Noninvasive measurement of forearm oxygen consumption during exercise by near infrared spectroscopy.
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Adult↗
Biomedical subjects
M Ferrari
Publications and source records attributed to M Ferrari.
Simultaneous detection of delta F508, G542X, N1303K and 1717-1G-->A mutations in cystic fibrosis by capillary electrophoresis in polymer networks.
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Alleles↗
Morphologic aspects of the resin-dentin interdiffusion zone with five different dentin adhesive systems tested in vivo.
The new generation of enamel dentin adhesive materials provides removal of the smear layer, inducing structural changes in the dentinal surface and creating a retentive interdiffusion zone or hybrid layer between the two substrates. Some studies have demonstrated hybrid layer formation in in vitro samples, but few articles have described it in in vivo specimens. The hybrid layer forms in peritubular and intertubular treated dentin and improves adhesion between tooth surface and adhesive resins. This in vivo study investigated the formation of a hybrid layer by use of five different enamel dentin adhesive systems. The dentin adhesives systems were tested on flat dentin preparations made on vestibular surfaces of periodontally compromised teeth. The sample teeth were extracted immediately after the resin was cured. Half of the samples were used to visualize the hybrid layer and the other half to observe the morphology of the resin tags by use of scanning electron microscopy. All the tested products formed a hybrid layer. In many areas of samples of Gluma 2000, Scotchbond Multipurpose, All Bond 2, and Super Bond D Liner systems, characteristic reverse cone-shaped tags were visible. Resin tags produced by Clearfil Liner Bond adhesive were narrower at the apertures of tubules than those of the other four adhesive materials. Morphology of the hybrid layer and of the resin tags of these samples were similar to in vitro samples observed in other studies.
Composite Resins↗
Immunosuppression as a factor in allowing mucosal disease to occur.
In order to verify the role of immunosuppression in the pathogenesis of Bovine Viral Diarrhea Virus (BVDV) infection, two experiments have been carried out. In one experiment, calves previously infected with cytopathogenic (CP) or non-cytopathogenic (NCP) BVDV were treated with dexamethasone (DMS) 30 days later. In the other experiment, calves were simultaneously exposed to BVDV infection and to DMS treatment. In both experiments the DMS treated calves developed a more serious disease which in one calf was fatal. It was speculated that immunosuppression represents one of the most significant "key factors" in the occurrence of the bovine viral diarrhea/mucosal disease in cattle.
Animals↗
Simultaneous 280 MHz EPR imaging of rat organs during nitroxide free radical clearance.
A radio frequency (RF) (280 MHz) electron paramagnetic resonance (EPR) spectroscopy and imaging apparatus has been used to localize a pyrrolidine nitroxide free radical in the rat abdomen and thorax. The nitroxide 2,2.5.5,-tetramethylpyrrolidine-1-oxyl-3- carboxylic acid (PCA) had a whole body monoexponential decay with half-life of 13.3 +/- 0.7 (n = 4), 19.4 +/- 0.2 (n = 3), and 23 +/- 2 (n = 6) min for 1, 2, and 3 mmol/kg PCA, respectively. Up to seven one-dimensional longitudinal projections were collected on six rats in the presence of a 8 mT/m field gradient. With an injection dose of 3 mmol/kg, PCA half-lives were 19 +/- 1, 17 +/- 2, and 22 +/- 2 min (n = 6) in the lower abdomen, in the liver, and in the thorax, respectively. Thorax half-life was significantly longer than liver half-life. Sequential two-dimensional images of PCA distribution in a plane longitudinal to the rat body were obtained from eight spectra in the presence of a gradient of 12 mT/m (acquisition time 5 min; spatial resolution 8 mm). After 7 min, the nitroxide was detectable in the left side of the thorax area, but it was mostly localized in the liver. PCA was more uniformly distributed in the image collected after 17 min.
Animals↗
Analysis of risk factors for the development of liver disease associated with cystic fibrosis.
