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K Saitoh

Publications and source records attributed to K Saitoh.

At least 91 records · Page 5Linked to original sources
PubMed1999

Noninvasive system for evaluating the allergen-specific airway response in a murine model of asthma.

In the present report, we show that the enhanced pause (Penh), a novel indicator of airway responsiveness to bronchoconstrictors, can also be a good marker of airway response to an allergen challenge in a murine model of asthma. Male BALB/c mice were sensitized with ovalbumin (OVA) through a combination of intraperitoneal injection and aerosol inhalation. After this immunization, the OVA-specific IgE titer in serum increased to a significantly higher level than in a saline/PBS-treated control group. After the final OVA aerosol challenge, Penh was repeatedly measured in conscious, unrestrained mice, according to the time schedule. Penh increased gradually after the challenge and reached a maximal value at 24 hours that was significantly higher than the control value (p < 0.01). Histologic examination of the lung revealed airway inflammation with an invasion by eosinophils and lymphocytes from vessels into the peribronchial interstitium and the mucosal and submucosal areas of the bronchus. There was a strong correlation between the Penh value and eosinophil number in bronchoalveolar lavage fluid (r = 0.699, p < 0.0001). Moreover, Penh also correlated strongly with the intensity score of histologic findings. These results suggest that the bronchial response to a specific allergen could be followed in a particular individual through the noninvasive Penh method, and that Penh accurately reflects the intensity of eosinophilic bronchial inflammation. This system would be applicable to a noninvasive, chronological evaluation of various experimental interventions in a murine model of asthma.

Allergens↗
PubMed1999

[Detection of pyrazinamidase activity for differentiation of Campylobacter, Arcobacter, and Helicobacter spp. by using a high-performance liquid chromatography method].

A high-performance liquid chromatography method was investigated for the detection pyrazinamidase activity by Campylobacter, Arcobacter, and Helicobacter spp. Pyrazine carboxilic acid, one of the end products of pyrazinamide hydrolysis by microorganisms, was detected by using a high-performance liquid chromatography (HPLC). A loopful of organism colonies was emulsified in 0.5 ml of a 0.5% pyrazinamide solution. The suspens on was incubated in a 37 degrees C water bath for 18-20 hr. After centrifugation, the supernatant was analyzed by HPLC. This HPLC method does not require microaerobic incubation and was easy to interpret for strains with weak enzymatic activity. By this method, we tested 111 clinical isolates, type and reference strains of Campylobacter spp., Arcobacter spp., and Helicobacter spp. , C. jejuni, C. jejuni subsp. doylei, C. coli, C. upsaliensis, C. lari, C. lari (urease+), C. helveticus, C. hyolei, C. sputorum subsp. fecalis, C. gracilis, C. concisus, C. curvus were positive for pyrazinamidase. C. fetus subsp. fetus, C. hyointestinalis, C. sputorum subsp. sputorum, C. sputorum subsp. bubulus, C. mucosalis, A. butzleri, A. skirrowii, A. cryaerophilus, H. pylori, H. cinaedi, H. fennelliae, H. mustelae, H. felis, H. muridarum, H. canis, H. nemestrinae, H. pamentensis, H. pullourum were negative.

Amidohydrolases↗
PubMed1998

Lineage involvement of stem cells bearing the philadelphia chromosome in chronic myeloid leukemia in the chronic phase as shown by a combination of fluorescence-activated cell sorting and fluorescence in situ hybridization.

Chronic myeloid leukemia (CML) is thought to arise from a pluripotent hematopoietic stem cell that has undergone a reciprocal translocation between the BCR gene on chromosome 22 and the ABL proto-oncogene on chromosome 9. This rearrangement results in a shortened chromosome 22, designated the Philadelphia (Ph) chromosome. The Ph chromosome has been found in cells from all hematopoietic lineages except mature T lymphocytes. To examine this issue, we combined fluorescence-activated cell sorting (FACS) and fluorescence in situ hybridization (FISH) to study lineage involvement of mature cells and stem cells in 12 patients with CML in the chronic phase. We found Ph chromosomes in myeloid cells and most B lymphocytes (CD19(+)) but not in mature T cells (CD3(+)) or natural killer (NK) cells (CD3(-)56(+)). Moreover, evidence of BCR/ABL fusion was found in pluripotent stem cells (CD34(+)Thy-1(+)), B-progenitor cells (CD34(+)CD19(+)), T/NK progenitor cells (CD34(+)CD7(+) cells), and T progenitor cells (CD34(+)CD7(+)CD5(+)) with a frequency equal to that in all CD34(+) cells isolated by FACS from bone marrow cells. T lymphocytes showed a marked decrease in Ph+ cells between progenitor cells and mature cells. Moreover, the ratios of Ph+ to Ph- cells in mature T cells and NK cells were below background levels, whereas Ph+ B lymphocytes also decreased during their maturation. These data suggest that Ph+ lymphocytes are eliminated during differentiation. In contrast to FISH of blood and bone marrow, which gives information principally about mature cells, the technique of "sorter FISH (FACS + FISH)" provides a powerful tool to explore the cytogenetic changes in immature cell populations of stem cell diseases based on immunophenotypes. Further clarification of genetic changes in stem cells could be achieved by using sorter FISH with monoclonal antibodies.

