Can a combination of interventions accelerate outcomes to deliver on the Sustainable Development Goals for young children? Evidence from a longitudinal study in South Africa and Malawi

BACKGROUND

This study aimed to identify possible entry points for interventions that can act as development accelerators for children and adolescents in South Africa and Malawi.

METHODS

This study was a secondary data analysis. Data were sourced from the Child Community Care longitudinal study which tracked child well-being outcomes among 989 children (4-13 years) and their caregivers affected by HIV and enrolled in community-based organizations in South Africa and Malawi. We examined associations between five hypothesized accelerating services/household provisions-measured as access at baseline and follow-up and 12 child outcomes that relate to indicators within the Sustainable Development Goals (SDGs) framework. We calculated the adjusted probabilities of experiencing each SDG aligned outcome conditional on receipt of single, combined or all identified accelerators.

RESULTS

The results show household food security is associated with positive child education and cognitive development outcomes. Cash grants were positively associated with nutrition and cognitive development outcomes. Living in a safe community was positively associated with all mental health outcomes. Experiencing a combination of two factors was associated with higher probability of positive child outcomes. However, experiencing all three accelerators was associated with better child outcomes, compared with any of the individual factors by themselves with substantial improvements noted in child education outcomes.

CONCLUSIONS

Combined delivery of specific interventions or services may yield greater improvements in child outcomes across different developmental domains. It is recommended that multiple support avenues in combination like improving food security and safe communities, as well as social protection grants, should be provided for vulnerable children to maximize the impact.

Adolescent Motherhood and HIV in South Africa: Examining Prevalence of Common Mental Disorder

The mental health of adolescents (10–19 years) remains an overlooked global health issue, particularly within the context of syndemic conditions such as HIV and pregnancy. Rates of pregnancy and HIV among adolescents within South Africa are some of the highest in the world. Experiencing pregnancy and living with HIV during adolescence have both been found to be associated with poor mental health within separate explorations. Yet, examinations of mental health among adolescents living with HIV who have experienced pregnancy/parenthood remain absent from the literature. As such, there exists no evidence-based policy or programming relating to mental health for this group. These analyses aim to identify the prevalence of probable common mental disorder among adolescent mothers and, among adolescents experiencing the syndemic of motherhood and HIV. Analyses utilise data from interviews undertaken with 723 female adolescents drawn from a prospective longitudinal cohort study of adolescents living with HIV (n = 1059) and a comparison group of adolescents without HIV (n = 467) undertaken within the Eastern Cape Province, South Africa. Detailed study questionnaires included validated and study specific measures relating to HIV, adolescent motherhood, and mental health. Four self-reported measures of mental health (depressive, anxiety, posttraumatic stress, and suicidality symptomology) were used to explore the concept of likely common mental disorder and mental health comorbidities (experiencing two or more common mental disorders concurrently). Chi-square tests (Fisher’s exact test, where appropriate) and Kruskal Wallis tests were used to assess differences in sample characteristics (inclusive of mental health status) according to HIV status and motherhood status. Logistic regression models were used to explore the cross-sectional associations between combined motherhood and HIV status and, likely common mental disorder/mental health comorbidities. 70.5% of participants were living with HIV and 15.2% were mothers. 8.4% were mothers living with HIV. A tenth (10.9%) of the sample were classified as reporting a probable common mental disorder and 2.8% as experiencing likely mental health comorbidities. Three core findings emerge: (1) poor mental health was elevated among adolescent mothers compared to never pregnant adolescents (measures of likely common mental disorder, mental health comorbidities, depressive, anxiety and suicidality symptoms), (2) prevalence of probable common mental disorder was highest among mothers living with HIV (23.0%) compared to other groups (Range:8.5–12.8%; Χ² = 12.54, p = 0.006) and, (3) prevalence of probable mental health comorbidities was higher among mothers, regardless of HIV status (HIV & motherhood = 8.2%, No HIV & motherhood = 8.2%, Χ² = 14.5, p = 0.002). Results identify higher mental health burden among adolescent mothers compared to never-pregnant adolescents, an increased prevalence of mental health burden among adolescent mothers living with HIV compared to other groups, and an elevated prevalence of mental health comorbidities among adolescent mothers irrespective of HIV status. These findings address a critical evidence gap, highlighting the commonality of mental health burden within the context of adolescent motherhood and HIV within South Africa as well as the urgent need for support and further research to ensure effective evidence-based programming is made available for this group. Existing antenatal, postnatal, and HIV care may provide an opportunity for mental health screening, monitoring, and referral.

Food Should not be Forgotten: Impacts of Combined Cash Transfer Receipt and Food Security on Child Education and Cognition in South Africa and Malawi

Social protection can take many forms. Both cash transfers and food security may have important contributions to child cognitive development. This study examines the potential impact of combinations of cash transfers and food security status on child cognitive development and educational outcomes. Cross-sectional data for 796 HIV-affected children in the Child Community Care study were utilised for this analysis. Children and caregivers completed interview schedules comprised of standardised items on socio-demographics, household data, cash grant receipt and food security status, school achievement, and cognition. A series of logistic and linear regression models and marginal effects analyses were undertaken to explore the impacts of differing levels of social protection (none; either cash grant receipt or food secure status or, both in combination) on child educational and cognitive outcomes. Although all children lived in poverty-stricken households, 20% (157/796) of children did not live in a household in receipt of a cash grant and did not report food security; 32.4% (258/796) reported either component of social protection and, 47.9% (381/796) received both measures of social protection in combination. Compared to no social protection, being in receipt of either component of social protection was found to be significantly associated with being in the correct class for age, higher scores of non-verbal cognition, and higher working memory scores. Receiving both social protection measures in combination was found to be significantly associated with reduced educational risk scores, improved odds of being in the correct class for age, regular school attendance, missing less than a week of school in the previous two weeks, higher scores on measures of nonverbal cognition, higher working memory scores, and learning new things more easily. Educational and cognitive outcomes for children can be bolstered by social protection measures (cash grant receipt or food security). Benefits are enhanced when social protection is received in combination. Such findings support the notion of synergistic social protection responses for children living in environments impacted by high levels of HIV burden and deprivation.

