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Biomedical subjects

M Z Khan

Publications and source records attributed to M Z Khan.

At least 37 records · Page 2Linked to original sources
PubMed1999

Paracetamol-propyphenazone interaction and formulation difficulties associated with eutectic formation in combination solid dosage forms.

Polymorphic behaviours of paracetamol and propyphenazone and interaction between these two compounds were investigated using differential scanning calorimetry (DSC), X-ray powder diffraction and Fourier transform-infrared (FT-IR)-spectroscopy. Binary mixtures containing various ratios of the compounds were prepared as physical and fused mixtures and analysed by DSC to study their thermal behaviours. Phase diagrams obtained from the melting endotherms of the binary mixtures demonstrated formation of an eutectic mixture at a paracetamol-propyphenazone combination of about 35:65 (w/w) with an eutectic temperature of 56 degrees C. The FT-IR spectroscopy revealed no chemical interaction due to eutectic formation, and a lower degree of crystallinity of the eutectic mixture than individual substances was observed by X-ray powder diffraction analysis. The DSC and X-ray powder diffraction data demonstrated a polymorphic change in propyphenazone as a result of melting of the compound. Tablets, containing both paracetamol and propyphenazone in a combination formulation and prepared using standard wet granulation technology, were found to have physical instability when packed in either polyvinylchloride// aluminium or polyvinylchloride/polyvinyldienechloride// aluminium blisters and stored for one month at 40 degrees C with either 75% relative humidity or without any humidity control. The instability of the tablets was more apparent under the high humidity condition.

Acetaminophen↗
PubMed1998

Macrophages in the chicken oviduct: morphometrical studies by light and transmission electron microscopy and the possible influence of sex hormones.

Light and electron microscopic techniques were used to study the morphometry and dynamic changes of macrophages in the postnatal and sex hormone-treated chicken oviduct, respectively. Abundant typical macrophages, containing clear vacuoles, well-developed mitochondria, Golgi complexes and lysosomal bodies in their cytoplasms, were observed in the lamina propria of all segments of the postnatal chicken oviduct, occurring more frequently in the vaginal part. When 7-day-old chickens were injected with diethylstilbestrol (DES), and DES plus progesterone, infiltration of a significant number of macrophages in both groups, but not in controls could be seen. The light and electron microscopic structures of the macrophages in both postnatal and sex hormone-treated chicken oviduct were similar. These results show that typical macrophages are present in the chicken oviduct; their frequency of occurrence varies with different oviductal segments, and they are influenced by sex hormones.

Aging↗
PubMed1998

Hormonal profiles of callipyge and normal sheep.

Five sheep expressing the callipyge gene, which causes muscle hypertrophy, were compared with five normal sheep to determine whether endocrine differences existed between genotypes. Blood samples were taken at 15-min intervals for 6 h to measure serum concentrations of growth hormone and insulin. Thyroxine and IGF-I levels were determined in single samples. No differences were found in mean serum growth hormone concentrations, growth hormone pulse amplitude, or pulse frequency (P > .3). Insulin concentrations were not different between genotypes before or after feeding (4.5 +/- 1.3 ng/mL callipyge vs 4.9 +/- 1.7 ng/mL normal, P > .4). The IGF-I concentrations did not differ (273.8 +/- 17.6 ng/mL callipyge vs 261.4 +/- 12.3 ng/mL normal). Serum thyroxine concentrations also were not different (5.9 +/- 2.3 microg/mL for callipyge vs 5.1 +/- 2.1 microg/mL normal, P > .3). In a separate experiment, five ewe lambs with and five without the callipyge gene were stressed to determine whether the adrenocortical response to stress differed between genotypes. Blood samples were taken at 15-min intervals for 2 h before, during, and after restraint stress. Restraint increased serum cortisol concentrations in both groups (P < .001), but genotypes did not differ at any time (P > .3). These results suggest that differences in muscling are not due to differences in systemic hormone secretion. The results of the second experiment indicate that callipyge and normal sheep have similar adrenocortical responses to stress.

Animals↗
PubMed1998

Furazolidone toxicosis in female Japanese quail (Coturnix coturnix japonica): pathomorphological changes in reproductive tract and reversibility of the induced changes.

