Biomedical subjects

A Yoshikawa

Publications and source records attributed to A Yoshikawa.

At least 19 recordsLinked to original sources

PubMed2006

The useful combination of a higher frequency miniprobe and endoscopic submucosal dissection for the treatment of T1 esophageal cancer.

BACKGROUND: There are few published data on the discrimination ability of endoscopic ultrasonography (EUS) among each subdivision of T1 cancer, and overdiagnosis is an unsolved problem that eventually causes overtreatment. The purpose of this study was to verify whether our treatment strategy incorporating EUS realizes a tailored patient management of T1 esophageal cancer. METHODS: This study comprised 20 esophageal cancer patients undergoing 12- to 20-MHz miniprobes for T staging and a 7.5-MHz dedicated echoendoscope for N staging. Initial therapy constituted endoscopic submucosal dissection (ESD) for endosonographically node-negative, mucosal, or slight submucosal cancers and a primary esophagectomy with three-field lymphadenectomy for deeper cancers. If the ESD specimen revealed no cancer involvement of the muscularis mucosa, the patients entered a follow-up program; otherwise, they were advised to undergo a subsequent esophagectomy and three-field lymphadenectomy. RESULTS: Perfect discrimination accuracy was achieved among T1, T2, and T3 cancers. Whether cancer depth was up to the slight submucosal layer or deeper was correctly differentiated in 12 of 14 T1 cancers (86%). EUS categorized all patients correctly into candidates for either ESD or surgery. The pathological cancer depth of the resected specimens revealed that no patients experienced unnecessary overtreatment. CONCLUSIONS: A higher frequency miniprobe is useful for the detailed evaluation of cancer depth, contributing to decision making for treatment options of T1 esophageal cancer. A miniprobe and echoendoscope in combination with ESD provide an appropriately tailored management plan on an individual basis, avoiding unnecessary treatment or indicating radical surgery.

Adenocarcinoma↗

PubMed2005

Epidemiology of blood donors in Japan, positive for hepatitis B virus and hepatitis C virus by nucleic acid amplification testing.

BACKGROUND AND OBJECTIVES: The Japanese Red Cross screens seronegative blood donors by nucleic acid amplification testing (NAT) for hepatitis B, hepatitis C and human immunodeficiency virus-1 markers. NAT-positive donors thus identified seemed to have a different infectious background from serologically positive donors. The purpose of our study was to characterize this background in the hepatitis B virus (HBV) and hepatitis C virus (HCV) NAT-positive donors. MATERIALS AND METHODS: Some 328 HBV DNA-positive and 44 HCV RNA-positive donors were detected by NAT testing of seronegative blood donors. These were characterized regarding age, gender and genotype of HBV and HCV. RESULTS: Those who were HBV NAT-positive were mainly young, in particular teenage girls. In Japan, genotypes C and B have previously been dominant, but recently genotype A has increased, and genotype H was recently detected. In HBV NAT-positive donors, the rate of genotype A was high (12.2%) compared with patients in hospital (1.7-2%). Donors who were HCV NAT-positive were also young, but mostly men in their twenties. The ratio of genotype 1b to 2a or 1b to 2b in HCV NAT-positive donors differed from that of hospitalized patients in Japan. We did not find genotype 1a, which is dominant in the USA. CONCLUSIONS: The high-risk donors detected by NAT were mainly young, with a different distribution of genotypes from that of hospitalized patients, regarding both HBV and HCV. The rare HBV genotype H has been found for the first time in Japan. The findings reflect the present spread of hepatitis viruses B and C.

Adolescent↗

PubMed2004

Functional modulation of activated lymphocytes by time-varying magnetic fields.