Understanding Mental Health in the Context of Adolescent Pregnancy and HIV in Sub-Saharan Africa: A Systematic Review Identifying a Critical Evidence Gap

Adolescent (10-19 years) mental health remains an overlooked global health issue. Rates of adolescent pregnancy within sub-Saharan Africa are some of the highest in the world and occur at the epicentre of the global HIV epidemic. Both experiencing adolescent pregnancy and living with HIV have been found to be associated with adverse mental health outcomes, when investigated separately. Poor mental health may have implications for both parent and child. The literature regarding mental health within groups experiencing both HIV and adolescent pregnancy is yet to be summarised. This systematic review sought to identify (1) the prevalence/occurrence of common mental disorder amongst adolescents who are living with HIV and have experienced pregnancy, (inclusive of adolescent fathers) in sub-Saharan Africa (2) risk and protective factors for common mental disorder among this group, and (3) interventions (prevention/treatment) for common mental disorder among this group. A systematic search of electronic databases using pre-defined search terms, supplemented by hand-searching, was undertaken in September 2020. One author and an independent researcher completed a title and abstract screening of results from the search. A full-text search of all seemingly relevant manuscripts (both quantitative and qualitative) was undertaken and data extracted using pre-determined criteria. A narrative synthesis of included studies is provided. Quality and risk of bias within included studies was assessed using the Newcastle-Ottawa scale. A systematic keyword search of databases and follow-up hand searching identified 2287 unique records. Of these, thirty-eight full-text quantitative records and seven full-text qualitative records were assessed for eligibility. No qualitative records met the eligibility criteria for inclusion within the review. One quantitative record was identified for inclusion. This study reported on depressive symptomology amongst 14 pregnant adolescents living with HIV in Kenya, identifying a prevalence of 92.9%. This included study did not meet the high methodological quality of this review. No studies were identified reporting on risk and protective factors for common mental disorder, and no studies were found identifying any specific interventions for common mental disorder for this group, either for prevention or for treatment. The limited data identified within this review provides no good quality evidence relating to the prevalence of common mental disorder among adolescents living with HIV who have experienced pregnancy in sub-Saharan Africa. No data was available relating to risk and protective factors or interventions for psychological distress amongst this group. This systematic review identifies a need for rigorous evidence regarding the mental health of pregnant and parenting adolescents living with HIV, and calls for granular interrogation of existing data to further our understanding of the needs of this group. The absence of research on this topic (both quantitative and qualitative) is a critical evidence gap, limiting evidence-based policy and programming responses, as well as regional development opportunities.

Evaluating quality in adolescent mental health services: a systematic review

OBJECTIVES

To evaluate the quality of adolescent mental health service provision globally, according to the WHO Global Standards of adolescent mental health literacy, appropriate package of services and provider competencies.

DESIGN AND DATA SOURCES

Systematic review of 5 databases, and screening of eligible articles, from 1 January 2008 to 31 December 2020.

STUDY ELIGIBILITY CRITERIA

We focused on quantitative and mixed-method studies that evaluated adolescent mental health literacy, appropriate package of services and provider competencies in mental health services, and that targeted depression, anxiety and post-traumatic stress disorder among adolescents (10-19 years). This included adolescents exposed to interventions or strategies within mental health services.

STUDY APPRAISAL AND SYNTHESIS METHODS

Study quality was assessed using the National Institutes for Health Study Quality Assessment Tools. Data were extracted and grouped based on WHO quality Standards.

RESULTS

Of the 20 104 studies identified, 20 articles were included. The majority of studies came from high-income countries, with one from a low-income country. Most of the studies did not conceptualise quality. Results found that an online decision aid was evaluated to increase adolescent mental health literacy. Studies that targeted an appropriate package of services evaluated the quality of engagement between the therapist and adolescent, patient-centred communication, mental health service use, linkages to mental health services, health facility culture and intensive community treatment. Provider competencies focused on studies that evaluated confidence in managing and referring adolescents, collaboration between health facility levels, evidence-based practices and technology use.

CONCLUSIONS AND IMPLICATIONS

There is limited evidence on quality measures in adolescent mental health services (as conforms to the WHO Global Standards), pointing to a global evidence gap for adolescent mental health services. There are several challenges to overcome, including a need to develop consensus on quality and methods to measure quality in mental health settings.

PROSPERO REGISTRATION NUMBER

CRD42020161318.

Relationships with caregivers and mental health outcomes among adolescents living with HIV: a prospective cohort study in South Africa

BACKGROUND

Mental health problems may impact adherence to anti-retroviral treatment, retention in care, and consequently the survival of adolescents living with HIV. The adolescent-caregiver relationship is an important potential source of resilience. However, there is a lack of longitudinal research in sub-Saharan Africa on which aspects of adolescent-caregiver relationships can promote mental health among adolescents living with HIV. We draw on a prospective longitudinal cohort study undertaken in South Africa to address this question.

METHODS

The study traced adolescents aged 10-19 initiated on antiretroviral treatment in government health facilities (n = 53) within a health district of the Eastern Cape province. The adolescents completed standardised questionnaires during three data collection waves between 2014 and 2018. We used within-between multilevel regressions to examine the links between three aspects of adolescent-caregiver relationships (caregiver supervision, positive caregiving, and adolescent-caregiver communication) and adolescent mental health (depression symptoms and anxiety symptoms), controlling for potential confounders (age, sex, rural/urban residence, mode of infection, household resources), n=926 adolescents.

RESULTS

Improvements in caregiver supervision were associated with reductions in anxiety (0.98, 95% CI 0.97-0.99, p=0.0002) but not depression symptoms (0.99, 95% CI 0.98-1.00, p=.151), while changes in positive caregiving were not associated with changes in mental health symptoms reported by adolescents. Improvements in adolescent-caregiver communication over time were associated with reductions in both depression (IRR=0.94, 95% CI 0.92-0.97, p<.0001) and anxiety (0.91, 95% CI 0.89-0.94, p<.0001) symptoms reported by adolescents.

CONCLUSIONS

Findings highlight open and supportive adolescent-caregiver communication and good caregiver supervision as potential factors for guarding against mental health problems among adolescents living with HIV in South Africa. Several evidence-informed parenting programmes aim to improve adolescent-caregiver communication and caregiver supervision, and their effect on depression and anxiety among adolescents living with HIV should be rigorously tested in sub-Saharan Africa. How to improve communication in other settings, such as schools and clinics, and provide communication support for caregivers, adolescents, and service providers through these existing services should also be considered.

Depressive symptoms among children attending community based support in South Africa - pathways for disrupting risk factors

Children in Southern Africa are exposed to high rates of structural and family adversities. This study tests whether services from Community Based Organisations (CBOs) in South Africa can promote children's resilience against depression exposed to such adversities. Two linked longitudinal studies were conducted, comprising n = 1848 children aged 9 to 13 years. One group received CBO services, whilst the other (quasi-control) did not. Analyses used interaction terms in regression models to test for potential moderation effects of CBO attendance, and marginal effects models to interpret significant interactions. Two interaction effects were shown, demonstrating moderation effects of CBO attendance on common structural disadvantages. First, children exposed to community violence showed increased depression (contrast = 0.62 [95%CI 0.43, 0.82], p < .001), but this association was removed by CBO access (contrast = 0.07 [95%CI -0.28, 0.43], p = .682). Second, children living in informal housing showed increased depression (contrast = 0.63 [95%CI 0.42, 0.85], p < .001), however, this association was removed by CBO access (contrast = 0.01 [95%CI -0.55, 0.56], p = .977). CBO attendance is associated with fewer depressive symptoms, and can buffer against important structural adversities of poor housing and violence that are common in high HIV-prevalence areas. However, CBO attendance was not able to remove the increased psychosocial distress associated with some family-level vulnerabilities such as orphanhood and abuse. These findings highlight the centrality of CBO-provided psychosocial support for children in Southern Africa, and suggest areas for bolstering provision.

