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Biomedical subjects

F Scaglione

Publications and source records attributed to F Scaglione.

At least 19 recordsLinked to original sources
PubMed1991

In vivo and in vitro studies on modulation of the pineal endocrine function by L-acetyl-carnitine in the rat.

Male Sprague-Dawley rats injected (i.p.) at 1500h with L-acetyl-carnitine in doses of 10, 30 or 90 mg/kg exhibited a notable increase in their pineal and serum melatonin content 1 hr later. Likewise, L-acetyl-carnitine administered in the same dose range induced a significant increase of pineal and serum melatonin content in rats treated at 0100h, following exposure of 30 min to bright white light to suppress endogenous melatonin. Under in vitro experimental conditions, however, 60 min of coincubation of isolated rat pineal glands with L-acetyl-carnitine (10(-5) M) did not result in an elevation in melatonin accumulated in the incubation medium. These results demonstrate that, in vivo, L-acetyl-carnitine can exert a modulatory action on synthesis and release of melatonin, possibly by modifying noradrenergic transmission and signal transduction in the pineal gland.

Acetylcarnitine↗
PubMed1991

Impact of rokitamycin, a new 16-membered macrolide, on serum theophylline.

Side effects have been observed when 14-membered macrolides, erythromycin and troleandromycin, have been prescribed concurrently in patients receiving therapeutic doses of theophylline. Rokitamycin is a new 16-membered macrolide antibiotic. We have evaluated its effect on theophylline serum concentrations in 12 adult patients suffering from chronic obstructive pulmonary disease. Initially, six patients were treated for four consecutive days with theophylline as sustained-release formulation in the amount of 600 mg daily; six other patients received for four consecutive days a short term intravenous infusion of 240 mg aminophylline, given over a period of 30 min twice daily. On the last day, blood samples were taken for theophylline determination. Theophylline concentrations were measured serially for 12 hours after oral formulation and 4 hours after aminophylline by enzyme immunoassay technique. Subsequently, while theophylline and aminophylline treatments were continued at the same dosage, each patient received in addition rokitamycin tablets, 400 mg every 12 hours. After seven days of this combined medication, the serial assays of serum theophylline were repeated at the same time intervals as before. Concomitant administration of therapeutic doses of rokitamycin did not affect significantly the steady-state pharmacokinetics of oral theophylline and did not alter the (pseudo-) steady-state pharmacokinetics of intravenous aminophylline, showing that the two drugs may be coadministered without any theophylline dose adjustment.

Aged↗
PubMed1991

The diffusion of clarithromycin and roxithromycin into nasal mucosa, tonsil and lung in humans.

The diffusion of clarithromycin and roxithromycin into respiratory tract tissues was studied in 174 adult patients undergoing surgery. Patients received clarithromycin 250 mg orally (500 mg in the case of lung tissue), or roxithromycin 150 mg orally, both given every 12 h, for three days with the last dose administered at different times before surgery. Clarithromycin reached peak tissue levels 4 h after administration and achieved mean peak concentrations of 8.32 mg/kg +/- 2.57 in nasal mucosa, 6.47 mg/kg +/- 2.8 in tonsil, and 17.47 mg/kg +/- 3.29 in lung tissue. Roxithromycin reached peak tissue levels between 4 and 6 h after administration, achieving mean peak concentrations of 1.78 mg/kg +/- 0.73 in nasal mucosa, 2.2 mg/kg +/- 1.21 in tonsil, and 2.14 mg/kg +/- 0.87 in lung tissue. Clarithromycin and roxithromycin demonstrated contrasting pharmacokinetic behaviour. Roxithromycin was characterized by high concentrations in serum and low concentrations in tissues. Clarithromycin on the other hand, is characterized by therapeutic serum concentrations and high tissue concentrations.

Administration, Oral↗
PubMed1991

Simple measurement of isepamicin, a new aminoglycoside antibiotic, in guinea pig and human plasma, using high-performance liquid chromatography with ultraviolet detection.

