[The problem of a long-term follow up in patients with renal cell carcinoma]

PURPOSE

We investigated on a problem of long-term follow up in patients with renal cell carcinoma.

PATIENTS AND METHODS

A total of 287 patients with renal cell carcinoma treated in Nara Medical University and affiliated facilities from January 1980 to December 1990 were examined. And we investigated the trend of explanation to patients including 287 patients from 1991 to 1995.

RESULTS

Up to December 1995, there are 76 patients (26.5%) unable to be followed and 211 patients able to be followed. The former group patients were less declared cancer rather than the latter group patients. Of 76, 22 patients (28.9%) might misunderstand completely recovering from the cancer disease. For the recent 5 years, those patients who were declared cancer increased, and those patients who were explained benign disease decreased.

CONCLUSION

These results suggested that declaration of cancer is important for patients with renal cell carcinoma to be followed for a long-term.

Analysis of HLA antigens in Mycobacterium avium-intracellulare pulmonary infection

Mycobacterium avium-intracellulare (MAI) pulmonary infection may occur in subjects with no preexisting lung disease and no known immunodeficiency, showing radiologically nodular bronchiectasis. There have remained some unresolved problems in the pathogenesis of the disorder, including the predominance in elderly women and the presence of not deteriorated or deteriorated disease. In the present study, we examined whether immunogenetic susceptibility is present in the disorder. We evaluated 64 cases of MAI disease and analyzed their short-term natural history by assessing symptoms, sputum bacteriology, and chest computed tomographic findings. The frequencies of human leukocyte antigen (HLA) alleles in patients were compared with those in 100 healthy Japanese control subjects. We assayed the HLA-A, -B, -C, -DR, and -DQ antigens serologically. Among 64 patients, 37 (35 females) did not show deterioration, whereas 27 (24 females) showed deterioration after an interval of 30 +/- 15 mo. There was no significant frequency of HLA-B and -C alleles in either group. In 37 not deteriorated patients, DR-6 was positive in 14 (37.8%) patients but in only 16 (16%) control subjects (p = 0.0061, odds ratio [OR] = 3.20). DQ-4 was positive in 10 (27.0%) patients but in only 10 (10%) control subjects (p = 0. 0122, OR = 3.33). In 27 deteriorated patients, HLA-A26 was positive in 14 (51.9%) patients but in only 21 (21.0%) control subjects (p = 0.0015, OR = 4.05). MAI pulmonary infection with nodular bronchiectasis shows two types of outcome, deteriorated and not deteriorated. The subjects with A-26 antigen might indicate the deterioration of MAI infection.

Inhibition of retinoic acid-inducible transcription by COUP-TFI in human salivary gland adenocarcinoma cell line HSG

Human salivary gland adenocarcinoma cells (HSG) express nuclear receptors, all-trans-retinoic acid (at-RA) receptors (RARs), and retinoid X/9-cis-retinoic acid (9-c-RA) receptors (RXRs). In order to investigate whether the endogenous RARs or RXRs of HSG cells can induce transcription activation, the thymidine kinase promoter (TK)-driven luciferase reporter gene containing the retinoic acid response element (RARE), of RARbeta, betaRARE2-TK-Luc, was transfected into HSG cells and ligand-dependent transcription activation was examined. Luciferase activity of cell lysate increased by the treatment with either at-RA or 9-c-RA. Co-transfection of RARalpha and (or) RXRalpha-expression plasmids with the reporter gene enhanced the luciferase activity, suggesting that endogenous RARs and RXRs work as ligand-dependent transfactors in HSG cells. Reverse transcriptase - polymerase chain reaction analysis revealed that HSG cells express chicken ovalbumin upstream promoter - transcription factor I (COUP-TFI). Co-transfection of COUP-TFI-expression plasmid suppressed the at-RA-induced transcription activation of the reporter gene. Similar results were shown using a chromatin-integrated reporter gene system, using a stably transfected beta-RARE2-TK-beta-galactosidase (beta-Gal) reporter gene. The at-RA-dependent increase in the beta-Gal expression was completely inhibited by COUP-TFI. The transfection of antisense oligonucleotide of COUP-TFI squelched the RA-dependent growth inhibition induced by RAR-RXR heterodimers. Conclusively, RARs and RXRs of HSG cells are functional and play roles as transactivators in at-RA-sensitive processes such as the proliferation or differentiation of cells. COUP-TFI very likely regulates these processes by repressing the functions of these transactivators.

Maternal plasma viral RNA levels determine marked differences in mother-to-child transmission rates of HIV-1 and HIV-2 in The Gambia. MRC/Gambia Government/University College London Medical School working group on mother-child transmission of HIV

OBJECTIVES

To determine the rates of, and risk factors for, mother-to-child transmission (MCT) of HIV-1 and HIV-2 infection in The Gambia.

DESIGN

A blinded, prospective, community-based cohort study of 29.549 pregnant women attending the eight largest antenatal clinics in The Gambia.

METHODS

Women were tested for HIV-1 and HIV-2 infection. Infected subjects and a group of HIV-seronegative women were followed with their babies until 18 months after delivery. Maternal CD4 cell count percentages were measured before and 18 months after delivery, and the antenatal plasma viral load was determined. Babies were tested for HIV by the polymerase chain reaction and/or serology at 2, 9 and 18 months of age.

RESULTS

The study enrolled 144 women positive for HIV-1 and 294 for HIV-2 plus 565 seronegative pregnant women: the mean antenatal percentage CD4 cell counts of 96 HIV-1-positive, 223 HIV-2-positive and 125 HIV-seronegative mothers were 31% [95% confidence interval (CI) 28-33], 41% (95% CI 39-42) and 47% (95% CI 45-49), respectively. The geometric mean antenatal plasma viral load of 94 HIV-1-infected women was 15,100 copies x 10(3) ml (95% CI 10,400-19,000) which was much higher than that of 60 randomly selected HIV-2-infected women, which was 410 copies x 10(3) ml (95% CI 150-910) (P < 0.001). The estimated transmission rate of HIV-1 was 24.4% (95% CI 14.6-33.9) and that of HIV-2 was 4.0% (95% CI 1.9-7.4). Five of 17 HIV-1-positive and three of eight HIV-2-positive babies were infected after 2 months of age. Birth in the rainy season [odds ratio (OR) 2.9; 95% CI 1.2-7.2], a low postnatal CD4 cell percentage (OR for a 10% fall 2.4; 95% CI 1.1-5.1) and a high maternal plasma viral load (OR for a 10-fold increase 2.9; 95% CI 1.1-7.8) were risk factors for transmission that applied equally to both viruses.

CONCLUSION

Low maternal HIV-2 RNA levels, which on average are 37-fold less than in HIV-1 infection, relate to the low MCT rate of HIV-2.

