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Biomedical subjects

K Ali

Publications and source records attributed to K Ali.

At least 19 recordsLinked to original sources
PubMed2003

Neonatal estrogen exposure of male rats alters reproductive functions at adulthood.

The effects of neonatal exposure to different doses of diethylstilbestrol (DES) on the reproductive functions of male rats at adulthood were evaluated. Sprague-Dawley rats (5-8/group) received sc injections of 25 microl olive oil containing DES (Sigma Chemical Co., St. Louis, MO) at a dose of 10 microg, 1 microg, 100 ng, 10 ng, or 1 ng per rat on alternate days from Postnatal Days 2-12. Control animals received olive oil only. All animals were allowed to develop until 83-91 days of age; however, when they were 70 to 80 days old, four male rats each from the 10 microg, 1 microg, 100 ng, and control groups were cohabited with untreated 60- to 70-day-old females (1:1) for 12 days. At the end of cohabitation, both mated and unmated male rats were weighed, and blood and tissue samples were collected and processed. Results revealed that although sperm motility patterns and sperm morphology were adversely affected in the 10- microg group, other reproductive parameters, including 1). daily sperm production (DSP)/testis; 2). absolute and relative weights of the testis, epididymis, and seminal vesicle; and 3). sperm numbers in both regions of the epididymis declined significantly in a dose-dependent manner in the 10- and 1- microg groups. Conversely, in the <1- microg groups, none of these parameters (except DSP/testis and weight of the epididymis in the 100-ng group, and sperm numbers in the epididymis of the 100- and 10-ng groups) was different from controls. Generally, plasma testosterone levels decreased in the 10- and 1- microg groups, FSH level increased in the 10-microg group, and prolactin and LH levels were unaltered. In the fertility study, although each male in the 1-microg, 100-ng, and control groups produced a copulatory plug and impregnated a female, none could do so in the 10-microg group. The mean number of pups per litter was reduced to eight in the 1-microg group, in contrast to 15 each in the 100-ng and control groups. In conclusion, exposure of neonatal male rats to DES altered sperm motility patterns, sperm fertility (as evident from the reduced number of pups in the 1-microg group), and sexual behavior (as evident from the absence of copulatory plugs in the 10-microg group) and reduced weights of reproductive organs, DSP/testis, and sperm numbers in the epididymis. Whether these alterations/reductions persist in older rats (6-8 mo of age) is under investigation.

Animals↗
PubMed2003

Antioxidant vitamins improves hemoglobin level in children with group a beta hemolytic streptococcal infection.

A study was done on school children infected with group A beta hemolytic streptococci to examine whether antioxidant vitamins play a role in improving the hemoglobin level. A total of 606 primary school children aged 5 to 15 years were randomly divided into two intervention groups. Group 1 (n=299) was treated with pehnoxymethyl penicillin V and group 2 (n=307) was treated with phenoxymethyl penicillin V plus antioxidant vitamins for eight weeks. From each group two blood samples were drawn in acute and convalescent (after eight weeks) states. Before treatment, mean hemoglobin values were 11.0 and 10.8 mg/dL in groups 1 and 2 respectively. After treatment hemoglobin values were 10.5 and 11.6 mg/dL respectively. Values were significantly decreased in group 1 (P=0.0001), whereas increased in group 2 (P=0.001). Adjustment for age and sex by ANCOVA confirmed the difference in hemoglobin levels between group (LS means-0.5 vs 0.8 in groups 1 and 2 respectively (P=0.0001). Hemoglobin level increases after antioxidant vitamin supplementation in children suffering from group A beta hemolytic streptococcal infection.

Adolescent↗
PubMed2000

Ancient adaptation of the active site of tryptophanyl-tRNA synthetase for tryptophan binding.

The amino acid binding domains of the tryptophanyl (TrpRS)- and tyrosyl-tRNA synthetases (TyrRS) of Bacillus stearothermophilus are highly homologous. These similarities suggest that conserved residues in TrpRS may be responsible for both determining tryptophan recognition and discrimination against tyrosine. This was investigated by the systematic mutation of TrpRS residues based upon the identity of homologous positions in TyrRS. Of the four residues which interact directly with the aromatic side chain of tryptophan (Phe5, Met129, Asp132, and Val141) replacements of Asp132 led to significant changes in the catalytic efficiency of Trp aminoacylation (200-1250-fold reduction in k(cat)/K(M)) and substitution of Val141 by the larger Glu side chain reduced k(cat)/K(M) by 300-fold. Mutation of Pro127, which determines the position of active-site residues, did not significantly effect Trp binding. Of the mutants tested, D132N TrpRS also showed a significant reduction in discrimination against Tyr, with Tyr acting as a competitive inhibitor but not a substrate. The analogous residue in B. stearothermophilusTyrRS (Asp176) has also been implicated as a determinant of amino acid specificity in earlier studies [de Prat Gay, G., Duckworth, H. W., and Fersht, A. R. (1993) FEBS Lett. 318, 167-171]. This striking similarity in the function of a highly conserved residue found in both TrpRS and TyrRS provides mechanistic support for a common origin of the two enzymes.

