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Biomedical subjects

A Ali

Publications and source records attributed to A Ali.

At least 163 records · Page 9Linked to original sources
PubMed1999

Laboratory evaluation of biotic and abiotic factors that may influence larvicidal activity of Bacillus thuringiensis serovar. israelensis against two Florida mosquito species.

A technical powder of Bacillus thuringiensis serovar. israelensis (B.t.i.) (VectoBac TP, 5,000 international toxic units [ITU]/mg), an aqueous suspension (VectoBac 12AS, 1,200 ITU/mg), and a granular formulation (VectoBac CG, 200 ITU/mg) were tested in the laboratory under different biotic and abiotic, conditions for efficacy against larvae of saltwater (Aedes taeniorhynchus) and freshwater (Culex nigripalpus) mosquitoes. Second-, 3rd-, and 4th-instar larvae of Cx. nigripalpus were 1.3-3-fold more susceptible to both VectoBac TP and VectoBac 12AS than were the respective larval instars of Ae. taeniorhynchus. For each species, 2nd-instar larvae were several-fold more susceptible to these B.t.i. preparations than were the 4th instars. In test cups, larvae under lower densities exposed to B.t.i. concentrations sustained 5-9-fold higher mortalities than larvae under high-density conditions. VectoBac TP and VectoBac 12AS stayed in suspension for up to 24 h with similar larvicidal efficacy, which was greater at 32-35 degrees C than at 15-20 degrees C. At 60 degrees C maintained for 24 h, VectoBac 12AS was adversely affected 2-3-fold in terms of potency, but VectoBac TP was not affected. Significant loss of potency of both VectoBac 12AS and VectoBac TP occurred when exposed to 35-37 degrees C under high light intensity (140,000-170,000 lux) for 6 h. Increasing salinity levels from 0 (fresh water) to 50% sea water caused gradual efficacy declines of VectoBac 12AS and VectoBac TP against Ae. taeniorhynchus larvae. VectoBac CG caused insignificant initial and residual (up to 8 days) larval mortalities of both mosquito species. This formulation did not release the active ingredient of B.t.i. in any significant mosquito larvicidal concentration in surface layers of water, and the formulation was more effective in shallower water. Storage of all 3 formulations under constant laboratory and variable field conditions for up to 8 months did not produce detectable potency loss of these products.

Aedes↗
PubMed1999

Laboratory evaluation of selected larvicides and insect growth regulators against field-collected Culex quinquefasciatus larvae from urban Dhaka, Bangladesh.

Five organophosphates (OPs) (chlorpyrifos, chlorpyrifos methyl, fenthion, malathion, and temephos), 3 pyrethroids (bifenthrin, cypermethrin, and permethrin), 1 phenyl pyrazole (fipronil), 2 microbial pesticides (Bacillus thuringiensis serovar. israelensis [B.t.i.] and Bacillus sphaericus), and 3 insect growth regulators (IGRs) (diflubenzuron, methoprene, and pyriproxyfen) were evaluated against field-collected Culex quinquefasciatus larvae from urban Dhaka, Bangladesh. The LC90 values of all OPs, except for temephos (LC90 = 0.0096 ppm), were high, ranging from 0.13 ppm (fenthion) to 2.882 ppm (chlorpyrifos methyl). Pyrethroid LC90 values were 0.021 ppm (bifenthrin), 0.00061 (cypermethrin), and 0.017 ppm (permethrin). Fipronil exhibited a superior activity with LC90 value of 0.000896 ppm. Technical powders of B.t.i. and B. sphaericus (VectoBac TP and VectoLex TP) were considered highly effective against the Cx. quinquefasciatus larvae. The IGRs also were effective with pyriproxyfen (LC90 = 0.0011 ppm), being 3 times and 47 times more active than diflubenzuron (LC90 = 0.0034 ppm) and methoprene (LC90 = 0.052 ppm), respectively. In general, toxicity ranking of chemicals and microbials tested was phenyl pyrazole > IGRs > pyrethroids > microbials > OPs.

Animals↗
PubMed1999

Comparison of spiramycin and clarithromycin for community-acquired lower respiratory tract infections.

This open multicentre study compared the efficacy and tolerability of clarithromycin and spiramycin in the treatment of lower respiratory tract infections in Brazil and Colombia. A total of 125 patients with a clinical and radiological diagnosis of pneumonia, acute bronchitis or exacerbation of chronic bronchitis were randomised to receive oral doses of either clarithromycin (500 mg) or spiramycin (3 MIU) every 12 hours for courses of 5-10 days. Patients were assessed before the start of treatment, and at days 3-4 and days 9-17. Twenty-six (26) patients (16 in the spiramycin group and 10 in the clarithromycin group) reported adverse events, seven of whom withdrew from the trial. Statistical analysis detected no significant differences between efficacy (p = 0.768) or tolerability (p = 0.236) for the two treatment groups. Spiramycin therefore has similar efficacy to clarithromycin in the treatment of community-acquired lower respiratory tract infections.

