Biomedical subjects

N Konishi

Publications and source records attributed to N Konishi.

At least 19 recordsLinked to original sources

PubMed2000

Abnormalities of primitive myeloid progenitor cells expressing granulocyte colony-stimulating factor receptor in patients with severe congenital neutropenia.

To define the basis for faulty granulopoiesis in patients with severe congenital neutropenia (SCN), the expression of granulocyte colony-stimulating factor receptor (G-CSFR) in primitive myeloid progenitor cells and their responsiveness to hematopoietic factors were studied. Flow cytometric analysis of bone marrow cells based on the expression of CD34, Kit receptor, and G-CSFR demonstrated a reduced frequency of CD34(+)/Kit(+)/ G-CSFR(+) cells in patients with SCN. The granulocyte-macrophage colony formation of CD34(+)/Kit(+)/G-CSFR(+) cells in patients was markedly decreased in response to G-CSF alone and to the combination of stem cell factor, the ligand for flk2/flt3, and IL-3 with or without G-CSF in serum-deprived semisolid culture. In contrast, no difference in the responsiveness of CD34(+)/Kit(+)/G-CSFR(-) cells was noted between patients with SCN and subjects without SCN. These results demonstrate that the presence of qualitative and quantitative abnormalities of primitive myeloid progenitor cells expressing G-CSFR may play an important role in the impairment of granulopoiesis in patients with SCN. (Blood. 2000;96:4366-4369)

Antigens, CD34↗

PubMed2000

ELISA for a complexed antigen with a monoclonal antibody blocking reaction with the free antigen-assay-specific for complexed prostate-specific antigen.

We have developed an enzyme-linked immunoassay (ELISA) for serum complexed-antigen (prostate-specific antigen; PSA)(c-PSA) with simultaneous blocking of free-antigen (PSA)(f-PSA). The assay utilizes three different monoclonal antibodies (MAbs) recognising three distinct PSA epitopes. The detection limit was established as 0.19 microg/l (n=20, mean of zero standard+2S.D.) and the average recovery of f-PSA was 98-100%. The within-run and between-day coefficients of variation (CV) ranged from 2.1% to 3.2% and 2.8% to 6.3%, respectively. There was a good correlation between serum c-PSA measured by the present ELISA and PSA-alpha(1)-antichymotrypsin complex (PSA-ACT) concentrations (r=0.991). This method should provide a better tool for discriminating between benign and malignant prostatic disease.

Antibodies, Blocking↗

PubMed2000

Effects of cyclosporin A on water-immersion stress-induced gastric lesion and gastric secretion in rats.

Cyclosporin A is an immunosuppressive agent which is well known as a specific inhibitor of calcineurin (protein phosphatase 2B). In this study, we investigated the effects of cyclosporin A on water-immersion stress-induced gastric ulcer formation and gastric acid secretion in rats. We also examined the localization of calcineurin immunohistochemically. Calcineurin was specifically expressed in gastric parietal cells and chief cells of the gastric mucosa. The intraperitoneal administration of cyclosporin A dose-dependently suppressed the development of gastric mucosal lesions induced by water-immersion stress and inhibited gastric acid secretion, as assessed by pylorus ligation. These results indicated that calcineurin may play an important role in gastric acid secretion.

Animals↗

PubMed2000

Insulin and insulin-like growth factor I support the proliferation of erythroid progenitor cells in bone marrow through the sharing of receptors.

The effects of insulin and insulin-like growth factor I (IGF-I) on the proliferation of erythroid progenitor cells in bone marrow were studied in serum-deprived culture. Primitive human bone marrow cells were purified by cell sorting on the basis of the expression of CD34 and the Kit receptor. Insulin and IGF-I with erythropoietin (EPO) dose dependently supported the formation of erythroid colonies of CD34+/Kit+ cells in bone marrow. The direct effect of insulin and IGF-I on the stimulation of primitive erythroid progenitor cells was confirmed by single-cell proliferation studies in serum-deprived liquid suspension culture. The addition of insulin and/or IGF-I to stem cell factor (SCF) resulted in an additive increase in the number of erythroid colonies. The erythroid colonies formed by insulin and IGF-I with EPO were different in size from those formed by SCF with EPO. These findings imply that erythroid progenitor cells responding to insulin and IGF-I might be at a different developmental stage of erythropoiesis from those responding to SCF in CD34+/Kit+ cells. Similarly, insulin and IGF-I with EPO supported the proliferation of the mature erythroid progenitor cells in light-density bone marrow mononuclear cells (LDBMCs). The addition of the anti-receptor antibody to IGF-I receptor or insulin receptor partially suppressed erythroid colony formation supported with insulin or IGF-I in both CD34+/Kit+ cells and LDBMCs. The simultaneous addition of both receptor antibodies completely abrogated the erythroid colony formation. These results suggest that insulin and IGF-I directly stimulate the proliferation of the late stage of primitive erythroid progenitor cells and mature erythroid progenitor cells through the sharing of receptors.

