Structural and social changes due to the COVID-19 pandemic and their impact on engagement in substance use disorder treatment services: a qualitative study among people with a recent history of injection drug use in Baltimore, Maryland

BACKGROUND

Substance use disorder treatment and recovery support services are critical for achieving and maintaining recovery. There are limited data on how structural and social changes due to the COVID-19 pandemic impacted individual-level experiences with substance use disorder treatment-related services among community-based samples of people who inject drugs.

METHODS

People with a recent history of injection drug use who were enrolled in the community-based AIDS Linked to the IntraVenous Experience study in Baltimore, Maryland participated in a one-time, semi-structured interview between July 2021 and February 2022 about their experiences living through the COVID-19 pandemic (n = 28). An iterative inductive coding process was used to identify themes describing how structural and social changes due to the COVID-19 pandemic affected participants' experiences with substance use disorder treatment-related services.

RESULTS

The median age of participants was 54 years (range = 24-73); 10 (36%) participants were female, 16 (57%) were non-Hispanic Black, and 8 (29%) were living with HIV. We identified several structural and social changes due the pandemic that acted as barriers and facilitators to individual-level engagement in treatment with medications for opioid use disorder (MOUD) and recovery support services (e.g., support group meetings). New take-home methadone flexibility policies temporarily facilitated engagement in MOUD treatment, but other pre-existing rigid policies and practices (e.g., zero-tolerance) were counteracting barriers. Changes in the illicit drug market were both a facilitator and barrier to MOUD treatment. Decreased availability and pandemic-related adaptations to in-person services were a barrier to recovery support services. While telehealth expansion facilitated engagement in recovery support group meetings for some participants, other participants faced digital and technological barriers. These changes in service provision also led to diminished perceived quality of both virtual and in-person recovery support group meetings. However, a facilitator of recovery support was increased accessibility of individual service providers (e.g., counselors and Sponsors).

CONCLUSIONS

Structural and social changes across several socioecological levels created new barriers and facilitators of individual-level engagement in substance use disorder treatment-related services. Multilevel interventions are needed to improve access to and engagement in high-quality substance use disorder treatment and recovery support services among people who inject drugs.

Dynamic data-enabled stratified sampling for trial invitations with application in NHS-Galleri

BACKGROUND

Participants of health research studies such as cancer screening trials usually have better health than the target population. Data-enabled recruitment strategies might be used to help minimise healthy volunteer effects on study power and improve equity.

METHODS

A computer algorithm was developed to help target trial invitations. It assumes participants are recruited from distinct sites (such as different physical locations or periods in time) that are served by clusters (such as general practitioners in England, or geographical areas), and the population may be split into defined groups (such as age and sex bands). The problem is to decide the number of people to invite from each group, such that all recruitment slots are filled, healthy volunteer effects are accounted for, and equity is achieved through representation in sufficient numbers of all major societal and ethnic groups. A linear programme was formulated for this problem.

RESULTS

The optimisation problem was solved dynamically for invitations to the NHS-Galleri trial (ISRCTN91431511). This multi-cancer screening trial aimed to recruit 140,000 participants from areas in England over 10 months. Public data sources were used for objective function weights, and constraints. Invitations were sent by sampling according to lists generated by the algorithm. To help achieve equity the algorithm tilts the invitation sampling distribution towards groups that are less likely to join. To mitigate healthy volunteer effects, it requires a minimum expected event rate of the primary outcome in the trial.

CONCLUSION

Our invitation algorithm is a novel data-enabled approach to recruitment that is designed to address healthy volunteer effects and inequity in health research studies. It could be adapted for use in other trials or research studies.

