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Biomedical subjects

S Saitoh

Publications and source records attributed to S Saitoh.

At least 127 records · Page 7Linked to original sources
PubMed1999

Chronic liver disease in the extremely elderly of 80 years or more: clinical characteristics, prognosis and patient survival analysis.

BACKGROUND/AIMS: This study aimed to elucidate the clinical characteristics of patients with chronic liver disease aged 80 years or more, especially the factors affecting prognosis and carcinogenesis. METHODS: A total of 135 patients aged 80 years or above were divided into chronic liver disease without cirrhosis (non-LC) and cirrhosis (LC) groups according to the severity of fibrosis, and the clinical characteristics and prognoses were evaluated. RESULTS: Seventy-three (54.1%) of 135 patients were in the LC group and 79 patients (58.5%) had hepatitis C virus. Various concomitant diseases were seen in 122 patients (90.4%). Liver-related deaths occurred in only 19 (36.5%) of 52 patients who died during observation, although 28 patients (53.8%) had liver cancer at the time of death. Cumulative survival rates in the non-LC and the LC groups were 85.7% and 58.8% at the 5th year, and 69.4% and 19.4% at the 9th year, respectively. Cumulative liver cancer appearance rates in the non-LC and the LC groups were 1.6% and 6.1% at the 1st year, 12.4% and 19.9% at the 5th year, and 12.4% and 32.0% at the 7th year, respectively. A multivariate Cox regression analysis revealed that the presence of liver cancer (p=0.0001), platelet count (p=0.0242), and fibrotic stage (p=0.0118) were independently associated with survival period, and alfa-fetoprotein (p=0.0194) and bilirubin (p=0.0282) were independently associated with carcinogenesis. CONCLUSIONS: Cirrhosis is the major risk factor affecting the prognosis. On the other hand, we must pay more attention to concomitant diseases specific to advanced age.

Aged↗
PubMed1999

Single-cell analysis of mitochondrial DNA in patients and a carrier of the tRNA(Leu)(UUR) gene mutation.

We examined heteroplasmy of mutated mitochondrial DNA in single peripheral lymphocytes derived from 4 individuals carrying the nt 3243 A-to-G mutation, including two patients with MELAS, a patient with cardiomyopathy, deafness and diabetes mellitus, and the asymptomatic mother of one of the MELAS patients. In these subjects, all lymphocytes examined were heteroplasmic to different degrees, with a wider range of heteroplasmy evident in the symptomatic patients than in the healthy carrier.

Abnormalities, Multiple↗
PubMed1999

Detection of lymphocytes and granulocytes expressing the mutant WASP message in carriers of Wiskott-Aldrich syndrome.

Wiskott-Aldrich syndrome (WAS) is an X-linked recessive disease caused by mutations in the recently identified WAS protein gene (WASP). In some X-linked genetic disorders skewed X-inactivation has been observed in all cell populations or some specific cell lineages of female carriers. Recently, female carriers of WAS were also revealed to present skewed X-inactivation patterns at the haemopoietic stem cell level. However, it is not clear if all haematological cells expressing the mutant WASP allele are eliminated in WAS carriers. By reverse transcription PCR methods, we studied 14 WAS carriers from 10 different families to assess whether blood cells expressing the mutant WASP message were present in their peripheral blood. The mutations of each WAS patient were known and carrier diagnosis of their female family members was performed using specific mutation analysis. We detected circulating lymphocytes and granulocytes expressing the mutant WASP message in most of the WAS carriers, nevertheless they showed skewed X-chromosomal inactivation patterns. Interestingly, the presence of blood cells expressing the mutant WASP message seemed to correlate to the WASP genotype and the age of the carriers.

Adult↗
PubMed1999

Prevalence of TT virus before and after blood transfusion in patients with chronic liver disease treated surgically for hepatocellular carcinoma.

BACKGROUND: To examine the prevalence of TT virus (TTV) before and after blood transfusion, we retrospectively examined serum samples obtained from 55 patients who received blood transfusions before, during and after resection of hepatocellular carcinoma. METHODS: TT virus DNA was extracted from serum samples and detected by nested polymerase chain reaction. Before transfusion, seven (12.7%) were positive for TTV. Patients were transfused whole blood or separated blood components (fresh frozen plasma, platelet and/or red blood cells), the total amount of transfused fresh frozen plasma ranging from 12 to 271 (median 38) units. RESULTS: Seven (14.6%) of the 48 TTV-negative patients became positive for TTV-DNA 1 month after transfusion. Only one of the seven patients, who was already positive for HCV-RNA, exhibited elevation of alanine aminotransferase. Five of the newly infected seven patients become negative for TTV during a 2 year follow up. CONCLUSIONS: Our findings suggest that the proportion of patients with TTV was relatively high in this sample, and that the prevalence of TTV transmission by blood components was also relatively high (14.6%). Although TTV persisted for more than 6 months in some patients, infection was not noticeable during the course of chronic liver disease.

