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Biomedical subjects

A Mussi

Publications and source records attributed to A Mussi.

At least 91 records · Page 5Linked to original sources
PubMed1990

Hemodynamic and humoral effects of chronic antihypertensive treatment with fenquizone: importance of aldosterone response.

The effects of 1-year antihypertensive treatment with the diuretic fenquizone were evaluated in 16 patients with mild essential hypertension. During treatment with placebo, after 2, 4, 24, and 52 weeks of treatment we measured blood pressure, heart rate, forearm blood flow (FBF) and vascular resistance (FVR) at rest and after 10 minutes ischemia, and forearm venous distensibility. Subjects whose diastolic blood pressure after fenquizone was reduced at least 10% were classified as responders. On this basis, 56% of patients after 1 month and 68% after 1 year responded to fenquizone. Responders, in comparison to nonresponders, were characterized by a greater increase in FBF and a greater decrease in FVR. The reduction in diastolic blood pressure was significantly related to the fall in FVR whereas no correlation was found between blood pressure and venous compliance changes. Nonresponders had a PRA increase similar to that observed in responders but they showed a much greater increase in aldosterone, whose changes were inversely related to modifications of both FVR and blood pressure. Our results demonstrate that chronic therapy with fenquizone causes a reduction of FVR, and that nonresponders have an exaggerated rise in aldosterone. This observation further reinforces the hypothesis that factors influencing the secretion of aldosterone are important determinants of the antihypertensive mechanism of diuretics.

Adult↗
PubMed1990

Short-term plasma renin activity suppression by saline and release of a plasma endogenous Na/K ATPase inhibitor in essential hypertension.

The present study was conducted in 15 essential hypertensives to evaluate the modifications of plasma levels of an endogenous Na/K ATPase inhibitor, blood pressure, forearm hemodynamics and plasma renin activity (PRA) elicited by an intravenous saline infusion (0.9% NaCl at the mean rate of 0.22 mL/min/kg body weight for 2 h). The response to saline was determined in the whole hypertensive population as well as in two subgroups of patients classified according to their rate of PRA suppression in response to volume expansion by comparison with normotensive controls (Normal- and Low-suppressors: N-S, L-S). Over the whole group of hypertensive patients, NaCl load provoked an increase in Na/K ATPase inhibitory activity, measured by enzyme-coupled assay, which was linearly related to PRA decline (r = 0.73) and to the increase in mean blood pressure (r = 0.57). These effects were clearly enhanced by considering L-S patients alone. Urinary Na/K ratio after saline infusion was significantly higher in L-S as result of a lesser potassium excretion in this subgroup. Our results support the hypothesis that acute volume expansion with saline causes an increase in plasma levels of an endogenous sodium pump inhibitor with hemodynamic effects and whose release is related to the individual handling of infused fluids and to the degree of renin-angiotensin-aldosterone suppression.

Adult↗
PubMed1990

Alarm reaction and serum K+ in hypertensive patients.

The effect of serum K+ of the alarm reaction induced by the participation to an experimental noninvasive study was evaluated in 35 subjects with borderline hypertension and in 18 essential hypertensives. A group of 44 inpatients undergoing routine blood sampling served as a control. Serum K+, blood pressure and heart rate were measured before (casual) and after (baseline) 20 min of rest in the recumbent position. Baseline serum K+ values were significantly higher than casual values in patients participating to the experimental protocol while no change was observed in inpatients undergoing routine blood sampling. The increase in serum K+ induced by relaxation was significantly related to heart rate decrease (r = 0.73). After relaxation 75% of patients had an increase in serum K+ with a change greater than 10% in about 35% of patients. In a subgroup of patients who repeated the same test three times, the alarm reaction was still evident and not reproducible within each patient. These data suggest that when potassium levels are measured in outpatients undergoing diagnostic or experimental procedures falsely reduced levels can be found in a large proportion of subjects.

Adult↗
PubMed1990

Pulmonary lipid peroxidation in cigarette smokers and lung cancer patients.

