Fine mapping of the 1q21 breakpoint of the papillary renal cell carcinoma-associated (X;1) translocation

A combination of Southern blot analysis on a panel of tumor-derived somatic cell hybrids and fluorescence in situ hybridization (FISH) techniques was used to map a series of DNA markers relative to the 1q21 breakpoint of the renal cell carcinoma (RCC)-associated (X;1)(p11;q21) translocation. This breakpoint maps between several members of the S100 family which are clustered in the 1q21 region and a conserved region between man and mouse containing the markers SPTA1-CRP-APCS-FcER1A-ATP1A2-APOA2. The location of the breakpoint coincides with the transition of a region of synteny of human chromosome 1 with mouse chromosomes 3 and 1. Received: 10 November 1995 / Revised: 3 February 1996     

Scanning electron microscope study ofTorulopsis ethanolitolerans prepared by glutaraldehyde—Thiosemicarbohydrazide procedure

Torulopsis ethanolitolerans subject to both the sparing and coarse heat treatment were studied in the scanning electron microscope. The reduction of adhesivity, increased permeability and higher rigidity of the yeast wall was achieved by an original glutaraldehyde—paraformaldehyde fixation, low osmolarity in vacuo and subsequent thiosemicarbohydrazide incubation, followed by addition of metal salt. The impregnation of the metal throughout the specimen due to the reaction of the thiosemicarbohydrazide with glutaraldehyde allowed viewing of small or intricate surface details of the yeast. Structural differences of the yeast processed by sparing and coarse heat treatment were shown to be better from the thiosemicarbohydrazide incubated samples compared to those that were prepared with osmium tetroxide.     

Regional genetic diversity patterns in Antarctic hairgrass (Deschampsia antarctica Desv.)

Aim  To determine patterns in diversity of a major Antarctic plant species, including relationships of Antarctic populations with those outside the Antarctic zone.
Location  Antarctic Peninsula, Maritime Antarctica, sub-Antarctic islands, Falkland Islands and South America.
Methods  Amplified fragment length polymorphisms (AFLPs) and chloroplast sequences were used to study patterns of genetic diversity in Antarctic hairgrass ( Deschampsia antarctica Desv.) and the genetic relationships between populations over its distribution range. Thirty-eight populations were sampled from a large part of the distribution of D. antarctica , and additionally, herbarium specimens were included for areas from which we could not obtain fresh samples.
Results  A gradient in AFLP diversity was observed going from the Falklands southwards into the Antarctic. This gradient in diversity was also observed within the Antarctic Peninsula: diversity was lower further south. Diversity in the chloroplast genome of D. antarctica was low. Only three chloroplast haplotypes were found, each with a strong regional distribution.
Main conclusions  The phylogenetic construction of AFLP marker frequencies in meta-populations of D. antarctica supports a stepping-stone model of colonization, whereby gene flow mainly occurs between neighbouring populations. It is concluded that long-distance gene flow is very limited in D. antarctica . A very low diversity was found in the sub-Antarctic islands in the Indian Ocean, indicating that these populations have experienced a recent evolutionary bottleneck.     

Membrane structure and interactions of a short Lycotoxin I analogue.

Lycotoxin I and Lycotoxin II are natural anti-microbial peptides that were identified in the venom of the Wolf Spider Lycosa carolinensis. These peptides were found to be potent growth inhibitors for bacteria (Escherichia coli) and yeast (Candida glabrata) at micromolar concentrations. Recently, shortened analogues of LycoI and LycoII have been reported to have decreased haemolytic effects. A shorter Lyco-I analogue studied, LycoI 1-15 (H-IWLTALKFLGKHAAK-NH2), was active only above 10 microM, but was also the least haemolytic. On the basis of these findings, we became interested in obtaining a deeper insight into the membrane activity of LycoI 1-15, as this peptide may represent the first major step for the future development of selective, i.e. non-haemolytic, Lycotoxin-based antibiotics. The interaction of this peptide with liposomes of different composition was studied by microcalorimetry [differential scanning calorimetry (DSC) and isothermal titration calorimetry (ITC)] and CD. The results obtained from the calorimetric and spectroscopic techniques were jointly discussed in an attempt to further understand the interaction of this peptide with model membranes.     

Submicroscopic structure of glycosaminoglycans in osteocyte capsule of human embryonic bone as revealed by polarization microscopy

Using qualitative and quantitative polarization microscopical techniques, an axiparallel orientation of chondroitin sulfate molecules and collagen fibrils could be detected in the osteocyte capsule of human embryonic and fetal bones. It is suggested that this spatially oriented microstructure plays a role in ana- and catabolic transport processes of the bone tissue.     

Genetic stability (in vivo) of the attenuated oral rabies virus vaccine SAD B19

The distribution of oral rabies vaccine baits containing replication-competent live viruses poses certain environmental safety risks; among others, the possibility of reversion to or an increase in virulence. Hence, the genetic stability of the complete genome of the most widely used oral rabies vaccine virus, SAD B19, was examined after four and 10 serial i.c. passages in foxes and mice, respectively. It was shown that the consensus strain of SAD B19 was extremely stable in vivo . After 10 consecutive passages in mice not a single mutation was observed. In foxes, seven single nucleotide exchanges were found between the first and fourth passage, of which only one resulted in an amino acid exchange at position 9240 of the L-gene. This mutation was not observed during the first three passages and, furthermore, it was shown that this mutation was not linked to enhanced virulence.