Long-term prospective study on the natural history of Wolff-Parkinson-White syndrome detected during a heart screening program at school

In the period 1985 to 1993, a total of 802 school-aged children (284 first-graders and 518 seventh-graders) were referred to our hospital for further evaluation of electrocardiographic abnormalities. Among them, 57 (male 24 and female 33) children were confirmed as having Wolff-Parkinson-White (WPW) syndrome based on the findings of 12-lead surface electrocardiograms (ECG). According to Lindsay's criteria, the locations of the accessory pathways were as follows: Left-lateral in 10 (18%), left-posterior in 2 (4%), right-free-wall in 28 (49%), anterior-septum in 13 (23%) and posterior-septum in 3 (5%). One 12-y-old girl had multiple accessory pathways. Six patients had associated diseases: Ebstein's anomaly in 4, epilepsy in 1 and mental retardation with scoliosis in 1. Follow-up periods ranged from 2.0 to 13.0 y (mean +/- SD: 8.0 +/- 3.3 y) for 23 first-graders with WPW syndrome, and from 2.0 to 13.0y (mean +/- SD: 7.3 +/- 4.2y) for 34 seventh-graders, respectively. Initially, 5 children had at least one episode of supraventricular tachycardia (SVT) by history and 6 children developed SVT during the follow-up. One girl with multiple accessory pathways and recurrent SVT required long-term drug therapy.

CONCLUSIONS

The outcome of children with WPW syndrome detected by a heart screening program at school was favorable. Our 8 y follow-up of 57 children with WPW syndrome will serve as additional information concerning the indication of radio-frequency catheter ablation therapy for WPW syndrome in children.

Genetic studies with the fission yeast Schizosaccharomyces pombe suggest involvement of wee1, ppa2, and rad24 in induction of cell cycle arrest by human immunodeficiency virus type 1 Vpr

Accessory protein Vpr of human immunodeficiency virus type 1 (HIV-1) arrests cell cycling at G(2)/M phase in human and simian cells. Recently, it has been shown that Vpr also causes cell cycle arrest in the fission yeast Schizosaccharomyces pombe, which shares the cell cycle regulatory mechanisms with higher eukaryotes including humans. In this study, in order to identify host cellular factors involved in Vpr-induced cell cycle arrest, the ability of Vpr to cause elongated cellular morphology (cdc phenotype) typical of G(2)/M cell cycle arrest in wild-type and various mutant strains of S. pombe was examined. Our results indicated that Vpr caused the cdc phenotype in wild-type S. pombe as well as in strains carrying mutations, such as the cdc2-3w, Deltacdc25, rad1-1, Deltachk1, Deltamik1, and Deltappa1 strains. However, other mutants, such as the cdc2-1w, Deltawee1, Deltappa2, and Deltarad24 strains, failed to show a distinct cdc phenotype in response to Vpr expression. Results of these genetic studies suggested that Wee1, Ppa2, and Rad24 might be required for induction of cell cycle arrest by HIV-1 Vpr. Cell proliferation was inhibited by Vpr expression in all of the strains examined including the ones that did not show the cdc phenotype. The results supported the previously suggested possibility that Vpr affects the cell cycle and cell proliferation through different pathways.

Rat and guinea pig pancreatic acini possess both VIP(1) and VIP(2) receptors, which mediate enzyme secretion

Pancreatic acini from most species possess vasoactive intestinal peptide (VIP) receptors. Recently, two subtypes of VIP receptors, VIP(1)-R and VIP(2)-R, were cloned. Which subtype exists on pancreatic acini or mediates secretion is unclear. To address this, we examined pancreatic acini from both rat and guinea pig. VIP(1)-R and VIP(2)-R mRNA were identified in dispersed acini from both species by Northern blot analysis and in rat by Southern blot analysis. With the use of the VIP(2)-R-selective ligand Ro-25-1553 in both species, inhibition of binding of (125)I-labeled VIP to acini showed a biphasic pattern with a high-affinity component (10%) and a second representing 90%. The VIP(1)-R-selective ligand, [Lys(15),Arg(16),Leu(27)]VIP-(1-7)-GRF-(8-27), gave a monophasic pattern. Binding of Ro-25-1553 was better fit by a two-site model. In both rat and guinea pig acini, the dose-response curve of Ro-25-1553 for stimulation of enzyme secretion was biphasic, with a high-affinity component of 10-15% of the maximal secretion and a low-affinity component accounting for 85-90%. At low concentrations (10 nM) of Ro-25-1553 and [Lys(15),Arg(16), Leu(27)]VIP-(1-7)-GRF(8-27), which only occupy VIP receptors, a 4-fold and a 56-fold increase in cAMP occurred, respectively. These results show that both VIP(1)-R and VIP(2)-R subtypes exist on pancreatic acini of rat and guinea pig, their activation stimulates enzyme secretion by a cAMP-mediated mechanism, and the effects of VIP are mediated 90% by activation of VIP(1)-R and 10% by VIP(2)-R. Because VIP has a high affinity for both VIP-R subtypes, its effect on pancreatic acini is mediated by two receptor subtypes, which will need to be considered in future studies of the action of VIP in the pancreas.

