High frequency of OPA1 mutations causing high ADOA prevalence in south-eastern Sicily, Italy.

Optic atrophy type 1 (OPA1) gene mutation causes autosomal dominant optic atrophy (ADOA, MIM #165500). Prevalence of ADOA ranges from 1:50,000 in most populations to 1:12,000 in Denmark. Seventy members of nine families were analysed for the presence of OPA1 gene mutations by polymerase chain reaction (PCR) and direct sequencing. We identified three OPA1 gene mutations in 48 patients with variable signs of optic atrophy. Two mutations, c.784-21_784-22insAluYb8 and c.876_878delTGT, were found in two different families. The third mutation, c.869G>A, was found in 28 patients from seven families. The haplotype analysis data suggested that the c.869G>A mutation is a founder mutation. Our main result suggests a higher ADOA prevalence in south-eastern Sicily than previously found in Denmark. This is because of not only the founder effect but also to the presence of three different mutations in the geographical area of the study. Our hypothesis is that a combination of social pressure because of blindness and migration factors is involved. In fact, in Siracusa, a provincial capital in south-eastern Sicily, St. Lucy, the patron saint of the blind was born and died.

Four novel CYP27A1 mutations in seven Italian patients with CTX.

BACKGROUND AND PURPOSE: Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disease, because of sterol 27-hydroxylase deficiency. Clinical manifestations of CTX are tendon xanthomas, juvenile cataracts, osteoporosis, diarrhoea and multiple progressive neurological dysfunctions. More than 300 patients with CTX have been reported to date worldwide and about fifty different mutations identified in CYP27A1 gene. This study describes the clinical and laboratory findings of seven new patients. METHODS: We report the molecular and clinical characterization of seven new Italian patients with CTX carrying four novel mutations. RESULTS: We identified four novel mutations located in different exons, in particular in the region of exons 2-5 of the CYP27A1 gene. Phenotypical expression did not differ from classical CTX presentation except for absence of tendon xanthomas in two patients.

Chronic progressive external ophthalmoplegia: a new heteroplasmic tRNA(Leu(CUN)) mutation of mitochondrial DNA.

We sequenced all genes of mitochondrial tRNAs of a patient with chronic progressive external ophthalmoplegia with 5% ragged red fibres and 15% COX-negative fibres but without macrorearrangements of mitochondrial DNA (mtDNA). Direct sequencing showed a novel heteroplasmic G>A substitution in position 12316 of tRNA(Leu(CUN)) gene. This change destroys a highly conserved G-C base coupling in tRNA TpsiC branch. By RFLP analysis we could demonstrate different degrees of heteroplasmy in different patient's tissues. This alteration, absent in a population of 110 patients with different encephalomyopathies, can be considered pathogenic: it is the tenth tRNA(Leu(CUN)) pathogenic mutation described up to date.

Genotype-phenotype and OCT correlations in Autosomal Dominant Optic Atrophy related to OPA1 gene mutations: Report of 13 Italian families.

Mutations in OPA1 are responsible of 32-89% cases of Autosomal Dominant Optic Atrophy (ADOA). OPA1 ADOA usually presents in childhood with bilateral, progressive visual loss due to retinal ganglion cells neurodegeneration, but environmental factors are supposed to influence onset and phenotype. Sixty Italian OPA1 mutations carriers (fifty-two symptomatic), belonging to thirteen families, underwent neuro-ophthalmologic evaluation. Visual acuity (n=60) and Optical Coherence Tomography (OCT) (n=12) were compared in missense mutations (OPA-M) versus haploinsufficiency-inducing mutations (OPA-H) and correlated with age. Presence of plus phenotypes was investigated. We found four known mutations, the most common being missense c.1034G>A, and a new missense mutation, c1193A>C, the latter in a 54-yrs old female with late-onset phenotype. Visual acuity, colour sensitivity, and optic disc atrophy were sensitive indicators of disease. OCT RNFL thickness was reduced in OPA1 compared to controls. OPA-M showed worst visual acuity than OPA-H, but not more frequent plus-phenotype, observed only in four OPA-H patients. In both groups, visual acuity worsened with age. Our data confirm worst vision in OPA-M, but not increased plus-phenotype. Since most patients belonged to nine families from south-eastern Sicily (a famous region for the cult of St. Lucy, patron of the blinds) local genetic and environmental factors might have accounted for the low occurrence of plus-phenotypes.

