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Biomedical subjects

L Rossi

Publications and source records attributed to L Rossi.

665 records · Page 37Linked to original sources
PubMedDate not supplied

[Plasma levels of diphenylhydantoin (DPH) and phenobarbitone (PB) in epileptic patients resistant to drug treatment (author's transl)].

The Authors present and discuss the results obtained by assaying plasma DPH and PB in 123 patients chronically treated with antiepileptic drugs. The subjects examined were considered resistant to medical therapy and were all at their first laboratory control. The data obtained show: 1) the very poor correlation existing between the doses of drugs administered and their actual plasma levels; 2) the very high percentage of patients with DPH and PB plasma levels not in the therapeutic range of these drugs. The Authors discuss some of the most frequent errors in planning chronic therapy with DPH and barbiturates due to the lack of knowledge of drug blood levels.

Adolescent↗
PubMedDate not supplied

Fibroblasts regulate the migration of MCF7 mammary carcinoma cells in hydrated collagen gel.

We have defined a tissue culture method suitable to study cell-cell interactions in an environmental set close to in vivo conditions. It consists of heterotypic cell populations mixed together inside a collagen gel in a chamber slide for a period of up to 14 days. When the three-dimensional system is saturated, cells will start to move on the plastic surface as monolayers surrounding the gel, with a characteristic speed depending on cell type. Usually fibroblasts move fast, while epithelial cells demonstrate a much lower pace of migration. At any given time gel contraction can be measured, and thus the rate of cell expansion, by knowing the distance from the edge of the gel to the leading edge of cell migration. By using this approach it was found that MCF7 mammary carcinoma cells display a great variety of morphologies following their mixture with different fibroblastic cell lines. In particular, when MCF7 cells were mixed with fibroblasts from human fetus, dog thymus and rat kidney, they migrated up to the leading edge of the fibroblastic front as isolated single cells or as cellular aggregates, many of which became necrotic in time, or took on an elongated morphology. Selective necrosis of MCF7 cells was also induced with serum concentration of 15% and 20% FCS, but only when they were mixed with fibroblasts. No necrosis was induced in MCF7 cells cultured alone. From these observations it is suggested that necrosis may sometimes favor the detachment and infiltration of resistant epithelial tumor cells by increasing their autonomous behaviour. Fibroblasts seem to be instrumental in regulating this process.

3T3 Cells↗
PubMedDate not supplied

[Intraoperative colonoscopy: current indications].

From January 1987 to December 1991, 37 patients underwent intraoperative colonoscopy for several indications; these latter can be summarized in the need to define the site or extension of the lesions treated or detected by endoscopy before surgery. This procedure is therefore necessary in those cases in whom intraoperative endoscopy is likely to be useful in planning the surgical treatment. The use of intraoperative colonoscopy should be however considered complementary, but not substitutive, of the preoperative colonoscopy.

Adult↗
PubMedDate not supplied

[A probabilistic approach to the natural course of liver cirrhosis: a model of interactive simulation].

We propose a computerized mathematical model of the natural history of patients with liver cirrhosis in order to investigate the relationships between the various events that characterize the clinical course of the disease. By means of a rigorously probabilistic approach, the stimulation exposes each hypothetical patient to a series of risks of significant clinical events; whether or not these events occur is determined by preestablished probabilities. Analysis of the effects of arbitrary modifications of these theoretical risks provides useful information on the prospective relevance of the clinical events examined. For example, we compared the simulated follow-up of a population of control cirrhotic subjects with follow-ups of patient groups in whom different degrees of reduction of the risk for gastroesophageal bleeding were postulated on the basis of hypothetical primary or secondary prophylaxis. Our data confirm that the size of the investigated population strongly influences the threshold level of the bleeding-risk reduction able to determine a significant improvement in overall survival. In fact, in large populations (a 6 year follow-up of 3000 cirrhotic subjects), the threshold level was 25% (primary risk) and 45% (secondary risk) with respect to control subjects, while in more limited populations (300 subjects) even a 100% risk-reduction does not seem sufficient to bring about significant improvement in overall survival. Our data may help to explain the different results of controlled trials found in the literature; in fact, only the conclusions arrived at through meta-analysis procedures in large populations have been confirmed.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer Simulation↗
PubMedDate not supplied

Fluconazole prophylaxis and Candida fungemia in neutropenic children with malignancies.

From March, 1990 to February, 1992, we administered fluconazole as antifungal prophylaxis at doses of 3-5 mg/kg/day to 40 patients with prolonged and severe neutropenia following intensive chemotherapy. Fungemia was observed in 3 out 40 patients, and all three of them were due to Candida non-albicans strains: two Candida parapsilosis and one Candida guilliermondi. In vitro sensitivity tests showed that all three isolated strains were susceptible to amphotericin. In one case, Candida guilliermondi was tested for sensitivity to fluconazole and found to be resistant. We conclude that fluconazole prophylaxis proved effective in preventing Candida albicans infections, but it could also contribute to the emergence of Candida non-albicans strains. It might be possible that fluconazole at higher doses could prevent the selection of less susceptible Candida strains.