Isepamicin, the 1-N-(S-alpha-hydroxy-beta-aminopropionyl) derivative of gentamicin B, is a new aminoglycoside antibiotic, which not only has most of the properties of amikacin but also is effective against several amikacin-resistant strains of bacteria. The drug was assayed in guinea-pig and human plasma with a high-performance liquid chromatographic procedure using precolumn derivatization with 1-fluoro-2,4-dinitrobenzene and ultraviolet detection. Linearity was established over the range 0.5-40 micrograms/ml using 50 microliters of plasma. Accuracy has a mean relative error of less than 3% and precision a mean coefficient of variation of 5%. Isepamicin was determined without interference from plasma constituents or other drugs commonly prescribed during aminoglycoside therapy. This procedure correlates well with radioimmunoassay and can be used either in experimental studies or therapeutic monitoring of plasma levels.

Animals↗
PubMed1991

Characterization and mapping of melatonin receptors in the brain of three mammalian species: rabbit, horse and sheep. A comparative in vitro binding study.

Melatonin receptors were characterized in the brains of three mammals (rabbit, horse and sheep) by an in vitro binding technique, using 2-[125I]iodomelatonin as labelled ligand. Although binding sites for melatonin have been described recently in several vertebrate species (including the sheep), the rabbit and the horse have not been the subject of investigation so far. Apart from characterization, the present report describes receptor distribution in a number of brain regions, thus allowing for direct interspecies comparison under the same methodological conditions. 2-[125I]iodomelatonin labelled high-affinity binding sites in crude membrane preparations from these species. A series of kinetic and saturation experiments revealed that the binding was rapid, stable, saturable, reversible, of high affinity (Kd in the low picomolar range) and low capacity (Bmax between 1 and 20 fmol/mg protein). The competition studies showed that the relative order of potency of a variety of indoles for inhibition of 2-[125I]iodomelatonin binding was as follows: 2-iodomelatonin greater than 6-chloromelatonin greater than melatonin much much greater than 5-methoxytryptophol greater than 5-methoxytryptamine, and that it was similar in the different brain regions. Prazosin, which has been reported as an extremely potent melatonin analog in the hamster brain, possessed no potency in all preparations from different regions in the three species under investigation. The regional distribution of the receptor showed insignificant species differences. Highest density was always recorded in the median eminence/pars tuberalis (ME/PT) area. Other regions (SCN, POA and certain cortical areas), showed lower, but significant, receptor content. Saturation and competition studies revealed that these binding sites were also of high affinity, low capacity and high specificity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Kinetic profile of miocamycin in middle ear fluid and mucosa.

A group of 18 patients, before undergoing otoplastic surgery, was treated with miocamycin 600 mg in a single dose; middle ear tissue samples were collected at 2, 3, 4 and 6 h. A group of 20 patients suffering from secretory otitis media (SOM) was also treated with 600 mg of miocamycin in a single dose; collections of middle ear fluid (MEF) were performed at 1, 2, 4 and 6 h. Blood withdrawals from all patients occurred at the same time intervals. The miocamycin determination was performed by means of a microbiological method employing Sarcina lutea ATCC 9341. The highest serum levels (1.06 +/- 0.13 mg/l) were found at 2 h in the group from which middle ear mucosa had been withdrawn and at 1 h (2.2 +/- 0.5 mg/l) in the group from which the MEF had been collected; at 6 h miocamycin could be determined in both groups, with values ranging from 0.1 to 0.2 mg/l. In middle ear mucosa the miocamycin concentration was 1.52 +/- 0.27 mg/kg at 2 h and 0.2 +/- 0.09 mg/kg at 6 h. In MEF, the miocamycin concentration was 2.1 +/- 0.27 mg/l at 1 h and 0.24 +/- 0.05 mg/l at 6 h. The miocamycin concentration determined at 1 h in MEF was virtually equal to that in serum at the same time. At the following experimental times of withdrawal, the miocamycin concentration in mucosa specimens, as well as in MEF samples, proved to be markedly higher than values simultaneously found in serum.

Adult↗
PubMed1990

T cell subpopulations in vitiligo: a chronobiologic study.

