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.

Role of hydrophobic amino acids in gurmarin, a sweetness-suppressing polypeptide

The sweetness-suppressing polypeptide gurmarin isolated from Gymnema sylvestre consists of 35 amino acid residues and contains three intramolecular disulfide bonds. Nuclear magnetic resonance analysis showed that the hydrophobic side chains of Tyr-13, Tyr-14, Trp-28, and Trp-29 in gurmarin are oriented outwardly. Together with the hydrophobic side chains of Leu-9, Ile-11, and Pro-12, they form a hydrophobic cluster, and therefore these hydrophobic groups are assumed to act as the site for interaction with the receptor protein. To examine the roles of these hydrophobic amino acids, they were replaced by Gly. The resulting [Gly13,14,28,29] gurmarin and [Gly9,11,13,14,28,29]-gurmarin did not suppress the responses to sucrose, glucose, fructose, or Gly. This result strongly suggests that these hydrophobic amino acids are involved in the interaction with the receptor protein.

Major histocompatibility complex class II alleles in an Uygur population in the Silk Route of Northwest China

HLA class II (DRB1, DQA1, DQB1 and DPB1) genotyping was performed in 57 unrelated Uygur individuals inhabiting the northwestern China area by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Among 98 DRB1 alleles tested, 23 alleles were detected, and DRB1*0701 (16.7%) and DRB1*0301 (14.0%) were the most and the second most common alleles, respectively. In 8 DQA1 alleles detected, DQA1*05 (26.3%), DQA1*03 (21.9%) and DQA1*0201 (21.1%) were very frequent. Of 21 DQB1 alleles tested, 13 were observed. Among them, DQB1*02 was highly predominant with the gene frequency of 32.5%. Of 46 DPB1 alleles tested, 15 were detected, among which DPB1*0401 (31.6%) was the most frequent. Two haplotypes predominate clearly; DRB1*0701-DQA1*0201-DQB1*02 (15.5%) and DRB1*0301-DQA1*05-DQB1*02 (12.6%). The dendrogram constructed by the neighbour-joining (NJ) method based on the allele frequencies of the DRB1, DQA1, DQB1 and DPB1 genes of 13 representative populations all over the world suggested that Uygur belonged to the Asian group and lay at the closest genetic distance to a Kazak population inhabiting the same area.

[Aging of macular function as seen in multifocal electroretinograms]

Multifocal electroretinograms were recorded from 32 eyes of 32 young and aged healthy volunteers to investigate the change in electrophysiological functions with age in the central, nasal, temporal, superior, and inferior retina. The amplitude and latency of the first negative and positive waves were analyzed statistically in correlation with age. In all regions, amplitudes of focal responses tended to diminish with age. There was significant inverse correlation between amplitude and age in the central retina at 2 and 8 degrees, but no significant correlation was found in the other regions. These facts suggest that the macular retina tends to show functional deterioration with age when compared with other retinal areas.

Cytotoxic T lymphocyte clone specific for autologous human hepatocellular carcinoma cell line SUHC-1

We established a cytotoxic T lymphocyte (CTL) clone directed against an autologous hepatocellular carcinoma (HCC) cell line SUHC-1 which had been established in our department from a patient with HCC associated with hepatitis C virus infection. The CTL clone lysed autologous SUHC-1 cells but did not lyse autologous Epstein-Barr (EB) virus-transformed B cells, natural killer (NK) cell-sensitive erythroleukaemia cell line K562, the NK-resistant B cell line Daudi, or allogeneic HCC cell lines, Hep-G2, Hep-3B, Mahlavu and PLC/PRF/5. The CTL clone expressed CD3 and CD8 molecules. The cytotoxic activity of the clone was inhibited by anti-CD3, anti-CD8 and anti-histocompatibility antigen (HLA) class I monoclonal antibodies. These results indicated that the CTL clone recognized HCC tumour antigen in an HLA class I-restricted manner. Furthermore, we investigated the T cell receptor (TCR) gene usage of the CTL clone. The CTL clone expressed TCR alphabeta. We searched for expression of TCR variable (V) alpha and beta regions and sequenced complementary determining region (CDR) 3 of the clone. The clone expressed V alpha14, junctional (J) region alpha9.7 and V beta7, J beta2.1. The amino acid sequence of the N region of the of chain was S-P-G-G-G-G-A-D-G-L-T and of the N-D-N region of the beta chain was S-W-T-G-A-S-T-D-T-Q-Y. These results suggested that HLA class I-restricted CTL play an important role in the elimination of human HCC cells.

