The incremental yield of prenatal exome sequencing over chromosome microarray for congenital heart abnormalities: A systematic review and meta-analysis

OBJECTIVES

To determine the incremental yield of prenatal exome sequencing (PES) over standard testing in fetuses with an isolated congenital heart abnormality (CHA), CHA associated with extra-cardiac malformations (ECMs) and CHA dependent upon anatomical subclassification.

METHODS

A systematic review of the literature was performed using MEDLINE, EMBASE, Web of Science and grey literature January 2010-February 2023. Studies were selected if they included greater than 20 cases of prenatally diagnosed CHA when standard testing (QF-PCR/chromosome microarray/karyotype) was negative. Pooled incremental yield was determined. PROSPERO CRD 42022364747.

RESULTS

Overall, 21 studies, incorporating 1957 cases were included. The incremental yield of PES (causative pathogenic and likely pathogenic variants) over standard testing was 17.4% (95% CI, 13.5%-21.6%), 9.3% (95% CI, 6.6%-12.3%) and 35.9% (95% CI, 21.0%-52.3%) for all CHAs, isolated CHAs and CHAs associated with ECMs. The subgroup with the greatest yield was complex lesions/heterotaxy; 35.2% (95% CI 9.7%-65.3%). The most common syndrome was Kabuki syndrome (31/256, 12.1%) and most pathogenic variants occurred de novo and in autosomal dominant (monoallelic) disease causing genes (114/224, 50.9%).

CONCLUSION

The likelihood of a monogenic aetiology in fetuses with multi-system CHAs is high. Clinicians must consider the clinical utility of offering PES in selected isolated cardiac lesions.

Impact of a dissemination strategy on family day care educators' intentions to adopt outdoor free play guidelines introduced in response to COVID-19: a randomized controlled trial

In 2021, guidelines for early childhood education and care were released recommending children are provided access to outdoor areas during all free play sessions to reduce the risk of coronavirus disease of 2019 transmission, aligning with the existing recommendations to increase children's physical activity. There is a need to understand how to disseminate guidelines in this setting as dissemination is a prerequisite of adoption and implementation. This randomized controlled trial explored the impact of a video-based strategy to disseminate guidelines on family day care educators' intentions to adopt outdoor free play guidelines. Educators (N = 255) were randomized to receive a video (intervention) or text-based (usual care) resource via email describing recommendations. Educators were invited to participate in a post-intervention survey at 5-week follow-up assessing intentions to adopt guidelines. The secondary outcomes included knowledge, beliefs about capabilities, beliefs about consequences, social/professional role and identity, goals, implementation of guidelines, acceptability of resource and intervention reach. There was no statistically significant difference between groups in intentions to adopt guidelines [ß = 0.01 (95% confidence interval -0.50 to 0.52), P = 0.97], nor for any secondary outcomes. Further investigation is needed to identify effective dissemination strategies in the family day care setting to increase the adoption of public health guidelines.

A qualitative study on the influence of COVID-19 on smoking behaviors through changing social and physical contexts

Globally, COVID-19 has been a major societal stressor and disrupted social and physical environments for many. Elucidating mechanisms through which societal disruptions influence smoking behavior has implications for future tobacco control efforts. Qualitative interviews were conducted among 38 adults who smoked combustible cigarettes in 2020 and 2021. The majority were women (75.7%), identified as Black (56.8%), were employed (61.3%), had a smoke-free home (66.7%) and lived in a small metro or rural (79.0%) county, primarily in rural southwest Georgia. Participants reported more time at home, increased isolation and less socializing, changed work and financial situations and altered household and family contexts. The vast majority of participants smoked more at some point during the pandemic with about half of these continuing to smoke more at the time of the interview. More time at home, multiple sources of stress and boredom were the main reasons for increased smoking. Decreases in smoking were attributed to financial strain, smoke-free home rules and nonsmoking family members, concerns about COVID-19 and less socializing with friends who smoke. Future tobacco control efforts during societal stressors such as pandemics should take into account specific psychosocial and environmental influences in attempts to minimize negative changes to smoking patterns.

Adapting implementation strategies: a case study of how to support implementation of healthy canteen policies

OBJECTIVES

Although evidence-based interventions (EBIs) and effective strategies to implement them exist, they cannot be used by policy makers and practitioners if they do not align with end users' needs. As such, adaptations to EBIs and implementation approaches are likely to occur to increase 'fit' with end users' capacity. This article describes an approach undertaken by a population health service delivery unit in one Australian state to develop an adapted implementation strategy to support the implementation of the mandatory healthy canteen policy (EBI) to all schools located in the service delivery region.

STUDY DESIGN

This is a case study of adapting an intervention to improve implementation of the healthy canteen policy.

METHODS AND RESULTS

This is a six-step pragmatic, empirically driven approach. The steps include (i) adapt, where appropriate, the EBI to facilitate implementation; (ii) identify end users' capacity for implementation; (iii) identify opportunities to adapt the implementation interventions while preserving meaningful intervention impact; (iv) undertake program adaptation; (v) develop training and resources to support delivery of implementation strategies and; (vi) evaluate the adapted intervention. This article describes the application of these steps by the authors to develop an adapted support strategy consistent with end users' needs.

CONCLUSIONS

This study provides some guidance on how to adapt implementation support approaches particularly when EBIs cannot be adapted. Future empirical research providing guidance on making practical adaptation decisions are needed.

Bone replaces articular cartilage in the rat knee joint after prolonged immobilization

BACKGROUND

Lost joint range of motion (ROM) is common in chronic osteoarthritis, alters regional weight-bearing across the articular surfaces, and contributes to loss of cartilage and bone alterations. Limited data exist on the regional effects on joints subjected to chronic losses of ROM.