The circadian rhythms of helper (CD4) and suppressor (CD8) T cells from the peripheral blood of 12 vitiligo patients (seven with active disease, five with static) and 12 healthy control subjects were studied. Patients with active vitiligo had a lower percentage of CD4+ cells than did control subjects at 0000 hours and at 0600 and 1200 hours; there were no differences between these values in patients with static vitiligo and those in control subjects. The percentage of CD8+ cells were lower at 1200 and 1800 hours in both active and static vitiligo patients than in control subjects. Cosinor analysis of the CD4+ cells showed a circadian rhythm in static vitiligo, whereas the rhythmicity was lost in active vitiligo. CD8+ cells did not show any circadian rhythm in either active or static vitiligo. Our data show more striking aberrations for T cell subtypes in active vitiligo than in static vitiligo. They suggest that cell-mediated immunity may play a role in the pathogenesis of the disease.

Adolescent↗
PubMed1990

Pharmacokinetics and tissue distribution of amoxicillin plus clavulanic acid after oral administration in man.

Augmentin (875 amoxicillin and 125 mg potassium clavulanate) was administered orally to patients with chronic bronchitis. Concentrations of amoxicillin and clavulanic acid were measured in serum, sputum and urine. Peak serum levels for amoxicillin of 11.23 +/- 2.61 micrograms/ml were observed at 2 hours and for clavulanic acid of 2.55 +/- 0.54 micrograms/ml at 1 hour. After 9 hours, 50% of the amoxicillin and 39% of the clavulanic acid had been renally excreted. The peak sputum concentration of amoxicillin was 1.31 +/- 0.42 micrograms/ml at 4 hours and of clavulanate was 0.79 +/- 0.23 micrograms/ml at 2 hours. Patients awaiting surgery received an oral dose of augmentin as above. Samples of lung, tonsil, middle ear mucosa and prostate were obtained and tissue concentrations of both compounds measured. Peak levels of amoxicillin ranged from 0.87 micrograms/g (tonsil) to 2.56 micrograms/g (lung) and of clavulanic acid from 0.20 micrograms/g (prostate) to 0.56 micrograms/g (lung) between 3 and 4 hours after dosing.

Administration, Oral↗
PubMed1990

Pathogen-host interaction.

Host defense, as it generally applies to humans, refers to the individual's ability to withstand infections. Human host defense mechanisms are numerous, diversified, complex, and often interdependent. The administration of drugs may influence some phases of immunocompetence mechanisms. The effect of several antimicrobial agents on organic defenses has been studied. The parameters considered were chemotaxis, phagocytosis, intracellular killing, superoxide-anion production, antibody production, lymphocyte subset behavior, and natural killer cell activity. Some antibacterial agents inhibit these parameters, whereas others can enhance some of these immune parameters to differing extents. Some antibacterial agents have a neutral effect on these parameters.

Anti-Bacterial Agents↗
PubMed1990

In-vitro postantibiotic effects of miocamycin and erythromycin on gram-positive cocci.

The capability of miocamycin to induce a postantibiotic effect (PAE) on a Group A Streptococcus beta-haemolyticus clinical isolate and on Staphylococcus aureus ATCC 29213 has been studied. Erythromycin was chosen as a reference molecule. The exposure time to antibiotics was 90 min. The removal technique of the antibiotic agents consisted of a 1:200 dilution in cultural broth. Miocamycin displayed a PAE of 2 h 30 min in relation to the minimum inhibitory concentration (MIC) of Streptococcus and a PAE of 2 h 30 min in relation to the MIC of Staphylococcus. The PAE value lasting longer than the others was of 5 h 40 min towards Streptococcus and of 4 h 18 min towards Staphylococcus at a concentration eightfold the MIC. Erythromycin showed a PAE of 1 h 36 min in relation to the MIC of Streptococcus and a PAE of 1 h 30 min in relation to the MIC of Staphylococcus. The PAE value lasting longer than the others was of 3 h 15 min against Streptococcus and of 2 h 30 min against Staphylococcus at a concentration eightfold the MIC. In some cases a PAE was observed in relation to subinhibitory concentrations (1/2 MIC). Miocamycin therefore proved to possess a more evident capability to induce a PAE against the clinical isolate of Group A Streptococcus beta-haemolyticus and on Staphylococcus aureus ATCC 29213 than did erythromycin.

Adult↗
PubMed1990

Miocamycin distribution in tonsillar and pulmonary tissues after repeated administration.

