PubMed Health⌕ Search

Biomedical subjects

A Porcu

Publications and source records attributed to A Porcu.

At least 37 records · Page 2Linked to original sources
PubMed1993

Progeny of mothers drinking corticosterone during lactation has lower stress-induced corticosterone secretion and better cognitive performance.

In order to test the hypothesis that maternal corticosterone influences hypothalamus-pituitary-adrenal (HPA) system activity in the adult rat and behaviors related to it, we induced a moderate increase in maternal plasma level of corticosterone by adding the hormone to the drinking water of the dams (200 micrograms/ml) from the day after delivery to weaning. Our previous experiments have shown that this procedure produces plasma levels of the hormone in the range of those following a mild psychic stress (from 4.3 +/- 0.5 to 9.5 +/- 1.8 micrograms/100 ml in the dams, and from 0.7 +/- 0.1 to 1.2 +/- 0.2 micrograms/100 ml in the pups at 10 days of lactation). Adrenal weights were slightly and temporarily decreased by treatment in both mothers and offspring. Only the male progeny was investigated in this study. Corticosterone-nursed rats had significantly less corticosterone and ACTH in basal conditions and after a 2 min restraint stress at 3 months of age, and showed better performances at weaning and at 1, 2 and 3 months of life in the Morris water maze. Our results demonstrate that a moderate increase in maternal corticosterone during lactation influences the activity of HPA axis and improves spatial learning ability of the adult offspring.

Adrenal Glands↗
PubMed1993

Hypothalamic involvement in the activation of the pituitary-adrenocortical axis by nerve growth factor.

Intravenous injection of nerve growth factor (NGF) into rats produces a dose-dependent (from 0.1 to 5 nmol/kg) increase in circulating concentrations of adrenocorticotropin (ACTH) and corticosterone. We have investigated whether this effect is produced through a direct action on a component of the hypothalamo-pituitary-adrenocortical axis. NGF (50 and 500 nM), added to the incubation medium of in vitro isolated pituitary segments or dispersed adrenal cells, did not modify either basal and stimulated release of biologically active or immunoreactive ACTH or release of corticosterone, respectively. The presence of NGF in the incubation medium of in vitro isolated hypothalami produced a dose-dependent (from 150 to 600 nM) increase of both release and content of some material with corticotropin-releasing bioactivity. The nature of this corticotropin-releasing bioactivity was determined directly by radioimmunoassays. Results have indicated that NGF induced an increase of both release and content of hypothalamic arginine-vasopressin (AVP), while no changes were observed in the release and content of hypothalamic corticotropin-releasing hormone (CRH). These results suggest that adrenocortical stimulation by NGF in vivo could be mediated by the release of hypothalamic AVP rather than CRH. The finding that in vivo NGF stimulatory effect was not abolished by the specific CRH antagonist alpha-helical CRH(9-41), while it was accompanied by an increase in circulating AVP levels, supports this interpretation. However, the fact that the hypothalamus is stimulated in vitro by NGF concentrations higher than those expected to reach this structure after systemic injection of active doses raises the possibility that other brain areas such as the hippocampus participate in NGF-induced adrenocortical activation.

Adrenal Cortex↗
PubMed1992

[Reducing bleeding during extracorporeal circulation interventions by high doses of aprotinin].

The great risk of severe infectious diseases transmission through blood transfusion, has increased during the last years the effort to reduce the bank blood and its derivates use. Many techniques have proposed to achieve this purpose during and post cardiopulmonary bypass: normovolemic hemodilution, perioperative blood autotransfusion, postoperative return of extra corporeal circuit and chest drains blood and the particular use of some drugs. In the last few years several reports have been presented in the literature concerning the reduction of intra and postoperative bleeding in cardiac surgery by high dose Aprotinin administration. A randomized study with the use of this pharmacologic agent is presented: a group of patients was treated with Aprotinin (shared in two subgroups receiving respectively a different dose of the drug) and a control group. The results were highly encouraging both because of the reduction of peri and postoperative bleeding and because of the bank blood use important reduction.

Adult↗
PubMed1992

[Temperature monitoring and sites of measurement of body temperature].

The authors report an investigation of 331 consecutive patients submitted to major surgery to evaluate the reliability of temperature monitoring in different body sites in relation to central temperature. After having considered the minimal temperature changes and the difficulties due to the different techniques used, it is concluded that the measurement at the middle 3rd of the oesophagus is the most reasonable measurements site.

Body Temperature↗
PubMed1992

[The propofol-fentanyl-pancuronium combination in aorto-coronary bypass. Experience and personal caseload].

The authors report the use of a total intravenous anaesthesia in CABG. An association of propofol-fentanyl-pancuronium with a bolus at induction, then with continuous perfusion was used. Hemodynamic and oxymetric data obtained from the right heart and radial artery samples show good hemodynamic stability during surgery. It is underlined that, in order to reduce possible hemodynamic changes it is very important to use, during the surgical procedure, the lowest drug concentration.

Aged↗
PubMed1992

[Circulation effects of noradrenaline in hyperdynamic septic shock].

