Rethink analgo-sedation in digestive endoscopy: the role of scientific societies in tracing training path

OBJECTIVE

The Italian Society of Anesthesia, Analgesia, Reanimation and Intensive Care Medicine (SIAARTI) and the Italian Society of Digestive Endoscopy (SIED) worked together to produce a joint Good Clinical Practice (GCP) on analgo-sedation in digestive endoscopy and launched a survey to support the document. The aim was to identify and describe the actual clinical practice of sedation in Italian digestive endoscopy units and offer material for a wider and more widespread discussion among anesthetists and endoscopists.

SUBJECTS AND METHODS

A national survey was planned, in order to support the statements of the GCP. Twelve thousand and five hundred questionnaires were sent to the members of SIAARTI and SIED in June 2020.

RESULTS

A total of 662 forms (5.3%) returned completed. Highly complex procedures are performed according to 70% of respondents; daily anesthesiologist's assistance is guaranteed in 26%, for scheduled sessions in 14.5% and as needed in 8%. 69% of respondents declared not to have a dedicated team of anesthesiologists, while just 5% reported an anesthesiologist in charge. A complete monitoring system was assured by 70% of respondents. Dedicated pathways for COVID-19-positive patients were confirmed in <40% of the answers. With regard to moderate/deep sedation, 90% of respondents stated that an anesthetist decides timing and doses. Propofol was exclusively administered by anesthetists according to 94% of answers, and for 6% of respondents the endoscopist is allowed to administer propofol in presence of a dedicated nurse, but with a readily available anesthetist. Only 32.8% of respondents reported institutional training courses on procedural analgo-sedation.

CONCLUSIONS

The need to provide patients scheduled for endoscopy procedures with an adequate analgo-sedation is becoming an increasing concern, well-known in almost all countries, but many factors compromise the quality of patient care. Results of a national survey would give strength to the need for a shared GCP in gastrointestinal endoscopy. Training and certification of non-anesthetist professionals should be one of the main ways to center the objective.

Improving Visual Field Forecasting by Correcting for the Effects of Poor Visual Field Reliability

Purpose

The purpose of this study was to accurately forecast future reliable visual field (VF) mean deviation (MD) values by correcting for poor reliability.

Methods

Four linear regression techniques (standard, unfiltered, corrected, and weighted) were fit to VF data from 5939 eyes with a final reliable VF. For each eye, all VFs, except the final one, were used to fit the models. Then, the difference between the final VF MD value and each model's estimate for the final VF MD value was used to calculate model error. We aggregated the error for each model across all eyes to compare model performance. The results were further broken down into eye-level reliability subgroups to track performance as reliability levels fluctuate.

Results

The standard method, used in the Humphrey Field Analyzer (HFA), was the worst performing model with an average residual that was 0.69 dB higher than the average from the unfiltered method, and 0.79 dB higher than that of the weighted and corrected methods. The weighted method was the best performing model, beating the standard model by as much as 1.75 dB in the 40% to 50% eye-level reliability subgroup. However, its average 95% prediction interval was relatively large at 7.67 dB.

Conclusions

Including all VFs in the trend estimation has more predictive power for future reliable VFs than excluding unreliable VFs. Correcting for VF reliability further improves model accuracy.

Translational Relevance

The VF correction methods described in this paper may allow clinicians to catch VF worsening at an earlier stage.

Archetypal Analysis Reveals Quantifiable Patterns of Visual Field Loss in Optic Neuritis

Purpose

Identifying and monitoring visual field (VF) defects due to optic neuritis (ON) relies on qualitative clinician interpretation. Archetypal analysis (AA), a form of unsupervised machine learning, is used to quantify VF defects in glaucoma. We hypothesized that AA can identify quantifiable, ON-specific patterns (as archetypes [ATs]) of VF loss that resemble known ON VF defects.

