Algal phagostimulants for marine herbivorous gastropods

Methanol extracts of the green algaUlva pertusa contain four kinds of glycerolipids that are active as feeding-stimulants for marine herbivorous gastropods. These compounds are digalactosyldiacylglycerol (DGDG), 1,2-diacylglycerly-4-O-(N,N,N-trimethyl)-homoserine (DGTH), 1-monoacylglyceryl-4'-O-(N,N,N-trimethyl)-homoserine (MGTH), and 6-sulfoquinovosyldiacylglycerol (SQDG). The various gastropods exhibit marked specificity, however, as young abaloneHaliotis discus respond to DGDG and DGTH at minute dosages of 20–30 g/sample zone, but do not respond to 300 g of SQDG, which is a phagostimulant for two other kinds of gastropods,Turbo comutus andOmphalius pfeifferi.Chemical Studies on Phagostimulants for Marine Gastropods. Part VI. For Part V, see Sakata et al. (1986b).     

Electrochemical behaviour of pyridinoline, a crosslinking amino acid of collagen

Pyridinoline is a crosslinking amino acid isolated from collagen. Polarographic oxidation and reduction potentials of pyridinoline were measured and compared with those of structurally related compounds, 3-hydroxypyridine, pyridoxine, pyridoxal, and N-methylpyridoxine. Oxidation and reduction potentials of these compounds were found to be near anodic and cathodic limit potentials, respectively, except for pyridoxal. This indicates that a 3-hydroxypyridine ring is very difficult to be reduced or oxidized. The reducibility of pyridinoline with a reducing agent, sodium borohydride, was also studied. It was not reduced by the reagent, however, it was found to be decomposed by light during the treatment. These results indicate that pyridinoline is a so-called "non-reducible" crosslink.     

The interaction between molten gallium and the hydrocarbon medium induced by ultrasonic energy—can gallium carbide be formed?

Ultrasonic irradiation of molten gallium in organic liquids (decane, dodecane, etc.) results in dispersion of the gallium into nanometric spheres. These were examined by several analytical methods XRD, DSC, Raman and IR spectroscopy) as well as electron microscopy (SEM, TEM) and found to be composed of Ga and C. The DSC analysis indicates that the Ga has possibly reacted with carbon, while the Raman spectrum of the product demonstrates a strong additional peak that could not be identified. This work explores the possibility that the product is gallium carbide or another gallium‐carbon complex. To investigate the nature of the product, we performed detailed extended X‐ray absorption fine structure (EXAFS) and X‐ray absorption near‐edge structure (XANES) analyses. On the basis of DSC, IR, and Raman it appear to be formation of GaC, whereas the analysis by EXAFS and XANES demonstrated that the gallium is found to be in a higher reduced state (almost metallic), supported by carbon. The question that remains open in addition to the one related to the formation of galium carbide is whether a complex structure, including oxygen contamination is involved in the layers surrounding the Ga as indicated by the EXAFS results.     

Elevated plasma bile acids in hypergalactosaemic neonates: a diagnostic clue to portosystemic shunts

To determine whether plasma levels of total bile acids may provide a useful index for hypergalactosaemia due to porto-systemic shunts, these levels were determined in hypergalactosaemic neonates. Increased levels were found in all cases with portohepatic venous or portocaval shunts. The levels of both total bile acids and galactose were normalized when the shunts disappeared on the echograms. Both bile acids and galactose are almost completely absorbed by the liver via the first portal blood passage. Portosystemic shunts contribute to elevated levels of bile acids and galactose. CONCLUSION: Increased plasma levels of total bile acids serve as a diagnostic clue to the presence of portosystemic shunts in neonates with hypergalactosaemia.     

The advantages of the lateral decubitus position after spinal anesthesia with hyperbaric tetracaine

Exercise-induced bronchoconstriction (EIB) is widely prevalent in asthmatic patients. Eosinophilic airway inflammation is considered to be a major factor in the pathogenesis of asthma. However, the effects of eosinophilic airway inflammation on EIB have been elucidated insufficiently. To examine the relationship between the severity of EIB and eosinophilic inflammation, sputum induction and exercise challenge were performed in 21 asthmatic patients. Significantly higher percentages of eosinophils and levels of eosinophil cationic protein (ECP) were found in induced sputum in EIB-positive asthmatics (median (range), eosinophils: 23.5 (11.0-61.0)%; ECP: 1,475 (74.8-17,701) ng x mL(-1)) than in EIB-negative asthmatics (eosinophils: 6.0 (1.0-41.5)% (p=0.006); ECP: 270.6 (10.8-7,700) ng x mL(-1) (p=0.049)). There was a significant correlation between the severity of EIB and the sputum eosinophil percentage (r=0.59, p=0.009) and the level of ECP (r=0.47, p=0.037). The area under the curve of the forced expiratory volume in one second for 30 min after exercise correlated with the percentage of eosinophils (r=0.60, p=0.008) and the level of ECP (r=0.45, p=0.04). There was no correlation between airway responsiveness to methacholine on the one hand and EIB, sputum eosinophils or ECP on the other. In conclusion, these results provide evidence that the severity of bronchoconstriction evoked by exercise is more closely related to eosinophilic airway inflammation than airway hyperresponsiveness to methacholine in asthmatic patients.     

