PubMed Health⌕ Search

Biomedical subjects

Y Suga

Publications and source records attributed to Y Suga.

At least 19 recordsLinked to original sources

Basic and clinical research on photodynamic therapy at Tokyo Medical University Hospital.

BACKGROUND AND OBJECTIVES: We have been engaged in basic and clinical research on photodynamic therapy (PDT) and photodynamic diagnosis (PDD) for more than 25 years. STUDY DESIGN/MATERIALS AND METHODS: PDT for 264 centrally located early-stage lung cancer lesions yielded an initial complete response (CR) rate of 84.8%. PDT is now becoming a standard option for centrally located stage 0 (TisN0M0) and stage I (T1N0M0) lung cancer. It is an attractive option for elderly patients in poor physical condition. RESULTS: Recent results of interstitial PDT for peripheral-type lung cancers suggest that it may be a promising local curative treatment modality for lesions less than 1.0 cm in diameter. CONCLUSIONS: In this article, we introduce our recent clinical trials of PDT for lung cancers (both central and peripheral), and new techniques of PDD in sentinel node navigation biopsy for breast cancers. Moreover, we introduce basic research on cancers and infectious diseases in order to expand the clinical applications of PDT.

Adult↗

A case of a Japanese neonate with congenital ichthyosiform erythroderma diagnosed as Netherton syndrome.

We report a 6-day-old Japanese girl showing generalized erythroderma accompanied by yellowish, exfoliative scaling that was accentuated on the face and scalp. Histological analysis showed psoriasiform dermatitis with acanthotic epidermis and premature shedding of the stratum corneum. Measurement of trypsin-like hydrolytic activity in SC showed six-fold greater activity compared with age-matched controls. DNA analysis revealed two mutations, 375delAT and 966insC, in exons 5 and 11, respectively, of the SPINK5 gene. Although at 4 weeks the child was still too young to display characteristic hair abnormalities or atopic diathesis, we diagnosed Netherton syndrome based on enzyme assay and DNA analysis.

Carrier Proteins↗

A Japanese infant with localized ichthyosis linearis circumflexa on the palms and soles harbouring a compound heterozygous mutation in the SPINK5 gene.

We report a 6-month-old Japanese boy showing ichthyosis linearis circumflexa localized on the palms and soles. He showed bamboo hairs and aminoaciduria, and was positive for cow's milk and egg IgE antibodies by radioallergosorbent tests. Trypsin-like hydrolytic activity in the patient's lesional stratum corneum showed an activity seven times higher than that in age-matched controls. DNA analysis showed that the patient harboured the compound heterozygous mutations R790X and 1220+1 G-->C in the SPINK5 gene, compatible with the diagnosis of Netherton syndrome (NS). As the genotype/phenotype correlations in NS have not yet been fully clarified, the position of the premature termination codon in the SPINK5 gene may contribute to explain such a mild form of NS in our patient.

Asian People↗

Search for electron neutrino appearance in a 250 km long-baseline experiment.

We present a search for electron neutrino appearance from accelerator-produced muon neutrinos in the K2K long-baseline neutrino experiment. One candidate event is found in the data corresponding to an exposure of 4.8 x 10(19) protons on target. The expected background in the absence of neutrino oscillations is estimated to be 2.4+/-0.6 events and is dominated by misidentification of events from neutral current pi(0) production. We exclude the nu(micro) to nu(e) oscillations at 90% C.L. for the effective mixing angle in the 2-flavor approximation of sin((2)2theta(microe)( approximately 1/2sin((2)2theta(13))>0.15 at Deltam(2)(microe)=2.8 x 10(-3) eV(2), the best-fit value of the nu(micro) disappearance analysis in K2K. The most stringent limit of sin((2)2theta(microe)<0.09 is obtained at Deltam(2)(microe)=6 x 10(-3) eV(2).

Journal Article↗

Indications of neutrino oscillation in a 250 km long-baseline experiment.

The K2K experiment observes indications of neutrino oscillation: a reduction of nu(mu) flux together with a distortion of the energy spectrum. Fifty-six beam neutrino events are observed in Super-Kamiokande (SK), 250 km from the neutrino production point, with an expectation of 80.1(+6.2)(-5.4). Twenty-nine one ring mu-like events are used to reconstruct the neutrino energy spectrum, which is better matched to the expected spectrum with neutrino oscillation than without. The probability that the observed flux at SK is explained by statistical fluctuation without neutrino oscillation is less than 1%.

Journal Article↗

A Japanese case of de novo dominant dystrophic epidermolysis bullosa.

