Development and validation of an instrument to measure the impact of genetic testing on self-concept in Lynch syndrome.

A positive genetic test result may impact on a person's self-concept and affect quality of life. The purpose of the study was to develop a self-concept scale to measure such impact for individuals carrying mutations for a heritable colorectal cancer Lynch syndrome (LS). Two distinct phases were involved: Phase 1 generated specific colorectal self-concept candidate scale items from interviews with eight LS carriers and five genetic counselors, which were added to a previously developed self-concept scale for BRCA1/2 mutation carriers, Phase II had 115 LS carriers complete the candidate scale and a battery of validating measures. A 20-item scale was developed with two dimensions identified through factor analysis: stigma/vulnerability and bowel symptom-related anxiety. The scale showed excellent reliability (Cronbach's α = 0.93), good convergent validity by a high correlation with impact of event scale (r(102) = 0.55, p < 0.001) and Rosenberg self-esteem scale (r(108) = -0.59, p < 0.001), and a low correlation with the Fear questionnaire (r(108) = 0.37, p < 0.001). The scale's performance was stable across participant characteristics. This new scale for measuring self-concept has potential to be used as a clinical tool and as a measure for future studies.

Characterization of the rat GAD67 gene promoter reveals elements important for basal transcription and glucose responsiveness.

GAD65 and GAD67 are two isoforms of the enzyme glutamic acid decarboxylase which catalyze the production of GABA from glutamate, primarily in the brain. However, GAD and GABA also prevail in the retina, testes and islets of Langerhans. The main function of GABA is in neurotransmission, and it is involved in paracrine signalling in islets, but has also been suggested to play a role as a trophic factor in synaptogenesis and to be an important metabolite feeding into the tricarboxylic acid cycle via the GABA-shunt. Both GAD isoforms are subject to regulation, e.g. by synaptic activity. GAD65 is regulated at the level of enzyme activity by association and dissociation from its cofactor, PLP, whereas GAD67 is controlled at the level of its mRNA. To study this process in further detail, we have isolated and characterized the 5'-flanking region of the rat GAD67 gene. We report the transcriptional initiation sites and promoter sequences important for expression in islet beta-cells and C6 glioma cells, and demonstrate that the GAD67 promoter harbors elements that are responsive to glucose in primary islet cells.

Mammography utilization after a benign breast biopsy among Hispanic and non-Hispanic women.

BACKGROUND: In spite of the effectiveness of mammography screening for early detection of breast carcinoma, the use of screening mammography varies widely across racial and ethnic groups. Recently, concerns have been raised about the potential adverse effect a benign breast biopsy may have on subsequent mammography utilization, including subsequent use among minority women. METHODS: Computerized health care claims data for 1991 through 1997 from a managed care organization were used to compare mammography use among Hispanic and non-Hispanic women who had had a mammogram followed by an incisional or excisional benign breast biopsy to women who had had a mammogram and no biopsy. Through survival analysis methods, the time-to-next mammogram was compared among these three groups. RESULTS: The sample included 693 (3.2%) and 289 (1.3%) women who had had a mammogram followed by an incisional biopsy or an excisional biopsy, respectively, and 20,540 (95.4%) women who had had a mammogram and no biopsy. Both Hispanic and non-Hispanic women with a biopsy returned sooner for subsequent mammograms than women without a biopsy (P < 0.0001). Hispanic women without a biopsy returned later than non-Hispanic women without a biopsy (P < 0.0001). However, Hispanic women with an excisional biopsy returned sooner than non-Hispanic women (P < 0.05). CONCLUSIONS: Within a managed care organization, both Hispanic and non-Hispanic women who had had a mammogram followed by a benign breast biopsy returned sooner for a subsequent mammogram than women who had had a mammogram and no biopsy. However, ethnic differences in time-to-next mammogram were observed for women without a biopsy and those with an excisional biopsy. Hispanic women without a biopsy returned later for a subsequent mammogram than non-Hispanic women in similar groups, but those with an excisional biopsy returned sooner.

The excess costs of breast cancer health care in Hispanic and non-Hispanic female members of a managed care organization.