A case of sporadic Creutzfeldt-Jakob disease with both plaque and synaptic-type deposition of prion protein

We report a Japanese case of sporadic Creutzfeldt-Jakob disease (CJD) with particular clinical course and neuropathological findings. A 74-year-old female exhibited parkinsonism and later, dementia, myoclonus as well as visual hallucinations, lacking periodic synchronous discharges in the electroencephalogram. The duration of her illness was 2 years, longer than typical CJD cases which average 8 months' duration. Gray matter was severely affected, the Ammon's horn and subicular cortex were well preserved and many kuru plaques were observed in the cerebellum using routine histological stainings. Immunohistochemistry for prion protein (PrP) using both formic acid and hydrolytic autoclaving pretreatment revealed numerous prion plaques throughout the brain together with intense synaptic-type deposition of PrPCJD (abnormal isoform of PrP) in all gray matter examined, particularly in the Ammon's horn and subicular cortex. The definite combination of these two types of stain has never been reported previously in Japan other than in Gerstmann-Sträussler-Scheinker syndrome. Relative resistance of the Ammon's horn and subicular cortex to the PrPCJD deposition is also discussed.

Comparison of in vitro cytotoxicity of N-acetyl and N-propionyl derivatives of phenolic thioether amines in melanoma and neuroblastoma cells and the relationship to tyrosinase and tyrosine hydroxylase enzyme activity

Our laboratory has synthesized two new phenolic thioether amines, N-propionyl-4-S-cysteaminylphenol (N-Pr-4-S-CAP) and N[2-[(4-propionyloxyphenyl)thio]ethyl] propionamide (N,O-diPr-4-S-CAP). These compounds, along with the previously described phenolic thioether amine N-acetyl-4-S-cysteaminylphenol (N-Ac-4-S-CAP) and its acetyl form (N,O-diAc-4-S-CAP), are tyrosine-amine derivative analogues. The cytotoxicity of these compounds is thought to be tyrosinase dependent, which may make them suitable for targeted anti-melanoma therapy since only melanocytes and their malignant counterparts contain this active enzyme. To further investigate this hypothesis, we performed MTT [3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide] assays to determine the cytotoxicity of these compounds in 10 different cell lines. Specifically, we examined to what extent cytotoxicity is related to tyrosinase and tyrosine hydroxylase activity using melanoma and neuroblastoma cells, which have a common metabolic pathway using tyrosinase and tyrosine hydroxylase, respectively. The most sensitive cell line was the highly pigmented SK-MEL-23 melanoma cell line, which shows a very high tyrosinase activity with the highest melanin pigmentation. KAN and SK-NSH (two neuroblastoma cell lines), which have no tyrosinase activity but high tyrosine hydroxylase, were also sensitive. However, C32 (a non-pigmented melanoma with a lower tyrosinase activity) was also sensitive, and MeWo (a moderately pigmented melanoma with a high tyrosinase activity) was less sensitive. This in vitro study may indicate that there is a non-tyrosinase-mediated mechanism of cytotoxicity for phenolic thioether amines in addition to the tyrosinase-mediated one described previously.

DNA data bank of Japan (DDBJ) in collaboration with mass sequencing teams

We at DDBJ (http://www.ddbj.nig.ac.jp) process and publicise the massive amounts of data submitted mainly by Japanese genome projects and sequencing teams. It is emphasised that the collaboration between data producing teams and the data bank is crucial in carrying out these processes smoothly. The amount of data submitted in 1999 is so large that it alone exceeds the total amount submitted in the preceding 10 years. To cope with this situation, we have developed tools not only for processing such massive amounts of data but also for efficiently retrieving data on demand.

Two cases of pyoderma gangrenosum complicated with nasal septal perforation

We report two patients with pyoderma gangrenosum complicated with nasal septal perforation. An 18-year-old woman and a 65-year-old man had typical lesions of pyoderma gangrenosum on the legs that responded well to oral prednisolone. Both patients complained of mild nasal discharge, and nasal fibroscopy revealed nasal septal perforation. Biopsy of the nasal lesions showed an active inflammatory infiltrate, mainly of neutrophils. Systemic investigations failed to show any pulmonary or renal lesions of Wegener's granulomatosis. Cytoplasmic immunofluorescent pattern antineutrophil cytoplasmic antibody was negative. In both cases, intense neutrophilic infiltration was observed not only in skin lesions but also in nasal lesions, which may indicate that the nasal lesions had a pathogenesis in common with the skin lesions.

Significant associations of HLA-B*5101 and B*5108, and lack of association of class II alleles with Behçet's disease in Italian patients

Behçet's disease has been known to be strongly associated with human leukocyte antigen (HLA) B51, one of the split antigens of HLA-B5. An increased incidence of HLA-B51 in the patient group has also been reported in an Italian population. Since the B51 antigen has been recently identified to comprise nine alleles, B*5101-B*5109, we performed HLA-B51 allele genotyping by the polymerase chain reaction-sequencing based typing (PCR-SBT) method as well as serological HLA-A and -B typing among 21 Italian patients with Behçet's disease in order to investigate whether there is any correlation of one particular B51-associated allele with Behcet's disease. In addition, HLA class II genotyping was performed by the PCR-restriction fragment length polymorphism (RFLP) method. As a result, only the phenotype frequency of the B51 antigen was found to be significantly increased in the patient group as compared to the ethnically matched control group by the corrected P-value analysis (71.4% in patients vs. 17.9% in controls; chi2 = 14.26, Pc = 0.0042, R.R. = 11.5). In the B51 allele genotyping, 11 out of 15 B51-positive patients were B*5101 and the remaining four were B*5108, whereas all of 5 normal controls were B*5101, showing significant association of each allele with Behçet's disease. No significant difference was observed between the patient and control groups in the HLA class II allelic distribution. This study revealed a strong association of Behçet's disease in Italian with B*5108 as well as B*5101, providing important insight into the molecular mechanism underlying an HLA association with Behçet's disease.

D1S80 subtyping by PCR-RFLP: new nomenclature and further characterization

In a previous study, we screened out sequence variations within alleles at the D1S80 locus of a Japanese population using PCR-RFLP with EcoRII as a restriction enzyme. In the present study, through analyzing the alleles in a Chinese population, we were able to demonstrate four new electrophoretic band patterns that were complementary to the Japanese data. After summarizing the band patterns and sequencing results of these two populations, we established a new nomenclature for the PCR-RFLP band patterns, closely relating them to their corresponding sequences so that the new types could be designated easily and accurately. After PCR-RFLP subtyping, nineteen alleles in the Chinese population were revealed to have a total of thirty-seven subtypes. The discrimination power of this locus in the Chinese population was elevated from 0.974 to 0.988, and the Hardy-Weinberg equilibrium in this population showed no deviation when checked. Two samples typed as homozygotes 24/24 and 30/30 were identified to be actually heterozygous according to their band patterns. The result was supported by the sequencing analysis of the two samples in which overlapping of eight and eleven repeat units, respectively, were revealed. The heterozygosity was thus elevated from 0.85 to 0.87. The present study proved that PCR-RFLP was an effective method for subtyping D1S80 alleles in the Chinese.

