Middle Branch Research Articles

ЗАВИСИМОСТЬ ПЛОЩАДЕЙ КРОВОСНАБЖЕНИЯ НАДПОЧЕЧНИКОВ ЧЕЛОВЕКА ОТ ОСОБЕННОСТЕЙ АРТЕРИАЛЬНОГО ИСТОЧНИКА

The current article describes the determined blood supply areas of each of the suprarenal arteries. It is stated, that the intraorganic arteries branch out in the capsule and cortex mainly dichotomically, while in the brain matter the arteries are distributed according to the evriareal type of the vascular tree. The superior suprarenal arteries supply blood to the upper pole of the adrenal gland, to its anterior and posterior surfaces till the level of the horizontal fissure. The area of the blood supply ranges from 1.95 х 10 3 to 4.12 х 10 3 mm 2 , the degree of involvement 34 %. The middle suprarenal artery branches gives off branches in the area of the medial pole and middle third of the adrenal gland and also in the area of the medial part of the renal surface. The size of the blood supply area - from 1.4 х 10 3 to 2.83 х 10 3 mm 2 . The rate of involvement into the blood supply - 22.96 %. The branches of the inferior suprarenal artery supply blood to the inferior surface of the adrenal gland, and some of these branches reach its lateral pole. The size of the blood supply area here is from 1.75 х 10 3 to 3.24 х 10 3 mm 2 , the rate of involvement into the blood supply is on the second position -26.53 %. The smallest area of blood supply of the adrenal gland is covered by the collateral suprarenal artery, which in 47 % of cases branches from the arcuate artery of the adipose capsule of the kidney (from 1,26 х 10 3 to 1,93 х 10 3 mm 2 ). The rate of involvement -16.47 %.

Spatio-temporal dynamics of vertical charge transport in a semiconductor heterostructure

In this work the authors present a theory of space- and time-dependent electrical transport in the heterostructure hot-electron diode if the device is driven under current-controlled conditions in the middle branch of its S-shaped current-density-voltage characteristic, spatially homogeneous relaxation oscillations as well as the formation of stationary filamentary patterns, can be found. Additionally, they predict a new type of self-organized, spatially inhomogeneous oscillation where an inhomogeneous current distribution appears and vanished periodically. This periodicity is very sensitive to stochastic fluctuations.

Anatomical Background for Nephron-Sparing Surgery in Renal Cell Carcinoma

3-Dimensional endocasts of intrarenal structures were analyzed on the basis of their importance for performing nephron-sparing surgery. In 86.6% of the endocasts the superior pole was related to 3 arteries involved in its resection. Management of the superior (apical) segmental artery as well as ligature of the artery related to the anterior surface of the upper infundibulum are generally not difficult. Ligature of the posterior segmental artery branch related to the superior pole is critical due to the risk of injuring this segmental artery and loss of a great portion of renal parenchyma. In 62.2% of the endocasts the inferior pole resection involved ligature of the inferior segmental artery with no risk to the posterior segmental artery. A deep anatomical knowledge is mandatory to perform mid kidney resection. In 36.4% of the endocasts this region received subdivision branches of arteries from superior and inferior poles, and in 62.2% the mid kidney resection involved amputation of calices that are dependent on polar calices. The middle branch of the posterior segmental artery also is involved in mid kidney resection and its ligature demands much care to avoid injury to the posterior segmental artery itself. In the dorsal kidney the posterior segmental artery is involved and must be safeguarded in all cases of either superior pole or mid kidney resection. In 37.8% of the cases the posterior segmental artery also may be involved in inferior pole resection. When present (69.2%), the retropelvic vein must be previously ligated to provide safe management of the posterior segmental artery. Accepted for publication August 12, 1991.

