91 research outputs found

    Activation of Brainstem Neurons by Underwater Diving in the Rat

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    The mammalian diving response is a powerful autonomic adjustment to underwater submersion greatly affecting heart rate, arterial blood pressure, and ventilation. The bradycardia is mediated by the parasympathetic nervous system, arterial blood pressure is mediated via the sympathetic system and still other circuits mediate the respiratory changes. In the present study we investigate the cardiorespiratory responses and the brainstem neurons activated by voluntary diving of trained rats, and, compare them to control and swimming animals which did not dive. We show that the bradycardia and increase in arterial blood pressure induced by diving were significantly different than that induced by swimming. Neuronal activation was calculated after immunohistochemical processing of brainstem sections for Fos protein. Labeled neurons were counted in the caudal pressor area, the medullary dorsal horn, subnuclei of the nucleus tractus solitarii (NTS), the nucleus raphe pallidus (RPa), the rostroventrolateral medulla, the A5 area, the nucleus locus coeruleus, the Kölliker–Fuse area, and the external lateral and superior lateral subnuclei of the parabrachial nucleus. All these areas showed significant increases in Fos labeling when data from voluntary diving rats were compared to control rats and all but the commissural subnucleus of the NTS, A5 area, and RPa were significantly different from swimming rats. These data provide a substrate for more precise experiments to determine the role of these nuclei in the reflex circuits driving the diving response

    A role for non-coding Tsix transcription in partitioning chromatin domains within the mouse X-inactivation centre

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    <p>Abstract</p> <p>Background</p> <p>Delimiting distinct chromatin domains is essential for temporal and spatial regulation of gene expression. Within the X-inactivation centre region (<it>Xic</it>), the <it>Xist </it>locus, which triggers X-inactivation, is juxtaposed to a large domain of H3K27 trimethylation (H3K27me3).</p> <p>Results</p> <p>We describe here that developmentally regulated transcription of <it>Tsix</it>, a crucial non-coding antisense to <it>Xist</it>, is required to block the spreading of the H3K27me3 domain to the adjacent H3K4me2-rich <it>Xist </it>region. Analyses of a series of distinct <it>Tsix </it>mutations suggest that the underlying mechanism involves the RNA Polymerase II accumulating at the <it>Tsix </it>3'-end. Furthermore, we report additional unexpected long-range effects of <it>Tsix </it>on the distal sub-region of the <it>Xic</it>, involved in <it>Xic</it>-<it>Xic </it>trans-interactions.</p> <p>Conclusion</p> <p>These data point toward a role for transcription of non-coding RNAs as a developmental strategy for the establishment of functionally distinct domains within the mammalian genome.</p

