Association of microalbuminuria with brachial-ankle pulse wave velocity: the Ohasama study

BACKGROUND

Microalbuminuria is recognized as a marker of generalized vascular dysfunction. However, the associations between microalbuminuria and pulse wave velocity (PWV), carotid intima-media thickness (IMT), and ambulatory blood pressure (ABP), respectively, have not been investigated.

METHODS

Brachial-ankle PWV (baPWV), IMT, and ABP were determined in 328 individuals (mean age, 65.7 +/- 6.4 years) from the general population of Ohasama, a rural Japanese community. The participants were assigned to groups with microalbuminuria and with normoalbuminuria, and their characteristics were compared. We also examined the association between microalbuminuria and baPWV, IMT, and ABP, respectively, using multivariate analyses.

RESULTS

Seventy-nine participants (24%) with microalbuminuria had significantly higher baPWV (P < 0.001) and 24-h systolic BP (SBP) (P = 0.006) than those with normoalbuminuria, although 24-h pulse pressure and mean IMT did not significantly differ between the groups. Multiple logistic regression analyses showed that baPWV, but not 24-h ABP, was independently associated with microalbuminuria (P = 0.002) when adjusted for various confounding factors. After further adjustment for 24-h SBP, the association between baPWV and microalbuminuria remained significant (P = 0.012). The trend was significant even when daytime or nighttime SBP was used instead of 24-hour SBP in this model.

CONCLUSIONS

Microalbuminuria appears to be associated with baPWV more closely than with IMT and ABP, and its association with baPWV is independent of ABP and other cardiovascular risk factors.

Dynamic anisotropy and heterogeneity of polystyrene thin films as studied by inelastic neutron scattering

We studied the dynamic anisotropy and heterogeniety of polystyrene thin films in glassy state with inelastic neutorn scattering. Adjusting the scattering vector to the directions parallel and perpendicular to the film surface, we observed the elastic scattering intensities as a function of temperature. It was found for the 200 A film that the elastic intesity decreased with increasing temperature more rapidly in the perpendicular direction than in the pararell direction, showing the higher mobility in the perpendicular direction. However, such dynamical anisotropy was not observed in the 1000 A film. The decrease in the mobility was observed with the film thickness in both the directions. These results were explained in terms of an interface hard layer. We also evelauated the dynamical heterogeniety from the non-Gaussian parameter A0, which increased with decreasing the film thickness, showing the increase in the dynamical heterogeneity. Assuming a simple bi-layer model consisting of the interface hard layer and the bulk-like layer, we analyzed the thickness dependence of the non-Gaussian parameter A0 and the mean square displacement (u2) to find that the hard layer has a thickness of approximately 130 A and a mean square displacement of approximately 0.018 A2 at 230 K.

Myosin light chain kinase-independent inhibition by ML-9 of murine TRPC6 channels expressed in HEK293 cells

BACKGROUND AND PURPOSE

Myosin light chain kinase (MLCK) plays a pivotal role in regulation of cellular functions, the evidence often relying on the effects of extracelluarly administered drugs such as ML-9. Here we report that this compound exerts non-specific inhibitory actions on the TRPC6 channel, a transient receptor potential (TRP) protein.

EXPERIMENTAL APPROACH

Macroscopic and single channel currents were recorded from transfected HEK293 cells by patch-clamp techniques.

KEY RESULTS

Cationic currents elicited by carbachol (CCh; 100 microM) in HEK293 cells overexpressing murine TRPC6 (I(TRPC6)) were dose-dependently inhibited by externally applied ML-9 (IC(50)=7.8 microM). This inhibition was voltage-dependent and occurred as fast as external Na(+) removal. Another MLCK inhibitor, wortmannin (3 microM), and MLCK inhibitory peptides MLCK-IP(11-19) (10 microM) and -IP(480-501) (1 microM) showed little effects on I(TRPC6) density and the inhibitory efficacy of ML-9. The extent of the inhibition also unchanged with co-expression of wild-type or a dominant negative mutant of MLCK. Inhibitory effects of ML-9 on I(TRPC6) remained unaffected whether TRPC6 was activated constitutively or by a diacylglycerol analogue OAG (100 microM). Similar rapid inhibition was also observed with a ML-9 relative, ML-7. Intracellular perfusion of ML-9 via patch pipette, dose-dependently suppressed I(TRPC6). In inside-out patch configuration, bath application of ML-9 (and ML-7) rapidly diminished approximately 35pS single TRPC6 channel activities. Contrarily, currents due to TRPC7 expression were rapidly enhanced by externally applied ML-9 and ML-7, which was not prevented by MLCK inhibitory peptides.

