Chemistry of Tropical Root Crops: Significance for Nutrition and Agriculture in the Pacific

Crop Production/Industries,

Analytical, Nutritional and Clinical Methods Section Total cyanide determination of plants and foods using the picrate and acid hydrolysis methods

Abstract A general method has been developed for determination of the total cyanide content of all cyanogenic plants and foods. Ten cyanogenic substrates (cassava, flax seed, sorghum and giant taro leaves, stones of peach, plum, nectarine and apricot, apple seeds and bamboo shoot) were chosen, as well as various model compounds, and the total cyanide contents determined by the acid hydrolysis and picrate kit methods. The hydrolysis of cyanoglucosides in 2 M sulfuric acid at 100 o C in a glass stoppered test tube causes some loss of HCN which is corrected for by extrapolation to zero time. However, using model compounds including replicate analyses on amygdalin, the picrate method is found to be more accurate and reproducible than the acid hydrolysis method. The picrate kit method is available free of charge to workers in developing countries for determination of cyanide in cassava roots and cassava products, flax seed, bamboo shoots and cyanide containing leaves. For eleven different samples of flax seed and flax seed meal the total cyanide content was 140-370 ppm. Bamboo shoots contained up to 1600 ppm total cyanide in the tip reducing to 110 ppm in the base. The total cyanide content of sorghum leaves was 740 ppm 1 week after germination but reduced to 60 ppm 3 weeks later. The acid hydrolysis method is generally applicable to all plants, but is much more difficult to use and is less accurate and reproducible than the picrate method, which is the method of choice for plants of importance for human food.

Control of konzo in the Democratic Republic of Congo

Konzo is an upper motor neuron disease that causes irreversible paralysis of the legs mainly in children and young women^1,2^, due to consumption of large amounts of cyanogens from poorly processed cassava, the staple food of tropical Africa^3^. Konzo occurs in the Democratic Republic of Congo (DRC),Mozambique, Tanzania, Cameroon, Central African Republic and Angola. In March 2010 the wetting method, which removes cyanogens from cassava flour^4,5,6^, was taught to and used by the mothers of Kay Kalenge village. This reduced the total cyanide content of cassava flour to the FAO/WHO limit of 10ppm^7^. Cyanogen intake of school children, monitored by urinary thiocyanate analyses, decreased from mean values of 332 to 130 μmole/L. The percentage of urine samples that exceeded the danger level of about 350 μmole/L decreased from 26 in March 2010 to zero by May 2011. In 2009 there were many new cases of konzo, but none in 2010-2011. Konzo was first identified in1938 in Popokabaka area^8^ and it has now been prevented for the first time in the same area. This methodology is being used in three villages in Boko area and we believe it is the way to control konzo in tropical Africa

Persistent Konzo and cyanogens toxicity from cassava in Northerm Mozambique.

Abstract We aimed to detect new cases of konzo and monitor cyanogen exposure from cassava flour in communities previously affected by konzo epidemics in Nampula Province, northern Mozambique. Other objectives were to detect subclinical upper motor neuron damage in schoolchildren and test a new kit to measure urinary thiocyanate concentration. In 1999 and 2000, we carried out active and passive case detection for konzo in Memba and Mogincual Districts. In July and October, 1999, we collected cassava flour from 30 houses in three communities and measured cyanogen concentrations with a picrate kit. In October 1999, we examined all schoolchildren in three communities for ankle clonus and measured urinary thiocyanate concentration in thirty schoolchildren in each of five communities with a picrate kit. We found 27 new cases of konzo in Mogincual District. Mean total cyanogen concentrations in cassava flour varied between both seasons and years, but were always high, ranging from 26 to 186 ppm. Very high mean levels at three sites in November 1998 and July 1999 were probably due to low rainfall in the 1997-1998 season. The proportion of schoolchildren with ankle clonus varied from 8 to 17%. The new picrate kit for urinary thiocyanate worked well; mean concentrations in schoolchildren ranged from 225 to 384 mmol l − 1 . Konzo and sub-clinical upper motor neuron damage persist in poor rural communities in northern Mozambique, associated with high cyanogen concentrations in cassava flour and high urinary thiocyanate concentrations in schoolchildren

Priorities and strategies for improving disabled women's access to maternity services when they are affected by domestic abuse:a multi-method study using concept maps

