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Biomedical subjects

R Rossi

Publications and source records attributed to R Rossi.

At least 235 records · Page 13Linked to original sources
PubMed1996

Emergency medical training for dental students.

Twenty-four of the thirty-two German universities that have dental schools replied to a questionnaire survey that showed that all the schools responding held lectures on the topic "Medical Emergencies" although this is not mandatory for registration. All of the universities in the former East Germany also offered practical training sessions as part of the curriculum. The proportion of West German universities offering such courses is only 60%. The basic essentials of the theory and practice of emergency medicine should only be taught in courses with mandatory participation.

Education, Dental↗
PubMed1996

[Shortening of atrioventricular interval improves ventricular filling and clinical outcome in patients with DDD pacemaker and left ventricular hypertrophy].

The influence and clinical consequences of different atrioventricular delays on ventricular filling have been studied in 30 patients (mean age 60 +/- 5 years) who implanted DDD pacemaker for complete A-V block. All patients presented a normal ejection fraction: 63.9 +/- 6.5%. In 18 subjects (Group I) an echo-Doppler examination revealed ventricular hypertrophy (mean end-diastolic wall thickness of 1.4 +/- 0.16 cm; left ventricular mass index 155 +/- 17 g/m2) and an abnormal relaxation pattern (isovolumic relaxation time 124 +/- 11: early to late peak velocity 0.6 +/- 0.03; deceleration time of the early diastolic peak 296 +/- 34 ms). Group II included the remaining 12 patients without left ventricular hypertrophy and normal filling pattern. In all 30 patients the filling pattern was reassessed following modification of the A-V delay (200, 150, 100 and 75 ms). Patients at baseline (200 ms of A-V delay) underwent an exercise test with determination of respiratory gas exchange. In Group I, 13 (72.5%) patients were classified as Weber class B (VO2 max 16.8 +/- 1.7 ml/min/kg) and 5 (27.5%) as class A (VO2 max 22.5 +/- 1.4 ml/min/kg). In Group II, all 12 patients were classified as Weber class A (VO2 max 23.1 +/- 1.1 ml/ min/kg). In Group II, changes in A-V delay caused no homogeneous variation in filling pattern. A-V delay was not modified in this group. In Group I, the reduction of A-V delay to 100 ms resulted in filling normalization. In this group A-V delay was programmed definitely to 100 ms. Graded exercise test repeated at 6 months follow-up showed an improved Weber class in 13 patients (from B to A) and greater VO2 max in the remaining 5 already in class A. We conclude that, in sequential paced patients with normal ejection fraction but abnormal relaxation pattern, a modification of A-V delay can induce filling normalization and improve cardiac functional capacity.

Atrioventricular Node↗
PubMed1996

[Brain metastases in patients with malignant ovarian epithelial tumors].

From September 1983 to September 1994, 23 patients with Central Nervous System (CNS) metastases from ovarian carcinoma were observed in our institution. The mean age at the time of CNS metastases diagnosis was 59 years, the mean interval between diagnosis of ovarian carcinoma and documentation of the CNS involvement was 35 months. All the patients presented neurological symptoms. One patient had meningeal carcinomatosis; 22 presented parenchymal lesions. Nine patients had a single CNS lesion and 13 had multiple metastatic sites. CNS was the only site of disease in 9 patients, while 8 had concomitant extraperitoneal dissemination. Four patients received hormonal treatment with a mean survival (MS) of 3 months; 14 received radiotherapy alone (MS 5.5 months), 5 underwent surgical resection of solitary lesion followed by radiotherapy (MS 17 months). Number of CNS lesions, extent of the disease at time of CNS metastases and the treatment were the factors which significantly affected survival. The prognosis of these patients appears poor, however, early diagnosis followed by multimodal treatment may result in significant palliation an improve overall survival in a selected group of patients.

Adult↗
PubMed1996

[Handling of thyroid diseases: usefulness and limitations of rapid and fine-needle percutaneous biopsy].

Fine needle aspiration biopsy of the thyroid (FNAB) has become an accepted procedure for evaluation of the thyroid nodule, with 899 performed at the Lahey Clinic from 1981 to 1990. We examined them by medical record, pathology, and cytology review, with follow-up by chart or personal communication. Three-hundred-forty-five came to surgery, of which 188 (34%) were malignant; the specificity of the aspirate was 97%, sensitivity 92%, with false negative of 8% and false positive of 3%. By comparison, the frozen section had a false negative rate of 1% and false positive rate of 5%. In combination with frozen section, the fine needle aspirate result improved the accuracy of the intraoperative estimate of malignancy (p = 0.03). When the aspiration was benign but the lesion was clinically suspicious, a cancer was found at surgery in 13% of cases. Of the patients observed for a minimum of 5 years, 1.3% developed a carcinoma. Both cases had a non diagnostic FNAB None of the patients with a clinical and cytological benign lesion developed cancer. The complication rate of FNAB was 1.3% FNAB is a helpful and low risk diagnostic procedure but it needs to be done and read appropriately and its result used within the clinical context. Each medical team needs to monitor their results (continued quality control).

