Effects of dantrolene sodium on progression of left ventricular hypertrophy induced by pressure overload in rats

We studied the long-term effects of dantrolene sodium (D), a specific sarcoplasmic reticulum (SR) Ca2+-release inhibitor, on the progression of left ventricular pressure-overloaded hypertrophy in rats. We treated abdominal aorta-constricted rats with one of two doses of D for 4 weeks. The extent of hypertrophy was expressed as the ratio of left ventricle to body weight. Hemodynamic parameters were measured by using a microtip catheter manometer. Although a low dose of D (500 mg/L in drinking water) decreased blood pressure to normal levels, the progression of cardiac hypertrophy was not inhibited. In contrast, a high dose of D (5 mg/kg, i.p.) also reduced blood pressure and inhibited the progression of cardiac hypertrophy. Dantrolene sodium had no effect on cardiac function in sham-operated rats. Thus control of Ca2+ release from the SR might be crucial in regulating the progression of cardiac hypertrophy, the final mediator possibly being intracellular Ca2+ concentration.     

Thoracoscopic transdiaphragmatic microwave coagulation therapy for a liver tumor

BACKGROUND: Microwave coagulation therapy (MCT) for hepatocellular carcinoma, which induces tumor coagulonecrosis, is now recognized as an efficient treatment. However, when a tumor is located just below the top of the diaphragmatic dome, laparotomical MCT requires a large incision, and percutaneous MCT is sometimes impossible. PATIENTS AND METHODS: The patients were four men and two women. There were four cases of hepatocellular carcinoma and two cases of liver metastasis from colorectal cancer. All tumors were located below the top of the diaphragmatic dome. Thoracoscopic transdiaphragmatic MCT (TTMCT) was performed under general anesthesia using an endotracheal double-lumen tube. Identification of the tumor site in the liver was performed using an ultrasonic probe under thoracoscopic observation. After the diaphragm above the tumor was opened, a needle electrode to transmit microwaves was inserted directly into the tumor. Microwave irradiation was repeated to coagulate the entire lesion. After completion of TTMCT, the diaphragm was closed thoracoscopically. RESULTS: TTMCT was successfully administered to cancerous lesions in all six patients. The postoperative course was uneventful, and the average postoperative hospitalization period was 10.5 days. None of the patients has shown any recurrence during a follow-up period of 4-23 months. CONCLUSIONS: TTMCT was performed without any difficulty using the thoracoscopic surgical technique, and its therapeutic outcome was satisfactory. This is effective for tumors located just below the top of the diaphragmatic dome.     

直喷汽油(DIG)汽车发动机无声链条系统用温压-高温烧结粉末冶金链轮的开发

作者们以前报导过非直喷汽油 (一般MPI汽油 )发动机滚子链条系统用温压 -常规温度 ( 114 0℃ )烧结的粉末冶金链轮。在这个新开发的项目中 ,研究了几种温压 -高温烧结的粉末冶金钢的力学性能。为测定这些材料的耐磨性 ,用虚拟发动机进行了磨耗试验。最终开发出了可承受严酷磨耗条件的DIG发动机无声链条系统的链轮。使用的基础粉末是混合粉 (DistaloyDC1)。其含 2 %Ni(质量分数 ) ,Ni粉是通过扩散粘结在Fe - 1 5 %Mo(质量分数 )粉末颗粒上的 ,温压是在 130℃下 ,用这种粉末、阴模及模具进行的。烧结温度为 1190℃。链轮还进行了热处理     

Identification of vasopressor phospholipid in crude soybean lecithin

The vasopressor phospholipid in crude soybean lecithin was isolated by column chromatography on Sephadex LH-20. It represented 0.1% of crude soybean lecithin. The isolated phospholipid was identified to be lysophosphatidic acid by gas chromatography-mass spectrometry analysis of TMS-deacylated product and acetolysis product. Nuclear magnetic resonance analysis favored the 1-monoacyl isomer over the 2-isomer. By enzymic determination with L-3-glycerophosphate dehydrogenase, the isolated phospholipid was identified as 1-monoacyl-L-3-glycerophosphate. Gas chromatographic examination revealed that it was composed of a large percentage of unsaturated fatty acids, especially linoleic acid. The activity of isolated lysophosphatidic acid was slightly less than that of synthetic 1-linoleoyl-L-3-glycerophosphate.     

