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Biomedical subjects

M Dotti

Publications and source records attributed to M Dotti.

14 recordsLinked to original sources
PubMed2004

Effect of the initial implant fitting on the predicted secondary stability of a cementless stem.

A numerical model able to investigate the influence of biomechanical factors on the long-term secondary stability of implants would be extremely useful for the design of new cementless prosthetic devices. A purely biomechanical model of osseo-integration has been developed, formulated as a rule-based adaptation scheme. Due to its complexity, the problem was divided into three steps: preliminary implementation of the model (proof of concept); implementation of the complete model and investigation of the model solution; and model validation. The paper describes the first of these three steps. The model was implemented as a discrete-states machine, and the few parameters required were derived from the literature. It was then applied to a real clinical case. The study was conducted using the frictional contact finite element model of a human femur implanted with a cementless anatomical stem. A stable solution was achieved after between three and 15 iterations for all initial positions considered. Similar initial conditions yielded similar final configurations. The model predicted all initial configurations, with the exception of a partial osseo-integration, ranging between 62% (distal fit) and 78% (proximal fit) of the viable interface. This is in good agreement with the values reported in the literature that never exceed 75%, even in the best conditions, and report better clinical results for proximal fit. For the varus configuration, which lacks cortical support, the algorithm predicted a completed loosening.

Arthroplasty, Replacement, Hip↗
PubMed2003

Hepaticogastrostomy by echo-endoscopy as a palliative treatment in a patient with metastatic biliary obstruction.

A palliative hepaticogastrostomy was performed under endoscopic ultrasound guidance in a patient with inoperable hepatic hilar obstruction, creating an anastomosis between the dilated left hepatic duct and the stomach, to relieve symptoms of cholangitis and to allow biliary drainage. This therapeutic procedure was used as an alternative method of drainage of the biliary tree because endoscopic retrograde cholangiopancreatography was not possible and because the percutaneous metallic stent which had been inserted earlier had become occluded (probably by tumor overgrowth). It was a two-step procedure. In the first step a hepatic duct was punctured through the gastric wall with placement of a plastic stent, which created a fistula between them. In a second step a covered, metallic, self-expandable stent was substituted for the plastic stent to maintain the anastomosis and to improve patency over the medium term. The patient's fever was relieved and the bilirubin level fell; the patient remained asymptomatic at the five-months-follow-up.

Adenocarcinoma↗
PubMed1998

Volatile halocarbons in a drinking water supply system: forecasting contamination values and estimating health risk.

The network, which supplies drinking water to the city of Milan, has a number of sampling points, where the concentrations of several contaminants are periodically measured. From the time series of total volatile halocarbon (VHC) concentration values (in the ppb range) autoregressive models can be obtained for each sampling point. A suitable figure of merit is minimized, which depends on the backcast error and on the model order. The best model is then applied to predicting concentration one time step e.g., one year, forward. The experimental data pertain to the years 1981 to 1992. Predicted values are compared with the measured ones. The results obtained in 1991 contributed to avert a major emergency situation in Milan. Population exposure and the related health risk, based on the proportional dosage-response model, were also estimated. The excess casualty figure for Milan was computed. The method and the procedures described herewith may be used by public authorities to manage drinking water resources, whenever detailed models of the aquifer and of the network are not applicable.

Environmental Monitoring↗
PubMed1997

Is the sugar intestinal permeability test a reliable investigation for coeliac disease screening?

BACKGROUND: The lactulose/mannitol (L/M) intestinal permeability test is a simple, non-invasive screening test for coeliac disease. The reliability of the L/M test has so far only been tested in selected groups of patients with coeliac disease. AIM: To evaluate the reliability of the L/M test in a group of patients with coeliac disease who had been diagnosed during mass serological screening of the general population. PATIENTS AND METHODS: Twenty nine patients with coeliac disease detected by screening and 54 age matched coeliac disease free controls aged 11-15 years underwent an L/M test with 5 g lactulose and 2 g mannitol in isotonic aqueous solution. Urinary sugars were measured by high performance liquid chromatography. RESULTS: The median % urinary recovery of lactulose (lactulose UR) was significantly higher in patients with coeliac disease than in controls (0.63 v 0.18, p < 0.001). The mean mannitol % UR was lower in patients with coeliac disease than in controls (17.6 v 18.5) but the difference was not significant. The median urinary L%/M% ratio was significantly higher in patients with coeliac disease than in controls (0.038 v 0.014, p < 0.001). However, 16 of the 29 patients with coeliac disease showed an L%/M% ratio within normal limits (< 0.044). CONCLUSIONS: The L/M intestinal permeability test is not a valuable tool for screening of coeliac disease in the general population. The pattern of the urinary probe recovery suggests that many patients with coeliac disease could remain symptomless because the extent of their intestinal mucosal damage is small ("short" coeliac disease).

Adolescent↗
PubMed1996

The coeliac iceberg in Italy. A multicentre antigliadin antibodies screening for coeliac disease in school-age subjects.

