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Biomedical subjects

G Rosa

Publications and source records attributed to G Rosa.

At least 37 records · Page 2Linked to original sources

Characterization of the beta-dystroglycan-growth factor receptor 2 (Grb2) interaction.

The beta-dystroglycan/Grb2 interaction was investigated and a proline-rich region within beta-dystroglycan that binds Grb2-src homology 3 domains identified. We used surface plasmon resonance (SPR), fluorescence analysis, and solid-phase binding assay to measure the affinity constants between Grb2 and the beta-dystroglycan cytoplasmic tail. Analysis of the data obtained from SPR reveals a high-affinity interaction (K(D) approximately 240 nM) between Grb2 and the last 20 amino acids of the beta-dystroglycan carboxyl-terminus, which also contains a dystrophin-binding site. A similar K(D) value (K(D) approximately 280 nM) was obtained by solid-phase binding assay and in solution by fluorescence. Both Grb2-SH3 domains bind beta-dystroglycan but the N-terminal SH3 domain binds with an affinity approximately fourfold higher than that of the C-terminal SH3 domain. The Grb2-beta-dystroglycan interaction was inhibited by dystrophin in a range of concentration of 160-400 nM. These data suggest a highly regulated and dynamic dystrophin/dystroglycan complex formation and that this complex is involved in cell signaling.

Animals↗

Elimination of bancroftian filariasis (Wuchereria bancrofti) in Santa Catarina state, Brazil.

During the 1950s, three foci of Wuchereria bancrofti transmission were identified in the State of Santa Catarina, Brazil. In Florianópolis, São José da Ponta Grossa and Barra da Laguna community treatment of bancroftian filariasis with diethylcarbamazine (DEC) was performed using two distinct approaches, without vector control or improvements in sanitation. In two of the three communities only microfilaraemic individuals were treated, while in Barra da Laguna the entire population received DEC treatment regardless of their infection status. In both cases, transmission of the parasite was blocked and no new cases were detected in all localities for up to 10 years. Recently, a new survey in São José da Ponta Grossa and Barra communities revealed no microfilaria-positive individuals, including residents that were positive in the 1950s. These data confirm that transmission of W. bancrofti was interrupted in Santa Catarina, and mass treatment appears to be more effective than treatment of microfilaraemic individuals only.

Animals↗

The influence of dietary nucleotides and long-chain polyunsaturated fatty acids on the incorporation of [3H] arachidonic acid on experimental liver cirrhosis.

The purposes of this study were to determine: a) the incorporation of labeled [3H] arachidonic acid on the intestinal mucosa, the liver and plasma, after 1,3 and 5 hours of administration, b) preferential incorporation by different tissues, c) and the effects on experimental rats with thioacetamide-induced cirrhosis, after four weeks of a dietary supplementation with nucleotides and long-chain polyunsaturated fatty acids. 209 female Wistar rats were divided into two groups (control and TAA group). The TAA group was given 300 mg of thioacetamide/L, in their drinking water for four months. After this period, a sample of 6 rats were taken from each group and examined, to evaluate the biochemical and histological changes of the experimental model, and 36 rats were taken to determine the incorporation of radioactivity by the groups. The rest of the animals were divided into four subgroups. Each group, receiving a supplementary diet with only long-chain polyunsaturated fatty acids and/or nucleotides or neither, for 4 weeks. After four months of thioacetamide, the incorporation of the [3H] arachidonic acid showed: a) an increased within 3 h in the intestinal mucosa, b) a decreased in the liver after 3 to 5 h c) and a drastic decrease in the plasma after 3 to 5 h. With a dietary supplementation of long-chain polyunsaturated fatty acids and nucleotides combined, there was a decrease of accumulate [3H] arachidonic acid in the intestine and a increase in the liver and plasma. The simultaneous supply of dietary polyunsaturated fatty acids and nucleotides was beneficial in the reversal of abnormalities of the lipid metabolism, in this experimental model of liver cirrhosis.

Analysis of Variance↗

Pulmonary transit of sonicated albumin microbubbles during controlled mechanical ventilation: a transthoracic echocardiographic study.

