A strong association between HLA-B*5101 and Behçet's disease in Greek patients

Behçet's disease is known to be associated with HLA-B51, one of the split antigens of HLA-B5, among many different ethnic groups. In a Greek population, an increased incidence of HLA-B5 in the patient group has also been reported. Because the B51 antigen has been recently identified to comprise seven alleles, B*5101-B*5107, we performed HLA-B51 allele genotyping by the PCR-SSP method as well as serological HLA-A and -B typing among 31 Greek patients with Behçet's disease to investigate whether there is any correlation between one particular B51-associated allele and Behçet's disease. The frequency of B51 was remarkably high (80.6%) in the patient group as compared to the ethnically matched control group (26.7%). In addition, HLA-A26 was also increased in the patients (29.0%) as compared with the healthy controls (3.3%). B51 allele genotyping revealed that all these B51-positive patients carried B*5101. This study revealed a strong association of Behçet's disease in Greeks with one of the B51 subantigens, providing insight into the molecular mechanism underlying an HLA association with Behçet's disease.

Nucleotide sequence analysis of the HLA class I region spanning the 237-kb segment around the HLA-B and -C genes

To elucidate the detailed gene organization of the human leukocyte antigen (HLA) class I region on chromosome 6, seven contiguous cosmid genomic clones covering the 237-kb segment around the HLA-B and -C loci were subjected to DNA sequencing by the shotgun strategy to give a single contig of 236,822 bp from the MICA gene (58.2 kb centromeric of HLA-B) to 90.8 kb telomeric of HLA-C. This region was confirmed to contain four known genes, MICA, HLA-17, HLA-B, and HLA-C, from centromere to telomere. Further, a new member of the P5 multicopy genes was found to be about 1.3 kb upstream of the HLA-17 gene and designated P5.8. Five novel genes designated NOB1-5 were identified by RT-PCR and Northern blot hybridization. In addition, two pseudogenes, dihydrofolate reductase pseudogene (DHFRP) and ribosomal protein L3 homologous gene (RPL3-Hom), were also found in the vicinity of the HLA-B and -C genes, respectively. The two segments (about 40 kb) downstream of the HLA-B and HLA-C genes showed high sequence homology to each other, suggesting that segmental genome duplication including the major histocompatibility complex (MHC) class I gene must have occurred during the evolution of the MHC.

Usefulness of directional coronary atherectomy in patients with acute anterior myocardial infarction

To assess the usefulness of directional coronary atherectomy (DCA) in acute myocardial infarction (AMI), 139 consecutive patients with anterior wall AMI undergoing successful catheter intervention were studied. The reocclusion rate was significantly lower in the last 70 patients who underwent DCA as aggressively as possible compared with the first 69 patients treated with coronary balloon angioplasty (12.1% vs 3.0%, p <0.05).

DNA damage-induced apoptosis and Ice gene induction in mitogenically activated T lymphocytes require IRF-1

Lymphocytes are highly sensitive to DNA damage-induced apoptosis. In thymocytes, the tumor suppressor p53 has been shown to be required for this type of apoptosis. However an as yet unknown, p53-independent pathway(s) appears to mediate the same event in mitogenically activated mature T lymphocytes. By using mice with a null mutation in the IRF-1 gene, we revealed that DNA damage-induced apoptosis in the latter cell type is dependent on the anti-oncogenic transcription factor interferon regulatory factor-1 (IRF-1). Thus two different anti-oncogenic transcription factors, p53 and IRF-1, are required for distinct apoptotic pathways in T lymphocytes. Furthermore, we found that mitogen induction of the interleukin-1 beta-converting enzyme (Ice) gene, a mammalian homolog of the Caenorhabditis elegans cell death gene ced-3, is also IRF-1-dependent. An IRF-1 binding sequence was identified in the 5' flanking region of the Ice gene. In addition, ectopic overexpression of IRF-1 results in the activation of the endogenous Ice gene and enhances the sensitivity of cells to radiation-induced apoptosis. Thus, induction of Ice gene may be involved in IRF-1 dependent DNA damage-induced apoptosis in activated mature T lymphocytes.

