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Biomedical subjects

T H Khan

Publications and source records attributed to T H Khan.

17 recordsLinked to original sources
PubMed2006

The effects of GnRH analogue (buserelin) or hCG (Chorulon) on Day 12 of pregnancy on ovarian function, plasma hormone concentrations, conceptus growth and placentation in ewes and ewe lambs.

The objectives of this study were to determine the effect of GnRH analogue (buserelin) or human chorionic gonadotrophin (hCG, Chorulon) treatment on Day 12 of pregnancy on ovarian function, plasma hormone concentrations, conceptus growth and placentation in ewes and ewe lambs. After oestrus synchronization with progestagen sponges and eCG, all the animals were mated with fertile rams. Both ewes and ewe lambs (20 per treatment group) were given either normal saline or 4 microg GnRH or 200 IU hCG on Day 12 post-mating. Pre- and post-treatment plasma hormone concentrations were determined in seven pregnant animals per treatment group in samples collected 1h before and 0, 2, 4, 6, 8, 24, 48 and 72 h after treatment. Overall mean progesterone concentrations were higher (P<0.001) in ewes as compared with ewe lambs in saline-treated controls. GnRH or hCG treatment increased (P<0.001) mean plasma progesterone concentrations in both age groups, however, post-treatment concentrations were significantly (P<0.05) higher in ewes than in ewe lambs. Oestradiol concentrations were similar in the two control groups. In ewes, but not in ewe lambs, both GnRH and hCG treatments significantly (P<0.05) increased the mean oestradiol concentrations above pre-treatment levels. Moreover, post-treatment oestradiol concentrations in GnRH- and hCG-treated animals were significantly (P<0.05) higher than those in the saline-treated controls. LH release in response to GnRH treatment was greater (P<0.05) in ewes than in ewe lambs, whereas FSH release in ewes was less (P<0.05) than that of ewe lambs. The effects of GnRH or hCG on conceptus growth and placentation was determined at slaughter on Day 25. In ewes, GnRH treatment increased (P<0.05) luteal weight, amniotic sac width and length, and crown-rump length compared with controls, but had no effect on these parameters in ewe lambs. In ewes, hCG treatment also enhanced (P<0.05) luteal weight, amniotic sac width and length, crown-rump length, embryo weight and number of placentomes as compared with controls. In ewe lambs, there was no difference (P<0.05) between hCG and control groups in luteal weight, embryo weight and amniotic sac width but crown-rump length, amniotic sac length and the number of placentomes forming the placenta were greater (P<0.05). In conclusion, GnRH or hCG treatment on Day 12 of pregnancy can increase ovarian function, conceptus growth and placental attachment in ewes. However, these treatments were less effective in ewe lambs.

Animals↗
PubMed2005

Butea monosperma and chemomodulation: protective role against thioacetamide-mediated hepatic alterations in Wistar rats.

The present study was carried out to study the effect of Butea monosperma, a known liver acting drug on the tumor promotion related events of carcinogenesis in rat liver. Thioacetamide (TAA) was used to induce tumor promotion response and oxidative stress and caused significant depletion in the detoxification and antioxidant enzyme armory with concomitant elevation in malondialdehyde (MDA) formation, hydrogen peroxide (H(2)O(2)) generation, ornithine decarboxylase (ODC) activity and unscheduled DNA synthesis. However, B. monosperma pretreatment at two different doses restored the levels of the above-said parameters (p < 0.001) in a dose-dependent manner. The alcoholic extract of B. monosperma used in the present study seems to offer dose-dependent protection and maintain the structural integrity of hepatic cells. This was evident from the significant reduction in TAA-induced serum GOT, GPT, Lactate dehydrogenase (LDH) and gamma-Glutamyl transpeptidase activity (GGT) activities (p < 0.001). These investigations validate the use of B. monosperma in liver disorders by Ayurvedic physicians. Overall results indicate that the methanolic extract of B. monosperma possesses hepatoprotective effects and also it might suppress the promotion stage via inhibition of oxidative stress and polyamine biosynthetic pathway.

Animals↗
PubMed2005

Effect of post-mating GnRH analogue (buserelin) treatment on PGF2alpha release in ewes and ewe lambs.

