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Biomedical subjects

K Imai

Publications and source records attributed to K Imai.

At least 937 records · Page 52Linked to original sources
PubMed1992

Acquired cystic disease of the kidney and renal carcinoma in haemodialysis patients: ultrasonographic evaluation.

Ultrasonography was performed in 661 dialysis patients and acquired cystic disease of the kidney was found in 156 (125 men and 31 women). A higher incidence of cystic disease was found in males. There was no significant difference between the patients with and those without acquired cystic disease in terms of average age, but the duration of haemodialysis in those with acquired cystic disease was significantly longer. There was an increased incidence of cystic disease in patients with glomerulonephritis and the duration of haemodialysis in these patients was significantly longer. This suggests that the increased incidence of acquired cystic disease of the kidneys in the patients with glomerulonephritis is simply related to the longer duration of treatment. Twelve patients with renal carcinoma were found in this study. The average age at diagnosis of renal carcinoma was not significantly different between the patients with and those without acquired cystic disease, but the duration of dialysis was significantly longer in renal carcinoma patients with acquired cystic disease. The incidence of renal carcinoma in dialysis patients with acquired cystic disease was 3.85% and in those without it was 1.19%. These rates are considerably higher than those found in the general population and indicate that the risk of renal carcinoma is higher in dialysis patients both with and without acquired cystic disease.

Adult↗
PubMed1992

A novel chromosomal translocation t(3;17)(q29;q11) in a case with polycythemia vera.

We report a novel chromosomal translocation t(3;17)(q29;q11) in a case with polycythemia vera (PV). The present case (38-year-old male) developed the spent phase of PV after a 10 years' clinical course and showed excessive proliferation of myeloid cells in the bone marrow. The karyotype analysis of the bone marrow cells showed chromosomal translocation t(3;17)(q29;q11), and the same aberration was detected in the granulocyte-colony-stimulating-factor-stimulated peripheral blood cells, suggesting the cells with the t(3;17)(q29;q11) showed myeloid differentiation. It is known as well that the retinoic acid receptor gene, which is related with a myeloid disorder, is located in 17q11. Thus, the novel chromosomal translocation could be associated with the pathogenesis of the disorder in this patient.

Adult↗
PubMed1992

A new restriction fragment length polymorphism of the human alpha-fetoprotein gene in Japanese individuals: detection of loss of heterozygosity in human hepatocellular carcinoma.

By using the cDNA probe for the human alpha-fetoprotein (AFP) gene, one restriction fragment length polymorphism (RFLP) was discovered in Japanese patients. A variety of combinations of restriction enzymes and probes were evaluated in DNA samples from 25 Japanese individuals who were genetically unrelated. As a result, AvaII identified one invariant band of 8 kb and polymorphic bands at either 2.8 or 2.0 kb with the 5'-region probe from a cDNA clone, pHAF7. With the AvaII/pHAF7 combination, we examined the loss of heterozygosity in 14 patients with hepatocellular carcinoma (HCC). Of 6 informative specimens, 2 showed loss of heterozygosity. These data suggest that the AFP cDNA probe could be useful for analyzing loss of heterozygosity on chromosome 4q in human HCC.

Aged↗
PubMed1992

cDNA cloning of new protein tyrosine phosphatases in the human colon.

Oligonucleotide probes corresponding to three invariant amino acid sequence motifs within the protein tyrosine phosphatase (PTPase) catalytic domain were synthesized and employed in the polymerase chain reaction (PCR). PCR products amplified from human colonic tissues were analyzed. Among 41 cDNA clones sequenced, two putative novel PTPases designated as CL-6 and CL-2B were isolated. cDNA cloning of CL-6 was performed, and three overlapped cDNA clones encoding part of the coding region, which was 2.1 kb long, were obtained. Expression of mRNAs of these clones was then investigated by Northern blot analysis or reverse transcriptase-PCR, suggesting that CL-6 mRNA may be expressed in a cell-type-specific manner, whereas the expression of CL-2B mRNA could be ubiquitous.