Female Japanese quail (Coturnix coturnix Japonica) placed in 3 equal groups were given 600, 400 or 0 mg furazolidone (Fz)/kg feed for 4 w and then withdrawn for another 4 w. Another (pair-fed) group of same size was given basal feed as much as was consumed by the quail fed 600 mg Fz/kg feed. Fz feeding decreased body weight, feed intake and egg production. Ovaries of the Fz-fed quail decreased in weight and size and were studded with small follicles. Magnum, isthmus and uterus in Fz-fed groups had decreased area, height and number of mucosal folds compared with the control group. Microscopically, in Fz-fed groups, the mucosal glands in magnum and isthmus had decreased cell height with centrally located nuclei and foamy cytoplasm. In the 600 mg Fz-fed group, some birds had atrophy of the glandular tissue in the mucosa and infiltration of mononuclear cells and fibroblasts. Upon cessation of the Fz feeding, all parameters reversed gradually and became non-significantly different from control quail. These observations suggested that Fz-induced changes in mature female quail were reversible.

Animals↗
PubMed1997

Postnatal development of B lymphocytes and immunoglobulin-containing plasma cells in the chicken oviduct: studies on cellular distribution and influence of sex hormones.

Postnatal development of B lymphocytes and plasma cells containing different classes of immunoglobulins (IgG, IgA, and IgM) was immunohistochemically studied in the oviduct of the Dekalb strain of the White Leghorn chicken. B lymphocytes first appeared in the lamina propria of the chicken oviduct at 5 weeks of age. Their frequency of occurrence peaked at 15 weeks from the infundibulum to the uterus (glandular part), while in the vagina (aglandular part) it did so at 21 weeks. Intraepithelial B lymphocytes were very rare and exclusively located in the vagina at 19 and 21 weeks. Plasma cells first appeared in the lamina propria of the oviduct at 11 weeks of age, and this frequency peaked at 32 weeks. IgG-containing plasma cells were most numerous in the glandular part, whereas in the aglandular part IgA and IgM cells were more numerous than IgG cells. When 7-day-old-chickens were treated with sex hormones, B lymphocytes and plasma cells appeared 12 h and 5 days after the hormone injection, respectively. Their frequency of occurrence was statistically higher in diethylstibestrol (DES)-treated chickens than in DES plus progesterone-treated chickens. This suggests that the postnatal development of B lymphocytes and plasma cells in the oviduct of the chicken is correlated to estrogen secretion.

Animals↗
PubMed1997

A preliminary comparison of plasma fibrinogen concentrations, leukocyte numbers and erythrocyte sedimentation rate as non-specific indicators of inflammatory conditions in buffalo (Bubalis bubalis).

The plasma fibrinogen concentration (Fib), total leukocyte count (TLC), neutrophil, lymphocyte and monocyte numbers, and the erythrocyte sedimentation rate (ESR) were determined in 153 buffaloes suffering from different clinical conditions. Fib increased significantly (p < 0.05) in chronic mastitis, pyrexia, pyometra, cutaneous abscesses, tail gangrene and acute indigestion, whereas in most of the other conditions studied it varied non-significantly. TLC increased significantly in chronic mastitis, pyrexia, endometritis, cutaneous abscesses and infected skin wounds. An increase in neutrophils was associated with an increased TLC. Numbers of lymphocytes varied non-significantly in most of the conditions. Monocytes decreased significantly in most of the acute conditions. ESR was significantly elevated in all clinical conditions. Significantly increased mean Fib values in the different conditions varied from 703 +/- 119 to 725 +/- 140 mg/dl, while the maximum individual value was 1510 mg/dl in a case of cutaneous myiasis. The significantly increased mean TLC ranged from 9.48 +/- 2.91 to 11.1 +/- 3.5 x 10(3)/microliter, while it was 21.7 x 10(3)/microliter in a case of meningitis. ESR values in sick buffaloes varied from 57 to 111 mm in the first hour.

Animals↗
PubMed1996

Development of T-lymphocyte subpopulations in the postnatal chicken oviduct.

Postnatal development of t-cell subpopulations in the oviduct was investigated in the Dekalb strain of the White Leghorn chicken by using an immunohistochemical method. T-lymphocytes first infiltrated the oviduct at 5 weeks. The number of T cells peaked at 15 weeks in the magnum, isthmus and uterus, and at 19 weeks in the infundibulum and vagina. The epithelium of the oviduct contained both granular and agranular lymphocytes. TcR1+ cells were predominant in the epithelium, whereas TcR2+ cells were more numerous than TcR1+ cells in the lamina propria. TcR3+ cells were absent from the epithelium and were not numerous in the lamina propria. CT8+ cells, equivalent to CD8+ cells in mammals, were located both in the epithelium and in the lamina propria. The relative frequency of T-cell subpopulations was found to be higher in the vaginal part than in the other parts of the oviduct. These results suggest that the postnatal developmental changes of T-cell subpopulations depend on different anatomical regions of the oviduct and on the age of the chicken.