From bistability to temporal oscillations and spatial pattern formation

The idea ‘‘from bistability to oscillations,’’ originally proposed by De Kepper and Boissonade for studying and designing chemical oscillations, is extended to ‘‘from bistability to spatial pattern formation.’’ To carry out such extension, the idea from bistability to oscillations is discussed again by intuitive arguments based on the analysis of the intersection of the nullclines of kinetic equations and the linear stability analysis. By analogy between the kinetic equations of homogeneous reactions and the stationary equations of reaction–diffusion processes, similar intuitive arguments and linear stability analysis are applied to the reaction–diffusion equations, which leads to the conclusion that the homogeneous steady state being on the middle branch of the nullcline of the bistable subsystem is a necessary condition for spatial pattern formation. This condition becomes sufficient if the diffusion coefficients of the species involved in the feedback subsystem are much larger than those of the species which constitute the bistable subsystem. To demonstrate the validity of these conclusions, an example of heterogeneous catalysis system is studied analytically and numerically, and various temporal-spatial patterns, including the coexistence of a homogeneous steady state and an oscillating state or a spatial pattern, are revealed. The potential applications of the idea from bistability to spatial pattern formation to the experimental study and design of spatial patterns are discussed.

Geostrophic transport of the South Equatorial Current in the Atlantic

Geostrophic transport calculations from historical data of the equatorial South Atlantic are presented for the investigation of the flow field in the South Equatorial Current region. On the basis of water mass distribution, the potential density surface of sigma-1 = 32.15 kg m-3 is used as a reference for geostrophic shears. This reference surface is located at a depth of 1000 to 1200 m and represents the boundary between the upper branch of the Circumpolar Deep Water and the Upper North Atlantic Deep Water. The southern band of the South Equatorial Current (SSEC) is fed by the Benguela Current, which crosses the Greenwich Meridian south of 20S. West of the Greenwich Meridian the subtropical gyre has its northermost current band as the westward flowing SSEC. The SSEC was found to be a broad sluggish flow between 10S and 25S. The transport of the SSEC in the upper 500 m is in the order of 20 Sv, with surface velocities of around 10 cm s-1. At 30W the SSEC turns northward. A small part of the water turns poleward south of 10S to form the Brazil Current, whereas the bulk of the flow contributes to the North Brazil Current and the South Equatorial Countercurrent (SECC). The SECC seems to cross the entire South Atlantic eastward to at least the Greenwich Meridian, but part of the flow might contribute to the middle branch of the South Equatorial Current flowing westward. The northernmost current band sampled is the eastward flowing South Equatorial Undercurrent. From this data no seasonality in the geostrophic field can be proven.

EXPERIMENTAL STUDY OF THE HEAT TRANSFER CHARACTERISTICS OF A TWO-PHASE DOUBLE-LOOP THERMOSYPHON

An experimental study is presented for the heat transfer characteristics of a rectangular, two-phase, double-loop thermosyphon with water-steam as the working fluid. The evaporator was installed in the middle branch and shared by the two condensers. Local temperature measurements of the core fluid and the wall were made, and the overall heat transfer coefficients of the evaporator, the condensers, and the loop system were obtained and correlated in terms of the fluid properties, heat flux conditions, and the liquid charge level V+. Results show that the overall heat transfer coefficients increase with decreasing V+ and increasing heat flux. The heat transfer performance of the entire system can be viewed as a parallel combination of the thermal resistances of the evaporator and two condensers. Results also confirm the previous findings that if the liquid charge level is below the fractional volume of the bottom connecting tubes, an overheat phenomenon will take place.

Chronic Trigeminal Ganglionectomy or Topical Capsaicin Application to Pial Vessels Attenuates Postocclusive Cortical Hyperemia but Does Not Influence Postischemic Hypoperfusion

