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Biomedical subjects

A Fabbri

Publications and source records attributed to A Fabbri.

At least 199 records · Page 11Linked to original sources
PubMed1987

Distribution of amiodarone and desethylamiodarone in a patient with acute myocardial infarction after intravenous administration.

The autopsy tissues concentration of amiodarone and desethylamiodarone of a man with acute myocardial infarction treated acutely with intravenous amiodarone is reported. Our data indicate that amiodarone is quickly distributed into all highly perfused tissues after intravenous administration with a high amiodarone/desethylamiodarone ratio. We also report here the autopsy case of a woman who died after 30 days of oral therapy with amiodarone. The increase in heart/plasma ratio of amiodarone and desethylamiodarone concentrations and the decrease in amiodarone/desethylamiodarone ratio after one month of therapy could explain the latency in the antiarrhythmic action of the drug.

Amiodarone↗
PubMed1987

Emerging microorganisms in cystic fibrosis.

Pseudomonas aeruginosa is the most common bacterial isolate obtained from patients with cystic fibrosis of the lungs. Recently, however, new multiresistant organisms have emerged, whose identification may be difficult and whose pathogenic role proves hard to define. Of the 71 strains isolated from 24 patients with cystic fibrosis during acute flareups of pulmonary symptoms, 48 turned out to be Pseudomonas aeruginosa (67.6%); 11 were Pseudomonas non-aeruginosa (15.5%); and 12 were Achromobacter xylosoxidans (16.9%). Each bacterial isolate was tested for sensitivity to nine antibiotics (ceftazidime, azlocillin, piperacillin, aztreonam, cefsulodin, cefoperazone, amikacin, tobramycin, and sisomycin) in terms of minimum inhibitory concentration and minimum bactericidal concentration values. In this series, Achromobacter xylosoxidans proved the species least responsive to treatment, and ceftazidime the most active antibiotic both against Achromobacter and against strains of the genus Pseudomonas. Twenty-three different associations of ceftazidime with aminoglycosides, tested for activity on the multiresistant strains, failed to show synergism of action.

Alcaligenes↗
PubMed1987

5-Fluorocytosine and Candida yeasts.

The authors report 5-fluorocytosine's activity against 101 Candida albicans and 42 Candida non-albicans strains. They point out the drug's lower inhibitory and lethal activity against Candida non-albicans. A 1.56 microgram/ml concentration inhibits 83% of Candida albicans while only 40% of Candida non-albicans is inhibited.

Candida↗
PubMed1987

[Late aortic dissection after aortic valve substitution. Considerations on 5 operative cases].

This study analyses the clinical course of five patients who developed acute ascending aortic dissection 45.8 months (17-87 months) after aortic valve replacement (AVR) and underwent reoperation in our Department. All except one had aortic insufficiency with mild dilatation of the ascending aorta. No evidence of aortic wall degeneration was present at the time of AVR. Prostheses implanted were: Hancock 2, St. Jude 2, Bjork-Shiley 1. Associated procedures (coartectomy, coronary artery by-pass) were carried out in two patients. The dilated aorta was managed at the first operation by longitudinal resection in 3 of them. Emergent aortic dissection repair was performed: in 3 cases with composite graft according to the Bentall procedure, in one case with non valved dacron conduit and in the last case with teflon patch. Histological examination of the dissected aortic wall showed elastic fiber degeneration like cystic medial necrosis. Three patients survived surgical repair and are doing well at 22.4 months of mean post-operative follow-up. Surgical strategy of this complication is discussed; particular emphasis is given to the method of treatment of ascending aorta dilatation during AVR.

Adult↗
PubMed1986

Inhibition of luteinizing hormone release by morphine and endogenous opiates in cultured pituitary cells.