Enhancements in nickel-catalyzed hydrogasification of carbon by surface treatments

A pitch coke was given 4 types of pretreatment to modify the surface state; air oxidation, heatingquenching, steam treatment and hydrogen treatment. The treated cokes were impregnated with nickel and gasified in an atmospheric hydrogen flow. The catalytic reactivity of the pitch coke was enhanced by these pretreatments. Several properties of pretreated cokes were compared and it seemed that highly hydrophilic or acidic surfaces of carbon were unfavorable to metal-catalyzed hydrogasification. The reactivity enhancement was ascribed to an increase in the hydrogen adsorption capacity of nickel on the pretreated coke. The oxygen-containing surface groups are presumed to inhibit the spillover of atomic hydrogen from nickel to carbon. The effect of 1 type of pretreatment. heating-quenching, seems to relate to the expansion in pore volume.     

DUSP-1 Induced by PGE2 and PGE1 Attenuates IL-1β-Activated MAPK Signaling,Leading to Suppression of NGF Expression in Human Intervertebral Disc Cells

The molecular mechanism of discogenic low back pain (LBP) involves nonphysiological nerve invasion into a degenerated intervertebral disc (IVD), induced by nerve growth factor (NGF). Selective cyclooxygenase (COX)-2 inhibitors are mainly used in the treatment of LBP, and act by suppressing the inflammatory mediator prostaglandin E₂ (PGE₂), which is induced by inflammatory stimuli, such as interleukin-1β (IL-1β). However, in our previous in vitro study using cultured human IVD cells, we demonstrated that the induction of NGF by IL-1β is augmented by a selective COX-2 inhibitor, and that PGE₂ and PGE₁ suppress NGF expression. Therefore, in this study, to elucidate the mechanism of NGF suppression by PGE₂ and PGE₁, we focused on mitogen-activated protein kinases (MAPKs) and its phosphatase, dual-specificity phosphatase (DUSP)-1. IL-1β-induced NGF expression was altered in human IVD cells by MAPK pathway inhibitors. PGE₂ and PGE₁ enhanced IL-1β-induced DUSP-1 expression, and suppressed the phosphorylation of MAPKs in human IVD cells. In DUSP-1 knockdown cells established using small interfering RNA, IL-1β-induced phosphorylation of MAPKs was enhanced and prolonged, and NGF expression was significantly enhanced. These results suggest that PGE₂ and PGE₁ suppress IL-1β-induced NGF expression by suppression of the MAPK signaling pathway, accompanied by increased DUSP-1 expression.     

A New Method for Albuminuria Measurement Using a Specific Reaction between Albumin and the Luciferin of the Firefly Squid Watasenia scintillans

This study demonstrates that the luciferin of the firefly squid Watasenia scintillans, which generally reacts with Watasenia luciferase, reacted with human albumin to emit light in proportion to the albumin concentration. The luminescence showed a peak wavelength at 540 nm and was eliminated by heat or protease treatment. We used urine samples collected from patients with diabetes to quantify urinary albumin concentration, which is essential for the early diagnosis of diabetic nephropathy. Consequently, we were able to measure urinary albumin concentrations by precipitating urinary proteins with acetone before the reaction with luciferin. A correlation was found with the result of the immunoturbidimetric method; however, the Watasenia luciferin method tended to produce lower albumin concentrations. This may be because the Watasenia luciferin reacts with only intact albumin. Therefore, the quantification method using Watasenia luciferin is a new principle of urinary albumin measurement that differs from already established methods such as immunoturbidimetry and high-performance liquid chromatography.