The food of life: an evaluation of the impact of cash grant receipt and good parenting on child nutrition outcomes in South Africa and Malawi

Social protection interventions (inclusive of cash grant receipt and care provision) have been found to be effective in response to some of the negative implications of the HIV epidemic on children and families. This study explores the impact of cash grant receipt and care provision (operationalised as good parenting) on child nutritional outcomes. In this cross-sectional study, 854 children and younger adolescents (5–15 years) and caregivers affected by HIV, attending community-based organisations in South Africa and Malawi, were interviewed. Interviews comprised inventories on socio-demographic information, family data, cash grant receipt and child nutrition. Parenting was measured using a composite scale. Logistic regression and marginal effects analyses were used to explore the associations between differing levels of social protection (none; either cash or good parenting; cash and good parenting) and child nutritional outcomes. One hundred and sixty children (20.3%) received neither cash nor good parenting; 501 (63.5%) received either cash or good parenting and 128 (16.2%) received both cash and good parenting. In comparison to no intervention, receipt of either cash or good parenting was significantly associated with child non-stunting, the child having sufficient food, and the child not looking thin. Three (3/7) nutritional outcomes showed increased improvement amongst children receiving both cash and good parenting care including child-reported non-hunger, child non-stunting and parental report of sufficient food. Marginal effects analyses further identified an additive effect of cash and good parenting on child nutritional outcomes. This study indicates that receipt of combined cash and good parenting, when compared to cash grant receipt alone, has positive effects on nutrition-related child outcomes.

Adolescent mothers affected by HIV and their children: A scoping review of evidence and experiences from sub-Saharan Africa

While adolescents have received increasing attention in the global HIV response and international strategies and commitments, adolescent mothers and their children remain largely overlooked in research, funding and, programming for health-related outcomes. We conducted an extensive scoping review of current evidence on the experiences of adolescent mothers affected by HIV and their children in this region. We included published literature and conference abstracts, complemented by consultations with key stakeholders, and a review of documents through grey literature searching. First, we summarise the experiences of adolescent mothers and their children related to HIV and key health and development indicators. The syndemic of early motherhood and HIV in sub-Saharan Africa increases the vulnerability of adolescent mothers and their children. We then highlight lessons from a series of promising programmes focused on supporting adolescent mothers through novel approaches. In sub-Saharan Africa, supporting adolescent mothers living in high HIV-risk communities is critical not only to eliminate HIV/AIDS, but also to attain the Sustainable Development Goals. While research on and programming for adolescent mothers and their children is growing, the complex needs for this vulnerable group remain unmet. We conclude with evidence gaps and programming priorities for adolescent mothers affected by HIV and their children.

Gemcitabine-based adjuvant chemotherapy in subtypes of ampullary adenocarcinoma: international propensity score-matched cohort study

BACKGROUND

Whether patients who undergo resection of ampullary adenocarcinoma have a survival benefit from adjuvant chemotherapy is currently unknown. The aim of this study was to compare survival between patients with and without adjuvant chemotherapy after resection of ampullary adenocarcinoma in a propensity score-matched analysis.

METHODS

An international multicentre cohort study was conducted, including patients who underwent pancreatoduodenectomy for ampullary adenocarcinoma between 2006 and 2017, in 13 centres in six countries. Propensity scores were used to match patients who received adjuvant chemotherapy with those who did not, in the entire cohort and in two subgroups (pancreatobiliary/mixed and intestinal subtypes). Survival was assessed using the Kaplan-Meier method and Cox regression analyses.

RESULTS

Overall, 1163 patients underwent pancreatoduodenectomy for ampullary adenocarcinoma. After excluding 187 patients, median survival in the remaining 976 patients was 67 (95 per cent c.i. 56 to 78) months. A total of 520 patients (53·3 per cent) received adjuvant chemotherapy. In a propensity score-matched cohort (194 patients in each group), survival was better among patients who received adjuvant chemotherapy than in those who did not (median survival not reached versus 60 months respectively; P = 0·051). A survival benefit was seen in patients with the pancreatobiliary/mixed subtype; median survival was not reached in patients receiving adjuvant chemotherapy and 32 months in the group without chemotherapy (P = 0·020). Patients with the intestinal subtype did not show any survival benefit from adjuvant chemotherapy.

CONCLUSION

Patients with resected ampullary adenocarcinoma may benefit from gemcitabine-based adjuvant chemotherapy, but this effect may be reserved for those with the pancreatobiliary and/or mixed subtype.

Propensity-matched analysis of the influence of perioperative statin therapy on outcomes after liver resection

Background

Perioperative use of statins is reported to improve postoperative outcomes after cardiac and non‐cardiovascular surgery. The aim of this study was to investigate the influence of statins on postoperative outcomes including complications of grade IIIa and above, posthepatectomy liver failure (PHLF), and 90‐day mortality rates after liver resection.

Methods

Patients who underwent hepatectomy between 2013 and 2017 were reviewed to identify statin users and non‐users (controls). Propensity matching was conducted for age, BMI, type of surgery and preoperative co‐morbidities to compare subgroups. Univariable and multivariable analyses were performed for the following outcomes: 90‐day mortality, significant postoperative complications and PHLF.

Results

Of 890 patients who had liver resection during the study period, 162 (18·2 per cent) were taking perioperative statins. Propensity analysis selected two matched groups, each comprising 154 patients. Overall, 81 patients (9·1 per cent) developed complications of grade IIIa or above, and the 90‐day mortality rate was 3·4 per cent (30 patients), with no statistically significant difference when the groups were compared before and after matching. The rate of PHLF was significantly lower in patients on perioperative statins than in those not taking statins (10·5 versus 17·3 per cent respectively; P = 0·033); similar results were found after propensity matching (10·4 versus 20·8 per cent respectively; P = 0·026).

Conclusion

The rate of PHLF was significantly lower in patients taking perioperative statins, but there was no statistically significant difference in severe complications and mortality rates.

Evaluation of the clinical and economic impact of delays to surgery in patients with periampullary cancer

Background

Early treatment is the only potential cure for periampullary cancer. The pathway to surgery is complex and involves multiple procedures across local and specialist hospitals. The aim of this study was to analyse variability within this pathway, and its impact on cost and outcomes.

Methods

Patients undergoing surgery for periampullary cancer (2011–2016) were identified retrospectively and their pathway to surgery was analysed. Patients who had early surgery (shortest quartile, Q1) were compared with those having late surgery (longest quartile, Q4).

Results

A total of 483 patients were included in the study, with 121 and 124 patients in Q1 and Q4 respectively. The median time from initial CT to surgery was 21 days for Q1 versus 112 days for Q4 (P < 0·001). Diagnostic delays were common in Q4; these patients required significantly more investigations than those in Q1 (endoscopic ultrasonography (EUS): 74·2 versus 18·2 per cent respectively, P < 0·001; MRI: 33·6 versus 20·6 per cent, P = 0·036). The median time to diagnostic EUS was 13 days in Q1 versus 59 days in Q4 (P < 0·001). Some 42·1 per cent of jaundiced patients in Q1 underwent preoperative biliary drainage, compared with all patients in Q4. There were significantly more unplanned admissions and associated longer duration of hospital stay per patient and costs in Q4 than in Q1 (median: 8 versus 3 days respectively; €5652 versus €2088; both P < 0·001). There was a higher likelihood of potentially curative surgery in Q1 (82·6 per cent versus 66·9 per cent in Q4; P = 0·005).

