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K Yoneyama

Publications and source records attributed to K Yoneyama.

At least 19 recordsLinked to original sources
PubMed2006

Iatrogenic amyloid neuropathy in a Japanese patient after sequential liver transplantation.

A 57-year-old woman in Japan, the first recipient of part of a liver from a 58-year-old man with familial amyloidotic polyneuropathy (FAP) amyloidogenic transthyretin Val30Met who had had sensorimotor polyneuropathy in the lower limbs for 3 years, started to develop sensory neuropathy 7 years after transplantation. Before the July 1998 sequential transplantation, she had been in a hepatic coma at the terminal stage of primary biliary cirrhosis and waiting for deceased donor liver transplantation. In September 2004, biopsy samples of her duodenum first showed amyloid deposition. Although biopsy materials in 2005 and 2006 showed no changes in amyloid deposition, decreased temperature sensation and pain in fingertips and toes were detected at a neurologic examination in March 2006. Thus, clinical symptoms of FAP appeared about 2 years after amyloid deposition started. Nerve conduction velocity studies revealed mild to moderate axonal sensory polyneuropathy without demyelination. Our findings confirmed iatrogenic sensory neuropathy induced by amyloid deposition 7 years after sequential liver transplantation.

Amyloid Neuropathies, Familial↗
PubMed2006

Dynamics of capillary condensation in aerogels.

Dynamics of capillary condensation of liquid 4He in various density silica aerogels was investigated systematically. Interfaces were clearly visible when bulk liquid was rapidly sucked into the aerogel. Time evolution of the interface positions was consistent with the Washburn model and their effective pore radii were obtained. Condensation was a single step in a dense aerogel and two steps in a low density aerogel. Crossover between the two types of condensation was observed in an intermediate density aerogel. Variety of the dynamics may be the manifestation of the fractal nature of aerogels which had a wide range of distribution of pore radii.

Journal Article↗
PubMed2006

Prognostic factors of primary biliary cirrhosis detected by health screening.

AIM: The liver cirrhosis is likely to differ in the Japanese and Western populations. Thus, we performed a retrospective cohort analysis by a review of clinical records to clarify prognostic factors after the onset of primary biliary cirrhosis (PBC) detected by health screening. METHODS: The subjects were 52 patients with PBC. Thirty-nine factors were evaluated concerning clinical data and extracted prognostic factors using the Cox proportional hazard model. RESULTS: The mean duration of the follow-up period was 5.1 years, during which 6 (11.5%) of the patients died. The cumulative survival rate after the onset of PBC was 93.4% after 5 year, and 67.8% after 10 years. Multivariate analysis indicated 2 factors, i.e. the body mass index (BMI), and IgG, as independent prognostic factors. Their hazard ratios were 0.399 (per 1 kg/m2 of BMI) and 1.282 (per 100 mg/dL of IgG). The prognostic index (PI) was calculated by the following formula using these 2 factors. PI = 0.919 x BMI+0.249 x IgG. CONCLUSIONS: The prediction of the outcome using PI based on the 2 factors provides additional information for the determination of the therapeutic approach in PBC after health screening.

Cohort Studies↗
PubMed2006

Evaluation of paraumbilical vein as a prognostic index of severe liver cirrhotic patients with portal-systemic shunts.

AIM: The aim of this study was to predict the outcome in severe liver cirrhotic patients with portal-systemic shunts. METHODS: One-hundred and sixteen patients with liver cirrhosis diagnosed as Child-Pugh class B and C with portal-systemic shunts confirmed by abdominal ultrasonography, computed tomography and magnetic resonance imaging were enrolled in this study. Twenty-three factors were evaluated concerning clinical laboratory parameters and extracted prognostic factors using the Cox proportional hazards model, and the prognostic index (PI) was prepared by combining these factors. RESULTS: The cumulative survival rates after admission were 64.6%, 35.6% and 25% after 1, 3 and 5 years, respectively. Using multivariate analysis, age, the presence of hepatocellular carcinoma (HCC), portal vein tumor thrombosis (PVTT) and paraumbilical vein (PUV) shunt were selected as significant prognostic factors that contributed independently to the prognosis of severe liver cirrhotic patients with portal-systemic shunts. The PI was calculated with the following formula using these 4 factors. PI = 0.042 x Age + 0.913 x HCC + 0.989 x PVTT + 1.079 x PUV shunt. The group with a high score for PI was found to die with significantly higher frequency than the group with a low score. CONCLUSIONS: It was found that tumor related factors and PUV shunt were the most important factors for severe liver cirrhotic patients with portal-systemic shunts. The PI is suggested to be an appropriate index to predict the prognosis for these patients.