Cutting edge: absence of expression of RAG1 in peritoneal B-1 cells detected by knocking into RAG1 locus with green fluorescent protein gene

It has been proposed that Ig gene rearrangement in the peritoneal cavity (Pc) B-1 cells might be involved in autoantibody generation. To study possible secondary B cell maturation, we prepared mice carrying a target integration of gfp gene into a rag1 locus (rag1/gfp mice). The GFP+ cells express rag1 mRNA and are undergoing Ig gene rearrangement. RAG1 expression was studied in Pc B-1 cells to detect cells during the stage of Ig gene rearrangement. In contrast to previous reports, Pc B-1 cells did not show RAG1 expression in adolescent or elderly mice. RAG1 expression was not induced in Pc B-1 cells in vivo after stimulation by oral or i.p. administration of LPS. Our results suggest that RAG1 expression in Pc B-1 cells is inhibited for a long period under normal condition and that this suppression is an essential state which maintains allelic exclusion of Ig genes.

Doc2alpha is an activity-dependent modulator of excitatory synaptic transmission

Doc2alpha is a synaptic vesicle-associated Ca2 + -binding protein. To study the role of Doc2alpha in synaptic transmission and modulation, we generated homozygous null Doc2alpha mutant mice. In the CA1 region of hippocampal slices in the mutant mice, excitatory synaptic responses evoked with prolonged 5 Hz stimulation showed a significantly larger frequency facilitation followed by a steeper depression than those in wild-type mice, whereas there was no difference in synaptic transmission at lower frequencies or in paired-pulse facilitation. These results suggest that Doc2alpha regulates synaptic transmission when high Ca2 + concentrations in the presynaptic terminal are sustained. Furthermore, the mutant mice showed impairment in long-term potentiation and passive avoidance task. Thus, Doc2alpha may regulate transmitter release during repetitive synaptic activation, thereby contributing to memory formation.

[Studies on brain pyruvate dehydrogenase (PDH) activity and energy metabolites during ischemia and reperfusion]

Pyruvate dehydrogenase is one of the mitochondrial enzymes considered important in the regulation of oxidative metabolism. To further understand the relationship between its activity and ischemic brain damage we conducted three experiments. We studied the effects of (1) duration of cerebral ischemia, (2) the Ca2+ channel blocker, nicardipine, and (3) the immunosuppressant, FK506, on PDH activity and energy metabolites during ischemia and reperfusion. In the first study we also measured regional cerebral blood flow (rCBF). (1) Increasing the duration of the ischemic insult delayed the deactivation of PDH, slowed the resynthesis of high energy phosphates and the clearance of lactate, and impaired recovery of rCBF. Additionally, (2) nicardipine normalized PDH activities and improved the impaired metabolism after reperfusion, and (3) FK506 did not effect PDH activity, but significantly improved the impaired metabolism during the early phase of reperfusion. From these studies we conclude that PDH plays a role in the recovery of metabolism during reperfusion, and both nicardipine and FK506 improve metabolism during the early phase of reperfusion.