We prospectively screened for liver disease patients with cystic fibrosis who were more than 3 years of age and who were followed at the cystic fibrosis center of the University of Milan. From January 1991 to December 1992, we screened 189 patients; clinical, biochemical, and echographic abnormalities suggestive of overt liver disease were present in 34 (18%). To define risk factors for the development of liver disease associated with cystic fibrosis, we evaluated the possible role of specific mutations of the CFTR (cystic fibrosis transmembrane regulator) gene and of different clinical and demographic characteristics (sex, pancreatic status, meconium ileus or its equivalent) through a comparison of patients with cystic fibrosis and overt liver disease (n = 34) and those without liver disease (n = 155). Genetic analysis failed to reveal any significant difference in the allele frequencies of defined (delta F508, 1717-1G-A, G542X, N1303K, W1282X, R553X) and undefined mutations of the CFTR gene in the two groups of patients; genotype frequencies were also not significantly different. Pancreatic insufficiency was present in all patients with liver disease and in 87.3% of those without liver disease. A male predominance was found in the group with liver disease. The frequency of meconium ileus or its equivalent was significantly higher in patients with cystic fibrosis and liver disease (35.3%) than in patients without liver disease (12.3%) (p = 0.0025). In the 31 patients with a history of meconium ileus or its equivalent, the following hepatic abnormalities occurred more frequently than in the 155 patients with cystic fibrosis who did not have meconium ileus: hepatomegaly, biochemical abnormalities, heterogeneous echographic pattern of the liver, and microgallbladder. Twenty-four patients with a history of meconium ileus or its equivalent underwent hepatobiliary scintigraphy (with technetium-labeled iminodiacetic acid derivatives), which showed morphologic abnormalities suggestive of impaired biliary drainage in 21 patients and abnormalities in function in 11. The risk of acquiring liver disease was increased almost fourfold in patients with a history of meconium ileus or its equivalent, in comparison with patients who had cystic fibrosis but were unaffected by these complications (odds ratio, 3.9043; 95% confidence interval, 1.666 to 9.149). We conclude that patients with cystic fibrosis and meconium ileus or its equivalent may benefit from prophylactic treatment with ursodeoxycholic acid; genetic analysis of the major mutations present in this population failed to provide evidence of the existence of a specific genetic marker for the development of liver disease in patients with cystic fibrosis.
Adolescent↗
Adrenocortical tumors in children: a report of 12 cases.
Adrenocortical tumors in children are extremely rare, accounting only for 0.3-0.4% of all neoplasms in this age. Most frequently they secrete hormones, resulting in virilization, Cushing's syndrome or feminization, while the non-functioning ones are unusual. The authors describe 12 cases observed in 13 years (1976-1989), with a mean age of 5 years. 9 cases showed virilization, 4 presented with Cushing's syndrome and in 5 patients an abdominal mass was palpable. One case was affected by Beckwith-Wiedemann's syndrome. I.V. urography was performed in 8 patients, arteriography in 4 and since 1982 all patients were submitted to abdominal sonography and CT scan or MR imaging. Urinary 17-ketosteroids, 17-hydroxycorticoids and serum testosterone and cortisol were tested in all children. Dexamethasone suppression test was performed in 7. All patients were treated with surgery which seems to be the most suitable treatment, while the real effectiveness of treatment by drug therapy with suppressors of steroidogenesis is not confirmed in children. Histopathological examination showed typical features of adenoma in 5 cases, of adenocarcinoma in 4, while three cases revealed border line forms classified as "atypical adenomas". At the moment 10 patients are alive with a follow-up ranging from 18 months to 14 years, while 2 children with adenocarcinoma are dead.
Adenocarcinoma↗
A novel mutation (M1V) in the translation initiation codon of the cystic fibrosis transmembrane conductance regulator gene, in three CF chromosomes of Italian origin.
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Codon, Initiator↗
Informativity of intragenic microsatellites for carrier detection and prenatal diagnosis of cystic fibrosis in the Italian population.
