Biomedical subjects

G Rosa

Publications and source records attributed to G Rosa.

At least 55 records · Page 3Linked to original sources

PubMed1997

[Surgery of the descending thoracic and thoraco-abdominal arteries. Report of 105 cases].

The Authors show their casistic of about 105 cases of thoracic descending and thoraco-abdominal aorta pathologies between 1.1.1993 and 30.12.1995. After a short introduction about the improvements in anesthesia and reanimation of these pathologies as well as the good reliability of diagnostic and currently available instruments, mortality and mobility parameters are taken into account, the last one referring to paraplegia and ARF. The casistic is evaluated splitting the cases into 2 groups, urgent surgery and election surgery, and differentiating the aneurysm type from the dissection type. Besides, the mortality and mobility are reported for any pathology, with a discussion of the parameters which drove the choice of the most suitable methodology to be adopted (ECC femoro-subclavian shunt, simple clamping). The results achieved show a mortality of 40% in urgency, between 5 and 15% in election, with a rate of paraplegia around 8-10% and a ARF between 5 and 15%. These data match the literature statistics and support the quality of the adopted methodologies.

Adult↗

PubMed1996

Localization of the dystrophin binding site at the carboxyl terminus of beta-dystroglycan.

Alpha- and beta-dystroglycan form a heteromeric transmembrane complex linking the extracellular matrix to the cytoskeleton. In muscle beta-dystroglycan interacts with dystrophin on the inside of the cell and with alpha-dystroglycan, which binds the extracellular matrix protein laminin, on the outside. Dystroglycan is expressed not only in muscle but also in other tissues. We cloned beta-dystroglycan from rabbit brain by RT-PCR and expressed deletion mutants of the beta-dystroglycan cytoplasmic domain as GST-fusion proteins. We identified the dystrophin binding region on beta-dystroglycan by protein overlay and co-precipitation assays with skeletal muscle dystrophin and recombinant apo-dystrophin I. We demonstrate that the beta-dystroglycan carboxyl terminus interacts with dystrophin and that the binding site is restricted to the last 20 amino acids. Our data also suggest that the region adjacent to the beta-dystroglycan transmembrane domain might modulate beta-dystroglycan-dystrophin interaction.

Animals↗

PubMed1996

Pharmacological characterization of the ETA receptor in the vascular smooth muscle comparing its analogous distribution in the rat mesenteric artery and in the arterial mesenteric bed.

The potency of ET-1, ET-2, and ET-3 to contract the isolated perfused rat arterial mesenteric bed was 2.73 +/- 0.57, 1.63 +/- 0.32, and 144 +/- 30 nM, respectively. The vasomotor effect of the ETs was slow in onset, persistent but reversible. Sarafotoxin S6b mimicked the ETs with a potency twofold lower than ET-1; sarafotoxin S6c and the C-terminal hexapeptide of ET-1 was inactive. ETH agonists such as IRL-1620 and AGETB-89 were inactive as vasoconstrictors within the range of concentrations examined. Minor chemical modifications of ET-1 amino acids residues in position 7 or 21 decreased significantly the peptide potency; ET-1 analogues with one or none of the disulfide bonds resulted inactive. The vasomotor effect of ETs was blocked in a competitive, reversible, and selective manner by FR 139317 and BQ-123, the latter being about threefold less potent than the former antagonist. The potency of FR 139317 was 20-fold higher to antagonize ET-3 than ET-1, and threefold higher to block ET-2 than ET-1. In strict analogy to FR 139317, BQ-123 was 12-fold more potent to antagonize ET-3 than ET-1, and fourfold more potent to antagonize ET-2 than ET-1. Upon removal of the endothelial cell layer, the vasomotor potency of ET-1 or the antagonist potency of FR 139317 remained unaltered, suggesting that the vasomotor receptors are localized in the arterial smooth muscles. The ET-1-induced vasomotor responses desensitized, an effect not crossed to noradrenaline (NA); perfusion with 10 microM indomethacin did not alter the vasomotor potency of ET-1, excluding the participation of eicosanoids in the arteriolar effects of ET-1. In isolated rings of the rat mesenteric artery, set to record isometric contractions of the circular muscular layer, the potency of the ETs and their structural analogues was as follows; ET-2 = ET-1 = sarafotoxin S6b > ET-3 > sarafotoxin S6c. The C-terminal hexapeptide of ET-1 and [Ala 1,3,11,15]ET-1 were inactive. The ET-1-induced vasoconstriction was antagonized in a concentration-dependent fashion by FR 139317. These results allow to conclude that the ETA receptors present in the arterial mesenteric circulation are localized in the vascular smooth muscle of the large-sized arteries as well as the smaller arterioles and precapillary vessels of the rat arterial mesenteric bed.