Twenty patients undergoing tonsillectomy were treated with a peroral administration of 600 mg of miocamycin every 12 hours for 4 days. On the 5th day, after a last administration of a dose of 600 mg the ablation of the tonsils was carried out on groups of 4 subjects, each one at the following times after oral intake of the drug: 2, 4, 6, 8, 12 h. Twenty-nine patients, admitted to hospital to undergo lung resection were treated with peroral administration of miocamycin in accordance with the above mentioned dose scheme. The operation was carried out on groups of 5 subjects, each on the fifth day at the following times after the last administration: 2, 3, 4, 6, 8 and 12 h (4 subjects). Simultaneously blood was withdrawn for the determination of miocamycin in serum. Miocamycin was measured by a microbiological procedure using Sarcina lutea ATCC 9341. The highest levels of miocamycin were observed after 2h in tonsils (3.2 +/- 0.82 mg/kg) and serum (1.3 +/- 0.33 mg/l). After 12h miocamycin proved to be still measurable in the tissue (0.12 +/- 0.05 mg/kg), whereas it was not detected in serum. In pulmonary tissue, the highest levels of miocamycin were likewise identified at the 2nd hour (2.82 +/- 0.59 mg/kg), simultaneously with the highest serum levels (2.3 +/- 0.61 mg/l). At the 12th hour miocamycin could still be dosed in 3 tissue samples, with values between 0.1 and 0.2 mg/kg and was found just at dosing limits in only one serum sample.

Adolescent↗
PubMed1990

Serum protein binding and extravascular diffusion of methoxyimino cephalosporins. Time courses of free and total concentrations of cefotaxime and ceftriaxone in serum and pleural exudate.

A new approach to the study of the distribution pharmacokinetics of variably bound beta-lactams is to plot the concentration time course of their free (dialysable) and total (free and bound) forms. In the present study, the 6-h concentration time course was plotted of the total and free concentrations of cefotaxime and ceftriaxone in serum and pleural exudate in 12 patients per group, after iv dosing with 1 g of either cefotaxime or ceftriaxone. Samples were taken at 0.5, 1, 1.5, 2, 3, 4 and 6h after dosing. The results of a study of similar design, but conducted over 24 h in ten patients per group, following iv dosing with either cefotaxime 1 g 12-hourly or ceftriaxone 1 g daily are also reported. Samples were taken at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 14, 16 and 24 h after dosing. Areas under the curve of free cefotaxime in pleural fluid were greater than those of free ceftriaxone, in both the 6 h (+54.6%) and 24 h studies (+29.8% after 12 h and +71.0% after 24 h). The free cefotaxime/free ceftriaxone Cmax ratio was 1.75 in the 6 h study. Cefotaxime was superior to ceftriaxone in terms of the diffusion of the free (antibacterially active) fraction into a typical inflammatory exudate. Assessment of the effects of protein binding must be taken into account in antibiotic pharmacokinetic profiles.

Adult↗
PubMed1990

Alpha-1 adrenoceptor involvement in the control of melatonin secretion in the golden hamster.

The nocturnal peak in pineal and serum melatonin content was reduced following administration of the selective alpha-1 adrenoceptor antagonist prazosin in a dose of 0.25 mg/kg. The effect was pronounced one hour post treatment during the late dark phase of the daily photocycle. These data confirm the reported findings that the hamster pineal sensitivity to adrenergic challenge is confined to the second part of the dark phase and indicate that postsynaptically located alpha-1 adrenoceptors are also involved in the physiological control of melatonin synthesis and/or release in that species.

Animals↗
PubMed1990

Failure of prazosin to mimic the effects of melatonin under in vivo and in vitro conditions.

The gonads of male hamsters exposed to short photoperiod (LD, 10:14) or treated with melatonin in the late afternoon under long photoperiod (LD, 14:10) had undergone complete regression by the end of the treatments (8 weeks). Animals treated for the same period of time with prazosin (a putative melatonin analogue) under the same conditions failed to show a difference in their gonadal status as compared to the long photoperiod controls. Prazosin was unable to prevent melatonin-induced gonadal atrophy when injected either in the morning or 30 min before melatonin. Moreover, prazosin was without any effect on (and unable to prevent the melatonin-stimulated) progesterone production by rat adrenals under in vitro conditions. These data demonstrate that prazosin, which reportedly inhibits 2-[125I]iodomelatonin binding in the hamster brain in an affinity-related manner, does not possess properties of a biological melatonin analogue under conditions of two different model systems in two species.

