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Biomedical subjects

C Grassi

Publications and source records attributed to C Grassi.

At least 55 records · Page 3Linked to original sources

Bioavailability of isoniazid, rifampicin and pyrazinamide (in free combination or fixed-triple formulation) in intermittent antituberculous chemotherapy.

A study was carried out in six human volunteers, to assess the blood kinetics of isoniazid, rifampicin and pyrazinamide, administered in a fixed-triple combination intended for use in intermittent chemotherapy of tuberculosis. The formulation employed contained 125 mg of isoniazid (H), 100 mg of rifampicin (R) and 375 mg of pyrazinamide (Z) per tablet; six tablets were administered to every subject, giving a total dosage of 750 mg of isoniazid, 600 mg of rifampicin and 2,250 mg of pyrazinamide. In each subject, the same dose of each drug was administered individually in separate sessions and the results compared. The results indicated that, at the level of dose of the intermittent tablet, no negative interactions between the drugs were observed.

Adult

Lomefloxacin versus amoxicillin in the treatment of acute exacerbations of chronic bronchitis: an Italian multicenter study.

Nine centers in Italy participated in a worldwide, multicenter study comparing the effectiveness and safety of lomefloxacin and amoxicillin in patients with acute exacerbations of chronic bronchitis caused mainly by gram-negative pathogens. The 157 enrolled patients received either 400 mg lomefloxacin once daily (n = 78) or 500 mg amoxicillin every 8 hours (n = 79) for 7-10 days. A total of 131 patients were evaluable for bacteriologic efficacy and 154 for clinical efficacy. At 2-4 days after the conclusion of treatment, the bacterial eradication rate was 84.8% for lomefloxacin-treated patients and 64.6% for amoxicillin-treated patients (p = 0.0065); the clinical success rate (cure plus improvement) for lomefloxacin was 94.7% and for amoxicillin was 83.3% (p = 0.0212). The reinfection rate was lower in the lomefloxacin group than in the amoxicillin group (3.0% vs 13.8%, p = 0.0382). Both drug regimens were well tolerated. Once-a-day treatment with 400 mg lomefloxacin was more effective than 500 mg amoxicillin three times daily for the treatment of acute exacerbations of chronic bronchitis caused by gram-negative pathogens.

Acute Disease

Hepatitis C: reality of a renal unit.

Hepatitis C virus (HCV) seems to be the most important agent of non-A, non-B hepatitis. This study was undertaken to assess the prevalence of hepatitis C in our renal unit. Twelve patients (29%) had antibodies against HCV (anti-HCV). Seropositive patients were on hemodialysis for a longer period than seronegatives. Statistically significant associations with anti-HCV were: blood transfusions, at least 1 episode of elevated value of transaminases (2-fold) and fluctuations of transaminases. Our findings confirm the high prevalence of anti-HCV in hemodialyzed patients, the importance of parenteral transmission and the high probability of liver disease in anti-HCV-positive patients.

Female

Immunological and clinical effect of long-term oral treatment with RU 41740 in patients with chronic bronchitis: double-blind trial long-term versus standard dose regimen.

The immunological and clinical effects of two oral treatment schedules of RU 41740 (standard for 3 months vs. long-term for 6 months) were assessed in 40 patients with chronic bronchitis by a controlled, double-blind, randomized trial. Both treatments significantly improved phagocytosis index of both neutrophils and monocytes, and the phagocytosis frequency and the candidacidal activity of neutrophils, showing the maximum stimulation at the end of the third course of treatment. Both treatment schedules reduced the number and the duration of infectious exacerbations of chronic bronchitis with respect to those observed in the corresponding period of the previous year. However, no significant difference between standard and long-term treatment with RU 41740 was found with respect to the immunological and clinical effect and tolerability.

Administration, Oral

Reference values of maximal respiratory mouth pressures: a population-based study.