Interruptions to HIV Care Delivery During Pandemics and Natural Disasters: A Qualitative Study of Challenges and Opportunities From Frontline Healthcare Providers in Western Kenya

During public health crises, people living with HIV (PLWH) may become disengaged from care. The goal of this study was to understand the impact of the COVID-19 pandemic and recent flooding disasters on HIV care delivery in western Kenya. We conducted ten individual in-depth interviews with HIV providers across four health facilities. We used an iterative and integrated inductive and deductive data analysis approach to generate four themes. First, increased structural interruptions created exacerbating strain on health facilities. Second, there was increased physical and psychosocial burnout among providers. Third, patient uptake of services along the HIV continuum decreased, particularly among vulnerable patients. Finally, existing community-based programs and teleconsultations could be adapted to provide differentiated HIV care. Community-centric care programs, with an emphasis on overcoming the social, economic, and structural barriers will be crucial to ensure optimal care and limit the impact of public health disruptions on HIV care globally.

Effect of food additives on key bacterial taxa and the mucosa-associated microbiota in Crohn's disease. The ENIGMA study

Food additives have been linked to the pro-inflammatory microbial dysbiosis associated with Crohn's disease (CD) but the underlying ecological dynamics are unknown. Here, we examine how selection of food additives affects the growth of multiple strains of a key beneficial bacterium (Faecalibacterium prausnitzii), axenic clinical isolates of proinflammatory bacteria from CD patients (Proteus, Morganella, and Klebsiella spp.), and the consortia of mucosa-associated microbiota recovered from multiple Crohn's disease patients. Bacterial growth of the axenic isolates was evaluated using a habitat-simulating medium supplemented with either sodium sulfite, aluminum silicate, carrageenan, carboxymethylcellulose, polysorbate 80, saccharin, sucralose, or aspartame, intended to approximate concentrations found in food. The microbial consortia recovered from post-operative CD patient mucosal biopsy samples were challenged with either carboxymethylcellulose and/or polysorbate 80, and the bacterial communities compared to unchallenged consortia by 16S rRNA gene amplicon profiling. Growth of all F. prausnitzii strains was arrested when either sodium sulfite or polysorbate 80 was added to cultures at baseline or mid-exponential phase of growth, and the inhibitory effects on the Gram-negative bacteria by sodium sulfite were conditional on oxygen availability. The effects from polysorbate 80, saccharin, carrageenan, and/or carboxymethylcellulose on these bacteria were strain-specific. In addition to their direct effects on bacterial growth, polysorbate 80 and/or carboxymethylcellulose can drive profound changes in the CD mucosa-associated microbiota via niche expansion of Proteus and/or Veillonellaceae - both implicated in early Crohn's disease recurrence. These studies on the interaction of food additives with the enteric microbiota provide a basis for dietary management in Crohn's disease.

Novel strain-level resolution of Crohn's disease mucosa-associated microbiota via an ex vivo combination of microbe culture and metagenomic sequencing

The mucosa-associated microbiota is widely recognized as a potential trigger for Crohn's disease pathophysiology but remains largely uncharacterised beyond its taxonomic composition. Unlike stool microbiota, the functional characterisation of these communities using current DNA/RNA sequencing approaches remains constrained by the relatively small microbial density on tissue, and the overwhelming amount of human DNA recovered during sample preparation. Here, we have used a novel ex vivo approach that combines microbe culture from anaerobically preserved tissue with metagenome sequencing (MC-MGS) to reveal patient-specific and strain-level differences among these communities in post-operative Crohn's disease patients. The 16 S rRNA gene amplicon profiles showed these cultures provide a representative and holistic representation of the mucosa-associated microbiota, and MC-MGS produced both high quality metagenome-assembled genomes of recovered novel bacterial lineages. The MC-MGS approach also produced a strain-level resolution of key Enterobacteriacea and their associated virulence factors and revealed that urease activity underpins a key and diverse metabolic guild in these communities, which was confirmed by culture-based studies with axenic cultures. Collectively, these findings using MC-MGS show that the Crohn's disease mucosa-associated microbiota possesses taxonomic and functional attributes that are highly individualistic, borne at least in part by novel bacterial lineages not readily isolated or characterised from stool samples using current sequencing approaches.