Time-varying magnetic fields (TVMF), especially those of extremely low frequency (below 250 Hz), have been reported to have profound effects on biological systems due to the induced currents since the biological systems consist of electrolyte solution. We have been interested in utilizing TVMF for cellular immunomodulations, and have shown that the TVMF could augment macrophage activation. In this study, the effect of TVMF on lymphocyte activation was studied. Murine spleen lymphocytes were isolated from DDY mice and incubated in the presence of Concanavalin A (ConA) for 72 h. The lymphocytes were exposed to TVMF for various durations, from 20 min to 2 h. The proliferation activities of lymphocytes were assayed by ELISA by use of 5-bromo-2'-deoxy-uridine Labeling and Detection Kit III (Roche Diagnostic Corp. Indianapolis, IN, USA). The IL1beta and IL2 concentrations in the culture medium were measured by ELISA assay. The IL2 receptor expression on the lymphocytes was evaluated by FACS analysis by use of FITC-conjugated monoclonal antibody. The proliferation activities were significantly enhanced by the TVMF for up to 40 min exposure from the initiation of ConA stimulation. The degree of augmentation effects, defined by the ratio of activation index of with and without TVMF, was varied from 1.1 to 2.7, and related to the lymphocyte responsiveness to the ConA. The less responsive cells showed more TVMF augmentation effects. The TVMF exposure after 40 min from ConA addition showed no effect, suggesting that the TVMF effects are most likely related to the Ca ion influx. The prolonged exposure of TVMF depressed the augmentation effects, which was caused by the depressed IL-2 receptor expression although both IL1-beta and IL-2 productions were not affected.

Animals↗

PubMed2003

Superiority of minipool nucleic acid amplification technology for hepatitis B virus over chemiluminescence immunoassay for hepatitis B surface antigen screening.

BACKGROUND AND OBJECTIVES: The Japanese Red Cross (JRC) have developed a fully automated multiplex (MPX) nucleic acid amplification technology (NAT) system for hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus 1 (HIV-1). This is used to test serologically negative blood units from volunteer, non-remunerated donors. The system utilizes a 50-sample pool for NAT screening with an input volume of each pool. This results in a significantly higher sensitivity for hepatitis B than that seen with highly sensitive hepatitis B surface antigen (HBsAg) testing. MATERIALS AND METHODS: From 1 February 2000 to 15 October 2001, over 11 million donations, which were serologically negative, were tested using the MPX NAT system. Donations found to be HBV DNA positive were further tested by using the chemiluminescence immunoassay (CLIA). RESULTS: Out of 181 HBV DNA-positive donations, 96 (53%) and 76 (42%) were negative by individual enzyme immunoassay (EIA) and CLIA testing, respectively. CONCLUSIONS: The sensitivity of the 50-sample pool MPX NAT system was higher than that of individual HBsAg screening by CLIA. By adopting this NAT-screening system, the JRC has improved the safety of the blood supply and maintained supply across Japan.

Blood Donors↗

PubMed2002

Analysis of the entire genomes of thirteen TT virus variants classifiable into the fourth and fifth genetic groups, isolated from viremic infants.

TT virus (TTV) DNA in serum samples obtained from 24 TTV-infected infants was amplified by polymerase chain reaction (PCR) with inverse primers derived from the untranslated region. The amplified PCR products were molecularly cloned; six clones each were analyzed. Seventy-six (53%) of the 144 TTV clones were classified into group 4 (YONBAN isolates), and 22 (15%) into a novel genetic group (group 5). The TTV clones in group 4 were classified into 9 types, and those in group 5 into 4 types. The entire nucleotide sequence of one representative clone each from the 13 types were determined; they comprised 3570-3770 nucleotides, and had poor homology to TTVs of groups 1-3 (TA278, PMV and SANBAN isolates). A phylogenetic tree based on the entire nucleotide sequence of open reading frame 1 confirmed the presence of five distinct clusters separated by a bootstrap value of 100%. Analysis of 13 TTV variants demonstrated preservation of the genomic organization and transcription profile in all TTV groups. TTV group 4 was detected in 54% or 72% of 7-to-12-month-old infants in Japan and China, respectively, which is comparable with that among adults in the respective country, indicating early and frequent acquisition of this TTV group in infancy.

Adult↗

PubMed2002

Status of NAT screening for HCV, HIV and HBV: experience in Japan.

Blood↗

PubMed2001

Analysis of the complete genome of indigenous swine hepatitis E virus isolated in Japan.

