Search PubMed⌕ Search

Biomedical subjects

S Hussain

Publications and source records attributed to S Hussain.

At least 73 records · Page 4Linked to original sources
PubMed1999

Demographic aspects of hepatitis C in northern Pakistan.

OBJECTIVE: To find out the prevalence of hepatitis C in various, age, sex and ethnic groups in Pakistan. SETTING: Specimens obtained from military/civil hospitals and General Practitioners of Rawalpindi Islamabad, region and other areas of Northern Pakistan, in vicinity. SUBJECTS: Serum of 1710 patients of hepatitis C, diagnosed at Armed Forces Institute of Pathology (AFIP), Rawalpindi between 1st July 1996 and Dec 31, 1997, tested for Anti HCV by 3rd generation Murex Elisa. Required information was collected on a proforma filled for each patient. RESULTS AND CONCLUSION: The majority of the cases were between 30-60 years of age. There was male preponderance. The infection was more common in Urdu speaking fraction of the patients as compared with others.

Adolescent↗
PubMed1999

Quranic description of gametes.

There are several important characteristic properties of reproductive fluid. Gametes are the reproductive cells consisting of sperms in males and ovum in females. These cells combine to form Zygote in the process of fertilization. The characters of Gametes have been narrated by Holy Quran in a very well-suited and selected terminology. This paper enumerates various Quranic terms related to gametes, and then discusses their scientific significance.

Arab World↗
PubMed1998

Effect of acute exposure to 3-nitropropionic acid on activities of endogenous antioxidants in the rat brain.

The response of endogenous antioxidants to acute exposure of the mitochondrial inhibitor, 3-nitropropionic acid (3-NPA), was investigated in selected rat brain regions. Rats treated with 3-NPA (30 mg/kg, s.c.) were sacrificed at 30, 60, 90 and 120 min after injection to examine the alterations in reduced glutathione levels (GSH), and activities of antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) in the hippocampus (HIP), frontal cortex (FC), and caudate nucleus (CN). CAT activity increased in the HIP 90 min after 3-NPA treatment. While cytosolic copper/zinc SOD (CuZn-SOD) and mitochondrial manganese SOD (Mn-SOD) levels increased in the FC at 120 min, only the Mn-SOD increased in the CN 90 min after treatment. The activity of GPx decreased in the HIP 120 min after 3-NPA injection. When compared with the control, administration of 3-NPA led to GSH depletion in HIP within 120 min. The depletion of GSH and induction of antioxidant enzyme activities after the 3-NPA exposure suggest conditions favorable for oxidative stress.

Animals↗
PubMed1998

An oncogenic mutation uncouples the v-Jun oncoprotein from positive regulation by the SAPK/JNK pathway in vivo.

Stimulation of c-Jun transcriptional activity via phosphorylation mediated by the stress-activated or c-Jun amino-terminal (SAPK/JNK) subgroup of mitogen-activated protein kinases (MAP kinases) is thought to depend on a kinase-docking site (the delta region) within the amino-terminal activation domain, which is deleted from the oncogenic derivative, v-Jun [1] [2] [3]. This mutation markedly enhances v-Jun oncogenicity [4] [5]; however, its transcriptional consequences have not been resolved. In part, this reflects uncertainty as to whether binding of SAPK/JNK inhibits c-Jun function directly [6] [7] or, alternatively, serves to facilitate and maintain the specificity of positive regulatory phosphorylation [8]. Using a two-hybrid approach, we show that SAPK/JNK stimulates c-Jun transactivation in yeast and that this depends on both catalytic activity and physical interaction between the kinase and its substrate. Furthermore, c-Jun is active when tethered to DNA via SAPK/JNK, demonstrating that kinase binding does not preclude transactivation. Taken together, these results suggest that SAPK/JNK acts primarily as a positive regulator of c-Jun transactivation in situ, and that loss of the docking site physically uncouples v-Jun from this control. This loss-of-function model accounts for the deficit of v-Jun regulatory phosphorylation and repression of TPA response element (TRE)-dependent transcription observed in v-Jun-transformed cells and predicts that an important property of the oncoprotein is to antagonise SAPK/JNK-dependent gene expression.

Animals↗
PubMed1998

Alcohol-heightened aggression in mice: attenuation by 5-HT1A receptor agonists.

