Decoding of sorting signals by coatomer through a GTPase switch in the COPI coat complex

Sorting signals on cargo proteins are recognized by coatomer for selective uptake into COPI (coatomer)-coated vesicles. This study shows that coatomer couples sorting signal recognition to the GTP hydrolysis reaction on ARF1. Coatomer responds differently to different signals. The cytoplasmic signal sequence of hp24a inhibits coatomer-dependent GTP hydrolysis. By contrast, the dilysine retrieval signal, which competes for the same binding site on coatomer, has no effect on GTPase activity. It is inferred that, in vivo, sorting signal selection is under kinetic control, with coatomer governing a GTPase discard pathway that excludes dilysine-tagged proteins from one class of COPI-coated vesicles. The concept of competing sets of sorting signals that act positively and negatively during vesicle budding through a GTPase switch in the COPI coat complex suggests mechanisms for cargo segregation in which specificity is conferred by GTP hydrolysis.

Two comparisons of the performance of positional scanning and deletion synthesis for the identification of active constituents in mixture combinatorial libraries

Two libraries of 120 compounds each were prepared as individual compounds and as full mixtures. The corresponding scanning and deletion synthesis deconvolution libraries were prepared and tested (L-1210, IC(50)) alongside the individual compounds and mixture libraries. This testing, where the properties of each compound in the mixtures were known, was used to compare the performance of scanning and deletion deconvolution libraries. Each has its own intrinsic strengths, with the former being capable of identifying multiple hits at the expense of accurately identifying the most potent library member, while the latter typically is more sensitive to identifying the most potent hit but at the expense of differentiating weaker activities. The protocols complement one another and together more thoroughly identify potent library members.

Muscle changes in the neuroleptic malignant syndrome

AIMS

To characterise the skeletal muscle changes in the neuroleptic malignant syndrome (NMS).

METHODS

Detailed light and ultrastructural examination was carried out on skeletal muscle from three cases of NMS, two associated with recreational drugs (3,4-methlenedioxymethylamphetamine (MDMA, Ecstasy) and lysergic acid diethylamide (LSD)) and one with antipsychotic drugs (fluoxetine (Prozac) and remoxipride hydrochloride monohydrate (Roxiam)).

RESULTS

The muscles were grossly swollen and oedematous in all cases, in one with such severe local involvement that the diagnosis of sarcoma was considered. On microscopy, there was conspicuous oedema. In some fascicles less than 10% of fibres were affected whereas in others more than 50% were pale and enlarged. There was a spectrum of changes: tiny to large vacuoles replaced most of the sarcoplasm and were associated with necrosis. A striking feature in some fibres was the presence of contraction bands separating segments of oedematous myofibrils. Severe endomysial oedema was also detectable. There was a scanty mononuclear infiltrate but no evidence of regeneration.

CONCLUSIONS

The muscle changes associated with NMS are characteristic and may be helpful in differential diagnosis.

Lifetime prevalence of mood and anxiety disorders in twin pairs discordant for schizophrenia

There have been long questions about the relationship of schizophrenia to other mental disorders. Lifetime DSM-III-R diagnoses of mood and anxiety disorders in twins with clinically diagnosed schizophrenia (n = 24) and their non-affected co-twins (n = 24) were compared with twins from pairs without schizophrenia (n = 3327) using a sample from the Vietnam Era Twin Registry. Schizophrenic probands had significantly elevated rates of all included disorders (bipolar disorder, major depression, dysthymia, generalized anxiety disorder, panic disorder, and PTSD) compared with controls (P<0.01). The odd ratios comparing co-twins of schizophrenic probands with controls was greater than three for every disorder, but did not attain statistical significance. A similar pattern was observed when analyses were restricted to only monozygotic twins (n = 12). Consistent with other studies, schizophrenics appeared to have higher rates of a range of mental disorders. Our results suggest that schizophrenia per se represents a risk factor for other psychiatric disorders, but the absence of significantly elevated risk among non-schizophrenic co-twins suggested that family environmental and/or genetic factors that contribute to risk of schizophrenia do not increase the risk of mood and anxiety disorders to the same extent that the risk of these other disorders is increased by the presence of schizophrenia.

Evidence for genetic influences common and specific to symptoms of generalized anxiety and panic

BACKGROUND

Generalized anxiety disorder (GAD) and panic disorder (PD) often co-occur and have been shown to be heritable. Researchers have debated the validity of the distinction between GAD and PD. To test for distinction between disorders, we estimated the genetic and environmental contributions which were specific and common to GAD and PD in a cohort of male-male twin pairs.

METHODS

Data were obtained from a telephone interview performed in 1992 utilizing the Diagnostic Interview Schedule Version 3-Revised. Interviews were administered to 6724 male-male monozygotic and dizygotic twin pair members of the Vietnam Era Twin Registry. We defined lifetime GAD by the report of six or more DSM-III-R symptoms and lifetime PD by the report of four or more DSM-III-R symptoms.

RESULTS

The lifetime co-occurrence of GAD and PD was best explained by a model which did not include family environmental influences. The variance in risk for GAD was due to a 37.9% influence from additive genetic factors with the remainder due to unique environmental influences. The variance in risk for PD was due to a 22.6% additive genetic contribution which was common with GAD and a 21.2% non-additive genetic contribution specific to PD with the remainder of variance in risk for PD due to unique environmental influences.

LIMITATIONS

Results may be limited to middle aged males. Model fitting with full diagnostic criteria was not possible due to low prevalences.

CONCLUSIONS

Our data suggest a distinction in liability for GAD versus PD. The common genetic influence to GAD and PD may partially account for the risk of the co-occurrence of these disorders in a lifetime.

Genetic and environmental influences on transitions in drug use

Genetic and environmental factors influence drug abuse, but abuse represents the culmination of a sequence of events. Different levels of use may have different determinants and these determinants may differ across drug types. Approximately 3200 male-male twin pairs from the Vietnam Era Twin Registry were interviewed by telephone. Data were obtained regarding exposure to six categories of illicit drugs, initiation of use, continuation of use, regular usage, and diagnosis of drug abuse/dependence. Genetic, common environmental, and unique environmental influences on transitions of drug involvement, defined as movement from one level of drug use to the next, were investigated. Marijuana had the highest conditional probability for the transition from exposure to use, from use to use more than five times, and from use more than five times to regular use. The rate of transition to regular use of heroin was higher than the rate for amphetamine, cocaine, sedatives, and psychedelics. Cocaine had the highest conditional probability for the transition from regular use to abuse/dependence. Significant genetic influences were observed for a number of transitions in marijuana, amphetamine, and cocaine usage.

Imaging of autism: lessons from the past to guide studies in the future

OBJECTIVE

To review the scientific literature on the imaging of autism with a view to understanding how imaging can contribute to future studies.

METHODS

Medline was searched, and bibliographies from retrieved articles were reviewed. Inclusion criteria were a diagnosis of autism according to Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria, third edition or later, and a control group without autism.

RESULTS

The field suffers from a lack of replication studies and poor methodology in terms of not controlling for confounding variables. Enlarged brain size, particularly in the temporoparietal brain region, and decreased size of the posterior corpus callosum are the only findings that have been independently replicated.