The aim of our study was to measure values of maximal inspiratory (MIP) and expiratory (MEP) mouth pressures in 625 (266 male, 359 female) clinically and functionally normal subjects drawn out of a sample representative of the general population. MEP (near TLC and FRC) was found to be significantly higher when compared with MIP (near RV and FRC), and pressures in male subjects were significantly higher than those in female subjects. MEP values at TLC and FRC were found to be closely related, as were values of MIP near RV and near FRC. Among the tested body-size variables, body surface area (BSA) for all parameters had the highest degree of correlation. Stepwise linear regression analysis was performed to define the equation of normality for all four parameters, employing BSA, sex, age, and relative interaction terms. R2 values, although the variables employed for the equations were highly significant, were relatively low and didn't fully explain the source of variability. The influence of age was smaller than the influence of BSA, although age did reduce the unexplained variance in MEP and MIP. These results confirm that the most useful employment of MIP and MEP is to monitor their changes in each patient, but they point out, however, the usefulness of reliable reference equations.

Adolescent

Sister chromatid exchange analysis in familial groups of malignant melanoma patients.

Sister chromatid exchange (SCE) analysis was carried out on peripheral blood lymphocytes of 20 familial malignant melanoma (FMM) and 39 sporadic malignant melanoma (SMM) untreated patients, belonging to 10 and 39 families, respectively. The study was extended to 39 unaffected close relatives of FMM patients, to 187 unaffected close relatives of SMM patients, and to 20 unaffected unrelated individuals (control group), all examined under the same conditions. The mean SCE rates/cell were significantly higher in MM families than in the control group, and in melanoma patients than in their close relatives. The mean SCE levels of FMM and SMM patients, (8.4 +/- 0.8 and 8.0 +/- 0.3, respectively) were similar, and so were the distributions of individuals in classes of increasing SCE values (with a modal value at 7-8 SCEs/cell). The mean SCE levels of close relatives of FMM and SMM patients were also similar (5.4 +/- 0.2 and 5.4 +/- 0.1, respectively, with a modal value at 4-5 SCEs/cell), and slightly higher than in the control group (4.7 +/- 0.2 SCEs/cell). More than 7 SCEs/cell were observed in the majority (41 of 59) of FMM or SMM patients, in a smaller fraction (25 of 227) unaffected relatives, and in none of 20 unrelated unaffected individuals. These observations favor the hypothesis that higher SCE levels may be an expression of constitutional lesions predisposing to this neoplastic disease.

Adult

Pefloxacin in lower respiratory tract infections.

To determine the efficacy and safety of pefloxacin in the treatment of lower respiratory tract infections, a multicentre trial involving four departments of respiratory diseases was performed. One hundred and eight patients were admitted to the study: most of them were affected with exacerbations of chronic bronchitis or with pneumonia complicating lung cancer. Isolation and identification of responsible microorganisms from bronchial secretions was possible in 78 patients. Seven patients were withdrawn, one for worsening of the underlying disease and six for early side-effects. Thus, of 108 patients recruited, 101 completed the course of therapy (pefloxacin 400 mg bd for 5-14 days) and could be submitted to final evaluation. Of these 43 (42.6%) were cured and 48 (47.5%) showed improvement. Eradication of responsible microorganisms was achieved in 70 (90.9%) of 77 patients microbiologically evaluated. Side-effects of moderate severity were observed in 12 patients (gastrointestinal disturbances in 11 and dyspnoea in one); these did not necessitate discontinuation of therapy.

Administration, Oral

Familial elevation of serum angiotensin converting enzyme activity.

A clustering of high levels of serum angiotensin converting enzyme (S-ACE) was found in an Italian family. The elevation affected five subjects, two of whom were completely healthy and free from known causes of S-ACE increase. The values of S-ACE in hyperACEmic subjects exceeded the values found in normal relatives severalfold. HyperACEmia seemed to be inherited as an autosomal dominant trait. Immunogenetic studies were performed, but we did not find a genetic marker for this condition. The S-ACE activity was inhibited in vitro by edetic acid (EDTA) and SQ 14,225 (captopril). The S-ACE activity was also determined after 1:8 dilution and dialysis against saline of sera. From these experiments we deduced that Lieberman's intrinsic ACE inhibitor was lacking in the hyperACEmic sera. In the presence of remarkable S-ACE increase, a congenital elevation of S-ACE should be considered and it would be useful to perform a familial investigation.

Female

Studies of MR 889, a new synthetic proteinase inhibitor.