CONCLUSION AND IMPLICATIONS

These results strongly suggest that ML compounds inhibit TRPC6 channels via a mechanism independent of inhibition of MLCK activity.

Oral treatment with probiotic Lactobacillus johnsonii NCC533 (La1) for a specific part of the weaning period prevents the development of atopic dermatitis induced after maturation in model mice, NC/Nga

BACKGROUND

The inhibitory effect of probiotic bacteria on atopic dermatitis has been shown in human infants, but the mechanism is still unclear.

OBJECTIVE

This study aimed to show the effects of the administration of a probiotic during the weaning period in mouse models on production of the intestinal secretory IgA (sIgA) and on the development of atopic dermatitis (AD) in later life.

METHODS

The effects of the administration of Lactobacillus johnsonii NCC533 (La1) during weaning were evaluated using a mouse model (Balb/c). The weaning period of mice was divided into three phases according to the evolution of faecal IgA. La1 was administered in each phase and the evolution of the faecal IgA was estimated. In the next experiment, the effect of the administration of La1 in phase 2 on host immunity after maturation was further assessed by using the model NC/Nga mouse for human AD.

RESULTS

Administration of La1 in each phase showed a distinct effect on the production of sIgA. But sIgA production was only positively stimulated when La1 was administrated in phase 2. The development of AD induced by mite antigen from 6 weeks old was significantly prevented by the primary administration of La1 in phase 2. AD-like lesions were significantly milder than those of the control mice, and histological observations showed an almost normal appearance of the epidermis and upper dermis of the mice treated with La1.

CONCLUSION

This study suggested that the primary administration of La1 in a specific part of the weaning period is effective in preventing or inhibiting the development of AD after maturation by modulating or accelerating the gut immune response.

Single nucleotide polymorphisms in DNA repair genes might be prognostic factors in muscle-invasive bladder cancer patients treated with chemoradiotherapy

DNA repair enzymes repair DNA damaged by platinum agents and ionising radiation. Single nucleotide polymorphisms (SNPs) in DNA repair genes modulate the repair capacity and might affect response and prognosis following platinum-based chemoradiotherapy (CRT). We investigated associations between the functional SNPs in DNA repair genes and response and survival in muscle-invasive bladder cancer patients treated with CRT to determine the predictive value of the SNPs in patient selection for bladder conservation therapy. The study group comprised 78 patients who underwent CRT for transitional cell carcinoma of the bladder. Single nucleotide polymorphisms in xeroderma pigmentosum complementation groups C (Lys939Gln, A/C), D (XPD; Lys751Gln, A/C), and G (Asp1104His, G/C), and X-ray repair cross-complementing groups 1 (XRCC1; Arg399Gln, G/A) and 3 (Thr241Met, T/C) genes were genotyped. Combined genotypes with at least one variant allele in XPD or XRCC1 were significantly associated with improved cancer-specific survival compared with remaining groups (P=0.009). In multivariate analysis, only the combined XPD and XRCC1 genotypes were independently associated with cancer-specific survival (P=0.04). The association was stronger in stage T3/T4 patients (P=0.0008). These results suggest that combined XPD and XRCC1 genotypes might be prognostic factors in muscle-invasive bladder cancer patients treated with CRT.

Heterogeneity and tissue specificity of tropomyosin isoforms from four species of bivalves

Heterogeneity and tissue specificity of tropomyosin isoforms obtained from four species of bivalves (Scapharca broughtonii (ark shell), Mytilus galloprovincialis (mussel), Atrina pectinata (surf clam) and Crassostrea gigas (Pacific oyster)), were examined. Tropomyosins were extracted from translucent and opaque portions of posterior adductor muscle, respectively, and cardiac muscle of each bivalve. There were two tropomyosin isoforms in the ark shell, the surf clam and the Pacific oyster. They were designated as TMa and TMb. In the ark shell, TMa was the common isoform and TMb was specific for the opaque portion of the adductor muscle. In the surf clam, TMb was the common isoform present in all tissues. TMa was found only in the translucent portion of muscle. In the Pacific oyster, TMb was the major component in both portions of adductor muscle and TMa was the major component in cardiac muscle, although both tropomyosins were included in all tissues. The mussel had only one tropomyosin.