One of the critical mechanisms by which alcohol heightens aggression involves forebrain serotonin (5-HT) systems, possibly via actions on 5-HT1A receptors. The present experiments tested the hypothesis that activating 5-HT1A receptors by selective agonists will block the aggression-heightening effects of ethanol. Initially, the selective antagonist WAY 100635 was used to assess whether or not the changes in aggressive behavior after treatment with 8-OH-DPAT and flesinoxan result from action at the 5-HT1A receptors. Resident male CFW mice engaged in aggressive behavior (i.e. attack bites, sideways threats, tail rattle) during 5-min confrontations with a group-housed intruder male. Quantitative analysis of the behavioral repertoire revealed systematic reductions in all salient elements of aggressive behavior after treatment with 8-OH-DPAT (0.1-0.3 mg/kg, i.p.) or flesinoxan (0.1-1.0 mg/kg, i.p.). The 5-HT1A agonists also reduced motor activities such as walking, rearing and grooming, although to a lesser degree. Pretreatment with the antagonist WAY 100635 (0.1 mg/kg, i.p.) shifted the agonist dose-effect curves for behavioral effects to the right. In a further experiment, oral ethanol (1.0 g/kg, p.o.) increased the frequency of attacks in excess of 2 SD from their mean vehicle level of attacks in 19 out of 76 resident mice. Low doses of 8-OH-DPAT (0.03-0.3 mg/kg) and flesinoxan (0.1, 0.3, 0.6 mg/kg), given before the ethanol treatment, attenuated the alcohol-heightened aggression in a dose-dependent fashion. By contrast, these low 5-HT1A agonist doses affected motor activity in ethanol-treated resident mice to a lesser degree, suggesting behavioral specificity of these anti-aggressive effects. The current results support the hypothesized significant role of 5-HT1A receptors in the aggression-heightening effects of alcohol. If these effects are in fact due to action at somatodendritic 5-HT1A autoreceptors, then the anti-aggressive effects would be associated with decreased 5-HT neurotransmission.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1998

Feasibility of adrenalectomy with radical nephrectomy.

OBJECTIVES: To evaluate the justification of routine removal of ipsilateral adrenal gland as part of radical nephrectomy for renal cell carcinoma (RCC). METHODS: The medical records, pathologic specimens, and computed tomographic (CT) scans of 77 patients who underwent radical nephrectomy and ipsilateral adrenalectomy for RCC were reviewed. Comparison was made between radiologic analysis and pathologic findings regarding involvement of the adrenal gland. RESULTS: The size of the renal tumor varied between 3.5 and 19 cm (mean 8.5). The upper pole was involved in 45%, the lower pole in 28%, and the midpole in 18% of the patients, and in 9% the whole kidney was involved by the tumor. Histologic findings showed that 72 (94%) of the 77 adrenal glands were normal and 70 of these were normal on CT as well. Two adrenal glands involved by metastases showed heterogeneous contrast entrancement on CT. The benign lesions of three adrenal glands were also picked up as abnormal on CT. In 2 patients adrenal glands could not be visualized on CT because of a paucity of retroperitoneal fat. CONCLUSIONS: Adrenalectomy with nephrectomy may not be performed in patients with RCC in whom CT demonstrates normal adrenal glands. In patients with adrenal abnormality on CT, magnetic resonance imaging can separate metastases from incidental benign adrenal adenoma, further reducing the number of patients requiring removal of the adrenal gland.

Adrenalectomy↗
PubMed1998

Comparison of responses of spontaneously active cells in the cerebellar Purkinje layer to parallel fibre stimulation in slice preparations and urethane-anaesthetised rats: effects of benzodiazepine receptor ligands.

