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Biomedical subjects

M Rizzotti

Publications and source records attributed to M Rizzotti.

At least 19 recordsLinked to original sources
PubMed1998

Use of Gianturco-Roubin stents for treating abrupt occlusion of unprotected left main stem during elective PTCA.

Abrupt occlusion of the left main during elective coronary angioplasty has a high mortality rate despite emergent surgery. Coronary stents are useful for managing abrupt occlusion during balloon angioplasty, but patients treated with bail-out stenting to obviate life-threatening occlusions are usually operated after stabilization. Two cases of multiple bail-out stenting of the left main as a stand-alone treatment and their long-term follow-up are reported.

Adult↗
PubMed1998

[False left atrial mass caused by hiatal hernia: a clinical case and review of the literature].

Two-dimensional echocardiography is the technique of choice for identifying cardiac masses. Unfortunately, adjacent structures compressing the atrial wall may lead to misdiagnosis. Clinicians should promptly recognize this phenomenon and the related diagnostic features. The case of a 90-year-old woman presenting with a history of recent onset effort dyspnea is described. On transthoracic two-dimensional echocardiography a left atrial mass which closely mimicked an atrial myxoma was evident. A tomographic scan revealed a large sliding hiatus hernia, which was confirmed on traditional radiographic examination. The echocardiographic characteristics of the mass are described in detail, as well as a review of the literature for the purpose of a correct differential diagnosis.

Aged↗
PubMed1996

[The use of a check list for quality assurance of the treatment of acute myocardial infarction in the coronary care unit].

UNLABELLED: The implementation of Quality Assurance programs for the treatment of acute myocardial infarction in the Cardiac Intensive Care Unit may be specially important. In fact several therapeutic options are available in these patients, and delay in treatment must be as short as possible. A Quality Assurance program has been started in our center with a registry of all patients admitted within 24 hours of onset of acute myocardial infarction. PATIENTS AND METHODS: The following data were recorded: 1) indicators of Organization: pathway to admission, pre-hospital and in-hospital delay; 2) Process Indicators: duration of hospital stay, initial choice of therapy (conservative, intravenous lysis, primary angioplasty), and further diagnostic and interventional procedures; 3) Outcome Indicators: mortality and complications during admission, and 6-12 months follow-up. RESULTS: Since february 1994 to August 1995, 211 consecutive patients were included in the registry; 156 were male, mean age 66 years. Mean pre-hospital delay was 286 minutes. Admission was decided by a physician in 99 cases and by the patient him/herself in 112 cases; pre-hospital delay was 390 min. In the former group, and 194 min. In the latter (p < .001). Mean in-hospital delay was 61 minutes. Conservative treatment, intravenous lysis, and primary angioplasty were chosen by the attending cardiologist in 89 patients (group A), 69 patients (group B), and 53 patients (group C) respectively. The latter group included patients with highest risk on the basis of clinical and electrocardiographic characteristics. In-hospital mortality was 17, 7 and 9% In the 3 groups, respectively. An echocardiogram and coronary angiography were performed before discharge in 81% and 57% of patients, respectively. The mean duration of hospital stay was 11 days, irrespective of the initial therapeutic choice. CONCLUSIONS: A registry for patients with acute myocardial infarction provides information which is essential in the evaluation of therapeutic protocols; it may also help in improving the cooperation between the Emergency Department, the attending cardiologists, and the family physicians.

Aged↗
PubMed1994

[Experience in primary prevention of cardiovascular risk factors in children].

Pathologic studies have shown that atherosclerosis may already be present in childhood as reversible fatty streaks in the aortic intima. These findings are directly related to total serum cholesterol and inversely related to serum HDL cholesterol. This study was aimed at screening children and young adolescents of Novara for cardiovascular risk factors and achieving a specific health educational program. We screened a sample of 2560 children and young adolescents aged 10 to 16 years (mean 12) for known family history of cardiovascular diseases and hyperlipidemia, blood pressure values, serum cholesterol fractions and triglycerides. Of the 2560 children, 786 were considered at risk according to pre-defined cutoff points for systolic BP (> 120 mmHg) 10.6%, diastolic BP (> 80 mmHg) 3.4%, total serum cholesterol (= > 160 mg/dl) 18.7%, serum HDL cholesterol (< 40 mg/dl) 49.5%, total serum cholesterol/HDL ratio (> 4) 28.0%, and triglycerides (> 150 mg/dl) 3.7%. Parents were invited to change family lifestyle according to a specific health educational program, which included advice about diet and physical activity. All children at risk were re-examined 1 year later. Mean values of total serum cholesterol (129 +/- 26 vs 143 +/- 30, p < 0.001), triglycerides (86 +/- 28 vs 91 +/- 32, p < 0.01) and total serum cholesterol/HDL ratio (3.7 vs 3.8, p NS) were found to be lower than at index evaluation. The distribution of total cholesterol curve shifted to the left, and the high risk cases (total serum cholesterol > 200 mg/dl) lowered from 56 to 24 at the follow-up evaluation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Cartilage chips synthesized with fibrin glue in rhinoplasty.