Selective incorporation and specific cytocidal effect as the cellular basis for the antimelanoma action of sulphur containing tyrosine analogs

Tyrosine analogs are good candidates for developing melanoma chemotherapy because melanogenesis is inherently toxic and uniquely expressed in melanocytic cells. Sulphur containing substrate (tyrosine) analogs, N-acetyl-4-S-cysteaminylphenol (NAcCAP) and N-propionyl-4-S-cysteaminylphenol (NPrCAP), have been shown to have potent antimelanoma activity in mice bearing melanoma. Both NAcCAP and NPrCAP show selective cytotoxicity towards melanoma cell lines. But the mechanism leading to selectivity is not clear as these drugs are also toxic to other cell lines to a lesser extent. Here we show that these drugs have both cytostatic and cytocidal effects, which could account for this. Cytostatic effect is suggested by DNA flow cytometry. The drug causes cell cycle changes in four human cell lines (normal skin fibroblasts, HeLa cells, and melanoma cell lines, C32 and SK-MEL-23) in a dose-dependent manner blocking cells in S phase with concomitant decrease in the number of cells in G1 phase. There is also a gradual decrease in cells in G2 + M phases. The dose-concentration curves give IC50 values in the range of 50-400 microM and the melanotic melanoma cell line SK-MEL-23 has the lowest IC50 value consistent with our hypothesis that these drugs are selective towards melanoma cells. The concentration-dependent accumulation of cells in S phase suggest a cytostatic effect as a consequence of inhibition of DNA synthesis in agreement with [3H] thymidine incorporation assay. There is a highly specific uptake of [14C]NAcCAP and irreversible damage to DNA synthesis machinery in SK-MEL-23 cells, indicating a melanotic-specific cytocidal effect as well. Trypan blue exclusion study and competitive inhibition assay indicated that visible cytocidal effect occurs slowly and oxidative stress resulting from tyrosinase mediated oxidation of the drug appears to be the underlying mechanism. The primary antimelanoma effect of cysteaminylphenols derives from a selective cytostatic effect, but is followed by a specific cytocidal action rendering the drugs useful for targeted melanoma chemotherapy.

Association analysis using refined microsatellite markers localizes a susceptibility locus for psoriasis vulgaris within a 111 kb segment telomeric to the HLA-C gene

The HLA-Cw6 antigen has been associated with psoriasis vulgaris despite racial and ethnic differences. However, it remains unclear whether it is the HLA-Cw6 antigen itself or a closely linked, hitherto unidentified, locus that predisposes to the disease. Here, in order to map the susceptibility locus for psoriasis vulgaris precisely within the HLA class I region, 11 polymorphic microsatellite markers distributed throughout a 1060 kb segment surrounding the HLA-C locus were subjected to association analysis in Japanese psoriasis vulgaris patients. Statistical analyses of the distribution and deviation from Hardy-Weinberg equilibrium of the allelic frequency at each micro-satellite locus revealed that the pathogenic gene for psoriasis vulgaris is located within a reduced interval of 111 kb spanning 89-200 kb telomeric of the HLA-C gene. In addition to three known genes, POU5F1, TCF19 and S, this 111 kb fragment contains four new, expressed genes identified in the course of our genomic sequencing of the entire HLA class I region. Therefore, these seven genes are the potential candidates for susceptibility to psoriasis vulgaris.

Cooperative approach for the protein fold recognition

We, four independent predictors, organized a team and tackled blind protein structure predictions using fold recognition methods. We tried to assign the homologous or analogous folds in the protein structure database for a number of target sequences that showed no apparent sequence homology to the proteins of known folds. After primary analyses by conventional softwares, these sequences were threaded through the structural library using three different programs developed by ourselves, which employed different compatibility functions. Collecting the results of our individual analyses, and the available biological knowledge about the target, we held meetings and discussed all plausible structures for the target. For 25 target sequences, we submitted 56 models including NONE: This was the first time the fold was determined. At the time of the meeting (CASP3), 19 protein structures (21 domains) categorized as the threading targets were available. We succeeded in predicting eight out of 18 targets (20 domains) that we submitted; however, alignment accuracies were not satisfactory for some of the models. We often obtained correct answers even if some of us missed the right prediction; therefore it would appear that our threaders compensated each other. When all the information is managed effectively, the prediction gains more accuracy.

[Efficacy of adjuvant hepatic arterial infusion chemotherapy following resection of colorectal liver metastases]

PURPOSE

The aim of this study is to evaluate the effect of adjuvant hepatic arterial infusion chemotherapy (HAIC) following liver resection on the frequency of residual liver recurrence and overall survival.

PATIENTS AND METHODS

During 1992 to 1997, 84 patients with liver metastasis from colorectal cancer resected curatively had undergone adjuvant HAIC. The regimen of the HAIC is 1,500 mg of 5-FU by 24-hr continuous infusion once a week for eight weeks. 37 cases in the HAIC group, including patients given more than 7 g of 5-FU, were compared with the control group.

RESULT

The cumulative 5-year liver recurrence-free ratios were 72.6% in the HAIC group and 29.8% in the control group (p = 0.0005). The cumulative 5-year survival ratios were 61.4% in the HAIC group and 28.0% in the control group (p = 0.0069). Multivariate analysis revealed that more than 5 mm of surgical margin and adjuvant HAIC significantly decreased the risk of recurrences in residual liver.

CONCLUSION

Adjuvant HAIC is an effective procedure to prevent recurrence in residual liver and improve the prognosis of patients with liver metastasis from colorectal cancer.

Strong hydrophobic nature of cysteine residues in proteins

The differences between disulfide-bonding cystine (Cys_SS) and free cysteine (Cys_SH) residues were examined by analyzing the statistical distribution of both types of residue in proteins of known structure. Surprisingly, Cys_SH residues display stronger hydrophobicity than Cys_SS residues. A detailed survey of atoms which come into contact with the sulfhydryl group (sulfur atom) of Cys_SH revealed those atoms are essentially the same in number and variety as those of the methyl group of isoleucine, but are quite different to those of the hydroxyl group of serine. Moreover, the relationships among amino acids were also determined using the 3D-profile table of known protein structures. Cys_SH was located in the hydrophobic cluster, along with residues such as Met, Trp and Tyr, and was clearly separated from Ser and Thr in the polar cluster. These results imply that free cysteines behave as strongly hydrophobic, and not hydrophilic, residues in proteins.

Association analysis between the MIC-A and HLA-B alleles in Japanese patients with Behçet's disease

OBJECTIVE

Behçet's disease is known to be strongly associated with HLA-B51 in many different ethnic groups. Recently, by association analysis using refined microsatellite mapping, the critical region for Behçet's disease was identified as a 46-kb segment centromeric to the HLA-B gene. No expressed gene has been detected in this segment to date except the MIC-A (major histocompatibility complex class I chain-related gene A) and HLA-B genes. The present study was undertaken to analyze allelic distribution of the MIC-A gene among Japanese patients with Behçet's disease.

METHODS

Ninety-five Japanese patients with Behçet's disease and 116 ethnically matched healthy controls were enrolled in this study. MIC-A genotyping was performed by direct sequencing of polymerase chain reaction products from exons 2, 3, and 4 of the MIC-A gene, using an automated DNA sequencer.

