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Biomedical subjects

R Ashraf

Publications and source records attributed to R Ashraf.

13 recordsLinked to original sources

To evaluate and compare the effects of first generation anti-histamine (chlorpheniramine maleate) and second generation anti-histamine (loratadine) on isolated trachea of rabbit.

OBJECTIVE: The incidence of respiratory allergy has increased gradually over the past several years and current estimates suggest that allergic rhinitis affects approximately 20% of the population. Large scales population surveys indicate that up to 38% of patients with rhinitis have asthma. The allergic response in the airways is an important pathogensis to cause bronchoconstriction owing to increased responsiveness of tracheo bronchial tree to various stimuli and also causes the release of histamine and other chemical mediators from mast cells. Histamine has been shown to be an important mediator of an allergic reaction in both the upper and lower respiratory airways. Chlorpheniramine maleate is a stable, most potent, sedative first generation anti-histamine and is effective in the treatment of allergic disorders. Loratadine is a highly potent, non-sedating, long acting tricyclic, second generation anti-histamine. It is indicated in allergic rhinits, chronic idiopathic urticaria and allergic bronchial asthma. The purpose of study was to evaluate the antagonistic effects of chlorpheniramine maleate and loratadine on histamine induced contractions in isolated trachea of rabbit and also to compare the effects of first generation anti-histamine (chlorpheniramine maleate and second generation anti-histamine loratadine). METHODS: In this study twenty-four experiments were performed on isolated trachea of rabbit, in the presence of selected standard concentration of histamine dihydrochloride, antagonistic effects of various concentrations of chlorpheniramine maleate (10-18 to 10(-3) gm/ml) and loratadine from concentrations 10(-18) to 10(-3) gm/ml were recorded by Polygraph Model 7B in terms of rate and amplitude. RESULTS: Chlorpheniramine maleate showed non-significant antagonistic effect from concentrations 10(-18) to 10(-3) gm/ml in case of rate and 10(-18) to 10(-8) gm/ml in case of amplitude. Significant response showed from concentrations 10(-8) to 10(-3) gm/ml in case of rate (P<0.001) and 10(-7) to 10(-3) gm/ml in case of amplitude (P<0.001) while, loratadine showed non-significant response from concentrations 10(-18) to 10(-12) gm/ml in case of rate and from concentration 10(-18) to 10(-14) gm/ml in case of amplitude. Significant response observed from concentrations 10(-11) to 10(-3) gm/ml in case of rate and 10(-13) to 10(-3) gm/ml in case of amplitude. CONCLUSION: It was concluded that chlorpheniramine maleate antagonized the histamine induced contractions 80.65% at concentration 10(-3) gm/ml in case of amplitude and 11.35% at concentration 10(-3) gm/ml in case of rate and loratadine 76.82% in case of amplitude and 10.59% in case of rate.

Animals↗

The mammary gland-infant intestine immunologic dyad.

The human infant has a very small immune system and needs the support of the mother with the transplacentally arrived IgG antibodies to protect tissues with inflammatogenic and energy-consuming defense. The mucous membranes, where most infections occur, need support via the specialized secretory IgA antibodies and the many other mucosal defense mechanisms provided via the mother's milk. This defense is not inflammatogenic and energy-consuming. We learn about additional defense factors in the milk, like the anti-secretory factor, which seems to protect against diarrhoea. The milk contains numerous growth factors and cytokines, like leptin, which may promote the development of the intestine as well as the immune system. Results are appearing giving interesting evidence for enhanced protection against infection also after the termination of breastfeeding. This may occur via the priming of the infant's immune system after uptake of anti-idiotypic antibodies and lymphocytes from the milk. A breastfeeding motivation study in a large Pakistani village resulted in a 50% decrease of diarrhoea and infant mortality. Deep interviews with the mothers and the traditional birth attendants suggested that even better results may be obtained.

Adjuvants, Immunologic↗

Radiation-induced bronchial stenosis: a new cause of platypnea-orthodeoxia.

Platypnea-orthodeoxia is encountered in a variety of cardiac, pulmonary, and hepatic disorders. We report its occurrence in a 59-year-old man who had had combined external-beam and high dose-rate iridium brachytherapy for a stage I non-small-cell carcinoma of the right upper lobe 2 years earlier. The post-radiation course was complicated by a severe radiation bronchitis; the onset of platypnea-orthodeoxia signalled the development of severe bronchial stenosis that was transiently relieved, initially by dilatation, and later by stent placement, though the patient ultimately died of a pulmonary hemorrhage. The dosage of brachytherapy given, the combined external-beam therapy, and the long survival after completion of radiation therapy were likely factors in the development of bronchial stenosis. We discuss the tomographic and bronchoscopic features of radiation-induced bronchial stenosis.

Blood Gas Analysis↗

Efficacy and safety of clonazepam in refractory neurally mediated syncope.