Questioning the utility of pooling samples in microarray experiments with cell lines.

We describe a microarray experiment using the MCF-7 breast cancer cell line in two different experimental conditions for which the same number of independent pools as the number of individual samples was hybridized on Affymetrix GeneChips. Unexpectedly, when using individual samples, the number of probe sets found to be differentially expressed between treated and untreated cells was about three times greater than that found using pools. These findings indicate that pooling samples in microarray experiments where the biological variability is expected to be small might not be helpful and could even decrease one's ability to identify differentially expressed genes.

Risk factors for endometrial cancer at different ages.

The importance of the major risk factors for endometrial cancer in women of different ages was evaluated with the use of data from a hospital-based case-control study conducted in Milan, Italy, on 283 women with endometrial cancer and 566 age-matched controls. Current weight was related strongly to the risk of endometrial cancer both in younger (premenopausal) and in older women (with risk estimates for the heaviest categories of 20.3 and 7.7, respectively), thus confirming that obesity is the major cause of endometrial cancer in Northern Italy. Endometrial cancer risk appeared to be approximately proportional to the second power of body mass index. Early menarche and nulliparity were associated with an increased risk of endometrial cancer in premenopausal women, the point estimate for nulliparity rising to 35.1 (with lower confidence limit of 10.2) after adjustment for marital status. However, no association with these factors was evident in postmenopausal women. Combination oral contraceptives were used by 2 cases and 19 controls only [relative risk (RR) = 0.2, with 95% confidence interval = 0.1-0.8]. The use of noncontraceptive estrogens was associated with an elevated risk, which was greater in perimenopausal women (RR = 5.1 for greater than 2 yr of use), and decreased progressively with increasing time after menopause. Late menopause was also related to endometrial cancer. However, the risk estimates for late menopause apparently were more elevated in older women (greater than or equal to 65 yr) than in perimenopausal women. Most of the risk factors identified (excluding late menopause) apparently act on one of the later stages of the process of carcinogenesis, because the excess risk drops after cessation of exposure.

Benign breast disease and consumption of beverages containing methylxanthines.

The relationship between methylxanthine (Mx) consumption and benign breast disease was evaluated in a case-control study of 288 women with histologically confirmed benign breast lumps (203 dysplastic lesions and 85 benign tumors) and 2 groups of control women--285 patients in the hospital for acute conditions apparently unrelated to the consumption of Mx-containing beverages and 291 outpatients. The relative risk estimates of dysplastic breast lesions (fibrocystic disease), with allowance for all identified potential distorting factors, for women who drank 1-2 or 3 or more cups of coffee per day were 4.1 and 6.4, respectively, when the hospital controls were the comparison group and 2.0 and 3.7, respectively, when the outpatient controls were the comparison group. The relationship was even stronger when the total consumption of Mx-containing beverages (coffee plus tea) was considered and increased with increasing duration of use. The association was not explained by any of the major risk factors for fibrocystic breast diseases or by differences in general characteristics or other lifestyle habits between cases and controls. Mx consumption was not related to the risk of benign breast tumors (fibroadenomas). These findings support the hypothesis that Mx consumption is related to the risk of dysplastic lesions of the breast.

Monitoring surgical and medical outcomes: the Bernoulli cumulative SUM chart. A novel application to assess clinical interventions.

