Hyperglycemia per se can reduce plasma free fatty acid and glycerol levels in the acutely insulin-deficient dog

To evaluate the in vivo effect of hyperglycemia per se on plasma free fatty acid (FFA) and glycerol concentrations, euglycemic and hyperglycemic clamp studies were performed in six overnight fasted dogs in the state of insulin deficiency produced by somatostatin (SRIF) infusion. The mean blood glucose concentrations during the steady-state (the second hour of each study) averaged 4.65 +/- 0.10 mmol/L in euglycemic clamp and 14.11 +/- 0.10 mmol/L in hyperglycemic clamp. During the SRIF infusion, plasma FFA concentrations increased from 0.32 +/- 0.05 mumol/mL at the basal state to 0.76 +/- 0.04 mumol/mL at the steady-state in euglycemic clamp and from 0.26 +/- 0.04 mumol/mL to 0.43 +/- 0.02 mumol/mL in hyperglycemic clamp. Plasma glycerol concentrations increased from the basal value of 0.07 +/- 0.01 mumol/mL to 0.15 +/- 0.01 mumol/mL during the steady-state in euglycemic clamp and from 0.06 +/- 0.01 mumol/mL to 0.08 +/- 0.01 mumol/mL in hyperglycemic clamp. The steady-state concentrations of plasma FFA and glycerol in hyperglycemic clamp were significantly lower than those in euglycemic clamp (P less than .001; respectively). These results suggest that hyperglycemia per se might decrease plasma FFA and glycerol concentrations at least in part by decreasing lipolysis in the acutely insulin-deficient dog.     

Decreased expression of phospholipase C-beta 2 isozyme in human platelets with impaired function

Platelets from a patient with a mild inherited bleeding disorder and abnormal platelet aggregation and secretion show reduced generation of inositol 1,4,5-trisphosphate, mobilization of intracellular Ca2+, and phosphorylation of pleckstrin in response to several G protein mediated agonists, suggesting a possible defect at the level of phospholipase C (PLC) activation (see accompanying report). A procedure was developed that allows quantitation of platelet PLC isozymes. After fractionation of platelet extracts by high-performance liquid chromatography, 7 out of 10 known PLC isoforms were detected by immunoblot analysis. The amount of these isoforms in normal platelets decreased in the order PLC- gamma 2 > PLC-beta 2 > PLC-beta 3 > PLC-beta 1 > PLC-gamma 1 > PLC- delta 1 > PLC-beta 4. Compared with normal platelets, platelets from the patient contained approximately one-third the amount of PLC-beta 2, whereas PLC-beta 4 was increased threefold. These results suggest that the impaired platelet function in the patient in response to multiple G protein mediated agonists is attributable to a deficiency of PLC-beta 2. They document for the first time a specific PLC isozyme deficiency in human platelets and provide an unique opportunity to understand the role of different PLC isozymes in normal platelet function.     

Five-Year Subjective Outcomes of Obstructive Sleep Apnea Surgery: A Multiinstitutional Study

Objectives

To evaluate the effect of obstructive sleep apnea (OSA) surgery on long-term (5-year) subjective outcomes, including sleep disordered breathing (SDB) symptoms and other complications, in patients with OSA.

Methods

We enrolled patients who underwent diagnostic polysomnography for OSA between January 2006 and December 2006 in ten hospitals. Patients either were treated for OSA or were not treated for OSA. All patients completed a brief telephone survey regarding their SDB signs and symptoms (e.g., snoring, apnea, nocturnal arousals, and daytime sleepiness), positive airway pressure (PAP) compliance, and any adverse effects of either the surgery or PAP. A positive subjective outcome for either surgery or no treatment was taken to be the alleviation of apnea, defined as a ≥50% increase in score. A positive subjective outcome (compliance) for PAP was defined as a PAP usage of ≥4 hours per night and ≥5 days per week.

Results

A total of 229 patients were included in this study. Patients were divided into three groups: a surgery group (n=87), a PAP group (n=68), and a control (untreated) group (n=74). The surgery group exhibited significant improvement in all SDB symptoms compared with the control group. The long-term subjective outcomes of the surgery (52.9%) and PAP (54.4%) groups were significantly better than those of the control group (25.0%). The subjective outcome of the surgery group was not significantly different from that of the PAP group. The overall surgical complication rate was 23.0% (20 of 87) in the surgery group, and 55.0% (22 of 40) of all patients with PAP experienced adverse effects.

Conclusion

The extent of SDB symptoms was consistently improved in patients with OSA at 5 years postsurgery. Information about the potential long-term subjective outcomes should be provided to patients when considering surgery.     

Dual Antiplatelet Therapy Duration Determines Outcome After 2- But Not 1-Stent Strategy in Left Main Bifurcation Percutaneous Coronary Intervention

Objectives

The aim of this study was to investigate clinical outcomes after left main coronary artery (LM) bifurcation percutaneous coronary intervention (PCI) and the impact of the duration of dual antiplatelet therapy (DAPT) according to treatment strategy.