Adult↗
PubMed1998

Fluorescence in situ hybridization of progenitor cells obtained by fluorescence-activated cell sorting for the detection of cells affected by chromosome abnormality trisomy 8 in patients with myelodysplastic syndromes.

Myelodysplastic syndrome (MDS) is believed to be a stem-cell disorder involving cytopenia and dysplastic changes in three hematopoietic lineages. However, the involvement of pluripotent stem cells and progenitor cells has not been clarified conclusively. To address this issue, we used fluorescence in situ hybridization (FISH) of blood and bone marrow (BM) smears for mature cells and FISH of cells sorted by fluorescence-activated cell sorting for progenitor cells. Seven patients with MDS associated with trisomy 8 were studied. FISH showed +8 in granulocytes, monocytes, and erythroblasts, but not in lymphocytes. Sorted cells of T (CD3(+)), B (CD19(+)), and NK cells (CD3(-)CD56(+)) from peripheral blood did not contain +8, nor did CD34(+) subpopulations from BM including B (CD34(+)CD19(+)), T/NK (CD34(+)CD7(+)) progenitors, and pluripotent stem cells (CD34(+)Thy1(+)). The +8 chromosome abnormality was identified in stem cells only at the level of colony-forming unit of granulocyte-erythrocyte-macrophage-megakaryocyte (CFU-GEMM; CD34(+)CD33(+)). It may thus be concluded that cells affected by trisomy 8 in the context of MDS are at the CFU-GEMM level and that cells of lymphoid lineage are not involved. These results provide new insights into the biology of MDS and suggest that intensive chemotherapy and autologous BM transplantation may become important therapeutic strategies.

Adult↗
PubMed1998

Allelotype analysis of early colorectal cancers with lymph node metastasis.

Several studies have indicated that frequent allelic losses in some specific chromosomal regions occur during colorectal cancer (CRC) progression. To clarify the correlation between such allelic losses and metastatic potential, the allelotype of lymph node-positive early CRCs, which are small but extremely malignant cancers consisting of metastatically competent cells, were investigated. Nineteen paraffin-embedded specimens of early CRC (pT1 tumors according to TNM classification) with positive lymph nodes were collected. The tumor tissues were examined for loss of heterozygosity (LOH), using microsatellite markers on chromosomes 1p34-36, 8p21-22, 14q32, 18q21 and 22q12-13. The relationship between p53 protein expression and the metastatic status was also investigated by immunohistochemical staining. A group of 20 early CRCs with negative lymph nodes having a similar distribution of macroscopic appearance were used as controls. Among the 19 node-positive tumors, LOH at 8p21-22 and 18q21 was detected in 11 cases (57.9%) and 17 cases (89.4%), respectively. Allelic losses within these 2 regions in node-positive tumors were significantly more frequent than that in node-negative ones (p < 0.01). No significant correlation was found between LOH at 1p34-36, 14q32 or 22q12-13 and lymph node metastasis. p53 protein expression was not significantly associated with lymph node metastasis. Our results suggest that putative tumor suppressor genes, which may be involved in the metastatic process of CRC, are located on chromosomes 8p21-22 and 18q21. Allelic losses in these regions are possible risk factors for lymph node metastasis of early CRC.

Adult↗
PubMed1998

A new variant translocation of t(15;17) in a patient with acute promyelocytic leukemia (M3): t(15;19;17)(q22;p13;q12).