Adverse cardiovascular ageing among older women and cardiometabolic ageing

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): National Medical Research Council (NMRC)

Background

Despite longer life expectancies, women may experience reduced ‘health-span’ (period of life spent in good health) due to accumulation of risks over their longer life spans. Metabolic factors present in diet and lifestyle may provide modifiable solutions to tackle burdens of cardiovascular (CV) ageing in women.

Objective

We aim to study gender differences in CV structure and function among community older adults without clinical CV disease, as well as metabolic perturbations in their study samples.

Methods

We examined a prospective cohort study of older adults, obtaining their medical history, serum sampling, echocardiography and cardiac magnetic resonance (CMR) imaging on a single day visit. Echo E/A ratio was computed as a ratio of peak velocity flow in early diastole E (m/s) to peak velocity flow in late diastole by atrial contraction A (m/s) mitral inflow velocities. Longitudinal strain (ε) at any time point (t) in the cardiac cycle from end-diastole (time 0) was calculated as: ε(t)=(L(t)-L0)/L0, obtaining left atrial (LA) reservoir strain (εs), conduit strain (εe) and booster strain (εa) by CMR. Metabolomics profiling was performed by standard mass spectrometry techniques.

Results

Among n = 492 (49.6%, n = 244 women, mean age 73 ± 4 years) participants, women had lower prevalence of hypertension (52% vs 58%, p < 0.0001), smoking (4% vs 35%, p < 0.0001), but higher prevalence of dyslipidemia (52% vs 50%, p = 0.001) compared to men. Women had lower left ventricular mass index (69 vs 71 g/m2, p < 0.0001) compared to men. However, women had more adverse CV function, such as lower E/A ratio (0.78 vs 0.85, p < 0.0001), lower LA booster (εa) (16.5 vs 17.8, p = 0.027) and lower LA reservoir (εs) strain rate (1.5 vs 1.6, p = 0.012), compared to men. Amino acids such as alanine, arginine, aspartate, citrulline, glycine, phenylalanine and valine were similar between gender. However, women had higher levels of tyrosine (76 vs 68 μM, p = 0.015). On multivariate adjustment, apart from age, tyrosine was independently associated with E/A ratio (β=0.002, 95%CI 0.00-0.004, p = 0.044) and εs (β=0.004, 95%CI 0.00-0.009, p = 0.048) among women. 

Conclusion

Utilizing conventional and sensitive CV imaging, women appeared to have more adverse CV functions with ageing. As a branched chain amino acid linked to future risk of CV disease, tyrosine may be linked to adverse CV function. Factors that contribute to these cardiometabolic profiles, such as menopause, diet or lifestyle warrant further research.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

The presentation, management and outcome of inflammatory breast cancer cases in the UK: Data from a multi-centre retrospective review

OBJECTIVES

Inflammatory Breast cancer (IBC) is a rare but aggressive form of breast cancer. Its incidence and behaviour in the UK is poorly characterised. We collected retrospective data from hospitals in the UK and Ireland to describe the presentation, pathology, treatment and clinical course of IBC in the UK.

MATERIALS AND METHODS

Patients with IBC diagnosed between 1997-2014 at fourteen UK and Irish hospitals were identified from local breast unit databases. Patient characteristics, tumour pathology and stage, and details of surgical, systemic and radiotherapy treatment and follow-up data were collected from electronic patient records and medical notes.

RESULT

This retrospective review identified 445 patients with IBC accounting for 0.4-1.8% of invasive breast cancer cases. Median follow-up was 4.2 years. 53.2% of tumours were grade 3, 56.2% were oestrogen receptor positive, 31.3% were HER2 positive and 25.1% were triple negative. 20.7% of patients had distant metastases at presentation. Despite trimodality treatment in 86.4%, 40.1% of stage III patients developed distant metastases. Five-year overall survival (OS) was 61.0% for stage III and 21.4% for stage IV patients.

