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Biomedical subjects

M Ferrari

Publications and source records attributed to M Ferrari.

At least 181 records · Page 10Linked to original sources
PubMed1999

Serious childhood respiratory infections and asthma in adult life. A population based study. ECRHS Italy. European Community Respiratory Health Survey.

BACKGROUND: A number of epidemiologic studies have tried to establish whether respiratory tract infections in early childhood cause obstructive pulmonary disease in adult life. OBJECTIVE: To determine whether reported serious respiratory infection before the age of 5 years (SRI) is a significant risk factor for subsequent development of bronchial asthma and/or bronchial hyperresponsiveness in adults. METHODS: We investigated a random population sample of 1,104 subjects (aged 20 to 40 years), participating in the European Respiratory Health Survey in Italy. Bronchial response to methacholine and answers to a standardized questionnaire were analyzed. RESULTS: The prevalence of SRI (ie, a positive response to the question "Have you ever had a serious respiratory infection before the age of 5 years?") was significantly higher in the subjects with a positive family history of allergic diseases than in those with a negative one (O.R. 1.89; 95% C.I. 1.24 to 2.87, P < .01). No relationship was found between SRI and current adult asthma; however, asthma in the past was found in 20.5% of the SRI positive subjects and in 9.1% of SRI negative subjects (O.R. 2.47; 95% C.I. 1.47 to 4.15, P < .05). No difference in the response to methacholine and in FEV1, FEV1/FVC values was found between SRI positive and SRI negative subjects. CONCLUSIONS: We suggest that a positive family history of atopy is associated with a significantly higher prevalence of SRI. Furthermore our results indicate that exposure to SRI is a risk factor for asthma in the past (ie, asthma in childhood and adolescence) but not for adult asthma or for the development of bronchial impairment in adult life.

Adult↗
PubMed1999

Filtration of sub-100 nm particles using a bulk-micromachined, direct-bonded silicon filter.

For successful size separation in biomedical applications, the filter used must meet several strict criteria. Not only must it have precisely-machined sub-100 nm pores (<5% variation), but it must also be able to handle large and small volumes with very high reduction ratios (>10(4)). In this paper, we will present a bulk-micromachined, direct-bonded silicon nanofilter that can remove particles as small as 44 nm. In doing so, we will describe the fabrication, the gas and liquid characterization, and the filtrations studies done on 44 nm and 100 nm beads.

Journal Article↗
PubMed1999

Microfabricated biocapsules provide short-term immunoisolation of insulinoma xenografts.

This study examines the viability and functionality of two insulinoma cell lines, RIN (1048) and betaTC6F7, encapsulated within microfabricated biocapsules. Surface and bulk micromachining are integrated in the biocapsule fabrication process, resulting in a diffusion membrane with uniform pore size distribution as well as mechanical and chemical stability, surrounded by an anisotropically-etched silicon wafer, which serves as the encapsulation cavity. Insulinoma cells (4500 cells/biocapsule) were enclosed within these microfabricated biocapsules and subjected to a static incubation study after either implantation in BALB-C mice or incubation in vitro. Examination of retrieved microfabricated biocapsules revealed an insulin stimulatory index of approximately 1.5 for encapsulated RIN cells and 3.6 for encapsulated betaTC6F7 cells for biocapsules with 18 nm pore sized microfabricated membranes, similar to indices of biocapsules incubated in vitro. There was an 80% decrease in cell stimulatory response between in vitro and in vivo 66 nm-biocapsules as compared to 20% for 18 nm-biocapsules, indicating that the immunoisolatory effectiveness depends greatly on achieving uniform pore sizes in the size range of 18 nm or smaller. The present study demonstrates the feasibility of using microfabricated biocapsules for the immunoisolation of insulinoma cells lines. The microfabricated biocapsule may serve as an alternative to conventional polymeric based biocapsules for possible use as in vivo insulin secreting bioreactor.

Journal Article↗
PubMed1999

The role of central fat distribution in coronary artery disease in obesity: comparison of nondiabetic obese, diabetic obese, and normal weight subjects.

