Oral Cavity Cancers: Ethnic Differences in Radiotherapy Outcomes in a Majority South Asian Leicester Community

AIMS

Squamous cell carcinoma oral cavity cancers (SCCOCCs) have a higher reported incidence in South Asian countries. We sought to compare presenting stage and outcome by ethnicity in patients with SCCOCC treated with radical radiotherapy in a single centre in the UK.

MATERIALS AND METHODS

All patients with SCCOCC treated with radical radiotherapy at an oncology department in Leicester (UK) between 2011 and 2017 were identified. Baseline demographic, clinical data and 2-year treatment outcomes were reported.

RESULTS

Of the 109 patients included, 40 were South Asian and 59 were non-South Asian. South Asians had significantly poorer 2-year disease-free survival compared with non-South Asians (54.6% versus 73%, P = 0.01).

CONCLUSION

Our analysis suggests that South Asians with SCCOCC have poorer outcomes despite a younger age and similar disease characteristics. Environmental, social factors and differing biology of disease may be responsible and further research is required to inform targeted interventions.

CHAMPP4KIDS: Mixed methods study protocol to evaluate acceptability and feasibility of Parenting for Lifelong Health materials in a Canadian context

BACKGROUND

Parents and caregivers play a key role in children's healthy development and well-being. Traditional parenting interventions promote positive parenting practices and are key to preventing child maltreatment. However, numerous barriers can limit access to programs, barriers which were further exacerbated by the COVID-19 pandemic. The Parenting for Lifelong Health group developed mass media and public health communication materials to promote positive caregiving behaviours on a population level. The Champions of Positive Parenting 4 Kids (CHAMPP4KIDS) study will examine the acceptability and feasibility of these materials for service providers and caregivers of children aged 2-6 years in Ontario, Canada.

METHODS

This study will use a convergent mixed-methods design. Consenting service providers (n = 200) and caregivers (n = 100) will complete a quantitative survey to rate, rank and give feedback on Parenting for Lifelong Health tip sheets and social media ads. Caregivers will also complete self-report scales measuring depression and anxiety. We will hold focus group discussions with a sub-sample of surveyed providers (n = 40) and caregivers (n = 25). An adapted Trials of Improved Practices methodology will explore caregiver perspectives after implementing the tip sheets. Primary quantitative outcomes will be descriptive statistics of rankings, Likert Scale scores and descriptive analysis of caregiver depression and anxiety. Qualitative data will be analyzed using Rapid Qualitative Inquiry and triangulated through a convergent coding matrix.

DISCUSSION

The Parenting for Lifelong Health COVID-19 parenting materials offer succinct, engaging parenting information in a mass media format that addresses some challenges associated with accessing in-person programming. The CHAMPP4KIDS study will provide mixed methods insights on the materials' acceptability and feasibility from different groups in a Canadian context, with a focus on marginalized families. The use of Trials of Improved Practices methodology could prove a useful tool for participant-led adaptation of existing parenting, early childhood development and other health intervention materials.

A film-based intervention to reduce child maltreatment among migrant and displaced families from Myanmar: Protocol of a pragmatic cluster randomized controlled trial

BACKGROUND

Child maltreatment is a global public health crisis with negative consequences for physical and mental health. Children in low- and middle-income countries (LMIC)-particularly those affected by poverty, armed conflict, and forced migration-may be at increased risk of maltreatment due to heightened parental distress and disruptions to social support networks. Parenting interventions have been shown to reduce the risk of child maltreatment as well as improve a range of caregiver and child outcomes, yet large-scale implementation remains limited in low-resource displacement settings. This study will examine the impact of an entertainment-education narrative film intervention on reducing physical and emotional abuse and increasing positive parenting among migrant and displaced families from Myanmar living in Thailand.

METHOD

The study is a pragmatic, superiority cluster randomized controlled trial with approximately 40 communities randomized to the intervention or treatment as usual arms in a 1:1 ratio. Participating families in the intervention arm will be invited to attend a community screening of the film intervention and a post-screening discussion, as well as receive a poster depicting key messages from the film. Primary outcomes are changes in physical abuse, emotional abuse, and positive parenting behaviour. Secondary outcomes include caregiver knowledge of positive parenting, caregiver attitudes towards harsh punishment, caregiver psychological distress, and family functioning. Outcomes will be assessed at 3 time points: baseline, 4 weeks post-intervention, and 4-month follow up. A mixed methods process evaluation will be embedded within the trial to assess intervention delivery, acceptability, perceived impacts, and potential mechanisms of change.