The differences in costs for health care services between women with breast cancer and those without were estimated for Hispanic and non-Hispanic members of a managed care organization. A total of 317 cases of breast cancer and 949 controls were selected using a comprehensive patient database. All health care costs for the 4-12 months prior to the case's diagnosis and for the 12 months following the case's diagnosis were obtained. Costs were defined as charges to the health plan. Mean differences in total health care costs between cases and controls were predicted using Tobit models for 4-12 months prior to diagnosis and the year after diagnosis by age group. Compared to controls, women diagnosed with in situ breast cancers in all age groups had significantly higher health care costs 4-12 months prior to diagnosis. For women under 50 years of age, the difference in costs for cases compared to controls 12 months after diagnosis was almost three times greater for women with regional/distant disease ($17,093 +/- $1,559) compared to in situ disease ($5,089 +/- $1,050). For women in the two other age groups (50-70 years and over 70 years), the difference was over twice as great for those with regional/distant disease compared to those with in situ disease. Mean differences between cases and controls in health care costs 12 months after diagnosis were similar for Hispanic and non-Hispanic women for all stages of disease.

The PDX-1 activation domain provides specific functions necessary for transcriptional stimulation in pancreatic beta-cells.

PDX-1 is a homeodomain transcription factor whose targeted disruption results in a failure of the pancreas to develop. Mutations in the human pdx-1 gene are linked to an early onset form of non-insulin-dependent diabetes mellitus. PDX-1 binds to and transactivates the promoters of several physiologically relevant genes within the beta-cell, including insulin, glucose transporter 2, glucokinase, and islet amyloid polypeptide. This study focuses on the mechanisms by which PDX-1 activates insulin gene transcription. To evaluate the role of PDX-1 in transcription of the insulin gene, a chloramphenicol acetyltransferase reporter construct was designed with a single yeast GAL4-DNA binding site in place of the A3/PDX-1 binding element in the rat insulin II enhancer. In the presence of GAL4:PDX chimeras containing N-terminal transactivation domain sequences, this GAL4-substituted insulin construct was active in PDX-1-expressing beta-cells and not non-beta-cells. PDX-1 activation was mediated through three highly conserved segments of the transactivation domain. In addition, when cotransfected together with the GAL4-substituted insulin enhancer reporter gene in glucose-responsive MIN-6 beta-cells, glucose-induced activation is observed with GAL4:PDX-1 but not with fusions of the heterologous activation domains from herpes virus VP16 or adenovirus-5 E1A proteins. Using A3 element-substituted GAL4 insulin enhancer reporter constructs containing mutations in two additional key control elements, E1 and C1, we also show that full activation requires cooperative interactions between other enhancer-bound factors, particularly the E1 element activators. In contrast, the activity of the VP16 activation factor was not dependent on the activators of either the E1 or C1 sites. These results suggest that the PDX-1 transactivation domain is specifically required for appropriate regulation of insulin enhancer function in beta-cells.

Health care utilization in chronic obstructive pulmonary disease. A case-control study in a health maintenance organization.

BACKGROUND: Information about health care utilization and costs among patients with chronic obstructive pulmonary disease (COPD) is needed to improve care and for appropriate allocation of resources for patients with COPD (COPD patients or cases) in managed care organizations. METHODS: Analysis of all inpatient, outpatient, and pharmacy utilization of 1522 COPD patients continuously enrolled during 1997 in a 172,484-member health maintenance organization. Each COPD case was matched with 3 controls (n = 4566) by age (+/-5 years) and sex. Information on tobacco use and comorbidities was obtained by chart review of 200 patients from each group. RESULTS: Patients with COPD were 2.3 times more likely to be admitted to the hospital at least once during the year, and those admitted had longer average lengths of stay (4.7 vs 3.9 days; P<.001). Mean costs per case and control were $5093 vs $2026 for inpatient services, $5042 vs $3050 for outpatient services, and $1545 vs $739 for outpatient pharmacy services, respectively (P<.001 for all differences). Patients with COPD had a longer smoking history (49.5 vs 34.9 pack-years; P =.002) and a higher prevalence of smoking-related comorbid conditions and were more likely to use cigarettes during the study period (46.0% vs 13.5%; P<.001). CONCLUSIONS: Health care utilization among COPD patients is approximately twice that of age- and sex-matched controls, with much of the difference attributable to smoking-related diseases. In this health maintenance organization, inpatient costs were similar to and outpatient costs were much higher than national averages for COPD patients covered by Medicare.