BACKGROUND: Domestic abuse is a significant public health issue. It occurs more frequently among disabled women than those without a disability and evidence suggests that a great deal of domestic abuse begins or worsens during pregnancy. All women and their infants are entitled to equal access to high quality maternity care. However, research has shown that disabled women who experience domestic abuse face numerous barriers to accessing care. The aim of the study was to identify the priority areas for improving access to maternity services for this group of women; develop strategies for improved access and utilisation; and explore the feasibility of implementing the identified strategies. METHODS: This multi-method study was the third and final part of a larger study conducted in the UK between 2012 and 2014. The study used a modified concept mapping approach and was theoretically underpinned by Andersen’s model of healthcare use. Seven focus group interviews were conducted with a range of maternity care professionals (n = 45), incorporating quantitative and qualitative components. Participants ranked perceived barriers to women’s access and utilisation of maternity services in order of priority using a 5-point Likert scale. Quantitative data exploration used descriptive and non-parametric analyses. In the qualitative component of each focus group, participants discussed the barriers and identified potential improvement strategies (and feasibility of implementing these). Qualitative data were analysed inductively using a framework analysis approach. RESULTS: The three most highly ranked barriers to women’s access and utilisation of maternity services identified in the quantitative component were: 1) staff being unaware and not asking about domestic abuse and disability; 2) the impact of domestic abuse on women; 3) women’s fear of disclosure. The top two priority strategies were: providing information about domestic abuse to all women and promoting non-judgemental staff attitude. These were also considered very feasible. The qualitative analysis identified a range of psychosocial and environmental barriers experienced by this group of women in accessing maternity care. Congruent with the quantitative results, the main themes were lack of awareness and fear of disclosure. Key strategies were identified as demystifying disclosure and creating physical spaces to facilitate disclosure. CONCLUSIONS: The study supports findings of previous research regarding the barriers that women face in accessing and utilising maternity services, particularly regarding the issue of disclosure. But the study provides new evidence on the perceived importance and feasibility of strategies to address such barriers. This is an important step in ensuring practice-based acceptability and ease with which improvement strategies might be implemented in maternity care settings

Expertise in research integration and implementation for tackling complex problems: when is it needed, where can it be found and how can it be strengthened?

© 2020, The Author(s). Expertise in research integration and implementation is an essential but often overlooked component of tackling complex societal and environmental problems. We focus on expertise relevant to any complex problem, especially contributory expertise, divided into ‘knowing-that’ and ‘knowing-how.’ We also deal with interactional expertise and the fact that much expertise is tacit. We explore three questions. First, in examining ‘when is expertise in research integration and implementation required?,’ we review tasks essential (a) to developing more comprehensive understandings of complex problems, plus possible ways to address them, and (b) for supporting implementation of those understandings into government policy, community practice, business and social innovation, or other initiatives. Second, in considering ‘where can expertise in research integration and implementation currently be found?,’ we describe three realms: (a) specific approaches, including interdisciplinarity, transdisciplinarity, systems thinking and sustainability science; (b) case-based experience that is independent of these specific approaches; and (c) research examining elements of integration and implementation, specifically considering unknowns and fostering innovation. We highlight examples of expertise in each realm and demonstrate how fragmentation currently precludes clear identification of research integration and implementation expertise. Third, in exploring ‘what is required to strengthen expertise in research integration and implementation?,’ we propose building a knowledge bank. We delve into three key challenges: compiling existing expertise, indexing and organising the expertise to make it widely accessible, and understanding and overcoming the core reasons for the existing fragmentation. A growing knowledge bank of expertise in research integration and implementation on the one hand, and accumulating success in addressing complex societal and environmental problems on the other, will form a virtuous cycle so that each strengthens the other. Building a coalition of researchers and institutions will ensure this expertise and its application are valued and sustained

Stages of development and injury patterns in the early years: a population-based analysis

