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Biomedical subjects

S Hussain

Publications and source records attributed to S Hussain.

At least 19 recordsLinked to original sources
PubMed1996

A longitudinal investigation of duration and temporal variability in children's speech production.

A number of cross-sectional, acoustic studies have found that young children's speech segments tend to be longer and more variable than those of older children and adults. However, very little longitudinal information of this nature is available that considers changes across time for individual children. The present investigation is a longitudinal analysis of several temporal characteristics of the speech of 12 children of various ages who were each seen twice, approximately 1 1/2 years apart. For the group, durations decreased on average from the initial to the follow-up recordings by approximately 10%, and temporal variability decreased by about 40%. For the individual children, however, it was found that some of them showed few, if any, changes in some of the temporal measurements made at the two different times, whereas others showed substantial differences. Younger children also did not necessarily show longer durations or greater variability than older children, nor did younger children always show greater changes across time than older children. Thus, although cross-sectional studies indicate that there is a general tendency when comparing groups for increased age to be associated with shorter durations and reduced variability, individual children may not evidence such patterns or changes across time.

Adolescent↗
PubMed1996

Gantry angulation in CT-guided percutaneous adrenal biopsy.

OBJECTIVE: This study was performed to test a new method for CT-guided adrenal biopsy using angulation of the CT gantry. MATERIALS AND METHODS: In 23 patients, 26 biopsies were performed on patients in the prone position using CT gantry angulation and the introduction of the biopsy needles along the same angle, guided by the gantry locating light. The use of angulation ensured a safe needle path that avoided vital structures, such as the pleura, while monitoring of the needle course and its tip on one or two CT slices. RESULTS: Twenty-two of 23 adrenal masses (96%) were successfully biopsied without complications. Fifteen (65%) of the target masses were 1.5 cm or smaller. CONCLUSION: Using an angled gantry during percutaneous biopsy is a safe and preferred method over other techniques for biopsy of adrenal masses and can be used easily for small adrenal masses.

Adrenal Glands↗
PubMed1995

Rhinocerebral invasive mycosis: occurrence in immunocompetent individuals.

We report the computed tomographic appearance of invasive fungal disease of the paranasal sinuses in 13 patients. Coronal and axial computed tomographic images were obtained in each patient and data were analysed. Eight patients had Aspergillus flavus infection, four had Mucormycosis, and one had mixed Candida and Mucor. Our experience was different from that of other workers in many respects. All of our patients were immunocompetent. On radiological imaging by computed tomography, ethmoid sinuses were involved in 85% of our patients. In previously reported series maxillary sinuses were most frequently affected. Calcification in the inflammatory mass was not encountered in any of our patients, whereas this feature was present in many reported cases. Features in our patients that were similar to other studies were contrast enhancement, extension of the disease into the orbit and cranial cavity and a high mortality. The clinical course and radiological features of invasive mycosis simulate malignancy. Certain features that may help to differentiate invasive fungal infection from malignancy are discussed. We conclude that invasive fungal infection can affect immunocompetent individuals and should be considered in the differential diagnosis in appropriate clinical settings.

Adolescent↗
PubMed1995

Age-related changes in antioxidant enzymes, superoxide dismutase, catalase, glutathione peroxidase and glutathione in different regions of mouse brain.

It has been proposed that neurodegenerative processes of aging are associated with the generation of reactive oxygen species (ROS) during cellular metabolism. These reactive oxygen species are scavenged by antioxidant enzymes in biological systems. The present study was designed to determine the selective distribution of the antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase activity and reduced glutathione (GSH) levels in different regions of the C57BL/6N mouse brain and to determine if any alterations occurred with age. Catalase activity did not show any significant change except in cerebellum. Activity of superoxide dismutase was increased with age in all regions of the brain except in hippocampus of 2-yr-old mice. The glutathione peroxidase activity in the caudate nucleus increased in all regions of the brain, however, the activity did not change at one, six and 12 months. A significant increasing pattern of glutathione content was found in the cerebellum and brain stem with age. These data demonstrate that although the level of antioxidant enzymes varied in different regions of the brain, overall the enzyme activities tend to increase with age.

Aging↗
PubMed1995

Characterization of lymphocyte beta-adrenoceptor activity and Gs-protein in patients with rheumatic heart valvular disease.