OBJECTIVE: To investigate the degree of coronary artery disease (CAD) in relation to obesity and fat distribution in obese patients with normal glucose tolerance, in comparison with CAD of diabetic obese patients and of normal weight subjects with CAD. DESIGN: Patients listed for coronary angiography with different body mass index (BMI) with or without diabetes: study of the correlation between severity of coronary damage and fat distribution. SUBJECTS: 92 patients subdivided into: 30 normal glucose tolerant obese (BMI 31.7+/-0.5, aged 53+/-1.7 y), 28 type 2 diabetic obese (BMI 30.7+/-0. 3, aged 57+/-1.2 y), and 34 normal weight patients (BMI 23.1+/-0.3, aged 54+/-1.7 y). MEASUREMENTS: CAD assessed by angiography and evaluated according to the method of Gensini. Fat mass and fat distribution assessed by bioelectrical impedance and anthropometry. Clinical, biochemical and hormonal variables, as well as smoking habits and alcohol intake. RESULTS: The angiographic coronary scores were similar in nondiabetic obese and in diabetic obese patients, and were significantly higher than those of normal weight subjects. In the entire population coronary score correlated with indices of abdominal fat distribution. In the stepwise analysis of each group separately, waist hip ratio (WHR) correlated with coronary score only in normal weight nondiabetic patients. CAD was inversely associated with BMI only in nondiabetic obese patients. CONCLUSION: CAD of obese patients: 1) is similar to that of diabetic obese patients; 2) is more severe than that of normal weight individuals; and 3) is inversely correlated with BMI. CAD appears to be associated with WHR, not with BMI, only in nondiabetic patients with normal body weight. On the contrary, CAD of diabetic obese patients is unrelated to BMI and parameters of fat distribution, but is associated with smoking habits.

Adipose Tissue↗
PubMed1999

Myocardial region (right or left ventricle) and aetiology of heart failure can influence the inotropic effect of ouabain in failing human myocardium.

AIMS: To investigate whether the inotropic effect of ouabain in failing human myocardium varies according to the heart chamber tested (right or left ventricle) or the aetiology of the heart disease, i.e. ischaemic or idiopathic. METHODS: The inotropic effect of ouabain was measured, as the percentage change in baseline tension, in myocardial strips isolated from right (RV; n=21) and left ventricles (LV; n=21) of hearts explanted from patients with idiopathic (IDC; n=11) and ischaemic cardiomyopathy (CAD; n=10). Concentration-effect curves obtained with ouabain (0.05-1.6 micromol l-1 ) were analysed using the Emax sigmoidal model, and the following parameters were calculated: Emax, EC50, n and EC10 (threshold concentration). The influence of ventricular chamber and heart failure aetiology on these parameters was evaluated by means of a two-way anova. RESULTS: Age and baseline haemodynamic parameters did not differ between IDC and CAD patients. Baseline strip contractility was highly variable (range: 0.48-10.0 mN), but neither ventricular chamber nor aetiology could explain such variability. A two-way anova showed that EC10 was greater in CAD than in IDC preparations (0.097+/-0.013 micromol l-1 vs 0.059+/-0. 009 micromol l-1; 95% C.I. for difference 0.043, 0.071) and Emax was lower in RV than in LV (121+/-21% vs 250+/-38%; 95% C.I. -221, -36), while EC50 and n were not significantly different between groups. CONCLUSIONS: The inotropic effect of ouabain in human myocardium may vary according to aetiology of heart failure and the ventricle being tested. Although our results do not support the hypothesis of increased sensitivity to cardiac glycosides in CAD patients, they may explain the diminished effect observed in patients with RV failure.

Aging↗
PubMed1999

Fibrinogen and mortality in chronic critical limb ischaemia.

OBJECTIVE: Plasma fibrinogen predicts cardiovascular events in patients with stable peripheral arterial occlusive disease, but its predictive value in patients with chronic critical limb ischaemia, a condition associated with a high risk of death, is unknown. DESIGN: A prospective cohort study. SETTING: Determination of fibrinogen and other potential predictors during clinic-based work-up of patients admitted for diagnostic and therapeutic evaluation. SUBJECTS: A total of 108 patients (72 +/- 10 years, 78 males) with atherosclerotic occlusive disease and critical limb ischaemia (pain at rest and/or trophic lesions) followed up for a median period of 1.6 years). (range: 8 days-5.5 years; 218 patient-years). MAIN OUTCOME MEASURES: Total mortality. RESULTS: Forty-five deaths (71% cardiovascular) occurred during the follow-up. Baseline fibrinogen was higher in those who died in the early follow-up period (first 6 months), as were white cell count and serum creatinine, while haematocrit was lower. Plasma fibrinogen values correlated positively with white cell count, and negatively with haematocrit; other cardiovascular prognostic factors did not differ. Only plasma fibrinogen predicted survival independently in multivariate age-corrected Cox regression analysis. Relative risk of death doubled for each standard deviation above the mean and increased with each tertile increase in fibrinogen. CONCLUSIONS: Fibrinogen predicted death in these elderly arteriopaths with critical limb ischaemia, particularly those who died in the first months following critical ischaemia. Inflammatory stimuli secondary to severely defective tissue oxygenation and possibly sepsis and necrosis, might have stimulated fibrinogen, an acute-phase reactant, thereby compromising organ perfusion through increased blood viscosity and/or promoting thrombosis.

