Fine structure of the dorsal epithelium of the tongue of the freshwater turtle,Geoclemys reevesii (Chelonia,Emydinae)

Scanning electron microscopy shows that lingual papillae occur all over the dorsal surface of the tongue of the freshwater turtle, Geoclemys reevesii. The surface of each papilla is composed of compactly distributed hemispherical bulges, each composed of a single cell. Microvilli are widely distributed over the surface of cells. Histological examination reveals that the connective tissue penetrates deep into the center of papillae and that the epithelium is stratified columnar. Under the transmission electron microscope, the cells of the basal and the deep intermediate layers of the epithelium appear rounded. A large nucleus lies in the central area of each cell. The cytoplasm contains mitochondria, endoplasmic reticulum and free ribosomes. The cell membrane form numerous processes. The shallow intermediate layer contains two types of cell. The cytoplasm of the first has numerous fine granules, in addition to mitochondria, ribosomes, and endoplasmic reticulum. The other type of cell contains highly electron-dense granules. The surface layer shows two cell types. One type consists of typical mucous cells. The other type of cell contains fine, electron-lucent granules. The latter cells lie on the free-surface side, covering the mucous cells, and have microvilli on their free surfaces.     

Humans but Not Chimpanzees Vary Face-Scanning Patterns Depending on Contexts during Action Observation

Human and nonhuman primates comprehend the actions of other individuals by detecting social cues, including others’ goal-directed motor actions and faces. However, little is known about how this information is integrated with action understanding. Here, we present the ontogenetic and evolutionary foundations of this capacity by comparing face-scanning patterns of chimpanzees and humans as they viewed goal-directed human actions within contexts that differ in whether or not the predicted goal is achieved. Human adults and children attend to the actor’s face during action sequences, and this tendency is particularly pronounced in adults when observing that the predicted goal is not achieved. Chimpanzees rarely attend to the actor’s face during the goal-directed action, regardless of whether the predicted action goal is achieved or not. These results suggest that in humans, but not chimpanzees, attention to actor’s faces conveying referential information toward the target object indicates the process of observers making inferences about the intentionality of an action. Furthermore, this remarkable predisposition to observe others’ actions by integrating the prediction of action goals and the actor’s intention is developmentally acquired.     

How to discriminate between vibration syndrome and local fatigue of motorcyclists

Motorcyclists who work in some offices sometimes complained of coldness, pain and numbness of upper limbs. We studied how to discriminate between vibration syndrome and local fatigue of the motorcyclists. Subjects are 42 motorcyclists of an office in Aichi prefecture. 25 of them held several letters in their left hand when they delivered the letters. They complained of coldness, pain and numbness in the left upper limbs more than in the right limbs (p less than 0.01). We think that it is the local fatigue rather than the disorder of vibration syndrome that causes such symptoms. So it is very important to recognize the existence of local fatigue in order to know how to discriminate between vibration syndrome and local fatigue of the motorcyclists.     

Immunogold Labeling of Terminal Cellulose-Synthesizing Complexes

Received 20 September 2001/ Accepted in revised form 10 October 2001     

Correction to: Herding mechanisms to maintain the cohesion of a harem group: two interaction phases during herding

Journal of Ethology - The article Herding mechanisms to maintain the cohesion of a harem group.     

Protective effect of sulfhydryl compounds on acute toxicity of morphinone

The ability of sulfhydryl compounds to provide protection against the acute toxicity of morphinone was investigated in mice. Subcutaneous administration of morphinone produced a reduction of hepatic non-protein sulfhydryl concentration. Pretreatments of mice with glutathione or cysteine significantly increased the survival rate of mice given a lethal dose of morphinone, whereas morphinone lethality was markedly potentiated by diethyl maleate. On the other hand, the administration of morphine produced a dose dependent reduction of hepatic non-protein sulfhydryl contents. However, neither glutathione nor cysteine protected mice from the acute toxicity of morphine. A possible explanation for these observations was proposed as follows: morphine is oxidized by morphine 6-dehydrogenase to morphinone, and the morphinone thus produced decreases the sulfhydryl contents in the liver. This mechanism is supported by the fact that morphinone reacts easily with glutathione and cysteine $\text{in vitro}$.     