Conclusion

There is wide variation across the entire pathway, suggesting that multiple strategies are required to enable early surgery. Defining an effective pathway by anticipating the need for investigations and avoiding biliary drainage reduces unplanned admissions and costs and increases resection rates.

Enzyme replacement improves survival among patients with pancreatic cancer: Results of a population based study

BACKGROUND

Pancreatic exocrine insufficiency (PEI) and malnutrition are prevalent among patients with pancreatic adenocarcinoma. Pancreatic enzyme replacement therapy (PERT) can correct PEI but its use among patients with pancreatic cancer is unclear as are effects upon survival. This population-based study sought to address these issues METHODS: Subjects with pancreatic adenocarcinoma were identified from the UK Clinical Practice Research Datalink (CPRD). Propensity score matching generated matched pairs of subjects who did and did not receive PERT. Progression to all-cause mortality was compared using parametric survival models that included a range of relevant co-variables RESULTS: PERT use among the whole cohort (987/4554) was 21.7%. Some 1614 subjects generated 807 matched pairs. This resulted in a total, censored follow-up period of 1643 years. There were 1403 deaths in total, representing unadjusted mortality rates of 748 and 994 deaths per 1000 person-years for PERT-treated cases and their matched non-PERT-treated controls, respectively. With reference to the observed survival in pancreatic adenocarcinoma patients, adjusted median survival time was 262% greater in PERT-treated cases (survival time ratio (STR) = 2.62, 95% CI 2.27-3.02) when compared with matched, non-PERT-treated controls. Survival remained significantly greater among subjects receiving PERT regardless of the studied subgroup with respect to use of surgery or chemotherapy CONCLUSIONS: This population based study observes that the majority of patients with pancreatic adenocarcinoma do not receive PERT. PERT is associated with increased survival among patients with pancreatic adenocarcinoma suggesting a lack of clinical awareness and potential benefit of addressing malnutrition among these patients.

Ninety day mortality following pancreatoduodenectomy in England: has the optimum centre volume been identified?

BACKGROUND

Mortality following pancreatoduodenectomy is related to centre volume although the optimal volume is not defined.

METHODS

Patients undergoing PD between 2001 and 2016 were identified from UK national databases. The effects of patient variables, centre volume and time period upon 90 day mortality were studied.

RESULTS

90 day mortality (970/14,935, 6.5%) was related to advanced age, comorbidity, diagnosis, ethnicity, deprivation, centre volume and time period. Mortality rates fell markedly from 10.0% in 2001-4 to 4.1% in 2013-16. There was no difference in 90 day mortality between high (36 -60 PD per year) and very high volume (>60) centres. However, patients operated upon at very high volume centres were more elderly (66, 58 -73 vs 65, 56 -72; median, IQR; p = 0.006), deprived (38.7 vs 34.6%; p < 0.001) and co morbid (48.9 vs 46.1%; p = 0.027).

CONCLUSION

Although a plateau in the centre volume and mortality relationship appears to have been demonstrated those patients treated at the highest volume centres were at higher risk of mortality. This data suggests therefore that to further understand outcomes from specialist centres characteristics of the patient population should be defined, not just centre volume.

Development and multicentre validation of a prognostic model to predict resectability of pancreatic head malignancy

Background

At the time of planned pancreatoduodenectomy patients frequently undergo exploratory laparotomy without resection, leading to delayed systemic therapy. This study aimed to develop and validate a prognostic model for the preoperative prediction of resectability of pancreatic head tumours.

Methods

This was a retrospective study of patients undergoing attempted resection for confirmed malignant tumours of the pancreatic head in a university hospital in Hannover, Germany. The prognostic value of patient and tumour characteristics was investigated in a multivariable logistic regression model. External validation was performed using data from two other centres.

Results

Some 109 patients were included in the development cohort, with 51 and 175 patients in the two validation cohorts. Eighty patients (73·4 per cent) in the development cohort underwent resection, and 37 (73 per cent) and 141 (80·6 per cent) in the validation cohorts. The main reasons for performing no resection in the development cohort were: local invasion of vasculature or arterial abutment (15 patients, 52 per cent), and liver (12, 41 per cent), peritoneal (8, 28 per cent) and aortocaval lymph node (6, 21 per cent) metastases. The final model contained the following variables: time to surgery (odds ratio (OR) 0·99, 95 per cent c.i. 0·98 to 0·99), carbohydrate antigen 19-9 concentration (OR 0·99, 0·99 to 0·99), jaundice (OR 4·45, 1·21 to 16·36) and back pain (OR 0·02, 0·00 to 0·22), with an area under the receiver operating characteristic (ROC) curve (AUROC) of 0·918 in the development cohort. AUROC values were 0·813 and 0·761 in the validation cohorts. The positive predictive value of the final model for prediction of resectability was 98·0 per cent in the development cohort, and 91·7 and 94·7 per cent in the two external validation cohorts. [Corrections added on 18 July 2018, after first online publication: The figures for OR of the variables time to surgery and CA19-9 in the abstract and in Table 3 and Table 4 were amended from 1·00 to 0·99].

Conclusion

For preoperative prediction of the likelihood of resectability of pancreatic head tumours, this validated model is a valuable addition to CT findings.

Examination of inequivalent wetting on the crystal habit surfaces of RS-ibuprofen using grid-based molecular modelling

Synthonic engineering tools, including grid-based searching molecular modelling, are applied to investigate the wetting interactions of the solute and four crystallisation solvents (ethanol, ethyl acetate, acetonitrile and toluene) with the {100}, {001} and {011} forms of RS-ibuprofen. The grid-based methods, in particular the construction of a crystal slab parallel to a given plane in a coordinate system with one axis perpendicular to the surface, are defined in detail. The interaction strengths and nature (dispersive, hydrogen bonding (H-bonding) or coulombic forces) are related to the crystal growth rates and morphologies. The solute is found to interact strongest with the capping {011}, then the side {001} and weakest with the top {100} habit surfaces. The solute interactions with the {100} and {001} surfaces are found to be almost solely dominated by dispersive force contributions, whilst the same with the {011} surfaces are found to have a greater contribution from H-bonding and coulombic forces. The increased surface rugosity, at the molecular level of the {011} surfaces, results in a favourable docking site in a surface 'valley', not present in the {100} and {001} surfaces. The H-bonding solvents ethanol, acetonitrile and ethyl acetate are found to strongly interact with the {011} surfaces and weakly with the {001} surfaces, with the {011} interactions having a much greater contribution from H-bonding and coulombic forces. The interaction energies of the apolar and aprotic solvent toluene, with the {011} and {001} surfaces, are found to be very close. Toluene is found having slightly stronger interactions with the {001} than the {011} surfaces, which are all dominated by dispersive interactions. The ratio of the average energy of the top 100 solvent interactions with the {001} surface divided by the average energy of the top 100 interactions with the {011} surface is compared to the ratio of the experimentally measured growth rates of the same forms. In general, the interaction energy ratio is found to have an inverse ratio with the growth rates, implying that the solvents which are calculated to interact strongly with a particular surface are impeding the growth of that surface and reducing the growth rate, in turn impacting upon the final morphology of the material.