[Assessment of left ventricular systolic function derived from ECG-gated myocardial SPECT with 99mTc-tetrofosmin: automatic determination of LV epi- and endocardial surface]

Non-invasive assessment of ischemic heart disease requires information of both LV function and myocardial perfusion. Recently, ECG-gated myocardial SPECT with technetium-labeled radiopharma-ceuticals can provide both of them. Gated myocardial SPECT were performed in thirty-three patients with cardiac disease using a two-headed rotating gamma camera system (ADAC; VERTEX), 30-60 minutes after resting injection of 555-740 MBq of 99mTc-Tetrofosmin. Then, the SPECT data were used to determine the LV epi- and endocardial surface, and LV volume for measurement of LVEF was calculated automatically. This entire computational process required only 210 seconds per 16 frame study. Interobserver agreement of EF values obtained from gated SPECT was excellent (r = 0.996, n = 10, p < 0.01). LVEFs obtained from gated SPECT showed good correlation to those calculated from radionuclide ventriculography (MUGA) (r = 0.91, p < 0.01). In conclusion, this automatic method using gated myocardial SPECT data was considered to be useful for assessment of LV function with reproducibility.

[The usefulness and the problems of attenuation correction using simultaneous transmission and emission data acquisition method: studies on normal volunteers and phantom]

Attenuation correction using simultaneous transmission data (TCT) and emission data (ECT) acquisition method was applied to 201Tl myocardial SPECT with ten normal adults and the phantom in order to validate the efficacy of attenuation correction using this method. Normal adults study demonstrated improved 201Tl accumulation to the septal wall and the posterior wall of the left ventricle and relative decreased activities in the lateral wall with attenuation correction (p < 0.05: paired t-test). The counts of the posterior wall were however, significantly higher than those of the anterior wall and the lateral wall (p < 0.05: unpaired t-test). Moreover, relative low uptake of the apex was enhanced using attenuation correction. Static phantom studies revealed the self scatter from high 201Tl uptake organs such as the liver and the stomach pushed up the activities in the septal wall and the posterior wall. Cardiac dynamic phantom studies showed partial volume effect due to cardiac motion contributed to under-correction of the apex, which might be overcome using gated SPECT. Although simultaneous TCT and ECT acquisition was conceived of the advantageous method for attenuation correction, miss-correction of the special myocardial segments should be taken into account in assessment of attenuation correction compensated images.

[Histological findings of specimens obtained by directional coronary atherectomy from patients with acute myocardial infarction]

The histological characteristics of acute myocardial infarction were examined in specimens obtained from infarct-related coronary artery lesions (20 left anterior descending artery, 2 left circumflex artery, 8 right coronary artery) in 30 patients with initial acute myocardial infarction who underwent directional coronary atherectomy following intracoronary thrombolysis within 6 hours after the onset of chest pain. Resected tissues were fixed in 10% buffered formalin and embedded in paraffin, and the 4 microns-thick paraffin sections were stained with hematoxylin-eosin and examined by light microscopy. Thrombus and/ or intramural hemorrhage were present in all samples. There were high incidences of cholesterol cleft in 19 (63%), foam cell in 21 (70%), calcium deposit in 19 (63%) and intimal proliferation in 16 (53%). These data suggest that thrombus and/or intramural hemorrhage are important in the onset of acute myocardial infarction.

[Practical localization of the central sulcus using a video display during surgery by cortical somatosensory evoked potentials and how to discern precentral P20 and central P25]

In patients with lesions around the central sulcus, cortical surface somatosensory evoked potentials (SEPs) have been applied for the purpose of localization of the central sulcus based on the polarity inversion of postcentral N20 to precentral P20 across the central sulcus. We have intraoperatively monitored SEPs to infer the location of the central sulcus in 16 cases since December 1988. Intraoperative localization of the central sulcus has been most useful in patients with frontal lobe gliomas in which the localization of the central sulcus enables the surgeon to extensively resect tumor without postoperative motor weakness. The localization of the central sulcus, however, might be misjudged by using the polarity inversion criterion alone, because central P25 following N20 and P20 complicates SEP waveforms. It is significant that P25, which is recorded also posterior to the central sulcus, is discerned from the precentral P20. In order to solve this matter, we regarded only the positivity in SEP waveforms having the identical peak latency to that of N20 as the precentral P20. Positive potentials having a later peak latency than that of N20 are the superposition of P20 and P25, and might also be recorded posterior to the central sulcus. For the observation of the polarity inversion of N20 to P20 across the central sulcus, a multi-channel SEP should be recorded using a sheet of silicone rubber embedded in a 16-electrode array consisting of a 4 by 4 grid. We projected the exposed cortical surface on the video display through the microscope apparatus and marked the locations of the recording electrodes on the video display. This enabled the location of the recording electrodes to correspond easily and precisely to the cortical surface. Our reliable and simple method of intraoperative localization of the central sulcus by cortical SEPs monitoring is presented in a practical case.

