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Biomedical subjects

K Imai

Publications and source records attributed to K Imai.

At least 811 records · Page 45Linked to original sources
PubMed1994

[An epidemiological study of urogenital cancer in Gunma Prefecture].

The incidence and mortality rate of urogenital cancers in Japan are both low compared to those in western countries. However, the incidence and mortality patterns of cancer in Japan are currently becoming closer to those of western countries, and the importance of urogenital cancers is increasing. We conducted an analysis of urogenital cancers in Gunma Prefecture. The subjects were newly detected urogenital cancer patients living in Gunma Prefecture diagnosed between 1985 and 1992. Details were as follows: prostate cancer 1411, bladder cancer 1253 (male 937, female 316), renal cell carcinoma 411 (male 287, female 124), renal pelvic and ureter cancer 187 (male 127, female 60) and testicular cancer 162. Incidence rate was calculated by year, district and age, and was expressed per 100,000/year and was adjusted to world population. Regarding the incidence rate per year for males, that of prostate cancer and renal cell carcinoma increased dramatically from 8.3 to 13.6 and from 1.1 to 3.2, respectively. Incidence rate of other cancers in males showed a slight increase or remained almost stable. Incidence rate by year for females showed a slight increase or remained almost stable as a whole. Gunma Prefecture was divided into 10 districts by the range of daily life of people and the incidence rates of prostate cancer, bladder cancer and renal cell carcinoma for each district were calculated. Incidence rate of prostate cancer tended to be higher in the northern parts of the prefecture, while that of bladder cancer showed no detectable trend.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

[The significance of six sextant biopsy for prostate cancer].

The significance of six sextant ultrasound guided biopsies of the prostate (SS-biopsy) was evaluated in a total of 114 patients. The presence of prostate cancer was suspected (Pca) in 59 subjects through mass screening (MS) for Pca and in 47 patients in out-patient clinics (OPC). The recurrence (REC) was suspected in 3 patients diagnosed previously as Pca. All of them had elevated PSA, abnormal digital rectal examination (DRE) and/or abnormal transrectal ultrasonography (TRUS). All of these tests in 5 patients with benign prostate hypertrophy (BPH) were normal. Moreover, in 34 patients among them, oriented biopsies were performed to the area where Pca was suspected by DRE and or TRUS. Twelve Pca patients were detected in MS group (20.3%), 17 Pcas in OPC group (36.2%) and 3 Pcas in REC group (100%). No Pca patients were detected in BPH group. In 12 Pca patients with T1 or T2, only one Pca patient (8.3%) had over 3 Pca samples among the samples obtained by SS-biopsy. In 20 patients with T3 or T4, 13 patients (65%) had over 3 Pca samples. There was significant relationship between T category and Pca sample numbers among 6 samples obtained by SS-biopsy (p < 0.01). Ten of 12 Pca patients in MS group (83.3%) and 8 of 17 patients in OPC group (47.1%) had less 3 Pca samples. Pca was detected in 9 of 34 patients examined by the oriented biopsy. However al of these Pca were detected by SS-biopsy. It may be not necessary to examine Pca suspected patients by the oriented biopsy if they were examined by this SS-biopsy.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopsy↗
PubMed1994

Clinical significance of prostate specific antigen for early stage prostate cancer detection.

The characteristics of serum prostate specific antigen (PSA) in normal Japanese men were studied in 1480 subjects examined by mass screening (MS) for prostate cancer (Pca) in Gunma Prefecture in 1992. The serum PSA concentration was correlated with patient age. The average serum PSA level increased by 0.04 ng/ml/year. The upper normal limits (95 percentiles) of age specific PSA for normal men are 1.33 ng/ml for those aged 39-49 years, 3.65 ng/ml for those aged 50-59 years, 4.06 ng/ml for those aged 60-69 years, 5.09 ng/ml for those aged 70-79 years and 5.66 ng/ml for those aged 80-89 years. Among 227 normal men examined by our MS in 1991 and 1992, the PSA velocity (PSAV) was calculated to be 0.05 ng/ml/year. Among 10 Pca patients with normal PSA levels (< 6 ng/ml) detected previously by our MS, three had an abnormal PSAV. We demonstrated the possibility that PSA density could distinguish between Pca and benign prostate hypertrophy. The significance of PSA as a Pca screening modality should be evaluated across multiple age ranges and in combination with previous PSA data and/or prostate volume estimated by sonography.

Adult↗
PubMed1994

[Concentrations of new quinolone agents in serum and prostate tissue].

