Ultrafiltration coefficient and glomerular capillary resistance in a model of immune complex glomerulonephritis

Ultrafiltration coefficient and glomerular capillary resistance in a model of immune complex glomerulonephritis. Decreased ultrafiltration coefficient, LpA or Kf, was documented previously in micropuncture studies of glomerulonephritis in rats. Observations were made immediately following an injection of antiglomerular basement membrane (anti-GBM) antibody, later in the course of glomerulonephritis, and during the chronic phase of Heymann nephritis. To gain further insight into the basis of reduced glomerular filtration rate in immune-complex glomerulonephritis, we studied the anatomic, physiologic, and rheologic properties of isolated glomeruli from female Buffalo rats with nephritis which developed during infection withTrypanosoma rhodesiense. Immune-complex mediated glomerulonephritis was present 2 weeks after inoculation and progressed throughout the 4 weeks of study. Renal insufficiency occurred, with serum creatinine concentrations rising to 5 to 10 times control values by week 4. Mesangial hypercellularity, mesangial electron dense deposits, and endothelial cell swelling were observed. Increased numbers of mononuclear cells were present within the glomerulus. Total glomerular water volume was greater in nephritic than in normal animals. Increased cell volume accounted for most of the volume increment. When filtration into the capillaries was induced in vitro by imposing an oncotic gradient of 6.5mm Hg or greater across the capillary wall, rapid and uniform erythrocyte movement occurred within the capillaries of control glomeruli and erythrocytes were ejected into the medium. In contrast, a transcapillary gradient of 30 to 40mm Hg was required to produce erythrocyte movement in glomeruli from nephritic animals studied 4 weeks after inoculation. The ultrafiltration coefficient of nephritic glomeruli was estimated in vitro and was not different from that of control glomeruli (5.81 ± 0.35 vs. 6.21 ± 0.49 nl/minmm Hg). An impairment of capillary perfusion may be responsible for the decreased rate of glomerular filtration observed in this model of glomerulonephritis.Evaluation in vitro du coefficient d'ultrafiltration et de la résistance capillaire glomérulaire dans un modèle de glomérulonéphrite des comples immuns. La diminution du coefficient d'ultrafiltration, LpA ou Kf, a été établie précédement au cours de travaux utilisant les microponctions chez des rats atteints de glomérulonéphrite, immédiatement après l'injection d'anti-corps anti-membrane basale glomérulaire (anti-GBM) et, ultérieurement, au cours de l'évolution de glomérulonéphrite et durant la phase chronique de la néphrite de Heymann. Afin d'obtenir plus d'informations sur les fondements de la diminution du débit de filtration glomérulaire au cours de la néphrite des complexes immuns, nous avons étudié les propriétés anatomiques, physiologiques, et biologiques des glomérules isolés de rats femelles de la souche Buffalo atteints de néphrite développée au cours de l'infection parTrypanosoma rhodesiense. Une glomérulonéphrite des complexes immuns existait deux semaines après l'inoculation et évoluait pendant les 4 semaines de l'étude. Il existait une insuffisance rénale et la créatinine sérique atteignait des valeurs 5 à 10 fois plus grandes que les contrôles à la 4 semaine. L'hypercellularité mésangiale, sous la forme de dépôts denses mésangiaux en microscopie électronique, et le gonflement des cellules endothéliales ont été observés. Le nombre des cellules mononucléés du glomérule était augmenté. Le volume total d'eau du glomérule était plus grand chez les animaux atteints de néphrite que chez les contrôles. L'augmentation du volume cellulaire rendait compte de la plus grande partie de l'augmentation de volume. Quand la filtration dans les capillaires a été declenchée par l'imposition d'un gradient oncotique de 6,5mm Hg ou plus à travers la paroi capillaire, un mouvement rapide et uniforme des érythrocytes est apparu et les érythrocytes ont été éjectés dans le milieu. Par contre, pour les glomérules provenant d'animaux néphritiques, étudiés quatre semaines après l'inoculation, un gradient de 30 à 40mm Hg était nécessaire pour produire un mouvement des érythrocytes. Le coefficient d'ultrafiltration des glomérules d'animaux néphritiques a été évalué in vitro et n'est pas différent de celui des animaux contrôles (5,81 ± 0,35 vs. 6,21 ± 0,49 nl/minmm Hg). L'altération de la perfusion capillaire est responsable de la diminution du débit de filtration glomérulaire observée dans ce modèle de glomérulonéphrite

Concise Syntheses of Insect Pheromones Using Z-Selective Cross Metathesis

The use of insect sex pheromones to limit specifically targeted pest populations has gained increasing popularity as a viable, safe, and environmentally friendly alternative to insecticides. While broad-spectrum insecticides are toxic compounds that have been shown to adversely affect human health,[1] extensive studies have shown that insect pheromones are nontoxic and safe for human consumption at the levels used in pest control practices.[2] Female sex pheromones are mainly employed in pest control in a process termed mating disruption. This involves dispersing pheromones over a large area, overloading the sensory organs of male insects and preventing them from locating and mating with females who are releasing a much smaller amount of the same pheromone blends; this strategy has proven to reduce specific insect populations dramatically.[3] To date, the United States Environmental Protection Agency (EPA) has approved approximately twenty lepidopteran female sex pheromones as active ingredients for pest control.[2

Discrete mode laser diodes with ultra narrow linewidth emission <3kHz

Ex-facet, free-running ultra-low linewidth (<3 kHz), single mode laser emission is demonstrated using low cost, regrowth-free ridge waveguide discrete mode Fabry-Perot laser diode chips

Magnetic Properties of Linear Chain Systems: Metamagnetism of Single Crystal Co(pyridine)₂CI₂

The metamagnetic behavior of the low temperature properties of single crystal Co(pyridine)2Cl2 is discussed. At 1.25 K oriented single crystals exhibit a two-step metamagnetic transition at applied fields ~0.8 and 1.6 kG along the b-axis, a single transition at ~0.7 kG for applied fields along the a* axis, and a single transition at ~4.2 kG for an applied field along the c axis. Just above the transition fields a moment of 2µB/Co atom is measured for B0 parallel to the a* axis or b axis, and 0.4µB/Co atom is measured for the B0 parallel to the c axis. A large field dependent moment is observed at high fields. Many features of this compound closely mirror the behavior of CoCl2-2H20. However, the Co(pyridine)2Cl 2 has a much smaller interchain exchange, so that many features can be examined at lower fields. The basic features are consistent with a six-sublattice model for the ordered antiferromagnetic system. Measurements of magnetic moment versus temperature show that Co(pyridine)2Cl 2 does not obey a Curie-Weiss law even at relatively high temperatures

SmaggIce 2.0: Additional Capabilities for Interactive Grid Generation of Iced Airfoils

The Surface Modeling and Grid Generation for Iced Airfoils (SmaggIce) software toolkit has been extended to allow interactive grid generation for multi-element iced airfoils. The essential phases of an icing effects study include geometry preparation, block creation and grid generation. SmaggIce Version 2.0 now includes these main capabilities for both single and multi-element airfoils, plus an improved flow solver interface and a variety of additional tools to enhance the efficiency and accuracy of icing effects studies. An overview of these features is given, especially the new multi-element blocking strategy using the multiple wakes method. Examples are given which illustrate the capabilities of SmaggIce for conducting an icing effects study for both single and multi-element airfoils