Clinical features of patients with chronic liver disease associated with hepatitis C virus genotype 1a/I in Okinawa, Japan

The clinical characteristics of chronic hepatitis C virus (HCV) carriers with HCV genotype 1a/I infection were investigated and compared with those of chronic HCV carriers infected with 1b/II, 2a/III, 2b/IV and the mixed type of infection. We found that 16 of 408 (3.9%) carriers had HCV genotype 1a infection, comprising four of 67 (6.0%) blood donors, 11 of 263 (4.2%) patients with chronic hepatitis and one of 39 (2.6%) patients with liver cirrhosis. Three of 408 subjects had a mixed infection of genotypes 1a/I and 1b/II. All carriers with genotype 1a (including those with the mixed infection) were of Japanese origin and all, except one who was born in Brazil, were born in Okinawa Prefecture. Nine of 14 patients infected with genotype 1a for whom medical records were obtained had a history suggestive of infection through blood exposure; six had had blood transfusions, one had tattoos, one is a nurse and one had a history of drug addiction. There were no haemophiliacs or other multitransfused patients in the genotype 1a group. Of 10 patients infected with genotype 1a who received interferon (IFN) therapy, four (40%) showed a complete response. Although the small number of patients infected with genotype 1a in the present study precluded statistical analysis of the response to IFN, the response in patients with genotype 1a was better than the response in those infected with genotype 1b and poorer than the response in those patients infected with genotype 2a/III or 2b/IV.

Importance of 2-O-sulfate groups of uronate residues in heparin for activation of FGF-1 and FGF-2

Complete drying of heparin with various concentrations of NaOH by lyophilization caused specific 2-O-desulfation to various degrees without detectable depolymerization or other chemical changes. In order to assess the importance of 2-O-sulfate groups in uronate residues to promote FGF-1 and FGF-2 activities, various 2-O-desulfated (2-O-DS-) heparins were quantitatively examined for their effects on FGF-1 and FGF-2-induced proliferation of BALB/c3T3 clone A31 (A31) cells and the chlorate-treated cells. Twenty-seven percent or less loss to the 2-O-sulfate groups had no effect on the ability to activate both FGF-1 and FGF-2, while 44% loss resulted in a significant loss of the ability. Complete loss of the ability was observed in 2-O-DS-heparins with 75% or more 2-O-desulfation. These results suggest that a high content of 2-O-sulfate groups in uronate residues of heparin is required for activation of both FGF-1 and FGF-2.

Analysis of allelic variation of the TAP2 gene in sarcoidosis

Sarcoidosis is a systemic granulomatous disease and the DRB1 gene of the DR subregion has been implicated for determining the genetic susceptibility to the disease. We evaluated the allelic variation of the TAP2 gene using the PCR-RFLP method as well as the mismatched PCR-RFLP method in 82 Japanese patients with sarcoidosis and 92 healthy controls. A new allele, TAP2*0103 and a new polymorphic variation at codon 577 in addition to TAP2*0101, TAP2*0102 and TAP2*0201 have been recognized in the Japanese subjects. No significant differences were observed in the frequencies of any TAP2 alleles or dimorphism at codon 577 between the patients and healthy controls. Polymorphic variation of the TAP2 gene does not confer the susceptibility to sarcoidosis.

Structure of fucose branches in the glycosaminoglycan from the body wall of the sea cucumber Stichopus japonicus

Fucose-branched chondroitin sulfate E was prepared from the body wall of sea cucumber Stichopus japonicus. The purified glycosaminoglycan (GAG) was chemically desulfated, followed by carboxyl reduction. Intact, desulfated, and desulfated/carboxyl-reduced GAG fractions were subjected to per-O-methylation. GC-MS analyses of the resultant partially methylated alditol acetates demonstrated that the fucose branch is formed by two fucopyranosyl residues linked glycosidically through position (1-->3), and that the fucose branch and glucuronic acid are almost equimolar. In addition, it was elucidated that about 20% of the branches stretch from O-3 position of a glucuronic acid moiety of the core chondroitin sulfate polymer, while remaining fucose branches are postulated to protrude from O-4 and/or O-6 position(s) of a N-acetylgalactosamine moiety. This fucose branch was also confirmed to be highly sulfated according to six kinds of substitution pattern in methylation analysis.

