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Biomedical subjects

Z A Khan

Publications and source records attributed to Z A Khan.

At least 19 recordsLinked to original sources
PubMed2002

Esophageal melanotic schwannoma presenting with superior vena caval obstruction.

A rare tumor with an unusual presentation can pose a diagnostic and management dilemma. In this paper, we will discuss the management of a 47-year-old lady with melanotic schwanoma of the esophagus who presented with superior vena caval obstruction. The initial histological diagnosis of esophageal metastatic malignant melanoma did not corroborate the clinical and operative findings. Further evaluation revealed positivity for HMB45, S-100 protein, and vimentin, and confirmed the diagnosis of melanotic schwannoma.

Diagnosis, Differential↗
PubMed2001

P53 mutation and response to hepatic arterial floxuridine in patients with colorectal liver metastases.

PURPOSE: To establish the relationship between the number and site of p53 genomic mutations in metastatic colorectal cancer, and the response to hepatic arterial floxuridine. METHODS: Liver metastasis biopsies were collected, at the time of laparotomy for hepatic arterial cannulation. in 28 patients with metachronous colorectal liver metastases. p53 Gene mutations were assessed using reverse transcription, nested polymerase chain reaction, single strand conformational polymorphism and gene sequencing. Chemotherapy response was determined from computerised liver tomograms after 4 months of treatment. RESULTS: Liver metastasis p53 mutation was identified in 21 (75%), and p53 "hot spot" mutation in 11 (39%) patients. There was a significantly lower prevalence (Fisher's, P=0.001) of patients with p53 "hot spot"-mutated liver metastases in stable disease and partial response (5/22) than in progressive (6/6) disease groups. Significantly fewer (Mann-Whitney U, P=0.002) p53 "hot spot" mutations/biopsy were observed in liver metastases from stable disease and partial response (median 0, iqr. 0-0) than in progressive (median 1, iqr 1-2) disease patients. p53 "Hot spot"-mutated liver metastases were associated with significantly shorter survival times (logrank P=0.05) after hepatic arterial floxuridine. Significant response or survival-time differences by total or L2/L3 zinc-binding site p53 mutations were not detected. CONCLUSIONS: The results support a role for p53 "hot spot" mutations in colorectal liver metastasis resistance to fluorinated pyrimidines, and suggest that the presence of such mutations may be a contra-indication to treatment of colorectal liver metastases with hepatic arterial floxuridine.

Adult↗
PubMed2001

Toxicity studies in mice of Commiphora molmol oleo-gum-resin.

Acute (24 h) and chronic (90 days) oral toxicity studies on Commiphora molmol (oleo-gum-resin) were carried out in mice. Dosages in acute study were 0.5, 1.0 and 3 g/kg, while in chronic study dosage was 100 mg/kg per day. All external morphological, biochemical and haematological changes, in addition to body and vital organ weights were recorded. There was no significant difference in mortality in acute or chronic treatment as compared to controls. At the end of the treatment, weight gain in the treated as well as control group was significant. There was a significant increase in weight of testes, caudae epididymides and seminal vesicles in C. molmol treated group. Biochemical studies revealed no differences in C. molmol treated animals, however, haematological studies revealed a significant increase in RBC and haemoglobin levels as compared to the control group. C. molmol failed to show any spermatotoxic effects.

Animals↗
PubMed2001

Inhibition of oxalate nephrolithiasis with Ammi visnaga (AI-Khillah).

We investigated the effect of Ammi visnaga seeds on experimentally - induced kidney stones - in male Wistar albino rats. Oxalate nephrolithiasis was experimentally induced by 3% glycolic acid (added in their diet) given for the period of four weeks. A highly significant amount of deposits were found in the kidneys, which were analyzed quantitatively. These deposits were mainly of calcium oxalate in composition. Daily oral (gavage) treatment with Ammi visnaga (500 mg/kg) highly reduced the incidence of nephrolithiasis (calcium oxalate deposition in the kidneys). Ammi visnaga seeds extract showed highly potent diuretic activity. The reduction in body weight, increase in kidneys weight, increase in water intake, decrease in urine output found in glycolic acid control group were prevented to various extent on Ammi visnaga treatment; and the values became to insignificant difference with control group. The changes in weights of liver, heart and lungs of the three groups were insignificant. Uraemia and hyperbilirubinaemia observed in glycolic acid control group were found to be ameliorated by Ammi visnaga seed extract treatment.

Ammi↗
PubMed2001

A missing vas.

Explore the source record for details and available documents.

