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Biomedical subjects

A Singhal

Publications and source records attributed to A Singhal.

At least 55 records · Page 3Linked to original sources
PubMed1998

Yoga-based intervention for carpal tunnel syndrome: a randomized trial.

CONTEXT: Carpal tunnel syndrome is a common complication of repetitive activities and causes significant morbidity. OBJECTIVE: To determine the effectiveness of a yoga-based regimen for relieving symptoms of carpal tunnel syndrome. DESIGN: Randomized, single-blind, controlled trial. SETTING: A geriatric center and an industrial site in 1994-1995. PATIENTS: Forty-two employed or retired individuals with carpal tunnel syndrome (median age, 52 years; range, 24-77 years). INTERVENTION: Subjects assigned to the yoga group received a yoga-based intervention consisting of 11 yoga postures designed for strengthening, stretching, and balancing each joint in the upper body along with relaxation given twice weekly for 8 weeks. Patients in the control group were offered a wrist splint to supplement their current treatment. MAIN OUTCOME MEASURES: Changes from baseline to 8 weeks in grip strength, pain intensity, sleep disturbance, Phalen sign, and Tinel sign, and in median nerve motor and sensory conduction time. RESULTS: Subjects in the yoga groups had significant improvement in grip strength (increased from 162 to 187 mm Hg; P = .009) and pain reduction (decreased from 5.0 to 2.9 mm; P = .02), but changes in grip strength and pain were not significant for control subjects. The yoga group had significantly more improvement in Phalen sign (12 improved vs 2 in control group; P = .008), but no significant differences were found in sleep disturbance, Tinel sign, and median nerve motor and sensory conduction time. CONCLUSION: In this preliminary study, a yoga-based regimen was more effective than wrist splinting or no treatment in relieving some symptoms and signs of carpal tunnel syndrome.

Adult↗
PubMed1998

Systemic effect of human growth hormone after intramuscular injection of a single dose of a muscle-specific gene medicine.

A muscle-specific gene medicine is described that provides for long-term secretion of biologically active human growth hormone (hGH) from skeletal muscle into the systemic circulation. The hGH gene medicine is composed of a muscle-specific hGH plasmid expression system complexed with a protective, interactive, non-condensing (PINC) delivery system. The muscle-specific gene expression system, pSK-hGH-GH, was constructed by linking the promoter/enhancer regions of chicken skeletal alpha-actin to hGH gene. C2C12 myoblast transfection with pSK-hGH-GH resulted in the synthesis of hGH in a muscle-specific manner. Direct injection into rat tibialis cranialis muscle of pSK-hGH-GH complexed with a polymeric PINC delivery system, polyvinylpyrrolidone (PVP), produced hGH levels in muscle that were 10- to 15-fold higher compared with plasmid formulated in saline at 14 days post-injection. Intratracheal instillation in rat lung of pSK-hGH-GH did not produce significantly detectable levels of hGH. In hypophysectomized rats, a single intramuscular dose of the pSK-hGH-GH/PVP complex resulted in hGH expression and a subsequent increase in serum levels of rat IGF-I and growth. hGH expression and effects on rat serum IGF-I levels were detectable up to 28 days after injection of formulated plasmid and effects on growth were detectable unto 21 days. Anti-hGH antibodies were detectable in serum at 14 days post-injection, reached a plateau at 21 days, and remained elevated through the study period. Cyclosporin treatment of the pSK-hGH-GH/PVP-injected animals completely inhibited the antibody response and resulted in increased hGH expression.

Actins↗
PubMed1998

Axial dispersion model for upflow anaerobic sludge blanket reactors

Fluid flow in UASB reactors is usually described by multicompartment models consisting of separate ideally mixed zones, plug flow zones, and stagnant zones linked with bypassing flows and back-mixing flows. A closer look at UASB reactor behavior indicates that this complexity is unnecessary. Our study on the startup and steady-state operation of a UASB reactor shows that its fluid flow can be explained just as well with a simple axial dispersion model. The physical transitions, which occur in different zones of the UASB reactor as the microorganisms acclimate to the wastewater, are adequately described by the model. Further, the number of parameters, which is six in standard UASB reactor models, is reduced to four in the case of the axial dispersion model.