OBJECTIVE

To characterize the regional replacement by bone as part of articular cartilage degeneration after prolonged immobilization.

METHODS

Eleven rat knees were rigidly-immobilized in flexion for 32weeks with contralateral and sham-operated (n=6) knees as controls. Sagittal medial tibial epiphysis histological sections assessed the anterior (non-weight-bearing), middle and posterior (both weight-bearing) regions. We quantified the distribution of collagen I, collagen II, cartilage thickness, glycosaminoglycan (GAG) staining, Mankin scoring, and subchondral bone plate cross-sectional area. Using immunohistochemistry (IHC), we visualized blood vessels, osteoblasts, and mesenchymal stem cells (MSCs).

RESULTS

Immobilized cartilage had increased collagen I content in the anterior tibial region with picrosirius red staining (immobilized=61±20%; contralateral=43±12%, p=0.033; sham=20±10%, p=0.028) and collagen I IHC (immobilized=40±10%; contralateral=11±4%, p=0.003; sham=5±3%, p=0.043). Articular cartilage was thinner anteriorly (18±30μm) in immobilized knees versus contralateral (124±40μm, p<0.001) and sham (125±43μm, p=0.043). GAG staining covered 2±4% of the anterior articular area in immobilized knees versus 28±12% contralaterally (p=0.003) and 26±7% in sham (p=0.043). Mankin scores in immobilized knees were 4.7±1.7 versus 0.2±0.4 and 0±0 for contralateral and sham (p=0.003, p=0.042), respectively. The trabecular bone plate area of anterior and posterior regions showed relative loss of cross-sectional area in immobilized knees compared to controls (immobilized/contralateral area ratios of 0.67 and 0.46 respectively, both p=0.003), while the area in the middle region was preserved. Movat's pentachrome stain and CD31 staining showed chondral vascular ingrowth from subchondral bone. Osteocalcin and CD90 MSC staining were decreased in immobilized knees versus contralateral (p=0.003, p=0.036 respectively).

CONCLUSIONS

Bony replacement characterizes articular cartilage degeneration of knees immobilized for 32weeks in the anterior, non-weight bearing region of the tibia. Replacement of cartilage by bone may have been mediated by chondral vascularization, suggesting irreversible changes. These findings stress the importance of weight-bearing and joint motion to maintain cartilage structure.

Time Since Migration and HIV Risk Behaviors Among Puerto Ricans Who Inject Drugs in New York City

BACKGROUND

Among people who inject drugs (PWID) in the United States, those who initiated drug injection in Puerto Rico (immigrant Puerto Rican PWID) engage in more injection and sexual risk behaviors, and have higher HIV incidence than non-Hispanic whites.

OBJECTIVE

Understand the persistence of these HIV behaviors.

METHODS

In a cross-sectional study conducted in New York City (NYC) in 2012 (National HIV Behavioral Surveillance), PWID aged ≥18 years were recruited using Respondent-Driven Sampling, interviewed, and tested for HIV. Participants were categorized into 5 different groups: (1) US-born non-Hispanic PWID, (2) US-born Puerto Rican PWID, (3) recent immigrant Puerto Rican PWID (≤3 years in NYC), (4) medium-term immigrant Puerto Rican PWID (>3 and ≤10 years in NYC), and (5) long-term immigrant Puerto Rican PWID (>10 years in NYC). We examined the relationship between time since migrating on sexual and injection risk behaviors among immigrant Puerto Rican PWID, compared with U.S.-born Puerto Rican PWID and US-born non-Hispanic PWID. Adjusted odds ratios (aOR) and 95% confidence intervals (95% CI) were estimated using logistic regression.

RESULTS

A total of 481 PWID were recruited. In adjusted analyses using US-born non-Hispanic PWID as the comparison group, syringe sharing was significantly more likely among medium-term immigrants; and unprotected sex with casual partners was more likely among recent and long-term immigrants.

CONCLUSIONS

The risk-acculturation process for immigrant Puerto Rican PWID may be nonlinear and may not necessarily lead to risk reduction over time. Research is needed to better understand this process.

Evolution of the oxygen sensitivity of cytochrome c oxidase subunit 4

Vertebrates possess two paralogs of cytochrome c oxidase (COX) subunit 4: a ubiquitous COX4-1 and a hypoxia-linked COX4-2. Mammalian COX4-2 is thought to have a role in relation to fine-tuning metabolism in low oxygen levels, conferred through both structural differences in the subunit protein structure and regulatory differences in the gene. We sought to elucidate the pervasiveness of this feature across vertebrates. The ratio of COX4-2/4-1 mRNA is generally low in mammals, but this ratio was higher in fish and reptiles, particularly turtles. The COX4-2 gene appeared unresponsive to low oxygen in nonmammalian models (zebrafish, goldfish, tilapia, anoles, and turtles) and fish cell lines. Reporter genes constructed from the amphibian and reptile homologues of the mammalian oxygen-responsive elements and hypoxia-responsive elements did not respond to low oxygen. Unlike the rodent ortholog, the promoter of goldfish COX4-2 did not respond to hypoxia or anoxia. The protein sequences of the COX4-2 peptide showed that the disulfide bridge seen in human and rodent orthologs would be precluded in other mammalian lineages and lower vertebrates, all of which lack the requisite pair of cysteines. The coordinating ligands of the ATP-binding site are largely conserved across mammals and reptiles, but in Xenopus and fish, sequence variations may disrupt the ability of the protein to bind ATP at this site. Collectively, these results suggest that many of the genetic and structural features of COX4-2 that impart responsiveness and benefits in hypoxia may be restricted to the Euarchontoglires lineage that includes primates, lagomorphs, and rodents.