Aged↗
PubMed1999

Radiation protection in radioguided surgery of breast cancer.

The protocols for sentinel lymph node biopsy and radioguided occult lesion localization could potentially be of great value in the management of breast cancer patients. Both involve the injection of a 99Tcm-labelled radiopharmaceutical close to or into the lesion, localization of the sentinel lymph node or occult lesion by scintigraphy, and surgical removal with the aid of a hand-held gamma-ray detector. We present dosimetric data on patients and hospital personnel involved in these procedures. For evaluation of radiation protection, we measured the absorbed dose and air kerma rate. Activity levels in excised tissues and surgical instruments were also determined. For patients, the mean absorbed dose to the abdomen was 0.45 mGy, which is low compared to doses received from other diagnostic examinations. For surgeons after 100 operations, the mean absorbed dose to the hands was 0.45 mGy and the mean effective dose 0.09 mSv. Absorbed doses to all hospital personnel involved in the procedures were very low compared to recommended annual limits stipulated by the International Commission on Radiological Protection. We conclude that these procedures, performed according to protocols laid down by the European Institute of Oncology, Milan, are safe from the point of view of radiological protection and that only routine precautions are necessary.

Breast Neoplasms↗
PubMed1999

Effect of leisure time and working activity on principal risk factors and relative interactions in active middle-aged men.

DESIGN: This study was designed to evaluate, in a cohort of 1039 middle-aged men, the interaction between the duration and intensity of physical activity performed either during leisure time (competitive sports, walking, cycling) or work, and principal coronary disease risk factors. METHOD: A cohort of subjects aged 45-64 years were recruited in 1993. Subjects included both individuals who were physically active and those who were sedentary, and were age-matched. RESULTS: Leisure time physical activity was inversely related to levels of total cholesterol, triglycerides, and fibrinogen, and to diastolic and systolic blood pressure. High-density lipoprotein cholesterol level was directly related to leisure time activity. Working activity, even if strenuous, was not related to risk profile. Leisure time activity did not favorably influence lipid levels in smokers, obese subjects or those with known dyslipidemia. CONCLUSIONS: This study further reinforces the use of continuous diet and drug treatment in dyslipidemic subjects and in smokers, who have to refrain from smoking if they are to benefit fully from the effects of physical activity.

Body Mass Index↗
PubMed1999

Dye leakage and SEM study of roots obturated with Thermafill and dentin bonding agent.

The apical seal of roots obturated with a dentin bonding agent and Thermafill with and without the use of sodium hypochlorite as an irrigating solution was compared by a dye leakage test. Roots obturated with Thermafill and a zinc oxide eugenol sealer were used as controls. Thirty-eight roots were prepared chemomechanically and divided into three experimental groups. The teeth of group 1 were filled with Thermafill and the dentin bonding agent using sodium hypochlorite as the irrigant. The teeth of group 2 were filled in the same way, but saline solution was used as the irrigant. Before the root canal was filled the smear layer was removed from the root canal walls of both groups by rinsing the root canal with a 17% EDTA solution. The teeth of group 3 were filled with Thermafill and a zinc oxide eugenol sealer. The teeth were immersed in 2% methylene blue solution. The root fillings of groups 1 and 2 leaked significantly more than those of group 3. The resin-dentin-guttapercha interface of group 1 was observed by scanning electron microscopy and showed a typical hybrid layer. An intimate contact between resin and dentin was present in group 2, but a resin-dentin interdiffusion zone was only occasionally observed. The use of dental adhesives and the hybrid layer formation did not improve the seal of Thermafill root canal fillings.

Coloring Agents↗
PubMed1999

Detection of rifampin resistance in Mycobacterium tuberculosis by double gradient-denaturing gradient gel electrophoresis.

We applied double gradient-denaturing gradient gel electrophoresis (DG-DGGE) for the rapid detection of rifampin (RMP) resistance from rpoB PCR products of Mycobacterium tuberculosis isolates and clinical samples. The results of this method were fully concordant with those of DNA sequencing and susceptibility testing analyses. DG-DGGE is a valid alternative to the other methods of detecting mutations for predicting RMP resistance.

Adult↗
PubMed1999

Blood lactate accumulation and muscle deoxygenation during incremental exercise.

