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S Koga

Publications and source records attributed to S Koga.

At least 55 records · Page 3Linked to original sources
PubMed2000

Early expression of interferon-gamma inducible protein 10 and monokine induced by interferon-gamma in cardiac allografts is mediated by CD8+ T cells.

BACKGROUND: Our goal was to test the intragraft mRNA expression and production of two chemokines that are potent chemoattractants for antigen-primed T cells, interferon-gamma inducible protein 10 (IP-10) and monokine-induced by IFN-gamma, (Mig), in allogeneic heart grafts. METHODS: Syngeneic or allogeneic A/J (H-2a) hearts were heterotopically transplanted to wild-type, CD4-/-, CD8alpha-/-, or IFN-gamma-/- C57BL/6 (H-2b) recipients. To test expression of IP-10 and Mig, grafts were removed 1-8 days posttransplant for RNA isolation and Northern blot analysis. To test the potential recipient leukocyte populations mediating intraallograft expression of IP-10 and Mig, recipients were treated with anti-NK 1.1, anti-CD4, and/or anti-CD8 monoclonal antibodies before transplantation. RESULTS: Allogeneic heart grafts transplanted to wild-type, but not IFN-gamma-/-, recipients expressed IP-10 and Mig at day +2 posttransplant that increased thereafter until rejection was completed. Expression of IP-10 and Mig in isografts was low or undetectable. Cardiac allografts from CD8+ T cell depleted, but not NK cell or CD4+ T cell depleted, recipients had low to undetectable expression of IP-10 and Mig on day +2 posttransplant. Similarly, cardiac allografts from CD8-/-, but not CD4-/-, recipients had low to undetectable expression of IP-10 and Mig on day +2 posttransplant. CONCLUSIONS: Early intraallograft expression of Mig and IP-10 during primary rejection of cardiac allografts is dependent on the activities of recipient CD8+ T cells.

Animals↗
PubMed2000

Early and delayed Tc-99m ECD brain SPECT in SLE patients with CNS involvement.

We compared early and delayed Tc-99m ECD SPECT scans in 32 SLE patients (Group 1, definite neuropsychiatric disorders; Group 2, minor neurologic symptoms or normal) with those of normal controls by visual inspection and semi-quantitative evaluation. With visual interpretation, 13 out of 14 patients in Group 1 (93%) and 7 out of 18 patients in Group 2 (39%) had diffuse uneven decrease in early scans. Seven patients in Group 2 (39%) who had normal early scans demonstrated focal decrease in the medial frontal lobe in delayed scans. With cerebral region to cerebellar ratios, in early scans, the medial frontal lobe in Group 1 and Group 2 was significantly lower than in normal controls, and lateral frontal lobe and occipital lobes in Group 1 were significantly lower than in normal controls. Nevertheless, in delayed scans, every cortical region except for the parietal lobe in Groups 1 and 2 was significantly lower than in normal controls. The retention rates in all regions in SLE patients were significantly lower than in normal controls. No case showed SPECT improvement on follow-up studies in either group in spite of clinical improvement. Delayed Tc-99m ECD brain SPECT of high sensitivity might be useful in detecting CNS involvement. Although the SPECT findings did not correlate with the neuropsychiatric symptoms, early and delayed Tc-99m ECD SPECT seems to provide useful objective diagnostic information in SLE patients.

Adult↗
PubMed2000

Outcome of surgery in cystic renal cell carcinoma.

OBJECTIVES: To review cases of cystic renal cell carcinoma treated surgically at our institution and define their clinical and histopathologic features. METHODS: Between 1986 and 1998, 21 patients with cystic renal cell carcinoma were treated surgically. Cystic renal cell carcinoma was categorized using Hartman's classification. RESULTS: Histopathologic examination demonstrated cystic necrosis in 11 patients, multilocular cystic renal cell carcinoma in 9, and unilocular cystic renal cell carcinoma in 1 patient. Tumors were incidentally found during an evaluation of unrelated disease or a general health checkup in 14 patients (67%). The mean tumor size was 5.6 cm (range 0.5 to 12) for cystic necrosis and 5.4 cm (range 2 to 9) for multilocular cystic renal cell carcinoma. All 9 cases of multilocular cystic renal cell carcinoma were of the clear cell type and tumor grade 1. The mean follow-up period was 65 months (range 9 to 141). The 5-year disease-specific survival rates for multilocular cystic renal cell carcinoma and cystic necrosis were 100% and 80%, respectively. CONCLUSIONS: The prognosis for patients with cystic renal cell carcinoma is better than that for patients with solid tumors. In particular, the prognosis of multilocular cystic renal cell carcinoma is excellent. Multilocular cystic renal cell carcinoma represents a distinct subtype of renal cell carcinoma that can be completely cured by surgery.

