In search of susceptibility genes for type 2 diabetes in West Africa: the design and results of the first phase of the AADM study

PURPOSE

The purpose of this study is to map type 2 diabetes susceptibility genes in West African ancestral populations of African-Americans, through an international collaboration between West African and US investigators.

DESIGN AND METHODS

Affected sib-pairs (ASP) along with unaffected spouse controls are being enrolled and examined in West Africa, with two sites established in Ghana (Accra and Kumasi) and three in Nigeria (Enugu, Ibadan, and Lagos). Eligible participants are invited to study clinics to obtain detailed epidemiologic, family, and medical history information. Blood samples are drawn from each participant to measure glucose, insulin, C-peptide, total cholesterol, LDL, HDL, triglycerides, albumin, creatinine, urea, uric acid, total calcium and to detect autoantibodies to glutamic acid decarboxylase (GAD). DNA is isolated from frozen white blood cells obtained from 20 ml of EDTA whole blood samples.

RESULTS

With full informed consent, 162 individuals from 78 families have been enrolled and examined since the Africa America Diabetes Mellitus (AADM) study began in June of 1997. Logistics of field examinations and specimen shipping have been successfully established. At the end of the third year of field activity (September 2000) the AADM study will have enrolled and performed comprehensive examination on 400 ASP with type 2 diabetes, for a minimum of 800 cases and 200 controls from Ghana and Nigeria. At the current participation rate, the goal of 400 sib-pairs and 200 controls will be met before the scheduled closing date.

CONCLUSIONS

The AADM study will create a comprehensive epidemiologic and genetic resource that will facilitate a powerful genome-wide search for West African susceptibility genes to type 2 diabetes.

A comprehensive interactive competency program. Part II: Implementation, outcomes, and followup

The department of medicine/oncology nursing of an academic medical center developed and implemented a comprehensive interactive competency program. The program proved to be valuable to the individual nurse and the organization. Part II of this two-part series describes the implementation, outcomes, and followup of the program.

Intravenous azathioprine in severe ulcerative colitis: a pilot study

OBJECTIVE

Azathioprine use in acute ulcerative colitis has been limited by its perceived long onset of action. The aim of this study was to determine the safety and clinical effect of an i.v. loading dose of azathioprine in the setting of severe steroid refractory ulcerative colitis.

METHODS

Nine hospitalized patients with severe steroid refractory ulcerative colitis were enrolled. Patients 1-3 received 20 mg/kg i.v. azathioprine over 36 h. Patients 4-6 received 40 mg/kg i.v. azathioprine over 36 h. Patients 7-9 received 40 mg/kg i.v. azathioprine as three 8-h infusions over 3 days. Clinical remission was defined as steroid withdrawal and an Ulcerative Colitis Disease Activity Index score of 0. The Inflammatory Bowel Disease Questionnaire was obtained at each visit. White blood cell concentrations and erythrocyte concentrations of 6-thioguanine were obtained.

RESULTS

Five of nine patients (56%) had a response and avoided colectomy. Three of nine patients (33%) met the definition for clinical remission. Response was seen within 4 wk. The mean 6-thioguanine concentration for those five patients at 12 wk after infusion was 148.2 pmol/8 x 10(8). Two patients had transient leukopenia and one had transient hepatotoxicity.

CONCLUSIONS

Intravenous azathioprine appears to be safe and of clinical benefit in inducing response and avoiding colectomy in severe steroid refractory ulcerative colitis. Data from an i.v. azathioprine trial in Crohn's disease suggests oral dosing alone may obtain the same results. The role of oral dosing alone in severe ulcerative colitis and the role of azathioprine metabolite levels in monitoring efficacy should be investigated further.

The evolution of mutation rates: separating causes from consequences

Natural selection can adjust the rate of mutation in a population by acting on allelic variation affecting processes of DNA replication and repair. Because mutation is the ultimate source of the genetic variation required for adaptation, it can be appealing to suppose that the genomic mutation rate is adjusted to a level that best promotes adaptation. Most mutations with phenotypic effects are harmful, however, and thus there is relentless selection within populations for lower genomic mutation rates. Selection on beneficial mutations can counter this effect by favoring alleles that raise the mutation rate, but the effect of beneficial mutations on the genomic mutation rate is extremely sensitive to recombination and is unlikely to be important in sexual populations. In contrast, high genomic mutation rates can evolve in asexual populations under the influence of beneficial mutations, but this phenomenon is probably of limited adaptive significance and represents, at best, a temporary reprieve from the continual selection pressure to reduce mutation. The physiological cost of reducing mutation below the low level observed in most populations may be the most important factor in setting the genomic mutation rate in sexual and asexual systems, regardless of the benefits of mutation in producing new adaptive variation. Maintenance of mutation rates higher than the minimum set by this "cost of fidelity" is likely only under special circumstances.

