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Biomedical subjects

L Vaccari

Publications and source records attributed to L Vaccari.

11 recordsLinked to original sources
PubMed2000

Crystallization and preliminary X-ray analysis of two pH-dependent forms of cytochrome c2 from Rhodopseudomonas palustris.

Cytochrome c(2) from Rhodopseudomonas palustris has been crystallized in two different crystal forms: a monoclinic form I at pH 4.4 from both reduced and oxidized protein solution and a trigonal form II at pH 9.0 from reduced protein solution. Complete 1. 7 and 1.4 A resolution data sets were collected from the oxidized form I and from the form II, respectively. The preliminary structures show an important change in the iron coordination environment in the trigonal form obtained at basic pH arising from the substitution of the Met ligand by an ammonia molecule.

Crystallization↗
PubMed1999

Evaluating psychiatric morbidity in a general hospital: a two-phase epidemiological survey.

BACKGROUND: This study aimed to assess psychiatric morbidity and to collect information on disability, life events and family support in a representative sample of patients admitted to a general hospital. METHODS: On the basis of information collected in a pilot study a systematic sample of patients consecutively admitted to seven general medical and seven surgical wards of the Academic General Hospital of Verona was selected and interviewed using a two-phase screening procedure and standardized instruments (GHQ-12, HADS, BDQ and CIDI-PHC). All data were analysed using appropriately weighted logistic regression procedures. RESULTS: A total of 1039 patients completed the GHQ-12 and 298 (28.7%) were high-scorers: 363 patients were interviewed with CIDI-PHC. The prevalence of ICD-10 cases was 26.1%. The most common psychiatric diagnoses were current depression (12.8%) and generalized anxiety disorder (10.8%), followed by alcohol related disorders (5 %). A higher prevalence of ICD-10 cases was found in medical wards, among females, patients older than 24 years, unemployed and separated/divorced people. Life events were associated with psychopathology, and so was the number of disability days. Although 49.8% of ICD-10 cases were identified by the hospital doctors as having a psychological disorder, 23.1% of ICD-10 cases were referred to the liaison psychiatric service. CONCLUSION: The results of the present study stress the need to collect epidemiologically-based data on psychological disorders and their recognition not only in general practice, but also in general hospital settings, in order to have a more complete picture of the pathways to specialist care.

Academic Medical Centers↗
PubMed1995

The inhibition of a leaf proteinase by L-lysine homopolymers.

The role of interlinked positively charged amino acids in the mechanism of inhibition of a monomeric trypsin-like proteinase has been investigated using high molecular mass L-lysine homopolymers ranging from 3.8 to 109 kDa. The data show that the degree of polymerization enhances the inhibitory efficiency which is maximal for homopolymers with more than eighteen interlinked lysine residues. The inhibition is cooperative and, under the maximal inhibition conditions, nine lysine residues of the polymer are involved in the electrostatic binding to the enzyme. A limited conformational change of the protein molecule accompanies the transition from a fully active to a fully inactivated enzyme.

Endopeptidases↗
PubMed1988

Clinical significance of mitral regurgitation in patients with recent myocardial infarction.

The prognostic implications of the presence of mitral regurgitation (MR) in patients with recent myocardial infarction has not been clarified yet. In March 1983, we undertook a prospective study in patients surviving a first episode of acute myocardial infarction. Over a 4-year period, 266 patients entered the study. Left ventriculography documented the presence of MR in 51 patients, while 215 did not have angiographic evidence of MR. The presence of MR was associated with larger infarcts, as shown by greater values of peak CK (P less than 0.05) and by the prevalence of Q-wave vs non-Q-wave infarctions (P less than 0.05). Transient left ventricular failure during hospitalization was more frequent in patients with MR (P less than 0.05), while the occurrence of early post-infarction angina was similar in the two groups of patients. No difference was found in the extent of coronary disease, yet patients with MR had higher values of left ventricular end diastolic pressure (LVEDP) (P less than 0.005) and a lower ejection fraction (EF) (P less than 0.001). Patients with MR had a reduced exercise capacity (P less than 0.005), but signs of myocardial ischaemia were similarly distributed in the two groups. Patients with anterior infarcts and MR had higher left ventricular volumes than patients without MR, while no difference was found between patients with and patients without MR and inferior infarction, suggesting that left ventricular dilatation may play an important role in the pathogenesis of MR in patients with anterior but not in those with inferior infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Angiography↗
PubMed1986

Clinical and angiographic data in early post-infarction angina.

