Islet autoantibodies, nationality and gender: a multinational screening study in first-degree relatives of patients with Type I diabetes.

AIMS/HYPOTHESIS: First-degree relatives of patients with Type I (insulin-dependent) diabetes mellitus diagnosed at 20 years of age or under were screened for islet cell antibodies (ICA) in the course of recruitment to an international diabetes prevention trial. Our aim was to evaluate the influence of age, gender, proband characteristics and nationality on the prevalence of ICA and co-existence of autoantibodies to GAD, IA-2 and insulin. METHODS: A central laboratory screened samples from 10 326 non-diabetic relatives who were aged less than 40 years, from eight European countries for ICA. Antibodies to GAD and IA-2 were measured in all samples with ICA of 10 JDF units or more. RESULTS: Overall, 8.9 % of relatives had ICA of 10 JDF units or more, 3.8 % with ICA of 20 JDF units or more. Of 921 relatives with ICA of 10 JDF units or more, 29 % had co-existing antibodies to GAD or IA-2 or both. ICA of 10 JDF units or more were more prevalent in males (10.8 %) than females (7.3 %). ICA with GAD or IA-2 antibodies or both were also more common in males (3.4 %) than females (1.9 %) and in relatives under 20 years of age (3.5 % vs 1.5 %). Multiple regression analysis showed nationality to be a determinant of ICA of 10 JDF units or more but not of ICA of 20 JDF units or more or of ICA with co-existing islet antibodies, and confirmed the importance of age and gender as determinants of islet autoimmunity. CONCLUSIONS/INTERPRETATION: Relatives from different European countries have similar rates of islet autoimmunity despite wide variation in the background incidence of childhood diabetes, and male excess is equally evident in all populations. The male excess of ICA and islet autoimmunity over 10 years of age reflects the higher male incidence of Type I diabetes in this age group, and suggests that boys may be more likely than girls to develop islet autoimmunity during adolescence.

Safety of high-dose nicotinamide: a review.

Nicotinamide, the amide derivative of nicotinic acid, has over the past forty years been given at high doses for a variety of therapeutic applications. It is currently in trial as a potential means of preventing the onset of Type I (insulin-dependent) diabetes mellitus in high-risk, first-degree relatives. Nicotinamide is for regulatory purposes classed as a food additive rather than a drug and has not therefore required the formal safety evaluation normally expected of a new therapy. Because the safety of treatment with megadoses of vitamins cannot be assumed, a full literature review has been undertaken. The therapeutic index of nicotinamide is wide but at very high doses reversible hepatotoxicity has been reported in animals and humans. Minor abnormalities of liver enzymes can infrequently occur at the doses used for diabetes prevention. There is no evidence of teratogenicity from animal studies and nicotinamide is not in itself oncogenic; at very high doses it does however potentiate islet tumour formation in rats treated with streptozotocin or alloxan. There is no evidence of oncogenicity in man. Growth inhibition can occur in rats but growth in children is unaffected. Studies of its effects on glucose kinetics and insulin sensitivity are inconsistent but minor degrees of insulin resistance have been reported. The drug is well tolerated, especially in recent studies which have used relatively pure preparations of the vitamin. Experience to date therefore suggests that the ratio of risk to benefit of long-term nicotinamide treatment would be highly favourable, should the drug prove efficacious in diabetes prevention. High-dose nicotinamide should still, however, be considered as a drug with toxic potential at adult doses in excess of 3 gm/day and unsupervised use should be discouraged.

Measurement of N-methyl-2-pyridone-5-carboxamide in urine by high performance liquid chromatography.

We have previously described a simple and reproducible method for the measurement of nicotinamide and its major metabolite N-methyl-2-pyridone-5-carboxamide (2-pyr) in human plasma. We now describe a low-cost high-throughput method for measurement of urinary 2-pyr, and demonstrate that Isolute C18 bulk can replace use of the column to clean up the samples prior to injection into the HPLC apparatus. Using a standard curve together with an internal standard for each sample, with mean recovery of 2-pyr greater than 95%, the assay has proved reproducible, with considerable savings in cost and time. The principal advantages of this method are the rapid column clean up of samples prior to injection and the simple but effective methodology.

Measurement of nicotinamide and N-methyl-2-pyridone-5-carboxamide in plasma by high performance liquid chromatography.