Listeners as co-narrators

A collaborative theory of narrative story-telling was tested in two experiments that examined what listeners do and their effect on the narrator. In 63 unacquainted dyads (81 women and 45 men), a narrator told his or her own close-call story. The listeners made 2 different kinds of listener responses: Generic responses included nodding and vocalizations such as "mhm." Specific responses, such as wincing or exclaiming, were tightly connected to (and served to illustrate) what the narrator was saying at the moment. In experimental conditions that distracted listeners from the narrative content, listeners made fewer responses, especially specific ones, and the narrators also told their stories significantly less well, particularly at what should have been the dramatic ending. Thus, listeners were co-narrators both through their own specific responses, which helped illustrate the story, and in their apparent effect on the narrator's performance. The results demonstrate the importance of moment-by-moment collaboration in face-to-face dialogue.

Gay and lesbian couples in therapy: perspectives for the contemporary family therapist

This paper outlines the major concerns of gay and lesbian couples who seek therapy. Presenting problems are classified as either internal to the relationship or as external (contextual) ones that reflect the influence of oppressive cultural and gender biases. Throughout the article, distinctive therapy methods are described that address the unique concerns of lesbian and gay couples, with special sensitivity to heterosexist and homophobic bias.

Cytotoxic clerodane diterpene esters from Laetia corymbulosa

Three cytotoxic clerodane diterpene esters, corymbulosins A-C, were isolated from an organic extract of the fruit of Laetia corymbulosa (Flacourtiaceae) from Peru. The structures were determined by spectroscopic methods as clerodane diterpenes unsaturated at C-3, C-13(16) and C-14. Corymbulosin A was esterified at C-2 with a decadienoate moiety, while corymbulosins B and C were C-2 epimers esterified at C-6 with a decanoate moiety.

A comprehensive interactive competency program. Part I: Development and framework

The department of medicine/oncology nursing of an academic medical center developed and implemented a comprehensive interactive competency program. The program proved to be valuable to nurses and the organization. Part I of this two-part series describes the process of program development and the resulting framework.

Functional health pattern assessment on-line. Lessons learned

Assessment of patient care needs is the foundation for planning patient care and documenting the nursing process to enhance the nurse's ability to coordinate care, plan discharges effectively, and provide appropriate patient/family education. An on-line assessment module in the hospital clinical information system was implemented. This module uses Gordon's Functional Health Pattern Assessment as the foundation for the professional nursing documentation system in this academic, health science center. The article provides a description of the design of the pathways for the on-line assessment, analysis of the design, benefits of using the on-line assessment, and lessons learned from the design and implementation of the pathways.

Oral paclitaxel and concurrent cyclosporin A: targeting clinically relevant systemic exposure to paclitaxel

Oral paclitaxel is not inherently bioavailable because of the overexpression of P-glycoprotein by intestinal cells and the significant first-pass extraction by cytochrome P450-dependent processes. This study sought to simulate the toxicological and pharmacological profile of a clinically relevant schedule of paclitaxel administered on clinically relevant i.v. dosing schedules in patients with advanced solid malignancies using oral paclitaxel administered with cyclosporin A, an inhibitor of both P-glycoprotein and P450 CYP3A. Nine patients were treated with a single course of oral paclitaxel in its parenteral formulation at a paclitaxel dose level of 180, 360, or 540 mg. Cyclosporin A was administered at a dose of 5 mg/kg p.o. 1 h before and concurrently with oral paclitaxel. Blood sampling was performed to evaluate the pharmacokinetics of paclitaxel, 6-alpha-hydroxypaclitaxel, 3-p-hydroxypaclitaxel, and cyclosporin A. The pharmacokinetic behavior of paclitaxel was characterized using both compartmental and noncompartmental methods. Model-estimated parameters were used to simulate paclitaxel concentrations after once daily and twice daily oral administration of paclitaxel and cyclosporin A. Aside from an unpleasant taste, the oral regimen was well tolerated, and there were no grade 3 or 4 drug-related toxicities. The systemic exposure to paclitaxel, as assessed by maximum plasma concentration (Cmax) and area under the plasma concentration versus time curve (AUC) values, did not increase as the dose of paclitaxel was increased from 180 to 540 mg, and there was substantial interindividual variability (4-6-fold) at each dose level. Mean paclitaxel Cmax values approached plasma concentrations achieved with clinically relevant parenteral dose schedules, averaging 268+/-164 ng/ml. AUC values averaged 3306+/-1977 ng x h/ ml, which was significantly lower than AUC values achieved with clinically relevant i.v. paclitaxel dose schedules. However, computer simulations using pharmacokinetic parameters derived from the present study demonstrated that pharmacodynamically relevant steady-state plasma paclitaxel concentrations of at least 0.06 microM would be achieved after protracted once daily and twice daily dosing with oral paclitaxel and cyclosporin A. Paclitaxel metabolites were detectable in three patients, and the 6-alpha-hydroxypaclitaxel: paclitaxel and 3-p-hydroxypaclitaxel:paclitaxel AUC ratios averaged 0.63 and 0.86, respectively; these values were substantially higher than values reported in patients treated with i.v. paclitaxel. Oral paclitaxel was bioavailable in humans when administered in combination with oral cyclosporin A 5 mg/kg 1 h before and concurrently with paclitaxel treatment, and plasma paclitaxel concentrations achieved with this schedule were biologically relevant and approached concentrations attained with clinically relevant parenteral dose schedules. However, treatment of patients with oral paclitaxel using a single oral dose administration schedule failed to achieve sufficiently high systemic drug exposure and pharmacodynamic effects. In contrast, computer simulations demonstrated that clinically relevant pharmacodynamic effects are likely to be achieved with multiple once daily and twice daily oral paclitaxel-cyclosporin A dosing schedules.