Acylation↗
PubMed2000

Study of water quality of Hudiara drain, India-Pakistan.

This paper examines the extent of pollution in Hudiara drain water due to untreated industrial and sewage waste of India and Pakistan. Ninety-nine surface water samples from the Pakistani side of the Hudiara drain were collected during September 1997, and April and June 1998. The analytical results of the Hudiara drain samples point out the industrial and sewage inputs from India and Pakistan. Higher values of biochemical oxygen demand (BOD), chemical oxygen demand(COD), total organic carbon(TOC), and trace metals in drain samples from the Indo-Pak border clearly indicate the Indian industrial and sewage pollution. Large variations in the levels of various measured parameters (COD, BOD, TOC, pH, total soluble substances, and trace metals) were observed along the Hudiara drain in the Pakistani vicinity. These variations were due to different types of industrial effluents and small village drains. The study showed that suspended solids(SS), COD, and fecal coliform (FC) were the major pollutants. Accordingly, the most feasible alternative is to convert the drainage network to a sedimentation and temporary storage reservoir. If disinfected, the runoff water can be used for restricted irrigation. Groundwater samples taken from the drain's surrounding area have also been analyzed. Thirty percent of the samples are not fit for drinking purposes due to NO3-N, Se and FC counts as prescribed by World Health Organization (WHO) guidelines. A trilinear diagram clearly indicates the influence of surface water of the Hudiara drain on ground water; moreover, higher values of nitrate and FC clearly indicate the seepage from the Hudiara drain.

Environmental Monitoring↗
PubMed2000

Outcome of pediatric thromboembolic disease: a report from the Canadian Childhood Thrombophilia Registry.

The outcome for children with deep vein thrombosis (DVT) and pulmonary embolism (PE) is unknown. An understanding of morbidity and mortality of DVT/PE is crucial to the development of rational treatment protocols. The Canadian Childhood Thrombophilia Registry has followed 405 children aged 1 mo to 18 y with DVT/PE for a mean of 2.86 y (range, 2 wk to 6 y) to assess outcome. The all-cause mortality was 65 of 405 children (16%). Mortality directly attributable to DVT/PE occurred in nine children (2.2%), all of whom had central venous line-associated thrombosis. Morbidity was substantial, with 33 children (8.1%) having recurrent thrombosis, and 50 children (12.4%) having postphlebitic syndrome. Recurrent thrombosis and postphlebitic syndrome were more common in older children, although deaths occurred equally in all age groups. The incidence of recurrent thrombosis and postphlebitic syndrome are likely underestimated because of difficulties in diagnosis, especially in younger children. The significant mortality and morbidity found in our study supports the need for international multicenter randomized clinical trials to determine optimal prophylactic and therapeutic treatment for children with DVT/PE.

Adolescent↗
PubMed1997

Retroperitoneal actinomycosis masquerading as inflammatory pseudotumor.

Inflammatory pseudotumors present clinically as mass lesions and microscopically show a spectrum of nonspecific inflammatory and regenerative changes. When the mesentery or retroperitoneum are involved, differentiation from inflammatory fibrosarcoma poses a diagnostic problem. The authors report on a 7-year-old boy who presented with fever, anemia, weight loss, and a retroperitoneal mass. Needle biopsy results of the mass showed features consistent with inflammatory pseudotumor. Examination of the resected mass showed actinomycosis.

Actinomycosis↗
PubMed1996

Correcting for ethnicity when defining large for gestational age infants in diabetic pregnancies.

