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Biomedical subjects

A Kaneko

Publications and source records attributed to A Kaneko.

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

Long-term observations of a patient with choroidal melanoma following fractionated stereotactic radiotherapy: a case report.

A 60-year-old man with choroidal melanoma was treated with fractionated stereotactic radiotherapy and followed for 6 years. During this period, the tumor has not changed in size, and the patient has experienced only a slight decrease in visual acuity. In this case, stereotactic radiotherapy appears to have been safe and effective and may also be a cost-effective alternative to particle or plaque therapy.

Choroid Neoplasms↗
PubMed2000

Cytokine requirement for the development of T-lymphoid lineage potential in clonal lymphohaematopoietic progenitors in vitro.

The early process of T-cell development prior to thymic colonization has been poorly investigated because of the lack of a sensitive assay. We have developed a two-step in vitro culture system by combining a clonal culture with a fetal thymus organ culture (FTOC) and analysed the early development of T cells from lymphohaematopoietic progenitors. Cells of immature colonies derived from bone marrow cells of 5-fluorouracil (5FU)-treated mice using various combinations of early acting cytokines were transferred into a FTOC. All the combinations of stem cell factor (SCF), interleukin (IL)-3 and IL-6 capable of inducing colony formation supported T-cell generation. IL-11 and the Flt3 ligand possessed T-lineage promotional effects similar to IL-6 and SCF respectively. However, there were some quantitative differences in the final T-cell yield among cytokine combinations. Thus, the commitment towards T lineage in lymphohaematopoietic progenitors may be an event determined intrinsically rather than induced by specific stimuli, but there may be a hierarchy between the activity of cytokines in further development. Furthermore, we examined the T-lineage potential of individual colonies derived from Lin(-)c-Kit(+)Sca-1(+) cells clone-sorted from post-5FU marrow cells. No colonies that contained only myelocytic progenitors showed T-lineage potential, but 23.3% of colonies with a haematopoietic multipotentiality did. Therefore, the divergence of the T lineage from other lineages such as myeloid potential may occur at an early stage of the hierarchy of haematopoiesis. The proposed method should prove valuable for exploring the molecular and cellular changes that occur during early T-cell development before thymic colonization.

Animals↗
PubMed2000

Trans-mesosigmoid cutaneous ureterostomy.

BACKGROUND: A new method was developed in order to create a single stoma cutaneous ureterostomy in which both ureters traverse the abdominal cavity and yet are buttressed by the mesosigmoid and covered by its visceral peritoneum. METHODS: The long mesenterium which is attached to the most mobile part of the sigmoid colon was used for the bilateral ureteral pathway. Tunnels for the ureteral path were made just underneath the visceral peritoneum on the bilateral side of the mesosigmoid. Through the tunnels both ureteral ends were brought from the retroperitoneal space to the mesenterocolonic junction (MCJ) and the MCJ is then approximated and sutured to the inside of the ureteral tract through the abdominal wall. The ureters brought outside the skin, are conjoined and sutured to the V skin flap. Eight patients who carried a high risk for operation and/or had a bladder tumor judged to be incurable underwent this cutaneous ureterostomy. RESULTS: All cases except one with low urinary output could be managed without catheter indwelling during the follow-up period. Three patients suffered from paralytic ileus and one required laparotomy for mechanical ileus during the short postoperative period. Postoperative excretory urography evaluated 14 kidneys during the follow-up period from 2 to 61 months and showed normal upper urinary tract in 11 and a mildly hydronephrotic tract in three. CONCLUSIONS: Transmesosigmoid cutaneous ureterostomy provides a single catheterless stoma even when the available ureters are relatively short. It appears to be a good method for supravesical urinary diversion when indicated.

Aged↗
PubMed2000

Comparison of gyrA and parC mutations and resistance levels among fluoroquinolone-resistant isolates and laboratory-derived mutants of oral streptococci.