PKCα is involved in phorbol ester TPA-mediated stabilization of p14ARF

We generated A21-13 cells expressing p14(ARF) in the presence of doxycycline in order to examine the stability of p14(ARF) protein. The effects of proteasome inhibitor MG132 on p14(ARF) protein stabilization were detectable using our experimental procedure. Introduction of mutant p53 did not affect MG132-mediated p14(ARF) protein stabilization. We found that phorbol ester TPA (12-o-tetradecanoyl-phorbol 13-acetate) stabilized p14(ARF) protein and that p53 status had no effect on TPA-mediated stabilization. TPA-mediated stabilization was abolished by staurosporine but not by lovastatin or U0126. We further investigated which isoforms of PKC were involved in TPA-mediated p14(ARF) stabilization using short-interference RNA. Knockdown of PKCalpha, but not PKCdelta, attenuated TPA-mediated p14(ARF) stabilization. These findings suggest that PKCalpha is involved in TPA-mediated stabilization of p14(ARF) protein, and this effect of TPA was not affected by the Ras/MAPK pathway or p53 status. Our results are indicative of a novel role of PKC in p14(ARF) protein stability.

Characterization of T-cell clones specific to ovomucoid from patients with egg-white allergy

BACKGROUND

Allergic reactions to foods are specific problems for infants and young children. Ovomucoid (OM) is one of the major allergens found in egg-white. We previously established several T-cell clones (TCCs) specific to OM in non-polarizing conditions from 4 patients (TM and YN are immediate-type, IH and YT are non-immediate-type) with egg-white allergy. We characterized their reactive epitopes, antigen-presenting molecules (HLA class II), and usage of TCR alpha and beta genes and the CDR3 loop sequence.

OBJECTIVE

The objective of this study was to characterize these seven clones (TM 1.3, TM1.4,YN 1.1, YN1.5, IH3.1, IH3.3 and YT6.1) for cytokine production patterns and cell-surface-marker phenotypes.

METHODS

We measured the production of cytokines, namely interleukin (IL)-4, IL-5 and interferon-gamma (IFN-gamma) by stimulation with ovomucoid peptides and stained intracellular IL-4 and IFN-gamma, and determined cell-surface markers using anti-interleukin-12 receptor (IL-12R) beta1, anti-IL-12Rbeta2 and anti-interleukin-18 receptor alpha (IL-18Ralpha).

RESULTS

Most TCCs secreted both IL-4 and IFN-gamma in response to the OM peptide mixture, but the secretion patterns were variable; an IFN-gamma dominant pattern was seen in IH3.1 andYT6.1, an IFN-gamma>IL-4 pattern in TM1.3 and TM1.4, an IL-4> IFN-gamma pattern in YN1.5. In intracellular IFN-gamma and IL-4 staining, IFN-gamma single-positive cells were predominant in TM1.3, TM1.4, IH3.1 and YT6.1 and IFN-gamma and IL-4 double-positive cells were predominant in YN1.1, YN1.5 and IH3.3. All TCCs were IL-12Rbeta1-positive, and TM1.3, IH3.1, IH3.3 and YT6.1 were both IL-12Rbeta2- and IL-18Ralpha-positive. TM1.4 and YN1.1 were both IL-12Rbeta2- and IL-18Ralpha-negative. Based on these results, TM1.3 and TM1.4, IH3.1 and YT6.1 had a predominantly Th1 character and YN1.1, YN1.5, and IH3.3 possessed a predominantly Th0 character.

CONCLUSIONS

The phenotypes of TCCs were not in accordance with their clinical manifestations. TCCs established from patients with immediate-type hypersensitivity had either the Th1 or Th0 phenotype as well as those with non-immediate-type hypersensitivity.

