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Biomedical subjects

F Scaglione

Publications and source records attributed to F Scaglione.

At least 73 records · Page 4Linked to original sources

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↗

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↗

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↗

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↗

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↗

Immunomodulatory effects of two extracts of Panax ginseng C.A. Meyer.

The effect of Panax ginseng extracts on cell-mediated immune functions in man has been investigated. Three groups, each consisting of twenty healthy volunteers, were treated under conditions of double blindness with capsules containing lactose (Control Group B), with capsules containing 100 mg of aqueous extract of the drug (Group A), and with capsules containing 100 mg of standardized extract of the drug (Group C). All the patients took one capsule every 12 h for 8 weeks. Blood samples were withdrawn before beginning the treatment, at the fourth week and at the eighth week. The immune parameters examined were the following: chemotaxis of PMNs, phagocytosis index (PHI), phagocytosis fraction (PHF), intracellular killing, total lymphocytes (T3), T helper (T4) subset, suppressor cells (T8) subset, blastogenesis of circulating lymphocytes, natural killer-cell activity (NK). Chemotaxis proved to be enhanced (p less than 0.05) already at the fourth week in Group A as well as in Group C; the increase became even more marked (p less than 0.001) at the eight week in subjects belonging to Group C. PHI and PHF proved to be enhanced (p less than 0.05) at the eighth week in subjects of Group A; these increases were found to be higher in subjects of Group C (p less than 0.001) already starting at the fourth week. Intracellular killing was shown to be significantly increased (p less than 0.05) already at the fourth week in Groups A and C; the increase becomes highly significant in both groups (p less than 0.001) at the eighth week; however, a significant increase (p less than 0.05) at the eighth week was also noticed in the placebo group (Group B).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Cefonicid distribution into tonsillar tissue.

The kinetic profile in tonsils of cefonicid has been studied in 30 patients who underwent tonsillectomy after administration of a single intramuscular dose of 1 g. Blood and tissue samples were withdrawn 1, 2, 3, 6, 12 and 24 h after administration of the drug. The analytical determination was performed employing a microbiological method. Peak serum levels appeared at the first hour (94.2 +/- 9.83 mg/l), while peak tissue values were determined in samples collected at the third hour (11.9 +/- 3.68 mg/kg). Serum levels at the 24th hour were 3.82 +/- 1.25 mg/l. Levels in the tonsils were 7.54 +/- 2.96 mg/kg at the sixth hour, 3.34 +/- 1.42 mg/kg at the twelfth hour and 0.40 +/- 0.31 mg/kg at the 24th hour.

Adolescent↗

[Pulmonary and tonsillar distribution of ceftriaxone and cefonicid and the resultant bactericidal activity of the organ].

The therapeutic efficacy of Ceftriaxone and Cefonicid 1 g I.M. single-dose against S. Pneumoniae, H. Influenzae and K. Pneumoniae in tonsil and lung infections was studied using bactericidal quotient (BQ). Samples of lung tissue and serum were obtained from two groups of surgical patients, treated with Ceftriaxone or Cefonicid 1 g I.M., 2-8-16 and 24 hours before surgery. From two other groups of 10 surgical patients, treated as above, samples of tonsil tissue and serum were obtained. In lung tissue the higher levels of Ceftriaxone and Cefonicid appeared at the second hour (11.54 +/- 1.59 mcg/g and 11.4 +/- 2.49 mcg/g respectively); the lower values were observed at the 24th hour (2.18 +/- 0.47 mcg/g for Ceftriaxone and 0.64 +/- 0.21 mcg/g for Cefonicid). Higher Ceftriaxone and Cefonicid levels also appeared in tonsil tissue at the 2nd hour (11.12 +/- 2.42 mcg/g and 9.22 +/- 3.12 mcg/g respectively); the lower values were observed at the 24th hour (1.54 +/- 0.46 mcg/g for Ceftriaxone and 0.42 +/- 0.23 mcg/g for Cefonicid). BQ values were estimated using the ratio between the mean concentrations of Ceftriaxone and Cefonicid in tissue samples and the MBC mean values determined for the above mentioned pathogens, isolated in hospital. Ceftriaxone always showed BQ values greater than 1 during 24 hours versus levels observed for the three reported pathogens. Cefonicid showed BQ values greater than 1 during 24 hours against S. Pneumoniae and BQ values less than 1 for 6-8 hours against H. Influenzae and for 1-4 hours against K. Pneumoniae.

Adolescent↗

[Antibiotic therapy of bacterial infections of the oral cavity].

More than 300 commencial bacterial species may be found in the oral cavity. Other microorganisms, such as mycoplasms, mycetes, protozoa and viruses are present as well. The virulency of the saprofites and additional contamination by outside microorganisms are factors determining the development of infectious process in the oral tissues. Moreover, streptococci and anaerobes are the most frequent aetiology agents. The antibiotic therapy should comply with the general treatment criteria, on the one hand, and should be specific for these microorganism, on the other. The penicillines (ampicillin, bacampicillin and especially amoxycillin) process pharmacokinetic properties which make them a favorable choice for treatment. These drugs are effective in case of streptococcal infections, with cariogenic processes involvement and dissemination (endocarditis, glomerulonephritis). Other, frequently used drugs are spiramycin, erythromycin, josamycin and myocamycin that are selectively taken up by the oral tissues and present in large quantities in the saliva. The macrolides have a large spectrum of action on microorganisms normally found in the oral cavity. Lincosamides (lincomycin and clindamycin) are active on anaerobes and are drugs of choice for treatment of staphylococcal osteomyelitis. Tetracycline therapy is restricted usually to parodontite cases caused by Actinobacillus actinomycetemcomitans and Capnocytophaga. In conclusion, the choice of antibacterial therapy should be based on the bacterial aetiology, as well as on the intrinsic drug characteristics (pharmacokinetic, side effects, toxicity etc.).