BACKGROUND: Recent studies suggest that coeliac disease (CD) is one of the commonest, life-long disorders in Italy. The aims of this multicentre work were: (a) to establish the prevalence of CD on a nationwide basis; and (b) to characterize the CD clinical spectrum in Italy. PATIENTS AND METHODS: Fifteen centres screened 17,201 students aged 6-15 years (68.6% of the eligible population) by the combined determination of serum IgG- and IgA-antigliadin antibody (AGA) test; 1289 (7.5%) were IgG and/or IgA-AGA positive and were recalled for the second-level investigation; 111 of them met the criteria for the intestinal biopsy: IgA-AGA positivity and/or AEA positivity or IgG-AGA positivity plus serum IgA deficiency. RESULTS: Intestinal biopsy was performed on 98 of the 111 subjects. CD was diagnosed in 82 subjects (75 biopsy proven, 7 not biopsied but with associated AGA and AEA positivity). Most of the screening-detected coeliac patients showed low-grade intensity illness often associated with decreased psychophysical well-being. There were two AEA negative cases with associated CD and IgA deficiency. The prevalence of undiagnosed CD was 4.77 x 1000 (95% CI 3.79-5.91), 1 in 210 subjects. The overall prevalence of CD, including known CD cases, was 5.44 x 1000 (95% CI 4.57-6.44), 1 in 184 subjects. The ratio of known to undiagnosed CD cases was 1 in 7. CONCLUSIONS: These findings confirm that, in Italy, CD is one of the most common chronic disorders showing a wide and heterogeneous clinical spectrum. Most CD cases remain undiagnosed unless actively searched.

Adolescent↗
PubMed1995

A longitudinal study of the T cell activation marker CD26 in chronic progressive multiple sclerosis.

Activated T cells are implicated in the pathogenesis of multiple sclerosis (MS), an autoimmune demyelinating disease of the central nervous system. Serial measurements of T cell activation molecules and T cell subpopulations were performed over 12 months in patients with chronic progressive multiple sclerosis and healthy controls, and correlated with clinical indices of disease progression measured by standardized disability scores. Of the markers studied, the activation molecule CD26 appeared to exhibit a more consistent pattern and to be elevated in MS patients; therefore we concentrated our attention on this marker, especially in view of recent evidence of its role in T cell activation. In this small patient group, the elevation of CD26 in the MS patients did not reach statistical significance, when compared to the level in the controls. Interestingly, the percentage of CD26 but not CD25 or HLA-DR correlated with the MS patients' disability scores. However, the clinical significance of this observation as an indication of disease activity in chronic progressive MS remains to be demonstrated in studies of larger patient populations.

Adult↗
PubMed1994

Olfactory function in Parkinson's disease subtypes.

Decreased olfactory function commonly occurs in idiopathic Parkinson's disease (PD), regardless of stage, treatment, or duration of disease. In the present study, we sought to determine whether different subtypes of PD, categorized according to well-defined clinical criteria, evidence different degrees of olfactory dysfunction. Significantly different scores on the University of Pennsylvania Smell Identification Test (UPSIT) were present between patients with benign PD and malignant PD (respective means [SD] = 22.51 [8.50] and 17.38 [6.29]) and between tremor-predominant PD and postural instability-gait disorder (PIGD)-predominant PD (23.43 [8.18] versus 17.35 [6.00]). No statistically significant differences in UPSIT scores were observed between young-onset and older-onset PD patients. Women outperformed men in most subtypes examined.

Adult↗
PubMed1991

Imipenem use in serious childhood infections.

Imipenem plus cilastatin is a beta-lactam antibiotic with a broad spectrum and good tolerance. For this its use is indicated in serious infections even in children. The authors carried out a preliminary bacteriological study in patients affected by serious infection, cystic fibrosis, tumors, neutropenia, subjects undergoing intensive therapy and those with abdominal surgical infection. Isolated microorganism sensitivity in these patients, towards imipenem was very high (89%-100%). With these premises, 35 patients with serious infections in various locations were treated only with imipenem. Of these, 15 were oncologic neutropenic and 20 normal. In the first group therapeutic success was 66.6% and in the second one 80%. Local and systemic tolerance always showed good results.

Antineoplastic Agents↗
PubMed1988

Changes of erythrocyte membrane fluidity associated with childhood obesity: a molecular study using fluorescence spectroscopy.

Fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene has been used to investigate the physical state of erythrocyte membranes from 36 obese children in absence of endocrine and metabolic disorders involving alterations of blood lipid pattern. A decrease of membrane fluidity, as shown by an increase of fluorescence polarization, was evident in obese subjects in comparison with the controls. The study of membrane composition has revealed an increase of cholesterol content and of cholesterol to phospholipid molar ratio, both being positively correlated with the observed changes of membrane fluidity. Moreover a correlation of membrane fluidity is also observed with body-mass index and plasma cholesterol levels. The results are discussed in the light of the possible use of erythrocyte membrane as a model to detect early alterations in the exchanges between erythrocyte membrane and lipoproteins in obesity.

Adolescent↗
PubMed1987

Changes of membrane fluidity in erythrocytes of obese children: a spin label study.

Red blood cells depend on circulating lipoproteins for the turnover of membrane phospholipids. Thus abnormalities in lipid and lipoprotein metabolism are frequently associated with changes in composition and fluidity of erythrocyte membranes. Using the electron spin resonance technique we studied the physical state of erythrocyte membranes from 15 obese children with a body mass index ranging from 22.8 to 34 kg . m-2 and slight alterations of plasma lipids. The spin labels used, 5-doxylstearate and 16-doxylstearate, have shown an increase of the order parameter and of the correlation time, respectively. These observations indicate a decrease of fluidity at the surface and in the hydrophobic core of erythrocyte membranes from obese subjects. The results are statistically significant and they are discussed in relation to clinical aspects of childhood obesity. Studies on erythrocyte membrane molecular organization could represent a sensitive way to find out small metabolic alterations hardly detectable with compositional studies.

Adolescent↗