Lesion location influences perception of homonymous scotomata during flickering random dot pattern stimulation

An attempt was made to clarify whether the site of postchiasmal lesions affects subjective perception of homonymous visual field defects during stimulation with flickering random dot patterns (white noise-field). Out of 56 patients with homonymous hemianopia, 38 (68%) perceived scotomata in this situation, but 18 (32%) discerned none at all. Neuroradiologic superposition of cerebral lesions detected by computed tomography (CT) or magnetic resonance imaging (MRI) showed that nearly all patients who perceived their scotomata had lesions involving the primary visual cortex or the perigeniculate region, whereas those who received no scotoma had lesions centered within the optic radiation. Functional MRI of six normal subjects during stimulation with flickering random dot patterns indicated predominant activation of the primary visual cortex. Since noise-field defects were most frequently perceived by patients whose lesion involved the primary visual cortex, it appears that the sensitivity of noise-field campimetry depends on the site of damage in the visual pathway. The explanation for this may be that damage to long-range horizontal connections impairs filling-in processes.     

SAP NetWeaver: Slicing the fridge

Zusammenfassung Das Schlagwort NetWeaver ist seit einiger Zeit in unserer Branche en vogue. Wie so oft, ist es nicht leicht, Marketingaspekte vom informatischen Wesensgehalt zu unterscheiden. Dieser Beitrag m?chte hier helfen.     

The longitudinal distribution of cadmium, zinc, copper, iron, and metallothionein in the small-intestinal mucosa of rats after administration of cadmium chloride

Different routes of Cd intake may influence the intestinal distribution of Cd, metallothionein (MT), and trace metals differently. Therefore, we compared the effects of parenteral and enteral administration of Cd on the distribution of trace metals and MT along the small intestine. In a first experiment three groups of rats were employed: a control, one receiving CdCl2 within the drinking water, and another receiving sc injections of CdCl2. In a second experiment, rats were fed three different diets with either 0, 0.3, or 1 mmol CdCl2/kg for one and two weeks to study the time- and dose-dependent effects of orally administered Cd. Metal concentrations (Cd, Zn, Cu, Fe) were measured by atomic emission spectrometry and MT was determined by radioimmunoassay. Intestinal MT levels did not show proximodistal gradients in controls or after sc administration of Cd, but orally administered Cd increased mucosal MT levels longitudinally from the duodenum to the ileum. Cd levels paralleled those of MT. Compared with the metal concentrations in the controls, sc administration of Cd did not change intestinal Zn, Cu, and Fe levels. Oral administration of Cd, however, increased Cu and decreased Fe levels in the intestinal mucosa significantly. The second experiment revealed that only high dietary concentrations of Cd increase intestinal Cd and MT levels longitudinally toward the distal parts, whereas at lower dietary concentration the longitudinal distribution was reversed. This shows that different routes and doses of Cd intake lead to a different trace metal and MT distribution and emphasizes the role of dietary Cd in the local induction of small-intestinal MT.     

Assessment of drug release from oil depot formulations using an in vitro model -- potential applicability in accelerated release testing

In vitro drug release and transport rates from oil depot formulations under nonsink conditions have been investigated in the rotating dialysis cell model. Eight model drug compounds and eight oil vehicle compositions were used for the releaseexperiments. The experimentally obtained apparent first-order rate constants related to the drug appearance in the acceptor phase after initial instillation of a drug-containing oil solution were found to be in excellent agreement with the rate constants obtained from a theoretically derived expression. It was observed that the drug oil-water distribution coefficient was the key parameter influencing the release characteristics. As compared with ketoprofen, flurbiprofen exhibited a higher affinity for the oil, resulting in a significantly lower and more slowly decreasing drug concentrations in the aqueous donor compartment. Release profiles for prilocaine and the more lipophilic agent bupivacaine after incorporation of both drugs in fractionated coconut oil were characterized by a fast release of prilocaine, whereas bupivacaine was liberated much slower to the acceptor phase. The high oil-buffer interfacial area generated in vitro by rotation of the donor cell tends to overestimate release rates in comparison to those expected in vivo, for example, after intra-articular administration of oil solutions. The present in vitro method may constitute a valuable tool in accelerated in vitro release testing of parenteral oil depot formulations in areas comprising formulation design and product quality control.     

