153 research outputs found
Heterogeneity of proliferative markers in pancreatic ÎČ-cells of patients with severe hypoglycemia following Roux-en-Y gastric bypass.
Severe postprandial hypoglycemia with neuroglycopenia is an increasingly recognized, debilitating complication of Roux-en-Y gastric bypass (RYGB) surgery. Increased secretion of insulin and incretin hormones is implicated in its pathogenesis. Histopathologic examination of pancreas has demonstrated increased islet size and/or nuclear diameter in post-RYGB patients who underwent pancreatectomy for severe refractory hypoglycemia with neuroglycopenia (RYGBÂ +Â NG). We aimed to determine whether ÎČ-cell proliferation or apoptosis is altered in RYGBÂ +Â NG.
We performed an observational study to analyze markers of proliferation, apoptosis, cell cycle, and transcription factor expression in pancreatic tissue from affected RYGB + NG patients (n = 12), normoglycemic patients undergoing pancreatic surgery for benign lesions (controls, n = 6), and individuals with hypoglycemia due to insulinoma (n = 52).
Proliferative cell nuclear antigen (PCNA) expression was increased in insulin-positive cells in RYGB + NG patients (4.5-fold increase, p < 0.001 vs. controls) and correlated with ÎČ-cell mass. Ki-67 immunoreactivity was low in both RYGB + NG and controls, but did not differ between groups. Phospho-histone H3 levels did not differ between RYGB + NG and controls. PCNA and Ki-67 were both significantly lower in both controls and RYGB + NG than insulinomas. Markers of apoptosis and cell cycle (M30, p27, and p21) did not differ between groups. PDX1 and menin exhibited similar expression patterns, while FOXO1 appeared to be more cytosolic in RYGB + NG.
Markers of proliferation are heterogeneous in patients with severe post-RYGB hypoglycemia. Increased ÎČ-cell proliferation in some individuals may contribute to increased ÎČ-cell mass observed in severely affected patients
Lipid-biomarker-based sea surface temperature record offshore Tasmania over the last 23Â million years
The Neogene (23.04â2.58âMa) is characterised by progressive buildup of ice volume and climate cooling in the Antarctic and the Northern Hemisphere. Heat and moisture delivery to Antarctica is, to a large extent, regulated by the strength of meridional temperature gradients. However, the evolution of the Southern Ocean frontal systems remains scarcely studied in the Neogene. Here, we present the first long-term continuous sea surface temperature (SST) record of the subtropical front area in the Southern Ocean at Ocean Drilling Program (ODP) Site 1168 off western Tasmania. This site is, at present, located near the subtropical front (STF), as it was during the Neogene, despite a 10â northward tectonic drift of Tasmania. We analysed glycerol dialkyl glycerol tetraethers (GDGTs â on 433 samples) and alkenones (on 163 samples) and reconstructed the paleotemperature evolution using TEX86 and U37kâČ as two independent quantitative proxies. Both proxies indicate that Site 1168 experienced a temperate âŒâ25ââC during the early Miocene (23â17âMa), reaching âŒâ29ââC during the mid-Miocene climatic optimum. The stepwise âŒâ10ââC cooling (20â10ââC) in the mid-to-late Miocene (12.5â5.0âMa) is larger than that observed in records from lower and higher latitudes. From the Pliocene to modern (5.3â0âMa), STF SST first plateaus at âŒâ15ââC (3âMa), then decreases to âŒâ6ââC (1.3âMa), and eventually increases to the modern levels around âŒâ16ââC (0âMa), with a higher variability of 5â compared to the Miocene. Our results imply that the latitudinal temperature gradient between the Pacific Equator and the STF during late Miocene cooling increased from 4 to 14ââC. Meanwhile, the SST gradient between the STF and the Antarctic margin decreased due to amplified STF cooling compared to the Antarctic margin. This implies a narrowing SST gradient in the Neogene, with contraction of warm SSTs and northward expansion of subpolar conditions.</p
Ancient marine sediment DNA reveals diatom transition in Antarctica
