Computerized topographical analysis of functionally homogeneous neuronal sets.

A computer-assisted analysis of the spatial distribution of neurons having homogeneous characteristics is described in this paper. The camera lucida drawings of sections of a brain nucleus and the points representing the neurons labeled on the basis of a specific behavior of discharge rates were digitized on a personal computer Amiga 2000 or IBM compatible. Our software provided: a) the computerized, stereotaxically oriented reconstruction of the stored sections and of the plotted neurons; b) the identification within each section of the mass center (MC) of the units sharing a given behavior and of the area where the density of such neurons was maximal (MDA). The routine was tested on the spatial distribution of neuronal responses to serotonin in the lateral vestibular nucleus.     

Glucose compensation, serum lipids and thyroid hormones (rT3 and rT3/T3 ratio in non-insulin-dependent (type 2) diabetics: 2

In 45 type 2 diabetics it was unable to be found a relation between the plasma lipids and the fasting blood glucose (G), HbA1c, reverse T3 (rT3), rT3/T3 ratio, and relative body weight (R.B.W.). The conclusion was reached that the alteration of the lipoprotein metabolism and the thyroid hormones in type 2 diabetics could be primitive and independent from the availability of the insulin.     

Phylogeny of Greya (Lepidoptera: Prodoxidae), based on nucleotide sequence variation in mitochondrial cytochrome oxidase I and II: congruence with morphological data

The phylogeny of Greya Busck (Lepidoptera: Prodoxidae) was inferred from nucleotide sequence variation across a 765-bp region in the cytochrome oxidase I and II genes of the mitochondrial genome. Most parsimonious relationships of 25 haplotypes from 16 Greya species and two outgroup genera (Tetragma and Prodoxus) showed substantial congruence with the species relationships indicated by morphological variation. Differences between mitochondrial and morphological trees were found primarily in the positions of two species, G. variabilis and G. pectinifera, and in the branching order of the three major species groups in the genus. Conflicts between the data sets were examined by comparing levels of homoplasy in characters supporting alternative hypotheses. The phylogeny of Greya species suggests that host-plant association at the family level and larval feeding mode are conservative characters. Transition/transversion ratios estimated by reconstruction of nucleotide substitutions on the phylogeny had a range of 2.0-9.3, when different subsets of the phylogeny were used. The decline of this ratio with the increase in maximum sequence divergence among taxa indicates that transitions are masked by transversions along deeper internodes or long branches of the phylogeny. Among transitions, substitutions of A-->G and T-->C outnumbered their reciprocal substitutions by 2-6 times, presumably because of the approximately 4:1 (77%) A+T-bias in nucleotide base composition. Of all transversions, 73%-80% were A<-->T substitutions, 85% of which occurred at third positions of codons; these estimates did not decrease with an increase in maximum sequence divergence of taxa included in the analysis. The high frequency of A<-->T substitutions is either a reflection or an explanation of the 92% A+T bias at third codon positions.      

Immunocytochemical Localization of Serotonin and Neuropeptides in the Neuroendocrine Paraneurons of Teleost and Lungfish Gills*

Neuroendocrine (NE) cells in the gills of six fish species were identified by serotonin and peptide immunohistochemistry. They occur either as single cells or as cell clusters within the filamental epithelium. Two populations of NE cells were identified that exhibit an immunoreactivity either for serotonin alone or for met-enkephalin and leu-enkephalin co-distributed in the same cells. We demonstrate for the first time the occurrence of open-type endocrine cells in the fish gill epithelium and confirm the presence of only serotonin-immunopositive cells of the closed type. The NE cells of the species studied do not react positively to other neuroendocrine markers occurring in the mammalian lung. Great differences probably exist in the expression of these epitopes on antigenic structures among various animal species. Although the physiological role of neuropeptides and serotonin in the fish gill NE cells is unknown, the presence of these molecular markers is of interest not only from an evolutionary aspect, but also in terms of a potential animal model to study the supposed functions of the airway neuroendocrine system in the vertebrates.     

Behavior of thyroid hormones and TSH in chronic active hepatitis

The authors studied total and free circulating thyroid hormones, rT3, TBG and TSH behaviour on chronic liver disease in 11 subjects with cirrhosis of the liver with ascites(C.E.) and in 6 subjects with chronic active hepatitis (E.C.A.) in comparison with 15 healthy and euthyroid controls. Serum T3,FT3,T4 and FT4 levels were decreased significantly and serum rT3 values increased significantly both in the subjects with C.E. and in patients with E.C.A. Moreover no significantly changes of TSH and TBG levels has been found in 3 groups studied. These data suggest that the alteration of circulating thyroid hormones in chronic liver disease, may represent a compensatory way of reducing the patient's metabolic requirements.