We investigated the proteinase inhibitory activity of MR 889, a thiolactic acid derivative. It is able to in vitro inhibit at low concentration (10(-5),10(-6)M) the activity of porcine pancreatic elastase, human neutrophil elastase and bovine chymotrypsin. In addition, MR 889 is able to inhibit the residual activity of alpha 2-macroglobulin-trapped human neutrophil elastase, paralleling the efficacy of phenylmethylsufonylfluoride. Finally, MR 889 has been shown to in vitro reduce the burden of elastase- and chymotrypsin-like activity found in sputum sol-phases of patients admitted for chronic bronchitis exacerbation.

Chymotrypsin

A randomized trial of methylprednisolone and chlorambucil in idiopathic membranous nephropathy.

We conducted a controlled trial to investigate the long-term effects of treatment with methylprednisolone and chlorambucil in patients with idiopathic membranous nephropathy. We have previously reported that after a mean of 31 months, treated patients did better. We now report the results of a longer follow-up. Eighty-one patients with proteinuria (greater than or equal to 3.5 g per day) and biopsy-proved membranous nephropathy were randomly assigned to receive either supportive therapy alone or a six-month course of corticosteroids alternated with chlorambucil (0.2 mg per kilogram of body weight per day) every other month. Methylprednisolone was first given intravenously in three pulses (1 g per day) and was then given orally (0.4 mg per kilogram per day) for 27 days. The patients were followed for 2 to 11 years (median, 5). Two patients in the control group and one in the treatment group died. At the last follow-up visit, 9 of 39 patients assigned to the control group (23 percent) and 28 of 42 patients assigned to the treatment group (67 percent) did not have the nephrotic syndrome. At five years there were more remissions of the nephrotic syndrome in treated patients than in controls (22 of 30 vs. 10 of 25; P = 0.026). Compared with base-line values, the mean reciprocal of the plasma creatinine level declined significantly in the control group (33 percent; P = 0.0002) but not in the treatment group (6 percent; P not significant). Plasma creatinine increased by 50 percent or more in 19 controls (49 percent) and in 4 treated patients (10 percent). We conclude that a six-month course of methylprednisolone and chlorambucil can bring about sustained remission of the nephrotic syndrome and help to preserve renal function in patients with idiopathic membranous nephropathy.

Administration, Oral

Smoking habit and bronchial reactivity in normal subjects. A population-based study.

The relationship between smoking habits and airway responsiveness has been studied in a cross-sectional sample of subjects in a small Lombardy (Italy) town. The subjects were between 15 and 64 yr of age; they were representative of the general population. There were 295 normal nonsmokers, 70 normal smokers, and 50 past smokers. All clinically asymptomatic and functionally normal subjects underwent methacholine challenge. The distribution of responsiveness to methacholine (as expressed by LnPD15FEV1) was found to be significantly different between these normal smokers and nonsmokers. A multinomial logistic regression model showed a statistically significant difference in the response to the challenge on the basis of pack-years. When the number of years of smoking and the daily number of cigarettes were separately considered, the current amount had the significant correlation with LnPD15FEV1. Bronchial reactivity for past smokers was found not to be different from that for normal nonsmokers. We conclude that smoking habits, especially current habits, affect bronchial reactivity even in the absence of airway obstruction.

Adolescent

Action of the sympathetic system on skeletal muscle.

The action exerted by the sympathetic system on skeletal muscle is briefly reviewed with regard to the effects induced by the adrenergic mediator on extra-fusal muscle fibre contractility and on muscle spindle receptor organs. In particular, the different responses of slow - and fast - contracting muscles to catecholamine administration and to sympathetic stimulation are reported. Also, the sympathetically--induced effects on muscle spindle afferent activity are discussed on the basis of recent anatomical and functional data suggesting the existence of a direct action exerted by noradrenergic axons on intrafusal muscle fibres. Some of the possible implications of these data are then briefly mentioned.

Humans

Evaluation of systemic host defense mechanisms in chronic bronchitis.

