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Biomedical subjects

G Villa

Publications and source records attributed to G Villa.

At least 109 records · Page 6Linked to original sources
PubMed1990

Continuous acidity monitoring in the study of gastric antisecretory drugs: pH or antilog transformation of pH, mean or median?

The expression of gastric acidity as pH or antilog transformation of pH and the use of the mean or the median as the better summary variable are among the major problems concerning the assessment of antisecretory drugs' effects by means of continuous intraluminal pH monitoring. In this study, we reviewed data deriving from 23 normal subjects, 69 asymptomatic duodenal ulcer patients treated with bedtime (52) or twice daily (17) doses of H2-antagonists, and 10 H2-receptor blocker nonresponders. The whole group underwent continuous 24-h acidity monitoring, and the arithmetic mean and median were calculated on each individual pH and pH antilog transformed profile. One-way analysis of variance and Kruskall-Wallis test were used for statistical comparison between the four subgroups studied. The greatest discrimination between them was obtained when using the mean of pHs [p(F) approximately 0, p[KW] = 2.10(-12)), instead of the median of pHs (p[F] = 8.10(-8), p[KW] = 7.10(-8)). The antilog transformation of pH did not improve the results. It can be concluded that the use of pH to express gastric acidity and the choice of the mean to summarize the drug-related profiles provides a better characterization of the acidity behavior than would the antilog transformation of pHs and the median.

Adult↗
PubMed1989

Multicenter comparative study of aztreonam and gentamicin in the treatment of renal and urinary tract infections.

A multicenter comparative study was carried out to evaluate the efficacy of aztreonam and gentamicin in 186 patients with symptomatic renal or urinary tract infections. Patients were divided randomly into two groups: 94 patients received aztreonam 1 g/day intramuscularly and 92 patients received gentamicin 80 mg i.m. twice daily. The clinical and microbiologic results found a single daily dose of aztreonam to be more effective than gentamicin b.i.d. Furthermore, no evidence of side effects was seen with aztreonam. Such results are generally thought to ensure better compliance in outpatients.

Adult↗
PubMed1989

[Pulmonary edema. A rare complication of the percutaneous insertion of silastic central venous catheters].

Seven newborn infants (birth weight 920 to 1,900 g) who developed pulmonary oedema as a complication of the use of percutaneous silastic central venous catheters are described. Clinical symptoms occurred three to forty days after catheter placement. In each case, radiographic detection, performed by the injection of radiopaque dye, localized the tip of the catheter in the pulmonary artery or in its collateral branches. Clinical symptoms decreased after catheter replacement in the right atrium. The casistic examination allows the Authors to suggest some aetiopathogenetic hypothesis.

Catheterization, Central Venous↗
PubMed1988

Pharmacokinetics of teicoplanin in the elderly.

The pharmacokinetic profile of teicoplanin was studied in 12 elderly patients with a moderate degree of renal impairment (mean creatinine clearance, 51.3 ml/h/kg before treatment), after a single 6 mg/kg iv dose. Pharmacokinetic parameters were estimated both by a three-compartment open pharmacokinetic model and by non-compartmental analysis; peak plasma levels, 15 min after administration, averaged 45 mg/l. The half-lives of two distributive phases were 0.39 and 7.3 h, respectively. The elimination half-life averaged 107 h, with similar estimates obtained from the three-compartment analysis and from urinary data. The volume of distribution from the central compartment was 0.09 l/kg while the volumes of distribution at steady state and during the elimination phase were 1.3 and 1.6 l/kg, respectively. The total teicoplanin clearance averaged 10.6 ml/h/kg, with renal clearance accounting for about 40% of the total. There was a linear correlation between teicoplanin total or renal clearance and endogenous creatinine clearance. The average total recovery of teicoplanin in urine over eight days was 28%. There were no local or systemic adverse reactions to teicoplanin.

Aged↗
PubMed1988

Effects of ibopamine in combination with furosemide on renal function in patients with chronic congestive heart failure.

The effects of ibopamine and furosemide on renal function given alone and in combination at single doses were studied in 6 men and 6 women aged 45 to 73 years with chronic congestive heart failure of NYHA class II. After 3 days of dietary stabilization, the patients received either ibopamine 200 mg, furosemide 40 mg, or furosemide 40 mg plus ibopamine 200 mg with 2-day washout between treatments, according to a double-blind, balanced three-way crossover design using all possible treatment sequences. On each treatment day urine collections were performed at 2-hourly intervals from 2 h before to 6 h after dosing, and urine volume and Na+, K+, Cl-, and creatinine concentrations were measured for every period. The patients received a standardized breakfast 3 h before treatment and then were allowed 250 ml tap water to drink before starting each urine collection period. Venous blood samples were taken before breakfast and midway between each urine collection period for analysis of serum Na+, K+, Cl-, creatinine, and glucose. Heart rate, blood pressure, and physical signs were recorded 2, 1 h, immediately before, and then 0.5, 1, 2, 3, 4, 5, and 6 h after treatment. At the same times the patients were asked for any symptoms. The time course of the diuretic effect of furosemide 40 mg was consistent with the data reported by other authors.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Pharmacokinetics of ibopamine in patients with renal impairment.

