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Biomedical subjects

L Rossi

Publications and source records attributed to L Rossi.

At least 469 records · Page 26Linked to original sources
PubMed1981

Clinicopathologic assessment of arrhythmias in a case of scleroderma heart disease with sudden death.

Electrophysiologic and histopathologic correlation has been carried out in a patient with scleroderma heart disease, affected by syncopal seizures, who died of recorded ventricular fibrillation. The electrophysiological investigation disclosed dysfunction of sinoatrial conduction, revealed by sinoatrial blocks and by an abnormal return cycle pattern after premature atrial beats. Atrial effective and functional refractory periods were increased and an unusual 'pseudo-Wenckebach' phenomenon between artificial stimulus and atrium was observed during atrial pacing. Intra-AV nodal conduction time was at normal upper limits and Wenckebach-type AV block was obtained on pacing the atrium at 100 beats/min. HV conduction was moderately prolonged in the presence of left anterior hemiblock. The histopathologic substrates of these electrophysiologic disturbances were fibrosis of the sinus node, disrupted internodal pathways and atrio-AV nodal connections, and left bundle branch atrophy. As far as fatal tachyarrhythmia is concerned, myofibrillar degeneration may have contributed to its pathogenesis. It is suggested that both lesions of the ordinary myocardium and specialized conduction system account for the electrical instability of sclerodermic patients.

Adult↗
PubMed1981

Fourth interlaboratory study of methods for determining total migration of plastic materials in liquids simulating fatty foodstuffs.

Results are reported for the fourth interlaboratory study organized by the Commission of the European Communities for the adoption of an official method for determining the total migration of plastic materials in liquids simulating fatty foodstuffs. In each method, a sample of plastic material was weighed before and after it was placed in contact with fatty simulants. The fat absorbed by the sample, extracted or dissolved by suitable solvents, was determined by gas chromatography or radiometry. The results obtained confirm the conclusions given previously. Each method was moderately satisfactory, but less so between laboratories.

Chromatography, Gas↗
PubMed1981

[Interatrial defect functionally cancelled by a left atrial myxoma within the framework of embolizing mitral stenosis and insufficiency].

The case is presented by a 54 year-old woman, studied because of a clinical diagnosis of mitral valve disease, in which echocardiographic and angiocardiographic examination afforded the diagnosis of left atrial tumor. The surgical finding was of a large myxoma implanted on the atrial septum and prolapsing into the mitral opening and engaging with a branch into an atrial septal defect of the cavalis superior type. Some considerations are made on the times of possible origin and growth of the tumor; the complete absence of the increased pulmonary flow in the presence of a large interatrial communication suggested an early beginning of the tumor that, obstructing the defect, might have hindered the hemodynamic derangement.

Diagnosis, Differential↗
PubMed1981

[Dynamic ECG, exercise stress testing and coronary arteriography for the diagnosis of ischaemic heart disease. A Bayesian analysis of probability (author's transl)].

In spite of great technological improvement in Ambulatory ECG Monitoring (AEM), there is still debate about its reliability in detecting ECG signs of myocardial ischemia and about the utility of AEM and Exercise Stress Testing (ET)--apart and/or in association--to predict Coronary Artery Disease (CAD). 50 consecutive male patients (pts) (mean age 51 +/- 69 years, 37 to 64 years) were studied for precordial chest pain. 17 had evidence of previous myocardial infarction. Resting ECG was normal in 21 pts and abnormal in 29; no pt received therapy during the examination period. ECG recordings were considered positive for ischemic ECG changes if there was greater than or equal to 1 mm of horizontal or down sloping ST-segment depression or ST-segment elevation of the same degree for greater than or equal to 0.08 sec in at least 15 consecutive beats; coronary arteriography was considered positive for significant CAD if any major vessel had greater than or equal to 75% luminal diameter narrowing. The percentage of false negative results was similar in AEM and ET (22.7% vs 22.2%); the false positives were few with both tests: 2 pts and 1 pt respectively; Bayesian probability (post-test likelihood for disease) calculated using the prevalence of CAD estimated from 2124 male pts who underwent coronary angiography in our Laboratory, for a given test result was very high: 97.1% +/- 1.3% (AEM), 98.6% +/- 1.1% (ET) and 98.1% +/- 1.1% (AEM & ET if concordant); post-test likelihood for CAD in a patient who did not show the given test result decreased to 67.8% +/- 1.3% (AEM), 60.9% +/- 1.1% (ET) and 52.1% +/- 1.1% (AEM & ET if concordant). The application of Bayes' theorem to these two non invasive tests improves the evaluation of patients with suspected CAD; the association of AEM and ET enhances the diagnostic accuracy.

Adult↗
PubMed1980

Carcinogenicity study of 3-(5-nitro-2-furyl)-imidazo(1,2-alpha) pyridine in mice and rats.

3-(5-nitro-2-furyl)-imidazo(1,2-alpha) pyridine was tested for carcinogenicity by long-term administration in the diet to CTM mice at 0.1, 0.2 and 0.4% dose levels and to Wistar rats at 0.2 and 0.4% dose levels, and by short-term intraperitoneal injections to suckling BALB/c mice. The compound was a strong carcinogen. In CTM mice it induced carcinomas of the esophagus and forestomach at all dose levels and thymic lymphosarcomas at the two highest doses. In male and female rats, esophagus and forestomach papillomas were observed at all dose levels, whereas esophagus and forestomach carcinomas and kidney tumors were observed only at the high dose. In female rats, an increased incidence of mammary tumors was seen at the high dose. The treatment of BALB/c suckling mice by intraperitoneal injections did not induce a clear carcinogenic response.