Infectious delivery of the 132 kb CDKN2A/CDKN2B genomic DNA region results in correctly spliced gene expression and growth suppression in glioma cells

The expression of genes from genomic loci can be relatively complex, utilizing exonic, intronic and flanking sequences to regulate tissue and developmental specificity. Infectious bacterial artificial chromosomes (iBACs) have been shown to deliver and express large genomic loci (up to 135 kb) into primary cells for functional analyses. The delivery of large genomic DNA inserts allows the expression of complex loci and of multiple splice variants. Herein, we demonstrate for the first time that an iBAC will deliver and correctly express in human glioma cells the entire CDKN2A/CDKN2B genomic region, which encodes for at least three important cell-cycle regulatory proteins (p16(INK4a), p14(ARF) and p15(INK4b)). Two of these proteins are expressed from overlapping genes, utilizing alternative splicing and promoter usage. The delivered locus expresses each gene at physiological levels and cellular responses (apoptosis versus growth arrest) occur dependent on cellular p53 status, as expected. The work further demonstrates the potential of the iBAC system for the delivery of genomic loci whose expression is mediated by complex splicing and promoter usage both for gene therapy applications and functional genomics studies.

Identification of somatic and germline mosaicism for a keratin 5 mutation in epidermolysis bullosa simplex in a family of which the proband was previously regarded as a sporadic case

Epidermolysis bullosa simplex (EBS) is an autosomal-dominant inherited blistering skin disease characterized by intraepidermal blistering due to mechanical stress-induced degeneration of basal keratinocytes. EBS is caused by mutations in either keratin 5 or keratin 14, the major keratins expressed in the basal layer of the epidermis. We experienced a unique EBS-affected family. The proband had a heterozygous 1649delG mutation in the keratin 5 gene and had been reported as a case of de novo mutation, because the mutations were not detected in the parents' DNA from blood samples. However, the proband's younger sister was revealed to have the same disease at birth and we found the same mutation in her. We reinvestigated the familial segregation of the 1649delG mutation and it was shown that the mother's DNA from hair bulb and buccal cell samples had the 1649delG mutation heterozygously, but her DNA from blood samples did not. A careful check on the mother's history disclosed that she had migratory circinate pigmentation in her skin in childhood, which means maternal somatic and germline mosaicism. The demonstration of somatic and gonadal mosaicism in the keratin 5 gene is important for accurate genetic counselling of families with sporadic cases of EBS.

Long-term duration of reduced serum complement level following burn injury

We report the case of a boy whose serum CH50 was below the detection limit following burn injury and skin transplantation. The APCH50 level was slightly decreased, although C3, C4, and the other complements were within the normal range. Cold activation was not detected in his plasma. His peripheral blood monocyte ratio slightly elevated to 19% and then decreased to 5.9%. In this case, burn injury caused the depletion of the complement, particularly in the alternative pathway, and resulted in the reduced CH50 level, although C3 did not show the typical pattern of alternative pathway depletion. In previously reported cases of burn injury, the CH50 level returned to the normal range within 2 weeks. In this patient the reduced level of CH50 continued for 4 months. We should consider burn injury one of the causes of complement deficiency even in cases with a duration of more than 1 month.

The correlation between ovomucoid-derived peptides, human leucocyte antigen class II molecules and T cell receptor-complementarity determining region 3 compositions in patients with egg-white allergy

BACKGROUND

Food allergies are more prevalent in children, due to the immature gastrointestinal epithelial membrane barrier allowing more proteins through the barrier and into circulation. Ovomucoid (OM) is one of the major allergens that is found in egg white.

OBJECTIVE

The aim of this study was to determine T cell epitopes, antigen-presenting human leucocyte antigen (HLA) class II molecules of the T cell lines (TCLs) and T cell clones (TCCs), and complementarity determining region (CDR) 3 loops of the T cell receptor (TCR) alpha and beta chains of the TCCs specific to OM.

METHODS

We established TCLs and TCCs specific to OM from peripheral blood mononuclear cells (PBMCs) of four atopic patients with egg-white allergy using a mixture of a panel of overlapping synthetic peptides corresponding to the amino acid sequence of the entire OM. We identified the T cell epitopes by antigen-induced proliferative responses, antigen-presenting molecules using allogeneic PBMCs and CDR3 loops of the TCR alpha and beta chains by cloning and sequence analysis.