Near-infrared spectroscopy (NIRS) could allow insights into controversial issues related to blood lactate concentration ([La](b)) increases at submaximal workloads (). We combined, on five well-trained subjects [mountain climbers; peak O(2) consumption (VO(2peak)), 51.0 +/- 4.2 (SD) ml. kg(-1). min(-1)] performing incremental exercise on a cycle ergometer (30 W added every 4 min up to voluntary exhaustion), measurements of pulmonary gas exchange and earlobe [La](b) with determinations of concentration changes of oxygenated Hb (Delta[O(2)Hb]) and deoxygenated Hb (Delta[HHb]) in the vastus lateralis muscle, by continuous-wave NIRS. A "point of inflection" of [La](b) vs. was arbitrarily identified at the lowest [La](b) value which was >0.5 mM lower than that obtained at the following. Total Hb volume (Delta[O(2)Hb + HHb]) in the muscle region of interest increased as a function of up to 60-65% of VO(2 peak), after which it remained unchanged. The oxygenation index (Delta[O(2)Hb - HHb]) showed an accelerated decrease from 60- 65% of VO(2 peak). In the presence of a constant total Hb volume, the observed Delta[O(2)Hb - HHb] decrease indicates muscle deoxygenation (i.e., mainly capillary-venular Hb desaturation). The onset of muscle deoxygenation was significantly correlated (r(2) = 0.95; P < 0.01) with the point of inflection of [La](b) vs., i.e., with the onset of blood lactate accumulation. Previous studies showed relatively constant femoral venous PO(2) levels at higher than approximately 60% of maximal O(2) consumption. Thus muscle deoxygenation observed in the present study from 60-65% of VO(2 peak) could be attributed to capillary-venular Hb desaturation in the presence of relatively constant capillary-venular PO(2) levels, as a consequence of a rightward shift of the O(2)Hb dissociation curve determined by the onset of lactic acidosis.

Acidosis, Lactic↗
PubMed1999

External jugular vein hemangioma occurring as a lateral neck mass.

Hemangioma is an extremely frequent tumor, accounting for 7% of all benign neoplasms. In contrast, hemangioma arising in blood vessels is rare and should be differentiated from other neoplasms of vascular origin, such as hemangioendothelioma, hemangiopericytoma, hemangiosarcoma, and leiomyosarcoma. The case we report has the peculiarity of occurring as a lateral neck mass in which color-coded duplex sonography contributed significantly to diagnosis.

Female↗
PubMed1999

[A hyperhomocysteinemia study in a population with a familial factor for acute myocardial infarct and sudden cardiac death at a young age].

The alterations of the metabolism of methionine determining an accumulation of homocysteine in blood (hyperhomocysteinemia) recognize a multifactorial etiology, hereditary as well as acquired. To date several case-control studies have documented that the condition of hyperhomocysteinemia can be considered an independent risk factor of coronary disease and its noxious effects are dose-dependent. It exerts its effect by different mechanisms both prothrombotic and endothelial. In our study we started from an initial cohort of 2227 subjects (1210 males, 1017 females) aged between 45 and 64 years among which we selected 22 persons with at least 2 first-degree relatives below age 50 who had had either a major cardiovascular event (acute myocardial infarction or sudden death) or angiographically documented cardiac disease. We reconstructed the proper pedigrees obtaining 22 families in whom we identified four main subgroups to carry out analyses and comparisons: case-control, composed respectively of all the subjects who survived a major cardiovascular event or a coronary disease documented angiographically and clinically healthy subjects; affected line and non affected line, composed respectively of members belonging to the family line of the proband and members of collateral family line. Each of the subjects involved in the study underwent a complete history regarding job and sports activities, a standardized physical examination, 12-lead digital ECG according to the European Standard Communication Protocol. A blood sample was taken in fasting conditions to determine total cholesterol, HDL and LDL cholesterol, triglycerides, glycemia, fibrinogen, plasma homocysteine. The results indicate how among the cases there were more subjects with homocysteine higher than the 95 degrees percentile in males alone (p = 0.03), the estimated odds ratio calculated from Fisher's test was 8.34 (95% confidence interval 1.32-52.7). Despite the fact that mean age was significantly lower (p = 0.01) in males of the affected line compared to those of the non affected line, the results show much higher homocysteine values in the affected family line in both males and females: a difference quite evident in the distribution especially as regards the 95 degrees percentile. These results obtained in the subjects belonging to the same families emphasize that familial aggregation, which influences the sharing of the genetic patrimony, socio-cultural environment and food habits can induce a differential risk for homocysteinemia. The study of mutations of genes coding for the key enzymes of the metabolism of homocysteine, methylenetetrahydrofolate reductase and cystathionine beta-synthase, which we prepared, will enable use to evaluate the relative influence feeding habits and genetic factors have in the development of hyperhomocysteinemia.

Adult↗