Major histocompatibility complex class II alleles in Kazak and Han populations in the Silk Route of northwestern China

Genetic polymorphism of the HLA class II loci including the DRB1, DQA1, DQB1 and DPB1 genes was investigated by the polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method in a Kazak population inhabiting the most northwestern part of China, Urümqi in the Xinjiang Uygur Zizhiqu as well as in a Han population in the same area. Forty-two Kazak and 59 Han unrelated volunteers were enrolled in this study. Among 51 DRB1 alleles tested, 29 alleles were detected, and DRB1*0301 (13.1%) and DRB1*07 (10.7%) in Kazak and DRB1*0901 (11.9%), DRB1*1501 (11.0%) and DRB1*07 (11.0%) in northwestern Han were highly predominant. In 8 DQA1 alleles detected, DQA1*0501 (29.8%) and DQA1*0301 (23.8%) in Kazak, and DQA1*0301 (28.8%) and DQA1*0102 (19.5%) in northwestern Han were the most and the second most common alleles, respectively. Of 18 DQB1 alleles tested, 14 were observed, among which DQB1*0201 and DQB1*0301 were very frequent both in Kazak (23.8% and 21.4%, respectively) and northwestern Han (18.6% and 16.9%, respectively) populations. Of 37 DPB1 alleles tested, 14 were detected. Among them, the frequencies of DPB1*0401 (21.4%), DPB1*0501 (20.2%), DPB1*0402 (19.0%) and DPB1*0201 (16.7%) in Kazak, and those of DPB1*0501 (38.1%) and DPB1*0201 (16.1%) in northwestern Han were highly increased. Several three-locus haplotypes were recognized to predominate significantly, namely DRB1*0301-DQA1*0501-DQB1*0201 (13.1%) and DRB1*0701-DQA1*0201-DQB1*0201 (8.3%) in Kazak; and DRB1*0901-DQA1*0301-DQB1*0303 (11.9%) and DRB1*0701-DQA1*0201-DQB1*0201 (10.2%) in northwestern Han. The dendrogram constructed by the neighbor-joining (NJ) method based on the allele frequencies of the DRB1, DQA1, DQB1 and DPB1 genes of 12 representative populations all over the world including northern Han, southern Han, Manchu and Japanese suggested that Kazak and northwestern Han were the closest to each other, but Kazak was a little farther from the Asian ethnic groups than northwestern Han.

Retinal toxicity of nitric oxide released by administration of a nitric oxide donor in the albino rabbit

PURPOSE

Nitric oxide (NO), which has been identified as an endothelium-derived relaxing factor, might be involved in regulation of retinal circulation and intraocular pressure. Recently, it was suggested that NO might also be related to neuronal excitotoxicity mediated by the N-methyl-D-aspartate receptor and to the pathologic changes induced by some kinds of uveitis. However, ocular toxicity of NO released by an NO donor has not been clearly demonstrated. In the current study, NO neurotoxicity in the retina was investigated.

METHODS

S-nitroso-N-acetyl-DL-penicillamine (SNAP, 200 nmol) was injected into the vitreous of albino rabbits as an NO donor. The changes of retinal function were evaluated at 1, 2, and 3 hours and 1 and 4 weeks after SNAP injection, using electroretinogram and visual-evoked potentials. Histologic changes of the retina were also examined.

RESULTS

Injection of SNAP reduced the a-wave amplitude. In contrast, the amplitudes of the oscillatory potentials were increased during the 3-hour observation period. Histologic examination showed vacuolar degeneration and loss of the nuclei of the photoreceptors. In the inner retina, some ganglion cells were lost, and cell density in the internal nuclear layer was decreased.

CONCLUSION

Retinal toxicity of NO was demonstrated functionally and histologically, suggesting that NO may play a pathophysiologic role in retinal ischemia or in degenerative retinal diseases.

Allelic variants of the human MHC class I chain-related B gene (MICB)

The human major histocompatibility complex (MHC) is located within a 4 megabase segment on chromosome 6p21.3. Recently, a highly divergent MHC class I chain-related gene family, MIC was identified within the class I region. The MICA and MICB genes in this family have unique patterns of tissue expression. The MICA gene is highly polymorphic, with more than 20 alleles identified to date. To elucidate the extent of MICB allelic variations, we sequenced exons 2 (alpha 1), 3 (alpha 2), 4 (alpha 3), and 5 (transmembrane) as well as introns 2 and 4 of this gene in 46 HLA homozygous B-cell lines. We report the identification of eleven alleles based on seven non-synonymous, two synonymous, and four intronic nucleotide variations. Interestingly, one allele has a nonsense mutation resulting in a premature termination codon in the alpha 2 domain. Thus, MICB appears to have fewer alleles than MICA, not unlike the allelic ratio between the HLA-C and -B loci. A preliminary linkage analysis of the MICB alleles with those of the closely located MICA and HLA-B genes revealed no conspicuous linkage disequilibrium between them, implying the presence of a potential recombination hotspot between the MICB and MICA genes.