RESULTS

The MIC-A009 allele was significantly more frequent in the patient group (69.5%) compared with the healthy controls (31.0%) (relative risk 5.06, corrected P = 0.00000024). In stratification analysis on the confounding effect of MIC-A009 on HLA-B*51 association and vice versa, Behçet's disease was distinctively associated only with HLA-B*51. Further, MIC-A009 was found to be strongly associated not only with HLA-B51, but also with HLA-B52, which was not increased in the patient group to any degree.

CONCLUSION

These results imply that the real disease susceptibility gene involved in the development of Behçet's disease is the HLA-B*51 allele itself and that the significant increase of the MIC-A009 allele in the patient group results secondarily from a strong linkage disequilibrium with HLA-B*51.

The judgment of a gunshot wound with severe post-mortem changes

This is a report on an autopsy case that revealed a gunshot wound to the back of the head. On examination of the external surface, an entrance and exit wound could not be found in the head region because of the severe post-mortem changes and the atypical entrance wound position and direction of the bullet tract; X-rays taken before the internal examination were effective in this case. In this case, the direction of the bullet tract was supposed to be similar to that of the suboccipital puncture.

New polymorphic microsatellite markers in the human MHC class I region

The human major histocompatibility complex (MHC) class I region is believed to contain a large number of genes encoding susceptible factors for diseases such as Behcet's disease, Graves disease and psoriasis vulgaris. To identify the causative genes of those diseases, we have conducted large-scale genomic sequencing and determined the 1.8 Mb entire HLA class I region from the MICB gene to the HLA-F gene. During the course of genomic sequencing, a total of 731 microsatellite sequences with dinucleotide to pentanucleotide repeats were found in this region. Previously, we reported that 26 microsatellites between MICB and S on the most centromeric side of the class I region, and between HSR1 and HLA-92/L in the midst of the class I region were highly polymorphic, and served as excellent genetic markers. In this paper, in order to fill the gaps with no known polymorphic microsatellites available in the HLA class I region, 12 new polymorphic microsatellite markers were recruited from the 1.8 Mb region including the remaining class I segments, namely between S and HSR1, and between HLA-92/L and HLA-F The average number of alleles at these new microsatellite loci was 8.2 with a polymorphism content value (PIC) of 0.63. These 38 markers in total almost uniformly interspersed in the HLA class I region will enable us to search precisely for the location of disease susceptible loci within the HLA class I region by association and for linkage analyses.

HLA class I and II typing of the patients with Behçet's disease in Saudi Arabia

Thirteen Saudi Arabian patients with Behçet's disease (BD) were typed for HLA-A and -B alleles by the conventional serologic typing and for HLA-DRB1, -DQB1 and -DPB1 alleles by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. As a result, the phenotype frequency of the B51 antigen was significantly increased in the patient group as compared to the ethnically matched control group (76.9% in patients vs. 22.20% in controls), but no significant difference was observed in HLA-A, -DRB1, -DQB1 or -DPB1 alleles between the patients and controls, as previously observed in Japanese BD. Further, by HLA-B51 allelic genotyping performed by the polymerase chain reaction-sequence specific primers (PCR-SSP) method, all of the B51-positive patients and controls were found to carry one particular allele, B*5101, except one patient with B*5108.

T cell repertoire in the liver of patients with autoimmune hepatitis

Despite a large number of T cells infiltrating into the liver of patients with autoimmune hepatitis (AIH), little is known about their roles or target antigens. To investigate the roles of these T cells in the pathogenesis of AIH, we have studied the clonality of alphabeta T cell populations in liver tissue by size spectratyping the complementarity-determining region (CDR)3 size lengths of T cell receptor (TCR) Vbeta-chain transcripts. Analysis of nine AIH patients who had the HLA DR4 haplotype showed clonal expansion in all samples. More than two T cell clones expanded in most patients. Although the expression of the TCR Vbeta genes was different among the nine patients, clonal expansion of T cells expressing either TCR Vbeta2, 3, 4, 16, or 22 was observed in two patients or more. TCR Vbeta4 clones expanded in 5 cases. Cloning and sequencing of TCR Vbeta CDR3 from PCR products revealed no whole CDR3-shared clones among different patients. In conclusion, several T cell clonotypes first recognize target antigens, then expand and accumulate in the liver of AIH patients. These suggest heterogeneity of autoantigens and the complexity of AIH immunopathogenesis in individual patients.

Allopurinol increases ear swelling and mortality in a dinitrofluorobenzene-induced contact hypersensitivity mouse model

The immunomodulatory effects of allopurinol were investigated in a mouse contact hypersensitivity model. Allopurinol caused a time- and dose-dependent lethal effect in dinitrofluorobenzene (DNFB)-sensitized mice. Furthermore, allopurinol markedly increased ear swelling in the remaining mice. In contrast, TMX-67, a newly synthesized xanthine oxidase/xanthine dehydrogenase (XOD/XDH) inhibitor, had almost no effect on DNFB-sensitized mice. Allopurinol reduced both the spleen weight and white blood cell count in DNFB-sensitized mice without affecting the T cell subset of splenocytes. The production of interferon (IFN)-gamma, in the splenocytes of DNFB-sensitized mice was reduced by allopurinol administration. Death due to allopurinol was much lower in the non-sensitized mice than in the DNFB-sensitized mice. These findings indicate that allopurinol may interact with DNFB to enhance its toxicity and allopurinol might also modulate or enhance the inflammatory effect of DNFB. Also, DNFB may cause metabolic alterations via inflammation, leading to enhanced allopurinol toxicity.

Experimental verification of the 'stability profile of mutant protein' (SPMP) data using mutant human lysozymes

The stability profile of mutant protein (SPMP) (Ota,M., Kanaya,S. and Nishikawa,K., 1995, J. Mol. Biol., 248, 733-738) estimates the changes in conformational stability due to single amino acid substitutions using a pseudo-energy potential developed for evaluating structure-sequence compatibility in the structure prediction method, the 3D-1D compatibility evaluation. Nine mutant human lysozymes expected to significantly increase in stability from SPMP were constructed, in order to experimentally verify the reliability of SPMP. The thermodynamic parameters for denaturation and crystal structures of these mutant proteins were determined. One mutant protein was stabilized as expected, compared with the wild-type protein. However, the others were not stabilized even though the structural changes were subtle, indicating that SPMP overestimates the increase in stability or underestimates negative effects due to substitution. The stability changes in the other mutant human lysozymes previously reported were also analyzed by SPMP. The correlation of the stability changes between the experiment and prediction depended on the types of substitution: there were some correlations for proline mutants and cavity-creating mutants, but no correlation for mutants related to side-chain hydrogen bonds. The present results may indicate some additional factors that should be considered in the calculation of SPMP, suggesting that SPMP can be refined further.