The authors report on a group of 8 patients in septic shock, treated with NA in association with dopamine and/or dobutamine, according to a personal therapeutic protocol. The use of NA in septic shock with low SVR showed an improvement in hemodynamic condition and a higher survival rate in the treated patients. During the study many clinical, laboratory and microbiologic data were also recorded.

Female↗
PubMed1991

[Botallo's duct with pulmonary hypertension in the adult].

A patent ductus arteriosus in adults is a rare eventuality. After correct diagnosis, an accurate evaluation of pulmonary vascular resistances is necessary with, in case of normality, a straightforward indication to surgery, because the evolution of the disease cannot be predicted. In case of pulmonary hypertension irreversible pulmonary vascular damage must be excluded. Haemodynamic data such as pressures, flows and resistance ratios are not reliable. According to the majority of Authors the value of pulmonary resistances seems to be more accurate, and when more then 8 u/m2 an histological specimen must be obtained. In our experience a comparative study between the Health and Edwards method and the Yamaki et al., one shows, confirmed by postoperative follow-up, a greater reliability of the second one.

Adult↗
PubMed1991

[Peroperative blood autotransfusion in heart surgery].

A drastic reduction in homologous blood or plasma transfusion becomes necessary to prevent the risks of severe infections disease transmission. The authors studied the possibility of homologous blood save in cardiac surgery by peroperative autotransfusion. This procedure, although it diminished the average blood bank requirements, above all for an unexplained decrease in postoperative bleeding, did not obtain the good results that other authors had with the technique of 2 or 3 preoperative withdrawal, storage and postoperative reinfusion. In future our trend is to associate preoperative and intraoperative withdrawals to take advantage of both techniques.

Blood Loss, Surgical↗
PubMed1989

[Revascularization of the distal arteries of the lower limbs with "in situ" saphenous vein].

Over a 3-year period 21 patients underwent "in situ" saphenous vein by-pass graft for lower extremity arterial occlusive disease, all of them with critical ischemia for limb salvage. The proximal anastomosis was performed in all patients end to end to the first segment of the previously endarterectomized superficial femoral artery. The distal graft was taken to the popliteal artery below the knee in 8 cases, to the tibial-peroneal trunk in 4, to the posterior tibial artery in 3, to the peroneal artery in 3, to the anterior tibial artery in 2 and last a sequential posterior tibial-peroneal by-pass graft was performed. The perioperative mortality was nil. The immediate patency rate was 90.5%, while the cumulative patency rate at 36 months was 71.4% overall, 87.5% for the popliteal grafts and 61.1% for the infrapopliteal ones. If we consider that was successful for limb salvage in more than 80% and if the encouraging preliminary results of this technique will be confirmed at a longer follow-up, we believe that this technique could become the procedure of choice for limb salvage even in the high risk patients group.

Adult↗
PubMed1983

Chronic electrode for long-term electrophysiological recording from insect chemosensilla.

Insertion of a chronic, non-damaging Pt electrode for electrophysiological recording from chemosensilla in Phormia is described. The experimental procedure did not modify in a significant way the survival capabilities or the general behaviour of the operated insects as compared to control, untreated ones. This method, which allows the performance of subsequent tests on the same specimen up to its full lifespan with fairly constant results, proved to be suitable in long-term experiments on the chemosensory function of insects.

Animals↗
PubMed1983

Mechanism of JH influence on the function of labellar chemosensilla in Phormia: experimental suggestions.

The aim of this research study was to determine at which level the JH effect of increasing chemosensillar sensitivity in Phormia could take place. Two-day-old adult female Phormia regina (Meigen) flies were used. Variations in electrical resistance and spike firing frequency of labellar chemosensilla stimulated with NaCl solutions were measured before and after topical application of a JH analogue (JHA). Variations in the above two parameters were also determined in a group of control flies. Results showed that an inverse linear relationship exists between electrical resistance and spike firing frequency in both JHA-treated and control flies. On this basis, we conclude that the above sensitivity variations depend on a mechanism common to both groups of flies. As regards the mode of action of this mechanism, we suggest that JH may influence the mucopolysaccharide secretory function of the accessory cells, the activity of which seems to account for changes in electrical resistance and therefore in sensitivity of the labellar chemosensilla.

Animals↗
PubMedDate not supplied

[Unusual case of benign neoplasm of the breast mimicking a carcinoma: granular cell tumor. Case report].

Granular cell tumors are rare, usually benign neoplasms of soft tissues which most commonly occur in the tongue, skin and subcutaneous tissue. Although the histogenesis is still object of debate, recent immunohistochemical studies and ultrastructural findings support the origin of this neoplasm from the peripheral nervous tissue, most likely from Schwann's cells. Occurrence of this neoplasm in the breast, although uncommon, warrants special attention, since its clinical, mammographic and pathological appearances on frozen sections "may often closely resemble" hose of breast malignancy. The authors analyze and commenton, with special reference to clinical aspects and surgical treatment, a case of benign granular cell tumor of the breast occurring in a 42 year-old woman. The mammographic and clinical findings suggested a breast carcinoma. The correct diagnosis was established by definitive microscopic examination of the paraffin-embedded specimens and the treatment was a simple local excision of the tumour and a small rim of surrounding breast parenchyma. Although the granular cell tumor of the breast is a rare entity, surgeons and pathologists should be aware of its existence in order to avoid inappropriate radical surgery not justified by the benign behavior of the neoplasm.

