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Biomedical subjects

R Bertolini

Publications and source records attributed to R Bertolini.

At least 19 recordsLinked to original sources
PubMed2000

Synthesis of aminoglycoside-modified oligonucleotides.

[structure: see text] To study the structural requirements of aminoglycoside binding to nucleic acids, compound 1-an analogue of the naturally occurring nucleoside J-was synthesized. When incorporated into oligodeoxynucleotides, 1 leads to thermal stabilization of the resulting duplexes. The increase in pairing affinity is stronger with complementary RNA than with DNA.

Aminoglycosides↗
PubMed1999

Calculated and measured oxygen consumption in mechanically ventilated surgical patients in the early post-operative period.

Oxygen consumption (VO2) measured by indirect calorimetry (Nellcor-Puritan-Bennett 7250; Carlsbad, CA, USA) has been compared with VO2 calculated by the Fick method in 22 volume-controlled ventilated general surgical patients in the early post-operative period. For 198 pairs of measurements, VO2 Fick and VO2 indirect calorimetry correlated significantly (y = 1.00x - 35.8, P = 0.0001, r = 0.77). VO2 indirect calorimetry was 212 +/- 32 mL min-1 and VO2 Fick was 177 +/- 41 mL min-1 (P = 0.0001). The bias was 35 +/- 26 mL min-1. This difference represents 16 +/- 13% of the total body VO2. VO2 calculated by the Fick method did not accurately predict VO2 measured by indirect calorimetry, and the two methods were not interchangeable. VO2 calculated by the Fick method underestimated VO2 as measured by indirect calorimetry by a systematic quantity that could be attributed, in part, to VO2 of the lung. Indirect calorimetry should be the preferred method for measuring total body VO2 in mechanically ventilated surgical patients.

Abdomen↗
PubMed1999

Effects of ventilator resetting on indirect calorimetry measurement in the critically ill surgical patient.

OBJECTIVE: To evaluate the effect of acute changes in minute ventilation (VE) on oxygen consumption (VO2), carbon dioxide production (VCO2), respiratory quotient, and energy expenditure during volume-controlled mechanical ventilation in the critically ill surgical patient. The effects on some oxygen transport variables were assessed as well. DESIGN: Prospective, randomized clinical study SETTING: Adult surgical intensive care unit of a university teaching hospital. PATIENTS: Twenty adult critically ill surgical patients were studied during volume-controlled mechanical ventilation. INTERVENTIONS: After a basal period of stability (no changes over time in body temperature, energy expenditure, blood gases, acid-base status, cardiac output, and ventilatory parameters), VE was then randomly either increased or reduced (+/-35%) by a change in tidal volume (VT), while respiratory rate and inspiratory/expiratory ratio were kept constant. Settings were then maintained for 120 mins. During the study, patients were sedated and paralyzed. MEASUREMENTS AND MAIN RESULTS: VO2, VCO2, and respiratory quotient were measured continuously by a Nellcor Puritan Bennett 7250 metabolic monitor (Nellcor Puritan Bennett, Carlsbad, CA). Hemodynamic and oxygen transport parameters were obtained every 15 mins during the study. Despite large changes in VE, VO2 and energy expenditure did not change significantly either in the increased or in the reduced VE groups. After 15 mins, VCO2 and respiratory quotient changed significantly after ventilator resetting. VCO2 increased by 10.5 +/- 1.1% (from 2.5 +/- 0.10 to 2.8 +/- 0.12 mL/min/kg, p< .01) in the increased VE group and decreased by 12.4 +/- 2.1% (from 2.7 +/- 0.17 to 2.4 +/- 0.16 mL/min/kg, p< .01) in the reduced VE group. Similarly, respiratory quotient increased by 16.2% +/- 2.2% (from 0.87 +/- 0.02 to 1.02 +/- 0.02, p< .01) and decreased by 17.2% +/- 1.8% (from 0.88 +/- 0.02 to 0.73 +/- 0.02, p< .01). VCO2 normalized in the reduced VE group, but remained higher than baseline in the increased VE group. Respiratory quotient did not normalize in both groups and remained significantly different from baseline at the end of the study. Cardiac index, oxygen delivery, and mixed venous oxygen saturation increased, while oxygen extraction index decreased significantly in the reduced VE group. Neither of the mentioned parameters changed significantly in the increased VE group. CONCLUSIONS: We conclude that, during controlled mechanical ventilation, the time course and the magnitude of the effect on gas exchange and energy expenditure measurements caused by acute changes in VE suggest that VO2 and energy expenditure measurements can be used reliably to evaluate and quantify metabolic events and that VCO2 and respiratory quotient measurements are useless for metabolic purposes at least for 120 mins after ventilator resetting.