Amplification of FISH signals using intermittent microwave irradiation for analysis of chromosomal instability in gastric cancer

Gastrointestinal tract tumours are notorious for their difficulty in relation to conventional cytogenetic analysis. In particular, necrosis, the presence of stromal inflammatory and other cells, and poor attachment of tumour cells have led to problems with the quality and reliability of cytogenetic preparations, even with the recently developed fluorescence in situ hybridisation (FISH) technique. Furthermore, background autofluorescence masks the weak hybridisation signals in the nuclei. To overcome this problem, brief microwave treatment was applied for the identification of centromeres by in situ hybridisation in gastric cancer cells. Using this technique, a panel of 17 centromeric specific alpha-satellite probes was used to detect chromosomal instability in these cells. Lymphocyte controls and cancer cells subjected to irradiation achieved the hybridisation threshold in 30 minutes, providing a significant difference when compared with the non-irradiated samples (mean (SD) frequency of diploid cells 97% (2.1%) v 76% (4.6%), respectively). Therefore, this protocol of intermittent microwave treatment is recommended as a simple, rapid, and highly reproducible technique for application to various types of probe. It also gives well defined hybridisation signals and reduces background "noise".

Organophosphate metabolic changes in the rat lens during the development of galactose-induced cataract

Using phosphorous-31 nuclear magnetic resonance (31P-NMR) spectroscopy, we observed the metabolic kinetics of organophosphate compounds in the rat lens during cataract development induced by different doses of galactose (5%, 15%, 25%, and 40%) added to rat chow. The metabolic and histologic changes in the lenses were compared among the rats fed with different doses of galactose. alpha-Glycerophosphate significantly increased in response to the galactose doses, followed by a decrease to steady values of approximately 120% of the base line value, except in the 40% galactose group, which had a marked decrease to 68% of the base line value. Choline phosphate decreased rapidly during dosing in all but the 5% group, but no changes in those levels were observed after 2 weeks of galactose dosing. ATP decreased significantly when the histologic destruction progressed in the entire lens. Although inorganic phosphate increased significantly in a dose-dependent manner, it did not exceed the peak level. The histologic changes were closely related to the dynamic changes in the phosphorous compounds in the rat lens during formation of the galactose-induced cataract. Our results indicated that the development of a galactose-induced cataract was associated with the metabolic changes of the phosphate compounds.

Activity and substrate specificity of the murine STK2 Serine/Threonine kinase that is structurally related to the mitotic regulator protein NIMA of Aspergillus nidulans

We isolated a murine STK2 (mSTK2) cDNA that is homologous to murine Nek1 serine/threonine kinase, a family member related to the cell cycle regulator kinase NIMA of Aspergillus nidulans. Structural comparison demonstrated that the kinase domain of mSTK2 is highly similar to NIMA/Nek family but the C-terminal region is not similar to any proteins except for human STK2 (hSTK2). Similarly to Nek1, mSTK2 is expressed ubiquitously among various organs and is upregulated in the testis. The expression and localization of mSTK2 are not associated with the cell cycle progression of mitogen-activated lymphocyte and DNA-transfected fibroblast. The substrate specificity of mSTK2 is similar to NIMA, but the phosphorylation is observed exclusively upon threonine residues rather than serine. The mSTK2 is shown to be a new member of the NIMA/Nek family with similar substrate specificity, which might participate in a different role from NIMA kinase involved in the cell cycle regulation.

Regulation of small intestinal transit by central nervous calcitonin receptor

Salmon calcitonin (sCT) suppresses small intestinal transit (SIT) or motility, but the mechanism is not well understood. Bolus s. c. administration of a pharmacologic dose of sCT (140 IU/kg) to mice significantly decreased plasma calcium and phosphorus, and suppressed SIT from 1 to 8 h for plasma calcium and phosphorus or 20 h for SIT (respective maximal effects were seen at 5 h, between 2 and 8 h, and between 1 and 5 h). Significant SIT inhibition did not occur at doses smaller than 140 IU/kg. Reverse transcription-polymerase chain reactions and Southern analysis demonstrated high levels of calcitonin receptor mRNA in diencephalon and lung, moderate levels of mRNA in cerebellum, kidney, and muscle, and barely detectable amounts in cerebral cortex and thymus. No message was detectable in duodenum, jejunum, liver, testis, or heart. Specific binding of [125I] sCT was demonstrated in the diencephalon. Intracerebroventricular (i.c.v.) administration of sCT inhibited SIT time- and dose-dependently. Maximal inhibition was obtained at a dose of 4 IU/kg, 20 min after injection. Pretreatment with sCT (140 IU/kg s.c.) completely abolished inhibition of SIT by i.c.v. sCT (4 IU/kg). These results suggest that sCT binds to receptors in the central nervous system and inhibits small bowel transit.

