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1.
Effects of high glucose on human cavernous endothelial cells.
Ning, H, Qiu, X, Baine, L, Lin, G, Lue, TF, Lin, CS
Urology. 2012;(5):1162.e7-11
Abstract
OBJECTIVE To obtain experimental evidence for a causal effect of high glucose (HG) on cavernous endothelial dysfunction. METHODS Cavernous tissues were obtained from patients undergoing surgery for penile prosthesis implantation. Endothelial cells were isolated by binding to anti-CD31 antibody, followed by magnetic capture. Their endothelial identity was verified by flow cytometry and immunofluorescence staining for endothelial markers CD31, von Willebrand factor, and endothelial nitric oxide synthase, and by their ability to form tube-like structures in matrigel (tube formation) and to endocytose acetylated low-density lipoprotein (low-density lipoprotein uptake). The cells were then cultured under normal glucose (NG) (5 mM) or HG (25 mM) conditions, followed by analysis for endothelial gene expression, function, proliferation, apoptosis, and mitochondrial fragmentation. RESULTS Human cavernous endothelial cell (HCEC) strains were established and determined to be nearly 100% pure endothelial cells. In the HG culture condition, HCECs expressed approximately 50% less CD31, von Willebrand factor, and endothelial nitric oxide synthase, but nearly twice as much collagen IV compared with HCECs grown in NG medium. HG also suppressed low-density lipoprotein uptake and tube formation by approximately 50%. HCECs grew significantly slower in the high-glucose medium than in the NG medium. Approximately 3 times as many cells exhibited apoptosis in the HG medium as in the NG medium. Approximately 4 times as many cells contained fragmented mitochondria in the HG medium as in the NG medium. CONCLUSION HG caused a decrease in endothelial proliferation, function, and marker expression. It also caused an increase in endothelial collagen IV expression, apoptosis, and mitochondrial fragmentation. Together, these HG-induced changes in cavernous endothelial cells provide an explanation for hyperglycemia's detrimental effects on erectile function.
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2.
Differences in excitability between median and superficial radial sensory axons.
Fujimaki, Y, Kanai, K, Misawa, S, Shibuya, K, Isose, S, Nasu, S, Sekiguchi, Y, Ohmori, S, Noto, Y, Kugio, Y, et al
Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology. 2012;(7):1440-5
Abstract
OBJECTIVE The aim of this study was to investigate differences in excitability properties of human median and superficial radial sensory axons (e.g., axons innervating the glabrous and hairy skin in the hand). Previous studies have shown that excitability properties differ between motor and sensory axons, and even among sensory axons between median and sural sensory axons. METHODS In 21 healthy subjects, threshold tracking was used to examine excitability indices such as strength-duration time constant, threshold electrotonus, supernormality, and threshold change at the 0.2 ms inter-stimulus interval in latent addition. In addition, threshold changes induced by ischemia for 10 min were compared between median and superficial radial sensory axons. RESULTS Compared with radial sensory axons, median axons showed shorter strength-duration time constant, greater threshold changes in threshold electrotonus (fanning-out), greater supernormality, and smaller threshold changes in latent addition. Threshold changes in both during and after ischemia were greater for median axons. CONCLUSIONS These findings suggest that membrane potential in human median sensory axons is more negative than in superficial radial axons, possibly due to greater activity of electrogenic Na(+)/K(+) pump. These results may reflect adaptation to impulses load carried by median axons that would be far greater with a higher frequency. SIGNIFICANCE Biophysical properties are not identical in different human sensory axons, and therefore their responses to disease may differ.
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3.
An eight-week, multicenter, randomized, double-blind study to evaluate the efficacy and tolerability of fixed-dose amlodipine/benazepril combination in comparison with amlodipine as first-line therapy in chinese patients with mild to moderate hypertension.
Ueng, KC, Lin, LC, Voon, WC, Lin, MC, Liu, YB, Su, HM, Chang, PY, Lin, TH, Chen, WL, Wu, CC, et al
Blood pressure. Supplement. 2008;:24-31
Abstract
AIMS: This study sought to compare the antihypertensive efficacy and tolerability of a fixed-dose combination with amlodipine/benazepril with that of amlodipine monotherapy in Chinese hypertensive subjects. RESULTS This multicenter, double-blind, 8-week study randomized 111 patients to fixed-dose amlodipine besylate/benazepril HCl (2.5/5 mg/day titrated to 5/10 mg/day as needed at week 4 to reach goal blood pressure (BP) <140/90 mmHg) or amlodipine besylate monotherapy (5 mg/day titrated to 10 mg/day as needed). At week 8, patients randomized to combination therapy compared with monotherapy had a comparable BP control rate (56.0% vs. 46.2%; p = 0.32). Fixed-dose combination resulted in similar reductions in sitting systolic (SBP) and diastolic BP (DBP) compared with monotherapy (SBP: -19.3 +/- 12.5 vs. -20.9 +/- 13.3 mmHg; DBP: -9.2 +/- 10.4 vs. -11.3 +/-9.3 mmHg; both p=NS). Safety profiles did not differ between groups, but cough was more common in the combination group (11.0% vs. 0%; p = 0.013). CONCLUSIONS In this group of patients, comparable antihypertensive effects were seen with the fixed-dose combination therapy, compared with amlodipine monotherapy. Both treatments appeared well tolerated in the studied population, but cough was more common in the fixed-dose combination group.
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4.
Responses of human sensory and motor axons to the release of ischaemia and to hyperpolarizing currents.
Lin, CS, Kuwabara, S, Cappelen-Smith, C, Burke, D
The Journal of physiology. 2002;(Pt 3):1025-39
Abstract
This study compared directly the post-ischaemic behaviour of sensory and motor axons in the human median nerve, focusing on the excitability changes produced by ischaemia and its release and by continuous polarizing DC. The decrease in threshold during ischaemia for 13 min was greater, the post-ischaemic increase in threshold was more rapid, and the return to the pre-ischaemic excitability took longer in sensory axons. However, a transient depolarizing threshold shift developed in sensory axons a few minutes after release of ischaemia. This pattern could not be reproduced by polarizing currents designed to mimic the probable pump-induced changes in membrane potential, even though the applied currents produced greater changes in threshold. Hyperpolarizing currents of equivalent intensity produced a greater increase in threshold for motor axons than sensory axons and, in studies of threshold electrotonus using graded hyperpolarizing DC, accommodation was greater in sensory than motor axons. The post-ischaemic changes in threshold were not uniform for axons of different threshold, whether sensory or motor, the threshold increase was usually less prominent for low-threshold axons. A transient post-ischaemic depolarization could be produced in motor axons with ischaemia of 20 min duration. Greater ischaemic and post-ischaemic changes in threshold for sensory axons could reflect greater dependence on the electrogenic Na+-K+ pump to maintain resting membrane potential and/or greater extracellular K+ accumulation in ischaemic sensory axons. Inward K+ currents due to extracellular K+ accumulation would then be more likely to trigger a depolarizing shift in membrane potential, the degree of K+ accumulation and pump activity being dependent on the duration of ischaemia. In sensory axons the greater tendency to accommodate to hyperpolarizing stimuli presumably contributes to shaping their post-ischaemic behaviour but is probably insufficient to explain why their behaviour differs from that of motor axons.