Marked hyperemia accompanies reperfusion after ischemia in the brain, and may account for the propensity of cerebral hemorrhage to follow embolic stroke or carotid endarterectomy, and for the morbidity that follows head injury or the ligation of large arteriovenous malformations. To evaluate the contribution of trigeminal sensory fibers to the hyperemic response, CBF was determined in 12 symmetrical brain regions, using microspheres with up to five different isotopic labels, in four groups of cats. Measurements were made at 15-min intervals for up to 2 h of reperfusion after global cerebral ischemia induced by four-vessel occlusion combined with systemic hypotension of either 10- or 20-min duration. In normal animals, hyperemia in cortical gray matter 30 min after reperfusion was significantly greater after 20 min (n = 10) than after 10 min (n = 7) of ischemia (312 ml/100 g/min versus 245 ml/100 g/min; p less than 0.01). CBF returned to preischemic levels approximately 45 min after reperfusion and was reduced to approximately 65% of basal CBF for the remaining 75 min. In cats subjected to chronic trigeminal ganglionectomy (n = 15), postocclusive hyperemia in cortical gray matter was attenuated by up to 48% on the denervated side (249 versus 150 ml/100 g/min; p less than 0.01) after 10 min of ischemia. This effect was maximal in the middle cerebral artery (MCA) territory, and was confined to regions known to receive a trigeminal innervation. In these animals, substance P (SP) levels in the MCA were reduced by 64% (p less than 0.01), and the density of nerve fibers containing calcitonin gene-related peptide (but not vasoactive intestinal polypeptide or neuropeptide Y) was decreased markedly on the lesioned side. Topical application of capsaicin (100 nM; 50 microliters) to the middle or posterior temporal branch of the MCA 10-14 days before ischemia decreased SP levels by 36%. Postocclusive hyperemia in cortical gray matter was attenuated throughout the ipsilateral hemisphere by up to 58%, but the cerebral vascular response to hypercapnia (PaCO2 = 60 mm Hg) was unimpaired. The duration of hyperemia and the severity of the delayed hypoperfusion were not influenced by trigeminalectomy, capsaicin application, or the intravenous administration of ATP. These data demonstrate the importance of neurogenic mechanisms in the development of postischemic hyperperfusion, and suggest the potential utility of strategies aimed at blocking axon reflex-like mechanisms to reduce severe cortical hyperemia.

Multiple Steady-State Solutions in a Multijunction Semiconductor Device

Multiple steady-state solutions are constructed for a multijunction semiconductor device using a combination of asymptotic and numerical techniques. The multijunction device is modeled by the drift-diffusion equations of semiconductor physics. In the drift-diffusion model three sign alterations of the doping are assumed, and a Shockley-Read-Hall recombination is allowed for. In the parameter range for which the current-voltage relation is monotonic, the quasi-neutral approximation to the drift-diffusion model is found to be valid and solutions are constructed asymptotically in the limit of large doping densities. In contrast, in the parameter range for which the current-voltage relation is S-shaped, the quasi-neutral approximation is found to poorly approximate solutions to the full model on the middle and lower branches. A suitable modification to the quasi-neutral approximation is then introduced to describe the middle and lower branches of the current-voltage relation under the assumption of no recombi...

Embolic stroke after smoking "crack" cocaine.

A 39-year-old woman had an embolic upper division middle cerebral artery branch occlusion 3 hours after smoking the free base of cocaine ("crack"). Radionuclide ventriculography demonstrated cardiomyopathy, and echocardiography documented a left atrial thrombus. This case demonstrates that embolism is one mechanism of ischemic stroke after cocaine use, and that cardiomyopathy, possibly cocaine induced, may be the source of embolus. A cardiac source of embolus should be sought in patients with cocaine-associated cerebral infarction.

Selective occlusion of blood supply to the anterior perforated substance of the dog: a highly reproducible stroke model

We created a highly reproducible stroke model in dogs by the selective occlusion of middle and anterior cerebral artery branches that penetrate the anterior perforated substance and supply much of the basal forebrain. We also analyzed the anatomic organization of the arterial supply to this region in this animal. Perforators came from anterior communicating artery branches similar to the recurrent artery of Heubner in humans and from the middle cerebral artery at several sites distal to the bifurcation of the internal carotid artery. Although some animals had a single source of the perforating arteries, most had two or more. In 50% of our specimens, the anterior communicating artery was the dominant source of arterial supply, in 21% the middle cerebral artery was dominant, and in 24% neither source dominated. Occlusion of all microscopically visible perforators to the anterior perforated substance reliably resulted in infarction of the internal capsule (100%), caudate nucleus (91%–100%), putamen or globus pallidus (82%–91%), and anterior commissure (73%). Structures involved less frequently in infarctions include the external capsule, claustrum, anterior commissure, and septal nuclei. We believe this anatomic information is useful for understanding why previous focal ischemia lesions in the distribution of the middle cerebral artery in the dog have been highly variable as well as for planning and interpreting future studies in this species. The proposed model of focal ischemia may be of use for the study of stroke.

The value of T1-weighted images in the differentiation between MS, white matter lesions, and subcortical arteriosclerotic encephalopathy (SAE).