CONCLUSIONS

This is the largest series of UK IBC patients reported to date. It indicates a lower incidence than in American series, but confirms that IBC has a high risk of recurrence with poor survival despite contemporary multi-modality therapy. A national strategy is required to facilitate translational research into this aggressive disease.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Moderate intensity sports and exercise is associated with glycaemic control in women with gestational diabetes

AIM

To assess the association of regular, unsupervised sports and exercise during pregnancy, by intensity level, with glycaemic control in women with gestational diabetes (GDM).

METHODS

Prospective cohort study of 971 women who, shortly after being diagnosed with GDM, completed a Pregnancy Physical Activity Questionnaire assessing moderate and vigorous intensity sports and exercise in the past 3 months. Self-monitored capillary glucose values were obtained for the 6-week period following the questionnaire, with optimal glycaemic control defined≥80% values meeting the targets<5.3mmol/L for fasting and <7.8mmol/L 1-hour after meals. Logistic regression estimated the odds of achieving optimal control; linear regression estimated activity level-specific least square mean glucose, as well as between-level mean glucose differences.

RESULTS

For volume of moderate intensity sports and exercise ([MET×hours]/week), the highest quartile, compared to the lowest, had significantly increased odds of optimal control (OR=1.82 [95% CI: 1.06-3.14] P=0.03). There were significant trends for decreasing mean 1-hour post breakfast, lunch and dinner glycaemia with increasing quartile of moderate activity (all P<0.05). Any participation in vigorous intensity sports and exercise was associated with decreased mean 1-hour post breakfast and lunch glycaemia (both P<0.05). No associations were observed for fasting.

CONCLUSION

Higher volumes of moderate intensity sports and exercise, reported shortly after GDM diagnosis, were significantly associated with increased odds of achieving glycaemic control. Clinicians should be aware that unsupervised moderate intensity sports and exercise performed in mid-pregnancy aids in subsequent glycaemic control among women with GDM.

TOWARDS CONSISTENT MAPPING OF URBAN STRUCTURES – GLOBAL HUMAN SETTLEMENT LAYER AND LOCAL CLIMATE ZONES

Although more than half of the Earth’s population live in urban areas, we know remarkably little about most cities and what we do know is incomplete (lack of coverage) and inconsistent (varying definitions and scale). While there have been considerable advances in the derivation of a global urban mask using satellite information, the complexity of urban structures, the heterogeneity of materials, and the multiplicity of spectral properties have impeded the derivation of universal urban structural types (UST). Further, the variety of UST typologies severely limits the comparability of such studies and although a common and generic description of urban structures is an essential requirement for the universal mapping of urban structures, such a standard scheme is still lacking. More recently, there have been two developments in urban mapping that have the potential for providing a standard approach: the Local Climate Zone (LCZ) scheme (used by the World Urban Database and Access Portal Tools project) and the Global Human Settlement Layer (GHSL) methodology by JRC. In this paper the LCZ scheme and the GHSL LABEL product were compared for selected cities. The comparison between both datasets revealed a good agreement at city and coarse scale, while the contingency at pixel scale was limited due to the mismatch in grid resolution and typology. At a 1 km scale, built-up as well as open and compact classes showed very good agreement in terms of correlation coefficient and mean absolute distance, spatial pattern, and radial distribution as a function of distance from town, which indicates that a decomposition relevant for modelling applications could be derived from both. On the other hand, specific problems were found for both datasets, which are discussed along with their general advantages and disadvantages as a standard for UST classification in urban remote sensing.

