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Biomedical subjects

G Bernocchi

Publications and source records attributed to G Bernocchi.

78 records · Page 5Linked to original sources
PubMedDate not supplied

Tissue damage after acute intoxication by polychlorinated biphenyls in cockroaches.

It is common knowledge that polychlorinated biphenyls (PCBs) represent a serious threat to the health of both vertebrates and invertebrates. As far as the former are concerned, especially as regards human beings, a broad literature describes the direct and indirect effects induced by the PCBs on their systems and organs. Among invertebrates, the information available is mostly related to arthropods and is, however, very scarce. The aim of this work was to evaluate the effects of polychlorinated biphenyls (PCBs) on tissues and organs of individuals belonging to a species of Blattaria (Blattella germanica) treated with various doses of this toxic material. The pathologies found became more serious as the dosage increased and were present throughout the entire digestive system, in the fat body and in the male gonads: in these areas cell and tissue breakdown and severely damaged spermiogenesis were observed. In particular, the testes, Malpighian tubules and fat body accumulated an amorphous basophilic PAS-positive substance. Furthermore, the NOS-dependent NADPH diaphorase activity pattern in the retina and optic lobes was more evident in the treated than in the control insects.

Animals↗
PubMedDate not supplied

Inhibitory cerebellar circuits: GAD immunoreactivity in the frog cerebellum.

The presence of GABAergic structures in the frog cerebellum with simple nervous circuits was investigated with an immune serum raised against glutamic acid decarboxylase (GAD). GAD immunoreactivity is detectable in all the cerebellar layers. The most obvious difference in comparison with mammals is the scarcity of GAD-positive terminal boutons on Purkinje cells and this is consistent with neurophysiological data indicating that the inhibition on frog Purkinje cells is weaker than in mammals. However, there are numerous GAD synapses on cerebellar and vestibular nuclei. A large number of GAD immunoprecipitates are present in the molecular and granular layers, though their morphological organization is different from that in mammals. In the upper part of the molecular layer GAD immunoreactive cells and fibres form a plexus-like structure and in the internal granule layer immunoreactive varicosities are not arranged in the ring-like assemblies of mammals.

Animals↗
PubMedDate not supplied

The action of cisplatinum (cis-DDP) on the postnatal growth of the rat liver. Cytokinetics and ultrastructural studies.

The early and late effects of cis-DDP treatment on liver cell kinetics were analyzed after its intraperitoneal injection into 17-day old rats. Frequency of binucleate hepatocytes, cellular DNA content distribution, 3H-thymidine labelling and ultrastructure of the nuclei were analyzed. Two days after treatment, a block of mononucleate hepatocytes in the S phase and in the G2 phase was demonstrated by the increase of intermediate 2c-4c and 4c DNA values in the absence of changes in 3H-thymidine labelling; 8c binucleate cells, which are essential for the formation of tetraploid mononucleate cells, were not found. In cell nuclei, large areas of more condensed chromatin appeared, perhaps providing further evidence for a G2 block. Seven days after treatment, there was a tendency to catch up with the normal situation, as shown by the unblocking of the S phase in mononucleate cells indicated by both cytophotometry and autoradiography. The presence of 8c binucleate cells and 4c-8c mononucleate cells indicates that 4c mononucleate hepatocytes are either diploid cells in the G2 phase or true tetraploid G1 cells. The decrease in the heterochromatin areas and the appearance of hypertrophic nucleoli demonstrate an increase in the metabolic activity of the nuclei. Thirty six days after treatment, the incidence of different DNA hepatocyte classes and the 3H-thymidine labelling were already similar in control and in treated rats.

Aging↗
PubMedDate not supplied

Alteration of complex IV and acetylcholine-related enzymes in experimental spinal cord injury.

Acute, severe injury of the rabbit spinal cord, induced by the weight-drop method, causes alterations of the enzyme activities related to cholinergic and energy metabolism. Morphological examinations at the trauma site show degenerative processes in neurons 0.5 hr posttrauma and a marked decrease in the number of living cells 24 hrs later. Both biochemical and cytochemical findings show that the tissue metabolic and morphologic derangement, caused by severe spinal cord injury, is mostly confined to the gray matter at an early stage (0.5 hr), whereas 24 hrs later the white matter is also involved. The decrease in choline acetyl-transferase and acetylcholinesterase activities in the gray matter parallels the impairment of complex IV (cytochrome c oxidase) of the respiratory chain and the presence of morphological alteration in neurons. The dramatic drop in the enzyme activities, observed 24 hrs after the induction of the severe trauma is clearly associated with the loss of cells.

Acetylcholinesterase↗