Improving outcomes in patients with resectable pancreatic cancer

State of the art

Parenting, the other oldest profession in the world - a cross-sectional study of parenting and child outcomes in South Africa and Malawi

BACKGROUND

Parenting quality is important in child development. In the presence of HIV poverty and life stress, parenting may be challenged and child development affected.

METHODS

This study examines cross-sectional associations of situational factors such as poverty, mental health, HIV status, living with a biological parent, and stigma with good parenting and child outcomes (n=989; age=4-13 years) within the Child Community Care study (South Africa and Malawi). A parenting measure was created from 10 variables comprising 6 child and 4 parent ratings. These were highly correlated. Total parenting score was generated on a 10 point continuous scale, with a good parenting cut off then defined as >=8 out of a possible 10.

RESULTS

Five factors were associated with good parenting. Positively associated with good parenting were being the biological parent of the child, parental mental health and dwelling in households with multiple adults. Poverty and stigma were negatively associated with good parenting. Using multiple mediation analysis, a positive direct effect of good parenting was found on child self-esteem, child behaviour and educational risks with a partial mediation via child depression and trauma.

CONCLUSIONS

These data highlight possible intervention points. Influences on parenting could be seen through being the biological parent, parental mental health, poverty and stigma. In these challenging environments, health, nutrition, mental health, education, and treatment to keep parents alive are all clearly identified as potential pathways to ensure child well-being.

Child violence experiences in institutionalised/orphanage care

Institutions are not necessarily good environments for children. In the face of challenges such as HIV, Ebola, poverty, conflict and disaster the numbers have grown rather than reduced. Some countries have closed institutions down -driven by findings that cognitive developmental delay is associated with institutional care. Yet insight into abuse and violence within institutionalised settings is neglected. Maltreatment -violence and abuse -may be an issue. This systematic review series addresses violence and abuse experiences in institutionalised care, exploring firstly the frequency of abuse/violence in institutions, secondly any interventions to reduce such violence or abuse and thirdly the perpetrators of such violence or abuse. The final systematic review updates the findings on cognitive delay associated with institutionalised care. With a violence lens, cognitive delay may well be considered under the umbrella of neglect. Maltreatment and abuse may be a driver of cognitive delay. The keyword search covered several electronic databases and studies were included for data abstraction if they met adequacy criteria. Eight studies were identified on the prevalence of abuse in institutions and a further three studies reported on interventions. Only one study was identified documenting peer on peer violence in institutions. Sixty-six studies were identified examining cognitive development for institutionalised children. All but two of these record cognitive deficits associated with institutionalisation. Only two asked about violence or abuse which was found to be higher in institutionalised children. Overall the abuse experiences of children in institutions are poorly recorded, and in one study violence was associated with high suicidal attempts. The major intervention pathway for ameliorating cognitive challenge seems to be placement out of the institutions which shows benefits and redresses some cognitive outcomes - yet not a total panacea. The single study providing training and monitoring of harsh punishment and maltreatment showed immediate and decided reductions. This data suggest, despite the paucity of studies, violence and abuse, by commission or omission is prevalent in institutions, has an effect on child well-being and is amenable to intervention. Simple training or more complex structures to place children within conducive alternative environments (or to avoid institutionalised placements in the first place) seem to be the main pathway of intervention.

Comparison of preoperative CT-based imaging parameters to predict postoperative pancreatic fistula

AIM

To review all reported methods of preoperative computed tomography (CT) in one patient cohort and to identify which were the strongest to predict postoperative pancreatic fistula (POPF) after pancreatoduodenectomy.

MATERIALS AND METHODS

Consecutive patients undergoing pancreatoduodenectomy were included if they had unenhanced CT images for review. Eighteen variables and two scores were tested. Receiver operator characteristics (ROC) were explored.

RESULTS

POPF affected 26 of 107 patients (24.3%). Nine variables were significantly related to POPF with pancreatic duct width having the largest area under the ROC curve (AUROC; 0.808, p<0.001). An obese body habitus was associated with POPF with six of nine related variables using data from CT images associated with POPF; of these intra-abdominal wall thickness yielded the largest AUROC (0.713, p=0.001). This corresponded to the finding that body mass index (BMI) was related to POPF (AUROC 0.705, p=0.002). The largest AUROC of all was associated with one of the predictive scores (0.828, p<0.001). Substituting BMI for intra-abdominal wall thickness in this score yielded a non-significant increase to predict POPF (AUROC 0.840, p=0.676). None of the assessments of organ density (in Hounsfield Units) were associated with POPF.

CONCLUSION

Data from preoperative CT imaging provides valuable information regarding a patient's risk of POPF. Obesity as assessed by CT images strongly relates to POPF, but the largest single risk factor for POPF is a narrow pancreatic duct.

Performance of the revised Atlanta and determinant-based classifications for severity in acute pancreatitis

BACKGROUND

Severity classification systems aim to stratify patients with acute pancreatitis reliably into coherent risk groups. Recently, the Atlanta 1992 classification has been revised (Atlanta 2012) and a novel determinant-based classification (DBC) system developed. This study assessed the ability of the three systems to stratify disease severity among patients with acute pancreatitis.

METHODS

This was an observational cohort study of patients with acute pancreatitis identified from an institutional database. Cohort characteristics, investigations, interventions and outcomes were identified. Systems were compared using receiver operating characteristic (ROC) analysis and Spearman's correlation coefficients.

RESULTS

The in-hospital mortality rate was 6·6 per cent (15 of 228 patients). All of the outcomes considered correlated significantly with the three systems, with the exception of the need for surgery in Atlanta 1992. Atlanta 2012 and the DBC had higher area under the curve (AUC) values than Atlanta 1992 for all outcomes. The revised Atlanta and DBC systems both performed similarly with regard to ICU admission (AUC 0·927 and 0·917 respectively; both P < 0·001), need for percutaneous drainage (AUC 0·879 and 0·891; both P < 0·001), need for surgery (AUC 0·827 and 0·845; P = 0·006 and P = 0·004 respectively) and in-hospital mortality (0·955 and 0·931; both P < 0·001). However, the critical category in the DBC system identified patients with the most severe disease; seven of eight patients in this group died in hospital, compared with 15 of 34 with severe pancreatitis according to Atlanta 2012.

CONCLUSION

The Atlanta 2012 and DBC perform equally well for classification of disease severity in acute pancreatitis. The addition of a critical category in the DBC identifies patients with the most severe disease.

Exposure to violence predicts poor educational outcomes in young children in South Africa and Malawi

Background

Violence during childhood may affect short and long-term educational factors. There is scant literature on younger children from resource poor settings.

Methods

This study assessed child violence experiences (harsh punishment and exposure to domestic or community violence) and school enrolment, progress and attendance in children attending community-based organisations in South Africa and Malawi (n=989) at baseline and at 15 months' follow-up, examining differential experience of HIV positive, HIV affected and HIV unaffected children.