Molecular diagnosis of cystic fibrosis (CF) in the Italian population, based on the detection of the deltaF508 mutation (51.2% of CF chromosomes), provides full informativity for prenatal diagnosis (PDN) in about 28% of families at risk. Identification of the predominant non-deltaF508 mutations allows the characterization of about 70% of CF chromosomes, making approximately 48% of couples fully informative. In families where at least one chromosome remains uncharacterized, allele segregation is still determined using RFLPs closely linked to the CF gene. The recent identification of three polymorphic clusters of dinucleotide repeats (IVS8/GT, IVS17b/TA and IVS17b/CA) led us to evaluate whether their analysis might improve feasibility studies for prenatal diagnosis or heterozygote identification. One hundred nuclear families with a CF child, reflecting the general Italian deltaF508 mutation distribution, were genotyped for the three microsatellites. In this study microsatellite analysis using IVS8/GT and IVS17b/TA allowed the identification of both parental CF chromosomes in 94% of couples; inclusion in the study of the less polymorphic repeat locus, IVS17b/CA, slightly improved this percentage (97%). Hence, a strategy involving primarily the detection of the deltaF508 mutation and secondarily microsatellite analysis makes possible PDN of CF in virtually all Italian CF families.
Base Sequence↗
Noninvasive measurement of forearm blood flow and oxygen consumption by near-infrared spectroscopy.
We applied near-infrared spectroscopy (NIRS) for the simultaneous measurement of forearm blood flow (FBF) and oxygen consumption (VO2) in the human by inducing a 50-mmHg venous occlusion. Eleven healthy subjects were studied both at rest and after hand exercise during vascular occlusion. FBF was also measured by strain-gauge plethysmography. FBF measured by NIRS was 1.9 +/- 0.8 ml.100 ml-1.min-1 at rest and 8.2 +/- 2.9 ml.100 ml-1.min-1 after hand exercise. These values showed a correlation (r = 0.94) with those obtained by the plethysmography. VO2 values were 4.6 +/- 1.3 microM O2 x 100 ml-1.min-1 at rest and 24.9 +/- 11.2 microM O2 x 100 ml-1.min-1 after hand exercise. The scatter of the FBF and VO2 values showed a good correlation between the two variables (r = 0.93). The results demonstrate that NIRS provides the particular advantage of obtaining the contemporary evaluation of blood flow and VO2, allowing correlation of these two variables by a single maneuver without discomfort for the subject.
Adult↗
Need for active left-ventricular decompression during percutaneous cardiopulmonary support in cardiac arrest.
During ventricular fibrillation, myocardial hemodynamic and metabolic effects of percutaneous cardiopulmonary support (PCPS) were analyzed in 11 adult sheep (body weight 77-112 kg). During supported fibrillation, an abrupt increase in left-ventricular pressures with alignment to aortic pressures was observed in 2 animals, which was probably due to spontaneous aortic regurgitation, and resulted in deterioration of coronary perfusion. In 9 animals, left-ventricular pressures rose from 22.9 +/- 4.9 to 31.2 +/- 7.9 mm Hg elevating left ventricular wall stress from 16,750 +/- 8,745 to 28,835 +/- 8,892 dyn/cm2 after 10 min of PCPS-supported fibrillation (mean flow rate 4.5 +/- 0.7 liters/min). Simultaneously, myocardial perfusion pressures decreased from an average of 32.4 +/- 11.7 to 22.3 +/- 9.4 mm Hg and myocardial lactate release was observed. Additional transapical LV venting using a 9-Fr catheter led to a decrease in both LV pressure (to 25.7 +/- 5.3 mm Hg) and wall stress (to 20,612 +/- 7,499 dyn/cm2). Left-ventricular decompression decreased myocardial oxygen consumption (from 5.3 +/- 1.4 to 4.8 +/- 0.9 ml/min.100 g), and reduced myocardial lactate release, which indicates myocardial protection. Protective effects were most pronounced using 12-Fr-, and 21-Fr-venting cannulas (with 21 Fr: decrease in myocardial oxygen consumption to 2.7 +/- 0.6 ml/min.100 g, and reversal of myocardial lactate release to lactate uptake during fibrillation). Conclusions. Hemodynamic and metabolic data clearly demonstrate the deleterious effects of PCPS to the unvented left ventricle during cardiac arrest. The results emphasize the need for active left-ventricular decompression during PCPS in ventricular fibrillation.