Twenty five patients with benign prostate hypertrophy were administered ofloxacin (OFLX) simultaneously with norfloxacin (NFLX) in 6 patients, ciprofloxacin (CPFX) in 10, tosfloxacin (TFLX) in 5 and enoxacin (ENX) in 4 patients. The dose of these new quinolones was 100 mg (except 150 mg of TFLX). Their concentrations in the serum and the prostate tissue were measured by high performance liquid chromatography (HPLC). The serum concentration of OFLX was significantly higher than that of NFLX, CPFX, TFLX or ENX. The prostate tissue concentration of OFLX was significantly higher than that of CPFX or TFLX. The ratio of tissue versus serum concentration of each new quinolone agent was not significantly different. The high OFLX tissue concentration appeared to be caused by the high serum concentration.

4-Quinolones↗
PubMed1994

[Screening test for prostate cancer].

Prostate specific antigen (PSA), digital rectal examination (DRE) and transrectal ultrasonography (TRUS) are widely used for the detection of prostate cancer. The sensitivity and positive predictive value of PSA are most excellent among these modalities. However, the sensitivity of PSA was 73% when the cut off value was 6ng/ml. In the general clinical practice the use of three screening modalities must be recommended to improve the detection rate. However, the mass screening which has to diagnose many subjects during a short period should be mainly conducted by PSA, because blood sampling for PSA was performed with other kind of mass screening without any specialists (urologists). We are now investigating the effects of age specific PSA and PSA velocity to improve the sensitivity of PSA. It is estimated that the prostate cancer death and the prevalence will rapidly increase in Japan. Therefore, we had better start the preventative research including mass screening. To prove the significance of mass screening program, pilot studies in well executed randomized prospective protocols are urgently needed.

Adult↗
PubMed1994

Cytokines involved in graft-versus-host disease.

Graft-versus-host disease (GVHD) is one of the major complications which should be resolved to improve the survival rates in allogeneic bone marrow transplantation (BMT). Recently, several cytokines have been identified, suggesting that they form a cytokine network and play an important role in immune system and hematopoiesis. Among several cytokines, it has been reported that tumor necrosis factor alpha (TNF alpha) and interleukin-6 (IL-6) are mainly involved in GVHD. In the present report, we analyzed the role of cytokines in GVHD. When we measured serum cytokine levels, IL-6, interferon gamma (IFN gamma), and TNF alpha levels were increased prior to the onset of acute GVHD. For chronic GVHD, a similar pattern of cytokine increment was observed. Interestingly, these cytokines appeared to interact synergistically to induce clinical GVHD, suggesting that none of those cytokines does not function solely. Reverse transcriptase-polymerase chain reaction (RT-PCR) showed that increased IL-1 beta mRNA expression was also observed in acute GVHD in addition to increased IL-6 and TNF alpha mRNA expressions. Unexpectedly, no increased IL-2 levels were observed in both assays. In hyperacute GVHD, only IL-6 level was increased. However, in vivo administration of IL-6 into allogeneic bone marrow chimeras did not induce severe GVHD. Therefore, some other factors also appeared to be involved in inducing hyperacute GVHD. Furthermore, it is important to consider the role of inhibitory cytokines such as transforming growth factor beta (TGF beta) or IL-10.

Animals↗
PubMed1994

Relationships between the slope of the oxygen equilibrium curve and the cooperativity of hemoglobin as analyzed using a normalized oxygen pressure scale.

The oxygen equilibrium curve (OEC) for hemoglobin, which is usually expressed as a S vs. P plot, was expressed by normalizing P by Pdmax, where S is oxygen saturation, P is partial pressure of oxygen, and Pdmax is P at which the slope of the usual OEC is maximized. The maximal slope of normalized OEC gives Pdmax.S'max, where S'max is the maximal slope of the usual OEC, a measure for the oxygen transport efficiency of hemoglobin. Here, the term "efficiency" is used in the sense that the oxygen release from hemoglobin becomes more sensitive to oxygen pressure changes as S'max becomes larger. An analysis using 38 sets of published oxygen equilibrium data for human adult hemoglobin under various experimental conditions showed that (a) expressing OEC by means of S vs. P/Pdmax or S vs. log P is advantageous for analyzing the slope of OEC compared to usual S vs. P plot and (b) while the OEC differs depending on experimental conditions, S'max varies in close linear correlation to nmax (the maximal slope of the Hill plot which measures oxygen binding cooperativity), and Pdmax.S'max is almost equal to nmax/4. Thus, the parameter expressing oxygen transport efficiency is closely related to the parameter expressing oxygen binding cooperativity.

