HLA-B is the best candidate of susceptibility genes in HLA for Japanese ulcerative colitis.

Recently, a genome-wide association study for ulcerative colitis (UC) in the UK population was reported, and several susceptibility loci including the human leukocyte antigen (HLA) region were identified. The strongest association in the HLA region was found at a 400 kb haplotype block containing HLA-DRB1. In Japanese population, previous study suggested the association between UC and HLA-B*52; however, HLA typing was determined using serotyping with the small sample size. The purpose of this study was to perform an association study in HLA-B by genotyping. A total of 320 patients with UC and 322 healthy controls were recruited in this case-control study. All subjects were Japanese. Genotyping of HLA-B was performed by polymerase chain reaction using a sequence-specific primer. When the allele frequencies were compared, significant associations were found with B*52 [odds ratio (OR) = 3.65, P = 1.6 x 10(-17), P(c) = 3.7 x 10(-16)] and B*4002 (OR = 0.52, P = 0.00030, P(c) = 0.0068). The allele frequency of B*52 was significantly higher in patients diagnosed before 40 years of age than in those diagnosed after 40 years (OR = 1.79, P = 0.010, P(c) = 0.020). A combination association map of Japanese UC using our current and previous studies showed two equal peaks of association on HLA-DRB1 and HLA-B, indicating the possible existence of two casual variants in the HLA region inside and outside the 400 kb block found in UK. We conclude that HLA-B contributes to the susceptibility to Japanese UC, especially cases with younger age of onset. The strength of association for HLA-B was equal to that for HLA-DRB1 in Japanese UC, in contrast to the UK population.

Butyrophilin-like 2 gene is associated with ulcerative colitis in the Japanese under strong linkage disequilibrium with HLA-DRB1*1502.

The human leukocyte antigen (HLA) region has been implicated in the pathogenesis of inflammatory bowel disease (IBD), which is classified into Crohn's disease (CD) and ulcerative colitis (UC). Recently, an association between sarcoidosis and the butyrophilin-like 2 (BTNL2) gene was reported. BTNL2 is located in the HLA region and its messenger RNA is expressed most abundantly in the intestine. In this study, we performed a case-control association study of BTNL2 in the Japanese patients with IBD and performed linkage disequilibrium (LD) analysis between BTNL2 and HLA-DRB1. We analyzed eight polymorphisms selected after direct sequencing and found that none of the polymorphisms were associated with the Japanese CD cohort. In contrast, five polymorphisms were significantly associated with UC, especially three single nucleotide polymorphisms (BTNL2_19, BTNL2_22 and BTNL2_23) were associated as a haplotype. The most frequent haplotype (GGC haplotype) was a low-risk haplotype (P= 0.000052), whereas the other TCT haplotype was a high-risk haplotype (P= 0.0000085). Among the eight polymorphisms, the strongest association with UC was found in BTNL2_19 (OR = 1.92, P= 0.0000035). As expected, the BTNL2_19-T allele showed strong LD with DRB1*1502 (D'= 0.92). When BTNL2_19 was tested as conditional on the DRB1*1502 carrier status, the significant association disappeared, suggesting that the association was because of its strong LD with DRB1*1502. We conclude that BTNL2 does not contribute to the susceptibility to Japanese CD but is associated with Japanese UC because of the strong LD with HLA-DRB1*1502. The strong LD between BTNL2 and HLA-DRB1 raises another issue about the potential role of BTNL2 in other diseases associated with HLA-DRB1.

Telomere size and telomerase activity in Epstein-Barr virus (EBV)-positive and EBV-negative Burkitt's lymphoma cell lines.

The telomere repeat lengths of BL cell lines were quantified by measuring terminal restriction fragment (TRF). Epstein-Barr virus (EBV)-positive Namalwa, Raji, and EB-3 cell lines have long telomeres, i.e. TRFs 10-19 kbp, whereas the Daudi cell line, producing a transformation-defective EBV mutant, has TRFs approximately 2.2 kbp. EBV-negative BJAB and DG75 cell lines have short TRFs 3.9-5.4 kbp, shorter than the approximately 12 kbp TRFs in PBLs. Telomerase activities of these BL cell lines are similar. TRFs of non-BL lymphoma cell lines are 2.3-5.5 kbp. Fluorescent in situ hybridization (FISH) studies of these cell lines showed remarkable heterogeneity of telomere size in chromosomes in the same BL cell. These results suggest that EBV-positive and EBV-negative BL cell lines have experienced various telomere dynamics.

[A case of sarcoidosis acutely aggravated with high fever and diffuse interstitial pulmonary infiltrates].