DISCUSSION

To our knowledge, this study will be the first randomized controlled trial evaluation of a film-based intervention to reduce child maltreatment among migrant and displaced families in a LMIC. An integrated knowledge translation approach will inform uptake of study findings and application to potential scale up pending evaluation results.

TRIAL REGISTRATION

The study was prospectively registered with the Thai Clinical Trials Registry on 22 February 2023 (TCTR20230222005).

Strengthening Community Roots: Anchoring Newcomers in Wellness and Sustainability (SCORE!): A protocol for the co-design and evaluation of a healthy active living program among a newcomer community in Canada

BACKGROUND

The burden of childhood obesity and cardiometabolic risk factors affecting newcomer Canadians living in lower socioeconomic circumstances is a concerning public health issue. This paper describes Strengthening Community Roots: Anchoring Newcomers in Wellness and Sustainability (SCORE!), an academic-community research partnership to co-design interventions that nurture and optimize healthy activity living (HAL) among a community of children and families new to Canada in Hamilton, Ontario, Canada.

METHODS/DESIGN

Our overarching program is informed by a socio-ecological model, and will co-create HAL interventions for children and families new to Canada rooted in outdoor, nature-based physical activity. We will proceed in three phases: Phase 1) synthesis of existing evidence regarding nature based HAL interventions among children and families; Phase 2) program development through four data collection activities including: i) community engagement activities to build trustful relationships and understand barriers and facilitators, including establishing a community advisory and action board, qualitative studies including a photovoice study, and co-design workshops to develop programs; ii) characterizing the demographics of the community through a household survey; iii) characterizing the built environment and HAL programs/services available in the community by developing an accessible real-time systems map; and iv) reviewing municipal policies relevant to HAL and sustainability; leading to Phase 3) implementation and evaluation of the feasibility of co-designed HAL programs.

CONCLUSION

The etiology of childhood obesity and related chronic diseases is complex and multifactorial, as are intervention strategies. The SCORE! program of research brings together partners including community members, service providers, academic researchers, and organizational leaders to build a multi-component intervention that promotes the health and wellness of newcomer children and families.

Reimagining mental health care for newcomer children and families: a qualitative framework analysis of service provider perspectives

BACKGROUND

Persistent disparities in access to mental health care for refugee and immigrant children and their families pose unique challenges to policy and practice. This study examined service provider perspectives on the barriers and opportunities for improving mental health supports for newcomer children and families in Canada.

METHODS

Semi-structured individual and group interviews were conducted with 33 leadership and frontline staff from 14 organizations in the health, education, settlement, and social service sectors in Hamilton, Ontario. Interview data were analyzed using the framework method.

RESULTS

Participants described barriers at the systems, provider, and individual and family levels that prevented newcomer families from accessing and benefiting from mental health supports. Structural barriers included inadequate services and funding, complexity of systems, cultural tensions, and, lack of prevention and early identification. Provider-level barriers included lack of representation, mental health knowledge and cultural competency, and staff shortages and burnout. Individual and family-level barriers included lack of mental health literacy, primacy of settlement needs, stigma, fear, and the high threshold for help-seeking. Participants' recommendations for "reimagining care" related to newcomer engagement, person- and family-centered care, cultural responsiveness, mental health promotion and prevention, workforce diversity and development, collaborative and integrated care, and knowledge generation and uptake.

CONCLUSIONS

The intersection of structural, provider, and individual/family-level barriers reduce newcomer families' access to and effectiveness of mental health supports. Reducing disparities in mental health and access to care will require a paradigm shift in the way that mental health care is conceptualized and delivered to newcomer children and families.