Using reverse transcription-polymerase chain reaction with primers derived from well-conserved genomic areas among all four hepatitis E virus (HEV) genotypes (I-IV), the HEV sequence was identified in serum samples obtained from 3 (3%) out of 95 60- to 90-day-old pigs in Japan and characterized molecularly. In the partial sequence of open reading frame (ORF) 2 of 421 nucleotides, the three swine isolates (swJ570, swJ681, and swJ791) showed the highest similarity of 83-87% to genotype III HEV representing human and swine strains (US1, US2, and swUS1) in the United States. The full-length nucleotide sequence of swJ570 consisted of 7225 nucleotides excluding the poly(A) tail and contained ORF 1 encoding 1703 amino acids (aa), ORF2 encoding 660 aa, and ORF3 encoding 122 aa. The swJ570 strain was most closely related to a Japanese strain (JRA1), which had been obtained from a hepatitis patient who had not traveled outside Japan. The overall nucleotide sequence identity between them was 89% and the deduced amino acid sequence identities of ORF1, ORF2, and ORF3 were 96, 99, and 98%, respectively. These results indicate that a certain proportion of pigs in Japan are HEV-viremic and may act as reservoirs of HEV infection, and that the presence of an indigenous strain(s) of HEV should be taken into consideration for the diagnosis of acute hepatitis in Japan.

3' Untranslated Regions↗

PubMed2001

Heterogeneous distribution of TT virus of distinct genotypes in multiple tissues from infected humans.

TT virus (TTV) DNA was quantitated in the serum and nine autopsy tissues (bone marrow, lymph node, muscle, thyroid gland, lung, liver, spleen, pancreas, and kidney) obtained from each of three TTV-infected subjects by real-time polymerase chain reaction (PCR), which can detect all TTV genotypes. TTV DNA was detected in all examined tissues, with the viral load being equal to or up to 300 times higher than that in the corresponding serum (2.1 x 10(5) to 5.3 x 10(7) copies/g vs 1.2-3.9 x 10(5) copies/ml). Generally, the TTV viral load was higher in the bone marrow, lung, spleen, and liver than in the other tissues, although it varied by individual. Restriction fragment length polymorphism (RFLP) analysis of the PCR-amplified TTV DNA of 3.3 kilobases (kb) revealed considerable differences among the TTVs in the serum and tissue specimens from each subject. Further, the 3.3-kb amplicons from the serum and tissue specimens from one subject were molecularly cloned, and 30 clones each from the serum and each tissue specimen were subjected to RFLP and sequence analysis (total, 300 clones): the TTV clones were classified into six genotypes including four novel genotypes. The genotypic variability was remarkable: each specimen had one to five TTV genotypes at different frequencies. TTV DNA in replicative intermediate forms and TTV mRNA were detectable in all tissues tested. These results indicate the broad, uneven distribution of TTV genotypes in tissues and suggest that viral replication takes place in multiple tissues at distinct levels in infected individuals.

Base Sequence↗

PubMed2001

A case of improved obstructive sleep apnea by distraction osteogenesis for midface hypoplasia of an infantile Crouzon's syndrome.

We performed Le Fort III midfacial advancement with gradual distraction using internal devices on a 2-year 5-month-old boy with Crouzon's syndrome with associated severe obstructive sleep apnea. The device was not activated until 7 days after surgery, after which the distraction was initiated, 1 mm per day, and the midface was advanced 4 mm intraoperatively and distracted 12 mm postoperatively. A total advancement of 16 mm was obtained. The obstructive sleep apnea improved remarkably after the distraction. In infants and younger children with associated severe obstructive sleep apnea, advancement by distraction osteogenesis of the midface in Le Fort III maxillary osteotomy will be initially indicated to obviate tracheostomy improving the upper airway obstruction.

Craniofacial Dysostosis↗

PubMed2001

Surgical program for craniosynostosis using three-dimensional solid model, combined with autologous blood transfusion in a Japanese craniofacial unit.