Age Factors↗
PubMed1980

Occurrence and significance of coagulative myocytolysis in the specialized conduction system: clinicopathologic observations.

In 5 of 18 selected human hearts (15 from patients with early myocardial infarction and severe coronary arterial obstruction), coagulative myocytolysis (myofibrillar degeneration with contraction bands) was demonstrated in the specialized conduction tissue. Its morphologic peculiarities, apparently inherent in the number and arrangement of the affected myofibrils in each type of specific myocell, are described. In nine cases the ordinary cardiac muscle was also involved; in all hearts concomitant changes were present. The debated toxic catecholamine and anoxic aspects of coagulative myocytolysis are briefly reviewed in light of the finding that specialized tissue seems to withstand myocytolytic damage (or any ischemic-anoxic injury) better than ordinary myocardium. This may also explain why coagulative myocytolysis is observed less frequently and evidently in specific rather than in ordinary myocells. Clinicopathologic comparisons focused on arrhythmias, although hampered by inadequacies in routine electrocardiographic documentation, suggest that coagulative myocytolysis of the conduction system may be relevant to life-threatening disturbances in impulse formation and conduction. These data, with their bearing on important current problems in cardiologic emergencies, deserve better morphopathophysiologic assessment.

Adult↗
PubMed1980

Sleep and Michaelis-Menten elimination of ethanol.

Ethanol (0.6 gm/kg) was given orally as a cocktail to 6 healthy fasted volunteers (3 men and 3 women) on 4 separate occasions at 2300 hr. Subjects were recumbent and remained awake in 2 sessions while sleep was allowed in the other 2. An indwelling forearm venous catheter was used to allow blood sampling without disturbance of sleep, and 20 serial blood samples (2 ml) were drawn at appropriate intervals in the 8 hr after the cocktail. Blood ethanol concentration was determined by a head-space gas chromatographic technique and Michaelis-Menten parameters (Vm and Km) were estimated from data in the terminal elimination phase. Mean estimates were Vm awake = 0.214 +/- 0.009 mg/ml/hr (SEM), Vm asleep = 0.221 +/- 0.017, Km awake = 0.069 +/- 0.009 mg/ml, and Km asleep = 0.085 +/- 0.016. These values were slightly lower than literature reports for elimination in ambulant patients during the daytime. Mean differences in Vm and Km between the awake and asleep groups and between sexes were not significant (p greater than 0.05).

Adult↗
PubMed1980

His bundle in electrocardiographic semantics of AV block. Anatomoclinical considerations.

The AV conducting system was examined histologically in 13 selected human hearts (7 control and 6 AV block specimens), focusing attention upon normal His bundle (HB) structure, and upon the histopathologic basis of intrahisian block, with supraventricular QRS configuration. HB revealed a poor morphologic identity, often failing to represent the "undivided stem" of the AV pathway, either due to an early partition into separate longitudinal fascicles, or to varied types and sites of bifurcation, without any definite boundary between nonbranching and branching portions. Split His potentials, the distal component of which has been suggested as arising in the proximal bundle branch system, has been found in a case free of HB histologic abnormality. Supraventricular QRS configuration in escape rhythm was observed in two cases of AV block, not withstanding destruction of the entire His bifurcation, and in experimental bilateral bundle branch block. Pertinent explanations have been suggested. The overall semantic value and usefulness of the current HB nomenclature do not seem to imply, as yet, a precise and constant anatomoclinical correlation.

Adult↗
PubMed1980

[The acromegalic heart disease (author's transl)].

The clinical and pathological findings of 3 patients with acromegalic heart disease are reported. In 2 of them no other causes of the cardiopathy could be recognized but a primitive involvement of the myocardium. The GH is responsible of cardiac hypertrophy without overload, which would shift towards progressive congestive heart failure. A possible depletion of intramyocardial cathecolamines is postulated in acromegalic heart disease as much as in cardiomegalies with pressure or volume overload.

Acromegaly↗
PubMed1980

BK papovavirus immune complexes in glomerulonephritis.

Kidney biopsies from 98 patients were studied for BK virus (BKV) antigens by indirect immunofluorescence. Intense fluorescent staining was observed in 11/12 cases of lupus nephritis, 11/12 cases of membranous nephropathy, 21/23 cases of IgA mesangial glomerulonephritis, 3/4 cases of membrano-proliferative Glomerulonephritis and 5/12 cases of exudative glomerulonephritis. Antisera of different viruses did not react with any kidney sample. Deposition of BKV was strictly related to the presence of immunoglobulins in renal glomeruli. The specificity of reaction for antigens related to BKV was demonstrated by absorption of sera with different substances and BKV. Absorption of rabbit anti-BKV serum with human immunoglobulins completely abolished glomerular fluorescence. We conclude that the fluorescence obtained in kidney biopsies by staining with anti-BKV serum was a false positive reaction dependent on common antigenic determinants present in BKV capsid proteins and human immunoglobulins.

Antigen-Antibody Complex↗
PubMed1980

[Postheparin diamineoxidase (DAO) increase in the plasma and gastrointestinal mucosa (author's transl)].

Haparin given i.v. in doses of 50 I.U./kg/body weight induces in the man a synchronous increase of plasmatic and gastrointestinal mucosa Diamineoxidase (DAO) bioptically obtained in course of gastroscopy. The DAO increase is maximum 5 min after heparin injection, and afterwards less evident. The possible practical meaning of the use of DAO increasing substances and so for histamine catabolism in digestive apparatus mucosa is discussed.

Adult↗