Morphine sulfate was found to have a direct inhibitory effect on both basal and GnRH-stimulated LH release by cultured rat pituitary cells. The inhibitory effect of morphine on LH release was prevented by the opiate antagonist naltrexone, and treatment of cells with naltrexone or beta-endorphin antiserum significantly increased basal LH release. Also, incubation of pituitary cells with CRF caused a significant decrease in basal LH release, an effect that was reversed by naltrexone. Saturable opiate-binding sites were demonstrated in enriched gonadotrophs by [3H]etorphine binding studies. The ability of morphine to inhibit gonadotropin secretion through a direct action on pituitary opiate receptors suggests that long term exposure to exogenous opiates may suppress reproductive function at the hypophyseal level. In addition, the converse effects of CRF and naltrexone or beta-endorphin antiserum on LH release indicate that intrapituitary opioid peptides could exert a paracrine inhibitory action on the gonadotroph.

Animals↗
PubMed1986

Evidence for the presence of specific receptors for N-formyl chemotactic peptides on human spermatozoa.

Synthetic N-formylated peptides are potent chemoattractants for human spermatozoa in vitro. The specific structure-activity relations for eliciting a chemotactic response and the ability of the antagonist tertbutoxycarbonyl-phenylalanyl-leucyl-phenylalanyl-leucyl- phenylalanine (Boc-Phe-Leu-Phe-Leu-Phe) to inhibit the chemotaxis induced by these peptides strongly suggest the presence of receptors on human spermatozoa. The following studies were performed to identify specific binding sites on human spermatozoa by using [35S]-N-formyl-methionyl-leucyl-phenylalanine [( 35S]f-Met-Leu-Phe), a potent chemotactic peptide. Binding of the [35S]formyl-peptide to human spermatozoa was rapid (t1/2, 8 min) and reversible. Binding isotherms of the saturation experiments revealed a single class of high affinity, low capacity binding sites (equilibrium dissociation constant, 17.7 nM; maximal binding, 109 fmol/2 X 10(6) cells) and an average number of 60,000 receptors per cells. The biological potencies of a series of formyl peptides as chemoattractants correlated closely with their relative abilities to compete with [35S]f-Met-Leu-Phe for specific binding to human spermatozoa. These data fulfill the major criteria for demonstration of specific receptors for chemotactic peptides on human spermatozoa. It is likely that these receptor sites initiate the chemotactic response of human spermatozoa to N-formyl peptides.

Adult↗
PubMed1986

Susceptibility of enterococci. I. Inhibitory and bactericidal activity of several chemoantibiotics against Streptococcus faecalis and Streptococcus faecium.

The authors present a microbiological study of 100 strains of Enterococcus (70 strains of Streptococcus faecalis and 30 strains of Streptococcus faecium) tested for susceptibility to the following antibiotics, amoxicillin, ampicillin + flucloxacillin, piperacillin, rifampicin, vancomycin, netilmicin, ofloxacin, and norfloxacin. The assessment of minimum inhibitory and minimum bactericidal concentrations of these substances indicates that all have good inhibitory activity except netilmicin, which is active at higher concentrations; with rifampicin and vancomycin showing very poor bactericidal activity. The bactericidal activity of penicillins was hard to assess because of tolerance and paradoxical effect phenomena. The quinolones showed good inhibitory and bactericidal activity.

Anti-Bacterial Agents↗
PubMed1986

Susceptibility of enterococci. II. Inhibitory and bactericidal activity of drugs in combination against Streptococcus faecalis and Streptococcus faecium.

The microbiological utility of antibiotic combinations against Streptococcus faecalis and Streptococcus faecium strains was studied. The drugs used were netilmicin + amoxicillin (20 strains); netilmicin + piperacillin (20 strains); netilmicin- + vancomycin (20 strains); netilmicin + rifampicin (20 strains). Netilmicin used in combination with the penicillins was advantageous against Streptococcus faecalis, but not uniformly against Streptococcus faecium. The combinations of netilmicin with vancomycin or rifampicin were no more effective than the single drugs in most cases, although the response varied for the different strains of the two species.

Anti-Bacterial Agents↗
PubMed1986

The acid-base balance and the electroencephalographic pattern in patients on biofiltration treatment.

