Novel method for collecting hippocampal interstitial fluid extracellular vesicles (EVISF ) reveals sex-dependent changes in microglial EV proteome in response to Aß pathology.

Brain-derived extracellular vesicles (EVs) play an active role in Alzheimer's disease (AD), relaying important physiological information about their host tissues. The internal cargo of EVs is protected from degradation, making EVs attractive AD biomarkers. However, it is unclear how circulating EVs relate to EVs isolated from disease-vulnerable brain regions. We developed a novel method for collecting EVs from the hippocampal interstitial fluid (ISF) of live mice. EVs (EVISF ) were isolated via ultracentrifugation and characterized by nanoparticle tracking analysis, immunogold labelling, and flow cytometry. Mass spectrometry and proteomic analyses were performed on EVISF cargo. EVISF were 40-150 nm in size and expressed CD63, CD9, and CD81. Using a model of cerebral amyloidosis (e.g., APPswe, PSEN1dE9 mice), we found protein concentration increased but protein diversity decreased with Aß deposition. Genotype, age, and Aß deposition modulated proteostasis- and immunometabolic-related pathways. Changes in the microglial EVISF proteome were sexually dimorphic and associated with a differential response of plaque associated microglia. We found that female APP/PS1 mice have more amyloid plaques, less plaque associated microglia, and a less robust- and diverse- EVISF microglial proteome. Thus, in vivo microdialysis is a novel technique for collecting EVISF and offers a unique opportunity to explore the role of EVs in AD.

Supracondylar Humeral Fracture Documentation: A Performance Improvement Study.

BACKGROUND: Supracondylar fractures of the humerus (SCH) are the most common fractures about the elbow in children that require operative stabilization. Considering the possible complications involved including nerve deficit and compartment syndrome, documentation is crucial to good patient care. It also is of prime importance for justification or defense of our care should this arise. One of the common concerns in transition from written documentation to an electronic medical record (EMR) is availability of proper documentation. We sought to develop an established EMR protocol to streamline and improve proper care and documentation for SCH fractures. This was in response to poor documentation in an initial retrospective evaluation. METHODS: Documentation before and after the implementation of a clinical pathway were compared. A retrospective chart review was used to collect documentation information before the implementation of the clinical pathway and a prospective study design was used to collect information after the implementation of the clinical pathway. Proportions of preclinical and postclinical pathway documentation were compared before and after the implementation of the clinical pathway using a χ test, or the Fisher exact test for measures in which at least 20% of the expected frequencies were <5. A 2-sided 0.05 α level was used to define statistical significance. RESULTS: We saw an improvement in documentation after implementation of the clinical pathway, with statistically significant differences in nursing preoperative, physician preoperative, and physician postoperative. Nursing postanesthesia care unit, nursing postoperative, and physician clinic follow-up trended toward improvement but did not meet statistical significance. Although we did see improvement, we still did not meet ideal 100% documentation in all categories. CONCLUSIONS: Documentation is crucial to good medical care and legal defense should any arise. The implementation of a clinical pathway demonstrated significant improvement by physicians and nurses. Although overall improvement was obtained, there were areas associated with EMR identified that still require further improvement. LEVEL OF EVIDENCE: Level III.

Patient knowledge of antithyroid drug-induced agranulocytosis.

BACKGROUND: Agranulocytosis is a serious side effect of antithyroid drugs. OBJECTIVE: To ascertain the knowledge of patients and review the quality of information available on the internet. METHODS: A questionnaire survey was performed for patients receiving antithyroid drugs. Patients attending endocrine clinics who were receiving antithyroid drug treatment (group A, n = 33) were interviewed. A further national cohort of patients (group B, n = 100) treated with antithyroid drugs, participated in an online survey. RESULTS: 60.9% of responders were not aware of the common symptoms of agranulocytosis. 18.6% had never received any information about side effects. Of the 108 patients who recalled receiving information, 30% rated the quality as 'poor' or 'not good at all'. Structured interviews of group A patients revealed that almost half (45.5%, 15/33) had experienced symptoms that could be indicative of agranulocytosis, but only 53.3% (8/15) had a blood count checked. A review of 20 selected patient information internet sites revealed a significant variation in advice given to patients. CONCLUSIONS: Inadequate knowledge about agranulocytosis among patients receiving antithyroid drug treatment is common. The available information on the internet is variable and inconsistent.

Cerebrovascular responses to insulin in rats.

Effects of insulin on cerebral arteries have never been examined. Therefore, we determined cerebrovascular actions of insulin in rats. Both PCR and immunoblot studies identified insulin receptor expression in cerebral arteries and in cultured cerebral microvascular endothelial cells (CMVECs). Diameter measurements (% change) of isolated rat cerebral arteries showed a biphasic dose response to insulin with an initial vasoconstriction at 0.1 ng/mL (-9.7%+/-1.6%), followed by vasodilation at 1 to 100 ng/mL (31.9%+/-1.4%). Insulin also increased cortical blood flow in vivo (30%+/-8% at 120 ng/mL) when applied topically. Removal of reactive oxygen species (ROS) abolished the vasoconstriction to insulin. Endothelial denudation, inhibition of K(+) channels, and nitric oxide (NO) synthase, all diminished insulin-induced vasodilation. Inhibition of cytochrome P450 enhanced vasodilation in endothelium-intact arteries, but promoted vasoconstriction after endothelial denudation. Inhibition of cyclooxygenase abolished vasoconstriction and enhanced vasodilation to insulin in all arteries. Inhibition of endothelin type A receptors enhanced vasodilation, whereas endothelin type B receptor blockade diminished vasodilation. Insulin treatment in vitro increased Akt phosphorylation in cerebral arteries and CMVECs. Fluorescence studies of CMVECs showed that insulin increased intracellular calcium and enhanced the generation of NO and ROS. Thus, cerebrovascular responses to insulin were mediated by complex mechanisms originating in both the endothelium and smooth muscle.

Unusual cause of visual symptoms after bilateral laser in situ keratomileusis.

We present a case involving a serious systemic cause of visual symptoms after successful bilateral laser in situ keratomileusis. There were no signs in the anterior segment to explain the visual symptoms. Ancillary tests and investigations confirmed a pituitary tumor, which was removed. We recommend comprehensive ophthalmological examination and full investigation of symptoms in all patients before and after laser treatment.

Management of recurrent pituitary cysts with pituitary-nasal drain.

Pituitary cysts are usually craniopharyngiomas or remnants of Rathke's cleft. Histologically craniopharyngiomas are lined by stratified squamous epithelium whereas Rathke's cleft cysts are lined by cuboidal or columnar epithelium. The management of pituitary cysts remains difficult because of the risks associated with attempts at complete removal and the chances of recurrence after inadequate resection. We describe 3 cases of cystic craniopharyngiomas and one case of Rathke's cleft cyst which recurred after surgery and were subsequently managed successfully with pituitary-nasal drains.