Factors associated with recent HIV testing among men who have sex with men in New York City

Understanding factors associated with recent HIV testing among men who have sex with men (MSM) is important for designing interventions to increase testing rates and link cases to care. A cross-sectional study of MSM was conducted in NYC in 2011 using venue-based sampling. Associations between HIV testing in the past 12 months and relevant variables were examined through the estimation of prevalence ratios (PR) and 95 % confidence intervals (CI). Of 448 participants, 107 (23.9 %) had not been tested in the past 12 months. Factors independently associated with not testing in the previous 12 months were: lack of a visit to a healthcare provider in the past 12 months (aPR: 2.5; 95 % CI: 1.9, 3.2); age ≥30 (adjusted PR: 1.9; 95 % CI: 1.4, 2.7); not having completed a bachelor's degree (aPR: 1.6; 95 % CI: 1.0, 2.4); and non-gay sexual identity (aPR: 1.4; 95 % CI: 1.0, 1.8); such MSM may be less aware of the need for frequent HIV testing.

Herpes simplex virus type 2 incidence and associated risk factors among female sex workers in a high HIV-prevalence area of China

Herpes simplex virus type 2 (HSV-2) can contribute to the spread of HIV. From March 2006 to November 2009, female sex workers (FSWs) in Yunnan, China were recruited into an open cohort study to determine incidence and risk factors for HSV-2 acquisition. Participants were interviewed and tested for HSV-2 and other sexually transmitted infections (STIs) every six months. A multivariate Cox proportional hazards regression model with time-dependent variables was used to measure associations with HSV-2 acquisition. In 3.5 years, 83 incident cases of HSV-2 infection were diagnosed, yielding an overall incidence of 21.9 per 100 person years (PY) (95% confidence interval [CI], 17.8-26.3). Working in higher risk commercial sex venues, current Neisseria gonorrhoeae infection, age of sexual debut <18 years and lack of a regular sex partner were independent factors associated with HSV-2 acquisition. The high incidence of HSV-2 suggests that prevention methods for HIV/STI control are urgently needed.

Secular trends in the prevalence of general and abdominal obesity among Chinese adults, 1993-2009

The objective of this study is to examine the trends in body mass index (BMI), waist circumference (WC) and prevalence of overweight (BMI 25-27.49 kg m(-2) ), general obesity (BMI ≥ 27.5 kg m(-2) ) and abdominal obesity (WC ≥ 90 cm for men and ≥80 cm for women) among Chinese adults from 1993 to 2009. Data were obtained from the China Health and Nutrition Survey, which was conducted from 1993 to 2009 and included a total of 52,621 Chinese adults. During the period of 1993-2009, mean BMI values increased by 1.6 kg m(-2) among men and 0.8 kg m(-2) among women; mean WC values increased by 7.0 cm among men and 4.7 cm among women. The prevalence of overweight increased from 8.0 to 17.1% among men (P < 0.001) and from 10.7 to 14.4% among women (P < 0.001); the prevalence of general obesity increased from 2.9 to 11.4% among men (P < 0.001) and from 5.0 to 10.1% among women (P < 0.001); the prevalence of abdominal obesity increased from 8.5 to 27.8% among men (P < 0.001) and from 27.8 to 45.9% among women (P < 0.001). Similar significant trends were observed in nearly all age groups and regions for both men and women. The prevalence of overweight, general obesity and abdominal obesity among Chinese adults has increased greatly during the past 17 years.

Prevalence of bisexual behaviour among bridge population of men who have sex with men in China: a meta-analysis of observational studies

OBJECTIVE

To integrate the empirical estimates of bisexual behaviour among the bridge population of men who have sex with men (MSM) in China and their HIV and syphilis prevalences stratified by sexual behaviour.

METHODS

The Pubmed, Chinese Biomedical, Chinese National Knowledge Infrastructure, VIP, Wanfang and Google Scholar databases were searched to January 2011 to identify relevant articles. Data of eligible citations were extracted by two reviewers. All analyses were performed using Stata 10.0.

RESULTS

Forty-nine articles (including 28 739 MSM subjects) met the selection criteria. Aggregated findings indicated that the estimated prevalence of bisexual behaviour among MSM in China is 31.2% (95% CI 28.1% to 34.5%). HIV and syphilis prevalences were 5.4% and 11.4%, respectively, among MSM engaging in bisexual behaviour and 3.8% and 9.3% among MSM only having sex with men. HIV prevalence among MSM engaging in sex with both men and women was significantly higher than in those who only have sex with men (OR 1.30; 95% CI 1.04 to 1.62; p=0.02).

CONCLUSION

There is a high prevalence of bisexual behaviour among MSM in China and bisexual behaviour is significantly associated with increased HIV infection risk. The results of this meta-analysis highlight a critical pattern of HIV transmission among MSM in China and indicate that targeted interventions aimed at encouraging safe sex practices and promoting societal and family acceptance of MSM are urgently needed.

Increase in Body Mass Index, Waist Circumference and Waist-to-Height Ratio is Associated with High Blood Pressure in Children and Adolescents in China

This study compared the association between blood pressure (BP) and obesity in 1145 Chinese children and adolescents (608 males, 537 females) using data from the 2006 China Health and Nutrition Survey. Obesity was diagnosed by body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR). Analysis of variance was used to analyse the difference in BP among different subgroups. Odds ratios (OR) were calculated and multivariate logistic regression analysis was carried out. The prevalence of high systolic and diastolic BP increased directly with corresponding increments in BMI, WC and WHtR, although the prevalence and OR of high BP were higher when increased BMI was combined with WC (OR 3.39; 95% confidence interval [CI] 1.79, 6.41) or WHtR (OR 3.28; 95% CI 1.71, 6.30). In conclusion, increased BMI, WC and WHtR were directly associated with high BP in Chinese children and adolescents.