The large-for-gestational-age (LGA) infant, defined as > 90th birthweight percentile, is associated with mild disturbances of maternal glucose tolerance. In the UK the same birthweight percentile charts are used for all ethnic groups when assessing LGA infants. The influence of maternal hyperglycaemia on LGA infants of Asian (Indian Subcontinent) mothers in the UK is likely to be under-reported, as Asian birthweights tend to be lower than White/Europid birthweights. We assessed the number of LGA infants born consecutively to 21 Asian and 26 White/Europid mothers with gestational diabetes mellitus (GDM), delivered between 37 and 42 weeks gestation, and also in 34 Asian and 121 White/Europid mothers with a positive screening test for GDM but a normal 75 g oral glucose tolerance test (OGTT). Large-for-gestational-age infants were identified using both the standard UK percentile charts of the Medical Research Council and percentile charts constructed from 30,418 Asian and 162,477 White/Europid singleton births, delivered between 37 and 42 weeks gestation to non-diabetic mothers delivered in the North West Thames Region of England. The standard Medical Research Council percentile charts, compared with the ethnically derived charts, identified fewer LGA Asian (7/56 vs 15/56) but more White/Europid infants (33/147 vs 21/147). When correcting for ethnicity more Asian than White/Europid GDM mothers delivered LGA infants (9/21 vs 3/26, chi 2 = 4.76, p < 0.05). The maternal 2 h OGTT plasma glucose was a significant independent contributor to birthweight in the Asian (r2 = 0.319, p < 0.0005) but not the White/Europid infants, in whom gestational age and maternal height were significant independent contributors to birthweight (r2 = 0.158, p < 0.0001). We conclude that ethnic influences are important when defining LGA infants and that mild disturbances of maternal glycaemia have a greater influence on the birthweight of Asian than White/Europid infants.

Adult↗
PubMed1996

Overnight metabolic fuel deficiency in patients treated conventionally for hypopituitarism.

BACKGROUND: Hormone replacement in hypopituitary adults attempts to reproduce normal physiology. Conventional regimens fail to mimic normal hormone profiles over 24 hours. OBJECTIVE: To investigate the metabolic consequences of conventional hormone replacement in hypopituitary adults by measuring circulating levels of the major fuels, glucose, non-esterified fatty acids (NEFA), glycerol and 3-hydroxybutyrate (3-OHB) over 24 hours in hypopituitary subjects and controls. SUBJECTS: Ten GH and adrenocorticotrophin deficient hypopituitary adults on conventional replacement and 13 controls matched for age, sex and body mass index were studied. The patients received replacement with hydrocortisone twice daily (at 0730 and 1730 h; mean (range) daily dose 22 (10-30) mg/24 h) but not with GH. Other hormones were replaced as clinically necessary. MEASUREMENTS: Circulating glucose, NEFA, glycerol and 3-OHB levels were measured over 24 hours together with concentrations of cortisol (total and free), GH and insulin, and urinary free cortisol. RESULTS: Levels of glucose, NEFA and 3-OHB were lower in patients than controls (mean +/- SEM) (4.3 +/- 0.1 vs 5.3 +/- 0.1 mmol/l, P = 0.0001; 291 +/- 46 vs 448 +/- 48 mumol/l, P = 0.015; 78 +/- 8 vs 136 +/- 24 mumol/l, P = 0.035, respectively) before breakfast. This decrease in glucose, NEFA and 3-OHB was observed in the patient group throughout the night, from midnight to breakfast. For NEFA, the decrease persisted throughout the 24 hours. Glycerol did not differ significantly in patients and controls. Integrated levels of total and free plasma cortisol, and 24-hour urine cortisol excretion, were normal in patients but total and free plasma cortisol concentrations overnight were markedly decreased (overnight area under the curve (AUC) of total cortisol: 440 +/- 154 vs 1593 +/- 267 nmol/l h, P = 0.0024; overnight AUC of free cortisol: 24 +/- 8 vs 161 +/- 26 nmol/l h, P = 0.0001). GH levels were low throughout the whole 24 hours in the patient group (24-hour AUC: 10.6 +/- 5.1 vs 74.6 +/- 19.6 mU/l h, P = 0.008). CONCLUSIONS: Hypopituitary adults on conventional hormone replacement regimens have low concentrations of metabolic fuels, glucose, non-esterified fatty acids and 3-hydroxybutyrate throughout the night, possibly related to GH deficiency or to decreased overnight circulating cortisol levels. This overnight fuel deficiency may underlie the mechanism for the non-specific symptoms, such as fatigue and headache in the early morning, which are frequent in this group of patients.

3-Hydroxybutyric Acid↗
PubMed1996

[Feasibility of obtaining a highly active mutant of Streptomyces hygroscopicus SU-A5 using induced mutagenesis].