Aged↗
PubMed2005

Development of an in vitro skin sensitization test using human cell lines; human Cell Line Activation Test (h-CLAT). II. An inter-laboratory study of the h-CLAT.

Recent regulatory changes have placed a major emphasis on in vitro safety testing and alternative models. In regard to skin sensitization tests, dendritic cells (DCs) derived from human peripheral blood have been considered in the development of new in vitro alternatives. Human cell lines have been also reported recently. In our previous study, we suggested that measuring CD86 and/or CD54 expression on THP-1 cells (human monocytic leukemia cell line) could be used as an in vitro skin sensitization method. An inter-laboratory study among two laboratories was undertaken in Japan in order to further develop an in vitro skin sensitization model. In the present study, we used two human cell lines: THP-1 and U-937 (human histiocytic lymphoma cell line). First we optimized our test protocol (refer to the related paper entitled "optimization of the h-CLAT protocol" within this journal) and then we did an inter-laboratory validation with nine chemicals using the optimized protocol. We measured the expression of CD86 and CD54 on the above cells using flow cytometry after a 24h and 48h exposure to six known allergens (e.g., DNCB, pPD, NiSO(4)) and three non-allergens (e.g., SLS, tween 80). For the sample test concentration, four doses (0.1x, 0.5x, 1x, and 2x of the 50% inhibitory concentration (IC(50))) were evaluated. IC(50) was calculated using MTT assay. We found that allergens/non-allergens were better predicted using THP-1 cells compared to U-937 cells following a 24 h and a 48 h exposure. We also found that the 24h treatment time tended to have a better accuracy than the 48 h treatment time for THP-1 cells. Expression of CD86 and CD54 were good predictive markers for THP-1 cells, but for U-937 cells, expression of CD86 was a better predictor than CD54, at the 24h and the 48 h treatment time. The accuracy also improved when both markers (CD86 and CD54) were used as compared with a single marker for THP-1 cells. Both laboratories gave a good prediction of allergen/non-allergen, especially using THP-1 cells. These results suggest that our method, human Cell Line Activation Test (h-CLAT), using human cell lines THP-1 and U-937, but especially THP-1 cells at 24h treatment, may be a useful in vitro skin sensitization model to predict various contact allergens.

Allergens↗
PubMed2005

Development of an in vitro skin sensitization test using human cell lines: the human Cell Line Activation Test (h-CLAT). I. Optimization of the h-CLAT protocol.

The aim of this study is to optimize the experimental conditions for an in vitro skin sensitization test using the human cell lines THP-1 and U-937. As regards pre-culturing time, the expression of CD86 on DNCB-treated THP-1 cells tended to be higher after 48h and 72h pre-culture compared with other time points evaluated. Next, we investigated the effect of chemical treatment time, and found that induction of CD86 expression on THP-1 cells by DNCB reached a plateau after 24h. Augmentation of CD86 expression is often observed when cells are treated with a subtoxic dose of allergens. To determine the appropriate dose of test samples, the cytotoxicity of test samples to THP-1 and U-937 cells was assessed with MTT assay, and the 50% inhibitory concentration (IC50) of each test sample was calculated. Based on the cytotoxicity assay data, four concentrations in the range between toxic and non-toxic were selected (0.1x, 0.5x, 1x and 2x IC50). Several kinds of antibodies were tested for staining THP-1 and U-937 cells treated with allergens/non-allergens (e.g., DNCB, Ni/SLS), and suitable antibodies for staining CD86 and CD54 were selected. We confirmed that the working dilutions of the selected CD86 and CD54 antibodies were appropriate for use in our method. The effect of an FcR blocking procedure was also evaluated. The mean fluorescence intensity (MFI value) was decreased by the FcR blocking procedure, which indicated that non-specific staining was blocked. Therefore, this procedure should be included in the method. Based on our findings, the protocol for this assay was optimized and the experimental conditions to be used in a future validation study were identified. We propose to call this kind of in vitro skin sensitization test h-CLAT, which is short for human Cell Line Activation Test.