Important role of endothelium-derived hyperpolarizing factor in shear stress--induced endothelium-dependent relaxations in the rat mesenteric artery

Shear stress is one of the most important stimulators for the release of endothelium-derived relaxing factors. Although shear stress-induced release of nitric oxide (NO) has been extensively investigated, it remains to be elucidated whether endothelium-derived hyperpolarizing factor (EDHF) contributes to the endothelium-dependent relaxations to shear stress. This study was designed to address this point in the isolated rat mesenteric artery. Large mesenteric arteries (400-500 microm) and resistance mesenteric arteries (150-250 microm) of the rat were precontracted with phenylephrine (at 80 mm Hg of perfusion pressure), and the changes in vessel diameter in response to variable flow (0-300 microl/min) were continuously examined. The relative contributions of vasodilator prostaglandins, NO, and EDHF were analyzed by the inhibitory effects of indomethacin (10(-5) M), N(G)-nitro-L-arginine (L-NNA, 10(-4) M), and KCl (40 mM), respectively. The shear stress-induced relaxations were totally endothelium dependent in both-sized blood vessels, and the contribution of NO was more prominent in large arteries than in resistance arteries, whereas that of EDHF was noted in both-sized blood vessels. Tetrabutylammonium (a nonselective inhibitor of K channels) almost abolished, whereas the combination of charybdotoxin (an inhibitor of both large- and intermediate-conductance Ca2+ -activated K channels) and apamin (an inhibitor of small-conductance Ca2+ -activated K channels) significantly inhibited the EDHF-mediated component of the shear stress-induced relaxations. These results indicate that EDHF plays an important role in shear stress-induced endothelium-dependent relaxations, where K channels, especially calcium-activated K channels, appear to be involved.

Reduction of telomeric repeats as a possible predictor for development of hepatocellular carcinoma: convenient evaluation by slot-blot analysis

Hepatocellular carcinoma (HCC) mainly arises from the liver with chronic inflammation. Because telomere reduction reflects replicative history in somatic cells, we analyzed the possibility that liver tissues surrounding HCC consist of the cells carrying substantial reduction of telomere. We studied 20 HCC and surrounding noncancerous liver tissues (SL) obtained by surgical resection, and 10 laparoscopically obtained needle biopsy specimens of the liver with chronic inflammation including no overt HCC (CI). Five liver tissues without chronic liver diseases (ND) were also examined. Extracted genomic DNAs were blotted on a nylon membrane, and probed at first with radio-labeled d(TTAGGG)(3) and reprobed with radio-labeled d(CCT)(7). The intensity caused by d(TTAGGG)(3) was divided by that of d(CCT)(7). The ratio was defined as telomeric repeats content (TC). Dilution experiments reproducibly revealed almost the same TC. The reduction rate of telomere length through aging estimated by regression analysis of TC was 0.62% per year. Concomitant analyses of TC and average telomere length revealed that both values were significantly correlated (r =.45; P =.009). To compare TC in the liver with respect to chronic inflammation, the value was divided by TC in peripheral blood leukocytes (PBL) from the same donor. The ratio was defined as relative TC (RTC). There was a statistically significant decrease of RTC in CI compared with that in ND (P =.03). Furthermore, RTC in SL was significantly lower than that in CI (P =.0001). These observations suggest that RTC value in liver tissues may digitally indicate a replicative history of hepatocytes under chronic inflammation, and a risk of HCC development.

