Malignant hypertension and cerebral haemorrhage in Seckel syndrome

Seckel syndrome is an autosomal recessive condition with severe short stature and facial and neurological anomalies. Intracranial haemorrhage, due to rupture of a cerebral aneurysm, is a very rare complication of this syndrome. Malignant hypertension may play an important role in the aetiology of the aneurysm and early detection is essential in order to prevent organ damage. Conclusion:we report a new case of Seckel syndrome associated with malignant hypertension and cerebral haemorrhage.Abbreviations BA basilar artery - MCA middle cerebral artery - PICA posterior internal cerebral artery - PICU paediatric intensive care unit - SS Seckel syndrome     

In vitro reversal of chloroquine resistance in Plasmodium falciparum with dihydroethanoanthracene derivatives

The effects of combining four dihydroethanoanthracenic (DEA) derivatives and chloroquine were assessed in vitro against Plasmodium falciparum chloroquine resistant parasites W2, Palo Alto, FCR3, and Bres1. Like verapamil or promethazine, the four dihydroethanoanthracenic derivatives tested can be added to the growing list of agents that show capability in enhancing the activity of chloroquine against resistant parasites. The structurally related tricyclic antihistaminic compounds examined in this study exerted different intrinsic antimalarial activity, but the same chloroquine-potentiating activity as verapamil or promethazine. They may act both on the rate of chloroquine accumulation and on its access to ferriprotoporphyrin IX. The reversal mechanism would be assumed to result from competition between DEA derivatives and chloroquine for efflux translocation sites, thus causing an increase in steady-state accumulation of chloroquine and a return to susceptibility. Restoration of therapeutic efficacy of chloroquine against resistant parasites by the administration of an additional drug available at relatively low cost may be a more effective strategy than the introduction of another antimalarial drug at the national level.     

In Vitro Potentiation of Antibiotic Activities by a Catecholate Iron Chelator against Chloroquine-Resistant Plasmodium falciparum

FR160, a catechol iron chelator, and tetracyclines or norfloxacin exert in vitro additive or synergistic activity against a chloroquine-resistant Plasmodium falciparum clone. FR160 shows antagonistic effects in association with macrolides, ofloxacin, and rifampin.     

Iron chelators as antimalarial agents: in vitro activity of dicatecholate against Plasmodium falciparum

The present study was undertaken to explore the antimalarial effect of a series of dicatecholate iron chelators. They may be made more or less lipophilic by increasing or reducing the length of the R substituent on the nitrogen. In vitro activity against the W2 and 3D7 clones of Plasmodium falciparum, toxicity on Vero cells and toxicity on uninfected erythrocytes by measure of the released haemoglobin were assessed for each compound. These findings were compared with the ability of iron(III), iron(II) and ferritin to reverse the inhibitory effect of catecholates. This study shows that increased lipid solubility of catecholate iron chelators does not lead to improved antimalarial activity. However, their activity is well correlated with their interaction with iron and with their toxicity against Vero cells. This study demonstrates a potent antimalarial effect of FR160 (R = C9H19) on five different strains of P. falciparum in vitro. FR160 inhibited parasite growth with an IC50 between 0.8 and 1.5 micro M. The effects of FR160 on mammalian cells were minimal compared with those obtained with malaria parasites. FR160 acted on parasites at considerably higher rates than desferrioxamine, and at all stages of parasite growth. The drug was more effective at the late trophozoite and young schizont stages, although FR160 affected rings and schizonts as well. Ascorbic acid, a free radical scavenger, reduced the activities of FR160 and artesunate. FR160 might induce formation of free radicals, which could explain why FR160 antagonized the effects of artesunate and dihydroartemisinin.     

Russell Strong and the History of Reduced-Size Liver Transplantation

On the basis of their innovation and experience with reduced-size grafts in children, 20 years ago, Russell Strong and his team in Brisbane, Australia, performed the first successful living donor liver transplant in the world from a mother to her son. The mismatch between supply and demand for deceased donor organs has fueled the expansion of all forms of reduced-size grafts, including split-liver and living donor transplantation. This review outlines the story of Russell Strong, reduced-size liver transplantation techniques, and the development of living donor liver transplantation.     

Venous thromboembolism and bleeding in critically ill patients with severe renal insufficiency receiving dalteparin thromboprophylaxis: prevalence, incidence and risk factors

Background

Critically ill patients with renal insufficiency are predisposed to both deep vein thrombosis (DVT) and bleeding. The objective of the present study was to evaluate the prevalence, incidence and predictors of DVT and the incidence of bleeding in intensive care unit (ICU) patients with estimated creatinine clearance <30 ml/min.

Methods

In a multicenter, open-label, prospective cohort study of critically ill patients with severe acute or chronic renal insufficiency or dialysis receiving subcutaneous dalteparin 5,000 IU once daily, we estimated the prevalence of proximal DVT by screening compression venous ultrasound of the lower limbs within 48 hours of ICU admission. DVT incidence was assessed on twice-weekly ultrasound testing. We estimated the incidence of major and minor bleeding by daily clinical assessments. We used Cox proportional hazards regression to identify independent predictors of both DVT and major bleeding.