The objectives of this study were to determine the effects of buserelin or saline treatment on ovarian function (Experiment 1), plasma PGFM concentrations and oxytocin stimulated prostaglandin F(2alpha) (PGF(2alpha)) release (Experiment 2) in ewe lambs and ewes. Welsh Halfbred ewes (n=26) and ewe lambs (n=24) were mated to vasectomised rams at synchronised oestrus and on Day 12 post-mating each animal was injected intramuscularly either normal saline or 4 microg buserelin. In Experiment 1, plasma progesterone and oestradiol concentrations were determined in samples collected by jugular venepuncture 1h before and at 0, 2, 4, 6, 8, 24, 48 and 72 h after treatment (n=7 per treatment group). Progesterone concentrations increased (P<0.05) from 2 to 8h after buserelin treatment and returned to basal levels after 72 h, whereas oestradiol concentrations were maximal at 2h post-treatment and returned to basal levels after 24h (P<0.05). Oestradiol concentrations were lower (P<0.05) in buserelin-treated animals than controls at 72 h post-treatment. Basal and post-treatment progesterone concentrations were greater (P<0.05) in ewes than in ewe lambs but oestradiol levels were similar for both age groups. Ovulation rate, determined by laparoscopy on Day 14, was similar for both age groups (ewes 1.1; ewe lambs 1.0). Buserelin treatment induced accessory corpora lutea in ewes (4/7; 57%) but not in ewe lambs (0/7; 0%). In the Experiment 2, plasma PGFM concentrations were determined in samples collected at 20-min intervals for 6h on Day 14 and at 20-min intervals for 1h before and at 10-min intervals for 1h and then at 20-min intervals for a further 3h period after an intravenous injection of oxytocin (1IU/kg body weight) on Day 15 post-oestrus. In this experiment there were five ewe lambs and six ewes per treatment group. There was no effect of buserelin treatment or age on basal PGFM concentrations on either Day 14 or 15. Although peak PGFM concentrations tended to be lower in buserelin-treated animals, the difference was not significant (P>0.05). However, peak duration following oxytocin challenge on Day 15 post-mating was shorter (P<0.05) in control ewes compared with control ewe lambs. In conclusion, buserelin treatment given on Day 12 post-oestrus enhances luteal function more in ewes than ewe lambs and after a transitory increase, reduces oestradiol concentrations in both ewes and ewe lambs. However, buserelin treatment does not significantly attenuate the luteolytic signal.

Age Factors↗
PubMed2004

Analgesic, antiinflammatory and CNS depressant activities of sesquiterpenes and a flavonoid glycoside from Polygonum viscosum.

Analgesic, antiinflammatory and CNS depressant activities of four sesquiterpenes, viscosumic acid, viscozulenic acid, viscoazucine and viscoazulone, and a flavonoid glycoside, quercetin-3-O-(6''-feruloyl)-beta-D-galactopyranoside isolated form the aerial parts of Polygonum viscosum (Polygonaceae) have been assessed. All test compounds exhibited CNS depressant activity in open field test, all but viscoazulone showed analgesic activity in Eddy's hot plate test, all sesquiterpenes inhibited acetic acid induced abdominal writhing in mice, and all but viscoazucine and the flavonoid glycoside exhibited mild to moderate antiinflammatory effect on carrageenan induced rat paw edema.

Acetic Acid↗
PubMed2003

hCG treatment on day of mating improves embryo viability and fertility in ewe lambs.

An investigation was conducted to determine the effects of supplementing hCG at mating time on luteal function, conceptus growth, placentation and reproductive performance in TexelxClun Forest ewe lambs. After oestrus synchronisation with progestagen sponges and PMSG ewe lambs were treated either with normal saline (n=102) or 150 IU of hCG (n=105) at mating time. At 25 days after mating 24 animals were slaughtered from each group to determine embryo viability and placental development. hCG significantly (P<0.05) increased crown-rump length (saline: 11.9+/-0.2 mm; hCG: 12.7+/-0.2 mm), amniotic sac width (saline: 11.4+/-0.4 mm; hCG: 12.0+/-0.3 mm) and the number of placentomes (saline: 90.8+/-7.3; hCG=122.4+/-6.3). Among the pregnant animals that were slaughtered on 25 days post-mating, ovulation rate tended to be higher in the hCG group compared to controls (saline: 1.16; hCG: 1.54). However, no difference was observed either in mean plasma progesterone concentrations (saline: 4.6 ng/ml; hCG: 4.9 ng/ml; sed 0.56) or in progesterone production from luteal slices when cultured in vitro (saline: 239.6+/-11.8 ng/mg; hCG: 263.2+/-13.6 ng/mg) between controls and hCG treated animals. Reproductive performance was also recorded in ewe lambs that were either treated with saline (n=78) or hCG (n=81). The total number of lambs born (saline: 38; hCG: 58) was significantly (P<0.05) greater in hCG group compared to saline-treated controls. Both lambing percentage (saline: 36%; hCG: 48%) and litter size (saline: 1.35; hCG: 1.48) tended to be greater (P<0.10) in hCG-treated animals compared to the controls. In conclusion, these data suggest that treatment of ewe lambs with hCG at the time of mating improves conceptus growth, placentation and number of lambs born.

