Electron microscopic studies of endocrine hyperplasia in duodenal adenomas in familial adenomatous polyposis

Summary Electron microscopical studies on endocrine cell hyperplasia of duodenal adenomas from five patients with familial adenomatous polyposis were performed. All the endocrine cell types normally found in the duodenal mucosa were identified. A constant feature was proliferation of duodenal-enterochromaffin cells but an increase in the number of all other endocrine cell types apart from pyloricgastrin cells and somatostatin cells, was also observed. Certain types of intestinal endocrine cells (the intestinal enterochromaffin cell and the glicentin cell) are rare cells in the normal duodenal mucosa. The finding of these cells may indicate increased biological aggressivity.     

睡眠剥夺对内隐记忆的影响

目的:探讨不同时间睡眠剥夺(sleep deprivation,SD)对内隐记忆的影响。方法:将32名青年男性随机分为4组:对照组、SD21、SD45和SD69组,每组8名。采用补笔测验和组词测验对4组被试进行测试。结果:SD 后无论知觉启动还是语义启动,启动量降低,并随SD 时间延长而减少。同一组内,两种测验进行比较,除对照组外,其他SD 组两两比较,语义启动的启动量大于知觉启动(P<0.05)。知觉启动中,SD45同SD69 相比无显著差异(P=0.245),其他两两比较差异均有统计学意义(P<0.01);语义启动中,SD21同对照组相比差异无统计学意义(P=0.316),其他两两比较差异均有统计学意义(P<0.01)。结论:SD 后内隐记忆受损,并同SD 时间有关;SD 后语义启动和知觉启动出现分离,知觉启动更受SD 影响。     

Novel single nucleotide polymorphisms of the human nuclear factor kappa-B 2 gene identified by sequencing the entire gene

The nuclear factor kappa-B 2 (NFKB2) gene is a member of the NFKB/Rel gene family, which is known to be a pivotal regulator of the acute phase of the inflammatory response and of immune responses. We identified three novel single nucleotide polymorphisms (SNPs) and determined their allelic frequencies, as determined by the sequencing of 48 alleles of the entire gene in a Japanese population sample. Two of the three polymorphisms were identified at nucleotide (nt) position 1837 (T/C) and nt position, 1867 (GG/G) in the upstream region of the gene. The other polymorphism was identified at nt position 2584 (G/T) within intron 1. These polymorphisms will be useful in genetic studies of the processes involved in inflammatory responses and in bone differentiation. Received: October 17, 2000 / Accepted: October 23, 2000     

Cluster-Randomized Controlled Trial of An Athletic Trainer-Directed Spit (Smokeless) Tobacco Intervention for Collegiate Baseball Athletes: Results After 1 Year

Context: Athletes in the United States are at high risk for using spit (smokeless) tobacco (ST) and incurring its associated adverse health effects.Objective: To examine whether an athletic trainer-directed ST intervention could decrease initiation and promote cessation of ST use among male collegiate baseball athletes.Design: Stratified, cluster-randomized controlled trial.Setting: Fifty-two California colleges.Patients or Other Participant(s): A total of 883 subjects in 27 intervention colleges and 702 subjects in 25 control colleges participated, as did 48 certified athletic trainers.Intervention(s): For college athletic trainers and associated dental professionals, a 3-hour video conference, and for collegiate athletes, an oral cancer screening with feedback and brief counseling during the preseason health screenings, athletic trainer support for cessation, and a peer-led educational baseball team meeting.Main Outcome Measure(s): The subjects' ST use over 1 year was assessed by self-report. At the end of the study, the certified athletic trainers were mailed a survey assessing their tobacco use and perceptions and behavior related to tobacco control in the athletic environment. We used multivariable logistic regression models for clustered responses (generalized estimating equations) to test the difference between groups in ST-use initiation and cessation and to identify significant overall predictors of noninitiation and cessation of ST use.Results: Of the 1585 athletes recruited, 1248 (78.7%) were followed up at 12 months. In addition, 48 of the 52 athletic trainers (92%) responded to the 1-year follow-up survey. The ST-use initiation (incidence) was 5.1% in intervention colleges and 8.4% in control colleges (generalized estimating equation odds ratio = 0.58, 95% confidence interval = 0.35-0.99). Predictors of ST noninitiation were low lifetime tobacco and monthly alcohol use (odds ratio = 1.98, 95% confidence interval = 1.40- 2.82) and athletic trainers' report that the baseball coach supported ST-use prevention activities (odds ratio = 1.43, 95% confidence interval = 1.11-1.83). Although at 1 year, cessation of ST use was relatively high in both groups (36%), we noted no significant difference between the groups (odd ratio = 0.94, 95% confidence interval = 0.70-1.27).Conclusions: The intervention was significantly effective in preventing incident ST use but did not significantly increase cessation beyond that seen in the control group. The latter finding is inconsistent with previous studies and may be explained by spillover of the intervention to control colleges, other anti-tobacco activity in control colleges, and/or the small sample of dependent ST users enrolled in the study.     

