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Biomedical subjects

A Conti

Publications and source records attributed to A Conti.

At least 181 records · Page 10Linked to original sources
PubMed1992

Role of pineal melatonin and melatonin-induced-immuno-opioids in murine leukemogenesis.

The relationship between the pineal gland, melatonin and melatonin-induced-immuno-opioids with the response of C57Bl/6 mice to A-RadLV induced T cell lymphomas was investigated. Mice were injected at day 0 with A-RadLV and from day 10 they were treated chronically with melatonin 4 mg/kg body weight, naltrexone 1 mg/kg or phosphate buffered saline, throughout the experiment. In another protocol, groups of mice were a) surgical pinealectomized at day-14, b) functional pinealectomized (24:24 hours light) from day -20 and c) sham pinealectomized. At day 0 each group was inoculated intrathymically with A-RadLV. The results show that melatonin accelerated (p < 0.005) leukemogenesis whereas the surgical pinealectomy and the functional pinealectomy delayed it (p < 0.005 and p < 0.01). Moreover, the action of melatonin was blocked by naltrexone (p < 0.005), indicating the involvement of melatonin-induced-immuno-opioids in the development of the lymphomas.

Animals↗
PubMed1992

The amino-acid sequence of two isoforms of alpha-lactalbumin from donkey (Equus asinus) milk is identical.

The complete primary structure of donkey alpha-lactalbumin A and B has been determined by sequencing of the peptides obtained after tryptic, Glu-C proteinase or cyanogen bromide cleavage. Although preparative purification of alpha-lactalbumin by flat-bed isoelectric focusing gave two protein fractions A and B, their amino-acid sequence revealed no differences. Donkey alpha-lactalbumin shows two, four and five differences in comparison to the horse alpha-lactalbumin A, B and C. Thus donkey alpha-lactalbumin is homogeneous and belongs to the horse A-type variant.

Amino Acid Sequence↗
PubMed1992

[Radiodiagnosis of ureteral and bladder hernia. A further case contribution].

The radiologic features of ureteral and bladder hernias are poorly known. These hernias can be located in 5 compartments, being extremely rare in 2 of them--the chest and lumbar sectors, where only 2 cases are reported in literature. In the other 3 compartments--i.e., ischiatic, crural and inguinal sectors--bladder and ureteral hernias are less uncommon findings. Over a relatively short period of time, 5 bladder hernias were observed--3 ischiatic, 1 inguino-scrotal and 1 crural cases--and 1 double ureteral hernia, which was inguinal on the right-hand side and ischiatic on the left-hand side. Thus, we reviewed the main urographic and cystographic signs on the basis of a previous report by one of us. In discussing the new cases, we emphasize the importance of a few typical diagnostic signs, which follow: asymmetry and anomalous location of herniated organs, ureter protrusion beyond the pelvic bones outline, the presence of ureteral spiral ("curlicue sign"), and bladder walls indentation.

Female↗
PubMed1991

[Postoperative mortality and morbidity of patients in their late eighties].

During the 12 year period, 1978-1989, 555 operations were performed at the Department of Clinica Chirurgica III of the University of Bologna, on 530 patients greater than 80 years old at the time of surgery. These were the indications for surgical procedure in these patients: malignant neoplasm of digestive system (243), other diseases of the digestive system (111), abdominal wall hernia (74), biliary disease (77), miscellaneous (50). The purpose of this paper is to define the role of surgery in patients over 80 years old. An acute complication required an emergency operation in 295 cases (53%). In all the other cases (260, 47%) an elective operation was performed. There were 63 deaths with an operative mortality rate of 11%. Among the patients who underwent elective surgery there were 11 deaths (4%); in the emergency group there were 52 deaths (17.6%). These rates were found to be statistically significant. The overall morbidity rate was 37.6% in the elective group and 49% in the emergency group. Also these rates were found to have a statistic significance. Then we have compared morbidity and operative mortality of over-eighty years old patients with the ones of two younger groups of patients: I group (age greater than 80 years), II group (age 65-80 years), III group (age less than 65 years). Patients of the three groups had undergone identical surgical operations for the same pathology. The operative mortality was 11% in the I group, 5.2% in the II group and 1.4% in the III group. The morbidity was 46%, 30% and 17% respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

DNA binding properties of a new class of linked anthramycin analogs.

We have investigated the DNA binding properties of the anthramycin analogues 4, 5, and 6 using fluorescence spectroscopy. A considerable fluorescence enhancement occurs when pyrrolo [1,4] benzodiazepines (P[1,4]Bs) are covalently attached to duplex DNA, which was used to show that neither the presence of RNA, single-stranded DNA, or protein had any effect on the degree of fluorescence enhancement resulting from the incubation of 5 and 6 with DNA. The enhancement was found to be dependent on the presence of the imine functionality in each of the compounds. A wavelength of 320 nm was used to excite the chromophore and its emission wavelength maximum was 420 nm. Additionally, we have discovered that the P[1,4]B ring system exhibits exceptionally favorable fluorescence polarization anisotropy (FPA) decay characteristics. For these more detailed fluorescence measurements, we used the structurally simpler analogue 4,. The time resolved maximum FPA for 4 in glycerol at 25 degrees C is 0.28. This result indicates that the P[1,4]B family of antibiotics could serve as sensitive probes of DNA dynamics in the 0.1 to 35 ns time scale.