A comparison of two methods for estimating the health care costs of epilepsy.

PURPOSE: Previous studies have estimated medical care costs of epilepsy by applying unit costs to estimated utilization or by summing costs for (a) ambulatory care and hospitalizations coded as epilepsy and (b) procedures and drugs specifically associated with the diagnosis or treatment of epilepsy. These methods may underestimate the cost of medical care for epilepsy. Two methods for estimating the medical care costs of epilepsy ("epilepsy-attributable cost method" and "case-control cost method") were compared. METHODS: The study population was 655 individuals with an epilepsy diagnosis enrolled in a managed care plan in the southwestern United States. The epilepsy-attributable costs were determined by summing costs for inpatient and outpatient encounters coded as epilepsy, procedures for the diagnosis or treatment of epilepsy, and drugs used to treat epilepsy. The case-control method determined costs by calculating the difference in total costs between cases and 1,965 age- and gender-matched controls. RESULTS: The case-control epilepsy costs were $2,923 per case compared with epilepsy-attributable costs of $1,335 per case. The case-control method found statistically significant differences in costs between cases and controls for inpatient care, prescription drugs, and 8 of 11 categories of outpatient care. The largest contributors to the discrepancy between estimates were inpatient care, emergency department care, laboratory tests, and "other specialist" care. CONCLUSIONS: Epilepsy-attributable costs accounted for only 46% of the total difference in costs between epilepsy cases and controls. Persons with epilepsy use more medical services than controls, but a substantial portion of this care is not coded to epilepsy.

NeuroD/BETA2 gene variability and diabetes: no associations to late-onset type 2 diabetes but an A45 allele may represent a susceptibility marker for type 1 diabetes among Danes. Danish Study Group of Diabetes in Childhood, and the Danish IDDM Epidemiology and Genetics Group.

Mutations in the NeuroD/BETA2 gene have been shown to associate with type 2 diabetes. In the present study, we examined mutations in the NeuroD/BETA2 gene for association with either type 1 or 2 diabetes. Three variants were identified in patients with type 2 diabetes: Ala45Thr (allelic frequency 0.36, 95% CI 0.31-0.41), Pro197His (0.01), and Ser259Ser (0.01). Ala45Thr and Pro197His were not associated with type 2 diabetes, but the transmission disequilibrium test showed unequal transmission of the A45 allele to offspring with type 1 diabetes (chi2 = 5.90, P < 0.02, odds ratio 1.55, 95% CI 0.91-2.63). This association could not be explained by linkage disequilibrium between the Ala45 allele and IDDM7 (D2S152), which is also located on chromosome 2q32. When tested in vitro, the biological activity of Thr45 (117+/-36% vs. Ala45) and His197 (90+/-28% vs. Pro197) on the regulation of the human insulin gene promoter appeared normal. In conclusion, mutations in the NeuroD/BETA2 gene are not a common cause of late-onset type 2 diabetes among Danes. However, in the type 1 diabetic Danish population, the Ala45Thr variant of NeuroD/BETA2 may represent a susceptibility marker independent of IDDM7 on chromosome 2q32.

Pax4 represses pancreatic glucagon gene expression.

The paired box and homeodomain containing transcription factors Pax4 and Pax6 are known to be essential for development of the pancreatic endocrine cells. In this report we demonstrate that stable expression of Pax4 in a rat glucagon-producing cell line inhibits the endogenously expressed glucagon gene completely. Furthermore, Pax4 represses Pax6 independent transcription of the insulin promoter, suggesting that Pax4 can actively repress transcription in addition to acting by competition with the transcriptional activator Pax6.

Utilization in COPD: patient characteristics and diagnostic evaluation.