Adolescent↗
PubMed1999

Review of oesophageal foreign bodies in Harare Central Hospital.

OBJECTIVE: To review our experience in the management of patients with oesophageal foreign bodies. DESIGN: Retrospective analysis. SETTING: Harare Central Hospital, Harare, Zimbabwe. SUBJECTS: Sixty eight patients who presented with foreign body ingestion from October 1990 to December 1991. INTERVENTION: All but two patients underwent rigid oesophagoscopic examination. RESULTS: Sixty five of the cases with foreign bodies in the oesophagus had their foreign bodies retrieved by rigid oesophagoscopic procedure. CONCLUSION: A high index of suspicion will help in early diagnosis especially in children who present with recent and inexplicable onset of respiratory symptoms.

Adolescent↗
PubMed1999

Unusual complications following laparoscopic Nissen fundoplication.

Laparoscopic Nissen fundoplication is commonly used to treat medically refractory gastroesophageal reflux disease. The most frequent severe complications following laparoscopic Nissen fundoplication are pneumothorax, gastroesophageal leak, and splenic injury. Prompt recognition and treatment of complications are important in reducing subsequent morbidity and mortality. This report describes two postoperative complications: (1) delayed diagnosis of a postoperative gastric perforation despite an unrevealing work-up for postoperative fever and abdominal pain; and (2) postoperative pancreatitis following revision of a fundoplication.

Adult↗
PubMed1998

Modulatory impact of cardiac rehabilitation on hyperhomocysteinemia in patients with coronary artery disease and "normal" lipid levels.

In coronary patients with "relatively normal" lipid values and hyperhomocystinemia (levels > or =15 micromol/L), significant 12% reductions in homocysteine levels occurred after cardiac rehabilitation and exercise training. This benefit from cardiac rehabilitation and exercise training may lead to 20% to 30% reductions in overall coronary artery disease risk.

Aged↗
PubMed1998

Induction of the DNA-binding and transcriptional activities of heat shock factor 1 is uncoupled in Xenopus oocytes.

The DNA-binding and transcriptional activities of the heat shock transcription factor 1 (HSF1) are repressed under normal conditions and rapidly upregulated by heat stress. Here, we tested for the ability of various stress agents to activate HSF1 in the Xenopus oocyte model system. The HSE-binding activity of HSF1 was induced by a number of chemical stresses including cadmium, aluminum, iron, mercury, arsenite, ethanol, methanol, and salicylate. HSE-binding was not induced by several stresses known to induce the synthesis of hsps in other cell types in different organisms including zinc, copper, cobalt, manganese, recovery from anoxia, UV-irradiation, and increased pH. The inability of several known inducers of the stress response to activate the HSE-binding ability of HSF1 suggests that certain stress activation pathways may be absent or inactive in oocytes. The transcriptional activity of oocyte HSF1 was induced by heat, cadmium, and arsenite, but many of the agents that induced HSE-binding failed to stimulate HSF1-mediated transcription. The apparent uncoupling of inducible HSE-binding and transcriptional activities of HSF1 under a variety of stress regimes indicates that these events are regulated by independent mechanisms in the oocyte.

Animals↗
PubMed1998

The cloning, expression and characterization of a cellobiase gene encoding a secretory enzyme from Cellulomonas biazotea.

A 4.7-kb DNA insert encoding a secretory cellobiase (Cba) was cloned from Cellulomonas biazotea in Escherichia coli using an excretion vector, pM. Host cells transformed with the recombinant construct, designated pBZ4.7, were able to utilize cellobiose as the sole carbon source. Part of the Cba activity encoded by pBZ4.7 could be detected in the periplasm and even in the culture supernatant. The Cba protein was purified from the culture supernatant and analyzed by SDS-PAGE to have an apparent M(r) of 86,000. The insert consisted of two PstI fragments with lengths of 0.75 and 3.95 kb, both of which were found to be crucial for expressing the Cba activity. Sequencing of the first 3.95 kb of the insert revealed that the coding sequence for Cba, designated the cba gene, was 2484 bp long. Comparison of the deduced Cba sequence with those of published beta-glucosidases revealed a potential active site located at the N-terminal portion of the former. The cba gene has a high G + C content of 76.4% and is flanked by a putative ribosome-binding site and potential transcriptional termination signals upstream and downstream from its coding sequence, respectively.

Amino Acid Sequence↗
PubMed1998

Association of ventricular ectopy with nuclear scintigraphic perfusion defects during dipyridamole stress testing.