Adrenal Glands↗
PubMed1990

Comparison of the rat pinealocyte ultrastructure with melatonin concentrations during daytime and at night.

The aim of this study was to investigate the ultrastructure of rat pinealocyte during daytime (1600 h) and at night (0100 h) and to compare these observations with serum melatonin levels in the same animals. In addition, pineal melatonin concentrations were determined in other animals. Both serum and pineal melatonin concentrations were significantly higher at night than during daytime (34 and 21 times, respectively). Sizes of pinealocytes, their nuclei, and nucleoli, as well as cross-sectional areas of mitochondria and granular endoplasmic reticulum were also higher at night than during daytime, whereas areas of lysosomes, Golgi apparatus, and vacuoles containing flocculent material did not differ at the time points studied. In contrast, the number of dense-core vesicles was higher during daytime. The results of the present study show that morphological patterns of higher metabolic activity of the rat pinealocyte at night when compared to those during daytime correlate with melatonin concentrations.

Animals↗
PubMed1990

Lymphocyte subsets in bronchoalveolar lavage fluid and in circulating blood in epidermoid bronchogenic carcinoma.

Alveolar macrophages, lymphocyte and granulocyte percentages, together with OKT3+, OKT4+, OKT8+ lymphocyte subsets and OKT4+/OKT8+ ratio, were evaluated in bronchoalveolar lavage (BAL) fluid and in peripheral venous blood (PVB) of neoplastic and nonneoplastic subjects, in order to assess these aspects of immunity in neoplastic disease and to find out if the modifications in the bronchoalveolar environment are correlated to the ones in the circulation blood. BAL was performed in 30 patients undergoing fiberoptic bronchoscopy to ascertain the presence of lung cancer. Twelve of them had positive findings for epidermoid bronchogenic carcinoma, while in the remaining subjects the diagnosis was not confirmed. The 30 examined subjects were then grouped according to their smoking habit. In PVB, no significant difference was seen between neoplastic and nonneoplastic subjects, whereas in BAL the neoplastic patients showed a significant increase of lymphocytes OKT3+ and OKT8+. This tends to confirm that PVB is not a good indicator of organ immunity and may justify the reduced activity of alveolar macrophages in subjects affected by bronchogenic neoplasia. Between smokers and nonsmokers, lymphocyte subsets showed more significant differences than between neoplastic and nonneoplastic subjects (decrease of T4+ lymphocytes, increase of T8+ lymphocytes and, therefore, reduction of T4/T8 ratio); there were also scalar variations in the three groups (smokers with cancer, smokers without cancer and nonsmokers without cancer). Thus, the possible autonomous role of cigarette smoke and the presence of neoplasia in the immunity alterations of the alveolar environment with final joint effects were confirmed. These data may indicate a possible correlation between cigarette smoking, immunological alterations in BAL and the onset of bronchogenic carcinoma.

Adult↗
PubMed1990

Comparison of the clinical and bacteriological efficacy of clarithromycin and erythromycin in the treatment of streptococcal pharyngitis.

The efficacy and tolerability of clarithromycin and erythromycin stearate in the treatment of documented Group A beta-haemolytic streptococcal pharyngitis were compared in a single-centre, open, out-patient study. One hundred and twenty patients were randomly assigned to each treatment group. Dosage of clarithromycin and erythromycin was 250 mg twice daily and 500 mg twice daily, respectively; each patient was given a 10-day supply of medication. Clinical success (cured or improved) was observed in 111 (96.5%) of 115 and in 108 (93.9%) of 115 clinically-evaluable patients treated with clarithromycin and erythromycin, respectively. Eradication of the pathogen occurred in 108 (97.3%) of 111 and in 98 (92.5%) of 106 bacteriologically-evaluable clarithromycin and erythromycin patients, respectively. Adverse events reported by 7 (5.8%) of the clarithromycin-treated and by 12 (10%) of the erythromycin-treated patients included epigastritis and nausea and vomiting. In general, the severity of adverse events was greater for the patients treated with erythromycin, necessitating the discontinuation of therapy in 8 (6.7%) patients treated with erythromycin as opposed to 1 (0.8%) patient treated with clarithromycin. Although clarithromycin and erythromycin were comparable in terms of efficacy, clarithromycin was better tolerated.

Administration, Oral↗