Enzymatic ligation for synthesis of single-chain analogue of monellin by transglutaminase

Monellin, a sweet protein, consists of two noncovalently associated polypeptide chains: an A chain of 44 amino acid residues and a B chain of 50 residues. Microbial transglutaminase (MTGase) was used for ligation of the monellin subunits without any protecting groups, and without activation of the C alpha-carboxyl group at the C-terminus. Since a peptide fragment LLQG is a good substrate for MTGase to form an amide bond between the gamma-amide group of the Gln residue and the epsilon-amino group of Lys, a monellin B chain analogue in which LLQG was elongated at the C-terminus (B-LLQG) was synthesized by solid-phase synthesis. The monellin A chain analogue in which KGK was elongated at the N-terminus (KGK-A) was synthesized by the same method as that of the B chain analogue. The KGK-A chain and the B-LLQG chain were coupled by MTGase to give single-chain analogue of monellin. The single-chain analogue of monellin was characterized by analytical reverse phase high performance liquid chromatography, electrospray ionization, and amino acid analyses. All analyses gave satisfactory results. The single-chain analogue of monellin was more heat stable than natural monellin.

Association of MICA gene and HLA-B*5101 with Behçet's disease in Greece

PURPOSE

Behçet's disease (BD) is known to be associated with HLA-B51 in many different ethnic groups. Recently MICA, a member of a novel family of the human major histocompatibility complex (MHC) class I genes termed MIC (MHC class I chain-related genes), was identified near the HLA-B gene, and a triplet repeat microsatellite polymorphism was found in the transmembrane (TM) region. Because a strong association with BD of one particular MICA-TM allele, A6, was shown in a Japanese population, the present study was conducted to investigate microsatellite polymorphism in Greek patients with BD to know whether this association is generally observed in BD occurring in other populations.

METHODS

Thirty-eight Greek patients with BD and 40 ethnically matched control subjects were examined for MICA microsatellite polymorphism using polymerase chain reaction (PCR) and subsequent automated fragment detection by fluorescent-based technology.

RESULTS

Similar to the Japanese patients with BD, the phenotype frequency of the MICA-TM A6 allele was significantly increased in the Greek patients with BD (50.0% in control subjects versus 86.8% in BD cases), with an odds ratio (OR) of 6.60 (P = 0.0012). The MICA-A6 allele was found in a high frequency both in males and females (weighted OR = 6.68; P = 0.0017). No association was found between the A6 allele and several disease features. A strong association exists between the MICA-TM A6 allele and the B*5101 allele in both the control subjects and patients with BD (weighted OR = 44.39; P = 0.0000023).

CONCLUSIONS

This study revealed in Greek patients a strong association of BD with a particular MICA-TM allele, MICA-A6, providing insight into the molecular mechanism underlying the development of BD.

Sequencing based typing for genetic polymorphisms in exons, 2, 3 and 4 of the MICA gene

We have established a sequencing based typing (SBT) method for detection of genetic polymorphism in the exon 2 to 4 domains of the major histocompatibility complex (MHC) class I chain-related gene A (MICA) and applied it to allele typing of 130 healthy Japanese individuals. A 2.2-kb segment including exons 2, 3 and 4 of the MICA gene was amplified by a pair of generic primers followed by cycle sequencing using exon-specific nested primers. In total, 8 alleles were observed in a Japanese population and the most frequent allele was MICA008 with the gene frequency of 30.8%. MICA009 was the second most frequent (16.5%), while the rarest one was MICA007 (1.2%). MICA alleles displayed strong linkage equilibria with HLA-B antigens (i.e. MICA008 with B7, B48, B60 and B61; MICA009 with B51 and B52; MICA002 with B35, B39, B58 and B67; MICA004 with B44, MICA007 with B13 and B27; MICA010 with B46, B62 and B48, MICA012 with B54, B55, B56 and B59; MICA019 and B70, B71 and B62). Recently, the B48 haplotype has been reported to lack the entire MICA gene by a large-scale deletion in a Japanese population. Among 8 serologically B48 homozygous individuals, 4 were found to represent this MICA null allele as assessed by no polymerase chain reaction (PCR) amplification using MICA-specific primers, while the remaining four possessed the intact MICA gene with MICA008 or MICA010.

MIC-A allele profiles and HLA class I associations in Behçet's disease

Recently a new family of non-classical MHC molecules, the MHC class I chain-related protein (MIC), encoded by genes located in the major histocompatability complex have been identified. On the basis of the location of MIC genes and the structure and expression of MIC molecules it has been postulated that MIC may be a susceptibility factor in Behçet's disease (BD). We investigated the association of the 16 described external domain alleles and the transmembrane triplet repeats of MIC-A with BD in a Middle Eastern population. DNA from ninety-five patients and 102 age- and sex-matched controls were analyzed by polymerase chain reaction using allele specific primers. Our results show an increase of MIC-A*009 in the BD patient group 44/95 (46%) compared with controls 24/102 (24%) (chi2=11.3, OR=2.8, P=0.00078). MIC-A*009 was also found to be strongly associated with HLA-B51 in the patients 39/44 (88%) when compared with controls 10/24 (42%) (chi2=4, P=0.04). MIC-A*009 was also found in linkage disequilibrium with HLA-B52, but only in controls. The A6 form of a MIC-A transmembrane triplet repeat was found to be significantly raised in the patients (80/95; 84%;) compared with controls (58/102, 57%) (chi2=17.5, OR=4, P=0.000028). Although the MIC-A associations described are highly significant, the association with HLA-B51 independently remains the most significant factor (chi2=56.8, P<10(-6)). The data suggests that as both MIC-A*009 and A6 are in strong linkage disequilibrium with HLA-B51, they are unlikely to be the susceptibility gene for BD but may be markers for additional risk factors.

Design and synthesis of a globin fold

We propose a simple method to find an amino acid sequence that is foldable into a globular protein with a desired structure based on a knowledge-based 3D-1D compatibility function. An asymmetric alpha-helical single-domain structure of sperm whale myoglobin consisting of 153 amino acid residues was chosen for the design target. The optimal sequence to fit the main-chain framework has been searched by recursive generation of the protein 3D profile. The heme-binding site was designed by fixing His64 and His93 at the distal and proximal positions, respectively, and by penalizing residues that protrude into the space with a repulsive function. The apparent bumps among side chains in the computer model of the converged, self-consistent sequence were removed by replacing some of the bumping residues with smaller ones according to the final 3D profile. The finally obtained sequence shares 26% of sequence with the natural myoglobin. The designed globin-1 (DG1) with the artificial sequence was obtained by expression of the synthetic gene in Escherichia coli. Analyses using size-exclusion chromatography, circular dichroism spectroscopy, and solution X-ray scattering showed that DG1 folds into a monomeric, compact, highly helical, and globular form with an overall molecular shape similar to the target structure in an aqueous solution. Furthermore, it binds a single heme per protein molecule, which exhibited well-defined spectroscopic properties. The radius of gyration of DG1 was determined to be 20.6 A, slightly larger than that of natural apoMb, and decreased to 19.5 A upon heme binding based on X-ray scattering analysis. However, the heme-bound DG1 did not stably bind molecular oxygen as natural globins do, possibly due to high conformational diversity of side-chain structures observed in the NMR and denaturation experiments. These results give insight into the relationship between the sequence selection and the structural uniqueness of natural proteins to achieve biological functions.

