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Biomedical subjects

G Conti

Publications and source records attributed to G Conti.

At least 55 records · Page 3Linked to original sources
PubMed1998

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↗
PubMed1998

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↗
PubMed1997

Immunocytochemical expression of human muscle cell p75 neurotrophin receptor is down-regulated by cyclic adenosine 3',5'-monophosphate.

To investigate whether the immunocytochemical expression of low affinity neurotrophin receptor (p75) in human muscle is modulated by increased levels of intracellular cyclic adenosine 3',5'-monophosphate (cAMP), human cultured myogenic cells were treated with cAMP analogues dibutyryl cAMP (dbcAMP 0.5-1 mM) and 8-bromo cAMP (1 mM) or the adenylate cyclase activator forskolin (10-100 microM). Cultures were processed for indirect immunofluorescence microscopy using an anti-human p75 mAb. The treatment of cultured muscle cells with cAMP analogues or forskolin for two days induced a decrease of immunoreactivity for p75 and a reduction of both myotube formation and morphological cell differentiation. Removal of cAMP derivatives from the medium resulted in a return of immunoreactive cells to the levels of untreated controls. These data indicate that adenylate cyclase is involved in the regulation of human muscle p75.

Adenylyl Cyclases↗
PubMed1997

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↗
PubMed1997

Calcyclin gene expression modulation by medroxyprogesterone acetate.

Calcyclin is a cell-cycle-related gene corresponding to a calcium-binding protein whose expression is mainly controlled by platelet-derived growth factor. This paper illustrates medroxyprogesterone acetate (MPA) inhibition of endogenous calcyclin RNA expression of both estrogen-dependent human mammary carcinoma cells and estrogen-independent hamster fibroblasts. Transfection of fragments of the calcyclin promoter driving the chloramphenicol-acetyl-transferase (CAT) gene into hamster fibroblasts was used to evaluate the hormone sensitivity of different promoter regions by considering calcyclin expression at both the RNA and protein level, as evaluated by the CAT assay. A 164 bp promoter fragment showed a good activity that was inhibited by MPA, thereby confirming the results of the observation of endogenous calcyclin gene: smaller fragments, however, required cotransfection of progestin receptor to show full activity, with MPA displaying a stimulatory effect. These findings show that progestin modulation of calcyclin gene expression may be independent of progestin receptors, and that MPA has opposite effects on different promoter regions.

Animals↗
PubMed1997

p75 neurotrophin receptor induction and macrophage infiltration in peripheral nerve during experimental diabetic neuropathy: possible relevance on regeneration.

In this study we examined the expression of the neurotrophin receptor p75 (p75NTR) and the activation of macrophages in the sciatic nerve of rats at different time points after the induction of diabetes with streptozotocin (STZ). Northern blot and immunocytochemical analysis showed that p75NTR was not detectable in the sciatic nerve by Week 2 after STZ treatment. At this time, single nerve fiber immunostaining using ED1 monoclonal antibody revealed that active macrophages were infiltrating the endoneurium, which had a normal morphological aspect. By Weeks 5 and 15 p75NTR mRNA and protein were induced in the endoneurium of diabetic animals. Immunocytochemical analysis of teased single nerve fibers showed that p75NTR protein was distributed uniformly along isolated fibers with no pathological evidence of axonal degeneration or myelin disruption. At this time, cells of the phagocyte lineage had already disappeared from the nerve. These data show that during experimental diabetic neuropathy, the endoneurial induction of p75NTR is localized along isolated nerve fibers showing no morphological alterations, and in time, follows the recruitment of active macrophages in the nerve, suggesting that these cells, directly or through their products, can influence p75NTR induction. This process might play an important role in STZ diabetic neuropathy, as a response to decreased levels of neurotrophins such as NGF and promoting nerve regeneration in the early phases of the disease.

Animals↗
PubMed1997

L-histidine/medroxyprogesterone acetate interaction modulates human breast cancer cell growth and progestin receptor expression in vitro.

The effect of different L-histidine concentrations on human mammary tumour cell (CG5) proliferation was studied to test the hypothesis of a role of histidine in modulating sex steroid-regulated cell proliferation. Cell growth was only possible in the 10(-5) M and 10(-2) M range, while its inhibition by medroxyprogesterone acetate was confined to the 10(-4) M and 10(-3) M range. 10(-3) M L-histidine enhanced the effect of medroxyprogesterone acetate in reducing the number of cells in the S phase. The results show also that 10(-3) M L-histidine favours progestin diffusion into cells and increases progestin receptors density. The present data are in line with previous observations of the effect of histidine on the growth of experimental animal tumours, add evidence that histidine concentration influences the control of cell proliferation by sex steroids, and suggest a possible use of histidine in association with progestational drugs in the treatment of human neoplasia.

