Effect of maturation and senescence on carbohydrate utilization and insulin responsiveness of rat adipose tissue

Summary The aim of the present investigation was to study the effect of aging upon the metabolism and the responsiveness to insulin of epididymal adipose tissue from rats (6 weeks, 6 and 24 months). Basal glucose metabolism by these tissues and adipocytes was positively related to cell size, for each age group. But age per se plays an important role: for the same diameter, the U-¹⁴C-glucose oxidation to CO₂ and its incorporation into triglycerides decreased markedly between 6 weeks and 6 months, as reported previously, and decreased still further between 6 months and 24 months, for any diameter. In contrast, insulin responsiveness of adipose tissue fragments and fat cells was negatively correlated to adipose cell size, when we analyzed the role of cell diameter for a group of given age. When comparing the sensitivity to hormone for a given cell volume but at different ages, it appeared that insulin resistance increased considerably between 6 weeks and 6 months and was still more marked in old age. The mechanisms underlying these facts have been discussed.     

Left atrial myxoma and mitral valve endocarditis--a cause and effect: a case report

We report the case of a 55-year-old man who presented with an infected left atrial myxoma that seeded a normal native mitral valve. Despite the absence of mitral regurgitation or heart failure, prior to the patient completing a course of IV antibiotic therapy we removed the tumor, replaced the mitral valve, and added 3 coronary artery bypass grafts, following a single embolic event. Although a completed course of antibiotic therapy may have allowed preservation of the native mitral valve, we believed that the risk of recurrent embolization from either the mass or the mitral valve vegetations was greater that the long-term risks of valve replacement.     

Variation in the von Willebrand factor gene is associated with von Willebrand factor levels and with the risk for cardiovascular disease

High levels of von Willebrand factor (VWF) are associated with an increased risk for cardiovascular disease (CVD). Although VWF levels are strongly heritable and genetic susceptibility is an important risk factor for CVD, information on the contribution of common VWF gene variants to VWF levels and CVD risk is limited. In a case-control study of 421 young patients with a first event of acute coronary heart disease (CHD) or ischemic stroke (IS), and 409 healthy control participants (men aged ≤ 45 years, women aged ≤ 55 years), 27 haplotype-tagging single-nucleotide polymorphisms (ht-SNPs), covering the total common VWF gene variation, were selected and genotyped. The associations between these SNPs, VWF antigen (VWF:Ag) levels, VWF collagen-binding (VWF:CB) activity, and CVD risk was investigated. Two new associations were identified. For ht-SNP rs4764478 (intron 45), the increase in VWF:Ag levels and VWF:CB activity per minor allele was 0.082 (± 0.026) IU/mL (P = .001) and 0.096 (± 0.030) IU/mL (P = .002), respectively. ht-SNP rs216293 (intron 17) was associated with CVD risk (odds ratio, 1.44; 95% confidence interval [CI], 1.12-1.86 per minor allele). We confirmed the association between rs1063857 and CVD risk. Our data show that common variants in the VWF gene are associated with VWF levels and with the risk for CVD.     

Hyperglycemia in bacterial meningitis: a prospective cohort study

Background  

Hyperglycemia has been associated with unfavorable outcome in several disorders, but few data are available in bacterial meningitis. We assessed the incidence and significance of hyperglycemia in adults with bacterial meningitis.     

Open lung ventilation does not increase right ventricular outflow impedance: An echo-Doppler study

OBJECTIVE: Ventilation according to the open lung concept (OLC) consists of recruitment maneuvers, followed by low tidal volume and elevated positive end-expiratory pressure (PEEP). Elevated PEEP is associated with an increased right ventricular afterload. We investigated the effect of OLC ventilation on right ventricular outflow impedance during inspiration and expiration in patients after cardiac surgery using transesophageal echo-Doppler. DESIGN: A prospective, single-center, crossover, randomized, controlled clinical study. SETTING: Cardiothoracic intensive care unit of a university hospital. PATIENTS: Twenty-eight patients scheduled for elective cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: In the intensive care unit, each patient was ventilated for approximately 30 mins according to both OLC and conventional ventilation. During OLC ventilation, recruitment maneuvers were applied until PaO2/FiO2 was >375 torr (50 kPa); during conventional ventilation no recruitment maneuvers were performed. MEASUREMENTS AND MAIN RESULTS: Transesophageal echo-Doppler measurements were performed at end-inspiration and end-expiration in a steady-state condition, 20 mins after initiation of a ventilation strategy. Mean acceleration of flow was determined in the long axis of the pulmonary artery in a transverse axis view. During OLC ventilation, a total PEEP of 14 +/- 4 cm H2O was applied vs. 5 cm H2O during conventional ventilation. Mean acceleration during expiration was comparable between groups. During inspiration, OLC ventilation did not cause a decrease of mean acceleration compared with expiration, whereas this did occur during conventional ventilation. CONCLUSIONS: Despite the use of elevated PEEP levels, ventilation according to OLC does not change right ventricular outflow impedance during expiration and decreases right ventricular outflow impedance during inspiration.     

Community-acquired bacterial meningitis in older people

OBJECTIVES: To describe clinical features of bacterial meningitis in older people. DESIGN: Cohort study. SETTING: Hospitals in the Netherlands. PARTICIPANTS: Patients aged over 16 with community-acquired bacterial meningitis, confirmed using cerebrospinal fluid culture. MEASUREMENTS: Data were collected prospectively. The cohort was dichotomized with respect to age (>or=60 vs 17-59). RESULTS: Two hundred fifty-seven of 696 episodes of community-acquired bacterial meningitis (37%) occurred in elderly patients and 439 (63%) in younger adults. Older people more often presented with the triad of fever, neck stiffness, and altered mental status than younger adults (58% vs 36%; P<.001). In older people, meningitis was due to Streptococcus pneumoniae in 176 episodes (68%). In younger adults, Neisseria meningitidis was the most common pathogen, responsible for 221 episodes (50%). Elderly patients more often developed complications than younger adults (72% vs 57%; P<.001), which resulted in a higher mortality rate (34% vs 13%; P<.001). Older people tended to die more often from cardiorespiratory failure (25% vs 11%; P=.06), whereas younger adults more often died from brain herniation (23% vs 2%; P=.004). CONCLUSION: Elderly patients with bacterial meningitis often present with classic symptoms of bacterial meningitis. Bacterial meningitis within this age group is predominantly due to S. pneumoniae and is associated with high morbidity and mortality rates. Whereas older people die frequently of cardiorespiratory failure, younger adults more often die of brain herniation.     

The effect of open lung ventilation on right ventricular and left ventricular function in lung-lavaged pigs

Introduction  

Ventilation according to the open lung concept (OLC) consists of recruitment maneuvers, followed by low tidal volume and high positive end-expiratory pressure, aiming at minimizing atelectasis. The minimization of atelectasis reduces the right ventricular (RV) afterload, but the increased intrathoracic pressures used by OLC ventilation could increase the RV afterload. We hypothesize that when atelectasis is minimized by OLC ventilation, cardiac function is not affected despite the higher mean airway pressure.