Recommendations for Canada's National Action Plan to End Gender-Based Violence: perspectives from leaders, service providers and survivors in Canada's largest city during the COVID-19 pandemic

INTRODUCTION

The Canadian government has committed to a national action plan (NAP) to address violence against women (VAW). However, a formalized plan for implementation has not been published. Building on existing recommendations and consultations, we conducted the first formal and peer-reviewed qualitative analysis of the perspectives of leaders, service providers and survivors on what should be considered in Canada's NAP on VAW.

METHODS

We applied thematic analysis to qualitative data from 18 staff working on VAW services (11 direct support, 7 in leadership roles) and 10 VAW survivor participants of a community-based study on VAW programming during the COVID-19 pandemic in the Greater Toronto Area (Ontario, Canada).

RESULTS

We generated 12 recommendations for Canada's NAP on VAW, which we organized into four thematic areas: (1) invest into VAW services and crisis supports (e.g. strengthen referral mechanisms to VAW programming); (2) enhance structural supports (e.g. invest in the full housing continuum for VAW survivors); (3) develop coordinated systems (e.g. strengthen collaboration between health and VAW systems); and (4) implement and evaluate primary prevention strategies (e.g. conduct a gender-based and intersectional analysis of existing social and public policies).

CONCLUSION

In this study, we developed, prioritized and nuanced recommendations for Canada's proposed NAP on VAW based on a rigorous analysis of the perspectives of VAW survivors and staff in Canada's largest city during the COVID-19 pandemic. An effective NAP will require investment in direct support organizations; equitable housing and other structural supports; strategic coordination of health, justice and social care systems; and primary prevention strategies, including gender transformative policy reform.

Resettlement, mental health, and coping: a mixed methods survey with recently resettled refugee parents in Canada

BACKGROUND

Resettlement experiences of refugee parents are under-researched despite evidence indicating higher risk of poor mental health. The current study integrates family systems and social determinants of refugee mental health frameworks to examine: (1) Refugee parents' experiences of resettlement stressors and mental health; (2) Perceived impacts of resettlement stressors on individual and family indicators of well-being; and (3) Refugee parents' coping strategies and resources.

METHODS

The study draws on data from a mixed methods survey conducted with 40 Government-Assisted Refugee parents who had resettled to Hamilton, Canada within the past 4 years. Quantitative and qualitative data were analyzed separately and then integrated at the results stage using a weaving approach.

RESULTS

Results indicate significant exposure to economic and social stressors across multiple domains of daily life, as well as high levels of parental psychological distress. Parents drew linkages between resettlement stressors and negative mental health impacts that were compounded by intersecting risk factors of ill health, caregiving burden, single parenthood, and low levels of education and literacy. Most parents rated themselves as coping well or very well and described various coping strategies such as positive reframing, problem solving, planning, and turning to religion. Quantitative and qualitative findings indicate high frequency of positive parent-child interaction and low frequency of family conflict, and highlight the importance of family as a protective resource for coping with adversity. Exploratory regression analyses suggest that longer stay in Canada, poorer self-rated health, higher levels of resettlement stressors, and more conflict between adults in the household may be associated with greater psychological distress.

CONCLUSION

Study findings highlight both the resilience of refugee parents and the psychological toll of navigating their families through a new and challenging environment. Policies and programs to provide comprehensive social and economic supports to refugees beyond the first one to two years after arrival are necessary to mitigate the mental health impacts of displacement over time and strengthen individual and family resilience. Such programs should include culturally responsive and family-based models of mental health care that acknowledge collective experiences and impacts of adversity, as well as harness family resources to overcome past and present challenges.

Neighbourhood and family correlates of immigrant children's mental health: a population-based cross-sectional study in Canada

BACKGROUND

Immigrant children exhibit significant variation in their mental health outcomes despite disproportionate exposure to socio-economic adversity compared to their non-immigrant peers. Identifying aspects of neighbourhood and family contexts that are most salient for immigrant children's mental health can help to inform and target interventions to prevent mental disorder and promote mental well-being among this population.

METHODS

The study analyzed multi-informant data from 943 first- and second-generation immigrant caregiver and child dyads from the Hamilton Youth Study, a representative sample of immigrant and non-immigrant families in Hamilton, Ontario. Multivariate multilevel regression models examined associations between neighbourhood and family characteristics and processes, and parent and child self reports of internalizing and externalizing problems.

