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Biomedical subjects

M Porta

Publications and source records attributed to M Porta.

At least 55 records · Page 3Linked to original sources
PubMed2000

Different risk factors of microangiopathy in patients with type I diabetes mellitus of short versus long duration. The EURODIAB IDDM Complications Study.

AIMS/HYPOTHESIS: To identify factors associated with early development of and late protection from microvascular complications in subjects with Type I (insulin-dependent) diabetes mellitus. METHODS: The frequency of microvascular complications and their relation to risk factors were studied in 300 Type I diabetic subjects with short duration of disease (< or = 5 years) compared with 1062 subjects with long duration (> or = 14 years). Microvascular disease was defined as the presence of either retinopathy (assessed from centrally-graded retinal photographs) or urinary albumin excretion rate of more than 20 micrograms/min. RESULTS: The prevalence of microvascular disease was 25% in the short duration group. In the long duration group 18% had no evidence of microvascular complications. In the short duration group factors associated with early development of complications were cigarette smoking and a family history of hypertension. Subjects free of microvascular complications in spite of long duration of diabetes had better glycaemic control, lower blood pressure, better lipid profile and lower von Willebrand factor levels. CONCLUSION/INTERPRETATION: At the early stages of Type I diabetes, cigarette smoking and genetic susceptibility to hypertension are important risk factors for microvascular complications. At a later stage, additional risk factors are poorer glycaemic control, higher blood pressure, and an unfavourable lipid profile possibly associated with endothelial dysfunction. Many of these factors are amenable to long-term intervention which should be started as soon as possible in the course of the disease.

Cohort Studies↗
PubMed2000

A comparative trial of botulinum toxin type A and methylprednisolone for the treatment of tension-type headache.

Tension-type headache (TH) is a common condition, the pathophysiology of which remains undetermined. Evidence implicates sustained contraction of pericranial muscles to be a major cause. A recent preliminary study demonstrated the effectiveness of botulinum toxin type A (BTX-A) in patients suffering from chronic TH. To further investigate this, we performed a study to compare the efficacy of BTX-A with the steroid methylprednisolone (both administered with the local anesthetic lidocaine), when administered by injection into the tender points of cranial muscles in patients with TH. A significant decrease in the median pain score (assessed using a standard visual analogue scale ) was observed at 60 days post injection of BTX-A compared with the pain score achieved following steroid therapy. All patients treated with BTX-A experienced a gradual decrease in median pain severity scores at 30 days and 60 days post treatment. The beneficial effects of BTX-A therapy continued to improve 60 days following injection, whereas the effects of steroid therapy at this time point began to decline. This study clearly demonstrates the effectiveness of BTX-A for the treatment of TH.

Adolescent↗
PubMed2000

A comparative trial of botulinum toxin type A and methylprednisolone for the treatment of myofascial pain syndrome and pain from chronic muscle spasm.

Myofascial pain syndrome (MPS) is a common illness, characterised by acute or chronic focal pain, muscle stiffness and fatigue. The pathophysiology of MPS remains unclear. Previous preliminary studies have demonstrated therapeutic efficacy of the muscle relaxant botulinum toxin type A (BTX-A) in the treatment of MPS. A single-centre, randomised trial compared the effects of BTX-A with the steroid methylprednisolone (both administered intramuscularly with 0.5% bupivacaine), in 40 patients suffering from chronic myofascial pain in the piriformis, iliopsoas or scalenus anterior muscles. Thirty days after receiving an injection of either BTX-A or steroid followed by post-injection physiotherapy, pain severity had decreased significantly from baseline in both treatment groups, with no significant difference between the two treatment groups. However, the baseline pain score was significantly higher in the BTX-A treatment group compared with the steroid group (7.9 vs. 7.3), and the reduction in pain score between baseline and 30 days post-injection was greater in the BTX-A group compared with the steroid group (-3.9 vs. -3.5; P=0.06). At 60 days post-injection, the pain severity score for the BTX-A-treated patients was statistically significantly lower than the pain score for the steroid-treated population (2.3 vs. 4.9). Furthermore, the reduction in pain score in the BTX-A group at 60 days post-injection was greater than at 30 days (-5.5 vs. -3.9), whereas the effect of the steroid had begun to wane. These results indicate the superior efficacy of BTX-A over conventional steroid treatment in patients suffering from MPS, when combined with appropriate physiotherapy.

