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Biomedical subjects

A M Khan

Publications and source records attributed to A M Khan.

At least 73 records · Page 4Linked to original sources
PubMed1998

Eating induced by perifornical cAMP is behaviorally selective and involves protein kinase activity.

It has previously been shown that agents that increase endogenous cAMP elicit robust eating when injected into the perifornical hypothalamus (PFH) but not when injected into surrounding brain sites, suggesting that PFH cAMP may play a role in eating control. We report here that bilateral microinjection of the adenylyl cyclase activator 7-deacetyl-7-O-(N-methylpiperazino)-gamma-butyryl-forskolin dihydrochloride (MPB forskolin; 300 nmol/0.3 microl) into the PFH is sufficient to elicit intense eating (up to 15.7 +/- 2.3 g in 2 h) in satiated rats, without concomitant effects on other behaviors, including gnawing and drinking. In contrast, the inactive analog 1, 9-dideoxyforskolin is ineffective, suggesting that the effects of MPB forskolin are behaviorally selective and pharmacologically specific. We also show that injection of the protein kinase A inhibitor H-89 (100 nmol) into the PFH reduced MPB forskolin-induced eating by up to 50%. Collectively, these results suggest that increased cAMP production in a single brain area may be sufficient to selectively generate a patterned, goal-oriented behavior by activating cAMP-dependent protein kinase.

Adenylyl Cyclases↗
PubMed1998

Hyposplenism from Mycobacterium avium complex infection in a patient with AIDS and immune thrombocytopenia.

We describe a patient with HIV-related immune thrombocytopenic purpura with known Mycobacterium avium complex (MAC) infection presenting with intracerebral hemorrhage associated with severe thrombocytopenia who failed splenectomy following unsuccessful trials of corticosteroids and intravenous immunoglobulin. His presplenectomy peripheral blood smear showed Howell-Jolly bodies and microscopic examination of his spleen demonstrated multiple granulomas with numerous acid-fast organisms replacing the normal splenic tissue. We postulate that splenic hypofunction secondary to overwhelming MAC infection contributed to the failure of the thrombocytopenia to promptly respond to splenectomy.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Long-term effect of diethylcarbamazine citrate on microfilaraemia status in treated individuals.

Follow up of microfilaraemic individuals infected with Wuchereria bancrofti at five years after treatment was carried out in a tea workers population. Diethylcarbamazine citrate in the dose schedule of 72 mg/kg body weight given in equal daily doses over a period of 21 days cleared 51.6 per cent microfilaraemic individuals five year post-treatment. Eighty five subjects were successfully followed and among these, 10 (11.8%) showed increase in mf counts, 31 (36.4%) showed reduction but remained microfilaraemic and 44 (51.8%) became amicrofilaraemic. The age and sex of the host had no significant effect on the clearance of mf. Persistence of a relatively stable low number of mf in treated individuals is more likely due to survival of one or more female worms after the therapy or due to reinfection which could not be ruled out in the present study. Overall, findings indicated that diethylcarbamazine citrate appeared to give a long-term benefit to treated individuals.

Adolescent↗
PubMed1997

Autologous peripheral blood progenitor cell transplantation for non-Hodgkin's lymphoma with extensive bone marrow necrosis.

A patient with malignant lymphoma, large cell type and extensive bone marrow necrosis at presentation is reported. Bone marrow necrosis persisted even after a complete remission was induced with standard chemotherapy. Because of this adverse prognostic factor, circulating stem cells were collected and reinfused following a myeloablative regimen consisting of busulfan, etoposide and cyclophosphamide. The patient engrafted rapidly and a subsequent bone marrow examination was free of both lymphoma and necrosis. To the best of our knowledge, this is the first reported patient with extensive bone marrow necrosis in whom circulating progenitor cells were harvested and utilized successfully.

Adult↗
PubMed1997

Endopyelotomy: experience with 320 cases.