RESULTS

Positive and negative parenting behaviours were significantly associated with internalizing and externalizing problems, with negative parenting demonstrating associations with externalizing problems across both parent and child reports (b = 0.26-1.27). Neighbourhood social disorder and parental trauma exposure were associated with greater internalizing and externalizing problems, and neighbourhood immigrant concentration was associated with fewer externalizing problems for parent reports only. Adding parental distress and parenting behaviour to the models reduced the coefficients for parental trauma exposure by 37.2% for internalizing problems and 32.5% for externalizing problems and rendered the association with neighbourhood social disorder non-significant. Besides the parenting variables, there were no other significant correlates of child-reported internalizing and externalizing problems.

CONCLUSIONS

Results highlight the importance of parenting behaviour and parental experiences of trauma and distress for immigrant children's mental health. While not unique to immigrants, the primacy of these processes for immigrant children and families warrants particular attention given the heightened risk of exposure to migration-related adverse experiences that threaten parental and family well-being. To prevent or mitigate downstream effects on child mental health, it is imperative to invest in developing and testing trauma-informed and culturally responsive mental health and parenting interventions for immigrant families.

Resilience in the Face of Adversity: Family Processes and the Immigrant Paradox in Youth Externalizing Problems

BACKGROUND

Despite increased exposure to social adversity, immigrant youth have fewer externalizing problems compared to non-immigrants. Explanations for this apparent advantage remain unclear. This study examined the extent to which socio-economic characteristics and family processes account for group differences in externalizing problems between immigrant and non-immigrant youth.

METHODS

Data come from a population-based cross-sectional study of 1,449 youth and their primary caregiver in Hamilton, Ontario. Computer-assisted structured interviews were administered separately to primary caregivers and youth, which included assessments of externalizing problems and measures of family obligation, parental monitoring, value of education and socio-economic characteristics.

RESULTS

First- and second-generation immigrant youth had lower levels of externalizing problems compared to non-immigrants. The magnitude of group differences was larger for parent (d = 0.37-0.55) versus youth reports of externalizing behaviours (d = 0.15-0.29). Family socio-economic and process characteristics partially accounted for group differences, which remained significant in the parent-reported model but rendered non-significant in the youth-reported model.

CONCLUSION

Results suggesting the potential protective effects of positive family processes for immigrant youth could be extended to non-immigrant youth to inform the development of parenting and family skills interventions. Promoting familial sources of resilience is a potential avenue for reversing downward trends in mental health seen across successive generations of immigrant youth, while also reducing risk of behavioural difficulties among non-immigrant youth.

Assessing trauma and related distress in refugee youth and their caregivers: should we be concerned about iatrogenic effects?

Assessment of potentially traumatic events and related psychological symptoms in refugee youth is common in epidemiological and intervention research. The objective of this study is to characterize reactions to assessments of trauma exposure and psychological symptoms, including traumatic stress, in refugee youth and their caregivers. Eighty-eight Somali youth and their caregivers participated in a screening and baseline interview for a psychological intervention in three refugee camps in Ethiopia. Participants were asked about their levels of distress prior to, immediately after, and approximately two weeks after completing the interview. Other quantitative and qualitative questions inquired about specific reactions to interview questions and procedures. Children and caregivers became increasingly relaxed over the course of the interview, on average. Few children (5.3%) or caregivers (6.5%) who reported being relaxed at the beginning of the interview became upset by the end of the interview. Some children and caregivers reported that certain assessment questions were upsetting and that feeling upset interfered with their activities. Despite some participants reporting persistent negative reactions, most reported liking and benefitting from the interview. While the majority of refugee youth and their caregivers reported positive experiences associated with completing trauma-related assessments, some reported negative reactions. Researchers and practitioners must consider the necessity, risks, and benefits of including questions about potentially traumatic events and related symptoms that are particularly upsetting in screening, survey research, and clinical assessment. When included, it is important that researchers and practitioners monitor negative reactions to these assessments and connect participants who become distressed with appropriate services.

An evaluation of a common elements treatment approach for youth in Somali refugee camps

BACKGROUND

This paper reports on: (1) an evaluation of a common elements treatment approach (CETA) developed for comorbid presentations of depression, anxiety, traumatic stress, and/or externalizing symptoms among children in three Somali refugee camps on the Ethiopian/Somali border, and (2) an evaluation of implementation factors from the perspective of staff, lay providers, and families who engaged in the intervention.