Base Sequence↗
PubMed1992

Detection of xenogeneic anti-idiotypic antibodies specific to murine monoclonal antibody 17-1A in patients with gastrointestinal cancer.

Murine monoclonal antibody (MoAb) 17-1A, which reacts with an adenocarcinoma-associated antigen, has recently been utilized in a phase I clinical trial for patients with gastrointestinal tract cancers in Japan. In order to analyze anti-idiotypic (Id) antibodies to murine MoAb 17-1A in the sera of these cancer patients, we established a simple and specific assay. In a modified sandwich assay, normal mouse sera were utilized for neutralization of rat antimouse immunoglobulin (Ig) antibodies and reduction of their nonspecific effects. When the modified sandwich assay was applied to the sera of patients who had been treated with MoAb 17-1A, anti-Id antibodies were induced in 53% of 13 cancer patients with gastrointestinal cancers at 3-4 weeks after infusion of MoAb.

Animals↗
PubMed1992

Comparison of ultrasonography, computerized tomography and angiography in dialysis patients with renal cell carcinoma.

Seventeen dialysis patients with renal cell carcinoma were examined preoperatively by ultrasonography, computerized tomography (CT) and angiography. Ultrasonography, CT and angiography correctly predicted the diagnosis of renal cell carcinoma in 17 (100%) and 12 (71%) of 17, and 11 (69%) of 16 patients, respectively. All renal tumors of more than 3.0 cm in diameter were detected by the three diagnostic procedures. However, ultrasonography, CT and angiography detected renal tumors of less than 3.0 cm in 12 (100%) and 7 (58%) of 12 patients and 6 (55%) of 11 patients, respectively. Seven renal cell carcinomas were associated with acquired cystic disease of the kidney (ACDK). All renal tumors were found by ultrasonography. However, CT predicted the correct diagnosis in 3 (43%) of 7 patients with ACDK and in 9 (90%) of 10 patients without ACDK, and angiography was correct in 3 (50%) of 6 patients with ACDK and 8 (80%) of 10 patients without ACDK. Our results indicate that ultrasonography is an effective procedure to detect renal cell carcinomas in dialysis patients.

Adult↗
PubMed1992

Differential expression of aminopeptidase-N on human ovarian granulosa and theca cells.

The expression of aminopeptidase-N and neutral endopeptidase in human ovarian tissue was examined using specific monoclonal antibodies for each of these peptidases and histochemical staining for enzyme activity. Aminopeptidase-N is a membrane-bound metalloprotease catalyzing the removal of N-terminal amino acids from peptides and was detected by immunofluorescence staining on theca interna cells in secondary follicles and on luteinized thecal cells in preovulatory follicles and corpora lutea. However, aminopeptidase-N was not detected on granulosa cells. Peptidase activity was also detected by histochemical staining on theca interna cells and luteinized thecal cells. Luteinized granulosa cells showed peptidase activity, despite the lack of aminopeptidase-N. Neutral endopeptidase was not detected in ovarian granulosa and thecal cells. These observations indicate that aminopeptidase-N can be a useful surface marker for thecal cells.

Adult↗
PubMed1992

Human luteal cells express dipeptidyl peptidase IV on the cell surface.

We previously reported that human theca interna cells and small luteal cells express membrane-bound aminopeptidase N, and suggested that membrane-bound peptidases are involved in folliculogenesis and luteal function by regulating extracellular peptide concentrations. In this study, we examined the expression of dipeptidyl peptidase IV (DPP IV), which is a membrane-bound peptidase and has its catalytic domain at extracellular sites, in human granulosa cells, thecal cells of growing, preovulatory, and atretic follicles, as well as corpora lutea. Indirect immunofluorescence staining of ovarian tissues with specific monoclonal antibodies revealed that DPP IV was present in large and small luteal cells in corpora lutea. DPP IV peptidase activity was also detected histochemically in corpora lutea. In growing, preovulatory, and atretic follicles, there was weak immunoreactivity and DPP IV peptidase activity on luteinized theca interna cells, but not on granulosa cells. The expression of DPP IV on the cell surface of large and small luteal cells was confirmed by indirect immunofluorescence staining of freshly isolated luteal cells. These results indicate that DPP IV is a useful surface differentiation marker of human luteal cells and suggest that peptidases are involved in luteal function.

