Efficacy of Low-dose Dexamethasone for Preventing Postoperative Nausea and Vomiting following Strabismus Repair in Children

We studied the efficacy of a range of doses of dexamethasone for prevention of postoperative nausea and vomiting following strabismus repair in children in a hospital-based, prospective, double-blinded, randomized, placebo-controlled trial.

Two hundred and ten children were randomized to receive either dexamethasone in one of four dosages: 50 μg/kg (Group 1), 100 μg/kg (Group 2), 200 μg/kg (Group 3) and 250 μg/kg (Group 4) or normal saline (Group 5) prior to corrective surgery for strabismus. Anaesthesia was standardized and included nitrous oxide, pethidine, intubation and the use of muscle relaxant and reversal with neostigmine. Postoperative nausea and vomiting were evaluated in epochs of 0-2 hours, 2-6 hours and 6-24 hours after surgery. Parent satisfaction was assessed 24 hours after surgery and the operated eye was examined for wound infection and delayed healing one week later.

Dexamethasone was effective in preventing nausea and vomiting after strabismus repair: 57.1% children in Group 1, 42.9% in Group 2, 52.4% in Group 3, and 59.5% in Group 4 were free from postoperative nausea and vomiting compared with 7.1% in placebo group. The lowest dose of 50 μg/kg was as efficacious as the higher dosages of dexamethasone during the 24 hours studied. Of the children who developed postoperative nausea and vomiting, those who received dexamethasone had significantly fewer episodes than those in the placebo group.

We conclude that dexamethasone 50 μg/kg is effective for the prevention of postoperative nausea and vomiting following strabismus repair in children.

Possible role of miR-2909 RNomics in arsenic mediated pancreatic β-cell dysfunction

Chronic exposure of humans to inorganic arsenic as a potential risk for the incidence of diabetes has received wide attention. However, the biological mechanism through which arsenic plays a role in the development of diabetes is still being evaluated. One of the hallmark of diabetes is the β-cell dysfunction followed by the changes in the insulin secretion. Pancreatic duodenal homeobox 1 (PDX1) has been widely recognized to play crucial role in the β-cell development, survival and its regulation of insulin gene expression. Many of the arsenic mediated cellular affects have been shown to be regulated by miR-2909 in vitro. Our present study provides evidence to reveal that arsenic affects miR-2909 expression in the pancreatic β-cell and this novel miRNA regulates PDX1 transcriptional expression indirectly through genes coding for c-Jun, MafA, PI3K and directly at the translational level by targeting the PDX1 mRNA. We provide further evidence for this miR-2909 RNomics in pancreatic tissue obtained from NOD mice where the expression of miR-2909 was high compared to the control mice. Keeping in view the fact that arsenic is known to cause β-cell dysfunction and most of the cellular effects of arsenic have been shown to be mediated through miR-2909 RNomics, our study revealed that arsenic employs miR-2909 (at low doses) and c-Jun (at high doses) to down regulate PDX1 in order to cause β-cell dysfunction leading to diabetic state.

Imaging findings after acute sport-related concussion in American football players: A systematic review

Sport-related concussion (SRC) has emerged as a major public health problem. The results of brain imaging studies following SRC have raised questions about long-term neurologic health, but the clinical implications of these findings remain unknown. A systematic review of brain imaging findings after SRC was performed utilizing the following inclusion criteria: football players, brain imaging within 6 months of SRC, and sample size >5. Studies were assessed for: 1) methodology, 2) imaging outcomes, and 3) number of positive statistical comparisons. Imaging was classified as immediate (≤1 week post-injury) or subacute (>1 week to 6 months post-injury). Eleven studies met inclusion criteria. Eight of the 11 studies conducted a total of 809 comparisons of brain function, of which 149 (18%) were statistically significant. Nine of the 11 studies (82%) reported positive immediate findings, but were more likely to be subject to recall bias (86% vs. 0%) and to lack baseline advanced brain imaging (78% vs. 50%) than negative studies. Only 3 of 9 studies that reported subacute findings (33%) reported positive results, and these positive studies were also more likely to be subject to recall bias (100% vs. 40%) and to lack baseline advanced brain imaging (100% vs. 67%) than negative studies. The results of the study demonstrate the transitory nature of positive imaging findings and methodological limitations that complicate study interpretation. Further research is required to correlate imaging findings with clinical outcomes.