1. GABA-mediated inhibitory responses were induced in spontaneously active Purkinje cells by parallel fibre stimulation in cerebellar slices or in urethane-anaesthetised rats. Effects of agonist and inverse agonist benzodiazepine (BDZ) receptor ligands were compared in the preparations. 2. Purkinje cells fired simple spikes at higher rates in slice preparations while complex spikes were seldom (in vivo) or never observed (slice). Cells fired more regularly in vivo resulting in the occurrence of rhythmic postinhibitory responses in the PSTH analysis in some preparations. 3. Single pulse stimulation of parallel fibres at just suprathreshold intensity induced inhibition of Purkinje cell activity in both preparations. At lower firing rates there was a marked increase in the duration of this response, which was more evident in vivo where more slowly firing cells were encountered. 4. BDZ receptor ligands modified inhibitory responses in slice preparations with only weak effects on the firing rates of the cells. These compounds predominately induced changes in firing rate in the anaesthetised rat with little evidence of direct modification of GABA-mediated synaptic transmission. 5. In a few experiments, following injection of the partial inverse agonists beta-CCE and beta-CCM, block of the inhibitory response was observed independent of changes in firing rate. Bidirectional efficacy of BDZ receptor ligand (agonists decrease firing and increase inhibitory response, inverse agonists increase firing and decrease inhibitory response) was demonstrated for modulation of inhibitory responses in slices and for changes in firing rate in vivo. The increased firing rate response in vivo was biphasic the magnitude of the later phase being correlated with efficacy of inverse agonists. 6. It is concluded that cerebellar slice preparations are more appropriate for studying direct effects of BDZ receptor ligands on GABA-mediated synaptic inhibition than in vivo preparations.

Action Potentials↗
PubMed1998

Structures of acrolein-guanine adducts: a semi-empirical self-consistent field and nuclear magnetic resonance spectral study.

The structures and conformations of adducts formed by reaction of guanosine with several mutagenic alpha,beta-unsaturated carbonyl compounds have been investigated by semi-empirical molecular orbital calculations and compared with NMR spectral results. Two cyclization processes taking place on the pyrimidine ring of guanine leading to two sets of regioisomers, 11-hydroxy- and 13-hydroxytetrahydropyrimidinoguanines (THPG), were considered. Relative stabilities and geometries of all configurations and conformations of adducts with acrolein, crotonaldehyde, and alpha-chloroacrolein were calculated by PM3, AM1, and MNDO methods. PM3 results were the most compatible with experimental structures based on 400-MHz 1H NMR spectroscopy. The most stable structures for the 11-hydroxy and 13-hydroxy THPG isomers from acrolein are predicted to have chair-like structures for the tetrahydropyrimidine ring and axial hydroxyl groups, as suggested by the NMR spectra of the isolated adducts. Of the possible isomers from guanine and crotonaldehyde, cis-11-hydroxy-13-methyl THPG with methyl and hydroxyl groups axial is predicted to be the most stable. The only isolated adduct is the trans-13-hydroxy-11-methyl THPG with methyl shown to be equatorial and hydroxyl axial by 1H NMR. This is completely consistent with the geometry predicted by PM3 for the 13-hydroxy regioisomer of crotonaldehyde. In the case of adducts of alpha-chloroacrolein, one stereoisomer predominates for each of the two possible regioisomers. For the 12-chloro-11-hydroxy isomer, the cis configuration with chlorine axial and hydroxyl quasi-axial is calculated to have the most stable geometry. In contrast, the 1H NMR spectrum supports a trans diaxial orientation, although the cis computed structure could also be accommodated by the spectrum. The 12-chloro-13-hydroxy regioisomer is unambiguously assigned as trans diaxial by PM3 calculations and 1H NMR spectroscopy.

Acrolein↗
PubMed1998

Percutaneous core biopsy of the penis.

To describe the efficacy of percutaneous core biopsy of penile corporal tissue, on ten impotent men, the biopsy was performed with a 19 and a 20 gauge core biopsy co-axial system using an automatic biopsy device. All biopsies were performed on an outpatient basis under local anesthesia. Adequate biopsy specimens were obtained in all. Percutaneous core biopsy of the penis is a safe procedure that is technically easy to perform.

Anesthesia, Local↗
PubMed1998

Auxin production is a common feature of most pathovars of Pseudomonas syringae.

We investigated indole-3-acetic acid (IAA) production by 57 pathovars of Pseudomonas syringae and related species. Most of those analyzed produced IAA, especially in the presence of tryptophan. Eight strains produced high IAA concentrations in the absence of Trp. The iaaM and iaaH genes of P. savastanoi pv. savastanoi were detected in a limited number of strains only, including the eight above-mentioned strains. Thus, IAA synthesis in most assayed strains of P. syringae and related species does not involve genes highly similar to iaaM and iaaH. In contrast, the iaaL gene encoding an IAA-lysine synthase was detected in most pathovars, and was often found on plasmids.

Indoleacetic Acids↗
PubMed1998

Unenhanced helical CT criteria to differentiate distal ureteral calculi from pelvic phleboliths.