The role of foot and ankle assessment of patients with lower limb osteoarthritis

OBJECTIVES

Physiotherapists do not routinely examine the feet of patients with lower limb osteoarthritis, and there is no widely used tool for measuring foot posture. However, differences in foot posture have been demonstrated between patients with medial compartment osteoarthritis of the knee and osteoarthritis of the hip, and guidelines for managing these patients include interventions such as orthotics which presume foot assessment. This study considers a new clinical tool, the Foot Posture Index (FPI). It examines its utility in a physiotherapy outpatient setting with a cohort of patients with medial compartment osteoarthritis of the knee and osteoarthritis of the hip, and investigates the relationship of FPI scores with the range of dorsiflexion of the ankle.

DESIGN

Cross-sectional observational study.

SETTING

A specialist orthopaedic hospital.

PARTICIPANTS

In total, there were 60 participants: 20 patients with medial compartment osteoarthritis of the knee, 20 patients with osteoarthritis of the hip, and a control group of 20 age-matched healthy volunteers.

OUTCOME MEASURES

A single measurement of the FPI and range of dorsiflexion.

RESULTS

Significant differences in FPI scores and range of dorsiflexion were seen between groups. On average, patients with osteoarthritis of the hip had more supinated, plantarflexed feet, and patients with medial compartment osteoarthritis of the knee had pronated feet. Healthy controls fell within the normal range. Patients with osteoarthritis of the hip had a median FPI score of -4.5, patients with medial compartment osteoarthritis of the knee had a median FPI score of 7.0, and the healthy controls had a median FPI score of 1.0. The median difference in FPI scores between patients with osteoarthritis of the hip and medial compartment osteoarthritis of the knee was 12 [95% confidence interval (CI) 10 to 13]; between patients with osteoarthritis of the hip and the healthy group was 6 (95% CI 3 to 9); and between patients with medial compartment osteoarthritis of the knee and the healthy group was 5 (95% CI 3 to 8). The median difference in dorsiflexion scores between patients with osteoarthritis of the hip and medial compartment osteoarthritis of the knee was 10 degrees (95% CI 8 to 15); between patients with osteoarthritis of the hip and the healthy group was 10 degrees (95% CI 7 to 15); and between patients with medial compartment osteoarthritis of the knee and the healthy group was 0 degrees (95% CI -3 to 5). Foot posture and range of dorsiflexion were moderately positively correlated (rho 0.57), with pronated feet having a greater range of dorsiflexion.

CONCLUSION

The FPI is sufficiently sensitive to measure differences in foot posture of patients with medial compartment osteoarthritis of the knee and osteoarthritis of the hip, and is easy to use. Accurate foot assessment is useful as foot postures may be influenced by specific physiotherapy treatment modalities and orthotic interventions.

Diagnosis and treatment of lower urinary tract symptoms suggestive of overactive bladder and bladder outlet obstruction among men in general practice in the UK

OBJECTIVE

To assess the epidemiology and treatment of storage symptoms suggestive of overactive bladder (OAB) and voiding symptoms suggestive of bladder outlet obstruction (BOO) because of benign prostatic hyperplasia in UK general practice.

PATIENTS AND METHODS

This was a retrospective analysis of data collected between 2000 and 2006 and entered in The Health Improvement Network general practice database, containing medical records for > 1 million men (aged >or= 18 years) in the UK. Using Read codes, we analysed the prevalence of storage and voiding lower urinary tract symptoms (LUTS) as well as prescribing trends for 5alpha-reductase inhibitors (5ARIs) and alpha-blockers for LUTS secondary to BOO and antimuscarinics for OAB.

RESULTS

In 2006, the prevalence of diagnosed LUTS/OAB was only 0.3% and the recorded prevalence of LUTS/BOO was only 2.2%. Treatment rates also remained low throughout the study period. In the 12 months before 1 January 2006, only 25% of men diagnosed with OAB and 6-7% of men with storage LUTS received antimuscarinics, whereas 36% of men with a record of LUTS/BOO received alpha-blockers and/or 5ARIs. Alpha-blockers were prescribed to approximately 10% of men diagnosed with OAB or storage LUTS who did not have any recorded BOO diagnosis or symptoms.

CONCLUSION

Diagnosis of both storage and voiding LUTS occurs at much lower rates than indicated by prevalence estimates. Despite the availability of effective prescription therapies, many men with storage and/or voiding LUTS may not be receiving appropriate treatment in UK general practice.

Quantitative computer-assisted osteodensitometry in total hip arthroplasty

Several factors can cause bone loss and fixation failure following total hip arthroplasty (THA), including polyethylene wear debris, implant micromotion and stress shielding. Various techniques have been used in an effort to detect bone density loss in vivo, all with varying success. Quantitative computed tomography (qCT)-assisted osteodensitometry has been shown to be useful in assessing the in vivo structural bone changes after THA. It has a high resolution, accuracy and reproducibility, thereby making it a useful tool for research purposes, and it is able to differentiate between cortical and cancellous bone structures and assess the bone/implant interface. This technique also provides valuable information about the pattern of stress shielding which occurs around the prosthesis and can show early bony changes, which may prove informative about the quality of implant fixation and surrounding bone adaptation. In conjunction with finite-element analysis, qCT is able to generate accurate patient-specific meshes on which to model implants and their effect on bone remodelling. This technology can be useful to predict bone remodelling and the quality of implant fixation using prostheses with different design and/or biomaterials. In the future, this tool could be used for pre-clinical validation of new implants before their introduction in the market-place.

