Skin lipid profiling in normal and seborrhoeic shih tzu dogs

Background – Seborrhoea is a clinical condition resulting in excessive lipid and/or scale on the skin and is a common and important skin disease of dogs. However, there is little information on the skin surface lipid composition of dogs with seborrhoea. Hypothesis/Objectives – To compare skin surface lipid profiles in normal and seborrhoeic shih tzu dogs. Methods – Fourteen client‐owned dogs (seven seborrhoeic and seven normal) were investigated. Lipids in sebaceous glands (SGs) were extracted from homogenized tissues of SG hyperplasia. Surface lipid was collected by tape stripping [stratum corneum (SC)‐enriched fraction] and acetone‐wetted cotton swab (acetone‐extracted fraction). Lipids in SGs, SC‐enriched fractions and acetone‐extracted fractions were evaluated by high‐performance thin‐layer chromatography. Results – Lipids in SGs mainly consisted of cholesterol esters, wax esters and triglycerides, whereas lipids in the SC‐enriched fraction mainly consisted of ceramides. The acetone‐extracted fraction contained a mixture of lipid classes recognized in SG‐ and SC‐enriched fractions. In seborrhoeic dogs, concentrations of wax esters and triglycerides in the acetone‐extracted fraction were significantly higher than in control dogs (P = 0.0285). Amounts of total ceramides (in micrograms) per milligram of SC were not significantly different between the two groups (P = 0.5204). Interestingly, two unknown ceramide fractions, which accounted for 20% of the total ceramides, were recognized exclusively in seborrhoeic dogs. Conclusions and clinical importance – These results provide evidence that the skin surface lipid profiles are altered in shih tzu dogs with seborrhoea.     

Direct visualization of the formation of single-molecule conjugated copolymers

Electrochemical polymerization of two different kinds of thiophene monomers on an iodine-covered gold surface created highly assembled conjugated copolymers with different electronic structures. A scanning tunneling microscope revealed images of several linkage types: diblock, triblock, and multiblock. The single strand of conjugated copolymers exhibited an anomalous swinging motion on the surface. This technique presents the possibility of understanding the copolymerization process from the different monomers on the single-molecular scale and of building single-molecule superlattices on a surface through controlled electropolymerization.     

Spontaneous changes of neocortical code for associative memory during consolidation

After learning, the medial prefrontal cortex (mPFC) gradually comes to modulate the expression of memories that initially depended on the hippocampus. We show that during this consolidation period, neural firing in the mPFC becomes selective for the acquired memories. After acquisition of memory associations, neuron populations in the mPFC of rats developed sustained activity during the interval between two paired stimuli, but reduced activity during the corresponding interval between two unpaired stimuli. These new patterns developed over a period of several weeks after learning, with and without continued conditioning trials. Thus, in agreement with a central tenet of consolidation theory, acquired associations initiate subsequent, gradual processes that result in lasting changes of the mPFC's code, without continued training.     

DDT: inhibition of sodium chloride tolerance by the blue-green alga Anacystis nidulans

Anacystis nidulans, a freshwater blue-green alga, has been found to lerate sodium chloride (1 percent by weight) and DDT [1,1,1-trichloro-2,2-bis chlorophenyl) ethane] (800 parts per billion) separately, but growth was inhibited in the presence of both compounds. This inhibition was reversed by an increased calcium concentration. It is possible that inhibition of (Na+,K+)-activated adenosine triphosphatase) by DDT causes this species to lose the ability to lerate sodium chloride.     

Dependence of self-tolerance on TRAF6-directed development of thymic stroma

The microenvironments of the thymus are generated by thymic epithelial cells (TECs) and are essential for inducing immune self-tolerance or developing T cells. However, the molecular mechanisms that underlie the differentiation of TECs and thymic compartmentalization are not fully understood. Here we show that deficiency in the tumor necrosis factor receptor-associated factor (TRAF) 6 results in disorganized distribution of medullary TECs (mTECs) and the absence of mature mTECs. Engraftment of thymic stroma of TRAF6(-/-) embryos into athymic nude mice induced autoimmunity. Thus, TRAF6 directs the development of thymic stroma and represents a critical point of regulation for self-tolerance and autoimmunity.     

