The curvature sensitivity of a membrane-binding amphipathic helix can be modulated by the charge on a flanking region.

Membrane-induced amphipathic helices (m-AH) can act as membrane curvature sensors by binding preferentially to hydrophobic lipid packing defects enriched in curved surfaces. Reliance on hydrophobicity and membrane curvature for binding is enhanced when electrostatic interactions are weak. We probed the role of modifying membrane and protein charge on the curvature sensing of two m-AH-containing proteins, CTP:phosphocholine cytidylyltransferase (CCT) and α-synuclein (α-syn). The m-AH domains in both proteins are flanked by disordered tails with multiple phosphoserines (CCT) or acidic residues (α-syn), which we mutated to glutamate or serine to modify protein charge. Analysis of binding to vesicles of varying curvature showed that increasing the negative charge of the tail region decreased the binding strength and augmented the curvature dependence, especially for CCT. We attribute this to charge repulsion. Conversely, increasing the membrane negative charge dampened the curvature dependence. Our data suggest that discrimination of curved versus flat membranes with high negative charge could be modulated by phosphorylation.

The amphipathic helix of an enzyme that regulates phosphatidylcholine synthesis remodels membranes into highly curved nanotubules.

CTP:phosphocholine cytidylyltransferase (CCT) is an amphitropic protein regulating phosphatidylcholine synthesis. Lipid-induced folding of its amphipathic helical (AH) membrane-binding domain activates the enzyme. In this study we examined the membrane deforming property of CCT in vitro by monitoring conversion of vesicles to tubules, using transmission electron microscopy. Vesicle tubulation was proportional to the membrane density of CCT and proceeded either as growth from a pre-formed surface bud, or as a global transformation of roughly spherical vesicles into progressively thinner tubules. The tubulation pathway depended on the lipid compositional heterogeneity of the vesicles, with heterogeneous mixtures supporting the bud-extension pathway. Co-existence of vesicles alongside thick and thin tubules suggested that CCT can discriminate between flat membrane surfaces and those with emerging curvature, binding preferentially to the latter. Thin tubules had a limiting diameter of ~12nm, likely representing bilayer cylinders with a very high density of 1 CCT/50 lipids. The AH segment was necessary and sufficient for tubulation. AH regions from diverse CCT sources, including C. elegans, had tubulation activity that correlated with α-helical length. The AH motifs in CCT and the Parkinson's-related protein, α-synuclein, have similar features, however the CCT AH was more effective in its membrane remodeling function. That CCT can deform vesicles of physiologically relevant composition suggests that CCT binding to membranes may initiate deformations required for organelle morphogenesis and at the same time stimulate synthesis of the PC required for the development of these regions.

RNA Polymerase II transcription independent of TBP in murine embryonic stem cells.

Transcription by RNA Polymerase II (Pol II) is initiated by the hierarchical assembly of the pre-initiation complex onto promoter DNA. Decades of research have shown that the TATA-box binding protein (TBP) is essential for Pol II loading and initiation. Here, we report instead that acute depletion of TBP in mouse embryonic stem cells has no global effect on ongoing Pol II transcription. In contrast, acute TBP depletion severely impairs RNA Polymerase III initiation. Furthermore, Pol II transcriptional induction occurs normally upon TBP depletion. This TBP-independent transcription mechanism is not due to a functional redundancy with the TBP paralog TRF2, though TRF2 also binds to promoters of transcribed genes. Rather, we show that the TFIID complex can form and, despite having reduced TAF4 and TFIIA binding when TBP is depleted, the Pol II machinery is sufficiently robust in sustaining TBP-independent transcription.

Nutraceutical effects of garlic oil, its nonpolar fraction and a Ficus flavonoid as compared to vitamin E in CCl4 induced liver damage in rats.