Lipid peroxidation (LPO) was studied in lung tissues of patients with lung cancer (LC, n = 37) or nonlung cancer (NLC, n = 13) and its relationships with the smoking habits and the degree of airway obstruction were investigated. Specimens of peripheral lung parenchyma, free of tumor tissue, were taken and the malondialdehyde (MDA) content was measured in the S-12 fractions. Airway obstruction was assessed by flow-volume curves, and data were expressed as percentage of the predicted values. Cigarettes smoked were expressed as pack-years. The patients with LC and NLC did not differ by MDA content, age, and number of pack-years. On the contrary, FEF75-85 and MEF75 were significantly lower in LC than in NLC patients (p less than 0.05). The MDA content was inversely correlated to number of days patients had refrained from smoking (r = -0.66, p less than 0.001). The MDA content was higher in recent smokers (ie, people smoking during the last 30 days before surgery) than in the other patients (0.136 +/- 0.007 vs 0.116 +/- 0.007 mumol/g of tissue, p less than 0.05) and, by considering only recent smokers, MDA content was higher in LC patients (0.144 +/- 0.008 mumol/g of tissue) than in NLC patients (0.113 +/- 0.014 mmol/g tissue, p = 0.059). When patients were divided into "high MDA" and "low MDA" groups, MEF75 was much lower in the high MDA group (35.1 +/- 3.4 percent) than in the low MDA group (55.1 +/- 8.1 percent) (p less than 0.01). These results suggest the following: (1) enhanced level of prooxidant state in the lungs is associated with recent cigarette smoking; (2) LC patients may be more prone than respective NLC patients to oxidative stress; (3) MDA level and degree of small airway obstruction were associated and differed between LC and NLC patients even though these groups did not differ in the percentage of recent smokers; and (4) a common free-radical mediated pathway may be active for both LC and small airway obstruction.

Glutathione↗
PubMed1990

[Computerized tomography in post-operative recurrence of bronchial carcinoma].

The authors describe the different types of postoperative carcinoma recurrences, as seen on CT examinations of the chest, in 38 patients who underwent different surgical procedures for bronchogenic carcinoma (12 pneumonectomies, 22 lobectomies, 2 segmentectomies, and 2 atypical resections). The recurrences were classified as follows: 1) recurrence in the bronchial stump; 2) lymph node enlargement; 3) recurrence in the thoracic wall; 4) recurrence in the residual lobe; 5) pleural effusion; 6) nodule in the contralateral lung. The CT findings, correlated with those from plain chest radiographs and clinical symptoms, indicate a higher incidence of recurrences in the hilar region, either in the bronchial stump or as node enlargement. In the discussion, the problems faced after total and subtotal resection are separately analyzed. While after pneumonectomy plain chest radiographs fail to demonstrate the recurrence in most cases, so that CT is nearly always mandatory, after subtotal resection the diagnostic accuracy of conventional radiology appears higher since the residual parenchyma offers good natural contrast. Nevertheless, after subtotal resection, greater difficulties arise at a deeper radiological analysis due to lobar reassessment, the features of which are to be known.

Carcinoma, Bronchogenic↗
PubMed1989

Influence of T and N stages on long-term survival in resectable small cell lung cancer.

The influence of T and N stages on long-term survival was evaluated in 49 patients with small cell lung cancer treated between 1975 and 1982. Adjuvant chemotherapy was administered in 34 patients and consisted of cyclophosphamide, doxorubicin and vincristine or etoposide, while 15 patients were treated with surgery alone. To date, overall median survival is 12 months, with nine patients (18.4%), who received adjuvant chemotherapy, currently alive and disease-free at 60 to 150 months. Survival was statistically influenced by the N stage but not the T stage; patients at the N0 stage had a significant increase when compared to N1 and N2 patients, on both 5-year survival (p less than 0.05 and p less than 0.025, respectively) and long-term survivors (p = 0.006 and p = 0.004, respectively). Results suggest that surgery and adjuvant chemotherapy might be an effective form of treatment in small cell lung cancer for T1, T2 and also T3 tumours without hilar or mediastinal lymph node involvement.

Adult↗
PubMed1988

Hypolipidemic effects of long-term antihypertensive treatment with captopril. A prospective study.

In 27 hypertensive patients already receiving antihypertensive treatment and with serum total cholesterol levels between 260 and 350 mg/dl, captopril in a dosage of 50 mg twice a day was substituted for one of the drugs they were taking. Patients taking a diuretic continued the same diuretic at the same dosage. After six months of therapy that included captopril, patients resumed their former therapy. Diet and physical activity remained unchanged during the study. Biochemical and blood pressure determinations were performed before captopril was begun, after three and six months of captopril therapy, and three months after the former therapy was resumed. During the regimens that included captopril, the triglyceride value was reduced from 249 to 184 mg/dl (p less than 0.05), the total cholesterol level decreased from 287 to 237 mg/dl (p less than 0.005), and the high-density lipoprotein cholesterol value rose from 40 to 51 mg/dl (p less than 0.005). The reduction in cholesterol was unrelated to blood pressure changes or to changes in serum triglyceride, glucose, or potassium levels. Treatment regimens that included captopril also induced a greater diastolic blood pressure reduction than regimens that did not include captopril. The antihypertensive efficacy of a therapeutic regimen that includes captopril, along with its favorable effect on lipid profile, could be useful in preventing cardiovascular complications in hypertensive patients.