Adult↗
PubMed1992

[Subcellular distribution of porphyrins and anti-lipid peroxidative effect in protoporphyrin-administered rat liver].

The distribution and the anti-lipid peroxidative effects of porphyrins in the hepatic subcellular fractions in rats were studied after intravenous administration of protoporphyrin (PP). PP and/or PP-derived porphyrins were mainly distributed in the membrane-containing fractions of 600 x g-, 10,000 x g- and 100,000 x g-sediment from the liver homogenates of rats receiving a 20 mg/kg dose of PP. The lipid peroxidation induced by L-ascorbic acid in the fractions of 600 x g-, 10,000 x g- and 100,000 x g-sediment from the PP-treated rats was suppressed during 1-168 h, 1-168 h and 12-168 h, respectively, after the PP treatment. The suppression of the peroxidation in the liver mitochondria from the PP-treated rats was further enhanced by the addition of the hepatic cytosol from the PP-treated rats. The extent of the suppression by the addition of the cytosol from the PP-treated rats at 24 h after the PP administration was greater than those at 0 and 168 h after the PP administration. These results indicate that PP and/or PP-derived porphyrins distributed in the liver still exert antioxidative actions and that there might exist some unknown factors enhancing the actions in the hepatic cytosol.

Animals↗
PubMed1992

Blunted cardiac responses to exercise-induced sympathetic stimulation in non-failing aortic regurgitation: insight into role of cardiac dilation in hyporesponse of failing hearts.

Although blunted cardiac response to sympathetic stimulation in patients with heart failure is usually attributed to myocardial beta 1-adrenoceptor downregulation secondary to elevated circulating catecholamines, cardiomegaly per se may also play a role through presynaptic mechanisms such as reduction in cardiac norepinephrine (NE) concentration. To evaluate effects of cardiac dilatation on cardiac response to sympathetic stimulation, we studied left ventricular contractile and heart rate responses to plasma NE levels increased by exercise in 10 asymptomatic patients with a dilated left ventricle due to aortic regurgitation (AR), but with normal resting plasma NE levels, using 10 normal subjects and 10 patients with heart failure due to dilated cardiomyopathy (DCM) as controls. Plasma NE levels, systemic blood pressure, echocardiographic left ventricular dimensions, and heart rate were measured at rest, and at 3 submaximal levels of supine bicycle exercise. The ratio of peak systolic blood pressure to end-systolic dimension (P/D ratio), heart rate, and plasma NE increased with the intensity of exercise. In each subject, both P/D ratio and heart rate increased in a logarithmic manner against plasma NE levels. The slope of the regression line for log (plasma NE)--P/D ratio relation, and that for log (plasma NE)--heart rate relation, were significantly less in patients with AR than in normal subjects (p less than 0.001 and p less than 0.05, respectively), and were less in patients with DCM than in patients with AR (p less than 0.005 and p = 0.051, respectively). Thus, the left ventricular contractile and heart rate responses to sympathetic stimulation are blunted in patients with dilated hearts due to AR, even in the absence of overt heart failure and elevated plasma NE levels. These responses were further decreased in patients with heart failure due to DCM. Cardiac responses to sympathetic stimulation appear to be blunted by cardiac dilatation per se, independently of myocardial beta 1-receptor downregulation secondary to high circulating catecholamines. The decrease in mechanical response to sympathetic stimulation in failing hearts is likely to be combined result of cardiac dilatation and beta 1-receptor downregulation.

Adult↗
PubMed1992

Hypereosinophilic syndrome accompanied with necrosis of finger tips.