Allergens↗
PubMed2005

Interaction between Orobanche crenata and its host legumes: unsuccessful haustorial penetration and necrosis of the developing parasite.

BACKGROUND AND AIMS: Orobanche species represent major constraints to crop production in many parts of the world as they reduce yield and alter root/shoot allometry. Although much is known about the histology and effect of Orobanche spp. on susceptible hosts, less is known about the basis of host resistance to these parasites. In this work, histological aspects related to the resistance of some legumes to Orobanche crenata have been investigated in order to determine which types of resistance responses are involved in the unsuccessful penetration of O. crenata. METHODS: Samples of resistance reactions against O. crenata on different genotypes of resistant legumes were collected. The samples were fixed, sectioned and stained using different procedures. Sections were observed using a transmission light microscope and by epi-fluorescence. KEY RESULTS: Lignification of endodermal and pericycle host cells seems to prevent parasite intrusion into the root vascular cylinder at early infection stages. But in other cases, established tubercles became necrotic and died. Contrary to some previous studies, it was found that darkening at the infection site in these latter cases does not correspond to death of host tissues, but to the secretion of substances that fill the apoplast in the host-parasite interface and in much of the infected host tissues. The secretions block neighbouring host vessels. This may interfere with the nutrient flux between host and parasite, and may lead to necrosis and death of the developing parasite. CONCLUSIONS: The unsuccessful penetration of O. crenata seedlings into legume roots cannot be attributed to cell death in the host. It seems to be associated with lignification of host endodermis and pericycle cells at the penetration site. The accumulation of secretions at the infection site, may lead to the activation of xylem occlusion, another defence mechanism, which may cause further necrosis of established tubercles.

Fabaceae↗
PubMed2004

Dynamics and morphology of superfluid bubbles in 4He quantum crystals.

Superfluid bubbles in a 4He quantum crystal, which we refer to as quantum negative crystals, were investigated in bcc and hcp phases by visualizing their forms and motions at various temperatures. They were nearly spherical in bcc phase and faceted on the c-plane in their upper part in hcp phase. They steadily rose in the crystal due to gravity. Their direction was vertical in bcc phase and obliquely parallel to the c-facet in hcp phase. We also observed a slowing down of negative crystal in hcp phase caused by the appearance of the a-facet when temperature was lowered. Dynamics and morphology became successively anisotropic with cooling. The driving force by gravity for this motion was derived in the spherical case. Growth coefficient obtained by this model agreed well with the reported values.

Journal Article↗
PubMed2004

Pathological features and genetic alterations in colorectal carcinomas with characteristics of nonpolypoid growth.

We sought to clarify pathological features and genetic alterations in colorectal carcinomas with characteristics of nonpolypoid growth. Colorectal carcinomas resected at Showa University Hospital in Tokyo included 86 with characteristics of polypoid growth (PG) and 21 with those of nonpolypoid growth (NPG). Mutations of APC, Ki-ras, and p53 genes, as well as microsatellite instability (MSI), were analysed using fluorescence-based polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP). Carcinomas with an NPG pattern were smaller than PG tumours (P<0.0001). Carcinomas with a PG pattern were more likely to harbour Ki-ras mutations (36%) than NPG tumours (0%; P<0.0001). Mutation types in the APC gene differed significantly between PG and NPG carcinomas (P=0.0189), including frameshift mutations in 66% of PG carcinomas but no NPG carcinomas. Presence of a p53 mutation at a 'hot spot' also was more likely in PG carcinomas (37%) than in NPG carcinomas (0%; P=0.0124). No significant difference in presence of MSI was evident between carcinomas with PG and NPG patterns. In conclusion, significant genetic differences were evident between carcinomas with PG and NPG patterns. Genetic changes in NPG carcinomas differed from those of the conventional adenoma-carcinoma sequence. Assuming that some nonpolypoid growth lesions transform rapidly into advanced carcinomas, 20% of all colorectal carcinomas may progress in this manner.

