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Biomedical subjects

I Ahmed

Publications and source records attributed to I Ahmed.

At least 145 records · Page 8Linked to original sources
PubMed1995

Seven-day viable analysis of some ophthalmic preparations with different concentrations of benzalkonium chloride.

The efficacy of zinc sulphate and boric acid ophthalmic preparations, containing benzalkonium chloride as preservative have been investigated against Gram-negative Escherichia coli and Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus bacteria. The viability of bacteria was checked after 7 days though they were completely suppressed after 24 hours of inoculation. Zinc sulphate increased the antimicrobial activity of benzalkonium chloride, whereas the boric acid or its combination with zinc sulphate reduced the same. The Pseudomonas aeruginosa was found to be viable against zinc sulphate, boric acid or its combination at a concentration of 0.01% to 0.005% of the preservative. Escherichia coil and Staphylococcus aureus also exhibited resistance but to a lesser extent than Pseudomonas aeruginosa. This viability may be dangerous in case of multidose ophthalmic preparations.

Bacteria↗
PubMed1995

Percutaneous nephrostomy using hospital modified catheters for cost containment.

This paper describes our experience of percutaneous nephrostomy (PCN) using self-fabricated catheters. Our effort is to restrain the cost of this common procedure, and at the same time, deliver results comparable to other studies in the literature. In 152 patients, 175 PCN were performed for various indications using simple tools for "pulling catheters". All nephrostomy catheters were fabricated from commercially available 7.2 F polyethylene catheter material. Our success rate of 96%, major and minor complication rates at 2.3% and 6.3% respectively, compare favourably with the reported series. The variable cost of nephrostomy, in our cases, was less than one-third compared with that using commercially available nephrostomy sets. Use of self-fabricated nephrostomy catheters is a cost-effective way of performing nephrostomy especially in environments where health maintenance resources are scarce, health insurance is not freely available, and patients bear the cost of the treatment. This is particularly relevant to the developing countries where PCN is frequently needed but the nephrostomy sets are not easily available.

Adolescent↗
PubMed1995

Effectiveness of percutaneous nephrostomy in reversing obstructive renal failure.

A retrospective analysis of 34 patients of obstructive renal failure, initially managed by percutaneous nephrostomy was performed. Pre procedure blood biochemical profile was compared with upto one week follow-up of blood chemistry. There was a decline of 71.1% and 56.08% (P-values 0.0001 and 0.0028) in the mean values of serum creatinine and blood urea nitrogen respectively at 7 days after the procedure. Improvement in blood biochemical profile was solely dependent on performance of percutaneous nephrostomy.

Adolescent↗
PubMed1994

Anomalous response of oxonol-V to membrane potential in mitochondrial proton pumps.

The response of the fluorescent membrane potential probe oxonol-V (bis[3-phenyl 5 oxoisoxazol-4-yl]pentamethine oxonol) in submitochondrial particles (SMP) was dependent upon whether the potential (inside positive) was generated by active proton pumps or by valinomycin-aided passive K+ influx. The fluorescence intensity showed a decrease in the former case and an increase in the latter situation. This anomalous behavior was not observed with other similar anionic probes. Gradual inhibition of proton pumping activity showed that the difference in the response of oxonol-V is not due to possible difference in the magnitude of membrane potential generated in these two situations. In the presence of membrane permeant anions such as TPB- (tetraphenyl boron) or chlorate, the direction of response of oxonol-V fluorescence was the same in both situations. Time-resolved fluorescence of the oxonol-V-SMP system showed three populations: one free form (fluorescence lifetime approximately 60 ps) and two SMP-bound forms (lifetimes of 0.45 ns and 1.4 ns). A fourth population was created during the action of proton pumps. The shorter lifetime (approximately 250 ps) of this new bound form suggest this population to be an aggregated form. This population was absent during the action of proton pumps in the presence of TPB- or chlorate. These results suggest the creation of a charge separated state during the action of proton pumps. The decrease in fluorescence intensity could be the result of aggregation of oxonol-V around the positive end of a proton pump existing in a dipole or charge separated state.

Animals↗
PubMed1994

Probing of coenzyme quinone binding site of mitochondrial NADH:CoQ reductase by fluorescence dynamics.