Animals↗

PubMed1996

[Spinal cord protection in surgery of the thoracic, descending, and thoraco-abdominal aorta. Comparison of methods].

The authors compare the strategus needed for the elimination of paraplegia and for protection of abdominal organs after replacement of descending thoracic or thoraco-abdominal aorta. They analyse single technique considering the advantages and the controindications; furthermore they compare these properties and those of possible variants in the light of the presentation; type of disease and general conditions of the patient. These considerations are in agreement with later literature as well as the attitude of the surgeon.

Aortic Aneurysm↗

PubMed1995

Control of post anaesthetic shivering with nefopam hydrochloride in mildly hypothermic patients after neurosurgery.

Postoperative shivering may be prevented by maintaining normothermia intraoperatively or it may be treated using specific drugs. The aim of this study was to compare the efficacy of nefopam hydrochloride (nefopam) to that of clonidine and meperidine in patients undergoing elective neurosurgical procedures. Three groups of patients were included in the study. Patients in group A (60) received i.v., at random, 20 mg of nefopam, 50 mg of meperidine or 150 micrograms of clonidine in the immediate postoperative period. The incidence of shivering and the time at which shivering ceased were noted, along with central temperature and main haemodynamic changes. Group B (20) received i.v., at random, either 10 mg of nefopam or saline before awakening from anaesthesia. The effects of nefopam on central temperature, oxygen consumption (Vo2), carbon dioxide production (VcO2), basal metabolic rate (BMR) and energy expenditure (EE) were investigated. Group C (10) received i.v. 20 mg of nefopam during surgery: cerebrospinal fluid pressure (CSFP), cerebral perfusion pressure (CPP) and electroencephalogram (EEG) were monitored. In group A nefopam stopped shivering in 95% of patients when compared to meperidine and clonidine, which were effective in 32% and 40% of patients respectively. In group B, only 10% of patients receiving nefopam had postoperative shivering, Vo2, VcO2 and EE were significantly lower in patients treated with nefopam than those in the control group. No changes in CSFP, CPP or EEG were observed in group C. In conclusion, nefopam seems to be more effective than clonidine or meperidine in quickly suppressing shivering, without producing significant adverse reactions.

Adult↗

PubMed1995

High IL-6 serum levels are associated with septic shock and mortality in septic patients with severe leukopenia due to hematological malignancies.

The serum levels of immunoreactive interleukin-6 (IL-6) and tumor necrosis factor (TNF) were analyzed in 14 leukopenic patients with documented sepsis, at 60 min (T0), 24 h (T1), and one week (T3) after the onset of sepsis syndrome. Sera from 10 leukopenic patients without sepsis (controls) were also tested. All septic patients had high IL-6 levels at T0. These levels persisted only in the seven patients who died of septic shock, presenting a 30-fold increase (p<0.001) as compared to the survivors and the controls. At T3, 7 survivors had recovered from sepsis and showed low IL-6 serum levels. The TNF serum concentration always <30 pg/ml in both the subjects and in the controls. The C-reactive protein (CRP) and clinical parameters appeared to be less specifically associated with shock and mortality than IL-6.

Adult↗

PubMed1995

[Pseudoaneurysms after carotid endarterectomy].

Pseudoaneurysms after TEA of the internal carotid artery are one of the rarest and most severe complications of this form of surgery. Their etiology appears to depend on 3 causes: a suturing defect due to technical errors made by the surgeon or to the incorrect choice of threads; an infections, and lastly the arterial wall weakened by TEA. The patch increases the risk of false aneurysm approximately four fold. We therefore agree with other authors that, in spite of the undoubted value of the patch in the prevention of restenosis, it must only be used in the presence of an internal carotid of small diameter (less than 4 mm). Contrary to what is reported in the literature we performed both these operations under loco-regional anesthesia and a detailed knowledge of this method allows is to be performed on the carotid axis. Only through a careful follow-up of all the carotids operated can the small dilations which often do not require surgical treatmente identified. The two cases reported here were treated by the removal of the pseudoaneurysms and its replacement with a prosthesis in one case and with the vena saphena in the other. Both were monitored with clinical examination and echo-Doppler and no recidivation has been reported to date.

Aneurysm↗

PubMed1995

[Relapsing epistaxis: embolization as treatment of choice].

