Muscarinic receptor/G-protein coupling is reduced in the dorsomedial striatum of cognitively impaired aged rats

Behavioral flexibility, the ability to modify responses due to changing task demands, is detrimentally affected by aging with a shift towards increased cognitive rigidity. The neurobiological basis of this cognitive deficit is not clear although striatal cholinergic neurotransmission has been implicated. To investigate the possible association between striatal acetylcholine signaling with age-related changes in behavioral flexibility, young, middle-aged, and aged F344 X Brown Norway F1 rats were assessed using an attentional set-shifting task that includes two tests of behavioral flexibility: reversal learning and an extra-dimensional shift. Rats were also assessed in the Morris water maze to compare potential fronto-striatal-dependent deficits with hippocampal-dependent deficits. Behaviorally characterized rats were then assessed for acetylcholine muscarinic signaling within the striatum using oxotremorine-M-stimulated [(35)S]GTPγS binding and [(3)H]AFDX-384 receptor binding autoradiography. The results showed that by old age, cognitive deficits were pronounced across cognitive domains, suggesting deterioration of both hippocampal and fronto-striatal regions. A significant decline in oxotremorine-M-stimulated [(35)S]GTPγS binding was limited to the dorsomedial striatum of aged rats when compared to young and middle-aged rats. There was no effect of age on striatal [(3)H]AFDX-384 receptor binding. These results suggest that a decrease in M2/M4 muscarinic receptor coupling is involved in the age-associated decline in behavioral flexibility.

Chronic caloric restriction alters muscle membrane fatty acid content

Chronic caloric restriction (CR) has been demonstrated to increase longevity in lower species and studies are ongoing to evaluate its effect in higher species. A consistent metabolic feature of CR is improved insulin sensitivity and lowered lifetime glycemia, yet the mechanism responsible is currently unknown. However, the membrane's physiochemical properties, as determined by phospholipid composition, have been related to insulin action in animal and human studies and CR has been reported to alter membrane lipid content. We evaluated muscle membrane fatty acid content in rodents randomized to CR versus control diets for up to 29 months. CR was observed to increase the membrane content of C22:6 (docosahexaenoate) and to decrease C18:2 content. The membrane lipid content was related to insulin levels but not to parameters assessing glycemic control. This study suggests that membrane lipids, in particular 22:6, may contribute to the variation in insulin sensitivity seen with age.

Effect of age and caloric restriction on insulin receptor binding and glucose transporter levels in aging rats

We report on the effect of age and chronic caloric restriction (CR) on insulin binding and glucose transporter content in both diaphragm and heart muscle membrane of young (11 months), mid-age (17 months), and old (29 month) ad libitum fed and CR Brown-Norway rats. The control animals received rat chow ad lib and CR animals were allowed 60% of ad libitum food. The CR regimen was initiated at four months of age and the animals were maintained on their respective diets until necropsy. There was no effect of age on insulin binding for either ad libitum or CR animals at each age evaluated. Caloric restriction significantly lowered insulin levels at each age studied when compared to the ad libitum-fed rats. However, CR animals were noted to have increased insulin binding (p < 0.001) compared to ad libitum-fed animals at each age for diaphragm muscle. For the heart, there appeared to be a decreased binding, particularly at higher insulin concentrations, in CR-fed animals. There was no net change in Glut-1 or Glut-4 levels for heart muscle membrane, or Glut-4 levels for diaphragm muscle membrane between ad libitum or CR animals. This data indicates that caloric restriction may have tissue-specific effects for insulin receptor binding, and that the improved insulin sensitivity in CR states is not a result of altered glucose transporter protein content.

[The basis for ultrasonic phenomena during the injection of x-ray contrast media]

During the injection of contrast media for cerebral angiography, high-intensity ultrasound reflections can be recorded by Doppler sonography and B-mode scanning. This phenomenon was examined during carotid angiography and by in vitro experiments in tube models. Our results show that these high-intensity reflections are caused by: (1) transient interfaces of impedance between small compartments of contrast medium and blood and (2) small gas bubbles, which are always present in freshly aspirated contrast medium. Therefore, intraarterially injected contrast medium acts as an ultrasound contrast medium as well.

[The effect of cisplatin on the healing of intestinal anastomosis in the rat. Microangiography and light microscopy studies]

The influence of a single dose cisplatin on wound healing of enterostomies in rats was investigated by measurement of the wound-breaking strength, microangiographically and histologically. Cisplatin (5 mg/kg body weight) was given on day-1 or day-5 preoperatively. Cisplatin led to a significant reduction of the wound-breaking strength, mostly marked on day +14 after operation. The reasons are: a reduced induction of connective tissue proliferation; an inhibition of proliferation of fibroblasts and endothelial cells, and a retardation of vessel proliferation.

