The superficial cerebral veins

Estimated were the number, the course, and the width of the superficial cerebral veins. The veins on the superolateral surface of the brain are the prefrontal superficial lateral superior, the precentral superficial lateral superior, the central superficial lateral superior, the parietal superficial lateral superior, and the occipital superficial lateral superior veins which drain to the superior sagittal sinus, to bridging veins, and to the falx cerebri. The veins which drain the lateral surface of the brain downwards are the middle superficial cerebral veins, the temporal inferior, occipital inferior, and anastomotic veins. The diameters of these veins were measured at the perforation of the arachnoid membrane and the diameters of the anastomotic veins on their narrowest area. On the medial side of the hemispheres, we divided in precentral superficial superior medial, central superficial medial, parietal superficial medial, occipital superficial medial dorsal veins of the corpus callosum, and internal occipital veins. On the basal surface of the hemispheres, we studied and described the uncal veins and the inferior hemispheric veins. Studied and discussed are also the bridging veins in the course of the inferior cerebral veins, the paracavernous sinuses, and the last course of the veins and their connections with the dura mater or the course inside the dura. Given are besides the numbers of these veins, the area of perforation of the arachnoid membrane, and their width and medical importance.     

Biostatistical study on the arrangement of the superficial veins of the cubital fossa in Iraqis

A study of the arrangement of the superficial veins of the cubital fossa was made on 300 students and staff of the Military Medical College and the AlMustansiriya College of Medicine. Six types of variations of arrangement of the veins were found, two of which have not been mentioned before. The commonest type was that the median vein of the forearm divides in the cubital fossa into 2 veins, one of which joins the basilic vein, and the other the cephalic vein, although in a few cases this joining (or arrangement), occurred above the cubital fossa. The arrangements which have not been mentioned before were that the communication between basilic and cephalic veins was through a horizontal venous connection between 1 of the tributaries of these 2 veins and the basilic vein, and that the median vein of the forearm divides into median cephalic and median basilic, and a vein from the front of the forearm drains into the median basilic vein.     

Inhibition of chymase reduces vascular proliferation in dog grafted veins

In this study, new methods are used to control cellular membrane tension to evaluate the role it plays in electrofusion. The data show that membrane tension present during the application of an electric field facilitates electro-induced membrane fusion. No enhancement was detected if the strain was applied after the pulse. Analysis of the electromechanical process of fusion revealed a synergy between the two kinds of constraints in the membrane fusion. Both mechanical and electrical constraints apparently play a key role in membrane fusion between the granule membrane and the plasma membrane, i.e. the exocytosis process.     

Variability of canine microsatellites within and between different dog breeds

Polymorphic animal microsatellites have proved valuable genetic markers. For this project, the variability of 19 canine microsatellite loci was examined within and between three pure breeds of dog: Greyhounds, Labradors, and German Shepherds. The number of alleles, absolute and relative frequencies, and the statistics that express polymorphism within a breed were determined. The evolutionary relationships among these closely related dog breeds were estimated by genetic distance measures developed for use with microsatellite loci. According to the pairwise genetic distances, Greyhounds and German Shepherds had longer diverse evolutionary histories than Greyhounds and Labradors or Labradors and German Shepherds. Although a few breed-specific alleles were observed, the significant differences between breeds are in their relative frequencies and distribution of the alleles across a locus. None of the three pure dog breeds corresponds to Hardy-Weinberg equilibrium. A considerable reduction in intrapopulation variation was observed within three pure breeds, compared with the population of individuals belonging to 15 dog breeds. This reduction was especially pronounced in the Greyhound breed, which expressed the lowest degree of variation. Intrapopulation variations of Labradors and German Shepherds did not differ significantly, that of Labradors being only slightly higher. The intra-species variation of dogs is lower than in humans, mouse, or rat, but similar to that in domestic animals, probably reflecting similarly high inbreeding coefficients. However, some highly informative loci were common to all dog breeds tested so far. Such population data are necessary for mapping studies and linkage analysis in dogs. Received: 31 July 1996 / Accepted: 21 October 1996     

Biotinidase in the porcine cerebrum

Biotinidase activities found in porcine brains (n = 3) were as follows: cerebrum, 4.4 +/- 0.2 pmol/min per milligram of protein; cerebellum, 7.6 +/- 0.3 pmol/min per milligram of protein; medulla, 2.9 +/- 0.3 pmol/min per milligram of protein. These values are relatively high compared with the activities in rat or guinea pig brains. Subcellular distribution of biotinidase was found mainly in the soluble cytoplasmic fraction (S3), i.e., in the supernatant of 0.32 M sucrose S2 solution after ultracentrifugation at 105,000g for 90 min. This is in contrast to the guinea pig livers, in which the subcellular distribution of biotinidase is mainly found in the microsomal fraction. After a seven-step purification (22,200-fold enrichment), porcine brain biotinidase is identified as a single polypeptide by the sodium dodecyl sulfate-polyacrylamide gel electrophoresis system, and its molecular weight is determined as 68,000 Da. The isoelectric point of the enzyme was 4.3. Sialidase treatment strongly suggests the presence of sialyl residues in this enzyme. Amino acid analysis indicates relatively high hydrophilicity and high content of glycine and serine. The enzyme activity is inhibited by organic mercurials, but not by diisopropylfluorophosphate. Abundant soluble biotinidase in brain cytoplasm may play an important role which has not been discovered yet.     

Effects of elastic compression stockings on wall shear stress in deep and superficial veins of the calf

The purpose of this study was to estimate wall shear stress (WSS) in individual vessels of the venous circulation of the calf and quantify the effects of elastic compression based on change of vessel geometry and velocity waveform. The great saphenous vein and either a peroneal or posterior tibial vein have been imaged in four healthy subjects using magnetic resonance imaging, with and without the presence of a grade 1 medical stocking. Flow through image-based reconstructed geometries was numerically simulated for both a range of steady flow rates and ultrasound-derived transient velocity waveforms, scaled to give a standardized time averaged flow rate. For steady flow, the stocking produced an average percentage increase in mean WSS of approximately 100% in the great saphenous vein across a range of 0.125-1.25 ml/s. The percentage increase in the peroneal/posterior tibial veins varied from 490 to 650% across a range of 0.5-5 ml/s. In addition, application of the stocking eliminated periods of very low or zero flow from the transient waveforms. The average minimum value of WSS in all vessels without the stocking was <0.1 Pa. With the stocking, this was increased to 0.7 Pa in the great saphenous and 0.9 Pa in the peroneal/posterior tibial veins. The pathophysiological effects of these changes are discussed. In conclusion, the flight stocking was effective in raising venous WSS levels in prone subjects, and this effect was much more pronounced in the deep vessels. The stocking also tended to prevent cessation of flow during periods of increased downstream pressure produced by respiration.     

Morphological study on the thebesian veins of the right cavities of the heart in the dog.

The authors studied 48 dog hearts, using the injection-corrosion-fluorescence method to study the topography of thebesian veins in all the walls of the cardiac cavities. The thebesian veins are small, situated deep in the myocardium, opening after a short course into the cardiac cavities, by small openings with diameters in general not exceeding 1 mm, known 'foraminula'. They have a centripetal course, while every other vein in the heart has a centrifugal one, to reach the subepicardial zone. In the heart of the dog five types of thebesian veins were served: arboriform, sinuous, brush-like, canaliculated and stellate. The thebesian veins are almost regularly found in every wall of the cardiac cavities. The authors also observed that they predominated in the right ventricle (81.24%) and in the right atrium (77.43%).