Animals↗
PubMed1991

Effects of psychotropic drugs on somatosensory evoked potentials in cerebral ischemia.

Several authors have demonstrated a correlation between short latency somatosensory evoked potentials (short latency SEPs) and cerebral blood flow (CBF). It is also known that ischemia may modify the amplitude of the cortical SEP while its latency is less sensitive to CBF fluctuations. Phychotropic drugs--Oxiracetam, SAMe, Naloxone, L-acetylcarnitine and GM1--affect some parameters of the early components of cortical SEPs, chiefly the amplitude, which makes SEP recording a useful method for monitoring pharmacological activity in acute stroke.

Brain Ischemia↗
PubMed1991

Thyrotropin alpha- and beta-subunit responses to thyrotropin-releasing hormone and domperidone in normal subjects and in patients with microprolactinomas.

Microprolactinoma is a particular pathological situation characterized by the presence of increased hypothalamic dopaminergic tone reactive to tumoral hyperprolactinemia. Since dopamine (DA) is a physiological regulating factor of the secretion of thyroid-stimulating hormone (TSH), we investigated the responses of serum TSH (holo-TSH) and its subunits (alpha-subunit: alpha-sub, and TSH-beta) to thyrotropin-releasing hormone (TRH) and domperidone (DOM; an antidopaminergic drug acting outside the blood-brain barrier) in 36 euthyroid subjects (20 controls and 16 patients with microprolactinoma) in order to evaluate the possible in vivo effects of DA excess on TSH subunit secretion. No significant difference in serum TSH increase after TRH (200 micrograms i.v.) was observed between patients with microprolactinoma and controls (TSH net incremental area under the curve, nAUC: 146 +/- 9, mean +/- SE, and 143 +/- 7.7 micrograms/l/60 min, respectively), while serum alpha-sub and TSH-beta responses were markedly reduced in patients with microprolactinoma as compared to those found in normals (alpha-sub nAUC: 3.0 +/- 0.5 vs. 19.8 +/- 2.2 micrograms/l/60 min, p less than 0.001; TSH-beta nAUC: 5.0 +/- 0.8 vs. 9.5 +/- 0.9 micrograms/l/60 min, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Anti-stress role of the melatonin-immuno-opioid network: evidence for a physiological mechanism involving T cell-derived, immunoreactive beta-endorphin and MET-enkephalin binding to thymic opioid receptors.

Our previous work showed that the pineal neurohormone melatonin induces activated T lymphocytes to release opioid peptides with immunoenhancing and anti-stress properties. Here we present evidence that these peptides crossreact with anti-beta-endorphin and anti-met-enkephalin antisera, and bind specifically to thymic opioid receptors. Furthermore, the same antisera injected in prednisolone treated mice prevented the normal recovery of thymus cellularity and of the capacity to mount a primary antibody response against T-dependent antigens. Surgical pinealectomy, i.e. inhibition of endogenous melatonin and absence of antigen activation negated the effect of such antisera demonstrating the physiological relevance of this melatonin-immuno-opioids network. It is proposed that function of this network may be that of driving a correct immune recovery after the depression caused by the elevated corticosteroids level associated with immune responses and/or stressful situations.

Animals↗
PubMed1991

Immuno-derived opioids as mediators of the immuno-enhancing and anti-stress action of melatonin.

The pineal neurohormone melatonin was shown to stimulate the release of opioid peptides from activated CD4+, T lymphocytes. These immuno-derived opioids or "lymphomorphins" crossreact with anti-beta-endorphin and anti-metenkephalin antisera, bind to opioid receptors in the thymus and are the mediators of the immunoenhancing and anti-stress action of endogenous and/or exogenous melatonin. These findings proved the existence of a novel immunoneuroendocrine physiological mechanism which may be related for the long range maintenance of the immune homeostasis in spite of the unavoidable stress and/or infectious events occurring during the span of life in a normal unprotected environment.

Animals↗
PubMed1991

[Comparison of iopamidol 150 and 370 with the same iodine dosage (37 g) in urography].