Methods

We applied AA to a dataset of 3892 VFs prospectively collected from 456 eyes in the Optic Neuritis Treatment Trial (ONTT), and decomposed each VF into component ATs (total weight = 100%). AA of 568 VFs from 61 control eyes was used to define a minimum meaningful (≤7%) AT weight and weight change. We correlated baseline ON AT weights with global VF indices, visual acuity, and contrast sensitivity. For eyes with a dominant AT (weight ≥50%), we compared the ONTT VF classification with the AT pattern.

Results

AA generated a set of 16 ATs containing patterns seen in the ONTT. These were distinct from control ATs. Baseline study eye VFs were decomposed into 2.9 ± 1.5 ATs. AT2, a global dysfunction pattern, had the highest mean weight at baseline (36%; 95% confidence interval, 33%–40%), and showed the strongest correlation with MD (r = −0.91; P < 0.001), visual acuity (r = 0.70; P < 0.001), and contrast sensitivity (r = −0.77; P < 0.001). Of 191 baseline VFs with a dominant AT, 81% matched the descriptive classifications.

Conclusions

AA identifies and quantifies archetypal, ON-specific patterns of VF loss.

Translational Relevance

AA is a quantitative, objective method for demonstrating and monitoring change in regional VF deficits in ON.

Predicting eyes at risk for rapid glaucoma progression based on an initial visual field test using machine learning

OBJECTIVE

To assess whether machine learning algorithms (MLA) can predict eyes that will undergo rapid glaucoma progression based on an initial visual field (VF) test.

DESIGN

Retrospective analysis of longitudinal data.

SUBJECTS

175,786 VFs (22,925 initial VFs) from 14,217 patients who completed ≥5 reliable VFs at academic glaucoma centers were included.

METHODS

Summary measures and reliability metrics from the initial VF and age were used to train MLA designed to predict the likelihood of rapid progression. Additionally, the neural network model was trained with point-wise threshold data in addition to summary measures, reliability metrics and age. 80% of eyes were used for a training set and 20% were used as a test set. MLA test set performance was assessed using the area under the receiver operating curve (AUC). Performance of models trained on initial VF data alone was compared to performance of models trained on data from the first two VFs.

MAIN OUTCOME MEASURES

Accuracy in predicting future rapid progression defined as MD worsening more than 1 dB/year.

RESULTS

1,968 eyes (8.6%) underwent rapid progression. The support vector machine model (AUC 0.72 [95% CI 0.70-0.75]) most accurately predicted rapid progression when trained on initial VF data. Artificial neural network, random forest, logistic regression and naïve Bayes classifiers produced AUC of 0.72, 0.70, 0.69, 0.68 respectively. Models trained on data from the first two VFs performed no better than top models trained on the initial VF alone. Based on the odds ratio (OR) from logistic regression and variable importance plots from the random forest model, older age (OR: 1.41 per 10 year increment [95% CI: 1.34 to 1.08]) and higher pattern standard deviation (OR: 1.31 per 5-dB increment [95% CI: 1.18 to 1.46]) were the variables in the initial VF most strongly associated with rapid progression.

CONCLUSIONS

MLA can be used to predict eyes at risk for rapid progression with modest accuracy based on an initial VF test. Incorporating additional clinical data to the current model may offer opportunities to predict patients most likely to rapidly progress with even greater accuracy.

Infection prevention in endoscopy practice: comparative evaluation of re-usable vs single-use endoscopic valves

Re-usable air/water and suction valves used in endoscopes often demonstrate risk of infection. To the authors' knowledge, the safety and efficacy of re-usable and single-use valves have not been compared to date. As such, a laboratory investigation was undertaken to compare the safety and efficacy of re-usable and single-use valves at 11 Italian endoscopy sites. Safety was evaluated by analysing the rinse liquid of reprocessed re-usable valves ready for use, and efficacy was assessed based on the completion of endoscopic procedures without valve malfunction. This study found significantly lower contamination of single-use valves compared with re-usable valves (0 vs 29.1%, respectively; P=0.007) and similar efficacy (97.6 vs 98.8%, respectively; P=ns). Microbiological analysis of the rinse liquid of reprocessed re-usable valves identified various surviving micro-organisms and highlighted their potential pathogenicity. Such data suggest that sterile single-use valves may be safer than re-usable valves, and have comparable performance.