CONCLUSION

Future imaging studies should attempt to investigate more homogeneous subgroups of patients such as those with "the lesser variant of PDD" and high-functioning patients with PDD who do not have comorbid medical conditions. A different approach, examining the individual behaviours that constitute the PDD spectrum and exploring these separately along with other associated variables such as neuropsychological deficits, structural and functional brain abnormalities, and genetic information could help identify biological mechanisms that do not follow diagnostic boundaries.

Qualitative and quantitative studies of autoantibodies to phospholipids in diabetes mellitus

Diabetes mellitus is associated with vascular and neurological complications. We have investigated the presence of antibodies to phospholipids and to phospholipid binding plasma proteins in blood samples collected from 68 clinically and biochemically characterized type I and type II diabetic patients and from 252 healthy blood donor controls. Each sample was analysed for antibodies to three phospholipids (cardiolipin, phosphatidylserine and phosphatidylethanolamine), the antibody isotypes (IgA, IgG and IgM), and whether antibody activity was plasma protein-dependent. Patients were considered to have anti-phospholipid antibodies when one or more of these 18 tests was found above predetermined control values. The results of these experiments revealed an increased incidence of anti-phospholipid antibodies in diabetic patients compared with control subjects. The incidence of IgA isotype to phosphatidylethanolamine was higher than the incidence of other isotypes to other phospholipids, and their reactivities were independent of phospholipid-associated proteins. In addition, these antibody findings were studied for associations with prothrombin degradation products, activated factor VII and activated protein C, and with the incidence of diabetic complications. The anti-phosphatidylethanolamine antibody association with proliferative retinopathy was significant.

Long-term outcomes after function-sparing surgery without radiotherapy for soft tissue sarcoma of the extremities and trunk

PURPOSE

To define the rate of local recurrence (LR) and identify prognostic factors for LR for patients with soft tissue sarcoma (STS) treated with function-sparing surgery (FSS) without radiotherapy (RT).

PATIENTS AND METHODS

Between 1970 and 1994, 242 patients with STS of the trunk and extremity presented with primary localized disease, 74 of whom were treated with FSS without RT (31%). The median tumor size was 4 cm (range, 0.5 to 31 cm). There were 40 patients with grade 1 tumors and 34 with grade 2 and 3 tumors. Median follow-up was 126 months.

RESULTS

The 10-year actuarial local control rate was 93% +/- 4%. Resection margin status was a significant predictor for LR. Patients with closest histologic resection margins of less than 1 cm had a 10-year local control rate of 87% +/- 6% compared with 100% for patients with closest histologic resection margins of >/= 1 cm (P =.04). There was no significant association between LR and tumor grade, size, site (truncal v extremity), or depth (superficial v deep). For all patients, the 10-year actuarial survival rate was 73% +/- 6%.

CONCLUSION

The 7% LR rate after treatment of STS with FSS without RT reported herein is comparable to published rates following treatment where adjuvant RT is used. These results suggest there may be a select subset of patients with STS in whom carefully performed FSS may serve as definitive therapy and in whom adjuvant RT may not be necessary. However, further study is needed to carefully define this subset of patients and to identify the optimal surgical approach and technique for patients treated without RT.

Asbestos-induced phosphorylation of epidermal growth factor receptor is linked to c-fos and apoptosis

We examined the mechanisms of interaction of crocidolite asbestos fibers with the epidermal growth factor (EGF) receptor (EGFR) and the role of the EGFR-extracellular signal-regulated kinase (ERK) signaling pathway in early-response protooncogene (c-fos/c-jun) expression and apoptosis induced by asbestos in rat pleural mesothelial (RPM) cells. Asbestos fibers, but not the nonfibrous analog riebeckite, abolished binding of EGF to the EGFR. This was not due to a direct interaction of fibers with ligand, inasmuch as binding studies using fibers and EGF in the absence of membranes showed that EGF did not adsorb to the surface of asbestos fibers. Exposure of RPM cells to asbestos caused a greater than twofold increase in steady-state message and protein levels of EGFR (P < 0.05). The tyrphostin AG-1478, which inhibits the tyrosine kinase activity of the EGFR, but not the tyrphostin A-10, which does not affect EGFR activity, significantly ameliorated asbestos-induced increases in mRNA levels of c-fos but not of c-jun. Pretreatment of RPM cells with AG-1478 significantly reduced apoptosis in cells exposed to asbestos. Our findings suggest that asbestos-induced binding to EGFR initiates signaling pathways responsible for increased expression of the protooncogene c-fos and the development of apoptosis. The ability to block asbestos-induced elevations in c-fos mRNA levels and apoptosis by small-molecule inhibitors of EGFR phosphorylation may have therapeutic implications in asbestos-related diseases.

Sexual orientation and suicidality: a co-twin control study in adult men

BACKGROUND

Several recent studies have found a higher lifetime prevalence of suicide attempts in homosexual males compared with heterosexual control subjects or population rates. These studies used either convenience samples, most without controls, or population-based samples in which confounding factors such as depression and substance abuse were not measured.

METHODS

This study used twins from the population-based Vietnam Era Twin Registry, Hines, Ill. An analytic sample of 103 middle-aged male-male twin pairs from the registry was identified in which one member of the pair reported male sex partners after age 18 years while the other did not. Four lifetime symptoms of suicidality as measured by the Diagnostic Interview Schedule were analyzed: thoughts about death, wanting to die, thoughts about committing suicide, and attempted suicide. A composite measure of reporting at least one suicidality symptom was also assessed.

RESULTS

Same-gender sexual orientation is significantly associated with each of the suicidality measures. Unadjusted matched-pair odds ratios follow: 2.4 (95% confidence interval [CI], 1.2 - 4.6) for thoughts about death; 4.4 (95% CI, 1.7 - 11.6) for wanted to die; 4.1 (95% CI, 2.1 - 8.2) for suicidal ideation; 6.5 (95% CI, 1.5 - 28.8) for attempted suicide; and 5.1 (95% CI, 2.4 - 10.9) for any of the suicidal symptoms. After adjustment for substance abuse and depressive symptoms (other than suicidality), all of the suicidality measures remain significantly associated with same-gender sexual orientation except for wanting to die (odds ratio, 2.5 [95% CI, 0.7 - 8.81).

CONCLUSIONS

The substantially increased lifetime risk of suicidal behaviors in homosexual men is unlikely to be due solely to substance abuse or other psychiatric comorbidity. While the underlying causes of the suicidal behaviors remain unclear, future research needs to address the inadequacies in the measurement of both sexual orientation and suicidality in population-based samples.

The Chronic Fatigue Twin Registry: method of construction, composition, and zygosity assignment

Chronic fatigue syndrome (CFS) and the symptom of chronic fatigue are conditions of unknown etiology. The Centers for Disease Control and Prevention (CDC) define CFS as an illness characterized by > or = 6 months of disabling fatigue associated with muscle pain, pharyngitis, and alterations in mood, sleep and neurocognition. We constructed a registry of twins with chronic fatigue to facilitate research on the impact of illness, the associated medical and psychosocial factors, and the heterogeneous proposed mechanisms for these conditions. We have recruited 204 twin pairs in which one or both members reported persistent fatigue through patient support group newsletters (60%), clinicians/researchers familiar with CFS (12%), notices placed on electronic bulletin boards for CFS (11%), twin organizations and researchers (6%), relatives and friends (3%) and other sources (8%). Complete data are available for 177 pairs (87%). Twins completed an extensive questionnaire booklet that included measures of physical and mental health, functional status, and psychosocial factors; a structured psychiatric interview was also conducted by telephone. Twins were classified using three increasingly more stringent diagnostic criteria for chronic fatigue: 1) > or = 6 months of fatigue (115 discordant and 61 concordant pairs); 2) chronic fatigue with additional symptoms and application of the medial exclusions of the CDC CFS case definition as obtained by self-report (92 discordant and 41 concordant pairs) and; 3) chronic fatigue with additional symptoms unexplained by self-reported medical conditions and psychiatric diagnoses as determined by the structured interview (69 discordant pairs and 25 concordant pairs). Despite the limitations of a volunteer registry, the Chronic Fatigue Twin Registry promises to be an important resource for research on CFS and chronic fatigue.