RESULTS

The TCLs and TCCs responded to seven different peptides, and their antigen-presenting molecules were different from each other. Sequence analysis of the TCR alpha and beta gene usage of the TCCs showed marked heterogeneity, and the usage of the CDR3 loop of the TCCs involved heterogenous amino acid residues. Interestingly, TCCs 'IH3.3' and 'YT6.1' recognized the same OM peptides, and had the same TCR Vbeta-Jbeta gene usage. Considering that peptide motifs bind to HLA class II molecules, the electrically charged residue (positive or negative) on the CDR3alpha and the CDR3beta loops of TCR of TCC may form ionic bonds with a charged residue on the HLA class II molecules-peptide complex.

CONCLUSIONS

TCCs that have the same TCR gene usage were established from patients who had shown similar hypersensitivity-type, indicating that antigen recognition by a specific TCR is closely associated with the characteristics of each patient's symptoms.

Esophageal anthracosis: lesion mimicking malignant melanoma

A case of anthracosis of the esophagus is reported. The patient was a previously healthy 69-year-old Japanese woman. A black and slightly elevated lesion was detected in her esophagus by upper gastroesophageal fiberoscopic examination. Endoscopically, the lesion looked like malignant melanoma. Thoracic esophagotomy was then performed. Histological examination revealed a pigmented lesion beneath the mucosal epithelial layer. The lesion consisted of an aggregation of histiocytes containing an abundance of tiny black pigments. A few mature lymphocytes and plasma cells were also evident in the periphery of the lesion. Histologically, these findings looked like lymph nodes in the pulmonary hilus; however, no lymph nodal structure was evident in the esophageal wall. Traction diverticula were also noted in the pigmented lesion. The patient has remained well without disease for 9 months since the surgery. Although anthracosis is a rare condition in the esophagus, the present case gave warning to pathologists and clinicians that it does indeed occur. Endoscopists and pathologists should differentiate anthracosis from malignant melanoma because the treatment and outcome are quite different for each.

Sodium accumulation during ischemia induces mitochondrial damage in perfused rat hearts

OBJECTIVE

The present study aimed to elucidate the involvement of sodium overload and following damage to mitochondria during ischemia in the genesis of ischemia/reperfusion injury of perfused rat hearts.

METHODS

Isolated, perfused hearts were exposed to different durations (15-35 min) of ischemia followed by 60-min reperfusion. At the end of ischemia or reperfusion, myocardial sodium and calcium contents and myocardial high-energy phosphates were determined. The cardiac mitochondrial ability to produce ATP was measured using saponin-skinned bundles. The effects of sodium on the mitochondrial membrane potential and the oxidative phosphorylation rate were examined using isolated mitochondria from normal hearts.

RESULTS

Post-ischemic recovery of left ventricular developed pressure decreased in an ischemic duration-dependent manner. Ischemia induced an increase in myocardial sodium, but not calcium. This increase was dependent on the duration of ischemia. The oxygen consumption rate of skinned bundles from the ischemic heart decreased at the end of ischemia. Incubation of mitochondria with various concentrations of sodium chloride or sodium lactate in vitro resulted in a depolarization of mitochondrial membrane potential and a decrease in ATP-generating activity. This decrease was not restored after elimination of sodium compounds.

CONCLUSIONS

The present findings suggest that ischemia induces an increase in sodium influx from the extracellular space and that accumulated sodium may induce irreversible damage to mitochondria during ischemia. This mitochondrial dysfunction may be one of the most important determinants for the genesis of ischemia/reperfusion injury in perfused rat hearts.

Mitochondrial damage during ischemia determines post-ischemic contractile dysfunction in perfused rat heart