Abnormalities, Multiple↗
PubMed2000

P53 mutations in primary and metastatic tumors and circulating tumor cells from colorectal carcinoma patients.

Circulating tumor cells could provide a relatively noninvasive and repeatable source of information about tumor cell genotype that might influence treatment and estimation of prognosis. We developed a technique for identifying p53 mutations in tumor cells isolated from the peripheral venous blood of colorectal cancer patients and compared the prevalence and position of these mutations with multiple solid tumor samples from the same patient. We used immunomagnetic beads to isolate tumor cells, reverse transcriptase-nested polymerase chain amplification of the coding region between exons 4 and 9 within the p53 gene, and automated gene sequencing. Nineteen p53 mutations were detected in solid tumor samples from 19 of 41 colorectal carcinoma patients. An identical p53 mutation was invariably present in all samples from primary and metastatic colorectal tumor biopsies within the same patient. p53 mutations were detected in peripheral blood from 8 of these 19 patients with p53-mutated solid tumors. Where identified, the pattern of mutation in peripheral blood samples was invariably the same as in matching solid tumor samples. A single colorectal carcinoma biopsy provided reliable p53 gene mutational information in colorectal carcinoma. Detection of this p53 mutation in tumor cells from peripheral blood was achieved with an approach based on cell selection for epithelial characteristics, reverse transcription-PCR, and gene sequencing.

Biopsy↗
PubMed1999

Increased detection of circulating tumor cells in the blood of colorectal carcinoma patients using two reverse transcription-PCR assays and multiple blood samples.

The objectives of this study were to assess whether the use of two reverse transcription-PCR (RT-PCR) cDNA assays and multiple blood sampling increased circulating tumor cell detection in colorectal cancer patients. Systemic blood was sampled three times at 1-min intervals in 100 colorectal cancer patients (50 primary tumors only and 50 liver metastases), and in 70 control patients without known cancer. After removal of the erythrocytes, samples were subjected to separate RT-PCR reactions using specific primers for carcinoembryonic antigen (CEA) and cytokeratin 20 (CK20). Statistical analysis was performed by the two-sample binomial test and the one-sided McNemar test. There were significant increases in circulating tumor cell positivity when CEA and CK20 assays were used together as compared with either CEA or CK20 assay used alone. There were also significant increases in circulating tumor cell positivity for either CEA or CK20 assay used alone when the results from two blood samples were compared with the results from one sample. Circulating colorectal cancer cell positivity rose from 48% (CEA) and 34% (CK20) with one assay of one sample to 74% when both assays of three samples were used to identify circulating tumor cells. Three non-cancer control patients (4.3%) were positive for either CEA (two patients) or CK20 (one patient). Tumor cells were identified more frequently in the circulation of colorectal cancer patients than had been suggested previously. RT-PCR-based studies of the clinical significance of circulating cancer cells in colorectal cancer should involve multiple blood samples with identification of multiple tumor-related cDNA products.

Aged↗
PubMed1998

Hormonal profile of infertile Makkans.

Male factor infertility, being a complex and heterogeneous disorder, precludes any reliance on a single laboratory test and requires broad spectrum assessment. Sociobiological factors also influence the parameters. In this context we examined serum concentrations of nine hormones in infertile and fertile male Makkans. Infertility was implicated in 21% of the population with correlated abnormalities of gonadotrophins, thyroid, thyroid stimulating hormone (TSH), and testosterone. Hypothyroidism was established in 35% and hyperthyroidism in 14% of the infertile population, where 28% of thyroid abnormality constituted an independent infertile group. Hyperprolactinaemia associated with low levels of luteinizing hormone (LH) and testosterone signifies a cluster of 28%, while 14% of testosterone deficiency alone was causal for infertility. However, infertility in 9% of the patients examined might have been psychogenic in nature. We present a responder panel based on cluster analysis.

Adult↗
PubMed1997

The impact of physiological insulin concentration and depletion on the metabolism of glucose, endogenous glycogen, and triglycerides in the isolated perfused heart.

