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Biomedical subjects

C Grassi

Publications and source records attributed to C Grassi.

At least 37 records · Page 2Linked to original sources
PubMed1988

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↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1987

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↗
PubMed1987

Clinical efficacy of ofloxacin in lower respiratory tract infections. A multicentre study.

A multicentre clinical trial was carried out to determine the activity and tolerability of ofloxacin in the treatment of lower respiratory tract infections. 667 patients were randomly allocated to 1 of 3 different twice daily dosage regimens: 400 mg (245 patients), 600 mg (211) or 800 mg (211). The mean duration of treatment was 8.77 +/- 2.62 days. Satisfactory overall clinical results (i.e. cured or improved) were obtained in 612 of 667 patients (91.8%). Eradication of pathogens was achieved for 279 of 354 isolated strains (78.8%). Side effects were observed in 31 patients and consisted of gastrointestinal disturbance (22), skin rash (1), neurological disturbance (3) and others (5). No significant alteration of haematological parameters was reported.

Aged↗
PubMed1987

Roxithromycin (RU 28965) in the treatment of respiratory tract infections.

The clinical efficacy of roxithromycin, administered at the daily dosage of 300 mg (150 mg every 12 hours), was evaluated in 25 patients with respiratory tract infections, mostly infectious exacerbations of chronic bronchitis. Pathogens isolated before treatment were Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus beta-haemoliticus, Haemophilus influenzae. Clinical cure or improvement was achieved in 21 out of 22 evaluable patients. The eradication rate was 91%. Tolerability was good: two patients reported gastrointestinal side effects which caused treatment discontinuation. These preliminary data suggest that roxithromycin may have a place in the treatment of respiratory infections.

Adult↗
PubMed1987

International experiences with ceftriaxone in the treatment of lower respiratory tract infections.

The clinical efficacy and tolerability of ceftriaxone in the treatment of pneumonia and other lower respiratory tract infections were evaluated in 827 patients (515 pneumonia, 312 other lower respiratory tract infections) reported in the international literature (daily dose: 1 of 2 g.i.v. or i.m. in most patients). Therapeutic success was achieved in 738 patients (89.2%). Microbiological results were evaluated in 295 patients. Eradication of the most common respiratory pathogens was achieved in 100% of cases and of Enterobacteriaceae in 85.7%-100%. Adverse effects occurred in 4.9% of patients. A large multicenter trial was carried out in Italy using a single daily dose of 1-2 g by i.v. or i.m. Six hundred ninety-six patients were admitted to the study (370 pneumonia, and 326 other lower respiratory tract infections). Therapeutic success was achieved in 668 cases (96%). Pathogens were eradicated in 88% of cases (184 pts evaluated). Side effects were observed in 4.6% of cases.

Bacteria↗
PubMed1987

Influence of the carotid body on gas exchange during exercise.

The role of the carotid body in the ventilatory changes of exercise is reviewed. Peripheral chemoreceptor function was studied in 20 patients with chronic airways obstruction. The patients were treated double-blind and randomly allocated to placebo and almitrine bismesylate 50 mg b.d. before undertaking an exercise programme at day 0 and after 30 and 60 days of therapy. Patients on almitrine therapy had an improved resting arterial oxygen tension (PaO2) which was maintained during exercise. A statistically significant improvement of effort tolerance was observed after 60 days treatment with almitrine.

Aged↗
PubMed1986

Postsynaptic alpha 1- and alpha 2-adrenoceptors mediating the action of the sympathetic system on muscle spindles, in the rabbit.

In anaesthetized and curarized rabbits, the cervical sympathetic nerve (CSN) stimulation induces in jaw elevator muscles a tension response which can be mimicked by the intravenous injection of adrenaline, noradrenaline and phenylephrine. This response, previously described and attributed to the contraction of muscle spindle fibres, is entirely mediated by alpha-adrenoceptors. The administration of phenoxybenzamine (2.5-3.5 mg/kg) markedly inhibits the responses to the sympathetic stimulation and to the injection of adrenergic agonists. Rauwolscine (1 mg/kg) reduces the development of tension induced by both CSN stimulation and noradrenaline injection without significantly affecting the response to phenylephrine. These data suggest the presence of postsynaptic alpha 1- and alpha 2-adrenoceptors in intrafusal muscle fibres. Moreover, the possibility that alpha 2-adrenoceptors may also have an extrasynaptic location is entertained.

Animals↗
PubMed1986

Evaluation of the host defense system in asthmatic patients.