Results

Violence exposure was high: 45.4% experienced some form of psychological violence, 47.8% physical violence, 46.7% domestic violence and 41.8% community violence. Primary school enrolment was 96%. Violence was not associated with school enrolment at baseline but, controlling for baseline, children exposed to psychological violence for discipline were more than ten times less likely to be enrolled at follow-up (OR 0.09; 95% CI 0.01 to 0.57). Harsh discipline was associated with poor school progress. For children HIV positive a detrimental effect of harsh physical discipline was found on school performance (OR 0.10; 95% CI 0.02 to 0.61).

Conclusion

Violence experiences were associated with a number of educational outcomes, which may have long-term consequences. Community-based organisations may be well placed to address such violence, with a particular emphasis on the challenges faced by children who are HIV positive.

Towards an understanding of the nucleation of alpha-para amino benzoic acid from ethanolic solutions: a multi-scale approach

The molecular assembly and subsequent nucleation of para-amino benzoic acid (PABA) from ethanolic solutions is probed using a multi-scale and multi-technique approach. This is applied by examining and interrelating information regarding the molecular, solution-state, cluster, solid-state and surface structures to understand why the alpha form of PABA is crystallised in preference to its low temperature beta form. Calculations suggest that conformational changes within the solute molecule play little or no role in directing the nucleation of either the alpha or beta crystal forms. Combined ab initio and molecular dynamics calculations of the stability of small clusters in solution suggests that the hydrogen-bonded carboxylic acid dimers, present in the alpha structure, are the most stable in solution and play a major role in the self-assembly and polymorphic expression of the alpha form in ethanol in preference to the beta form. These calculations are in good agreement with X-ray small-angle scattering analysis which reveals the presence of PABA clusters in ethanol which are consistent with the size and shape of a carboxylic acid dimer. SAXS studies also reveal the presence of larger cluster structures in a size range 10-40 nm which appear to grow, perhaps reflecting a change in the balance between monomers and dimers within the solution during the nucleation process. The results of crystallisation-kinetics experiments indicate an instantaneous nucleation mechanism where the number of instantaneously nucleated crystallites is calculated to be 1360-660 nuclei per ml and the subsequent growth is found to be only rate limited by diffusion of the growth unit to the crystallite surface. A linear dependence of growth rate with respect to supersaturation is observed for the (0 1 -1) capping face, which is associated with strong π-π stacking interactions. This is consistent with a solid-on-solid mechanism associated with surface roughened growth and concomitant poor lattice-perfection. Conversely, the side (1 0 -1) surface has a growth mechanism consistent with a 2D nucleation birth and spread mechanism. Hence, these mechanisms result in very fast growth along the b-axis and the needle-like morphology that is observed for alpha-PABA.

Cost–utility analysis of operative versus non-operative treatment for colorectal liver metastases

Background

Surgical resection of colorectal liver metastases (CRLMs) is the standard of care when possible, although this strategy has not been compared with non-operative interventions in controlled trials. Although survival outcomes are clear, the cost-effectiveness of surgery is not. This study aimed to estimate the cost-effectiveness of resection for CRLMs compared with non-operative treatment (palliative care including chemotherapy).

Methods

Operative and non-operative cohorts were identified from a prospectively maintained database. Patients in the operative cohort had a minimum of 10 years of follow-up. A model-based cost–utility analysis was conducted to quantify the mean cost and quality-adjusted life-years (QALYs) over a lifetime time horizon. The analysis was conducted from a healthcare provider perspective (UK National Health Service) in a secondary care (hospital) setting.

Results

Median survival was 41 and 21 months in the operative and non-operative cohorts respectively (P &lt; 0·001). The operative strategy dominated non-operative treatments, being less costly (€22 200 versus €32 800) and more effective (4·017 versus 1·111 QALYs gained). The results of extensive sensitivity analysis showed that the operative strategy dominated non-operative treatment in every scenario.

Conclusion

Operative treatment of CRLMs yields greater survival than non-operative treatment, and is both more effective and less costly.

Preoperative identification of anomalous arterial anatomy at pancreaticoduodenectomy

The understanding of abdominal vascular anatomy and its anatomical variations is of considerable importance in upper abdominal surgery. We present the rare finding of a common hepatic artery arising from the superior mesenteric artery and passing anterior to the pancreatic gland in a patient undergoing a pancreaticoduodenectomy.

Performance of prognostic scores in predicting long-term outcome following resection of colorectal liver metastases

BACKGROUND

Ten-year survival appears to define cure following resection of colorectal liver metastases (CRLMs). Various scores exist to predict outcome at 5 years. This study applied several scores to a patient cohort with 10 years of actual follow-up to assess their performance beyond 5 years.

METHODS

The study included consecutive patients who underwent liver resection at a single institution between 1992 and 2001. The ability of eight prognostic scoring systems to predict disease-free (DFS) and disease-specific (DSS) survival was analysed using the C-statistic.

RESULTS

Among 286 patients, the 1-, 3-, 5- and 10-year actual DSS rates were 86.6, 58.3, 39.5 and 24.5 per cent respectively. Seventy patients underwent 105 further resections for recurrent disease, of which 84.8 per cent were within 5 years of follow-up. Analysis of C-statistics showed only one score--the Rees postoperative index--to be a significant predictor of DFS and DSS at all time points. The remaining scores performed less well, and regularly showed no significant improvement in predictive accuracy over what would be expected by chance alone. No score yielded a C-statistic in excess of 0.8 at any time point.

CONCLUSION

Although available risk scores can predict DFS and DSS, none does so with sufficient discriminatory accuracy to identify all episodes of recurrent disease. A non-negligible proportion of patients develop recurrent disease beyond 5 years of follow-up and so surveillance beyond this point may be advantageous.

Pinworm infection masquerading as colorectal liver metastasis

Enterobius vermicularis is responsible for a variety of diseases but rarely affects the liver. Accurate characterisation of suspected liver metastases is essential to avoid unnecessary surgery. In the presented case, following a diagnosis of rectal cancer, a solitary liver nodule was diagnosed as a liver metastasis due to typical radiological features and subsequently resected. At pathological assessment, however, a necrotic nodule containing E. vermicularis was identified. Solitary necrotic nodules of the liver are usually benign but misdiagnosed frequently as malignant due to radiological features. It is standard practice to diagnose colorectal liver metastases solely on radiological evidence. Without obtaining tissue prior to liver resection, misdiagnosis of solitary necrotic nodules of the liver will continue to occur.

Biliary and portal vein strictures following treatment of Hodgkin's lymphoma

Treatment of abdominal lymphoma can be associated with bowel stricture or perforation. Rarely, the common bile duct or portal vein can be involved. This is the first case of stricture formation of both the portal vein and common bile duct in a patient following successful treatment of lymphoma. The development of extensive hilar varices rendered surgical management high risk. A staged approach to treatment was used. First, a percutaneous portal vein stent was placed, resulting in resolution of the hilar varices. This was followed by a surgical hepaticojejunostomy, performed without complication. Gastrointestinal complications are rare following treatment of lymphoma but may affect a variety of sites. The safe and effective treatment of this case highlights the benefit of a multidisciplinary approach to complex medical and surgical problems.

