Isolation and identification methods of enterobacteria group and its technological advancement

In the last half-century, isolation and identification methods of enterobacteria groups have markedly improved by technological advancement. Clinical microbiology tests have changed overtime from tube methods to commercial identification kits and automated identification. Tube methods are the original method for the identification of enterobacteria groups, that is, a basically essential method to recognize bacterial fermentation and biochemical principles. In this paper, traditional tube tests are discussed, such as the utilization of carbohydrates, indole, methyl red, and citrate and urease tests. Commercial identification kits and automated instruments by computer based analysis as current methods are also discussed, and those methods provide rapidity and accuracy. Nonculture techniques of nucleic acid typing methods using PCR analysis, and immunochemical methods using monoclonal antibodies can be further developed.     

Large Na+ influx and high Na+, K+–ATPase activity in mitochondria-rich epithelial cells of the inner ear endolymphatic sac

Fluid in the mammalian endolymphatic sac (ES) is connected to the endolymph in the cochlea and the vestibule. Since the dominant ion in the ES is Na(+), it has been postulated that Na(+) transport is essential for regulating the endolymph pressure. This study focused on the cellular mechanism of Na(+) transport in ES epithelial cells. To evaluate the Na(+) transport capability of the ES epithelial cells, changes in intracellular Na(+) concentration ([Na(+)](i)) of individual ES cells were measured with sodium-binding benzofurzan isophthalate in a freshly dissected ES sheet and in dissociated ES cells in response to either the K(+)-free or ouabain-containing solution. Analysis of the [Na(+)](i) changes by the Na(+) load and mitochondrial staining with rhodamine 123 showed that the ES cells were classified into two groups; one exhibited an intensive [Na(+)](i) increase, higher Na(+), K(+)-ATPase activity, and intensive mitochondrial staining (mitochondria-rich cells), and the other exhibited a moderate [Na(+)](i) increase, lower Na(+), K(+)-ATPase activity, and moderate mitochondrial staining (filament-rich cells). These results suggest that mitochondria-rich ES epithelial cells (ca. 30% of ES cells) endowed with high Na(+) permeability and Na(+), K(+)-ATPase activity potentially contribute to the transport of Na(+) outside of the endolymphatic sac.     

Al-type generalized amyloidosis showing a solitary duodenal tumor.

An amyloid tumor of the duodenum is a rare occurrence. A patient who presented with epigastric discomfort, in whom a barium meal study revealed a tumor of the duodenum is described. Upper gastrointestinal endoscopy showed a submucosal location of the tumor, and examination of a biopsy revealed amyloid deposition of the AL type. Diffuse tumor involvement of adjacent tissues of the duodenum and also deposits of amyloid fibrils in the liver and skin with no evidence of a chronic pre- existing disease in the patient led to the diagnosis of primary systemic amyloidosis. The distinguishing feature of this case was the formation of a solitary and relatively large tumor in the duodenum mimicking a submucosal tumor, which is in contrast to most reported cases of multiple and smaller amyloid tumors in other parts of the gastrointestinal tract.     

Accumulation of heat-labile elongation factor 2 in the liver of mice and rats

Age-related changes of polypeptide chain elongation factor 2 (EF-2) in mouse and rat livers were investigated. The percentage of heat-labile components in EF-2 was 5 to 10% in young animals and 15 to 40% in old ones. These results and other findings (Takahashi et al., in press) support the idea that decrease in translational activity in old animals is due, in part, to alterations of protein components of the translational system.     

A case of eosinophilic gastroenteritis complicated with ileus and ascites collection]

A 30-year-old woman was admitted to our hospital because of ileus and ascites. Laboratory data on admission demonstrated marked eosinophilia (42.5% of WBC) but negative CRP-value. Abdominal CT showed marked ascites and diffuse thickening of intestinal walls. Ascites examination revealed eosinophilic ascites. The level of IL-5 both in the serum and in the ascites were also high. No evidence of eosinophilic infiltration was noted both gastric and colonic mucosal biopsy specimens. Oral prednisolone treatment (50 mg/day) was effective for her. We diagnosed her as a case of sub-serosal type eosinophilic gastroenteritis. It is essential to obtain eosinophilic ascites for correct diagnosis of the disease. And it is possible that serum and ascites IL-5 value would be reliable indicator of the activity of this disease.     

Histamine synthesis is required for granule maturation in murine mast cells

Mast cells are the major sources of histamine, which is released in response to immunological stimulations. The synthesis of histamine is catalyzed by histidine decarboxylase (HDC). Previous studies have shown that Hdc^?/? mast cells exhibit aberrant granule morphology with severely decreased granule content. Here, we investigated whether the histamine synthesized in mast cells regulates the granule maturation of murine mast cells. Several genes, including those encoding granule proteases and enzymes involved in heparin biosynthesis, were downregulated in Hdc^?/? peritoneal mast cells. Impaired granule maturation was also found in Hdc^?/? BM‐derived cultured mast cells when they were cocultured with fibroblasts in the presence of c‐kit ligand. Exogenous application of histamine and several H₄ receptor agonists restored the granule maturation of Hdc^?/? cultured mast cells. However, the maturation of granules was largely normal in Hrh4^?/? peritoneal mast cells. Depletion of cellular histamine with tetrabenazine, an inhibitor of vesicular monoamine transporter‐2, did not affect granule maturation. In vivo experiments with mast cell deficient Kit^W/Kit^W‐v mice indicated that the expression of the Hdc gene in mast cells is required for granule maturation. These results suggest that histamine promotes granule maturation in mast cells and acts as an proinflammatory mediator.