Aged↗
PubMed1999

Energy expenditure and severity of injury and illness indices in multiple trauma patients.

OBJECTIVE: To determine whether the energy expenditure of mechanically ventilated multiple trauma patients correlates with the severity of injury and illness indices before important systemic infection has complicated the clinical course, and to compare the energy expenditure with the energy expenditure expected from the Harris-Benedict equation adjusted with correction factors for trauma. DESIGN: Prospective, clinical study. SETTING: General intensive care unit of a university teaching hospital. PATIENTS: Immediate multiple trauma adult patients who required mechanical ventilation. INTERVENTIONS: Metabolic cart connected to the ventilator. MEASUREMENTS AND MAIN RESULTS: Data on admission to the emergency department and during the first 24 hrs of intensive care unit admission were collected for computation of severity of injury and illness indices, respectively. Resting and total energy expenditures were derived at least 48 hrs after intensive care unit admission by continuous indirect calorimetry. Predicted basal energy expenditure was obtained using the Harris-Benedict equation and predicted total energy expenditure was calculated using the Harris-Benedict value adjusted with correction factors for trauma. Twenty-six multiple trauma adult patients completed the study. No statistically significant correlations were observed between both the resting energy expenditure and the total energy expenditure and the Injury Severity Score, Revised Trauma Score, Simplified Acute Physiologic Score II, Acute Physiology and Chronic Health Evaluation II score, and Glasgow Coma Scale score. A regression model of total energy expenditure was developed with the following variables: Harris-Benedict equation, heart rate, and minute ventilation (p = .01; r2 = .74). The resting energy expenditure/predicted basal energy expenditure ratio was 1.17+/-0.2 and the total energy expenditure/predicted total energy expenditure ratio was 0.76+/-0.1. CONCLUSIONS: In mechanically ventilated multiple trauma patients the energy expenditure is not correlated to the severity of injury and illness indices but is dependent on the Harris-Benedict equation in addition to heart rate and minute ventilation. Furthermore, this patient population is characterized by a moderate state of hypermetabolism, and the Harris-Benedict prediction modified with correction factors for trauma systematically overestimates the total energy expenditure.

Adult↗
PubMed1998

[A strangulated perineal hernia. A rare case of intestinal obstruction].

A rare case of intestinal obstruction due to strangulated perineal hernia, observed among 533 small bowel obstructions operated since January 1982 until December 1994 (0.2%) is described. Less than 100 cases are reported in literature. The etiologic, anatomical and clinical aspects of perineal hernia are examined. The reported case is of the primitive, congenital type caused by defect of the rectovaginal fascia fusion, in correspondence of the Douglas. Preoperative diagnosis is very difficult. Strangulation of this type of hernia is rare, the hernial sac surrounding tissue being elastic. In case of strangulation, symptoms of intestinal obstruction appear. In the reported case the preoperative diagnosis was "acute abdomen", because there was defence in hypogastrium and in the right iliac fossa. A straight abdominal radiography has not been performed. In the reported case the patient, a 22-year-old woman, was promptly operated and the incarcerated intestinal loop released. A regular postoperative period followed. The importance of a complete clinical examination, of a straight abdominal radiography and of a promptly performed operation is underlined.

Abdomen, Acute↗
PubMed1997

Comparison between cardiac output measured by thermodilution technique and calculated by O2 and modified CO2 Fick methods using a new metabolic monitor.