We were the first to initiate endopyelotomy in Hungary (in 1986) and in Yemen and Pakistan (in 1993). Through the end of 1995, 320 cases of ureteropelvic junction (UPJ) stenosis have been operated upon. The procedure was performed under local anesthesia in adult patients and general anesthesia in children. The minimum age of the patient was 4 years, while the oldest patient was 80 years of age. The UPJ was incised longitudinally at the posterolateral aspect until the perinephric fat was seen, and a drain of 8F to 12F was inserted transrenally into the ureter through a nephroscope. Patients soon left the hospital and were able to start working in 5 days (average). The drain was removed after 6 weeks. During the follow-up period, ultrasonic examination was performed each 3 months. The success rate (mean of three centers) came out to be 87%. Open pyeloplasty was performed in cases where the symptoms of pyelectasia were persisting and caused complaints and stenosis was present even after 6 months. In our opinion, endopyelotomy should be the procedure of first choice for UPJ stenosis, because it is less troublesome for the patient than open pyeloplasty, and the results are real encouraging.

Adolescent↗
PubMed1997

Advanced colonic carcinoma in children.

We report two cases of colorectal carcinoma in children with a delay in diagnosis due to the low index of suspicion of this pathology as the cause of presenting symptoms. We conclude that any child presenting with unexplained rectal bleeding and abdominal pain should be investigated with endoscopy and barium enema.

Adenocarcinoma↗
PubMed1997

Stimulation of eating by the second messenger cAMP in the perifornical and lateral hypothalamus.

Despite intense study of neurotransmitters mediating hypothalamic controls of food intake, little is known about which second messengers are critical for these mechanisms. To determine whether adenosine 3',5'-cyclic monophosphate (cAMP) might participate in these mechanisms, we injected the membrane-permeant cAMP analog 8-bromo-cAMP (8-BrcAMP) hypothalamically in satiated rats. Injection of 8-BrcAMP (10-100 nmol) into the perifornical (PFH) and lateral hypothalamus (LH) dose dependently stimulated food intake of up to 15.7 g in 2 h. Significantly smaller responses were obtained with thalamic injections. In contrast to the strong stimulatory effects of PFH and LH 8-BrcAMP, cAMP and 8-bromo-guanosine 3',5'-cyclic monophosphate (100 nmol) were ineffective, suggesting a chemically specific, intracellular action. Consistent with this, combined PFH injection of 7-deacetyl-7-O-(N-methylpiperazino)-tau-butyryl-forskolin dihydrochloride and 3-isobutyl-1-methylxanthine, agents that increase endogeneous cAMP, stimulated eating of up to 9.9 g in 2 h. These results demonstrate that increases in PFH/LH cAMP can elicit complex, goal-oriented behavior, suggesting an important role for cAMP in hypothalamic mechanisms stimulating food intake.

1-Methyl-3-isobutylxanthine↗
PubMed1996

Effect of arteether alpha/beta on uncomplicated falciparum malaria cases in Upper Assam.

Thirty patients of uncomplicated Plasmodium falciparum malaria completed a clinical trial of arteether alpha/beta conducted in a malaria endemic tea garden of district Dibrugarh, Assam. Arteether was given intramuscularly in once a day dose of 150 mg for three consecutive days. The cure rate was 100 per cent with mean fever and parasite clearance time of 42.4 +/- 17.5 and 37.6 +/- 13.6 h respectively. Recrudescence/reinfection rate was 6.7 per cent. Palpable spleens of twenty out of twenty one cases on day 0 became non palpable within 28 days. Following the treatment, percentage of hemoglobin improved marginally with no remarkable change in total and differential leucocyte count. Arteether alpha/beta, besides being a potent and fast acting schizontocidal drug, also exhibited gametocytocidal action on P. falciparum.

Adolescent↗
PubMed1996

Correlation between degree of protection and humoral antibody response in hamsters immunized with somatic and excretory secretory antigens of Ancylostoma ceylanicum.