The pharmacokinetics of a single oral dose of ibopamine 100 mg were studied in 15 patients with various degrees of chronic renal impairment (CRI) and in 8 subjects with normal renal function and of comparable age, taken as a control group. Plasma total (mainly conjugated) and free epinine and urinary metabolites (total epinine, HVA and DOPAC) were measured. Both total and free epinine were detectable at the earliest sampling time (15 min) in CRI patients and in normal subjects, thus confirming the promptness of ibopamine absorption. Free epinine pharmacokinetic parameters did not show any appreciable differences among the groups with different degrees of renal impairment, and no statistically significant differences were observed between normal subjects and CRI patients. Progressive renal impairment was associated with higher Cmax, longer t1/2 and larger AUC infinity of total epinine, and with reduced urinary elimination of total epinine and metabolites. Statistically significant differences (p less than 0.01) in Cmax/70 kg, t1/2, and AUC infinity/70 kg of total epinine were found between normal subjects and patients with mild renal impairment. No statistically significant differences were observed in 24-h urinary recoveries of both total epinine and metabolites between normal subjects and patients with mild renal impairment. No adverse effects were experienced during the course of the study. As the kinetics of ibopamine's active moiety, free epinine, were not apparently altered by chronic renal failure, adjustment of its dosage should not be necessary in renal diseases.

Adolescent↗
PubMed1987

Teicoplanin pharmacokinetics in patients with chronic renal failure.

The pharmacokinetic profile of teicoplanin, a new glycopeptide antibiotic active against Gram-positive aerobic and anaerobic bacteria, was studied in 5 healthy male volunteers and 29 adult patients with various degrees of renal impairment, given a single 3 mg/kg intravenous dose. Teicoplanin was assayed in plasma and urine specimens by a microbiological method. Pharmacokinetic parameters for teicoplanin were estimated both by a 3-compartment open pharmacokinetic model and by non-compartmental analysis. Elimination half-life increased with the decrease in creatinine clearance and mean values ranged from 41 hours in volunteers to 163 hours in anuric patients. Renal failure did not affect either the volume of distribution of the central compartment (mean approximately 0.09 L/kg) or the steady-state volume of distribution (mean approximately 0.9 L/kg). Both total and renal clearance decreased with severity of disease, particularly the latter, while non-renal clearance was unaffected by renal failure. Average values were from 19 to 6 ml/min for total clearance and from 12 to 0.4 ml/min for renal clearance. There was a linear correlation between the total clearance of teicoplanin and creatinine clearance, as well as between renal clearance and creatinine clearance. The total urinary excretion of active teicoplanin averaged 65% of the administered dose in normal subjects, but was significantly reduced in the presence of renal insufficiency. Guidelines for administration of teicoplanin in patients with renal failure are given.

Adult↗
PubMed1986

Assessment of split renal function with 99mTc-aprotinin.

The aim of this work is to correlate the net kidney uptake of 99mTc-aprotinin (TcA) in 103 subjects with separate effective renal plasma flow (ERPF) and some blood chemistry parameters at 90, 180, and 360 min postinjection both in the normal and diseased kidney. Correlations found with separate ERPFs are highly significant at any time (P less than 0.001). However, although the slope of the regression line is steeper at 180 min, r tends to deteriorate slightly with time postinjection and a higher intercept on the y axis; this pattern is more pronounced if diseased kidneys are considered separately. The following are probably related to the renal handling of TcA: Early scans better reflect blood flow to the kidney, while later scans are more related to the metabolism/excretion tubular mechanisms; correlations found with urea, creatinine, urea clearance, and creatinine clearance are highly significant at any time; in 20 additional patients with diseased kidneys, renal uptake measurements done 360 min postinjection first with TcA and then with DMSA showed better correlations with ERPF employing TcA. Our results indicate that TcA is a feasible indicator of split renal function even at 90 min postinjection when a scan is easily carried out on an outpatient basis.

Adolescent↗
PubMed1986

Constructive disabilities in focal brain-damaged patients. Influence of hemispheric side, locus of lesion and coexistent mental deterioration.

The performance of 185 focal brain-damaged patients on two non-verbal constructive tasks ('Copying Drawings' and 'Copying Drawings with Landmarks') was evaluated with regard to three variables: laterality of cerebral lesion, intrahemispheric locus of lesion, and coexistence of mental deterioration. The aim of the study was to assess the relationships between each of these variables and both the incidence and severity of constructional apraxia. Different evaluations were carried out in order to partial-out the possible interference of unilateral spatial neglect. Results showed that, regardless of whether faults attributable to unilateral spatial neglect were penalized or not: right brain-damaged patients performed slightly worse and showed a higher percentage of pathologic performances than left brain-damaged patients; subjects with parietal--and particularly with right parietal--damage obtained the poorest mean scores and exhibited the highest incidence of apraxic performances; and coexistence of mental deterioration was the most relevant variable associated with global decay of constructive scores and incidence of constructional apraxia.

Adult↗
PubMed1986

Anomia with and without lexical comprehension disorders.

Anomic patients are usually described as free from language comprehension disorders, but the status of lexical comprehension in anomia is still controversial. Most anomic patients are impaired on tasks of semantic-lexical discrimination, but some of them do not present clear signs of semantic-lexical deficit at the receptive level. The aim of the present research was to elucidate the nature of word-finding disturbances by contrasting results obtained by anomic patients with and without lexical comprehension disorders on a number of variables, namely severity of anomia, implicit knowledge of words that patients failed to name, presence of verbal-semantic paraphasias, and scores obtained on a test of phoneme discrimination and on the "Token Test." The results of our investigation seem to suggest that there are two types of anomia, caused by the impairment of two different sets of mechanisms. In "purely expressive anomia" the locus of defect seems to be near to the stage in which the selected lexical item is specified into the appropriate phonological form. In "anomia with lexical comprehension disturbances" the locus of defect seems to be much deeper within the lexicon, so that the semantic disorder affects both the expressive and the receptive levels in a roughly comparable manner.

Adult↗