Urinary-exosomal miR-2909: A novel pathognomonic trait of prostate cancer severity

The global occurrence of prostate cancer with a range of patient outcome has prompted various investigators to explore novel molecular biomarkers that can precisely detect and track this type of cancer severity. Several studies suggest that micro-RNAs have emerged to act as a new largely unexplored class of biomarkers because of their inherent stability, resilience and recruitment into exosomes present in various human body fluids. With this study, we aim to reveal the nature of urinary-exosomal miR-2909 & miR-615-3p recruitment in patients suffering from either prostate cancer (n=90) or bladder cancer (n=60) as compared to that in either prostate disease-control subjects having benign prostate hyperplasia (n=10) or healthy subjects (n=50). Unlike miR-615-3p, the urinary- exosomal miR-2909 recruitment was not only observed conspicuously in subjects having prostate cancer in comparison to bladder cancer but also the extent of urinary exosomal miR-2909 recruitment showed characteristic variation as a function of prostate cancer aggressiveness as compared to that of either urinary- exosomal miR-615-3p level or existing widely recognised serum prostate specifics antigen (PSA) biomarker of this cancer. In summary, we propose that the extent of urinary exosomal miR-2909 recruitment may provide a potential non-invasive candidate diagnostic marker for the detection of prostate cancer and its aggressiveness.

Subcutaneous Transplantation of Islets into Streptozocin-Induced Diabetic Rats

Pancreatic islet transplantation into type 1 diabetic patients is currently being performed by intraportal infusion. This method, albeit reproducible, has some disadvantages including potential development of portal hypertension, hemorrhage, and an inability to retrieve or detect the transplanted tissue. Other transplant sites have been examined in animal models including the omentum, peritoneal cavity, and the spleen. A transplant site that has not been successful in supporting functional islet tissue transplantation in humans is the subcutaneous space due primarily to the lack of a well-defined vascular bed. This site has many favorable characteristics such as ease of access for transplantation and potential for removal of the transplanted tissue with a minimally invasive surgical procedure. This report addresses the evaluation of a subcutaneously placed device for the support of rat syngeneic islet transplantation in a streptozocin-induced diabetic model. The data generated support the use of this device for islet engraftment. In addition, beta cell function in this device compared favorably with the function of islets transplanted to the renal subcapsular space as well as islets within the native pancreas.

Evolutionarily conserved dual lysine motif determines the non-chaperone function of secreted Hsp90alpha in tumour progression

Both intracellular and extracellular heat shock protein-90 (Hsp90) family proteins (α and β) have been shown to support tumour progression. The tumour-supporting activity of the intracellular Hsp90 is attributed to their N-terminal ATPase-driven chaperone function. What molecular entity determines the extracellular function of secreted Hsp90 and the distinction between Hsp90α and Hsp90β was unclear. Here we demonstrate that CRISPR/Case9 knocking out Hsp90α nullifies tumour cells' ability to migrate, invade and metastasize without affecting the cell survival and growth. Knocking out Hsp90β leads to tumour cell death. Extracellular supplementation with recombinant Hsp90α, but not Hsp90β, protein recovers tumourigenicity of the Hsp90α-knockout cells. Sequential mutagenesis identifies two evolutionarily conserved lysine residues, lys-270 and lys-277, in the Hsp90α subfamily that determine the extracellular Hsp90α function. Hsp90β subfamily lacks the dual lysine motif and the extracellular function. Substitutions of gly-262 and thr-269 in Hsp90β with lysines convert Hsp90β to a Hsp90α-like protein. Newly constructed monoclonal antibody, 1G6-D7, against the dual lysine region of secreted Hsp90α inhibits both de novo tumour formation and expansion of already formed tumours in mice. This study suggests an alternative therapeutic approach to target Hsp90 in cancer, that is, the tumour-secreted Hsp90α, instead of the intracellular Hsp90α and Hsp90β.

Clinical Predictors of Attention and Executive Functioning Outcomes in Children After Perinatal Arterial Ischemic Stroke

BACKGROUND

Children with perinatal arterial ischemic stroke (PAIS) are at risk for later neurocognitive and behavioral deficits, yet the clinical predictors of these outcomes are understudied. We examined the influence of clinical and infarct characteristics on attention and executive functioning in children following PAIS.