    Diabetes by Air, Land, and Sea: Effect of Deployments on HbA1c and BMI

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    INTRODUCTION: Service members (SMs) in the United States (U.S.) Armed Forces have diabetes mellitus at a rate of 2-3%. Despite having a chronic medical condition, they have deployed to environments with limited medical support. Given the scarcity of data describing how they fare in these settings, we conducted a retrospective study analyzing the changes in glycated hemoglobin (HbA1c) and body mass index (BMI) before and after deployment. MATERIALS AND METHODS: SMs from the U.S. Army, Air Force, Navy, and Marine Corps with diabetes who deployed overseas were identified through the Military Health System (MHS) Management Analysis and Reporting Tool and the Defense Manpower Data Center. Laboratory and pharmaceutical data were obtained from the MHS Composite Health Care System and the Pharmacy Data Transaction Service, respectively. Paired t-tests were conducted to calculate changes in HbA1c and BMI before and after deployment. RESULTS: SMs with diabetes completed 11,325 deployments of greater than 90 days from 2005 to 2017. Of these, 474 (4.2%) SMs had both HbA1c and BMI measurements within 90 days prior to departure and within 90 days of return. Most (84.2%) required diabetes medications: metformin in 67.3%, sulfonylureas in 19.0%, dipeptidyl peptidase-4 inhibitors in 13.9%, and insulin in 5.5%. Most SMs deployed with an HbA1c \u3c 7.0% (67.1%), with a mean predeployment HbA1c of 6.8%. Twenty percent deployed with an HbA1c between 7.0 and 7.9%, 7.2% deployed with an HbA1c between 8.0 and 8.9%, and 5.7% deployed with an HbA1c of 9.0% or higher. In the overall population and within each military service, there was no significant change in HbA1c before and after deployment. However, those with predeployment HbA1c \u3c 7.0% experienced a rise in HbA1c from 6.2 to 6.5% (P \u3c 0.001), whereas those with predeployment HbA1c values ≥7.0% experienced a decline from 8.0 to 7.5% (P \u3c 0.001). Those who deployed between 91 and 135 days had a decline in HbA1c from 7.1 to 6.7% (P = 0.010), but no significant changes were demonstrated in those with longer deployment durations. BMI declined from 29.6 to 29.3 kg/m2 (P \u3c 0.001), with other significant changes seen among those in the Army, Navy, and deployment durations up to 315 days. CONCLUSIONS: Most SMs had an HbA1c \u3c 7.0%, suggesting that military providers appropriately selected well-managed SMs for deployment. HbA1c did not seem to deteriorate during deployment, but they also did not improve despite a reduction in BMI. Concerning trends included the deployment of some SMs with much higher HbA1c, utilization of medications with adverse safety profiles, and the lack of HbA1c and BMI evaluation proximal to deployment departures and returns. However, for SMs meeting adequate glycemic targets, we demonstrated that HbA1c remained stable, supporting the notion that some SMs may safely deploy with diabetes. Improvement in BMI may compensate for factors promoting hyperglycemia in a deployed setting, such as changes in diet and medication availability. Future research should analyze in a prospective fashion, where a more complete array of diabetes and readiness-related measures to comprehensively evaluate the safety of deploying SMs with diabetes

    Glycemic Benefits with Adherence to testosterone therapy in men with hypogonadism and type 2 diabetes mellitus.

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    BACKGROUND: While previous studies have demonstrated testosterone\u27s beneficial effects on glycemic control in men with hypogonadism and Type 2 Diabetes, the extent to which these improvements are observed based on the degree of treatment adherence has been unclear. OBJECTIVES: To evaluate the effects of long-term testosterone therapy in A1C levels in men with Type 2 Diabetes Mellitus and hypogonadism, controlling for BMI, pre-treatment A1C, and age among different testosterone therapy adherence groups. MATERIALS AND METHODS: We performed a retrospective analysis of 1737 men with diabetes and hypogonadism on testosterone therapy for 5 years of data from 2008-2018, isolating A1C, lipid panels, and BMI results for analysis. Subjects were categorized into adherence groups based on quartiles of the proportion of days covered (\u3e 75% of days, 51-75% of days, 26-50% of days and 0-25% of days), with \u3e75% of days covered considered adherent to therapy. RESULTS: Pre-treatment median A1C was 6.8%. Post-treatment median A1C was 7.1%. The adherent group, \u3e75%, was the only group notable for a decrease in A1C, with a median decrease of -0.2 (p = 0.0022). BMI improvement was associated with improved post-treatment A1C (p = 0.007). When controlling for BMI, age, and pre-treatment A1C, the \u3e75% adherence group was associated with improved post-treatment A1C (p \u3c 0.001). DISCUSSION: When controlling for all studied variables, testosterone adherence was associated with improved post-treatment A1C. The higher the initial A1C at the initiation of therapy, the higher the potential for lowering the patient\u27s A1C with \u3e75% adherence. Further, all groups showed some reduction in BMI, which may indicate that testosterone therapy may affect A1C independent of weight loss. CONCLUSION: Even when controlling for improved BMI, pre-treatment A1C, and age, testosterone positively impacted glycemic control in diabetes patients with hypogonadism, with the most benefit noted in those most adherent to therapy (\u3e75%)

    Neutral Effect of Exenatide on Serum Testosterone in Men with Type 2 Diabetes Mellitus: A Prospective Cohort