Carcinoma, Hepatocellular↗
PubMed1999

Neoadjuvant therapy and bladder substitute for invasive bladder cancer: 20 years experience at Tohoku University.

BACKGROUND: Neobladder, using the intestine, was performed after neoadjuvant therapy and total cystectomy as a treatment for invasive bladder cancer. METHODS: Between January 1977 and April 1997, an ileocecal neobladder was used for 23 patients and a sigmoid neobladder was chosen for use in 32 patients. For the diagnosis of invasive bladder cancer and the evaluation of neoadjuvant therapy, we used whole-layer core biopsy (WLCB) of the bladder tumor and fine needle aspiration biopsy (FNAB) of pelvic lymph nodes after bipedal lymphography. For neoadjuvant therapy, two to four courses of internal iliac arterial infusion chemotherapy (IIA) were undertaken in 32 patients. Five patients were treated with IIA combined with 40 Gy irradiation to the pelvic space. RESULTS: Pretreatment WLCB revealed a tumor of stage T2b or greater in 10 patients. After neoadjuvant therapy, three patients were down-staged to pT0. In five patients, pretreatment FNAB revealed pelvic lymph node metastases that were not detected by computed tomography or magnetic resonance imaging. Fine needle aspiration biopsy post-neoadjuvant therapy revealed tumor stage N0 in all patients and lymph node dissection revealed pN0 in four patients. Of the five patients who received 40 Gy irradiation, none had any postoperative complications, such as intestinal fistula or urinary leakage. Four male patients (10%) had urethral recurrence, but all were successfully treated by transurethral resection. Two patients treated prior to 1985 experienced local recurrence. Neither was treated by neoadjuvant therapy. Eight patients who died after 1985 had metastatic cancer, but none had local recurrence. None of the patients who received a sigmoid neobladder required clean intermittent catheterization or had bilateral vesico-ureteral reflux. CONCLUSIONS: Neoadjuvant therapy seems to reduce local recurrence in invasive bladder cancer. The sigmoid colon may be suitable for neobladder.

Adult↗
PubMed1999

Contact area of the trapeziometacarpal joint.

Eighteen cadaver hands were studied to determine the contact area of the trapeziometacarpal joint by using silicone rubber casts. Casting material was introduced into the trapeziometacarpal joint during several motions of the thumb and the contact location was observed. The ratios of the contact area to the total joint area were calculated. The contact locations in opposition were the radial, volar, and ulnar segments of the trapezium and the dorsal, radial, and volar segments of the metacarpal. On average, 53% of the trapezium was in contact with 53% of the metacarpal in opposition, while 28% of the trapezium was in contact with 28% of the metacarpal in palmar abduction and 25% of the trapezium was in contact with 25% of the metacarpal in radial abduction. The contact area was the largest in opposition. The trapeziometacarpal joint is stable in opposition and facilitates a strong pinch.

Aged↗
PubMed1999

Scaphoid nonunion and flexor pollicis longus tendon rupture.

Four patients presented with a rupture of the flexor pollicis longus tendon that was associated with a longstanding scaphoid nonunion. A radiocarpal arthrosis was present in 3 of the 4 patients and a dorsiflexed intercalated segment instability deformity was also seen in 3 of the 4 patients. Three patients underwent surgery consisting of an osteosynthesis with an iliac bone graft for the scaphoid nonunion and a palmaris longus tendon graft for the ruptured flexor pollicis longus tendon. An osseous union of the scaphoid and a functional active range of motion of the thumb interphalangeal joint (33 degrees on average) was attained in all 3 of the patients treated surgically. Preoperative radiologic examinations and intraoperative findings suggest that the volarly protruding distal scaphoid segment is the cause of the rupture.

Aged↗
PubMed1999

Imprinting-mutation mechanisms in Prader-Willi syndrome.

Microdeletions of a region termed the "imprinting center" (IC) in chromosome 15q11-q13 have been identified in several families with Prader-Willi syndrome (PWS) or Angelman syndrome who show epigenetic inheritance for this region that is consistent with a mutation in the imprinting process. The IC controls resetting of parental imprints in 15q11-q13 during gametogenesis. We have identified a larger series of cases of familial PWS, including one case with a deletion of only 7.5 kb, that narrows the PWS critical region to <4. 3 kb spanning the SNRPN gene CpG island and exon 1. Identification of a strong DNase I hypersensitive site, specific for the paternal allele, and six evolutionarily conserved (human-mouse) sequences that are potential transcription-factor binding sites is consistent with this region defining the SNRPN gene promoter. These findings suggest that promoter elements at SNRPN play a key role in the initiation of imprint switching during spermatogenesis. We also identified three patients with sporadic PWS who have an imprinting mutation (IM) and no detectable mutation in the IC. An inherited 15q11-q13 mutation or a trans-factor gene mutation are unlikely; thus, the disease in these patients may arise from a developmental or stochastic failure to switch the maternal-to-paternal imprint during parental spermatogenesis. These studies allow a better understanding of a novel mechanism of human disease, since the epigenetic effect of an IM in the parental germ line determines the phenotypic effect in the patient.