We describe a simple and reproducible method for simultaneous determination of nicotinamide and its major human biological metabolite N-methyl-2-pyridone-5-carboxamide (2pyr). Previous assays for nicotinamide in plasma and in urine have been complicated by the use of tedious extraction procedures or HPLC conditions which, although often allowing simultaneous analysis of several metabolites, add to the difficulties of performing multiple analyses. The procedure we describe is simple, using a rapid column clean-up of samples prior to injection, which can then be done using an autosampler. Both nicotinamide and its major metabolite 2pyr can be assayed rapidly, with good reproducibility, and at the same time.

Influence of instrumental activities of daily living assessment method on judgments of independence.

OBJECTIVE: Occupational therapists frequently evaluate instrumental activities of daily living (IADL) performance with interviews and observation of simulated tasks. This study examined the congruence of judgments of independence when comparing task performance assessed by interview and simulation with task performance assessed by observation in the natural environment. METHOD: Twenty persons with severe mental illness were selected through convenience sampling and evaluated on two IADL tasks (making a purchase in a store and using the bus). The participants were evaluated on each task with two methods of assessment: interview and simulation and observation in the natural environment. RESULTS: Results indicated inconsistent performance across assessment approaches and tasks and supported the importance of considering contextual features in understanding the complexity of performance in the natural environment. A trend toward false positives was found in which several participants were judged independent on the IADL assessment but could not perform the same tasks in the natural environment. CONCLUSION: Occupational therapists should be cautious when making judgments of independence on the basis of interview and observation of simulated tasks. Evaluating IADL performance in the persons' natural environment may provide more accurate information.

Attitudes of medical students and primary care physicians regarding input of older and younger patients in medical decisions.

This study was designed to determine whether medical students, residents, and fully trained physicians differ in their attitudes toward decision-making input by older and younger patients, whether they believe that physicians should have greater input than patients in medical decisions, whether physicians grant different decision-making authority to younger versus older patients, and whether physician gender affects attitudes toward patient input in medical decisions. Respondents (n = 818) were first- (n = 311) and third-year (n = 227) medical students and family practice and internal medicine residents (n = 120) and faculty (n = 160) from the University of Kansas Medical Center (n = 367) and The Ohio State University Hospital (n = 451) who completed the Beisecker Locus of Authority: Geriatrics Scale to assess attitudes regarding involvement in medical decision making for either a 25- or 75-year-old patient. Respondents were alternately assigned to one of the two patient age vignettes. Analyses included descriptive statistics, t tests, and four-way analysis of variance. Ninety percent of respondents believed that physicians should have greater input in decisions than patients. Female respondents advocated greater patient input than male respondents. As training and experience increased beyond medical school, there was an increased tendency toward belief in physician-only decision making. For the older patient, residents advocated the most patient input and faculty advocated the least. Level of training influenced belief in patient input when its interaction with patient age and institution were examined.

Attitudes of oncologists, oncology nurses, and patients from a women's clinic regarding medical decision making for older and younger breast cancer patients.

To assess their attitudes toward patient input in medical decisions for breast cancer patients, 67 oncologists, 94 oncology nurses and 288 patients from a women's clinic completed the Beisecker Locus of Authority in Decision Making: Breast Cancer survey. Nurses and physicians responded in terms of a patient aged 40, 60, or 75 years. All groups believed that physicians should have the dominant role in decision making. Nurses felt that patients should have more input than patients or physicians felt they should. Physicians advocated the least patient input. Patient age was not a significant factor in explaining respondents' attitudes.

Prevalence of aneuploidy, overexpressed ER, and overexpressed EGFR in random breast aspirates of women at high and low risk for breast cancer.

