199 research outputs found

    Phelan-McDermid syndrome: a review of the literature and practice parameters for medical assessment and monitoring

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    The purpose of this study is to contribute to a deeper understanding about how placement discontinuities of children in foster care affect their learning. The aim is to find out more about their learning and what role school plays in their life. A life-world perspective is used and theories mainly developed by Alfred SchĂŒtz (2002) build the theoretical framework. The empirical research is mainly based on narratives of a pair of twins at 19 years of age, who agreed to share their life stories and experiences of their time in school. Meetings were arranged separately with Alex, the boy, and Helena, the girl, both eager to participate. They felt that their stories could contribute to knowledge. The stories show that placement discontinuities in their early childhood made memories and their perspective of time blurry. They both suffered severe neglect in two of their foster care placements. School offered them a safe place throughout their adolescent years. However, despite this, they are critical to the teachers who saw that they suffered neglect at home but never acted upon that knowledge. Hence their first-hand experiences suggest that teachers, considered important in earlier research studies, are not as important as friend made or the daily routines that provide certain security in an otherwise uncertain life. The social services didn’t listen or support them. Alex and Helena felt that they had to take care of themselves. Their stories show that both of them are goal-oriented and that they highly value a good education. This is evident since they have always taken responsibility to complete set homework and to make school a functional place where they have also learned to know themselves. Furthermore, it is obvious that the twins have played a tremendous role for each other when their life-world time after time has changed. Alex and Helena’s stories and experiences can give the social services a deeper understanding of what lies behind the statistics. A teacher, who listens, shows support and has ambitious expectations regarding the children’s academic performance, has been confirmed in previous research to be of significant importance. In addition, the study shows that teachers should learn more about children in foster care. A life-world perspective and life-world theories can contribute to an alternative point of view regarding learning in life-world discontinuities. Learning can be reflected on by using SchĂŒtz theory about “strangers” as a way of understanding learning in a wider range, especially when there are discontinues in the life-world. The reflections made in this study point out the possibility that schools, as organizations, seem to have independent cultures that can be transferred between one another. In fact there seems to be certain variables that are the same for schools in general and hence it is of significant value to recognize school as a regional life-world. The expectations of how you act as a student and among friends are important for the sense of belonging. It is possible that Alex and Helena succeeded in school partly because some of the things they learned about the first school could be transferred to their new school. The study contributes with two new concepts; “livsvĂ€rldsbrott”- life-world-disruption and “livsvĂ€rldsbevarande”- life-world-preservation

    Immunocytochemical localization of the alpha-1B adrenergic receptor and the contribution of this and the other subtypes to vascular smooth muscle contraction: analysis with selective ligands and antisense

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    ABSTRACT The contribution of the alpha-1B adrenergic receptor (AR) to vascular smooth muscle contraction has been assessed using a combination of immunological, molecular biological and pharmacological approaches. A subtype-selective antibody detected alpha-1B immunoreactivity in the medial layer of the aorta, caudal, femoral, iliac, mesenteric resistance, renal and superior mesenteric arteries. Receptor protection assays and antisense oligonucleotides were used to assess the contribution of the alpha-1B AR to contraction. The alpha-1B AR was implicated in mediating the phenylephrine-induced contraction of the mesenteric resistance artery. The alpha-1D AR was implicated in mediating the contraction of the aorta, femoral, iliac and superior mesenteric arteries. Similarly, the alpha-1A AR was implicated in mediating contraction of the caudal and renal arteries. In vivo application of antisense oligonucleotides targeted to the translational start site of the alpha-1B AR had no effect on the phenylephrine-induced contraction of the femoral or renal arteries. In contrast, antisense oligonucleotides directed against the alpha-1D AR significantly inhibited the phenylephrine response in the femoral artery but had no effect on the renal artery. Application of alpha-1A AR antisense oligonucleotides inhibited the contraction of the renal artery without effect on the femoral artery. These data show that (1) alpha-1B AR immunoreactivity is widely distributed in the same peripheral arteries in which previous studies detected its mRNA, and (2) despite this distribution, receptor protection and antisense oligonucleotide studies indicate that the alpha-1B AR mediates the contraction of only the mesenteric resistance artery. The alpha-1 AR family is a member of the G proteincoupled superfamily of receptors. In analogy to bacteriorhodopsin, these receptors have the now very familiar proposed structure of seven transmembrane spanning domains connected by hydrophilic loops alternately exposed to the extracellular and intracellular environment. The structure of G protein-coupled receptors in general and alpha-1 ARs specifically have been the subject of several reviews (Bylund et a

    Serum creatinine and cystatin C‐based estimates of glomerular filtration rate are misleading in acute heart failure