Adult↗
PubMed1999

A novel imprinted gene, encoding a RING zinc-finger protein, and overlapping antisense transcript in the Prader-Willi syndrome critical region.

We describe a complex imprinted locus in chromosome 15q11-q13 that encodes two genes, ZNF127 and ZNF127AS. The ZNF127 gene encodes a protein with a RING (C3HC4) zinc-finger and multiple C3H zinc-finger motifs, the former being closely related to a protein from variola major virus, the smallpox etiological agent. These motifs allow prediction of ZNF127 function as a ribonucleoprotein. The intronless ZNF127 gene is expressed ubiquitously, but the entire coding sequence and 5' CpG island overlaps a second gene, ZNF127AS, that is transcribed from the antisense strand with a different transcript size and pattern of expression. Allele-specific analysis shows that ZNF127 is expressed only from the paternal allele. Consistent with this expression pattern, in the brain the ZNF127 5' CpG island is completely unmethylated on the paternal allele but methylated on the maternal allele. Analyses of adult testis, sperm and fetal oocytes demonstrates a gametic methylation imprint with unmethylated paternal germ cells. Recent findings indicate that ZNF127 is part of the coordinately regulated imprinted domain affected in Prader-Willi syndrome patients with imprinting mutations. Therefore, ZNF127 and ZNF127AS are novel imprinted genes that may be associated with some of the clinical features of the polygenic Prader-Willi syndrome.

Adolescent↗
PubMed1999

Translocation of tyrosine-phosphorylated TCRzeta chain to glycolipid-enriched membrane domains upon T cell activation.

Recent studies point to glycolipid-enriched membrane (GEM) microdomains as the critical sites for TCR-mediated signal transduction. However, whether the TCR complex is localized in the GEM domain is not well-defined. In the present study, we analyzed localization of the TCR-CD3 complex in the GEM domain by isolating the GEM fraction with sucrose density gradient centrifugation. Although 10% of TCRzeta chains was localized in the GEM fraction, most of the TCR complexes were excluded from the GEM before and after T cell activation, and the amount of TCRzeta in the GEM was not increased after activation. However, the tyrosine-phosphorylated form of TCRzeta was strongly concentrated in the GEM fraction upon TCR engagement. A kinetic study revealed that tyrosine phosphorylation of TCRzeta occurred initially in the Triton X-100-soluble membrane fraction followed by the accumulation of phosphorylated TCRzeta in the GEM. Thus, these results indicate that phosphorylated TCRzeta migrates into the GEM domains on T cell activation. We speculate that the GEM microdomains may function as a reservoir of activation signals from triggered TCR.

Animals↗
PubMed1999

A case of advanced esophageal cancer showing a long-term complete response with chemotherapy with nedaplatin alone.

We describe a case of advanced esophageal cancer treated successfully by chemotherapy with nedaplatin alone. A 60-year-old male with type 2 advanced esophageal cancer, which was located in the upper part of the esophagus and had invaded adjacent organs, was treated with nedaplatin 150 mg/body (100 mg/m2) given intravenously every 4 weeks from January 6, 1991. He achieved a partial response (PR) and was discharged in March 1991. Subsequently, he received nedaplatin 75 mg/body in an out-patient setting almost every month until August 1992. Toxicities were tolerable and included mild thrombocytopenia and nausea/vomiting. From serial evaluation in October 1993, the esophageal tumor was not observed. After 7 years since initial chemotherapy was administered, he still survives without the disease.

Antineoplastic Agents↗
PubMed1999

Combined ursodeoxycholic acid and glycyrrhizin therapy for chronic hepatitis C virus infection: a randomized controlled trial in 170 patients.