Journal Article↗
PubMed1997

Growth and Structure of Zirconium Hydrous Polymers in Aqueous Solutions

Zirconium oxychloride solutions prepared at different pH were heated at elevated temperatures for various aging periods to gain an understanding of the growth mechanism and structure of zirconium hydrous polymers. Small angle X-ray scattering (SAXS) measurements were made on these solutions. It was observed that shape of clusters at the earlier stages of growth is close to a rod rather than a sheet as suggested earlier. The scattering data indicate that a rod-shaped primary particle is formed at pH 1.2, and on an increase in the pH, the primary particles become more branched. On aging more than 1250 min at 92°C, these primary particles form large aggregates while retaining the primary particle structure. These aggregates, which are mass fractal in nature, restructure while growing in size and eventually transform into dense particles. Scattering data in this study were not enough to determine a specific kinetic growth model of the aggregates because the scattering intensity at low q constantly changes with time during the restructuring process. Copyright 1997 Academic Press. Copyright 1997Academic Press

Journal Article↗
PubMed1997

Near nerve local insulin prevents conduction slowing in experimental diabetes.

Insulin may have direct effects on axons through its actions on insulin receptors or through cross occupancy of insulin-like growth factor-1 receptors. We tested the hypothesis that insulin itself influences conduction of myelinated fibers independent of hyperglycemia in experimental diabetes. Low dose intermittent (0.2 units thrice weekly) Toronto (regular) insulin was injected at the sciatic notch and knee near the left sciatic nerve of rats rendered diabetic with citrate buffered streptozotocin or nondiabetic rats given citrate only. Identical volumes of normal saline were injected near the contralateral right sciatic nerve. The diabetic rats developed hyperglycemia, elevated glycosylated hemoglobin levels and had slowing of right (saline treated) sciatic tibial motor and caudal sensory conduction velocity. In contrast, local insulin treatment on the left side prevented conduction slowing, unilaterally increasing conduction velocity. In nondiabetic rats, conduction velocities were slightly higher on the insulin treated side, but the influence of insulin was less robust than in diabetics. The insulin treated sural branches of the sciatic nerves in diabetics had a higher percentage of small (< or = 9.0 microm diameter) myelinated fibers than the saline treated nerves. Local insulin has a trophic influence on myelinated fibers that is prominent in diabetic nerves and is independent of hyperglycemia.

Animals↗
PubMed1997

Is there an energy deficiency in homozygous sickle cell disease?

The low weight, low height-for-age, delayed skeletal maturation, and retarded puberty in children with homozygous sickle cell disease are consistent with chronic malnutrition. Voluntary energy intake in sickle cell patients (SS) appears to be similar to that of control subjects with a normal hemoglobin genotype (AA) despite a higher resting metabolic rate (RMR), which suggests a suboptimal nutritional state. Patients may therefore conserve energy by reducing physical activity; this hypothesis was tested by comparing RMR, total daily energy expenditure (TDEE), and physical activity level (TDEE:RMR) in 16 postpubertal boys with sickle cell disease with those in 16 normal control subjects matched for age, sex, and pubertal stage. The RMR of sickle cell patients measured by indirect calorimetry (mean +/- SD: 7.0 +/- 0.9 MJ/d) significantly exceeded that of the normal control subjects (6.3 +/- 0.5 MJ/d; P = 0.018) but TDEE measured by the heart rate method was greater in the control subjects (13.8 +/- 4.9 MJ/d) than in the sickle cell patients (10.5 +/- 2.2 MJ/d; P = 0.034). Physical activity level was 46% greater in control subjects (2.2 +/- 0.8) than in sickle cell patients (1.5 +/- 0.3; P = 0.006). Adjustment for genotype differences in body weight reduced the genotype difference in physical activity level from 0.70 (95% CI: 0.3, 1.1) to 0.6 (95% CI: -0.06, 1.2). Reducing physical activity is a compensatory mechanism in children with an energy deficiency and a similar adaptive response may occur in sickle cell disease.