Prediction of hourly microenvironmental concentrations of fine particles based on measurements obtained from the Baltimore scripted activity study

Researchers have developed a variety of computer-based models to estimate population exposure to air pollution. These models typically estimate exposures by simulating the movement of specific population groups through defined microenvironments. During the summer of 1998 and winter of 1999, researchers with the Harvard School of Public Health (HSPH) conducted a field study in Baltimore, MD, to acquire data for improving microenvironmental models. Using a special roll-around instrument system, a technician measured 1- and 12-h pollutant concentrations while engaging in scripted sequences of activities typical of retirees. Each scripted activity assigned the technician to a geographic location and to a microenvironment. The technician recorded special conditions associated with each activity (e.g., open windows, environmental tobacco smoke) in a real-time diary. Data on ambient pollutant levels, temperature, and other potential explanatory factors were also collected. Eleven pollutants were measured by the roll-around instrument system, including particulate matter with an aerodynamic diameter less than 2.5 microm (PM2.5), ozone, carbon monoxide, and benzene. This article presents the results of statistical analyses performed solely on the 1-h PM2.5 data measured by a DustTrak monitor, which ranged from 1.5 to 444.8 microg/m3 with a median value of 14.6 microg/m3. Results of stepwise linear regression (SLR) suggest that PM2.5 exposure is significantly increased by passive smoking, high ambient PM2.5 concentrations reported by fixed-site monitors, food preparation, charcoal grills, car travel, outdoor roadside locations, and high humidity. Analysts should explicitly represent the effects of these parameters within any model developed to estimate population exposure to PM2.5. In a related study, a panel of volunteer retirees each carried a personal PM2.5 monitor and a real-time diary for nominal 24-h sampling periods as they engaged in normal daily activities. A regression equation derived from SLR analysis of the scripted activity database was applied to eight subject-days of diary data provided by the volunteer seniors to produce estimates of PM2.5 exposure for each event documented in each diary. The event-specific exposure estimates were then averaged over all events in each sampling period to produce nominal 24-h average exposure estimates. The absolute difference between the estimate obtained from the regression equation and the corresponding personal monitor measurement averaged 13%. The fixed-site monitors generally provided poorer estimates of exposure; the absolute differences for the Old Town and Clifton Park monitors averaged 26.7% and 19.5%, respectively, of the personal monitor values.

TA90-IC, a new marker for advanced colon cancer

BACKGROUND

Although carcinoembryonic antigen (CEA) is the most frequently used marker for colon cancer, it is elevated in only 70% of patients with advanced disease and in even fewer patients with earlier stages of disease. We previously identified a 90-kDa glycoprotein, TA90, which is present in serum in the form of circulating immune complexes. TA90 is found in a variety of solid neoplasms but rarely in healthy controls (3.2%). We hypothesized that this new tumor-associated antigen may be a useful marker for colon cancer.

METHODS

Serum samples from 59 patients with known colon adenocarcinoma were analyzed for the presence of CEA and TA90. Fifty-one (86%) patients had distant metastases; the remaining patients had clinically localized primary colon cancer. A murine monoclonal antibody-based enzyme-linked immunosorbent assay was used to measure concentrations of TA90-specific circulating immune complexes (TA90-IC). A positive value was defined as an optical density of more than 0.410 at 405 nm. Forty-seven (80%) of the 59 patients had serum samples for TA90 and CEA drawn at the same time.