OBJECTIVE AND DESIGN: To assess the efficacy and safety of combination therapy using ursodeoxycholic acid with glycyrrhizin for chronic hepatitis C virus infection, we conducted a prospective randomized controlled trial of glycyrrhizin (group G) compared with glycyrrhizin plus ursodeoxycholic acid (group G+U) in 170 patients. METHODS: All patients had elevated serum aminotransferase levels over 6 months before entry into the trial. Glycyrrhizin was administered to both groups for 24 weeks, and in group G+U, ursodeoxycholic acid (600 mg/day) was administered orally as well. RESULTS: Serum aspartate transaminase and alanine transaminase concentrations significantly decreased during treatment in both groups, but serum gamma-glutamyl transpeptidase concentrations fell significantly only in group G+U. Concentrations of all three enzymes fell significantly more in group G+U than in group G, and had normalized in more cases when the trial ended at 24 weeks. However, levels of HCV viraemia did not change during the trial in either group. Multiple regression analysis linked only the treatment regimen, not HCV-related factors or liver histology, to the degree of serum enzyme reduction. No adverse effects were noted in either group. CONCLUSIONS: The combined therapy with ursodeoxycholic acid and glycyrrhizin is safe and effective in improving liver-specific enzyme abnormalities, and may be an alternative to interferon in chronic hepatitis C virus infection, especially for interferon-resistant or unstable patients.

Alanine Transaminase↗
PubMed1999

Susceptibility of TT virus to interferon therapy.

TT virus (TTV) is a newly identified single-stranded DNA virus. We retrospectively analysed serum samples from sixteen patients, infected with both hepatitis C virus (HCV) and TTV, and who had been treated with interferon. An elevated serum alanine aminotransferase level after interferon was associated with persistence of HCV (abnormal in five of seven patients with persistence of HCV compared with normal in all nine patients who showed eradication of HCV) irrespective of persistence of TTV. Comparison of partial viral DNA nucleotide sequences and phylogenetic analysis showed that viral strains that had a high identity to the prototype virus were more resistant to interferon than those showing low nucleotide sequence identity. Although we observed no liver cell injury caused by persistent TTV infection, the mechanism(s) of TTV resistance to interferon should be further investigated for a better understanding of viral diseases and establishment of therapy.

Alanine Transaminase↗
PubMed1999

Time course of histological changes in patients with a sustained biochemical and virological response to corticosteroid withdrawal therapy for chronic hepatitis B.

OBJECTIVE: Although biochemical and virological responses to corticosteroid withdrawal therapy for chronic hepatitis B have been extensively studied, long term changes in liver histology have not been well documented. METHODS: We retrospectively analyzed 45 paired liver biopsy specimens taken before and after treatment from 40 patients who persistently showed biochemical remission and an absence of HBe antigen (RIA) for up to 20 yr. RESULTS: The grading scores for necroinflammatory and fibrotic activity in the liver specimens decreased significantly after corticosteroid withdrawal therapy. Histological scores graded according to Knodell's components improved significantly in every category after corticosteroid withdrawal therapy. However, inflammatory cell infiltrates remained within the liver for long periods. The disappearance rate of necroinflammation in the periportal, lobular, and portal regions of the liver were 25%, 7.4%, and 7.4%, respectively, at yr 5 after therapy, and were 84.4%, 78.2%, and 58.7%, respectively, at yr 10 after therapy. The cumulative disappearance rate, calculated using the Kaplan-Meier method, was significantly lower for portal inflammation than for periportal necroinflammation. CONCLUSIONS: Our results show that: 1) despite clinical remission of chronic hepatitis B virus infection, long periods are needed for histological resolution of necroinflammation in the liver; and 2) by a Cox proportional hazard analysis of the factors contributing to histopathological disappearance of disease-related inflammation, the degree of fibrosis of liver biopsy specimens from pretherapy patients was the most statistically significant factor (p = 0.049).

Adult↗
PubMed1999

Comparison of base specificity and other enzymatic properties of two protozoan ribonucleases from Physarum polycephalum and Dictyostelium discoideum.

Base specificity and other enzymatic properties of two protozoan RNases, RNase Phyb from a true slime mold (Physarum polycephalum) and RNase DdI from a cellular slime mold (Dictyostelium discoideum), were compared. These two RNases have high amino acid sequence similarity (83 amino acid residues, 46%). The base specificities of two base recognition sites, The B1 site (base recognition site for the base at 5'-side of scissile phosphodiester bond) and the B2 site (base recognition site for the base at 3'-side of the scissile bond) of the both enzymes were estimated by the rates of hydrolysis of 16 dinucleoside phosphates. The base specificities estimated of B1 and B2 sites of RNase Phyb and RNase DdI were A, G, U > C and A > or = G > C > U, and A > or = G, U > C and G > U > A, C, respectively. The base specificities estimated from the depolymerization of homopolynucleotides and those from the releases of four mononucleotides upon digestion of RNA coincided well with those of the B2 sites of both enzymes. Thus, in these enzymes, the contribution of the B2 site to base specificity seems to be larger than that of the B1 site. pH-stability, optimum temperature, and temperature stability, of both enzymes are discussed considering that RNase Phyb has one disulfide bridge deleted, compared to the RNase DdI with four disulfide bridges.

Amino Acid Sequence↗