Mutagenic and lethal effects of gamma-radiation, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and 4-nitroquanidine-1-oxide were investigated on spore suspensions of Streptomyces hygroscopicus SU-A5. It was shown that all the agents induced high percentage of plus mutants. The most stable and active ones were induced by gamma-radiation. The frequency of the plus mutants and the variation coefficient were used as the criteria of the mutagen efficiency. The successive exposure to gamma-radiation, MNNG and gamma-radiation resulted in the formation of a mutant with the activity 3 times higher than that of the parent strain.

4-Nitroquinoline-1-oxide↗
PubMed1995

The Canadian Hemophilia Registry as the basis for a national system for monitoring the use of factor concentrates.

BACKGROUND: Canada's publicly funded blood system has recently introduced high-purity concentrates as the standard treatment for individuals with hemophilia. The added cost and the need to document patient outcomes have prompted the consideration of a national blood product monitoring system. STUDY DESIGN AND METHODS: This study investigates the suitability of the Canadian Hemophilia Registry (CHR) as the basis of such a monitoring system by assessing the degree to which it represents users of factor concentrates. RESULTS: Currently, there are 1978 individuals registered with the CHR, of whom 1594 (81%) have hemophilia A and 384 (19%) have hemophilia B. The total prevalence is 7.2 per 10(5) population, with the prevalence of severe cases being 2.3 per 10(5). This overall prevalence is similar to that seen in other countries with national registries. The CHR national prevalence also compares favorably with that in the province of Quebec, where registration of users of blood products is compulsory. The CHR figures indicate that the number of persons currently infected with human immunodeficiency virus, both alive and dead, is 652, which is similar to the number of applicants (658) to the federal government's assistance program. The registry is stable, and the number of persons with severe cases, other than young children, newly registered or lost to follow-up during the last 2 years is very small. CONCLUSION: The CHR includes the vast majority of factor concentrate users and is therefore ideal as the basis for a national monitoring system.

Adolescent↗
PubMed1995

Insulin secretion and sensitivity in women fulfilling WHO criteria for gestational diabetes.

Abnormalities of insulin secretion rather than insulin sensitivity are described in women fulfilling the American criteria for gestational diabetes. We examined insulin secretion and insulin sensitivity in 38 women at risk of gestational diabetes categorized according to the less stringent WHO criteria, based on the 75 g oral glucose tolerance test, performed at 24 weeks gestation. Insulin sensitivity was assessed at 28 and 36 weeks using the short insulin tolerance test. Applying WHO criteria, 18 women had GDM. Age and body mass index of the GDM and glucose tolerant women were similar (32.4 +/- 1.1 (SE) vs 32.3 +/- 1.9 yr; 28.7 +/- 1.5 vs 28.8 +/- 1.7 kg m-2, respectively). Fasting glucose was higher in the GDM women than controls (5.1 +/- 0.2 vs 4.5 +/- 0.1 mmol l-1, p < 0.025) while fasting insulin was similar (75 +/- 18 vs 90 +/- 16 pmol l-1). The 30-min insulin concentration during the OGTT was lower in the GDM women than controls (436 +/- 61 vs 788 +/- 152 pmol l-1, p < 0.05), while the insulin sensitivity at 28 (87 +/- 5 vs 76 +/- 5 mumol l-1 min) and 36 weeks (73 +/- 8 vs 76 +/- 8 mumol l-1 min) was similar. A negative correlation existed between the 30-min insulin and 120-min glucose concentration during the OGTT (Rho -0.328, p < 0.05). The WHO criteria for GDM identify women with similar abnormalities of insulin secretion as the more stringent American criteria.

Adult↗
PubMed1995

Evaluation of enzyme immunoassay for the detection of anogenital infections caused by Chlamydia trachomatis.

