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Biomedical subjects

A M Khan

Publications and source records attributed to A M Khan.

At least 91 records · Page 5Linked to original sources
PubMed1993

Laparoscopically controlled and assisted percutaneous transperitoneal nephrolithotomy in a pelvic dystopic kidney.

Two renal pelvic stones were removed percutaneously from a pelvic dystopic kidney using a transabdominal, transperitoneal approach. The puncture was made antegrade and controlled partly fluoroscopically and partly laparoscopically. Where the kidney was covered by bowels, these were displaced with forceps inserted through another laparoscopic trocar. The dilation and stone removal were performed traditionally. As the kidney was just behind the uterus, the authors considered extracorporeal lithotripsy contraindicated in this case, so the only minimally invasive resolution was percutaneous nephrolithotomy, which could be performed only with the aid of laparoscopy.

Adult↗
PubMed1993

Effects of post-curing by heat on the mechanical properties of visible-light cured inlay composites.

The aim of this study was to evaluate the effects of post-curing by heat on the mechanical properties of visible-light (V-L) cured three inlay composites and three posterior filling composites. One group was only photo-cured according to the manufacturers' recommended methods, while the other group was heat-treated at 100 degrees C for 15 min following initial cure by V-L. Knoop hardness, diametral tensile strength and compressive strength were measured to evaluate the mechanical properties. Cure performance was checked out by the solvent immersion test. Upon secondary-curing by heat, it was confirmed that the mechanical properties of the composites were increased moderately and the cure performance of the composites was also improved.

Composite Resins↗
PubMed1993

Ultrasonic characterization of the saphenous vein.

The most frequently used conduit for infrainguinal or coronary artery bypass is the saphenous vein, and this report describes the ultrasonic evaluation of anatomic variations in over 1400 limbs. The thigh portion of the greater saphenous vein consisted of a single venous conduit in 67% of the limbs, a complete double system in 8%, a branching double system in 18% and a closed loop double system in 7%. In 92% of the cases, the vein was in medial position, with the remaining 8% positioned laterally. In the calf, a single vein was observed in 65% of the limbs with the remainder demonstrating a double venous system. The vein was positioned anteriorly in 85% of the limbs. The remaining 15% were positioned posteriorly, with 7% of these being a single dominant vein. Proper knowledge of saphenous vein anatomy is vital to the surgeon preparing to use this vein as a bypass conduit and can aid in its preoperative assessment.

Arteriosclerosis↗
PubMed1993

The role of 5-fluorouracil in complicated glaucomas.

The long-term efficacy of trabeculectomy in controlling intraocular pressure (IOP) has been found unsatisfactory in various complicated and refractory glaucomas. The most common cause for failure is excessive scarring at the filtering site. Several wound modulating agents which reduce scarring have been tested. In this study, 5-Fluorouracil (5-FU), a halogenated pyrimidine analogue and a potent anti-mitotic agent, was applied for seven days after trabeculectomy in eighteen complicated and unsuccessful filtering glaucomas, at a daily dosage of 5 mg in the form of 0.5 ml subconjunctival injections. The common postoperative complications encountered were corneal epithelial erosion (38%), wound leakage (16%), subconjunctival haemorrhage (32%) and hyphaema (10%), all during the first 7 to 10 days. Monitoring at regular intervals up to six months showed adequate control of IOP (less than 22mm Hg.) in 88% of the cases. Cases of aphakic glaucoma and neovascular glaucoma showed poor response. Use of 5-FU as an adjuvant to filtering surgery in various complicated glaucomas improves the long-term results.

Adult↗
PubMed1992

Treatment of shigellosis: III. Comparison of one- or two-dose ciprofloxacin with standard 5-day therapy. A randomized, blinded trial.

