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Biomedical subjects

I Zini

Publications and source records attributed to I Zini.

At least 73 records · Page 4Linked to original sources
PubMed1983

Prosthetic auricular reconstruction.

Large lesions may necessitate resection of critical amounts of auricle, such that surgical reconstructive efforts may prove to be futile. We favor the prosthetic rehabilitation of patients requiring near total auriculectomy. Fifteen patients seen for the treatment of auricular lesions from 1976 to the present were reviewed. Near total auriculectomy with postoperative prosthetic management provided satisfactory functional and aesthetic results. This presentation will highlight the significant technical features of the surgical ablation and subsequent prosthetic management of patients with tumors of the auricle, such that postoperative rehabilitation will be facilitated.

Aged↗
PubMed1983

Evidence for the existence of receptor--receptor interactions in the central nervous system. Studies on the regulation of monoamine receptors by neuropeptides.

Substance P (SP) (10(-8) M) can rapidly reduce the affinity and increase the density of 3H-5-HT binding sites in spinal cord membranes. CCK-8 and CCK-4 (10(-8) M) can rapidly and differentially change the characteristics of 3H-spiperone striatal binding sites linked to DA receptors of the D2 type. CCK-4 increase and CCK-8 reduce the number of striatal binding sites for 3H-spiperone, indicating for the first time separate CCK-4 binding sites. CCK-4 (10(-8) M) but not CCK-8 (10(-8) M) can rapidly reduce the affinity and increase the number of the 3H-spiperone binding sites linked to 5-HT receptors of the dorsal cerebral cortex of rats. CCK-8 (10(-8) M) only produces a trend for a small increase in the Bmax values of these receptors. These results again imply the existence of separate CCK-4 binding sites in this case in the cerebral cortex. Glutamate (10(-6) M), but not N-methyl-D-aspartate (10(-6) M) can rapidly change the characteristics of the 3H-N-propylnorapomorphine (3H-NPA) binding sites in striatal membranes of rats. Glutamate (10(-6) M) increases the density and especially reduces the affinity of the 3H-NPA binding sites, which label D2 and D3 types of DA receptors. Taken together the present findings give evidence that neuropeptide receptors and glutamate receptors can in vitro rapidly modulate the characteristics of different types of DA and 5-HT receptors by way of receptor--receptor interactions at the comodulate level or at the local circuit level. It is hypothesized that these receptor--receptor interactions are of importance for the encoding of short-term memory.

Animals↗
PubMed1982

A new approach to quantitate the density and antigen contents of high densities of transmitter-identified terminals. Immunocytochemical studies on different types of tyrosine hydroxylase immunoreactive nerve terminals in nucleus caudatus putamen of the rat.

By means of a semi-automatic image analyzer plugged into an Apple II computer and suitable computer programs it is possible to analyze transmitter-identified nerve terminals. Thus, a densitometric approach is applied on the original photograph followed by systematic sampling which is carried out by means of a grating of circles. This procedure allows the study quantitatively of density and intensities of different types of densely packed tyrosine hydroxylase (TH) immunoreactive nerve terminals of the nuc. caudatus putamen. It is shown that the islandic TH immunoreactive nerve terminals have a higher density, but a TH content similar to the diffuse types of TH immunoreactive nerve terminals in the nuc. caudatus putamen.

Animals↗
PubMed1982

Principles for the morphological characterization of transmitter-identified nerve cell groups.

Principles for a morphometric description of transmitter identified nerve cell groups have been introduced, exemplified on the 5-HT nerve cell group of nucleus raphe dorsalis (B7 cell group), using immunocytochemical procedures to visualize 5-HT. Both cell body parameters (mean diameter, mean perimeter, mean area, shape factor) and cell group parameters (number of cells, mean free distance among cells, volume fraction, gravity centre, major axis slope with respect to the midline) have been considered. These parameters have been obtained by the use of a semiautomatic image analyzer (Kontron MOP AMO2) plugged into an Apple II computer. By the use of this system and of suitable computer programs, it is possible to give a Cartesian representation of 5-HT nerve cell bodies in a coronal section under study. The present work has mainly one aim. To detect whether subgroups exist within a transmitter-identified cell group. Two approaches have been introduced to obtain, on objective grounds, evidence whether or not a group consists of subgroups. The first of these approaches is based on differences in cell body density within the cell group, while the second approach is based on frequency distribution analysis. This second approach is mainly sensitive to shape changes of the cell group.

Animals↗
PubMed1982

Neuroanatomical methods for the quantitative evaluation of coexistence of transmitters in nerve cells. Analysis of the ACTH- and beta-endorphin immunoreactive nerve cell bodies of the mediobasal hypothalamus of the rat.

A new statistical approach has been introduced to study in a quantitative way the coexistence of two neuromodulators in nerve cell bodies. The method has been exemplified on the ACTH-like and beta-endorphin-like immunoreactive nerve cell bodies of the mediobasal hypothalamus demonstrated by means of indirect immunofluorescence methodology. The method is based on the analysis of 3 adjacent sections which, in a random way, are stained with antiserum against neuromodulator 1, against neuromodulator 2 and with antisera against both neuromodulator 1 and neuromodulator 2. It could be shown that some neurons of the mediobasal hypothalamus do not contain at a detectable level both ACTH- and beta-endorphin-like immunoreactivity. The present method also involves an analysis of the two nerve cell groups by means of a morphometric procedure to collect additional information on the extent of coexistence. Thus, by this approach the gravity centers of the two cell groups can be calculated. The distances between the two gravity centers of the ACTH and beta-endorphin positive cell groups were significantly different at certain levels. The present method offers unique possibilities in increasing our understanding of the functional significance of coexistence of neuromodulators in one and the same nerve cell body since it makes possible a quantitative evaluation of coexistence. The usefulness of the present method is illustrated by the findings of a possible differential synthesis of ACTH- and beta-endorphin-like material in certain cell bodies of the mediobasal hypothalamus.

Adrenocorticotropic Hormone↗
PubMed1981

Theoretical implications of tolerance development in DA, ACh and GABA turnover after neuroleptic chronic treatment.

A theoretical model is introduced by which the tolerance to the increase in the dopamine turnover rate produced by neuroleptics both at cell body and nerve terminal levels is analyzed according to the principles of control theory. Thus, it is shown that tolerance development does not rule out the possibility that the therapeutic action of neuroleptics may be exerted at the level of that dopamine projection.

Acetylcholine↗
PubMed1980

Aspects on receptor regulation and isoreceptor identification.

The present paper introduces a classification of receptor regulation. This classification takes into consideration especially the type of regulation (homoregulation vs. heteroregulation) and the biochemical mechanisms subserving the regulation process. Furthermore, criteria for isoreceptor identification are introduced on a quantitative basis, that is by means of comparisons of ED50 values obtained, using a certain agonist, for the different responses triggered by the binding of the ligand with the respective class of receptors. Finally, a possible case of isoreceptor interconversion is extensively discussed and a model for such an interconversion is suggested.

Binding Sites↗
PubMed1978

Universal simplified mold technique for construction of facial prostheses.

This article presents a simple procedure for the construction of facial prosthesis. The use of a split mold lined by silicone 382 is recommended. Pertinent information concerning impression making, sculpturing, coloring, and processing to insure esthetically and functionally accepted prostheses is presented.

Adhesives↗