In order to test whether the beta-adrenoceptor activity in rheumatic heart valvular disease depends on the ventricular load conditions, we determined their density and binding affinity to [125I]-iodocyanopindolol in lymphocytes, as well as plasma catecholamine and cAMP levels in 69 patients with regurgitant and stenotic lesions of the aortic and mitral valves. The patients were classified as having left ventricular pressure overload (LVP), left ventricular volume overload (LVV), mixed lesions (MOL) or right ventricular pressure overload (RVP). The beta-adrenoceptor activity was determined by radioligand binding methods, catecholamines by high performance liquid chromatography using an electrochemical detector and cAMP by radioimmunoassay. The mean beta-adrenoceptor density (Bmax) of the control group was 60.1 +/- 9.5 fmol (n = 29) per 10(6) lymphocytes. In the study population, the density was decreased by 83% in LVP, 78% in LVV, 87% in MOL and 86% in RVP. Plasma norepinephrine was elevated by 89% in LVP and 60% in MOL, epinephrine by 43% in LVP, 50% in VOL, 115% in MOL and 20% in RVP, while dopamine was not significantly changed, and cAMP was slightly elevated in all four groups. Screening for activating mutational changes in the Gs alpha-protein gave negative results, possibly dissociating the elevation in plasma cAMP from stimulatory effects of such abnormalities in the Gs-protein signaling.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Use of drugs in child and adolescent psychiatry.

BACKGROUND: The prescription of psychotropic drugs for children is a sensitive and highly contentious subject which may explain the apparent lack of uniformity and consistency in clinical practice. METHOD: This review is based on Medline and manual search of the literature. RESULTS: More than 1000 relevant references were found, and information has been culled from all these. Fifty particularly relevant articles have been selected for the reference list. CONCLUSION: Recent years have seen considerable research in this field, and a clearer picture of the benefits and limitations of drug use in children is emerging.

Adolescent↗
PubMed1995

Percutaneous nephrostomy using hospital modified catheters for cost containment.

This paper describes our experience of percutaneous nephrostomy (PCN) using self-fabricated catheters. Our effort is to restrain the cost of this common procedure, and at the same time, deliver results comparable to other studies in the literature. In 152 patients, 175 PCN were performed for various indications using simple tools for "pulling catheters". All nephrostomy catheters were fabricated from commercially available 7.2 F polyethylene catheter material. Our success rate of 96%, major and minor complication rates at 2.3% and 6.3% respectively, compare favourably with the reported series. The variable cost of nephrostomy, in our cases, was less than one-third compared with that using commercially available nephrostomy sets. Use of self-fabricated nephrostomy catheters is a cost-effective way of performing nephrostomy especially in environments where health maintenance resources are scarce, health insurance is not freely available, and patients bear the cost of the treatment. This is particularly relevant to the developing countries where PCN is frequently needed but the nephrostomy sets are not easily available.

Adolescent↗
PubMed1994

In vitro studies of glucocorticoid effects on neurons and astrocytes.

Studies using immunocytochemistry and RNase protection assay demonstrate that glucocorticoid and mineralocorticoid receptors (GR, MR) and their corresponding mRNAs are co-expressed in hippocampal neurons cultured in serum-free, defined medium and at lower levels in cultured astrocytes. Addition of serum or medium conditioned by astrocytes increases the levels of MR mRNA, but has little effect on the levels of GR mRNA. Cellular levels of both GR mRNA and MR mRNA are upregulated by growth of embryonic hippocampal neurons in corticosterone. This is in distinct contrast to regulation of receptor expression in vivo where mRNAs for these receptors are downregulated in the rat hippocampus by corticosterone treatment of the adult adrenalectomized rat. However, in cultured astrocytes, GR and MR mRNAs are also downregulated by corticosterone. To begin to define the role of glucocorticoids in gene expression in astrocytes, we have used giant two-dimensional (2D) gel electrophoresis to separate astrocyte cellular proteins and translation products synthesized in vitro from astrocyte poly A+ RNA. Analysis of approximately 1,500 in vitro translation products by giant 2D gel electrophoresis reveals 11 protein inductions and 1 repression that occur at the level of mRNA in the absence of protein synthesis following treatment of astrocytes with corticosterone. Interestingly, these changes appear to be mediated by GR, but not by MR. The in vitro studies described here are relevant to identifying the role of GR and MR in gene expression in specific cell types in the hippocampus.

