Pyrolysis behavior of levoglucosan as an intermediate in cellulose pyrolysis: polymerization into polysaccharide as a key reaction to carbonized product formation

Pyrolysis behavior of levoglucosan (1,6-anhydro--d-glucopyranose), the major anhydromonosaccharide formed during cellulose pyrolysis, was studied at 250°–400°C under nitrogen. The pyrolysis products were found to change stepwise: levoglucosan MeOH-soluble fraction (lower-molecular-weight products and oligosaccharides) water-soluble fraction (polysaccharides) insoluble fraction (carbonized products). From the present experimental results, a pathway of cellulose pyrolysis via anhydromonosaccharide is proposed including polymerization to polysaccharides (a reversible reaction) as a key reaction to carbonized product formation.Part of this study was presented at the XIXth International Carbohydrate Symposium, San Diego, August 1998; and the 50th Annual Meeting of the Japan Wood Research Society, Kyoto, April 2000     

Expression of genes related to corticotropin production and glucocorticoid feedback in corticotroph adenomas of dogs with Cushing's disease

Cushing's disease caused by pituitary corticotroph adenoma is a common endocrine disease in dogs. A characteristic biochemical feature of corticotroph adenomas is their relative resistance to negative feedback by glucocorticoids. In this study, we examined gene expression related to adrenocorticotropic hormone (ACTH) production and secretion, and the negative feedback by glucocorticoids in canine corticotroph adenoma. We used resected corticotroph adenomas from 10 dogs with Cushing's disease. In order to investigate the alteration of gene expression between corticotroph adenoma and normal corticotrophic cells, ACTH-positive cells in the anterior lobe were microdissected using a laser-capture microdissection system, and mRNA levels of proopiomelanocortin (POMC), corticotropin releasing hormone receptor 1 (CRHR1), glucocorticoid receptor (GR), mineralocorticoid receptor (MR), and 11 beta hydroxysteroid dehydrogenase (11HSD) type 1 and type 2 were determined using real-time RT-PCR. POMC, CRHR1, and 11HSD2 mRNA levels in corticotroph adenoma were greater than those in normal corticotrophic cells (POMC, 5.5-fold; CRHR1, 4.9-fold; 11HSD2, 4.2-fold, P<0.01, respectively). MR and 11HSD1 mRNA levels in corticotroph adenoma were lower than those in normal corticotrophic cells (MR, 2.2-fold; 11HSD1, 2.9-fold, P<0.01, respectively). GR mRNA levels did not differ between corticotroph adenoma and normal corticotrophic cells. Our results may help to understand the increased ACTH production and the resistance to negative feedback suppression by glucocorticoids in canine corticotroph adenomas. These changes in gene expression may have a role in the growth of canine corticotroph adenoma, and help elucidate the pathophysiology of dogs with Cushing's disease.     

Superficial necrolytic dermatitis associated with extrapancreatic glucagonoma in a dog

An 11-year-old Shih Tzu presented with crusting and erythema, mainly on the abdomen and the root of the tail. Based on histopathological findings, blood examinations and necropsy findings, the condition was diagnosed as superficial necrolytic dermatitis associated with a glucagon-secreting extrapancreatic neuroendocrine tumour. Gross necropsy revealed tumour invasion into the spleen, liver, adrenal glands and mesenteric lymph nodes. Immunohistochemical analysis of the neoplastic cells revealed that the tumour was a glucagonoma, consistent with earlier findings of persistent glucagonaemia and hypoaminoacidaemia.     

Measurement of erythrocyte carbonic anhydrase isozymes (CA-I and CA-II) in racehorses and riding horses

Equine carbonic anhydrase isozymes (CA-I and CA-II) were purified from erythrocytes by several column chromatography. Polyclonal anti-CA-I and anti-CA-II sera were produced in rabbits. Sensitive competitive enzyme-linked immunosorbent assays (ELISA) were established to determine the developmental changes in CA-I and CA-II levels in equine erythrocytes. Concentrations of CA-I and CA-II in erythrocytes from 150 clinically normal thoroughbreds (123 racehorses and 27 riding horses) were determined by ELISA. Mean (+/- SD) concentrations of CA-I and CA-II in racehorses were 1.70 +/- 0.48 and 0.94 +/- 0.13 mg/g hemoglobin (Hb), respectively. Mean concentrations of CA-I and CA-II in riding horses were 2.34 +/- 0.52 and 0.76 +/- 0.08 mg/g Hb, respectively. When the CA levels in racehorses and riding horses were compared, the CA-I level in riding horses was higher than that in racehorses (p=0.01). The CA-II level in racehorses was higher than that in riding horses (p=0.02). These data suggest that the levels of CA isozymes in erythrocytes of racehorses were influenced by chronic physical stress. The CA-I concentration in erythrocytes of 2-month-old horses was approximately 0.25 mg/g Hb. The CA-I level noticeably increased during the first year of life and approached normal adult levels by 2 years. The CA-II level decreased slightly with age, indicating different regulation of CA-I and CA-II expression during development.     

