title: Network of mental activities, cognitive function and depression in older men and women

authors: Hopkins, Ella G.

subjects: Cognition

abstract: BACKGROUND: Evidence suggests that lifestyle activities impact cognitive and mental health in older populations. However, how lifestyle factors are associated with one another, and which factors are most important for cognitive function and mental health has received comparatively little attention. DESIGN: Bayesian-Gaussian network analysis was used to investigate unique associations between mental activities (MA; i.e., activities involving cognitive engagement), global cognition, and depression at three time-points in a large sample of older adults (baseline, 2 years, and 4 years follow-up). SETTING: This study used longitudinal data from participants living in Australia and participating in the Sydney Memory and Ageing Study. PARTICIPANTS: The sample included 998 participants (55% female) aged between 70 and 90, without a diagnosis of dementia at baseline. MEASUREMENTS: Neuropsychological assessment of global cognition, self-reported depressive symptoms, and self-reported information about daily MA. RESULTS: Cognitive functioning was positively associated with playing tabletop games and using the internet in both sexes at all time-points. MA were differentially linked in men and women. Depression was not consistently associated with MA in men across the three time-points; women who visited artistic events consistently had lower depression scores. CONCLUSIONS: Engaging with tabletop games and using the internet was associated with better cognition in both sexes, however sex acted as a modifier for other associations. These findings are useful for future investigations that consider interactive associations between MA, cognition, and mental health in older adults, and their possible roles in promoting healthy aging.

text: Network of mental activities, cognitive function and depression in older men and women BACKGROUND: Evidence suggests that lifestyle activities impact cognitive and mental health in older populations. However, how lifestyle factors are associated with one another, and which factors are most important for cognitive function and mental health has received comparatively little attention. DESIGN: Bayesian-Gaussian network analysis was used to investigate unique associations between mental activities (MA; i.e., activities involving cognitive engagement), global cognition, and depression at three time-points in a large sample of older adults (baseline, 2 years, and 4 years follow-up). SETTING: This study used longitudinal data from participants living in Australia and participating in the Sydney Memory and Ageing Study. PARTICIPANTS: The sample included 998 participants (55% female) aged between 70 and 90, without a diagnosis of dementia at baseline. MEASUREMENTS: Neuropsychological assessment of global cognition, self-reported depressive symptoms, and self-reported information about daily MA. RESULTS: Cognitive functioning was positively associated with playing tabletop games and using the internet in both sexes at all time-points. MA were differentially linked in men and women. Depression was not consistently associated with MA in men across the three time-points; women who visited artistic events consistently had lower depression scores. CONCLUSIONS: Engaging with tabletop games and using the internet was associated with better cognition in both sexes, however sex acted as a modifier for other associations. These findings are useful for future investigations that consider interactive associations between MA, cognition, and mental health in older adults, and their possible roles in promoting healthy aging.

year: 2023-06

title: A structural basis for the reduced toxicity of dinophysistoxin-2

authors: Huhn, Jason

subjects: dinophysistoxin

abstract: Okadaic acid (OA), dinophysistoxin-1 (DTX-1), and dinophysistoxin-2 (DTX-2) are algal toxins that can accumulate in shellfish and cause diarrhetic shellfish poisoning. Recent studies indicate that DTX-2 is about half as toxic and has about half the affinity for protein phosphatase 2A (PP2A) as OA. NMR structural studies showed that DTX-1 possessed an equatorial 35-methyl group but that DTX-2 had an axial 35-methyl group. Molecular modeling studies indicated that an axial 35-methyl could exhibit unfavorable interactions in the PP2A binding site, and this has been proposed as the reason for the reduced toxicity of DTX-2. Statistical analyses of published data indicate that the affinity of PP2A for DTX-1 is 1.6-fold higher, and for DTX-2 is 2-fold lower, than for OA. We obtained X-ray crystal structures of DTX-1 and DTX-2 bound to PP2A. The crystal structures independently confirm the C-35 stereochemistries determined in the earlier NMR study. The structure for the DTX-1 complex was virtually identical to that of the OA-PP2A complex, except for the presence of the equatorial 35-methyl on the ligand. The favorable placement of the equatorial 35-methyl group of DTX-1 against the aromatic π-bonds of His191 may account for the increased affinity of PP2A toward DTX-1. In contrast, the axial 35-methyl of DTX-2 caused the side chain of His191 to rotate 140° so that it pointed toward the solvent, thereby opening one end of the hydrophobic binding cage. This rearrangement to accommodate the unfavorable interaction from the axial 35-methyl of DTX-2 reduces the binding energy and appears to be responsible for the reduced affinity of PP2A for DTX-2. These results highlight the potential of molecular modeling studies for understanding the relative toxicity of analogues once the binding site at the molecular target has been properly characterized.