Carbon tetrachloride feeding (3.2g/kg/72hr) for one month increased significantly the serum and tissue lipid profile and deranged the enzyme levels viz; alkaline phosphatase, alanine transaminase, aspartate transaminase, glutathionze reductase, HMGCoA reductase, catalase, gluc.6.PDH and malic enzyme in rats. Simultaneously the lipid peroxidation level in liver was also raised. On administration of garlic oil and its major nonpolar fraction (NPFGO) and a flavonoid isolated from the bark of Ficus bengalensis Linn, viz; leucopelargonin derivative respectively to different groups(100mg/kg/day) the deleterious effects of CCl4 were significantly ameliorated. The liver damage by CCl4 was satisfactorily prevented by these samples as effectively as Vit. E (50 mg/kg/day). The results prove that important nutraceuticals (phytonutrients) like bioflavonoids and theols i.e. allylic sulphide rich fractions give protection from toxins like CCl4. The order of beneficial effects of the drugs are Leucopelargonin > NPFGO > Garlic oil and their effects are comparable to that of vitamin E used at a minimal dose.

Surgical risk factors in total anomalous pulmonary venous connection.

Eighty-three patients underwent surgical correction of total anomalous pulmonary venous connection (TAPVC) between 1973 and 1986. There were 46 boys and 37 girls. Median age at operation was 60 days (1 to 240) and median weight 3.9 kg (1 to 22). The anatomic types encountered included infracardiac connection (16 patients), supracardiac connection (32) and pulmonary venous drainage connected directly to the coronary sinus (27). Mixed anomalous drainage or pulmonary venous return connected directly to the right atrium occurred in 8 patients. Diagnosis was established by cardiac catheterization and angiography (56 patients), clinical examination (3) and cross-sectional echocardiography alone in 24 of the last consecutive 28 patients. Pulmonary hypertension was present in 26 (55%) of those who underwent cardiac catheterization. The median pulmonary vascular resistance was 4.2 units/m2 (body surface area) for all the patients, whereas in those with infracardiac pulmonary venous connection the median value was 10 units/m2. The median interval between admission and operation was 72 hours. Surgical correction was performed using profound hypothermia and circulatory arrest in 68; for the remainder, conventional cardiopulmonary bypass with profound to moderate hypothermia was used. Ten patients developed 1 or more pulmonary hypertensive crises during the early postoperative period. These were diagnosed in 8 by direct pulmonary artery pressure measurement and in 2 by clinical examination. Late reoperation was necessary in 6 patients (10%). Analyses of risk factors for 30-day survival for all patients showed that the risk of early death was associated with the type of anomaly (infradiaphragmatic), occurrence of pulmonary hypertensive crises, year of the operation, set of the patient and pressure of preoperative congestive heart failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of a thermoresistant tissue culture rinderpest vaccine virus.

The currently used Plowright's tissue culture rinderpest vaccine (RBOK strain) gives full protection and lifelong immunity, but it is highly thermolabile and requires maintenance of cold chain from vaccine production till delivery. Keeping in view the need for a thermostabile vaccine in tropical developing countries with limited refrigeration facilities, we passaged serially the RBOK strain of rinderpestvirus (RPV) at gradually elevated temperature up to 40 degrees C to obtain a thermoresistant RPV (TR-RPV) mutant. The thermoresistance (thermostability) and antigenicity of TR-RPV were compared with those of the vaccine virus by various methods, confirming the acquired properties. Thus, the infectivity titres of the TR-RPV mutant and vaccine virus were determined after incubation for various times at 37 degrees C. Regression analysis indicated that TR-RPV had a half-life of 1.81 hr and a degradation constant of 0.1656, while the parent vaccine virus had a half-life of 1.11 hr and a degradation constant of 0.2686. In capture ELISA with four different monoclonal antibodies (MAbs) to the N protein of RPV, TR-RPV showed a 10-fold higher reactivity with one MAb as compared to the vaccine virus. Although TR-RPV did react also with the other three MAbs, its reactivity was only 4-5 times higher than that of the vaccine virus. A treatment of the virus with Triton X-100 resulted in 2-4 times higher reactivity with the MAbs. The 35S-methionine-labeled vaccine virus-and TR-RPV-infected Vero cell lysates showed 6 polypeptide bands with identical pattern of migration in polyacrylamide gel electrophoresis in the presence of SDS (SDS-PAGE). Radioimmunoprecipitation assay (RIPA) of the TR-RPV and vaccine virus with a rabbit anti-RPV immune serum (RHIS) and bovine anti-RPV hyperimmune serum (BHIS) showed the presence of four identical antigenic proteins, namely H, N, F and M, for both viruses. It can be concluded that TR-RPV has indeed retained the antigenic properties of the parental vaccine virus besides acquiring thermoresistance.