METHODS

Forty children born at term (≥37 weeks' gestation) with PAIS (28 with neonatal arterial ischemic stroke and 12 with presumed PAIS) underwent a comprehensive neuropsychological battery at age three to 16 years (median age 7.2 years; 58% male) to assess attention and executive functioning. Parents also completed questionnaires regarding real-world functioning. Clinical variables including perinatal stroke subtype, infarct characteristics (location, laterality, and volume), and the presence of comorbid epilepsy were ascertained from the medical record.

RESULTS

Presumed PAIS, larger infarct volume, and comorbid epilepsy negatively influenced the performance on attention and executive functioning measures. These clinical variables were also associated with greater functional problems on parent reports, including a higher frequency of attention-deficit/hyperactivity disorder symptoms and greater difficulties in some subdomains of executive functioning. Infarct location and laterality were not associated with performance measures or parental report of functioning.

CONCLUSION

Although all children with PAIS are at risk for later deficits in attention and executive functioning, those with presumed PAIS, larger infarct size, and comorbid epilepsy appear to be the most vulnerable. As they approach and reach school age, these children should undergo neuropsychological assessment to ensure timely implementation of therapeutic interventions and behavioral strategies.

Global temperature change potential of nitrogen use in agriculture: A 50-year assessment

Nitrogen (N) use in agriculture substantially alters global N cycle with the short- and long-term effects on global warming and climate change. It increases emission of nitrous oxide, which contributes 6.2%, while carbon dioxide and methane contribute 76% and 16%, respectively of the global warming. However, N causes cooling due to emission of NOx, which alters concentrations of tropospheric ozone and methane. NOx and NH3 also form aerosols with considerable cooling effects. We studied global temperature change potential (GTP) of N use in agriculture. The GTP due to N2O was 396.67 and 1168.32 Tg CO2e on a 20-year (GTP20) and 439.94 and 1295.78 Tg CO2e on 100-year scale (GTP100) during years 1961 and 2010, respectively. Cooling effects due to N use were 92.14 and 271.39 Tg CO2e (GTP20) and 15.21 and 44.80 Tg CO2e (GTP100) during 1961 and 2010, respectively. Net GTP20 was 369.44 and 1088.15 Tg CO2e and net GTP100 was 429.17 and 1264.06 Tg CO2e during 1961 and 2010, respectively. Thus net GTP20 is lower by 6.9% and GTP100 by 2.4% compared to the GTP considering N2O emission alone. The study shows that both warming and cooling effects should be considered to estimate the GTP of N use.

Interleukin-18-induced cell adhesion molecule expression is associated with feedback regulation by PPAR-γ and NF-κB in Apo E-/- mice

Focal recruitment of monocytes and lymphocytes is one of the earliest detectable cellular responses in atherosclerotic lesion formation. Endothelium may regulate leukocyte recruitment by expressing specific adhesion molecules. Interleukin-18 is a proinflammatory cytokine that plays an important role in vascular pathologies. The present study highlights the modulation of adhesion molecules and PPAR-γ by IL-18 and proposes a novel feedback mechanism by which PPAR-γ may regulate IL-18 expression. Three groups of normal chow diet-fed, male Apo E-/- mice, aged 12 weeks (n = 6/group) were employed: Gp I, phosphate-buffered saline (PBS) (2 mo): Gp II, recombinant IL-18 (rIL-18) (1 mo) followed by PBS (1 mo); Gp III, rIL-18 (1 mo) followed by pyrrolidine dithiocarbamate (PDTC) (1 mo). Significantly augmented mRNA expression of ICAM-1 (~5.7-fold), VCAM-1 (~3.6-fold), and NF-κB (~7-fold) was observed in Gp II mice as compared to Gp I, whereas PPAR-γ expression was not altered. PDTC treatment caused a significant downregulation of ICAM-1 (~4.2-fold), VCAM-1(~2-fold), and NF-κB (~4.5-fold) and upregulation of PPAR-γ expression (~5-fold) in Gp III mice. A similar trend was observed in protein expression. In vivo imaging results demonstrated a marked increase in probe (CF750 dye conjugated to VCAM-1 antibody) fluorescence intensity for VCAM-1 expression in Gp II mice, whereas it was moderately decreased in Gp III. PPAR-γ was found to significantly downregulate both IL-18 levels and IL-18-induced adhesion molecules. The underlying mechanism was found to be via inhibition of NF-κB activity by PDTC, thereby leading to decreased adherence of monocytes to the activated endothelial cells and a step to halt the progression and development of atherosclerotic lesions.