BACKGROUND: Monitoring clinical interventions is an increasing requirement in current clinical practice. The standard CUSUM (cumulative sum) charts are used for this purpose. However, they are difficult to use in terms of identifying the point at which outcomes begin to be outside recommended limits. OBJECTIVE: To assess the Bernoulli CUSUM chart that permits not only a 100% inspection rate, but also the setting of average expected outcomes, maximum deviations from these, and false positive rates for the alarm signal to trigger. METHODS: As a working example this study used 674 consecutive first liver transplant recipients. The expected one year mortality set at 24% from the European Liver Transplant Registry average. A standard CUSUM was compared with Bernoulli CUSUM: the control value mortality was therefore 24%, maximum accepted mortality 30%, and average number of observations to signal was 500-that is, likelihood of false positive alarm was 1:500. RESULTS: The standard CUSUM showed an initial descending curve (nadir at patient 215) then progressively ascended indicating better performance. The Bernoulli CUSUM gave three alarm signals initially, with easily recognised breaks in the curve. There were no alarms signals after patient 143 indicating satisfactory performance within the criteria set. CONCLUSIONS: The Bernoulli CUSUM is more easily interpretable graphically and is more suitable for monitoring outcomes than the standard CUSUM chart. It only requires three parameters to be set to monitor any clinical. INTERVENTION: the average expected outcome, the maximum deviation from this, and the rate of false positive alarm triggers.

Age-specific incidence and duration of known diabetes. The Cremona Study.

OBJECTIVE: To estimate the overall and age-specific incidence of known diabetes and its total duration through prevalence data and to assess the consistency of the results by mortality analysis of the same cohort. RESEARCH DESIGN AND METHODS: Two different sources were used. The first was a representative sample of 2,274 prevalent known-diabetic subjects. These data provided overall and age-specific incidence estimates by fitting a logistic model to the partial incidence rates for different diagnosis cohorts and to the disease duration. The age at diagnosis structure was built from the age-specific estimates. Prevalence data also provided total duration estimates by converting the prevalent duration-to-date structure into an incident total duration structure. The second source was 145 deceased subjects who were taken from the 6-year follow-up sample of 1,132 prevalent subjects. The age at diagnosis and estimates of total disease duration were provided for these subjects, who paralleled the characteristics of the incident cohort. RESULTS: The two independent estimates of total disease duration were similar (prevalent subjects, 15.7 years; deceased subjects, 14.1 years): the average duration was 14.9 years. The ratio between prevalence and total duration yielded an independent yearly incidence estimate of 2.2 per 1,000 person-years (men, 2.0; women, 2.4), which was close to the value given by the model of 2.1 per 1,000 person-years (men, 1.9; women, 2.3). Also, the independently determined age structures overlapped, and their average was used to calculate the age-specific incidence. Incidence was negligible for individuals < 30 years of age, and it was about 6.0 per 1,000 person-years for individuals > 50 years of age. CONCLUSIONS: This study provided reliable estimates of NIDDM age-specific incidence rates and total disease duration, data that are seldom investigated in this type of disease.

Factors related to glycemic control in IDDM and insulin-treated NIDDM patients in current practice. A comparison of care policies. SIEMTIC Group. Studio Italiano Epidemiologico Multicentrico su Terapia Insulin e Controllo Metabolico.

OBJECTIVE: To evaluate, under routine conditions, the relation between different diabetes care policies and glycemic control through a by-center analysis procedure aimed at reducing some drawbacks of cross-sectional data. RESEARCH DESIGN AND METHODS: A survey on insulin-treated diabetes care management (IDDM and NIDDM) involved 16 Italian randomly selected diabetes outpatient clinics. A total of 2,142 representative patients were investigated. The standardized HbA1c average value of each center was related, by regression models, to some indicators of center care policy (average number of injections, average BMI, proportion of cases with recent fundus oculi examinations, or frequent visits) as well as to patients' average social levels (employment type). Homogeneity in patient admission criteria is assumed among the investigated centers as a basic condition for the procedure validity. Some known imbalance were controlled for both design and analysis. RESULTS: HbA1c showed a univariate inverse relation with daily number of injections in IDDM (P = 0.0009, r2 = 0.56) but not in NIDDM (P = 0.33). It was inversely related to both fundus examination (IDDM P = 0.04; NIDDM P = 0.099) and qualified employment (IDDM P = 0.06; NIDDM P = 0.026). A stepwise regression analysis left in the model insulin injections (P = 0.0002) in IDDM (total r2 = 0.68) and qualified employment (P = 0.016) and fundus examination (P = 0.14) in NIDDM (total r2 = 0.53), after controlling for age, sex, disease duration, insulin therapy starting delay, and insulin dose per kilogram. CONCLUSIONS: These results suggest that the confirmed benefits of a multiple-injection regimen in IDDM cannot be simply extrapolated to NIDDM, where patients' awareness and medical attention to complications proved to be the most important factors in current practice.