Breast Neoplasms↗
PubMed1997

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↗
PubMed1997

Respiratory system mechanics in the early phase of acute respiratory failure due to severe kyphoscoliosis.

OBJECTIVE: To evaluate respiratory mechanics in the early phase of decompensation in a group of seven patients with severe kyphoscoliosis (KS) (Cobb angle > 90 degrees) requiring mechanical ventilatory support. DESIGN: Prospective clinical study with a control group. SETTING: General intensive care unit at University of Rome "La Sapienza". PATIENTS: Seven consecutive patients affected by severe KS in the early phase of acute decompensation and a control group of six ASA (American Society of Anesthesiology) 1 subjects who were mechanically ventilated during minor surgery. MEASUREMENTS AND RESULTS: Respiratory mechanics were evaluated during constant flow-controlled mechanical ventilation at zero end-expiratory pressure with the end-inspiratory and end-expiratory occlusion technique. In five patients who showed increased ohmic resistance (RRSmin), we evaluated the possibility of reversing this increase with a charge dose of 6 mg/kg doxophylline i.v. In four KS patients, in whom a reliable esophageal pressure was confirmed by a positive occlusion test, we separated respiratory system data into lung and chest wall component. All KS patients showed reduced values of respiratory compliance (CRS) and increased respiratory resistance (RRS). The average basal values of CRS were 36 +/- 10 vs 58 +/- 8.5 cmH2O in control patients; RRSmax was 20 +/- 3.1 vs. 4.5 +/- 1.2 cmH2O/1 per s; RRSmin 6.2 +/- 1.2 vs. 2 +/- 0.5 cmH2O/1 per s: delta RRS 14 +/- 2.6 cmH2O vs 2.4 +/- 0.7 cmH2O/1 per s. All KS patients showed low values of intrinsic positive end-expiratory pressure (PEEPi) (1.8 +/- 1.5 cmH2O). Separation of lung and chest-wall mechanics, performed only in four patients, showed a reduction in both lung (66.7 +/- 7.2 ml/cmH2O) and chest wall values (84 +/- 8.2 ml/cmH2O), while both RmaxL and RmaxCW were increased (16.6 +/- 2 and 2.8 +/- 0.4 cmH2O/1 per s, respectively). Infusion of doxophylline did not significantly change respiratory mechanics when evaluated 15, 30, and 45 min after the infusion. CONCLUSIONS: During acute decompensation, both lung and chest-wall compliance are severely reduced in KS patients: conversely, and, contrary to that in patients with chronic obstructive pulmonary disease, increases in airway resistance and PEEPi seem to play only a secondary role.

Airway Resistance↗
PubMed1997

Modification of cytoskeleton and prosome networks in relation to protein synthesis in influenza A virus-infected LLC-MK2 cells.

Modifications of the cytoskeleton and protein synthesis were investigated in LLC-MK2 cells during infection by FPV/Ulster 73, an avian strain of influenza A virus. During infection, the cytoskeleton and the prosome networks undergo a dramatic reorganization, which seems to be at least temporally differentiated for each cytoskeletal system, i.e. microfilaments (MFs), microtubules (MTs), intermediate filaments (IFs). In order to evaluate the role of the three different cytoskeletal networks during FPV/Ulster infection, studies were carried out on cellular and virus-specific protein synthesis and viral production, using drugs which selectively affect individual cytoskeletal systems. Our data show that the perturbation of the IF system, but not that of the MFs or MTs, seems to have a strong inhibitory effect on virus production and cellular and viral protein synthesis. Furthermore, the dynamics of IFs and prosomes were investigated during viral infection and, at no time, dissociation of the prosome and IF networks was observed. Taken together, these results strongly support the idea that the interactions between the protein synthesis machinery, the cytoskeleton, and the prosomes are all affected by viral infection in a partially coordinated manner.

Acrylamides↗
PubMed1997

The use of radioimmune western blotting to evaluate indeterminate western blotting results in blood donor HIV serodiagnosis.

The serodiagnosis of HIV infection is sometimes puzzling due to questionable "indeterminate" results obtained by western blotting (wb), the confirmatory test used world-wide after a positive or borderline ELISA result. These situations cause anxiety in the person being tested and determine additional laboratory costs. We showed that radioimmune western blottting (riwb) an improved and sensitive modification of conventional wb, was able to resolve most "indeterminate" results in individuals who later fully seroconverted. We report in this paper the use of riwb in sera of 20 uninfected blood donors with an indeterminate wb continuing for at least 6 years, to verify the serological status in indeterminate not at risk individuals. Thirteen out of the 20 were indeterminate with conventional wb due to the presence of antibodies to p 24, two to p 17, two to p 55, two to p 51 and p 55 and one to p 24 and p 51 antibodies. The presence of all these bands was confirmed using riwb; moreover, in comparison with wb, the intensity of all bands was clearly enhanced. Despite the use of this highly sensitive method no new bands were found with riwb in indeterminate sera; negative results were obtained when sera borderline or positive with ELISA but negative with wb, were subjected to riwb.