The efficiency of some components of the host defense system has been evaluated in 32 atopic patients with rhinitis, asthma or asthma and rhinitis. No alterations in components of complement (C3 and C4), serum immunoglobulins (IgG, IgA, and IgM) and neutrophil functional parameters were found. As expected, serum IgE values were higher than in controls. A decreased percentage of total circulating T lymphocytes, an increased percentage of Ia1-positive cells, but normal values of OKT4- and OKT8-positive T lymphocytes were demonstrated. However, a greater heterogeneity in the distribution of the suppressor-cytotoxic subset was shown in atopic patients.

Adolescent↗
PubMed1986

A review of clinical studies carried out in Italy with almitrine bismesylate.

The authors refer to a double-blind versus placebo multicentric study, carried out in Italy on 128 hypoxaemic patients suffering from COLD, with Almitrine bismesylate, a new chemoreceptor stimulant drug, given by mouth for a period of two months. Almitrine induced significant changes (p less than 0.001) of PaO2, with a mean increase of 7.6 mmHg, and of PaCO2, with a mean decrease of 4.1 mmHg, without variations of lung volumes and caliber of large and/or small airways. Almitrine, well tolerated within the time limits of this trial, seems an effective oral respiratory drug, acting through a favourable effect on V/Q mismatching due mainly to a reduction of the shunt effect, but also to an improvement of the ventilatory pattern.

Almitrine↗
PubMed1985

Controlled trial of methylprednisolone pulses and low dose oral prednisone for the minimal change nephrotic syndrome.

In a multicentre, randomised, prospective trial 89 patients (67 children and 22 adults) with the minimal change nephrotic syndrome were treated with three intravenous pulses of methylprednisolone followed by low dose oral prednisone for six months (group given methylprednisolone) or with high dose oral prednisone for four weeks followed by low dose oral prednisone for five months (control group). Five patients in the group given methylprednisolone and one in the control group did not respond initially. The time to response was shorter in children treated with methylprednisolone. No significant differences between the two groups were observed in the number of patients who relapsed or number of relapses per patient per year. Patients given methylprednisolone tended to relapse earlier than patients in the control group. Side effects related to treatment were significantly fewer in the group given methylprednisolone than in the control group. These data suggest that a short course of methylprednisolone pulses followed by low dose oral prednisone is only marginally less effective than a regimen of high dose oral steroids but can improve the ratio of risk to benefit associated with treatment of the minimal change nephrotic syndrome.

Administration, Oral↗
PubMed1985

Sympathetically-induced development of tension in jaw muscles: the possible contraction of intrafusal muscle fibres.

In rabbits, cats and rats anaesthetized, curarized, with the skull fixed in a stereotaxic apparatus, the peripheral stump of the cervical sympathetic nerve (c.s.n.) was electrically stimulated at frequencies within the physiological range and the isometric tension was recorded at the lower jaw. In a group of experiments the afferent discharge from the jaw elevator muscle spindles was also recorded, in the mesencephalic nucleus of the fifth cranial nerve. Unilateral stimulation of the c.s.n. induced in jaw elevator muscles of rabbits an increase of tension of 5.5 +/- 0.5 g (latency: 0.5-2 s, time constant: 2.5-5 s) maintained with little or no decrement until the end of stimulation. This response proved not to be secondary to vasomotor changes since: i) approximately half of it was mediated by the fastest conducting component of the c.s.n. fibres, ii) it was not mimicked by a sudden reduction of blood supply to the muscles, iii) it was unaffected by 10 min bilateral occlusion of both the external and the internal carotid arteries. During c.s.n. stimulation the afferent discharge from spindles belonging to jaw elevator muscles exhibited an increase of firing (often preceded by a transient decrease) lasting throughout the stimulation. Also, the position sensitivity of all the spindle afferents tested was modified by the sympathetic stimulation. The results presented are interpreted to suggest that the sympathetic system may induce an intrafusal muscle fibre contraction in jaw elevator muscles. The possible functional implications are also discussed.

Animals↗
PubMed1985

Pharmacokinetic studies on antituberculosis regimens in humans. I. Absorption and metabolism of the compounds used in the initial intensive phase of the short-course regimens: single administration study.

The absorption and metabolism of streptomycin, isoniazid, rifampicin, and pyrazinamide were evaluated after administration of each drug alone and in combination. In the combination sessions, isoniazid, rifampicin, and pyrazinamide were administered orally, either individually or in a single fixed-ratio triple preparation. The results have shown that the pattern of absorption and metabolism (acetyl-isoniazid, desacetyl-rifampicin, and pyrazinoic acid) found after administration of each drug alone did not differ from that found after administration of the drugs in free and fixed combination. The 3 orally administered drugs given in a fixed combination resulted in a reduction of the order of 50% of the total number of tablets to be ingested.

Absorption↗