Adult↗
PubMed2004

In vitro infection of host roots by differentiated calli of the parasitic plant Orobanche.

Root parasites of the genus Orobanche are serious weeds in agriculture. An aseptic infection system of host roots using calli of three Orobanche species was developed for the study of host-parasite interaction. The response of calli to various hormonal combinations was studied, because a requirement for infection is the differentiation of root-like protrusions, which are capable of producing haustorial connections to the host. Infectious root-like protrusions develop under the influence of 0.5-1.0 mg l(-1) IAA, and under the combination of 0.2 mg l(-1) NAA with 5.0 mg l(-1) kinetin. These protocols produced root protrusions with pad-like structures that resembled attachment organs of Orobanche seedlings, and proved effective in parasitizing host roots. Direct contact with the medium inhibited haustorium development and prevented infection. To overcome this problem, certain root portions were isolated from the medium by inserting thin glass plates underneath. Calli were then placed on the raised root portions and successfully infected the roots and developed young Orobanche tubercles with vascular system that directly connected to the host.

Brassica napus↗
PubMed2004

Prognostic index of liver cirrhosis with ascites with and without hepatocellular carcinoma.

BACKGROUND: In Japan, the incidence of liver cirrhosis caused by hepatitis viruses is higher, and cirrhosis is more likely to be complicated by hepatocellular carcinoma, than in Western countries. The aim of this study was to predict the outcome in liver cirrhosis with ascites with and without hepatocellular carcinoma. METHODS: The subjects were 146 patients with liver cirrhosis complicated by ascites. Forty-six factors were evaluated concerning clinical laboratory parameters and extracted prognostic factors using the Cox proportional hazards model. RESULTS: The mean duration of the follow-up period was 634.9 days, during which 89 (61%) of the patients died, 27 (18.5%) survived, and 30 (20.6%) were lost to follow-up. The cumulative survival rate after the onset of ascites was 59.7% after 1 year, 44.5% after 2 years, and 29.5% after 5 years. Multivariate analysis indicated 9 factors, i.e. age, total bilirubin (T-Bil), alkaline phosphatase (ALP), blood urea nitrogen (BUN), alpha-fetoprotein (AFP), mean arterial pressure (MAP), gastrointestinal bleeding, infection, and portal vein tumor thrombosis (PVTT), as independent prognostic factors. The prognostic index (PI) was calculated by the following formula using these 9 factors. PI = 0.045 x age + 0.180 x T-Bil + 0.088 x ALP + 0.020 x BUN + 0.467 x AFP + (-0.022 x MAP) + 0.662 x gastrointestinal bleeding + 0.521 x infections + 0.882 x PVTT. CONCLUSION: Prediction of the outcome using PI based on the 9 factors provides additional information for the determination of the therapeutic approach in cirrhotic patients with ascites with and without hepatocellular carcinoma.

Age Factors↗
PubMed2002

Changes in the proportion of T helper 1 and T helper 2 cells in cord blood after premature rupture of membranes.

This study investigated changes in the proportion of T helper (Th)1 and Th2 cells in cord blood after premature rupture of membranes (PROM), and evaluate the effects of PROM on the intrauterine fetal immune status. The proportion of CD3-positive T cells secreting interferon (IFN)-gamma as an index of Th1 cells, and interleukin (IL)-4 as an index of Th2 cells in cord blood of 12 newborns with and without PROM, were analyzed by flow cytometry. In cord blood of newborns with PROM, the proportion of IFN-gamma secreting cells significantly increased, and the proportion of IL-4 secreting cells was rather high but not significantly higher than that of newborns without PROM. These changes eventually caused a shift in the Th1/Th2 ratio to Th1 dominance in PROM. There was no significant correlation between the proportion of IFN-gamma secreting cells and the duration of PROM before the onset of labor. These results suggest that the increase in the proportion of IFN-gamma secreting cells after PROM, which eventually cause the Th1/Th2 ratios to show the Th1 predominance, may reflect in part intrauterine fetal immune responses to PROM.