[Evaluation of three-dimensional CT angiography (3D-CTA) for the diagnosis of cerebral vasospasm]

We evaluated the usefulness of three-dimensional CT angiography (3D-CTA) for the diagnosis of cerebral vasospasm following subarachnoid hemorrhage (SAH). Eleven patients with SAH who were suspected of having cerebral vasospasm on the basis of their clinical symptoms were examined by 3D-CTA with a spiral CT scanner after an intravenous bolus administration of contrast medium. 3D-CTA revealed vasospastic changes of the cerebral vessels in eight patients. Conventional angiography was performed in six patients immediately after the 3D-CTA examination, and demonstrated the cerebral vasospasm. In eight patients, a second 3D-CTA was performed with the same technique one week after the first 3D-CTA examination. The second 3D-CTA showed the cerebral vessels without vasospastic change. In conclusion, 3D-CTA is a promising, minimally invasive strategy for the assessment of cerebral vasospasm.

Detection of antibodies to Borrelia species among patients with confirmed sarcoidosis in a region where Lyme disease is nonendemic

BACKGROUND

Lyme disease is a multisystemic disorder caused by the spirochete Borrelia burgdorferi, while sarcoidosis is a multisystemic granulomatous disease of unknown etiology. The purpose of this study was to evaluate the relationship between Lyme disease and sarcoidosis.

METHODS

We examined the seroprevalence of antibody to Borellia species in patients with sarcoidosis. We performed the enzyme-linked immunosorbent assay, using three Japanese Borrelia species in addition to B. burgdorferi, and dotblot analysis using purified Borrelia-specific proteins in 38 patients with histopathologically confirmed sarcoidosis and 80 healthy controls.

RESULTS

Two patients (5.3%) were positive for antibodies to Borrelia species according to one or both assays, and one (1.2%) healthy control was positive. In both patients it was suspected that Borrelia infection had developed prior to the development of sarcoidosis.

CONCLUSION

Borrelia species were thought not to be responsible for the development of sarcoidosis in a nonendemic region in Japan. Since clinical manifestations of Lyme disease share certain similarities with those seen in sarcoidosis, ophthalmologists should be aware of the need to differentiate between the two diseases and the need for prompt treatment in each case.

LMP7 polymorphism in Japanese patients with sarcoidosis and Behçet's disease

To evaluate the influence of the MHC-linked LMP7 gene on disease susceptibility in HLA class I and class II-associated diseases, the distribution of LMP7 alleles was determined using the PCR-RFLP method in 69 Japanese patients with Behçet's disease, 65 patients with sarcoidosis, and 100 unrelated healthy controls. No differences were found between either of the patient groups and the healthy control group, indicating that LMP7 allelic variation may not contribute to the pathogenesis of either Behçet's disease or sarcoidosis. We also analyzed linkage disequilibria between LMP7 and HLA class II alleles in Japanese populations.

Effect of zeta potential of cationic liposomes containing cationic cholesterol derivatives on gene transfection

Cationic liposomes are known to be useful tools for gene transfection. However, the relation between transfection efficiency and physicochemical properties of liposomes has not been well understood. Here, we synthesized eight cationic derivatives of cholesterol which contain a tertiary amino head group with a different spacer arm. Transfection of plasmid pSV2CAT DNA into cells was done by cationic liposomes made of a mixture of dioleoylphosphatidylethanolamine (DOPE) and each cationic cholesterol derivative. At the same time we measured zeta potential of cationic liposomes by laser Doppler spectroscopy. The present results indicated that zeta potentials of cationic liposomes were well related to transfection activity of pSV2CAT DNA. This suggested that zeta potential of cationic liposomes is one of important factors which control gene transfection.