BACKGROUND--Infection caused by Chlamydia trachomatis is now recognised as the most prevalent sexually transmitted disease in many parts of the world. Anorectal infections caused by C. trachomatis is not uncommon. Enzyme-linked immunoassay (EIA) detects an antigen lipopolysaccharide (LPS) of C. trachomatis directly in clinical specimens. OBJECTIVE--Our aim was to compare an enzyme immunoassay, Wellcozyme Chlamydia (WZ04) with cell culture for the diagnosis of chlamydial infection of the anogenital tract. METHOD--Rectal swabs were taken from 100 prostitutes (80 females and 20 males) for chlamydia culture, WZ04 and direct immunofluorescence (DIF). In addition, endocervical specimens were obtained from the females for the above three tests. MAIN FINDINGS--All the positive rectal specimens were from females. Nine patients had a positive chlamydia culture from the rectum but negative WZ04 and DIF. Two patients had false positive results by WZ04 but negative culture and DIF. For cervical specimens, WZ04 identified 43% (3/7) of the culture positive cases. Specificity was 98.6%. WZ04 identified an additional specimen as positive which was also confirmed as positive by DIF. CONCLUSION--Our study shows that in our hands enzyme-linked immunoassays such as Wellcozyme Chlamydia are neither sensitive nor specific in detecting C. trachomatis infection of the rectum. For cervical infections, the sensitivity of WZ04 was 43% and the specificity 98.6% as compared to culture, with a positive predictive value of 75% and a negative predictive value of 94.7%.

Adult↗
PubMed1995

Human immunodeficiency virus (HIV) antigen testing to detect HIV infection in female sex workers in Singapore.

Human immunodeficiency virus (HIV) infection is characterised by seroconversion after a ¿window¿ period of 2 to 3 months. After this period antibodies are usually detectable by screening tests (enzyme immunoassay or particle agglutination) confirmed by Western blot analysis. We studied 1000 newly enrolled female sex workers who had not been previously tested for HIV to assess the usefulness of HIV antigen testing to improve the efficacy of HIV infection detection. Blood was taken at enrollment for HIV antigen and HIV antibody testing. The Abbott HIVAG-1 test was used to detect antigen; antibody detection was by the Abbott recombinant HIV-1/HIV-2 3rd generation enzyme immunoassay (EIA) test, the Fujirebio Serodia-HIV particle agglutination (PA) test for screening, and the Diagnostic Biotechnology HIV Blot 2.2 Western blot (WB) test for antibody confirmation. Of the 1000 samples, 26 were positive for HIV antibody testing (26/26 for EIA, 25/25 for PA, 26/26 for WB), giving a prevalence rate of 2.6%, Of these 26 seropositive samples 1 was positive on HIV antigen testing. There were no samples which were antigen-positive and antibody-negative. HIV antigen testing does not add to increased efficacy of HIV detection among female sex workers in Singapore.

Blotting, Western↗
PubMed1994

Randomised trial of intravenous immunoglobulin G, intravenous anti-D, and oral prednisone in childhood acute immune thrombocytopenic purpura.

The most serious complication of childhood acute immune thrombocytopenic purpura (ITP), intracranial haemorrhage, occurs in about 1% of children with platelet counts below 20 x 10(9)/L. We conducted a randomised study to explore three treatment options in this high-risk group. 146 children (> 6 months and < 18 years old) with typical acute ITP and platelet counts of 20 x 10(9)/L or lower were randomised to receive high-dose intravenous immunoglobulin G (IVIgG) 1 g/kg on 2 consecutive days (n = 34), 0.8 g/kg once (n = 35), intravenous anti-D 25 micrograms/kg on 2 consecutive days (n = 38), or oral prednisone 4 mg/kg per day with tapering and discontinuation of prednisone by day 21 (n = 39). The rate of response as reflected by the number of days with platelet counts at 20 x 10(9)/L or lower and the time taken to achieve a platelet count 50 x 10(9)/L or more was significantly faster for both IVIgG groups than for the anti-D group (p < 0.05); the difference between prednisone and IVIgG was significant (p < 0.05) only for the IVIgG 0.8 g/kg group, and responses to the two IgG groups were similar. These differences in response rates were reflected in the percentages of children with platelet counts of 20 x 10(9)/L or lower at 72 hours following the start of treatment: 3% (IVIgG 0.8 g/kg x 1), 6% (IVIgG 1 g/kg x 2), 18% (anti-D), and 21% (oral prednisone 4 mg/kg/day). Treatment-associated toxicities included a fall in haemoglobin with anti-D (to less than 100 g/L in 24% of cases); weight gain with oral prednisone; and fever, nausea, vomiting, and headache with IVIgG. On the basis of these results, intravenous anti-D cannot be recommended as initial therapy for children with acute ITP and platelet counts of 20 x 10(9)/L or lower. A single dose of 0.8 g/kg IVIgG offers the fastest recovery for the least treatment; additional IgG or oral prednisone can be reserved for the one-third of children who continue to have platelet counts of 20 x 10(9)/L or less at 48-72 hours after the start of treatment.

Adolescent↗