The reciprocal translocation (15;17) is specifically associated with acute promyelocytic leukemia [APL; M3 subtype according to French-American-British (FAB) classification]. A few patients with this disease have complex variant translocations. We describe a patient with M3 carrying t(15;19;17)(q22;p13;q12), which is a new type of variant translocation. The karyotypic interpretation was confirmed by Southern blot analysis with the use of RAR alpha and by fluorescence in situ hybridization (FISH) with the use of painting probes of chromosomes 15, 17, and 19 and a (15;17) translocation DNA probe. The results support the idea that the key event in APL is the formation of fusion gene PML/RAR alpha on the der(15).

Adolescent↗
PubMed1998

Differential expression of fos and jun family members in the developing chicken gastrointestinal tract.

We have analysed the expression patterns of all the known fos/jun family genes, which encode the components of the transcription factor AP-1, in the chicken embryonic digestive tract that develops into the esophagus, proventriculus, gizzard, small intestine, ceca and large intestine. From soon after formation of the tubular structure, each gene transcript was localized in distinct domains of the epithelium and mesenchyme in all of these major gastrointestinal organs, independently of the anterior-posterior axis. fra-2 was expressed predominantly in epithelium, which also expressed junD, while low-level expression of junD was also detected in smooth muscle cell precursors in mesenchyme. Expression of c-jun and c-fos was detectable in both mesenchyme and epithelium through the whole tract. In the differentiated proventriculus, the developed glandular epithelium expressed c-jun and junD, but not fra-2, while luminal epithelium expressed fra-2 and junD, but not c-jun. These results suggest that distinct Fos/Jun protein heterodimers play important roles in maintaining the epithelial-mesenchymal interactions. Similar expression patterns to those of fra-2 and junD were established from earlier stages by Sonic hedgehog gene and the Indian hedgehog gene, respectively, both of which are important in forming the inductive network between epithelium and mesenchyme of the digestive tract.

Animals↗
PubMed1998

Genetic alterations are frequent in APC but rare in the TGF-beta type II receptor gene in cancer in adenomas of the colon.

Cancer in adenomas are thought to be an excellent model of colorectal carcinogenesis based on the adenoma-carcinoma sequence. We searched for alterations in the APC mutation cluster region, the whole coding regions of TGF-beta type II receptor (RII) and beta-catenin exon 3 in 16 cases of cancer in adenomas of the colon. Overexpression of the p53 protein was also analyzed. Nine of the 16 cases showed APC mutations in both the adenoma and cancer regions. Loss of heterozygosity in APC was found in one cancer in adenoma that had no mutation. p53 overexpression was detected in one adenoma and 10 cancerous regions, most of which also exhibited APC alterations. Two cases showed a missense mutation at codon 191 or loss of heterozygosity in TGF-beta RII in both the adenoma and cancer. Our data support the hypothesis that alterations of APC and p53 are responsible for most of the adenoma-carcinoma pathway, rather than TGF-beta RII alterations.

Adenoma↗
PubMed1998

Origin and phenotypic features of hyperplastic epithelial cells in collapsing glomerulopathy.

The characteristic pathological feature of collapsing glomerulopathy (CG) is marked cell hyperplasia and hypertrophy within the glomeruli. The present study investigated the phenotypic alteration of hyperplastic epithelial cells in CG to determine their origin. Renal biopsy specimens from two patients with CG were analyzed by immunohistochemical staining, using markers for podocytes (PHM-5), parietal epithelial cells (PECs; cytokeratin), and cell proliferation (Ki-67). In collapsed glomeruli, hyperplastic and hypertrophic epithelial cells were frequently connected to PECs and collapsed glomerular basement membranes (GBMs). These epithelial cells were more often Ki-67 positive and expressed cytokeratin, whereas PHM-5 was almost invariably negative. Serial section analysis showed that a small number of hyperplastic epithelial cells expressed both PHM-5 and cytokeratin, suggesting phenotypic conversion between podocytes and PECs. Moreover, cytokeratin-positive cells were associated with the sclerotic glomerular segments. Thus, we suggest that the majority of hyperplastic and hypertrophic epithelial cells in CG are of PEC origin. These epithelial features may participate in the development of characteristic tuft collapse and glomerulosclerosis in CG.

Biopsy↗
PubMed1998

Effect of nonsteroidal anti-inflammatory drugs on lipid peroxidation by hydroxyl radical.