Antibodies↗

PubMed2000

[Increasing nalidixic-acid-resistance in Salmonella strains isolated from sporadic cases in Tokyo].

A total of 118 nalidixic-acid (NA)-resistant Salmonella strains consisting of 68 domestic strains and 50 imported strains isolated during 1988-1998 in Tokyo were examined regarding their annual incidence, serovars, drug-resistance patterns, and minimum inhibitory concentrations(MIC) to fluoroquinolones (NFLX, OFLX, ENX, and CPFX). NA-resistant strains accounted for 1.3% of all Salmonella (5,302 strains) isolated from domestic cases, and 2.5% of all Salmonella (1,981 strains) isolated from imported cases. The incidence of NA-resistant strains has increased since 1995, and it has been remarkable in imported cases. The results of the serotyping showed that the NA-resistant strains were classified into 25 serovars, excluding untypable strains. Among those, S. Enteritidis (21 strains), S. Blockley (13 strains), S. Litchifield (13 strains), S. Typhimurium (13 strains), S. Hadar (9 strains), and S. Virchow (8 strains) were predominant. Drug-resistance patterns of NA-resistant strains, including other drugs (CP, TC, SM, KM, ABPC, ST, FOM, and NFLX) tested varied among the 26 types. Among those, multidrug-resistant strains accounted for 61.9% (73 strains), and one strain among them was high-resistant to NFLX. MIC distribution of NA-resistant strains to fluoroquinolones showed that the ranges of all drugs were 4-128 times higher than NA-sensitive strains used for controls.

Anti-Infective Agents↗

PubMed2000

[Species and serovar-distribution, and drug-resistance of Shigella strains isolated from imported and domestic cases during 1995-1999 in Tokyo].

A total of 290 Shigella strains consisting of 180 imported strains and 110 domestic strains isolated during 1995-1999 in Tokyo were examined regarding their species and serovar-distribution and their drug-resistance. In both groups, S. sonnei (70.0% in the imported strains, 80.9% in the domestic strains) was found to be the most prevalent species, followed by S. flexneri (20.0% in the imported strains, 19.1% in the domestic strains). S. dysenteriae and S. boydii were only isolated in the imported cases. Among the S. flexneri serovar, 1b, 2a, 6, 2b, and 3a were predominant in the imported strains, whereas 1b and 2a were predominant in the domestic strains. Provisional new serovar Shigella strains were isolated from 11 imported cases and 2 domestic cases. The drug-resistance test using 9 drugs (CP, TC, SM, KM, ABPC, ST, NA, FOM, and NFLX) showed that 92.2% of the imported strains and 94.5% of the domestic strains were resistant to some of the drugs tested. Drug-resistance patterns of the resistant strains varied in 25 types. Among those, a triple drug-resistance type with TC.SM.ST was found as the most frequent pattern in both groups. None of the strains were resistant to NFLX.

Anti-Bacterial Agents↗

PubMed2000

Analysis of prognostic and survival factors related to treatment of low-grade astrocytomas in adults.

Prognostic factors for low-grade astrocytomas have been proposed, but optimal treatment remains controversial. Eighty-eight consecutive adult patients with supratentorial low-grade astrocytomas were retrospectively reviewed to determine specific factors influencing outcome. All underwent craniotomy (43 radical resections, 45 nonradical resections). Sex, age at diagnosis, preoperative Karnofsky performance status (KPS), tumor location, estimated extent of resection, radiation, chemotherapy, histological type, p53 status, MIB-1 staining and the apoptotic index were assessed as parameters for prognostic significance. KPS (p = 0.03), tumor location (p < 0.001), extent of surgical resection (p < 0.001) and radiotherapy (p = 0.01) were significantly associated with longer survival rates by univariate analysis. Multivariate analysis also showed a significant correlation between radiation therapy after surgical removal and survival time (p < 0.001). p53 status was not of importance in determining the necessity for radiotherapy. Radical surgical removal is the most important factor in the management of low-grade astrocytomas. Radiation therapy appears to be effective in improving the prognosis regardless of the extent of surgical resection or the p53 status.