Adult↗
PubMedDate not supplied

Three cases of cardiac hydatidosis: diagnosis, surgical treatment, and complications.

Three cases of cardiac hydatid disease from among the many cases of hydatidosis (>300) in various organs observed by the authors are reported. The sites of the cysts and the complications that arose are described. The first case developed hydatid pulmonary embolism caused by rupture into the right ventricular cavity, the second suffered peripheral hydatid embolism caused by rupture into the left ventricular cavity, and the third, whose diagnosis was fortuitous, had no complications. The first patient died shortly after admission. The other two underwent radical pericystectomy and partial pericystectomy with cardiopulmonary bypass. The best result was obtained in the third case where rupture had not occurred. The second patient recovered but developed hemiparesis. The various diagnostic tools available are discussed, as well as some technical aspects of pericystectomy, which has a high mortality rate. The importance of early diagnosis and treatment of this rare localization of Echinococcus granulosus is emphasized, and echocardiography is recommended even for nonspecific cardiac symptoms in areas where the parasite is endemic.

Adult↗
PubMedDate not supplied

[Primary aortoenteric fistula. Report of a case].

Primary aortoenteric fistulas (PAEF) are rare entities associated with a high mortality. Although several causes have been reported, their occurrence is usually due to erosion of an abdominal aortic aneurysm into the intestinal tract. The most common sites for the fistula are the third and fourth portions of duodenum. The classical triad of gastrointestinal hemorrhage, abdominal mass and abdominal or back pain, though highly suggestive for PAEF, is uncommon. The typical bleeding pattern associated with PAEF is characteristically intermittent, starting with a brief "herald bleeding" followed eventually by major gastrointestinal hemorrhage, often with fatal outcome. The pre-operative examinations are often not helpful and can lead to delayed diagnosis and surgery. In a patient with risk factors for atherosclerosis and significant upper gastrointestinal bleeding in the absence of an evident source, PAEF should be suspected. A high index of suspicion of this condition allows correct diagnosis and definitive treatment to be carried out. If PAEF is suspected and the patient is unstable the surgeon should be prepared to skip the preoperative investigations in favour of early surgical exploration. Definitive treatment includes primary duodenal repair and aortic aneurismal resection with graft "in situ" replacement. The authors present a successfully treated case and stress the importance of clinical suspicion in order to achieve correct diagnosis and treatment.

Aged↗
PubMedDate not supplied

[Our experience in the treatment of superior vena cava syndrome].

In clinical practice SVC syndrome is an important problem, given both the nature of the disease and its fast lethal evolution. Therapy must be instituted as soon as possible because the chances of a positive result are directly related to the staging of the primary illness. Surgery, chemotherapy and high energy therapy can be used. From the literature, although controversial, the superiority of surgical therapy is clear; particularly if up-to-date vascular reconstruction techniques are employed. From March 1980 to March 1988 8 cases of SVC syndrome were observed in which the aetiology was as follows: Hodgkin's disease (2 cases); secondary catheter thrombosis (1 cases); lung carcinoma (5 cases). The 2 cases of Hodgkin's disease were treated by chemotherapy; the secondary thrombosis by open thrombectomy. In the other 5 cases an innominate vein right appendage by-pass was used (3 PTFE, 2 pericardial grafts). The results were encouraging: complete, long-term remission was observed in the Hodgkin and thrombectomy patients. A PTFE graft thrombosis occurred in 2 cases but in the other cases the by-pass is functioning well at a mean 13 months follow-up.

Adult↗
PubMedDate not supplied

[The influence of click polarity and stimulation rate on the auditory evoked response in relation to age].

In order to study the changes which occur in phase of the click stimulus and its relation to the stimulus repetition rate on the auditory brainstem response (ABR) as a function of age, the Authors recorded the ABR from the scalp's surface of 10 newborns and 40 infants, 3 months, 6 months, 1 year and 3 years old as well as from 10 normal adults. The stimulus was a square wave of 0.1 msec duration and 90 dBHL level. The stimulus equipment was calibrated twice under visual inspection to ensure that the C and R clicks resulted in an initial membrane deflection toward and from the ear drum respectively. No significant differences could be found for the latencies and amplitude in the C-R comparison. However, the mean values of the complete group of test subjects showed most intraindividual stability for the conventional click stimulation. The latency of the ABR with excitation of the cochlea seemed to be mainly determined by the internal oscillation sequence in the cochlea and not by the stimulus polarity. The amplitudes and latencies of the ABR components tend to decrease when the stimulus rate increases and the age decreases. The importance of the stimulus characteristics is discussed and some suggestions for clinical use of ABR are made.

Acoustic Stimulation↗