Flexible fiberoptic bronchoscopy.

The value of flexible fiberoptic bronchoscopy in children are increasing day by day, but still underutilized even in many advanced institutions. 630 Fiberoptic bronchoscopy procedures under local anaesthesia were performed for various clinical conditions for diagnosis and therapy. Nasal route is preferred than oral route. Therapeutic indications are more in children than adults. Nearly one third of children with collapse, consolidation have shown radiological clearance after repeated bronchoscopy.

Photosynthesis in Polyploid Tall Fescue : II. PHOTOSYNTHESIS AND RIBULOSE-1, 5-BISPHOSPHATE CARBOXYLASE OF POLYPLOID TALL FESCUE.

Net photosynthesis on a leaf area and leaf weight basis increased significantly with ploidy in a 4X, 6X, 8X and 10X allopolyploid series of tail fescue (Festuca arundinacea Schreb.). Total protein did not increase significantly with ploidy. Rocket immunoelectrophoresis was used to quantitate ribulose-1, 5-bisphosphate carboxylase (RuBPCase) protein. RuBPCase content, expressed on both a concentration basis and as a percentage of total protein increased significantly with ploidy in both field and greenhouse experiments. The range of RuBPCase content was 16 to 73% of total protein and 2.8 and 6.5 mg/ml of extract. Specific activity of RuBPCase did not increase significantly with ploidy. Chlorophyll concentration increased as a quadratic function of ploidy, with the mean for 8X genotypes representing maximal chlorophyll content. Evidence is presented that increasing concentrations of RuBPCase are associated with higher net photosynthesis rates in tall fescue. This suggests that RuBPCase may represent a marker for increased net photosynthesis. RuBPCase was extracted in a partially active state or inhibited state and must be fully activated by Mg(2+) and HCO(3) (-) to measure maximal activities. Polyploidization appeared to increase selectively the allocation of total protein for synthesis of RuBPCase; however, there was also a range for carboxylase content among the genotypes within a given ploidy level.

A light-sectioning technique for contouring and measuring a child's face.

A contouring device for measuring the face (Cobb, 1972) was adopted and developed to make it suitable for use with children. Modifications were made to overcome incomplete facial coverage and lack of common head orientation by incorporating a method of optical head positioning which had been invented during the assessment of a stereophotogrammetric technique (Ainsworth and Joseph 1976). The precise alignment of a series of exposures with a common datum enables a set of contour maps to be processed by computer to produce three-dimensional measurements and sections of the complete face.

Severe heart failure in child with ventricular septal defect and acute tricuspid regurgitation.

A case is reported in which acute tricuspid regurgitation developed in a child with a ventricular septal defect resulting in a left ventricular-right atrial shunt. This was successfully treated by closure of the defect and tricuspid valve replacement. The anterior leaflet of the tricuspid valve was almost completely destroyed by endocarditis, though in previous reports of tricuspid valve endocarditis in association with ventricular septal defect in children, it has beem invariably the septal leaflet which is damaged.

Blood pressure and effect of exercise in children before and after surgical correction of coarctation of aorta.

Systolic blood pressure was measured at rest and during exercise in 43 children who had undergone operation for correction of coarctation of the aorta, five children awaiting surgery for coaractation, and 22 control children. Ages ranged from 2 to 15 years, mean 7-6 years. The mean blood pressure of children with coarctation in both the pre- and postoperative groups was significantly higher at rest than in the controls. Of 43 postoperative patients, 15 (35%) were hypertensive (systolic blood pressure more than 95th centile), and 12 of these had a gradient between the upper and lower limb. Seven of the 28 normotensive patients also had a gradient postoperatively. Exercise increased the blood pressure more in children with coarctation than in controls, but there was much individual variability and this difference was not significant. Some children with coarctation developed very high blood pressures on exercise, but this was not related to the presence of a gradient. The mean interval after operation was significantly shorter in the hypertensive group, independent of the age at operation. Hypertension with or without a gradient commonly persists despite apparent successful surgical correction, but exercise is of limited value in its assessment in this age group.