Biopsy↗
PubMed1996

[Positron emission tomography (PET) with fludeoxyglucose F 18 in the study of adrenal masses: comparison of benign and malignant lesions].

In this study, 15 patients (4 men and 11 women, mean age: 50 +/- 13 years) with unilateral adrenal masses detected on ultrasound (US), Computed Tomography (CT) and/or Magnetic Resonance (MR) studies were submitted to positron emission tomography (PET) with fluorine-18 deoxyglucose (FDG). Histology demonstrated 3 adenomas, 1 myelolipoma, 1 angiolipoma, 1 neurinoma, 1 cyst, 1 malignant pheochromocytoma, 4 carcinomas and 3 metastases. The patient population was divided into two groups. Group 1 (n = 7) consisted of benign adrenal lesions. Group 2 consisted of malignant adrenal tumors. Lesion measurements were performed on the basis of the results of US, CT and/or MR images. In Group 1, no FDG uptake was observed in adrenal masses. Conversely, in Group 2 adrenal lesions showed abnormally increased FDG uptake, suggesting high glucose tumor metabolism. No significant difference in lesion size was observed between Groups 1 and 2 (5.6 +/- 4.0 vs 6.3 +/- 3.0 cm). Furthermore, in 6 patients of Group 2, total body PET images showed abnormal FDG uptake in extra-adrenal locations, such as chest (n = 2) and abdominal (n = 5) lymph nodes, lungs (n = 6), liver (n = 5), pancreas (n = 1), bone (n = 1) and muscle (n = 1) tissues. In conclusion, the results of this study suggest that PET imaging with FDG can characterize adrenal masses. In particular, abnormally increased FDG uptake in adrenal malignancies allows to differentiate these abnormalities from benign lesions. Furthermore, total body imaging PET can identify extra-adrenal tumor sites in patients with malignant tumors.

Adrenal Gland Neoplasms↗
PubMed1996

Helicobacter pylori infection in families of Helicobacter pylori-positive children.

Relatives of Helicobacter pylori positive patients show a higher incidence of Helicobacter pylori infection than the general population, probably due to relapses and/or reinfections between members of the family. Aim of this study was to evaluate the prevalence of the infection in 121 relatives of 41 children with Helicobacter pylori positive gastritis. Specific IgG antibodies (ELISA) were evaluated, and bacteria on gastric biopsy specimens were investigated by urease-rapid test, culture test and GIEMSA or acridine orange staining. Of the eighty-two relatives, 68% were antibody positive. Thirty-five agreed to undergo endoscopy. With the exception of one brother, all subjects (97%) were found to be infected by Helicobacter pylori. Two symptomatic relatives, with normal antibody titres, were submitted to endoscopy and found to be colonized by Helicobacter pylori. The present data confirm the high prevalence of infection within families and appear to demonstrate the usefulness of endoscopy for all subjects showing positive antibody titres as well as for symptomatic relatives, even if serologically negative, to confirm the presence of any pathological conditions and reduce the risk of relapses within families.

Antibodies, Anti-Idiotypic↗
PubMed1996

[Liver neoplasms in patients with glycogen storage disease. Diagnostic and therapeutic problems].

In a family composed by eight brothers, five had a type I glycogen storage disease and three presented with liver tumors complicated with hemorrhage or malignant transformation, during the follow up. The periodic ultrasonographic control allowed the early diagnosis of these neoplasms. We describe the clinical picture and treatment of two patients. Metabolic alterations were corrected during the preoperative period with parenteral nutrition. Resection was successful in both cases. It is concluded that a close follow up and early treatment of these lesions is effective and avoids complications. In patients with multiple lesions and severe metabolic alterations, liver transplantation is the treatment of choice.

Adult↗
PubMed1996

[The imperative of medical involvement in the implementation of quality control systems].

Changes in health care delivery in Chile over the last years include rising costs and the relative increase of prepaid private insurance programs. It is expected that there will be increasing pressures on health providers to decrease cost while maintaining or improving quality. A series of common clinical problems are reviewed (hernia repair, appendicitis, gallstone disease, trauma, preoperative evaluation) to demonstrate that using a scientific method-continuous quality improvement- and considering the local socioeconomic reality, this challenge can be met. Emphasis is made on the need for physicians to participate in such a process and on the teaching of these concepts. Medical societies and schools should consider these health care developments and adopt to this changes.

Cost-Benefit Analysis↗
PubMed1995

Survival after early treatment for carbamyl phosphate synthetase (CPS) I deficiency associated with increase of intramitochondrial CPS I.