We report a Japanese case of dominant dystrophic epidermolysis bullosa with a de novo mutation in the triple-helical domain of the type VII collagen. Mutation detection revealed a glycine --> aspartic acid substitution at amino acid position 2012 in exon 73 (G2012D). This previously unreported mutation underlies a clinical phenotype of moderately severe, localized skin blistering.

Child, Preschool↗

Beneficial effect of JTV-803, a new synthetic inhibitor of activated factor X, against both lipopolysaccharide-induced and tissue factor-induced disseminated intravascular coagulation in rat models.

We examined whether JTV-803, a specific activated factor X inhibitor independent of antithrombin III (ATIII), is effective against disseminated intravascular coagulation (DIC) in rat models induced by tissue factor (TF) or lipopolysaccharides (LPS). In male Wistar rats, DIC was induced by a 4 h infusion of thromboplastin (3.75 U/kg) or LPS (50 mg/kg). The rats were given JTV-803 (0.3 or 3 mg/kg, bolus intravenously) (JTV-803 groups) or low molecular weight heparin (LMWH groups) (200 U/kg, bolus intravenously) prior to an injection of TF or LPS. The results showed that JTV-803 was dose-dependently effective against DIC in both TF-induced and LPS-induced rat models. This anti-DIC effect of JTV-803 at higher doses was almost equivalent to that of LMWH in both types of DIC. Plasma ATIII activity was more prominent in the group treated with JTV-803 than in that treated with LMWH. None of rats died in the TF-induced DIC model with or without drug administration. On the contrary, seven of 22 rats died (mortality rate, 31.8%) in the LPS-induced DIC model without drug administration. Although the mortality rate of rats induced with LPS and treated with LMWH was quite high (6/16, 37.5%), none of the LPS-induced rats treated with JTV-803 died. These findings suggested that JTV-803 can treat both TF-induced and LPS-induced DIC models, and that this drug has greater potential in preserving ATIII and in improving the prognosis of DIC.

Animals↗

Decreased plasma activity of antithrombin or protein C is not due to consumption coagulopathy in septic patients with disseminated intravascular coagulation.

We investigated whether depressed plasma antithrombin and protein C activity, considered as a specific finding of disseminated intravascular coagulation (DIC), is due to consumption coagulopathy in septic patients with DIC. An analysis of hemostatic parameters was performed in 139 septic patients (68 with DIC and 71 without DIC). Plasma activity of antithrombin and protein C tended to be significantly decreased in septic patients with DIC but not in those without DIC (p < 0.001). However, when the septic patients were classified into three groups according to the albumin (or choline esterase) level, no significant differences in antithrombin activity or protein C activity were observed between the patients with and without DIC in any of the subgroups. Notably, neither the plasma activity of antithrombin nor protein C was decreased even in septic patients with DIC who had normal plasma levels of albumin (or choline esterase). No significant correlation was observed between plasma levels of thrombin-antithrombin complex (TAT) and antithrombin activity, or between plasma levels of TAT and protein C activity either in septic patients with DIC or without DIC. It is reasonable to conclude that the markedly reduced plasma activity of antithrombin and protein C is not due to consumption coagulopathy in septic patients with DIC.

Aged↗

Elevated levels of free tissue factor pathway inhibitor antigen in cases of disseminated intravascular coagulation caused by various underlying diseases.

Tissue factor pathway inhibitor (TFPI) is primarily synthesized by vascular endothelial cells and is found in vivo in association with endothelial cells, lipoproteins, or in free form. Free TFPI is the most potent and important type, because it is released from endothelial cells following an injection of heparin, or as a result of pathological stimuli. In order to study the role of TFPI in disease, the concentration of free form TFPI was measured in the plasma of 114 patients suffering from disseminated intravascular coagulation (DIC), as the result of several underlying diseases. Plasma antigen levels of free TFPI were significantly higher even in those patients not exhibiting DIC than in normal healthy subjects. These levels were even higher among patients exhibiting DIC, especially those with acute promyelocytic leukemia or cancer, receiving continuous heparin drip infusions. A significant correlation was observed between the plasma antigen levels of free form TFPI and those of fibrin/fibrinogen degradation products, and free form TFPI and plasmin inhibitor complex (r = 0.428, P < 0.0001 and r = 0.329, P < 0.0001, respectively) among 114 DIC patients. There were no significant differences between the plasma levels of free TFPI in DIC patients with or without multiple organ failure. It has been suggested that the plasma levels of free TFPI are closely related to the levels of fibrinolysis occurring in DIC patients, although further study is required to clarify the degree to which TFPI is expressed by endothelial cells during DIC.