Head and neck mucosal squamous cell carcinoma: results of palliative management

OBJECTIVE

To document the outcome of patients deemed at initial diagnosis to be appropriate for palliative care.

MATERIALS AND METHODS

Over a five-year period, all patients with head and neck mucosal squamous cell carcinoma (HNMSCC) were referred to one consultant surgeon, and data were collated retrospectively.

RESULTS

Of 286 patients with HNMSCC, 60 (21 per cent) were deemed appropriate for palliative care at initial diagnosis. Their median survival was 154 days, with hypopharyngeal and oropharyngeal tumours forming a disproportional percentage of the initial diagnoses (p < 0.001). After initial assessment, 66 per cent of patients were discharged to their home, 17 per cent to hospice care and 17 per cent were transferred to other institutions. Including deaths during the initial admission, 29 per cent of patients did not return home after diagnosis. Palliative treatment included operative interventions in 35 per cent and radiotherapy in 43 per cent. Time spent in further hospital care averaged 47 days, and 47 per cent of patients eventually died in hospital.

CONCLUSION

One in five patients presenting with HNMSCC were deemed appropriate for palliative care at initial presentation and survived less than six months after diagnosis. More than one-third required surgical intervention, and 29 per cent never returned home.

Autoradiographic localization of (125)i[Tyr(14)] nociceptin/orphanin FQ binding sites in macaque primate CNS

Nociceptin/orphanin FQ (N/OFQ) is a recently identified neuropeptide that has been implicated in a multitude of CNS functions. These include nociception, feeding, cognition, locomotion, stress and neuroendocrine control. The endogenous receptor for this ligand is the nociceptin/orphanin FQ peptide (NOP) receptor. The distribution of NOP in rodent has been widely reported by the use of in situ hybridization, immunohistochemistry and autoradiographic radioligand binding but less is known of its localization in higher species. We have therefore sought to optimize and determine the distribution of (125)I[Tyr(14)]N/OFQ binding sites in macaque primate brain and spinal cord. Highest levels of binding were observed in neocortical areas, hippocampus, amygdala, caudate nucleus and putamen, medial thalamic nuclei and superficial laminae of the superior colliculus. These novel data present for the first time, the distribution of N/OFQ receptors in non-human primate CNS and, by comparison with localization in the rat, reveal that species differences may exist in the distribution of this neuropeptide receptor. These data have important implications regarding the roles of N/OFQ across species and may have ramifications in the interpretation of preclinical pharmacological studies.

Lotus corniculatus condensed tannins decrease in vivo populations of proteolytic bacteria and affect nitrogen metabolism in the rumen of sheep

Condensed tannins in forage legumes improve the nutrition of sheep by reducing ruminal degradation of plant protein and increasing crude protein flow to the intestine. However, the effects of condensed tannins in forage legumes on rumen bacterial populations in vivo are poorly understood. The aim of this study was to investigate the specific effects of condensed tannins from Lotus corniculatus on four proteolytic rumen bacteria in sheep during and after transition from a ryegrass (Lolium perenne)-white clover (Trifolium repens) diet (i.e., low condensed tannins) to a Lotus corniculatus diet (i.e., higher condensed tannins). The bacterial populations were quantified using a competitive polymerase chain reaction. Lotus corniculatus was fed with or without ruminal infusions of polyethylene glycol (PEG), which binds to and inactivates condensed tannins, enabling the effect of condensed tannins on bacterial populations to be examined. When sheep fed on ryegrass-white clover, populations of Clostridium proteoclasticum B316T, Butyrivibrio fibrisolvens C211a, Eubacterium sp. C12b, and Streptococcus bovis B315 were 1.5 x 10(8), 1.1 x 10(6), 4.6 x 10(8), and 7.1 x 10(6) mL(-1), respectively. When the diet was changed to Lotus corniculatus, the average populations (after 8-120 h) of C. proteoclasticum, B. fibrisolvens, Eubacterium sp., and S. bovis decreased (P < 0.001) to 2.4 x 10(7), 1.1 x 10(5), 1.1 x 10(8), and 2.5 x 10(5) mL(-1), respectively. When PEG was infused into the rumen of sheep fed Lotus corniculatus, the populations of C. proteoclasticum, B. fibrisolvens, Eubacterium sp., and S. bovis were higher (P < 0.01-0.001) than in sheep fed Lotus corniculatus without the PEG infusion, with average populations (after 8-120 h) of 4.9 x 10(7), 3.8 x 10(5), 1.9 x 10(8), and 1.0 x 10(6), respectively. Sheep fed the Lotus corniculatus diet had lower rumen proteinase activity, ammonia, and soluble nitrogen (P < 0.05-0.001) than sheep that were fed Lotus corniculatus plus PEG. The Lotus corniculatus diet reduced rumen nitrogen digestibility (P < 0.05) and ammonia pool size and increased the flow of undegraded feed nitrogen to the abomasum. The nitrogen intake, rumen non-ammonia nitrogen pool size, rumen microbial non-ammonia nitrogen pool size, and abomasal microbial non-ammonia nitrogen fluxes were similar both in sheep fed only Lotus corniculatus and in sheep fed Lotus corniculatus plus PEG, but nonmicrobial non-ammonia nitrogen flux to the abomasum was higher (P < 0.01) for the sheep fed only Lotus corniculatus. Although condensed tannins in Lotus corniculatus reduced the populations of some proteolytic bacteria, total ruminal microbial protein and microbial protein outflow to the abomasum were unchanged, suggesting a species-specific effect of condensed tannins on bacteria in the rumen.