Five-year risk of CIN3 after short-term HPV-DNA negativity in cytology-negative women: a population-based cohort study

OBJECTIVE

To assess the 5-year risk of high-grade lesions in women with a transient high-risk HPV infection.

DESIGN

Population-based cohort study.

SETTING

HPV primary testing within population-based organised cervical cancer screening programmes.

POPULATION

Italian women enrolled in seven pilot projects and attending the second round.

METHODS

On the basis of the cytology triage performed on HPV-positive women, immediate colposcopy or HPV repeat at 12 months was recommended. Data were collected at the subsequent round 3-4 years after HPV infection clearance.

MAIN OUTCOME MEASURES

Rates of HPV infection, CIN2+ and CIN3+ detection at subsequent round after HPV clearance, and relative risks (RR) in comparison with HPV-negative women (with 95% confidence interval).

RESULTS

Data on 1230 women (1027 aged 25-64 years and 203 aged 35-64 years) have been analysed. Overall compliance with repeat HPV testing was 84%. In comparison with HPV-negative women, those with a transient HPV infection had higher proportions of HPV positivity (15% versus 3.7%) and of CIN2+ lesions (0.87% versus 0.23%) in round two; most of these (7/10) were CIN2; no cancers were detected, and CIN3 occurred in 3/1230 (0.24%).

CONCLUSIONS

HPV-based protocols for cervical cancer screening allow long intervals for HPV-negative women; it is important to monitor the clinical outcome in the women with transient high-risk HPV infection. CIN3 detection is similar to that observed in routine European cytology-based screening programmes (CIN3+: 2.7‰); 5-year intervals may provide reasonable protection but longer intervals are not recommended.

TWEETABLE ABSTRACT

A screening interval of 5 years (but no longer) appears safe in women with transient HPV detection.

Cervical cancer screening with HPV testing in the Valcamonica (Italy) screening programme

OBJECTIVE

We present the results of the first screening round and the first year of the second round of the Valcamonica Human Papillomavirus (HPV) pilot screening project.

SETTING

From 2010 to 2012, the entire target female population (aged 25-64) was invited to the first HPV screening round in an area where Pap test screening had been active since 2002.

METHODS

For HPV-negative women, the interval was three years. For HPV-positive women, a cytological smear was stained and interpreted. Positive cytologies were referred to colposcopy; negatives were referred to repeat HPV after one year. If HPV was persistently positive, women were referred to colposcopy; if negative, to normal screening.

RESULTS

In 2010-12 18728 women were screened, slightly higher participation than with Pap test (18233 64.7%); 1633 were HPV-positive (8.7%); 843 were positive at cytology triage (referral rate at baseline 4.5%). Of those referred at the one year HPV test, 84% complied (660/780); 356 were persistently positive (1.9%). The total referral rate was 6.4% compared with 3.7% for the Pap test. The detection rate was 9.2/1000 compared with 5.0% for the Pap test. The HPV positivity rate during the second round in women previously negative was 3.9% and the detection rate in HPV-positive cytology-positive women was 0.8/1000.

CONCLUSIONS

HPV-based screening increases colposcopies at the first round, but also strongly increases the detection rate. At the second round, HPV prevalence was much lower and the detection rate also fell, corroborating the need for longer screening intervals in HPV-negative women.