Anemia, Sickle Cell↗
PubMed1997

Psychiatric complications of homozygous sickle cell disease among young adults in the Jamaican Cohort Study.

BACKGROUND: This study aimed to determine the prevalence of psychiatric disorder in young adults with homzygous sickle cell (SS) disease and in controls with normal haemoglobin, and to examine factors associated with psychiatric disorder. METHOD: The study design was cross-sectional. Subjects were aged 18-20 years: 63 with SS disease and 89 controls. The Psychiatric Assessment Schedule was used to determine psychiatric disorder at index of Definition level 5. RESULTS: Psychiatric disorder was identified in 18 (29%) SS disease patients and in 22 (25%) controls. In SS patients, psychiatric disorder was not related to illness severity but was associated with leaving school early, difficulties in social adjustment, impaired cognitive function and having previous psychiatric difficulties. Male SS patients with psychiatric disorder all had low body mass index (BMI < 17.60). In controls, psychiatric disorder was associated with female gender, unemployment and difficulties in social adjustment. CONCLUSIONS: The prevalence of psychiatric disorder was similar in patients and controls, although associated factors tended to be different. The association with low BMI in SS men merits further study.

Adolescent↗
PubMed1996

Modified latex agglutination test for rapid detection of Streptococcus pneumoniae and haemophilus influenzae in cerebrospinal fluid and direct serotyping of Streptococcus pneumoniae.

A modified latex agglutination test was designed and evaluated for the rapid detection of Streptococcus pneumoniae and haemophilus influenzae type b capsular antigens, and for direct serotyping of Streptococcus pneumoniae in the cerebrospinal fluid. Reagents were prepared by sensitizing latex particles with Omniserum (against 83 capsular serotypes of pneumococci) and Haemophilus influenzae type b burro antiserum. For serotyping reagents, latex particles were similarly coated with nine pneumococcal pool (a to I) antisera and 46 individual pneumococcal serogroup/serotype specific antisera. The test was performed on cerebrospinal fluid from 298 patients with suspected meningitis. Serotyping was done directly on untreated cerebrospinal fluid samples showing positive reactions with the Omniserum reagent. Pneumococcal or Haemophilus influenzae type b antigens were detected in 41 patients; in 32 of these the etiology was established by culture and in 2 by smear examination. Five of the remaining seven cases were judged clinically and by cytological examination of cerebrospinal fluid to have partially treated bacterial meningitis. In two cases the test was false positive. The overall sensitivity and specificity of the latex agglutination test for the detection of Streptococcus pneumoniae and Haemophilus influenzae type b antigens was 100% and 96.8% respectively. The commonest pneumococcal serotypes were type 1 (30%), types 6 and 19 (10% each). The latex agglutination test is rapid and simple to perform, yielding serotype data directly by testing of cerebrospinal fluid.

Adult↗
PubMed1996

Factors affecting prepubertal growth in homozygous sickle cell disease.

OBJECTIVE: To investigate the role of haematological indices, socioeconomic status, and morbidity in prepubertal growth in homozygous sickle cell (SS) disease. METHOD: Height, weight, and haematology were serially recorded in a cohort study of 315 children with SS disease from birth to 9 years at the sickle cell clinic of the University Hospital of the West Indies, Kingston, Jamaica. RESULTS: Height increment between 3 and 9 years correlated positively with total haemoglobin at age 7 years in boys but not girls. Attained height and weight at age 7 years correlated positively with haemoglobin and fetal haemoglobin in boys but not girls. Only the correlation between haemoglobin and weight showed a significant gender difference. Partial correlation analysis suggested that the effect of haemoglobin was accounted for by the effect of fetal haemolglobin and further analysis indicated that height correlated with F reticulocyte count (a measure of fetal haemoglobin production) in both sexes but not with the ratio of F cells to F reticulocytes (a measure of F cell enrichment). Growth was not significantly related to mean red cell volume, proportional reticulocyte count, alpha thalassaemia, socioeconomic status, or morbidity. CONCLUSION: A high concentration of fetal haemoglobin in boys with SS disease is associated with greater linear growth. It is postulated that in boys, low concentrations of fetal haemoglobin increase haemolysis and hence metabolic requirements for erythropoiesis, putting them at greater risk of poor growth. Differences in the relationship of haematology and growth between boys and girls with SS disease dictate that future analyses of growth take gender into account.