Animals↗
PubMed1996

Tibial reconstruction by ipsilateral vascularized fibular transfer.

Between 1979 and 1991 ipsilateral vascularized fibular transposition was performed on eight patients with segmental tibial defects following injury. We report these cases with a minimum follow-up of 2.5 years. All the tibial defects were the result of severe open fractures (Gustilo Grade III) and either bone loss or infected non-union, and ranged in size from 1 to 12 cm. The patients had an average of seven procedures and a delay of 33 months before fibular transfer. The procedure was successful in achieving fracture union in all cases, with an average time to union of 15 months (range, 5-33 months). Shortening of up to 3 cm and some residual ankle stiffness was found, but all patients were ambulating bearing full weight and six had returned to their previous occupation by their final follow-up. Only one patient had significant pain affecting function. This is a successful and relatively simple technique compared to microvascular and bone transport procedures for reconstructing segmental tibial defects with relatively avascular graft beds.

Adolescent↗
PubMed1996

Hormonal regulation of T-cell subsets in the oviduct: an immunohistochemical study using sex-hormone-treated chicken.

The present immunohistochemical study deals with dynamic alteration of T-cell subsets in the oviduct sex-hormone-treated chickens. Monoclonal antibodies (CT3, CT4, and CT8) specific for the chicken homologues of CD3, CD4, and CD8 were used in estrogen- or progesterone-treated chickens. In control animals, no lymphocytes appeared throughout the oviduct until 4 weeks of age. When 7-day-old chickens were injected with either diethylstilbestrol (DES) or (DES) plus progesterone, T cells immunoreactive for CT3 first infiltrated the oviduct at 12 hr after the hormone treatment. Their frequency of occurrence rose from 48 to 96 hr. Subsequently, CT3+ cells in the magnum declined in number per area coincident with the proliferation of albuminous glands in the lamina propria, while in the vagina no decline of T cells was observed. The population of T-cell subsets in the lamina propria of both the magnum and vagina was significantly higher in the DES-treated chickens than in DES plus progesterone-treated chickens. Among T-cell subsets CT8+ cells were more numerous than CT4+ cells throughout the study, this relative frequency being shared by normal adults. Depopulation of lymphocytes from the thymus, spleen and cecal tonsil, their mobilization to the circulating blood, and subsequent dynamic infiltration into the oviduct suggested that the sex hormones induced the traffic of T cells from the lymphoid organs into the oviduct.

Animals↗
PubMed1996

An immunohistochemical analysis of T-cell subsets in the chicken bursa of Fabricius during postnatal stages of development.

T-cell subsets in the chicken bursa of Fabricius were analysed immunohistochemically during postnatal stages. Distinct types of T cells were present both in the surface epithelium and lamina propria of the bursa. TcR1+ and CT8+ cells were predominant in the surface epithelium, while TcR2+ and CT8+ cells were numerous in the lamina propria. These T-cell subsets peaked in frequency of occurrence at 5 weeks. They then decreased in number, and a few T cells remained in the bursa until 15 weeks of age. This result showed that the bursa of chickens is furnished with the distinct types of T-cell subsets at early postnatal stages of development to maintain its local immunity.

Aging↗
PubMed1996

Reversibility of furazolidone-induced changes in testes and secondary sex characters of White Leghorn cockerels.

Furazolidone (Fz) was fed to 4 groups of cockerels 15 w of age at 0, 400, 800 and 1200 mg/kg feed for 3 w and then was withdrawn for another 3 w. In a second experiment conducted simultaneously cockerels were fed these same Fz levels for 6 w and then were withdrawn from Fz feed for 4 w. In both experiments, 800 and 1200 mg Fz/kg feed resulted in decreases in comb and wattle size and in the weight of testes. The testes had smaller seminiferous tubule diameters and increased relative and decreased absolute volumes of interstitium. Spermatogenesis was not observed in cockerels fed 800 and 1200 mg Fz/kg feed. Withdrawal of Fz resulted in increased comb and wattle size, weight of testes and diameter of the seminiferous tubules. There was also an increase in absolute volume of interstitium along with decreased relative interstitium volume. Spermatogenesis was restored.

Administration, Oral↗
PubMed1995

Effect of concurrent feeding of furazolidone and sodium chloride upon some clinical, pathological and cardiac morphometric parameters in broiler chicks.

