Rigid rods with flexible side chains — A route to molecular reinforcement?

Liquid-crystalline main-chain polyesters with polystyrene side chains of different length and number per main chain were synthesized using aromatic hydroxyfunctional polystyrene (PS) macromonomers, terephthalic acid derivatives and tert-butylhydroquinone as co-diol. The molecular weight of the polystyrene side chain was varied in the range from 1000 to 20000. The influence of this novel type of substituent on the solubility, thermal behaviour and miscibility with PS as a flexible matrix polymer is discussed. The properties of the new compounds are compared to those of the respective homopolyester. The graft copolyesters are, depending on the characteristics of the polymeric substituent, soluble in common organic solvents and their thermal transition points are lowered compared to the homopolyester. Compared to blends of the homopolyester, the improvement of miscibility of the polymer-substituted rigid rods with PS as an example for a flexible matrix polymer can be valued as a step to molecular reinforcement.     

The Mutants of the Vitamin-D-Binding Protein: More than 120 Variants of the GC/DBP System

In this report 40 newly observed GC/DBP mutants are described. A list of the thus far identified GC mutants is presented: in addition to the three common alleles, a total of 124 Gc variants are recorded. Their population distribution is described and their relationship to the molecular features of the DBP protein is discussed. The methods currently in use for the delineation of GC mutants are briefly considered.     

Characterization and opioid modulation of inflammatory temporomandibular joint pain in the rat.

PURPOSE: Experimental inflammation of the rat temporomandibular joint (TMJ) is commonly used to study trigeminal nociceptive processing. This study describes spontaneous pain-related behaviors following TMJ inflammation in the rat. The ability of preemptive systemic morphine to attenuate behaviors as well as immediate-early gene expression in the trigeminal nucleus is described. MATERIALS AND METHODS: Adult male Sprague-Dawley rats received an intra-articular injection of mustard oil (0% to 20%, 50 microL) and were observed for behavioral changes. Morphine sulfate (0 to 10 mg/kg SC) was given 30 minutes before mustard oil; this was reversed in one group with naltrexone hydrochloride (5 mg/kg SC). Two hours after injection rats were killed and perfused. Immunohistochemistry for the protein product of the immediate-early gene c-fos was performed, and brain stem sections including the trigeminal subnucleus caudalis were examined for positive nuclei. RESULTS: Mustard oil inflammation of the rat TMJ induces dose-dependent, morphine-sensitive behaviors. Behaviors observed included excessive grooming of the region, a chewing-like behavior, and head shaking. Fos expression in the trigeminal subnucleus caudalis parallels changes in behaviors. Morphine dose dependently attenuates the number of behaviors, as well as Fos expression; this effect is reversed by the micro-opioid receptor antagonist naltrexone. CONCLUSIONS: Mustard oil inflammation of the rat TMJ causes reliable behavioral changes, which may be quantified and, together with Fos expression, used to assess various experimental TMJ treatment modalities.     

Immune control of mammalian aging: a T-cell model.

A competent immune response appears to play an important role in retarding aging. On the other hand, the aged immune system is assumed to accelerate the general aging process. In order to approach the underlying mechanism of this paradoxical immune response, the process of clonal deletion in the thymus is addressed under the aspect of aging. It is assumed that T-cell deletion in the thymus brings about a control of cell differentiation in the organism. For proper functioning, this control is suggested to be directed, in the sense of a feedback mechanism, primarily to thymic stromal cells involved in the process of clonal deletion. At the expense of a thymus atrophy, the control system can retard aging up into the reproductive period of life. With the progress of thymic involution, however, the control is predetermined to undergo a breakdown and, in consequence, through loss of self-tolerance it speeds up the whole aging process.     

Orale Zytologie

Zusammenfassung Die orale Zytologie erf?hrt eine Renaissance, die durch die Einführung der Bürste als Entnahmetr?ger und durch die Anwendung zus?tzlicher moderner Verfahren bedingt ist. Die Bürste kann tiefe Schichten der oralen Mukosa erfassen, in denen die squam?se intraepitheliale Neoplasie (SIN) beginnt. Zus?tzliche Verfahren zur Bewertung der biologischen Potenz der gewonnenen oralen Epithelzellen sind: die computerunterstützte Bildanalyse (OralCDx^?), die DNA-Zytometrie, die Immunzytochemie, die Dünnschichtzytologie und molekularbiologische Analysen. Alle genannten Verfahren sind geeignet, die Sensitivit?t (bis zu 100%) und Spezifit?t (bis zu 100%) der oralen Zytologie zu erh?hen. Dennoch gibt es Berichte über orale Plattenepithelkarzinome, die mithilfe der Bürstenbiopsie nicht erkannt wurden. Die Wertigkeit der einzelnen Verfahren kann aktuell aufgrund fehlender vergleichender Studien nicht abschlie?end beurteilt werden. Die Immunzytochemie mit kommerziellen Antik?rpern gegen Laminin 5 ist allseits verfügbar und methodisch einfach. Das nichtinvasive diagnostische Verfahren der methodisch unterstützten oralen Bürstenbiopsie kann einen Beitrag zur frühen Erkennung ausgew?hlter Mundschleimhautl?sionen leisten. Ein positiver Befund oder eine Progression der L?sion bei negativem Befund sind Indikationen zur überweisung des Patienten an Fachkliniken und zur dort durchgeführten Skalpellbiopsie mit histopathologischer Untersuchung. Die histopathologische Begutachtung bleibt der Goldstandard in der definitiven Diagnostik maligner oraler L?sionen.      

Age-related structural and functional changes in the DNA of human lymphocytes

Characteristic changes of DNA winding and repair are detected in human peripheral lymphocytes with advancing donor age between 20 and 90 years, suggesting a progressively undifferentiated cell state. From a model approach it appears likely that the existence of immature lymphocytes favors aging as a general dysdifferentiation of somatic cells.