Gastroprotective effect of propacetamol against cold/restraint stress ulcers in rats.

BACKGROUND: Comparative evaluation of propacetamol and morphine on the cold restraint stress ulcers in rats. METHODS: The present study compared the effects of propacetamol hydrochloride (250 and 500 mg.kg-1 i.p.) and morphine hydrochloride (10 mg.kg-1 i.p.) against gastric mucosal damage induced by cold/restraint stress (4 degrees C for 3 h) in rats. Morphometrical and histomorphological studies were carried out. Mean ulcer number and length were calculated. RESULTS: The results show that propacetamol in the lower dose tested decreases the ulcer number and length by 56.4% (p > 0.05) and by 68.94% (p < 0.01). After propacetamol 500 mg.kg-1 the ulcer number and length were found significantly decreased by 74.83% and 83.5%. Marked decrease was found in morphine-pretreated group (-77.03% and -85.09%). The morphometrical results have been confirmed histomorphologically. CONCLUSIONS: It might be concluded that morphine (10 mg.kg-1) and propacetamol (500 mg.kg-1) are equipotent in their ability to prevent the stress ulceration in rats.     

Endothelium-mediated relaxation in transplanted aorta.

This study compares the vasodilating effect of endothelium-derived relaxing factors (EDRFs) in free arterial grafts with that in their normal control vessels. The infrarenal aorta of Sprague-Dawley rats was transplanted into the same position in other inbred recipient rats. A Krebs buffer solution (4 degrees C) served as the preservation solution. The ischemic time for the grafts (n = 8) was 42 +/- 1 minutes. Two grafts were studied after 3 days and six grafts, after 60 days. Ring segments were cut from all vessels, and isometric contractions were recorded in organ baths. The vessel segments were constricted with noradrenaline, a thromboxane A2 mimic (U-46619), or prostaglandin F2 alpha. Concentration-response curves with acetylcholine, which was used as the endothelium-stimulating substance causing release of EDRFs, were obtained. The patency of the grafts was 100%. Acetylcholine induced relaxation in all vessel segments with intact intima, whereas no relaxation was seen when the endothelium was manually removed. No significant differences were found between the grafts and the normal control vessels. Histology of the 60-day grafts showed elastomuscular arteries without intimal thickening and a media consisting of eight to ten muscle layers interrupted by five to six elastic lamellae. Scanning electron microscopy showed no major differences between normal endothelium and the endothelium of 3-day or 60-day grafts. This study indicates that free elastomuscular arterial grafts, in which the morphology of the intima is preserved, will retain their full ability to release EDRFs.     

Cycloadditionen von Cyclopropenon an 1,2,4-Triazine,eine neue Synthese von Pyrazolo[1,2-a]1,2,4-triazin-6-onen

Cycloaddition Reactions of Cyclopropenone with 1,2,4-Triazines, a New Synthesis of Pyrazolo[1,2-a]1,2,4-triazin-6-ones Contrary to cycloaddition reactions of cyclopropene, 3,3-dimethoxycyclopropene, and 1,2-diphenylcyclopropenone the unsubstituted cyclopropenone reacts regioselectively with the N? N-bond of various 1,2,4-triazines to yield novel pyrazolo[1,2-a]1,2,4-triazin-6-ones in fair yields. The crystal structure of the pyrazolo[1,2-a]1,2,4-triazine 11 has been determined by X-ray diffraction.     

Pyrrolobenzodiazepines and related systems. 2. Synthesis and biological properties of isonoraptazepine derivatives.

The synthesis of some derivatives and analogues of 12,13,14,14a-tetrahydro-9H,11H-pyrazino-[2,1-c]pyrrolo[1,2- a][1,4]benzodiazepine (isonoraptazepine) is reported. The new derivatives have been subjected to pharmacological tests for evaluation of antidepressant effects. Neurobehavioral assays were also carried out to acquire data on neurotoxicity and sedative action. Isonoraptazepine analogues and derivatives lacked the pharmacological activity of mianserin and aptazepine and showed properties similar to imipramine. Molecular modeling studies revealed structural similarities between isonoraptazepine derivatives and imipramine, thus explaining the similar pharmacological profile found in some of the tests employed. Based on pharmacological data the title compounds cannot be regarded as alpha 2 presynaptic adrenoceptors antagonists. In vitro studies for receptor binding gave support to this observation. The above studies lead us to conclude that isonoraptazepine derivatives are conformationally restricted analogues of imipramine, but their antidepressant activity cannot be correlated to inhibition of 5HT uptake. Among the derivatives tested, 7b and 8e show some affinity for the d-fenfluramine receptor site, a serotonin presynaptic site connected with anorectic activity.     