STUDY OBJECTIVES: Information on current practices of COPD diagnosis and treatment is needed to identify opportunities for improving care. This study describes the clinical characteristics and diagnostic evaluations of COPD patients in a health maintenance organization (HMO) and a university-affiliated county medical center (UMC). DESIGN: Cross-sectional survey performed in a 174,484-member regional HMO and in The University of New Mexico Hospitals and Clinics (UNMH). PATIENTS: Two hundred COPD patients from each system randomly selected from administrative databases based on discharge diagnoses. RESULTS: COPD patients in the UMC, compared to those in the HMO, were younger (mean age, 59.3 vs 66.9 years, respectively), were more likely to be using home oxygen (33% vs 20%, respectively), and had fewer chronic medical conditions (mean number of conditions, 3.1 vs 3.7, respectively) (p < 0.01 for all differences). Approximately half of the COPD patients in both groups continued to smoke cigarettes during the study year. Only 38% of patients in the HMO and 42% in the UNMH system had spirometry results documented in their medical records. CONCLUSIONS: The demographic and clinical characteristics of the COPD patients in these two health-care systems were very different, but smoking status and utilization of diagnostic tests were similar. The diagnosis of COPD in most patients was based only on a history of chronic respiratory symptoms and smoking; spirometry often was not used to confirm the diagnosis. An increased emphasis on smoking cessation and more effective utilization of spirometry are needed to improve the management of COPD in these health-care systems.

Missense mutations in the human insulin promoter factor-1 gene and their relation to maturity-onset diabetes of the young and late-onset type 2 diabetes mellitus in caucasians.

Increasing evidence suggests that defects in genes encoding transcription factors that are expressed in the pancreatic beta-cells may be important contributors to the genetic basis of type 2 diabetes mellitus. Maturity-onset diabetes of the young (MODY) now exists in five subtypes (MODY1-5), four of which are caused by mutations in transcription factors hepatocyte nuclear factor-4alpha (HNF-4alpha), HNF-1alpha, insulin promoter factor-1 (IPF-1), and HNF-1beta (MODY1, -3, -4, and -5). Recent evidence from the British population even suggested that IPF-1 may be a predisposing gene for type 2 diabetes. Thus, highlighting the potential role of this transcription factor in the genetic basis of Danish and Italian MODY as well as in Danish patients with late-onset type 2 diabetes mellitus, we have examined the human IPF-1 gene for mutations by single strand conformation polymorphism and heteroduplex analysis in 200 Danish patients with late-onset type 2 diabetes and in 44 Danish and Italian MODY patients. In the patients with late-onset type 2 diabetes we identified a noncoding G insertion/deletion polymorphism at nucleotide -108, a silent G54G, and a rare missense D76N variant. Moreover, a Danish MODY patient was carrier of an A140T variant. Neither the D76N nor the A140T segregated with diabetes, and their transcriptional activation of the human insulin promoter expressed in vitro was indistinguishable from that of the wild type (115 +/- 21% and 84 +/- 12% vs. 100%). We conclude that variants in IPF-1 are not a common cause of MODY or late-onset type 2 diabetes in the Caucasian population, and that in terms of insulin transcription both the N76 and the T140 mutations are likely to represent functionally normal IPF-1 variants with no direct role in the pathogenesis of MODY or late-onset type 2 diabetes mellitus.

Pax6 and Cdx2/3 form a functional complex on the rat glucagon gene promoter G1-element.

Alpha-cell specific transcription of the glucagon gene is mainly conferred by the glucagon promoter G1-element, while additional elements G2, G3, and G4 have broad islet cell specificity. Transcription of the glucagon gene has been shown to be stimulated by Pax6 through binding to the glucagon gene promoter G3-element. In this report, we show that Pax6 additionally binds the glucagon gene promoter G1-element and forms a transcriptionally active complex with another homeodomain protein, Cdx2/3. Two distinct mutations in the G1-element, that both reduce promoter activity by 85-90%, is shown to eliminate binding of either Pax6 or Cdx2/3. Additionally, Pax6 enhanced Cdx2/3 mediated activation of a glucagon reporter in heterologous cells. We discuss how Pax6 may contribute to cell-type specific transcription in the pancreatic islets by complex formation with different transcription factors.