METHODS

This project was conducted in three refugee camps and utilized locally validated mental health instruments for internalizing, externalizing, and posttraumatic stress (PTS) symptoms. Participants were recruited from either a validity study or from referrals from social workers within International Rescue Committee Programs. Lay providers delivered CETA to youth (CETA-Youth) and families, and symptoms were re-assessed post-treatment. Providers and families responded to a semi-structured interview to assess implementation factors.

RESULTS

Children who participated in the CETA-Youth open trial reported significant decreases in symptoms of internalizing (d  =  1.37), externalizing (d  =  0.85), and posttraumatic stress (d  =  1.71), and improvements in well-being (d  =  0.75). Caregivers also reported significant decreases in child symptoms. Qualitative results were positive toward the acceptability and appropriateness of treatment, and its feasibility.

CONCLUSIONS

This project is the first to examine a common elements approach (CETA: defined as flexible delivery of elements, order, and dosing) with children and caregivers in a low-resource setting with delivery by lay providers. CETA-Youth may offer an effective treatment that is easier to implement and scale-up versus multiple focal interventions. A fullscale randomized clinical trial is warranted.

Pathways linking war and displacement to parenting and child adjustment: A qualitative study with Syrian refugees in Lebanon

Forcibly displaced children are at risk of a range of negative outcomes, yet little is known about how to support war-affected caregivers in promoting children's psychosocial resilience. The current study uses qualitative methods to examine the mechanisms underlying the effects of war and displacement on parenting and child adjustment in order to inform intervention development. In April and November 2016, group and individual interviews were conducted with 39 Syrian parents and 15 children in partnership with a humanitarian organization in Lebanon. Interviews were transcribed and analyzed using a grounded theory approach. Results show three interrelated pathways linking daily displacement stressors to various dimensions of parenting: (1) economic hardship prevents parents from meeting their children's basic needs and forces adaptation strategies that impair positive parent-child interactions; (2) parental psychological distress contributes to harsh parenting; and (3) perceptions and experiences of insecurity in the community results in increased parental control. Greater economic resources and social support emerged as potential protective factors for maintaining positive parenting despite exposure to war and displacement-related adversity. Our findings suggest that implementation of policies and programs to remove structural barriers to refugees' physical and economic security can have tangible impacts on parental mental health, parenting quality, and child psychosocial outcomes. Future research priorities include a stronger focus on the effects of war and displacement on family processes, taking into account interactions with the broader social, economic and political context.

Laparoscopic radical nephrectomy with inferior vena cava thrombectomy: highlight of key surgical steps

Objective:

Vascular involvement in the form of renal vein (RV) or inferior vena cava (IVC) thrombus can be seen in 4-10% of patients presented with RCC. In patients without presence of metastasis, surgical treatment in the form of radical nephrectomy remains the treatment of choice with 5-year survival rates of 45-70%. Open surgery is still the first treatment option of choice at the moment for RCC patients with IVC thrombus.

Materials and Methods:

In our study, we are reporting a case of patient with RCC and level I IVC thrombus treated with laparoscopy. Our patient is a 72 years old man with underlying co-morbidity of hypertension and chronic kidney disease (CKD) presented with right-sided RCC. The CT scan done showed a large right renal upper pole tumor measuring 8.4x5.2cm with level I IVC thrombus (Figure-1). There were no regional lymphadenopathy and the staging scans were negative.

Results:

The operative time was 124 minutes and blood loss was minimal. The patient was progressed to diet on POD 1 with bowel movement on POD 2. There was no significant change in the pre and post-operative glomerular filtration rate (GFR). The surgical drain was removed on POD2. The patient was discharged well on POD 5. There were no perioperative complications. The pathology was pT3bN0M0 Fuhrman grade II clear cell RCC.

Conclusions:

As a conclusion, laparoscopic radical nephrectomy and IVC thrombectomy is a complex and technically demanding surgery. With advancement of surgical skills as well as technology, more cases of minimally invasive laparoscopic radical nephrectomy and IVC thrombectomy can performed to improve the perioperative outcomes of carefully selected patients in a high volume center.