The critical region for Behçet disease in the human major histocompatibility complex is reduced to a 46-kb segment centromeric of HLA-B, by association analysis using refined microsatellite mapping

The HLA-B51 allele is known to be associated with Behçet disease. Recently, we found a higher risk for Behçet disease in the MICA gene, 46 kb centromeric of HLA-B, by investigation of GCT repetitive polymorphism within exon 5 of MICA. The pathogenic gene causing Behçet disease, however, has remained uncertain. Here, eight polymorphic microsatellite markers, distributed over a 900-kb region surrounding the HLA-B locus, were subjected to association analysis for Behçet disease. Statistical studies of associated alleles detected on each microsatellite locus showed that the pathogenic gene for Behçet disease is most likely found within a 46-kb segment between the MICA and HLA-B genes. The results of this mapping study, and the results of an earlier study of ours, suggest that MICA is a strong candidate gene for the development of Behçet disease.

Feasibility in the inverse protein folding protocol

Methods for protein structure (3D)-sequence (1D) compatibility evaluation (threading) have been developed during the past decade. The protocol in which a sequence can recognize its compatible structure in the structural library (i.e., the fold recognition or the forward-folding search) is available for the structure prediction of new proteins. However, the reverse protocol, in which a structure recognizes its homologous sequences among a sequence database, named the inverse-folding search, is a more difficult application. In this study, we have investigated the feasibility of the latter approach. A structural library, composed of about 400 well-resolved structures with mutually dissimilar sequences, was prepared, and 163 of them had remote homologs in the library. We examined whether they could correctly seek their homologs by both forward- and inverse-folding searches. The results showed that the inverse-folding protocol is more effective than the forward-folding protocol, once the reference states of the compatibility functions are appropriately adjusted. This adjustment only slightly affects the ability of the forward-folding search. We noticed that the scoring, in which a given sequence is re-mounted onto a structure according to the 3D-1D alignment determined by the dynamic programming method, is only effective in the forward-folding protocol and not in the inverse-folding protocol. Namely, the inverse-folding search works significantly better with the score given by the 3D-1D alignment per se, rather than that obtained by the re-mounting. The implications of these results are discussed.

Triplet repeat polymorphism in the MICA gene in HLA-B27 positive and negative caucasian patients with ankylosing spondylitis

Previously, we reported a triplet repeat polymorphism in the transmembrane region within the MICA gene closely linked to HLA-B in a limited number of B27-positive Caucasian patients with ankylosing spondylitis (AS) (N = 48). In this study, we enrolled much more patients including some negative for B27, 162 AS subjects consisting of 140 B27-positive, and 22 B27-negative patients. The microsatellite allele consisting of 4 repetitions of (GCT/AGC) (A4 allele) was present at a significantly higher phenotype frequency in the patient group than in the ethnically matched control group (Pc < 0.000001). However, the frequency of the A4 allele was not significantly higher in the B27-positive and B27-negative patient groups, as compared to the B27-positive and B27-negative control groups, respectively. The higher phenotype frequency of the A4 allele in the patient group was supposed to be due to a strong linkage disequilibrium between the MICA and HLA-B genes. Thus, the possibility that the MICA gene is involved in the pathogenesis of AS can be excluded, supporting the hypothesis of a primary association of AS with HLA-B27.

The Protein Mutant Database

Currently the protein mutant database (PMD) contains over 81 000 mutants, including artificial as well as natural mutants of various proteins extracted from about 10 000 articles. We recently developed a powerful viewing and retrieving system (http://pmd.ddbj.nig.ac.jp), which is integrated with the sequence and tertiary structure databases. The system has the following features: (i) mutated sequences are displayed after being automatically generated from the information described in the entry together with the sequence data of wild-type proteins integrated. This is a convenient feature because it allows one to see the position of altered amino acids (shown in a different color) in the entire sequence of a wild-type protein; (ii) for those proteins whose 3D structures have been experimentally determined, a 3D structure is displayed to show mutation sites in a different color; (iii) a sequence homology search against PMD can be carried out with any query sequence; (iv) a summary of mutations of homologous sequences can be displayed, which shows all the mutations at a certain site of a protein, recorded throughout the PMD.

Accumulation of p300 mediates transcriptional repression of simian virus 40 enhancer in undifferentiated F9 embryonal carcinoma cells

The SV40 enhancer is repressed in embryonal carcinoma (EC) cells, and it is also repressed by the adenovirus E1A oncoprotein. Repression by E1A is mediated by the binding of E1A to the p300 transcriptional coactivator. Thus, we examined the role of p300 in the repression of the SV40 enhancer activity in EC cells. We demonstrated that high levels of p300 protein are accumulated in undifferentiated EC cells and that the levels decline dramatically upon differentiation because of the changes of protein stability. Furthermore, we showed that overexpression of p300 does not stimulate the SV40 enhancer activity in undifferentiated F9 cells. However, the activity of a p300 mutant deficient for E1A binding can be restored by the presence of excess E1A. In addition, low-level expression of E1A causes derepression of the enhancer activity in F9 cells. These results indicate that the accumulation of p300 protein participates in repression of the SV40 enhancer activity in undifferentiated F9 cells.

[A case of untreatable progressive bladder carcinoma effectively treated by single administration of tegafur and uracil]

Bloody urine was grossly observed and multinodular shadow confirmed in both lungs of an 81-year-old male, who had been referred to our department. The diagnosis was bladder cancer (TCC, G3, T4N3M1) from detailed examination. With his advanced age and lowered ADL, the family did not wish for aggressive treatment, so no combination multidrug chemotherapy was attempted. Instead he was given 300 mg/day UFT per os. After 4 weeks administration, the metastatic focus decreased and tended to contract; at the same time gross observation revealed no more bloody urine. Moreover, following 7 weeks of administration, the bladder tumor disappeared, the lung metastatic focus showed overall shrinkage of over 50%, the lymph node metastasis also was more than 50% less, and the case was considered to be PR. The literature reveals UFT was efficacious in only 2 other cases of progressive bladder carcinoma. Since UFT has fewer complications, such as myelosuppression, among antitumor agent, it is considered worth trying in cases where intensive treatment is not feasible.

Genes from nine genomes are separated into their organisms in the dinucleotide composition space

A set of 16 kinds of dinucleotide compositions was used to analyze the protein-encoding nucleotide sequences in nine complete genomes: Escherichia coli, Haemophilus influenzae, Helicobacter pylori, Mycoplasma genitalium, Mycoplasma pneumoniae, Synechocystis sp., Methanococcus jannaschii, Archaeoglobus fulgidus, and Saccharomyces cerevisiae. The dinucleotide composition was significantly different between the organisms. The distribution of genes from an organism was clustered around its center in the dinucleotide composition space. The genes from closely related organisms such as Gram-negative bacteria, mycoplasma species and eukaryotes showed some overlap in the space. The genes from nine complete genomes together with those from human were discriminated into respective clusters with 80% accuracy using the dinucleotide composition alone. The composition data estimated from a whole genome was close to that obtained from genes, indicating that the characteristic feature of dinucleotides holds not only for protein coding regions but also noncoding regions. When a dendrogram was constructed from the disposition of the clusters in the dinucleotide space, it resembled the real phylogenetic tree. Thus, the distinct feature observed in the dinucleotide composition may reflect the phylogenetic relationship of organisms.