Adolescent↗
PubMedDate not supplied

[Congestive gastropathy in liver cirrhosis].

Congestive gastropathy has emerged as a new nosological entity that can be included among the complications of advanced liver cirrhosis. It has been defined as the macroscopic changes of gastric mucosa occurring in portal hypertension that are associated with vascular mucosal and submucosal dilatation and ectasia without significant inflammatory changes. The pathogenesis of congestive gastropathy has not been completely cleared up. Many epidemiological and clinical studies and some tests on animals lead most Authors to think that the cause of this disease is a chronic increase of pressure in the portal vascular system. However the involvement of humoral factors cannot be excluded as, for example, the presence of high plasma levels of gastrin and histamine or a decrease of E2 prostaglandin in the gastric mucosa. The macroscopic lesions typical of congestive gastropathy can be seen through endoscopy. Up to now mosaic-like pattern, red points, cherry-red and black-brown spots and erosions have been observed. These changes are prominent in the area near the gastric body and cardias, but can be present in all parts of the stomach. The frequently reported spontaneous bleeding corresponding to cherry-red spots make the presence of these lesions to be considered a sign of severe congestive gastropathy. The prevalence of congestive gastropathy in cirrhotic patients is between 30% and 70%. This condition is more frequent in patients with large esophageal varices and severe liver disease and in patients submitted to endoscopic variceal sclerotherapy. Congestive gastropathy is a frequent cause of acute and chronic bleeding: 10-20% of gastrointestinal bleeding episodes occurring in cirrhotic patients are caused by this condition and about 30% of cirrhotics with portal hypertension will have one or more acute bleeding in a four year follow-up. The percentage of subjects with chronic hemorrhage in the same period can reach 90%. At the moment is not possible to suggest a therapy able to prevent or cure the acute or chronic bleeding associated with congestive gastropathy. beta-blockers seem to be a promising treatment. However, further and larger clinical trials are necessary to settle definitively their efficacy.

Gastric Mucosa↗
PubMedDate not supplied

[Cardiac metastasis of malignant melanoma].

Cardiac metastatic malignant melanoma. Secondary tumors frequently involve the heart, but the main data about incidence, rate and localization into the specialized myocardium are poor and fragmentary. Post-mortem examination of the conduction system of arrhythmic hearts was studied in two cases of malignant melanoma. In the first case signed by AV block and fibrillation, metastases involved the myocardium over atrioventricular (AV) node and the left and right bundle branch (L and RBB). The second case had not arrhythmias in the clinical picture, but a large metastatic mass involved the junctions between sinoatrial (SA) node and myocardium of the crista terminalis, the junctions between atrium and AV node and the left branch.

Aged↗
PubMedDate not supplied

[Ultrasonography in hypertrophic stenosis of the pylorus: clinico-therapeutic implications in borderline cases].

Previous publications attempted to define normal and abnormal ranges in the measurement of pyloric length (L), breadth (D), muscle thickness (S), volume (V) and muscle index (MI). We examined with US 286 patients with suspected hypertrophic pyloric stenosis and investigated all the above diagnostic criteria. Normal and abnormal ranges were in agreement in all five measurements, though less apparent for pyloric volume and muscle index. The patients with borderline values were 46 (16%) for pyloric muscle thickness, 98 (34%) for breadth, 52 (18%) for length, but only 22 (7.7%) for pyloric volume and muscle index. Borderline patients received medical therapy with the antispasmodic drug metaclopramide hydrochloride and they were examined with US after 15 days. Only 8 of 22 borderline patients (36%) developed a typical hypertrophic pyloric stenosis. In the others, pyloric volume was reduced and the symptoms subsided. Pyloric parameters cannot be always measured accurately, but pyloric volume and muscle index measures better distinguish normal from abnormal findings. The formula for pyloric volume calculation is simpler than that for pyloric muscle index calculation and easier to memorize, also because no correction for body weight is necessary.

Humans↗
PubMedDate not supplied

[The expression of transforming and epidermal growth factors in organ cultures of embryonic lungs].

Bronchial branching of the early embryonic lung rudiments (Day 12 of pregnancy) cultivated on polycarbonic millipore TM filters was studied on the total preparations. Each lobe of the embryonic lung of the 12-day embryos has three to four terminal buds. After four days of cultivation, their number increased to 18. Immuno-reactive staining of EGF and its receptor was observed both in the cells lining the primitive airway and in the cells and extracellular matrix surrounding the airway of embryonic lung explants cultivated for four and 10 days on TM and MF filters. Expression of TGF-alpha was co-localized with that of EGF but on MF filters only. This mat be connected with the phenomenon of autoinduction.