[Treatment of invasive bladder cancer: robot-assisted radical cystectomy and intracorporeal urinary diversion]

PURPOSE

Robot-assisted radical cystectomy (RARC) and intracorporeal urinary diversion are only performed in a few centers of excellence worldwide. Functional and oncologic outcomes are comparable. We report on our experience with RARC and intracorporeal diversion.

PATIENTS AND METHODS

We retrospectively identified 86 RARCs in 72 men and 14 women (mean age 69.7 years). All patients underwent robot-assisted radical cystectomy and pelvic lymphadenectomy followed by intracorporeal urinary diversion using ileal conduit or neobladder. Of the 86 patients, 24 patients (28%) underwent intracorporeal ileal conduit and 62 patients (72%) underwent intracorporeal neobladder formation. A Studer pouch was created in all who underwent intracorporeal neobladder diversion. Cancer specific survival (CSS) and overall survival (OS) are reported.

RESULTS

The mean operative time was 418.9 min (range 205-690 min) and blood loss was 380 ml (range 100-1000 ml). The mean hospital stay was 17.5 days (range 5-62 days). All the surgeries were completed with no open conversions. Minor complications (grade I and II) were reported in 23 patients, while major complications (grade III and above) were reported in 21 patients. The mean nodal yield was 20.3 (range 0-46). Positive margins were found in in 8%. The average follow-up was 31.5 months (range 3-52 months). Continence could be achieved in 88% of patients who received an intracorporeal neobladder. The cancer-specific survival (CSS) and overall survival (OS) were 80% and 70%, respectively.

CONCLUSION

RARC with intracorporeal diversion seems to be safe and reproducible in tertiary centers with robotic expertise. Operative times are acceptable and complications as well as functional and oncologic outcomes are comparable. Further standardization of RARC with intracorporeal diversion may lead to a wider adoption of the approach.

The importance of establishing reliability and validity of assessment instruments for mental health problems: An example from Somali children and adolescents living in three refugee camps in Ethiopia

Assessing mental health problems cross-culturally for children exposed to war and violence presents a number of unique challenges. One of the most important issues is the lack of validated symptom measures to assess these problems. The present study sought to evaluate the psychometric properties of two measures to assess mental health problems: the Achenbach Youth Self-Report and the Child Posttraumatic Stress Disorder Symptom Scale. We conducted a validity study in three refugee camps in Eastern Ethiopia in the outskirts of Jijiga, the capital of the Somali region. A total of 147 child and caregiver pairs were assessed, and scores obtained were submitted to rigorous psychometric evaluation. Excellent internal consistency reliability was obtained for symptom measures for children and their caregivers. Validation of study instruments based on local case definitions was obtained for the caregivers but not consistently for the children. Sensitivity and specificity of study measures were generally low, indicating that these scales would not perform adequately as screening instruments. Combined test-retest and inter-rater reliability was low for all scales. This study illustrates the need for validation and testing of existing measures cross-culturally. Methodological implications for future cross-cultural research studies in low- and middle-income countries are discussed.

Cost analysis of a community pharmacy 'minor ailment scheme' across three primary care trusts in the North East of England

BACKGROUND

A large proportion of primary care medical consultations relate to minor ailments, placing a substantial burden on the UK National Health Service (NHS). In response, minor ailment schemes (MAS) have been introduced in several community pharmacies.

METHODS

Patients using MAS across three neighbouring primary care trusts were asked what action they would have taken if the MAS had not been in place. The net cost impact of the MAS was calculated using standard health-care reference costs. The observation period was one calendar month with annualized cost data.

RESULTS

During the observation period 396 patients used the MAS of whom 230 (58.1%) stated they would have made an appointment with their general practitioner (GP) if the MAS was not in place. A further 155 (39.1%) would have bought a medicine from the pharmacy. Other responses included attending the accident and emergency department at hospital (n= 2), consulting a health visitor (n= 1), or doing nothing (n= 8). The MAS is estimated to reduce local health-care costs by £6739 per month.

CONCLUSIONS

MAS release NHS resources (especially in relation to GP consultations) by preventing (or minimizing) patient use of alternative and more costly branches of the NHS.