Intima-media thickness after pravastatin stabilizes also in patients with moderate to no reduction in LDL-cholesterol levels: the carotid atherosclerosis Italian ultrasound study.

The Carotid Atherosclerosis Italian Ultrasound study (CAIUS), a multicenter, double-blind clinical trial, performed in 305 asymptomatic, moderately hypercholesterolemic patients, clearly demonstrated beneficial effects of pravastatin on the carotid intima-media thickness (IMT) progression. The database of the CAIUS study was examined in order to investigate the presence of a relationship, if any, between the activity of pravastatin on IMT progression rate and its hypocholesterolemic effect. Quantitative B-mode ultrasound imaging was used to quantify the individual mean maximum IMT progression rate in 3 years. In the overall group of patients (placebo and pravastatin) covariance analysis showed that while the variable 'treatment' (0 = placebo, 1 = pravastatin) was significantly related to the reduction of IMT progression (F= 6.6, P = 0.01), the IMT progression did not correlate with the extent of LDL-C lowering (F= 0.00, P = 0.98). To further investigate this issue. the pravastatin treated group was stratified into quartiles of LDL-C reduction. In contrast to what was observed in the placebo group, in which a positive mean IMT progression rate was observed, independent of the extent of LDL-C reduction, no IMT progressionwas observed in any subgroup treated with pravastatin. No significant difference was found among quartiles and no trend could be identified. In conclusion, the effect of pravastatin treatment on carotid IMT progression rate is beneficial; however the CAIUS study demonstrated that lowering LDL-C by itself, does not explain the variability of beneficial changes in IMT.

Pravastatin reduces carotid intima-media thickness progression in an asymptomatic hypercholesterolemic mediterranean population: the Carotid Atherosclerosis Italian Ultrasound Study.

PURPOSE: The Carotid Atherosclerosis Italian Ultrasound Study (CAIUS) was performed to test the effects of lipid lowering on the progression of carotid intima-media thickness (IMT) in 305 asymptomatic patients from a Mediterranean country. PATIENTS AND METHODS: Eligibility included hypercholesterolemia (baseline means: low-density lipoprotein [LDL] = 4.68 mmol/L, high-density lipoprotein [HDL] = 1.37 mmol/L), and at least one 1.3 < IMT < 3.5 mm in the carotid arteries. Patients (mean age 55 years, 53% male) were assigned to pravastatin (40 mg/day, n = 151) or placebo (n not equal to 154). Ultrasound imaging was used to quantify IMT at baseline, and semiannually thereafter for up to 3 years. The mean of the 12 maximum IMTs (MMaxIMT), was calculated for each patient visit, and used to determine each patient's longitudinal progression slope. The intention-to-treat group difference in the MMaxIMT progression was chosen a priori as the primary end point. RESULTS: Five serious cardiovascular events (1 fatal myocardial infarction), and 7 drop-outs for cancer were registered. In the pravastatin group, LDL decreased -0.22 after 3 months versus -0.01 in the placebo group, and remained substantially unchanged afterward (-0.23 versus +0.01 at 36 months, respectively). Progression of the MMaxIMT was 0.009 +/- 0.0027 versus -0.0043 +/- 0.0028 mm/year (mean +/- SE, P < 0.0007) in the placebo and pravastatin groups, respectively. IMT progression slopes diverged after 6 months of treatment. CONCLUSIONS: Pravastatin stops the progression of carotid IMT in asymptomatic, moderately hypercholesterolemic men and women. This finding extends the beneficial effects of cholesterol lowering to the primary prevention of atherosclerosis in a population with relatively low cardiovascular event rates, and suggests that this benefit is mediated by specific morphological effects on early stages of plaque development.