Genome-wide association study and meta-analysis of intraocular pressure

Elevated intraocular pressure (IOP) is a major risk factor for glaucoma and is influenced by genetic and environmental factors. Recent genome-wide association studies (GWAS) reported associations with IOP at TMCO1 and GAS7, and with primary open-angle glaucoma (POAG) at CDKN2B-AS1, CAV1/CAV2, and SIX1/SIX6. To identify novel genetic variants and replicate the published findings, we performed GWAS and meta-analysis of IOP in >6,000 subjects of European ancestry collected in three datasets: the NEI Glaucoma Human genetics collaBORation, GLAUcoma Genes and ENvironment study, and a subset of the Age-related Macular Degeneration-Michigan, Mayo, AREDS and Pennsylvania study. While no signal achieved genome-wide significance in individual datasets, a meta-analysis identified significant associations with IOP at TMCO1 (rs7518099-G, p = 8.0 × 10(-8)). Focused analyses of five loci previously reported for IOP and/or POAG, i.e., TMCO1, CDKN2B-AS1, GAS7, CAV1/CAV2, and SIX1/SIX6, revealed associations with IOP that were largely consistent across our three datasets, and replicated the previously reported associations in both effect size and direction. These results confirm the involvement of common variants in multiple genomic regions in regulating IOP and/or glaucoma risk.

Lack of association of polymorphisms in homocysteine metabolism genes with pseudoexfoliation syndrome and glaucoma

PURPOSE

To evaluate genes involved in homocysteine metabolism as secondary risk factors for pseudoexfoliation syndrome (PXFS) and the associated glaucoma (PXFG).

METHODS

One hundred eighty-six unrelated patients with PXFS, including 140 patients with PXFG and 127 unrelated control subjects were recruited from the Massachusetts Eye and Ear Infirmary. All the patients and controls were Caucasian of European ancestry. Seventeen tag SNPs from 5 genes (methylenetetrahydrofolate reductase [MTHFR], methionine synthase [MTR], methionine synthase reductase [MTRR], methylenetetrahydrofolate dehydrogenase [MTHFD1], and cystathionine beta-synthase [CBS]) were genotyped. Single-SNP association was analyzed using Fisher's exact test (unconditional) or logistic regression after conditioning on the effects of age and three LOXL1 SNPs (rs1048661, rs3825942, and rs2165241). Interaction analysis was performed between the homocysteine and LOXL1 SNPs using logistic regression. Haplotype analysis and the set-based test were used to test for association of individual genes. Multiple comparisons were corrected using the Bonferroni method.

RESULTS

One SNP (rs8006686) in MTHFD1 showed a nominally significant association with PXFG (p=0.015, OR=2.23). None of the seventeen SNPs tested were significantly associated with PXFS or PXFG after correcting for multiple comparisons (Bonferroni corrected p>0.25). After controlling for the effects of age and three associated LOXL1 SNPs, none of the seventeen tested SNPs were associated with PXFS (p>0.12). No significant interaction effects on PXFS were identified between the homocysteine and LOXL1 SNPs (p>0.06). Haplotype analysis and the set-based test did not find significant association of individual genes with PXFS (p>0.23 and 0.20, respectively).

CONCLUSIONS

Five genes that are critical components of the homocysteine metabolism pathway were evaluated as secondary factors for PXFS and PXFG. Our results suggest that these genes are not significant risk factors for the development of these conditions.

DNA sequence variants in the LOXL1 gene are associated with pseudoexfoliation glaucoma in a U.S. clinic-based population with broad ethnic diversity

Background

Pseudoexfoliation syndrome is a major risk factor for glaucoma in many populations throughout the world. Using a U.S. clinic-based case control sample with broad ethnic diversity, we show that three common SNPs in LOXL1 previously associated with pseudoexfoliation in Nordic populations are significantly associated with pseudoexfoliation syndrome and pseudoexfoliation glaucoma.

Methods

Three LOXL1 SNPs were genotyped in a patient sample (206 pseudoexfoliation, 331 primary open angle glaucoma, and 88 controls) from the Glaucoma Consultation Service at the Massachusetts Eye and Ear Infirmary. The SNPs were evaluation for association with pseudeoexfoliation syndrome, pseudoexfoliation glaucoma, and primary open angle glaucoma.

Results

The strongest association was found for the G allele of marker rs3825942 (G153D) with a frequency of 99% in pseudoexfoliation patients (with and without glaucoma) compared with 79% in controls (p = 1.6 × 10^-15; OR = 20.93, 95%CI: 8.06, 54.39). The homozygous GG genotype is also associated with pseudoexfoliation when compared to controls (p = 1.2 × 10^-12; OR = 23.57, 95%CI: 7.95, 69.85). None of the SNPs were significantly associated with primary open angle glaucoma.

