An overview of new pharmacological treatments for cerebrovascular dysfunction after experimental subarachnoid hemorrhage

Cerebral vasospasm and the resulting cerebral ischemia occurring after subarachnoid hemorrhage (SAH) are still responsible for the considerable morbidity and mortality in patients affected by cerebral aneurysms. Mechanisms contributing to the development of vasospasm, abnormal reactivity of cerebral arteries and cerebral ischemia after SAH have been intensively investigated in recent years. It has been suggested that the pathogenesis of vasospasm is related to a number of pathological processes, including endothelial damage, smooth muscle cell contraction resulting from spasmogenic substances generated during lyses of subarachnoid blood clots, changes in vascular responsiveness and inflammatory or immunological reactions of the vascular wall.A great deal of experimental and clinical research has been conducted in an effort to find ways to prevent these complications. However, to date, the main therapeutic interventions remain elusive and are limited to the manipulation of systemic blood pressure, alteration of blood volume or viscosity, and control of arterial dioxide tension.Even though no single pharmacological agent or treatment protocol has been identified which could prevent or reverse these deadly complications, a number of promising drugs have been investigated. Among these is the hormone erythropoietin (EPO), the main regulator of erythropoiesis. It has recently been found that EPO produces a neuroprotective action during experimental SAH when its recombinant form (rHuEPO) is systemically administered.This topic review collects the relevant literature on the main investigative therapies for cerebrovascular dysfunction after aneurysmal SAH. In addition, it points out rHuEPO, which may hold promise in future clinical trials to prevent the occurrence of vasospasm and cerebral ischemia after SAH.     

Use of colistin and sorbitol for better isolation of Serratia marcescens in clinical samples

A comparison was made of different culture media and procedures for detection of Serratia marcescens from faecal, pharyngeal and ocular swabs collected from 213 neonates. MacConkey agar and MacConkey agar with sorbitol (1%) and/or colistin (200 i.u./ml) were used both for primary isolation and after enrichment using Mossel Enterobacteriaceae broth with colistin (200 i.u./ml). The use of MacConkey agar supplemented with colistin for primary isolation improved considerably the isolation rate of S. marcescens from faecal swabs but not from pharyngeal swabs; the number of ocular isolations were insufficient to demonstrate differences between procedures. Moreover the enrichment procedures consistently increased the number of S. marcescens isolates especially from pharyngeal and ocular swabs. Use of sorbitol made detection of S. marcescens from clinical specimens easier and time- and cost-efficient.     

Butylated hydroxyanisole (BHA) does not cause forestomach hyperplasia by inhibiting the release of gastric mucus

High doses of BHA cause hyperplasia and subsequent neoplasia in the rodent forestomach and can inhibit gastric prostaglandin (PG) synthesis in vitro. This paper examines the hypothesis that BHA induced forestomach hyperplasia occurs in response to a reduction of gastric mucus, with consequent irritation of the forestomach. This could result from inhibition of the formation of the PG's which mediate the synthesis and release of protective mucus. Groups of 10 rats received 0 or 2% BHA in the diet for 1 or 3 weeks and a positive control group was fed a diet containing indomethacin (3.5 mg/kg), a potent inhibitor of PG synthesis. After 1 week BHA caused focal erosion and ulceration of the forestomach consistent with an irritant effect, but 2 weeks later the epithelium was healed, thickened and markedly hyperplastic. Histochemical staining for mucus showed that the development of forestomach hyperplasia was associated with increased amounts of gastric and duodenal mucus and increased numbers of serotonergic-cells in the gastric and duodenal epithelium. In contrast, indomethacin caused a marked reduction in both gastric and Brunner's gland mucus. Neither BHA nor indomethacin exerted an effect on one specific type of mucus (viz: neutral, acidic or mixed) in the stomach. These results do not support the hypothesis that forestomach hyperplasia arises from an inhibition of either the synthesis or release of gastric mucus. It is possible that the increased numbers of serotonergic-cells are related to the initial ulcerative, or subsequent hyperplastic response.     

华蟾蜍毒素对离体豚鼠输精管的作用

华蟾蜍毒素(华蟾素)使离体豚鼠输精管产生剂量依赖性收缩反应,利血平化豚鼠输精管及冷藏输精管对华蟾素反应减弱。给酚妥拉明、维拉帕米后,输精管对华蟾素反应均受抑制,溴苄胺可使反应潜伏期缩短。结果提示华蟾素收缩输精管反应可能与其促进肾上腺素能神经末稍NA释放有关。     

Revisiting the prognostic role of gallium scintigraphy in low-grade Non-Hodgkin’s lymphoma

The purpose of this study was threefold: to evaluate the role of gallium-67 scintigraphy in the staging of low-grade non-Hodgkin’s lymphomas (LGNHL), to assess the relationship between the expression of CD71 on the surface of the neoplastic cells and the ⁶⁷Ga uptake by the tumour, and to establish the contribution of ⁶⁷Ga scan in defining the prognosis of LGNHL. Forty-eight patients with untreated LGNHL diagnosed in a single institution over a decade were reviewed. The end point of the study was survival of the patients according to the scintigraphic ⁶⁷Ga score at diagnosis. In addition to ⁶⁷Ga scan, other prognostic variables were studied, relating to the neoplastic burden, the biology of the tumour and the host. Univariate and multivariate analyses were used. ⁶⁷Ga scan identified only 116/286 (41%) nodes involved by lymphoma that were detected by clinical examination or computed tomography scan. A scintigraphic scoring system with an arbitrary cut-off value of 3 (high scan score) was able to predict patients with a dismal prognosis: with a mean follow-up of 47 months (range: 1–146 months) the median survival time was 28 months in patients with a high scan score and 74 months in patients with a low scan score (P=0.002). CD71 values were 27.4%±14.9% (mean ±SD) in the former and 8.9%±7.2% in the latter (P=0.0001). Only performance status and extranodal sites were significant variables for prognosis in multivariate analysis. It is concluded that ⁶⁷Ga scan is inaccurate in staging but might be very important in defining the prognosis in LGNHL, in association with other prognostic variables. Received 1 May and in revised form 6 August 1997     

Perfluorochemicals as US contrast agents for tumor imaging and hepatosplenography: preliminary clinical results

In animals, perfluorochemicals (PFCs) are effective ultrasound (US) contrast agents that produce hepatic, splenic, and tumor enhancement. The use of Fluosol-DA 20%, an emulsion of perfluorodecalin and perfluorotripropylamine, was studied in nine non-critically ill patients with cancer who had liver lesions. US studies without Fluosol were compared with studies obtained 24, 48, and 72 hours after Fluosol infusion. Vital signs and extensive laboratory analyses are performed before and after Fluosol infusion. Liver metastases from colonic, pancreatic, and gastric carcinoma exhibited rim or diffuse enhancement after a Fluosol dose of 1.6 g/kg or greater. Fluosol produced echogenic enhancement of the liver and spleen relative to kidney at a dose of 2.4 g/kg, allowing the detection of nonenhancing lesions. In addition, Fluosol at a dose of 1.6 g/kg or greater allowed detection of lesions not seen before contrast medium was administered in three of the seven patients studied. There was a mild increase in the level of serum glutamic oxaloacetic transaminase in two patients, one given 2.4 and the other 3.2 g/kg of Fluosol. Mild and transient allergic reactions without change in vital signs were experienced by two patients.