Challenges in creating a vaccine to prevent hepatitis E

Recombinant hepatitis E virus capsid protein (HEV CP) assembles orally immunogenic virus-like particles (VLP) when expressed in an insect cell system. We used plant expression cassettes, pHEV101 and pHEV110, for transformation of potato to express HEV CP, and 10 independent transgenic lines of HEV101 and 6 lines of HEV110 were obtained. ELISA for HEV CP was performed on tuber extracts. Accumulation of HEV CP in tubers varied from about 5 to 30 microg/g fresh tuber depending on the transgenic plant line. We further compared the expression levels with the yield of tubers for each line. Tuber yield varied less than expression levels, and ranged from about 600 to 1000 g per pot. Although Western blot showed that apparently intact HEV CP accumulated, we observed very limited assembly of virus-like particles in potato tubers. Oral immunization of mice with transgenic potatoes failed to elicit detectable anti-CP antibody response in serum, suggesting that VLP assembly is a key factor in orally delivered HEV CP vaccines.     

Studies on myocardial reperfusion injury. I. Favorable modification by adjusting reperfusate pH.

This study tests the hypothesis that postischemic myocardial depression can be reduced by providing an initial reperfusate pH which is appropriate for myocardial temperature (i.e., metabolic systems function optimally when pH is kept slightly alkaline to the neutral point, which changes with temperature in concordance with the pK of water). Ten dogs underwent 1 hour of ischemic arrest with topical hypothermia (intramyocardial temperature 16+/-2 degrees C). The initial reperfusate (500 cc of blood from the extracorporeal circuit) was infused (100 cc/minute) into the proximal aorta just before removing the cross-clamp. Reperfusate pH was kept at 7.4 in five dogs (control) and raised to 7.8 with THAM [tris (hydroxymethyl) aminomethane] in five dogs. Measurements 30 minutes after reperfusion showed that raising reperfusate pH to 7.8 resulted in (1) higher subendocardial blood flows (109+/-20 vs 61 cc+/-8 cc/100 gm/minute), (2) redistribution of postischemic blood flow toward the subendocardium (endocardial/epicardial flow 1.25+/-0.1 vs 1.0+/-0.03), (3) higher left ventricular oxygen uptakes (0.046 vs 0.033 cc/100 gm/beat), (4) better postischemic left ventricular compliance (56+/-3% more compliant), and (5) improved left ventricular performance (88+/-7% recovery vs only 57+/-3% recovery at pH 7.4). Postischemic edema (2% water gain) was unchanged by pH modification. We conclude that initial reperfusion with the appropriate pH provides an optimal milieu for restoration of cellular metabolism, counteracts the acidosis of ischemia, and improves postischemic left ventricular blood flow, distribution, oxygen uptake, compliance, and performance.     

Denaturation of Protein by in Vacuo Drawing of Blood

In two experimental series dog blood was drawn under high vacuum and by gravity into glass flasks containing heparin sodium solution as anticoagulant. After centrifugation various tests were applied to detect possible changes in the proteins of the supernatant plasma. These tests included viscosity measurement, protein solubility determination, and paper electrophoresis. The results obtained by viscosity measurement and paper electrophoresis demonstrate that drawing of blood into high vacuum and the foaming that occurs therewith results in measurable denaturation of plasma proteins. The precise clinical significance of this finding is uncertain, but it seems logical to assume that denaturation of plasma proteins may be undesirable.     

Dipyridamole and postoperative ischemic deficits in aneurysmal subarachnoid hemorrhage

Recent evidence has suggested that the delayed cerebral ischemic deficits that often follow surgery for aneurysmal subarachnoid hemorrhage (SAH) may be due to a proliferative vasculopathy. This vascular pathology may result from an interaction between the platelets and the vessel wall. A single-blind controlled trial of dipyridamole administration in 677 patients presenting with SAH (of whom 348 came to surgery) was undertaken to test the hypothesis that the modification of platelet behavior might reduce the incidence of ischemic deficits. Blind independent assessment of the outcome in the surgical group based on the Glasgow Outcome Scale and the specific neurological deficits revealed no significant differences between the control and treatment groups.     

Kabuki syndrome: new ocular findings but no evidence of 8p22-p23.1 duplications in a clinically defined cohort

The underlying cause of the multiple congenital anomalies/mental retardation syndrome Kabuki syndrome (KS, OMIM 147920) has not yet been established. We identified seven patients who fulfilled the classical clinical criteria for this syndrome and undertook a detailed clinical, ophthalomological and molecular cytogenetic review. Three of the seven patients had previously undetected ocular anomalies including myopia, ptosis, strabismus and tilted discs. The identification of preventable causes of loss of vision underlines the value of detailed ophthalmologic examination of KS patients. Using BAC fluorescence in situ hybridisation, there was no evidence of the duplication of 8p recently reported by Milunsky and Huang. We conclude that the cause of KS has yet to be established.