The basis for the benefit of early treatment in urea-cycle defects might be an increase in intramitochondrial mutant enzyme in hepatocytes in the postnatal period. In two siblings with carbamyl phosphate synthetase I (CPS I) deficiency, immunoreactive CPS I was greatly reduced in the liver and no residual enzyme activity was detectable. The elder child died at age 4 days, before the diagnosis of CPS I deficiency was established, but in the younger child, age 9 months, treatment was initiated on the 2nd day of life when ammonia concentration was moderately increased, and she has survived. Intramitochondrial CPS I was substantially higher in this sibling than in the elder sister. The different outcome in the younger patient was probably attributable to prompt treatment after early diagnosis.

Amino Acid Metabolism, Inborn Errors↗
PubMed1995

Hyperpolarization of the liver cell membrane by palmitate as affected by glucose and lactate: implications for control of feeding.

Since the membrane potential of liver cells being in contact with vagal afferents has been proposed to represent a major signal in metabolic control of food intake, we investigated the effect of palmitate, glucose and lactate on the membrane potential of hepatocytes with microelectrodes using superfused mouse liver slices. The mice used for the experiments were fed a fat-enriched diet (18% fat). Palmitate (0.5 mM) hyperpolarized the membrane of hepatocytes by 3-4 mV, and this hyperpolarization was not affected by 5-10 mM glucose and 0.5-1 mM lactate. Glucose alone did not influence the potential, even when mice fed a high carbohydrate diet were employed. At lactate concentrations > or = 2 mM the palmitate induced hyperpolarization was eliminated and 5 mM lactate or pyruvate alone hyperpolarized the liver cell membrane. Similar to the palmitate induced hyperpolarization, the lactate induced hyperpolarization was prevented by the K-channel blocker TEA, suggesting that activation of K channels is involved in the hyperpolarization. The results show that physiological concentrations of glucose and lactate do not affect the hyperpolarization of the liver cell membrane due to fatty acid oxidation. The implications of these findings with regard to control of food intake by fatty acid oxidation and lactate metabolism are discussed. The observations are consistent with a signal function of the hepatic membrane potential in physiological control of food intake by fatty acid oxidation. Hepatic lactate metabolism at supraphysiological lactate concentrations may also produce a satiety signal coded by the hepatic membrane potential.

Animals↗
PubMed1995

Hydrocephalus, skeletal anomalies, and mental disturbances in a mother and three daughters: a new syndrome.

We report on a family in which a mother and her 3 daughters have delayed psychomotor development and/or psychosis, hydrocephalus with white matter alterations, arachnoid cysts, skeletal anomalies consisting of brachydactyly, and Sprengel anomaly. Biochemical and cytogenetic analyses were normal on all 4 patients. The pattern of inheritance, clinical manifestations, and variability of expression suggest that this is a new hydrocephalus syndrome possibly transmitted as an X-linked dominant trait.

Adolescent↗
PubMed1995

Characterization of human DNA ligase I expressed in a baculovirus-insect cell system.

The baculovirus expression system was used to overexpress human DNA ligase I (hLig I). Approx. 2 mg of recombinant hLig I was produced per 10(8) Spodoptera frugiperda Sf9 insect cells infected with the recombinant baculovirus. The optimum time point for the production of biologically active recombinant hLig I was 48 h post-infection. Lig I activity was demonstrated by auto-adenylating, polynucleotide joining and DNA relaxation assays. The baculovirus system has the advantage over previously described methods for producing hLig I of generating large amounts of a full-length active protein.

Animals↗
PubMed1995

Effect of propionyl-l-carnitine and enalapril on cardiac function of pressure-overloaded rats during increase in load.

Chronic administration of propionyl-l-carnitine has been recently shown to correct hypertrophy related abnormalities in muscle mechanics. Accordingly, this study investigated whether the drug would similarly improve cardiac dynamics in rats with pressure overload. Enalapril was used for comparison. Drugs were administered in the drinking water for 3 weeks to Wistar Kyoto rats with a 2 week abdominal aortic constriction. Cardiac function was studied under urethane anaesthesia in basal conditions, during increase in preload, and during increase in afterload. Basal cardiac function was comparable in pressure-overloaded and sham-operated animals. Neither propionyl-l-carnitine nor enalapril affected the basal performance. Compared to sham-operated animals, untreated pressure-overloaded rats showed an impaired cardiac response (cardiac output, stroke volume) to preload increase induced by saline i.v. infusion. Propionyl-l-carnitine dose dependently improved cardiac function in the range 30-180 mg/kg, without affecting cardiac hypertrophic growth. Enalapril (3 mg/kg) reduced cardiac hypertrophy and improved cardiac function. The two effects were unrelated. The afterload increase by total aortic occlusion evidenced a reduction in the left ventricle pressure generating capacity of hypertrophied hearts. Propionyl-l-carnitine did not modify this parameter, while enalapril afforded a significant improvement. Results show that propionyl-l-carnitine significantly improves in vivo cardiac dynamics under conditions of increased energy demand. The effect is not due to inotropic efficacy, but presumably to increased cardiac efficiency.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1995

The N-terminal domain of human DNA ligase I contains the nuclear localization signal and directs the enzyme to sites of DNA replication.