Animals↗
Transcutaneous oxygen tension measurement in patients with chronic arterial obstructive disease: reliability and long-term variability of the method.
Although transcutaneous oxygen tension (TcpO2) measurement may be useful for assessing changes in regional perfusion induced over time by drug or surgical treatment in patients with chronic arterial obstructive disease (CAOD), the reliability of the method over a long-term period is not know. To approach this problem, the authors evaluated retrospectively the behavior of TcpO2 measurement over time in patients with CAOD. To eliminate confounding influences due to the concomitant vascular disease at the limb level, data analysis was performed on TcpO2 measured at the right infraclavicular position. The median length of follow-up ranged from twenty days in 34 patients to 832 days in 3 patients (n = 2 and n = 10 individual sequential replications respectively). Initial and final TcpO2 values did not differ significantly even at the longest follow-up term, which indicates that the parameter is constant over time. The intrapatient variation coefficient of TcpO2 (calculated over at least three individual replications) ranged between an average of 11% to 16.2%. The corresponding interpatient variation fluctuated between 15.5% and 33.4%, a variability explained to some extent by sex-related influences, but, at least in the range of this sample, not by age, arterial oxygen levels, or disease status. Thus TcpO2 levels per se are stable, implying that TcpO2 measurement has the potential to record consistent changes caused by specific therapeutic interventions or the clinical evolution of patients with CAOD. However, the intrapatient and interpatient variability of the method has to be taken into account when TcpO2 is used for the follow-up and the physiopathologic study of patients with CAOD.
Aged↗
Micromorphologic relationship between resin and dentin in Class II restorations: an in vivo and in vitro investigation by scanning electron microscopy.
The wetting property of dentinal bonding systems may play an important role in the mechanism of adhesion to dentin. Some studies have observed that tags penetrate 100 microns or more in nonvital teeth and less than 10 microns in vital teeth. This investigation was designed to evaluate the micromorphologic relationship between in vivo and in vitro dentin after application of two new dentinal bonding systems in Class II restorations. Class II cavities were restored in vitro and in vivo with Gluma 2000 adhesive and Pekafill hybrid resin or Scotchbond Multi-purpose adhesive and Z100 composite resin. After dissolution of dental structures, the restorations were observed with a scanning electron microscope. No morphologic differences were found between in vivo and in vitro specimens with either of the new dentinal adhesive systems tested. Short resin tags were often found in vivo, particularly at the cavity walls. Only a few areas in vivo had deep resin tags (longer than 100 microns) and these were always at the cavity floor.
Adhesiveness↗
The micromorphologic relationship between resin and dentin in Class V restorations: an in vivo and in vitro investigation.
Recently several new bonding agents that show promising in vitro performance have been marketed. Frequently there is inconsistency between in vitro test results and in vivo performance of new adhesive materials. This investigation was designed to evaluate the micromorphologic relationship between in vivo and in vitro dentin after application of two new dentinal bonding systems. V-shaped cavities were restored in vitro and in vivo with Gluma 2000 bonding system and Pekafill composite resin and Scotchbond Multi-Purpose bonding system and Z100 composite resin. After dissolution of dental structures, the restorations were observed with scanning electron microscope. No morphologic differences were found between in vivo and in vitro specimens of either dentinal adhesive system. Intertubular and peritubular dentin was reproduced accurately in every specimen.
Composite Resins↗
BAEP and E.M.G. changes from whiplash injuries.
The frequent negativity of neuroradiological changes after neck injury despite the constant complaints (neck pain and stiffness, limited neck movements, arm pains) experienced after a motor vehicle crash has led us to verify the diagnostic and prognostic validity of different neurophysiological tests in these patients. To this aim 120 young patients (67 females and 53 males) referred for a whiplash syndrome aged 18-31 years without neuroradiological abnormalities have been submitted to EMG and BAEP studies immediately after the traffic accident and after six months. Constant slowing of median MNCV and SNCV and ulnar SNCV without changes in morphology, amplitude and duration of MAP and SAP have been observed in 92 patients, with persistent abnormalities in 64 cases after six months. Increase in I-III or I-V interpeak interval of BAEP have been observed unilaterally in 45 patients and bilaterally in 32 ones without changes in absolute latencies and V/I amplitude ratio, with persistence of such abnormalities in 31 and 16 patients respectively after six months. Simultaneous abnormalities of all neurophysiological tests have been observed in 31 patients, with unmodified recordings after six months in 24 patients. The above findings could be accounted for subtle cerebral lesions and a possible damage to brain stem structures as claimed by Ettlin et al. (1992). The usefulness of the above proposed neurophysiological tests in assessment of asymptomatic dysfunction of central motor and sensory pathways in whiplash injuries is discussed.
