Inhibitory effects of Keishi-bukuryo-gan on free radical induced lysis of rat red blood cells

Keishi-bukuryo-gan (KBG) prevents the progression of atherosclerosis in cholesterol-fed rabbits by its antioxidative effect. The present study was to test our hypothesis that ingestion of KBG would protect red blood cell (RBC) membranes from free radical induced oxidation if polyphenolic antioxidants in KBG could be absorbed and circulated in the blood. When incubated with a RBC suspension, KBG and four of five herb medicines constituting KBG provided strong protection for RBC membranes against haemolysis induced by 2,2-azo-bis (2-amidinopropane) dihydrochloride (AAPH), an azo free radical initiator. The inhibitory effect was dose dependent at concentrations of 100-1000 microg/mL. Furthermore, the ingestion of 200 mg of KBG was associated with a significant decrease in susceptibility of RBC to haemolysis in rats.     

Basic examination of in-plane spatial resolution in multi-slice CT

In computed tomography(single-slice spiral CT, conventional CT), in-plane(x-y plane) spatial resolution is consistently identified as depending on the detector density of the in-plane(x-y plane). However, we considered that the in-plane(x-y plane) spatial resolution of multi-slice CT (MSCT) was influenced by an error in the detector's sensitivity to the Z-axis and by the frequency of use of direct row data and complementary row data when the image of spiral pitches(SP) was reconstructed. Our goal in this experiment was to analyze the relationship of the in-plane(x-y plane)spatial resolution of an asymmetric-type detector in MSCT to SP, tube current, and rotation time. By employing a tungsten wire phantom of 0.2 mm in diameter, we examined modulation transfer functions(MTF) by point-spread functions(PSF) of CT-images. Next, using the mean-square-root bandwidth theory, we analyzed the MTF of wire phantoms. The analysis of in-plane(x-y plane) spatial resolution revealed that various tube currents had no effect on the value of the mean-square-root bandwidth. However, rotation time and high spiral pitch did have an effect on mean-square-root bandwidth. Considering the results mentioned above, spiral pitch(z-axis reconstruction algorithm) had a slight effect on in-plane(x-y plane) spatial resolution of asymmetric-type detectors in MSCT. Accordingly, we proposed a new general view of VDDz(view/mm) in MSCT that considered view data density on the Z-axis according to spiral pitch(mm/rotation), rotation time(view/rotation), and slice collimation.     

Appearance of rectal varices in extrahepatic portal obstruction after treatment for esophago-gastric varices: a case report

We report a case of rectal varices that developed after endoscopic injection sclerotherapy (EIS) and Hassab's operation for esophageal varices with extrahepatic portal obstruction. A 54-year-old woman was admitted to our hospital in September 1997 for treatment of hematochezia. Emergent colonoscopy revealed tortuous rectal varices with a white plug. Angiography revealed that rectal varices were provided with backward blood flow by the inferior mesenteric vein due to extrahepatic portal obstruction. In this case, previous treatment, EIS and Hassab's operation, for esophago-gastric varices might have inhibited the development of collaterals apart from surface of gastrointestinal tract, such as para-esophageal collateral veins or spleno-renal shunt. Since the thrombus in the extrahepatic portal vein causes strong pressure on inferior mesenteric vein which is connected to the inferior vena cava via the inferior rectal vein, rectal varices might be developed. In this case, it was considered that rectal varices were not treated enough by endoscopic therapy because of regurgitant hyper blood flow against portal venous pressure. Therefore, rectal transection was performed. After the treatment, the patient suffered no further episodes of bleeding from rectal varices.     

Vasodilator effect of extract prepared from Uncariae ramulus on isolated rat aorta

Uncariae ramulus et Uncus (URE) has a vasodilator effect. Its mechanism consists of not only endothelium-independent relaxation with Ca2+ channel blocking effect but also endothelium-dependent relaxation with nitric oxide. The active components are alkaloids and tannin contained in Uncariae ramulus et Uncus. They also show a superoxide dismutase-like effect and suppressed vasocontraction induced by xanthine and xanthine oxidase. These mechanisms may also influence vasodilatation by Uncariae ramulus et Uncus in vivo.     

Shosaiko-to and other Kampo (Japanese herbal) medicines: a review of their immunomodulatory activities

The use of alternative medicine, including consumption of herbal products and dietary supplements, has been increasing substantially both in the United States and in Western Europe. One area that is garnering increased attention is the use of Oriental Medicine including Kampo, or Japanese herbal medicine. Herein, we review representative examples of research available on the most common use of Kampo medicinals, namely to improve the immune response. We also provide an extensive background on the history of Kampo. There are more than 210 different Kampo formulae used in Japan and most uses of Kampo are to modulate the immune response, i.e. to improve immunity. We have extracted data on seven common Kampo medicinals, and the data are reviewed with respect to in vitro and in vivo activities for both humans and experimental animals; the ingredients as well as the problems with classification of these materials are presented. Research suggests that Kampo herbals are biologically active and may have therapeutic potential. While it is believed that Kampo medicines have few side effects, there is a paucity of data on their toxicity as well as a relative lack of knowledge of the bioactive constituents and potential drug interactions of these agents.     