Development of high-throughput, polarization-maintaining, near-field probes

A novel, chemical-etching technique produces very high throughput, polarization-maintaining probes for near-field, scanning, optical microscopy (NSOM). The process includes coating the tips with aluminum and forming the apertures with a focused ion beam (FIB). The elliptical core fibers used resulted in elliptical apertures for the probes. The throughput of the probes depends on the incident polarization. For polarization parallel to the minor axis, the tip presents an insertion loss of only 20 dB for aperture widths of 55 nm. Probes have a typical polarization extinction of 100 to 1 in the far field. These tips produced NSOM images of gold dots on a GaAs substrate in reflection mode.     

Progressive atrophy of pyramidal neuron dendrites in autoimmune MRL-lpr mice

The autoimmune-prone MRL-lpr substrain of mice develop an autoimmunity-associated behavioral syndrome (AABS) which resembles in many respects the behavior of animals exposed to chronic stress. The present study examined whether these mice show changes in the morphology of neuronal dendrites, as found in animals exposed to chronic stress. A modified Golgi-Cox procedure was used to visualize the dendrites of pyramidal neurons in the parietal cortex and in the CA1 hippocampal field of 5-week and 14-week old MRL-lpr mice and MRL + / + controls. Reduced dendritic branching and length, and an up to 20% loss of dendritic spines were observed in parietal and hippocampal pyramidal neurons of MRL-lpr mice at both ages. In the parietal cortex, there was an age-dependent potentiation in the reduction of basilar, but not apical, dendrite branching and length, as well as in the loss of spines on basilar segments. Loss of spines in the hippocampus followed an age-related course for apical but not basilar dendrites. Moreover, compared to age-matched controls, brain weight was smaller in MRL-lpr mice at 14 but not 5 weeks of age. Considering that dendritic atrophy becomes more extensive when autoimmune disease is florid in MRL-lpr mice, it is proposed that immune/inflammatory factor(s) produce dendritic loss. Reduced dendritic complexity may represent, at least in part, a structural basis for the altered behavioral profile of MRL-lpr mice.     

Biegeversuche und Prüfung des Brandverhaltens an Trägern aus verleimten Buchenschälfurnieren

Zusammenfassung An drei verleimten Tr?gern aus Buchenfurnieren wurde, das Verhalten im statischen Biegeversuch erkundet. Die Festigkeits-werte lagen zwischen den Werten, die an Tr?gern aus Buchenbrettern und aus Fichtenbrettern erzielt worden sind. Die im Brandversuch unter Last geprüften Biegetr?ger aus verleimten Buchenfurnieren, Querschnitt rd. 12 cm × 30 cm, entsprachen ungeschützt den Anforderungen der Widerstandsklasse F 30 nach DIN 4102, Blatt 2. Die Vollimpr?gnierung bewirkte einen deutlich kleineren Abbrand. Ein Tr?ger, der mit einer „Feuerschutztapete”, ummantelt war, konnte der Feuerbeanspruchung mehr als 60 min widerstehen.

---

Tests on the bending strength and fire tests with glulam-girders of beech veneers

Summary Three glulam-girders of beech veneers, were tested as to their behavior in a static bending test The strength values were found between those obtained from girders of beech boards and spruce boards. The glulam-girders of beech veneers with a cross-section of approx. 12 cm by 30 cm were subjected to a fire test under load in an unprotected condition and met, the requirements of the fire resistance class F 30 in accordance to DIN 4102, sheet 2. The full cell impregnation caused a definitely smaller fire loss. One girder, sheathed with a fire protective wall-paper, was able to resist the fire attack over more than 60 min.

---

---

Mitteilung aus dem Otto-Graf-Institut, Stuttgart

---

Die Mittel zur Durchführung der Untersuchungen sind in dankenswerter Weise vom Bayerischen Staatsministerium für Ern?hrung, Landwirtschaft und Forsten, München, über die Deutsche Gesellschaft für Holzforschung zur Verfügung gestellt worden.