Prostaglandin-H synthase-1 (PGHS-1) gene is expressed in specific neurons of the brain of the late gestation ovine fetus

Prostaglandin (PG) E2 acts on the brain stem to modulate breathing activity in the ovine fetus. The source of this PGE2 is unknown and we hypothesized that it is produced locally in the developing brain and functions in a paracrine and/or autocrine manner. The purpose of the present study was to establish whether prostaglandin-H synthase-1 (PGHS-1), a crucial enzyme in de novo prostaglandin synthesis, is present and its gene expressed in the ovine fetal brain. Immunohistochemical and molecular hybridization techniques were used to identify sites of PGHS-1 immunoreactivity and PGHS-1 mRNA expression respectively in the brain of the ovine fetus in late gestation (approximately 126 days gestation, term 145 days). PGHS-1 immunoreactivity was localized to specific regions of the fetal brain, including the cortex, hypothalamus, hippocampal formation, superior colliculus of the midbrain, parabrachial nucleus of the pons, and the reticular formation, raphe, nucleus of the solitary tract, and gracile and cuneate nuclei of the medulla. The relative abundance of PGHS-1 mRNA in selected brain regions, as determined by Northern blot analysis, correlated qualitatively with the number of PGHS-1 immunoreactive neurons identified in each region. In situ hybridization demonstrated PGHS-1 mRNA to be localized in the same neurons or nuclei as PGHS-1 immunoreactivity. These results indicate that PGHS-1 synthesized de novo in many brain regions including two that are important in respiratory control: the pneumotaxic center (parabrachial nucleus) and the dorsal respiratory group (nucleus tractus solitarius) suggesting that prostaglandins that modulate fetal respiratory activity are synthesized endogenously.     

Clavicular osteomyelitis as a complication of head and neck surgery

To investigate the development of airway hyperresponsiveness in infantile guinea pigs, animals (10 days old) were immunized twice and challenged by inhalation of 1% ovalbumin for 10 min with 7 days intervals. Similar to adult guinea pigs, infantile ones developed an increased airway responsiveness to acetylcholine 24 hr after antigen challenge. There was a marked increase in the number of total leukocytes, eosinophils and lymphocytes in bronchoalveolar lavage fluid (BALF). Suplatast tosilate (suplatast) and pemirolast potassium (pemirolast) given orally throughout the experiments suppressed the development of airway hyperresponsiveness in infantile animals. They showed similar potency in the suppression of eosinophil accumulation in BALF and lung tissue, while suplatast inhibited lymphocyte accumulation stronger than pemirolast. Collectively, the present model of airway hyperresponsiveness in infantile guinea pigs may be useful in predicting the efficacy of antiallergic agents in the treatment of asthmatic children.     

Adherent neutrophils activate endothelial myosin light chain kinase: role in transendothelial migration

Increased vascular endothelial cell (EC) permeability and neutrophilic leukocyte (PMN) diapedesis through paracellular gaps are cardinal features of acute inflammation. Activation of the EC contractile apparatus is necessary and sufficient to increase vascular permeability in specific models of EC barrier dysfunction. However, it is unknown whether EC contraction with subsequent paracellular gap formation is required for PMN transendothelial migration in response to chemotactic factors. To test this possibility, we assessed migration of human PMNs across confluent bovine pulmonary arterial EC monolayers. Transendothelial PMN migration in the absence of a chemotactic gradient was minimal, whereas abluminal addition of leukotriene B4 (LTB4; 5 microM) resulted in significantly increased PMN migration. Reductions in EC myosin light chain kinase (MLCK) activity by EC monolayer pretreatment with specific MLCK inhibitors (KT-5926 or ML-7) or by increases in cAMP-protein kinase A activity (cholera toxin) significantly reduced PMN transmigration (30-70% inhibition). In contrast, pretreatment with the myosin-associated phosphatase inhibitor calyculin resulted in the accumulation of phosphorylated myosin light chains, EC contraction, and significantly enhanced PMN migration. Finally, the interaction of PMNs with 32P-labeled EC monolayers was shown to directly increase EC myosin phosphorylation in a time-dependent fashion. Taken together, these results are consistent with the hypothesis that the phosphorylation status of EC myosin regulates PMN migration and further indicate that EC MLCK is activated by chemoattractant-stimulated PMNs. Neutrophil-dependent activation of the EC contractile apparatus with subsequent paracellular gap formation may be a key determinant of transendothelial PMN migration responses to chemotactic agents.     

Tuberculosis control in the face of the HIV epidemic

A retrospective survey of postoperative nausea and vomiting (PONV) in the recovery room over a five year period was conducted, followed by a prospective study of 200 adult patients to estimate the incidence and predisposing factors to nausea and vomiting during the first 24 hours after anaesthesia and surgery in Nigerians. In the retrospective study only records of 61 patients (0.79%) out of the 7714 post anaesthetic recovery room charts reviewed revealed documentation of vomiting. These were 20 males (32.8%) and 41 females (67.2%). In the prospective study, the incidence of post operative nausea and vomiting within twenty four hours of surgery was 41.6% and 19.6%, respectively. But only two out of 39 patients (one per cent) vomited within the first three hours in postoperative period. The frequency of vomiting varied from one to 15 times and women had significantly more emetic symptoms than men (p < 0.05). Preoperative administration of pethidine and morphine was associated with postoperative nausea and vomiting. It is suggested that Nigerian women should be considered for prophylactic anti-emetic therapy, especially when narcotic analgesic are to be employed in their anaesthetic management.     