OBJECTIVE: To determine whether a single dose, or 2 doses, of ciprofloxacin are as effective as 5-day, 10-dose therapy for the treatment of shigellosis in adult men who are moderately to severely ill. DESIGN: Randomized, double-blind clinical trial. SETTING: A diarrhea treatment center in the capital city of a developing country, Bangladesh. PATIENTS: A total of 128 adult men with dysentery of less than 96 hours duration. All had Shigella organisms isolated from a culture of stool. INTERVENTIONS: Patients were randomly assigned to receive either a single 1-gram dose of ciprofloxacin at admission to the study (single-dose group; n = 40), a 1-gram dose of ciprofloxacin at admission and 24 hours later (2-dose group; n = 43), or 500 mg of ciprofloxacin every 12 hours for 5 days (10 dose group; n = 35). All patients were hospitalized for 6 days. MEASUREMENTS: Stools were collected individually; their character and consistency were recorded and cultured daily. A physical examination and recording of symptoms were done daily, and the temperature was measured every 4 hours. Therapy was considered to have failed in patients who did not have improvement in the signs and symptoms of dysentery after 72 hours of therapy or in patients who on study day 5 had more than nine stools, or more than two watery stools, or were febrile. RESULTS: There were no treatment failures in the 78 patients infected with species of Shigella other than Shigella dysenteriae type 1. Among the 40 patients infected with S. dysenteriae type 1, treatment failed in 4 of the 10 patients who received single-dose therapy, 2 of the 15 patients who received 2-dose therapy, and none of the 15 patients who received 10-dose therapy (P = 0.017, single-dose therapy group compared with 10-dose group; P = 0.15 for the single-dose group compared with the 2-dose group; P > 0.2 for the 2-dose group compared with the 10-dose group). CONCLUSIONS: A single 1-gram dose of ciprofloxacin is effective therapy for patients infected with species of Shigella other than S. dysenteriae type 1. Single-dose therapy is inferior to 10-dose therapy for treating patients infected with S. dysenteriae type 1.

Adult↗
PubMed1992

Characterization of inorganic fillers in visible-light-cured dental composite resins.

Inorganic fillers in seven visible-light (VL)-cured dental composite resins were examined for their size, composition, phase and content, employing the following analytical instruments. SEM observations indicated that five samples could be classified into the hybrid type while the remaining two belonged to micro-filled and sub-micron types. EDX analyses revealed that five samples contained BaO while others lacked BaO. XRD analyses showed that three were in vitreous phase, two were in the crystalline phase and two were mixtures of both. DTG thermal analyses indicated that the hybrid type composites had the higher inorganic filler content (wt%) than the composites of two other types. In conclusion, wide varieties exist in the inorganic fillers in VL-cured dental composite resins currently utilized.

Aluminum Oxide↗
PubMed1992

In-vitro and in-vivo wear profile of composite resins.

The aim of this study was to evaluate in-vitro wear by two types of slurry of 10 commercial composite resin materials (seven hybrid and three microfilled composites). There was great variation in the in-vitro wear pattern by two types of slurry. The wear rate of microfilled composites was greater than that of hybrid composites, and a negative correlation was observed between wear rate and Knoop hardness values among all materials when hydroxyapatite slurry was used. In contrast, the wear rate of hybrid composites was greater than that of microfilled composites when abraded by green carborundum slurry. These abraded surfaces were compared with SEM micrographs of in-vivo composites surface after 4 years of service. The profile of in-vivo wear surfaces was found to be similar to that of in-vitro wear surfaces abraded with hydroxyapatite slurry.

Composite Resins↗
PubMed1992

Evaluation of the common cockroach Periplaneta americana (L.) as carrier of medically important bacteria.

The bacterial flora associated with external body parts, stomach and intestine of male and female Periplaneta americana inhabitating students' halls, teachers' residences and houses of low-paid employees in Jahangirnagar, University Campus were examined and analysed qualitatively and quantitatively. The qualitative study in P. americana revealed the presence of 31 species of bacteria belonging to 16 genera. Most of these bacteria are pathogenic to man and domestic animals. The total viable bacterial counts (TVBC/g) in students' halls, teachers' residences and houses of low-paid employees were 1.27 x 10(8), 6.04 x 10(7) and 1.65 x 10(8) respectively in the male and 1.43 x 10(8), 5.83 x 10(7) and 1.63 x 10(8) respectively in the female cockroaches. The highest prevalence of bacterial flora both in number and types occurred in stomach followed by intestine and the external body parts.

Animals↗
PubMed1991

Ancylostoma ceylanicum: immunological consequences after anthelmintics therapy in hamsters (Mesocricetus auratus).

