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Biomedical subjects

M Zafar

Publications and source records attributed to M Zafar.

18 recordsLinked to original sources
PubMed2004

Landfill surface runoff and its effect on water quality on river Yamuna.

During 2000, the estimated quantity of solid waste generated in Delhi, India was more than 9000 tones per day. This is one of the biggest sources of environmental degradation in capital city of India. Since 1950's over 12 large landfill have been packed with all kinds of nonbiodegradable and toxic waste of Delhi. The area covered is at least 1% (14.83 square kilometer) of total Delhi's area. All the landfill sites except Tilak Nagar, Hastal, and Chattarpur are located very closely (0.5-6 km) to the river Yamuna. It contributes the pollution to river Yamuna in a significant way in a form of surface runoff from landfill site especially in rainy season. The chemical analysis of leachate produced by these landfill sites and corresponding river section (at five river points) has been performed for 16 selected parameter (Temperature, Odor, pH, Turbidity, Conductivity, COD, Total Solids, Sulphide, Chloride, Nitrate, Iron) in the first stage and for 8 parameters (pH, Conductivity, COD, Total Solids, Chloride, Nitrate, Iron) in second stage. The study was conducted between August to October, 2000 (rainy season). It is clear from the study that the river water quality is affected by the presence of landfill surface runoff. Its impact can be seen in the region where the drains are meeting the river. This is one of the causes of river pollution apart from other major municipal and industrial sources.

Agriculture↗
PubMed2000

Effectiveness of supplemental grasp-force feedback in the presence of vision.

Previous studies have shown that supplemental grasp-force feedback can improve control for users of a hand prosthesis or neuroprosthesis under conditions where vision provides little force information. Visual cues of force are widely available in everyday use, however, and may obviate the utility of supplemental force information. The purpose of the present study was to use a video-based hand neuroprosthesis simulator to determine whether grasp-force feedback can improve control in the presence of realistic visual information. Seven able-bodied subjects used the simulator to complete a simple grasp-and-hold task while controlling and viewing pre-recorded, digitised video clips of a neuroprosthesis user's hand squeezing a compliant object. The task was performed with and without supplemental force feedback presented via electrocutaneous stimulation. Subjects had to achieve and maintain the (simulated) grasp force within a target window of variable size (+/- 10-40% of full scale). Force feedback improved the success rate significantly for all target window sizes (8-16%, on average), and improved the success rate at all window sizes for six of the seven subjects. Overall, the improvement was equivalent functionally to a 35% increase in the window size. Feedback also allowed subjects to identify the direction of grasp errors more accurately, on average by 10-15%. In some cases, feedback improved the failure identification rate even if success rates were unchanged. It is thus concluded that supplemental grasp-force feedback can improve grasp control even with access to rich visual information from the hand and object.

Adult↗
PubMed1995

Cell-specific expression of estrogen receptor in the human pituitary and its adenomas.

Estrogen affects the synthesis and release of several pituitary hormones. The estrogen receptor (ER), a member of the steroid hormone receptor family, is thought to mediate transcriptional effects in a cell-specific fashion. We investigated whether ER is expressed in specific hormone-producing cell types in the human pituitary and its adenomas. Pituitary adenomas (n = 34) were collected at the time of surgery, and normal glands were obtained from autopsy. Expression of ER messenger ribonucleic acid (mRNA) was determined by reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization. ER was also localized with immunohistochemistry and protein extraction. By RT-PCR, ER mRNA was found in the nontumorous pituitary and in pituitary adenomas expressing only PRL, in those producing GH and PRL, and in adenomas expressing the gonadotropic hormones. No ER mRNA was detected in adenomas expressing only GH without PRL or gonadotropins, nor in tumors producing ACTH without PRL or gonadotropins. In situ hybridization was not as sensitive or specific as RT-PCR. Biochemical analysis performed on seven tumors that were positive for ER mRNA by RT-PCR detected ER protein in only one PRL adenoma and one oncocytoma and yielded negative or equivocal results in one PRL adenoma, three GH-PRL adenomas, and one null cell adenoma. ER protein was localized by immunohistochemistry in scattered cells of the nontumorous adenohypophysis and in a few PRL and gonadotroph adenomas. We conclude that ER expression, as determined by RT-PCR, correlates with the expression of PRL or gonadotropins; in contrast, ER mRNA was not detected in adenomas that express only GH or ACTH. These findings implicate ER as a cell-specific transcription factor that may regulate cytodifferentiation in the pituitary.

Adenoma↗
PubMed1994

Idiopathic chronic active hepatitis: a diagnostic and therapeutic dilemma.