RESULTS

TA90-IC concentrations were elevated more frequently than CEA concentrations (82.9% vs. 70.2%; P = .134). The combination of both markers identified more patients with colon carcinoma than did either marker alone (93.6%; P < .001).

CONCLUSIONS

Concomitant use of TA90-IC and CEA identified 93.6% of patients with advanced colon cancer. The role of TA90-IC in screening and monitoring progression of earlier disease deserves further investigation.

Substituted benzamide inhibitors of human rhinovirus 3C protease: structure-based design, synthesis, and biological evaluation

A series of nonpeptide benzamide-containing inhibitors of human rhinovirus (HRV) 3C protease was identified using structure-based design. The design, synthesis, and biological evaluation of these inhibitors are reported. A Michael acceptor was combined with a benzamide core mimicking the P1 recognition element of the natural 3CP substrate. alpha,beta-Unsaturated cinnamate esters irreversibly inhibited the 3CP and displayed antiviral activity (EC(50) 0.60 microM, HRV-16 infected H1-HeLa cells). On the basis of cocrystal structure information, a library of substituted benzamide derivatives was prepared using parallel synthesis on solid support. A 1.9 A cocrystal structure of a benzamide inhibitor in complex with the 3CP revealed a binding mode similar to that initially modeled wherein covalent attachment of the nucleophilic cysteine residue is observed. Unsaturated ketones displayed potent reversible inhibition but were inactive in the cellular antiviral assay and were found to react with nucleophilic thiols such as DTT.

Continuous pH and Pco2 monitoring during respiratory failure in children with the Paratrend 7 inserted into the peripheral venous system

CONTEXT

The Paratrend monitor provides continuous arterial blood gas monitoring after insertion through a >/=20-gauge arterial cannula.

OBJECTIVE

To determine the correlation of arterial blood gas values and the Paratrend monitor placed through a peripheral intravenous catheter.

DESIGN

Prospective, open-label evaluation.

SETTING

University-based pediatric intensive care unit.

PATIENTS

Infants and children with respiratory failure and arterial access.

RESULTS

The cohort included 23 infants and children. A total of 100 sample sets (Paratrend/ABG Pco(2) and pH values) were collected. The absolute difference between the arterial and Paratrend Pco(2) was 2. 9 +/- 1.8 mm Hg (range 0 to 9 mm Hg). Linear regression analysis of Paratrend Pco(2) versus arterial Pco(2) resulted in r = 0.97 and r(2) = 0.9479 (P <.001). Bland-Altman analysis of Pco(2) values demonstrated a bias +/- precision of -2.1 +/- 2.7 mm Hg. The absolute difference between arterial and Paratrend pH was 0.04 +/- 0. 02 units (range 0 to 0.15 units). Linear regression analysis of Paratrend pH versus arterial pH resulted in r = 0.83 and r(2) = 0. 7016 (P <.0001). Bland-Altman analysis of pH values revealed a bias +/- precision of 0.03 +/- 0.03 units.

CONCLUSIONS

Inserted through a peripheral intravenous cannula, the Paratrend monitor can be used to provide an accurate estimation of arterial blood gas values in children with respiratory failure.

Novel cytotoxic diterpenes from Casearia arborea

Cytotoxicity-guided fractionation of the dichloromethane-methanol extract of the roots of Casearia arborea yielded five novel clerodane diterpenes, casearborins A-E (1-5), as well as cucurbitacin B. The presence of cucurbitacins glycosides was also detected. The absolute configuration of casearborin E was determined by X-ray crystallography.

Socioeconomic status and the expectation of disability in old age: estimates for England

OBJECTIVES

The longer life expectancy in old age of more privileged socioeconomic groups is well established, but less clear is whether the net effect of additional years of life is a lengthened, stable or reduced duration of disability. Estimates of healthy and disabled life expectancy (using definitions including dependency in activities of daily living and cognitive impairment) were made, contrasting occupational classes I and II (professional and managerial) with the rest.

DESIGN

Disability prevalence was estimated from the Medical Research Council Cognitive Function and Ageing study. Sullivan's method was used to calculate health expectancy.

SUBJECTS

10,377 people aged 65 years or over in Cambridgeshire, Newcastle, Nottingham and Oxford. Subjects were classified as disabled if they had evidence of dementia (using the Automated Geriatric Examination Computer Assisted Taxonomy) or scored 11 or more on the modified Townsend Disability scale, at baseline screen.