Adult↗
PubMed2002

Serum adenosine deaminase activity and its isoenzyme pattern in women with normal pregnancies.

Adenosine deaminase (ADA) is a purine enzyme which is essential for the proliferation, maturation and function of lymphoid cells, and congenital deficiency of this enzyme is associated with severe combined immunodeficiency disease. The activity of ADA has changed in diseases characterized by the alteration of cell-mediated immunity such as rheumatoid arthritis, systemic lupus erythematosus and tuberculosis, so ADA has been considered as a nonspecific marker of cell-mediated immunity. In this study we examined changes in serum total ADA activity and the patterns of two ADA isoenzymes, ADA1 and ADA2 in normal pregnant women, and evaluated the possible role of the alteration of cell-mediated immunity during normal pregnancy as causes of changes in ADA activity. We measured serum activities of total ADA, ADA1 and ADA2 in normal pregnant women in the third trimester (n=24) and age-matched healthy nonpregnant women (n=24). Peripheral blood lymphocytes and monocytes were also measured. In normal pregnant women, serum total ADA activity averaged 10.5 +/- 0.5 U/L, which was significantly lower than in nonpregnant women (14.0 +/- 0.5 U/L ) (p<0.05), and mean serum ADA2 activity also significantly reduced that of nonpregnant women (p<0.05). There was no significant difference in ADA1 activity in normal pregnant and nonpregnant women. The decrease in total ADA activity was accompanied by the decrease in lymphocyte count. These results suggest that reduced serum total ADA activity reflects decrease in ADA2 activity, and which may be in part associated with depressed cell-mediated immunity during normal pregnancy.

Adenosine Deaminase↗
PubMed2001

Prognosis of patients with advanced carcinoma of the esophagus with complete response to chemotherapy and/or radiation therapy: a questionnaire survey in Japan.

BACKGROUND: We estimated the survival of patients with advanced carcinoma of the esophagus in Japan who achieved complete response (CR) with chemotherapy and/or radiation therapy. METHODS: A questionnaire was designed for patients with cancer of the esophagus with pretreatment stage II-IV (excluding organ metastasis [M1]), who were treated with chemotherapy and/or radiation therapy and achieved either a clinical CR continuing for more than 1 year, or a pathological CR in surgical specimens. All patients were treated between January 1, 1990, and December 31, 1997, in Japan. RESULTS: Of the 169 eligible patients for whom adequate data were available, 106 patients with continuing clinical CR were defined as group A and 63 with pathological CR as group B. The overall survival rates at 5 years were 62.4% in group A and 64.8% in group B. In each of groups A and B, there was no significant difference in overall survival among subgroups of patients classified by initial pretreatment clinical stage. In group A, the survival rate of patients with concurrent chemotherapy and radiation therapy was significantly better than the rates for patients with chemotherapy alone or radiotherapy alone. In group A, the frequency of first failure at the local site of esophageal carcinoma was 7.7%. Of the 12 patients in group B (19%) who died less than 1 year postoperatively, 6 died of postoperative complications. CONCLUSION: The effect of CR to chemotherapy and/or radiation therapy for carcinoma of the esophagus on survival was marked. In patients with esophageal carcinoma who achieve CR, the prognosis may be independent of the initial pretreatment stage. Local failure in group A patients remains a problem, however.

Adult↗
PubMed2001

A specific brassinosteroid biosynthesis inhibitor, Brz2001: evaluation of its effects on Arabidopsis, cress, tobacco, and rice.