Conclusion

The pseudoexfoliation syndrome is a common cause of glaucoma. These results indicate that the G153D LOXL1 variant is significantly associated with an increased risk of pseudoexfoliation and pseudoexfoliation glaucoma in an ethnically diverse patient population from the Northeastern United States. Given the high prevalence of pseudooexfoliation in this geographic region, these results also indicate that the G153D LOXL1 variant is a significant risk factor for adult-onset glaucoma in this clinic based population.

Endoscopic management of symptomatic choledocholithiasis in pregnancy without the use of radiations

We report a case of 26-year-old woman at 10th week of gestation with cholestatic jaundice due to a common bile duct (CBD) stone managed by endoscopical retrograde cholangiopancreatography (ERCP). The procedure was successfully carried out without the use of ionizing radiations and under trans-abdominal ultrasonographical (US) control. A few cases are reported in literature in which ERCP was performed without fluoroscopy examination. We believe that ERCP with US guidance is an effective and safe procedure to treat symptomatic choledocholithiasis in pregnant women.

Antibody response to Helicobacter pylori CagA and heat-shock proteins in determining the risk of gastric cancer development

OBJECTIVE

To investigate whether the systemic antibody response to Helicobacter pylori heat shock protein B can be considered, in addition to anti cytotoxin-associated protein [CagA) antibody determination, a further serological marker of increased risk of gastric cancer development.

METHODS

A total of 98 Giemsa positive Helicobacter pylori patients (28 with gastric cancer, 30 with duodenal ulcer and 40 with nonulcer dyspepsia) were studied. Serum samples obtained from all patients were tested for IgG antibodies to CagA (116 kDa), VacA [89kDa) and heat skock protein B (54 kDa) antigens of Helicobacter pylori by the Western blot technique.

RESULTS

26/28 patients [(92.9% with gastric carcinoma, 29/30 patients [96.7%) with duodenal ulcer and 30/40 patients (75.0%) with non-ulcer dyspepsia were seropositive for CagA protein. The prevalence of serum IgG antibody to CagA in the cancer patients was not significantly higher than in duodenal ulcer and non-ulcer dyspepsia patients. The prevalence of antibodies to VacA was not significantly different between gastric carcinoma and non-ulcer dyspepsia patients. In contrast the prevalence of systemic antibodies to heat skock protein B was significantly higher in gastric cancer patients (78.6%) than in duodenal ulcer (36.7%, p=0.002) or nonulcer dyspepsia patients (52.5%, p=0.029).

CONCLUSIONS

The detection of antibodies to heat shock protein B is proposed as an additional test which, in association with the determination of serum antibodies to CagA, could help in determining the risk of developing severe gastroduodenal disease, and gastric cancer, in particular.

Complex segregation analysis for obsessive compulsive disorder and related disorders

Complex segregation analysis was applied to a sample of 107 Italian families with probands with obsessive compulsive disorder (OCD), using regressive logistic models to test for possible models of genetic transmission. We used two different phenotypic definitions of affection: 1) OCD; and 2) OCD plus Tourette's syndrome/chronic motor tics (CMT). Because of the potential relationship between OCD, Tourette's syndrome (TS), and other tic disorders, we considered these diagnoses to be determined by the same liability in subsequent steps of the analysis. For the 107 OCD families, the best fit was a dominant model of transmission (with a higher penetrance for females). When the phenotype boundaries were widened (OCD + CMT + TS), an unrestricted model of transmission became the best fit. We concluded that additional data are needed to support the hypothesis that Tourette's syndrome and OCD share a common etiology: on the basis of clinical and epidemiological considerations, the OCD phenotype probably presents a higher level of heterogeneity than the TS phenotype, and it could be regulated through different etiologic pathways.