Breast tissue biomarkers which accurately predict breast cancer development within a 10 year period in high risk women are needed but currently not available. We initiated this study to determine 1) the prevalence of one or more breast tissue abnormalities in a group of women at high risk for breast cancer, and 2) if the prevalence of biomarker abnormalities is greater in high risk than in low risk women. Eligible high risk women were those with a first degree relative with breast cancer, prior breast cancer, or precancerous mastopathy. Low risk women were those without these or other major identifiable risk factors. Ductal cells were obtained via random fine needle aspirations and cytologically classified. Biomarkers included DNA ploidy, estrogen receptor (ER), and epidermal growth factor receptor (EGFR). The prevalence of DNA aneuploidy was 30%, overexpression of ER 10%, and overexpression of EGFR 35%, in the 206 high risk women whose median 10 year Gail risk (projected probability) of developing breast cancer was 4.5%. The prevalence of aneuploidy and overexpressed EGFR was significantly higher in the high risk women than in the 25 low risk controls (p < 0.002), whose median 10 year Gail risk was 0.7%. The difference in the prevalence of ER overexpression between high and low risk groups was not statistically significant (p = 0.095). This may be due to the low prevalence of overexpressed ER and the small number of controls. A significant difference was noted in the prevalence of one or more abnormal biomarkers between the high risk and low risk women (p < 0.001). A large prospective trial is needed to determine if one or more of these biomarkers, is predictive of breast cancer development.

Biomarker and cytologic abnormalities in women at high and low risk for breast cancer.

Fine needle aspirates (FNA) from 106 high-risk women and 25 low-risk women were evaluated for overexpression of estrogen receptor (ER), epidermal growth factor receptor (EGFR), mutant p53, and HER-2/neu by immunocytochemistry, and for aneuploidy by image analysis. Aspirates were also classified cytologically as normal, apocrine metaplasia, epithelial hyperplasia (EH), or dysplasia. High-risk women were those with a first-degree relative with breast cancer (76%), precancerous breast disease (26%), prior cancer of the contralateral breast (9%), or multiple abnormalities (11%). Low-risk women had none of the above risk factors, nor a prior breast biopsy or clinical evidence of fibrocystic disease. The median 10-year Gail risk for the high-risk group was 4%, compared to 0.7% for the low-risk group. There were significant differences (p < 0.01) between high- and low-risk women in the prevalences of hyperplasia (55% versus 12%), dysplasia (19% versus 0%), aneuploidy (32% versus 0%), overexpressed EGFR (32% versus 4%), and overexpressed p53 (29% versus 4%). The prevalence of multiple biomarker abnormalities was also greater in high-risk than in low-risk women (28% versus 0%; p < 0.01). Four percent (4%) of FNAs from high-risk women with normal cytology, 29% of aspirates with hyperplastic cytology, and 60% of those with dysplasia were associated with two or more biomarker abnormalities. The differences in the prevalence of multiple biomarker abnormalities among various cytologic categories were statistically significant (p = 0.02, normal versus EH; p = 0.02, EH versus dysplasia; p < 0.01, normal versus dysplasia).(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of L-cell growth stimulating antibody as anti-actin.

Anti-L-cell antisera having potent cell growth stimulatory properties were shown by Western blotting to have predominant specificity toward a protein with a molecular weight of 42K which we identified as actin. Extractions of L cells, based upon the known insolubility of cytoskeletal proteins (including actin) in Triton X-100 and the solubility of actin in low ionic strength Ca2+ and ATP-containing buffer, led to actin-enriched preparations that retained immunoreactivity with the anti-L-cell antisera. The 42-kDa antigen binds to deoxyribonuclease I, has a pI = 5.2-5.4, and has an amino acid composition, including the presence of 3-methylhistidine, compatible with compositions determined for actins from other sources. Rabbit antiserum specific for this 42-kDa protein, isolated by SDS-PAGE, reproduced the cell growth stimulation by the anti-L-cell antisera and absorption of the antiserum with purified L-cell actin eliminated this stimulation. Moreover, these antibodies bind to the microfilaments of 3T3 fibroblasts. When purified actins were used as soluble antigen inhibitors of the immune reactivity of antiserum to 42-kDa protein with intact L cells, rabbit thymus actin competed with the surface molecules on L cells and reduced the stimulatory effect of the antiserum by 80% at an actin concentration of 150 micrograms/ml. Chicken muscle actin reduced the antibody stimulation effect by only 24% at the same protein concentration, and mouse muscle actin was ineffective as an inhibitor. The F(ab')2 fraction of anti-42K IgG was effective in stimulating L cells, thus documenting the immune nature of the actin-anti-42K interaction. We conclude that anti-actin antibodies, upon binding to actin-like cell surface determinants on L cells, stimulate cellular metabolism.