Study on the common teratogenic pathway elicited by the fungicides triazole-derivatives.

Triazole-derivatives alter the pharyngeal apparatus morphogenesis of rodent embryos cultured in vitro. The hindbrain segmentation and the rhombencephalic neural crest cell (NCCs) migration are altered by Fluconazole exposure in vitro. The aim of the present work is to identify if a common pathogenic pathway is detectable also for other molecules of this class of compounds. 9.5 days post coitum (d.p.c.) old rat embryos were exposed in vitro to the teratogenic concentrations of Flusilazole, Triadimefon and Triadimenol and cultured for 24, 48 or 60 h. The expression and localisation of Hox-b1 and Krox-20 proteins (used as markers for hindbrain segmentation) were evaluated after 24 h of culture. The localisation and distribution of NCC was evaluated after 24, 30 and 48 h of culture. The morphology of the embryos was analysed after 48 h, while the branchial nerve structures were evaluated after 60 h of culture. Hindbrain segmentation and NCC migration alteration as well as pharyngeal arch and cranial nerve abnormalities were detected after exposure of the tested molecules. A common severe teratogenic intrinsic property for the tested molecules of this chemical class has been found, acting through alteration of the normal hindbrain developmental pattern.     

Adaptation and delivery of a motivational interviewing-based counseling program for persons acutely infected with HIV in Malawi: Implementation and lessons learned

Objective

Individuals diagnosed with acute HIV infection (AHI) are highly infectious and require immediate HIV prevention efforts to minimize their likelihood of transmitting HIV to others. We sought to explore the relevance of Motivational Interviewing (MI), an evidence-based counseling method, for Malawians with AHI.

HbF reactivation in sibling BFU-E colonies: synergistic interaction of kit ligand with low-dose dexamethasone

Mechanisms underlying fetal hemoglobin (HbF) reactivation in stress erythropoiesis have not been fully elucidated. We suggested that a key role is played by kit ligand (KL). Because glucocorticoids (GCs) mediate stress erythropoiesis, we explored their capacity to potentiate the stimulatory effect of KL on HbF reactivation, as evaluated in unilineage erythropoietic culture of purified adult progenitors (erythroid burst-forming units [BFU-Es]). The GC derivative dexamethasone (Dex) was tested in minibulk cultures at graded dosages within the therapeutical range (10(-6) to 10(-9) M). Dex did not exert significant effects alone, but synergistically it potentiated the action of KL in a dose-dependent fashion. Specifically, Dex induced delayed erythroid maturation coupled with a 2-log increased number of generated erythroblasts and enhanced HbF synthesis up to 85% F cells and 55% gamma-globin content at terminal maturation (ie, in more than 80%-90% mature erythroblasts). Equivalent results were obtained in unicellular erythroid cultures of sibling BFU-Es treated with KL alone or combined with graded amounts of Dex. These results indicate that the stimulatory effect of KL + Dex is related to the modulation of gamma-globin expression rather than to recruitment of BFU-Es with elevated HbF synthetic potential. At the molecular level, Id2 expression is totally suppressed in control erythroid culture but is sustained in KL + Dex culture. Hypothetically, Id2 may mediate the expansion of early erythroid cells, which correlates with HbF reactivation. These studies indicate that GCs play an important role in HbF reactivation. Because Dex acts at dosages used in immunologic disease therapy, KL + Dex administration may be considered to develop preclinical models for beta-hemoglobinopathy treatment.     

Mucosal leishmaniasis mimicking squamous cell carcinoma in a liver transplant recipient

Organ transplant recipients living in endemic regions are at increased risk of Leishmania infections. Visceral leishmaniasis is the most common kind of presentation in the Mediterranean basin. Rarely, Leishmania infantum may cause localized mucosal disease. We present the first case, to our knowledge, of a liver transplant recipient with localized mucosal leishmaniasis. Twenty‐two years after transplantation, a painless, very slow growing ulcer appeared on the inner side of the patient's upper lip. A biopsy performed in the community hospital showed non‐specific chronic inflammation without neoplastic signs. Because of a high suspicion of malignancy, the patient was transferred to the referral hospital to consider complete excision. The excisional biopsy revealed a granulomatous inflammatory reaction together with intracellular Leishmania amastigotes within macrophages. Leishmaniasis was confirmed by the nested polymerase chain reaction assay. The clinical and laboratory findings did not suggest visceral involvement. The patient received meglumine antimoniate for 21 days without relevant adverse effects.