Nucleus accumbens cocaine-amphetamine regulated transcript mediates food intake during novelty conflict

Obesity is a persistent and pervasive problem, particularly in industrialized nations. It has come to be appreciated that the metabolic health of an individual can influence brain function and subsequent behavioral patterns. To examine the relationship between metabolic phenotype and central systems that regulate behavior, we tested rats with divergent metabolic phenotypes (Low Capacity Runner: LCR vs. High Capacity Runner: HCR) for behavioral responses to the conflict between hunger and environmental novelty using the novelty suppressed feeding (NSF) paradigm. Additionally, we measured expression of mRNA, for peptides involved in energy management, in response to fasting. Following a 24-h fast, LCR rats showed lower latencies to begin eating in a novel environment compared to HCR rats. A 48-h fast equilibrated the latency to begin eating in the novel environment. A 24-h fast differentially affected expression of cocaine-amphetamine regulated transcript (CART) mRNA in the nucleus accumbens (NAc), where 24-h of fasting reduced CART mRNA in LCR rats. Bilateral microinjections of CART 55-102 peptide into the NAc increased the latency to begin eating in the NSF paradigm following a 24-h fast in LCR rats. These results indicate that metabolic phenotype influences how animals cope with the conflict between hunger and novelty, and that these differences are at least partially mediated by CART signaling in the NAc. For individuals with poor metabolic health who have to navigate food-rich and stressful environments, changes in central systems that mediate conflicting drives may feed into the rates of obesity and exacerbate the difficulty individuals have in maintaining weight loss.

The use of Pillcam Colon in assessing mucosal inflammation in ulcerative colitis: a multicenter study

BACKGROUND AND STUDY AIM

Treatment of ulcerative colitis should be tailored to the severity of colonic inflammation, which in the past has been gauged mainly by clinical features and biochemical parameters. Recently, mucosal healing has been proposed as a standard to guide therapy. The aim of this multicenter study was to test whether mucosal appearance, as reported by colon capsule endoscopy (CCE), can be used to differentiate active from inactive ulcerative colitis.

PATIENTS AND METHODS

Adult patients from Hong Kong, Singapore, and Taiwan who were suspected or known to have ulcerative colitis were included in this prospective study. CCE and conventional optical colonoscopy were offered to these patients on the same day after receiving standard bowel preparation. The primary endpoint was the accuracy of CCE in assessing colonic inflammation (defined as the presence of ulcers, erythema, erosions, edema, exudates in mucosa), using optical colonoscopy as the gold standard.

RESULTS

At total of 100 patients (42 females; median age 50 years; range 22 - 68 years) were enrolled. Four cases were excluded from the analysis due to technical failure or slow transit of the capsule. In nine patients, the capsule was not excreted within 8.5 hours and required retrieval during colonoscopy. The sensitivity of CCE to detect active colonic inflammation was 89 % (95 % confidence interval [CI] 80 - 95) and specificity was 75 % (95 %CI 51 - 90). The positive and negative predictive values of CCE for colonic inflammation were 93 % (95 %CI 84 - 97) and 65 % (95 %CI 43 - 83), respectively. No serious adverse event related to the CCE procedure or preparation was reported.

CONCLUSION

CCE is a safe procedure to monitor mucosal healing in ulcerative colitis. However, at this stage, CCE cannot be recommended to replace conventional colonoscopy in the management of this condition.

The association of specific HLA class I and II alleles with type 1 diabetes among Filipinos