The aim of the study was to define reliable criteria for the differentiation of MR imaging between patients with MS and with "vascular" white matter lesions/SAE. We examined 35 patients with proven MS according to the Poser criteria and 35 patients with other white matter lesions and/or SAE. The result is that with MR a differentiation can be achieved provided that T1-weighted spin-echo sequences are included and the different pattern of distribution is considered. MS plaques are predominantly located in the subependymal region, vascular white matter lesions are mainly located in the water-shed of the superficial middle cerebral branches and the deep perforating long medullary vessels in the centrum semiovale. Infratentorial lesions are more often seen in MS. Confluence at the lateral ventricles is frequently accompanied by confluent abnormalities around the third ventricle, Sylvian aqueduct, and fourth ventricle, which is uncommon in SAE. In MS many lesions visible on T2-weighted images have a cellular or intracellular composition that renders them visible also on T1-weighted ones as regions with low signal intensity and more or less distinct boundary. "Vascular" white matter lesions and SAE mainly represent demyelination and can therefore be seen on T2-weighted images, but corresponding low signal intensity lesions on T1-weighted images are uncommon. In some exceptions there are such lesions with low signal representing lacunar infarcts or widened Virchow-Robin-spaces.

Changes in cerebral hemodynamics following encephalo-duro-arterio-synangiosis (EDAS) in young patients with moyamoya disease

To evaluate the effect of encephalo-duro-arterio-synangiosis, (EDAS), we obtained follow-up angiograms and measured regional cerebral blood flow in 21 young patients with Moyamoya disease. Carotid fork stenosis continued to progress after EDAS, although angiography demonstrated a marked increase in the number of middle cerebral artery branches via implanted arteries. Preoperative cortical blood flow was lower than normal. The post-EDAS increases in hemispheric and cortical flow were significant in patients with transient ischemic attacks, but not in patients with infarction. The increase in cortical flow at the site of EDAS was first noted 2 weeks after EDAS.

THE CONTROL OF IRRITATING FRUIT HAIRS FROM STREET TREE PLATANUS

Summary For the past ten years fruit hairs of street tree planes (Platanus acerifolia Willd and P. occidentalis Linn) in several large Chinese cities have been responsible for causing extreme irritation to the eyes, noses, ears and throats of pedestrians. Many of these tree are over mature, and consequently produce an abundance of fruits, the hairs from which cause the extreme discomfort. By cutting back these trees to lower or middle truck branches the tree crown can be rejuvenated to some extent depending on pruning intensity; during the following five to seven years of canopy regeneration and after that, fruit production is greatly reduced and consequently the amount of hairs in the atmosphere is equally diminshed. The effectiveness of this practice and other methods of control are discussed.

脳動脈硬化の発生, 進展に関する病理学的研究

A topographical view of atherosclerotic lesions and the development of intimal thickening of branching sites, including internal carotid-anterior cerebral-middle cerebral arterial bifurcation and middle cerebral artery-first branch of humans, was studied. A fatty streak was observed in the second decade but its surface involvement did not develop with age. In contrast, a fibrous plaque first appeared in the fourth decade and progressed with age. The fibrous plaque revealed a distinct pattern with a high incidence on the outer walls of daughter vessels with bifurcations. The flow divider was free from fibrous plaques.In newborns and infants, the focal cellular intima (intimal pad) began to appear on the outer walls of daughter vessels of bifurcations and was replaced by cellulofibrous intimal thickening after one year of age. In similar topographic sites, a heterogeneous, stratified cellulofibrous intimal thickening, consisting of cellular component-rich layer and fibrous component-rich layer occurred in subjects more than 40 years of age. This frequency increased with age. The intima/media ratio increased progressively in successive age groups, and more rapid development was detected in subjects over 30 years old. In cases younger than 40 year-old, foam cells and fatty changes of collagen fibers were not observed in the intima, but LDL deposits were observed. In cases over 40 year-old, foam cells and fatty changes of collagen fibers in the intima were observed with LDL deposition. The cells observed in both the cellular and cellulofibrous intimal thickening demonstrated myosin and vimentin positivity. But the cells in the stratified cellulofibrous intimal thickening were immunohistochemically heterogeneous; some of them did not stain with antibodies to myosin or vimentin, though they were intimal smooth muscle cells.These findings suggest that the cellular and cellulofibrous intimal thickening, occurring on the outer wall of daughter vessels of bifurcations in young patients, may play an important nascent role as a lesion in atherogenesis.