Adolescent↗
PubMed2000

Validity of the hospital discharge diagnosis in epidemiologic studies of biliopancreatic pathology. PANKRAS II Study Group.

BACKGROUND: The aim was to analyse the magnitude, direction and predictors of change in the main hospital discharge diagnosis (HDD) after a clinical expert review, among patients included in a multicentre molecular epidemiologic study of biliopancreatic diseases. METHODS: A total of 602 patients with a suspicion diagnosis of pancreas cancer (PC), cancer of the extrahepatic biliary system (CEBS) or benign biliopancreatic pathologies (BPP) were prospectively recruited at five general hospitals. A structured form was used to collect information from medical records. A panel of experts revised all diagnostic information and established the main clinicopathological diagnosis (CPD) by consensus. RESULTS: Of the 204 cases with a HDD of PC, 176 (86%) were deemed to have a CPD of PC, eight of CEBS, twelve a neoplasm of different origin, four BPP and four syndromic diagnoses. Thus, 28 cases (14%) were false positives. Of the 129 patients with a HDD of CEBS, 15 (12%) were false positives. Nine of the 396 cases with a HDD of non-PC (2%) had a CPD of PC (false negatives), whilst 14 of 471 patients with a HDD of non-CEBS (3%) were deemed to have CEBS. Overall, sensitivity and specificity of HDD for PC were, respectively, 95 and 93%, and for CEBS, 89 and 97%. Cytohistological confirmation and laparotomy were independent predictors of diagnostic change. CONCLUSIONS: Validity of the HDD was high, but its association with some clinical variables suggests that sole reliance on HDD can significantly bias results, and highlights the need to review all HDDs. Alternatively, only patients at high risk of misdiagnosis could be reviewed: primarily, those lacking a cytohistological diagnosis or a laparotomy. No exclusions appear warranted solely on the basis of age, gender or tumour spread.

Aged↗
PubMed2000

Screening and prevention of diabetic blindness.

Diabetic eye disease remains a major cause of blindness in the world. Laser treatment for proliferative diabetic retinopathy and diabetic macular edema became available more than two decades ago. The outcome of treatment depends on the timing of laser treatment. The laser treatment is optimally delivered when high-risk characteristics have developed in proliferative retinopathy or diabetic macular edema and before this has significantly affected vision. Laser treatment is usually successful if applied during this optimal period whereas the treatment benefit falls sharply if the treatment is applied too late. In order to optimize the timing of laser treatment in diabetic eye disease screening programs have been established. The oldest screening program is 20 years old and several programs have been established during the last decade. In this paper the organisation and methods of screening programs are described including direct and photographic screening. The incidence and prevalence of blindness is much lower in populations where screening for diabetic eye disease has been established compared to diabetic populations without screening. Technical advantages may allow increased efficiency and telescreening. From a public health standpoint screening for diabetic eye disease is one of the most cost effective health procedures available. Diabetic eye disease can be prevented using existing technology and the cost involved is many times less than the cost of diabetic blindness.

Blindness↗
PubMed2000

GJB2 gene mutations in childhood deafness.

The frequency of childhood deafness is estimated at 1:1,000 and at least half of these cases are genetic. Recently, mutations in the GJB2 gene have been found in a great number of familial and sporadic cases of congenital deafness in Caucasians. The most common mutation (70%) is the frameshift mutation of a single guanine in position 35 (35delG). More than 20 mutations in the GJB2 gene are associated with DFNB1, a prevalent type of autosomal recessive non-syndromic neurosensory deafness. Last year we initiated a systematic screening programme to evaluate the causes of deafness in the population of prelingually deaf children who are referred to our cochlear implant programme. All of the deaf children and their parents undergo a comprehensive medical review, directed to identify causes of acquired deafness and manifestations of syndromic hearing impairment. DNA is extracted from the blood of all of the children. The technique AS-PCR (allele-specific polymerase chain reaction) is used for the identification of the mutation 35delG. Screening for other GJB2 gene mutations is carried out by single-strand conformation polymorphisms (SSCP). Our results on the identification of DFNB1 will be presented, as well as a discussion on the implications of an aetiological diagnosis in cochlear implantation.

Child↗
PubMed2000

Occupation and pancreatic cancer in Spain: a case-control study based on job titles. PANKRAS II Study Group.