Possible mechanisms underlying sodium overload-induced ischemia/reperfusion injury in perfused rat hearts were examined. Massive accumulation of myocardial Na(+) occurred during ischemia, suggesting cytosolic sodium overload in cardiac cells. Treatment of the pre-ischemic heart with 0.3 micromol/l tetrodotoxin or 3 micromol/l ethyl-isopropyl amiloride enhanced post-ischemic contractile recovery (72 or 82% of initial vs 24% for untreated group), which was associated with suppression of tissue Na(+) accumulation (138 or 141% of initial vs 270% for untreated group), restoration of tissue high-energy phosphates, and preservation of the ability of mitochondria to produce ATP in the ischemic/reperfused heart. The release of cytochrome c from the ischemic heart was observed, which was blocked by treatment of the pre-ischemic heart with these agents. The improvement of post-ischemic contractile recovery by these agents was closely correlated with the ability of mitochondria to produce ATP during ischemia. To examine the effects of sodium overload on mitochondrial function, isolated mitochondria were incubated in the presence of various concentrations of Na(+). Na(+) induced mitochondrial membrane perturbations such as depolarization of the membrane potential, mitochondrial swelling, cytochrome c release from isolated mitochondria, and a reduction in oxidative phosphorylation. These events in the isolated mitochondria were not blocked by the presence of the above agents. The results suggest that cytosolic sodium overload in cardiac cells may induce deterioration of the mitochondrial function during ischemia and that this mitochondrial damage may determine post-ischemic contractile dysfunction in perfused rat hearts.

Nicorandil preserves mitochondrial function during ischemia in perfused rat heart

A possible mechanism for the action of nicorandil on the improvement of energy metabolism of ischemic/reperfused hearts was examined. Perfused rat hearts were subjected to 35-min ischemia/60-min reperfusion. The heart was treated with nicorandil at concentrations of 10 to 100 microM for the last 30-min of pre-ischemia. Nicorandil preserved the mitochondrial oxygen consumption rate during ischemia and attenuated the decrease in mitochondrial function during reperfusion in association with the enhanced post-ischemic recovery of the left ventricular developed pressure. To assess the direct effect on mitochondria, myocardial saponin-skinned bundles were incubated under hypoxic conditions in vitro. Hypoxia-induced decrease in the mitochondrial oxygen consumption rate was attenuated by treatment of the bundles with 100 microM nicorandil. This attenuation was abolished by the combined treatment with the K(ATP) channel blocker, 5-hydroxydecanoate (5-HD). These results suggest that nicorandil is capable of attenuating ischemia/reperfusion injury of isolated perfused hearts through preservation of mitochondrial function during ischemia.

Protective effect of propranolol on mitochondrial function in the ischaemic heart

1. The present study was aimed to determine whether propranolol improves contractile function of the ischaemic/reperfused heart through protection of the mitochondrial function during ischaemia. 2. Isolated perfused rat hearts were subjected to 35-min ischaemia followed by 60-min reperfusion. Pre-treatment with propranolol at the concentrations of 10 to 100 microM for the final 3 min of pre-ischaemia resulted in the improvement of ischaemia/reperfusion-induced contractile dysfunction, release of creatine kinase (CK) into perfusate, and decrease in myocardial high-energy phosphates. Propranolol also attenuated ischaemia-induced accumulation in Na+, suggesting that cytosolic sodium overload during ischaemia was prevented by propranolol. 3. The mitochondrial oxygen consumption rate of skinned bundles from the perfused heart decreased at the end of ischaemia and it further decreased at the end of reperfusion. These decreases were cancelled by treatment with propranolol. A release of cytochrome c from the perfused heart was observed during ischaemia, and this release was suppressed by treatment with propranolol. 4. To elucidate the direct effect of propranolol on mitochondria, the mitochondria were isolated from normal hearts and their activities were determined in the presence of various concentrations of Na+ and propranolol. The addition of sodium lactate, which mimicked sodium overload in the ischaemic heart, reduced the state 3 respiration, whereas this reduction was not attenuated by the presence of propranolol. 5. These results suggest that cardioprotection of propranolol may be exerted via attenuating Na+ influx into cardiac cells followed by prevention of the mitochondrial dysfunction in the ischaemic heart, leading to improvement of energy production of the heart during reperfusion.

Interaction among human leucocyte antigen-peptide-T cell receptor complexes in cow's milk allergy: the significance of human leucocyte antigen and T cell receptor-complementarity determining region 3 loops

BACKGROUND

Allergic individuals respond to only a few specific antigens, therefore allergic diseases are characterized by antigen specificity. Clarification of the mechanism of antigen specificity will lead to progress in the therapy of allergic diseases.

OBJECTIVES

The purpose of this study is to determine the specific association among T cell epitopes, antigen-presenting molecules and T cell receptor (TCR), and to determine the TCR usage in the pathogenesis of allergies using antigen-specific T cell clones (TCCs). The results can clarify the mechanism of the antigen specificity of allergic diseases, and provide new therapeutic possibilities using analogue peptides.