Adult↗
PubMed2000

Combination therapy of malignant glioma cells with 2-5A-antisense telomerase RNA and recombinant adenovirus p53.

Malignant gliomas of astrocytic origin have commonly expressed several features such as alterations in the tumor-suppressor gene p53 or p16 or the acquisition of telomerase activity, which are distinctive from astrocytes. Therefore, restoration of the tumor-suppressor gene or telomerase inhibition is expected to provide a cure for malignant gliomas. We have recently demonstrated that the treatment with a 19-mer antisense oligonucleotide against human telomerase RNA linked to a 2',5'-oligoadenylate (2-5A-anti-hTR) inhibited the growth of malignant glioma cells. From a therapeutic point of view, it is very important to investigate the antitumor efficacy of 2-5A-anti-hTR combined with the restoration of p53 or p16 gene. In this study, we evaluated the antitumor effect of 2-5A-anti-hTR in combination with recombinant adenoviruses bearing p53, its associated p21WAF1/CIP1, or p16CDKN2 gene (Ad5CMV-p53, Ad5CMV-p21, or Ad5CMV-p16) against malignant glioma cells in vitro and in vivo. Five malignant glioma cell lines expressing the mutant p53 gene (A172, GB-1, T98G, U251-MG and U373-MG) were more sensitive to the combination of 2-5A-anti-hTR and Ad5CMV-p53 than to other combinations. The additive effect of the combination therapy was due to induction of caspase-dependent apoptosis and cell growth arrest. Furthermore, the 2-5A-anti-hTR treatment when combined with Ad5CMV-p53 showed greater efficacy against subcutaneous U251-MG tumors in nude mice. In contrast, U87-MG cells expressing the wild-type p53 gene were insensitive to Ad5CMV-p53, although the treatment with 2-5A-anti-hTR was significantly effective. These results indicate that combining 2-5A-anti-hTR with Ad5CMV-p53 has the most therapeutic potential for malignant gliomas with mutant p53. For tumors exhibiting wild-type p53, it may be useful to treat with 2-5A-anti-hTR. Gene Therapy (2000) 7, 2071-2079.

Adenoviridae↗
PubMed2000

Unilateral pedal lymphography in patients with filarial chyluria.

OBJECTIVE: To evaluate the usefulness of unilateral pedal lymphography in patients with filarial chyluria. PATIENTS AND METHODS: Of 114 patients with filarial chyluria, all underwent lymphography (unilateral pedal in 106) and 55 underwent selective ureteric sampling for chyle. RESULTS: Unilateral pedal lymphography in the 106 patients detected lymphaticorenal fistulae (LRF) in 104 (98%). Lymphatic crossover was seen in all 106 patients, from the second sacral segment to the first lumbar segment. The most frequent crossover site was at the L5 level (87%). There was complete correlation between the side of LRF and the side of chyluria as assessed by selective ureteric sampling. CONCLUSION: Unilateral pedal lymphography can detect LRF via lymphatic crossover even when it is on the opposite side from that injected with contrast agent. The advantages of unilateral lymphography over bilateral procedures are that it is easy to identify crossover channels, and the discomfort for the patient is reduced because there are fewer incisions and it is quicker. Unilateral lymphography is recommended as the initial method when lymphography is indicated in filarial chyluria.

Adult↗
PubMed2000

An evaluation of Bosniak's radiological classification of cystic renal masses.

OBJECTIVE: To determine the clinical usefulness of Bosniak's classification of cystic renal masses, the differentiation of which remains difficult despite significant advances in diagnostic imaging. PATIENTS AND METHODS: The computed tomography (CT) findings of all histopathologically examined cystic renal masses diagnosed at our institution were analysed retrospectively; 35 patients with cystic renal masses were treated between 1986 and 1998. Tissues surgically removed were examined pathologically and the final diagnosis compared with the preoperative CT category of Bosniak's classification. RESULTS: The histopathological examined showed cystic renal cell carcinoma in 21 patients, a benign renal cyst in 12, haemangiosarcoma in one and transitional cell carcinoma in one. Most of the 35 masses (26, 74%) were found incidentally during evaluation for an unrelated disease or a routine health check. All 11 masses of Bosniak category I were benign and one category II mass was malignant. All 10 masses of category III and 12 of category IV were malignant. CONCLUSIONS: Bosniak's classification is useful for differentiating category I, III and IV cystic renal masses. There were too few samples to allow meaningful conclusions to be drawn for category II renal masses. It is critical to differentiate between complicated cysts of category II and III because of the major implications for prognosis and clinical management.