Seventy-six chronic bronchitis patients were studied in order to determine the possible presence of disorders in their systemic defense mechanisms. No significant difference in lymphocyte subsets, in serum immunoglobulin and complement component (C3 and C4) levels was found in chronic bronchitis patients compared to normal adult controls. Skin tests for delayed hypersensitivity revealed a high frequency (39%) of hypoergic patients (with 1-2 positive reactions) in comparison to normal subjects. Altered values of many functional properties of both neutrophils and monocytes were demonstrated. The percentage of patients with intermediate (between 1 and 2 SD below the mean of controls) and defective (lower than 1.96 SD) values of chemotaxis, phagocytosis index and Candida killing was about 50%. Phagocytosis frequency and nitroblue tetrazolium reduction frequency were less frequently impaired.

Aged

Comparative bioavailability of isoniazid, rifampin, and pyrazinamide administered in free combination and in a fixed triple formulation designed for daily use in antituberculosis chemotherapy. I. Single-dose study.

A comparative bioavailability study of the antituberculosis drugs isoniazid, rifampin, and pyrazinamide was carried out in a group of 10 healthy volunteers after administration of the three compounds, once in individual association and once in a combined, fixed preparation. The investigation was designed as an open, crossover study where each subject received five tablets of a preparation containing 50 mg isoniazid, 120 mg rifampin, and 300 mg pyrazinamide (corresponding to a total dose of 250 mg isoniazid, 600 mg rifampin, and 1,500 mg pyrazinamide). The same doses were administered in the session where the drugs were combined using the individual formulations. For each subject and experimental session, 15 blood samples were collected over a period of 24 h, and the plasma concentrations of the three drugs were assessed. The results indicated the absence of negative pharmacokinetic interactions between the drugs when administered in both free and this new, fixed combination.

Adult

Comparative bioavailability of isoniazid, rifampin, and pyrazinamide administered in free combination and in a fixed triple formulation designed for daily use in antituberculosis chemotherapy. II. Two-month, daily administration study.

The time course of the plasma concentrations of isoniazid, rifampin, and pyrazinamide was assessed in a group of 13 patients with lung tuberculosis treated over a period of 2 months on a continuous daily basis with a fixed triple combination of the same drugs. The blood kinetics of the three antituberculosis drugs were determined on Days 1, 15, 30, and 60 of treatment. The triple combination employed in this study contained 50 mg isoniazid, 120 mg rifampin, and 300 mg pyrazinamide per tablet, the number of tablets ranging from four to seven per day according to the body weight of the patients. Almost superimposable plasma concentration curves for isoniazid were observed during the 4 days of the study. For rifampin, a fall in the plasma concentrations at the time intervals after the peak was observed comparing the data on Day 1 with those on Days 15, 30, and 60, which did not differ from each other. This finding is thought to be due to the well-known phenomenon of self-induction, which leads to an increased rate of disposal of the antibiotic from the blood compartment within the first and second weeks of continuous treatment. For pyrazinamide, an equilibrium in the opposite sense as that of rifampin seemed to take place within the 2 months of the study. Because of the relatively high plasma levels observed 24 h after each administration, an increase in plasma concentrations with respect to those observed on Day 1 was found on Days 15, 30, and 60, the levels on these days no differing from each other.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Tension development in lumbrical muscles and concomitant increase of activity in A alpha and A beta afferents during sympathetic stimulation in the cat.

In anaesthetized and curarized cats electrical stimulation of the lumbar sympathetic trunk, at frequencies within the physiological range, induces the development of a small tension in superficial lumbrical muscles (50-100 mg in different preparations). This effect can be reproduced in anaesthetized and curarized cats by stimulating the peripheral stump of the tibial nerve with parameters adequate to activate the entire C-fibre group, and therefore postganglionic sympathetic fibers. The collision technique was used to evaluate in the tibial nerve possible changes in afferent activity from the skinned foot. It was found that an increase of non-cutaneous activity consistently occurs in A beta and, occasionally, in A alpha fibre groups. Secondary and primary spindle afferents, respectively, belong to these fibre groups. It was also found that: (1) the tension development in lumbrical muscles and the increase of the afferent activity of non-cutaneous origin exhibit similar time courses; (2) the two events are affected in parallel by the same stimulus parameters; (3) both events are abolished by alpha-adrenoceptor antagonists. Therefore the possibility of a sympathetic fusimotor action affecting mainly secondary afferents is suggested and discussed.

Afferent Pathways