Case-Control Studies↗

Depressed plasma activity of plasminogen or alpha2 plasmin inhibitor is not due to consumption coagulopathy in septic patients with disseminated intravascular coagulation.

We have attempted to determine whether depressed plasma plasminogen and alpha2 plasmin inhibitor (or alpha2 antiplasmin) activity is, as a result of consumption coagulopathy, a specific finding of disseminated intravascular coagulation (DIC) in septic patients. The hemostatic parameters of 139 septic patients (68 with DIC and 71 without DIC) were analyzed. Among the group as a whole, plasma activities of plasminogen and alpha2 plasmin inhibitor were significantly depressed in septic patients with DIC relative to those without DIC (P < 0.01 and P < 0.05, respectively). Notably, a significant correlation was observed between plasma levels of albumin and plasminogen activity, as well as between plasma levels of albumin and alpha2 plasmin inhibitor activity both in septic patients with DIC and those without DIC. However, no significant correlation was observed between plasma levels of plasmin-alpha2 plasmin inhibitor complex (PIC) and plasminogen activity, nor between PIC and alpha2 plasmin inhibitor activity either in septic patients with DIC or those without DIC. We concluded that depressed activity of plasminogen or alpha2 plasmin inhibitor is not as a result of consumption coagulopathy, but rather a result of low synthetic function of the liver in septic patients with DIC.

Aged↗

All-trans retinoic acid is partially effective against lipopolysaccharide-induced but not against tissue-factor-induced disseminated intravascular coagulation in rat models.

All-trans retinoic acid (ATRA) has been introduced to the management of acute promyelocytic leukemia (APL) as a differentiation treatment. This drug not only causes complete remission, but also improves disseminated intravascular coagulation (DIC) without adding anticoagulants in APL. We have attempted to determine whether ATRA is effective against DIC in rat models induced by tissue factor (TF) or lipopolysaccharide (LPS), because the anticoagulant effect of ATRA has been considered to induce thrombomodulin upregulation and TF downregulation on endothelial cells as well as on APL cells. In male Wistar rats, DIC was induced by a 4-h infusion of thromboplastin (3.75 U/kg) or lipopolysaccharide (30 mg/kg). The rats were given ATRA orally each day at a dose of 100 mg/kg per day for 1 week before the injection of TF or LPS in ATRA treatment groups, or given low molecular weight heparin (LMWH) 10 min before the injection of TF or LPS (200 U/kg, bolus intravenously) in LMWH treatment groups. No significant changes in hemostatic parameters or markers of organ dysfunction were caused by the ATRA administration, while DIC was significantly improved by LMWH in the TF-induced model. DIC was significantly improved by both ATRA and LMWH in the LPS-induced model. These findings suggested that ATRA was useful for treating DIC only in the LPS-induced model, and that drug efficacy should be carefully assessed because the agents used to induce DIC considerably influenced the outcome.

Animals↗

Beneficial effect of the active form of vitamin D3 against LPS-induced DIC but not against tissue-factor-induced DIC in rat models.

1Alpha,25-dihydroxyvitamin D3 (active form of vitamin D3; vitamin D3) has been reported to induce the upregulation of thrombomodulin and downregulation of tissue factor (TF) on monocytes. The possibility exists that vitamin D3 prevents the development of disseminated intravascular coagulation (DIC). In particular, monocyte TF production plays an important role in the pathophysiology of DIC in septic patients. We have attempted to determine whether vitamin D3 is effective against DIC in a rat model induced by lipopolysaccharides (LPS) (30 mg/kg, 4 h) or TF (3.75 U/kg, 4 h) using selective hemostatic parameters, markers of organ dysfunction and pathological findings (assessment of glomelular fibrin deposition). Vitamin D3 was administered orally each day at a dose of 2.0 mg/kg/day for 3 days, or low molecular weight heparin (LMWH 200 u/kg; i.v.) was given 10 min before the injection of TF or LPS in each treatment group. Vitamin D3 was effective against DIC in the rat model induced by LPS only, whereas LMWH was effective against DIC in both rat models induced by either TF or LPS. The anti-DIC effect of vitamin D3 was equal to (or more potent than) that of LMWH. The results suggested that vitamin D3 was useful for the treatment of LPS-induced DIC, and that the assessment of a drug's efficacy should be done carefully given the markedly different results obtained according to the agents used to induce DIC.

Administration, Oral↗