Brassinazole is the only known specific brassinosteroid (BR)-biosynthesis inhibitor, and it has been shown to be useful for elucidating the function of BRs. In the course of a structure-activity relationship study of brassinazole, we found a more specific BR-biosynthesis inhibitor, Brz2001. This new inhibitor induced similar morphological changes to those seen in brassinazole-treated plants, including Arabidopsis thaliana (L.) Heynh., Nicotiana tabacum L., and Lepidium sativum L. These changes included dwarfism with altered leaf morphology, including downward curling and dark-green color, and the changes were reversed by brassinolide. Although the structure of Brz2001 is similar to that of uniconazole, a gibberellin-biosynthesis inhibitor, Brz2001-treated plants showed almost no recovery with the addition of gibberellic acid (GA3). Comparison of the responses of both brassinazole- and Brz2001-treated cress to brassinolide and GA3 suggested that Brz2001 is a more specific BR-biosynthesis inhibitor than brassinazole. Unlike the results just described, Brz2001-treated rice did not show any morphological changes. This suggests that the roles of BRs in rice may be different from those in the dicotyledonous plants examined in this study. Brz2001 can be used to clarify the function of BRs in dicots as a complement to BR-deficient mutants, and to elucidate the different roles of BRs in monocots and dicots.

Arabidopsis↗
PubMed2001

Gene fusion involving HMGIC is a frequent aberration in uterine leiomyomas.

HMGIC, a high-mobility-group protein gene encoding an architectural transcription factor, was recently identified as the target of gene fusion in a variety of human benign mesenchymal tumors; some of these events were chromosomal translocations involving 12q13-15. HMGIC consists of three DNA-binding domains (encoded by exons 1-3), a spacer, and an acidic carboxyl-terminal regulatory domain (exons 4-5). To determine the spectrum and nature of the aberrations in uterine myomas in Japanese patients, we systematically examined the tumors of 45 patients for all possible types of gene fusions involving HMGIC, by means of 3'-rapid amplification of cDNA ends (RACE) and reverse transcriptase-polymerase chain reaction (RT-PCR) experiments. HMGIC gene fusions were found in 16 (36%) of the tumors; aberrant splicings to five cryptic sequences located in introns of the HMGIC gene were found in 11 of these cases, and translocations causing juxtaposition to other genes, such as COX6C and RA D51B, were found in 5. In all fusion transcripts, the first two or three exons of HMGIC were fused to ectopic sequences. Our results suggest that a fusion event, resulting in the separation of the DNA-binding domains of HMGIC from the spacer and the acidic carboxyl-terminal regulatory domain, is a common tumorigenic mechanism in the development of uterine myomas.

Alternative Splicing↗
PubMed2001

Clinical significance of TT virus in chronic hepatitis C.

BACKGROUND AND AIMS: Much is still unknown about the clinical significance of TT virus (TTV), which has been reported as a candidate for non A-G hepatitis virus. The aim of this study was to clarify the clinical significance of TTV in patients coinfected with TTV and hepatitis C virus (HCV). METHODS: The 95 subjects studied had chronic hepatitis C (CHC), and underwent interferon (IFN) therapy. TT Virus DNA was detected by using polymerase chain reaction. The nucleotide sequences were determined by using a dideoxy chain termination method. A phylogenetic tree was drawn up by using the neighbor-joining method. RESULTS: TT Virus DNA was detected in 37.9% of patients with the use of an open reading frame 1 (ORF1) primer, and in 88.4% of patients by using a 5' untranslated region (5' UTR) primer. Using both sets of primers, no differences were found between TTV-DNA-positive and -negative subjects with CHC in the clinical findings. Serum TTV DNA was eradicated in 30.6% of patients with the ORF1 primer, and in 19.1% of patients with the 5' UTR primer at 6 months after the cessation of IFN therapy. The levels of TTV DNA before IFN therapy were significantly lower in the viral eradication group than in non-eradication group. The changes in alanine aminotransferase (ALT) concentrations were significantly correlated with changes in HCV-RNA in CHC patients with TTV. Moreover, there was no correlation between the changes in TTV DNA and the course of ALT. CONCLUSION: Hepatocellular injury in patients with chronic hepatitis who are coinfected with HCV and TTV appears to primarily be caused by HCV and is less attributable to TTV.

Adult↗