The coenzyme quinone (CoQ) binding region of mitochondrial NADH:CoQ reductase (complex-I) was investigated by the fluorescent probes erythrosine-5'-iodoacetamide (ER) and 3,3'-diethyloxadicarbocyanine iodide (DODCI). Both steady-state and time-resolved fluorescence was used in these experiments. Both probes competed for the binding site of 2,3-dimethoxy-5-methyl-6-decyl-1,4-benzoquinone (DB), an analogue of CoQ. The fluorescence lifetimes of the complex-I bound probes were approximately 600 ps and approximately 1.7 ns in the cases of ER and DODCI, respectively. Binding of the probes was not affected by the binding of the inhibitor rotenone. However, rotenone binding caused some changes in the lifetime of the bound probes. Reduction of the enzyme caused an increase in the level of binding of ER and a decrease in the level of binding of DODCI. The level of binding of cationic DODCI increased with the increase in pH, and in the case of anionic of ER the trend was reverse. Binding of Ca2+ to complex-I resulted in an increase in the level of binding of ER and a decrease in the level of binding of DODCI. Reaction with N,N'-dicyclohexylcarbodiimide (DCCD) resulted in alterations in the time-resolved fluorescence profiles of dye: complex-I system. All these results were interpreted as due to the presence of carboxyl group(s) with pKa approximately 6 in the probe/CoQ binding region. The rotational correlation time (tau r) of DODCI bound at the CoQ region was 2-3 ns.(ABSTRACT TRUNCATED AT 250 WORDS)

Acids↗
PubMed1994

Diclofenac and post-tonsillectomy haemorrhage.

The authors noticed a marked increase in the incidence of reactionary post-operative haemorrhage after tonsillectomy during the course of 1992. This increase appeared to be related to the introduction of diclofenac as a post-operative analgesic. A retrospective review of casenotes of patients having tonsillectomy under the care of the senior author (P.M.R.) in 1992 revealed that four of the 73 patients (5.5%) receiving diclofenac at induction of anaesthesia suffered reactionary haemorrhage requiring operative control, as compared with two of 293 (0.7%) receiving other analgesics.

Adolescent↗
PubMed1994

Validity of a patient-administered questionnaire for routine otolaryngology admissions.

In this study the accuracy of a questionnaire filled in by 109 parents of children admitted for routine ENT surgery was compared with the well recognized verbal clerking. A major problem in communication between doctors and parents was highlighted, as just 44% of the parents were able to state the operation their children were admitted for. The study also showed that it is impossible to rely on parents to give the information required in the form of replies to questionnaires as the sensitivity of the questions designed to recognize risk factors was poor.

Adenoidectomy↗
PubMed1994

Serum immunoglobulin profiles of septicemic versus healthy neonates.

We studied 125 clinically suspected septicemic neonates (Patient) aged from 1 to 28 days and 25 healthy neonates (control) of comparable age and sexes. Cultures of blood were done and serum immunoglobulins (IgG, IgA) were estimated in all the subjects. Blood cultures were found positive in 45 (36%) patients. Preterm patients showed significantly higher number of positive blood cultures as compared to term patients. The mean serum IgG level in patients was found significantly lower than that of the controls. The serum IgG levels were also found significantly lower in 75 preterm as compared to 50 term, and in 45 blood culture positive patients as compared to 80 blood culture negative patients. On the other hand, the mean serum IgM level in patients was found significantly higher as compared to controls. Similarly, serum IgM levels were found higher in preterm patients as compared to term patients and in blood culture positive patients as compared to blood culture negative patients. No significant difference of mean serum IgA level was found among the subjects. It is evident from our study, that blood culture positive patients were mostly preterm, in whom transplacental passage of IgG is insufficient and due to low IgG level, preterm baby cannot counteract bacterial invasion and as such, suffer from septicemia more frequently. Septicemic neonates as a rule showed higher level of serum IgM due to synthesis by themselves in primary response to infection.

Humans↗
PubMed1994

Inherited metabolic disorders in Pakistan: presentation, diagnosis and outcome of congenital hyperammonemias.

A total of 21 patients were admitted to Aga Khan University Hospital with suspected congenital hyperammonemias during the period 1989 to 1992. There were 11 patients with acidosis and 10 patients were without acidosis. Prominent clinical manifestations included positive family history (76%), onset in the first week of life (67%) and neurological manifestations (76%). Of patients with hyperammonemia and acidosis, 4 had severe metabolic acidosis with anion gap of 30mEq/L and above. Of patients with hyperammonemia without acidosis, 4 had ammonia level ranging from 1600-2000 mg/dl. Diagnosis was confirmed in only 1 patient and that was also done abroad. Overall mortality was 71%. In conclusion, these disorders are not uncommon in our country and should be suspected in all infants with above clinical or biochemical abnormalities.

Ammonia↗
PubMed1993

Fluoxetine induced insulin-like growth factor II (IGF-II) changes in hypothalami of normal, exercised and food restricted rats.

Hypothalamic and pituitary insulin-like growth factor II (IGF-II) peptide concentrations are differentially regulated by factors associated with metabolism such as insulin and glucoprivation. However, the effects of other metabolic stressors such as food restriction or exercise on hypothalamic IGF-II concentrations remain largely to be explored. In order to assess whether metabolic stress alters central nervous system IGF-II secretion, peptide analysis was conducted in rats exhibiting activity-based anorexia (ABA) compared to exercised-matched, body weight-matched or ad libitum fed controls. Further, the possibility of serotonergic control of IGF-II secretion was examined by determining IGF-II response to fluoxetine (FLX) injections (15 mg/kg body wt., i.p.). While ABA and body weight loss altered peripheral IGF-II concentrations compared to ad libitum fed or exercised controls, these treatments had no effect on hypothalamic or posterior pituitary IGF-II content. However, FLX administration increased IGF-II concentrations in the ventromedial hypothalamus and decreased IGF-II content in the lateral hypothalamus compared to vehicle injected. Anterior pituitary levels of IGF-II were also decreased by FLX. These data suggest that a serotonergic influence on CNS IGF-II exists and that IGF-II secretion may be altered by factors affecting serotonin metabolism or efficacy.