Laboratory-derived fluoroquinolone-resistant mutants were obtained by serial passage of Streptococcus sanguis and Streptococcus anginosus isolates on agar containing increasing concentrations of old and new fluoroquinolones, ofloxacin and DU-6859a, respectively. Sequencing of an S. sanguis isolate exposed to DU-6859a showed that resistance was associated with two mutations in the quinolone resistance determining region (QRDR) of the gyrA gene (Ser83-->Phe; Glu87-->Lys), and with a mutation in the parC gene (Ser79-->Ile). However, different mutations in the gyrA gene (Ser83-->Tyr) and parC gene (Ser79-->Phe) were found in a S. sanguis isolate exposed to ofloxacin. A fluoroquinolone-resistant isolate, QR-95101, from a dental infection, had a single mutation in the gyrA gene (Ser83-->Phe) and in the parC gene (Ser79-->Phe). Two fluoroquinolone-resistant mutants, QS-701OFm and QS-701DUm, were obtained from S. anginosus QS-701, by exposure to ofloxacin and DU-6859a, respectively. These mutants showed a common substitution at codon 83 (Ser-->Phe) in the gyrA gene but had different substitutions at codon 87 (QS-701OFm, Glu-->Gln; QS-701DUm, Glu-->Lys). They also had different substitutions at codons 79 and 135 in the parC gene (QS-701OFm, Ser79-->Leu but no change at Glu135; QS-701DUm, Ser79-->Ile and Glu135-->Gln). The resistance levels of the DU-6859a-selected resistant S. sanguis mutant QS-951DUm to DU-6859a, ofloxacin, ciprofloxacin and norfloxacin were higher than those of the ofloxacin-selected resistant mutant QS-951OFm. However, ampicillin susceptibilities of these mutants were not different from the parental strains. In S. anginosus, the DU-6859a-selected fluoroquinolone-resistant mutant QS-701DUm was resistant to all the fluoroquinolones tested, while the ofloxacin-selected mutant QS-701OFm was resistant to three fluoroquinolones, but not DU-6859a. The results indicate that different fluoroquinolones select distinct mutations in the QRDR of the gyrA and parC genes in oral streptococci. The gyrA or parC mutation in oral streptococci may determine the levels of fluoroquinolone resistance.

Anti-Infective Agents↗
PubMed2000

Six-year disease-free survival of a patient with metastatic eyelid squamous cell carcinoma and colon adenocarcinoma after repeated postoperative adoptive immunotherapy.

A 74-year-old male was affected concurrently with squamous cell carcinoma of the left eyelid and adenocarcinoma of the colon, both with lymph node metastasis. He underwent exenteration of the left orbit with left modified radical neck dissection and subsequently resection of the transverse colon with regional lymph node dissection. The patient has been treated by an adoptive immunotherapy as a sole postoperative modality without receiving any chemotherapeutic agents causing immunosuppression. For the adoptive immunotherapy, autologous peripheral blood lymphocytes were activated with an immobilized anti-CD3 antibody and IL-2 for 14 days (the CD3-AT cells). The infusion with 1.38 x 10(10) CD3-AT cells has been repeated 150 times in total at the time of writing. Neither recurrence nor additional metastasis has been detected for 6 years after surgery.

Adenocarcinoma↗
PubMed2000

Retreatment with interferon for chronic hepatitis C after transient response.

Approximately half of all patients with chronic hepatitis C show an initial biochemical response to interferon, but only 15% to 20% of patients achieve a sustained response. We studied the efficacy of retreatment with interferon for patients with chronic hepatitis C who showed transient biochemical responses to initial treatment. Thirty patients who relapsed were retreated 1 to 52 months (median 14) after the end of initial treatment, according to the previously used regimens. The responses were correlated with the pre-retreatment patient data. The liver histologic grades, compared with those found before the initial treatment, were better in eight (27%) patients but worse in six (20%), whereas the fibrosis stage was improved in five (17%) but worsened in eight (27%). All patients displayed end-of-retreatment biochemical responses. Of the 30 patients, 10 (33%) achieved sustained aminotransferase normalization and serum hepatitis C virus (HCV) RNA clearance, but the remaining 20 patients showed relapse within 1 year after cessation of retreatment. Univariate analysis associated the sustained response with low pre-retreatment viral loads (0.8 +/- 0.7 MEq/mL vs. 9.1 +/- 6.5 MEq/mL; p = 0.006), short treatment intervals (13 +/- 13 months vs. 22 +/- 14 months; p = 0.031), and low histologic grades (1.3 +/- 0.7 vs. 1.9 +/- 0.7; p = 0.039). However, multivariate analysis indicated that only the pre-retreatment viral load was predictive of the sustained response (p = 0.049). These findings suggest that transient responders to interferon are likely to respond to retreatment but the achievement of a sustained response depends on the HCV viral load before retreatment.

Adult↗
PubMed2000

GABA-Mediated inhibition between amacrine cells in the goldfish retina.