Two different volumes of iopamidol (250 and 100 ml, respectively) containing 37.5 and 37 g of iodine in different concentrations (150 mgI/ml and 370 mgI/ml) were injected in the same time (10 minutes) with varying injection rates, to compare diagnostic effectiveness, image quality, distension of the collecting system, and influence of the better iodine concentration. Sixty patients of both sexes were randomly subdivided into two groups. Their renal function, blood pressure and pulse rate were normal. Their weight ranged 55-85 kg, not to change the distribution volume of the contrast medium. None of them had been given iodine compounds recently. Radiographs were taken 2, 5, 15, 25, and 30 minutes after the end of the injection. The image quality of nephrograms, pyelograms, bladder views and the degree of collecting system filling were evaluated by a blind study, using grading scores (0 to 3). In both groups image quality and degree of filling were satisfying; the volume of injected iopamidol had poor significance. The clinical findings confirm that, with a nonionic contrast medium, iodine concentration in the collecting system is the most important factor for image quality.

Female↗
PubMed1991

Screening of HBV-DNA in chronic HBsAg carriers.

A series of 52 serum samples from chronic HBsAg carriers was tested for the presence of HBV-DNA by means of the Polymerase Chain Reaction (PCR) and Liquid Phase Hybridization (LPH). The samples were obtained from two groups of patients: group A included 34 chronic HBsAg carriers ("healthy" individuals) without hepatocytolysis or viral replication; group B included 18 chronic HBsAg carriers with signs of hepatocytolysis (ALT levels at least twice the normal value) and activated markers of viral replication. PCR was superior to LPH in group A, with 7/34 versus 5/34 positive samples being detected, respectively. No difference in sensitivity was found between the two techniques in group B, since 9/18 samples were positive both cases. The data stress the need to adopt PCR for the HBV-DNA screening of HBeAg-/HBsAg+-carriers.

Base Sequence↗
PubMed1991

[Relationship between blood insulin and arterial hypertension in obese adults].

The well know fact that high blood pressure and impaired glucose tolerance are frequently associated with obesity has suggested that hyperinsulinemia could represent one of the possible pathogenetic connections between obesity and systodiastolic hypertension. With the aim of verifying this hypothesis 67 obese subjects (36 hypertensive and 31 normotensive), males, were admitted to our study. All of the subjects underwent standard OGTT in order to measure their glycemic and insulinemic levels. No differences were found between two groups, as regard age and the degree of obesity; blood pressure values were significantly different (p less than 0.01). No significative differences were detected for glycemic and insulinemic levels between normotensive and hypertensive subjects; basal hyperinsulinemia was detected in a similar percentage (16.6 vs 19.3%) in the two groups. Under these circumstances it is not possible to confirm that hyperinsulinemia is the prominent link between obesity and high blood pressure, as previously observed by others.

Adult↗
PubMed1991

[Visceral toxocariasis. Description of 3 cases].

Three cases of visceral toxocariasis in adult patients are here described. Toxocariasis is a not uncommon, probably underestimated infection and the diagnosis should be considered also in adults who present clinical signs and it must be confirmed by serological tests.

Adult↗
PubMed1990

Role of 5-HT2 receptors in serotonin-induced contraction in the human mammary artery.

We studied the effects of serotonin (5-HT) on isolated human mammary arteries obtained from patients undergoing coronary by-pass grafting. 5-HT induced a concentration-dependent contractile response in the mammary artery, with an EC50 value of 0.34 microM. The 5-HT2 antagonist, ketanserin, reversed the contractions evoked by 5-HT in a competitive manner at a low concentration (10(-8) M), whereas non-competitive antagonism was apparent at higher concentrations (5 X 10(-8)-5 X 10(-7) M). To investigate whether the alpha 1-blocking component of ketanserin plays a role in the response observed in this vessel, we evaluated the effect of ketanserin on contractions induced by (-)-norepinephrine. Ketanserin, in concentrations up to 10(-7) M, did not influence the norepinephrine-induced contractions. Moreover, a threshold concentration of 5-HT (10(-7) M) amplified the contractile effect induced by norepinephrine (5 X 10(-8) M), and this response was inhibited by ketanserin (10(-7) M). The selective 5-HT3 antagonist, GR 38032F, did not affect the 5-HT-induced contractions. These findings indicate that the human mammary artery is a vascular tissue sensitive to 5-HT. The 5-HT2 receptor subtype appears to mediate the response.

Female↗
PubMed1990

5-Hydroxytryptamine induces contraction in isolated human mammary artery: effect of ketanserin.

5-hydroxytryptamine (5HT) treatment produced dose-related contractions in the human internal mammary artery with an EC50 value of 3.4 X 10(-7) M. The 5HT2 receptor antagonist ketanserin reversed the contractions evoked by 5HT in a competitive manner at a low concentration (10(-8) M), whereas a noncompetitive antagonism was apparent at higher concentrations (5 X 10(-8) M to 5 X 10(-7) M). The alpha 1-blocking component of ketanserin was evaluated by studying the effect of ketanserin upon the contractile response evoked by norepinephrine. Up to 10(-7) M, ketanserin did not influence norepinephrine-induced contractions. These findings indicate that the mammary artery is a vascular tissue sensitive to contractions induced by 5HT and that the drug ketanserin antagonizes this contractile response through the 5HT2 receptor subtype.

Female↗