Antarctica is one of the most vulnerable regions to climate change on Earth and studying the past and present responses of this polar marine ecosystem to environmental change is a matter of urgency. Sedimentary ancient DNA (sedaDNA) analysis can provide such insights into past ecosystem-wide changes. Here we present authenticated (through extensive contamination control and sedaDNA damage analysis) metagenomic marine eukaryote sedaDNA from the Scotia Sea region acquired during IODP Expedition 382. We also provide a marine eukaryote sedaDNA record of ~1 Mio. years and diatom and chlorophyte sedaDNA dating back to ~540 ka (using taxonomic marker genes SSU, LSU, psbO). We ïŹnd evidence of warm phases being associated with high relative diatom abundance, and a marked transition from diatoms comprising <10% of all eukaryotes prior to ~14.5 ka, to ~50% after this time, i.e., following Meltwater Pulse 1A, alongside a composition change from sea-ice to openocean species. Our study demonstrates that sedaDNA tools can be expanded to hundreds of thousands of years, opening the pathway to the study of ecosystem-wide marine shifts and paleo-productivity phases throughout multiple glacial-interglacial cycles.Antarctica is one of the most vulnerable regions to climate change on Earth and studying the past and present responses of this polar marine ecosystem to environmental change is a matter of urgency. Sedimentary ancient DNA (sedaDNA) analysis can provide such insights into past ecosystem-wide changes. Here we present authenticated (through extensive contamination control and sedaDNA damage analysis) metagenomic marine eukaryote sedaDNA from the Scotia Sea region acquired during IODP Expedition 382. We also provide a marine eukaryote sedaDNA record of ~1 Mio. years and diatom and chlorophyte sedaDNA dating back to ~540 ka (using taxonomic marker genes SSU, LSU, psbO). We find evidence of warm phases being associated with high relative diatom abundance, and a marked transition from diatoms comprising <10% of all eukaryotes prior to ~14.5 ka, to ~50% after this time, i.e., following Meltwater Pulse 1A, alongside a composition change from sea-ice to open-ocean species. Our study demonstrates that sedaDNA tools can be expanded to hundreds of thousands of years, opening the pathway to the study of ecosystem-wide marine shifts and paleo-productivity phases throughout multiple glacial-interglacial cycles.Postprin
Childbearing intentions in a low fertility context: the case of Romania
This paper applies the Theory of Planned Behaviour (TPB) to find out the predictors of fertility intentions in Romania, a low-fertility country. We analyse how attitudes, subjective norms and perceived behavioural control relate to the intention to have a child among childless individuals and one-child parents. Principal axis factor analysis confirms which items proposed by the Generation and Gender Survey (GGS 2005) act as valid and reliable measures of the suggested theoretical socio-psychological factors. Four parity-specific logistic regression models are applied to evaluate the relationship between the socio-psychological factors and childbearing intentions. Social pressure emerges as the most important aspect in fertility decision-making among childless individuals and one-child parents, and positive attitudes towards childbearing are a strong component in planning for a child. This paper also underlines the importance of the region-specific factors when studying childbearing intentions: planning for the second child significantly differs among the development regions, representing the cultural and socio-economic divisions of the Romanian territory
Religious socialisation and fertility: transition to third birth in the Netherlands
Although previous studies have demonstrated that religious people in Europe have larger families, the role played by religious socialisation in the context of contemporary fertility behaviour has not yet been analysed in detail. This contribution specifically looks at the interrelation between religious socialisation and current religiosity and their impact on the transition to the third child for Dutch women. It is based on data of the first wave of the Netherlands Kinship Panel Study (2002â2004) and uses event history analysis. The transitions to first, second and third birth are modelled jointly with a control for unobserved heterogeneity. The findings provide evidence for an impact of womenâs current church attendance as well as religious socialisation measured by their fathersâ religious affiliation, when they were teenagers. A religious family background remains influential even when a woman has stopped attending church. The effects of religious indicators strengthen over cohorts. Moreover, the combined religious make-up of the respondentâs parents also significantly determines the progression to the third child.Sâil est bien Ă©tabli que les croyants en Europe ont plus dâenfants que les autres, le rĂŽle de la socialisation religieuse dans le contexte de la fĂ©conditĂ© contemporaine nâa pas encore Ă©tĂ© analysĂ© Ă ce jour. Cette Ă©tude sâintĂ©resse au lien entre la socialisation religieuse et la religiositĂ© actuelle, et Ă leur impact sur la