Structural requirement of highly-conserved residues in globins

Globins have remarkable sequence diversity, and yet maintain a common fold. In spite of the diversity, there are highly-conserved residues at several sites. The conserved residues were examined in terms of the structural stability, by employing the pseudo-energy functions of the structure/sequence compatibility method. The fitness of each residue type to the structural environment was evaluated at seven highly-conserved sites: the Leu (at the B10 site), Phe (CD1), and Leu (F4) residues were found to fit their respective sites due to hydrophobic interactions; Pro (C2) stabilizes the N-terminal edge of an alpha-helical structure; and Phe (CD4) is stabilized by backbone hydrogen-bonding to Phe (CD1). On the other hand, the other two residues, His (E7) and His (F8), are poorly suited to the sites from a structural viewpoint, suggesting that their conservation clearly results from a heme-related functional requirement. The invariant Phe residue (CD1) has been suggested to be important for supporting the heme. The present analysis revealed that this residue is also well suited to the site in terms of energy.

Validation of HLA-DR locus typing in forensic specimens by combining PCR-SSP with PCR-RFLP

The applicability of HLA-DR DNA typing combined with PCR-SSP (sequence specific primers) and PCR-RFLP (restriction fragment length polymorphism) to forensic practice was investigated. PCR-SSP was as effective as serological HLA-DR typing in determining DR types. For more precise definition of DRB1 alleles encoding DR2, DR4, and DR8 antigens, which are fairly common in Japan, we used the PCR-RFLP method. For increasing the sensitivity of this system, we used the nested or semi-nested PCR technique. The minimum amount of template DNA needed for typing was 10 ng of genomic DNA in the case of ordinary PCR, whereas 10 pg of DNA was enough in nested and semi-nested PCR. HLA-DR and-DRB1 alleles were able to be determined from the small amounts of DNA available in forensic materials using the PCR-SSP and subsequent PCR-RFLP methods.

Neoadjuvant chemotherapy with cisplatinum/5-fluorouracil/low-dose leucovorin for advanced squamous cell carcinoma of the esophagus

Forty-four patients with advanced esophageal squamous cell carcinoma were treated with biochemical modulated combination chemotherapy and surgery. Treatment consisted of cisplatinum (70 mg/m2/day 1, day 22), 5-fluorouracil (5-FU; 700 mg/m2/day, days 1-5, 22-26), and leucovorin (20 mg/m2/day, days 1-5, 22-26) with nutritional support, and surgery (days 42-70, mean day 56). Surgery consisted of subtotal esophagectomy with extended lymphadenectomy. Postoperative adjuvant chemotherapy or additional irradiation to the mediastinum was restricted to patient with residual tumors. Clinical response rate was 63.6% in primary tumor, 52.6% in intramural metastasis, 100% in intraepithelial spread, and 30.9% for metastatic lymph nodes. There was a slight disagreement between the result of evaluation of histological and clinical effect. The incidence of postoperative complications was 25%, and the mortality rate was 2.3%. Overall 1-, 2-, 3-, and 4-year survival rates of the patients were 57%, 37.9%, 28.5%, and 28.5%, respectively. The median survival time was 14.7 months. Responders survived longer than nonresponders. The histological responders survived longer than clinical responders. The 4-year survival rate of patients without residual tumor after treatment was 75% in the superficial cases, 51% in the locoregional cases, and 50% in the widespread cases.

MICA gene and ankylosing spondylitis: linkage analysis via a transmembrane-encoded triplet repeat polymorphism

In order to address the possibility that the MICA gene located 47 kb upstream from HLA-B is involved in the pathogenesis of ankylosing spondylitis (AS), we have investigated microsatellite polymorphism in the transmembrane region of MICA in Caucasian patients with AS. The microsatellite allele consisting of 4 repetitions of GCT/AGC was present at significantly higher frequency in the patient group (Pc<0.0000001) than in the ethnically matched control group. However, the frequency of the (GCT/AGC)4 allele was significantly low in the B27-positive patients than in the B27-positive healthy controls (Pc=0.0145). These observations suggest that B27 itself remains the primary genetic marker for AS, although the significantly dissimilar phenotype frequency of the (GCT/AGC)4 allele in B27-positive patients and healthy individuals may reflect the existence of other genetic factor(s) in the HLA-B27 haplotype involved in the development of AS.