Adult↗
PubMed2000

Biochemical characterization, cloning, and sequencing of ADP-dependent (AMP-forming) glucokinase from two hyperthermophilic archaea, Pyrococcus furiosus and Thermococcus litoralis.

The ADP-dependent (AMP-forming) glucokinases from the hyperthermophilic archaea Pyrococcus furiosus and Thermococcus litoralis catalyze the phosphorylation of glucose using ADP as the essential phosphoryl group donor. Both enzymes were purified to homogeneity and characterized with regard to each other. The enzymes had similar enzymological properties as to substrate specificity, coenzyme specificity, optimum pH, and thermostability. However, a difference was observed in the subunit composition; while the T. litoralis enzyme is a monomer with a molecular mass of 52 kDa, the P. furiosus enzyme has a molecular mass of about 100 kDa and consists of two subunits with identical molecular masses of 47 kDa. The genes encoding these enzymes were cloned and sequenced. The gene for the P. furiosus enzyme contains an open reading frame for 455 amino acids with a molecular weight of 51,265, and that for the T. litoralis enzyme contains an open reading frame for 467 amino acids with a molecular weight of 53,621. About 59% similarity in amino acid sequence was observed between these two enzymes, whereas they did not show similarity with any ATP-dependent kinases that have been reported so far. In addition, two phosphate binding domains, and adenosine and glucose binding motifs commonly conserved in the eukaryotic hexokinase family were not observed.

Amino Acid Sequence↗
PubMed2000

[Analyses of factors preventing returning home in elderly patients on dialysis].

A significant number of elderly patients who begin dialysis are not able to return home even after attaining stable dialysis. The aim of the present study is to clarify the factors preventing returning home. Patients aged over 60 years who had newly started dialysis (103 cases) were studied. These were 58 men and 45 women. The age was 73 +/- 7 years (mean +/- standard deviation). In each patient, the cause of renal failure (non-diabetes/diabetes), nutritional state, complications, ambulation, cognitive function, urgency of the initiation into dialysis therapy, occurrence of access failure, presence or absence of the partner, presence or absence of members of the younger generation living in the same house, and the outcome (returning home or prolonged hospitalization) were surveyed. Of the 103 patients, 80 could return home, and 23 could not. First, we investigated the influence of the differences in each factor on the outcome. The subjects were divided into two groups by two categories in each factor. The numbers of patients who could not return home was calculated respectively. Comparisons were carried out by the chi 2 test. Statistically significant factors were ambulation (p < 0.0001), cognitive function (p < 0.0001), and cause of renal failure (p: 0.049). Multivariant logistic regression analysis was also performed using back-ground factors as explanatory variables and the outcome as a dependent variable. The factors presented by the nominal scale were converted to dummy variables. Statistically significant factors were ambulation (p < 0.0001), cognitive function (p: 0.001), and presence or absence of a partner (p: 0.012). Inability to walk, impaired cognitive function, and absence of a partner were the factors preventing returning home.

Aged↗
PubMed2000

[Analyses of factors prolonging the length of hospital stay in elderly patients beginning hemodialysis].