Systolic and pulse blood pressures (but not diastolic blood pressure and serum cholesterol) are associated with alterations in carotid intima-media thickness in the moderately hypercholesterolaemic hypertensive patients of the Plaque Hypertension Lipid Lowering Italian Study. PHYLLIS study group.

OBJECTIVE: The Plaque Hypertension Lipid Lowering Italian Study (PHYLLIS), is the first study in patients with hypertension (diastolic blood pressure (DBP) 95-115 mmHg; systolic blood pressure (SBP) 150-210 mmHg), moderate hypercholesterolaemia (LDL-cholesterol 4.14-5.17 mmol/l (160-200 mg/dl) and initial carotid artery alterations (maximum intima-media thickness (IMT) Tmax > or = 1.3 mm). The primary objective of PHYLLIS is investigating whether in these patients administration of an angiotensin converting enzyme inhibitor, fosinopril, and a statin, pravastatin, is more effective than administration of a diuretic and a lipid-lowering diet in retarding or regressing alterations in carotid IMT. While the study is in progress, baseline data are here reported to clarify the association of various risk factors with carotid IMT in these medium-high risk hypertensive patients. METHODS: Patients numbering 508 have been randomized to PHYLLIS by 13 peripheral units, in Italy. Age was (mean +/- SD) 58.4 +/- 6.7 years, males were 40.2%, current smokers 16.5%, means +/- SD of serum total, low-density lipoprotein (LDL), high-density lipoprotein (HDL) cholesterol and triglycerides concentrations were 6.79 +/- 0.67, 4.69 +/- 0.51, 1.37 +/- 0.38, 1.59 +/- 0.64 mmol/l (262.4 +/- 25.8, 181.3 +/- 19.8, 53.0 +/- 14.6, 141.0 +/- 56.7 mg/ dl). Means +/- SD of clinic sitting SBP/DBP were 159.8 +/- 9.0/98.3 +/- 4.2 mmHg. 483 of the 508 patients also had 24 h ambulatory BP monitoring, edited and read at a centralized unit (mean +/- SD 24 h SBP/DBP averages 136.3 +/- 14.1/84.0 +/- 10.0 mmHg). Quantitative B-mode ultrasound (Biosound 2000 II 5A, Biosound, Indianapolis, Indiana, USA) recordings of carotid arteries were taken by certified sonographers in the peripheral units and tracings were all read at a central unit. CBMmax (mean IMT of eight sites at common carotids and bifurcations) was 1.21 +/- 0.17; Mmax (mean of 12 sites also including internal carotids) 1.16 +/- 0.17, and Tmax (single maximum) 1.85 +/- 0.48 mm. RESULTS: Ambulatory SBP and pulse pressure (PP) (24 h, daytime, night-time averages) and their variability indices (24 h SD) were always significantly correlated with CBMmax and Mmax (P0.01 -0.001), and the correlations remained significant after adjustment for age, gender and smoking. No measurement of DBP was ever associated with any IMT measurement. Likewise, no lipid variable was found associated with any IMT measurement. CONCLUSIONS: Baseline data from PHYLLIS indicate that in this population of hypertensive patients with moderate hypercholesterolaemia, SBP and PP are with age among the most significant factors associated with carotid artery alterations. However, the narrow range of inclusion LDL-cholesterol and DBP values may have obscured an additional role of these variables.

The effect of cigarette-smoking on cardiovascular risk factors: a study of monozygotic twins discordant for smoking.