Solid-phase synthesis of single-chain monellin, a sweet protein

Single-chain monellin, a sweet protein, was synthesized by stepwise solid-phase synthesis. After deprotection, and purification with HPLC, single-chain monellin was obtained in a yield of 0.3% based on the starting resin.

Association between MICA gene A4 allele and acute anterior uveitis in white patients with and without HLA-B27

PURPOSE

Acute anterior uveitis is strongly associated with the HLA-B27 antigen and triggered by the involvement of some external factors. However, it is uncertain whether HLA-B27 itself or other gene(s) near the HLA-B region in a linkage disequilibrium with HLA-B27 predispose to this uveitis. We therefore investigated microsatellite polymorphism in the transmembrane region of the major histocompatibility complex class I chain-related gene A (MICA), located 47 kilobases (kb) on the centromeric side of the HLA-B gene on the short arm of chromosome 6 within 6p21.3.

METHODS

We examined the following patients for MICA gene polymorphism by means of polymerase chain reaction and subsequent automated fragment detection by fluorescent-based technology: 64 (37 HLA-B27-positive and 27 HLA-B27-negative) whites with acute anterior uveitis, 74 (67 HLA-B27-negative and 7 HLA-B27-positive) ethnically matched random controls, and 36 HLA-B27-positive healthy controls.

RESULTS

The microsatellite allele consisting of four repetitions of GCT/AGC (designated A4 allele) was present at the significantly higher phenotype frequency (71.9%) in the patient group than in the ethnically matched random control group (13.5%) (P < .0000001, corrected P < .0000001). The A4 allele was strongly linked to HLA-B27 in a white population. However, the A4 allele was also found at the significantly higher phenotype frequency (37.0%) even in the HLA-B27-negative patient group than in the ethnically matched HLA-B27-negative control group (4.5%) (P = .0086, corrected P = .043).

CONCLUSIONS

These results suggest that the MICA gene itself or other nearby gene(s) linked to the MICA A4 allele may be involved in the development of acute anterior uveitis in a white population.

Synthesis, characterization, and sweetness-suppressing activities of gurmarin analogues missing one disulfide bond

The sweetness-suppressing polypeptide gurmarin isolated from Gymnema sylvestre consists of 35 amino acid residues and includes three intramolecular disulfide bonds. The roles of the three disulfide bonds were investigated by replacing each with two alanine residues by solid-phase synthesis. Nine analogues of [Ala3,18]gurmarin, [Ala10,23]gurmarin, and [Ala17,33]-gurmarin were obtained. Three analogues had native disulfide bonds, while the other six had non-native disulfide bonds. The three analogues with native disulfide bonds suppressed the response to sucrose, but not those to glucose, fructose, saccharin, or glycine in rats. In contrast, the six analogues with non-native disulfide bonds did not suppress the responses to any of these sweeteners. These results suggest that the native disulfide bonds of gurmarin are necessary for interaction with the receptor protein, and that the sucrose-specific receptor site is present in rats.

Subtyping and characterization of D1S80 alleles in a Japanese population using PCR-RFLP

In a Japanese population study of the D1S80 locus 24 alleles ranging from allele 16 to allele43 were analysed using PCR-RFLP. As two repeat units were found to contain the restriction cleavage site (CCAGG) for EcoRII, we digested the alleles with EcoRII, separated the digested fragments on polyacrylamide gels and stained with ethidium bromide. Of the 24 alleles 11 band patterns were identified and tentatively labeled E1 to E11. A total of 42 subtypes were detected in a population group of 111 unrelated individuals. All samples of allele 18 were of the E3 type, while about 60% of the allele24 samples were of the E4 type and about 40% were of the E8 type. The third most frequent allele (allele30) contained four types, E4, E8, E5 and E6. No deviations from Hardy-Weinberg equilibrium were observed. Since this method could differentiate those samples which had the same length but different sequences, it is quite useful for paternity testing and individual identification.

Expression of retinoid X receptors and COUP-TFI in a human salivary gland adenocarcinoma cell line

The growth of the adenocarcinoma cell line derived from human salivary gland (HSG) is regulated by all-trans-retinoic acid (t-RA), which binds to its specific receptor, retinoic acid receptors (RARs), located in the nucleus, and thereby transactivates target genes. In this study, we examined the binding characteristics of the nuclear extract of HSG cells to the retinoic acid response element (RARE) compared with those of in vitro translated RAR alpha and retinoid X receptor alpha (RXR alpha), a heterodimeric partner of RAR alpha. Gel shift analysis using anti-RAR alpha and anti-RXR alpha antibodies revealed that the translated RAR alpha bound to RARE as a heterodimer with RXR alpha. In contrast, the binding of the nuclear extract of HSG cells to RARE showed a heterogeneous pattern, suggesting the existence of several species of RXRs as well as RARs in the nuclei of HSG cells. We therefore tried to clone these putative RXRs by the polymerase chain reaction using degenerated oligonucleotide primers conserved across the RXR family. The DNA sequencing of the recombinant clones revealed the expression of RXR alpha and RXR beta. In addition, chicken ovalbumin upstream promoter-transcription factor I (COUP-TFI), which is also an RXR family member, was cloned. To evaluate the transcriptional activity of RARs and RXRs endogenously expressed in HSG cells, we performed a transient transfection analysis. When HSG cells were transfected with a luciferase reporter plasmid containing two repeats of either the RARE of the RAR beta gene or that of cellular retinol-binding protein II gene, positioned upstream of a thymidine kinase promoter fused to the luciferase sequence, a 2-3-fold induction of luciferase activity was observed in both cases. These results suggest that RARs and RXRs endogenously expressed in HSG cells were transcriptionally active in vivo. Thus, our findings showed that RXR alpha, RXR beta, and COUP-TFI are expressed in HSG cells and suggest that these molecules function as heterodimeric partners of RARs and (or) competitive repressors for RAREs and are involved in cellular responses mediated by retinoids.

Effects of endothelin-induced nitric oxide on venous circulation and renal water-electrolyte handling

To assess the interaction of endothelin (ET) with nitric oxide (NO) and the effects on venous circulation and handling of renal water and electrolytes, ET (1.0 ng/kg/min) or saline was administered with or without three doses (0.27, 2.7 and 27 ng/kg/min for 40 min) of N omega-nitro-L-arginine methyl ester (L-NAME), and NO synthase inhibitor, in anesthetized dogs. ET increased total peripheral resistance (TPR), pulmonary capillary wedge pressure (PCWP), urine flow (UF), and urinary K excretion (UKV), and decreased cardiac output (CO), urinary osmolality (Uosm), renal plasma flow (RPF), and glomerular filtration rate (GFR). L-NAME increased blood pressure (BP), TPR, PCWP, right atrial pressure (RAP), and mean circulatory filling pressure (MCFP), and decreased CO, RPF, and GFR, ET plus L-NAME markedly increased TPR, resistance to venous return, and plasma atrial natriuretic peptide (ANP), but not BP and MCFP, and curtailed the ET-induced responses in UF, UKV, and Uosm. Plasma aldosterone (ALD) was decreased in all groups, but plasma vasopressin (AVP) and renin activity (PRA) were not altered in any group. These results indicate that ET-induced NO formation might mitigate increases in venous as well as arterial vascular resistance and changes in renal handling of water and electrolytes, and might also play an inhibitory role in ANP release but not in PRA or AVP and ALD release.