BACKGROUND: In Canada, there are many formal public health programs under development that aim to prevent injuries in the early years (e.g. 0–6). There are paradoxically no population-based studies that have examined patterns of injury by developmental stage among these young children. This represents a gap in the Canadian biomedical literature. The current population-based analysis explores external causes and consequences of injuries experienced by young children who present to the emergency department for assessment and treatment. This provides objective evidence about prevention priorities to be considered in anticipatory counseling and public health planning. METHODS: Four complete years of data (1999–2002; n = 5876 cases) were reviewed from the Kingston sites of the Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP), an ongoing injury surveillance initiative. Epidemiological analyses were used to characterize injury patterns within and across age groups (0–6 years) that corresponded to normative developmental stages. RESULTS: The average annual rate of emergency department-attended childhood injury was 107 per 1000 (95% CI 91–123), with boys experiencing higher annual rates of injury than girls (122 vs. 91 per 1000; p < 0.05). External causes of injury changed substantially by developmental stage. This lead to the identification of four prevention priorities surrounding 1) the optimization of supervision; 2) limiting access to hazards; 3) protection from heights; and 4) anticipation of risks. CONCLUSION: This population-based injury surveillance analysis provides a strong evidence-base to inform and enhance anticipatory counseling and other public health efforts aimed at the prevention of childhood injury during the early years

Role of Soluble Epoxide Hydrolase in Postischemic Recovery of Heart Contractile Function

Cytochrome P450 epoxygenases metabolize arachidonic acid to epoxyeicosatrienoic acids (EETs) which are converted to dihydroxyeicosatrienoic acids (DHETs) by soluble epoxide hydrolase (Ephx2, sEH). To examine the functional role of sEH in the heart, mice with targeted disruption of the Ephx2 gene were studied. Hearts from sEH null mice have undetectable levels of sEH mRNA and protein and cannot convert EETs to DHETs. sEH null mice have normal heart anatomy and basal contractile function, but have higher fatty acid epoxide:diol ratios in plasma and cardiomyocyte cell culture media compared with wild type (WT). sEH null hearts have improved recovery of left ventricular developed pressure (LVDP) and less infarction compared with WT hearts after 20 minutes ischemia. Perfusion with the putative EET receptor antagonist 14,15-epoxyeicosa-5(Z)-enoic acid (10 to 100 nmol/L) before ischemia abolishes this cardioprotective phenotype. Inhibitor studies demonstrate that perfusion with phosphatidylinositol-3 kinase (PI3K) inhibitors wortmannin (200 nmol/L) or LY294002 (5 μmol/L), the ATP-sensitive K+ channel (KATP) inhibitor glibenclamide (1 μmol/L), the mitochondrial KATP (mitoKATP) inhibitor 5-hydroxydecanoate (100 to 200 μmol/L), or the Ca2+-sensitive K+ channel (KCa) inhibitor paxilline (10 μmol/L) abolishes the cardioprotection in sEH null hearts. Consistent with increased activation of the PI3K cascade, sEH null mice exhibit increased cardiac expression of glycogen synthase kinase-3β (GSK-3β) phospho-protein after ischemia. Together, these data suggest that targeted disruption of sEH increases the availability of cardioprotective EETs that work by activating PI3K signaling pathways and K+ channels

AKT1 polymorphisms are associated with risk for metabolic syndrome

Converging lines of evidence suggest that AKT1 is a major mediator of the responses to insulin, insulin-like growth factor 1 (IGF1), and glucose. AKT1 also plays a key role in the regulation of both muscle cell hypertrophy and atrophy. We hypothesized that AKT1 variants may play a role in the endophenotypes that make up metabolic syndrome. We studied a 12-kb region including the first exon of the AKT1 gene for association with metabolic syndrome-related phenotypes in four study populations [FAMUSS cohort (n = 574; age 23.7 ± 5.7 years), Strong Heart Study (SHS) (n = 2,134; age 55.5 ± 7.9 years), Dynamics of Health, Aging and Body Composition (Health ABC) (n = 3,075; age 73.6 ± 2.9 years), and Studies of a Targeted Risk Reduction Intervention through Defined Exercise (STRRIDE) (n = 175; age 40–65 years)]. We identified a three SNP haplotype that we call H1, which represents the ancestral alleles at the three loci and H2, which represents the derived alleles at the three loci. In young adult European Americans (FAMUSS), H1 was associated with higher fasting glucose levels in females. In middle age Native Americans (SHS), H1 carriers showed higher fasting insulin and HOMA in males, and higher BMI in females. In older African-American and European American subjects (Health ABC) H1 carriers showed a higher incidence of metabolic syndrome. Homozygotes for the H1 haplotype showed about twice the risk of metabolic syndrome in both males and females (p < 0.001). In middle-aged European Americans with insulin resistance (STRRIDE) studied by intravenous glucose tolerance test (IVGTT), H1 carriers showed increased insulin resistance due to the Sg component (p = 0.021). The 12-kb haplotype is a risk factor for metabolic syndrome and insulin resistance that needs to be explored in further populations