Hypoxia-reoxygenation is as damaging as ischemia-reperfusion in the rat liver

OBJECTIVE: We hypothesized that the extent of injury and release of xanthine oxidase, an oxidant generator, into the circulation would be less in normal-flow hypoxia-reoxygenation than in equal duration no-flow ischemia-reperfusion. DESIGN: Randomized study. SETTING: University-based animal research facility. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: The livers were isolated, perfused, and then randomly subjected to 2 hrs of hypoxia (normal flow, low oxygen) or ischemia (no flow, no oxygen), and 2 hrs of reperfusion. Hepatocytes were also isolated, and were subjected to either: a) hypoxia (0, 2, 4, and 6 hrs); or b) hypoxia (2 and 4 hrs) with reoxygenation (2 hrs). MEASUREMENTS AND MAIN RESULTS: The extent of liver injury (as assessed by release of hepatocellular enzymes) and the release of xanthine oxidase were measured from isolated-perfused rat livers and cultured hepatocytes. The pattern of release of xanthine oxidase in isolated-perfused liver effluent was different in hypoxia-reoxygenation compared with ischemia-reperfusion. During hypoxia, xanthine oxidase gradually increased in the effluent; then, the xanthine oxidase decreased to low concentrations during reoxygenation. After ischemia, there was a sharp spike in xanthine oxidase at 1 min of reperfusion, with a rapid decrease to low concentrations. The total release of xanthine oxidase during hypoxia-reoxygenation was similar to that during ischemia-reperfusion. Lactate dehydrogenase and other markers of liver injury showed a pattern of release that was similar to that of xanthine oxidase, but the total release of markers was not different between the two groups. In hepatocytes, most of the release of enzymes occurred in hypoxia, and the rate of release was not different between hypoxia and hypoxia-reoxygenation. CONCLUSIONS: Hypoxia-reoxygenation results in as much damage to the liver as ischemia-reperfusion, and results in the release of a similar amount of oxidant-producing xanthine oxidase into the circulation.     

International Prognostic Index for aggressive non-Hodgkin's lymphoma is valid for all malignancy grades

An International Prognostic Index (IPI) for patients with aggressive non-Hodgkin's lymphoma (NHL) has recently been published. The IPI is based on pretreatment clinical characteristics and developed on clinical trial patients, classified as intermediate grade according to the Working Formulation (WF). We applied this IPI in a population-based registry of NHL patients. This registry does not have the restrictions that usually hold for patients in clinical trials, eg, with respect to age and performance status. Moreover, it covers all the three WF classes (low, intermediate, and high). The IPI turned out to be of prognostic value for response rate and survival in our unselected cohort of 744 patients, as well. In each of the three WF classes separately, the four IPI classes showed going from low to high substantially decreasing response rates and survival percentages. For our cohort of WF intermediate grade patients 5-year survival levels were lower in all four IPI classes (59%, 34%, 14%, and 10%, respectively), probably reflecting the selection of clinical trial patients in the original study (73%, 51%, 43%, and 26%).     

The effect of glipizide gastrointestinal therapeutic system on islet cell hormonal responses to a test meal in NIDDM

OBJECTIVE: To determine whether the abnormal glucagon and amylin secretions in NIDDM are secondary to hyperglycemia and relative hypoinsulinemia. RESEARCH DESIGN AND METHODS: A total of 13 patients with NIDDM were studied before and after treatment with glipizide gastrointestinal therapeutic system (GITS) in a randomized double-blind placebo-controlled fashion. Of the 13 subjects, 9 were randomized to the glipizide GITS arm and 4 were randomized to the placebo arm of the study. Serum glucose, insulin, C-peptide, plasma glucagon, and plasma amylin concentrations were measured under fasting and postprandial (post-Sustacal ingestion) conditions. The Sustacal challenge was performed at baseline and after 12 weeks of treatment with either glipizide GITS or placebo. RESULTS: Glipizide GITS treatment resulted in a significant reduction in hyperglycemia and increases in insulin and C-peptide secretion. Hyperglucagonemia was not ameliorated, and amylin secretion was not altered after glipizide GITS treatment. Placebo-treated patients did not show significant changes in any of the parameters measured. CONCLUSIONS: Glipizide GITS treatment failed to ameliorate the hyperglucagonemia of NIDDM and did not alter amylin secretion even though it increased insulin secretion and significantly ameliorated the hyperglycemia. These observations suggest that NIDDM related abnormalities in some of the islet cell hormonal responses are the result of changes inherent in the islet cells and may be independent of hyperglycemia and relative hypoinsulinemia.