BACKGROUND AND HYPOTHESIS: No information is available regarding the significance of ventricular ectopic activity induced during dipyridamole nuclear scintigraphic stress testing. This study tested the hypothesis that dipyridamole-induced ventricular ectopy predicts a thallium-201 or technetium-99m sestamibi perfusion defect. METHODS: A group of 186 consecutive patients with premature ventricular contractions and/or couplets occurring during dipyridamole stress testing (ventricular tachycardia did not occur) was compared with a control group of 194 patients without ventricular ectopy during dipyridamole stress testing. RESULTS: The results indicated that ventricular ectopy induced during dipyridamole infusion occurred more frequently in patients demonstrating either a fixed or reversible perfusion defect on scintigraphic imaging (p < 0.01). The higher frequency of perfusion defects in this group of patients was attributable to a higher frequency of "fixed" compared with "reversible" defects (p < 0.05). This finding is consistent with the additional observation that ventricular ectopy induced by dipyridamole was associated with the presence of Q waves on the resting ECG (p < 0.05). The positive and negative predictive values of the presence of ventricular ectopy in predicting a fixed myocardial perfusion defect were 59 and 54%, respectively. CONCLUSIONS: Ventricular ectopy induced during dipyridamole infusion suggests the presence of a fixed myocardial perfusion defect.

Aged↗
PubMed1998

The role of MRI in the diagnosis of occult hip fractures.

Undisplaced fractures of the hip can occasionally be difficult to diagnose on radiographs. We performed MRI scans on 33 patients who had post-traumatic painful hips but negative radiographs. Forty per cent of the patients had sustained a fractured neck of femur, 15 per cent had sustained an intertrochanteric fracture and 11 per cent had sustained other fractures around the hip; in one patient a tumour was demonstrated. No fracture was seen in 30 per cent of the patients scanned. MRI is well tolerated by elderly patients in pain, does not involve ionising radiation and provides early and accurate diagnosis in patients with X-ray negative post-traumatic hip pain.

Accidental Falls↗
PubMed1998

Features of eating disorders in patients with irritable bowel syndrome.

The relationship between characteristics of irritable bowel syndrome (IBS) and eating disorders (ED) was investigated in a clinical sample of 43 female and 17 male IBS patients who completed the Eating Disorder Inventory (EDI). A diagnosis of IBS was generally unrelated to the Body Dissatisfaction, Perfectionism, and Ineffectiveness subscales of the EDI, but symptom severity was correlated with Perfectionism and Ineffectiveness. Severe bouts of vomiting were significantly associated with desires for lower body weight and reported binge-purge behaviors and cognitions measured by the Bulimia subscale of the EDI. Results suggest the need for a more comprehensive understanding of both types of illness as well as a possible framework for future empirical work.

Adult↗
PubMed1998

A randomized biomechanical study of zone II human flexor tendon repairs analyzed in a linear model.

Komanduri et al showed that dorsal tendon repairs using Kessler and Bunnell techniques were stronger than the standard volar repair (J Hand Surg 1996;21 A:605-611). They concluded that when testing in the anatomic curvilinear mode, the differences in strength were due to tension banding. Soejima et al challenged that concept by stating that the difference in strength was in the biomechanics of the dorsal tendon itself (J Hand Surg 1995;20A:801-807). We set out to confirm Soejima et al's theory by using more core suture techniques. We compared the tensile strength at 2-mm gap and the ultimate tensile strength of Kessler, Strickland, Robertson, and modified Becker sutures. Ten repairs of each suture type were placed either dorsally or volarly in matched human cadaver flexor tendons. There was no statistical difference between volar and dorsal placement for either maximum tensile force or force at 2-mm gap. Our study does not confirm Soejima et al's in any of the four suturing techniques.

Biomechanical Phenomena↗
PubMed1998

A randomized biomechanical study of zone II human flexor tendon repairs analyzed in an in vitro model.

To study the effect of dorsally placed flexor tendon repairs on human cadaver tendons, we used the Kessler, Strickland, Robertson, and modified Becker techniques. The strengths of the repairs were tested in a previously described human cadaveric curvilinear model. There were statistically significant increases in dorsal versus volar grasping strength with the Kessler repair (38 N vs 33 N) and the Robertson repair (51 N vs 43 N). There were no differences with the locking Strickland and modified Becker repairs. One may infer that the locking techniques are intrinsically tighter and may not be as susceptible to the different forces between the tensile and compressive surfaces of a dynamic flexor tendon.

Cadaver↗
PubMed1998

Rilmenidine reveals differences in the pharmacological characteristics of prejunctional alpha2-adrenoceptors in the guinea-pig, rat and pig.

