Chromosomal mapping of 170 BAC clones in the ascidian Ciona intestinalis

The draft genome ( approximately 160 Mb) of the urochordate ascidian Ciona intestinalis has been sequenced by the whole-genome shotgun method and should provide important insights into the origin and evolution of chordates as well as vertebrates. However, because this genomic data has not yet been mapped onto chromosomes, important biological questions including regulation of gene expression at the genome-wide level cannot yet be addressed. Here, we report the molecular cytogenetic characterization of all 14 pairs of C. intestinalis chromosomes, as well as initial large-scale mapping of genomic sequences onto chromosomes by fluorescent in situ hybridization (FISH). Two-color FISH using 170 bacterial artificial chromosome (BAC) clones and construction of joined scaffolds using paired BAC end sequences allowed for mapping of up to 65% of the deduced 117-Mb nonrepetitive sequence onto chromosomes. This map lays the foundation for future studies of the protochordate C. intestinalis genome at the chromosomal level.     

Implications for induction of autoimmunity via activation of B-1 cells by Helicobacter pylori urease

Besides various gastroduodenal diseases, Helicobacter pylori infection may be involved in autoimmune disorders like rheumatoid arthritis (RA) or idiopathic thrombocytopenic purpura. Such autoimmune disorders are often associated with autoreactive antibodies produced by B-1 cells, a subpopulation of B lymphocytes. These B-1 cells are mainly located in the pleural cavity or mucosal compartment. The existence of H. pylori urease-specific immunoglobulin A (IgA)-producing B cells in the mucosal compartment and of their specific IgM in the sera of acutely infected volunteers suggests the possibility that urease stimulates mucosal innate immune responses. Here, we show for the first time that purified H. pylori urease predominantly stimulates the B-1-cell population rather than B-2 cells, which produce antigen-specific conventional antibodies among splenic B220(+) B cells. The fact that such stimulation of B-1 cells was not affected by the addition of polymyxin B indicates that the effect of purified H. pylori urease was not due to the contamination with bacterial lipopolysaccharide. Furthermore, the production of various B-1-cell-related autoreactive antibodies such as IgM-type rheumatoid factor, anti-single-stranded DNA antibody, and anti-phosphatidyl choline antibody was observed when the splenic B cells were stimulated with purified H. pylori urease in vitro. These findings suggest that H. pylori components, urease in particular, may be among the environmental triggers that initiate various autoimmune diseases via producing autoreactive antibodies through the activation of B-1 cells. The findings shown here offer important new insights into the pathogenesis of autoimmune disorders related to H. pylori infection.     

Dose-responsive alteration in hepatic lipid peroxidation and retinol metabolism with increasing dietary beta-carotene in iron deficient rats

Phosphatidylcholine hydroperoxide (PCOOH) levels are increased in the iron-deficient rat liver. We investigated the antioxidative effect of dietary beta-carotene and altered retinol metabolism in iron-deficient rats. Experiment 1: Male Wistar-strain rats were divided into six groups and fed a control diet, an iron-deficient diet, and iron-deficient diets with four different levels of dietary beta-carotene. The PCOOH concentration in the iron-deficient rat liver was decreased by supplementation with dietary beta-carotene. However, the beta-carotene dose response was not related to antioxidative potency. Hepatic and plasma beta-carotene concentrations were increased by iron deficiency. The hepatic retinol concentration was increased while the plasma retinol concentration was decreased in iron-deficient rats. Experiment 2: Male Wistar-strain rats were divided into two groups, with one group receiving a control diet with beta-carotene and the other an iron-deficient diet with beta-carotene. Intestinal iron was decreased and intestinal beta-carotene was unchanged in iron-deficient rats. The intestinal beta-carotene conversion ratio and beta-carotene cleavage enzyme activity were decreased in iron-deficient rats. Dietary beta-carotene played the role of an antioxidant in hepatic lipid peroxidation in the iron-deficient state, but there was no dose dependency. Moreover, intestinal beta-carotene cleavage and hepatic retinol release appear to be altered in iron-deficient rats.     

Accuracy and precision of a system for assessing severity of tooth wear

PURPOSE: The purpose of this study was to introduce a computer-assisted quantitative tooth wear-analyzing system and test its accuracy and precision. MATERIALS AND METHODS: An image of a horizontally projected dental arch was captured, and the facet area of each tooth was calculated using a digital image analyzer. For normalization, the facet area of the individual tooth was divided by the total area of the corresponding tooth; this result was the tooth wear score. The accuracy and precision of this method were determined through the intraclass correlation coefficient using 10 dental casts. Tooth wear on the dental casts of 50 subjects was actually measured. RESULTS: The accuracy of the tooth wear score determined by a newly trained examiner was greater than 0.85 of the intraclass correlation coefficient; this was tested against the score determined by consensus of three experienced examiners. The reproducibility within a 1-week interval was also greater than 0.85. With regard to the tooth wear score from 50 sets of dental casts, the distribution of tooth wear was generally consistent with data reported in the literature. CONCLUSION: The results suggest that the newly trained examiner can exhibit adequate accuracy and precision after appropriate training in identifying tooth wear facets. Recorded data from 50 subjects added face validity to this new system.     