Neurally mediated syncope is a complex syndrome that is often difficult to manage using currently available treatment strategies. The efficacy and safety of clonazepam was evaluated in 35 patients with refractory neurally mediated syncope. All patients had syncope (n = 33) or disabling presyncope (n = 2) and a positive head-up tilt table test (HUTT) despite treatment with one or more of the following therapies: beta-blocker, high-salt diet, fludrocortisone, elastic compression stockings, and disopyramide. Clonazepam was initiated at 0.5 mg/day and titrated in 0.25-0.5 mg/day increments for symptom control. Early (first 8 weeks) symptomatic response was achieved in 31 of 35 (89%) patients. Early HUTT reverted to negative in 29 of 35 (83%) patients. Two patients discontinued clonazepam during early follow-up due to side effects. Thirty-three patients received long-term clonazepam therapy. Twenty-five patients had late HUTT with 21 remaining negative. Of the eight patients who did not have late HUTT, one patient discontinued clonazepam prior to HUTT due to side effects. Seven patients refused late HUTT. All seven patients achieved symptomatic control on clonazepam with two requiring dose titration. Of the 21 patients with a negative late HUTT, 18 achieved symptomatic control with two of these patients requiring dose titration. Two patients who had only partial symptom control despite dose titration achieved total symptomatic control with the addition of disopyramide and beta-blockers. Two patients with a negative late HUTT discontinued clonazepam due to side effects. One patient had been symptomatically controlled while the other had recurrent symptoms with dose limiting side effects occurring after clonazepam dose titration. In the 4 patients with a positive late HUTT, 2 patients were symptomatically controlled, 1 patients required combination therapy with a beta-blocker to achieve symptomatic control, and 1 patient discontinued therapy due to side effects. Overall, 29 of 35 (83%) patients continue to receive clonazepam with symptom control. Based on intention-to-treat HUTT results, 21 of 35 (60%) patients were responders. Four patients required clonazepam dose titration and three required combination therapy with clonazepam plus disopyramide and/or a beta-blocker to achieve control. Clonazepam was discontinued in 6 patients, 5 for side effects and 1 following a transient ischemic attack. Clonazepam appears to be an effective therapeutic alternative in patients with refractory neurally mediated syncope. Based on our preliminary findings, a placebo controlled evaluation of clonazepam in neurally mediated syncope is warranted.

Adrenergic beta-Antagonists↗

Differing scintigraphic patterns of lumboperitoneal shunt dysfunction in patients with normal pressure hydrocephalus and pseudotumor cerebri.

The scintigraphic patterns of dysfunctioning lumboperitoneal shunts (LPS) may vary with the underlying disease. The authors reviewed 22 LPS studies performed on 15 patients during the past 2 years and correlated the findings with the patency status of the shunt as determined by brain CT/MRI and surgical revision. Most of the patients also had cerebrospinal fluid (CSF) pressure monitoring. Fifteen studies were performed in patients with LPS for the treatment of normal pressure hydrocephalus (NPH) and 7 were performed in patients with LPS for pseudotumor cerebri (PTC). After intrathecal administration of 0.5-1 mCi of In-111 DTPA, sequential 1 minute images of the abdomen were obtained for 20 minutes. Static images of the abdomen were then obtained at 30 minutes and 1, 2, 4, and 24 hours with imaging of the head at 4 and 24 hours. All NPH patients with partial obstruction had tracer activity in the peritoneal cavity with little or no shunt tubing visualization. However, all had marked penetration of the tracer into the lateral ventricles. Pseudotumor cerebri patients with partial obstruction also showed tracer entry into the peritoneal cavity. Shunt tubing and tracer extravasation into the needle tract, at the site of lumbar puncture was seen only in patients of PTC, probably because of high intracranial pressure. Although the tracer flowed quickly into the basal cistern in all patients with PTC, it entered the lateral ventricles. Complete shunt obstruction was characterized by nonvisualization of activity in the peritoneal cavity and flow of the tracer into the basal cistern within 1 hour after injection.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Breast feeding: overview and breast milk immunology.

The transfer of host defence capacity to the human offspring provides a remarkable model of passive transfer of immunity. In fact it may also provide an example of active immunization. The transfer of mucosal protection via breast feeding offers many additional advantages for the mother and infant. Through its contraceptive effects it increases the spacing between births, thus diminshing the infant mortality and the burden on the mother. It also enhances bonding between mother and child, it seems to increase the IQ and school result of the infant and might decrease the risk of certain malignancies and perhaps of juvenile diabetes. A fully breast-fed infant receives as much as 0.5-1 g of secretory immunoglobulin A (SIgA) antibodies daily, the predominant antibody of human milk. This can be compared to the production of some 2.5 g of SIgA per day for a 60 kg adult. These SIgA antibodies have been shown to protect against Vibrio cholerae, ETEC, Campylobacter, Shigella and Giardia. Furthermore, milk is rich in receptor analogues for certain epithelial structures which microbes need for attachment to host tissues as an initial step in infections. Thus the adherence of Haemophilus influenzae and pneumococci for example to retropharyngeal cells is efficiently inhibited by human milk. This may be one explanation for the fact that breast-fed babies have less otitis media than the non-breast-fed. Other milk factors like lysozyme and lactoferin may contribute to the host defence, but this has not yet been well defined. However, human milk also supports the well-being of the infant by being anti-inflammatory.(ABSTRACT TRUNCATED AT 250 WORDS)

Breast Feeding↗

Radioaerosol mucociliary clearance of tracheobronchial tree in normal subjects and in patients with respiratory diseases.

The rate of mucociliary clearance in the tracheobronchial tree was studied both in patients and controls using radioisotopic techniques. The radioisotope is deposited in the larger airways and its rate of movement is measured as it is being transported up the trachea due to mucociliary activity. The BARC aerosol generation system was modified and used for this purpose. One hour study was acquired on a computerised gamma camera in each case. The rate of movement of the bolus of radioactivity was calculated by measuring the distance travelled in a known period of time. The mean velocity of transport was 9.0mm/min in normal subjects. In patients variable speed of transportation was obtained ranging from absolutely no movement to near normal speeds. Different patterns of transport were observed including linear, spiral, static and regurgitative. It was concluded that this simple non-invasive technique can be used for in vivo monitoring of mucociliary tracheal activity.

Adult↗