Adolescent↗
[Decrease of insulin resistance after splenectomy in a diabetic patient with liver cirrhosis and portal hypertension. Physiopathologic evaluation].
Liver cirrhosis is characterized by an increased incidence of glucose intolerance, diabetes and insulin resistance. We report a cirrhotic man (41 years old) who developed glucose intolerance and diabetes with insulin resistance over a period of six years. This patient suffered from severe portal hypertension with oesophageal varices and a enormously increased spleen volume. The subject underwent prophylactic endoscopic sclerotherapy of oesophageal varices. Splenectomy was performed because of severe piastrinopenia with recurrent nose bleeding. During laparotomy, multiple liver biopsies confirmed diagnosis of liver cirrhosis. Intra-operatory exploration revealed a splenic vein thrombosis. For this reason the planned spleno-renal shunting was not performed and the patient was only submitted to splenectomy. Liver function improved in the month following splenectomy and concomitant decrease of insulin resistance was observed (with a reduction in daily insulin dosage from 126 to 10 I.U.). We propose the following explanations of this event: 1) A decrease of portal and pancreatic vein pressure may have induced a proportional decrease (as already reported) of glucagon secretion. 2) The ameliorated liver function may have induced an improvement of liver glucose, insulin and glucagon metabolism. 3) A reduction of insulin circulating level (proved by a decrease of C Peptide value) may have lessened the insulin receptor down-regulation.
Adult↗
A new technique for intraoperative blood recovery in the cancer patient.
Homologous blood transfusion in the cancer patient is dangerous because of an apparent immunodepressive action. Even a program of pre-deposit and isovolemic hemodilution, for reasons of immediacy and patient conditions, is often not feasible. Likewise, the intraoperative recovery of blood, although used by some, does not prevent the possible reinfusion of suspended neoplastic cells. A system that eliminates tumor cells could enable the recovery of blood in cancer patients in non-septic operative sites. A system that seems to correspond to these requisites has been set up by inserting two filters for the elimination of leucocytes from erythrocyte concentrates into a cell separator that is normally used in clinical practice. Laboratory studies, using immunohistochemical identification of tumor cells cultivated in vitro, have demonstrated the absence of contaminating cells in blood available for reinfusion.
Adenocarcinoma↗
[Consensus conference. Saving blood: which are still the doubts and the problems?].
The consensus conference on blood saving has allowed us to formulate some interesting guidelines. The autologous and homologous transfusion require the patient's consent. For volemic replacement crystalloid solutions are used for phlebotomies below 10-15%, and colloid solutions for those greater than 10-15% of the blood mass. Severe isovolemic hemodilution (Ht < 20%) necessitates the reduction of the dosage of some drugs. A limit of Hb around 9 g/dl after phlebotomy may be acceptable in the absence of cerebral and coronary vascular disease. Phlebotomies are therefore possible also when the Hb values are 10 g/dl (Ht 30%). Hb values around 7 g/dl in the late postoperative period (from day 3 to 6) may be accepted only if well tolerated. The blood salvaged during surgery and at the beginning of the postoperative phase must always be centrifugated, washed and microfiltered. Subsequently, in the first 8 hours it is possible to reinfuse red cells after sedimentation and microfiltration. The techniques of predeposit, hemodilution and recovery are valid especially if associated with careful control of postoperative bleeding by means of aspiration under controlled pressure (at minimum negative values and sometimes positive ones), monitoring of blood loss from drainage and application of elastic compression bandages.
Blood Loss, Surgical↗