A new type of cartilage graft that is synthesized from cartilage fragments minced by our instrument and mixed with fibrin glue is described. This new material is useful when particular grafts are required in primary or secondary rhinoplasty.

Cartilage↗
PubMed1986

Axiomatization of genetics 2. Formal development.

When certain assumptions are claimed to "found" a scientific theory, two kinds of controls are needed: it must be proved that every assertion of the theory is derived from the assumptions and that no assumption depends on (that is, derives from) the other ones. The formal approach (when possible) is the best method of achieving these results. In this paper the axiomatization of the elementary laws of genetics considered in Rizzotti & Zanardo (1986) is translated into a formal language and an axiomatic theory is defined in which the (translated) laws are deducible. Independence results are also considered.

Chromosomes↗
PubMed1986

Axiomatization of genetics. 1. Biological meaning.

Axiomatization is a trend in science to settle and reduce fundamental assertions, from which all the others are deducible. Classical genetics has been extensively axiomatized and formalized by Woodger (1952), who resorted to 53 axioms and 12 theorems. The molecular settlement of modern genetics provides the basis for a different axiomatic theory. In this paper 3 axioms and 14 theorems are informally expressed. They cover a few elementary laws of "chromosome genetics" in Eukaryotes. The biological problems connected with the further development of this first attempt are discussed.

Cells↗
PubMed1986

The effect of extracellular matrix modifications on UDP-glucose dehydrogenase activity in cultured human skin fibroblasts.

The effect of modifications of the extracellular matrix on the biosynthesis of glycosaminoglycans was investigated in human skin fibroblast cultures by studying UDPGDH activity in order to evaluate: a), the histoenzymological and biochemical modifications induced by chondroitinase ABC treatment (new experimental conditions were developed in order to obtain minimum cell damage); b), the reversibility of these modifications; c), the effect of growing the cells in the presence of chondroitinsulfate; d), the specificity of the modifications induced. The results demonstrated that our experimental conditions specifically affected intracellular UDPGDH activity. Chondroitinase ABC treatment induced a reversible increase of UDP-glucuronic acid synthesis. On the contrary, the presence of chondroitinsulfate in the growth medium completely inhibited UDPGDH activity.

Carbohydrate Dehydrogenases↗
PubMed1984

Influence of GABA on anaphylactic histamine release in vitro.

In this preliminary report an unreported inhibitory action of GABA on anaphylactic reaction has been described. In a functional model (Schultz-Dale reaction) GABA has been demonstrated to inhibit the antigen-evoked contraction. This effect depends on a modulation of anaphylactic histamine release. The phenomenon is dose-dependent and requires a period of time to develop. Since GABAergic neurons are present in the preparation, it is possible to speculate that GABA receptors are involved in this inhibitory action. However, pharmacological analysis of the phenomenon has to be carried out, especially in view of the latency of GABA to develop its effect.

Anaphylaxis↗
PubMed1980

The endocrine cells of the pyloric glands of adult ox.

As part of a project to identify the endocrine cells ("EC" and "APUD" series) of the gastroenteric apparatus of ruminants, the ultrastructure of the mucosa of the pyloric glands of adult ox was studied morphologically and cytochemically, in parallel with a light microscope histochemical analysis. The results show that: the "EC" cells (producing 5-HT) are recognizable by their secretory granules which are heavily osmiophilic, argentaffin ("Masson") and argyrophilic ("Grimelius"). A further distinction is possible on the basis of their morphological features: the ""EC" cells of the gastric type (which belong to the "ECn" group) contain granules fairly homogeneous in shape and size, while the "EC" cells of the intestinal type (or "EC1") show granules which are more pleiomorphic and variable in size. Of particular interest is the presence in some cells of granules typical of the "EC" cells of the intestinal type, in the vicinity of a few others, which appear quite similar to those of the adjoining exocrine cells; the "G" cells (gastrin producing) contain medium sized granules, which are unreactive to "Masson" and poorly argyrophilic. Their morphology is rather diverse; some of them (these are the "typical" cells) have a granular and weakly electron dense content, others (which we consider "atypical") show a homogeneous and heavily osmiophilic core, with an eccentrical empty area. Also present are granules whose appearance is intermediate and empty vesicles; the "D cells" (somatostatin producting) show round, medium sized granules which have a granular, moderately osmiophilic core, tightly encircled by the membrane. These granules are unreactive to "Masson" and to "Grimelius"; the "D1" cells (whose function is yet unclear) contain small, round granules whose core is variously but discretely electron dense and not always homogeneous; they are unreactive to "Masson" and fairly argyrophilic. These granules may be numerous and packed, or scarce; in this latter instance the few granules are intermingled with variously running tufts of parallel filaments, thus resembling the "P" cells, whose function is still undefined. These data show therefore that the types of endocrine cells we have identified in the pyloric glands of adult ox correspond to those described in other mammals; "X" and "F" or "PP" cell appear to be lacking.