Adeno-associated virus and development of cervical neoplasia

Evidence from several sources has suggested that adeno-associated virus (AAV) infection might protect against cervical cancer, in part, by interfering with human papillomavirus (HPV)-induced tumorigenesis. Detection of AAV type 2 (AAV-2) DNA in cervical tissues has been reported. However, there have been few in vivo studies of women with cervical HPV infection or neoplasia, and these have reported inconsistent results. Therefore, we used polymerase chain reaction (PCR) assays targeted to the AAV-2 rep and cap genes to test tissue specimens from women in an epidemiological study of cervical neoplasia in Jamaica. We tested 105 women with low-grade cervical intraepithelial neoplasia (CIN-1), 92 women with CIN-3/carcinoma in situ or invasive cancer (CIN-3/CA), and 94 normal subjects. PCR amplification of human beta-globin DNA was found in almost all cervical specimens, indicating that these materials were adequate for PCR testing. The prevalence of HPV DNA, determined by HPV L1 consensus primer PCR was, as expected, strongly associated with presence and grade of neoplasia. Each of the AAV PCR assays detected as few as 10 copies of the virus genome. However, none of the 291 cervical specimens from Jamaican subjects tested positive for AAV DNA. Negative AAV PCR results were also obtained in tests of cervical samples from 79 university students in the United States. Exposure to AAV was assessed further by serology. Using a whole virus AAV-2 sandwich enzyme-linked immunosorbent assay, we found no relationship between AAV antibodies and presence or grade of neoplasia in either the Jamaican study subjects or women enrolled in a U.S. cervical cancer case (n = 74) -control (n = 77) study. Overall, the data provide no evidence that AAV infection plays a role in cervical tumorigenesis or that AAV commonly infects cervical epithelial cells.

The impact of sociodemographics, comorbidity and symptom recency on health-related quality of life in alcoholics

OBJECTIVE

To obtain estimates of the relationship between alcoholism and health-related quality of life (HRQL) in twin pairs discordant for alcohol dependence.

METHOD

In 1995, 1,258 male-male twin pair members of the Vietnam Era Twin Registry (total Registry N = 7.375 pairs) were administered a modified Medical Outcomes Study 36 Item Short Form (SF-36) and the Diagnostic Interview Schedule (DIS) to obtain measures of HRQL and a DSM-III-R criteria lifetime diagnosis of alcohol dependence. Mean within pair differences on eight separate SF-36 subscales were calculated for 436 remitted (no alcohol symptoms in the past 5 years) alcohol-dependent discordant twin pairs and for 194 recent (at least one alcohol symptom in the past 5 years) alcohol-dependent discordant pairs before and after adjustment for covariates. Covariates included lifetime physical illness, lifetime psychiatric disorders, lifetime drug dependence, lifetime nicotine dependence, current marital status, current income and severity.

RESULTS

In the unadjusted analysis remitted alcoholic twins compared to their nonalcoholic co-twins reported significantly lower mean scores for six of eight SF-36 subscales. Recent alcoholic twins, compared to their nonalcoholic co-twins, reported significantly lower mean scores for all of the SF-36 subscales. However, after simultaneous adjustment for all covariates, no SF-36 subscale mean, except "vitality" among recent alcoholic twins, was significantly different between alcoholic twins and their nonalcoholic co-twins.

CONCLUSIONS

Differences in HRQL between alcoholic and nonalcoholic co-twins is due to covariation from physical and psychiatric problems, drug and nicotine dependence, marital status, income and severity.

Langerhans cell histiocytosis: retrospective evaluation of 123 patients at a single institution

The aim of this study was to retrospectively evaluate clinical characteristics at diagnosis and outcome of patients with Langerhans cell histiocytosis (LCH). From October 1987 to March 1996, 133 patients with confirmed LCH were admitted to Hospital JP Garrahan in Buenos Aires (123 evaluable). Median age was 5 years (range 15 days to 18 years). Initial organ involvement included bone 114 patients, ear 34, skin 30, liver 18, lung 14, lymph nodes 14, spleen 12, diabetes insipidus 9, and bone marrow 2. Nineteen patients had organ dysfunction, pulmonary 14, hematological 14, and hepatic 12. Two groups were defined: Group A included patients with single system disease (uni- or multifocal) and group B multisystem (with or without organ dysfunction). In group A (n = 82), 24 patients were treated with chemotherapy (prednisone and vinblastine), 21 with surgery, 15 received radiotherapy, and 22 were only observed. Patients of group B (n = 41) were treated with chemotherapy consisting of prednisone and vinblastine, DALHX 83, or LCH1-based chemotherapy. At a median follow-up of 3 years (range 1 month-8 5/12 years) 93% of patients of group A and 39% of group B survive free of reactivation. In group B, 22% had a reactivation and 39% died of progressive disease. Sequelae were detected in 35 patients (28%), which included diabetes insipidus in 17, hearing loss in 13, bony sequelae in 11, sclerosing cholangitis in 6, and lung fibrosis with bullae in 6. Two patients had a subsequent malignant disease. A total of 17 (14%) patients died and 16 of them belonged to the group B: 13 died of progressive disease, 2 due to sclerosing cholangitis (with sepsis in one case and encephalitis in the other one), 1 with progressive disease and associated myelofibrosis, and 1 patient of group A with active disease and brain stem tumor. Patients who had organ dysfunction had a reactivation free survival of 32%. All these patients survived with sequelae. Logistic regression analysis showed that organ dysfunction and hematological involvement had significant predictive values in relation to death. Patients of group A had an excellent survival rate, whereas in those of group B a high mortality was found, especially in the subgroup of patients with organ dysfunction. Lahey's criteria should be revised. Sequelae were also more common in this group.

Interrelationship of genetic and environmental influences on conduct disorder and alcohol and marijuana dependence symptoms

Data from the Vietnam Era Twin (VET) Registry were analyzed to explore the degree to which the same genetic and environmental factors contribute to childhood conduct disorder symptoms and to alcohol and marijuana dependence symptoms. Data on conduct disorder and alcohol and marijuana dependence were obtained from administration of the Diagnostic Interview Schedule to 1,856 monozygotic and 1,479 dizygotic male-male twin pair members of the VET Registry. Multivariate genetic models were compared to determine the genetic and environmental influences common and or specific to all three phenotypes. A full model that allowed for common genetic and environmental influences to all three phenotypes gave a good fit to the data, but the best fitting reduced model did not allow for a genetic influence on conduct disorder symptoms. Under the best fitting reduced model, genes explained 44.7% of the variance in risk for alcohol dependence symptoms. The genetic liability for symptoms of marijuana dependence was due to a 36.3% specific contribution and a 7.6% contribution from genes common with alcohol dependence symptoms. Family environmental contributions common to all three phenotypes explained 46.7%, 11.9%, and 21.3% of variance in risk for symptoms of conduct disorder, alcohol dependence, and marijuana dependence, respectively. Common family environmental factors contribute to risk of conduct disorder symptoms and alcohol and marijuana dependence symptoms. Common genetic influences contribute to risk of symptoms of alcohol dependence and marijuana dependence. While our findings suggest genes do not contribute to co-morbid conduct disorder symptoms, comparisons with other twin studies suggest that the role of genes in risk for conduct disorder remains uncertain.