Browsing affects intra-ring carbon allocation in species with contrasting wood anatomy

Current knowledge on tree carbon (C) allocation to wood is particularly scarce in plants subjected to disturbance factors, such as browsing, which affects forest regeneration worldwide and has an impact on the C balance of trees. Furthermore, quantifying the degree to which tree rings are formed from freshly assimilated vs. stored carbohydrates is highly relevant for our understanding of tree C allocation. We used (13)C labelling to quantify seasonal allocation of stored C to wood formation in two species with contrasting wood anatomy: Betula pubescens Ehrh. (diffuse-porous) and Quercus petraea [Matt.] Liebl. (ring-porous). Clipping treatments (66% shoot removal, and unclipped) were applied to analyse the effect of browsing on C allocation into tree rings, plus the effects on tree growth, architecture, ring width and non-structural carbohydrates (NSCs). The relative contribution of stored C to wood formation was greater in the ring-porous (55-70%) than in the diffuse-porous species (35-60%), although each species followed different seasonal trends. Clipping did not cause a significant depletion of C stores in either species. Nonetheless, a significant increase in the proportion of stored C allocated to earlywood growth was observed in clipped birches, and this could be explained through changes in tree architecture after clipping. The size of C pools across tree species seems to be important in determining the variability of seasonal C allocation patterns to wood and their sensibility to disturbances such as browsing. Our results indicate that the observed changes in C allocation to earlywood in birch were not related to variations in the amount or concentration of NSC stores, but to changes in the seasonal availability of recently assimilated C caused by modifications in tree architecture after browsing.

Control of gene expression by CpG island methylation in normal cells

The role of DNA methylation in the control of mammalian gene expression has been the subject of intensive research in recent years, partly due to the critical role of CpG island methylation in the inactivation of tumour suppressor genes during the development of cancer. However, this research has also helped elucidate the role that DNA methylation plays in normal cells. At present, it is also clear that DNA methylation forms an important part of the normal cell-regulatory processes that govern gene transcription. Methylation, targeted at CpG islands, is an important part of the mechanisms that govern X-chromosome inactivation; it is also essential for the maintenance of imprinted genes and, at least in some cases, is critical in determining the cell-type-specific expression patterns of genes. Study of these examples will be important in identifying the mechanisms that control targeting of DNA methylation and how these processes are disrupted during disease pathogenesis.

A role for mismatch repair in control of DNA ploidy following DNA damage

Many reports have shown a link between mismatch repair (MMR) deficiency and loss of normal cell cycle control, particularly loss of G2 arrest. However almost all of these studies utilized transformed cell lines, and thus the involvement of other genes in this phenotype cannot be excluded. We have examined the effects of cisplatin treatment on primary embryo fibroblasts (MEFs) derived from mice in which the MMR gene Msh2 had been inactivated (Msh2(-/-)). This analysis determined that both primary Msh2(-/-) and wild type (WT) fibroblasts exhibited an essentially identical G2 arrest following cisplatin treatment. Similarly, we observed a cisplatin-induced G2 arrest in immortalized MMR deficient (Mlh1(-/-) and Pms2(-/-)) and WT MEFs. p53 deficient primary MEFs (p53(-/-)) exhibited both a clear G2 arrest and an increase in cells with a DNA content of 8N in response to cisplatin. When the Msh2 and p53 defects were combined (p53(-/-)/Msh2(-/-)) the G2 arrest was essentially identical to the p53(-/-) fibroblasts. However, the p53(-/-)/Msh2(-/-) fibroblasts demonstrated a further increase in cells with an 8N DNA content, above that seen in the p53(-/-) fibroblasts. These results suggest that loss of MMR on its own is not enough to overcome G2 arrest following exposure to cisplatin but does play a role in preventing polyploidization, or aberrant DNA reduplication, in the absence of functional p53.