Captopril↗
PubMed1988

Use of captopril to reduce serum lipids in hypertensive patients with hyperlipidemia.

The effects on serum lipids of substituting captopril for other antihypertensive drugs were evaluated in 24 essential hypertensives with stable hypercholesterolemia (total cholesterol 250 to 350 mg/dL). Captopril, 50 mg bid, was substituted for one of the nondiuretic drugs the patients were already taking. Patients on a diuretic continued the same diuretic at the same dosage. After 6 months of treatment including captopril, patients returned for 3 months to their previous therapeutic scheme (rechallenge). Treatment with captopril caused a reduction in total cholesterol (-18%) and triglycerides (-26%) and an increase in high-density lipoprotein (HDL) cholesterol (+27%). When patients returned to their precaptopril therapy, total and HDL cholesterol returned to precaptopril values. These effects of captopril on lipid profile of hypertensive patients with hypercholesterolemia could be important for the reduction of cardiovascular complications in treated hypertensives.

Blood Pressure↗
PubMed1988

Importance of plasma renin activity suppression and venous distensibility on pressor and natriuretic responses to intravenous salt load in borderline hypertension.

Cardiopulmonary receptors influence renin release in a variety of physiological situations and in a fashion related to the degree of peripheral venous distensibility. We studied two groups of borderline hypertensives (BHTs) with different capacities to suppress plasma renin activity in response to saline infusion (0.20 mL/kg/per minute for 2 hours). Those BHTs with low suppressive capacity (L-supp) showed an increased venous distensibility in comparison with those with high suppressive capacity (H-supp). Saline infusion led to a significant increase in blood pressure only in L-supp BHTs, which was associated with enhanced 24-hour postloading natriuresis and raised plasma levels of an Na/K ATPase inhibitor (+12.2%). This result underlines the importance of venous distensibility as a determinant of pressor and humoral response to acute volume expansion.

Adenosine Triphosphatases↗
PubMed1988

Characterization of a Na+/K+-ATPase inhibitor from human plasma: preliminary data.

The role of an endogenous sodium pump inhibitor in the pathogenesis of hypertension has been reported in several papers. Unfortunately, because of the unknown structure and lack of biochemical characterization, some discrepancies have arisen. In this study we report a method to obtain extracts from human plasma that are able to inhibit Na+/K+-ATPase in vitro. Preliminary characterization was carried out, which showed that the extracts are able to inhibit Na+/K+-ATPase, pNPPase, and [3H]ouabain binding to red blood cells. The enzyme inhibition is not due to vanadate, FFA, or bivalent cations, and it seems to be reversible, dose-dependent, and largely prevented in E1 conformation of the enzyme. These results seem to support the hypothesis that human plasma contains a sodium pump inhibitor with many characteristics of a "ouabainlike" compound.

Blood Chemical Analysis↗
PubMed1988

Cellular ionic composition at the prehypertensive phase of essential hypertension.

This article reviews the data from literature regarding cell sodium and potassium content in young subjects at risk of developing essential hypertension (subjects with family history of hypertension or with borderline hypertension). The studies performed with red blood cells have produced conflicting results: approximately one-half of these studies have found an increase in intracellular Na+ in subjects with family history of hypertension (genetic normotensives) whereas the other studies found no difference. The reasons for these discrepancies are discussed. Studies with leukocytes gave more univocal results and the majority of these studies found an increase in intracellular Na+ in many genetic normotensives. These observations emphasize that it is possible to find a high intracellular Na+ in subjects with normal blood pressure. Longitudinal studies are need to clarify whether subjects with high Na+ are those who will develop hypertension. The data from our studies suggest that subjects with high Na+, even if they are normotensive, exhibit an exaggerated pressor response to mental and physical activities and that a reduction in dietary salt content produces a parallel decrease in intracellular sodium and in pressor reactivity. The data on borderline hypertension are even more scarce than those on genetic normotensives and the different classification criteria produce results which are frequently not comparable. Our studies showed that in borderline subjects not only intracellular Na+ can be increased, but also intracellular K+.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Penetration of clofoctol into human lung.

