Biomedical subjects

M Bassiouny

Publications and source records attributed to M Bassiouny.

6 recordsLinked to original sources

PubMed2000

Experimental intravenous inoculation of Klebsiella rhinoscleromatis bacilli in albino rats: a histopathological and bacteriological study.

Scleroma, chronic specific granuloma of the nose and upper respiratory tract, is endemic in Egypt and many other countries. The exact pathogenesis of the disease as regards the aetiological role of Klebsiella rhinoscleromatis is contradictory. This work investigated the effect of experimental intravenous injection of K. rhinoscleromatis in albino rats to demonstrate that the micro-organism can fulfil Koch's postulates. Micro-organisms were isolated from biopsy specimens taken from nasal lesions of 10 patients in the granulomatous stage of scleroma. Specimens were subjected to bacteriological and histopathological examinations to confirm the diagnosis. A 100 microl volume of freshly prepared bacterial inoculum containing 10(8) cfu/ml was injected weekly in the tail vein of each of 30 albino rats for 5 consecutive weeks. Biopsy specimens were taken from sacrificed animals and subjected to bacteriological and histopathological examinations. Positive histopathological diagnosis of scleroma was reported in the nose of 66.7% of rats, the larynx of 46.7%, the lungs of 26.7% and liver of 20% of rats. Bacteriological techniques were successful in revealing K. rhinoscleromatis from the nose of 36.7% of rats, the larynx of 30% and the lungs of 20% of rats. Various techniques were carried out to demonstrate the micro-organisms in tissue sections. Two histochemical stains for bacteria were employed: silver and Periodic Acid Schiff (PAS) stains. Immunoperoxidase technique using Klebsiella capsular type 3 antiserum was applied. It gave positive results in 66.7% of the 6 stained liver sections in spite of negative bacteriological cultures. The histiocytic nature of the Mikulicz cells was confirmed using alpha-1 antitrypsin, an immunohistochemical marker of histiocytes, and by studying the ultrastructural features of Mikulicz cells using the transmission electron microscope.

Adult↗

PubMed1998

U74389G prevents vasospasm after subarachnoid hemorrhage in dogs.

OBJECTIVE: Oxygen-derived free radicals may contribute to vasospasm after the rupture of an intracranial aneurysm through direct vasoconstricting effects occurring within the arterial wall or, secondarily, by causing lipid peroxidation in the subarachnoid erythrocytes with secondary induction of vasoconstriction. U74389G is a potent inhibitor of lipid peroxidation and a scavenger of oxygen-derived free radicals. This study determined the relative contributions of oxygen-derived free radicals and lipid peroxidation to vasospasm in the double-hemorrhage dog model. METHODS: Sixteen dogs underwent baseline (Day 0) cerebral angiography and induction of subarachnoid hemorrhage by two injections of blood into the cisterna magna 2 days apart. They were randomized to receive drug vehicle (n=8) or U74389G (n=8, 3 mg/kg of body weight/d) intravenously. Drug administration and end point analysis were blinded. The end points were angiographic vasospasm, as assessed by comparison of angiograms obtained before and 7 days after subarachnoid hemorrhage, and the levels of malondialdehyde and salicylate hydroxylation products (dihydroxybenzoic acids) in cerebrospinal fluid and of malondialdehyde in subarachnoid blood clots and basilar arteries 7 days after hemorrhage. RESULTS: Comparisons within groups of Day 0 and Day 7 angiograms and between groups of angiograms obtained at Day 7, showed significant vasospasm in animals in the vehicle group (mean+/-standard error, 51%+/-4) but not in the U74389G group (25%+/-11, P < 0.05, unpaired t test). High-pressure liquid chromatographic assays of malondialdehyde and dihydroxybenzoic acids in cerebrospinal fluid, subarachnoid blood clots, and basilar arteries showed no significant differences between groups. CONCLUSION: The significant prevention of vasospasm by U74389G without change in levels of indicators of free radical reactions suggests that the effect of the drug is related to other processes occurring in the arterial wall and that cerebrospinal fluid levels of oxygen radicals and lipid peroxides are not useful markers of vasospasm.

Animals↗

PubMed1997

Topical levocabastine for the treatment of perennial allergic rhinitis.

The ultrastructure of the nasal mucosa following the use of intranasal levocabastine was studied in 20 patients suffering from perennial allergic rhinitis. The patients received twice daily 0.05 per cent levocabastine spray with a treatment duration of four weeks. At the end of the treatment period regression of the allergic process was evidenced by progressive reappearance of normal cilia and microvilli on the columnar cells, decrease of intercellular oedema and cytoplasmic vacuoles, increased number of mucous acinar cells, gradual decrease of vascular congestion, as well as diminished oedema fluid formation. The drug, however, had no effect on mast cell degranulation nor on eosinophilic infiltration. Normalization of the ultrastructural features correlated well with clinical improvement. Considering the results of the present study, levocabastine nasal spray appears to be an effective treatment for perennial allergic rhinitis and can be used with, or as an alternative to, other anti-allergic medications.

