Differential distribution of N-acetylaspartylglutamate and N-acetylaspartate immunoreactivities in rat forebrain

Summary Contradictory immunohistochemical data have been reported on the localization of N-acetylaspartylglutamate in the rat forebrain, using different carbodiimide fixation protocols and antibody purification methods. In one case, N-acetylaspartylglutamate immunoreactivity was observed in apparent interneurons throughout all allocortical and isocortical regions, suggesting possible colocalization with GABA. In another case, strong immunoreactivity was observed in numerous pyramidal cells in neocortex and hippocampus, suggesting colocalization with glutamate or aspartate. Reconciling these disparate findings is crucial to understanding the role of N-acetylaspartylglutamate in nervous system function. Antibodies to N-acetylaspartylglutamate and a structurally related molecule, N-acetylaspartate, were purified in stages, and their cross-reactivities with protein conjugates of N-acetylaspartylglutamate and N-acetylaspartate were monitored at each stage by solidphase immunoassay. Reduction of the cross-reactivity of the anti-N-acetylaspartylglutamate antibodies to N-acetylaspartateprotein conjugates to about 1% eliminated significant staining of most pyramidal neurons in the rat forebrain. Utilizing highly purified antibodies, the distributions of N-acetylaspartylglutamate and N-acetylaspartate were examined in several major telencephalic and diencephalic regions of the rat, and were found to be distinct. N-acetylaspartylglutamate-immunoreactivity was observed in specific neuronal populations, including many groups thought to use GABA as a neurotransmitter. Among these were the globus pallidus, ventral pallidum, entopeducular nucleus, thalamic reticular nucleus, and scattered non-pyramidal neurons in all layers of isocortex and allocortex. N-acetylaspartate-immunoreactivity was more broadly distributed than N-acetylaspartylglutamate-immunoreactivity in the rat forebrain, appearing strongest in many pyramidal neurons. Although N-acetylaspartate-immunoreactivity was found in most neurons, it exhibited a great range of intensities between different neuronal types.     

Severe herpetic keratitis. I: Prevalence of visual impairment in a clinic population.

We report a prevalence study of the best visual acuity in the affected eye of 100 selected patients with herpetic keratitis seen during a two-year period. Sixty-two patients retained an acuity of 6/9 or better without requiring penetrating keratoplasty (PK). The prevalence of reduced visual acuity severe enough to warrant PK was 33%. Patients requiring PK for whom full clinical records were available suffered a mean of 6.8 episodes of keratitis. In this group of patients the vision of 18 fell from 6/6 to 6/60 over a mean period of 8.5 years. Once visual acuity was permanently reduced to 6/12, 78% of patients proceeded to lose vision to 6/60. Unilateral visual impairment occurs in at least a third of patients with severe herpetic keratitis. Once vision falls permanently to 6/12, the long-term prognosis for vision appears to be poor.     

Kardiale Manifestationen der HIV-Infektion

Zusammenfassung. Die Infektion mit dem humanen Immundefizienzvirus (HIV) betrifft nicht nur das Immunsystem des menschlichen Organismus, sondern schließt vielmehr eine Reihe weiterer Organsysteme mit ein. Es wird angenommen, dass bei 5-15% der HIV-positiven Patienten kardiale Manifestationen auftreten. Zu den häufigsten HIV-assoziierten kardialen Manifestationen gehören der Perikarderguss und die chronisch aktive, fokale oder diffuse Myokarditis. Endokardiale Manifestationen bei HIV-positiven Patienten treten in Form der infektiösen Endokarditis und der nichtbakteriellen thrombotischen Endokarditis auf. In der Regel weisen HIV-assoziierte kardiale Manifestationen einen langsam progredienten Krankheitsverlauf auf. Komplikationen sind Folge eines langfristig unentdeckten Fortschreitens der Erkrankung, aber auch schnell progredienter Verlaufsformen. Aufgrund der Vielzahl HIV-assoziierter kardialer Manifestationen und deren möglicher Komplikationen ist daher neben der Früherkennung ein effektives diagnostisches und therapeutisches Vorgehen erforderlich. Seit Einführung der Proteaseinhibitoren in den 90er Jahren und der Anwendung der hochaktiven antiretroviralen Kombinationstherapie (HAART) konnten sowohl Mortalität als auch Morbidität der HIV-Infektion deutlich gesenkt werden. Die Auswirkungen der HAART auf das kardiovaskuläre System sind bisher nur in Ansätzen bekannt. Als Nebenwirkungen wurden metabolische Veränderungen in Form von Hyperlipoproteinämie und Insulinresistenz bei einer Vielzahl HIV-positiver Patienten beobachtet. Es kann davon ausgegangen werden, dass durch den Anstieg der kardiovaskulären Risikofaktoren unter der HAART in den nächsten Jahren eine erhöhte Rate kardialer Erkrankungen bei HIV-positiven Patienten auftreten wird. In dem vorliegenden Übersichtsartikel wird ein Überblick über die häufigsten kardialen Erkrankungen bei HIV-Infektionen gegeben. Zusätzlich werden Vorschläge zu Diagnostik und Therapie unterbreitet und eine Einschätzung über Veränderungen der HIV-assoziierten kardialen Manifestationen nach Einführung der HAART vorgenommen. Abstract. The human immunodeficiency virus (HIV) does not only affect the immune system. Other organs including the cardiovascular system are influenced by the HIV as well. Most common HIV-associated cardiac manifestations are pericardial effusion and chronic active, focal or diffuse myocarditis. In addition to peri- and myocardial disease, endocardiac manifestations occur as infective endocarditis and nonbacterial thrombotic endocarditis in HIV-infected patients. Although most of the cardiac manifestations associated with HIV-infection exhibit a slow progression, rapid courses may lead to fatal complications. Early screening of HIV-infected patients will identify the potentially fatal complications of HIV disease and permit efficient treatment. The use of highly active antiretroviral therapy (HAART) significantly reduced the mortality and morbidity of HIV-infected patients. However, the impact that HAART will have on the incidence and prevalence of cardiac complications in HIV-infected patients is still unknown. It can be predicted, that the long-term viral infection and the increase of cardiovascular risk factors by HAART will probably lead to an increased prevalence of HIV-infected individuals with cardiac complications in the next decade. The present review describes the most frequent HIV-associated cardiac manifestations including diagnostic and therapeutic perspectives.     

Wall-thickness and midwall-radius variations in ventricular mechanics.

A fluid-fiber-collagen stress tensor is used to describe the rheology of the left ventricle of the heart. Linear theory is used to find the equilibrium solutions for the end-diastolic and end-systolic states of general axisymmetric shapes that are small perturbations of a thick-walled finite cylinder. The general problem can be studied by superposing the effects of variable midwall radius but constant wall thickness with those of variable wall thickness but constant midwall radius. A Fourier series representation is used to describe the midwall radius and thickness functions. Numerical calculations are performed to determine the deformed geometry and spatial distributions of tissue pressure, stresses, and fiber strains. The calculations proved to be highly accurate when compared to an analytical solution obtained for the special case of no fibers. The results show significant longitudinal differences when compared to results for the cylindrical geometry, with more sensitivity to variation in wall thickness than to variation in midwall radius.