Anemia, Sickle Cell↗
PubMed1996

Evaluation of an ELISA for the diagnosis of brucellosis.

Brucela serology using ELISA and standard agglutination test was performed on 23 patients with prolonged fever where the test was requested, on 26 randomly chosen patients with prolonged fever where it was not requested and on 17 controls. ELISA was positive in 39.1, 26.9 and 0 per cent respectively in these groups. Brucellosis may often be unsuspected because of its varied clinical manifestations and may be a more important cause of fever than previously considered. Our data reaffirm that ELISA is superior to the standard agglutination test for the diagnosis of brucellosis.

Agglutination Tests↗
PubMed1996

The effect of splenectomy for hypersplenism on whole body protein turnover, resting metabolic rate and growth in sickle cell disease.

OBJECTIVE: To determine whether, in the same individual, an observed fall in whole body protein turnover following splenectomy in children with hypersplenism and homozygous sickle cell (SS) disease is associated with a measurable fall in resting metabolic rate (RMR) and an increase in rate of growth. SUBJECTS: Six children (5 SS disease, 1 S beta degree thalassaemia), aged 68 to 126 months, were studied before and after splenectomy for hypersplenism. DESIGN: Protein turnover was measured by the end product method using prime/intermittent oral doses of 15N-glycine and RMR by indirect calorimetry before preoperative transfusion and repeated at least eight weeks after splenectomy. Height and weight velocities were measured over six month periods before and after splenectomy. SETTING: University Hospital of the West Indies in Jamaica and the Medical Research Laboratories (Jamaica). RESULTS: After splenectomy protein turnover fell significantly by 30% and RMR by 34 kJ/kg/d. Mean weight velocity which was below normal before surgery, z = -2.3, improved significantly after surgery, z = 0.7, (P = 0.03). Height velocity increased in two children but the mean height velocity did not change following splenectomy. The reduction in protein turnover was estimated to account for 62% of the fall in RMR. CONCLUSION: This study confirms that there is a significant reduction in energy expenditure following splenectomy for hypersplenism in SS disease. A reduction in protein turnover was a major contributor to the saving in energy, although it is not clear whether it accounted for all. In the present group of children the energy saved was associated with an improvement in the wasting present before splenectomy.

Anemia, Sickle Cell↗
PubMed1995

Activation of human immunodeficiency virus gene expression by ultraviolet light in stably transfected human cells does not require the enhancer element.

Ultraviolet light (UV) exposure of cells infected with human immunodeficiency virus type I (HIV) or transfected with HIV reporter genes increases virus-directed gene expression. Here we report the mapping of the UV response on the long terminal repeat (LTR) by using human cells stably transfected with HIV promoter plasmids harboring different mutations and controlling the expression of the chloramphenicol acetyltransferase (cat) reporter gene. Promoter mutation analysis revealed that no specific upstream region of the LTR was associated with UV activation, although a significant decrease was observed with mutations in the basal promoter elements Spl and TATA. Most importantly, UV activation was not diminished by removal of the - 119 to -69 region encompassing the LTR enhancer region or, more specifically, by point mutations in the NF -kappa B binding elements. Consistent with this result, we found that the phorbol ester (PMA) response, which is known to act through the enhancer, occurred independently and was synergistic with the UV response. Removal of the -119 to -69 region did not affect UV activation; however, it resulted in total abrogation of the PMA response. These results suggest that UV activation is distinct from NF -kappa B activation and does not act through the enhancer in stably transfected cells. This is in dramatic contrast to what is found with transient expression analysis of these responses. Lastly, RNA protection experiments revealed that UV may act on preassembled basal transcription complexes by allowing elongation of nascent short mRNAs generated from the LTR.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromatin↗
PubMed1995

Tumor-associated sialylated antigens are constitutively expressed in normal human colonic mucosa.