Exercise-induced bronchocontriction, skin sensitivity, and serum IgE in children with eczema.

Forty-two children with eczema were studied for exercise-induced asthma (EIA), skin sensitivity to prick testing, blood eosinophil count, and immunoglobulins. 29 had a fall in peak expiratory flow rate after exercise greater than 20% and of these, 23 had symptoms of wheezing. 13 of the eczematous children showed a fall of less than 20%. The children with EIA showed greater cutaneous sensitivity (p less than 0.001) and a higher total serum IgE (p less than 0.025). 3 of the group with a fall of less than 20% had allergic rhinitis with skin sensitivity to grass pollen. The remaining 10 had no clinical evidence of allergic disease, other than eczema and skin sensitivity, and total IgE fell within the normal range. It is suggested that in a proportion of chilren with eczema there is little evidence of reaginic allergy.

[Critical outflow valve obstruction under the age of one year (author's transl)]. / Lebensbedrohende Stenosen der Semilunarklappen bei Kindern unter einem Jahr

This report represents the Brompton Hospital experience of infants and neonates with critical pulmonary valve stenosis and aortic valve stenosis. There were 25 patients with critical pulmonary valve stenosis and 8 with critical aortic valve stenosis. Critical pulmonary stenosis: Among the 25 patients up to one year of age, 11 were girls and the commonest presenting symptom was cyanosis seen in 15, the commonest physical sign being a systolic ejection murmur with a single 2nd sound. A more detailed analysis of the symptoms, signs and findings at special investigation will be presented. The evolution of a satisfactory technique of operation will be indicated in these critically ill patients, and the late follow-up will be presented. Critical aortic stenosis: There were 8 patients in this group all of whom were male. Dyspnoea was the commonest presenting symptom with a systolic ejection murmur and hepatomegaly as the commonest signs. All patients in this group underwent open aortic valvotomy and/or valvuloplasty with 3 deaths. A late follow-up of the survivors will be presented. In summary, a series of 33 patients up to the age of one year with critical obstruction of either the pulmonary or aortic valves will be presented. (his is one of the larger series to be reported in this age group.

Arterial oxygen tension and response to oxygen breathing in differential diagnosis of congenital heart disease in infancy.

Arterial oxygen tension was measured from radial artery samples in 276 infants referred for cardiological investigation. Values obtained during air breathing in infants with congenital heart disease showed considerable overlap between 'cyanotic' and 'acyanotic' groups, and are of limited diagnostic use. By contrast, values obtained while breathing oxygen in concentrations of over 80%, measured in 182 infants, allowed clear differentiation between these groups. All infants with acyanotic, but only 2 of 109 with cyanotic lesions, achieved an arterial oxygen tension of more than 150 mmHg. In the cyanotic group the response to oxygen breathing was significantly greater in common mixing situations and in the hypoplastic left heart syndrome than with either pulmonary outflow tract obstruction or transposition of the great arteries. Infants with transposition had a significantly lower mean arterial oxygen tension in air than infants with other forms of cyanotic congenital heart disease. Of 23 infants whose final diagnosis was primary lung disease but in whom cyanotic congenital heart disease had been suspected, 7 achieved arterial oxygen tensions of more than 150 mmHg during oxygen breathing, and on this basis cardiac catheterization was not performed. We therefore conclude that measurement of the arterial oxygen tension while breathing high concentrations of oxygen should be routinely performed in the initial assessment of sick infants with suspected congenital heart disease.

M-mode echocardiography in the developing human fetus.