BACKGROUND: Occupational exposures may increase the risk of exocrine pancreatic cancer. This study aimed to identify occupations that in Spain may be associated with such risk. METHODS: Incident cases of pancreatic cancer and hospital controls were prospectively identified and interviewed during their hospital stay. Occupational history was obtained by direct interview with the patient and was available for 164 (89%) of 185 pancreatic cancer cases and for 238 (90%) of 264 controls. Occupations were coded according to the Spanish version of the International Standard Classification of Occupations 1988. RESULTS: A significant increased odds ratio (OR) was observed in men for 'physical, chemistry and engineering science technicians'. Elevated risks were also found for 'metal moulders, sheet-metal workers, structural metal workers, welders and related workers', 'painters and varnishers' and 'machinery mechanics and fitters'. 'Agricultural workers' did not present an increased risk for pancreas cancer in men. In women, however, high OR were observed for 'agricultural workers' and for 'textile and garment workers'. Most associations remained unchanged after considering long duration of the exposure and the period 5-15 years before diagnosis. CONCLUSIONS: Few occupations were at increased risk for pancreatic cancer, and the associations observed are in accordance with previous studies. The increases in risk observed for women in agricultural and textile jobs, and for men in the manufacture of dyes and pigments may deserve further attention.

Acute Disease↗
PubMed2000

Dose conversion factor for radon concentration in indoor environments using a new equation for the F-fP correlation.

Since 1994 the radon studies group at the Institut de Tècniques Energètiques (INTE) of the Universitat Politècnica de Catalunya in Barcelona, Spain, has carried out a campaign of continuous measurements of the equilibrium factor (F) and the unattached fraction (f(p)) of radon decay products at four sites which are representative of different environmental characteristics on the Mediterranean littoral of Catalonia, Spain. It has been established that these parameters vary widely, F(0.03-0.87) and f(p) (0-0.72), from one site to another and with time, according to the characteristics of the site and climate. In spite of this variation, the F and f(p) parameters are log-normally or normally distributed. The measurements of F and f(p) show that f(p) is negatively correlated to F by a log-power equation, Ln(1/f(p))=1.90[Ln(1/F)](-0.68), which can be used in all the F range, instead of the commonly used power equation f(p)=aFb suggested by Stranden and Strand and other authors, which fits well for a reduced range of F. Power and log-power equations have been introduced into a simplified dosimetric model in order to estimate the effective dose per unit radon exposure as a function of F. From the log-power equation this value is quite constant and ranged from 9 nSv per Bq m(-3) h to 12 nSv per Bq m(-3) h when F is higher than 0.15. In the case of a lower F factor, a linear function that passes through 0 fits quite well. A value of 12 nSv per Bq m(-3) h is proposed for the Mediterranean littoral of Catalonia as the best estimation.

Air Pollutants, Radioactive↗
PubMed2000

Occupational exposures and pancreatic cancer: a meta-analysis.

OBJECTIVES: Consolidation of epidemiological data on pancreatic cancer and worksite exposures. METHODS: Publications during 1969-98 were surveyed. Studies without verified exposures were excluded. Meta-analyses were conducted on data from 92 studies covering 161 populations, with results for 23 agents or groups of agents. With a standard format, five epidemiologists extracted risk estimates and variables of the structure and quality of each study. The extracted data were centrally checked. Random meta-models were applied. RESULTS: Based on 20 populations, exposure to chlorinated hydrocarbon (CHC) solvents and related compounds was associated with a meta-risk ratio (MRR) of 1.4 (95% confidence interval (95% CI) 1.0 to 1.8). Nickel and nickel compounds were considered in four populations (1.9; 1.2 to 3.2). Excesses were found also for chromium and chromium compounds (1.4; 0.9 to 2.3), polycyclic aromatic hydrocarbons (PAHs) (1.5; 0.9 to 2.5), organochlorine insecticides (1.5; 0.6 to 3.7), silica dust (1.4; 0.9 to 2.0), and aliphatic and alicyclic hydrocarbon solvents (1.3; 0.8 to 2.8). Evidence on pancreatic carcinogenicity was weak or non-positive for the following agents: acrylonitrile (1.1; 0.0 to 6.2); arsenic (1.0; 0.6 to 1.5); asbestos (1.1; 0.9 to 1.5); diesel engine exhaust (1.0; 0.9 to 1.3); electromagnetic fields (1.1; 0.8 to 1.4); formaldehyde (0. 8; 0.5 to 1.0); flour dust (1.1; 0.3 to 3.2); cadmium and cadmium compounds (0.7; 0.4 to 1.4); gasoline (1.0; 0.8 to 1.2); herbicides (1.0; 0.8 to 1.3); iron and iron compounds (1.3; 0.7 to 2.5); lead and lead compounds (1.1; 0.8 to 1.5); man-made vitreous fibres (1.0; 0.6 to 1.6); oil mist (0.9; 0.8 to 1.0); and wood dust (1.1; 0.9 to 2.5). The occupational aetiological fraction of pancreatic cancer was estimated at 12%. In a subpopulation exposed to CHC solvents and related compounds, it was 29%; to chromium and chromium compounds, 23%; to nickel and nickel compounds, 47%; to insecticides, 33%; and to PAHs, 33%. CONCLUSION: Occupational exposures may increase risk of pancreatic cancer. High quality studies are called for on interactions between occupational, environmental, and lifestyle factors as well as interactions between genes and the environment.