Animals↗
PubMedDate not supplied

The conduction system in corrected transposition with situs inversus.

The location and course of the conduction system were investigated by serial section in two hearts with corrected transposition of the great arteries in situs inversus. In the first case, characterized by dextrocardia, the interventricular septum was intact, while in the second case with levocardia, a high ventricular septal defect was associated with pulmonary atresia. In both hearts, a regular posterior connecting AV node was present, left-sided in one case and right-sided in the other. The bundle branches were distributed in the morphologically appropriate ventricles. Extensive hemorrhage and coagulation necrosis of the common bundle and bundle branches were observed in the first case, being consequent upon surgical replacement of the right-sided tricuspid valve. The common bundle ran below the membranous septum in this case. In the heart with ventricular septal defect it was related to the postero-inferior rim of the defect. In both cases, an accessory AV node was located anteriorly in the interatrial septum but did not connect with the ventricular musculature. The different position of the atrioventricular conducting tissue in corrected transposition, between cases in situs solitus and situs inversus, is emphasized.

Atrioventricular Node↗
PubMedDate not supplied

The clinical course of deep-vein thrombosis. Prospective long-term follow-up of 528 symptomatic patients.

BACKGROUND AND OBJECTIVE: In contrast to the extensive documentation on the short-term outcome of patients with acute deep vein thrombosis (DVT) of the lower extremities, little is known about the long-term clinical course of this disease. To determine the clinical course of patients with a first episode of symptomatic DVTn over an 8-year follow-up period. The primary aims were to assess the long-term incidence of recurrent venous thromboembolism and that of the post-thrombotic syndrome. In addition, we determined mortality and evaluated potential risk factors for all these outcomes. METHODS: This was designed as a prospective cohort follow-up study. Consecutive symptomatic outpatients with a first episode of venography proven DVT were treated with an initial course of full-dose (low molecular weight) heparin, followed by at least three months of oral anticoagulants. After discharge, they were instructed to wear compression elastic stockings for at least two years. Follow-up assessments were scheduled at three and six months, and then every six months up to eight years. Diagnosis of recurrent venous thromboembolism was made according to standard criteria. The presence of post-thrombotic syndrome was evaluated using a standardized scale. RESULTS: A total of 528 consecutive patients with a first episode of venography confirmed DVT were included in the study. The cumulative incidence of recurrent venous thromboembolism after two, five and eight years was 17.2, 24.3 and 29.7%, respectively. Malignancy and impaired coagulation inhibition increased the risk of recurrent venous thromboembolism (RR = 1.48 and 2.0, respectively). In contrast, surgery and recent trauma or fracture were associated with a diminished risk of recurrent venous thromboembolism (RR = 0.65 and 0.39, respectively). The cumulative incidence of post-thrombotic syndrome after two, five and eight years was 24.5, 29.6 and 29.8%, respectively. The development of ipsilateral recurrent DVT was strongly associated with the risk for post-thrombotic syndrome (risk ratio, 2.4). Survival after eight years was 69%. The presence of malignancy increased the risk of death remarkably (risk ratio, 7.1). INTERPRETATION AND CONCLUSIONS: Symptomatic DVT carries a high risk for recurrent venous thromboembolism that persists for many years, especially in patients without transient risk factors for DVT. The post-thrombotic syndrome occurs in almost one-third of patients and is strongly related to recurrent ipsilateral DVT. Our findings challenge the widely adopted short course of anticoagulation in patients with symptomatic DVT.

Adult↗
PubMedDate not supplied

[Sudden cardiac death in acromegaly. Anatomopathological observation of a case].

Involvement of the cardiovascular system in patients affected by acromegaly is an important factor in morbidity and mortality. The diagnosis in these subjects is acromegalic cardiomyopathy with cardiac decompensation, arrhythmias and sudden death. The pathologic substrate has rarely been described. The present study reports the findings in a case of sudden death in a 54-year-old man, affected by acromegaly. Subsequent diagnostic investigation revealed the characteristic aspects of acromegalic cardiomyopathy in the common myocardium and the presence of hyperacute myocardial infarct of the antero-septal wall of the left ventricle. Examination of conduction tissue revealed slight fibrolipomatosis and dispersion of the atrio-ventricular node (AVN), which extended to the His bundle and bifurcation. The right branch was prematurely intramural with sclerosis and lipomatosis. This location in atrio-ventricular conduction system has seldom been reported in the literature and if so, with different lesions from those found in the case we investigated. The results of microscopic examination convalidate the hypothesis of electrical instability in the heart, as confirmed by the subject's history of ventricular extrasystoles, left branch block and attacks of angina after effort. Death was correlated to hyperacute myocardial infarction of the anteroseptal wall of the left ventricle, in a subject with history of angina, affected by acromegalic cardiomegaly and electric instability. In this case, sudden death could also be considered arrhythmogenic in relation to the additional workload by persistent hormonal stimulation.

Acromegaly↗