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Biomedical subjects

M Mariani

Publications and source records attributed to M Mariani.

At least 271 records · Page 15Linked to original sources
PubMed1983

Diagnostic value of the glycerol lysis test.

The diagnostic value of the standard glycerol lysis test (GLT) has been evaluated by studying 95 cases of hereditary spherocytosis (HS), 513 beta- and 25 alpha-thalassemia trait (Th) carriers, 170 iron-deficient patients (ID), and 217 patients with miscellaneous hematological conditions. The sensitivity of the test, at 95% specificity, was 97% for beta-Th, 53% for ID, and only 36% for HS, so that the predictive value of a positive result is practically nil for HS, 50% to 85% for Th, and 10% to 35% for ID, depending on the prevalence ratio of the disease in the examined population. The technical variability of GLT, explored by a proper experimental design, was found to be rather high, its main components being repeatability and variability of reagent preparations. The dependence of the results on operators was negligible. It is concluded that GLT is not suitable as a laboratory test for the detection of abnormalities in red cell osmotic fragility because of its very low sensitivity toward increased fragility. For decreased red cell osmotic fragility, the sensitivity of GLT is high; however, it is less valuable than the traditional 0.35% NaCl method as mass screening test for the detection of beta-Th, giving more false positive results.

Analysis of Variance↗
PubMed1982

Phosphofructokinase (PFK) deficiency due to a catalytically inactive mutant M-type subunit.

A case of M-type PFK deficiency due to the synthesis of a structurally abnormal and catalytically inactive M-subunit was reported. PFK activity was reduced (39% of normal) in red cells, normal in leukocytes and platelets, and absent in muscle. The red cell enzyme was not inhibited by antiserum to human muscle PFK and displayed normal biochemical properties (Km for ATP and fructose-6-phosphate, storage stability at +4 degrees C and -80 degrees C, optimum pH, electrophoretic pattern and molecular weight). The complete lack of PFK activity in muscle was confirmed on both histological preparations and muscle extracts. Double immunodiffusion analysis using an antinormal M-PFK serum revealed that the enzyme molecule was present and immunologically identical with normal, although it was catalytically inactive. The muscle abnormality was also confirmed by electromyography, ischemic exercise testing, histochemistry and electron microscopy. Moreover, PFK activity was investigated in myoblast cultures maintained up to 25 days, and it was found to be absent.

Erythrocytes↗
PubMed1982

Acute hemodynamic effects of Brescia-Cimino arteriovenous fistula for hemodialysis.

In ten uremic patients, who were not yet undergoing periodic hemodialysis and in whom we were creating a 1 cm, distal, side-to-side arteriovenous fistula of Brescia-Cimino type for hemodialysis, the acute hemodynamic changes of the systemic and pulmonary circulations were studied immediately after the opening of the fistula. An increase in cardiac output (Q) was observed in one patient, the other patients showing either no change or a slight reduction. In the four patients in whom the Q decreased there was a significant reduction of total blood volume (TBV) and stroke volume (SV) and an increase in systemic vascular resistance (SVR) (p less than 0.05, p less than 0.05, p less than 0.01 respectively). At the level of pulmonary circulation, in these patients a decrease in pulmonary blood volume (PBV) (mean = 20%) and a significant increase in pulmonary vascular resistance (PVR) were also observed. In five patients who had been on chronic hemodialysis and who presented the clinical picture of cardiac failure, the acute hemodynamic changes following temporary closure of the fistula (by a sphygmomanometer) were studied: a significant decrease (p less than 0.05) in Q, TBV and SV was observed. The difference between the two values of Q (i.e. fistula open and closed) was considered to indicate the magnitude of the flow across the fistula.

Adult↗
PubMed1981

A modified 'low pH' lignocaine method to isolate human monocytes: a comparison with other separation procedures.

A modified 'low pH' lignocaine method for the recovery of human monocytes from untreated plastics is described and compared with other adherence separation procedures, viz. mechanical scraping by a rubber policeman, microexudate-coated plastic method and pretreatment of plastics by the fetal calf serum (FCS). Monocytes separated by each of the above-mentioned techniques carried out in parallel were characterised by morphological and functional criteria: non-specific esterase staining, contamination by T- and B-lymphocytes, viability, adherence, neutral red uptake, phagocytosis of yeast particles, random mobility, chemotaxis, and tumoricidal activity both in the absence and in the presence of interferon and lymphokines. The 'low pH' lignocaine method appears to be a simple and reproducible technique for the isolation of human monocytes. It seem preferable to other adherence procedures inasmuch as it yields viable, pure and functionally intact monocytes without requiring preconditioned plastics.

Blood↗
PubMed1980

The first stable variant of erythrocyte glucose-phosphate isomerase associated with severe hemolytic anemia.

A new variant of glucosephosphate isomerase (GPI) associated with hemolytic anemia, mental retardation, and muscular hypotonia is described. The defective enzyme showed increased affinity for fructose-6-phosphate (F-6-P), decreased affinity for glucose-6-phosphate (G-6-P) altered electrophoretic and isoelectrofocusing patterns, and shift to the left of the precipitin curve. The enzyme was stable under all the conditions tested (heat, urea, guanidine-HCl, and storage). Optimum pH, Ki for 6-phosphogluconic acid (6-PGA) and for erythrose-4-phosphate (E-4-P), molecular weight, GPI-related antigen concentration, immunodiffusion pattern, and immunoinactivation were in the normal range. This is the first example of the association of a stable mutant GPI with severe hemolytic anemia. Enzyme instability has been present in all previously reported cases.