Small lung tumors with the size of 1cm or less in diameter: clinical, radiological, and histopathological characteristics

BACKGROUND: The detection rate of small nodules in the peripheral lung area is increasing due to the widespread use of CT scanning. However, the radiological and pathological characteristics of very small tumors have not been fully investigated. METHODS: We evaluated 44 lung tumors with the size of 1cm or less in diameter resected from 38 patients (19 men and 19 women, with an average of 62 years) from 1997 through 2001. The clinical records, the findings of high-resolution CT (HRCT) and histopathological features of resected specimens were analyzed. Adenocarcinoma was histologically further subclassified into types A to F according to the Noguchi's classification. RESULTS: Lobectomy was performed in 20 patients, wedge resection in 15 and segmentectomy in 3, respectively. Thirty-two tumors were adenocarcinomas, 4 were squamous cell carcinomas, and eight were atypical adenomatous hyperplasia (AAH), respectively. All carcinoma cases were proved to be stage IA. In adenocarcinoma, type A was detected in 12 tumors, type B in 13, type C in 1, type D in 2, type E in 1, and type F in 3, respectively. Most of AAH and type A showed pure ground-glass attenuation on HRCT scan, whereas types B to F as well as squamous cell carcinoma frequently had malignant CT signs such as lobulation and convergence of peripheral vessels. Lymphatic or vascular invasion was observed in two adenocarcinomas (types D and F) and two squamous cell carcinomas, and HRCT scan of these four tumors showed soft-tissue attenuation occupying more than two-thirds of each nodule. All patients are currently alive without signs of recurrence after a mean follow-up period of 35.5 months. CONCLUSION: Types A and B of adenocarcinoma were the most common histologic types among lung tumors with the size of 1cm or less in diameter. Limited lung resection appears to be an adequate for such small lung tumors in which soft-tissue attenuation consists of less than two-thirds of the nodule on HRCT.     

Focal segmental membranoproliferative glomerulonephritis in children

Eight patients with focal segmental membranoproliferative glomerulonephritis (FSMPGN) were followed for 5–16 years. Their urinary abnormalities were detected by school urinary screening in seven, and one patient presented with nephrotic syndrome. All but one patient were treated with alternate-day (ALD) prednisolone. With time, urinalysis became normal in six and two continued to have proteinuria with or without hematuria. Serum albumin, cholesterol, and creatinine levels were normal at the last follow-up. Serum C3 returned to normal levels in six, but remained persistently decreased in two. Mesangial proliferation and matrix changes in glomeruli without MPGN lesions were mild. Subendothelial and mesangial electron-dense deposits and deposits containing C3 along capillary walls and mesangium were observed. MPGN lesions and mesangial proliferation improved. No severe growth retardation was observed, but the duration and dosage of ALD prednisolone could be reduced further, since the patients with FSMPGN seemed to have an excellent prognosis.     

Mucosa-associated lymphoid tissue lymphoma of the thymus resected using combined thoracoscopic and transcervical approaches

Mucosa-associated lymphoid tissue (MALT) lymphoma is a low-grade variant of B cell lymphoma that arises in extranodal tissue of the gastrointestinal tract, lung, salivary gland, thyroid, or other organ derived from the foregut. However, MALT lymphoma in the thymus is extremely rare. We report a case of thymic MALT lymphoma, extending to the neck, resected using combined thoracoscopic and transcervical approaches. To the best of our knowledge, thoracoscopic management of MALT lymphoma in the thymus has not previous been reported.     

Role of 5-HT1A receptors in the modulation of stress-induced lactate metabolism in the medial prefrontal cortex and basolateral amygdala

Rationale Lactate has been shown to play a significant role in energy metabolism and reflect neural activity in the brain.Objectives Using in vivo microdialysis technique, we measured extracellular lactate concentrations in the medial prefrontal cortex (mPFC) and the basolateral amygdaloid (BLA) nucleus of rats under electric foot shock stress. Moreover, to examine the role of serotonin (5-HT)_1A receptors in brain energy metabolism in response to stressors, we attempted to determine whether the stress-induced changes of extracellular lactate levels in the mPFC and BLA are attenuated by tandospirone, a partial agonist at 5-HT_1A receptors, or perospirone, a novel atypical antipsychotic with a 5-HT_1A receptor partial agonist and 5-HT_2A/dopamine-D₂ antagonist property.Results Foot shock stress led to an increase in extracellular lactate concentrations both in the mPFC and BLA. Tandospirone (2 mg/kg) attenuated the foot shock stress-induced increase of extracellular lactate concentrations in both of the brain regions, which was blocked by pretreatment with WAY-100635, a selective 5-HT_1A antagonist. On the other hand, perospirone (0.3 mg/kg) attenuated the increment of extracellular lactate concentrations in the mPFC and BLA, which was unaltered by pretreatment with WAY-100635.Conclusions These results indicate that the foot shock stress-induced increase in lactate metabolism is partly regulated by 5-HT_1A receptors both in cortical and limbic regions.