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    BACKGROUND: Endogenous testosterone increases with weight loss from diet, exercise, and bariatric surgery. However, little is known about testosterone levels after weight loss from medication. OBJECTIVES: Uncover the effects of Glucagon-Like Peptide-1 receptor agonist (GLP-1 RA) therapy on serum testosterone. MATERIAL AND METHODS: Prospective cohort study of men starting GLP-1 RA therapy for type 2 diabetes mellitus. RESULTS: 51 men lost 2.27 kg (p = 0.00162) and their HbA1c values improved by 0.7% (p = 0.000503) after 6 months of GLP-1 RA therapy. There was no significant change in testosterone for the group as a whole. However, in subgroup analyses, there was a significant difference in total testosterone change between men starting with baseline total testosterone/dL (238.5 ± 56.5 ng/dL to 272.2 ± 82.3 ng/dL) compared to higher values (438 ± 98.2 ng/dL to 412 ± 141.2 ng/dL) (p = 0.0172);free testosterone increased if the baseline total testosterone was/dL (55.2 ± 12.8 pg/mL to 57.2 ± 17.6 pg/mL) and decreased if \u3e320 ng/dL (74.7 ± 16.3 pg/mL to 64.2 ± 17.7 pg/mL) (p = 0.00807). Additionally, there were significant differences in testosterone change between men with HbA1c improvements ≥1% (351.6 ± 123.9 ng/dL to 394.4 ± 136.5 ng/dL) compared to men with HbA1c changes CONCLUSION: GLP-1 RA therapy improves weight and HbA1c without adverse effects on testosterone. Those starting with lower testosterone values or attaining greater improvement in HbA1c may see additional benefits

    Impact of Structured Insulin Order Sets on Inpatient Hypoglycemia and Glycemic Control

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    Objective: In hospitalized patients, glycemic excursions outside recommended glycemic targets have been associated with increased morbidity and mortality. Despite recommendations to avoid use of correctional insulin alone for managing hyperglycemia, this approach remains common. We performed a quality improvement project aimed at both reducing hypoglycemic events and promoting increased use of basal insulin by updating our insulin order sets to reflect clinical practice guideline recommendations. Methods: Brooke Army Medical Center correctional insulin order sets were modified to reflect higher treatment thresholds and targets, and a basal insulin order was added with a recommended weight-based starting dose. Pre- and postintervention analyses were performed. Patients were included if they were prescribed subcutaneous insulin during their hospital stay. The following outcomes were measured: (1) glucose levels, and (2) prescriptions for basal insulin. Results: A significant reduction in hypoglycemia events was noted following the intervention (glucose \u3c70 mg/dL: 9.2% pre-intervention vs. 8.8% postintervention; glucose \u3c55 mg/dL: 4.2% pre-intervention vs. 2.2% postintervention). When excluding patients that were ordered correctional insulin alone but did not receive a dose, an increase in basal insulin use was seen (50% pre-intervention vs. 61% postintervention). Rates and severity of hyperglycemia (glucose \u3e180 mg/dL) remained unchanged. Conclusion: The alteration in insulin order set parameters resulted in a significant reduction in hypoglycemia without significant increases in hyperglycemia. Although basal insulin use increased, optimal dosing recommendations were not often utilized. Further interventions are necessary to reduce hyperglycemia. Abbreviations: CPOE = computerized provider order entry; EMR = electronic medical record; HbA1c = hemoglobin A1c; LOS = length of stay; QI = quality improvement; SSI = sliding scale insulin

    Profound Depletion of HIV-1 Transcription in Patients Initiating Antiretroviral Therapy during Acute Infection

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    Early intervention resulted in profound depletion of PBMC expressing HIV-1 RNA. This is contrary to chronically infected patients who predominantly showed continuous UsRNA expression on cART. Thus, antiretroviral treatment initiated during the acute phase of infection prevented establishment or expansion of long-lived transcriptionally active viral cellular reservoirs in peripheral blood
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