Heavy metal uptake by polyphosphate bodies in living and killed cells of Plectonema boryanum (cyanophycae)

The study was conducted to determine whether living or killed cell polyphosphate bodies (PPB) would sequester more of several heavy metals. Living and heat- or glutaraldehyde-killed cells were exposed to 20 ppm of Zn, Pb, Mn and Al. Air-dried cells on Formvar-coated grids were first observed in the transmission electron microscope. The unit was then switched to the scanning transmission mode of operation with the spot setting. X-rays were collected on an energy dispersive X-ray spectrometer and mass fractions of the metals were determined. In all cases live cells sequestered a larger amount of the metal than cells killed by boiling or with glutaraldehyde. In all cases the cells killed by glutaraldehyde sequestered more of the heavy metals than cells killed by boiling. The results of the investigation show that PPB in living cells with active uptake systems take up and sequester more of the metals Zn, Pb, Mn and Al than killed cells.

Differential response of human osteoblast-like cells to commercially pure (cp) titanium grades 1 and 4

Common dental implants are made of different grades of commercially pure titanium (cpTi) that are more than 99% similar in chemical composition. The objective of this in vitro study was to determine if human osteoblast-like cells, Saos-2, would respond differently when plated on disks of cpTi Grade 1 and Grade 4. Glass disks served as controls. In spite of identical preparation, the two grades of cpTi acquired different surface topographies, as illustrated by scanning electron micrographs and profilometry. Cell responses, such as adhesion, morphology, and collagen synthesis also differed on the two grades of cpTi. Between 4 and 24 h, the rate of cell attachment to Grade 1 differed significantly compared to cell attachment to Grade 4 and to glass. Rhodamine phalloidin fluorescence microscopy showed variations in the actin-based cytoskeleton between grades 1 and 4 cpTi in cell spreading, shape, and the organization of stress fibers. Immunofluorescent staining showed differential expression of vinculin, a focal adhesion protein, on the substrates. At 24 h, the percent of collagen synthesized was significantly more on Grade 1 than on Grade 4 and on glass. Alkaline phosphatase activity was similar on all substrates. The calcium content was significantly higher on Grade 1 than on Grade 4 and on glass at 24 h and at 4 weeks. Thus, commonly used cpTi induced differential morphologic and phenotypic changes in human osteoblast-like cells depending on the grade of the material.

Common genetic vulnerability for nicotine and alcohol dependence in men

BACKGROUND

Nicotine and alcohol dependence often occur together. We examined data from male twin pairs to determine whether there are genetic or environmental influences common to nicotine and alcohol dependence, and, if so, to estimate the magnitude and correlation of these influences.

METHODS

Subjects were 3356 male-male twin-pair members of the Vietnam Era Twin Registry who participated in a 1992 telephone administration of the Diagnostic Interview Schedule Version 3 Revised. Genetic model fitting was performed to estimate the magnitude and correlation of genetic and environmental contributions to lifetime nicotine and alcohol dependence.

RESULTS

The heritability of nicotine dependence was 60.3% (95% confidence interval [CI], 55.4%-65.2%); that of alcohol dependence, 55.1% (95% CI, 49.7%-60.5%). The best-fitting model for the co-occurrence of lifetime nicotine and alcohol dependence included a substantial genetic correlation between both disorders (r = 0.68; 95% CI, 0.61-0.74) and a modest unique environmental correlation (r = 0.23; 95% CI, 0.14-0.32).

CONCLUSIONS

These data suggest a common genetic vulnerability to nicotine and alcohol dependence in men. This common genetic influence may partially explain the clinical and epidemiological observations that alcoholics are often dependent smokers.

Using 3 data sources and methods to shape a nutrition campaign

The first objective of this research was to define a target population of African-American women more clearly. The second was to provide specific information about the needs and preferences of that population in order to design an effective, culturally relevant, community-based communications campaign to promote more healthful lifestyles. Data collection and analysis included the following: interviews with 10 community nutritionists and the director of the State Office of Nutrition, 6 focus groups with a total of 47 members of the target population, and direct observation and documentation of key community resources. This approach, called "triangulation," permits more in-depth understanding of issues, provides different perspectives on the problem, and helps ensure accuracy of conclusions. Interviews with nutritionists identified young African-American women as the appropriate target population for the campaign. These interviews and the focus-group discussions confirmed the acceptability of higher weight and better body-esteem among African-American women than among white women. Both the nutritionists and the focus-group members identified the need and desire for information and skills related to food preparation and provided specific direction for program content. Community observation confirmed the need for food markets with merchandise of consistently high quality, especially in the fresh and frozen produce sections. Observation also helped identify community services and programs. The 3 sets of data, which augmented a comprehensive literature review, provided a firm foundation for the campaign's design and development. Dietitians and nutritionists working in community settings can use triangulation to gain a better understanding of their populations in order to develop more effective interventions.

The heritability of alcoholism symptoms: "indicators of genetic and environmental influence in alcohol-dependent individuals" revisited

There is consistent evidence from twin and adoption studies implicating genetic factors in the etiology of alcoholism, yet few studies have examined the role of genetic influences on individual symptoms of alcoholism. In a previous study of 113 male twins, Johnson et al. (1996a) identified 7 alcoholism symptoms that were more "genetic" and 14 that were more "environmental" (that is, non-genetic) in their etiology by examining symptom concordances among monozygotic and dizygotic twin pairs. The present study represents an attempt to replicate the results of this previous study and extend them by estimating the contribution of genetic factors to the variation in liability for different alcoholism symptoms. Subjects were 3356 male twin pairs from the Vietnam Era Twin Registry. Lifetime histories of alcoholism symptoms were assessed by a structured psychiatric telephone interview. The results of the previous study were not replicated. The correlations between symptom classifications as genetic and non-genetic in the present and previous study were nonsignificant and ranged from -0.27 to 0.11. However, within the present study the correlation between symptom classifications as genetic and non-genetic was statistically significant across random split-half subsamples (r = 0.59); nine alcoholism symptoms were consistently classified as genetic and six symptoms as non-genetic in their etiology. Model-fitting analyses applied to different alcoholism symptoms yielded heritability estimates ranging from 0.03 to 0.53 with broad and overlapping confidence intervals around these estimates, ranging from 0.00 to 0.65. The results of this study highlight the difficulty of identifying more or less heritable phenotypes in twin research, and suggest that it may not be possible to identify specific alcoholism symptoms that are more genetic in their etiology than others. Nevertheless, there appears to be potentially important variation in the relative magnitude of genetic influences for individual alcoholism symptoms, and exploring these differences may lead to further insights into the nosology and etiology of alcohol-related problems.