Anemia, Hemolytic, Congenital↗
PubMed1980

Metabolic impairment and membrane abnormality in red cells from Huntington's disease.

The following aspects have been investigated in 10 patients affected by Huntington's disease )HD): --extensive haematological investigations; --red cell enzyme activities and level of the most important glycolytic intermediate compounds; --protein, lipid and carbohydrate composition of the erythrocyte membrane and membrane polarity; --effects of in vitro aging on red cell membranes. Lack of 4.5 protein band in SDS-PAGE and 14-fold decrease in membrane-bound catalase were found in the in vitro aged red cells from the 10 HD patients examined. Na+ + K+ATPase was slightly higher than normal in all the patients. Red cells from 5 out of 8 patients showed a decrease in reduced glutathione and phosphoenolpyruvate levels and/or an increase in hexokinase, glucose-6-phosphate dehydrogenase, pyruvate kinase and glutathione reductase activities. The haematological investigations, the protein lipid and carbohydrate composition of the fresh red cells, the membrane polypeptide aggregates and the membrane polarity evaluated by microspectrofluorometric analysis were normal.

Acetylcholinesterase↗
PubMed1980

Quantitative evaluation of the regional left ventricular function in normal subjects by means of cineangiocardiography.

A method for analysing left ventricular cineangiograms is described, which not only provides information on the overall ventricular performance, but also evaluates the regional contraction of the left ventricle and the related haemodynamic patterns. This simplified Chapman's method (slice method) makes it possible to calculate the end-diastolic, end-systolic volumes, the stroke volume and the ejection fraction of the zones into which the left ventricle is divided by a longitudinal and by three transverse axes, according to Herman's technique. The hemiventriculograms of 21 normal subjects in the AP projection were evaluated using this method and a 10 of them were also studied in RAO projection. A uniform left ventricular contraction pattern was found for three hemiventricles outlined by the anterolateral, lateral, and postero-medial walls (ejection fraction 71.7 +/- 5.1%, 71.6 +/- 5.9%, 70.4 +/- 5.1%, respectively), the regional and zonal ejection fraction (EFR, EFZ) being similar in both projections. The ejection fraction of the hemiventricle outlined by the septal wall was, however, lower (65.6 +/- 6.0%). The standard zonal function curves of the left ventricle in normal subjects was then calculated on the basis of the results obtained, in order to assess, by comparison, zonal function abnormalities in cardiac patients.

Adult↗
PubMed1980

[The precoronary times in myocardial infarction: report of 80 cases observed in a country town (author's transl)].

The Authors intended to verify if in a CCU in a Hospital in a country town, the precoronary times were different from those pointed out in the series of cases relatives to the Hospitals of a big town and if the possible remark of different times is liable to be translated into different epidemiologic results. The remarks have been effected on 80 patients affected by acute myocardial infarction; the average of the precoronary time resulted into 13h,43', slightly lower than that observed in the other Hospitals in Lazio. Particularly the 27,5% of the patients was admitted into the Hospital within one hour from the onset of their symptoms and the 65% within six hours, which shows an hospitalization in the very early period. Though in this group dangerous arrhythmias (ventricular fibrillation included) have been observed frequently, it has not been remarked a mortality greater than in other series of cases, and explains the high mortality for arrhythmia observed in our series of cases (21,4% of all deaths), considering the high frequency of dangerous arrhythmias (V.F. included) noticed in the first hours of myocardial infarction.

Arrhythmias, Cardiac↗
PubMed1979

[Clinical, hemodynamic and cineangiocardiolographic findings in congestive cardiomyopathy].

Sixteen patients affected by congestive cardiomyopathy were studied by means of right and left cardiac catheterization and cineangiocardiography. Cardiac output and mean pulmonary circulation time were determined by the radiocardiographic method. Left ventriculograms were obtained in all the patients in the 45 degrees RAO projection; the left ventricular end diastolic and end systolic volumes were calculated both by the area-length and by the slice method. Among the several hemodynamic data (stroke index, mean pulmonary circulation time, left ventricular end diastolic pressure, left ventricular volumes and ejection fraction) the most early impaired and therefore usefull for an early diagnosis, were: the left ventricular end-systolic volume, the left ventricular end-diastolic volume and the left ventricular ejection fraction.

Adolescent↗
PubMed1978

Secondary treatment of fractures of the middle and lower third of the tibia unsuccessfully treated by primary internal fixation.

The authors present forty six cases, referred to us between 1969 and 1974, of fracture of the middle and lower thirds of the tibia, previously treated elsewhere by primary internal fixation using a plate and screws. The causes of failure are divided into defective indications and defective technique. The methods of treatment used in infected and non-infected lesions are described. They criticise the unnecessary use of plates and explain their reasons. They do not condemn the method outright, since in selected cases IT IS UNDOUBTEDLY A VALID METHod of treatment. They are opposed, however, to its indiscriminate use for lesions that may perfectly well be cured, with the minimum risk, either by conservative methods, or by intramedullary nailing.

Fracture Fixation, Internal↗
PubMed1977

[The quantitative cineangiography. Part II. Computerized analysis of the left ventricular volumes in man (author's transl)].

The values of left ventricular volumes (EDV and ESV) were determined in 35 patients with various heart diseases by computerized reading technique utilizying both the area-length and the slice methods. The data thus obtained were compared both with those derived manually and with those obtained following injection of 113mIn into the left ventricle and monitoring by external counting the dilution curve. Good agreement among the data obtained by the various methods was found. It appears, then, in the clinical practice, the computerized method has definite advantages over the others since it allows quick determination of the data and therefore examination of multiple frames.

Adolescent↗