5HT2C CYS23/SER23 polymorphism is not associated with obsessive-compulsive disorder

A great deal of evidence suggests that a genetic component underlies obsessive-compulsive disorder (OCD). The response to serotonergic medications and the worsening of obsessive symptoms after administration of serotonergic agonists indicate that serotonergic mechanisms are involved in OCD. We investigated the role of the Cys23Ser mutation of the 5HT2C receptor gene in the etiology of this disorder by performing an association study comparing a sample of 109 OCD patients with a sample of 107 healthy control subjects. No allelic or genotypic association of OCD with the 5HT2C receptor gene mutation was revealed in our data. We also extended the association analysis to a subsample of 39 OCD patients that had previously been submitted to a challenge test with clomipramine. In the subsample of OCD patients that received the challenge with clomipramine, no association between the 5HT2C receptor gene mutation and response to the challenge test was found. Our results exclude any specific role of the Cys23Ser mutation of 5HT2C receptor gene in the etiology of OCD: it seems probable that more complex genetic models are needed to explain the involvement of serotonergic elements in the etiology of this disorder.

Gastrectomy, lack of gastric first pass metabolism of ethanol and alcoholic liver disease. Results of a multicentre study

BACKGROUND

Some conditions characterized by a loss (anatomical or functional) of parietal cells of the gastric antrum, containing an alcohol-dehydrogenase, may reduce the first pass metabolism of ethanol at that level and, simultaneously, raise its bioavailability. The observation that the first pass metabolism was drastically suppressed after gastrectomy would appear to suggest that the latter condition represents a risk for the development of liver damage in patients who continue to consume alcohol even in a non relevant amount.

METHODS

Consecutively enrolled in the study were 304 individuals of both sexes aged between 45 and 70 years of whom 114 gastrectomized and 190 pair-matched control subjects all submitted to an Upper Gastrointestinal Endoscopy for whatever disturbance. All the patients were diagnosed as having liver disease with routine clinical and instrumental means. Information was collected concerning the mean daily alcohol intake, both before and after the operation.

RESULTS

The overall prevalence of hepatic lesions was shown to be higher in the gastrectomized than in the control group (42.1% vs 25.8%, p = 0.005). Moreover, referring only to alcohol-related hepatic lesions (steatosis, steato-fibrosis and cirrhosis), the prevalence was higher in the gastrectomized patients than in the controls (29.8% vs 17.9%, p = 0.02). As far as concerns alcohol consumption, the gastrectomized group had consumed 71 g/day and the control group 39 g/day alcohol per person (p < 0.05) in a similar period of time (35 and 33 years, respectively). Also the non alcohol-related liver damage (especially the viral type) was slightly higher in the gastrectomized patients (gastrectomized 12.3% vs control 7.9%, p = ns). Accordingly, the percentage of serum markers of viral infection was higher in this group (HBs Ag: gastrectomized 3.9% vs control 2.2%, p = ns; anti-HCV: gastrectomized 13.5% vs control 5.0%, p = 0.03). Finally, to test the eventual damaging effects of gastrectomy alone (excluding ethanol and/or viral infection), two groups of patients with a medium to low alcoholic negative assumption (30-60 g ethanol/day) and no signs of viral infection (HBsAg and anti-HCV negative) were extrapolated. In these two selected groups, the prevalence of alcoholic-related hepatic lesions were not statistically different (28 gastrectomized 20.3% vs 44 control 18.4%).

CONCLUSIONS

In conclusion, data emerging from investigations on the population under study indicate that the alcohol and viral infection appear to play a more important role in determining hepatic lesions than gastroresection.