The association of cigarette smoking with the development of occlusive vascular disease is firmly established. Unfavourable changes in a series of variables held independent risk factors for the development of vascular lesions (HDL-cholesterol, haematocrit, white blood cell count, fibrinogen and plasminogen activator inhibitor-1 (PAI-1)) are thought to be directly influenced by cigarette smoking. However, the role played by the genotype in the effect of smoking on the above parameters has not been investigated. To control the genotype, we studied the relationship between cigarette smoking and a series of cardiovascular risk factors in 27 monozygotic twin pairs (7 male and 20 female pairs, mean age +/- SD: 47.4 +/- 12.9 yrs) with a life-long discordance for smoking. Smoking twins had a life-long dose of smoking (Brickman index) of 287.3 +/- 241.5. Body mass index, blood pressure, haematocrit, haemoglobin and red blood cell counts, total cholesterol levels and the acute phase reactants alpha 1-acid glycoprotein and C-reactive protein were similar in smokers and non-smokers. Triglyceride was higher by 12.6% (9.5-35%, 95% confidence interval, p = 0.02) and HDL-cholesterol lower by 7.5% (0.2-15%, p = 0.04) in the smoking co-twins, who also had 8.4% (-0.2-17%, p = 0.06) higher white blood cell counts and 4.1% (1.2-7%, p < 0.01) larger mean platelet volume. There was no significant difference in clottable fibrinogen (by two methods) or in the activity of plasminogen activator inhibitor-1 between the two groups, nor was the within-pair difference in these parameters related to the smoking dose. Echo-doppler examination of the carotid arteries of 24 twin pairs showed mostly minor atherosclerotic lesions in 46% and 42% of the smoking and non-smoking co-twins. After adjustment for age, systolic blood pressure and platelet count and volume were the only variables significantly associated to the presence of vascular lesions. Cigarette smoking is associated with an atherogenic lipid profile and with changes in platelets and white cells potentially reflecting endothelial cell damage. When controlling the genotype, fibrinogen and PAI-1 activity levels did not seem directly influenced by cigarette smoking.

Incessant ovulation and ovarian cancer: a critical approach.

The total duration of 'ovulatory activity' or 'ovulatory age' has been reported to be the strongest indicator of the risk of ovarian cancer. In the case-control study examined in this paper this variable was found to be a strong correlate of the risk of ovarian cancer. However, the finding that in older women the major determinant of 'ovulatory age' was age at menopause (which is a very unreliable indicator of 'ovarian activity'), and that age at menopause by itself was related to the risk of ovarian cancer as strongly as the total duration of ovulatory age, threw doubt on the biological consistency of that model. Furthermore, the protection conferred by pregnancies was different at different ages, and age at first pregnancy was more strongly associated with the risk of ovarian cancer than the actual number of pregnancies. The model of carcinogenesis for epithelial ovarian cancer appears, therefore, to be more complex than is indicated simply by the total duration of 'ovarian activity.'

Oestrogens and obesity as risk factors for endometrial cancer in Italy.

In a case-control study to evaluate risk factors for endometrial cancer, obesity, history of various diseases, reproductive and menstrual characteristics, marital status, education, and lifetime use of female hormones were examined in 173 histologically proven endometrial cancers and 347 controls. Obesity, non-contraceptive oestrogen use, late menopause, low parity and history of uterine fibromyomas were associated with an increased risk of endometrial cancer. The relative risks of obesity and oestrogen use seem to fit well for an additive model. Histological differentiation was positively correlated both to oestrogen use and to level of overweight, supporting the hypothesis of a specific role of oestrogens in endometrial cancer.

Factors predicting chronic hepatic encephalopathy after distal splenorenal shunt: a multivariate analysis of clinical and hemodynamic variables.

BACKGROUND: This study was aimed at evaluating several factors that promote chronic hepatic encephalopathy by multivariate analysis of data for patients with cirrhosis with good or moderate liver function submitted to distal splenorenal shunts. METHODS: The study group comprised 131 patients: 55 had alcoholic and 76 nonalcoholic cirrhosis. Seventy patients were in Child's class A and 61 in class B. Cerebral function was assessed by a complete neurologic examination. Angiography with venous phase was performed before and within 1 month after the shunt operation. In 84 cases the original Warren technique was used and in 20 cases a Britton's modified procedure was used. Twenty-seven patients had distal splenorenal shunts with a splenopancreatic disconnection. Statistical analysis was performed by two multivariate analyses based on stepwise selection. RESULTS: Thirty-nine patients died during a follow-up period of 51 +/- 32 months. Chronic encephalopathy occurred in 18 patients (14%). According to the multivariate analysis of the preoperative prognostic factors, only age (p = 0.0001) and albumin values (p = 0.0002) were independent predictive risk factors for chronic encephalopathy. In the multivariate analysis concerning the hemodynamic consequences of the selective shunts, independent risk factors promoting chronic encephalopathy were postoperative portal perfusion (p = 0.0001), postshunt portal pressure (p = 0.001), and surgical disconnection (p = 0.0064). CONCLUSIONS: Our study has shown that chronic encephalopathy after selective shunt surgery is promoted by both clinical and hemodynamic factors. A better selection of the candidates for shunt surgery and prevention of the development of portal malcirculation by accurate surgical disconnection should further decrease the risk of chronic encephalopathy.