1. Effects of acetaminophen and sodium salicylate on hydoxyl radical elimination were studied using an electron-spin-resonance spin-trapping method. The effects of these agents on lipid peroxidation of the human erythrocyte membrane were also investigated by the thiobarbituric acid method. 2. Acetaminophen and sodium salicylate depressed hydroxyl radical generated by Cu2+/H2O2. 3. Acetaminophen inhibited Cu2+/H2O2-dependent lipid peroxidation; however, sodium salicylate enhanced Cu2+/H2O2-dependent lipid peroxidation.

Acetaminophen↗
PubMed1998

Construction of YAC-based mammalian artificial chromosomes.

To construct a mammalian artificial chromosome (MAC), telomere repeats and selectable markers were introduced into a 100 kb yeast artificial chromosome (YAC) containing human centromeric DNA. This YAC, which has a regular repeat structure of alpha-satellite DNA and centromere protein B (CENP-B) boxes, efficiently formed MACs that segregated accurately and bound CENP-B, CENP-C, and CENP-E. The MACs appear to be about 1-5 Mb in size and contain YAC multimers. Structural analyses suggest that the MACs have not acquired host sequences and were formed by a de novo mechanism. The accurate segregation of the MACs suggests they have potential as vectors for introducing genes into mammals.

Animals↗
PubMed1998

Pigmented primary carcinoma of the breast: a clinical mimic of malignant melanoma.

A 68-year-old man had a pigmented tumour in the breast. Although the clinical picture suggested a malignant melanoma, histology revealed that the tumour was a primary ductal carcinoma of the breast. There was no pagetoid cell proliferation in the epidermis. However, tumour nests contained numerous dendritic melanocytes that could survive in the tumour nests without the existence of epidermal keratinocytes. Further immunohistochemical study employing antibodies to melanocyte growth factors demonstrated that anti-basic fibroblast growth factor (bFGF) antibody was the only reagent to show a positive staining for tumour cells. This indicated that the breast cancer cells produced bFGF, which enabled survival of melanocytes within the tumour mass.

Breast Neoplasms, Male↗
PubMed1998

Thoracic and lumbar extradural structure examined by extraduroscope.

We examined the extradural space using a flexible extraduroscope in 113 patients undergoing extradural anaesthesia. Patients were classified into two groups to receive either thoracic or lumbar extradural anaesthesia as needed for perioperative analgesia. The extraduroscopy showed that the thoracic extradural space becomes widely patent after injecting a given amount of air and that the amount of fatty and fibrous connective tissue is less in the thoracic extradural space compared with the lumbar extradural space. We suggest that differences between the structure of these two vertebral regions may affect the spread of local anaesthetics in the extradural space.

Adipose Tissue↗
PubMed1998

Effects of lightwand (Trachlight) compared with direct laryngoscopy on circulatory responses to tracheal intubation.

We compared the effects of the lightwand technique on circulatory responses to tracheal intubation with those of direct-vision laryngoscopy. Forty adult patients received propofol and vecuronium, and their lungs were ventilated for 2 min via a mask with 5% sevoflurane in oxygen, after which the trachea was intubated orally using either the lightwand (Trachlight, n = 20) or the Macintosh laryngoscope (n = 20). Maximum mean arterial pressure changes did not differ between groups during (lightwand group, 25 (SD 21) mm Hg vs laryngoscopy group, 23 (19) mm Hg) and after (21 (24) mm Hg vs 21 (16) mm Hg) tracheal intubation. Maximum heart rate changes were similar for groups during (16 (14) beat min-1 vs 16 (15) beat min-1) and after (2 (11) beat min-1 vs 7 (19) beat min-1) tracheal intubation. There were no differences between the lightwand technique and direct-vision laryngoscopy in changes in mean arterial pressure and heart rate during and after tracheal intubation. We conclude that the effects of the lightwand technique on circulatory responses to tracheal intubation were similar to those of direct-vision laryngoscopy.

Adult↗
PubMed1998

The origin and differentiation of the heteromorphic sex chromosomes Z, W, X, and Y in the frog Rana rugosa, inferred from the sequences of a sex-linked gene, ADP/ATP translocase.