DNA replication in mammalian cells occurs in discrete nuclear foci called 'replication factories'. Here we show that DNA ligase I, the main DNA ligase activity in proliferating cells, associates with the factories during S phase but displays a diffuse nucleoplasmic distribution in non-S phase nuclei. Immunolocalization analysis of both chloramphenicol acetyltransferase (CAT)-DNA ligase I fusion proteins and epitope tagged DNA ligase I mutants allowed the identification of a 13 amino acid functional nuclear localization signal (NLS) located in the N-terminal regulatory domain of the protein. Furthermore, the NLS is immediately preceded by a 115 amino acid region required for the association of the enzyme with the replication factories. We propose that in vivo the activity of DNA ligase I could be modulated through the control of its sub-nuclear compartmentalization.

3T3 Cells↗
PubMed1995

Differential effects of deltorphin on arginine and galanin-induced growth hormone secretion in healthy man.

Recently we demonstrated the inhibitory action on Growth Hormone (GH) secretion of an opioid heptapeptide, deltorphin (DT), that is highly selective in binding delta-opioid receptors. To investigate the possible mechanism leading to the decrease in GH secretion by specific activation of delta-opioidergic pathway in man, we compared, in normal subjects, the effect of DT on GH secretion responses to two different GH secretagogues, namely arginine (ARG) and galanin (GAL). DT completely blunted the GH response to ARG, whereas it attenuated the GH response to GAL, but not at a statistically significant level. We suggest that the specific activation of delta-opioid receptors in man may exert an inhibitory influence on GH secretion principally by modulating endogenous hypothalamic somatostatin (SRIH) release.

Adult↗
PubMed1995

Thiol groups in proteins as endogenous reductants to determine glutathione-protein mixed disulphides in biological systems.

A novel method for glutathione-protein mixed disulphide (GSSP) determination, based on the use of protein sulphydryl groups as endogenous reductant and on the spectrophotometric determination of reduced glutathione, is described. The procedure is based on the observation that acid-precipitated proteins from different rat tissues rapidly release GSH from GSSP when brought to neutral pH. The basal GSSP content determined in rat liver, heart, lung, testis, spleen and brain corresponded to that reported in the literature and determined by more complex sample preparation or labor-intensive analytical procedures.

Animals↗
PubMed1995

Cytokine response to inactivated Candida albicans in mice.

Inactivated Candida albicans (CA) cells induce strong activation of natural cytotoxic effectors in mice. In the present study we examined the expression of cytokine genes involved in the immune response to CA. It has been reported that differential cytokine production by natural immune cells is important for regulating the development of specific TH response. Northern blot analysis was performed on peritoneal exudate cells (PEC) recovered from CD2F1 mice injected ip with five doses of CA (CA-5d, on Days -14, -10, -7, -3, 0 with respect to the in vitro assays at 2, 24, and 72 hr) or from mice injected ip with four doses of CA (CA-4d, on Days -14, -10, -7, -3 with respect to the in vitro assay on Day 0). On Day 0, before the fifth CA injection, PEC expressed a high level of IL-2 and a low level of IL-1 beta mRNAs while genes coding for IL-4, IL-5, IL-6, IL-10, IL-12, TNF alpha, and IFN gamma were not expressed and there was a high level of NK activity. Two hours after CA-5d a high level of IFN gamma and a low level of IL-10 mRNAs were already evident, while IL-2 and much more IL-1 beta had greatly increased. IL-6, TNF alpha, and IL-2R alpha chain mRNAs were also detectable, whereas IL-4, IL-5, and IL-12 were not expressed. IL-12 mRNA was also absent in earlier stages of the CA sensitization. Both cellularity and NK activity of peritoneal exudate had increased with respect to Day 0. At 24 hr whereas IL-2 mRNA remained high, both IL-1 beta and IFN gamma mRNAs expression had decreased. Expression of other cytokines was no longer detectable but NK activity remained high and a significant LAK activity was also induced. After 72 hr, while the IL-2 mRNA level and NK activity were still high the IL-1 beta mRNA expression had further decreased. These results indicate that CA induces a predominant production of IFN gamma and IL-2, cytokines involved in the development of TH1 response but it is unable to induce IL-12. This secondary pathway, without IL-12 involvement in the development of TH1 response, is probably the result of the ability of IL-2, IL-1 beta, and TNF alpha to synergize in inducing IFN gamma synthesis by NK cells.

Animals↗