Since April 1997 at St. Mary's Craniofacial Unit, simulated surgery using a three-dimensional solid model made preoperatively was carried out, which enable sufficient autologous blood banking before the surgery. This study was conducted in eight patients presenting with plagiocephaly, brachycephaly, and oxycephaly consisting of simple craniosynostosis and syndromic craniosynostosis. Four cases (numbers 1-4) conducted with simulated surgery using three-dimensional solid models and fronto-orbital advancement with reshaping, as well as autologous blood transfusion were selected for the later-term group. For the first-term group, four cases (numbers 5-8) that were performed before the introduction of the abovementioned treatment were selected. The later-term group compared with the first-term group showed a decrease in operating time by an average of 1 hour, blood loss during surgery by 90 ml, and one fifth the amount of homologous blood transfusion. Also, 2 cases in the later-term group (cases 3 and 4) were able to avoid homologous blood transfusion, and they had autologous blood transfusion of 30 to 33 ml/kg. The surgical techniques will be improved with repeated cases of simulated surgery, aiming for the minimum invasive surgery. Also, the use of autologous blood transfusion is expected to increase as a less invasive surgery.

Blood Loss, Surgical↗

PubMed2001

C-shape extended transconjunctival approach for the exposure and osteotomy of traumatic orbitozygomaticomaxillary deformities.

In the treatment of post-traumatic deformities of the orbitozygomaticomaxillary complex resulting from trauma, the most appropriate exposure must be used. The choice of exposures includes the bicoronal approach and the periorbital incisions. When the whole orbitozygomatic complex is malpositioned, the bicoronal approach is desirable; this can be combined with buccal and eyelid incisions. However, the bicoronal approach is complicated by a longer duration of operation time, post-surgical scars that tend to show, and potential damage to the temporal branch of the facial nerve. A new approach using a C-shape extended transconjunctival approach is possible to have one field of vision to osteotomize the frontozygomatic suture, the lateral orbital wall, inferior orbital rim, lateral maxillary buttress, and zygomatic arch. It takes less operating time and the post-surgical scars are shorter than the bicoronal approach.

Accidents, Traffic↗

PubMed2001

The first large-scale nucleic acid amplification testing (NAT) of donated blood using multiplex reagent for simultaneous detection of HBV, HCV, and HIV-1 and significance of NAT for HBV.

The first nationwide nucleic acid amplification testing (NAT) for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus type 1 (HIV-1) of voluntarily donated blood after serological pre-screening and before release of cellular components and plasma for fractionation was implemented by the Japanese Red Cross Blood Transfusion Services. From February 1, 2000 to April 30, 2001, specimens from 6,805,010 units of serologically negative donation were screened in minipools of 50 samples within 24 hr after blood donation by NAT using multiplex HBV/HCV/HIV-1 reagent for blood transfusion including short shelf-life platelets. Among them, 112 HBV DNA-positives, 25 HCV RNA positives and 4 HIV-1 RNA positives were screened out and we could prevent transfusion of these NAT positive units. Subtypes/genotypes of HBV DNA, adr/C, adw/A, adw/B, adw/C, ayr/C and ayw/D were found and adr/C was predominant. A total of 61.6 % of them (69/112) were negative by overnight EIA. Sixth three of HBV NAT-positive samples carried virus loads less than 10(4) copies/mL and 92.1 % of them (58/63) were negative by overnight EIA. The virus growth curves of HBV in 6 cases obtained by retrospective and prospective follow-up study showed exponential straight lines in the early stage of serological window periods and the log times of HBV growth (10 fold increase) in serological window period were between 4.6 and 7.6 days. NAT screening with highly sensitive reagents in pool of specimens is useful to exclude blood units with low level of HBV and HBV mutants from blood transfusion.

Blood Donors↗

PubMed2001

[Silent myocardial ischemia and exercise-induced arrhythmia detected by the exercise test in the total health promotion plan (THP)].