Long-term symptomatic relief following surgical sphincteroplasty for sphincter of Oddi dysfunction

INTRODUCTION

Surgical sphincteroplasty (SS) for sphincter of Oddi dysfunction (SOD) can be performed primarily or following failed endoscopic therapy. The role of SS in an era of endoscopic management is unclear. This study presents long-term follow-up of patients who had undergone SS at a tertiary referral unit.

METHODS

Patients were identified from a departmental database and sent post-operative questionnaires to review pain scores and satisfaction with the procedure. Indications, pre-operative interventions and complications were recorded.

RESULTS

Seventeen patients underwent SS over 13 years. Thirteen patients had objective features of biliary obstruction (delayed excretion of isotope or elevated sphincter pressures). The positive predictive value, sensitivity and specificity of morphine 99mTc-TBIDA in this series was 100, 100 and 92%, respectively. There were 12 responders of whom all but one had symptomatic improvement. Median follow-up was 5.1 years. Pain was significantly lower following SS (16 ± 9 vs. 67 ± 11; p = 0.003) and median satisfaction with the procedure was high (95%).

CONCLUSIONS

Excellent symptomatic pain relief following SS can be achieved in carefully selected patients. Manometry does not appear to be essential for diagnosing SOD and morphine provocation hepatic scintigraphy was used to reliably identify patients who would benefit from SS.

Abdominal organ donation after death

New approaches to increase donor organ supply

Chest decompression during the resuscitation of patients in prehospital traumatic cardiac arrest

BACKGROUND

Tension and bilateral pneumothorax can cause or contribute to death following trauma. A surgical incision (thoracostomy) or needle decompression through the chest wall rapidly treats these conditions. Resuscitation of patients in traumatic cardiac arrest focuses on treating common and reversible life-threatening conditions. A study was undertaken to observe the practice, findings and outcome of chest decompression when performed as part of the resuscitation strategy of these patients by air ambulance crews.

METHODS

Patients in prehospital traumatic cardiac arrest were identified over a 39-month period from an air ambulance database. The use of thoracostomy or needle decompression was identified together with indications, findings and outcome. Primary outcome was return of cardiac output by arrival at hospital.

RESULTS

18 of 37 cases underwent chest decompression (17 thoracostomy, 1 needle decompression). Four patients had a return of cardiac output (3 tension pneumothorax, 1 bilateral pneumothorax). Six further cases were positive for intrathoracic injury. In 2 cases the injuries identified were incompatible with life and resuscitation efforts were consequently ceased.

CONCLUSIONS

Chest decompression in traumatic cardiac arrest identifies and treats a high proportion of potentially life-ending injuries and should be considered as part of the resuscitation effort of patients in traumatic cardiac arrest. In a proportion of patients, non-survivable injuries are identified which guide resuscitation efforts.

An instrument for combining x-ray multiple diffraction and x-ray topographic imaging for examining crystal microcrystallography and perfection

Diffraction imaging using x-ray topography (XRT) and x-ray multiple diffraction (XRMD) provide valuable tools for examining the growth defects in crystals and the distributions from ideal lattice symmetry (microcrystallography). The topographic x-ray multiple diffraction microprobe (TMDM) combines the complementary aspects of both techniques enabling XRT and XRMD studies within the same instrument providing a useful resource for the structural characterization of materials that are not very stable in vacuum and electron beam environments. The design of the TMDM instrument is described together with data taken on GaAs (001) and potassium dihydrogen phosphate (001).

An analysis of results from 305 compounds tested with the yeast RAD54-GFP genotoxicity assay (GreenScreen GC)—including relative predictivity of regulatory tests and rodent carcinogenesis and performance with autofluorescent and coloured compounds

Data from 305 non-proprietary compounds tested using the yeast RAD54-GFP (Green Fluorescent Protein) assay, GreenScreen GC, are presented, together with a detailed comparison with results from in vitro and in vivo genotoxicity tests and rodent carcinogenesis. In addition, observations on reproducibility and the performance of the test with autofluorescent and coloured compounds are described. Like the Ames test, the GreenScreen assay is shown to exhibit high specificity (82%), meaning that compounds with positive results are very likely to be genotoxic carcinogens. This is in contrast to mammalian cell tests established for use in regulatory testing that provide disappointingly low specificity and the inevitable generation of confounding false positive data. The analysis confirmed the observations of earlier studies, showing that a combination of an Ames test (or surrogate) with the yeast test provides high specificity as well as high sensitivity in the identification of rodent carcinogens.

Simulation of energetic stability of facetted l-glutamic acid nanocrystalline clusters in relation to their polymorphic phase stability as a function of crystal size

A molecular modeling approach is used to study the stability of different polymorphic forms of l-glutamic acid through building and optimizing molecular clusters of different sizes and shapes with the latter corresponding to the predicted crystal growth morphologies. The results reveal that the initially nucleating (according to Oswald rule) metastable (alpha) form is the more energetically stable form at small cluster sizes of ca. 200 molecular units, whereas the stable (beta) form is more stable when the cluster size is larger.

Analysis of nitrite reductase (nirK and nirS) genes and cultivation reveal depauperate community of denitrifying bacteria in the Black Sea suboxic zone

Chemical profiles of the Black Sea suboxic zone show a distribution of nitrogen species which is traditionally associated with denitrification, i.e. a secondary nitrite maximum associated with nitrate depletion and a N(2) gas peak. To better understand the distribution and diversity of the denitrifier community in the Black Sea suboxic zone, we combined a cultivation approach with cloning and sequencing of PCR-amplified nitrite reductase (nirS and nirK) genes. The Black Sea suboxic zone appears to harbour a homogeneous community of denitrifiers. For nirK, over 94% of the sequences fell into only three distinct phylogenetic clusters, and for nirS, a single closely related sequence type accounted for 91% of the sequences retrieved. Both nirS and nirK genes showed a dramatic shift in community composition at the bottom of the suboxic zone, but overall, nirK-based community composition showed much greater variation across depths compared with the highly uniform distribution of nirS sequences throughout the suboxic zone. The dominant nirK and nirS sequences differed at the amino acid level by at least 17% and 8%, respectively, from their nearest database matches. Denitrifying isolates recovered from the suboxic zone shared 97% 16S rRNA gene sequence similarity with Marinobacter maritimus. Analysis of the recently discovered nirS gene from the anammox bacterium Candidatus'Kuenenia stuttgartiensis' revealed that mismatches with commonly used primers may have prevented the previous detection of this divergent sequence.

Distribution and diversity of archaeal ammonia monooxygenase genes associated with corals

Corals are known to harbor diverse microbial communities of Bacteria and Archaea, yet the ecological role of these microorganisms remains largely unknown. Here we report putative ammonia monooxygenase subunit A (amoA) genes of archaeal origin associated with corals. Multiple DNA samples drawn from nine coral species and four different reef locations were PCR screened for archaeal and bacterial amoA genes, and archaeal amoA gene sequences were obtained from five different species of coral collected in Bocas del Toro, Panama. The 210 coral-associated archaeal amoA sequences recovered in this study were broadly distributed phylogenetically, with most only distantly related to previously reported sequences from coastal/estuarine sediments and oceanic water columns. In contrast, the bacterial amoA gene could not be amplified from any of these samples. These results offer further evidence for the widespread presence of the archaeal amoA gene in marine ecosystems, including coral reefs.