Restriction fragment differences between the genomes of the Oka varicella vaccine virus and American wild-type varicella-zoster virus

The Oka vaccine strains of varicella-zoster virus (VZV) have a significantly different BgII DNA restriction pattern from that of American wild-type isolates of VZV. This difference consists primarily of an additional BgII site, which lies within the BamHI "D" fragment. In conjunction with a study of the efficacy of an experimental Merck/Oka VZV vaccine, the area of the genome from which the most marked restriction pattern alteration arises was studied more closely to determine if there are other significant differences between the Oka strains and American wild-type strains. BamHI "D" fragments from the DNA of the Oka parent strain (the progenitor of the vaccine strain), the RIT/Oka vaccine strain (a derivative of the Oka parent strain), the Merck/Oka vaccine strain, and the EF strain (an American wild type), were submitted to extensive endonuclease digestion studies to ascertain if additional unique restriction sites are present in the Oka parent or vaccine strains. The extra BgII restriction site characteristic of the Merck/Oka vaccine strain is also present in the DNA of the parent virus as well as its derivatives and was therefore not produced by the "attenuation" process. No other novel sites were found in the Oka parent or Oka-derived strains in this section of the genome. The Merck/Oka vaccine strain of VZV, despite its Japanese origin, is therefore quite similar to circulating American varicella-zoster virus strains. Varicella-zoster virus DNA, at least in the area of the BamHI D fragment, also appears to be remarkably stable from strain to strain.     

Accessibility, clinical effectiveness, and practice costs of providing a telephone option for routine asthma reviews: phase IV controlled implementation study.

BACKGROUND: Attendance for routine asthma reviews is poor. A recent randomised controlled trial found that telephone consultations can cost-effectively and safely enhance asthma review rates; however, concerns have been expressed about the generalisability and implementation of the trial's findings. AIM: To evaluate the effectiveness of a telephone option as part of a routine structured asthma review service. DESIGN OF STUDY: Phase IV controlled before-and-after implementation study. SETTING: A large UK general practice. METHOD: Using existing administrative groups, all patients with active asthma (n = 1809) received one of three asthma review services: structured recall with a telephone-option for reviews versus structured recall with face-to-face-only reviews, or usual-care (to assess secular trends). Main outcome measures were: proportion of patients with active asthma reviewed within the previous 15 months (Quality and Outcomes Framework target), mode of review, enablement, morbidity, and costs to the practice. RESULTS: A routine asthma review was provided for 397/598 (66.4%) patients in the telephone-option group compared with 352/654 (53.8%) in the face-to-face-only review group: risk difference 12.6% (95% confidence interval [CI] = 7.2 to 17.9, P<0.001). The usual-care group achieved a review rate of 282/557 (50.6%). Morbidity was equivalent in the three groups; however, enablement (P = 0.03) and confidence (P = 0.007) in asthma management were greater in the telephone-option versus face-to-face-only group. The cost per review achieved by providing the telephone-option service was lower than the face-to-face-only service (10.03 pounds versus 12.74 pounds, mean difference 2.71 pounds; 95% CI = 1.92 to 3.50, P<0.001); usual-care costs were 11.85 pounds per review achieved. CONCLUSION: Routinely offering telephone reviews cost-effectively increased asthma review rates, enhancing patient enablement and confidence with management, with no detriment to asthma morbidity. Practices should consider a telephone option for their asthma review service.     

The Heritability of Depression Symptoms in Elderly Danish Twins: Occasion-Specific Versus General Effects

Depression symptomatology was assessed up to four times at 2-year intervals on a sample of 2100 Danish twins initially aged 70 years and older. Data were analyzed using the biometric growth model approach proposed by Neale and McArdle (2000). Results show that occasion-specific depression is moderately and equally heritable in men and women (occasion-specific estimates of heritability ranged from 22% to 37%). Estimates of phenotypic variance, genetic variance, and heritability did not vary systematically across waves. In the best-fitting growth model, depression symptomatology was accounted for by two factors: (1) a level (i.e., average) effect that was highly heritable (estimate of 69% in women and 64% in men) and reflected overall vulnerability, and (2) a residual effect that was nonheritable and reflected occasion-specific circumstances that could either exacerbate or moderate inherited vulnerability. Attempts to identify specific genetic contributions to depression might profitably focus on average levels across multiple assessments, while attempts to identify specific environmental effects might profitably focus on deviations about this average.     