Broiler chicks in different groups were fed furazolidone (0, 400 and 800 mg/kg feed) and sodium chloride (500 and 1510 mg/kg feed) separately and concurrently from 1 to 30 days of age. Furazolidone (Fz) induced ascites, leg weakness, convulsions, depression and mortality was exacerbated by concurrent feeding of 1510 mg NaCl. Hemorrhages in the liver, swollen kidneys, pallor of the kidneys and cystic testes were present in all birds fed furazolidone either alone or in combination with NaCl. However, at microscopic level, necrotic changes were observed in the liver and kidneys of birds fed NaCl only. Fz-induced cardiac ventricular dilatation and thinning of walls were more severe when 400 mg Fz was fed concurrently with 1510 mg NaCl but feeding of 800 mg Fz with the same level of NaCl resulted in partial amelioration of cardiac changes. It is suggested that high dietary NaCl may exacerbate and alter the clinical and morphological picture of Fz toxicosis.

Animals↗
PubMed1995

Experimental furazolidone toxicosis in broiler chicks: effect of dosage, duration and age upon clinical signs and some blood parameters.

Groups of broiler chicks of one day and three weeks of age were given feeds containing 0, 400, 800 and 1000 mg furazolidone (Fz)/kg for three weeks. The age of the birds and the dose and duration of Fz treatment significantly (P < or = 0.05) influenced the parameters studied. Clinical signs of Fz toxicosis included ascites, leg weakness and nervous derangement like convulsions and torticollis. The body weight also decreased. Ascites and nervous derangement was not observed in birds fed 400 mg Fz from one day of age. Fz-fed birds developed anaemia and had lower plasma total protein and albumin levels than those fed no Fz. The decrease in body weight was related to reduced feed intake. Decreases found in the haematological parameters and plasma proteins showed no correlation with the chicks' age but were related to the dose and duration of Fz treatment.

Anemia↗
PubMed1995

Furazolidone toxicosis in young broiler chicks: morphometric and pathological observations on heart and testes.

Broiler chicks 1 d and 3 w of age were given 0, 400, 800, or 1000 mg furazolidone (Fz)/kg feed for 4 w. Bi-ventricular heart dilatation (as measured by increases in ventricular diameter and thinning of the ventricular walls) was present in 1-d-old chicks fed 800 mg Fz, whereas in 3-w-old groups these changes occurred at 1000 mg Fz. There was no heart hypertrophy. Microscopic changes in the heart were not discernible in and Fz-fed birds. The liver had congestion and cytoplasmic vacuolation of hepatocytes. About 37-50% of the male birds in the different Fz-fed groups had testicular degeneration varying from mild to cystic enlargement. The degenerated testes had dilatation of seminiferous tubules; in cystic testes the seminiferous tubules were extremely dilated and had flattened epithelium. The interstitial tissue between the dilated tubules was compressed and atrophic.

Administration, Oral↗
PubMed1995

Effect of different intensities of fluorescent light on the early development of chick embryos in ovo.

Artificial conditions of incubation light have been found to have profound effects on hatchability of chicken and turkey eggs. It has been shown that illumination of eggs throughout the incubation period reduces hatching time by approximately 20 h compared with dark incubation. Experiments carried out in the present study using different intensities of fluorescent light for first 40 h of incubation in ovo indicate significant acceleration of morphogenesis in chick embryos as determined by cell population analysis. The maximum acceleration of growth was observed at intensity range of 1500-3000 lux without any adverse effects as compared with dark-incubated controls (p < 0.01).

Animals↗
PubMed1994

Preliminary observations on plasma fibrinogen and plasma protein concentrations and on plasma protein:fibrinogen ratios in clinically healthy buffaloes.

The plasma fibrinogen concentration, the total plasma protein concentration and the plasma protein to fibrinogen ratio (PP:F) were determined in clinically healthy Nili Ravi buffaloes. The plasma fibrinogen concentrations in calves, lactating and non-lactating buffaloes were 513 +/- 62, 615 +/- 90 and 544 +/- 74 mg/dl, respectively, and were statistically different (p < 0.05). Total plasma protein concentrations in these animals were 7.15 +/- 0.28, 9.32 +/- 0.53 and 8.79 +/- 0.58 g/dl. PP:F for all animals was between 11 and 19. Fibrinogen levels were positively correlated with plasma protein (r = 0.59) and negatively correlated with PP:F (r = -0.59).

Animals↗