Correlation between the degree of protection and induced serum antibody response in hamsters immunized with somatic and excretory-secretory (ES) antigens of adult. A. ceylanicum was investigated. Hamsters were immunized with non purified and Sephadex G-200 fractions (F1, F2 and F3) of somatic and ES antigens. The degree of protection was assessed in terms of percent worm reduction compared to controls against challenge infection. Induced humoral antibody response was determined by ELISA. Both somatic and ES antigens had shown moderate to significant protection but the latter was found more immunogenic as highest level of protection (67.02%) was achieved by these antigens. Humoral antibody was found highly elevated in animals immunized with protective doses of somatic and ES antigens. The maximum serum antibody titer i.e. 1:3200 was noticed in animals immunized with high protective dose (64.59% protection) of fraction F1 of ES antigens. Antibody titer correspond to the degree of protection and a positive correlation between induced humoral antibodies and protection level was established.

Ancylostoma↗
PubMed1995

Septicemia due to Vibrio cholerae 0139 Bengal.

We describe septicemia due to Vibrio cholerae 0139 Bengal, the newly described causative agent of cholera, in a child who also had simultaneous intestinal infection with Shigella boydii. Because V. cholerae 0139 is capsulated, its propensity to cause extraintestinal infection is stressed.

Bacteremia↗
PubMed1995

Neonatal diarrhea caused by Vibrio cholerae 0139 Bengal.

Cholera rarely occurs in children under 2 years of age. We describe diarrhea due to Vibrio cholerae 0139 Bengal, the newly described etiologic agent of cholera in a 4-day-old breast-fed baby. However, the diarrhea was mild and was successfully treated with rehydration therapy and erythromycin.

Anti-Bacterial Agents↗
PubMed1995

Patellofemoral contact pressures exceed the compressive yield strength of UHMWPE in total knee arthroplasties.

To address mechanisms involved in wear and permanent deformation of patellofemoral components in total knee arthroplasties, a previously reported knee joint loading model and pressure-sensitive film were used to measure patellofemoral contact areas and pressures in human cadaver knee joints after implantation with six different total knee joint designs. The joints were tested at three different Q angles (physiologic, -10 degrees, and +10 degrees) and four different flexion angles (30 degrees, 60 degrees, 90 degrees, and 120 degrees). Patellofemoral contact areas at normal Q angles ranged from 0.13 to 0.68 cm2 and increased with flexion angle up to 90 degrees. These contact areas differed significantly with flexion angle but not with Q angle. Variations in contact area with type of knee system were only marginally significant (P < .04), and post hoc tests showed no significant differences between individual knee designs. Contact pressures at normal Q angle also increased with flexion angle and ranged from 10 MPa to more than 49 MPa. Contact pressures at flexion angles greater than 60 degrees were, for all systems, well in excess of the compressive yield strength of ultrahigh-molecular-weight polyethylene and at least three to four times greater than the recommended maximum compressive stress level of 10 MPa.

Adult↗
PubMed1995

Comparison of the vibriocidal antibody response in cholera due to Vibrio cholerae O139 Bengal with the response in cholera due to Vibrio cholerae O1.

Vibrio cholerae serogroup O139, now considered to be the second organism capable of causing epidemic severe dehydrating cholera, contains a capsular polysaccharide which makes it difficult for it to be used in the conventional vibriocidal antibody assay optimized for V. cholerae O1. After modification of the procedure, which involved the use of specific bacterial strains, a lower bacterial inoculum, and increased amounts of complement, the vibriocidal antibody responses to V. cholerae O139 were measured in acute- and convalescent-phase sera from 33 V. cholerae O139-infected and 18 V. cholerae O1-infected patients and in single serum samples from 20 healthy control subjects. The responses in these individuals to V. cholerae O1 strains were also determined. Significant elevations in the homologous antibody response were found only in the convalescent-phase sera from both groups of patients with cholera. These findings may explain the basis for the lack of heterologous protection between the two serogroups of V. cholerae. Healthy controls had higher background levels of vibriocidal antibody to V. cholerae O1 than to V. cholerae O139.

Adult↗