RESULTS

The prevalence of disability overall and need for "constant care" was lower in both men and women in social classes I and II compared with the rest. Men aged 65 to 69 in classes I and II can expect nearly 14 years of life free of disability compared with 11.5 years for those in classes III to V: for women the equivalent expectations are 15.5 and 13.8 years. Men aged 65 to 69 in classes I and II can also expect a shorter duration of disability: 1 year compared with 1.6 years for classes III to V. In women expectation of disability is higher overall, but shows little difference by occupational class.

CONCLUSIONS

Relatively privileged socioeconomic groups in England, especially men, can expect fewer years of disability despite longer overall life expectancy. These findings lend weight to optimistic scenarios for the future numbers of older people with disability.

The prevalence of breast-feeding in south Leicestershire

The consultative document, 'Our Healthier Nation' (Department of Health, 1998a), outlined areas for health improvement, and offers health professionals an opportunity to use the Government's programme to raise breast-feeding rates. This article reports the results of an audit to establish local breast-feeding prevalence rates in south Leicestershire, and when and why women stop breast-feeding. A simple questionnaire was used by health visitors to collect data on all babies born over a 3-month period (October 1997 - December 1997). The audit found that 57% of mothers were breast-feeding at birth compared with national breast-feeding figures of 64%. The rate at which women stopped breast-feeding substantially increased between 10 days and 6-8 weeks postpartum. Women stopped breast-feeding for a variety of reasons. The information provided by the audit will be used to inform health-visiting practice and in the long term will hopefully help to increase breast-feeding rates in this area.

Evaluation of efficacy and complications: primary pediatric orbital implants after enucleation

BACKGROUND

Orbital implants are used routinely in pediatric patients at the time of enucleation. Complications, such as exposure, ptosis, and infection, may occur after implantation. Controversy continues regarding the rate of complications with newer implants in the pediatric population.

OBJECTIVE

To examine the effects of orbital implants on children whose eyes have been enucleated.

METHODS

Records of orbital implantation after enucleation performed by 5 surgeons on 120 pediatric patients (123 eyes) over a 10.5-year period were reviewed retrospectively. Demographic data, ocular diagnosis, prior ophthalmic surgery, implant characteristics, and postoperative complications were described using a standardized format for all patients, with a minimum of 6 months of follow-up (mean, 3 years).

RESULTS

Complications were observed in 7 eyes (5.7%). Implant exposure (1 [0.8%]), implant extrusion (0 [0%), and implant migration (3 [2.4%) were rare. One hundred eighteen eyes (96%) had good cosmesis and 120 (98%) had good motility.

CONCLUSIONS

Orbital implantation after enucleation is successful in the pediatric population. Complications are minimal. Hydroxyapatite implants were not associated with unacceptable complications in this pediatric population.

A novel precursor recognition element facilitates posttranslational binding to the signal recognition particle in chloroplasts

Signal recognition particles (SRPs) in the cytosols of prokaryotes and eukaryotes are used to target proteins to cytoplasmic membranes and the endoplasmic reticulum, respectively. The mechanism of targeting relies on cotranslational SRP binding to hydrophobic signal sequences. An organellar SRP identified in chloroplasts (cpSRP) is unusual in that it functions posttranslationally to localize a subset of nuclear-encoded thylakoid proteins. In assays that reconstitute thylakoid integration of the light harvesting chlorophyll-binding protein (LHCP), stromal cpSRP binds LHCP posttranslationally to form a cpSRP/LHCP transit complex, which is believed to represent the LHCP form targeted to thylakoids. In this investigation, we have identified an 18-aa sequence motif in LHCP (L18) that, along with a hydrophobic domain, is required for transit complex formation. Fusion of L18 to the amino terminus of an endoplasmic reticulum-targeted protein, preprolactin, led to transit complex formation whereas wild-type preprolactin exhibited no ability to form a transit complex. In addition, a synthetic L18 peptide, which competed with LHCP for transit complex formation, caused a parallel inhibition of LHCP integration. Translocation of proteins by the thylakoid Sec and Delta pH transport systems was unaffected by the highest concentration of L18 peptide examined. Our data indicate that a motif contained in L18 functions in precursor recruitment to the posttranslational SRP pathway, one of at least four different thylakoid sorting pathways used by chloroplasts.

Quantitative genetics: Resolving wing shape genes

Recent high-resolution quantitative mapping experiments aimed at elucidating the genetics of natural variation for wing shape in fruit-flies suggest that very many genes can subtly influence the trait.