Design and use of 16S ribosomal DNA-directed primers in competitive PCRs to enumerate proteolytic bacteria in the rumen

Competitive Polymerase Chain Reaction primers were designed for Streptococcus, B. fibrisolvens, P. bryantii, Eubacterium sp., Prevotella, and a universal primer for the eubacteria. DNA was extracted from rumen contents collected from eight dairy cows fed four diets: adequate nitrogen, adequate nitrogen plus carbohydrate, low nitrogen, and low nitrogen plus carbohydrate. B. fibrisolvens was significantly higher on the adequate nitrogen plus carbohydrate and the low nitrogen plus carbohydrate diets compared with the other diets, while P. bryantii was significantly higher on the low nitrogen plus carbohydrate diet compared with the adequate nitrogen diet. The population of Eubacterium sp. was significantly lower on both the adequate nitrogen plus carbohydrate and low nitrogen plus carbohydrate diets. Streptococcus populations were significantly lower on the low nitrogen plus carbohydrate diet compared with all three other diets, whereas there were no significant differences in populations of Prevotella or total eubacteria on any of the diets.

Isolation and characterisation of a cassava catalase expressed during post-harvest physiological deterioration

Storage roots of cassava undergo a rapid, endogenous, post-harvest deterioration response that is thought to involve oxidative processes. A cassava catalase (MecCAT1) was isolated from a root cDNA library. The transcript is expressed predominantly in roots with little expression in leaves. Catalase enzyme activity and MecCAT1 transcript expression during the post-harvest period were compared in highly susceptible and less susceptible cultivars and suggest that high levels of catalase activity may play a role in delaying the deterioration response.

Modification of the human blink reflex by transient and sustained features of acoustic prestimulation

The effects of acoustic stimuli whose onsets and durations were controlled to vary their transient and sustained features on the size of a subsequently elicited blink reflex were examined in humans. Prestimuli both with and without transient features inhibited the reflex when they preceded the eliciting stimulus by brief lead intervals, showing that acoustic transients are sufficient, but not necessary, for reflex inhibition. Inhibition evoked by transient and sustained stimulus features showed partial summation, and inhibition evoked by stimuli with only transient and with transient and sustained features showed similar decay functions with increasing lead intervals. Blink augmentation was found at longer lead intervals early but not late in a session, and was more evident in women than men. Prestimuli with only transient features were more effective than those with both transient and sustained features, showing that sustained stimulus energy at the time of reflex elicitation is not only not necessary for blink augmentation, but also diminishes it.

Hydrogen peroxide and flavan-3-ols in storage roots of cassava (Manihot esculenta crantz) during postharvest deterioration

Cassava storage roots are an important staple food throughout the lowland humid tropics. However, cassava suffers from a poorly understood storage disorder, known as postharvest physiological deterioration (PPD), which constrains its exploitation. In an attempt to broaden the understanding of PPD, nine different cassava cultivars were analyzed for specific compounds accumulating during the process. The production of hydrogen peroxide (H(2)O(2)) is involved in the early stages of PPD in cassava roots. H(2)O(2) was quantified and localized histochemically at the tissue and cell level in deteriorating roots. This reactive oxygen species accumulated during the first 24 h after harvest, especially in the inner parenchymatic tissue. Three flavan-3-ols, (+)-catechin, (+)-catechin gallate, and (+)-gallocatechin, accumulated during the storage of cassava roots. However, these potential antioxidants cannot be related to early storage disorders or wound responses because they start to accumulate only after 4-6 days.

Nutrition, exercise, work, and sex in pregnancy

This article focuses on the effect of daily living on pregnancy outcome. Although most patients can continue their everyday activities without any concern about effect on pregnancy outcome, all pregnant patients want and need their physician's advice about all of these areas.

A novel alpha-amylase gene is transiently upregulated during low temperature exposure in apple fruit

An alpha-amylase gene product was isolated from apple fruit by reverse-transcriptase PCR using redundant primers, followed by 5' and 3' RACE. The gene is a member of a small gene family. It encodes a putative 46.9 kDa protein that is most similar to an alpha-amylase gene from potato (GenBank accession M79328). In apple fruit this new gene was expressed at low levels, as detected by reverse-transcriptase PCR, in a number of plant tissues and during fruit development. Highest levels of mRNA for this transcript were observed 3 to 9 days after placing apple fruit at 0.5 degrees C. Phylogenetic analysis of amino acid sequence places the potato and apple proteins as a distinct and separate new subgroup within the plant alpha-amylases, which appears to have diverged prior to the split between monocotyledonous and dicotyledonous plants. These two divergent alpha-amylases lack the standard signal peptide structures found in all other plant alpha-amylases, and have sequence differences within the B-domain and C-domain. However, comparisons with structures of known starch hydrolases suggest that these differences are unlikely to affect the enzymatic alpha-1,4-amylase function of the protein. This is the first report of upregulation of a dicotyledonous alpha-amylase in response to low temperature, and confirms the presence of a new family of alpha-amylases in plants.