Invited article: the fast readout low noise camera as a versatile x-ray detector for time resolved dispersive extended x-ray absorption fine structure and diffraction studies of dynamic problems in materials science, chemistry, and catalysis

Originally conceived and developed at the European Synchrotron Radiation Facility (ESRF) as an "area" detector for rapid x-ray imaging studies, the fast readout low noise (FReLoN) detector of the ESRF [J.-C. Labiche, ESRF Newsletter 25, 41 (1996)] has been demonstrated to be a highly versatile and unique detector. Charge coupled device (CCD) cameras at present available on the public market offer either a high dynamic range or a high readout speed. A compromise between signal dynamic range and readout speed is always sought. The parameters of the commercial cameras can sometimes be tuned, in order to better fulfill the needs of specific experiments, but in general these cameras have a poor duty cycle (i.e., the signal integration time is much smaller than the readout time). In order to address scientific problems such as time resolved experiments at the ESRF, a FReLoN camera has been developed by the Instrument Support Group at ESRF. This camera is a low noise CCD camera that combines high dynamic range, high readout speed, accuracy, and improved duty cycle in a single image. In this paper, we show its application in a quasi-one-dimensional sense to dynamic problems in materials science, catalysis, and chemistry that require data acquisition on a time scale of milliseconds or a few tens of milliseconds. It is demonstrated that in this mode the FReLoN can be applied equally to the investigation of rapid changes in long range order (via diffraction) and local order (via energy dispersive extended x-ray absorption fine structure) and in situations of x-ray hardness and flux beyond the capacity of other detectors.     

Reversed-phase high-performance liquid chromatographic assay method for quantitating 6-mercaptopurine and its methylated and non-methylated metabolites in a single sample

Methods of assaying 6-mercaptopurine (6MP) and its methylated and non-methylated metabolites are essential for the therapeutic dose in treating patients with acute lymphoblastic leukemia. However, previous methods are technically complicated and unsuitable for clinical use. Thus, we have now developed a method utilizing reversed-phase high-performance liquid chromatography (HPLC) in order to quantify these compounds in human red blood cells (RBCs) in a single sample to serve as an index of cytotoxic activity. The agents 6MP, 6-thioguanine (6TG) and 6-methylmercaptopurine (6MMP) were well separated by this assay. Linear relationships were observed between the peak areas and the RBC concentrations of 6MP, 6TG and 6MMP over the range of 20-2000, 18-1800 and 18-1800 pmol per 25 mg hemoglobin (Hb), respectively. The limit of quantitation of the assay is 20, 18 and 18 pmol per 25 mg Hb, respectively. This assay system is suitable for routine clinical use.     

Antinociceptive effects of ONO-9902, an enkephalinase inhibitor, after visceral stress condition in rats

PURPOSE: The present study was designed to examine the antinociceptive effects of orally administered ONO-9902, an enkephalinase inhibitor, on both somatic and visceral pain after visceral stress conditions. METHODS: Twenty six male rats were examined. Tail-flick (TF) and colorectal distension (CD) tests were used to determine somatic and visceral antinociceptive effects, respectively. Measurements were performed in rats under immediate post-stress conditions (group ST; n = 14) and in rats nor under stress conditions (group NST; n = 12). In the stressed group, the same device, CD, for visceral antinociceptive effects was used for visceral stress and was applied with an intracolonic pressure of 60 mmHg for 20 min after drug administration. The TF latency and CD threshold were measured before and at 30, 40, 50, 60 and 90 min after administration of ONO-9902 300 mg.kg-1 or distilled water. RESULTS: Orally administered ONO-9902 did not produce any changes in the % maximum possible effect (%MPE) in either TF or CD tests in the unstressed group. In the stressed group, %MPE in the CD test increased 18% and 31% at 30 and 40 min, respectively, after oral administration of ONO-9902 compared with the control group (P < 0.05). However, %MPE to TF test did not alter even after the CD-induced stress condition. CONCLUSION: These results suggest that ONO-9902 may have analgesic effects on visceral pain but not on somatic pain under immediate post-stress conditions.     

Periodontal inflammatory and cystlike lesions in BDF1 and B6C3F1 mice

Periodontal inflammatory and cystlike lesions were detected in aged BDF1 and B6C3F1 mice. Lesions were unilateral, single, and located in the labial region of the incisor teeth. The largest cystlike lesion deformed the skull. Histologically, the cystlike lesions were classified into three types: predominantly an inflammatory reaction, predominantly a cyst formation, and a mixed lesion. These periodontal inflammatory and cystlike lesions were pathogenetically similar and were considered sequential changes; the lesions showing both cyst formation and inflammatory reaction seemed to be intermediate along a path toward formation of large cysts. The cysts probably were derived from periodontal tissue and developed as a result of inflammatory reaction to foreign bodies, including hair. The term "murine periodontal cyst" is proposed for this lesion. Detailed pathogenetic studies on murine odontogenic cystic lesions may be warranted.