Intracytoplasmic Lumina in Human Oviduct Epithelium

Intracytoplasmic lumina (ICL) in human oviduct epithelium were investigated with transmission electron microscopy. ICL were found in 43 out of 60 cases examined. They were ultra-structurally characterized by microvilli lining the lumina, periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) staining-positive finely granular material in the lumina, and secretory vesicles in the cytoplasm surrounding the lumina. Although ICL were observed at various heights within the epithelium, they were mainly seen in basally located cells that did not face the oviduct lumen. Various stages of formation and development of ICL were observed in the basally located epithelial cells with secretory activities. Primary ICL were originated in the cytoplasm where the secretory granules were aggregated with smooth-surfaced tubular vesicles. Electron microscopic observations after PA-TCH-SP staining revealed that ICL were formed by fusion of the secretory granules with the tubular vesicles. ICL were enlarged into round profiles by further fusion of secretory granules and tubular vesicles, and subsequently opened to the oviduct lumen, or fused to each other to develop into large extracellular cysts within the epithelium.     

Mechano-active scaffold design of small-diameter artificial graft made of electrospun segmented polyurethane fabrics

To fabricate a "mechano-active" tubular scaffold of nonwoven mesh-type small-diameter artificial graft made of the synthetic durable elastomer, segmented polyurethane, the fabrication technique of electrospinning on a mandrel under a high rotation speed and transverse movement was used. Emphasis was placed on how the rotation speed of the mandrel and the fusion or welding states of fibers at contact points affect the compliance (ease of intraluminal pressure-dependent circumferential inflation) and Young's modulus determined by uniaxial stretching in the longitudinal and circumferential directions. The results showed that a high rotation speed is attributed to exhibit isotropic mechanical properties in the entire range of applied strain but reduces the compliance, and a high fusion state, which is produced using a mixed solvent with a high content of high-boiling-point solvent, reduces the compliance but is expected to exhibit high durability in a continuously loaded pulsatile stress field in an arterial circulatory system.     

Parvalbumin in rat cerebrum, cerebellum and retina during postnatal development

Radioimmunoassay and immunohistochemical studies were performed on the occurrence and distribution of parvalbumin-like immunoreactivity (PA-LI) in developing rat cerebrum, cerebellum and retina. No PA-LI was detected in the nervous tissues of the newborn animals. In the cerebrum, the PA-LI appeared in non-pyramidal neurons at the 2nd postnatal week and increased linearly until the 8th week. In the cerebellum, a rapid increase in the PA-LI took place at the 2nd week, with an enrichment of the antigen to Purkinje neurons. In the retina, amacrine cells contained PA-LI, the levels of which increased from the 2nd to 4th week. Regulation of intracellular Ca²⁺ concentration may be one of the important factors for the maturation of the central nervous system.     

Critical limb ischemia in a patient with von Recklinghausen's neurofibromatosis. Report of a case

A 42-year-old woman complicated with neurofibromatosis underwent both balloon percutaneous transluminal angioplasty (PTA) of the iliac artery and femoropopliteal (FP) bypass grafting for critical lower limb ischemia. Seven months after the initial intervention, a recurrence of stenosis in the iliac artery and at the anastomoses of the FP bypass necessitated both PTA and a repeat thrombectomy and finally resulted in the amputation of her left thigh. This is a rarely documented case of chronic arterial occlusion associated with neurofibromatosis, in which the prognosis of arterial reconstruction for such patients is suggested to be poor.     

Cigarette smoking augments sympathetic nerve activity in patients with coronary heart disease

It has been shown that cigarette smoking increases blood pressure (BP) and heart rate (HR), and decreases muscle sympathetic nerve activity (MSNA) in healthy young smokers. The decrease in MSNA might be secondary to baroreflex responses to the pressor effect. We tested the hypothesis that cigarette smoking increases MSNA in smokers with impaired baroreflex function. The effects of cigarette smoking on BP, HR, forearm blood flow (FBF), forearm vascular resistance (FVR), and MSNA were examined in 14 patients with stable effort angina (59+/-3 years, group CAD) and 10 healthy smokers (23+/-1 years, group C). In group CAD, the arterial baroreflex sensitivity (BRS) was significantly lower than in group C (4.7+/-0.8 versus 15.1+/-2.2 msec/mmHg, P<0.01). In both groups, cigarette smoking increased the plasma concentration of nicotine, systolic and diastolic BP, HR, and FVR significantly (P<0.01), but decreased FBF significantly (P<0.01). After smoking, MSNA was decreased significantly in group C (from 35.2+/-3.5 to 23.5+/-3.2 bursts/100 beats, P<0.01), but increased significantly in group CAD (from 48.8+/-5.4 to 57.3+/-5.5 bursts/100 beats, P<0.01). There was significant correlation between BRS and changes in MSNA (r= -0.62, P<0.01). Cigarette smoking increased MSNA in smokers with impaired baroreflex function. This demonstrates that cigarette smoking stimulates sympathetic nerve activity by both a direct peripheral effect and a centrally mediated effect.     

