Reduction of Tubular Flow Rate as a Mechanism of Oliguria in the Early Phase of Endotoxemia Revealed by Intravital Imaging

Urine output is widely used as a criterion for the diagnosis of AKI. Although several potential mechanisms of septic AKI have been identified, regulation of urine flow after glomerular filtration has not been evaluated. This study evaluated changes in urine flow in mice with septic AKI. The intratubular urine flow rate was monitored in real time by intravital imaging using two-photon laser microscopy. The tubular flow rate, as measured by freely filtered dye (FITC-inulin or Lucifer yellow), time-dependently declined after LPS injection. At 2 hours, the tubular flow rate was slower in mice injected with LPS than in mice injected with saline, whereas BP and GFR were similar in the two groups. Importantly, fluorophore-conjugated LPS selectively accumulated in the proximal tubules that showed reduced tubular flow at 2 hours and luminal obstruction with cell swelling at 24 hours. Delipidation of LPS or deletion of Toll-like receptor 4 in mice abolished these effects, whereas neutralization of TNF-α had little effect on LPS-induced tubular flow retention. Rapid intravenous fluid resuscitation within 6 hours improved the tubular flow rate only when accompanied by the dilation of obstructed proximal tubules with accumulated LPS. These findings suggest that LPS reduces the intratubular urine flow rate during early phases of endotoxemia through a Toll-like receptor 4–dependent mechanism, and that the efficacy of fluid resuscitation may depend on the response of tubules with LPS accumulation.     

Effects of adolescent online gaming time and motives on depressive,musculoskeletal, and psychosomatic symptoms

Aim. To investigate whether adolescent online gaming time and the additive effect of gaming motives were associated with depressive, musculoskeletal, and psychosomatic symptoms. The hypothesis was that adolescents who engage in online gaming with escape motives and increased online gaming time have higher probability for depressive, musculoskeletal, and psychosomatic symptoms compared to adolescents with other online gaming motives and/or less online gaming time.Method. An anonymous and voluntary questionnaire was completed during class hours by 7,757 Swedish adolescents aged 13–18 years. The questionnaire included demographic background, gaming habits, and depressive, musculoskeletal, and psychosomatic symptoms.Results. It was found that increased online gaming time during weekdays increased the probability of having depressive, musculoskeletal, and psychosomatic symptoms. However, these relations with time spent gaming were further explained by online gaming motives. Weekday online gaming for more than five hours a day, in combination with escape motives, was associated with an increased probability of depressive symptoms (odds ratio (OR) 4.614, 95% CI 3.230–6.590), musculoskeletal symptoms (OR 2.494, 95% CI 1.598–3.892), and psychosomatic symptoms (OR 4.437, 95% CI 2.966–6.637). The probability of ill health decreased when gaming was for fun or had social motives.Conclusion. Excessive gaming time and escape motives were found to be associated with increased probability of ill health among adolescents. Gaming motives may identify gamers in need of support to reduce unhealthy gaming behaviour as well as identify individuals at risk for ill health.     

Passive smoke effects on cough and airways in young guinea pigs: role of brainstem substance P

Children raised with extended exposure to environmental tobacco smoke (ETS) experience increased cough and wheeze. This study was designed to determine whether extended ETS exposure enhances citric acid-induced cough and bronchoconstriction in young guinea pigs via a neurokinin-1 (NK-1) receptor mechanism at the first central synapse of lung afferent neurons, the nucleus tractus solitarius. Guinea pigs were exposed to ETS from 1 to 6 weeks of age. At 5 weeks of age, guide cannulae were implanted bilaterally in the medial nucleus tractus solitarius at a site that produced apnea in response to the glutamate agonist D,L-homocysteic acid. At 6 weeks of age, either vehicle or a NK-1 receptor antagonist, SR 140333, was injected into the nucleus tractus solitarius of the conscious guinea pigs who were then exposed to citric acid aerosol. ETS exposure significantly enhanced citric acid-induced cough by 56% and maximal Penh (a measure of airway obstruction) by 43%, effects that were attenuated by the NK-1 receptor antagonist in the nucleus tractus solitarius. We conclude that in young guinea pigs extended exposure to ETS increases citric acid-induced cough and bronchoconstriction in part by an NK-1 receptor mechanism in the nucleus tractus solitarius.     