UNLABELLED: Air-filled human serum albumin microspheres are ultrasonic contrast tracers that pass through the right ventricle, traverse the lungs, and effectively opacify the left heart chambers in spontaneously breathing patients. In this clinical study, we assessed whether they also do so in anesthetized patients during and after mechanical ventilation. In 20 anesthetized patients undergoing intermittent positive pressure ventilation (IPPV) for elective peripheral neurosurgical procedures, a sonicated ultrasound contrast drug (0.06 mL/kg) was injected i.v. before inducing anesthesia in spontaneously breathing patients (baseline), during IPPV, and 5 and 30 min after tracheal extubation. Transthoracic echocardiograms were obtained in the four-chamber apical view and were recorded for off-line analysis. Time to contrast appearance in the right ventricle and pulmonary transit time were measured in cardiac cycles. The peak intensity of right and left ventricular chamber opacification were scored on a scale ranging from 1 (no contrast or traces only) to 5 (attenuation). After each injection, the time for contrast appearance in the right ventricle was similar in all patients. Pulmonary transit time increased significantly during IPPV and was normal 5 min and 30 min after extubation. Right ventricular chamber opacification achieved high-grade intensity and remained constant before, during, and after IPPV. Conversely, although the baseline contrast injection resulted in high-grade left ventricular chamber opacification, the intensity decreased significantly during IPPV, remained low 5 min after extubation, and was normalized 30 min after extubation. IMPLICATIONS: During intermittent positive pressure ventilation, i.v. sonicated albumin microbubbles pass through the lungs poorly and inefficiently opacify the left ventricle compared with the effects observed during spontaneous ventilation.

Anesthesia, General↗

Type III dissection according to DeBakey. Comments on 45 cases treated.

BACKGROUND: There is uncertainty regarding the most suitable form of treatment for both chronic and even more so the acute forms of DeBakey's type III aortic dissections. This retrospective study analyses the indications and methods used in 20 acute cases and 25 chronic cases of type III dissection. METHOD: The 45 patients included in this study presented a high index of operability given that they were selected from more than one coronary unit and referred to our service for this purpose. This study also confirmed a clear indication for medical treatment in uncomplicated acute forms, whereas it is necessary to opt for surgery in the case of ongoing or threatened complications. In chronic forms aorta diameter and/or thrombosis of the false lumen are a valid parameter. RESULTS: The incidence of mortality was 33.3% in the 12 acute forms undergoing surgery, with 4 deaths; in the case of chronic forms undergoing surgery, the incidence was 15% with 3 deaths. Of the 8 patients with acute pathology who were not operated, 87.5% died; whereas of the 5 non-operated chronic patients, 60% died (3 cases). During the post-operative period rethoracotomy was only necessary in 1 case following hemothorax on day 5, whereas at a respiratory level only 50% of patients were extubated within 48 hours, and in 12 cases it was necessary to continue until day 5-7, whereas tracheostomy was performed in 5 cases. CONCLUSIONS: The modern tendency in the treatment of DeBakey's type III acute dissections is to opt for surgery not only in the presence of manifest complications, but also when faced with threatened complications or the failure of medical treatment. Chronic forms present the two key indications for surgery, namely aneurysmatic evolution of the wall (> 5-6 cm) and absent thrombosis of the false lumen.

Acute Disease↗

Do we know the costs of what we prescribe? A study on awareness of the cost of drugs and devices among ICU staff.

OBJECTIVE: To evaluate the level of cost awareness of drugs and devices among intensive care unit (ICU) doctors with variable levels of experience (senior intensivists, junior intensivists, residents). DESIGN: Interview-questionnaire. SETTING: ICU of the University of Rome "La Sapienza". PARTICIPANTS: 60 ICU doctors (40 specialists in anaesthesia and intensive care, 20 residents). MEASUREMENTS AND RESULTS: The estimated prices of drugs and devices were compared with the correct prices; responses within a range +/- 20% of the true price were arbitrarily considered correct; all the subgroups of doctors made inaccurate estimates of the prices, showing an absence of any impact of professional experience of cost awareness. CONCLUSION: The doctors in the study showed a high level of inaccurate cost awareness of drugs and devices.