text: A structural basis for the reduced toxicity of dinophysistoxin-2 Okadaic acid (OA), dinophysistoxin-1 (DTX-1), and dinophysistoxin-2 (DTX-2) are algal toxins that can accumulate in shellfish and cause diarrhetic shellfish poisoning. Recent studies indicate that DTX-2 is about half as toxic and has about half the affinity for protein phosphatase 2A (PP2A) as OA. NMR structural studies showed that DTX-1 possessed an equatorial 35-methyl group but that DTX-2 had an axial 35-methyl group. Molecular modeling studies indicated that an axial 35-methyl could exhibit unfavorable interactions in the PP2A binding site, and this has been proposed as the reason for the reduced toxicity of DTX-2. Statistical analyses of published data indicate that the affinity of PP2A for DTX-1 is 1.6-fold higher, and for DTX-2 is 2-fold lower, than for OA. We obtained X-ray crystal structures of DTX-1 and DTX-2 bound to PP2A. The crystal structures independently confirm the C-35 stereochemistries determined in the earlier NMR study. The structure for the DTX-1 complex was virtually identical to that of the OA-PP2A complex, except for the presence of the equatorial 35-methyl on the ligand. The favorable placement of the equatorial 35-methyl group of DTX-1 against the aromatic π-bonds of His191 may account for the increased affinity of PP2A toward DTX-1. In contrast, the axial 35-methyl of DTX-2 caused the side chain of His191 to rotate 140° so that it pointed toward the solvent, thereby opening one end of the hydrophobic binding cage. This rearrangement to accommodate the unfavorable interaction from the axial 35-methyl of DTX-2 reduces the binding energy and appears to be responsible for the reduced affinity of PP2A for DTX-2. These results highlight the potential of molecular modeling studies for understanding the relative toxicity of analogues once the binding site at the molecular target has been properly characterized.

year: 2009

title: Te mana o te wahine: Young mothers healthcare experiences in pregnancy, birth, and into motherhood

authors: Kolo, Mia Elaine

subjects: Health

abstract: In Aotearoa-New Zealand being a young mother is often associated with clinical and societal ‘risks.’ Younger women have higher rates of maternal depression and suicide, complications during birth, and their babies are more likely to be born preterm, and of smaller gestational age and weight (Perinatal and Maternal Mortality Review Committee, 2012; Te Whatu Ora - Health New Zealand, 2023b, 2023a). Research also indicates that young mothers experience stigmatisation and discrimination that they attribute to their age and/or ethnicity (Adcock, 2016; Makowharemahihi et al., 2014; Rawiri, 2007; Ware, 2019).
In discussion with researchers, discrimination was the topic that young mothers at He Puaawai Teen Parent Centre wanted to talk about. They shared a strong desire to see change in the way that doctors, nurses, and midwives service young parents and were passionate about ensuring that future young mothers had more support. Thus, in responding to their call, 22 parents, including two fathers attending (or recent school-leavers of) He Puaawai Teen Parent Centre volunteered to participate in this study. This qualitative kaupapa Māori study employed a series of wānanga, individual kōrero, and an investigator-triangulation thematic analysis. The research questions explored both the positive and negative healthcare experiences of this cohort during pregnancy, birth, and into motherhood.
The aim of this study was to listen and learn about the experiences of these young parents and co-design informational and/or educational materials to help healthcare practitioners better understand and support young mothers/parents. To spread awareness of the experiences of these young parents, the co-design materials and findings of this study were disseminated via various healthcare seminars and meetings around the Waikato region. The findings of this study contribute to previous research that revealed over the last 20 years young parents have continued to report predominantly negative experiences in their maternity journey. Participants of this study reported experiences of unsolicited judgement and advice, a general lack of manaakitanga (care, empathy, respect), communication, and support from doctors, nurses, and midwives. The relatively small number of positive experiences shared in this study emphasises the importance of manaakitanga regardless of age. An unexpected finding was the impact that receptionists had on young parents’ healthcare experiences, as the face and entry point of healthcare services.

text: Te mana o te wahine: Young mothers healthcare experiences in pregnancy, birth, and into motherhood In Aotearoa-New Zealand being a young mother is often associated with clinical and societal ‘risks.’ Younger women have higher rates of maternal depression and suicide, complications during birth, and their babies are more likely to be born preterm, and of smaller gestational age and weight (Perinatal and Maternal Mortality Review Committee, 2012; Te Whatu Ora - Health New Zealand, 2023b, 2023a). Research also indicates that young mothers experience stigmatisation and discrimination that they attribute to their age and/or ethnicity (Adcock, 2016; Makowharemahihi et al., 2014; Rawiri, 2007; Ware, 2019).
In discussion with researchers, discrimination was the topic that young mothers at He Puaawai Teen Parent Centre wanted to talk about. They shared a strong desire to see change in the way that doctors, nurses, and midwives service young parents and were passionate about ensuring that future young mothers had more support. Thus, in responding to their call, 22 parents, including two fathers attending (or recent school-leavers of) He Puaawai Teen Parent Centre volunteered to participate in this study. This qualitative kaupapa Māori study employed a series of wānanga, individual kōrero, and an investigator-triangulation thematic analysis. The research questions explored both the positive and negative healthcare experiences of this cohort during pregnancy, birth, and into motherhood.
The aim of this study was to listen and learn about the experiences of these young parents and co-design informational and/or educational materials to help healthcare practitioners better understand and support young mothers/parents. To spread awareness of the experiences of these young parents, the co-design materials and findings of this study were disseminated via various healthcare seminars and meetings around the Waikato region. The findings of this study contribute to previous research that revealed over the last 20 years young parents have continued to report predominantly negative experiences in their maternity journey. Participants of this study reported experiences of unsolicited judgement and advice, a general lack of manaakitanga (care, empathy, respect), communication, and support from doctors, nurses, and midwives. The relatively small number of positive experiences shared in this study emphasises the importance of manaakitanga regardless of age. An unexpected finding was the impact that receptionists had on young parents’ healthcare experiences, as the face and entry point of healthcare services.

year: 2024