Novel reovirus isolation from an Ostrich (Struthio camelus) in Japan

An orthoreovirus was isolated from an Ostrich (Struthio camelus) and rapidly identified as orthoreovirus by the rapid determination of viral RNA sequences (RDV) system and electron microscopy. Phylogenetic analysis of the sigma A protein indicated that the isolate belonged to avian species and was closely related to chicken orthoreovirus strain 138. The results of the present study indicated that an ostrich orthoreovirus is slight different from other chicken orthoreoviruses and provided evidence of diversity among avian orthoreoviruses. To our knowledge, this is the first genetic report of an orthoreovirus isolated from an ostrich.     

Spontaneous iron accumulation in hepatocytes of a 7-week-old female rat

Spontaneous iron accumulation in hepatocytes was observed in a 7-week-old female Han Wistar GALAS rat. Very fine yellowish brown pigments, which showed a positive reaction with Berlin Blue stain, were apparent in the cytoplasm close to the bile canaliculi, with a diminishing periportal-to-centrilobular gradient. There were also differences in distribution between and within lobes. Transmission electron microscopy revealed cytosolic ferritin and pericanalicular siderosomes in hepatocytes. No degeneration or necrotic changes were observed, and non-hepatocyte cells did not demonstrate any obvious accumulation of iron. There were no abnormalities in the animal other than this finding in the liver.     

Female scent mobilizes leukocytes to airways in BALB/c male mice

The scent of receptive females as a signal to reproduction stimulates male mice to olfactory search of a potential breeding partner. This searching behavior is coupled with infection risk due to bacterial contamination of the fecal and urine scent marks. We hypothesized that sniffing of female soiled bedding induced the migration of immuno‐competent cells into airways as a possible adaptation to breeding‐related infection. Using bronchoalveolar lavage in a study on mice, we found the number of leukocytes to be significantly higher in male mice that were provided new portions of soiled bedding daily from female cages, in comparison with male mice that were kept in isolation from female scent. The number of leukocytes in blood was equal in both groups. However, monocytes were fewer in number in male mice exposed to female scent than in male mice isolated from female mice. Scent‐induced migration of leukocytes was accompanied by typical behavioral (increased sniffing activity and aggressiveness) and morphological (increase preputial glands and seminal vesicles) responses to olfactory sexual stimulus.     

Substitution mapping and characterization of brown planthopper resistance genes from indica rice variety, ‘PTB33’ (Oryza sativa L.)

Rice (Oryza sativa L.) yield is severely reduced by the brown planthopper (BPH), Nilaparvata lugens Stål, in Asian countries. Increasing resistance in rice against BPH can mitigate yield loss. Previous reports indicated the presence of three BPH resistance genes, BPH2, BPH17-ptb, and BPH32, in durable resistant indica rice cultivar ‘PTB33’. However, several important questions remain unclear; the genetic locations of BPH resistance genes on rice chromosomes and how these genes confer resistance, especially with relationship to three major categories of resistance mechanisms; antibiosis, antixenosis or tolerance. In this study, locations of BPH2, BPH17-ptb, and BPH32 were delimited using chromosome segment substitution lines derived from crosses between ‘Taichung 65’ and near-isogenic lines for BPH2 (BPH2-NIL), BPH17-ptb (BPH17-ptb-NIL), and BPH32 (BPH32-NIL). BPH2 was delimited as approximately 247.5 kbp between RM28449 and ID-161-2 on chromosome 12. BPH17-ptb and BPH32 were located between RM1305 and RM6156 on chromosome 4 and RM508 and RM19341 on chromosome 6, respectively. The antibiosis, antixenosis, and tolerance were estimated by several tests using BPH2-NIL, BPH17-ptb-NIL, and BPH32-NIL. BPH2 and BPH17-ptb showed resistance to antibiosis and antixenosis, while BPH17-ptb and BPH32 showed tolerance. These results contribute to the development of durable BPH resistance lines using three resistance genes from ‘PTB33’.