Infusion of neuropeptide Y into the stalk-median eminence stimulates in vivo release of luteinizing hormone-release hormone in gonadectomized rhesus monkeys

Studies in the rat and rabbit indicate that facilitatory effects of neuropeptide Y (NPY) as well as norepinephrine (NE) on LH and LHRH release are dependent on the presence of the ovarian steroid estrogen. However, we have previously found the NE and an alpha-1-adrenergic agonist are both stimulatory to pulsatile LHRH release in ovariectomized rhesus monkeys. In the present experiment the effects of NPY on LHRH release were examined in conscious monkeys using a push-pull perfusion method. Twelve gonadectomized monkeys (8 females and 4 males) were used. Perfusate samples from the stalk-median eminence (S-ME) were obtained through a push-pull cannula at 10-min intervals for 12 h, and the amount of LHRH in samples were determined with RIA. NPY dissolved in a modified Krebs-Ringer phosphate buffer solution at concentrations of 10(-8), 10(-7), 10(-6), and 10(-5) M was directly infused into the S-ME through the push cannula for 10 min at 90-min intervals. Vehicle was infused as a control. Since sex differences in LHRH response to NPY were not present, data from males and females were combined for analysis. NPY infusion into the S-ME stimulated LHRH release in a dose-dependent manner (P less than 0.001). The peak LHRH responses (mean +/- SEM) to NPY at different concentrations were: 10(-8) M = 2.1 +/- 0.4 pg/ml; 10(-7) M = 2.6 +/- 0.5 pg/ml; 10(-6) M = 6.5 +/- 1.1 pg/ml; 10(-5) M = 15.1 +/- 2.9 pg/ml, whereas to vehicle 0.37 +/- 0.17 pg/ml. All NPY doses tested were significantly effective as compared to vehicle (P less than 0.01). The LHRH response to 10(-6) M was greater (P less than 0.01) than that of 10(-8) M or 10(-7) M, and the response to 10(-5) M was greater (P less than 0.01) than that of all lower doses. The results indicate that NPY infusion into the S-ME elicits the release of LHRH in vivo in a dose-dependent manner in the monkey. The data further suggest that LHRH neurons and/or neuroterminals in the monkey are responsive to NPY stimulation in the absence of gonadal steroids. It is concluded that in addition to NE, NPY is an important regulator of pulsatile LHRH release in the nonhuman primate.     

Suppression of the Arthus reaction by Y-24180, a potent and specific antagonist of platelet-activating factor

A novel and potent antagonist of platelet-activating factor (PAF), Y-24180 (4-(2-chlorophenyl)-2-[2-(4-isobubylphenyl)ethyl]-6,9-dimethyl-6H-thieno[3,2-f][1,2,4]triazolo[4,3-a][1,4] diazepine) was investigated for the effects on the skin reactions induced by chemical mediators and the Arthus reactions. In the rat dorsal skin, Y-24180 (0.1–10 mg/kg, p.o.) inhibited increase in vascular permeability by the intradermal PAF injection in a dose dependent manner and the inhibitory activity was 60 times more potent than that of WEB 2086. While even at doses as large as 10 mg/kg, p.o., it had no effect on vascular permeability in the rat skin induced by histamine, serotonin, bradykinin and leukotriene D₄. On a reversed passive Arthus reaction in rat dorsal skin, Y-24180 (0.1–1 mg/kg, p.o.) markedly inhibited vascular permeability in a dose dependent manner and the inhibitory activity was 15 times more potent than that of WEB 2086. Y-24180 also inhibited the Arthus dermal reaction in rabbits (0.03–0.3 mg/kg, p.o.) and guinea pigs (0.1–1mg/kg, p.o.). In addition Y-24180 (0.1–10 mg/kg, p.o.) significantly reduced the exudate volume and the number of infiltrated inflammatory cells in the reversed passive Arthus pleural reaction in rats. Furthermore, in rat passive Arthus pancreatitis, Y-24180 (0.3–10 mg/kg, p.o.) significantly inhibited the dye extravasation from the pancreas. These results provide strong evidence that endogenous PAF plays an important role as a mediator in the type III allergic inflammation.     

Amino acids in the medulla oblongata contribute to baroreflex modulation by angiotensin II

We investigated the underlying mechanisms of baroreflex alteration produced by intravenous angiotensin II (ANG II) by monitoring the release of amino acids from the rostral ventrolateral medulla (VLM) using a brain microdialysis technique. Reflex changes in heart rate were elicited by bolus intravenous injection of phenylephrine (2–40 μg/kg) before and 120 min after the initiation of administration of a subpressor dose of ANG II (5.4 pmoVkg/min) or vehicle. The slope of the regression line obtained from changes in mean arterial pressure and heart rate elicited by phenylephrine was used as an Index of baroreceptor reflex sensitivity. ANG II administration for 120 min significantly attenuated the baroreflex sensitivity (from -0.59 ± 0.10 to -0.30 ± 0.08 bpm/mmHg). This attenuation was accompanied with an increase in the release of glutamate and glycine from the VLM (+40% and +20%, respectively) at 120 min. Glycine perfusion into this area resulted in an attenuation of baroreflex sensitivity with a magnitude similar to that obtained with infusion of a subpressor dose of ANG II, whereas glutamate perfusion caused a resetting of baroreflex. These results suggest that glycine and glutamate are involved in cardiovascular regulation in the VLM. Furthermore, the augmented releases of these amino acids may account for the underlying mechanism of ANG II-induced attenuation of baroreflex function.     

Estimation of detection limit from slope of B/B0 in competitive ELISA

A method has been proposed for determining the detection limit (L(D)) from the slope of a semilogarithmic plot of a B/B(0) curve in competitive enzyme linked immunosorbent assay (ELISA). As an application, this paper describes a graphic determination of L(D) from analogue data in the literature. The L(D) obtained corresponds to the concentration at which the relative standard deviation of concentration estimates is 30%.