Obsessive compulsive disorder and mood disorders: a family study

Obsessive compulsive disorder (OCD) often coexists with major depression (MD), with rates varying from 35 to 75%. The nature of the depressive symptomatology can be investigated by familial aggregation analysis, assuming that the disorder which occurs first is the one showing greater genetic liability and should have higher familial concentration. Therefore, the aim of our study was to assess the familial loading for OCD and mood disorders in the families of OCD patients with different chronology of onset for the mood disorder, to evaluate how the familial pattern of the diseases differs with different temporal sequences in which the two syndromes occur. A total of 172 OCD patients entered the study; 112 were pure OCD probands, 12 were unable to separate the onset of the two syndromes, 11 had prior mood disorder, and 37 of them had experienced their first depressive episodes after the onset of OCD. Information about the family history was collected by means of the Family History-Research Diagnostic Criteria (FH-RDC) and by directly interviewing at least 2 relatives per family. Morbidity risks for OCD indicate a familial concentration of the disorder in all groups, except the MD/OCD group. We found the highest rate of relatives affected by mood disorders in the families of patients with first onset of MD (28.8%), whereas in the other 3 groups MRs were much lower. These results suggest the affective nature of OCD patients who experienced first onset of MD. Thus, the chronology of onset seems to identify 2 different typologies of familial distribution.

Alcohol drinking among adolescents from town and mountainous areas in north Italy

Alcohol consumption was investigated among 9th and 13th grade high school students in the town of Brescia (an urban area) and in the Local Health Unit of Breno, a mountainous area in the province of Brescia. A total of 1364 students from Brescia and 1373 from Breno completed an anonymous questionnaire during school time. In both groups alcohol consumption was greater among 13th graders (modal age: 18 years) and males than 9th graders (modal age: 14 years) and females. Beer was the favourite alcoholic beverage, but wine was the most widely consumed daily beverage: among males, about 8% in grade 9 and 15% in grade 13 drank at least one glass of wine every day. The majority of both 9th and 13th graders had more than one type of alcoholic beverage a week, although many females drank beer only. Total alcohol consumption was higher among the mountainous area students than urban students, especially 9th graders, and greater differences were observed in the consumption of beer with respect to wine. The proportion of male students from Brescia and Breno who consumed more than 6 alcohol units a week were, respectively, 17% and 25% in grade 9 and 36% and 42% in grade 13. A higher prevalence of drunkenness was found among the students from the mountainous area with respect to the urban students, especially males. Among 13th grade males, 42% of students from Brescia and 60% from Breno claimed one or more episodes of drunkenness during the year prior to the interview.

[Factors associated with alcohol consumption in the youth of the province of Brescia]

We investigated factors related to adolescent alcohol consumption by administering an anonymous questionnaire to 2737 9th and 13th grade high-school students in the province of Brescia. A total of 1364 students coming from an urban area (the town of Brescia with about 200,000 inhabitants) and 1373 students from a mountainous area (Breno, Local Health Unit N. 37 in the Lombardy Region with 83,000 inhabitants) were interviewed. The associations between alcohol drinking and some demographic, socio-economic, behavioural and environmental variables were assessed by computing the correspective odds ratios (OR) by fitting logistic regression models for ordinal response variables ("cumulative odds" models). The results showed that the following variables were positively associated with alcohol consumption: 1) residence in a mountainous area, especially as regards spirits consumption; 2) experimental and regular smoking; 3) peer alcohol drinking (best friend and partner). Parents' daily alcohol consumption was associated with wine drinking, but not with either spirits consumption or frequency of drunkenness among students. A slight inverse relationship was also found between students' alcohol intake and their knowledge of the health hazards of alcohol, but it was not significant for all groups of students.

Drinking habits among high school students in Perugia, Italy, in 1981 and 1988: time trends and correlates

The prevalence of alcohol consumption among 9th (14-15 years old) and 13th grade (18-19 years old) high school students in Perugia, Italy, was investigated in 1981 and 1988. Wine was the most popular beverage, although its use declined in the 7-year period. Beer consumption remained stable, but it was at a lower level than wine. Overall, alcohol consumption showed a slight decline among both 9th and 13th graders. However, the proportion of excessive drinkers increased, and a growing phenomenon of drunkenness among students was observed. Alcohol consumption was positively associated with sex and smoking and negatively associated with father's education and knowledge of the health hazards of alcohol abuse by multivariate analysis.