Adult↗

PubMed2000

Expression of intrapulmonary surfactant apoprotein-A in autopsied lungs: comparative study of cases with or without pulmonary hypoplasia.

To investigate the functional maturity of the lungs of infants with pulmonary hypoplasia, we measured the expression of surfactant apoprotein-A (SP-A) in the autopsied lungs. Autopsied lungs were taken from 16 infants who died at birth or soon after. A lung-to-body weight ratio of less than 1.2% was defined as pulmonary hypoplasia. Eight infants were classified as belonging to the normal group, and eight as belonging to the pulmonary hypoplasia group. Many of the pulmonary hypoplasia group were complicated not only by pulmonary hypoplasia, but also by amniotic fluid volume abnormalities or an anatomical malformation. We measured the expression of SP-A immunologically using murine anti-human SP-A MAb in the autopsied lung tissue, and subjected the tissue to SP-A staining by the direct staining method. The expression of SP-A was assessed as one of four grades: -, +/-, 1+, 2+. The staining intensity of SP-A was high at 1+ or stronger in five infants of the normal group. SP-A expression was significantly reduced, however, in all infants of the pulmonary hypoplasia group except for one infant with normal amniotic fluid volume and relatively mild pulmonary hypoplasia. There was a significant negative correlation between the staining intensity of SP-A and two factors: pulmonary hypoplasia and abnormal amniotic fluid volume (p = 0.039 and p = 0.0063, respectively). In the present study, we demonstrated that SP-A expression was significantly reduced in infants with pulmonary hypoplasia. We speculate that the functional maturity of the lungs of infants with pulmonary hypoplasia is also suppressed.

Autopsy↗

PubMed2000

Epigenetic alterations in methylation in oral squamous cell carcinoma cell lines detected by two-dimensional gel electrophoresis.

It has been described that DNA alterations in human oral squamous cell carcinomas were successfully demonstrated as 6 spots being commonly reduced in more than 50% of 10 lesions using the restriction landmark genomic scanning (RLGS) method. In the present study, the question of whether the DNA alterations involve not only genetic but also epigenetic change was examined with the use of cell lines Ca9-22, HO-1-u-1, HSC-2 and KB and treatment with a demethylating agent 5-aza-2'-deoxycytidine (5-AzaCDR). Intensities of two of the reduced spots were amplified in the cell lines by the 5-AzaCDR treatment, showing that they were due to altered DNA methylation. Our study provides clear evidence that epigenetic changes, like the methylation are related to carcinogenesis in human oral squamous cell epithelium.

Antimetabolites, Antineoplastic↗

PubMed1999

Defective proliferation of primitive myeloid progenitor cells in patients with severe congenital neutropenia.

Although several mechanisms have been proposed to explain the pathophysiology of severe congenital neutropenia (SCN), the precise defect responsible for SCN remains unknown. We studied the responsiveness of primitive myeloid progenitor cells to hematopoietic factors in 4 patients with SCN. The number of granulocyte-macrophage (GM) colonies formed in patients was decreased in response to granulocyte colony-stimulating factor (G-CSF) in both serum-supplemented and serum-deprived culture. The polymerase chain reaction-single-strand conformational polymorphism analysis of the G-CSF receptor gene showed no variance in structure conformation between the 4 patients and the normal subjects. In patients with SCN, the nonadherent light density bone marrow cells and cells that were purified on the basis of the expression of CD34 and Kit receptor (CD34(+)/Kit(+) cells) showed the reduced response to the combination of steel factor (SF), the ligand for flk2/flt3 (FL), and interleukin-3 (IL-3) with or without G-CSF in serum-deprived culture. Furthermore, when individual CD34(+)/Kit(+) cells from patients were cultured in the presence of SF, FL, and IL-3, with or without G-CSF for 10 days, the number of clones proliferated and the number of cells per each proliferating clone was significantly less than those in normal subjects. These results suggest that primitive myeloid progenitor cells of patients with SCN have defective responsiveness to not only G-CSF, but also the early- or intermediate-acting hematopoietic factors, SF, FL, and IL-3.

