Sodium temperature/wind lidar based on laser-diode-pumped Nd:YAG lasers deployed at Tromsø, Norway (69.6°N, 19.2°E).

An Nd:YAG laser-based sodium temperature/wind lidar was developed for the measurement of the northern polar mesosphere and lower thermosphere at Tromsø (69.6N, 19.2E), Norway. Coherent light at 589 nm is produced by sum frequency generation of 1064 nm and 1319 nm from two diode laser end-pumped pulsed Nd:YAG lasers. The output power is as high as 4W, with 4 mJ/pulse at 1000 Hz repetition rate. Five tilting Cassegrain telescopes enable us to make five-direction (zenith, north, south, east, west) observation for temperature and wind simultaneously. This highly stable laser system is first of its kind to operate virtually maintenance-free during the observation season (from late September to March) since 2010.

Isolation and characterization of a high molecular weight type IV collagenase isolated from human carcinoma tissue.

A proform of high molecular weight type IV collagenase was isolated and purified 1230-fold from human metastatic carcinoma tissue. Like matrix metalloproteinases (MMPs), the enzyme was activated by trypsin and degraded type IV collagen and gelatin at a neutral pH, the activity was inhibited by EDTA and o-phenanthroline. However, the molecular weight was much higher than MMPs which degraded type IV collagen, gelatinase A (MMP-2; 72 kDa gelatinase/type IV collagenase) (EC 3.4.24.24), gelatinase B (MMP-9; 92 kDa gelatinase/type IV collagenase) (EC 3.4.24.35), stromelysin-1 (MMP-3; 57 kDa) (EC 3.4.24.17) and stromelysin-2 (MMP-10; 57 kDa) (EC 3.4.24.22). The other significant difference from MMPs was that the enzyme was not activated by 4-aminophenylmercuric acetate nor inhibited by TIMP. Taking together these results, this high molecular weight type IV collagenase might be a newly found enzyme different from MMPs or might have the same configuration as MMPs already reported.

Influence of fecal anorexigenic substance (FS-T) on plasma amino acids in Wistar and Zucker obese (fa/fa) rats.

An anorexigenic substance (FS-T), found in feces, isolated and injected intraperitoneally, induced significant feeding suppression in Wistar rats and in genetically obese Zucker rats (fa/fa) and their lean littermates. The concentration of total plasma amino acids 2 h after FS-T injection (the time of maximum feeding suppression) was 71.0, 68.6 and 60.2% of that of controls for Wistar and Zucker obese and lean rats, respectively. By 48 h after injection of FS-T, food intake and the concentration of total plasma amino acids had returned to normal. Plasma tryptophan levels and the ratio of tryptophan to neutral amino acids were also monitored to elucidate the relation between FS-T and appetite. Two h after injection of FS-T, the ratio of tryptophan to neutral amino acids had increased in Wistar rats, while no change was detected in either obese or lean Zucker rats. However, no change was observed in plasma glucagon levels in Wistar rats, but a significant increase was found in both obese and lean Zucker rats at 2 h after FS-T injection.

Impaired hypophagia induced by fecal anorexigenic substance in Zucker obese rats.

Influence of fecal anorexigenic substance (FS-T) on feeding by Zucker obese rats was compared to that by their lean littermates and Wistar King A rats. FS-T, which has been found to suppress food intake mainly by activation of glucoreceptor neurons in the ventromedial hypothalamus, was injected intraperitoneally in a dose of 7 U/kg at 1930 hr, immediately before the dark period. Potency of FS-T in feeding suppression was much less in the obese rats than in their lean littermates or the Wistar King A rats. Meal size of the obese rats was decreased after the injection, but meal duration was unaffected. The suppressive effect on the lean rats and the Wistar King A rats included decrease of both size and duration of the meal. These results suggest that chemosensitivity in the ventromedial hypothalamus of Zucker obese rats may be impaired, which may be one explanation of the obesity in Zucker obese rats.

Feeding suppression induced by a fecal anorexigenic substance (FS-T).

Intraperitoneal (IP) injection of a fecal anorexigenic substance (FS-T) induced significant suppression of feeding and this suppression recovered on the second day. At 2 hr after IP injection, at the time of maximum feeding suppression, plasma glucose, insulin and free fatty acid (FFA) levels did not change but amino acid level decreased. Intra-third cerebral ventricle (ICV) infusion of FS-T induced parallel but more potent feeding suppression. Analysis of meal patterns demonstrated that suppression of feeding after ICV treatment continued into the second day. FS-T was applied electrophoretically to glucose-sensitive and non glucose-sensitive neurons in the lateral hypothalamic area (LHA) and to glucoreceptor and non glucoreceptor neurons in the ventromedial hypothalamic nucleus (VMH). It significantly inhibited glucose-sensitive neurons but not non glucose-sensitive neurons, and excited both neuron types in the VMH. FS-T might thus work directly through the hypothalamic feeding control centers to suppress feeding. Even after pronase treatment of FS-T, a non-dialysable fraction of large molecular weight, consisting of protein and carbohydrate, maintained the original anorexigenic activity.

Anorexigenic substance isolated from feces of rat and mouse.

A substance was isolated from the feces of conventional rats and mice which were fed laboratory diets. Marked reduction in food intake occurred for a few hours after intraperitoneal administration of this substance, while water intake also decreased. Two hr after the injection, when the anorectic effect appeared to be the strongest, no change was found in body temperature or blood glucose, but free amino acids in plasma were decreased. A comparative study using germfree and conventional mice indicated that the anorexigenic substance was produced by gastrointestinal microflora, since the yields of the anorexigenic substance from germfree mice was less than one tenth of that from conventional mice. A partially purified form of the substance, with large molecular weight, was isolated by Sephadex G-150 fractionation. It contained protein but the anorexigenic activity was not diminished by protein digestion.