Adult↗
PubMed1994

Endocytosis of lysosomal acid phosphatase; involvement of mannose receptor and effect of lectins.

Acid phosphatase and beta-glucosidase are unique among lysosomal enzymes in that they have both high mannose and complex type sugasr chains, whereas oligosaccharide chains of lysosomal enzymes in matrix are of high mannose type. We have previously shown that beta-glucosidase was endocytosed into macrophages via an unidentified receptor different from a mannose/fucose receptor (K. Imai, Cell Struct. Funct. 13, 325-332, 1988). Here, we show that uptake of acid phosphatase purified from rat liver lysosomes into rat macrophages was inhibited by ligands for a mannose/fucose receptor and was mediated via an apparently single binding site with Kuptake of 24.7 nM. These results indicate that acid phosphatase and beta-glucosidase recognize different types of receptors even if they have similar sugar chains. Polyvalent concanavalin A which binds both to the enzyme and to macrophages specifically stimulated the uptake in a dose dependent manner, whereas wheat germ agglutinin and phytohaemagglutinin did not.

Acid Phosphatase↗
PubMed1994

Soluble interleukin-2 receptor in blood from patients with sarcoidosis and idiopathic pulmonary fibrosis.

Soluble interleukin-2 receptor (sIL-2R) concentration is considered to reflect disease activity in patients with sarcoidosis. However, it remains to be evaluated whether or not the sIL-2R concentration reflects the total burden of granulomatous lesions, or if it can be a useful marker for other interstitial lung diseases such as IPF, the lesions of which are restricted to the lungs. In this study, we demonstrated that sIL-2R concentrations in 16 patients with active sarcoidosis increased (2031 +/- 1222 U/ml), compared to those in 29 patients with inactive disease (796 +/- 313), 24 with IPF (859 +/- 694) and 33 healthy controls (467 +/- 174). sIL-2R concentrations in patients with IPF also increased, more than those in healthy subjects. sIL-2R concentrations in 10 patients with extrathoracic lesions (ETL) were not different from those in 6 patients without ETL. Correlation between serum sIL-2R concentrations and serum ACE activity, BAL macrophage %, and BAL lymphocyte % was shown in patients with sarcoidosis. In patients with IPF, a correlation between sIL-2R concentrations and BAL macrophage % was found but there was no correlation between sIL-2R concentrations and BAL lymphocyte %. In conclusion, serum sIL-2R concentrations seem to reflect total inflammatory lesions. In addition, they reflect total inflammatory lesions of the lungs in sarcoidosis and IPF. For clinical purposes, its measurement may be more useful than that of BAL fluid concentrations in patients with sarcoidosis and IPF.

Adult↗
PubMed1994

Cytokine gene expression by concanavalin A-stimulated peripheral mononuclear cells after bone marrow transplantation: an indicator of immunological abnormality due to chronic graft-versus-host disease.

The response of IFN-gamma, IL-2 and IL-5 mRNA expression to the stimulation of concanavalin A (Con A) in peripheral blood mononuclear cells (PBMC) after bone marrow transplantation (BMT) was analyzed using reverse-transcriptase polymerase chain reaction (RT-PCR) to assess the recovery of T cell function. The subjects were 23 patients undergoing allogeneic BMT, 1 syngeneic BMT, 1 autologous BMT and 2 normal individuals. IFN-gamma mRNA expression increased after Con A stimulation in 6 patients who had limited chronic graft versus host disease (GVHD), 14 patients who did not have chronic GVHD, each one patient receiving syngeneic and autologous BMT and 2 normal individuals. On the other hand, IFN-gamma mRNA expression was not increased by Con A stimulation in 4 patients who had extensive chronic GVHD. Also, the concentration of IFN-gamma in cultured medium in a patient with extensive chronic GVHD was not detectable. A similar low response of IL-2 and IL-5 mRNA expression to Con A was observed in these patients with extensive chronic GVHD. These findings indicate that the cytokine productive capacity of T cell (IFN-gamma and IL-2 could be produced by type 1 T helper (Th1) cells and IL-5 could be produced by type 2 T helper (Th2) cells) was suppressed in patients who had extensive chronic GVHD, while that capacity was almost normal in patients without chronic GVHD and with limited chronic GVHD. Therefore, the analysis of cytokine gene response to Con A stimulation may provide useful information regarding immune reconstitution after BMT.

Adolescent↗
PubMed1994

[Intercellular adhesion molecule 1 antigen in tuberculosis].