Automated sample preparation of Roxifiban tablets: transfer of a manual method to an automated workstation

Automation offers obvious advantages for the preparation of tablets prior to analysis by HPLC including unattended operation, minimization of human intervention and an electronic audit trail. However, significant effort has to be put in up front to develop and validate an automated method, particularly if it is required to closely follow an existing manual method. Here, method transfer for Roxifiban, a fibrinogen receptor antagonist, will be discussed. A Zymark tablet processing workstation II (TPWII) was used for all automated sample preparations. Manual methods for composite assay, content uniformity, weight variation and degradation products testing of a tablet formulation were transferred to the TPWII. The method involved weighing of the sample, disintegration of the dosage form by homogenization, extraction of the analyte in the homogenate solution, filtration of the homogenate, dilution of the filtrate and transfer to autosampler vials. Obstacles to a quick transfer included limitations in the volume capabilities of the TPWII, poor analyte solubility and achieving proper conditioning of the transfer lines and filter. After resolving these issues, a validated method was achieved. Spiked recoveries were from 99.4 to 101.1% (RSD's <0.5%). A cross-validation between automated and manual assay methods was compared by Westlake analysis giving a 0.7% calculated interval at the 95% confidence level. Carryover was 0.07% after 20 sample preparations at the highest tablet strength.

Mouse models of tumor development in neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a prevalent familial cancer syndrome resulting from germ line mutations in the NF1 tumor suppressor gene. Hallmark features of the disease are the development of benign peripheral nerve sheath tumors (neurofibromas), which can progress to malignancy. Unlike humans, mice that are heterozygous for a mutation in Nf1 do not develop neurofibromas. However, as described here, chimeric mice composed in part of Nf1-/- cells do, which demonstrates that loss of the wild-type Nf1 allele is rate-limiting in tumor formation. In addition, mice that carry linked germ line mutations in Nf1 and p53 develop malignant peripheral nerve sheath tumors (MPNSTs), which supports a cooperative and causal role for p53 mutations in MPNST development. These two mouse models provide the means to address fundamental aspects of disease development and to test therapeutic strategies.

Preliminary characterization of crystals of an in vitro evolved cyanocobalamin (vitamin B12) binding RNA

A 35-nucleotide pseudoknot that binds vitamin B12 been isolated using systematic evolution of ligands by exponential enrichment (SELEX). Affinity chromatography was used to purify functional, properly folded molecules and the hanging-drop vapor-diffusion method was used to crystallize this aptamer. Two crystal forms have been obtained and the preliminary crystallographic characterization is reported here. Both crystal forms (space groups I222 or I212121 and C2221) diffract to 2.9 A and should prove sufficient for structure determination.

An elective-titration study of the comparative effectiveness of two angiotensin II-receptor blockers, irbesartan and losartan. Irbesartan/Losartan Study Investigators

This multicenter, randomized, double-masked, elective-titration study was designed to compare the effectiveness, safety, and tolerability of irbesartan and losartan, two angiotensin II subtype AT1-receptor blockers, in the treatment of patients with mild-to-moderate hypertension. After a 3-week, single-masked, placebo lead-in period, 432 patients with a mean seated diastolic blood pressure (SeDBP) of 95 to 115 mm Hg were randomly allocated to receive either irbesartan 150 mg once daily (n = 213) or losartan 50 mg once daily (n = 219). At week 4, if SeDBP at trough (i.e., 24 +/- 3 hours after the previous dose) was > or = 90 mm Hg, the daily dose was doubled (to irbesartan 300 mg or losartan 100 mg). At week 8, if trough SeDBP was > or = 90 mm Hg, hydrochlorothiazide 12.5 mg once daily was added to the regimen; consistent with the prescribing information for losartan, the dose of losartan was reduced to 50 mg once daily on the addition of hydrochlorothiazide. A total of 370 patients (178 irbesartan and 192 losartan) were evaluable for efficacy. The mean change in trough SeDBP at week 8, the primary efficacy end point, was significantly greater in patients receiving irbesartan monotherapy than in those receiving losartan monotherapy (-10.2 mm Hg vs -7.9 mm Hg, respectively). At week 12, reductions in trough SeDBP and seated systolic blood pressure were greater with irbesartan treatment than with losartan treatment (-13.8 mm Hg vs -10.8 mm Hg and -18.0 mm Hg vs -13.9 mm Hg, respectively), and a greater proportion of irbesartan patients responded to therapy (i.e., trough SeDBP < 90 mm Hg or reduction in trough SeDBP > or = 10 mm Hg) compared with losartan patients (78% vs 64%, respectively). Both regimens were well tolerated.

Detection of Clostridium proteoclasticum and closely related strains in the rumen by competitive PCR

A competitive PCR technique was used to enumerate the proteolytic bacterium Clostridium proteoclasticum from the rumen. A PCR primer, which circumscribes this organism and several closely related strains, was designed for a variable region within their 16S rRNA genes and was used in conjunction with a universal forward primer. This primer pair was tested for specificity against 85 ruminal bacterial strains. An internal control DNA was constructed for use in competitive PCRs and was shown to amplify under the same reaction conditions and with the same amplification efficiency as the target DNA. DNA from a known number of C. proteoclasticum cells was coamplified with the internal control to construct a standard curve. Rumen samples were collected from eight dairy cows fed four diets in rotation: high nitrogen, high nitrogen supplemented with carbohydrate, low nitrogen, and low nitrogen supplemented with carbohydrate. DNA extracted from these and spiked with internal control DNA was amplified with the C. proteoclasticum primer pair. The relative intensities of the PCR products were used to quantitate the numbers of C. proteoclasticum cell equivalents from the rumen samples. The numbers ranged from 2.01 x 10(6) ml-1 to 3.12 x 10(7) ml-1. There was no significant effect on the numbers of C. proteoclasticum detected in rumen samples among cows fed the four diets. The utility of the competitive PCR approach for quantifying ruminal bacterial populations in vivo and the occurrence of C. proteoclasticum in forage-fed dairy cows are discussed.