Epistaxis is a very common disease. Fortunately it occurs most commonly in the anterior septal network of blood vessel and is therefore readily controlled with simple local measures. Severe posterior epistaxis is less frequent but is still a common and much more serious clinical problem and usually requires hospitalization. The classic treatment of these epistaxis is combined anterior-posterior nasal packing. Occasionally, however, this treatment does not control bleeding. The most popular alternative for these patient is arterial ligation. Initially only carotid ligation was performed. Later further advances in surgical technique and instrumentation, permitted internal maxillary and etmoid artery ligation to be carried out. However often arterial ligation cannot be easily performed in some ent departments and furthermore, surgical failure rate is not exceptionally high if one consider the numerous hypsilateral-contralateral arterial anastomoses present in the etmoid-nasal region. Fifteen patients with recurring nasal bleeding were treated with embolization between 1991 and 1993. Ten of them suffered of essential epistaxis while the other five had chronic local and/or systemic diseases (hereditary haemorrhagic teleangectasia and angiomas). Analysis of the results show a good control of bleeding in the first group of patients (90% after one embolization) and a satisfactory control in patients with haemorrhagic teleangectasia. In conclusion, owing to its efficacy, speed and safety therapeutic embolization with PVA particles may be considered treatment of choice in recurrent persistent epistaxis.

Adult↗

PubMed1994

[Handling of Foley catheter regarding urinary retention syndrome following vaginal surgery].

The post surgical urinary retention syndrome is a frequent problem after vaginal surgery. In many medical centers it is used a transurethral vesical drainage for three to five days with or without vesical reeducation to prevent it. In order to determine the importance of the time of drainage and vesical reeducation in the presence of this syndrome 106 patients submitted to vaginal surgery were studied at random and prospectively, in our service. Patients were distributed in three groups: the first one, with 37 women in which the drainage was withdrawn at 24 hours; in the second group it was retired at 72 hours and in the third group the drainage was removed at 72 hours with previous vesical reeducation. The results show that those patients who were less time under vesical drainage presented a minor frequency of urinary retention after surgery (24.3% vs 30.7% and 43.7%).

Adult↗

PubMed1994

[Laparoscopic surgery. Preliminary experience].

The first 23 cases of surgical laparoscopy carried out in the Obstetrics and Gynecology Department of the Valdivia Hospital are presented. The advantages of this surgical technique and its indication, in anexal pathology, specially in young women who wish to preserve their fertility is emphasized.

Adolescent↗

PubMed1994

[Invasion of the chest wall in primary lung neoplasms].

The authors analyse a series of 5 patients who underwent pulmonary and parietal resection between 1990 and 1993 due to non.microcytoma bronchogenic carcinoma with invasion of the thoracic wall. The patients comprised four men and one woman aged between 45 and 69 years old. Thoracic pain was present in two patients. Pulmonary resection with extrapleural stripping was performed in two patients whereas a block resection from one to five ribs and the corresponding intercostal spaces was performed in the other three patients. The authors' approach is not to perform these operations according to rigid protocols but to adapt them according to the local status of tumour invasion. Therefore to resort to extrapleural resection when there is a free cleavage plane between parietal pleura and rib wall; resection in block of the wall where the carcinoma has infiltrated the endothoracic fascia or deeper. The authors do not report any major complications and record a postoperative mortality rate of 0%. In two cases the thoracic wall was reconstructed using a sheet of Gore-Tex which did not provoke rejection phenomena. Radiotherapy was carried out in cases with positive lymph nodes. The series presented here is too recent to provide significant data regarding survival. However, the only factor seen to influence prognosis in the five patients was the presence or otherwise of lymph node metastasis, irrespective of the histological type and operation performed. The five year survival rate of T3N0M0 patients is in fact similar to that of T2N0M0 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1994

[Appendicular mucocele. A report of a case diagnosed preoperatively].

Mucocele of the appendix is an unusual clinical entity. Despite a recognized constellation of findings, the diagnosis is not usually made prior to surgical exploration. A 35 year old man is reported in whom clinical evaluation, including US and CT scans, resulted in the correct preoperative diagnosis confirmed at surgery and leading to appropriate operative decisions.

Adult↗

PubMed1994

[Continence in low resections].

Anorectal function is an important problem after low anterior resection procedure. This paper reports the results from 14 patients undergoing to low resection at Surgical Pathology Institute of the University of Verona. In 12 cases the restoration of the bowel continuity has been obtained by colon-anal anastomosis (Parks Operation) and in 3 cases by colo-rectal anastomosis at the anorectal ring level. The patients have been examined in the preoperative and in the postoperative period by clinical and manometric study. The results confirm that low resection does not involve faecal continence.

Anal Canal↗

PubMed1994

[Myomectomy to preserve fertility].

Myomectomies were performed an 38 patients and 69.9% of this patients become pregnant. The importance of this intervention is highlighted for the significance of pregnancy in older women.