We investigated the prevalence and characteristics of ischemic heart disease especially silent myocardial ischemia (SMI) and arrhythmia in need of careful observation in the exercise stress tests in the Total Health Promotion Plan (THP), which was conducted between 1994-96 for the purpose of measuring cardiopulmonary function. All workers (n = 4,918, 4,426 males) aged 18-60 yr old in an occupational field were studied. Exercise tests with an ergometer were performed by the LOPS protocol, in which the maximal workload was set up as a presumed 70-80% maximal oxygen intake, or STEP (original multistage protocol). ECG changes were evaluated with a CC5 lead. Two hundred and fifteen people refused the study because of a common cold, lumbago and so on. Of 4,703 subjects, 17 with abnormal rest ECG and 19 with probable anginal pain were excluded from the exercise tests. Of 4,667 who underwent the exercise test, 37 (0.79%) had ischemic ECG change, and 155 (3.32%) had striking arrhythmia. These 228 subjects then did a treadmill exercise test with Bruce protocol. Twenty-two (0.47% of 4,703) showed positive ECG change, 9 (0.19%) of 22 had abnormal findings on a 201Tl scan. 8 (0.17%) were diagnosed as SMI (Cohn I), in which the prevalence of hypertension, hyperlipidemia, diabetes mellitus, smoker and positive familial history of ischemic heart disease was greater than that of all subjects. In a 15-30 month follow up, none has developed cardiac accidents. Exercise-induced arrhythmia was detected in 11 (0.23%) subjects. Four were non-sustained ventricular tachycardia without any organic disease, 4 were ventricular arrhythmia based on cardiomyopathy detected by echocardiography, 2 were atrial fibrillation and another was WPW syndrome. It is therefore likely that the ergometer exercise test in THP was effective in preventing sudden death caused by ischemic heart disease or striking arrhythmia.

Adolescent↗

PubMed2000

Eel WT1 sequence and expression in spontaneous nephroblastomas in Japanese eel.

Nephroblastomas spontaneously developing in Japanese eel reared at farms for 5 to 9months after collection from the wild [Masahito et al., Cancer Res., 52 (1992) 2575-2579] were investigated to cast light on the role of Wilms' tumor 1 gene (WT1) in eel kidney tumorigenesis. Cloning of the WT1 counterpart, EWT1, revealed that conservation of an alternative splice II site, located between the third and fourth zinc fingers, was conserved. The zinc finger domain was highly conserved. The transregulator region, sequences corresponding to exons 4 and 5 in WT1, were lacking in EWT1 cDNA. EWT1 was found to be expressed in kidney, testis and spleen and in situ hybridization revealed dark-stained immature cells in elver kidney to be positive. Although no EWT1 gene mutations were found in 38 eel nephroblastomas, 26 polymorphic nucleic acid changes were observed. Aberrant WT1 expression was noted in epithelial (12 out of 27; 44%) and nephroblastic cell histological types (three out of five; 60%) of eel nephroblastomas. On in situ hybridization the EWT1 expressive cells resembled human blastema cells, similar to those in human Wilms' tumor. These data demonstrated strong signals that the EWT1 protein may function in the development of eel kidney and play a role in genesis of nephroblastomas as in mammals.

Amino Acid Sequence↗

PubMed2000

Tissue factor expression in human colorectal carcinoma: correlation with hepatic metastasis and impact on prognosis.

BACKGROUND: It has been suggested that tissue factor (TF) plays an important role in tumor metastasis. Its expression in sarcoma cells was reported to up-regulate the vascular endothelial growth factor (VEGF) gene and thereby enhance tumor angiogenesis, which is essential to tumor metastasis. Although many malignant tumors have been reported to express this protein constitutively, recent clinical studies have focused mainly on the correlations among TF expression, tumor progression, and histologic grade. Therefore, to address the role of TF and the underlying mechanism of hematogenous metastasis of colorectal carcinoma, the authors analyzed the correlations among TF expression, hepatic metastasis, and VEGF gene expression in surgical specimens. Furthermore, they analyzed the prognostic significance of TF expression with respect to overall patient survival. METHODS: Expression of TF and VEGF genes in 67 advanced colorectal carcinoma specimens was studied by immunohistochemistry and Northern blot analysis, respectively. The correlations among TF expression, hepatic metastasis, and other factors were analyzed with univariate and multivariate statistics. Survival rates were calculated using the Kaplan-Meier method. RESULTS: Univariate and multivariate analyses showed TF expression to be a significant (P = 0.0001) and independent risk factor for hepatic metastasis, whereas a weak but insignificant correlation was observed between TF and VEGF gene expression. The outcomes in the TF positive group were significantly worse in all cases (P = 0.0001) and in the cases without synchronous hepatic metastasis (P = 0.0156). CONCLUSIONS: Although the precise mechanisms are unknown, TF expression is a suitable indicator of both hepatic metastasis and prognosis for colorectal carcinoma patients.