Effect of nitrogen supply and defoliation on loss of organic compounds from roots of Festuca rubra

The aim of this study was to determine the effects of N-supply and defoliation on rhizodeposition from Festuca rubra, in the context of whole-plant C- partitioning and root morphology. Plants were grown for 36 d in axenic sand microcosms continuously percolated with nutrient solutions of either high or low N concentration (2 mM or 0.01 mM NH(4)NO(3), respectively). The effects of partial defoliation at weekly intervals were determined at high and low N. At low N, dry matter accumulation in roots and shoots was reduced significantly (P<0.001), with proportionately increased partitioning to roots, in comparison with the high N treatment. Root morphology was also affected by N-treatment; at low N, lower biomass production was offset by increased specific root length (P<0.001), reducing the magnitude of the significant (P=0.002) increase in total root length at high N. Cumulative release of organic C from roots of F: rubra over the experimental period was not altered significantly by N-treatment. However, as a proportion of net C-assimilation, rhizodeposition was significantly (P<0.001) greater at low N than at high N. Defoliation transiently (3-5 d) increased the release of soluble organic compounds from roots at each N-supply rate, and increased significantly (P<0.001) cumulative rhizodeposition over the experimental period. These effects of N-supply and defoliation on rhizodeposition are of importance in understanding interactions between plant and microbial productivity in grazed grasslands, and in interpretation of concurrent effects on microbially driven nutrient cycling processes in these systems.

Rivastigmine: a review

The acetylcholinesterase inhibitors are the first useful and useable drugs for palliative treatment of dementia of the Alzheimer type. This article reviews the second-generation carbamate cholinesterase inhibitor, rivastigmine (EXELON, Novartis, Basel) whose distinctive pharmacology is not only of immediate clinical relevance but also the key to some tantalizing therapeutic possibilities.

Cortical cell fluxes and transport to the stele in excised root segments of Allium cepa L. : IV. Calcium as affected by its external concentration

From compartmental analysis of radioisotope elutin measurements, fluxes of Ca(2+) were estimated for cortical cells in root segments of onion, Allium cepa L., relative to complete nutrient solutions containing a range of calcium concentrations ([Ca0]) from 2 μeq l(-1) to 20 meq l(-1), increasing in 10-fold steps for Ca(2+). Except for the calcium counter-ion (usually NO 3 (-) , sometimes Cl(-) at the highest [Ca0]), the composition of the nutrient solution was other-wise the same at all calcium concentrations. Compartmental analysis indicated that the cytoplasm had a high content of exchangeable Ca(2+) but, in the light of evidence from animal studies, ionic activity of calcium in the cytoplasm was assumed to be no greater than 0.002 μeq ml(-1). With the Ussing-Teorell flux equation as the criterion, it was concluded that at all values of [Ca0] tested, Ca(2+) entered the cytoplasm passively and was actively pumped back into the external solution. Entry of calcium to the vacuole from the cytoplasm was active in all cases. The conclusions regarding the character of ion transport across the plasmalemma were the same as when the whole calcium content of the cytoplasm was taken to contribute to the ionic activity. However, the electrochemical activity gradient was very much steeper than formerly estimated. Calcium was transported to the stele in proportion to the calcium content of the cytoplasm and moved in the xylem almost exclusively in the basipetal direction.

Cortical cell fluxes and transport to the stele in excised root segments of Allium cepa L. : III. Magnesium

From compartmental analysis of radioisotope elution measurements, concentrations and fluxes of Mg(2+) were estimated for cortical cells in root segments of onion, Allium cepa L., relative to a complete nutrient solution containing 0.25 mM Mg(2+). Five compartments for Mg(2+) in the cortex were found and, in order of increasing rates of exchange, identified with the vacuoles and the cytoplasm of the cortical parenchyma, the Donnan free space, the water free space, and the superficial film of solution on the segments. With the Ussing-Teorell flux ratio equation as the criterion, it was concluded that Mg(2+) entered the cytoplasm passively and was actively pumped back across the plasmalemma. Mg(2+) concentration in the vacuole could be estimated only as lying between wide limits (1.3 to 14.3 μeq ml(-1)), but whatever the concentration within this range, it was concluded that Mg(2+) was passively distributed across the tonoplast. Net flux was zero and the vacuolar concentration commensurate with this was found to be 6.6 μeq ml(-1). The transported fraction of total efflux, appearing at the segment cut ends, was estimated separately. Magnesium was found to be transported almost exclusively in the basipetal direction.