TWO CASES OF SCLEROSING HEMANGIOMA OF THE LUNG

Sclerosing hemagioma of the lung is a relatively rare disease, and has been ragarded as a benign tumor arising in the alveolar epithelial cells. Recently, however, the malignant cases have been found. We report two cases of the disease, together with a review of the domestic reference. Case 1 is a 42-year-old female who had a round shadow, 4×3cm in size with smooth and clear edge, in the right lower lung field, which was found at physical examination. Bronchographic examination showed a suppressed peripheral branch B5, in which incisurae were found by CT. The middle lobe was resected. Case 2 is a 48-year-old female who had atelectasis of the middle lobe and a round shadow of 3×2.5cm in chest X-ray film taken at when she suffered from fever. Bronchographic examination revealed a narrowed and suppressed introitus of the middle lobar branch, a convergence of peripheral branches, and a passage of the contrast medium into around the tumor. Bronchial angiography revealed a new formation of the peripheral vessels of the tumor, that is, so-called melon-peel-like stitched vascularity. The middle lobe which presented atelectasis as well as the tumor was resected. In both case 1 and 2, pathologic findings suggested a sclerosing hemangioma without heterologous cells in the tumor and no sign of lymph node metastasis.

Rice flower glumes as an interceptor of ultraviolet rays.

The effect of ultraviolet (uv) ray on rice (Oryza sativa L) kernel during its kernel development was investigated. Upper one-thirds portion of each flower glumes (palea and lemma) on the middle branches of panicles were cut off immeadiately after flowering. Panicles with the cut glumes were then covered with a vinyl film envelope of different light transmittance in uv range. Kernel development in the cut glumes was greatly inhibited by being exposed either to the natural light or to the light of uv range. Relative humidity, however, seemed not to have a great influence on the development of the glume-cut kernels. The inhibition was most outstanding when exposed to short wave uv rays, although it was lessened as exposed to longer wave uv rays. Inhibitory effect of visible light was very slight. Moreover, under dark conditions, kernels in cut glumes developed quite well beyond the untreated kernels and formed a Dahrma doll shape. In terms of kernel characters, uv radiation produced tapered kernels and promoted a browny coloring of kernel as well. Another experiment as to the degree of glume cutting revealed that under dark conditions, the effect of the extent of cutting on the inhibition was rather slight, although they were very conspicuous when exposed to the natural light. Rice flower glumes was found to intercept uv rays almost completely after the last stage of booting. These results indicate that exposure of young kernels to a short wave uv ray strikingly supresses their development and that rice flower glumes may take an important role in protecting their inside kernel through intercepting harmful uv rays. Rice kernels might substantially have an ability to develop beyond the volume of glumes though their development are usually restricted within the volume limit of their glumes.

Ischemic cortical lesions after permanent occlusion of individual middle cerebral artery branches in rats.

Our study describes the anatomy of the middle cerebral artery (MCA) in 65 Sprague-Dawley rats and the spatial distribution of ischemic cortical lesions caused by occluding major MCA branches. The rats characteristically had at least two major MCA branches, frontal and parietal. Many rats had additional branches supplying the pyriform and temporal cortexes. Permanent occlusion of the frontal or parietal branches combined with 30 minutes of bilateral carotid artery occlusion produced visible Evans blue dye uptake by ischemic cortical areas after 24 hours. No lesions distal to the occlusion were apparent in 38% and 43% of rats with frontal and parietal branch occlusions, respectively; small lesions contiguous with the occlusion site were observed in 38% and 32% of the rats. Only 6% of the frontal and 7% of the parietal branch occlusions produced isolated distal infarcts as expected if these branches were end-arteries. Blood flow was reversed in arteries distal to the occlusion. We conclude that extensive collateral connections of the frontal and parietal MCA branches with other arterial systems protect the anterior and posterior cortical regions. In contrast, occlusions of the pyriform branch of the MCA invariably caused infarcts in the frontopyriform region. In about one third of the rats, frontal or parietal branch occlusions produced lesions involving much of the proximal MCA territory; the frontopyriform region was most consistently affected. Combined, these data suggest that the pyriform MCA branch is an end-artery and that the cortical region it supplies is prone to ischemic damage resulting from any reduction of blood flow through the main MCA trunk.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of the role of rat liver Golgi endo-alpha-D-mannosidase in processing N-linked oligosaccharides.