Time course of impaired coronary flow reserve after reperfusion in patients with acute myocardial infarction

To evaluate the time course of coronary flow reserve after reperfusion, 14 patients with a first anterior wall acute myocardial infarction who underwent successful coronary angioplasty within 6 hours after symptom onset were studied. After angioplasty, coronary flow reserve of the left anterior descending artery was measured with a coronary Doppler guidewire and intravenous dipyridamole (0.56 mg/kg over 4 minutes). Measurements were repeated at predischarge (16 +/- 3 days, n = 12) and at follow-up (6 +/- 3 months, n = 9). Patients with restenosis at the time of repeat catheterization were excluded. An additional 13 patients with normal angiograms served as reference patients. Coronary flow reserve was 1.33 +/- 0.29 after angioplasty. It increased to 1.88 +/- 0.36 at predischarge (p <0.01) and further to 2.34 +/- 0.38 at follow-up (p <0.01 vs after angioplasty and at predischarge, respectively). However, compared with reference patients (3.15 +/- 0.48), coronary flow reserve was significantly reduced in the infarct patients even at follow-up (p <0.01). In infarct patients, the infarct region wall motion was initially -3.86 +/- 0.67 SD/chord. It significantly improved to -2.07 +/- 1.04 SD/chord at predischarge (p <0.01) and to -1.67 +/- 1.43 SD/chord at follow-up (p <0.01). However, there was no significant relation between coronary flow reserve and region wall motion after angioplasty (r = 0.10), at predischarge (r = 0.35), and at follow-up (r = 0.28). Thus, coronary flow reserve is severely impaired early after reperfusion. Coronary flow reserve improves over 2 weeks, but the impairment persists at 6 months after acute myocardial infarction. The impairment of coronary flow reserve cannot be predicted by left ventricular function. Small sample size is a potential limitation of this study, and a larger study should be performed to confirm these findings.

Attenuation of the no-reflow phenomenon after coronary angioplasty for acute myocardial infarction with intracoronary papaverine

The no-reflow phenomenon is observed as reduction of coronary blood flow on the angiograms (angiographic no-reflow) after immediate percutaneous transluminal coronary angioplasty (PTCA) in patients with acute myocardial infarction (AMI). To assess whether a potent coronary microvascular dilator--papaverine--could attenuate the no-reflow phenomenon, nine patients with AMI who were found to have angiographic no-reflow after PTCA were studied. Angiographic no-reflow was defined as the Thrombolysis in Myocardial Infarction flow grade 1 or 2 without any mechanical obstructions in the epicardial artery. A bolus dose of 10 mg of intracoronary papaverine was administered, and the flow grade was again evaluated. Intracoronary papaverine caused a significant improvement of the flow grade (p= 0.0152). The number of cineframes that were required for the contrast medium to pass two selected landmarks on the angiograms also significantly decreased (41 +/- 17 frames to 18 +/- 8 frames, p= 0.0039). Thus intracoronary papaverine attenuated angiographic no-reflow that occurred after PTCA for AMI.

[Evaluation of occult atherosclerosis in the left main coronary artery in patients with acute anterior myocardial infarction]

Intravascular ultrasound was performed in 30 patients with acute anterior myocardial infarction to evaluate occult atherosclerosis in the left main coronary artery which could not be detected by coronary angiography. The intravascular ultrasound catheter was positioned in the left main coronary artery after successful intracoronary thrombolysis, and cross-sectional coronary artery scanning was performed. Percentage area stenosis (%AS) was calculated as (plaque cross-sectional area/vessel cross-sectional area) x 100. Images of crescent-shaped eccentric plaque were obtained in all patients. The mean vessel cross-sectional area was 28.6 +/- 8.0 mm2, and mean plaque cross-sectional area was 7.7 +/- 4.2 mm2. Mean %AS was 27 +/- 15% (range from 6 to 58%). In five patients, intravascular ultrasound was repeated 3 months later, which showed increased %AS more than 15% in two patients. These findings indicate that occult atherosclerosis is present in the left main coronary artery in almost all the patients with acute anterior myocardial infarction and should be treated with caution when coronary intervention is performed.

Limited proteolysis by chymotrypsin of midkine and inhibition by heparin binding

When digested with a low concentration of chymotrypsin, midkine (MK) underwent limited proteolysis and produced two fragments with Mr of 11,000 and 6,000 Da. The cleavage site was identified as on the carboxyl side of Phe55. This limited proteolysis was specifically inhibited by heparin, but not by other glycosaminoglycans. Using various heparin-derived oligosaccharides with different chain lengths or chemically desulfated heparin derivatives, it was shown that a minimum of 6 monosaccharide units was necessary for the inhibition, and that sulfonyl groups of the heparin disaccharide unit were required for inhibition. The present study showed that MK consists of two domains, N- and C-domains, and that Phe55 localized to the hinge region is exposed on the surface of the molecule. It was also suggested that the N-domain may function as a stabilizing domain against proteolytic degradation of the C-domain in the intact molecule.