Leptin in postmenopausal women: influence of hormone therapy, insulin, and fat distribution

Whether use of hormone-replacement therapy (HRT) influences menopause-related changes in body weight is unclear. HRT may affect energy balance by influencing synthesis of the adipocyte-derived hormone leptin. The objectives of this study were to: 1) identify factors influencing circulating leptin in postmenopausal women; 2) determine whether HRT influences serum leptin after adjusting for confounding factors; and, 3) identify potential independent effects of HRT or leptin on resting energy expenditure (REE). Subjects were 54 postmenopausal women, 45-55 yr old, 35 of whom used HRT (estrogen plus progestin). Total and regional body composition and fat distribution were determined by dual-energy x-ray absorptiometry and computed tomography; fasting serum leptin and insulin, by RIA; and REE, by indirect calorimetry. Stepwise multiple linear regression analysis indicated that serum leptin could best be predicted from total fat mass, fasting serum insulin, and total lean mass [log leptin = 1.08 x log fat mass) + (0.46 x log insulin) + (-1.25 x log lean mass) + 1.88; model R2 = 0.78, P < 0.001]. Multiple linear regression analysis indicated that visceral fat was independently related to leptin (parameter estimate = 0.23, P < 0.05), after adjusting for s.c. abdominal fat and leg fat, as well as lean mass and insulin. After adjusting for total fat mass, total lean mass, and fasting insulin, serum leptin did not differ between users and nonusers of HRT (21.7 +/- 1.0 vs. 20.2 +/- 1.3 ng/mL, P = 0.369, adjusted mean +/- SE, respectively). Serum estradiol was inversely correlated with (adjusted) leptin in non-HRT users (r = -0.50), suggesting that ovarian senescence may lead to an increase in leptin. Multiple linear regression analysis indicated that REE (adjusted for fat mass, fat-free mass, and ethnicity) was not associated with leptin (P = 0.298) or hormone use status (P = 0.999; 1323 +/- 31 vs. 1316 +/- 42 kcal/day, adjusted mean +/- SE for users and nonusers, respectively). These results indicate that, in postmenopausal women: 1) total fat mass, lean mass, and fasting insulin, but not HRT, are significant determinants of serum leptin; 2) visceral and s.c. fat contribute to serum leptin; and, 3) neither HRT nor leptin is independently related to REE.     

Surprisingly high prevalence of anxiety and depression in chronic breathing disorders

STUDY OBJECTIVES: The objectives of this study were to assess the prevalence, screening, and recognition of depression and anxiety in persons with chronic breathing disorders, including COPD. DESIGN: Cross-sectional study. SETTING: The Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC). PARTICIPANTS: A large sample of 1,334 persons with chronic breathing disorder diagnoses who received care at the MEDVAMC. MEASUREMENTS: The prevalence of anxiety and depression was measured in a large sample of persons with a chronic breathing disorder diagnosis who received care at the MEDVAMC, using the Primary Care Evaluation of Mental Disorders (PRIME-MD) screening questions. The positive predictive value of the PRIME-MD questions was then determined. The prevalence of anxiety and depressive diagnoses in patients determined to have COPD was then measured, using the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (SCID). RESULTS: Of patients screened with the PRIME-MD, 80% screened positive for depression, anxiety, or both. The predictive value of a positive phone screen for either depression or anxiety was estimated to be 80%. In the subsample of patients who had COPD and received a diagnosis using the SCID, 65% received an anxiety and/or depressive disorder diagnosis. Of those patients, only 31% were receiving treatment for depression and/or anxiety. CONCLUSIONS: It is troubling that a mere 31% of COPD patients with depression or anxiety are being treated, particularly given their high prevalence in this population. Practical screening instruments may help increase the recognition of anxiety and depression in medical patients, as suggested by the excellent positive predictive value of the PRIME-MD in our study.     