Glycated haemoglobin as a predictor for metabolic syndrome in non-diabetic Korean adults.

AIMS: With increasing prevalence of diabetes mellitus and metabolic syndrome (MS), the importance of early detection of insulin resistance is emphasized. However, a simple and practical method of measurement is not readily available. Therefore, we examined the sensitivity and specificity of HbA(1c) for predicting impaired fasting glucose (IFG) and MS and its association with cardiovascular risk factors, particularly in the normal range of HbA(1c) levels in non-diabetic Korean subjects. METHODS: In 40,155 participants (median age 40 years) participating in a medical check-up programme, analysis of the distribution of HbA(1c) and its association with various cardiovascular risk factors was performed. In 22,465 selected participants, an analysis was conducted of the ability of HbA(1c) to predict MS and IFG. Anthropometric measurements were made in all subjects and fasting glucose, lipid profiles and HbA(1c) were measured. The presence of MS was defined according to the definitions of the Adult Treatment Panel III (ATP III) guideline and the new International Diabetes Federation (IDF) guideline. Patients with diabetes were excluded from the study. RESULTS: The incidence of MS was 12.2% according to ATP III criteria and 7.6% according to IDF criteria. When subjects were grouped by quartile of HbA(1c), cardiovascular risk factors significantly increased as the HbA(1c) increased. An HbA(1c) of 5.45% predicted the presence of MS (ATP III: sensitivity/specificity 57.4/64.3%, area under the curve 64.8%; IDF: sensitivity 60.2/63.4%, area under the curve 66.1%) and fasting blood glucose > or = 5.6 mmol/l (sensitivity/specificity 53.7/70%, area under the curve 66.1%). When the analyses were done separately by gender, female subjects showed higher cut-off of HbA(1c) for the prediction of MS (5.55% for both ATP III and IDF criteria). CONCLUSIONS: HbA(1c) increased as cardiovascular risk factors increased and HbA(1c) of 5.45% predicted the presence of MS. HbA(1c) might be a predictive measure of IFG and MS, and also cardiovascular risk factors in the Korean population.     

Predialysis Kidney Function and Its Rate of Decline Predict Mortality and Hospitalizations After Starting Dialysis

Objective

To determine whether kidney function level and its rate of decline in the immediate predialysis period among veterans transitioning to end-stage renal disease (ESRD) predict postdialysis mortality and hospitalization.

Predicting the electrical conductivity in polymer carbon nanotube nanocomposites based on the volume fractions and resistances of the nanoparticle,interphase, and tunneling regions in conductive networks

Some limited models have been suggested to determine the conductivity of polymer carbon nanotube (CNT) nanocomposites (PCNTs). However, earlier models (e.g., the Kovacs model) cannot properly consider the roles of the interphase regions or tunneling properties on the percolation threshold and subsequent conductivity of PCNTs. In this paper, the Kovacs model is further developed by assuming that the CNT, interphase, and tunneling regions are separate phases. Also, some simple equations are provided to calculate the percolation threshold as well as the volume fractions and resistances of the CNT, interphase, and tunneling regions in conductive networks. The experimental conductivity results for several samples are compared with the predictions of the developed model. In addition, the calculations of the developed model at different parameter levels are explained and justified. The conductivity calculations show good agreement with the experimental data. Moreover, the developed model reasonably explains the roles of the different parameters on the conductivity. For example, long, thin, and straight CNTs efficiently improve the conductivity because they form large networks in the nanocomposites. Additionally, a thick interphase enlarges the conductive networks, resulting in a desirable conductivity. The conductivity of PCNTs only depends on the tunneling resistance; this is the case because the poor resistance/significant conductivity of the CNT and interphase regions do not influence the conductivity. The developed equations can replace conventional approaches for predicting the conductivity of nanocomposites.

Some limited models have been suggested to determine the conductivity of polymer carbon nanotube (CNT) nanocomposites (PCNTs).     

Hemostatic efficacy of hydrophilic wound dressing after transradial catheterization

Here, we evaluate the efficacy of the Clo-Sur PAD nonwoven hydrophilic wound dressing (HWD) on hemostasis in an arterial-access site after transradial percutaneous coronary angiography compared with the RadiStop compression device (CD). Eighty patients who had undergone transradial coronary angiography with or without intravascular ultrasound were randomly assigned to the HWD or CD group. The time required to achieve hemostasis was measured, and the incidence of vascular complications was assessed. No significant differences in clinical and procedural characteristics were observed between the HWD group (n = 40) and the CD group (n = 40). A significant reduction in the time required to achieve hemostasis (58.7 +/- 32.6 minutes versus 131.3 +/- 59.1 minutes; p < 0.001) was associated with the use of HWD. The incidence of vascular complications was similar in both groups (5% for HWD versus 2.5% for CD; p = 0.500). No major complications, such as large hematoma or acute radial occlusion, occurred in the HWD group. In conclusion, HWD represents a safe alternative to the compression method. Hemostasis can be achieved more quickly using HWD, with no increase in access site complications, as compared to CD.