Condylar cartilage response to continuous passive motion in adult guinea pigs: A pilot study

This article reports on the development and testing of a continuous passive motion device suitable for experimental animals and on the effect of 1 week of continuous passive motion on the thickness of the condylar cartilage in adult guinea pigs. Continuous passive motion is currently used for postsurgical joint therapy and consists of moving a synovial joint passively and constantly through its normal range of motion. In this study continuous passive motion was applied to the temporomandibular joints of two experimental animals for 7 hours per day for 5 days. Two animals were restrained for the same amount of time that the experimental animals were on the continuous passive motion machines (control group 1), and two animals were allowed normal cage activity (control group 2). Six weeks later all animals were sacrificed. Each mandibular condyle was sectioned sagitally, and routine histologic sections were prepared with hematoxylin-eosin stain. Microscopic examination of the mandibular condylar cartilage of the animals placed on continuous passive motion showed a marked increase in thickness compared with the condylar cartilage found on the control animals. The condylar cartilage of the animals placed on continuous passive motion averaged 345 microm, and the controls averaged 232 microm. These findings demonstrate the application of continuous passive motion in an experimental model and provide interesting information regarding the response of the mandibular condyle to increased motion. More studies are necessary to further investigate the effect of continuous passive motion on the condylar cartilage.

Structural and functional analysis of the ARF1-ARFGAP complex reveals a role for coatomer in GTP hydrolysis

The crystal structure of the complex of ARF1 GTPase bound to GDP and the catalytic domain of ARF GTPase-activating protein (ARFGAP) has been determined at 1.95 A resolution. The ARFGAP molecule binds to switch 2 and helix alpha3 to orient ARF1 residues for catalysis, but it supplies neither arginine nor other amino acid side chains to the GTPase active site. In the complex, the effector-binding region appears to be unobstructed, suggesting that ARFGAP could stimulate GTP hydrolysis while ARF1 maintains an interaction with its effector, the coatomer complex of COPI-coated vesicles. Biochemical experiments show that coatomer directly participates in the GTPase reaction, accelerating GTP hydrolysis a further 1000-fold in an ARFGAP-dependent manner. Thus, a tripartite complex controls the GTP hydrolysis reaction triggering disassembly of COPI vesicle coats.

Sociodemographic and health status characteristics with prostate cancer screening in a national cohort of middle-aged male veterans

OBJECTIVES

To characterize variables associated with obtaining prostate cancer screening in a nonclinical, nationally distributed, middle-aged male population.

METHODS

Telephone interviews were administered to 2652 individual members of the Vietnam Era Twin Registry in 1992 and 1995. Dependent variables were self-report measures of having had a digital rectal examination (DRE) and/or a prostate-specific antigen (PSA) test in the past 5 years. Independent variables were current measures of age, household income, education, race, insurance, source of care, and lifetime measures of physical condition, psychiatric illness, and alcohol and nicotine dependence.

RESULTS

Thirty-five percent of the sample reported having had a PSA and DRE within the past 5 years. Prevalence of obtaining either a PSA or DRE varied with age, income, education, and race. Subjects with a regular source of care, a regular physician, and health insurance reported higher rates of having had a DRE or PSA and DRE. Persons with a physical or psychiatric illness reported more screening. A multiple regression model revealed that having a regular source of care, having a regular physician, physical illness, psychiatric illness, minority status, higher income, and age predicted having had some form of screening.

CONCLUSIONS

A substantial portion of middle-aged men have had both a PSA and DRE performed at least once in the preceding 5 years. It may be possible to further improve prostate cancer screening participation by directing educational programs at men who are not in contact with the healthcare system. If the PSA and DRE screening guidelines that are finally adopted discourage screening among low-risk men younger than age 50, educational programs that emphasize age screening criteria may be warranted.

Comparison of a new triazole antifungal agent, Schering 56592, with itraconazole and amphotericin B for treatment of histoplasmosis in immunocompetent mice

A murine model of intratracheally induced histoplasmosis was used to evaluate a new triazole antifungal agent, Schering (SCH) 56592, for treatment of histoplasmosis. MICs were determined for SCH 56592, amphotericin B, and itraconazole by testing yeast-phase isolates from 20 patients by a macrobroth dilution method. The MICs at which 90% of the isolates are inhibited were for 0.019 microgram/ml for SCH 56592, 0.5 microgram/ml for amphotericin B, and < or = 0.019 microgram/ml for itraconazole. Survival studies were done on groups of 10 B6C3F1 mice with a lethal inoculum of 10(5). All mice receiving 5, 1, or 0.25 mg of SCH 56592 per kg of body weight per day, 2.5 mg of amphotericin B per kg every other day (qod), or 75 mg of itraconazole per kg per day survived to day 29. Only 44% of mice receiving 5 mg of itraconazole/kg/day survived to day 29. Fungal burden studies done in similar groups of mice with a sublethal inoculum of 10(4) showed a reduction in CFUs and Histoplasma antigen levels in lung and spleen tissue in animals treated with 2 mg of amphotericin B/kg qod, 1 mg of SCH 56592/kg/day, and 75 mg of itraconazole/kg/day, but not in those treated with lower doses of the study drugs (0.2 mg of amphotericin B/kg qod, 0.1 mg of SCH 56592/kg/day, or 10 mg of itraconazole/kg/day). Serum drug concentrations were measured 3 and 24 h after the last dose in mice (groups of five to seven mice), each treated for 7 days with SCH 56592 (10 and 1 mg/kg/day) and itraconazole (75 and 10 mg/kg/day). Mean levels measured by bioassay were as follows: SCH 56592, 10 mg/kg/day (2.15 micrograms/ml at 3 h and 0.35 microgram/ml at 24 h); SCH 56592, 1 mg/kg/day (0.54 microgram/ml at 3 h and none detected at 24 h); itraconazole, 75 mg/kg/day (22.53 micrograms/ml at 3 h and none detected at 24 h); itraconazole, 10 mg/kg/day (1.33 micrograms/ml at 3 h and none detected at 24 h). Confirmatory results were obtained by high-pressure liquid chromatography assay. These studies show SCH 56592 to be a promising candidate for studies of treatment of histoplasmosis in humans.

Full robotic assistance for laparoscopic tubal anastomosis: a case report

Optical magnification and long instrumentation significantly increase surgical tremor, which makes laparoscopic microsuturing difficult. Therefore, laparoscopic tubal anastomosis has not gained wide acceptance among gynecologic surgeons. Robotic assistance facilitates this type of procedure by filtering tremor, reducing the surgeon's fatigue, and scaling the maneuvers. The authors have successfully completed a case of laparoscopic tubal reanastomosis using a "master-slave" robot to perform the standard microsuturing technique. A 33-year-old woman, gravida 2, para 2, requested reversal of her previous tubal ligature. A right isthmic-isthmic tubal anastomosis was performed laparoscopically, with faithful adherence to the authors' standard technique applied at laparotomy. Full robotic assistance was used to anastomose the tube. A chromotubation test showed anastomotic patency without leak. The patient recovered uneventfully after surgery and was discharged within 24 h after the procedure. Laparoscopic microsurgical tubal anastomosis with full robotic assistance is feasible and safe in humans.

A five-stage model for sustaining a community campaign

The Sisters Together, Move More Eat Better pilot communication program focuses on young Black women in three inner-city communities to encourage improved nutrition and increased physical activity. The design for Sisters Together is based on an expansion of a public health campaign that combines social marketing with community building efforts. The pilot program design comprises five phases: design, promotion, demonstration, transfer, and sustained activity. The proposed five-stage model holds potential for increasing the life span of a campaign and contributing to community building. Partnerships and coalition development promise to maintain the campaign beyond the limited budget period. This descriptive article illustrates the elements of a hybrid model for the design of a communication program with examples from Sisters Together, Move More Eat Better, a pilot program currently in the last year of implementation.