OBJECTIVE: To calculate cardiac ouptut from dual oximetry with carbon dioxide production (VCO2) and oxygen consumption (VO2) measured by a new metabolic monitor, and to compare these values with measurements made simultaneously using the thermodilution method during the steady state condition. DESIGN: Prospective, comparative clinical study. SETTING: The adult postsurgical intensive care unit (ICU) of a University Hospital. PATIENTS: Twenty mechanically ventilated postsurgical patients (70.7 +/- 7.8 years of age; range 50-84). MEASUREMENTS AND RESULTS: A new metabolic monitor (Puritan-Bennett 7250, Carlsbard, USA) connected to a ventilator (Puritan-Bennett 7200) was used to measure VCO2 and VO2. Measurements of arterial (SaO2) and mixed venous (SvO2) oxygen saturations were made using pulse and venous fiberoptic oximeters. Cardiac output starting from VCO2 (COVCO2) was obtained according to Mahutte's formula: COVCO2 = VCO2/[k (SaO2-SvO2)], where k represents a constant. The value for each patient was determined from the initial measurements of thermodilution cardiac output (COtd), VCO2, SaO2 and SvO2. COVCO2 calculated from the previous equation was compared to the COtd. Cardiac output calculated from the traditional O2 Fick equation (COVO2) was compared to the COtd. All patients were studied over a period of 120 min at 15-min intervals in reasonably stable conditions. COVCO2 was closely related to COtd (r = 0.94; SEE = 0.79; p = 0.0001; n = 180) with a bias of -0.10 and a precision of 0.45 l/min. The mean percent difference between the two methods was -2.2 +/- 8.3%. COVO2 was related to COtd (r = 0.77; SEE = 0.79; p = 0.0001; n = 180) with a bias of -0.57 and precision of 0.86 l/min. The mean percent difference between the two methods was -10.8 +/- 16.0%. CONCLUSIONS: In stable patients, cardiac output measurements obtained from dual oximetry with VO2 and VCO2 measured by this new metabolic monitor, show good correlation with measurements made using the thermodilution method. The values of cardiac output calculated from VCO2 are more accurate and precise than values from VO2. The validity of these measurements in hemodynamically unstable patients and during various modes of mechanical ventilation seems warranted.

Aged↗
PubMed1997

Indirect calorimetry in critically ill patients: clinical applications and practical advice.

Indirect calorimetry is the method by which metabolic rate and substrate utilization are estimated in human beings starting from respiratory gas exchange measurements and urinary nitrogen excretion. This method is based on some models and assumptions that must be known and taken into consideration to correctly interpret the results obtained. Recent advances in technology and the availability of precise and portable metabolic carts have made this technique practical at the beside even in critically ill patients. It must be considered that, particularly in the ICU, there may be several sources of error and many technical difficulties in applying this methodology. Taking into account the relevant clinical studies related to the outcomes of critically ill patient, this article defines when the assessment of energy expenditure by indirect calorimetry may provide useful and valid information. Review of the literature suggests that the clinical application of indirect calorimetry in critically ill patients, although promising, requires further evaluation. Currently, the potential useful clinical applications of indirect calorimetry in this category of patients can be summarized as follows: (1) assessment of energy expenditure in patients who fail to adequately respond to the estimated nutritional needs; (2) assessment of energy expenditure in patients with single- or multiple-organ dysfunction who need prolonged ICU care and artificial nutritional support; (3) assessment of the effects induced by artificial nutrition on the cardiocirculatory and respiratory systems in mechanically ventilated patients with acute respiratory failure; and (4) monitoring of VO2 during weaning from mechanical ventilation.

Calorimetry, Indirect↗
PubMed1996

Energy metabolism of thoracic surgical patients in the early postoperative period. Effect of posture.

