Synthesis and complexing properties of cyclic benzylopeptoids - a new family of extended macrocyclic peptoids.

An efficient protocol for the solid-phase synthesis of six members of a new class of extended macrocyclic peptoids (based on ortho-, meta- and para-N-(methoxyethyl)aminomethyl phenylacetyl units) is described. Theoretical (DFT) and experimental (NMR) studies on the free and Na+-complexed cyclic trimers (3-5) and tetramers (6-8) demonstrate that annulation of the rigidified peptoids can generate new hosts with the ability to sequestrate one or two sodium cations with the affinities and stoichiometries defined by the macrocycle morphology. Ion transport studies have been also performed in order to better appreciate the factors promoting transmembrane cation translocation.

Variation in vertebral number and its morphological implication in Galaxias platei.

Variation in the vertebral number of the puyen grande Galaxias platei was examined for specimens from 22 localities that span the entire distribution range of the species (from 40° to 55° S). The mean vertebral number (NMW ) increases towards high latitudes, i.e. Jordan's rule is applicable to this species. Owing to the wide geographic variation of the species, not only in latitude but also in altitude, the most explicative variable for NMW was mean winter air temperature, showing negative dependence. Morphological data suggest that the increment in vertebral number lies in the pre-pelvic region of the trunk and in the caudal region, but not in the segment between pelvic-fin insertion and the origin of the anal fin. As these alterations in body shape have important consequences for hydrodynamics and swimming performance, vertebral number variation in G. platei also holds implications for both individual and population fitness.

Development of rats' maternally directed orienting behaviors from birth to day 2.

We previously observed 2- to 3-day-old (P2-3) rats perform maternally directed orienting behaviors (MDOBs)-locomotion, torso flexion, rotation to the supine orientation, and snout probing, accompanied by audible vocalizations (barking)-under surfaces having properties of the dam's ventrum, which result in close contact between the pup's ventrum and the surface. We now report on the development of MDOBs from birth through P2. Wistar rats (24 litters) were tested at one of four times: 1 hr after birth before the first nursing bout (P0pre), on the day of birth after the first nursing bout (P0post), on postnatal Day 1 (P1), or on postnatal Day 2 (P2). Pups were placed prone on a warmed platform inside a corral where, for 4 min, they encountered one of two motherlike surfaces at head height: (a) a soft cotton roof or (b) a patch of the pup's own anesthetized dam's ventrum. Control pups received no overhead stimulus. The behaviors we had identified as MDOBs and others, including limb behaviors, are easily recognized at P0pre, and, in aggregate, are more frequent then than at any later age. The differential responsiveness of most of the behaviors to the dam's ventrum compared to the cotton roof or open condition is relatively low at P0pre, but rises rapidly through P2. Behavioral structure develops quickly from a rudimentary principal component with two behaviors at P0pre to two principal components incorporating seven behavior classes by P2. MDOBs are discussed in relation to late-term fetal behaviors, early postnatal righting responses, and the oral nipple grasp, and as a model of the development of filial attachment in an altricial mammal.

[Cyclophotocoagulation with the Nd:YAG-laser]. / Die Cyclophotocoagulation mit dem Nd:YAG-Laser.

Hopeless glaucoma cases fluctuate between excessive pressures and phthisis. Due to the underlying disease (neovascularization in the chamber angle, chronic inflammation, dysgenesis, aphakia) the customary surgical pressure-lowering operations often fail and medication is also useless. As a "last-ditch" measure, there remains only destruction of the ciliary body. In the Zurich eye department, noninvasive cyclophotocoagulation has been performed since 1987. The present paper reports on the first cases with long-term follow-up.

Transient synthesis of K6 and K16 keratins in regenerating rabbit corneal epithelium: keratin markers for an alternative pathway of keratinocyte differentiation.

Cultured rabbit corneal epithelial cells undergo three distinct stages of growth and differentiation characterized by the sequential appearance of K5/K14 keratin markers for basal keratinocytes, K6/K16 keratin markers for "hyperproliferative" keratinocytes, and K3/K12 keratin markers for corneal-type differentiation. Analyses of [35S]methionine-labeled, newly synthesized keratins revealed that K6/K16 are synthesized only briefly when the cells undergo exponential growth, and their synthesis is suppressed when the cells reach confluence and switch to synthesizing K3/K12. Transient synthesis of K6/K16 was also observed in vivo during corneal epithelial regeneration. Although K6/K16 expression in general correlates well with cellular growth, drug-induced inhibition of corneal epithelial growth and related data on human epidermal keratinocytes indicate that these two events are dissociable. These results establish clearly for the first time a reciprocal relationship, on a protein level, between the synthesis of K6/K16 and a differentiation-related keratin pair, K3/K12. Such a relationship strongly suggests a competitive mechanism controlling the synthesis of these two major classes of keratins in the suprabasal compartment. Our results also indicate that although hyperproliferation is usually accompanied by K6/K16 expression, the reverse is not always true. Taken together, the data suggest that K6/K16 are synthesized, perhaps by default, as an alternative suprabasal keratin pair under conditions that are nonpermissive for keratinocytes to express their normal, differentiation-related keratin pairs.