Analysis of changes in acute-phase plasma proteins in an acute inflammatory response and in rheumatoid arthritis using two-dimensional gel electrophoresis

Two-dimensional (2-D) gel analysis was used to examine differences in the levels of 19 plasma proteins: before and after an acute inflammatory reaction (parenteral typhoid vaccination) in normal subjects, between rheumatoid arthritis (RA) patients and normals and in RA patients treated with tenidap (120 mg) and piroxicam (20 mg). Typhoid vaccination increased levels of SAA, haptoglobin alpha1, haptoglobin alpha2, haptoglobin beta and alpha1-anti-chymotrypsin but decreased transthyretin and apolipoprotein E. In RA patients, serum amyloid A (SAA), haptoglobin alpha2, haptoglobin beta, alpha1-antichymotrypsin and C3 proactivator levels were elevated while apolipoprotein A-I, apolipoprotein A-IV, transthyretin, Gc-globulin, alpha2-HS glycoprotein, alpha2-macroglobulin and alpha1-B glycoprotein levels were decreased, compared to normals. Compared to piroxicam, tenidap lowered levels of alpha1-antiprotease and SAA but raised the levels of transthyretin, Gc-globulin, alpha2-HS-glycoprotein and alpha2-macroglobulin in RA patients. C-reactive protein (CRP) could not be quantified on 2-D gels but, when measured by rate nephelometry, levels were reduced after treatment with tenidap compared to piroxicam. The general pattern of the acute phase protein response to an acute inflammatory response to typhoid vaccination is similar to that in the chronic inflammatory condition, RA. The impact of tenidap on both positive and negative acute-phase proteins in RA patients could clearly be distinguished from that of piroxicam.

A biophysical study of integral membrane protein folding

In order to characterize the thermodynamic constraints on the process of integral membrane protein folding and assembly, we have conducted a biophysical dissection of the structure of bacteriorhodopsin (BR), a prototypical alpha-helical integral membrane protein. Seven polypeptides were synthesized, corresponding to each of the seven transmembrane alpha-helices in BR, and the structure of each individual polypeptide was characterized in reconstituted phospholipid vesicles. Five of the seven polypeptides form stable transmembrane alpha-helices in isolation from the remainder of the tertiary structure of BR. However, using our reconstitution protocols, the polypeptide corresponding to the F helix in BR does not form any stable secondary structure in reconstituted vesicles, and the polypeptide corresponding to the G helix forms a hyperstable beta-sheet structure with its strands oriented perpendicular to the plane of the membrane. [The polypeptide corresponding to the C helix spontaneously equilibrates in a pH-dependent manner between a transmembrane alpha-helical conformation, a peripherally bound nonhelical conformation, and a fully water soluble conformation; the conformational properties of this polypeptide are the subject of the accompanying paper: Hunt et al. (1997) Biochemistry 36, 15177-15192.] Our observations suggest that the folding of alpha-helical integral membrane proteins may proceed spontaneously. However, the preference for a non-native conformation exhibited by two of the polypeptides suggests that the formation of some transmembrane substructures could require external constraints such as the links between the helices, interactions with the rest of the protein, or the involvement of cellular chaperones or translocases. Our results also suggest a strategy for improving the thermodynamic stability of alpha-helical integral membrane proteins, a goal that could facilitate attempts to overexpress and/or refold them.

Seroepidemiologic studies of hantavirus infection among wild rodents in California

A total of 4,626 mammals were serologically tested for antibodies to Sin Nombre virus. All nonrodent species were antibody negative. Among wild rodents, antibody prevalence was 8.5% in murids, 1.4% in heteromyids, and < 0.1% in sciurids. Of 1,921 Peromyscus maniculatus (deer mice), 226 (11.8%) were antibody positive, including one collected in 1975. The highest antibody prevalence (71.4% of 35) was found among P. maniculatus on Santa Cruz Island, off the southern California coast. Prevalence of antibodies among deer mice trapped near sites of human cases (26.8% of 164) was significantly higher than that of mice from other sites (odds ratio = 4.5; 95% confidence interval = 1.7, 11.6). Antibody prevalence increased with rising elevation (> 1,200 meters) and correlated with a spatial cluster of hantavirus pulmonary syndrome cases in the Sierra Nevada.

Characterization of proteolytic activities of rumen bacterial isolates from forage-fed cattle

The proteolytic activities of eight strains of ruminal bacteria isolated from New Zealand cattle were characterized with respect to their cellular location, response to proteinase inhibitors and hydrolysis of artificial proteinase substrates. The Streptococcus bovis strains had predominantly cell-bound activity, which included a mixture of serine and cysteine-type proteinases which had high activity against leucine p-nitroanilide (LPNA). The Eubacterium strains had a mainly cell-associated activity with serine and metallo-type proteinases which showed high activity against the chymotrypsin substrate, N-succinyl alanine alanine phenylalanine proline p-nitroanilide (NSAAPPPNA) and some LPNA activity. A Butyrivibrio strain, C211, had a cell-bound mixture of cysteine and metallo-proteinase activities and strongly hydrolysed NSAAPPPNA and LPNA while the high activity Butyrivibrio-like strain, B316, had a cell-bound, mainly serine proteinase activity which strongly hydrolysed NSAAPPPNA. A Prevotella-like strain, C21a, had a mixture of cysteine, serine and metallo-proteinase activities which were cell-bound and hydrolysed LPNA. The activities of these strains did not match those of the bacterial fraction of rumen fluid, which contained activities mainly of the cysteine type with specificity towards the substrate N-succinyl phenylalanine p-nitroanilide. The contribution of these strains to proteolysis in the rumen is discussed.