Electroencephalogram (EEG) monitoring and arterial blood gases was performed during biofiltration (BF) treatment and during conventional acetate hemodialysis (HDA). Biofiltration is an ultrashort hemodiafiltration with 3 liters of substitution fluid (Na+ 145 mEq/l, HCO-3 100 mEq/l). Our data show a better correction of acid-base balance during BF than during HDA. Moreover, we observe a lower incidence of EEG disturbancies on BF, that suggests a better neurological tolerance of this treatment.

Acetates↗
PubMed1986

[Diverticular aneurysm of the right atrium].

A case of right atrium aneurysm (diverticulum) detected in an asymptomatic 61-year-old woman is described. Diagnosis was made according to echocardiographic and echocontrastographic findings and was confirmed by both angiographic data and surgical pathology. The rarity of this finding and the possibility of a correct non-invasive assessment can be considered the two most peculiar features of this case.

Angiocardiography↗
PubMed1985

Calcitonin receptors in the rat mesencephalon mediate its analgesic actions: autoradiographic and behavioral analyses.

Autoradiographic analyses of salmon calcitonin (sCT) binding in the rat mesencephalon revealed an exceptionally high concentration of receptors in the ventral and ventrolateral segments of the periaqueductal gray matter (PAG) extending along the entire rostral-caudal axis. Relatively heavy labeling was also seen along a band extending ventrolaterally through the mesencephalic reticular formation. Other receptor-rich areas include the nucleus linearis, pars compacta and lateralis of the substantia nigra, locus coeruleus, parabrachial nuclei and nucleus raphe pontis of the pontine reticular formation. Injections of sCT into the PAG induced a dose-dependent increase in hot-plate latencies. All rostral-caudal levels of these brain regions appeared to be equally responsive. Injections into the midline pontine reticular formation were also effective in increasing response latencies. Unilateral injections into the hypothalamus, medial thalamus, ventral thalamus and mesencephalic reticular formation proved to be ineffective. Human calcitonin (hCT) was considerably less potent. These biological effects are consistent with the potencies of both peptides in displacing 125I-sCT from slide-mounted sections of rat PAG. Naloxone failed to antagonize sCT-induced analgesia, suggesting an opiate independent mechanism for this peptide in eliciting analgesia.

Animals↗
PubMed1985

Calcitonin inhibits the phosphorylation of various proteins in rat brain synaptic membranes.

The present report examines the effect of different calcitonins and analogs on the in vitro phosphorylation of brain synaptic membrane proteins. The findings demonstrate that calcitonin is a potent inhibitor of several brain synaptic proteins and that salmon and eel calcitonins are considerably more potent than thyrocalcitonin in eliciting this effect. Deletion of leucine from position 16 in salmon calcitonin sequence resulted in a drastic loss of inhibitory activity, indicating the importance for a hydrophobic residue at position 16 in the intact calcitonin molecule. The mechanism of calcitonin inhibition of protein phosphorylation was likely due to the blockade of stimulation of protein kinases by calmodulin.

Animals↗
PubMed1985

Naloxone increases bioactive LH in man: evidence for selective release of early LH pool.

Opioid peptides inhibit LH secretion and the opiate antagonist naloxone provokes increases in plasma LH levels by release of endogenous GnRH from the hypothalamus. To explore the effect of endogenously released GnRH on the mobilization of bioactive LH pools, the bioactive LH response to a single iv bolus dose of 20 mg naloxone has been evaluated and compared to the immunoactive pattern of the hormone in eight young normal male volunteers. Blood samples were withdrawn at 15, 30, 45, 60, 90, 120 min after naloxone injection and LH levels were measured by RIA and rat interstitial cell testosterone (RICT) bioassay. A significant increase in both bio and immuno active LH was observed in all subjects after 15-30 min (p less than 0.05 to p less than 0.001), reaching maximal levels at 30-60 min for both forms of the hormone. The time course of the bioactive LH response magnified the immunoactive LH pattern, and the maximum fold increases were 1.4 and 1.3 fold (62.4 +/- 5.5 SE and 25.0 +/- 3.7 SE mIU/ml) from basal bio and immuno LH levels of 25.9 +/- 4.3 SE and 11.1 +/- 2.0 SE mIU/ml respectively. An early single peak response of bio and immunoactive LH was observed in six subjects while a biphasic pattern was observed in two subjects with a clearly defined and prominent early pool followed by a second pool of higher magnitude. Both bio and immunoactive LH levels began to decline at 45-60 min, but in most subjects remained significantly elevated by about 30% above the basal values at 120 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