Genetic relationships among Japanese, northern Han, Hui, Uygur, Kazakh, Greek, Saudi Arabian, and Italian populations based on allelic frequencies at four VNTR (D1S80, D4S43, COL2A1, D17S5) and one STR (ACTBP2) loci

The genetic polymorphism at four variable number of tandem repeats (D1S80, D4S43, COL2A1, D17S5) and one short tandem repeat (ACTBP2) loci was assessed by polymerase chain reaction analysis of genomic DNA obtained from blood samples of eight human populations (Japanese, Northern Han, Hui, Uygur, Kazakh, Saudi Arabian, Greek, Italian). Allele frequencies at all loci were in the Hardy-Weinberg equilibrium for each population. With the exception of ACTBP2, the allelic distribution patterns for these loci revealed a marked genetic divergence among the eight populations. A dendrogram constructed by the neighbor-joining method based on the allele frequencies of the five loci suggested that the five Asian populations (Japanese, Northern Han, Hui, Uygur, and Kazakh) formed one cluster, whereas the two European populations and one West Asian population (Italian, Greek, and Saudi Arabian) formed another. The genetic relationship among these populations may have been greatly influenced by admixture as a result of the migration of individuals along the Silk Road throughout history.

The development of extrahepatic portal obstruction after undergoing multiple operations for a congenital dilatation of the bile duct: report of a case

As a long-term complication after undergoing a cystenterostomy for a congenital dilatation of the bile duct, liver cirrhosis due to stenosis of the anastomosis or reflux cholangitis has been reported in conjunction with subsequent portal hypertension. We treated a 48-year-old Japanese woman who developed both portal hypertension and pancytopenia after undergoing multiple operations for a congenital dilatation of the bile duct. She underwent a Hassab's operation in July 1994, when an occlusion of the extrahepatic portal vein, which resulted in portal hypertension, was first noted; the liver was microscopically normal. The etiology of the extrahepatic portal obstruction in our patient was most likely due to either repeated inflammation or adhesion at the hepatic hilus. Based on these findings, the differential diagnosis of portal hypertension after an operation for a congenital dilatation of the bile duct should therefore include an extrahepatic portal obstruction in addition to liver cirrhosis.

Twenty-six new polymorphic microsatellite markers around the HLA-B, -C and -E loci in the human MHC class I region

The human major histocompatibility complex (MHC) class I region is believed to contain a large number of disease-related loci for diseases such as Behçet's disease and psoriasis vulgaris. Although many novel genes have recently been identified in this region, it still appears to be difficult to relate any of these new genes to MHC class I-associated diseases as causative genetic factors. During the course of large-scale genomic sequencing of the human MHC class I region, we identified 262 microsatellite sequences with dinucleotide to pentanucleotide repeats around the HLA-B, -C and HLA-E genes. Of these, 26 microsatellites were investigated for repeat polymorphism using 60 HLA homozygous B-cell lines and 60 healthy random individuals. The average number of alleles at these microsatellite loci was 9.6 with a PIC (polymorphism content value) of 0.69. These new polymorphic microsatellite markers will probably be very useful for precise mapping of disease-related genes within the HLA class I region in linkage analysis. Moreover, they will provide a powerful tool to study recombination events in this region, which contributes to haplotypic diversification.

Association of high-altitude pulmonary edema with the major histocompatibility complex

BACKGROUND

A constitutional susceptibility has been suggested in the development of high-altitude pulmonary edema (HAPE) because HAPE generally affects healthy young people, some of whom suffer recurrent episodes. We examined whether immunogenetic susceptibility is present in HAPE-susceptible subjects.

METHODS AND RESULTS

The frequencies of human leukocyte antigen (HLA) alleles in 28 male and 2 female subjects with a history of HAPE were compared with those in 100 healthy volunteers. We assayed the HLA-A, -B, -C, -DR, and -DQ antigens serologically. The pulmonary hemodynamics on admission to the hospital and the ventilatory response to hypoxia and hypercapnia were retrospectively examined in 10 of the HAPE-susceptible subjects. HLA-DR6 was positive in 14 (46.7%) of the subjects with HAPE but only 16.0% of the control subjects (P=.0005), and HLA-DQ4 was positive in 12 (40.0%) of the subjects with HAPE but only 10.0% of the control subjects (P=.0001). HLA-DR6 or HLA-DQ4 was positive in 8 (100%) of the subjects with recurrent HAPE. The pulmonary arterial pressure on admission of the HLA-DR6-positive subjects with HAPE was significantly higher than that of the HLA-DR6-negative subjects with HAPE.

CONCLUSIONS

There were significant associations of HAPE with HLA-DR6 and HLA-DQ4 and of pulmonary hypertension with HLA-DR6. An immunogenetic susceptibility, which is associated with HLA class II alleles located within the major histocompatibility complex, may underlie the development of HAPE, at least in some of its forms.

MICA gene polymorphisms and HLA-B27 subtypes in Japanese patients with HLA-B27-associated acute anterior uveitis

PURPOSE

HLA-B27-associated acute anterior uveitis (HLA-B27 AAU) seems to be triggered by external factors in persons with a particular genetic background. It is still uncertain whether HLA-B27 or other gene(s) near the HLA-B region predisposes to uveitis in a linkage disequilibrium with B27. The authors investigated microsatellite polymorphism within the transmembrane region of the MICA gene, located 47 kb centromeric of the HLA-B gene, and HLA-B27 subtypes.

METHODS

Seventeen HLA-B27-positive Japanese patients with HLA-B27 AAU, 51 Japanese controls, and 20 B27-positive Japanese controls were examined for MICA gene polymorphism within the transmembrane region using polymerase chain reaction (PCR) and subsequent automated fragment detection by fluorescent-based technology. Furthermore, B27-positive patients with HLA-B27 AAU and B27-positive controls were examined for HLA-B27 subtypes by the PCR-sequence-specific primer method.

RESULTS

The microsatellite allele in the MICA gene, consisting of four repetitions of GCT/AGC (designated A4 allele), was present at a significantly higher phenotype frequency in the patient group (64.7%) than in the control group (25.5%) (chi 2 = 6.95, Pc = 0.042). Furthermore, the frequency of the A4 allele was significantly higher, even when compared with 20% in the B27-positive control group (chi 2 = 5.88, Pc = 0.042). The frequency of HLA-B27 subtypes was not significantly different between B27-positive patients with HLA-B27 AAU and B27-positive controls.

CONCLUSIONS

These results suggest that the MICA gene itself, or other nearby gene(s), linked to the MICA A4 allele may be involved in the development of HLA-B27 AAU and that HLA-B27 subtypes are not important in the development of HLA-B27 AAU in a Japanese population.