Air Pollutants, Occupational↗
PubMed2000

A telemedical approach to the screening of diabetic retinopathy: digital fundus photography.

OBJECTIVE: The importance of screening for diabetic retinopathy has been established, but the best method for screening has not yet been determined. We report on a trial of assessment of digital photographs by telemedicine compared with standard retinal photographs of the same fields and clinical examination by ophthalmologists. RESEARCH DESIGN AND METHODS: A total of 129 diabetic inpatients were screened for diabetic retinopathy by slit-lamp biomicroscopy performed by an ophthalmologist and by two-field 50 degrees non-stereo digital fundus photographs assessed by six screening centers that received the images by electronic mail. Conventional 35-mm transparencies of the same fields as the digital photographs were assessed by a retinal specialist and served as the reference method for detection of diabetic retinopathy. Slit-lamp biomicroscopy was the reference method for the detection of macular edema. RESULTS: The prevalence of any form of diabetic retinopathy was 30% (n = 35); of sight-threatening retinopathy including macular edema, the prevalence was 6% (n = 7). The assessment of digital images by the six screening centers resulted in a median sensitivity of 85% and a median specificity of 90% for the detection of moderate nonproliferative or sight-threatening diabetic retinopathy. Clinically significant macular edema (n = 4) was correctly identified in 15 of the 24 grading reports. An additional seven reports referred the patients for further investigation because of concurrent diabetic retinopathy. CONCLUSIONS: Telescreening for diabetic retinopathy by an assessment of two-field 50 degrees non-stereo digital images is a valid screening method. Although detection of clinically significant macular edema using biomicroscopy is superior to digital or standard non-stereo photographs, only few patients with sight-threatening diabetic retinopathy are missed.

Computer Communication Networks↗
PubMed2000

Risk of pancreatic cancer and occupational exposures in Spain. PANKRAS II Study Group.

The objective of the study was to analyse the relationship between occupational exposures and risk of pancreatic cancer. Incident cases of pancreatic cancer and hospital controls were prospectively identified and interviewed during the hospital stay. Occupational history was obtained by direct interview with the patient, and was available for 164 (89%) of 185 pancreatic cancer cases, and 238 (90%) of 264 controls. Two industrial hygienists evaluated exposures to 22 suspected carcinogens previously associated with pancreatic cancer. Occupational exposures were also assessed using the Finnish job-exposure matrix (FINJEM). For each type of pesticide group, moderately increased odds ratios (OR) were apparent in the high-intensity category, highest for arsenical pesticides (OR=3.4; 95% CI 0.9-12.0), and 'other pesticides' (OR=3.17; 95% CI 1.1-9.2). ORs for aniline derivatives, and dyes and organic pigments, were also higher for high-intensity exposure, and increased when lagged and restricted to long duration of exposure. ORs above 3 were observed for the following agents evaluated by FINJEM: pesticides, benzo[a]pyrene, lead, volatile sulphur compounds, and sedentary work. Whilst generally negative, results lend moderate support to the hypothesis of an association between exposure to some pesticides and pancreatic cancer. Larger studies could address the potential for these compounds to modify the carcinogenic risk of other environmental exposures. Suggestive increases in risk from aniline derivatives, dyes and organic pigments, and benzo[a]pyrene may also deserve further attention.