Retinal amacrine cells have abundant dendro-dendritic synapses between neighboring amacrine cells. Therefore an amacrine cell has both presynaptic and postsynaptic aspects. To understand these synaptic interactions in the amacrine cell, we recorded from amacrine cells in the goldfish retinal slice preparation with perforated- and whole cell-patch clamp techniques. As the presynaptic element, 19% of the cells recorded (15 of 78 cells) showed spontaneous tetrodotoxin (TTX)-sensitive action potentials. As the postsynaptic element, all amacrine cells (n = 9) were found to have GABA-evoked responses and, under perforated patch clamp, 50 microM GABA hyperpolarized amacrine cells by activating a Cl(-) conductance. Bicuculline-sensitive spontaneous postsynaptic currents, carried by Cl(-), were observed in 82% of the cells (64 of 78 cells). Since the source of GABA in the inner plexiform layer is amacrine cells alone, these events are likely to be inhibitory postsynaptic currents (IPSCs) caused by GABA spontaneously released from neighboring amacrine cells. IPSCs were classified into three groups. Large amplitude IPSCs were suppressed by TTX (1 microM), indicating that presynaptic action potentials triggered GABA release. Medium amplitude IPSCs were also TTX sensitive. Small amplitude IPSCs were TTX insensitive (miniature IPSCs; n = 26). All of spike-induced, medium amplitude, and miniature IPSCs were Ca(2+) dependent and blocked by Co(2+). Blocking of glutamatergic inputs by DL-2-amino-phosphonoheptanoate (AP7; 30 microM) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; 2 microM) had almost no effect on spontaneous GABA release from presynaptic amacrine cells. We suggest that these dendro-dendrotic inhibitory networks contribute to receptive field spatiotemporal properties.

Action Potentials↗
PubMed2000

Characterization of tissue outgrowth developed in vitro in patients with rheumatoid arthritis: involvement of T cells in the development of tissue outgrowth.

BACKGROUND: The aim of this study was to analyze cellular and cytokine interactions governing the development of synovial tissue outgrowth in patients with rheumatoid arthritis (RA). METHODS: A single-cell suspension of dissociated synovial tissues of RA patients was cultured for a long period to develop tissue outgrowth. The resulting tissue outgrowth was characterized by immunohistochemical staining and ELISA. RESULTS: The tissue outgrowth developed in vitro included various cell types, such as macrophage-like synovial cells, fibroblast-like synovial cells and lymphocytes. Even after prolonged cultivation, synovial cells devoid of infiltrating T lymphocytes did not form tissue outgrowth. The outgrowth contained CD3+ cells, LeuM3 (CD14)+ cells and HLA-DR+ cells. The T cells expressed lymphocyte function-associated antigen (LFA)-1 and CD2, and the synovial cells expressed intracellular adhesion molecule (ICAM)-1 and LFA-3, suggesting possible interactions via LFA-1/ICAM-1 and CD2/LFA-3. Production of T-cell derived IFN-gamma and IL-17 and synovial-cell-derived fibroblast growth factor (FGF)-1 and IL-15 was confirmed in the tissue outgrowth as well as in RA synovial tissue. These cell types stimulate each other by secreting cytokines, leading to the secretion of proinflammatory cytokines and matrix metalloproteinase (MMP)-1 by the tissue outgrowth and proliferation of both lymphocytes and synovial cells. CONCLUSION: This study emphasizes the importance of cellular interactions between T cells and synovial cells, via adhesion molecules and the secretion of cytokines with stimulatory activity towards other cell types, for the hyperactivity of RA synovial cells.

Arthritis, Rheumatoid↗
PubMed2000

Construction of mutants of Sphingomonas paucimobilis defective in terminal mannose in the glycosphingolipid.

Mutants of Sphingomonaspaucimobilis defective in a part of the carbohydrate moiety of the glycosphingolipid (GSL) were constructed by transposon (Tn5)-insertional mutagenesis. Defective mutants were selected by ELISA using the antibody recognizing the tetrasaccharide-type GSL (GSL-4A) of S. paucimobilis. Eight defective mutants were selected from about 8,000 kanamycin-resistant strains, and seven of them were found to lack the terminal mannose of GSL-4A. The chemical structure of the mutant GSL was investigated, and proved that the rest of the structure was not changed by the mutation.

Carbohydrate Sequence↗
PubMed2000

Mechanism of liver-selective thyromimetic activity of SK&F L-94901: evidence for the presence of a cell-type-specific nuclear iodothyronine transport process.