hOGG1 Ser326Cys polymorphism and lung cancer susceptibility

The human homologue of the yeast OGG1 gene, hOGG1, has been cloned, and its genetic structure has been determined. Several polymorphisms in the hOGG1 gene were detected in the Japanese populations, and among them, the Ser-Cys polymorphism at codon 326 has been shown to have a functional difference in complementation of mutant Escherichia coli that is defective in the repair of 8-hydroxyguanine. Activity in the repair of 8-hydroxyguanine is greater in hOGG1-Ser326 protein than in hOGG1(326) protein. Because many environmental carcinogens produce 8-hydroxyguanine residue and mismatching to this modified base potentially causes oncogenic mutations, the capacity to repair these lesions can be involved in cancer susceptibility in human beings. We, therefore, examined allele distributions of the Ser326Cys polymorphism in a case-control study of male lung cancer in Okinawa. The analyses based on 241 cases and 197 hospital controls disclosed the following findings. (a) Those with the Cys/Cys genotype were at an increased risk of squamous cell carcinoma and nonadenocarcinoma compared to those with the Ser/Cys and those with the Ser/Ser genotypes combined. The odds ratios adjusted for age and smoking history were 3.01 (95% confidence interval, 1.33-6.83) and 2.18 (95% confidence interval, 1.05-4.54), respectively. (b) The odds ratios for other histological subtypes of lung cancer or those in total were not significant. Those for Cys/Cys or Ser/Cys genotype against Ser/Ser did not reach statistical significance in any cell type. (c) The distributions of this polymorphism varied for different populations (Chinese, Japanese, Micronesians, Melanesians, Hungarians, and Australian Caucasians), with much less prevalence of Cys allele in the latter three populations. Although our sample size was limited, these results indicate that the Ser326Cys variant may be related to squamous cell lung cancer susceptibility. The Cys/Cys genotype appears to be more susceptible to squamous cell carcinoma, although the risk is less than that previously reported to be associated with the CYP1A1 gene. Further studies are needed to assess the importance of the interpopulation variation to cancer susceptibility.

Diagnostic criteria for non-traumatic osteonecrosis of the femoral head. A multicentre study

Six major and seven minor diagnostic criteria have been developed by the Japanese Investigation Committee for osteonecrosis of the femoral head (ONFH). We have carried out a multicentre study to clarify these. We studied prospectively 277 hips in 222 patients, from six hospitals, who had ONFH and other hip pathology and from whom histological material was available. We identified five criteria with high specificity: 1) collapse of the femoral head without narrowing of the joint space or acetabular abnormality on radiographs, including the crescent sign; 2) demarcating sclerosis in the femoral head without narrowing or acetabular abnormality; 3) a 'cold-in-hot' appearance on the bone scan; 4) a low-intensity band on T1-weighted images (band pattern); and 5) evidence of trabecular and marrow necrosis on histological examination. With any combination of two of these criteria, the sensitivity and specificity of the diagnosis were 91% and 99%, respectively.

[Immunohistochemical study of p53 and Ki-67 antigen expression in bladder carcinoma]

We examined the relationship between the expression of mutant p53 and Ki-67 antigens in urinary bladder transitional cell carcinoma and the pathological and clinical findings. Tissues were obtained from 28 patients with bladder carcinoma who underwent total or partial cystectomy. An ABC immunostaining method and two primary antibodies (DO-7 and MIB-1 antibodies) were used. The percentages of p53 and Ki-67 antigen-positive cells to the total number of cells were regarded as the p53 and Ki-67 labeling indices (LI) respectively. There were no statistically significant correlations between p53 LI and the histological grade or stage, although p53 LI increased slightly in the high grade and high stage group. There was a statistically significant correlation between Ki-67 LI and the histological grade and stage (p < 0.05). The correlation between p53 LI and Ki-67 LI was linear. Some cases had a p53 LI below the mean even though the Ki-67 LI was higher. The clinical course was characteristic of superficial bladder carcinoma initially, but progressed to invasive bladder carcinoma over the next several years. These results suggest that even cases initially diagnosed as superficial bladder carcinoma with a low p53 LI may progress to invasive bladder carcinoma in subsequent years. Therefore, it is important that the patient be followed-up.

High serum levels of M-CSF and G-CSF in Kawasaki disease

To examine any role of macrophage colony-stimulating factor (M-CSF), in the immune responses in Kawasaki disease (KD), we serially assayed M-CSF and several related cytokines using ELISA. In 10 paediatric patients with KD the level of M-CSF was significantly higher in the acute phase than in the convalescent phase (1476.1 +/- 443.6 v 805.0 +/- 184.7 U/ml). Higher levels of serum granulocyte colony-stimulating factor (G-CSF) and interleukin-6 were also found in the acute phase. These results suggest that M-CSF, G-CSF and interleukin-6, derived from monocytes as monokines or derived from vascular endothelial cells, might play an important role in the acute phase of KD.