Influence of gender on early and one-year clinical outcomes after saphenous vein graft stenting

Compared with men, women may have a worse prognosis after native coronary revascularization. However, the influence of gender on clinical outcomes after saphenous vein graft (SVG) stenting is unknown. The purpose of this study was to compare early and 1-year clinical outcomes between men and women after stent implantation in SVG. A total of 1,199 consecutive patients with 1,858 SVG lesions were studied. Procedural success, in-hospital events, and late clinical outcomes were compared between men (n = 951) and women (n = 248). Overall procedural success was similar between men and women (97% vs 96%, p = NS). However, in-hospital (3.2% vs 1.6%, p = 0.07) and 30-day cumulative (4.4% vs 1.9%, p = 0.02) mortality rates were higher in women than in men. In addition, women had a higher incidence of vascular complications (12% vs 7.3%, p = 0.006) and postprocedural acute renal failure (8.1% vs 4%, p = 0.02). At 1-year follow-up, mortality was 13% in women and 11% in men (p = NS) and target lesion revascularization was 18% versus 23%, respectively (p = NS). By multivariate regression analysis, independent correlates of in-hospital mortality were female gender (odds ratio [OR] 3.6, confidence interval [CI] 1.0 to 12.5, p = 0.05) and left ventricular ejection fraction (OR 0.9, CI 0.9 to 1.0, p = 0.01). Female gender was found to predict 30-day mortality (OR 2.5, CI 1.1 to 5.5, p = 0.02). The sole predictor of 1-year mortality was diabetes mellitus (OR 1.6, CI 1.1 to 2.3, p = 0.01). This study shows that women compared with men treated with stent implantation in SVG lesions have (1) a trend toward higher in-hospital mortality, (2) higher risk of 30-day mortality, (3) increased incidence of vascular complications and postprocedure acute renal failure, and (4) similar 1-year clinical outcome.     

Cyclooxygenase inhibition in early onset of tumor growth and related angiogenesis evaluated in EP1 and EP3 knockout tumor-bearing mice

It is well established that prostanoids are essential for local inflammation including cell proliferation and apoptosis. Accordingly, prostaglandin E2 (PGE₂) is a critical factor in wound healing, tumor invasiveness and progression. Therefore, the aim of the present work was to evaluate effects by PGE₂ on tumor vascular density at early onset of tumor growth where hypoxia is limited. Wild-type mice (C57Bl, C3H/HeN) bearing either MCG-101 tumors or a malignant melanoma (K1735-M2) with either high or insignificant PGE₂ production and subsequently different in sensitivity to cyclooxygenase (COX) inhibition were used. Tumor angiogenesis was estimated by intravital microscopy and immune histochemical analysis in wild type and EP₁ or EP₃ subtype receptor knockout mice (C57Bl). Both MCG-101 and K1735-M2 tumor cells stimulated early outgrowth of tumor vessels in proportion to intrinsic growth rate of tumor cells. Indomethacin had no effects on tumor growth or tumor related vascular area in K1735-M2 bearing mice. By contrast, indomethacin decreased tumor cell proliferation and increased apoptosis in MCG-101 tumors with subsequent adaptation in tumor vascular density. Effects of indomethacin on early growth of MCG-101 tumors were not related to tumor content of bFGF protein, while our earlier studies on long-term tumor growth have shown decreased mRNA levels of bFGF during indomethacin treatment. Early onset of tumor growth was significantly promoted in EP₃- but not in EP₁-knockouts, although long-term tumor growth is attenuated in EP₁-knockouts as reported elsewhere. Our results demonstrate that tumor production of PGE₂ promotes primarily net growth of tumor cells with subsequent adaptations in development of the tumor vasculature. Therefore, it is likely that angiogenesis is not a limiting step at the early onset of tumor growth.