Antimicrobial Susceptibility of Clostridium difficile from Different Sources

A total of 79 Clostridium difficile strains from healthy young and elderly adults, elderly patients without gastrointestinal disease, elderly patients receiving antibiotics without gastrointestinal complications, and elderly patients with antibiotic-associated diarrhea or pseudomembranous colitis were tested for their susceptibilities to 24 antimicrobial agents. All of the 79 strains were inhibited by low concentrations of rifampicin, metronidazole, fusidic acid, vancomycin, ampicillin, and penicillin G. The strains were highly resistant to aminoglycosides, trimethoprim, sulfamethoxazole, nalidixic acid, and cycloserine and often resistant to neomycin, cefoxitin, and cefalexin. Wide variations in the susceptibility of C. difficile strains to erythromycin, clindamycin, lincomycin, chloramphenicol, and tetracycline were found. Strains resistant to erythromycin, clindamycin, and lincomycin were more frequently found among strains isolated from elderly adults than those isolated from young adults, with particularly high frequency among strains isolated from elderly patients receiving antibiotics. None of the 23 strains isolated from healthy young adults was resistant to chloramphenicol. All of the 14 strains resistant to erythromycin, clindamycin, lincomycin, and chloramphenicol were sensitive to tetracycline and all of the 15 strains resistant to erythromycin, clindamycin, lincomycin, and tetracycline were sensitive to chloramphenicol. Only one out of 19 tetracycline-resistant strains was highly toxigenic, whereas 42 (70%) of 60 sensitive strains were highly toxigenic.     

The carpal tunnel syndrome as a probable primary deficiency of vitamin B6 rather than a deficiency of a dependency state

The mean basal specific activities and the mean % deficiencies of the activity of the glutamic oxaloacetic transaminase of the erythrocytes were identical (n.s.) for a group of eight patients with a severe carpal tunnel syndrome and for a group of eight university students. There was no significant difference in the increases in the specific activities for the patients and the students at 4 concentrations of pyridoxal 5′-phosphate. The apparent K_m for the patients and the students was 95 μM and 61 μM (n.s.) respectively. It is concluded from these data in conjunction with previous findings that the carpal tunnel syndrome is a deficiency disease of vitamin B₆, which is probably primary rather than one of a dependency state.     

The effect of pyrazines on the metabolism of tryptophan and nicotinamide adenine dinucleotide in the rat Evidence of the formation of a potent inhibitor of aminocarboxy-muconate-semialdehyde decarboxylase from pyrazinamide

The intraperitoneal or oral administration of pyrazinamide and pyrazinoic acid (pyrazine 2-carboxylic acid) resulted in a marked increase of the NAD content in rat liver. The injections of pyrazine and pyrazine 2,3-dicarboxylic acid exhibited no significant effect on the hepatic NAD content. The boiled extract obtained from liver and kidney of rat injected with either pyrazinamide or pyrazinoic acid exhibited a potent inhibitory effect on the aminocarboxymuconate-semialdehyde decarboxylase (EC 4.1.1.45) activity in either liver or kidney, although pyrazinamide or pyrazinoic acid per se did not inhibit the enzyme activity. The unknown inhibitor of aminocarboxymuconate-semialdehyde decarboxylase was dialysable and heat-stable, and mostly excreted in urine by 6 and 12 h after injection of pyrazinoic acid and pyrazinamide, respectively. Pyrazine 2,3-dicarboxylic acid, pyrazine, nicotinamide, nicotinic acid, tryptophan, anthranilic acid, 5-hydroxyanthranilic acid and quinolinic acid exhibited no significant effect on the aminocarboxymuconate-semialdehyde decarboxylase activity in liver and kidney at the concentration of 1 mM in the reaction mixture. The expired ¹⁴CO₂ from l-[benzen ring-U-¹⁴C]tryptophan was markedly decreased by the pyrazinamide injection, while the urinary excretion of ¹⁴C-labeled metabolites from l-tryptophan, mainly quinolinic acid, was markedly increased. These results suggest that the glutarate pathway of l-tryptophan was strongly inhibited by the inhibitor produced after the administration of pyrazinoic acid and pyrazinamide. Pyrazinamide but not pyrazinoic acid also exhibited a significant inhibition of the nuclear enzyme poly(ADP-ribose) synthetase in rat liver.