Factors associated with non-participation of women in a breast cancer screening programme in a town in northern Italy

STUDY OBJECTIVE

The aim was to investigate the reasons for the high percentage of women refusing to attend a breast cancer screening programme in the Health District of Brescia, Italy.

DESIGN

This was a survey of a sample of non-attenders to the programme, who were interviewed using a structured questionnaire.

SETTING

Non-attenders all lived in a central area of the town near the screening centre.

PARTICIPANTS

Of the 612 non-attenders eligible for interview, 183 could not be interviewed: one had died, 86 were away from home at two different visits, 32 were no longer resident at the known address, eight had serious health problems, 17 had undergone mastectomy, and 39 refused the interview. Overall, a total of 429 of the 612 eligible women were interviewed (70.1%).

MEASUREMENTS AND MAIN RESULTS

Attenders and non-attenders were compared with respect to demographic and socioeconomic factors, use of preventive medicine, and prevalence of risk factors for breast cancer. The response was higher among less educated women, married and widowed women, and those born in the province than among more educated, single or divorced, and immigrant women. Most of the women interviewed gave practical reasons for non-participation, but lack of interest/distrust and fear/worry/anxiety also seemed important. The number of non-attenders who had had a Papanicolaou test within the previous three years was three times higher than those who had had mammography, suggesting that non-attenders were more interested in types of preventive medicine other than screening for breast cancer by mammography. Attenders and non-attenders appeared similar as regards distribution of conventional breast cancer risk factors.

CONCLUSIONS

Greater effort in the information campaign might increase the participation rate in screening for breast cancer, although to a lesser extent than expected: if non-attenders potentially recruitable in our screening were added to attenders, overall compliance of the programme was about 75%, lower than that observed in some programmes in northern Europe.

An experimental test of new theoretical models for the electrokinetic properties of biological membranes. The effect of UO2++ and tetracaine on the electrophoretic mobility of bilayer membranes and human erythrocytes

For a large smooth particle with charges at the surface, the electrophoretic mobility is proportional to the zeta potential, which is related to the charge density by the Gouy-Chapman theory of the diffuse double layer. This classical model adequately describes the dependence of the electrophoretic mobility of phospholipid vesicles on charge density and salt concentration, but it is not applicable to most biological cells, for which new theoretical models have been developed. We tested these new models experimentally by measuring the effect of UO2++ on the electrophoretic mobility of model membranes and human erythrocytes in 0.15 M NaCl at pH 5. We used UO2++ for these studies because it should adsorb specifically to the bilayer surface of the erythrocyte and should not change the density of fixed charges in the glycocalyx. Our experiments demonstrate that it forms high-affinity complexes with the phosphate groups of several phospholipids in a bilayer but does not bind significantly to sialic acid residues. As observed previously, UO2++ adsorbs strongly to egg phosphatidylcholine (PC) vesicles: 0.1 mM UO2++ changes the zeta potential of PC vesicles from 0 to +40 mV. It also has a large effect on the electrophoretic mobility of vesicles formed from mixtures of PC and the negative phospholipid phosphatidylserine (PS): 0.1 mM UO2++ changes the zeta potential of PC/PS vesicles (10 mol % PS) from -13 to +37 mV. In contrast, UO2++ has only a small effect on the electrophoretic mobility of either vesicles formed from mixtures of PC and the negative ganglioside GM1 or erythrocytes: 0.1 mM UO2++ changes the apparent zeta potential of PC/GM1 vesicles (17 mol % GM1) from -11 to +5 mV and the apparent zeta potential of erythrocytes from -12 to -4 mV. The new theoretical models suggest why UO2++ has a small effect on PC/GM1 vesicles and erythrocytes. First, large groups (e.g., sugar moieties) protruding from the surface of the PC/GM1 vesicles and erythrocytes exert hydrodynamic drag. Second, charges at the surface of a particle (e.g., adsorbed UO2++) exert a smaller effect on the mobility than charges located some distance from the surface (e.g., sialic acid residues).