Pax6 and Pdx1 form a functional complex on the rat somatostatin gene upstream enhancer.

The somatostatin upstream enhancer (SMS-UE) is a highly complex enhancer element. The distal A-element contains overlapping Pdx1 and Pbx binding sites. However, a point mutation in the A-element that abolishes both Pdxl and Pbx binding does not impair promoter activity. In contrast, a point mutation that selectively eliminates Pdx1 binding to a proximal B-element reduces the promoter activity. The B-element completely overlaps with a Pax6 binding site, the C-element. A point mutation in the C-element demonstrates that Pax6 binding is essential for promoter activity. Interestingly, a block mutation in the A-element reduces both Pax6 binding and promoter activity. In heterologous cells, Pdx1 potentiated Pax6 mediated activation of a somatostatin reporter. We conclude that the beta/delta-cell-specific activity of the SMS-UE is achieved through simultaneous binding of Pdx1 and Pax6 to the B- and C-elements, respectively. Furthermore, the A-element appears to stabilise Pax6 binding.

Glucose stimulates the activation domain potential of the PDX-1 homeodomain transcription factor.

Glucose-stimulated expression of the insulin gene in beta cells is mediated by the PDX-1 transcription factor. In this report, we show that stimulation results from effects on activation and DNA-binding potential. Thus, glucose specifically stimulated expression in MIN6 beta cells from chimeras of PDX-1 and the GAL4 DNA-binding domain which spanned the N-terminal PDX-1 activation domain located between amino acids 1 to 79. GAL4:PDX activity was induced over physiological glucose concentrations and was also regulated by effectors of this response. The level of endogenous PDX-1 binding and phosphorylation were also induced under these conditions. We discuss how changes in PDX-1 phosphorylation may influence activity in glucose-treated beta cells.

Mammography screening and breast cancer tumor size in female members of a managed care organization.

A study of temporal trends in mammography screening and changes in stage of disease at diagnosis was conducted among Hispanic and non-Hispanic white female members of the Lovelace Health Plan, Flexcare Plan, and Lovelace Senior Plan/Senior Options (LHP), a managed care organization. Two-year screening rates for female members ages 50-74 years were calculated for 1989-1996. From 1989-1996, mammography screening rates for non-Hispanic white female members increased from 65.5 to 71.6%, although this was not a statistically significant increase. Screening rates for Hispanic female members also increased from 50.6 to 62.7%, but they were significantly lower than for non-Hispanic white women. All breast cancers occurring among LHP female members ages 40-74 years were also identified for this same time period. A logistic regression model adjusting for age, year of diagnosis, ethnicity, and duration of enrollment prior to diagnosis found that statistically significant predictors of more advanced stage of disease at diagnosis included young age, diagnosis after 1991 for non-Hispanic white women, and diagnosis prior to 1992 for Hispanic women. Longer duration of enrollment prior to diagnosis was predictive of lower stage of disease, but the odds ratio was not statistically significant. For the time period 1992-1996, Hispanic women with breast cancer were more than twice as likely to have advanced stage of breast cancer compared with non-Hispanic white women (odds ratio, 2.12).

Transcription factors contributing to the pancreatic beta-cell phenotype.

Insulin promoter factor-1 (IPF1) (renamed to pancreatic-duodenal homeobox factor-1, PDX1) was originally cloned and characterized as an islet beta-cell specific insulin gene transcription factor (1) and later shown to be essential for the formation of the mature pancreas (2, 3). In the adult normal pancreas PDX1 is almost exclusively expressed in the beta-cell compartment and generally absent from the alpha-cell while it is widely expressed in the pancreatic epithelium during development. Using pluripotent rat islet tumor cultures and derived insulinomas and glucagonomas we have analyzed differential expression of a large number of genes including the transcription factors PDX1, Nkx6.1, Pax6, and NeuroD. While NeuroD and Pax6 expression was detectable among all phenotypes, PDX1 was expressed in the pluripotent culture and maintained in the insulinoma, while Nkx6.1 was selectively co-induced with insulin during insulinoma formation. Both factors were not detectable in the glucagonoma. Nkx6.1 proved to have a highly beta-cell restricted expression in the adult rat. Forced expression of recombinant PDX1 in the glucagonoma resulted in efficient transcriptional activation of the endogenous insulin and IAPP genes, but did not affect glucagon gene activity. In this hybrid alpha/beta-cell phenotype the endogenous Nkx6.1 gene remained silent. We conclude that PDX1 in synergy with NeuroD specifies part of the beta-cell phenotype including transcriptional activation of insulin and IAPP genes, but that other factors such as Nkx6.1 and Pax6 are required for additional features of the fully mature beta-cell phenotype.