Aged↗
PubMed1999

Bone metabolism in type 2 diabetes mellitus.

Several conditions have been described to cause osteoporosis, including diabetes mellitus. While the relationship between type 1 diabetes and osteopenia is well documented in the literature, data on the presence of this complication in type 2 diabetes have not been well established. We studied a population composed of 66 post-menopausal women with type 2 diabetes and a control population. We examined bone mineral density with the dual-energy X-ray absorptiometry (DXA) technique at the lumbar and femoral levels and, in a subgroup of patients, we also measured the levels of markers of bone remodelling. We found significantly higher levels of bone mineral density at the femoral (but not lumbar) level in the diabetic subjects compared with the control population in all the examined subregions, except Ward's triangle. Moreover, we found higher levels of some markers of bone resorption (urinary calcium and hydroxyproline, telopeptide) in the patients with diabetes, while urinary crosslinks were higher in the controls. On the basis of these results, we suggest that osteoporosis cannot be considered a complication of type 2 diabetes and that, from a metabolic point of view, bone resorption is greater in diabetic patients than in normal subjects, as suggested by the high levels of most of the markers of osteoclastic activity.

Absorptiometry, Photon↗
PubMed1999

Medical conditions in patients with pancreatic and biliary diseases: validity and agreement between data from questionnaires and medical records. PANKRAS II Study Group.

The aims of the study were to assess the agreement between data from personal interviews and medical records on selected medical conditions, to evaluate the validity of each source of information, and to estimate the prevalence of these conditions in pancreatobiliary pathology. Between 1992 and 1995, 602 patients with pancreatobiliary diseases were included in the PANKRAS II Study. Information from interview and medical records was available in 88% of cases. The agreement between both data sources was poor only for cholecystitis and mental disorders. The validity of both sources of information was high or acceptable for all conditions except for cholecystitis. Prevalence of past medical conditions was similar to that reported previously and varied according to diagnosis, gender, age, educational level, and hospital of admission. Research aimed at assessing the prevalence of less common diseases should consider subject- and health-related factors in collecting information.

Adolescent↗
PubMed1999

Association between coffee drinking and K-ras mutations in exocrine pancreatic cancer. PANKRAS II Study Group.

STUDY OBJECTIVE: To analyse the relation between coffee consumption and mutations in the K-ras gene in exocrine pancreatic cancer. DESIGN: Case-case study. Consumption of coffee among cases with the activating mutation in the K-ras gene was compared with that of cases without the mutation. SETTING AND PATIENTS: All cases of pancreatic cancer newly diagnosed at five hospitals in Spain during three years were included in the PANKRAS II Study (n = 185, of whom 121 whose tissue was available for molecular analysis are the object of the present report). Over 88% were personally interviewed in hospital. DNA was amplified from paraffin wax embedded tissues, and mutations in codon 12 of K-ras were detected by the artificial RFLP technique. MAIN RESULTS: Mutations were found in tumours from 94 of 121 patients (77.7%). Mutations were more common among regular coffee drinkers than among non-regular coffee drinkers (82.0% v 55.6%, p = 0.018, n = 107). The odds ratio adjusted by age, sex, smoking and alcohol drinking was 5.41 (95% CI 1.64, 17.78). The weekly intake of coffee was significantly higher among patients with a mutated tumour (mean of 14.5 cups/week v 8.8 among patients with a wild type tumour, p < 0.05). With respect to non-regular coffee drinkers, the odds ratio of a mutated tumour adjusted by age, sex, smoking and alcohol drinking was 3.26 for drinkers of 2-7 cups/week, 5.77 for drinkers of 8-14 cups/week and 9.99 for drinkers of > or = 15 cups/week (p < 0.01, test for trend). CONCLUSIONS: Pancreatic cancer cases without activating mutations in the K-ras gene had drank significantly less coffee than cases with a mutation, with a significant dose response relation: the less they drank, the less likely their tumours were to harbour a mutation. In exocrine pancreatic cancer the K-ras gene may be activated less often among non-regular coffee drinkers than among regular drinkers. Caffeine, other coffee compounds or other factors with which coffee drinking is associated may modulate K-ras activation.

Adolescent↗