APUD Cells↗
PubMed1980

The endocrine cells of the proper gastric glands of adult ox.

Unlike histochemical analysis, which permits only the certain identification of "EC" cells, an ultrastructural study on the bovine proper gastric glands shows the presence of "EC" cells of the gastric type, "ECL" and "D1" cells with the usual characteristics of their respective secretory granules. There are besides other cells whose granules show morphological and cytochemical characters resembling those of the "X" cells. All these endocrine cells are lacking in luminal connection and appear to be sorrounded by a folding of the cytoplasm of one or two exocrine cells, the most commonly being the parietal cells. We cannot identify the "A" cells: their absence may be a morphological confirmation of the lack of extractable glucagon in bovine abomasum. The ultrastructural analysis, therefore, enables us to emphasize in this species a correspondence with the proper gastric glands of the monogastrics.

Abomasum↗
PubMed1979

The endocrine cells of the rectum of adult ox.

In order to identify the endocrine cell types in various parts of the Ruminant gut, we have applied ultrastructural, both morphological and cytochemical, techniques, in parallel to the histochemical ones, to study the rectal mucosa of the adult Ox. In these studies we show that: "EC" cells, of the intestinal type, contain predominantly pleiomorphic granules, which are very electron dense and heavily reactive to "Masson" and "Grimelius" methods; "L" cells are recognizable by their numerous granules, which are fairly homogeneous in shape and osmiophilia. They do not react with "Masson" and are weak or negative to Grimelius s reaction. These granules occur near to others that are less dense, unreactive to "Masson", and that contain an argyrophilic matrix, with an eccentric electron dense core, which does not react with silver; "F-like" cells contain granules which are variable in shape, size and osmiophilia. They are unreactive to "Masson" and weak or unreactive to Grimelius silver; "H" cells contain few, small and uniformly osmiophilic granules. These are unreactive to "Masson" and uniformly reactive to "Grimelius". Our data suggest that the morphology, frequency and distribution of the cell types we have identified in the mucosa of the bovine rectum correspond with those reported in large intestine and rectum of Monogastrics, as by other authors described.

APUD Cells↗
PubMed1979

The endocrine cells of the rectum of adult ox.

In order to identify the endocrine cell types in various parts of the Ruminant gut, we have applied ultrastructural, both morphological and cytochemical, techniques, in parallel to the histochemical ones, to study the rectal mucosa of the adult Ox. In these studies we show that: "EC" cells, of the intestinal type, contain predominantly pleiomorphic granules, which are very electron dense and heavily reactive to "Masson" and "Grimelius" methods; "L" cells are recognizable by their numerous granules, which are fairly homogeneous in shape and osmiophilia. They do not react with "Masson" and are weak or negative to Grimelius's reaction. These granules occur near to others that are less dense, unreactive to "Masson", and that contain an argyrophilic matrix, with an eccentric electron dense core, which does not react with silver; "F-like" cells contain granules which are variable in shape, size and osmiophilia. They are unreactive to "Masson" and weak or unreactive to Grimelius silver; "H" cells contain few, small and uniformly osmiophilic granules. These are unreactive to "Masson" and uniformly reactive to "Grimelius". Our data suggest that the morphology, frequency and distribution of the cell types we have identified in the mucosa of the bovine rectum correspond with those reported in large intestine and rectum of Monogastrics, as by other authors described.

APUD Cells↗
PubMed1977

Osteogenesis imperfecta: morphological, histochemical and biochemical aspects. Modifications induced by (+)-catechin.

Two patients affected with two different forms of Osteogenesis Imperfecta were examined in order to study collagen and glycosaminoglycans (GAGs) in skin and iliac crest cartilage. A sharp decrease of the galactosamine to glucosamine ratio due to a reduced content of chondroitin sulfate was evidenced in both patients. Moreover the structure of proteoglycans appeared altered, this being more evident in the severe form of the disease. Morphological examination in light and electron microscopy of cartilage of the less severely diseased patient showed that GAGs in the extracellular matrix did not present regular connection with collagen fibers. Chondrocytes, elongated and disorderly scattered, showed large lipidic inclusions and, on histochemical basis, were devoid of UDPG dehydrogenase activity. Treatment with (+)-catechin produced an improvement, in both patients, of the biochemical pattern of collagen and GAGs. Similarly a shift of the cellular activity and of the matrix morphology towards normality was observed in the investigated cartilage of the less severely affected patient.

Adolescent↗