AIDS Serodiagnosis↗
PubMed1997

Effect of low dose fentanyl-droperidol administration on respiratory drive, respiratory pattern and gas exchange in ASA 1 spontaneously breathing patients.

The aim of this study was to investigate the short term effects of low doses of fentanyl and droperidol on central respiratory drive, gas exchanges, respiratory pattern and inspiratory impedance of the respiratory system in a group of ASA 1 patients. Fourteen ASA 1 patients scheduled for minor surgery or endoscopic procedures were enrolled in the study, thirty minutes before the intervention. During spontaneous breathing of air we evaluated, by recording airflow, airway opening pressure and volume, the following variables: Respiratory Rate (RR), Tidal Volume (TV), Total respiratory cycle, Inspiratory and Expiratory Time (Ti, Te), mean inspiratory flow, P0.1, pH, PaO2 and PaCO2. After obtaining basal measurements, droperidol and fentanyl were injected and the above mentioned variables evaluated at 5 min (T1), 10 min (T2), 15 min (T3) intervals. Arterial blood was age, sampled at T3 for blood gas evaluation. The administration of droperidol (0.1 mg/kg) and fentanyl (0.002 mg/kg) significantly reduced P0.1 and Tidal Volume comparing basal with T1 and, T2 values. The other variables did not significantly modify. Two patients showed transient respiratory rhythm abnormalities in the first 180 sec following the administration of droperidol+fentanyl. Our results suggest that, in ASA 1 patients, droperidol+fentanyl preoperative administration, has no significant effects on respiratory pattern, respiratory impedance and gas exchanges: however also at low doses, the association of droperidol+fentanyl can reduce the respiratory center activity, expressed as P0.1, with a consequent reduction in Tidal Volume.

Adjuvants, Anesthesia↗
PubMed1997

Comparative evaluation of the cardiorespiratory effects of assist control ventilation vs pressure support ventilation in patients following orthotopic liver transplantation.

OBJECTIVE: 1) To compare the haemodynamic tolerance of ACV and PSV in patients mechanically ventilated after orthotopic liver transplantation; 2) to compare patients comfort during ACV and PSV. DESIGN: Prospective randomized cross-over study. SETTING: General ICU of the University of Rome "La Sapienza". PATIENTS: Eighteen patients admitted in ICU after orthotopic liver transplantation. MEASUREMENT AND RESULTS: Haemodynamic, oxygen transport and blood gas data were compared during an ACV and PSV trial (30'). A statistically significant decrease of mean pulmonary and systemic arterial pressure, PCOP, LVSWI, occurred during the PSV trial. PaO2 and DO2I decreased during PSV, but were still in supranormal range; 16 out of 18 patients described PSV as more comfortable. CONCLUSIONS: ACV and PSV provided a comparable haemodynamic tolerance in our patients, although during PSV the PaO2 was slightly decreased, probably due to decreased mean airway pressure (from 9.3 +/- 1.2 cmH2O during ACV to 6.6 +/- 1 cmH2O during PSV). PSV can be considered as a good alternative to the standard weaning techniques following orthotopic liver transplantation.

Adult↗
PubMed1996

Severe form of Freeman-Sheldon syndrome associated with brain anomalies and hearing loss.

We describe a child with whistling face and multiple contractures, including ulnar deviation of fingers, compatible with a diagnosis of Freeman-Sheldon syndrome (FSS). This patient also presented severe hypertonicity, multiple episodes of pneumonia, difficulty in swallowing, and poor weight gain, which are characteristic of the most severe cases of FSS. A brain CT scan showed cerebellar and brainstem atrophy. Auditory brainstem responses were absent. The child died at 5 months of respiratory failure. This case suggests the possibility that, especially in the most severe forms, brain abnormalities may be responsible for some of the clinical manifestations of this syndrome, i.e., respiratory problems, difficulty in swallowing and severe hypertonicity. We assume that there is more than one pathogenetic mechanism (muscular, skeletal, and neurological) underlying FSS, which, together with the genetic heterogeneity and the wide range of clinical symptoms leads us to suggest that it is more appropriate to speak of a Freeman-Sheldon spectrum rather than syndrome and that thorough investigation for CNS and auditory abnormalities should be part of the initial work-up of these patients.