Animals↗
PubMed2002

The relationship of family income, family size, age and circumferences with blood pressure in the female students of the Bahauddin Zakariya University, Multan, Pakistan.

In a randomly selected sample of 600 female students of the Bahauddin Zakariya University, Multan, Pakistan, belonging to different socioeconomic groups, age, family income and family size were recorded and measurements were made of arm, waist, neck and total circumferences, systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP). The correlation coefficients between different independent (age, family income, family size, arm, waist, neck and total circumference) and dependent variables (SBP, DBP and MAP) showed that age had a strong association (p < 0.001) with all types of blood pressure, whereas the correlation coefficient of family income and family size was significant with SBP (p < 0.05) and non-significant with DBP and MAP. Moreover, all the circumferences had strong relationship (p 0.05 at least) with blood pressure. The regression coefficients of age were highly significant for SBP, DBP and MAP, whereas these were non-significant (p > 0.05) for family income and family size. The regression coefficients for arm and waist were significant (p < 0.05), whereas these were highly significant (p < 0.01 at least) for neck and total circumferences. The neck had a 0.46 mm Hg/cm with SBP, 0.41 mm Hg/cm for DBP and 0.44 Hg/cm for MAP, and these were highest among the circumferences.

Adolescent↗
PubMed2001

Melanocyte-Directed enzyme prodrug therapy (MDEPT): development of second generation prodrugs for targeted treatment of malignant melanoma.

Evaluation of second generation prodrugs for MDEPT, by oximetry, has highlighted structural properties that are advantageous and disadvantageous for efficient oxidation using mushroom tyrosinase. In particular, a sterically undemanding prodrug bis-(2-chloroethyl)amino-4-hydroxyphenylaminomethanone 28 was synthesised and found to be oxidised by mushroom tyrosinase at a superior rate to tyrosine methyl ester, the carboxylic acid of which is the natural substrate for tyrosinase. The more sterically demanding phenyl mustard prodrugs 9 and 10 were oxidised by mushroom tyrosinase at a similar rate to tyrosine methyl ester. In contrast, tyramine chain elongation via heteroatom insertion was detrimental and the rate of mushroom tyrosinase oxidation of phenyl mustard prodrugs 21 and 22 decreased by 10 nanomol/min.

Agaricales↗
PubMed1999

Novel inhibitors of carboxypeptidase G2 (CPG2): potential use in antibody-directed enzyme prodrug therapy.

The design and synthesis of potent thiocarbamate inhibitors for carboxypeptidase G2 are described. The best thiocarbamate inhibitor N-(p-methoxybenzenethiocarbonyl)amino-L-glutamic acid 6d, chosen for preliminary investigations of in vitro antibody-directed enzyme prodrug therapy (ADEPT), abrogated the cytotoxicity of a combination of A5B7-carboxypeptidase G2 conjugate and prodrug PGP (N-p-{N,N-bis (2-chloroethyl)amino}phenoxycarbonyl-L-glutamate) toward LS174T cells. This is the first report of a small-molecule enzyme inhibitor proposed for use in conjunction with the ADEPT approach.

Aniline Mustard↗
PubMed1999

Melanocyte-directed enzyme prodrug therapy (MDEPT): development of a targeted treatment for malignant melanoma.

A novel prodrug rationally designed to function as a tyrosinase substrate has been synthesised to allow targeted treatment of malignant melanoma. This agent has been evaluated for tyrosinase-mediated drug release, and has been shown to act in the desired manner. Furthermore, differential cytotoxicity has been demonstrated in cell lines which express tyrosinase and those which do not.

