Inhibition of a viral enzyme by a small-molecule dimer disruptor.

We identified small-molecule dimer disruptors that inhibit an essential dimeric protease of human Kaposi's sarcoma-associated herpesvirus (KSHV) by screening an alpha-helical mimetic library. Next, we synthesized a second generation of low-micromolar inhibitors with improved potency and solubility. Complementary methods including size exclusion chromatography and 1H-13C HSQC titration using selectively labeled 13C-Met samples revealed that monomeric protease is enriched in the presence of inhibitor. 1H-15N HSQC titration studies mapped the inhibitor binding site to the dimer interface, and mutagenesis studies targeting this region were consistent with a mechanism where inhibitor binding prevents dimerization through the conformational selection of a dynamic intermediate. These results validate the interface of herpesvirus proteases and other similar oligomeric interactions as suitable targets for the development of small-molecule inhibitors

The magnitude of postconvulsive leukocytosis mirrors the severity of periconvulsive respiratory compromise : a single center retrospective study

Background: Generalized epileptic convulsions frequently exhibit transient respiratory symptoms and non-infectious leukocytosis. While these peri-ictal effects appear to arise independently from one another, the possibility that they stem from a common ictal pathophysiological response has yet to be explored. We aimed to investigate whether peri-ictal respiratory symptoms and postictal leukocytosis coexist. Methods: We performed a single center retrospective chart review of 446 patients brought to our emergency department between January 1, 2017 and August 23, 2018 for the care of generalized epileptic convulsions with or without status epilepticus. We included 152 patients who were stratified based on the presence (PeCRC+) or absence (PeCRC-) of overt periconvulsive respiratory compromise (PeCRC). In addition, patients were stratified based on the presence or absence of postconvulsive leukocytosis (PoCL), defined as an initial postconvulsive white blood cell (WBC) count ≥ 11,000 cells/mm3. Triage vital signs, and chest x ray (CXR) abnormalities were also examined. Results: Overt PeCRC was observed in 31.6% of patients, 43% of whom required emergent endotracheal intubations. PoCL was observed in 37.5% of patients, and was more likely to occur in PeCRC+ than in PeCRC- patients (79.2 vs. 18.2%; OR = 17.0; 95% CI = 7.2-40.9; p < 0.001). Notably, the magnitude of PoCL was proportional to the severity of PeCRC, as the postconvulsive WBC count demonstrated a negative correlation with triage hemoglobin oxygen saturation (R = -0.22; p < 0.01; CI = -0.48 to -0.07). Moreover, a receiver operating characteristic analysis of the WBC count's performance as predictor of endotracheal intubation reached a significant area under the curve value of 0.81 (95% CI = 0.71-0.90; p < 0.001). Finally, PeCRC+ patients demonstrated frequent CXR abnormalities, and their postconvulsive WBC counts correlated directly with triage heart rate (R = 0.53; p < 0.001). Conclusion: Our data support the existence of an ictal pathophysiological response, which induces proportional degrees of PoCL and PeCRC. We suggest this response is at least partially propelled by systemic catecholamines

Tubular and Glomerular Kidney Effects in Swedish Women with Low Environmental Cadmium Exposure

Cadmium is a well-known nephrotoxic agent in food and tobacco, but the exposure level that is critical for kidney effects in the general population is not defined. Within a population-based women’s health survey in southern Sweden (Women’s Health in the Lund Area, WHILA), we investigated cadmium exposure in relation to tubular and glomerular function, from 1999 through early 2000 in 820 women (71% participation rate) 53–64 years of age. Multiple linear regression showed cadmium in blood (median, 0.38 μg/L) and urine (0.52 μg/L; density adjusted = 0.67 μg/g creatinine) to be significantly associated with effects on renal tubules (as indicated by increased levels of human complex-forming protein and N-acetyl-β-d-glucosaminidase in urine), after adjusting for age, body mass index, blood lead, diabetes, hypertension, and regular use of nephrotoxic drugs. The associations remained significant even at the low exposure in women who had never smoked. We also found associations with markers of glomerular effects: glomerular filtration rate and creatinine clearance. Significant effects were seen already at a mean urinary cadmium level of 0.6 μg/L (0.8 μg/g creatinine). Cadmium potentiated diabetes-induced effects on kidney. In conclusion, tubular renal effects occurred at lower cadmium levels than previously demonstrated, and more important, glomerular effects were also observed. Although the effects were small, they may represent early signs of adverse effects, affecting large segments of the population. Subjects with diabetes seem to be at increased risk

Running Exercise in Obese Pregnancies Prevents IL-6 Trans-signaling in Male Offspring

Purpose: Maternal obesity is known to predispose the offspring to impaired glucose metabolism and obesity associated with low-grade inflammation and hypothalamic dysfunction. Because preventive approaches in this context are missing to date, we aimed to identify molecular mechanisms in the offspring that are affected by maternal exercise during pregnancy. Methods: Diet-induced obese mouse dams were divided into a sedentary obese (high-fat diet [HFD]) group and an obese intervention (HFD-running intervention [RUN]) group, which performed voluntary wheel running throughout gestation. Male offspring were compared with the offspring of a sedentary lean control group at postnatal day 21. Results: HFD and HFD-RUN offspring showed increased body weight and white adipose tissue mass. Glucose tolerance testing showed mild impairment only in HFD offspring. Serum interleukin-6 (IL-6) levels, hypothalamic and white adipose tissue IL-6 gene expressions, and phosphorylation of signal transducer and activator of transcription 3 in HFD offspring were significantly increased, whereas HFD-RUN was protected against these changes. The altered hypothalamic global gene expression in HFD offspring showed partial normalization in HFD-RUN offspring, especially with respect to IL-6 action. Conclusion: Maternal exercise in obese pregnancies effectively reduces IL-6 trans-signaling and might be the underlying mechanism for the amelioration of glucose metabolism at postnatal day 21 independent of body composition