Adult↗
PubMed1996

Early and late onset bacteremia have different risk factors in trauma patients.

OBJECTIVE: The aim of this study was to identify risk factors and to describe epidemiological patterns for early-(EOB) and late-onset bacteremias (LOB) after trauma. DESIGN: A prospective study conducted on 141 consecutive trauma patients. SETTING: A general intensive care unit (ICU) of a university hospital. PATIENTS: All multiple trauma patients admitted to our general intensive care unit (ICU) from December 1990 to May 1992 were prospectively enrolled in the study. The following information was collected for each patient and recorded in a computer database: demography, severity of trauma according to the Abbreviated Injury Scale (AIS), severity of coma according to the Glasgow Coma Scale (GCS), presence of pneumothorax, pulmonary contusion, rib fractures, hemothorax, and abdominal trauma, use of mechanical ventilation, and placement of central venous catheters. Bacteremias were defined as EOB when onset occurred within 96 h after trauma, and as LOB when appearing after 96 h from trauma. RESULTS: Thirty-seven patients developed bacteremia during their ICU stay (26%): 11 (29.7%) EOB and 26 (70.3%) LOB. Gram-positive cocci were isolated more frequently in EOB than in LOB (chi 2 = 4.1, P = 0.04). The risk of EOB was significantly increased by the presence of pulmonary contusion [relative risk (RR) 15.0; confidence interval (CI) 1.99-113.25], pneumonia before the onset of bacteremia (RR 3.56; CI 1.17-10.69), AIS score greater than 32 and an abdominal injury score greater than 9 (RR 3.11; CI 1.02-9.49), while intravascular catheters and mechanical ventilation did not represent risk factors for EOB. LOB had a very different pattern and their risk was significantly increased by exposure to intravascular catheters (RR 4.96; CI 1.23-19.94) and to mechanical ventilation lasting more than 7 days (RR 3.6; CI 1.6-8.1). CONCLUSIONS: Scoring with the AIS of the abdominal and thoracic trauma at admission to the ICU appears a useful tool for identifying trauma patients at increased risk of EOB. A rigorous policy of catheter placement and maintenance as a means of reducing late bacteremias in trauma patients is essential.

Abdominal Injuries↗
PubMed1996

Induction of p75NGFR in human diabetic neuropathy.

In this immunohistochemical study we investigated the expression of low-affinity NGF receptor (p75NGFR) in peripheral nerves from 16 patients with type I or type II diabetes mellitus. Fourteen nerves from age- and sex-matched normal individuals and nine nerves from non-diabetic patients with ischemic neuropathy served as controls. All nerve samples were preliminarily examined by standard histology, fiber teasing and electron microscopy. Increased p75NGFR immunoreactivity was detectable within the endoneurium of cross-sections from ischemic and particularly from diabetic nerves. Immuno-teasing demonstrated that p75NGFR immunostaining was distributed along the entire length of isolated nerve fibers undergoing axonal degeneration. Quantitative assessment of p75NGFR immunoreactivity, performed by histospectrophotometry and expressed as percentage of adsorbance, was 21.20 +/- 3.50 in nerves from diabetic patients, 13.35 +/- 3.62 in nerves from non-diabetic patients with ischemic neuropathy and 9.02 +/- 2.75 in normal controls. The increased expression of p75NGFR in diabetic nerves is consistent with an axonopathic defect and further suggests involvement of NGF and other neurotrophins in the pathogenesis of human diabetic neuropathy.

Adult↗
PubMed1996

O2 consumption-O2 delivery relationship and arteriolar resistance in the forearm of critically ill patients measured by near infrared spectroscopy.

Eight patients with severe sepsis, four with septic shock, and eight without sepsis were studied to investigate whether skeletal muscle influences the whole body O2 consumption (VO2)-O2 delivery relationship and hemodynamics. A forearm VO2-O2 delivery dependency was observed only in nonseptic patients, in whom no whole body VO2-O2 delivery dependency appeared. No forearm VO2-O2 delivery relationship was observed in septic and shock patients, in whom whole body VO2-O2 delivery dependency was found. In shock patients the lack of forearm VO2-O2 delivery dependency was associated with low forearm arteriolar resistance (FAR) even at a relatively low forearm blood flow (FBF). Neither a relationship between forearm VO2 and whole body VO2 nor between FAR and SVR was found in any groups of patients. Septic shock was associated with low FAR that was not affected by the FBF decrease, indicating that in this condition, hemodynamics could be influenced by skeletal muscle resistance.

Aged↗