Kinetic characteristics of K-activated para-nitrophenylphosphatase in isolated adult dog heart myocytes

K⁺-activated para-nitrophenylphosphatase (K⁺-pNPPase) was characterized kinetically in isolated adult dog heart myocytes. The results show that: (i) the K_m and V_max for K⁺ activation were increased by increasing concentrations of Mg²⁺ and para-nitrophenylphosphate (pNPP); the highest V_max/K_m value was obtained at 5 m Mg²⁺, 5 m pNPP and 10 m K⁺; (ii) the optimal molar ratio of Mg²⁺ to pNPP was 1 when the concentration of K⁺ was 10 m and that of pNPP was higher than 1.25 m ; (iii) when the molar ratio of Mg²⁺ to pNPP was kept at 1 and the K⁺ concentration was 10 m , increases in Mg²⁺ and pNPP concentrations increased the enzyme activity sigmoidally with a Hill coefficient of 1.7 and a S_0.5 value of 2.3 m ; (iv) Na⁺ at low concentrations (< 10 m ) activated, while Na⁺ at high concentrations (> 10 m ) inhibited K⁺-pNPPase activity when K⁺ concentrations were greater than 1 m ; (v) Ca²⁺ at low concentrations (0.1 to 0.2 m ) inhibited K⁺-pNPPase activity by competing with K⁺, while Ca²⁺ at high concentrations (0.5 to 1.0 m ) inhibited K⁺-pNPPase activity by mixed (both competitive and non-competitive) competition with K⁺; (vi) ouabain inhibited K⁺-pNPPase activity with a Hill coefficient of 0.59 and a S_0.5 value of 4.8 × 10⁻⁷ ; the inhibitory effect of ouabain (< 10⁻⁶ ) was decreased in the presence of Ca²⁺ (0.1–0.5 m ). These results demonstrate that isolated adult heart myocytes possess K⁺-pNPPase activity which can be used as a sensitive and specific probe for studies of the myocardial sodium pump ATPase enzyme system.     

Metformin and liraglutide ameliorate high glucose-induced oxidative stress via inhibition of PKC-NAD(P)H oxidase pathway in human aortic endothelial cells

Objective

Metformin and glucagon like peptide-1 (GLP-1) prevent diabetic cardiovascular complications and atherosclerosis. However, the direct effects on hyperglycemia-induced oxidative stress in endothelial cells are not fully understood. Thus, we aimed to evaluate the effects of metformin and a GLP-1 analog, liraglutide on high glucose-induced oxidative stress.

Methods

Production of reactive oxygen species (ROS), activation of protein kinase C (PKC) and NAD(P)H oxidase, and changes in signaling molecules in response to high glucose exposure were evaluated in human aortic endothelial cells with and without treatment of metformin and liraglutide, alone or in combination. PKC-NAD(P)H oxidase pathway was assessed by translocation of GFP-fused PKCβ2 isoform and GFP-fused p47phox, a regulatory subunit of NAD(P)H oxidase, in addition to endogenous PKC phosphorylation and NAD(P)H oxidase activity.

Results

High glucose-induced ROS overproduction was blunted by metformin or liraglutide treatment, with a further decrease by a combination of these drugs. Exposure to high glucose caused PKCβ2 translocation and a time-dependent phosphorylation of endogenous PKC but failed to induce its translocation and phosphorylation in the cells treated with metformin and liraglutide. Furthermore, both drugs inhibited p47phox translocation and NAD(P)H oxidase activation, and prevented the high glucose-induced changes in intracellulalr diacylglycerol (DAG) level and phosphorylation of AMP-activated protein kinase (AMPK). A combination of these drugs further enhanced all of these effects.

Conclusions

Metformin and liraglutide ameliorate high glucose-induced oxidative stress by inhibiting PKC-NAD(P)H oxidase pathway. A combination of these two drugs provides augmented protective effects, suggesting the clinical usefulness in prevention of diabetic vascular complications.