1. The alpha2A and alpha2D-adrenoceptor subtypes are thought to be species homologs most easily differentiated on the basis of the potency of antagonists. In the present study we have compared the effect of rilmenidine with two other selective alpha2-adrenoceptor agonists, UK-14304 (5-bromo-6- [2-imidazolin-2-ylamino]-quinoxaline) and clonidine, against electrically-evoked contractions in five isolated preparations from the rat, guinea-pig and pig, and, where possible, determined the receptor subtype involved. 2. UK-14034, clonidine and rilmenidine produced concentration-dependent inhibition of the electrically-evoked contractions of the rat isolated vas deferens and tail artery and the guinea-pig ileum. These inhibitory effects were reversed by the selective alpha2-adrenoceptor antagonist, RX-811058 (1 microM), except in the rat tail artery preparations where the remaining neurogenic response was inhibited; evidence for the involvement of 'innervated' alpha2-adrenoceptors. Both clonidine and UK-14304 produced concentration-dependent inhibition of responses in the porcine isolated tail artery and urinary bladder but clonidine was markedly less efficacious in these preparations. In contrast, rilmenidine failed to inhibit the neurogenic contractions in either preparation. 3. Although rilmenidine failed to elicit a detectable response in either the porcine isolated tail artery or urinary bladder, it (10 microM and 30 microM, respectively) competitively antagonised the inhibitory effects of UK-14304 with an estimated dissociation constant of (pK(B)) 5.82 and 5.93, respectively. 4. Prazosin (1 microM) failed to alter the effect of UK-14304 against neurogenic contractions in the porcine isolated urinary bladder, while rauwolscine (pK(B) 8.87) was 10 fold more potent than phentolamine (pK(B) 7.56). On the other hand, phentolamine (pK(B) 8.42) was only marginally more potent than rauwolscine (pK 8.05) against clonidine-induced inhibition of electrically-evoked contractions of the guinea-pig isolated ileum. This pharmacological evidence with antagonists supports the presence of alpha2D-adrenoceptors in the rat and guinea-pig and the alpha2A-adrenoceptors in the pig. 5. We have demonstrated that rilmenidine, unlike clonidine and UK-14304, is devoid of any agonist activity at prejunctional alpha2A-adrenoceptors in the pig, but is an efficacious agonist at alpha2D-adrenoceptors in the rat and guinea-pig.

Adrenergic alpha-2 Receptor Agonists↗
PubMed1998

Cognitive-behavioral group therapy for patients with irritable bowel syndrome.

This article is divided into two parts, the first of which focuses on a general overview of irritable bowel syndrome (IBS) and provides a rationale for the use of cognitive-behavioral therapy (CBT) for IBS based on both theoretical and research perspectives. This section includes a critical review of CBT therapies for IBS and provides a model of CBT for IBS. The second section provides the clinician with practical information concerning the application of cognitive-behavioral group therapy for IBS. Possible scripts and case examples are incorporated into this section to highlight factors that may arise in working with IBS patients relative to other clinical groups. The second section also contains themes that are suggested content areas for group sessions. Contingent on the formulation of the presenting or emerging issues and goals, the order and inclusion of themes can be changed to fit the particular needs of a given group. Finally, this section provides initial preliminary data from a randomized controlled study that is suggestive of the efficacy of cognitive-behavioral therapy for IBS.

Adult↗
PubMed1998

Binding of naturally occurring anti-DNA antibodies to estradiol.

Binding of naturally occurring human anti-DNA autoantibodies to beta-estradiol and native DNA has been investigated. Sera from seven SLE patients were tested for their reactivity with beta-estradiol and native calf thymus DNA. Solid Phase enzyme immunoassay was performed using both colorigenic and fluorogenic substrates. The results show enhanced binding of human anti-DNA autoantibodies to beta-estradiol as compared to native DNA. This was further substantiated by increased binding of affinity purified SLE IgG to beta-estradiol. These results suggest a role for female sex hormone in the etiopathogenesis of SLE and are significant vis-a-vis female predominance of SLE.

Antibodies, Antinuclear↗
PubMed1998

Hematopoietic cytokine-mediated FDG uptake simulates the appearance of diffuse metastatic disease on whole-body PET imaging.

FDG-PET is increasingly being used to assess malignant tumors. However, leukocyte colony-stimulating factors (CSFs), which promote the expansion of hematopoietic bone marrow, have also been demonstrated to cause increased bone-marrow FDG uptake. Three hundred FDG-PET studies conducted over a 1-year period were reviewed for diffuse bone-marrow uptake. Elevated bone-marrow uptake on PET was correlated with pathological findings and courses of granulocyte-CSF (G-CSF) therapy. These results demonstrate that G-CSF mediated FDG uptake in bone marrow is often indistinguishable from that caused by disseminated metastatic disease. However, the bone-marrow response to G-CSF decreases rapidly following the last CSF administration. Therefore, FDG-PET in patients receiving G-CSF should be delayed, when possible, until 5 days after the end of G-CSF therapy.

Adolescent↗