[Strains of Shigella sonnei recently isolated in Tokyo]

A total of 341 Shigella sonnei strains consisting of 94 domestic strains and 247 imported strains isolated during 1990-1997 in Tokyo, were examined regarding their colicine-type, drug-resistance and ornithine-utilization. The colicine typing results showed that the domestic strains were classified into 7 types, and the imported strains were classified into 13 types. Among the colicine-types identified, 8-type, 0-type, 6-type and 12-type were predominant in the domestic strains, whereas 6-type, 0-type, 8-type, 9A-type and 12-type were predominant in the imported strains. The drug-resistance test using 9 drugs (CP, TC, SM, KM, ABPC, ST, NA, FOM and NFLX) showed that 89.4% of the domestic strains and 85.4% of the imported strains were resistant to some of the drugs except FOM and NFLX. Drugs with a high resistant rate were SM, TC and ST for both groups. Drug-resistance patterns of the resistant strains varied in 22 types. Among those, a triple drug-resistance type with TC.SM.ST was found in the most frequent pattern in both groups. The results of the ornithine-utilization test revealed that 28.7% of the domestic strains and 8.1% of the imported strains were negative. The ornithine-negative strains in the same source had a similar plasmid-profile, but generally there was no correlation between the different sources.

[Diagnostic value of urinary N-telopeptide of type I collagen in prostate cancer: comparison with bone scintigraphy]

The usefulness of a new biochemical marker of bone resorption, N-telopeptide of type I collagen (NTx), in the diagnosis of bone metastasis was assessed in 69 prostate cancer patients. Based on the bone scintigraphy findings, the patients were divided into a bone metastasis (+) group (n = 36) and a bone metastasis (-) group (n = 33). The urinary NTx level was significantly higher in the bone metastasis (+) group than in the bone metastasis (-) group (95.5 +/- 18.5 nM BCE/mM Cr vs. 63.3 +/- 7.9 nM BCE/mM Cr). There was a tendency for greater variability in urinary NTx levels during a 2 month-period in the bone metastasis (+) group than in the bone metastasis (-) group. The urinary NTx level of the 6 patients who were clinically staged as (4+) according to the extent of disease (EOD) grading system was 211.4 +/- 96.9 nM BCE/mM Cr, and was significantly higher (p < 0.05) than in the (-) group. However, there was not a significant difference in urinary NTx levels between the (1+) to (3+) groups and the (-) group. In conclusion, measuring urinary NTx levels in useful in diagnosing bone metastasis in view of the fact that it is a simple and noninvasive procedure. While it is not as sensitive as bone scintigraphy, it may be used to supplement bone scintigraphy.

Long-term vascular effects of Nomega-nitro-L-arginine methyl ester are not soley mediated by inhibition of endothelial nitric oxide synthesis in the rat mesenteric artery

Nomega-nitro-L-arginine methyl ester (L-NAME), one of the synthetic L-arginine analogues with inhibitory effects of nitric oxide (NO) synthesis, is now widely used to examine the role of NO in various organs. We and others demonstrated that long-term treatment with L-NAME causes hypertension and cardiovascular lesions (perivascular fibrosis and medial thickening), especially at microvascular levels. However, convincing evidence is still lacking that these long-term cardiovascular effects of L-NAME are solely mediated by the inhibition of the synthesis of endothelium-derived NO (EDNO). This study was thus designed to better understand the effects of long-term treatment with L-NAME with special reference to EDNO synthesis. Male Wister-Kyoto rats were orally administered L-NAME for 8 weeks. Blood pressure significantly increased at 3 days and 1 and 8 weeks of the treatment. Endothelium-dependent relaxations to acetylcholine (ACh) of the aorta were reduced 3 days after the treatment, recovered at 1 week, and again reduced at 8 weeks, whereas the relaxations of the small mesenteric artery were unaltered throughout the experimental periods. At 8 weeks, indomethacin-sensitive, endothelium-dependent contractions to ACh were noted. The relative contributions of NO and endothelium-derived hyperpolarizing factor also were unchanged. Citrulline assay demonstrated that substantial levels of constitutive NO synthase activity remained in the aorta during the experiments. The long-term treatment with L-NAME caused perivascular fibrosis and medial thickening, not only in the aorta but also in the mesenteric artery. These results suggest that mechanism(s) other than simple inhibition of EDNO synthesis is involved in the long-term cardiovascular effects of L-NAME in the rat mesenteric artery.