Results

Of 156 patients with a mean (standard deviation) creatinine clearance of 18.9 (6.5) ml/min, 18 had DVT or pulmonary embolism within 48 hours of ICU admission, died or were discharged before ultrasound testing – leaving 138 evaluable patients who received at least one dose of dalteparin. The median duration of dalteparin administration was 7 days (interquartile range, 4 to 12 days). DVT developed in seven patients (5.1%; 95% confidence interval, 2.5 to 10.1). The only independent risk factor for DVT was an elevated baseline Acute Physiology and Chronic Health Evaluation II score (hazard ratio for 10-point increase, 2.25; 95% confidence interval, 1.03 to 4.91). Major bleeding developed in 10 patients (7.2%; 95% confidence interval, 4.0 to 12.8), all with trough anti-activated factor X levels ≤ 0.18 IU/ml. Independent risk factors for major bleeding were aspirin use (hazard ratio, 6.30; 95% confidence interval, 1.35 to 29.4) and a high International Normalized Ratio (hazard ratio for 0.5-unit increase, 1.68; 95% confidence interval, 1.07 to 2.66).

Conclusion

In ICU patients with renal insufficiency, the incidence of DVT and major bleeding are considerable but appear related to patient comorbidities rather than to an inadequate or excessive anticoagulant from thromboprophylaxis with dalteparin.

Clinical Trial Registration

Number NCT00138099.     

Development and use of the lens epithelial explant system to study lens differentiation and cataractogenesis

Over the last two decades much progress has been made in identifying and characterizing many of the molecules involved in understanding normal lens biology and its pathology. Much of this has been made possible through the establishment and use of the lens epithelial explant system. This simplistic tissue culture model, comprised of a sheet of lens epithelium on its native substratum, has been used effectively to study many cellular processes, including lens epithelial cell proliferation, fiber cell differentiation, cell apoptosis as well as epithelial-to-mesenchymal transformation of cells. In doing so, a number of key growth factors and cytokines, including members of the FGF, Wnt and TGFβ family have been shown to play essential roles in many of these cellular events. This has led to further studies exploring the signaling pathways downstream of these molecules in the lens, paving the way for the development of a number of in situ models (primarily transgenic mouse lines) to further explore in more detail the nature of these molecular and cellular interactions. To reciprocate, the lens epithelial explant system is increasingly being used to further characterize the nature of many complex phenotypes and pathologies observed in these in situ models, allowing us to selectively isolate and examine the direct impact of an individual molecule on a specific cellular response in lens cells. There is no question that the lens epithelial explant system has served as a powerful tool to further our understanding of lens biology and pathology, and there is no doubt that it will continue to serve in such a capacity, as new developments are realized and putative treatments for aberrant lens cell behavior are to be trialed.     

The effects of multidisciplinary therapy on positron emission tomography of the brain in fibromyalgia: a pilot study

Aberrant central neurological functioning is believed to contribute to the abnormal sensations of fibromyalgia (FM). This pilot study sought to determine if alterations in regional brain metabolism from baseline occur in FM after undergoing a multidisciplinary therapeutic regimen. Regional brain metabolic activity was estimated using ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸FDG PET). Nine participants with FM received an 8-week comprehensive treatment program. Serial testing with ¹⁸FDG PET and the Fibromyalgia Impact Questionnaire were performed. Statistical analysis was performed using repeated Wilcoxon signed rank tests. A clinical improvement (FIQ median change 20.68, P = 0.005) was noted with treatment. With treatment, increases in brain metabolism were noted in various components of the limbic system (P = 0.004–0.1). An increase in limbic metabolism was noted with concomitant symptomatic improvement, suggesting that the limbic system attenuates FM symptoms.     

Compliance measurement of lower esophageal sphincter and esophageal body in achalasia and gastroesophageal reflux disease

Little is known about the effect of achalasia and gastroesophageal reflux disease (GERD) on compliance of the esophageal body and the lower esophageal sphincter (LES). Twenty-two patients with achalasia, 14 with GERD, and 14 asymptomatic volunteers were assessed. Recording apparatus consisted of a specially developed PVC bag tied to a compliance catheter, a barostat, and a polygraph. Intrabag pressures were increased incrementally while the bag volume was recorded. In each subject, pressure–volume graphs were constructed for both the esophageal body and LES and the compliance calculated. In achalasia, compliance of the esophageal body was significantly higher (P < 0.01) than in controls, whereas LES compliance was similar. Patients with GERD had a highly compliant LES in comparison to both controls and to patients with achalasia (P < 0.01 and P < 0.001, respectively); however there was no difference in their esophageal body compliance. In conclusion, foregut motility disorders can cause changes in organ compliance that are detectable using a barostat and a suitably designed compliance bag. Further measurement of compliance may provide clues to the pathogenesis of these disorders.