Sex chromosomes of the Japanese frog Rana rugosa are heteromorphic in the male (XX/XY) or in the female (ZZ/ZW) in two geographic forms, whereas they are still homomorphic in both sexes in two other forms (Hiroshima and Isehara types). To make clear the origin and differentiation mechanisms of the heteromorphic sex chromosomes, we isolated a sex-linked gene, ADP/ATP translocase, and constructed a phylogenetic tree of the genes derived from the sex chromosomes. The tree shows that the Hiroshima gene diverges first, and the rest form two clusters: one includes the Y and Z genes and the other includes the X, W, and Isehara genes. The Hiroshima gene shares more sequence similarity with the Y and Z genes than with the X, W, and Isehara genes. This suggests that the Y and Z sex chromosomes originate from the Hiroshima type, whereas the X and W chromosomes originate from the Isehara-type sex chromosome. Thus, we infer that hybridization between two ancestral forms, with the Hiroshima-type sex chromosome in one and the Isehara-type sex chromosome in the other, was the primary event causing differentiation of the heteromorphic sex chromosomes.

Animals↗
PubMed1998

Dose-related cardiovascular effects of amrinone and epinephrine in reversing bupivacaine-induced cardiovascular depression.

BACKGROUND: To ascertain the efficacy of amrinone and epinephrine in reversing bupivacaine-induced cardiovascular depression, we investigated the time course of recovery of cardiac function with 3 doses of both agents after bupivacaine administration. METHODS: In sevoflurane-anaesthetized dogs, bupivacaine was infused intravenously at 1 mg.kg-1.min-1 until mean arterial pressure fell to 60 mmHg or less. The 3 doses of amrinone (1, 2, and 4 mg.kg-1) or the 3 doses of epinephrine (2, 5, and 10 micrograms.kg-1) were administered as a bolus in randomized order in each dog. RESULTS: Amrinone improved maximum left ventricular dP/dt, a time constant of left ventricular isovolemic relaxation and cardiac index persistently and dose-relatedly. Amrinone increased heart rate and decreased left ventricular end-diastolic pressure and systemic vascular resistance index. Amrinone at 1 and 2 mg.kg-1 significantly increased mean arterial pressure, but amrinone at 4 mg.kg-1 did not. Epinephrine increased mean arterial pressure, maximum left ventricular dP/dt, and systemic vascular resistance dose-relatedly. The duration of action of epinephrine, peaking at 1 min and subsequently decreasing by 10 min after administration, did not differ among the groups. Epinephrine at all doses failed to improve a time constant of left ventricular isovolemic relaxation and cardiac index. ECG evidence of serious ventricular dysrhythmias was seen in 1 out of 6 dogs after administrating each dose of amrinone and in 3, 3 and 5 out of 6 dogs after administrating 2, 5 and 10 micrograms.kg-1 of epinephrine, respectively. CONCLUSION: Bolus amrinone may have a certain efficacy in reversing bupivacaine-induced cardiovascular depression, and improving cardiac contractility and relaxation dose-relatedly. In contrast to amrinone, bolus epinephrine remains indispensable for resuscitation, causing a rapid, massive, transient and dose-related rise in blood pressure. However, the use of amrinone may be limited predominantly by a decrease in systemic vascular resistance, while the use of epinephrine may be limited predominantly by the generation of serious ventricular dysrhythmias and lack of effectiveness on cardiac index and on cardiac relaxation.

Amrinone↗
PubMed1998

Fibrosing cholestatic hepatitis after living related-donor renal transplantation.

A 43-year-old man underwent living related-donor renal transplantation because of chronic renal failure in 1991. During the transplant period, both donor and recipient were seronegative for hepatitis B surface antigen (HBsAg). The donor was seropositive for antibody to hepatitis B surface antigen (anti-HBs) due to hepatitis B virus (HBV) vaccination. After transplantation, FK506 and methylprednisolone had been administered to the patient as immunosuppressants. In 1993, HBsAg appeared in his serum. His alanine aminotransferase level elevated gradually during 1995 and then in 1996, general fatigue, ascites and jaundice developed. At this time his serum was positive for hepatitis B e antibody, contained more than 100000 Meq/mL HBV-DNA and 100% precore mutant. Despite subsequent intensive therapy, liver dysfunction progressed and this patient died of hepatic failure 2 months following admission. At autopsy, the liver exhibited cholestasis, fibrosis extending from the portal tracts, mild inflammation and hepatocytes with a ground-glass appearance. In addition, HBsAg and hepatitis B core antigens had accumulated in the hepatocytes. Consequently, the final diagnosis was fibrosing cholestatic hepatitis (FCH) due to precore mutant HBV infection contracted after renal transplantation. It is unclear when and where the recipient liver became HBV infected. Nevertheless, after renal transplantation, while receiving immunosuppressive drugs, HBV appeared to have the potential to cause hepatic failure and FCH may have been a fatal complication for the recipient.

Adult↗