The genetic predisposition to type 1 diabetes among Filipinos was examined by PCR/SSOP HLA class I and II typing of 90 patients and 94 general population controls. The HLA-DRB1, DQB1, and the A, B, and C loci were typed using the reverse SSO probe line-blot method while the DPB1 and DPA1 loci were typed using the SSO probe dot blot method. The Filipino population has a distinctive frequency distribution of HLA class II alleles as well as linkage disequilibrium patterns: a DR-DQ haplotype, unique to Filipinos, contains a DRB1 allele (*0405) positively associated with type 1 diabetes in other populations and DQA1 and DQB1 alleles (*0101-*0503) that are negatively associated in other populations. Specific DR-DQ haplotypes or alleles could be identified as susceptible, neutral or protective based on the distribution among Filipino patients and controls. The DR9 and DR3 haplotypes showed the most dramatic increase among patients (0.156 vs 0.063) and (0.172 vs 0.042), respectively. Among Filipinos, the DR3/9 genotype confers approximately the same risk as the well-known high-risk DR3/4 genotype, similar to that for DR3/3 and DR9/9. The common DR2 haplotype in the Philippines (DRB1*1502-DQB1*0502) was only slightly decreased in type 1 diabetic patients (0.200 in patients vs 0.270 in controls). Another DR2 haplotype, DRB1*1502-DQB1*0501, was significantly decreased among patients. In addition, haplotypes containing DQB1*06 alleles, such as the DRB1*0803-DQB1*0601 (OR = 0.1), are strongly protective. The DR4 allele group was also increased in Filipino patients compared to controls. In this population there is, as in other populations, a hierarchy of type 1 diabetes associations among the many different DR4 haplotypes (n = 15). The high-risk haplotypes in this population are the very rare DRB1*0405-DQB1*0302 and DQB1*0405-DQB1*0201, followed by the more common DRB1*0405-DQB1*0401 and DRB1*0405-DQB1*0402. The DRB1*0403-DQB1*0302 is protective. The DRB1*0405-DQB1*05031 haplotype, which is unique to Filipinos, appears to be "neutral". HLA-DPB1*0202 was significantly increased among patients (0.056 vs 0.011; with OR = 5.3); this increase does not appear to simply reflect linkage disequilibrium with high risk DR-DQ haplotypes. The observed distribution of HLA class II alleles among Filipino patients and controls strongly supports the notion that specific combinations of alleles at the DRB1, DQB1, DQA1, and DPB1 loci are critical in determining the risk for type 1 diabetes. Specific HLA class I alleles also show significant associations with type 1 diabetes in this population. HLA-A*2402 and *2403 were increased among patients; however, 2407 was decreased. Inaddition, A *1101 was significantly decreased among patients (OR = 0.51). Moreover, these HLA-A associations do not appear attributable to linkage disequilibrium with the DR-DQ region. The allele B*5801 was increased in patients while B*1301 was decreased; both of these associations, however, reflected linkage disequilibrium with high-risk and with protective DR-DQ haplotypes, respectively. The HLA-C*0102 and *0302 alleles were increased (0.089 vs 0.037 and 0.122 vs 0.064) while C*1502 and *0702 (0.028 vs 0.080 and 0.217 vs 0.330) were decreased. The observed associations of C*0102 and C*1502 do not simply reflect linkage disequilibrium with high-risk DR-DQ haplotypes. Thus, specific HLA class I-A and C alleles were associated with type 1 diabetes in the Filipinos and may, in combination with high risk DR-DQ haplotypes, significantly modify disease risk.

Color Doppler imaging of retrobulbar hemodynamics after topical carteolol in normal tension glaucoma

BACKGROUND

Carteolol is a nonselective adrenergic blocking agent. The aim of this study was to evaluate the effect of topical carteolol on retrobulbar hemodynamics in patients with normal tension glaucoma (NTG).

METHODS

Twelve NTG patients received twelve-week topical treatment of 2% carteolol. Color Doppler imaging (CDI) was used to evaluate the hemodynamic effects before and after drug therapy. Measurements were obtained from the central retinal artery (CRA), the lateral posterior ciliary artery (LPCA) and the medial posterior ciliary artery (MPCA). From each vessel, peak systolic velocity (PSV), end-diastolic velocity (EDV), resistance index (RI) and Gosling's pulsatility index (PI) were collected and analyzed.

RESULTS

After topical carteolol treatment for twelve weeks, mean resistance index reduced significantly from 0.83 to 0.74 in the CRA (p = 0.03), from 0.74 to 0.68 in the LPCA (p = 0.09). Moreover, mean pulsatility index of the LPCA decreased from 1.45 to 1.26 (p = 0.08).

CONCLUSIONS

Twelve weeks of 2% carteoiol treatment may decrease the vascular resistance in NTG patients possibly due to the intrinsic sympathomimetic activity (ISA) of carteolol.

Diagnosis of Helicobacter pylori infection after gastric surgery for peptic ulcer: is the rapid urease test useful?