Stress-Related Gastrointestinal Bleeding in Patients with Aneurysmal Subarachnoid Hemorrhage: A Multicenter Retrospective Observational Study

BACKGROUND/OBJECTIVE: Stress-related mucosal bleeding (SRMB) occurs in approximately 2-4% of critically ill patients. Patients with aneurysmal subarachnoid hemorrhage (aSAH) have a (diffuse) space-occupying lesion, are critically ill, often require mechanical ventilation, and frequently receive anticoagulation or antiplatelet therapy after aneurysm embolization, all of which may be risk factors for SRMB. However, no studies have evaluated SRMB in patients with aSAH. Aims of the study were to determine the incidence of SRMB in aSAH patients, evaluate the effect of acid suppression on SRMB, and identify specific risk factors for SRMB. METHODS: This was a multicenter, retrospective, observational study conducted across 17 centers. Each center reviewed up to 50 of the most recent cases of aSAH. Patients with length of stay (LOS) \u3c 48 h or active GI bleeding on admission were excluded. Variables related to demographics, aSAH severity, gastrointestinal (GI) bleeding, provision of SRMB prophylaxis, adverse events, intensive care unit (ICU), and hospital LOS were collected for the first 21 days of admission or until hospital discharge, whichever came first. Descriptive statistics were used to analyze the data. A multivariate logistic regression modeling was utilized to examine the relationship between specific risk factors and the incidence of clinically important GI bleeding in patients with aSAH. RESULTS: A total of 627 patients were included. The overall incidence of clinically important GI bleeding was 4.9%. Of the patients with clinically important GI bleeding, 19 (61%) received pharmacologic prophylaxis prior to evidence of GI bleeding, while 12 (39%) were not on pharmacologic prophylaxis at the onset of GI bleeding. Patients who received an acid suppressant agent were less likely to experience GI bleeding than patients who did not receive pharmacologic prophylaxis prior to evidence of bleeding (OR 0.39, 95% CI 0.18-0.83). The multivariate regression analysis identified any instance of elevated intracranial pressure, creatinine clearance \u3c 60 ml/min and the incidence of cerebral vasospasm as specific risk factors associated with GI bleeding. Cerebral vasospasm has not previously been described as a risk for GI bleeding (OR 2.5 95% CI 1.09-5.79). CONCLUSIONS: Clinically important GI bleeding occurred in 4.9% of patients with aSAH, similar to the general critical care population. Risk factors associated with GI bleeding were prolonged mechanical ventilation (\u3e 48 h), creatinine clearance \u3c 60 ml/min, presence of coagulopathy, elevation of intracranial pressure, and cerebral vasospasm. Further prospective research is needed to confirm this observation within this patient population

Inhibition of a viral enzyme by a small-molecule dimer disruptor

Small molecule dimer disruptors that inhibit an essential dimeric protease of human Kaposi’s sarcoma-associated herpesvirus (KSHV) were identified by screening an α-helical mimetic library. Subsequently, a second generation of low micromolar inhibitors with improved potency and solubility was synthesized. Complementary methods including size exclusion chromatography and (1)H-(13)C HSQC titration using selectively labeled (13)C-Met samples revealed that monomeric protease is enriched in the presence of inhibitor. (1)H-(15)N-HSQC titration studies mapped the inhibitor binding-site to the dimer interface, and mutagenesis studies targeting this region were consistent with a mechanism where inhibitor binding prevents dimerization through the conformational selection of a dynamic intermediate. These results validate the interface of herpesvirus proteases and other similar oligomeric interactions as suitable targets for the development of small molecule inhibitors

Endocrine rhythms in the brown bear ( Ursus arctos

Many temperate zone animals adapt to seasonal changes by altering their physiology. This is mediated in large part by endocrine signals that encode day length and regulate energy balance and metabolism. The objectives of this study were to determine if the daily patterns of two important hormones, melatonin and cortisol, varied with day length in captive brown bears (Ursus arctos) under anesthetized and nonanesthetized conditions during the active (March–October) and hibernation periods. Melatonin concentrations varied with time of day and season in nonanesthetized female bears despite exceedingly low nocturnal concentrations (1–4 pg/mL) in the active season. In contrast, melatonin concentrations during hibernation were 7.5-fold greater than those during the summer in anesthetized male bears. Functional assessment of the pineal gland revealed a slight but significant reduction in melatonin following nocturnal light application during hibernation, but no response to beta-adrenergic stimulation was detected in either season. Examination of pineal size in two bear species bears combined with a phylogenetically corrected analysis of pineal glands in 47 other species revealed a strong relationship to brain size. However, pineal gland size of both bear species deviated significantly from the expected pattern. Robust daily plasma cortisol rhythms were observed during the active season but not during hibernation. Cortisol was potently suppressed following injection with a synthetic glucocorticoid. The results suggest that melatonin and cortisol both retain their ability to reflect seasonal changes in day length in brown bears. The exceptionally small pineal gland in bears may be the result of direct or indirect selection