Effect of peritoneal fluid from endometriosis patients on sperm motion characteristics and acrosome reaction

OBJECTIVE

To determine whether peritoneal fluid from women with endometriosis contributes to infertility by impairing sperm motion and functional characteristics.

METHODS

Women with endometriosis (n = 20) underwent laparoscopy for infertility or pelvic pain. Patients undergoing tubal ligation served as controls (n = 14). Peritoneal fluid was aspirated from women with endometriosis, or from women undergoing laparoscopic tubal ligation. Sperm motility, motion characteristics and acrosome reaction were assessed following incubation with peritoneal fluid.

RESULTS

Sperm motility, motion characteristics, and acrosome reaction did not differ significantly between the two groups after 3, 5, or 24 hours of incubation with peritoneal fluid.

CONCLUSIONS

Sperm motion or functional characteristics showed no significant impairment when sperm from normal donors were incubated with peritoneal fluid from patients with endometriosis. It is unlikely that peritoneal fluid in these patients contributes to infertility.

Effects of hyperbaric oxygen therapy on children with spastic diplegic cerebral palsy: a pilot project

Hyperbaric oxygen (HBO2) therapy for children with cerebral palsy (CP) is not new. Research documenting the effects in this population has been anecdotal. We evaluated the effects of HBO2 therapy for 25 children (X = 5.6 +/- 1.6 yr) with a functional diagnosis of spastic diplegic CP. Pre- and post-HBO2 evaluations consisted of the following measures: gross motor function measure (GMFM), fine motor function (Jebsen test for hand function), spasticity (modified Ashworth scale), video analysis, and parental questionnaire. The protocol for HBO2 therapy was 20 treatments of 95% oxygen at 1.75 atm abs for 60 min. The Wilcoxon matched-pairs signed-rank test for non-parametric measures was used to compare pre- and post-treatment data. Results showed improved gross motor function in three of the five items in the GMFM test, improved fine motor function in three of the six hand tests, reduced spasticity in three of four muscle groups when assessed by a physician specializing in CP, and improvements for four of nine questions posed to parents.

Co-occurrence of abuse of different drugs in men: the role of drug-specific and shared vulnerabilities

BACKGROUND

Previous research has demonstrated genetic and environmental influences on abuse of individual substances, but there is less known about how these factors may influence the co-occurrence of abuse of different illicit drugs.

METHODS

We studied 3372 male twin pairs from the Vietnam Era Twin Registry. They were interviewed using the Diagnostic Interview Schedule, Version III, Revised to investigate the extent to which the abuse of different categories of drugs occurs together within an individual, as well as the possibility that genetic and environmental factors are responsible for observed co-occurrence. Co-occurrence was quantified using odds ratios and conditional probabilities. Multivariate biometrical modeling analyses were used to assess genetic and environmental influences on co-occurrence.

RESULTS

Abusing any category of drug was associated with a marked increase in the probability of abusing every other category of drugs. We found evidence for a shared or common vulnerability factor that underlies the abuse of marijuana, sedatives, stimulants, heroin or opiates, and psychedelics. This shared vulnerability is influenced by genetic, family environmental, and nonfamily environmental factors, but not every drug is influenced to the same extent by the shared vulnerability factor. Marijuana, more than other drugs, was influenced by family environmental factors. Each category of drug, except psychedelics, had genetic influences unique to itself (ie, not shared with other drug categories). Heroin had larger genetic influences unique to itself than did any other drug.

CONCLUSION

There are genetically and environmentally determined characteristics that comprise a shared or common vulnerability to abuse a range of illicit drugs.

Structural basis for activation of ARF GTPase: mechanisms of guanine nucleotide exchange and GTP-myristoyl switching

Ras-related GTPases are positively regulated by guanine nucleotide exchange factors (GEFs) that promote the exchange of GDP for GTP. The crystal structure of the Sec7 domain GEF bound to nucleotide-free ARF1 GTPase has been determined at 2.8 A resolution and the structure of ARF1 in the GTP-analog form determined at 1.6 A resolution. The Sec7 domain binds to the switch regions of ARF1 and inserts residues directly into the GTPase active site. The interaction leaves the purine-binding site intact but perturbs the Mg2+ and phosphate groups to promote the dissociation of guanine nucleotides. The structure of ARF1 in the GTP-analog form closely resembles Ras, revealing a substantial rearrangement from the GDP conformation. The transition controls the exposure of the myristoylated N terminus, explaining how ARF GTPases couple the GDP-GTP conformational switch to membrane binding.

Why Americans eat what they do: taste, nutrition, cost, convenience, and weight control concerns as influences on food consumption

OBJECTIVE

To examine the self-reported importance of taste, nutrition, cost, convenience, and weight control on personal dietary choices and whether these factors vary across demographic groups, are associated with lifestyle choices related to health (termed health lifestyle), and actually predict eating behavior.

DESIGN

Data are based on responses to 2 self-administered cross-sectional surveys. The main outcomes measured were consumption of fruits and vegetables, fast foods, cheese, and breakfast cereals, which were determined on the basis of responses to questions about usual and recent consumption and a food diary.

SUBJECTS/SETTING

Respondents were a national sample of 2,967 adults. Response rates were 71% to the first survey and 77% to the second survey (which was sent to people who completed the first survey).

STATISTICAL ANALYSES

Univariate analyses were used to describe importance ratings, bivariate analyses (correlations and t tests) were used to examine demographic and lifestyle differences on importance measures, and multivariate analyses (general linear models) were used to predict lifestyle cluster membership and food consumption.

RESULTS

Respondents reported that taste is the most important influence on their food choices, followed by cost. Demographic and health lifestyle differences were evident across all 5 importance measures. The importance of nutrition and the importance of weight control were predicted best by subject's membership in a particular health lifestyle cluster. When eating behaviors were examined, demographic measures and membership in a health lifestyle cluster predicted consumption of fruits and vegetables, fast foods, cheese, and breakfast cereal. The importance placed on taste, nutrition, cost, convenience, and weight control also predicted types of foods consumed.

APPLICATIONS

Our results suggest that nutritional concerns, per sc, are of less relevance to most people than taste and cost. One implication is that nutrition education programs should attempt to design and promote nutritious diets as being tasty and inexpensive.

Higher order iminodiacetic acid libraries for probing protein-protein interactions

Higher order iminodiacetic acid diamide trimer (560 compounds) and tetramer libraries (1260 compounds) are described and were assembled in a convergent multistep solution-phase synthesis for use in studying protein-protein interactions.

Is geographic variation in hip fracture rates related to current or former region of residence?

This study examines geographic variation in male and female age-adjusted hip fracture rates in white elderly Medicare enrollees. We assembled a cohort of more than 2 million 1992 enrollees and followed them passively through record linkage for 2 years for a hospitalization containing a diagnostic code indicating hip fracture. We simultaneously estimated rate ratios by region of residence early (inferred from the Social Security number) and late in life. Residence region early in life is associated with substantial variation in hip fracture rates. Conversely, current region has little relation with hip fracture risk.