BACKGROUND

The usefulness of the rapid urease test (RUT) in diagnosing Helicobacter pylori infection after peptic ulcer surgery is unknown.

METHODS

Patients who had undergone peptic ulcer surgery were offered endoscopic examination if they presented with dyspepsia or gastrointestinal bleeding. Biopsy specimens were taken for RUT and histology from the corpus and the stoma in patients who had undergone partial gastrectomy or from the corpus and the antrum in patients who had undergone vagotomy. Histologic examination using haematoxylin and eosin stain and Warthin-Starry stain were used as the gold standard.

RESULTS

Ninety patients were studied (69 had partial gastrectomy and 21 had vagotomy). Forty-three patients (32 in the partial gastrectomy group and 11 in the vagotomy group) were positive for H. pylori by histology. The respective sensitivity of RUT was 59% (stoma) and 75% (corpus) in the partial gastrectomy group (P = 0.36) and 55% (antrum) and 73% (corpus) in the vagotomy group (P = 0.51).

CONCLUSIONS

RUT is not sensitive for detecting H. pylori after acid reduction surgery.

Polymers as surface-based tethers with photolytic triggers enabling laser-induced release/desorption of covalently bound molecules

A novel design for surface-based macromolecular docking and release is presented together with a strategy to improve and extend biopolymer structure determination capabilities. Polymeric surfaces with arrays of tethers for covalent molecular attachment were designed with photolytic triggers to enable spatially defined, laser-induced uncoupling/desorption of the tethered molecules. Upon photolytic cleavage, a defined portion of the tether ("tail") remains attached to the biomolecule as a probe. Chemically defined memory, determined by the number of reporter tails, reflects the biomolecule interaction with tether-probe devices encountered (i.e., footprint) on the probe surface. To demonstrate function, a surface of poly(4-vinylpyridine) was extended through the pyridinium nitrogens with spacer arms (-N-ethylsuccinamyl-) producing photolytic pyridinium nitrogen bonds. The photolabile tether was terminated with leaving groups (N-hydroxysulfosuccinimide) for covalent attachment of biopolymers. An 18-residue peptide (N terminus of human beta-casein) was covalently docked to these tether-probes, irradiated with coherent UV light, and released with two reporter tails of a mass predicted by tether formation at the two primary amine groups and subsequent photolytic cleavage at the intended site. This is the first demonstration of polymeric surface structure enabling the covalent docking and laser-induced uncoupling/desorption of intact macromolecules through the use of photolytic tethers. Surface-based tether-probe devices, operated by coherent light, should advance our ability to explore covalent modifications in biopolymer structure and alterations in conformation, generated either in advance of tethering or through chemical/enzymatic manipulations performed directly in situ.

Exoglucanase activities of the recombinant Clostridium thermocellum CelS, a major cellulosome component

The recombinant CelS (rCelS), the most abundant catalytic subunit of the Clostridium thermocellum cellulosome, displayed typical exoglucanase characteristics, including (i) a preference for amorphous or crystalline cellulose over carboxymethyl cellulose, (ii) an inability to reduce the viscosity of a carboxymethyl cellulose solution, and (iii) the production of few bound reducing ends on the solid substrate. The hydrolysis products from crystalline cellulose were cellobiose and cellotriose at a ratio of 5:1. The rCelS activity on amorphous cellulose was optimal at 70 degrees C and at pH 5 to 6. Its thermostability was increased by Ca2+. Sulfhydryl reagents had only a mild adverse effect on the rCelS activity. Cellotetraose was the smallest oligosaccharide substrate for rCelS, and the hydrolysis rate increased with the substrate chain length. Many of these properties were consistent with those of the cellulosome, indicating a key role for CelS.

New female perceptions of parental power

In a study of family roles, 85 adolescent sons and daughters from 27 families initially attributed "power" roles to fathers and "support" roles to mothers. Three years later, daughters perceived power and support roles as shared, while sons still perceived the earlier dichotomy.