Understanding the Polymorphic Behavior of Sibenadet Hydrochloride through Detailed Studies Integrating Structural and Dynamical Assessment

Three polymorphs of sibenadet hydrochloride (AR-C68397AA, Viozan) have been shown to exist at ambient temperature and have been characterized. Each undergoes a solid-state transition to a common high temperature form, which melts at approximately 220 degrees C. X-ray powder diffraction (XRPD) indicates that Polymorphs I and II share a similar layered structure not exhibited by Polymorph III. All three ambient temperature polymorphs show evidence of varying degrees of dynamic disorder of the terminal phenyl group as shown by solid-state NMR spectroscopy. Furthermore, the carbons alpha to the ether link also undergo different rates of mobility in Polymorphs I and II. This variation in the extent of dynamic disorder results in an alteration in the short-range structure resulting in distinct polymorphs. Polymorph I is the thermodynamically stable form at room temperature as indicated by solution calorimetry and assessment by thermodynamically driven solution mediated phase transition studies. The present study aims to address the types of discriminatory data required to make a clear distinction between physical forms and define, unequivocally, the presence of polymorphism.

Ubiquity and diversity of ammonia-oxidizing archaea in water columns and sediments of the ocean

Nitrification, the microbial oxidation of ammonia to nitrite and nitrate, occurs in a wide variety of environments and plays a central role in the global nitrogen cycle. Catalyzed by the enzyme ammonia monooxygenase, the ability to oxidize ammonia was previously thought to be restricted to a few groups within the beta- and gamma-Proteobacteria. However, recent metagenomic studies have revealed the existence of unique ammonia monooxygenase alpha-subunit (amoA) genes derived from uncultivated, nonextremophilic Crenarchaeota. Here, we report molecular evidence for the widespread presence of ammonia-oxidizing archaea (AOA) in marine water columns and sediments. Using PCR primers designed to specifically target archaeal amoA, we find AOA to be pervasive in areas of the ocean that are critical for the global nitrogen cycle, including the base of the euphotic zone, suboxic water columns, and estuarine and coastal sediments. Diverse and distinct AOA communities are associated with each of these habitats, with little overlap between water columns and sediments. Within marine sediments, most AOA sequences are unique to individual sampling locations, whereas a small number of sequences are evidently cosmopolitan in distribution. Considering the abundance of nonextremophilic archaea in the ocean, our results suggest that AOA may play a significant, but previously unrecognized, role in the global nitrogen cycle.

Sodium phenoxyacetate hemihydrate

The structure of the hemihydrate of sodium phenoxyacetate, Na(+) x C(8)H(7)O(3)(-) x 0.5H(2)O, has been redetermined at low temperature (160 K). The structure consists of ribbons containing octahedral NaO(6) units, and half of the Na(2)O(2) squares within the ribbon are bridged by water molecules which lie across twofold rotation axes in C2/c. The phenyl substituents lie on the outside of the ribbon.

Interatomic potential parameters for potassium tetrachlorozincate and their application to modelling its phase transformations

An empirical fitting procedure is applied to derive interatomic potential parameters for a model phase transition system, namely potassium tetrachlorozincate (K(2)ZnCl(4)). The derived potential is found to reliably model the known crystallographic structure for the ferroelectric and paraelectric phases of this compound. Potential transferability is demonstrated by applying the parameters derived to the optimization of the known molecular structure for a similar inorganic system (rubidium tetrachlorozincate).

Sodium hydrogen bis(phenoxyacetate)

In the title compound, Na(+) x H(+) x [2C(8)H(7)O(3)](-), the anion contains a short Speakman-type hydrogen bond [O...O = 2.413 (2) A]. The anions and the Na atoms lie across twofold axes.

Physician beliefs about antiretroviral adherence communication

Adherence to antiretroviral regimens is thought to be imperative for HIV-positive patients. However, little is known about health care professionals' willingness to discuss adherence with patients, nor what barriers, if any, may impede their adherence communication. The aims of the study were to examine physicians' beliefs regarding: (1) the efficacy of adherence communication, (2) the barriers which impede such communication, and (3) their roles and responsibilities regarding adherence communication. Semi-structured interviews were conducted with 15 physicians who specialize in providing care to HIV-positive patients. Results showed that most physicians believed that communicating with patients about adherence issues was important, even though doing so may not have an immediate impact on patients' behaviors. Physicians believed that adherence communication was a good use of their time and fell within their role as a primary care professional. However, time constraints were cited as a barrier to performing adherence communication, indicating that physicians may do less communicating about adherence than may be optimal if they are burdened with other tasks. Results highlight the need to develop innovative strategies, such as the use of multi-disciplinary adherence teams, to ensure that each HIV-positive patient receives the optimal amount of information about and support for adherence.

Barriers to antiretroviral medication adherence in HIV-infected women

Little is known about the barriers which women living with HIV/AIDS encounter that impede their adherence to antiretroviral medication regimens. Yet in order to design effective interventions to improve women's adherence, it is first imperative to identify the factors that contribute to their non-adherence. The purpose of this study was to explore, from HIV-infected women's own perspectives, the barriers they faced in adhering to combination antiretroviral therapies. Twenty HIV-infected women were asked to keep a personal journal for a period of one month. In the journals, women wrote about what their lives were like while taking antiretroviral medications. Line-by-line open coding was done to identify major ideas and themes within the journal entries. Results showed that women faced six main barriers to adherence, those related to: (1) medication regimens, (2) side effects, (3) social relationships, (4) medication beliefs, (5) daily schedules, and (6) body weight. The findings underscore the difficult nature of the antiretroviral regimens and illuminate the daily obstacles women face in adhering to therapy. Interventions that target women's unique barriers are needed to improve adherence to antiretroviral medication regimens.

Facilitators and barriers to use of the female condom: qualitative interviews with women of diverse ethnicity

Women in the United States, particularly African-Americans and Hispanics, are at increased risk for HIV. The female condom now offers women a potentially important option for HIV prevention, yet few efforts have been made to increase its use. To elucidate strategies to promote the use of the female condom, we conducted in-depth interviews with 62 women recruited from the four major racial/ethnic groups of the U.S. (African-American, Asian-American, Hispanic, and white). Subject recruitment took place at a family planning clinic in San Francisco during 1996-97. We identified four major types of facilitators and barriers to use of the female condom: mechanical, psychosexual, interpersonal, and situational. Specifically, the mechanical facilitators and barriers included positive and negative aspects of the device, and difficulty with insertion. The psychosexual factors were female empowerment, more options for contraception and disease prevention, discomfort with vaginal insertion, and condom use norms. The interpersonal factors included: enhanced communication, relationship status, partner preferences, and partner objections. Finally, the situations that made women disinclined to use the device were: no access to the female condom when having sex and using other forms of contraceptives. The implications of these findings for HIV prevention and future research are discussed.