Alterations in immunological response before and after chemotherapy were investigated in hamsters infected with A. ceylanicum. Four reference anthelmintics mebendazole, albendazole, levamisole and pyrantel pamoate and one newly synthesized anthelmintic compound 81-470 were used. Drugs in curative doses were administered on day 30 post infection and the humoral response was assessed by counter immunoelectrophoresis and ELISA and cell mediated immunity by delayed type of hypersensitivity reaction. In infected untreated animals the precipitins appeared on day 30 and remained prominent till day 250 post infection. However with ELISA the antibodies could be demonstrated as early as day 3 post infection and peaked on day 40. Delayed type of hypersensitivity could not be demonstrated during the course of infection. All the drugs including Comp. 81-470 were effective in removing the parasites. Precipitin antibodies were only demonstrable till day 60 post treatment. ELISA depicted gradual depletion of antibody titre following treatment with mebendazole, albendazole and pyrantel pamoate. In levamisole treated hamsters the initial fall in serum antibody was restored by day 20 post treatment. With Compound 81-470, immediately after the treatment there was sharp rise in antibodies concentration followed by gradual fall and on day 60 post treatment the titre was still higher than the pretreated titre. Thus the study denotes that effective therapy will bring down immune responses of the host if the drug possess no immunopotentiating action. Therefore the immune parameters may be used as supportive indicator to successful therapy particularly in systemic parasites where parasitic forms are nondemonstrable in excreta or blood.

Ancylostomiasis↗
PubMed1990

Anthelmintic profile of methyl 5(6)-(4-methylpiperidin-1-yl) carbonylbenzimidazole-2-carbamate in experimental helminthiases.

Biological evaluation of methyl 5(6)-(4-methylpiperidin-1-yl) carbonylbenzimidazole-2-carbamate against Ancylostoma ceylanicum, Nippostrongylus brasiliensis, Syphacia obvelata, Hymenolepis nana, H. diminuta and Cysticercus fasciolaris in experimental animals is reported. The compound (mg/kg) causes 100% elimination of A. ceylanicum (25 x 1), N. brasiliensis (100 x 1), S. obvelata (50 x 1), H. nana (250 x 3) and C. fasciolaris (50 x 10). It was also effective against the developing larvae (L3, L4 and L5) of A. ceylanicum at a single oral dose of 100 mg/kg. Another study indicated that the compound elicits 100% response within 32 hr of drug administration. The drug is well tolerated and LD50 is greater than 4500 mg/kg.

Animals↗
PubMed1989

In vitro color change of composite-based resins.

The adsorption of staining materials to resin restoratives was considered to be influenced by the physico-chemical properties of the resin-based monomers. To study the effects of the surface characteristics of resins on staining, we prepared five visible-light-cured experimental resins without fillers. Staining of these resins was colorimetrically measured. The staining solutions used were the Oil Orange and the Food Red 3 solutions. With the Oil Orange solution, the materials with higher hydrophobicity showed higher staining. With the Food Red 3 solution, the materials with higher water sorption showed higher staining.

Color↗
PubMed1989

Persistent diarrhoea: a preliminary report on clinical features and dietary therapy in Bangladeshi children.

Twenty-six infants and children aged 2-24 months suffering from diarrhoea for more than 2 weeks were studied in the ICDDRB's Dhaka Treatment Centre. They presented with watery diarrhoea and the majority had moderate dehydration. A stool pathogen was isolated in only one infant. Systemic infections co-existed in half of the subjects. Subjects between 4 and 12 months of age were moderately malnourished. The remainder were severely malnourished. A range of therapeutic diets were given according to the clinical progress of the subjects. Three children improved with a milk-based diet, two with a soya-based proprietary diet, eight with a rice-based diet, 12 with comminuted chicken, and one with yoghurt. Response to various diets appeared to be age related. Body weight of 21 subjects deteriorated before cessation of diarrhoea. Case fatality rate was 11 per cent due to septicaemia and bronchopneumonia. Most persistent diarrhoea patients without severe concurrent systemic infections were effectively treated using various locally prepared diets.

Bangladesh↗