Aged↗

PubMed2000

Activated protein C prevents multiple organ injury following extensive hepatectomy in cirrhotic rats.

BACKGROUND/AIMS: Extended hepatectomy for cirrhotic liver in patients with hepatocellular carcinoma often triggers posthepatectomy liver failure. It has been shown that the microcirculatory disturbance caused by microthrombus formation and sinusoidal endothelial cellular injury is one of the causes of post-hepatectomy liver dysfunction. We therefore investigated the effect of activated protein C (APC), a potent antithrombotic serine protease with anti-inflammatory effects, on posthepatectomy liver dysfunction and multiple organ injury in cirrhotic rats. METHODS/RESULTS: Dimethylnitrosamine-induced cirrhotic rats underwent 70% hepatectomy and received lipopolysaccharide (200 microg/kg) 48 h later to prepare a lethal posthepatectomy acute liver failure model. APC (1500 U/kg), given intravenously 15 min before and 1 h after endotoxin challenge, attenuated liver dysfunction and decreased serum tumor necrosis factor-alpha concentration. APC significantly improved the survival rate of rats at 12 h after endotoxin challenge. Histological examination revealed that APC treatment inhibited not only intrasinusoidal fibrin deposition and massive hepatocellular necrosis but also pulmonary injury and glomerular fibrin deposition. Immunohistochemically, expression of intercellular adhesion molecule-1 on sinusoidal cells and renal glomeruli was decreased in the APC-treated animals. CONCLUSIONS: APC administration prevented acute liver dysfunction and attenuated multiple organ injury following extended hepatectomy in cirrhotic rats, possibly via anticoagulant and anti-inflammatory effects.

Animals↗

PubMed2000

Consecutive imaging of the facial nerve using high-resolution magnetic resonance imaging.

This study examined the signal intensity of the facial nerve on T1-weighted images using the multiplanar reconstruction (MPR) method of the high-resolution magnetic resonance imaging technique. The facial nerves of 12 sides in 6 normal adults were consecutively observed from the mastoid area to the intraparotid area. Results indicated that facial nerves showed similar or relatively high signal intensity compared with the intensity of the parotid parenchyma. Although previous studies have indicated that the intraparotid facial nerve had a low signal intensity, facial nerves were probably confused with the intraparotid ductal system or vessels which show low signal intensity on T1-weighted images or with low signal lines due to chemical artifacts. All facial nerve trunks were clearly identified; however, 33% (4/12) of second branches of the nerves shifted or curved too strongly to be detected in the parotid parenchyma with this method.

Adult↗

PubMed2000

Production and product quality assessment of human hepatitis B virus pre-S2 antigen in submerged and solid-state cultures of Aspergillus oryzae.

Pre-S2 is a diagnostically important antigen of human hepatitis B virus (HBV). In order to produce pre-S2 antigen in Aspergillus oryzae, the gene [pre-S2]3, which encodes a tandemly triplicated repeat of pre-S2 polypeptides was fused with the partial glaA gene encoding glucoamylase lacking the starch-binding domain. In submerged culture, A. oryzae transformants carrying glaA-[pre-S2]3 secreted a heterogeneously glycosylated form of the fusion protein that was partially degraded. Contrarily, utilization of a wheat brain solid-state culture system resulted in the secretion of a homogeneous glycosylated form of the whole fusion protein. This is the first report of a dissimilarity in glycosylated modification between submerged and solid-state culture conditions in heterologous protein production in A. oryzae.

Journal Article↗