Animals↗
PubMed1993

Tuftsin-bearing liposomes as drug vehicles in the treatment of experimental aspergillosis.

Encapsulation of amphotericin B in tuftsin-bearing liposomes greatly increased its efficacy in treatment of human aspergillosis in mice. Also, the drug efficacy was significantly increased by pretreating the animals with drug-free tuftsin-bearing liposomes. These results demonstrate that macrophage activation can considerably enhance the therapeutic efficacy of antifungal drugs, like amphotericin B.

Amino Acid Sequence↗
PubMed1993

Fluoxetine induces vasopressin and oxytocin abnormalities in food-restricted rats given voluntary exercise: relationship to anorexia nervosa.

Anorexia nervosa is associated with vasopressin, oxytocin and serotonin abnormalities. Because of the relationship between exercise and anorexia nervosa, we explored the weight-loss syndrome produced by wheel running in food-deprived rats. Its effects on regional vasopressin and oxytocin concentrations were determined under basal conditions and following systemic fluoxetine. Weight-matched, exercised and unexercised rats served as controls. Fluoxetine caused abnormalities in suprachiasmatic vasopressin and dynorphin A content and in thymus oxytocin content that did not occur in weight-matched or exercised controls. No syndrome-specific anomalies occurred in the hypothalamo-neurohypophysial system or dorsal vagal complex (DVC). However, weight reduction and fluoxetine increased circulating vasopressin; moderate exercise caused fluoxetine-induced elevations in posterior pituitary vasopressin and oxytocin; and, unlike the other groups, fluoxetine increased DVC oxytocin in freely fed unexercised rats. It was concluded that syndrome-specific vasopressin and oxytocin abnormalities occur that are not secondary to weight loss or moderate exercise; that weight loss or fluoxetine increases circulating vasopressin; that moderate exercise alters neurohypophysial vasopressin and oxytocin content; and that weight loss or exercise inhibits a fluoxetine-stimulated increase in DVC oxytocin. Finally, it was argued that the fluoxetine abnormalities indicate possible serotonin dysfunction in the syndrome.

Animals↗
PubMed1993

Pseudocoarctation of the aorta: a magnetic resonance imaging correlation.

We present here the clinical and angiographic features in a patient with pseudocoarctation of the aorta and aortic valvular stenosis. An MRI study performed to delineate the aorta provided valuable correlations and highlighted the potential of this noninvasive modality for the diagnosis of pseudocoarctation of the aorta.

Aorta↗
PubMed1993

Possible interaction between fluoxetine and pimozide causing sinus bradycardia.

Fluoxetine has been reported to have interactions with antipsychotics and other antidepressants with symptoms of toxicity of these drugs. We report a case of a possible interaction with pimozide which led to a potentially life threatening bradycardia. Careful monitoring should be done when these two drugs are prescribed at the same time, especially in the elderly and in patients with cardiac disease.

Aged↗
PubMed1993

Diagnosis and outcome of congenital hyperammonemias.

A total of 21 patients were admitted to Aga Khan University Hospital with suspected congenital hyperammonemias during the period 1989 to 1992, 11 with acidosis and 10 without acidosis. Prominent clinical manifestations included positive family history (76%), onset in the first week of life (67%) and neurological manifestations (76%). Of patients with hyperammonemia and acidosis, 4 had severe metabolic acidosis with anion gap of 30mEq/L and above. Of patients with hyperammonemia without acidosis, 4 had ammonia level ranging from 1600-2000 micrograms/dl. Diagnosis was confirmed in only 1 patient and that was also done abroad. Overall mortality was 71%. These disorders are not uncommon in our country and should be suspected in all infants with above clinical or biochemical abnormalities.

Acidosis↗
PubMed1993

In vitro effect of 5-hydroxytryptamine on concanavalin-A agglutinability and multiplication of Entamoeba histolytica.

Six isolates of E. histolytica isolated and maintained by serial passage in modified Boeck and Drbohlav's medium were used in this study. When five of the isolates were grown in the above medium with 5-hydroxytryptamine (5-HT) added to the overlay, the agglutinability of the amoebae by concanavalin- A (con-A) was significantly increased compared to corresponding control cultures. Four isolates of E. histolytica grown with 5-HT had 1.5 to 2 times higher counts than the control cultures. Similarly the con-A agglutinability and counts of cultures of NIH-200 (an axenic strain of E.histolytica) were enhanced when grown in association with 5-HT.

Agglutination↗