Enzyme-linked immunosorbent assay for the detection of canine Leptospira antibodies using recombinant OmpL1 protein

OmpL1 is a 31-kDa outer membrane protein characterized in 1993 and known to be expressed only in pathogenic Leptospira spp. Recombinant OmpL1 (GST-rOmpL1) was expressed for use as an ELISA antigen for the detection of anti-Leptospira antibodies. In immunoblot analysis, the protein reacted with sera of dogs infected with three different serotypes of Leptospira interrogans, while did not react with sera of dogs both uninfected negative controls and infected with Borrelia burgdorferi, which is closely related to Leptospira spp. Moreover, in ELISA using GST-rOmpL1, the optical density (O.D.) values from the positive controls were very high (1.125 +/- 0.549). In contrast, the O.D. values from clinically healthy dogs and dogs with diseases other than leptospirosis were very low (0.109 +/- 0.046 and 0.089 +/- 0.046, respectively). These data suggest that the detection of anti-Leptospira antibodies by ELISA using the GST-rOmpL1 protein can be applied for diagnosis of canine leptospirosis.     

Detection of DNA of 'Candidatus Mycoplasma haemominutum' and Spiroplasma sp. in unfed ticks collected from vegetation in Japan

DNA fragments of 'Candidatus Mycoplasma haemominutum', a feline heamobartonella pathogen, were detected from unfed Ixodes ovatus collected from vegetation in Hokkaido, Fukushima and Yamaguchi Prefectures, and unfed Haemaphysalis flava in Yamaguchi Prefecture. This finding suggests that ixodid tick is a possible vector of 'C. Mycoplasma haemominutum'. Spiroplasma DNA was also detected from unfed I. ovatus in Hokkaido, Fukushima and Yamaguchi Prefectures. The analysis of nucleotides sequence suggested that this Spiroplasma was distinct from registered species.     

Equine pyoderma associated with malnutrition and unhygienic conditions due to neglect in a herd

Twelve horses kept at a riding club suffered from pyoderma. All the horses displayed crusting, scaling and alopecia. The lesions were distributed in the chest, back, rump and limbs. Some of the horse patients also showed epilation with an attached crust similar to a 'paintbrush lesion' of dermatophilosis, but normal skin flora or opportunistic pathogenic bacteria were only isolated from the lesions. Some patients clearly showed weight loss, anemia and low levels of serum protein and cholesterol. General condition and skin lesions of the patients were improved gradually with improvement of feed and environment after being moved to new stables. Malnutrition under conditions of poor hygiene and poor management due to neglect might be associated with these equine cases of pyoderma in the herd.     

Detection of the anti-P53 antibodies in dogs with tumors

To detect the anti-P53 antibodies of dogs with tumors, a GST-recombinant canine (rc) P53 fusion protein was expressed and purified. Immunoblot analysis was performed using this GST-rcP53 fusion protein as an antigen and serum samples from dogs suffering from tumors as primary antibodies. Out of 16 serum samples obtained from various tumor cases, four samples showed reaction with GST-rcP53. In contrast, serum from other 12 dogs with tumors, four dogs with non-neoplastic diseases and two control healthy dogs (as controls) did not show any reaction with GST-rcP53 in immunoblotting. The p53 gene mutation and the P53 protein expression were examined, using the tumor tissues to explore the relationship between the existence of the GST-rcP53 bands, gene mutations of p53 and the accumulation of P53 protein. One case, which showed a clear GST-rcP53 band, had a point mutation of the p53 cDNA and showed nuclear accumulation of P53 protein. These results suggest that the anti-P53 antibodies are also produced in tumor dogs with p53 gene mutations.     

Analysis of the 18S rRNA gene sequence of a Hepatozoon detected in two Japanese dogs

Partial sequences of the 18S rRNA gene (625 bp) from a Hepatozoon detected in two canine hepatozoonosis cases, one clinical and one subclinical, in Japan were analyzed. Both sequences were identical to each other and they were closely related to the Hepatozoon canis strain found in Israel with 99% (617/625) nucleotide identity. Both Hepatozoon americanum and Hepatozoon catasbianae were distantly related to the Japanese Hepatozoon with 94% (586/625) and 91% (566/625) identities, respectively. In a phylogenetic tree, the Japanese Hepatozoon was most closely related to H. canis from Israel but was significantly different than H. americanum and H. catasbianae. These results suggest that the Hepatozoon detected in the Japanese dogs might be a strain variant of H. canis, but is apparently a different species than H. americanum.