Pancreatic development and maturation of the islet B cell. Studies of pluripotent islet cultures.

Pancreas organogenesis is a highly regulated process, in which two anlage evaginate from the primitive gut. They later fuse, and, under the influence of the surrounding mesenchyme, the mature organ develops, being mainly composed of ductal, exocrine and endocrine compartments. Early buds are characterized by a branching morphogenesis of the ductal epithelium from which endocrine and exocrine precursor cells bud to eventually form the two other compartments. The three compartments are thought to be of common endodermal origin; in contrast to earlier hypotheses, which suggested that the endocrine compartment was of neuroectodermal origin. It is thus generally believed that the pancreatic endocrine-lineage possesses the ability to mature along a differentiation pathway that shares many characteristics with those of neuronal differentiation. During recent years, studies of insulin-gene regulation and, in particular, the tissue-specific transcriptional control of insulin-gene activity have provided information on pancreas development in general. The present review summarizes these findings, with a special focus on our own studies on pluripotent endocrine cultures of rat pancreas.

Strategic disaster preparedness and response: implications for military medicine under joint command.

With the end of the Cold War, renewed emphasis has been placed on humanitarian assistance such as disaster relief, refugee management, and humanitarian intervention during conflicts by the military forces of all nations. The role of the military in humanitarian assistance has been the subject of much recent debate, as the ability of the United States to mount an effective emergency response is linked to our nation's strategic policy and planning. This article describes and broadens the understanding of the evolving concepts of strategic disaster management and the role of Joint Military Commands in providing disaster relief. Examples of strategic humanitarian relief operations are discussed.

The homeodomain protein IPF-1/STF-1 is expressed in a subset of islet cells and promotes rat insulin 1 gene expression dependent on an intact E1 helix-loop-helix factor binding site.

The mouse homeodomain protein insulin promoter factor-1 (IPF-1) and the rat homologue somatostatin transactivating factor-1 (STF-1) are involved in early pancreatic development and have been implicated in the cell-specific regulation of insulin- and somatostatin-gene expression in mature islet beta- and delta-cells. The cell specificity of IPF-1/STF-1 expression in mature islets is, however, still unclear. Using antisera against recombinant IPF-1 and STF-1 in combination with antisera against islet hormones we find that all beta-cells in monolayers of newborn rat islet cells express STF-1, as do a fraction of the delta-cells. In adult rat and mouse pancreas we find a similar distribution. IPF-1/STF-1 expression was not detected in glucagon-producing alpha-cells. In islet cell tumour models we found that a glucagon/islet amyloid polypeptide (IAPP)-producing pluripotent rat islet cell line (NHI-6F-GLU) expresses STF-1 in all cells prior to insulin gene activation induced by in vivo culture. In contrast, a mouse alpha-cell line (alpha TC1) exclusively expressed IPF-1 in a small subset of insulin-producing cells while an insulin-negative subclone (alpha TC1.9) was negative for IPF-1. In transfection experiments using alpha TC1.9 cells STF-1 activated a rat insulin 1 reporter gene dependent not only on both STF-1-binding sites, but also on the E1-binding site for the helix-loop-helix factor IEF-1. However, the endogenous mouse insulin genes remained inactive in these cells. These results suggest that the insulin promoter acquires its very high, yet cell-specific, activity at least partly through the action of IPF-1/STF-1. This action is dependent on helix-loop-helix factors bound to the E1 element.