Awareness↗

Noninvasive ventilation for the treatment of acute respiratory failure in patients with hematologic malignancies: a pilot study.

OBJECTIVE: To evaluate treatment with noninvasive ventilation (NIV) by nasal mask as an alternative to endotracheal intubation and conventional mechanical ventilation in patients with hematologic malignancies complicated by acute respiratory failure to decrease the risk of hemorrhagic complications and increase clinical tolerance. DESIGN: Prospective clinical study. SETTING: Hematologic and general intensive care unit (ICU), University of Rome "La Sapienza". PATIENTS: 16 consecutive patients with acute respiratory failure complicating hematologic malignancies. INTERVENTIONS: NIV was delivered via nasal mask by means of a BiPAP ventilator (Respironics, USA); we evaluated the effects on blood gases, respiratory rate, and hemodynamics along with tolerance, complications, and outcome. MEASUREMENTS AND RESULTS: 15 of the 16 patients showed a significant improvement in blood gases and respiratory rate within the first 24 h of treatment. Arterial oxygen tension (PaO2), PaO2/FIO2 (fractional inspired oxygen) ratio, and arterial oxygen saturation significantly improved after 1 h of treatment (43+/-10 vs 88+/-37 mmHg; 87+/-22 vs 175+/-64; 81+/-9 vs 95+/-4%, respectively) and continued to improve in the following 24 h (p < 0.01). Five patients died in the ICU following complications independent of the respiratory failure, while 11 were discharged from the ICU in stable condition after a mean stay of 4.3+/-2.4 days and were discharged in good condition from the hospital. CONCLUSIONS: NIV by nasal mask proved to be feasible and appropriate for the treatment of respiratory failure in hematologic patients who were at high risk of intubation-related complications.

Adolescent↗

The dacron aorta.

Total aorta replacement is a major and increasingly successful surgical procedure. The paper describes a patient whose progressive aneursymatic disease spread from the ascending segment to the bifurcation over a three-years period during which time after three separate operations, the aorta was totally replaced. The paper describes the diagnostic and surgical procedures deployed and shows the results of angiographic and CT scans. Credit for the success of the replacement is also given to the highly skilled anaesthetists and nurses involved.

Aortic Aneurysm, Thoracic↗

[Neurogenic pulmonary edema during subarachnoid hemorrhage].

Neurogenic pulmonary oedema occurs in about 10% of SAH-patients being mainly due to cardiocirculatory changes related to imbalance of the central neurovegetative control. In particular, ESA should induce a sympathetic descending stress causing left ventricle failure. Physiopathologic, diagnostic and therapeutic data are briefly presented.

Humans↗

A splice variant of Dp71 lacking the syntrophin binding site is expressed in early stages of human neural development.

Dp71, a 71 kDa C-terminal isoform of dystrophin, is the major product of the DMD gene in brain. Two alternatively spliced transcripts of Dp71 were amplified by RT-PCR from different areas of human fetal neural tissue. Both transcripts were spliced out of exons 71 and 78. The shorter transcript was also alternatively spliced of exons 72-74, a region comprising the coding sequence for the binding site to syntrophin, one component of the dystrophin-associated protein complex. Results indicate that alternatively spliced forms of Dp71 are regulated during human neural development.

Alternative Splicing↗

Efficacy of nefopam for the prevention and treatment of amphotericin B-induced shivering.