The aim of the present study is to clarify the factors causing prolongation of the length of hospital stay in elderly patients beginning hemodialysis. Patients aged over 60 years who had newly started hemodialysis (98 cases) were studied. These were 59 men and 39 women. The age was 73 +/- 7 years (mean +/- standard deviation). In each patient, the cause of renal failure (non-diabetes/diabetes), body mass index, comorbid conditions (cerebrovascular disease, ischemic heart disease, etc.), ambulation, cognitive function, urgency of the initiation of dialysis, occurrence of access failure, marital status, younger cohabitants, and the length of stay after initiation of dialysis were surveyed. The median and the mean of the length of stay were 37 and 49 days. Because of this disparity, a normal distribution of the length of stay could not be obtained. However, the distribution was transformed to close to normal by logarithmic conversion of the number of days. We used the log-converted value as the length of stay for statistical analyses. We investigated the influence of the differences of each factor on the length of stay. The subjects were divided into two groups for each factor. The mean and standard deviation of the length of stay was calculated respectively. Comparisons were carried out by unpaired t-test. Multiple regression analysis was also performed using background factors as explanatory variables, and the length of stay as a dependent variable. The factors presented by the nominal scale were converted to dummy variables. Eight variables in the unpaired t-test and seven variables in multiple regression analysis were statistically significant. All but one variable were common to both analyses. The gender was statistically significant only in the unpaired t-test. It could be explained by close correlation of gender with marital status. Access failure and urgent initiation of dialysis were dominant factors for the prolongation of the length of stay. Ischemic heart disease, diabetes, inability to walk, impaired cognitive function, and absence of a partner also prolonged the length of stay.

Aged↗
PubMed2000

A novel type of factor XI deficiency showing compound genetic abnormalities: a nonsense mutation and an impaired transcription.

We studied a 29-year-old Japanese male patient with factor XI deficiency; we also studied his parents and one sibling. Factor XI coagulation activity and antigen levels were extremely low (less than 1% of normal level) in both the patient and his brother, and they were half the normal levels in both parents. Sequence analysis of all 15 exons and the exon-intron boundaries of the factor XI gene amplified by polymerase chain reaction revealed a nonsense mutation in exon 8 (Gln263-->Stop). Although the parents are first cousins, the mutation was unexpectedly heterozygous in all the family members except the father, who showed the homozygous wild type, indicating that this mutation alone was not sufficient to account for the factor XI deficiency. To explore the genetic abnormality in the father, we analyzed allele-specific expression of the platelet factor XI gene using reverse transcription-polymerase chain reaction and subsequent restriction enzyme digestion. As a result, gene expression from only one allele was severely impaired in the father. This result implies an additional mutation in some regulatory element of the factor XI gene from paternal inheritance. We concluded that the factor XI deficiency of the patient was caused by compound heterozygous genetic abnormalities.

Adult↗
PubMed2000

[Study on evaluation method of patient dose in diagnostic radiology required for introducing the guidance level: investigation of entrance surface dose of patient using direct measurement by TLD].

Using direct measurement, we investigated entrance surface doses of patients for routine radiographs in attempt to develop evaluation methods of patient dose in order to establish the guidance level in Japan. To date, patient doses have been evaluated by calculations based on radiographic conditions, or model experiments using phantoms. Their patient doses are then evaluated based on several assumptions. Direct measurement of patient dose is difficult to perform in many patients due to its time requirement, level of expertise required and difficulty in providing an explanation of the procedure to the patient. However, such direct measurement is essential since it incorporates all aspects of radiography from the radiographic equipment used, to the actual conditions of each patient without assumption. In this study, we examined the (1) need for introducing the guidance level, (2) controversial points in the calculation method for patient dose evaluation, (3) evaluation accuracy required for introducing the guidance level, and (4) necessity for a standardized method.

Guidelines as Topic↗
PubMed1999

Novel bacterial peroxidase without catalase activity from Flavobacterium meningosepticum: purification and characterization.

A novel bacterial peroxidase co-produced intracellularly with H(2)O(2)-forming nucleoside oxidase, was purified from the cell-free extract of Flavobacterium meningosepticum to homogeneity with 10.3% overall recovery through simple purification procedures including successive DEAE-Sephacel, phenyl-Sepharose CL-4B and Sephacryl S-300 chromatography. The relative molecular mass of the native enzyme was 220¿ omitted¿000 Da, and that of its subunit was 54¿ omitted¿000 Da. In contrast to other major intercellular peroxidases of bacterial origin, the enzyme did not show any catalase activity. The amino acid sequences of the 92 NH(2)-terminal amino acids and three internal peptides showed no significant homology with known peroxidases. The enzyme was not sensitive to the typical peroxidase inhibitors NaCN, NaF and NaN(3), while mercuric ion strongly inhibited the enzyme activity, and some carbonyl reagents were also found to have inhibitory effects. The enzyme showed a small K(m) value for H(2)O(2) (9.5 microM) compared to other peroxidases. On the basis of its visible absorption spectrum, the enzyme contained about 1.3 mol of heme per molecule.

Amino Acid Sequence↗