Immunohistochemical studies have indicated that sialylated carbohydrate antigens such as sialyl-Tn, sialyl-Le(a), and sialyl-Le(x) are expressed in a tumor-associated fashion in human colon. Since sialic acid residues are O-acetylated more extensively in normal colonic epithelium than in colon cancer cells, we examined whether deacetylation of colonic tissues might enable monoclonal antibodies to recognize these tumor-associated sialylated antigens. In normal colon, deacetylation turned most cases (82%) positive with anti-sialyl-Tn mAb TKH2; and in colon cancers, it increased the number of TKH2-positive cells. Sialyl-Le(a) and sialyl-Le(x) detection was also increased after deacetylation of normal and malignant colonic tissues so that the frequency of positive cases in normal tissues was similar to that in the cancers. However, in the stomach and pancreas, the same treatment rarely increased the detection of the sialylated epitopes in normal or cancerous tissues. Thus, the same sialylated epitopes can be expressed in a tumor-associated fashion by different mechanisms in different gastrointestinal organs; in the colon, these antigens are constitutively expressed and O-acetylated, whereas in the upper gastrointestinal tract, they are rarely O-acetylated, suggesting that other mechanisms such as differences in glycosylation account for the cancer-associated expression.

Adenocarcinoma↗
PubMed1995

Host-cell reactivation of reporter genes introduced into cells by adenovirus as a convenient way to measure cellular DNA repair.

In order to conveniently measure cellular DNA repair in immortalized and primary human cells we have combined the features of high cellular infectivity of adenovirus (Ad) with that of host-cell reactivation (HCR) of ultraviolet light (UV)-damaged reporter genes. We show that Ads having either the cat (chloramphenicol acetyltransferase) or seap (secreted alkaline phosphatase) reporter gene under control of a strong constitutive promoter can be used to measure relative levels of DNA repair by HCR. Most importantly, the SEAP assay allows for a convenient, inexpensive, and sensitive colorimetric microtiter assay. Only a few steps are involved and it is possible to process many samples simultaneously in a relatively short time, which is not as easily done with other reporter gene assays. Furthermore, we show that co-infection of UV-damaged SEAP Ad with an Ad carrying a prokaryotic repair gene significantly increased the HCR levels in xeroderma pigmentosum cells. The Ad gene delivery system, and the SEAP assay in particular, should simplify existing HCR assays considerably. By using non-lytic Ad as a vehicle it should be possible to quantitatively introduce normal or dominant negative mutant DNA repair genes into bulk cell populations for DNA repair studies.

Adenoviridae↗
PubMed1995

A bacteriological study in hospitalized children with pneumonia.

A total of 110 consecutive hospitalized children with severe lower respirator tract infection were studied with the aim of determining the main bacterial pathogens responsible. Of these, 57 were classified as severe pneumonia and 53 as very severe pneumonia. Streptococcus pneumoniae was the most common organism identified in 24.6% and 32.1% of cases of severe and very severe pneumonia, respectively, followed by Haemophilus influenzae type b, which was seen in 17.5% and 20.8%, respectively. The highest diagnostic yield was with the latex particle agglutination test on serum and urine. Blood culture was positive in only ten of the 110 children. No difference was found between the aetiological agents identified in severe and very severe cases of pneumonia. Therefore, the use of different parenteral antibiotics for two clinically defined groups of pneumonia, as recommended by WHO in their standard case management guidelines for the ARI control programme, does not seem necessary.

Acute Disease↗
PubMed1995

Acceleration in linear growth after splenectomy for hypersplenism in homozygous sickle cell disease.

Chronic hypersplenism in homozygous sickle cell (SS) disease markedly increases haemolysis and the resulting erythropoietic expansion is likely to have a high metabolic cost. Splenectomy for hypersplenism in SS disease is followed by highly significant changes in haematological indices and an increase in height, but not weight, velocity. This pattern is similar to that observed in the trichuris dysentery syndrome after treatment, and differs from the increases in both height and weight velocity that follow nutritional supplementation of severely malnourished children. It is postulated that accelerated linear growth after the reduction in erythropoietic stress may implicate a specific nutrient deficiency in hypersplenic children with SS.

Body Height↗