Golgi membranes from rat liver have been shown to contain an endo-alpha-D-mannosidase which can convert Glc1Man9GlcNAc to Man8GlcNAc with the release of Glc alpha 1----3Man (Lubas, W. A., and Spiro, R. G. (1987) J. Biol. Chem. 262, 3775-3781). We now report that this enzyme has the capacity to cleave the alpha 1----2 linkage between the glucose-substituted mannose residue and the remainder of the polymannose branch in a wide range of oligosaccharides (Glc3Man9GlcNAc to Glc1Man4GlcNAc) as well as glycopeptides and oligosaccharide-lipids. Whereas the tri- and diglucosylated species (Glc3Man9GlcNAc and Glc2Man9GlcNAc), which yielded Glc3Man and Glc2Man, respectively, were processed more slowly than Glc1Man9GlcNAc, the monoglucosylated components with truncated mannose chains (Glc1Man8GlcNAc to Glc1Man4GlcNAc) were trimmed at an increased rate which was inversely related to the number of mannose residues present. The endomannosidase was not inhibited by a number of agents which are known to interfere with N-linked oligosaccharide processing by exoglycosidases, including 1-deoxynojirimycin, castanospermine, bromoconduritol, 1-deoxymannojirimycin, swainsonine, and EDTA. However, Tris and other buffers containing primary hydroxyl groups substantially decreased its activity. After Triton solubilization, the endomannosidase was observed to be bound to immobilized wheat germ agglutinin, indicating the presence of a type of carbohydrate unit consistent with Golgi localization of the enzyme. The Man8GlcNAc isomer produced by endomannosidase action was found to be processed by Golgi enzymes through a different sequence of intermediates than the rough endoplasmic reticulum-generated Man8GlcNAc variant, in which the terminal mannose of the middle branch is absent. Whereas the latter oligosaccharide is converted to Man5GlcNAc via Man7GlcNAc and Man6GlcNAc at an even rate, the processing of the endomannosidase-derived Man8GlcNAc stalls at the Man6GlcNAc stage due to the apparent resistance to Golgi mannosidase I of the alpha 1,2-linked mannose of the middle branch. The results of our study suggest that the Golgi endomannosidase takes part in a processing route for N-linked oligosaccharides which have retained glucose beyond the rough endoplasmic reticulum; the distinctive nature of this pathway may influence the ultimate structure of the resulting carbohydrate units.

Induced absorption of extraordinary (Z-mode) waves via electron pumping

When induced by pitch-angle scattering, waves of the middle branch of the extraordinary mode will give up their energy to a plasma by magnetically pumping electrons. The damping decrement for small-amplitude extraordinary waves is calculated and the decrement for finite-amplitude waves is estimated. Because heating a plasma makes it a better absorber of extraordinary waves, such waves can produce localized hot cavities in plasmas. The evolution of electron distribution functions f(v) is examined and it is found that magnetic-pumping-mediated absorption leads to f∝v−3 tails.

Right vs. left hemispheric blood-brain barrier permeability in schizophrenia: A dynamic computed tomographic study

Dynamic computerized tomographic brain scanning was used to make determinations of mean cerebral tissue nonenhanced density and contrast-enhanced density in 10 bilateral brain regions in 10 psychotic subjects. Asymmetry of both nonenhanced and contrast-enhanced density was observed; left regional nonenhanced values were higher than right, whereas contrast-enhanced density values were higher on the right than on the left. No significant differences were observed in arterial mean transit time (AMTT) between right and left middle cerebral artery branches or in capillary or tissue mean transit time (CMTT) in the middle temporal cortex. However, corrected CMTT (CCMTT), i.e., CMTT minus AMTT, amy have been prolonged in five subjects either on the left or right, or in both homologous regions. Only 2 of 10 subjects exhibited anterior-posterior (AP) gradients that resembled to some extent the hyperfrontal pattern reported in normal subjects by other investigators with different techniques.