Trinucleotide repeat polymorphism within exon 5 of the MICA gene (MHC class I chain-related gene A): allele frequency data in the nine population groups Japanese, Northern Han, Hui, Uygur, Kazakhstan, Iranian, Saudi Arabian, Greek and Italian

We recently identified a trinucleotide repeat polymorphism, (GCT)n, within the transmembrane (TM) segment of the human MHC class I MICA gene (MHC class I chain-related gene A). Five distinct alleles (A4, A5, A5.1, A6, A9) corresponding to 4, 5, 5 with one nucleotide insertion, 6 and 9 repetitions, respectively, have been detected in various HLA-homozygous B cell lines. Here we present allele frequencies for this trimeric short tandem repeat (STR) in 604 unrelated individuals collected from nine human populations (Japanese, Northern Han, Hui, Uygur, Kazakhstan, Iranian, Saudi Arabian, Greek and Italian) determined using the polymerase chain reaction (PCR) combined with fluorescent-based automated fragment detection technology. All alleles were present in each population, but allelic distributions varied from one population to another. No new alleles (such as A7 or A8) were identified. The evolutionary and structural significance of these data as well as the potential application to forensic medicine is discussed.

Assessment of pseudo-energy potentials by the best-five test: a new use of the three-dimensional profiles of proteins

We propose a new assessment, called the best-five test, for the pseudo-energy potential empirically derived from the protein structural database. The object of the test is the three-dimensional (3D) profiles of proteins, which are directly connected to the pseudo-energy potentials. In the 3D profile, the fitness of each amino acid type is ranked at each residue site of a protein. A site whose native residue type is ranked within the best-five out of 20 amino acids is regarded as satisfactory and the ratio of the satisfactory sites over all the sites of all the proteins examined is indicative of the efficiency of the pseudo-energy potential employed. We applied the test to our potential function consisting of four terms; side-chain packing, hydration, backbone hydrogen-bonding and local conformation, by setting various kinds of definitions for each term. Through this test, the validity of the minus average operation is confirmed, where the energy level of potential functions is adjusted by referring to the random-environmental state of the proteins. Especially in the side-chain packing function, the success ratio increases from about 30 to 50% with this operation. Failure without the operation is ascribed to bulky hydrophobic residues, which almost always occupy higher ranking positions in the 3D profile table. A maximum success ratio of 55.6% was attained with the final potential set consisting of the above four terms. The efficiency of the final set was further checked in the fold-recognition test for distantly related proteins. The best-five test is a new use of the 3D profile table for assessing the ability of the pseudo-energy potentials.

Triplet repeat polymorphism in the transmembrane region of the MICA gene: a strong association of six GCT repetitions with Behçet disease

A member of a novel family of the human major histocompatibility complex (MHC) class I genes termed MIC (MHC class I chain-related genes), MICA, has been recently identified near the HLA-B gene on the short arm of human chromosome 6. The predicted amino acid sequence of the MICA chain suggests that it folds similarly to typical class I chains and may have the capacity to bind peptides or other short ligands. Therefore, MICA is predicted to have a specialized function in antigen presentation or T cell recognition. During nucleotide sequence analyses of the MICA genomic clone, we found a triplet repeat microsatellite polymorphism of (GCT/AGC)n in the transmembrane (TM) region of the MICA gene. In 68 HLA homozygous B cell lines, 5 distinct alleles of this microsatellite sequence were detected. One of them contained an additional one base insertion that created a frameshift mutation resulting in a premature termination codon in the TM region. This particular allele may encode a soluble, secreted form of the MICA molecule. In addition, we have investigated this microsatellite polymorphism in 77 Japanese patients with Behcet disease, which is known to be associated with HLA-B51. The microsatellite allele consisting of 6 repetitions of GCT/AGC was present at significantly higher frequency in the patient group (Pc = 0.00055) than in a control population. Furthermore, the (GCT/AGC)6 allele was present in all B51 positive patients and in an additional 13 B51 negative patients. These results suggest the possibility of a primary association of Behcet disease with MICA rather than HLA-B.

[Treatment of gingivitis in elderly patients in a nursing home]

For 3 months, 4 patients in a nursing home for the elderly received supervised professional oral care in conjunction with oral hygiene instruction. Within the first month after the start of this program, plaque was reduced to 1/3 and gingivitis was reduced to 1/9 of their respective initial levels. In 5 patients who did not receive either oral hygiene instruction or professional oral care, plaque retention and gingivitis were unchanged. We conclude that professional oral care combined with oral hygiene instruction supervised by dental professionals can help to control gingivitis in the elderly.

[Pharyngeal bacteria and professional oral health care in elderly people]

In 15 elderly residents of an old-age home, we measured the total number of bacteria and the numbers of streptococci and staphylococci in the pharynx over 5 months. Seven residents received professional oral health care from dentists and dental hygienists and eight practiced oral care by themselves or together with a helper. During the 5 months, the total number of bacteria and the numbers of streptococci and staphylococci decreased (p < 0.01) in those who received professional care. In contrast, the total number of bacteria and the numbers of streptococci and staphylococci neither did not change or increased in those who did not receive professional care. These findings show that professional oral health care by dentists and dental hygienists can decrease the total number of bacteria and the numbers of streptococci and staphylococci in the pharynx of elderly people, which might prevent aspiration pneumonia.