ACTH, beta-endorphin and met-enkephalin: peripheral modifications during the stress of human labor.

We investigated the psychoneuroendocrine and emotional correlates of the natural stress situation of human labor. State anxiety, subjective pain, plasma ACTH, peripheral plasma beta-lipotropin (Beta-LPH), beta-endorphin (Beta-EP), and met-enkephalin (Met-Enk) were serially evaluated at six predetermined time points before, and after labor in a sample of 14 women with normal pregnancies. State anxiety and subjective pain showed a progressive increase during labor, with a levelling during the final stage. Plasma Beta-EP and ACTH showed a similar progressive increasing from baseline until the end of labor. Beta-LPH showed no significant modification. Met-Enk remained at nearly baseline values throughout labor, with a marked progressive rise in the postpartum stage. The findings of this study seem to confirm the role of plasma Beta-EP as a stress hormone. Possible relationship between pain and anxiety curves and plasma Beta-EP are discussed in light of psychobiological studies on stress, the opioid system and analgesia. Plasma Met-Enk, according to our findings, should probably not be regarded as a stress hormone. Its rise in the postpartum stage might be as one of the psychoneuroendocrine mechanisms maintaining elevated prolactin levels during lactation.

Adrenocorticotropic Hormone↗
PubMed1985

Opiate receptors are present in the rat testis. Identification and localization in Sertoli cells.

We have characterized opioid binding sites in the Sertoli cells of adult and 18-day-old rat testes. Maximal specific etorphine binding was attained after 30 min at 4 C. The binding was reversible, with association and dissociation rate constants of 0.98 X 10(5) M-1 min-1 and 0.33 min-1, respectively. Scatchard analyses and saturation curves revealed a single class of high-affinity, low-capacity binding sites. No opioid binding was observed in Leydig cell cultures. Exposure to opioids for 3 days caused a significant increase in [3H]etorphine specifically bound to the Sertoli cells that was completely prevented by naloxone, demonstrating opioid up-regulation of its own receptor. Chronic opioid treatment of the cultures significantly inhibited androgen-binding protein production, and this effect was prevented by naloxone. Since the circulating concentrations of endorphins (10(-12) M) are lower than the Kd of testis opiate receptors, it is conceivable that opioids of Leydig cell origin act on the specific high-affinity receptors of the Sertoli cells, and may play a role in modulating their function.

Androgen-Binding Protein↗
PubMed1985

Human semen inhibits T rosette formation through an opiate mediated mechanism.

Seminal plasma contains high levels of opioid peptides and both seminal plasma and endogenous opioids can influence the immune system. In order to investigate whether these two findings can be related, semen was collected from 7 normal subjects, and assayed for beta-endorphin content and for its in vitro ability to inhibit the total T rosette formation of human lymphocytes in the presence or in the absence of 10(-6) M naloxone, an universal opiate antagonist. The results were as follows: 1) immunoreactive beta-endorphin content in seminal plasma was 4 to 12 times higher than the peripheral plasma levels detected in the same subjects (76.1 +/- 42.1 SD vs 10.5 +/- 2.0 SD pg/ml); 2) increasing concentrations of seminal plasma (1%, 5%, and 10%) in RPMI 1640 significantly depressed the T rosette formation ability of lymphocytes; and 3) the simultaneous addition to the incubation mixture of 10(-6) M naloxone prevented the phenomenon, while naloxone per se was ineffective. The possibility that endogenous opioids may play a role in the immunomodulatory action of human semen is suggested.

Adult↗