Administration, Intranasal↗

PubMed1996

Effect of BQ-123 and tissue plasminogen activator on vasospasm after subarachnoid hemorrhage in monkeys.

BACKGROUND AND PURPOSE: We aimed to determine the effect of intracisternal administration of an endothelin-A receptor antagonist (BQ-123) against vasospasm in a monkey model and to determine whether this drug would have adverse interactions with intracisternal tissue plasminogen activator (TPA). METHODS: Thirty-three monkeys were randomly allocated to undergo baseline cerebral angiography, creation of right subarachnoid hemorrhage (SAH), and intracisternal delivery of (1) placebo (n = 10); (2) low-dose BQ-123 (5 mg/kg per day, n = 7); (3) high-dose BQ-123 (10 mg/kg per day, n = 9); or (4) BQ-123 10 mg/kg per day plus TPA 1 mg every 12 hours for three doses (n = 7). Angiography was repeated after 7 days, and animals were killed. Vasospasm was assessed by comparisons of angiograms within groups across time by paired t test and by comparisons across groups at each time by ANOVA. RESULTS: Significant clot remained in the basal cisterns in all groups except those receiving TPA, in whom complete clot clearance was noted. Comparisons of angiograms at baseline and after 7 days showed significant vasospasm of the right middle cerebral artery in animals receiving placebo (mean +/- SEM reduction in diameter, 36 +/- 7%; P < .05) and low- and high-dose BQ-123 (16 +/- 4% and 18 +/- 7%, respectively). Animals that received TPA did not develop significant right cerebral artery vasospasm. Comparisons of arterial diameters at day 7 revealed significant variance in right middle cerebral artery diameter, with animals in the placebo group having significantly more and animals in the TPA group having significantly less vasospasm than the BQ-123 groups. Histopathological examination of the brains did not show inflammation or pathological change in animals that received BQ-123 or BQ-123 plus TPA. CONCLUSIONS: Intracisternal TPA was efficacious against vasospasm in monkeys. Combination therapy with TPA and BQ-123 was not associated with reduction in efficacy of either drug or with evidence of toxicity.

Animals↗

PubMed1994

Beta 2-transferrin confirms perilymphatic fistula in children.

beta 2-Transferrin is a protein that is unique to the cerebrospinal fluid and aqueous humor. On the basis of this information and a recent study from our institution that demonstrated that beta 2-transferrin was also unique to human perilymph, a prospective, double-blind study to evaluate perilymphatic fistula in children was performed. Attending otolaryngologists at Children's Hospital of Pittsburgh evaluated and recommended surgery for 10 children (10 ears) who were suspected of having a congenital perilymphatic fistula. During the operation, the surgeon decided whether a perilymphatic fistula existed, on the basis of otomicroscopic findings, and then separate pieces of gelatin sponge were placed on the oval and round windows, respectively, and sent to the immunopathology laboratory where they were analyzed for beta 2-transferrin. Ten patients (10 ears) undergoing tympanoplasty or tympanomastoidectomy were used as controls and tested in a similar fashion. During the study, both the surgeons and patients were blinded from the results of the test. Of the 10 control patients, none was observed to have a perilymphatic fistula, and all were negative for beta 2-transferrin. Of the 10 patients undergoing exploratory tympanotomy for perilymphatic fistula, 1 ear was thought to be negative for perilymphatic fistula on microscopic visual examination, whereas 9 were considered to be positive for perilymphatic fistula. No beta 2-transferrin was identified from the ear that was considered not to have a perilymphatic fistula, whereas six of the nine ears that were thought to have perilymphatic fistula tested positive for beta 2-transferrin.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

Beta 2 transferrin application in otology.

The diagnosis and management of perilymphatic fistula has received considerable attention in recent years. Despite the use of sophisticated technology, the diagnosis of perilymphatic fistula continues to rest primarily upon clinical suspicion and the exclusion of other disorders. In addition, the confirmation of a perilymphatic fistula during surgical exploration is usually based upon the subjective observation of fluid pooling in niches of the middle ear. A sensitive and objective laboratory test for identifying perilymph in the middle ear would be a useful adjunct for the diagnosis and management of perilymphatic fistula. The objective of this paper is to demonstrate the potential utility of beta 2 (beta 2) transferrin assay in the diagnosis of perilymphatic fistula. To accomplish this objective, we confirmed that beta 2 transferrin is present in living human perilymph and is absent in the normal or inflamed middle ear. In addition, the utility of beta 2 transferrin assay in the diagnosis of cerebrospinal fluid otorrhea is presented.

Aged↗