The preliminary results of a prospective study undertaken in patients with a first episode of acute myocardial infarction are presented. The clinical, electrocardiographic and angiographic characteristics of 34 patients who developed early post-infarction angina (group I) were compared with those of 144 patients who remained asymptomatic after the acute infarct (group II). No difference was found between the two groups as to age, sex prevalence, risk factors, presence of stable angina before infarction, severe ventricular arrhythmias or transient congestive heart failure in CCU and peak CK value. Patients of group I had more frequently ecg signs of myocardial infarction in anterior leads (P less than 0.01) than patients of group II. Exercise testing, performed by 23 patients of group I and by 140 patients of group II, was positive in 14 patients with early post-infarction angina and in 37 who remained asymptomatic after the acute infarct (P less than 0.01). The two groups had similar values of left ventricular end diastolic volume index, left ventricular end diastolic pressure and ejection fraction. Patients with early post-infarction angina however had more frequently double or triple vessel disease, while single vessel disease prevailed in group II patients. Although the follow-up period was limited (average 9 months), a higher incidence of cardiac complications was found in group I patients (P less than 0.01). These data show that early post-infarction angina defines a high-risk subset of patients among those with recent myocardial infarction. A more aggressive approach, including thrombolytic therapy and coronary angioplasty, seems warranted.

Angina Pectoris↗
PubMed1985

[Effects of medical and surgical therapy on the long-term survival of patients with variant angina].

To determine the effects on survival of the medical and surgical treatment of variant angina, we compared the prognosis of 75 surgically treated subjects with that of 75 medically treated patients, selected from a series of 340 consecutive patients observed between January 1969 and December 1982. The patients were selected on the basis of a developed computer program to match each medically treated patient with one surgically treated patient so that each pair was similar according to the following clinical and angiographic variables: sex, age, previous myocardial infarction, severe ventricular arrhythmias during pain, site of ST elevation (anterior or inferior), coronary artery disease (single or multivessel), left ventricular function (normal or abnormal). Patients who were considered unoperable because of poor ventricular function or distal vessel disease were not included in this study. Mantel-Haenszel log-rank analysis demonstrated a significantly better prognosis in surgically treated patients, particularly in those with multivessel disease as well as in those with ST elevation in anterior leads. However survival in 63 medical patients who were treated with calcium-antagonists was not significantly different from that of their surgical matched patients. During the follow-up period, anginal symptoms were more frequently found in medically treated patients (p less than 0.05). We conclude that in patients with variant angina surgical treatment does not improve survival as compared to medical treatment with calcium blocking drugs. Coronary artery bypass surgery can be carried out at low risk and is particularly indicated in those patients with angina refractory to medical treatment.

Angina Pectoris, Variant↗
PubMed1983

Variable threshold exertional angina in patients with transient vasospastic myocardial ischemia. Repeat exercise test results and therapeutic implications.

Thirty-five of 70 patients with vasospastic angina at rest complained of chest pain during exercise or during usual daily activity. In 22, the angina threshold was described as variable during exercise: that is, the amount of exertion that induced angina was not always the same. In 12 patients with variable threshold exertional angina, 3 exercise tests performed in the morning on different days yielded different results, because chest pain and ischemic electrocardiographic changes occurred at different work loads with a wide range in heart rate-systolic pressure product. Two patients, in whom great cardiac vein flow was measured during exercise before and after taking nifedipine, tolerated heavier work loads after receiving the drug, with a more marked increase in flow during exercise. It is concluded that variable threshold exertional angina can be objectively demonstrated by repeat exercise tests in patients with vasospastic angina. Variability of the angina threshold may be due to a functional mechanism that causes myocardial ischemia in addition to the increased myocardial metabolic requirements provoked by exercise. Because in such patients fluctuations in coronary arterial tone play an important role in determining the response to exercise, calcium antagonistic drugs, which lower coronary tone and prevent the occurrence of coronary spasm, are effective in increasing exercise capacity.

Adult↗
PubMed1978

Occurrence of 7-dehydrocholesterol in the uropygial gland of domestic fowls.

Histochemical studies on the uropygial gland of domestic fowls have shown the presence of sterols (among which cholesterol and its esters) in the lipidic fraction of the gland secret. beta-Glucuronidase activity beside A5 3beta- and 17beta-hydroxysteroid dehydrogenase activities suggests that uropygial gland might be involved in sterols metabolism. By thin layer chromatography cholesterol and 7-dehydrocholesterol can be separated from the uropygial extracts and these compounds can be identified in gas liquid chromatography.

17-Hydroxysteroid Dehydrogenases↗