Animals↗
PubMed1996

Blood pressure and its correlates in the population of Multan, Pakistan.

In a randomly selected sample of 1579 individuals (male = 1334 and female = 245), aging from 14 to 65 years and representing all the socioeconomic groups of Multan, age (Yr), height (cm), weight (kg), BMI (kg/ml) and blood pressure (mmHg) were recorded. Height was measured on a Holtain portable stadiometer, weight on beam scale and blood pressure was recorded with sphygmomanometer as per auscultatory method. The correlation coefficient between different independent (age, height, weight and BMI) and dependent (SBP, DBP and MAP) parameters in male, female and total population were calculated and strong association between different parameters was observed (p < 0.001 or p < 0.05). The regression equations (simple and multiple) were worked out. The regression coefficient of different independent parameters with dependent parameters are higher in female except for height and age-weight and age-BMI had higher contribution in female as compared with that of male.

Adolescent↗
PubMed1994

Blood pressure distribution in a school age population of Quetta, Pakistan.

Standardized measurements of blood pressure, height and weight were obtained in 8-11 years old children, attending school in Quetta, Balochistan, Pakistan. The sample consisted of 427 individuals (219 boys and 208 girls). The blood pressure was measured by auscultatory method. To calculate the body mass index (BMI), the weight (kg) of each subject was divided by the square of the subject's height. Association between various variables and blood pressure was judged through correlation coefficient. The net and joint effect of selected variables on blood pressure variability was calculated using simple/multiple regression. The correlation coefficients with that of systolic blood pressure were 0.365, 0.427 and 0.341 whereas these were 0.397, 0.430 and 0.320 for diastolic blood pressure. Height had a regression coefficient of 0.475 mmHg/cm with systolic pressure and 0.419 mmHg/cm with diastolic blood pressure. Weight had a regression coefficient of 0.878 mmHg/kg and 0.717 mmHg/kg with systolic and diastolic pressure respectively whereas BMI had a regression coefficient of 2.35 mmHg/BMI unit with systolic pressure and 1.79 mmHg/BMI unit with diastolic blood pressure.

Blood Pressure↗
PubMed1992

Kinetics of Bacillus cereus phosphatidylinositol-specific phospholipase C with thiophosphate and fluorescent analogs of phosphatidylinositol.

Thiophosphate analogs (C-S-P bond) of phosphatidylinositol (Cn-thio-PI: racemic hexadecyl-, dodecyl-, and octylthiophosphoryl-1-myo-inositol) and a fluorescent analog (pyrene-PI: rac-4-(1-pyreno)-butylphosphoryl-1-myo-inositol) were all substrates for phosphatidylinositol-specific phospholipase C from Bacillus cereus. Hydrolysis of thio-PI was followed by coupling the production of alkylthiol to a disulfide interchange reaction with dithiobispyridine. Hydrolysis of pyrene-PI was followed using a HPLC-based assay with fluorescence detection. The activity of PI-PLC with thio-PI analogs showed an interfacial effect. C16-Thio-PI, which had a critical micelle concentration (CMC) of 7 microM, gave a hyperbolic activity versus concentration curve between 0 and 2 mM, while C8-thio-PI, which had a CMC above 10 mM, showed very low activity which increased greatly upon introduction of an interface in mixed micelles with hexadecylphosphocholine (HDPC). Pyrene-PI, which aggregates above 0.3 mM, gave a sigmoidal activity curve with much higher activity above the CMC. All three thio-PI homologs as mixed micelles with HDPC gave hyperbolic activity curves with PI-PLC that were a function of bulk concentration of substrate at constant surface concentration and surface concentration of substrate at constant bulk concentration. The maximal activity of PI-PLC with pure C16-thio-PI micelles was 6.25 mumol min-1 mg-1, while that with pyrene-PI was estimated to be 68 mumol min-1 mg-1. With pure C16-thio-PI micelles, 0.022 mM substrate gave half Vmax, similar to that in mixed micelles with HDPC.

Bacillus cereus↗
PubMed1992

Arthroscopic resection of chondroblastoma of the knee.

We present a case of chondroblastoma of the upper tibia treated by complete arthroscopic excision. The diagnostic difficulties raised by the case are discussed. This method of treatment has not, to our knowledge, been reported in the literature.

Adolescent↗