Contribution of emotionally traumatic events and inheritance to the report of current physical health problems in 4042 Vietnam era veteran twin pairs

OBJECTIVE

To determine the contributions of psychological trauma (exposure to combat during the Vietnam War), genetic factors, childhood experiences shared by twin siblings, and unmeasured experiences not shared by twin siblings to the reporting of current physical health problems a mean of 19 years after military service.

METHODS

In 1987, a national sample of 2224 monozygotic and 1818 dizygotic male veteran members of the Vietnam Era Twin Registry participated in a survey of health. Genetic modeling was performed on cross-sectional physical health and combat exposure data derived from Registry twins.

RESULTS

Combat experiences explained a small proportion (0.7-8.4%) of the variance in the report of hypertension, respiratory conditions, persistent skin conditions, gastrointestinal disorders, joint disorders, and hearing problems. Childhood experiences shared by siblings are not clearly related to any health problem studied. By contrast, genetic factors explain 31 to 54% and noncombat experiences not shared by siblings explain 45 to 66% of the variance in current physical health status.

CONCLUSIONS

Greater than 90% of the variance in reported current physical health problems in Vietnam era veterans is attributable to inherited factors and unmeasured environmental experiences not shared by twin siblings. The traumatic experience of combat makes only a small contribution to the report of current physical health problems. These results do not preclude the possibility that combat influenced the prevalence of illness shortly after military service or that combat may influence the development of illness in the future.

Familial influences on gambling behavior: an analysis of 3359 twin pairs

BACKGROUND

Pathological gambling is becoming an increasing problem in the United States as the number of legalized gambling establishments grows. To examine vulnerability to pathological gambling, we estimated the familial contributions (i.e. inherited factors and/or experiences shared by twin siblings during childhood) to DSM-III-R pathological gambling symptoms and disorder.

METHODS

Data were obtained from a telephone interview performed in 1991-92 utilizing the Diagnostic Interview Schedule Version III-Revised. Interviews were administered to 6718 members of the nationally distributed Vietnam Era Twin Registry of male-male monozygotic and dizygotic twin pairs who served in the military during the Vietnam era.

RESULTS

Inherited factors explain between 35% (95% CI: 28%, 42%) and 54% (95% CI: 39%, 67%) of the liability for the five individual symptoms of pathological gambling behavior that could be estimated statistically. In addition, familial factors explain 56% (95% CI: 36%, 71%) of the report of three or more symptoms of pathological gambling and 62% (95% CI: 40%, 79%) of the diagnosis of pathological gambling disorder (four or more symptoms).

CONCLUSIONS

Familial factors have an important influence on risk for pathological gambling behavior. The increasing access to legalized gambling is likely to result in a higher prevalence of pathological gambling behavior among individuals who are more vulnerable because of familial factors.

Hip fracture incidence among elderly Hispanics

OBJECTIVES

This study estimated hip fracture incidence for elderly Hispanics in the United States.

METHODS

A cohort of Spanish-surnamed 1992 Medicare enrollees was followed for 2 years. Hip fractures were identified by inpatient diagnostic code.

RESULTS

For Hispanic women, the national age-adjusted hip fracture rate was 7.3 per 1000 person-years; for men, the rate was 3.3. Rates varied markedly, with higher rates for the predominantly Mexican-American southwestern states than for Puerto Ricans.

CONCLUSIONS

Nationally, the Hispanic population is at intermediate risk of hip fracture between Blacks and Whites, but geographic variation suggests that Mexican Americans are at higher risk than Puerto Ricans.

Higher order iminodiacetic acid libraries for probing protein-protein interactions

Full details of the preparation of iminodiacetic acid diamide dimer (2040 compounds), trimer (560 compounds), and tetramer (1596 compounds) libraries by multistep convergent solution-phase synthesis for studying protein-protein interactions are provided. The libraries were assembled in a format providing small 8-10 compound mixtures and the deconvolution of many of the small mixtures to identify screening leads by resynthesis of the individual components have been conducted for 320 of the individual compounds to date. A representative example of the subsequent exploration of the structure-activity relationships for an identified receptor binding antagonist (200 additional individual compounds) and steps taken for potential elaboration to a receptor dimerization agonist are defined with preparation of representative linked dimers (70 compounds).

Average African American three-dimensional computed tomography skull images: the potential clinical importance of ethnicity and sex

The production of average 'normative' three-dimensional (3D) computed tomography surface images of the bony skull has only recently been explored. The authors wish to determine the effect of using sex- and ethnicity-specific adult average 3D skull images for comparisons with patient images at various stages of craniofacial surgical management (i.e., diagnosis, treatment planning, prosthetic design, image-guided operative procedures, and outcomes assessment). Craniofacial surgical reconstruction for abnormal patterns of development, cancer resection, or trauma are most likely to benefit from these comparisons. To morphometrically test the significance of separating normative 3D skull data by sex and ethnicity, the authors collected 52 3D, anatomical landmarks from 3D computed tomography scans of dry skulls of 20 Americans of European ethnicity and 20 Americans of primarily African (i.e., primarily African and some European) ethnicity. A Procrustes-based morphometric analysis of shape detects 1.2 times as much interethnic variance as intersex variance. The African American sample presents 4.2% more dolichocephaly, wider orbits, flatter nasal area, larger gnathic anatomy, and more procumbent dentition. Pooling the sexes across both groups, it is seen that men tend to have less bulbous crania, more protruding brows, noses, and masticatory muscle attachments, and relatively less protrusive palettes and anterior mandibles. Despite a small sample size (N = 40), the authors' results are statistically significant (P approximately 0.001 overall) for both of the main factors, sex and ethnicity, separately.

[Presence of acinar pancreas in reflux esophagitis and Barrett's esophagus]

Pancreatic metaplasia in Barrett's esophagus was originally described by Krishnamurthy et al. They found that these focal clusters of cells resemble pancreatic acinar cells by immunohistochemistry and electron microscopy. Wang et al one year later, described these same cell clusters in normal and inflamed gastroesophageal junction. We studied 318 cases diagnosed as Barrett's esophagus (199 cases) and chronic esophagitis (119 cases) in the ABC Medical Center seen in 1996 and the first four months of 1997, to look for pancreatic acinar metaplasia. We found 14 cases of Barrett's esophagus and 11 cases of chronic esophagitis with pancreatic acinar metaplasia. By immunohistochemistry and electron microscopy that these cell clusters are actually acinar pancreatic cells. Our results are in keeping with those found by Krishnamurthy and Wang that the clusters represent pancreatic acinar cells and may be found in Barrett's esophagus and in chronic esophagitis. The significance of these findings remain to be elucidated.

Modelling ordinal responses from co-twin control studies

The co-twin control design has been widely used in studying the effects of environmental factors on the development of diseases. For binary outcomes that arise from co-twin control studies, the conditional likelihood method is commonly used. This approach, however, does not readily extend to ordinal response data because the standard conditional likelihood does not exist for cumulative logit or proportional odds models. In this paper, we investigate the applicability of the random-effects and GEE approaches in analysing ordinal response data from co-twin control studies. Using both approaches, we re-analyse data from a co-twin control study of the impact of military services during the Vietnam era on post-traumatic stress disorders (PTSD). The ordinal models have considerably increased power in detecting the effects of exposure when compared to the analyses using a dichotomized response. We discuss the interpretation of the estimates from GEE and random-effect models in the context of the twin data.

A registry-based twin study of depression in men

BACKGROUND

The only large, registry-based twin study of depression using diagnostic criteria assessed by structured interview included only women. We present results from a comparable study of men.