Animals↗
PubMed1994

Interaction of radiolabelled Na,K-ATPase-liposomes with human peripheral blood mononuclear cells.

Artificial phospholipid vesicles (liposomes) containing in their membrane about eight Na,K-ATPase (sodium pump) molecules per vesicle were incubated in the presence of [110mAg]silver nitrate to label the membrane protein; silver binds specifically to the Na,K-ATPase protein. When such silver-labelled liposomes were incubated with freshly isolated human peripheral blood mononuclear cells, a large number of liposomes was found in cells as evidenced by their 110mAg content after washing them with powerful silver chelators. Thus, liposomes containing an integral membrane protein can be transferred to human peripheral blood mononuclear cells rapidly and without toxicity.

Cell Separation↗
PubMed1994

Potent and reversible interaction of silver with pure Na,K-ATPase and Na,K-ATPase-liposomes.

The Na,K-ATPase (EC 3.6.1.37) is the receptor for cardioactive steroids, the only specific inhibitors known at the present time for this unique membrane bound transport system. We report here that silver is the most rapid and potent inhibitor of isolated Na,K-ATPase ever described. Inhibition of Na,K-ATPase activity by silver is immediate and strikingly distinct from other inhibitors: addition of 1 mM of cysteine or DMPS reactivates the silver blocked-enzyme immediately. The results reveal that silver interacts with Na,K-ATPase and inhibits differently by an on-off mechanism involving most likely a few critical sulfhydryl groups. Inhibition of Na-K transport by silver has been demonstrated also in an artificial membrane, e.g., in liposomes reconstituted with pure Na,K-ATPase performing active transport. Silver inhibits the active 86Rb transport mediated by the pure Na,K-ATPase molecule. The Na,K-ATPase contained in the liposomes was labeled specifically with 110mAg and appeared to bind two silver ions. Taken together, the results show that the mechanism of silver interaction with Na,K-ATPase might be different from other metals, for instance, mercury. The unique action mechanism of silver suggests a fundamental role of a few critical sulfhydryl groups for Na,K-transport.

Animals↗
PubMed1994

Effect of oral gamolenic acid from evening primrose oil on menopausal flushing.

OBJECTIVE: To evaluate the efficacy of gamolenic acid provided by evening primrose oil in treating hot flushes and sweating associated with the menopause. DESIGN: Randomised, double blind, placebo controlled study. SETTING: District general hospital and teaching hospital. SUBJECTS: 56 menopausal women suffering hot flushes at least three times a day. INTERVENTION: Four capsules twice a day of 500 mg evening primrose oil with 10 mg natural vitamin E or 500 mg liquid paraffin for six months. MAIN OUTCOME MEASURES: Change in the number of hot flushes or sweating episodes a month. RESULTS: 56 diaries were analysed, 28 from women taking gamolenic acid and 28 from those taking placebo. Only 18 women given gamolenic acid and 17 given placebo completed the trial. The mean (SE) improvement in the number of flushes in the last available treatment cycle compared with the control cycle was 1.9 (0.4) (P < 0.001) for daytime flushes and 0.7 (0.3) (P < 0.05) for night time flushes in women taking placebo; the corresponding values for women taking gamolenic acid were 0.5 (0.4) and 0.5 (0.3). In women taking gamolenic acid the only significant improvement was a reduction in the maximum number of night time flushes (1.4 (0.6); P < 0.05). CONCLUSION: Gamolenic acid offers no benefit over placebo in treating menopausal flushing.

Administration, Oral↗
PubMed1994

Development of mRNAs for glucocorticoid and mineralocorticoid receptors in rat hippocampus.

The hippocampus plays an important role in mediating glucocorticoid effects on the brain. Glucocorticoids are also implicated in neurogenesis and age-related neuronal death in the hippocampus. The effects of glucocorticoids in the hippocampus are elicited through two receptors with high-affinity for corticosterone, the glucocorticoid receptor (GR) and the mineralocorticoid receptor (MR). In this study, we used a sensitive RNase protection assay to quantify the ontogeny of GR mRNA and MR mRNA in hippocampus from embryonic day 18 (E18) to postnatal day 60 (P60). GR mRNA and MR mRNA are expressed at approximately equal levels in the E18 hippocampus. However, by birth, the level of MR mRNA is three-fold that of GR mRNA and remains elevated up to P60. The levels of both mRNAs increase gradually during the period of postnatal neurogenesis after which they markedly increase to adult levels. In addition, the levels of hippocampal MR mRNA are the same in male and female rats, whereas the levels of GR mRNA are significantly higher in the P60 female rat hippocampus, but not in younger female rats. Our data on the development of mRNA levels do not parallel the levels of glucocorticoid and mineralocorticoid receptors as reported in a number of binding studies. Therefore, our studies, when considered together with previous reports, suggest that posttranscriptional mechanisms play a major role in regulating the levels of glucocorticoid-binding sites in the hippocampus.

