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Biomedical subjects

A Minelli

Publications and source records attributed to A Minelli.

114 records · Page 7Linked to original sources
PubMedDate not supplied

Calcitonin gene-related peptide (CGRP) in the cat neocortex: evidence for a sparse but widespread network of immunoreactive fibers.

The morphology, and laminar and topographic distribution of fibers containing calcitonin gene-related peptide (CGRP) immunoreactivity were studied by light and electron microscopic methods in the cerebral cortex of adult cats using a rabbit antiserum raised against the C-terminal region of the rat alpha-CGRP. At the light microscopic level, a sparse number of CGRP-positive fibers were observed in the frontal, parietal, and occipital cortices. They showed numerous irregularly spaced varicosities, were mostly oriented vertically, and in rare cases gave rise to boutons terminaux as they ascended toward the pial surface. At the border between layers I and II, they branched into horizontal fibers that could be followed for several hundred microns in layer I and gave rise to terminal clusters of boutons. In some sections, CGRP-positive fibers were seen in close association with blood vessels. At the electron microscopic level, CGRP immunoreactivity was found in axon terminals containing few mitochondria and clear synaptic vesicles. CGRP-positive axon terminals were very sparse, and mainly of small size. The majority formed conventional synapses, all of the asymmetric type. CGRP-positive fibers showed an uneven topographic distribution through the cortical mantle, with the frontal areas exhibiting the highest density and the occipital cortex the lowest. These results show that CGRP-containing axons are more widely distributed than previously thought since they were observed in all the cortical areas examined, and cast some doubts on the hypothesis that the functional role of this peptide is restricted to the processing of visceral sensory information.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Abd-B expression in Porcellio scaber Latreille, 1804 (Isopoda: Crustacea): conserved pattern versus novel roles in development and evolution.

The Hox genes are intimately involved in patterning the animal body during development and are considered to have had a pivotal role in the evolution of different body plans among the metazoans. From this perspective, crustaceans, a group that has evolved an extreme diversity of body structures, represent a choice group in which to study the evolution of these genes and their expression. The expression of one of these genes, Abdominal-B (Abd-B), has only been studied in two distantly related crustaceans, Artemia and Sacculina, where it shows dissimilar patterns, highly differentiated from the one described in other arthropods. Moreover, we have no information for the Malacostraca. Thus, we cloned the gene Abd-B and followed its expression through development by in situ hybridization in the isopod Porcellio scaber. We found a highly dynamic expression pattern of PsAbd-B during embryonic development. In early stages, it is expressed in the posterior-most part of the germ band, in a domain common to several arthropods studied to date, and later it is expressed in the developing limb buds of the pleon and still later in the endopodites of the third to fifth pleopodites. This raises the interesting possibility of the involvement of this gene in the later respiratory specialization of these appendages. In association with the above expression domain, Abd-B appears to be expressed in later stages also in the ventral ectoderm, raising the further suggestion of its possible involvement in patterning the developing nervous system. Moreover, we show that the first pleopod and the endopodite of the second pleopod, whereas present as limb buds in early embryonic stages, are later reduced and actually absent in the first postembryonic stage, although they reappear again in adults. These appendages thus represent an example of Lazarus appendages. Our data show strong plasticity in the use of a key developmental gene and point out the necessity of further research that may end with a revision of the current understanding of its role in animal evolution.

Animals↗
PubMedDate not supplied

Rabbit spermatozoa: a model system for studying ATP homeostasis and motility.

This paper studies the adenosine triphosphate (ATP) homeostasis and the motility parameters of rabbit spermatozoa. Rabbit sperm, collected by artificial vagina, were studied in various buffer systems to determine motility over time. Sperms were also extracted to measure enzyme activity. Analyses of motility by Computer Assisted Semen Analyzer system were run in parallel with energy metabolic studies of sperm cells maintained in different physiological solutions sometimes containing inhibitors of energy metabolism. Rabbit spermatozoa were shown to be able to form ATP either via glycolysis or via oxidative phosphorylation. Both these metabolic pathways were active in viable cells where creatine kinase and adenylate kinase systems were also present (1.1 and 7,000 nmol/min per 100 x 10(6), respectively) and involved in maintaining high ATP levels. A dynamic balance between ATP synthesis and ATP-hydrolyzing enzymes was suggested by the fact that rabbit sperms in their seminal plasma preserved their motility for hours. The decrease in sperm ATP content was mainly due to its hydrolysis by dynein ATPases coupled with movements. Therefore, motility of rabbit spermatozoa appeared to be dependent only on the ATP available to dynein ATPases. In fact, statistical analyses of motility parameters and the concentrations of intracellular ATP or ATP-metabolite did not show any significant correlation.

Adenosine Triphosphate↗
PubMedDate not supplied

Erythrocyte formimino glutamate transferase in FIGLU aciduria.

A patient is described who presented at an early age with failure to thrive and vomiting, and had a gross excretion of formimino glutamic acid. She had normal concentration of serum folate and vitamin B12, and no haematological abnormalities, and is not mentally retarded. The Michaelis constant for erythrocyte formimino glutamate transferase was in the normal range, but the enzyme behaves differently from that from reference subjects with respect to inhibitors and activators.

Amino Acid Metabolism, Inborn Errors↗