Adult↗

PubMed1994

Iron uptake from lactoferrin by intestinal brush-border membrane vesicles of human neonates.

It is uncertain to what extent the binding of human lactoferrin (LF) to its receptor in the intestinal brush-border membrane affects iron uptake in infants. The purpose of this study was to investigate iron uptake from human LF by brush-border membrane vesicles (BBMV) obtained from the small intestine of human neonates. LF was purified from pooled human colostrum. Uptake experiments were performed by incubation of 55Fe-citrate or 55Fe-LF with BBMV, followed by rapid filtration through microporous filters. 55Fe uptake from LF by BBMV was dependent on pH, with a maximum at 7.5, and increased with incubation time, reaching a maximum at 1 min. When 55Fe was bound to citrate, uptake was slower (maximum at 5 min) and not dependent on pH. In both experiments, the maximum uptake of iron bound to LF was about twice that of iron bound to citrate (230 pmol and 105 pmol/mg microvillus protein, respectively). Partial degradation of LF in two fragments resulted in the loss of its capacity to increase iron uptake by BBMV. From these preliminary results we conclude that LF may increase iron absorption during the neonatal period, contributing to the high bioavailability of this mineral in human milk.

Colostrum↗

PubMed1994

Alcohol consumption among high school students and young athletes in north Italy.

Alcohol consumption was assessed among 366 male high school students and 330 young men playing in sports teams. On the average, the athletes drank less wine, beer and spirits than the students and reported fewer drunkenness episodes. The association of alcohol drinking with sporting activity and with some independent variables was estimated by logistic regression techniques, fitting models for ordinal or nominal response variables. Point estimates of the odds ratios and their confidence limits showed: 1) an inverse relationship between alcohol drinking and sporting activity, especially as regards the consumption of spirits; 2) a strong positive relationship of alcohol drinking with both experimental and regular smoking; 3) peer alcohol drinking (best friend's and girlfriend's drinking) was the strongest predictor of the participant's alcohol consumption.

Adolescent↗

PubMed1993

[Hepatic resection. A contribution and its analysis].

The authors outline their experience in the field of resective hepatic surgery, both with regard to benign and malignant pathologies, and analyse the results in relation to indications and techniques, but also focusing attention on the assessment of postoperative functional alterations, in order to evaluate the hepatic reserve and the organ's response to demolitive surgery. All operations were carried put in the First Division of Surgery at the Ospedale Civile, Asti, from January 1989 to September 1992. In all cases, even in major hepatectomies, a "trans-parenchymal" technique was adopted. Before surgery tests were carried out in relation to the topography of disease, its nature, associated pathologies and the functional hepatic reserve. Operative mortality was zero and morbidity was negligible, probably because rigorous selection criteria and indications for surgery were adopted. Morbidity was even restricted in the two patients suffering from HCC on cirrhosis (?) and this may probably be attributed to the limitation of resection to solely oncological purposes and their classification as Child-Pugh's stage A. The results regarding the liver response to demolitive surgery appear to be indicative and revealed a highly significant and discriminating difference between elective and emergency surgery.

Adolescent↗

PubMed1993

Energy cost and efficiency of riding aerodynamic bicycles.

Traction resistance (Rt) was determined by towing two cyclists in fully dropped posture on bicycles with an aerodynamic frame with lenticular wheels (AL), an aerodynamic frame with traditional wheels (AT), or a traditional frame with lenticular wheels (TL) in calm air on a flat wooden track at constant speed (8.6-14.6 m.s-1). Under all experimental conditions, Rt increased linearly with the square of air velocity (v2a); r2 equal to greater than 0.89. The constant k = delta Rt/delta v2a was about 15% lower for AL and AT (0.157 and 0.155 N.s2 x m-2) than for TL bicycles (0.184 N.s2 x m-2). These data show firstly, that in terms of mechanical energy savings, the role of lenticular wheels is negligible and, secondly, that for TL bicycles, the value of k was essentially equal to that found by others for bicycles with a traditional frame and traditional wheels (TT). The energy cost of cycling per unit distance (Cc, J.m-1) was also measured for AT and TT bicycles from the ratio of the O2 consumption above resting to speed, in the speed range from 4.7 to 11.1 m.s-1. The Cc also increased linearly with v2a, as described by: Cc = 30.8 + 0.558 v2a and Cc = 29.6 + 0.606 v2a for AT and TT bicycles. Thus from our study it would seem that AT bicycles are only about 5% more economical than TT at 12.5 m.s-1 the economy tending to increase slightly with the speed.(ABSTRACT TRUNCATED AT 250 WORDS)

Aerobiosis↗