine, 3,4-dihydroxyphenylacetic acid, serotonin, and 5-hydroxyindoleacetic acid concentrations did not show significant change in any group studied. These data indicate that gestational exposure to PCP decreases high affinity binding of PCP in term fetal brain at doses which do not alter maternal PCP receptor binding.

Animals↗
PubMed1987

Toxic effects of phencyclidine on developing chick embryo brain.

We studied the effects of Phencyclidine (PCP, Angel Dust) on the developing chick embryo brain. In Group-1, the eggs were injected with PCP on the 7th day of incubation and the embryo brains were studied on the 10th day. In Group-2, eggs were injected twice; first on the 7th day and then on the 10th day of incubation. Group-2 brains were then studied on the 16th day of incubation. PCP significantly depressed the development of embryo brains. Cerebral hemisphere weight, total protein and total DNA were significantly lower on day 10 of incubation in Group-1. Similar results were observed in Group-2. Concomitantly, the concentration of brain serotonin at day 10 was also significantly reduced when PCP was injected into the eggs on the 7th day of incubation. Since serotonin has been reported to influence development of the chick embryo brain, the present finding of the effect of PCP on brain development might be a secondary phenomenon. The possible implications of the effects of PCP on human brain development are also discussed.

Animals↗