We present a case of sarcoidosis acutely aggravated with high fever and diffuse interstitial pulmonary infiltrates in a female patient at the age of 64. Sarcoidosis was diagnosed in another hospital as a result of iritis, chest radiography findings, and a negative reaction in a tuberculin skin test. She was admitted to our hospital because of dyspnea and a high temperature of 39 degrees C in February 1994. A marked hypoxemia (PaO2 46.5 torr) was found in arterial blood gas analysis. Chest radiography revealed a bilateral diffuse reticulo-nodular shadows, and chest CT showed ground glass opacity predominant posteriorly. Analysis of bronchoalveolar lavage fluid revealed an increase in lymphocytes and an increased ratio of CD4 to CD8 T lymphocyte. Transbronchial lung biopsy revealed lymphocytic alveolitis and proliferation of epithelioid cell granulomas in the alveolar septa and intraalveolar spaces. The patient was treated for deterioration of sarcoidosis with 40 mg of prednisolone and her respiratory status and the radiographic findings improved rapidly. With dose tapering of prednisolone, dyspnea and deterioration of the radiographic findings occurred, but with addition of a weekly low dose of methotrexate, dose reduction of prednisolone was achieved.

[Telomere DNA and telomerase of lymphoma-derived cell lines--telomere hypothesis for cell growth control].

Telomere is the specialized structure of chromosome end. Telomeric DNA is essential for stabilization of linear double-stranded DNA molecules. Human telomeric DNA comprises the tandem repeat (AATGGG)n. Telomeres of normal somatic cells shorten progressively on every cell division, and telomere length is considered to determine cellular proliferative capacity. Most normal cells except germ line cells lack telomerase activity. Evidence of telomerase reactivation in human cancer cells was reported in 1994. The telomere hypothesis of aging and cell immortalization has drawn much attention in recent years. We examined telomere DNA and telomerase activity of Burkitt's lymphoma cell lines and EBV-infected proliferating B lymphocytes. All of these cells had varied average size of TRFs and the cell lines of lymphoma origin showed elevated telomerase activity.

Chloroplast DNA topoisomerase I from cauliflower.

An ATP-independent DNA topoisomerase has been isolated from chloroplasts of cauliflower leaves (Brassica oleracea var. botrytis) through DEAE-cellulose, AF-blue Toyopearl, and hydroxyapatite column chromatography. The sedimentation coefficient and Stokes radius of this enzyme are 3.6S and 3.6 nm, respectively, and the molecular weight of native enzyme is estimated to be 54,000. This enzyme changes the linking number in steps of one. The enzyme activity is stimulated by MgCl2, and this enzyme shows optimum activity at 30 degrees C in the range of 3 mM MgCl2 + 100 mM KCl-10 mM MgCl2 + 50 mM KCl. The enzyme activity was reduced remarkably by N-ethylmaleimide, indicating that a free sulfhydryl group is important for the activity; heparin and ellipticine also reduced the activity. Both cauliflower chloroplast topoisomerase and spinach chloroplast topoisomerase can relax positive supercoils as well as negative supercoils. From these properties, cauliflower chloroplast topoisomerase can be classified as a eukaryotic type I DNA topoisomerase.

[Reflex control on laryngeal functions--vibration effect of the laryngeal mucosa on recurrent laryngeal nerve reflexes].

Electromyographic (EMG) responses of the intrinsic laryngeal muscle have been investigated to clarify reflexogenic laryngeal controls from a viewpoint of its functional significance during phonation. Twenty-five adult cats were anesthetized with intraperitoneal injection of 4ml/kg of a mixture of 10% urethane and 1% alpha-chloralose. Either the internal branch of the superior laryngeal nerve (ISLN) or the recurrent laryngeal nerve (RLN) was carefully dissected and central end of the dissected nerve was electrically stimulated. EMG of the contra-lateral Thyro-Arytenoid muscle (TA muscle) to the stimulation was recorded using a hooked-wire electrode inserted through the laryngeal mucosa. EMG of the TA muscle evoked by the stimulation of the ISLN were analyzed with respect to its latency and discharge pattern inter-collicular brainstem transsected. Together with the stimulation of the RLN, vibratory stimuli were given mainly to the subglottic mucosa as conditioning stimuli. The vibratory frequency was changed from 50Hz to 400Hz step-wisely. Following results were obtained. 1. EMG response of the contra-lateral TA muscle to the stimulation of the ISLN showed two different kinds of latency, approximately 8-10msec, and 40-60msec. 2. After inter-collicular brainstem transsection, evoked response of the latter disappeared. This result indicates that the ISLN-RLN reflex loop consisted of more than two routes, different in the number of synaptic junctions. 3. The vibratory stimuli given to the laryngeal mucosa had facilitatory effect on the reflexive EMG response evoked by the stimulation of the RLN. 4. This facilitatory effect of the vibratory stimuli disappeared after topical anesthesia of the laryngeal mucosa. 5. The facilitatory effect on the reflex responses was partially increased depending on the vibratory frequencies applied. In conclusion, vibratory stimuli to the laryngeal mucosa reflexively modulate the activity of the intrinsic laryngeal muscles.