probabilitĂ© dâagrandissement de deux Ă trois enfants de la descendance des femmes nĂ©erlandaises. Les donnĂ©es exploitĂ©es sont celles de la premiĂšre vague du Panel NĂ©erlandais dâEtude de la ParentĂ© (the Netherlands Kinship Panel Study, 2002â2004). A lâaide des techniques de lâanalyse des biographies, les probabilitĂ©s dâagrandissement de rang 1, rang 2 et rang 3 ont Ă©tĂ© modĂ©lisĂ©es de façon conjointe, en contrĂŽlant lâhĂ©tĂ©rogĂ©nĂ©itĂ© non observĂ©e. Les rĂ©sultats mettent en Ă©vidence lâimpact de la frĂ©quentation actuelle de lâĂ©glise par les femmes et de leur socialisation religieuse, mesurĂ©e par lâappartenance religieuse de leur pĂšre quand elles Ă©taient adolescentes. Il apparaĂźt que la religiositĂ© du contexte familial exerce une influence, mĂȘme quand la femme ne frĂ©quente plus lâĂ©glise, et que les effets des indicateurs de pratique religieuse se renforcent dâune gĂ©nĂ©ration Ă lâautre. Enfin, lâappartenance religieuse conjointe des parents de la femme dĂ©termine significativement la probabilitĂ© dâavoir un troisiĂšme enfant
How are time-dependent childbearing intentions realized? Realization, postponement, abandonment, bringing forward
Our study aims to identify factors that facilitate or inhibit the realization of fertility intentions. The analysis uses data collected in the first two waves of a Hungarian longitudinal survey. Fertility intentions recorded at the first wave pertain to the subsequent 3-year period, just similar to the behavior variable measuring the realization of intentions, i.e., a birth within the 3-year period in question. For this analysis, we used the respondentsâ demographic, socio-structural, and orientational traits recorded at the first interview. Our findings show that age, parity, and partnership play a determining role in the realization of fertility intentions, but employment status, religious affiliation, and overall life satisfaction all exhibit significant effects. A marked gender difference was detected not only with regard to employment status but in the area of values and orientations as well.Lâobjectif de notre Ă©tude est dâidentifier les facteurs qui facilitent ou inhibent la rĂ©alisation des intentions de fĂ©conditĂ©. Lâanalyse sâappuie sur les deux premiĂšres vagues dâune enquĂȘte longitudinale menĂ©e en Hongrie. Les intentions de fĂ©conditĂ© recueillies dans le cadre de la premiĂšre vague concernent la pĂ©riode des trois annĂ©es Ă venir, de la mĂȘme façon que la variable de comportement mesurant la rĂ©alisation des intentions, Ă savoir, une naissance survenue au cours de cette mĂȘme pĂ©riode. Les caractĂ©ristiques dĂ©mographiques et socio-structurelles, de mĂȘme que certaines dispositions personnelles recueillies lors du premier entretien ont Ă©tĂ© utilisĂ©es dans lâanalyse. Nos rĂ©sultats indiquent quâĂ la fois lâĂąge, la paritĂ©, et la situation de couple jouent un rĂŽle capital dans la rĂ©alisation des intentions et aussi que la situation dâemploi, lâappartenance religieuse et le niveau de satisfaction par rapport Ă la vie exercent une influence significative. Une diffĂ©rence prononcĂ©e entre hommes et femmes est mise en Ă©vidence en matiĂšre de situation dâemploi et Ă©galement dans le domaine des valeurs et des dispositions personnelles
How Grandparents Matter: Support for the Cooperative Breeding Hypothesis in a Contemporary Dutch Population
Low birth rates in developed societies reflect womenâs difficulties in combining work and motherhood. While demographic research has focused on the role of formal childcare in easing this dilemma, evolutionary theory points to the importance of kin. The cooperative breeding hypothesis states that the wider kin group has facilitated womenâs reproduction during our evolutionary history. This mechanism has been demonstrated in pre-industrial societies, but there is no direct evidence of beneficial effects of kinâs support on parentsâ reproduction in modern societies. Using three-generation longitudinal data anchored in a sample of grandparents aged 55 and over in 1992 in the Netherlands, we show that childcare support from grandparents increases the probability that parents have additional children in the next 8 to 10Â years. Grandparental childcare provided to a nephew or niece of childless children did not significantly increase the probability that those children started a family. These results suggest that childcare support by grandparents can enhance their childrenâs reproductive success in modern societies and is an important factor in peopleâs fertility decisions, along with the availability of formal childcare
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