PURPOSE: To identify imaging features at unenhanced helical computed tomography (CT) that help differentiate distal ureteral calculi from pelvic phleboliths. MATERIALS AND METHODS: Retrospective analysis was performed of 184 pelvic calcifications identified at unenhanced helical CT in 113 patients. The size, shape, and attenuation of each calcification were recorded in addition to the presence of a central lucency and the appearance of the adjacent soft tissues. With profile analysis, a graphic representation was generated of attenuation in each pixel along a line drawn through each calcification. RESULTS: Geometric configuration was seen in eight (21%) calculi but not in any phleboliths. Differences were significant (P < .0001) between the mean attenuation of calculi and that of phleboliths. Among phleboliths, none had a mean attenuation greater than 278 HU, 13 (9%) had a visible central lucency, 31 (21%) had a bifid peak at profile analysis, 30 (21%) had the "comet sign" (adjacent eccentric, tapering soft-tissue mass corresponding to the noncalcified portion of a pelvic vein), and three (2%) had the soft-tissue rim sign (edema of the ureteral wall). Among calculi, none had a central lucency, bifid peak, or comet sign, but 29 (76%) had the soft-tissue rim sign. CONCLUSION: Analysis of pelvic calcifications at unenhanced helical CT can help differentiate calculi from phleboliths.

Calculi↗
PubMed1998

Complications of percutaneous ethanol ablation.

Percutaneous ethanol injection therapy performed with sonographic visualization is a steadily growing therapeutic method that can be used in the ablation of solid and cystic masses in a variety of anatomic locations. Ethanol has been used for many years as an angiographically administered agent for vascular embolization of tumors such as hepatic and renal neoplasms. It was first used as a percutaneously injected agent for the sclerosis of renal cysts. Local infiltration or intravascular injection of ethanol leads to cell death by causing cell membrane lysis, protein denaturation, and vascular occlusion. Because of the initial success in the sclerosis of renal cysts, percutaneously injected ethanol is now used in the ablation of hepatic cysts and solid tumors, such as hepatocellular carcinomas. As a treatment agent, ethanol combines the benefits of being widely available, inexpensive, efficacious, and relatively easy to administer. Optimal results require that the radiologist have considerable experience in ultrasonographic scanning techniques and facility with percutaneous needle insertion under real-time visualization. Alternatively, the radiologist may choose CT as a method to visualize needle placement. Percutaneous ethanol injection therapy usually is an effective alternative to conventional surgical resection of liver lesions and has a low complication rate. We present two patients in whom hypotensive complications occurred during percutaneous ethanol injection therapy and discuss the likely causative mechanisms.

Aged↗
PubMed1998

v-Jun represses c-jun proto-oncogene expression in vivo through a 12-O-tetradecanoylphorbol-13-acetate-responsive element in the proximal gene promoter.

c-jun proto-oncogene expression is extinguished in cells transformed by v-Jun; however, the mechanistic basis of this phenomenon has not been elucidated. c-jun mRNA levels are greatly reduced in v-Jun-transformed cells, and we show that this reduction is associated with a similar decrease in the rate of c-jun transcription. Transcriptional down-regulation was also evident in functional assays in which the c-jun gene promoter was approximately 10-fold less active in v-Jun-transformed cells than it was in normal cells. This reduction was largely attributable to a conserved 12-O-tetradecanoylphorbol-13-acetate-responsive element (TRE)-like motif at position -72 (the proximal junTRE) that was essential for efficient basal expression in normal cells but that conferred little, if any, detectable transcriptional activity in v-Jun-transformed cells. DNA-binding analysis showed that this element was recognized by a mixture of c-Jun/Fra and cyclic AMP-responsive element-binding protein/activating transcription factor-like complexes in normal cells but that v-Jun/Fra heterodimers predominated in v-Jun-transformed cells. Furthermore, ectopic expression of v-Jun repressed c-jun promoter activity in normal cells through the proximal junTRE. Thus, the deficit in transcription mediated by the junTRE correlates with and is most likely attributable to binding of v-Jun to this element in vivo. We also find that the c-jun promoter is refractory to induction via the stress-activated protein kinase/c-jun NH2-terminal kinase pathway in v-Jun-transformed cells, suggesting that v-Jun interferes with signal-regulated gene expression. Therefore, c-jun is an example of a cellular gene, the transcription of which is regulated negatively by v-Jun in vivo.

Activating Transcription Factors↗