Anti-Bacterial Agents↗

In-vivo and in-vitro interference of antibiotics with antigen-specific antibody responses: effect of josamycin.

The effects of josamycin on the antigen-specific primary antibody responses of human peripheral blood cells have been studied by the method of haemolytic colonies in soft agar. The tests were performed before and after the oral administration of 1 g of josamycin or by adding the drug directly to cultures of cells from untreated donors. The results demonstrate that josamycin, added in vitro or administered in vivo significantly depresses the primary antibody responses. The mechanism by which josamycin exerts its activity on antibody production has been partially elucidated. The immunodepression depends on the stimulation of hydrogen peroxide production by monocytes and requires the actual presence of josamycin during the immune response. The stimulation of the respiratory burst of the phagocytic cell is a common feature of macrolide antibiotics and suggests the need for more extensive clinical and preclinical trials on antibacterial antibiotics that alter the human immune responses.

Adult↗

Study on the relationship between pharmacokinetics and antibacterial activity: comparison between ceftriaxone and cefotaxime within the respiratory tract.

The aim of this research was to collect precise data on the antibacterial activity of ceftriaxone and cefotaxime in the respiratory tract. The diffusion into pulmonary tissue and bronchial secretion and the antibacterial activity of the two antibiotics were evaluated in vivo by means of the inhibitory quotient. Ceftriaxone administered at a dosage of 1 g (i.m.) every 24 h resulted in antibacterial levels against the sensitive pathogens over a period of 24 h after each dose. The antibacterial protection afforded by cefotaxime, given at the dosage of 1 g (i.m.) every 12 h, was not as marked and did not extend over the interval between two administrations.

Aged↗

Miokamycin and leukocyte activity in man.

The effects of miokamycin on the immune system were studied in healthy volunteers by means of the following assays: phagocytosis, intracellular killing and natural killer activity. The tests were performed before, 2 and 6 h after oral administration of 600 mg of miokamycin. The findings suggest that miokamycin stimulates phagocytosis and intracellular killing. These effects could be clearly shown 2 h after drug intake and disappeared at the 6th hour. On the contrary, the natural killer activity was not significantly stimulated by miokamycin.

Adult↗

Cortical and medullary kidney tissue levels of cefonicid in human beings.

Cefonicid concentration has been determined microbiologically in cortical and medullary tissue in 30 patient undergoing surgery because of neoplastic disease localized within the kidney. Each subject received 1 g of cefonicid intramuscularly in a single administration. The patients were divided into six groups, from which samples of blood and tissue were collected 2, 4, 6, 8, 12, 24 h respectively after treatment with the drug. The mean peak serum levels appeared at the second hour (74.96 +/- 8.14 mcg/ml) and the decay shows a monoexponential behaviour, reaching a minimum value of 5.4 +/- 2.33 mcg/ml at the 24th hour. In the cortical tissue of the kidney the peak levels appeared at the fourth hour (26.22 +/- 8.87 mcg/g), while at the 24th hour levels were about 3.08 +/- 0.81 mcg/g. A very similar behaviour could also be observed in the medullary tissue of the kidney with peak levels at the fourth hour (25.82 +/- 10.06 mcg/g) and levels of 3.48 +/- 0.85 mcg/g at the 24th hour. A delay in the decay of tissue levels in comparison with the decay of blood levels could be observed from the eighth hour.

Adult↗

Pharmacokinetics of dactimicin in rats.

Dactimicin is a new pseudo-disaccharidic aminoglycosidic antibiotic produced by Dactylosporangium matsuzakiense. The aim of the present research was to evaluate the pharmacokinetics of dactimicin intramuscularly administered, at the dosage of 20 mg/kg, in male Sprague-Dawley rats with an average b.w. of 200-220 g. Dactimicin levels were assessed by using a microbiological method (agar diffusion) employing Bacillus subtilis ATCC 6633 as test organism. Samples were collected immediately before and 0.25, 0.50, 1, 1.15 and 2 h after drug administration. The mean peak serum level, reached after 15 min, was 33.6 micrograms/ml (range 30.3-40 micrograms/ml); T1/2 beta was 0.42 h; extrapolated AUC was 26.8 mg h/l.

Aminoglycosides↗

Efficacy and safety of enoxacin in the treatment of respiratory infections.

The present report concerns an open clinical trial aimed to investigate the efficacy and safety of enoxacin (Zami 8401), a new quinolone drug, in bacterial infections of the lower respiratory tract. A total of 30 hospital in patients, 25 males and 5 females, of a mean age of 67 years (range 39-84 years), suffering from bronchopneumonia, or acute exacerbation of chronic bronchitis, were treated. Enoxacin was administered at the dose of 800 mg twice daily by the oral route. As a rule the patients received the drug for ten days. Efficacy was assessed on the basis of radiological, bacteriological and clinical changes. Tolerance was monitored by the daily recording of any sign or symptom possibly related with the drug as well as by laboratory tests performed before, during and after the treatment. Efficacy was excellent in 80%, good in 17%, poor in 3% of the patients. Tolerance was excellent in all except one patient. Enoxacin appears a very effective and safe drug in the treatment of the infections of the lower respiratory tract.

Adult↗