Intercellular adhesion molecule 1 (ICAM-1) plays an important role in inflammatory diseases. We investigated levels of circulating soluble ICAM-1 in patients with miliary tuberculosis (n = 8) and pulmonary tuberculosis (n = 49). We also attempted to compare ICAM-1 levels among pulmonary tuberculosis patients according to chest X ray classification of the Japanese Society for Tuberculosis. Significantly increased levels of circulating ICAM-1 were found in patients with miliary tuberculosis and extensive (extent 3) pulmonary tuberculosis (n = 9) compared to those of controls (n = 48), but not in patients with extent 1 (n = 24) or extent 2 pulmonary tuberculosis (n = 16). Immunohistochemical examination of the tuberculous lung tissues from the patients showed intensive cellular ICAM-1 on epithelioid cells and giant cells as well as on vascular endothelial cells. These results suggest that ICAM-1 is an important adhesion molecule in tuberculosis.

Adult↗
PubMed1994

Hyperacute graft-versus-host disease accompanied by increased serum interleukin-6 levels.

Hyperacute graft-versus-host disease (GVHD), which progresses severely and rapidly, was observed in three patients with acute leukemia transplanted with bone marrow cells from human leukocyte antigens (HLA)-identical and mixed leukocyte reactions (MLR)-negative siblings. Hyperacute GVHD developed in these patients within 7 days after bone marrow transplantation (BMT) and was rapidly aggravated inspite of cyclosporin A (CyA) and short-term methotrexate (MTX) prophylaxis and treatment with bolus methylprednisolone (mPSL). These patients showed markedly increased serum interleukin-6 (IL-6) levels after BMT, whereas other cytokines such as interferon gamma (IFN gamma), tumor necrosis factor alpha (TNF alpha), and IL-2 were not increased compared with pretreatment levels. These findings suggest that markedly increased IL-6 levels may be related to hyperacute GVHD.

Acute Disease↗
PubMed1994

[Intraoperative fluorescein angiography with an ultrasensitive imaging tube].

Fluorescein angiographic examination may be prevented by vitreous hemorrhage or opacities in vitreoretinal diseases before vitrectomy. We performed intraoperative fluorescein angiography for such cases, using a conventional light source and an ultrasensitive video camera equipped with a silicone intensifier target tube to avoid retinal phototoxicity. Intraoperative fluorescein angiograms allowed evaluation of neovascular vessels, proliferative tissues, and avascular areas associated with diabetic retinopathy. Indentation of the pars plicata enabled us to also record fluorescein images of the area. This device may aid intraoperative assessment of vitreoretinal diseases including diabetic retinopathy.

Fluorescein Angiography↗
PubMed1994

Matrix metalloproteinase-9 (92-kd gelatinase/type IV collagenase equals gelatinase B) can degrade arterial elastin.

Degradation of elastic fibers in the arterial walls is an important step in the development of atherosclerosis. To identify the enzyme(s) responsible for the elastinolysis, we have designed an ex vivo model of aortic explants cultured with or without THP-1 cells (human monocyte/macrophage-like cells). After culturing with THP-1 cells for 5 days elastic fibers of the aortic explants were fragmented and lost. With insoluble [3H] elastin as a substrate, elastin-degrading activity could be detected in the culture medium. Zymography in sodium dodecyl sulfate-polyacrylamide gel electrophoresis containing alpha-elastin showed the presence of elastinolytic activity with 92 kd in the medium from the aortic tissue with THP-1 cell cultures, whereas the medium from the aortic tissue without THP-1 cells contained negligible elastinolytic activity. The activity was inhibited by ethylenediamine tetraacetic acid but not by phenylmethane sulfonyl fluoride, N-ethylmaleimide, or pepstatin A, indicating that the enzyme belongs to a class of metalloproteinases. In addition, destruction of the elastic fibers of the aortic explants cultured with THP-1 cells was completely inhibited only by metalloproteinase inhibitors. Immunoblot analyses demonstrated that the proteinase responsible for the elastinolytic activity is matrix metalloproteinase-9 (92-kd gelatinase/type IV collagenase = gelatinase B). Using immunocytochemistry, the metalloproteinase was localized in the THP-1 cells but not in the medial smooth muscle cells. These results suggest that matrix metalloproteinase-9 produced by THP-1 cells is of importance to degradation of elastic fibers in the aortic explants. The role of macrophages in the atherosclerosis is discussed with reference to elastinolysis of the arterial walls.

Animals↗