BACKGROUND: Shivering is experienced by up to 70% of patients undergoing amphotericin B therapy. Treatment with meperidine hydrochloride, currently the most widely used medication for controlling amphotericin B-induced shivering, was compared with nefopam hydrochloride, which has been successfully used to treat post-operative shivering. METHODS: Forty-five patients with cancer and systemic fungal infections randomly received nefopam hydrochloride, 0.3 mg/kg, meperidine hydrochloride, 0.7 mg/kg, or saline solution intravenously 15 minutes before the cessation of amphotericin B infusion (1 mg/kg for 45 minutes). If shivering persisted, patients in the control (saline solution) group received either nefopam hydrochloride, 0.3 mg/kg, or meperidine hydrochloride, 0.7 mg/kg. RESULTS: Occurrence of shivering 15 minutes after the cessation of amphotericin B infusion was significantly less frequent in the nefopam (6.6%) and meperidine (40%) groups compared with the control group (66.6%). The incidence of shivering in the nefopam group with respect to the meperidine group was also significantly reduced. Moreover, nefopam administration to 5 persistently shivering patients in the control group definitively stopped the shivering in all of them (100%) in a mean (+/- SD) time of 29.1 +/- 4.8 seconds, while meperidine terminated shivering in 4 (80%) of 5 patients in a mean (+/- SD) time of 200.0 +/- 30.2 seconds. The adverse reactions that can be ascribed to nefopam or meperidine use were nausea and sedation, respectively, and may be considered negligible. CONCLUSION: Nefopam seems to be more effective than meperidine in preventing and quickly suppressing amphotericin B-induced shivering.

Adult↗

Enhanced expression of glucose-6-phosphate dehydrogenase in human cells sustaining oxidative stress.

Recent reports have demonstrated that glucose-6-phosphate dehydrogenase (G6PD) activity in mammalian cells is necessary in order to ensure cell survival when damage is produced by reactive oxygen intermediates. In this paper we demonstrate that oxidative stress, caused by agents acting at different steps in the biochemical pathway controlling the intracellular redox status, determines the increase in G6PD-specific activity in human cell lines of different tissue origins. The intracellular level of G6PD-specific mRNA also increases, with kinetics compatible with the induction of new enzyme synthesis. We carried out experiments in which cells were exposed to oxidative stress in the presence of inhibitors of protein or RNA synthesis. These demonstrated that increased G6PD expression is mainly due to an increased rate of transcription, with a minor but significant contribution of regulatory mechanisms acting at post-transcriptional levels. These results provide new information on the defence systems that eukaryotic cells possess in order to prevent damage caused by potentially harmful oxygen derivatives.

Carcinoma, Hepatocellular↗

Treatment of acute respiratory failure by prolonged non-invasive ventilation in a child.

PURPOSE: To evaluate the feasibility and the efficacy of non-invasive ventilation (NIV) by nasal mask in a paediatric patient. CLINICAL FEATURES: A four-year-old girl with acute lymphocytic leukaemia (ALL L1, pre-pre B) complicated by acute respiratory failure was treated with NIV. ON admission she exhibited hyperpyrexia (40C), pancytopaenia and severe hypoxia with hypocapnia (PaO2 = 45 mmHg; PaCO2 = 28.2 mmHG; pH = 7.30; SpO2 = 76%; ABE = -7.3 mmol.L-1. With NIV, PaO2 improved (PaO2 = 78 +/- 8 mmHG; SpO2 = 86 +/- 2; PaCO2 = 39 +/- 2) throughout the first day. Treatment was continued for six days until the patient was discharged. No complications were recorded. CONCLUSION: Non-invasive ventilation by nasal mask may represent a choice in the treatment of acute respiratory failure of parenchymal origin in paediatric haematological patients.

Child, Preschool↗

Surgical treatment of carotid kinking.

The authors take in exam 34 anatomical variation in the extracranial internal carotid artery (compared with more than 450 operated carotid artery), 15 of which involved kinking in patients with overt neurological symptoms, underwent corrective surgical treatment, and test the most useful and appropriate techniques in any case.

Adolescent↗

[The superior vena cava occlusion syndrome. A case of neoplastic thrombosis due to hepatocarcinoma and cirrhosis].

The authors report their experience with 11 patients, surgically treated since 1990, affected with superior vena cava syndrome. A peculiar case of neoplastic thrombosis in hepatocarcinoma is stressed. In fact a similar case hadn't been reported in the last ten-year literature, although hepatocarcinoma may spread in different organs. A subject review and a discussion are presented.

Aged↗