Acute Disease↗

PubMed1999

Carcinogenic effects of N-ethyl-N-hydroxyethylnitrosamine and its metabolites in rats and mice.

N-ethyl-N-hydroxyethylnitrosamine (EHEN), a member of the nitrosamine class of carcinogens induces renal cancer. However, since very little is known about the metabolic products of EHEN and their effects, these were investigated in rats and mice. EHEN, N-ethyl-N-formylmethylnitrosamine (EFMN) and N-ethyl-N-carboxymethyl-nitrosamine (ECMN) were administered in the drinking water for 2 weeks and the animals were then maintained until sacrifice at week 32. The urine of the rats was collected over the 2-week exposure period and analyzed by HPLC. The results showed that EHEN but not EFMN or ECMN induces tumors in the kidneys of rats. In mice the lungs were targeted not only by the parent compound but also by both metabolites. The findings suggest that the kidney is the most susceptible organ to EHEN effects in the rat while the lung is the most susceptible organ in mice. These results are consistent with inter-species variation in the metabolism of xenobiotics.

Animals↗

PubMed1999

A novel sperm-specific hypomethylation sequence is a demethylation hotspot in human hepatocellular carcinomas.

Certain human DNA regions are strikingly undermethylated at CpG sites in sperm compared to adult somatic tissues. These sperm-specific hypomethylation sequences are thought to function early in embryogenesis or gametogenesis. By using the restriction landmark genomic scanning (RLGS) cloning method, we have isolated a novel sperm-specific hypomethylation sequence, the status of which changes during spermatogenesis, embryonal growth and differentiation. This sequence is a part of a new 'NotI repeat' consisting of a 1.4 kb repetitive unit sequence named DE-1. The sequence is GC-rich and has high homology to a CpG DNA clone that was isolated by a methyl CpG protein binding column, indicating that it was normally highly methylated. We investigated the methylation status of this sequence. In the normal genome the sequence was methylated, but in the human hepatocellular carcinoma (HCC) genome, the target sequence was demethylated at the cytosine residue of the CpG dinucleotides with high frequency (75% in the previous study). These data suggest that this regional DNA hypomethylation may play a role in both cell differentiation and hepatocarcinogenesis.

Animals↗

PubMed1999

Isolation of NotI clusters hypomethylated in HBV-integrated hepatocellular carcinomas by two-dimensional electrophoresis.

To examine genetic and epigenetic alterations associated with HBV integration in hepatocarcinogenesis, we compared genomic DNA profiles of primary hepatocellular carcinomas (HCCs) and cell lines that either contained or did not contain integrated HBV. To accomplish this, we carried out Restriction Landmark Genomic Scanning (RLGS), a two-dimensional system that displays 2000-3000 Not I landmark sites in a single gel electrophoresis experiment. We identified one Not I landmark spot that showed high signal intensity in HBV-integrated cell lines or in primary HCCs, but not in HCCs or tumor-cell lines free of HBV integration. Cloning of this spot revealed that it consisted of a Not I cluster sequence enriched with CpG dinucleotides. This sequence, hypomethylated in association with HBV integration, was found in the peri-centromeric region of human acrochromosomes. The results demonstrate that epigenetic changes at specific sequences in the genome occur in association with HBV integration during the process of hepatocarcinogenesis.

Base Sequence↗

PubMed1999

Effect of polyphenon-60 on the development of renal cell tumors in rats treated with N-ethyl-N hydroxyethylnitrosamine.

Green tea consumed as a beverage in Asia contains polyphenols, which contain about a 15% mixture of catechins. The present paper reports the effect of polyphenon-60 (60% pure catechin) on the development of renal cell neoplasms in Wistar rats pretreated with N-ethyl-N-hydroxyethylnitrosamine (EHEN): 0.1% polyphenon-60 in block diet was given over a period of 30 weeks while EHEN was given in drinking water for 2 weeks. The results appears to show a tendency for green tea catechins (GTC) to decrease the incidence of renal cell tumors greater than 3 mm in diameter in Wistar rats but not tumors that are less than 3 mm in diameter. Polyphenon-60 did not affect EHEN initiation in the kidneys of rats. It is postulated that free radicals induced by EHEN may be suppressed by GTC, resulting in a lowering of the tendency for tumor growth.

Animals↗

PubMed1999

Posttraumatic intestinal stenosis presenting as a perforation: report of a case.