A 56-year-old Saudi male was admitted with abnormal liver chemistry values and a > 5-month history of lethargy, malaise, anorexia, and jaundice. Extensive investigations did not establish an etiological diagnosis. Liver histology confirmed the clinically apparent aggressive hepatitis with fibrosis but gave no clue to its etiology. The patient was empirically treated with alpha-interferon for presumed non-A, non-B hepatitis, with clinical and biochemical worsening. Interferon was discontinued and the patient was started on immunosuppression. Dramatic clinical and biochemical improvement occurred, with normalization of the liver chemistry within 4 weeks. The patient has been followed-up for 12 months and has not suffered a relapse. This case highlights the etiological heterogeneity of chronic active hepatitis. The entity of autoimmune chronic active hepatitis is unclear, and perhaps it is better defined as steroid-responsive hepatitis. Steroid-responsive hepatitis should always be considered in cases of cryptogenic chronic active hepatitis.

Autoimmune Diseases↗
PubMed1993

Histologically advanced chronic hepatitis C treated with recombinant alpha-interferon: a randomized placebo-controlled double-blind cross-over study.

Chronic hepatitis C is common in Saudi Arabia and most often presents in an advanced stage. To assess the response of patients to interferon, a randomized placebo-controlled double-blind study was undertaken. All but 1 patient had cirrhosis or fibrosis before interferon. After a 24-week observation period patients received alpha 2a interferon, 3 mega units sc tiw or placebo for 24 weeks, then the opposite treatment for another 24 weeks followed by 24 weeks of observation. Liver biopsies were performed before and after each of the treatment phases. Twenty-two out of 24 patients completed the study. The mean alanine aminotransferase (ALT) levels fell from 150.7 +/- 118.7 units/l to 91.0 +/- 42.6 units/l after 6 months interferon treatment (P = 0.03) but only 3 patients (14%) had complete normalization of mean ALT levels and 4 (18%) had > 50% reduction. The mean hepatitis activity index fell from 12.2 +/- 2.6 immediately before to 11.6 +/- 2.5 just after interferon (P = 0.4). After interferon there was an insignificant raise in 6-month mean ALT. Hepatitis C virus-RNA was positive in all 17 patients tested and remained so after treatment. Side-effects were mild and well tolerated. Alpha interferon 3 mega units tiw for 24 weeks is not an effective treatment of histologically advanced chronic hepatitis C.

Adult↗
PubMed1993

Primary hepatic vipoma.

A 35-yr-old male presented with a 3-yr history of voluminous watery diarrhea. He had episodes of severe generalized weakness which responded to fluid and electrolyte replacement therapy. Investigations revealed a solitary liver mass and an elevated vasoactive intestinal polypeptide level. An extensive work-up did not show any other extrahepatic primary lesion. Surgical resection ameliorated all of his symptoms, accompanied by a decrease in the vasoactive intestinal polypeptide level. We believe that this patient represents a case of primary hepatic vipoma syndrome. To our present knowledge, this has not been reported previously. We discuss the clinical manifestations, investigations, and management of the case.

Adult↗
PubMed1991

Can isolation of Aeromonas hydrophila from human feces have any clinical significance?

A total of 27,480 stool specimens from 15,548 patients with gastroenteritis were analyzed for bacterial enteropathogens during a 4-year period between 1986-89 at a major referral center in Saudi Arabia. Bacterial pathogens were isolated from 1,152 patients, Salmonella being the most frequent, followed by Campylobacter, Shigella, and Aeromonas hydrophila. The latter bacterium was found in 58 patients; seven of them were associated with other enteric pathogens, but A. hydrophila was the only organism in 51 patients. All had gastrointestinal symptoms, the most common being diarrhea (92%), followed by abdominal pain (68%), fever (37%), and vomiting (27%). Stool specimens from 1,368 control patients were negative for A. hydrophila.

Adolescent↗
PubMed1981

Surgical drains.

Explore the source record for details and available documents.

Drainage↗
PubMed1977

Folate deficiency during intravenous hyperalimentation.

Two alcoholic patients were supported with hyperalimentation therapy during the management of complicated surgical problems. Folate deficiency was documented after ten and two weeks of intravenous feeding. One patient developed severe pancytopenia. Folic acid treatment resulted in hematologic recovery in both cases. Early development of folate deficiency in these patients seems to be related to multiple factors, viz., poor folate stores related to chronic alcoholism, poor dietary intake before and during the hospitalization, infection, prolonged gastric suction, and lack of folate in the intravenous hyperalimentation fluids. Rationale for the supplementation of folates in such patients is discussed.

Adult↗
PubMed1977

Microaggregate counts in frozen-preserved erythrocytes: effects of washing in three blood processors and filtration.

Since microaggregates have been implicated in posttransfusion pulmonary insufficiency, their elimination has become an active concern in blood transfusion. Various types of filters, as well as frozen-preserved erythrocytes, have been used to provide blood relatively low in microaggregates. We have counted particles in frozen-stored blood before deglycerolization, after washing in each of three cell processing systems, and after filtration through a 40-micrometer filter. Washing frozen erythrocytes reduced the total particle counts by an average of 89%. Slight differences were found among the three blood processors with respect to particle removal. Passing washed blood through a 40-micrometer filter did not result in significant further reduction in particle counts. Hence, the use of such filters in a frozen-preserved blood system is not warranted.

Blood Preservation↗