Cell fusion as a mechanism for the formation of giant cells (Langhans' type). Autoradiographic findings in autoimmune tubulo-interstitial nephritis of the rat

The formation of multinuclear giant cells of the Langhans' type in tubulo-interstitial auto-immune nephritis in the rat has been investigated by means of autoradiography. While in the majority of giant cells all nuclei were radiolabeled, in a few both labeled and unlabeled nuclei were present. This latter finding represents strong evidence in favour of the hypothesis that giant cells do not form by endomitotic processes but rather through fusion of certain precursor cells. According to previous studies this precursor cell population consists mainly of epitheloid cells, i.e. modified monocytes.

D-penicillamine in Wilson's disease presenting as acute liver failure with hemolysis

Wilson's disease in a young woman presenting with an acute course is described. The clinical manifestations were fulminant hepatic failure associated with marked intravascular hemolysis. Immediate D-penicillamine and high-dose steroid therapy did not influence the course of the disease. Necropsy revealed an increased hepatic copper content and cirrhosis with extensive necrosis of the liver.

[A combined allogenic implant for the dorsum of the nose (author's transl)]

Report of three patients with small bony defects on the lateral bony wall or the bridge of the nose. Reconstruction was performed with a combined cushion like implant of lyodura polsted with merthiolate preserved allongene crashed cartilage. Over a follow up time period of two years the cosmetic results are good. The histological behavior of these implants was studied in animals.

[Polyploidisation - a phenomenon of aging? (author's transl)]

By means of cytophotometric determination of DNA in different cellular systems an increase in polyploidisation correlated to age could be demonstrated. The latter is well demonstrable if compensatory hyperplasia or hypertrophy occurs. It is discussed that cellular systems of older individuals can increase their DNA - content, but they are not able to carry out a caryo-and cytocinesis.

[The vascularisation of the granulation tissue in different ages. - Its importance for wound healing (author's transl)]

The part of capillaries of a plastic sponge granuloma was determined in rats of different ages. It was found that granulation tissue of older rats contains significantly fewer capillaries than that of young animals. The diminished vascularisation of granulation tissue may be responsible for the deterioration of wound healing in aged individuals.

[Investigations regarding the pathogenesis of fibromatosis of the palmar fascia (Dupuytren's contracture) (author's transl)]

The palmar aponeuroses of five patients suffering from Duputyren's disease were examined by means of light and electron microscopy. In all cases myofibroblasts could be found in the alterated regions of the palmar aponeuroses. The role of the fibroblasts for the pathogenesis of the disease is discussed.

The effect of complete Freund--adjuvant on chronic proliferating inflammation in an experimental granuloma model

Histometric, biochemical, radiochemical and autoradiographic studies were undertaken to investigate the influence of complete Freund-adjuvant (CFA) on a defined chronic proliferating inflammation of a granuloma model in two different experimental situations. Where as the percentage fraction of the fibroblasts, 3H-thymidine marking index of the fibroblasts and the impulse rate of the fibroblasts and endothelial cells do not differ from the values found for the control animals, both the protein and DNA content of the implanted sponges, as well as the DNA content of the individual fibroblasts in the implants increased, independent of the stage of the chronic proliferating inflammation at which the CFA was administered. Surprisingly the quantity of the fibroblast specific synthetic product, collagen, did not increase in proportion to the absolute number of fibroblasts, but remained either constant or even significantly decreased. A possible inhibition of collagen synthesis after CFA administration during chronic proliferating inflammation is discussed.

Veränderungen des RHS der Ratte nach parenteraler Gabe yon Dextran (Mw 40000) und Hydroxyäthylstärke (Mw 40000). Chemische, licht- und elektronenmikroskopische Untersuchungen

Im Tierversuch wurde nach mehrmaliger parenteraler Gabe die Wirkung von Dextran (Mw 40000) und HAS (Mw 40000) auf die Zellen des RHS (retikulohistiozytäres System) am Beispiel verschiedener Lymphknotenstationen mit chemischen, licht- und elektronenmikroskopischen Methoden untersucht. Offensichtlich werden beide Plasmaexpander teilweise in den Zellen des RHS gespeichert. Als wesentlicher Unterschied findet sich jedoch nur nach Dextran-40-Gabe eine so exzessive Speicherung, daβ einzelne Zellen zerstört werden. Gleichartige Veränderungen können nach HÄS-40 nicht beobachtet werden. Eine Blockade des RHS scheint nach Gabe beider Plasma-expander nicht aufzutreten.

The development of the rolling texture in copper measured by neutron diffraction

Three-dimensional orientation distribution functions of the crystallites in copper sheets, cold rolled to different degrees of reduction, have been determined using neutron diffraction pole figures. The main features of the textures may be represented by the orientation `tube' already described in prior publications. Two ranges of rolling reduction can be distinguished, a lower one (30 to 50%) and a higher one (70 to 95%) the texture changes of which correspond to those calculated after the Taylor theory. In an intermediate range (50 to 70%) a different deformation mechanism occurs which leads to an intermediate (001) [110] texture component. It is supposed that anisotropic hardening may have occurred in this range.