Using linked markers to infer the age of a mutation

Advances in sequencing and genotyping technologies over the last decade have enabled geneticists to easily characterize genetic variation at the nucleotide level. Hundreds of genes harboring mutations associated with genetic disease have now been identified by positional cloning. Using variation at closely linked genetic markers, it is possible to predict the times in the past at which particular mutations arose. Such studies suggest that many of the rare mutations underlying human genetic disorders are relatively young. Studies of variation at genetic markers linked to particular mutations can provide insights into human geographic history, and historical patterns of natural selection and disease, that are not available from other sources. We review two approaches for estimating allele age using variation at linked genetic markers. A phylogenetic approach aims to reconstruct the gene tree underlying a sample of chromosomes carrying a particular mutation, obtaining a “direct” estimate of allele age from the age of the root of this tree. A population genetic approach relies on models of demography, mutation, and/or recombination to estimate allele age without explicitly reconstructing the gene tree. Phylogenetic methods are best suited for studies of ancient mutations, while population genetic methods are better suited for studies of recent mutations. Methods that rely on recombination to infer the ages of alleles can be fine‐tuned by choosing linked markers at optimal map distances to maximize the information available about allele age. A limitation of methods that rely on recombination is the frequent lack of a fine‐scale linkage map. Maximum likelihood and Bayesian methods for estimating allele age that rely on intensive numerical computation are described, as well as “composite” likelihood and moment‐based methods that lead to simple estimators. The former provide more accurate estimates (particularly for large samples of chromosomes) and should be employed if computationally practical. Hum Mutat 18:87–100, 2001. © 2001 Wiley‐Liss, Inc.     

Genetic markers in the Tuvan population of Todja, Siberia

Todja is a secluded region of northern Tuva situated in the Sayany Mountains, Siberia. The aboriginal population of Todja is Tuvan. A total of 128 healthy Tuvans living in Todja were typed for HLA-A, -B and -C antigens and several plasma and erythrocyte protein polymorphisms (Hp, Tf, Gc, ESD, ACP, PGM1, PGD and ADA). The observed frequencies of all 8 blood protein and HLA genotypes were in agreement with Hardy-Weinberg expectations. The most frequent HLA antigens in Todjans are A2 (0.36). A3 (0,24), A9 (0.50), B15 (0.34) and B40 (0.50). HLA haplotypes A2B5, A2B40, A9B15 and A9B40 are most common in this population. The observed frequencies of protein polymorphisms and HLA antigens and haplotypes in Todjans are similar to those of other Mongoloid populations. A comparison of HLA frequencies currently observed in Todjans with those obtained 20 years ago at the same locality showed minor changes attributable to the effect of migration.     

Can subjects with a positive allergen skin test be selected by a short questionnaire?

The objective was to evaluate a postal questionnaire screening procedure for selection of subjects with positive reactions to skin prick tests with common allergens. The project consisted of a screening, with subsequent skin prick test of two selected groups. The setting was the Glostrup Population Studies institute in Copenhagen, Denmark. Participants in the screening included 8000 subjects, aged 15–69 years. The subjects were randomly selected from the population of western Copenhagen County, Denmark. From the 6998 respondents (87.5%), 793 subjects were randomly selected (Random Group), and 788 subjects were chosen on the basis of their answers to the questionnaire (Symptom Group). Both groups were invited to take skin prick tests. Attendance rates were 75.5% (Random Group) and 80.6% (Symptom Group).
The main outcome measures were responses (yes or no) to the specific questions and the subjects' skin reaction (positive or negative). The association between symptoms and skin reactivity, adjusted for the effects of sex and age, was summarized by odds ratios. Symptoms on exposure to allergens were highly associated with positive skin reactivity. In the Symptom Group the percentage of subjects with at least one positive skin reaction was 57.7%, which was twice as much (28.4%) as in the Random Group. The results show that it was possible to select a group with high skin reactivity on the basis of the symptoms reported in the screening. Questions about exposure to allergens were the most appropriate for selection of this group.