The thyromimetic compound SK&F L-94901 shows more potent thyromimetic activity in the liver than in the pituitary gland or heart when administered to rats. The mechanisms of liver-selectivity of SK&F L-94901 were examined using cultured rat hepatoma cells (dRLH-84) and rat pituitary tumor cells (GH3), both of which showed saturable cellular uptake of tri-iodothyronine (T(3)). When isolated nuclei with partial disruption of the outer nuclear membrane were used, SK&F L-94901 competed for [(125)I]T(3) binding to nuclear receptors almost equally in dRLH-84 and GH3 cells. SK&F L-94901 also did not discriminate thyroid hormone receptors (TR) alpha1 and beta1 in terms of binding affinity and activation of the thyroid hormone responsive element. In intact cells, however, SK&F L-94901 was a more potent inhibitor of nuclear [(125)I]T(3) binding in dRLH-84 cells than in GH3 cells at an early phase of the nuclear uptake process and after binding equilibrium. These data suggest that SK&F L-94901 is more effectively transported to nuclear TRs in hepatic cells than in pituitary cells and therefore shows liver-selective thyromimetic activity. In conclusion, SK&F L-94901 discriminates hepatic cells and pituitary cells at the nuclear transport process. The cellular transporters responsible for this discrimination were not evident.

Animals↗
PubMed2000

Enzyme immunoassay for autoantibodies to human liver-type arginase and its clinical application.

BACKGROUND: Arginase is an enzyme of the urea cycle, and one of the two isoenzymes is the liver-type enzyme. We examined serum autoantibodies to this liver-type enzyme in patients with hepatitis. METHODS: Antibodies to recombinant human liver-type arginase were measured by ELISA in 95 patients and 55 healthy controls. RESULTS: The mean absorbance values in the ELISA assays of patients with definite autoimmune hepatitis (n = 11; P <0.0001), probable autoimmune hepatitis (n = 31; P <0.0001), and hepatitis C (HCV; n = 20; P <0.01) were significantly different from those of healthy controls, but the values in patients with hepatitis B (HBV; n = 23) and other autoimmune diseases (n = 10) were not significantly different from those of healthy controls. When the cutoff was fixed at the upper 95th percentile of the absorbance value in healthy controls, positive reactions were found in 18.2%, 32.3%, 20.0%, 13. 0%, and 10.0% of patients with definite autoimmune hepatitis, probable autoimmune hepatitis, HCV hepatitis, HBV hepatitis, and other autoimmune diseases, respectively. All of these positive reactions were abolished by inhibition of serum with recombinant antigen. The specificity and sensitivity of this ELISA were 96% and 29%, respectively. The intraassay and interassay coefficients of variation were 2.3-7.5% and 9.8-11%, respectively. There was no relationship between these antibodies and anti-nuclear, anti-smooth muscle, or anti-cytochrome P450IID6 antibodies. CONCLUSIONS: The ELISA for anti-liver-type arginase autoantibody improved the detectability of autoimmune hepatitis when compared with established assays for liver-specific autoantibodies.

Arginase↗
PubMed2000

Acute intrathoracic incarceration of the stomach after laparoscopic Nissen fundoplication.

A rare case of paraesophageal hernia with complete intrathoracic incarceration of the stomach after laparoscopic Nissen fundoplication is described. An 85-year-old woman who had undergone laparoscopic Nissen fundoplication for gastroesophageal reflux disease presented 14 months later with nausea and vomiting. Esophagogastroendoscopy showed obstruction of the esophagogastric junction and gastric mucosal necrosis. Emergency laparotomy showed the stomach to be entirely strangulated into the thorax, with areas of necrosis. Gastrotomy was followed by resection of the necrotic anterior wall of the stomach, closure of the hiatus, and suturing of the stomach to the diaphragm. Appropriate closure of crura and anchoring suture between the stomach and diaphragm are helpful to prevent recurrent hernia after laparoscopic Nissen fundoplication.

Aged↗
PubMed2000

[Retinoblastoma].

Hereditary retinoblastoma is different from non-hereditary retinoblastoma in the following ways. It has a germinal mutation of Rb gene located in 13q14. Its inheritance is autosomally dominant with 80% penetrance. Retinal tumors are present usually multiply (average number is three) in both eyes. The patients are found at a younger age than those non-hereditary retinoblastoma. About 5% of them are accompanied by a pineal tumor or paracellular neuroectodermal tumor, in such cases they are called trilateral retinoblastoma. Secondary malignancies such as osteosarcoma and rhabdomyosarcoma are more frequent, and they are the main causes of death of patients with hereditary retinoblastoma. Considering these facts, education of patients and their family members and development of new modalities of treatment for preserving eyeballs without inducing secondary malignancies are important.

Age Factors↗