Prevalence of retinopathy in diabetic subjects from out-patient clinics in Lombardy (Italy), and associated risk factors. A multicentre epidemiologic study.

There is little information on the prevalence of diabetic complications in Italy. For this reason, a multicentre population-based study was carried out in 1983-1985 in 12 representative out-patient clinics for the treatment of diabetes in the Lombardy region. Out of a total population of 17,704 patients 1160 diabetic subjects were randomly selected within strata based on their duration of disease (less than or equal to 5; 6-10; 11-20; greater than 20 years). Eight hundred and thirty-eight responders were examined using standardised protocols. The estimated prevalences (adjusted for duration of disease) for the total population involved in the study were 29.7% and 7.6% for background and proliferative retinopathy respectively. The overall standardised rates were higher in insulin-dependent diabetes mellitus (IDDM) (53.6%) than in non-insulin-dependent diabetes mellitus (NIDDM) (34.7%) for both background (41.1%, 28.4% respectively) and proliferative (12.5%, 6.2% respectively) retinopathy, and increased with the duration of disease. The analysis of the relationship between diabetic retinopathy and the calculated risk factors did not show any association with hypertension or metabolic control, except for post-prandial blood glucose in subjects with durations 6-10 and greater than 20 years; an association with azotaemia was found in subjects with durations less than or equal to 5 and 11-20 years. Diabetic retinopathy appeared to be independently associated with the type of treatment and not with the type of diabetes, metabolic control, or hypertension.

Snoring in twins.

Snoring is a prerequisite for obstructive sleep apnoea (OSA) and is known to run in families. Recent studies have provided sufficient evidence for a familial predisposition to OSA. In our study, 492 monozygotic and 284 dizygotic twins were contacted by telephone and asked to attend an interview which included questions of life habits, medical history, sleep habits and disorders, with particular emphasis on snoring. Our study showed that the probandwise concordance rate for habitual snoring was higher in monozygotic twins than in dizygotic ones, but the difference was not significant. The comparison of concordant pairs for habitual snoring vs. concordant pairs for non-snoring confirmed that habitual snoring is significantly associated with older age, male gender, higher body mass index (BMI), smoking and respiratory diseases. The multivariate analysis in the discordant groups confirmed that BMI is more strongly associated to habitual snoring in dizygotic twins than in the monozygotic ones. Our logistic analysis showed that other variables, such as smoking and respiratory diseases, are associated with habitual snoring in dizygotic pairs, but not in monozygotic ones. These findings suggest a genetic predisposition to habitual snoring.

Blood culture as a guide for the diagnosis of central venous catheter sepsis.

The purpose of this study was to evaluate the predictability of peripheral (PBC) and central blood cultures (CBC) in the diagnosis of central venous catheter (CVC) sepsis (growth of the same microorganism in the peripheral blood and on the catheter tip). The contamination and sepsis rate of 256 CVCs and the relationship with PBC and CBC was evaluated in a series of cancer patients included in a prospective protocol on CVC infections at the Istituto Nazionale Tumori of Milan. Overall CVC contamination was 10.5% and sepsis rate was 3.1%. The positive predictive value for CVC sepsis was 46.7% for positive PBC + CBC, 38.1% for positive PBC and 16.6% for positive CBC. The small gain in the predictive positive value obtained with the use of PBC and CBC and the slight increase in the specificity does not justify, in our opinion, the use of both these parameters for the diagnosis of CVC sepsis.