STUDY OBJECTIVE: To determine the effect of elective thoracic surgery on energy metabolism and gas exchange and to evaluate whether the 30-degree sitting position would affect these variables. DESIGN: Prospective, unblinded, controlled study. SETTING: Surgical ICU in a university hospital. PATIENTS: Twenty-two adult patients undergoing elective pulmonary resection. INTERVENTIONS: Posture change from supine to 30-degree sitting position. MEASUREMENTS AND RESULTS: Oxygen consumption (VO2), carbon dioxide production (VCO2), respiratory quotient (RQ), and energy expenditure (EE) were measured by means of computerized indirect calorimetry before and after surgery. Heart rate and respiratory frequency were measured continuously during gas exchange measurement. Blood gases were analyzed with an automated blood gas analyzer. Preoperatively, altering position did not affect energy metabolism, gas exchange, and cardiopulmonary variables. Postoperatively, the measured EE was 116% of the expected value. Mean EE and VO2 values for each position were higher than the preoperative values for the corresponding postures (p<0.05 for each position), while VCO2 increased only in the supine position (p<0.05). Mean percent increases in EE, VO2, and VCO2 were significantly lower in the 30-degree sitting position than in the supine position (EE: 7.9+/-2.7% vs 14.4+/-2.3%; p<0.001; VO2: 9.0+/-3.0% vs 16.4+/- 2.6%; p<0.001; VCO2: 3.2+/-2.1% vs 6.5+/-1.4%: p<0.05). Arterial oxygen tension and all the physiologic indexes of gas exchange for each position were worse than the preoperative values for the corresponding postures (p<0.05 for each position). Mean arterial pressure, heart rate, and respiratory frequency for each position were higher than the preoperative values for the corresponding postures (p<0.05 for each position). No changes in mean values of these variables occurred between the two positions postoperatively. CONCLUSIONS: The early postoperative period of patients undergoing elective thoracic surgery is characterized by a condition of impaired gas exchange and by a hypermetabolic state. Hypermetabolism can be partly mitigated by assuming the 30-degree sitting position.

Aged↗
PubMed1992

[Rare neoplasms of the pancreas: the papillary-cystic tumor. A report of 2 cases].

The authors report two cases of papillary-cystic tumor of the pancreas in two young women. Making a review of literature, they emphasize the rarity of this neoplasm and analyze the possible histopathologic origin, the difficult diagnosis before surgery, surgical therapy and the good prognosis of this pancreatic "curable" tumor.

Adult↗
PubMed1990

[Manual versus mechanical sutures in gastric surgery in cancer].

The Authors, on the basis of their experience in San Camillo Hospital of Rome, compare the results between manual and mechanical sutures in 597 gastric cancers operated in the last 12 years. They confirm that at present staplers are of great reliability.

Adolescent↗
PubMed1989

[Prognostic factors in acute mesenteric ischemia. Experience of 64 cases].

A retrospective study of 64 cases of acute mesenteric ischaemia is reported. The patients have been treated, during the past 12 years, at the Department of Surgery "Flaiani", Ospedale San Camillo de Lellis-Rome. In terms of favourable prognosis, the following factors have shown to be statistically significant: enteric resection carried out, thrombosis of superior mesenteric vein, preoperative normal BUN and WBC count. The diagnostic value of CPK-BB is emphasized as well as the prognostic significance of a prompt surgical treatment.

Acute Disease↗
PubMed1985

[Topography of the infratemporal fossa in the newborn infant].

We compared in our investigations the shape and extent of the infratemporal fossa in newborn, children, and adult specimen. By macroscopical preparation we watched the course of the branches of the mandibular nerve and the maxillary artery and their relations to the masticatory muscles. For identifying of arterial and venous blood vessels the external carotid artery was injected with black ink. In the newborn a fibrous membrane was found coating the internal aspect of the mandibular ramus. The membrane is absent in adults.

Blood Vessels↗
PubMed1984

[Accessory mandibular canals in the human].

Besides the persisting mandibular canal accessory ducts pass through the bony lower jaw in fetuses and children. 2 of the ducts are more constant than others. They are named according to the first authors canals of Serres and Robinson. By histological and macroscopical methods and by X-ray technique we studied these ducts during development in human fetuses and children and counted their occurrence in the adult.

Adolescent↗