METHODS

Data were collected using a standardized telephone interview of men from the Vietnam Era Twin Registry. Both twins from 3372 pairs participated. Proband-wise concordance rates and biometric modeling were used to analyze the data.

RESULTS

The diagnosis of major depression (MD), as defined by DSM-III-R, and the subtype of severe/psychotic MD were significantly affected by genetic (h2=0.36 and 0.39, respectively) and nonshared environmental (e2=0.64 and 0.61, respectively) factors but not by family environmental factors. Dysthymia and mild and moderate MD were affected by family environmental (c2=0.27, 0.08, and 0.14, respectively) and nonshared environmental (e2=0.73, 0.92, and 0.86, respectively) factors but not by genetic factors. Early-onset (before age 30 years) and late-onset (after age 30 years) MD were significantly affected by genetic (h2=0.47 and 0.10, respectively) and nonshared environmental (e2=0.53 and 0.90, respectively) factors. Early-onset MD was significantly more heritable than late-onset MD.

CONCLUSIONS

The magnitude of genetic and environmental effects on depression in men is similar to that previously reported in women. Also similar to previous findings, more severe and earlier-onset depression may be more strongly affected by genetic factors, but differences in the reliability of reports of depression associated with severity may inflate estimates of the effect of the unique environment and deflate heritability estimates for less severe depression.

Long-term reliability and validity of alcoholism diagnoses and symptoms in a large national telephone interview survey

The long-term reliability and validity of telephone lay interview assessments of alcoholism were examined in the context of a large national community-based survey of over 8,000 male Vietnam era veterans. A subsample of 146 men was interviewed twice by telephone using the same structured interview an average of 15 months apart to evaluate the long-term reliability of alcoholism symptoms and diagnoses. In addition, a search of Department of Veterans Affairs patient treatment files of inpatient hospitalizations between 1970 and 1993 yielded a subsample of 89 interviewed men with a past discharge diagnosis of alcohol dependence. The test-retest reliability of alcohol abuse and alcohol dependence diagnoses was good, with kappa coefficients of 0.74 and 0.61, respectively. The reliability of individual alcoholism symptoms was fair to good, with kappas of 0.46 to 0.67. Ninety-six percent of individuals identified by Department of Veterans Affairs patient treatment files as having an alcohol dependence diagnosis were correctly diagnosed by the telephone interview. The results of the present study provide additional evidence for the long-term reliability and validity of lifetime alcoholism diagnoses, and suggest that the reliability and validity of telephone interview assessments of alcoholism are as good as that of an in-person interview. Telephone administration of structured psychiatric interviews appears to be an attractive alternative to in-person interviewing for gathering information about alcoholism and alcohol-related problems.

Comparison of population-averaged and subject-specific approaches for analyzing repeated binary outcomes

Several approaches have been proposed to model binary outcomes that arise from longitudinal studies. Most of the approaches can be grouped into two classes: the population-averaged and subject-specific approaches. The generalized estimating equations (GEE) method is commonly used to estimate population-averaged effects, while random-effects logistic models can be used to estimate subject-specific effects. However, it is not clear to many epidemiologists how these two methods relate to one another or how these methods relate to more traditional stratified analysis and standard logistic models. The authors address these issues in the context of a longitudinal smoking prevention trial, the Midwestern Prevention Project. In particular, the authors compare results from stratified analysis, standard logistic models, conditional logistic models, the GEE models, and random-effects models by analyzing a binary outcome from two and seven repeated measurements, respectively. In the comparison, the authors focus on the interpretation of both time-varying and time-invariant covariates under different models. Implications of these methods for epidemiologic research are discussed.

Attitudes about genetic risk of couples undergoing in-vitro fertilization

Many couples undergoing in-vitro fertilization (IVF) are at a higher risk of having a child with a genetic abnormality. In a sample of 55 consecutive couples starting IVF, only 33% had no genetic risk factor. The most common genetic risks were advanced maternal age and possible abnormalities associated with severe male infertility. Despite education on these risks, 71% of couples had no interest in receiving formal genetic counselling. Only 14% of couples at risk would consider using a gamete donor to avoid transmitting a genetic disorder to a child. The triple test to screen for fetal abnormalities was acceptable to 82% of couples, but only 47% planned to have amniocentesis or chorionic villi sampling. Couples were significantly more likely to opt for prenatal testing if they would consider terminating a pregnancy should the fetus have a severe genetic abnormality (P < 0.01). Roman Catholic couples tended to have more conservative attitudes about pregnancy termination. Socio-economic status and whether the infertility factor was male or female were not predictors of a couple's attitudes.

[Doxycycline-induced esophageal ulcers]

Tetracycline is known as one of the antibiotics that induce esophageal ulcers.

PURPOSE

Understand how these ulcers may behave and respond to treatment with sucralfate.

METHOD

During the last two years we studied all patients complaining of dysphagia and odinophagia with an upper GI endoscopy, who were taking doxycycline in the last few days. All of them discontinued the drug once the diagnosis was done and most of them were treated also with sucralfate, 1 g tid.

RESULTS

Eleven patients took doxycycline prescribed for: pelvic inflammatory disease, acne, urinary tract and pulmonary infections. Odinophagia was the most common symptom over the next few days of treatment with some risk factors previously documented, such as taking pills just before bedtime and with a small amount of water. The esophageal ulcers were multiple and located mainly in the middle esophageal third. Symptoms disappeared 3.7 days after the medication was stopped, while those taking sucralfate did not change the period of symptoms.

CONCLUSIONS

Physicians must be aware of the doxycycline induced esophageal ulcers and discontinuation of the antibiotic as the main treatment, while sucralfate even though has shown to cover these ulcers, does not change the outcome. Therefore, they must encourage then patients to take the pills with enough liquid, in supine position and have special attention to the elderly and those with any kind of esophageal disease.

Mechanisms of asbestos-induced nitric oxide production by rat alveolar macrophages in inhalation and in vitro models

To evaluate the contribution of reactive nitrogen species to inflammation by asbestos, Fischer 344 rats were exposed to crocidolite or chrysotile asbestos by inhalation to determine whether increases occurred in nitric oxide (NO.) metabolites from alveolar macrophages (AMs). AMs from animals inhaling asbestos showed significant elevations (p < .05) in nitrite/nitrate levels which were ameliorated by NG-monomethyl-L-arginine (NMMA), an inhibitor of inducible nitric oxide synthase (iNOS) activity. Temporal patterns of NO. generation from AMs correlated with neutrophil influx in bronchoalveolar lavage samples after asbestos inhalation or bleomycin instillation, another model of pulmonary fibrosis. To determine the molecular mechanisms and specificity of iNOS promoter activation by asbestos, RAW 264.7 cells, a murine macrophage-like line, and AMs isolated from control rats were exposed to crocidolite asbestos in vitro. These cells showed increases in steady-state levels of iNOS mRNA in response to asbestos and more dramatic increases in both iNOS mRNA and immunoreactive protein after addition of lipopolysaccharide (LPS). After transfection of an iNOS promoter/luciferase reporter construct, RAW 264.7 cells exposed to LPS, crocidolite asbestos and its nonfibrous analog, riebeckite, revealed increases in luciferase activity whereas cristobalite silica had no effects. Studies suggest that NO. generation may be important in cell injury and inflammation by asbestos.