Effects of barium on stimulus-induced changes in [K+]o and field potentials in dentate gyrus and area CA1 of human epileptic hippocampus

Congenital para-oesophageal hiatal hernia (PEHH) is a rare problem in infancy, however, it constitutes a clinical entity that mandates surgical repair once the diagnosis is made. In the paediatric age group, acquired PEHH has been described as a major complication in a number of patients who were treated surgically for gastro-oesophageal reflux (GER) by Nissen fundoplication. PEHH is a frequently encountered condition in elderly patients; it accounts for 5% of diaphragmatic hiatal hernias. In both paediatric and adult patients PEHH, whether congenital or acquired in origin, is usually associated with potentially lethal complications such as gastric volvulus, incarceration, and perforation. In clinical practice true PEHH is extremely rare. The term has been expanded to include large gastric hiatal hernias where most of the stomach and the gastro-oesophageal junction are in the chest. Six infants with congenital PEHH are presented, together with an attempt to understand its possible aetiology and a review of its current surgical management.     

Intracorporeal laparoscopic resections for colorectal cancer: report of cases of abdominoperineal rectal excision and right hemicolectomy with 2 year follow-up

Techniques for total intracorporeal laparoscopic abdominoperineal excision of rectum and right hemicolectomy for colorectal cancer are described in two patients with 2-year follow-up. Potential advantages over laparoscopically assisted procedures may be offset by increased operating time and expense for right hemicolectomy but the laparoscopic approach seems well suited to abdominoperineal rectal excision. The use of a secure retrieval system is advocated for specimen removal after right hemicolectomy.     

Molecular dynamics simulation of the stability of a 22-residue alpha-helix in water and 30% trifluoroethanol

A molecular dynamics (MD) simulation was performed on the alpha-helix H8-HC5, the C-terminal part of myoglobin (residue 132-153), under periodic boundary conditions in two different solutions, water and water with 30% (v/v) 2,2,2-trifluoroethanol (TFE), at 300 K to investigate the stability of the helix. In both simulations, the initial configuration was a canonical right-handed alpha-helix. In the course of the MD trajectory in water (200 ps), the helix clearly destabilized and began to unfold after 100 ps. In the TFE solution, two stable parts of helical regions were observed after 70 ps of a 200-ps MD simulation, supporting the notion that TFE acts as a structure-forming solvent.     

Mucolipidosis type II in a domestic shorthair cat

A seven-month-old, female domestic shorthair cat was presented to the Veterinary Teaching Hospital, University of Zurich, with abnormal facial features, retarded growth and progressive hindlimb paresis. On physical examination the cat had a flat, broad face with hypertelorism, frontal bossing, small ears and thickened upper and lower eyelids. The corneas of both eyes were clear and the pupils were dilated. The skin was generally thickened, most prominently on the dorsal aspect of the neck. Radiography of the entire skeleton revealed a severely deformed spinal column, bilateral hip luxation with hip dysplasia, an abnormally shaped skull and generalised decreased bone opacity. The clinical features and radiographic changes were suggestive of mucopolysaccharidosis. The toluidine blue spot test on a urine sample, however, was negative for glycosaminoglycans. Further biochemical investigations revealed a deficiency of the enzyme N-acetylglucosamine-1-phosphotransferase (GlcNAc-phosphotransferase, EC 2.7.8.17) in peripheral leukocytes and an elevation of many lysosomal enzymes in the serum of the cat which is diagnostic for mucolipidosis type II. Histology and electron microscopy of different tissues are briefly summarised. The findings of this cat, the first reported case of mucolipidosis type II are compared with other similar storage diseases described in the cat.     

Reproducibility of color Doppler imaging in orbital vessels

The purpose of this study was to evaluate the short-term reproducibility, the long-term reproducibility, and the reproducibility of the measurements made between two different examiners of blood-flow velocity in extraocular vessels using color Doppler imaging (CDI). In a group of 10 healthy volunteers, measurements of the peak-systolic velocity (PSV), end-diastolic velocity (EDV), and resistivity index (RI) in the ophthalmic artery and the central retinal artery as well as one lateral and one medial short posterior ciliary artery were performed. The best intraindividual reproducibility, expressed as the relative error, was found for the PSV and RI measured in the ophthalmic artery (OA; PSV 5.9%, RI 3.1%) and the central retinal artery (CRA; PSV 7.7%, RI 4.7%). The PSV and RI determined in the posterior ciliary arteries were less reproducible but as much so as the EDV measured in the OA (11.8%) and CRA (19.9%). No systematic trend could be found between the first and second measurements. However, the long-term fluctuation was considerable high. Measurements of PSVs showed good concurrence between the two observers in all four vessels measured. The EDVs and RIs differed statistically significantly between the two observers. This difference was most pronounced in the posterior ciliary arteries.     

Three electronic state model of the primary phototransformation of bacteriorhodopsin

The primary all-trans --> 13-cis photoisomerization of retinal in bacteriorhodopsin has been investigated by means of quantum chemical and combined classical/quantum mechanical simulations employing the density matrix evolution method. Ab initio calculations on an analog of a protonated Schiff base of retinal in vacuo reveal two excited states S1 and S2, the potential surfaces of which intersect along the reaction coordinate through an avoided crossing, and then exhibit a second, weakly avoided, crossing or a conical intersection with the ground state surface. The dynamics governed by the three potential surfaces, scaled to match the in situ level spacings and represented through analytical functions, are described by a combined classical/quantum mechanical simulation. For a choice of nonadiabatic coupling constants close to the quantum chemistry calculation results, the simulations reproduce the observed photoisomerization quantum yield and predict the time needed to pass the avoided crossing region between S1 and S2 states at tau1 = 330 fs and the S1 --> ground state crossing at tau2 = 460 fs after light absorption. The first crossing follows after a 30 degrees torsion on a flat S1 surface, and the second crossing follows after a rapid torsion by a further 60 degrees. tau1 matches the observed fluorescence lifetime of S1. Adjusting the three energy levels to the spectral shift of D85N and D212N mutants of bacteriorhodospin changes the crossing region of S1 and S2 and leads to an increase in tau1 by factors 17 and 10, respectively, in qualitative agreement with the observed increase in fluorescent lifetimes.     

Retroperitoneal adrenalectomy: open or endoscopic?

Conventional adrenalectomy requires relatively large incisions. To assess the value of retroperitoneal endoscopic adrenalectomy, a case-control study was performed comparing the endoscopic technique to conventional posterior adrenalectomy. All patients had adrenal tumors less than 7 cm in diameter. Endoscopic retroperitoneal adrenalectomy required more operative time (90 vs. 60 minutes, p < 0.0001) than the open approach but was associated with less blood loss (20 vs. 125 ml, p < 0.0001). Endoscopic adrenalectomy caused less pain postoperatively (p = 0.0005) and was associated with fewer complications (p = 0.035). The hospital stay was shorter after endoscopic adrenalectomy than after open adrenalectomy (p < 0.0001). In conclusion, we advocate endoscopic retroperitoneal adrenalectomy in patients with small adrenal tumors.