A 78-year-old woman was admitted to the hospital after falling into a ditch approximately 1 m deep and sustaining a blunt abdominal trauma with a left femur fracture. On the tenth day after admission, symptoms of a small bowel obstruction occurred. A nasogastric tube was inserted, and the symptoms thus improved. She sometimes complained of abdominal pain during the 12 months after the fall, but recovered with conservative management. The next year, she was readmitted to the hospital for a pin extraction of the left femur bone. During this admission, 15 months since her admission after her fall, she again complained of abdominal pain. Abdominal pain increased with a muscular defense, and abdominal X-rays revealed free air. She was referred to our hospital with a diagnosis of perforative peritonitis, and emergency surgery was performed. Upon laparotomy, circumferential stenoses of the small bowel were recognized in the proximal segments about 40cm, 80cm, and 100cm from the ileocecal region. In addition, a perforation and prominent dilatation of the bowel segment was observed just proximal to the stenosis about 100cm from the ileocecal region. She underwent a small intestinal resection at two sites. There were no findings of an intestinal specific ulcer, such as Crohn's disease, intestinal tuberculosis, or malignancy, based on the results of a histopathological examination.

Abdominal Injuries↗

PubMed1999

A highly sensitive enzyme-linked immunoassay for serum free prostate specific antigen (f-PSA).

Monoclonal antibodies (MAbs) were generated against human prostate specific antigen (PSA) to allow development of a sensitive free-PSA (f-PSA) assay. Of a total of 211, 12 could detect only f-PSA, the other 199 MAbs binding to both f-PSA and complex-PSA. In the present study, one MAb (no. 5C6) specific for f-PSA and another (no. 79) reacting with both forms were used to develop an enzyme-linked immunoassay (ELISA) for serum f-PSA. The detection limit was established as 0.008 microg/l (n = 20, mean of zero standard + 3 S.D.) and the average recovery of f-PSA was 93-102%. The within-run and between-day coefficient of variation (CV) varied from 5.4-7.4% and 4.8-6.5%, respectively. The cross-reactivity of the assay to PSA-alpha1-antichymotrypsin complex was determined to be < 0.4%.

Animals↗

PubMed1999

Association of 72-kDa heat shock protein expression with adaptation to aspirin in rat gastric mucosa.

It is well documented that gastric mucosa can increase its resistance to mucosal damage caused by aspirin during repeated long-term administration of aspirin. However, the underlying mechanism of this adaptation is not well established. In the present study, we investigated the effect of long-term (chronic) administration of aspirin on expression of heat shock proteins (HSPs), which are known as endogenous cytoprotectants, in rat gastric mucosa. Rats were administered aspirin (100 mg/kg) daily for up to 20 days. After various periods of aspirin administration, a high dose of aspirin (250 mg/kg) was administered, and the mucosal damage was assessed. Expression of heat shock proteins (HSPs) in gastric mucosa was evaluated by Western blot. Intracellular localization of each HSP was studied immunohistochemically. Prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) levels were also investigated. Long-term aspirin administration resulted in development of resistance to aspirin-induced mucosal damage, and the increase of HSP72 expression correlated with mucosal resistance to aspirin. No significant increase was observed in HSP60 and HSP90 levels. Immunohistochemical study showed an increase of HSP72 in the cytoplasm of mucosal surface cells. The PGE2 level was suppressed and no change in the level of LTB4 was observed. It is possible that HSP72 could play important roles in gastric mucosal adaptation when the PGE2 level is suppressed by NSAIDs.

Adaptation, Physiological↗

PubMed1999

E-cadherin and alpha-, beta- and gamma-catenin expression in prostate cancers: correlation with tumour invasion.

The E-cadherin-catenin complex plays an important role in establishing and maintaining intercellular connections and morphogenesis and reduced expression of its constituent molecules is associated with invasion and metastasis. In the present study, we examined E-cadherin and alpha-, beta- and gamma-catenin levels in tumour tissues obtained by radical prostatectomy in order to investigate the relationship with histopathological tumour invasion. Immunohistochemical findings for 45 prostate cancer specimens demonstrated aberrant expression of each molecule to be associated with dedifferentiation and, in addition, alteration of staining patterns for the three types of catenin was significantly correlated with capsular but not lymphatic or vascular invasion. The data thus suggest that three types of catenin may be useful predictive markers for biological aggressiveness of prostate cancer.

Aged↗