The disposition of clofoctol was determined in plasma and lung tissue from 34 patients undergoing pulmonary resection for lung cancer. Clofoctol 1.5 g was given as a rectal suppository; samples of plasma and pulmonary tissue were collected between 15 and 270 min post-dose. Plasma and lung peak concentrations of the drug were 38.07 +/- 0.73 mg/l and 93.13 +/- 6.68 mg/kg at 30 and 90 min, respectively. Mean values for areas under the concentration-time curve and half-life for plasma and lung were 80.91 mg/l/h, 229.65 mg/h, and 1.18 h and 1.21 h, respectively. Tissue to plasma ratios were 0.85 +/- 0.06, 3.82 +/- 0.21 and 6.19 +/- 0.63 at 30, 90 and 180 min post-dose, respectively. Clofoctol is well absorbed from the rectum and accumulates in lung tissue. This may explain its efficacy in bacterial respiratory infections.

Aged↗
PubMed1987

Reproducibility of pressor response to handgrip: influence of time intervals, strength and duration of exercise.

1. The reproducibility of pressor response to handgrip performed at different time intervals and with different combinations of the product duration x strength of the exercise was evaluated in 14 normotensive subjects recording blood pressure with a noninvasive automatic device. 2. Subjects underwent five consecutive tests (30% of maximal voluntary contraction x 90 s) at 30 min, and 24 h intervals and repeated the test after 12 months. Furthermore, they underwent at 24 h intervals a randomized sequence of handgrip tests whose product strength x duration was combined in order to achieve either a constant or an increasing level of exercise. 3. Blood pressure response to exercise performed at 30 min intervals was much less reproducible than that induced by handgrip performed at time intervals greater than or equal to 24 h. 4. Increasing gradually the product strength x duration of the handgrip test there was a proportional blood pressure increase, whereas when the product was maintained constant diastolic blood pressure increase was also constant and reproducible within each subject. 5. This study shows that it is possible to obtain reproducible diastolic blood pressure responses to handgrip test measuring blood pressure with a non-invasive automatic device when the tests are performed at a time interval of at least 24 h. The choice of the strength and of the duration of the exercise is very important for the reproducibility of the test.

Adult↗
PubMed1987

Pressor response to stress and exercise in the young: intracellular ion content relationships and prognostic implications.

The relationships between intracellular Na+ (Nai) and K+ (Ki) content, blood pressure and peripheral hemodynamics were investigated in young subjects with a family history of hypertension or with borderline hypertension. A direct correlation was found between Nai and pressor response to stress and exercise; after a short-term low-salt diet a parallel decrease was found in Nai and in pressor response to provocative tests. On the contrary, Ki was inversely related to diastolic blood pressure (DBP) both a rest and during mental and physical stimulation. The mechanism by which alterations in intracellular ion content lead to hemodynamic changes may be mediated by a reduced vasodilatory capacity. In fact, during handgrip testing, the increase in forearm vascular resistance (FVR) was directly related to the Nai/Ki ratio while after the exercise, FVR decrease in subjects with normal Nai/Ki and increases in those subjects with high Nak/Ki. In borderline subjects FVR at rest was inversely related to Nai but acute salt loading causes an increase in FVR proportional to Nai. These observations suggest that in subjects with borderline hypertension FVR at rest is normal perhaps as a response to a high cardiac output; however, a further hemodynamic load (salt loading) causes an increase in FVR directly related to Nai and inversely related to Ki. The study of Nai can also give useful information about the risk of developing sustained hypertension. While no subject with borderline hypertension with normal Nai developed hypertension within five years, 31% of those subjects with high Nai developed hypertension after five years.

Adult↗
PubMed1986

Cadralazine and chlorthalidone as a second-step drug with atenolol in hypertensive patients: differences in blood pressure control during exercise.

The long-term efficacy of a new vasodilator, cadralazine (ISF 2469), and chlorthalidone have been compared in 20 hypertensive patients not adequately controlled by atenolol. After 4 weeks of treatment with atenolol 100 mg once daily, patients whose diastolic blood pressure was greater than 95 mmHg were randomly divided into two groups to receive in addition to atenolol, either cadralazine 15 mg once daily or chlorthalidone 25 mg once daily. Both treatments were administered for 6 months. At the end of treatment with atenolol and after 3 and 6 months of combination therapy, blood pressure and heart rate were measured at rest and during bicycle exercise 24 h after the last dose. Compared to atenolol alone, both cadralazine and chlorthalidone caused a significant and similar reduction in resting blood pressure. Both groups showed an increase in diastolic blood pressure during exercise while receiving atenolol alone. The addition of chlorthalidone did not modify the pressor response to exercise, whereas patients taking cadralazine had a decrease in exercise diastolic blood pressure, which was fully evident after 6 months of therapy. The reduction in exercise diastolic blood pressure induced by cadralazine was proportional to the increase in exercise heart rate, suggesting a fall in peripheral vascular resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