Abundance and diversity of predominant sulfate-reducing bacteria in the gut of pufferfish

Sulfate-reducing bacteria (SRB) exist in anaerobic environments, such as marine sediments, and produce hydrogen sulfide, which is toxic to marine animals. However, little is known about the ecology of SRB in the gut of fish. In the present study, we used molecular techniques to analyze the predominant SRB community in the gut of pufferfish inhabiting coastal areas of Japan. The density of the dissimilatory sulfite reductase alpha gene, dsrA, derived from SRB and total count of bacteria in guts of pufferfish was 4.4í—106 - 1.8í—107 copies/g and 3.5í—108 - 6.3í—109 cells/g, respectively, in all specimens. Clones of dsrA associated with Desulfobulbus oligotrophicus, a dominant SRB species, were detected in all 12 libraries, accounting for 57.7-94.3% of clones in each library. These results strongly suggest that SRB are indigenous bacteria in the gut of pufferfish and that hydrogen sulfide produced by SRB may be a risk factor for fish health

p53 gene mutation analysis in porokeratosis and porokeratosis-associated squamous cell carcinoma

In this and previous studies, we have shown p53 overexpression immunohistochemically in 14 of 17 porokeratotic specimens obtained from 14 lesions of nine cases, and in all six specimens of squamous cell carcinoma (SCC) arising on porokeratotic lesions of two cases. We screened mutations in exons 5 to 10 of the p53 gene in all these specimens by polymerase chain reaction-single strand conformation polymorphism analysis. Mutations of the p53 gene were detected in two of the six SCCs but not in any of the 17 porokeratotic specimens. These two mutations were C to T transitions at codons 146 and 175 in exon 5, which were a nonsense mutation at a dipyrimidine site and a missense mutation at a CG site, respectively. To our knowledge, neither of these mutations has been identified in skin cancers before. Our observations indicate that mutations of the p53 gene are not the major molecular etiology for porokeratosis, but are related to its skin carcinogenesis, and that p53 overexpression in porokeratosis is not due to p53 gene mutations

Slow and Fast Oscillation Electrooculography in Central Retinal Vein Occlusion: A Comparison between Affected Eyes and Fellow Intact Eyes

Using an automated electrooculograph, the Nidek EOG-2, slow and fast oscillations (SO and FO) of an electrooculogram (EOG) were recorded in 21 patients with unilateral, ischemic central retinal vein occlusion (CRVO). Patient age ranged from 49 to 81 years (average: 68 years of age). Fellow eyes in all patients were intact, and served as controls. Results showed that the L/DSO (the light peak/dark trough ratio of the SO), the RfFO [the average ratio in percentage of the maximum amplitude in the dark period (AD)/the minimum amplitude in the light period (AL) during FO measurement], the dfFO (the average difference in ?V between AD and AL), and the df/mFO [the percentage ratio of the dfFO to the average amplitude of AD + AL (m)] were significantly decreased in the affected eyes compared with the fellow eyes. These results suggest that with regard to SO and FO origin and occurrence, the outer layer of the retina, especially the basal membrane of the retinal pigment epithelium or the choroid may be involved in the etiology of CRVO. These findings correlate with the grade of microcirculatory disturbance or ischemia in the inner layer of the retina. Furthermore, a statistically significant difference was detected in the correlation between each FO parameter and corrected visual acuity at the time of examination of the affected eyes. There was no significance between the SO parameter and the visual acuity. Therefore, it might be possible to presume that the FO parameters can be used as indicators for detecting the severity of macular functional disturbance and predicting the visual outcome for this entity

Characteristics of urine spraying and scraping the ground with hind paws as scent-marking of captive cheetahs (Acinonyx jubatus)

Olfactory communication is common in felids. We observed two scent-markings, urine spraying and scraping the ground with hind paws during excretion, of 25 captive cheetahs. We analyzed the association of sniffing with the timing of urine spraying and scraping, and differences in these behaviors based on sex, age, and captive environment to understand the olfactory communication among cheetahs. Both scent-markings were strongly associated with sniffing, especially scraping, and the presence or absence of scent was thought to be a trigger. Both behaviors were observed only in adults; scraping was observed only in males. To our knowledge, this study was first to confirm the discharge of secretions from the anal glands during scraping. The frequencies of both behaviors were significantly higher in males kept in shared enclosures containing other individuals than in males kept in monopolized enclosures, while there was no difference in the frequencies among females. Female cheetahs are solitary and have non-exclusive home range, whereas male cheetahs are either solitary or live in coalition groups and there are territorial and non-territorial males. Our results could be attributed to the differences in sociality between the sexes and effect of the living environment