In isolated nonworking hearts perfused with substrate-free medium for 90 min, 2000 microU insulin.mL-1 reduced the rates of glycogenolysis and lipolysis, whereas 50 microU insulin.mL-1 reduced the rate of lipolysis with no significant effect on glycogenolysis. Glycogen and triglycerides were the chief energy sources during the course of depletion in the presence and absence of insulin. In hearts perfused with medium containing 5 mM glucose for 3 h, glycogen and triglycerides contributed to the heart energy requirement, but in the presence of insulin (50 or 2000 microU.mL-1) endogenous triglycerides contributed to the heart energy requirement with net glycogen synthesis. In hearts preperfused with substrate-free medium for 90 min and perfused for another 90 min with medium containing 5 mM glucose, the depletion of endogenous glycogen and triglycerides stimulated the utilization of glucose and the synthesis of glycogen and triglycerides. In hearts preperfused with substrate-free medium for 90 min and perfused for another 90 min with medium containing glucose (5 mM) and insulin (50 or 2000 microU.mL-1), insulin enhanced the utilization of glucose and the synthesis of glycogen and triglycerides. Glucose utilization, glycogenolysis, lipolysis, and synthesis of glycogen and triglycerides were sensitive to the physiological insulin concentration and were also affected by the heart content of glycogen and triglycerides, in the isolated nonworking perfused rat heart.

Animals↗
PubMed1997

Non-visualization of lung markings below hemidiaphragm in subtle subpulmonic effusion: an old sign resuscitated.

To assess the lack of visibility of vascular markings under the hemidiaphragm on a frontal chest radiograph as a sign of pleural effusion, fifteen patients were collected showing this sign. Pleural effusion was diagnosed by ultrasound, comparison with previous or subsequent chest x-ray or computed tomography. Patients in the study group exhibited this sign in the absence of the classical signs of pleural effusion. In the control group, lack of visibility of blood vessels was observed in only 4.2% cases. Non-visualization of vascular markings below the hemidiaphragm should alert the interpreter to the possible presence of pleural effusion and a lateral or decubitus view or ultrasound examination may be carried out to rule out effusion.

Adolescent↗
PubMed1992

Effect of Caralluma tuberculata on the cytological and biochemical changes induced by cyclophosphamide in mice.

Treatment with Caralluma tuberculata extract induced complex biochemical and cytological changes in mice. Its cytotoxicity in the bone marrow cells of mice was comparable with that of the standard drug cyclophosphamide (CP); however, unlike CP, C. tuberculata was not clastogenic (as shown by the micronucleus assay). A dose-dependent decrease in the RNA content of liver and testes was produced by C. tuberculata treatment whereas there was no effect on the content of nucleic acid and protein in the brain. In the extract-treated animals there was a significant and dose-dependent increase in the DNA content of the liver, with a negligible effect on the protein content. Combined treatment with C. tuberculata and CP showed that C. tuberculata diminished the effect of CP on DNA levels; however, RNA levels were further suppressed, resulting in increased cytotoxicity. Pretreatment with C. tuberculata extract significantly reduced the clastogenicity of CP. These results indicated the involvement of different phytoconstituents acting by different routes.

Animals↗
PubMed1986

RNA-directed RNA polymerases from healthy and from virus-infected cucumber.

Much work has been done on the isolation, purification, and characterization of the RNA-directed RNA polymerase (EC 2.7.7.48) of cucumber mosaic virus (CMV)-infected cucumbers. Uninfected plants were reported to have no such enzyme, but we recently detected low levels of the activity in cucumber. Since tobacco and cowpea contain such an enzyme that is variably increased in amount by various virus (as well as viroid) infections, we assumed that this would also be the case upon CMV infection of cucumber. However, further purification and characterization of the RNA-directed RNA polymerases from healthy and from infected cucumber suggests that these are different enzymes. The presumed CMV replicase was obtained pure and consists of a major polypeptide of Mr 100,000 and minor components of Mr 110,000 and about 10,000. The Km is 5 microM ([3H]GTP) when tobacco mosaic virus RNA is used as template.

Molecular Weight↗
PubMed1983

Clinical and experimental keratitis caused by the Colletotrichum state of Glomerella cingulata and Acrophialophora fusispora.

Two cases of mycotic keratitis caused by the Colletotrichum state of Glomerella cingulata and Acrophialophora fusispora are reported for the first time. Both the isolates produced experimental corneal lesions in rabbit eyes but A. fusispora was more pathogenic. The experimental infection was more severe, with both the fungi, in rabbits pretreated with cortisone as compared with untreated animals. In vitro A. fusispora was most sensitive to miconazole and tolciclate followed by clotrimazole, amphotericin B and lactones while clotrimazole exerted maximum inhibitory effect on Colletotrichum followed by miconazole, lactones, amphotericin B and arnebins. Arnebins and tolciclate were inactive respectively against A. fusispora and Colletotrichum. Of the 3 drugs tested in vivo, against A. fusispora keratitis in rabbit, amphotericin B showed better results than tolciclate and miconazole.

Adult↗