METHODS

Short-term T cell clones specific to beta-lactoglobulin (BLG) were established from peripheral blood mononuclear cells (PBMCs) collected from five patients allergic to cow's milk. We then identified the T cell epitopes and antigen-presenting molecules, and examined TCR usage. We also determined the sequence of the TCR-complementarity-determining region 3 (CDR3).

RESULTS

Six TCCs established from the five patients recognized three different peptides, and BLGp97-117 was recognized by four of the six TCCs. BLGp101-112 (KYLLFCMENSAE) was the core sequence in the fragment. Sequence analysis of TCR by the RT-PCR method revealed a marked heterogeneity in TCR usage, and similar amino acid sequences were recognized in the CDR3 region. Four of the six TCCs recognized BLG in association with human leucocyte antigen (HLA)-DRB1*0405 as antigen-presenting molecules.

CONCLUSION

We proposed the motif of the interaction between the HLA-DRB1*0405 allele and antigen peptide, and suggested that HLA-DRB1*0405 is an immunoregulatory gene product for T cell responses to BLG.

Genetic identification of two distinct DNA polymerases, DnaE and PolC, that are essential for chromosomal DNA replication in Staphylococcus aureus

We isolated and characterized temperature-sensitive mutants for two genes, dnaE and polC, that are essential for DNA replication in Staphylococcus aureus. DNA replication in these mutants had a slow-stop phenotype when the temperature was shifted to a non-permissive level. The dnaE gene encodes a homolog of the alpha-subunit of the DNA polymerase III holoenzyme, the replicase essential for chromosomal DNA replication in Escherichia coli. The polC gene encodes PolC, another catalytic subunit of DNA polymerase, which is specifically found in gram-positive bacteria. The wild-type dnaE or polC gene complemented the temperature-sensitive phenotypes of cell growth and DNA replication in the corresponding mutant. Single mutations resulting in amino-acid exchanges were identified in the dnaE and polC genes of the temperature-sensitive mutants. The results indicate that these genes encode two distinct DNA polymerases which are both essential for chromosomal DNA replication in S. aureus. The number of viable mutant cells decreased at non-permissive temperature, suggesting that inactivation of DnaE and PolC has a bactericidal effect and that these enzymes are potential targets of antibiotics.

Dissecting receptor-mediated Ca2+ influx pathways: TRP channels and their native counterparts

Cellular stimulation from the surrounding extracellular environment via receptors and other pathways evoke activation of Ca2+-permeable cation channels that form essential signaling pathways in controlling biological responses. An important clue to understand the molecular mechanisms underlying these cation channels (tentatively termed as receptor-mediated cation channels (RMCC)) was first provided through molecular studies of the transient receptor potential (trp) protein (TRP), which controls light-induced depolarization in Drosophila photoreceptor cells. Use of the genetic information and recombinant expression technique lead to the discovery of numerous mammalian TRP homologues revealing novel RMCCs. In this review, we focus on the dramatic progress in the molecular investigation of RMCC in mammalian systems. The recent findings should provide powerful tools for the development of novel pharmaceutical targets.

Merits of duplicate LAN cabling in hospitals

Our hospital wired three LAN cables separately to improve the data distribution range. One LAN is between the various sections of the hospital (hospital LAN), another is within each section (section LAN), and the other is connected to the Internet (open LAN). The section LAN was connected to the hospital LAN to enable data exchange. Data from the section LAN for common use is collected through the hospital LAN and stored in the central server The duplicate cabling and separate LANs increased the independence of each LAN and the system within each section. The section systems can be changed at anytime without the necessity of reconstructing the whole hospital information system. The data transfer speed of each cable increased. Hospital information processing systems often use a distributed-processing centralized management system. Because of advances in technology, each section can now take responsibility for developing their own system, making the responsibility of the information processing section responsible for hospital information systems more limited than previously. Herein, we show the merits of separate cable installation.

[Structure and function of Ca2+ channels]

Ca(2+) influx across plasma membrane is critical to evoke increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) that controls various physiological and pathological responses. Recently, diverse Ca(2+) channels responsible for Ca(2+) influx have been identified. In this review, we attempt to overview molecular entities of Ca(2+) channels, and their structure, function, and biological roles.