The M-mode echocardiogram can be obtained in the developing human fetus from around the 16th week of gestation until term. Errors in interpretation of the M-mode echocardiogram can be avoided by concurrent two dimensional fetal cardiac examination. The pattern of motion of the mitral, tricuspid, aortic, and pulmonary valves and ventricular wall motion can be studied. Motion of the foramen ovale flap, which is characteristic in fetal life, can also be observed. Using the M-mode tracing, measurement data for six variables were made and growth charts constructed. The variables recorded were septal and left ventricular wall thickness, right and left ventricular internal dimension in diastole, aortic root dimension, and left atrial internal dimension. The measurements were made in normal pregnancies where the fetal heart was structurally normal. Confidence limits for each measurement were derived for gestational ages between 16 and 39 weeks.

Balloon atrial septostomy under two dimensional echocardiographic control.

Two dimensional echocardiography has been used to guide balloon atrial septostomy in five cases of transposition of the great arteries. A single lumen balloon catheter was used. The catheter can be accurately located within the left atrium before inflation of the balloon, thus avoiding some of the traumatic accidents possible during septostomy. The balloon can be observed creating the atrial defect and the approximate size of the resulting defect noted. It can also be seen if the foramen ovale is only being stretched and not torn. The use of the two dimensional echocardiogram during septostomy should significantly contribute to the speed, efficiency, and safety of the procedure.

Detection of rinderpest virus using N-protein monoclonal antibodies.

A panel of monoclonal antibodies (mAbs) was generated against the RBOK strain of rinderpest virus (RPV). All of them bound to the N protein of RPV. The antigen capture ELISA using the mAbs could detect the virus in crude viral preparations. The mAb 12BF8.1.1 showed higher reactivity with cell-associated (CA) virus, whereas the mAbs 12AD10.1.1, 12BD7.1.1 and 12DG7.1.1 showed higher reactivity with extracellular virus (hereafter referred to as cell-free (CF) virus). The mAbs 12BF8.1.1 and 12AD10.1.1 could detect the virus in infected Vero cell culture supernatants (CCS) as early as 24 h post-cytopathic effect (CPE) initiation. Detergent treatment (Triton X-100) of RPV preparations enhanced the binding of the mAbs to the virus. All the seven mAbs showed specific fluorescence in virus-infected cell cultures. The immunofluorescence (IFA) using mAbs was found to be more sensitive and reliable than the immunoperoxidase test (IPT) for detection of rinderpest.

Postmarketing surveillance study of permethrin creme rinse.

BACKGROUND: An observational, epidemiological study was undertaken to evaluate the safety of permethrin 1% creme rinse (Nix) for treatment of head lice infestations. METHODS: Thirty-seven local public health departments enrolled a total of 38,160 patients for 47,578 treatments with permethrin or other pediculicides from September 1, 1986, through January 31, 1988. Follow-up safety information was collected between 7 and 14 days following treatment via return visit or telephone contact. RESULTS: One hundred three adverse events were reported among 41,955 evaluable treatments. The rates of reported adverse events were 2.2 per 1000 treatments among permethrin treatments, 3.4 per 1000 treatments among lindane treatments, and 1.5 per 1000 treatments among other over-the-counter treatments. No serious, unexpected adverse events were detected in the 18,950 patients treated with permethrin. CONCLUSIONS: This study confirmed the safety profile of permethrin in conditions of general use, as seen in clinical trials. Postmarketing safety monitoring in public health departments of drugs used to treat public health conditions was shown to be feasible.

Criss-cross heart with congenitally corrected transposition: report of a case with d-transposed aorta and ventricular preexcitation.

A case is described of corrected transposition in a situs solitus individual, in which, despite the presence of atrioventricular discordance (1-bulboventricular looping), the aorta was right-sided. A ventricular septal defect and pulmonary stenosis were also present, and the case had been erroneously diagnosed during life as complete transposition. The true diagnosis was not appreciated at surgery, and correction of the anomaly was attempted using a modification of Fontan's operation. The criss-cross atrioventricular connections were only fully appreciated at autopsy. The patient also exhibited ventricular preexcitation of Wolff-Parkinson-White variety type A. Histopathological examination revealed the presence of two atrioventricular nodes in the right atrium, each contacting the ventricular conduction tissue which was distributed to the morphologically appropriate ventricles. In addition, a left-sided accessory atrioventricular connection perforated the anulus of the left-sided, morphologically tricuspid, valve.