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Biomedical subjects

E Mariani

Publications and source records attributed to E Mariani.

At least 127 records · Page 7Linked to original sources
PubMed1980

[Separation and characterization of human T G and T M lymphocyte populations].

During the last few years a number of experimental evidences have shown the presence of Fc receptors for IgG or IgM on the membrane of human T cells. These two different receptors are detectable and mutually exclusive on distinct cell populations named respectively TG, TM and T "null" (which lack detectable receptors). Studies on the functional activities of these cells have shown that TM and TG lymphocytes play an antitetical role in regulating B cell response, TM exerting an "helper" activity on the differentiation of B lymphocytes while TG having a "suppressor" one. The aim of this study has been to determine the values of these two subpopulations in a group of twenty control subjects. Our results have shown that TG constitute 10%, whereas TM represent 40% of the total T cells. After EA-G rosetting, the purification of this subpopulation on a density gradient has shown an enrichment of more than 90% in TG cells, while TM contaminate this fraction for less than 4%. The purity of the fraction containing TM has been evaluated using the localization of alpha-naphthyl acetate esterase activity, which has shown that more than 88% of the cells in this fraction are positive for this enzyme.

Adult↗
PubMed1980

A circuit for safe diagnostic electrical stimulation of the human brain.

An electronic circuit for controlled electrical stimulation of the human brain has been designed to optimize safety in charge transfer from electrodes to brain and to eliminate the likelihood of unwanted currents from the neurostimulator resulting from component failure. The circuit schematics feature the following designs: (1) a highly accurate and versatile rate generator 0.5 p.p.s. to 99 in increments of 0.5 p.p.s., (2) symmetrically-biphasic lead and lag pulses of 100 musec duration, (3) photo-isolated driver amplifiers with accurate waveform, reproduction, (4) true biphasic passive-current regulators driven by an isolated battery supply voltage for switch-selectable currents of 0.25 to 5 ma or variable current regulation, (5) accurate current and voltage waveform monitors that isolate the stimulating electrodes from the monitors, and (6) capacity-coupled outputs to guarantee no net D.C. component at the end of each biphasic pulse. Relay-switching circuits are also shown that allow sequential stimulation and recording from one or several electrodes. This neurostimulator has been in use for over two years without evidence of electrolytic damage at identifiable electrode tips. The utility of simultaneous stimulation of several different electrodes at safe charge levels is described.

Amygdala↗
PubMed1979

[Surface immunoglobulins (SmIg) in human B-lymphocytes: effect of enzymatic digestion].

In order to determine the number of circulating B lymphocytes which can synthetize their surface membrane immunoglobulins, we have evaluated by immunofluorescence their presence before and after enzymatic exposure to pronase. After pronase treatment the majority of lymphocytes carrying SmIg has been disappeared (from 7.8% to 1.9%; p < .0.0005). After 18 hours incubaton only a small proportion (4.6%) of B lymphocytes risynthetized their SmIg. This observation support the hypothesis that a subset of lymphocytes present in the peripheral blood carries on its membrane only cytophilic SmIg and therefore may interfere in the determination of the number of B lymphocytes.

Adult↗
PubMed1979

[Lymphocytotoxicity in alcoholic hepatitis: evalutation of effector cells].

Alcohol induced liver damage has been recently suggested to occur in some cases as a consequence of a true autoimmune reaction. However the nature of the effector cells is still debated. Microlymphocytotoxicity "in vitro" test against rabbit hepatocytes has been performed in 29 patients with alcoholic cirrhosis and 8 with acute alcoholic hepatitis. The diagnosis has been done on clinical and histological grounds. The mean cytotoxicity index (CI) of subjects with alcoholic cirrhosis was 15.12 +/- 14.18 and with acute alcoholic hepatitis 62.49 +/- 16.33 (normal range: 0 -37.90). To further characterize the effector cells in our system, the test has been performed again either using T-enriched fractions of peripheral lymphocytes or after pronase-induced digestion of SmIg of total lymphocytes in 5 patients with acute alcoholic hepatitis and high CI. In both instances a disappearance of citotoxic activity has been observed. These data suggest: a) autoimmune reaction can occur only in patients with acute alcoholic liver damage; b) non T-cells are responsible for cytotoxicity; c) the immune reaction appears to be of cell-mediated antibody-dependent type.

Adolescent↗
PubMed1978

A sample and hold amplifier system for stimulus artifact suppression.

A sample and hold amplifier system has been described which is capable of eliminating stimulus artifacts from a variety of biological recordings which would otherwise be impossible to interpret during electrical stimulation. Factors contributing to the prolongation of stimulus artifact are discussed in relation to the design requirements of this system. The application of this artifact suppression circuit to monitoring EEG seizures during electrical stimulation is demonstrated.

Amplifiers, Electronic↗
PubMed1978

Nitrogen mustards derived from alpha-hydroxymethyleneketones.

alpha-[Bis-(2-chloroethyl)]aminomethyleneketones were prepared starting from alpha-hydroxymethyleneketones and N-(2-chloroethyl)-2-chloroethanamine. Also 3-[2-(2-chloroethylthio)ethyl]aminomethylene-2-bornanone was synthesized from 2-(2-chloroethylthio)ethanamine and 3-hydroxymethylene-2-bornanone. This compound and 3-[bis-(2-chloroethyl]aminoemthylene-2-norbornanone were active against P388 lymphocytic leukemia in mice.

Animals↗
PubMed1977

[The polysaccharide components of the ground substance of the connective tissue in retraction of the palmar aponeurosis (Dupuytren's disease)].

Histochemical methods were employed to study the behaviour of connectival glycoproteins in Dupuytren's disease. Increases were observed in glycoproteins and acid glycosaminoglycans in the sections with higher cell intensity. In segments where fibrosis was more marked, a prevalence of neutral polysaccharides was encountered. A possible role of these alterations in the development of palmar aponeurosis retraction is discussed.

Adult↗
PubMed1977

[Stenosis of the left angle of the colon caused by chronic pancreatitis].

Case of stenosis of the left flexure of the colon caused by pancreatitis is reported. The relevant literature is surveyed and an account is given of the pathogenesis of this forms, and the examinations required in its diagnosis, particularly coloscopy. A preference is expressed for an internal colic derivation (colon-colon anastomosis) rather than resection, on account of the smaller degree of risk involved.

Adult↗
PubMed1977

[Post-traumatic stenosis of the small intestine].

A case of intestinal stenosis in a subject who had received an abdominal injury four weeks earlier is presented. The relevant literature is surveyed and the pathogenesis of this unusual condition is examined. Post-traumatic stenosis of the small intestine is seen as an example of ischaemic stenosis.

Abdominal Injuries↗
PubMed1977

[Semeiology of bronchogenic carcinoma. Limitations of explorative thoracotomy].

Modern methods of semeiological detection of bronchiogenic cancer are discussed in the light of experience gained in a hospital chest surgery centre. Emphasis is laid on the advantages offered by new advances in nuclear diagnosis and bronchial endoscopy. The limitations of exploratory thoractomy are explained. Attention is drawn to the by no means inconsiderable number of cases in which early knowledge of the nature of the process could not be obtained. A series of illustrative cases are presented.

Adult↗