Animals↗
PubMed1994

Cross-resistance to heavy metals in hydrogen peroxide-resistant CHO cell variants.

Hydrogen peroxide-resistant Chinese hamster ovary (CHO) cells displayed cross-resistance to CdCl2, HgCl2 and NaAsO2 but not to Na2Cr2O7, ZnCl2, NiCl2 and CuSO4. Resistance to hydrogen peroxide and to the metals was partially retained by these cells for many generations despite growth in drug-free medium. The loss of resistance was a slow process, and was different for the various metal compounds. Cell variants had a slightly higher content of non-protein intracellular thiols (NPSH) than sensitive cells. This biochemical feature did not seem to be the cause of resistance to CdCl2 but accounted for at least part of the resistance to HgCl2 and NaAsO2. Increased metallothionein synthesis did not seem to be responsible for the metal-resistant phenotype. These results suggest that resistance to specific metal compounds in cultured mammalian cells adapted to hydrogen peroxide is dependent on a number of factors which differ for the various metal compounds and which are characterized by a different stability.

Animals↗
PubMed1994

Determination of haemophilia A carrier status from hair samples using polymerase chain reaction technique.

The usefulness of intragenic restriction fragment length polymorphisms (RFLPs) for BclI, HindIII and XbaI, adapted for polymerase chain reaction (PCR), was tested for the detection of haemophilia A carrier status in the consultant of a family in which only haematological information was available on the inheritance of the trait. Hair follicles were used as the non-invasive source of DNA. The mother was found to be homozygous for BclI and heterozygous for HindIII sites, whereas her status as regards informativeness could not be established for XbaI. On the basis of HindIII RFLP, the daughter was found to be a carrier of the haemophilia trait. This was confirmed by sequencing the amplified intron 19 of the mother and the daughter. The RFLP for XbaI did not appear to be suitable for carrier detection using PCR due to the difficulty of establishing homozygosity or heterozygosity from the results of digestion of the amplified product.

Base Sequence↗
PubMed1994

Complications and length of hospital stay following stented and unstented paediatric pyeloplasties.

OBJECTIVES: To ascertain the necessity for the use of nephrostomies and ureteric stents after paediatric pyeloplasties. PATIENTS AND METHODS: Seventy children with a pelvi-ureteric junction obstruction underwent a dismembered pyeloplasty between March 1983 and March 1991 at The Bristol Royal Hospital for Sick Children. A nephrostomy and stent were not used routinely except for the first few months of the survey. Indications for their use were: surgery on a single kidney, an inflamed renal pelvis or a revision pyeloplasty. Urinary catheters were only used for those patients with proven or suspected vesicoureteric reflux. RESULTS: Thirteen patients had a nephrostomy and stent inserted (Group 1) of whom three patients (23%) developed complications. Fifty-seven patients had only a wound drain inserted (Group 2) of whom nine (16%) developed complications. The hospital stay of 12.1 days for patients in Group 1 was significantly longer than the 5.4 days for Group 2 (P value < 0.05). Long-term radiological and/or radio-isotopic follow-up showed improvement in function and/or drainage in 95% of both groups. CONCLUSIONS: These findings support the concept that paediatric pyeloplasties can be safely performed at any age without the insertion of a nephrostomy tube or stent and that hospital stay is therefore significantly reduced.

Adolescent↗
PubMed1993

Paralysis of occipitofrontalis in a borderline case of leprosy.

A patient with neuritic leprosy developed borderline skin lesions. Later, another skin lesion developed on the left side of the forehead with clinical involvement of the supraorbital branch of the ophthalmic division of the trigeminal nerve. Simultaneously, paralysis of the occipitofrontalis and mild paresis of orbicularis oculi occurred.

Adult↗