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    Aims: We aimed to test whether the endogenous filtration markers serum creatinine or cystatin C and equation-based estimates of glomerular filtration rate (GFR) based on these markers appropriately reflect changes of measured GFR in patients with acute heart failure. Methods: In this prospective cohort study of 50 hospitalized acute heart failure patients undergoing decongestive therapy, we applied an intravenous visible fluorescent injectate (VFI), consisting of a low molecular weight component to measure GFR and a high molecular weight component to correct for measured plasma volume. Thirty-eight patients had two sequential GFR measurements 48 h apart. The co-primary endpoints of the study were safety of VFI and plasma stability of the high molecular weight component. A key secondary endpoint was to compare changes in measured GFR (mGFR) to changes of serum creatinine, cystatin C and estimated GFR. Results: VFI-based GFR measurements were safe and consistent with plasma stability of the high molecular weight component and glomerular filtration of the low molecular weight component. Filtration marker-based point estimates of GFR, when compared with mGFR, provided only moderate correlation (Pearson's r, range 0.80-0.88, depending on equation used), precision (r(2), range 0.65-0.78) and accuracy (56%-74% of estimates scored within 30% of mGFR). Correlations of 48-h changes GFR estimates and changes of mGFR were significant (P 15% decrease in mGFR. Conclusions: In patients hospitalized for acute heart failure, serum creatinine- and cystatin C-based predictions performed poorly in detecting actual changes of GFR. These data challenge current clinical strategies to evaluate dynamics of kidney function in acute heart failure

    Discordance between estimated and measured changes in plasma volume among patients with acute heart failure

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    Aims: In acute heart failure (AHF), changes of venous haemoglobin (Hb) concentrations, haematocrit (Hct), and estimated plasma volume (ePV) have been proposed as surrogates of decongestion. These estimates are based on the theoretical assumptions that changes of Hb concentrations and Hct are driven by the intravascular volume status and that the intravascular Hb pool remains stable. The objective of this study was to assess the relationship of changes of measured plasma volume (mPV) with changes of Hb, Hct, and ePV in AHF. Methods and results: We studied 36 AHF patients, who received two sequential assessments of mPV, measured red cell volume (mRCV) and measured total blood volume (mTBV) (48 h apart), during the course of diuretic therapy using a novel visible fluorescent injectate (VFI) technique based on the indicator dilution principle. Changes of ePV were calculated based on the Kaplan-Hakim or Strauss formula. AHF patients receiving diuretics (median intravenous furosemide equivalent 160 mg/48 h) displayed a wide range of changes of mPV (-25.4% to +37.0%). Changes in mPV were not significantly correlated with changes of Hb concentration [Pearson's r (r) = -0.241, P = 0.157], Hct (r = -0.307, P = 0.069), ePV(Kaplan-Hakim) (r = 0.228, P = 0.182), or ePV(strauss) (r = 0.237, P = 0.163). In contrast to theoretical assumptions, changes of mTBV were poorly correlated with changes of Hb concentrations and some patients displayed unanticipated variability of mRCV, suggesting an unstable intravascular red cell pool. Conclusions: Changes of Hb or Hct were not reflective of directly measured changes of intravascular volume status in AHF patients. Basing clinical assessment of decongestion on changes of Hb or Hct may misguide clinical decision-making on an individual patient level

    Mammalian BTBD12 (SLX4) Protects against Genomic Instability during Mammalian Spermatogenesis

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    The mammalian ortholog of yeast Slx4, BTBD12, is an ATM substrate that functions as a scaffold for various DNA repair activities. Mutations of human BTBD12 have been reported in a new sub-type of Fanconi anemia patients. Recent studies have implicated the fly and worm orthologs, MUS312 and HIM-18, in the regulation of meiotic crossovers arising from double-strand break (DSB) initiating events and also in genome stability prior to meiosis. Using a Btbd12 mutant mouse, we analyzed the role of BTBD12 in mammalian gametogenesis. BTBD12 localizes to pre-meiotic spermatogonia and to meiotic spermatocytes in wildtype males. Btbd12 mutant mice have less than 15% normal spermatozoa and are subfertile. Loss of BTBD12 during embryogenesis results in impaired primordial germ cell proliferation and increased apoptosis, which reduces the spermatogonial pool in the early postnatal testis. During prophase I, DSBs initiate normally in Btbd12 mutant animals. However, DSB repair is delayed or impeded, resulting in persistent γH2AX and RAD51, and the choice of repair pathway may be altered, resulting in elevated MLH1/MLH3 focus numbers at pachynema. The result is an increase in apoptosis through prophase I and beyond. Unlike yeast Slx4, therefore, BTBD12 appears to function in meiotic prophase I, possibly during the recombination events that lead to the production of crossovers. In line with its expected regulation by ATM kinase, BTBD12 protein is reduced in the testis of Atm−/− males, and Btbd12 mutant mice exhibit increased genomic instability in the form of elevated blood cell micronucleus formation similar to that seen in Atm−/− males. Taken together, these data indicate that BTBD12 functions throughout gametogenesis to maintain genome stability, possibly by co-ordinating repair processes and/or by linking DNA repair events to the cell cycle via ATM
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