We report a case of hypereosinophilic syndrome (HES) with marked eosinophilia (59.7%) and mononeuritis multiplex (upper limbs and buttocks). Necrosis of the finger tips was the primary manifestation which simultaneously occurred on both sides. These clinical manifestations were improved dramatically by subsequent steroid therapy. Interestingly, an elevation of serum tumor necrosis factor (TNF) was observed. These findings suggest that TNF may play a role in the etiology of necrosis of the finger tips.

Adult↗
PubMed1992

Hb Kanagawa [alpha 40(C5)Lys----Met]: a new alpha chain variant with an increased oxygen affinity.

An abnormal hemoglobin was suspected in a 70-year-old Japanese male with cerebral infarction and erythremia with high performance liquid chromatography assay of Hb A1c. The hemoglobin variant migrated to the anode more rapidly than Hb A. Structure determination studies, including amino acid analysis of the abnormal peptide and DNA sequencing of a partially cloned alpha-globin gene, demonstrated that it is a new hemoglobin variant which has been named Hb Kanagawa [alpha 40(C5)Lys----Met]. This variant showed an increased oxygen affinity, decreased heme-heme interaction, and a lowered 2,3-diphosphoglycerate effect relative to normal.

Aged↗
PubMed1992

[Significance of prostatic specific antigen in the mass screening for prostate cancer].

The significance of prostatic specific antigen (PSA) was investigated in the subjects examined by the mass screening for prostate cancer from 1985 to 1990. All subjects was examined by digital rectal examination (DRE) and with prostatic acid phosphatase (PAP) and the subjects in whom prostate cancer (Pca) was suspected from abnormal DRE and/or elevated PAP were recommended to receive the secondary screening to confirm the presence of Pca. PSA was measured by radioimmunoassay using Ball-Elsa-PSA-kit. 1,600 serum samples were obtained from our serum bank. The relationship among PSA, prostate size estimated by DRE and age was investigated. PSA was increased with age and the prostate size, PSA being more closely related with the latter. Therefore, we estimated that PSA has an ability to detect benign prostatic hypertrophy (BPH) in the mass screening. This estimation should be confirmed by using an ultrasound tomography because the prostate size obtained by DRE is inaccurate as compared with that obtained by ultrasound tomography. The cut off level of PSA was determined by control which was composed from the subjects with normal size prostate and one with BPH. When the cut off level was 8.6 ng/ml, the sensitivity, specificity and efficiency as Pca marker was 73.9%, 97.4% and 97.1%, respectively. PSA was more than 8.6 ng/ml in all of Pca with elevated PAP. PSA was expected to improve the Pca detection rate in our mass screening system.

Aged↗
PubMed1992

[Endocrine environment of benign prostatic hyperplasia--relationships of sex steroid hormone levels with age and the size of the prostate].

To determine the influence of endocrine factors on benign prostatic hyperplasia (BHP), the levels of three sex steroid hormones i.e., total testosterone (Total-T), free testosterone (Free-T) and estradiol (E2), were measured in serum of healthy 154 men. Their ages ranged from 18 to 91 years old. In 59 men, prostatic size was estimated by digital examination and was subdivided into three groups: smaller than or equal to walnut size, small hen's egg size and equal to or larger than hen's egg size. Firstly, relationships of sex hormone levels with age were studied. There was a slight decrease in Total-T over 60 years old, a significant decrease in Free-T, and no change in E2 with age. Thus, E2/Total-T and E2/Free-T ratio increased significantly after middle-age. Secondly, relationships of hormone levels with prostatic size were studied. In the larger prostate group, a significantly lower level of Total-T and significantly higher level of E2 were detected. But there was no difference in Free-T. Thus, the prostatic size was correlated positively with E2 level, E2/Total-T and E2/Free-T ratio. These suggest that the endocrine environment tended to be estrogens-dominant with age, in particular, after middle-age, and that patients with large prostates have more estrogens-dominant environments. We conclude that estrogens are key hormones for the induction and the development of BPH.

Adolescent↗
PubMed1992

[Prostatic specific antigen (PA) in mass screening for prostate cancer].

The usefulness of prostatic specific antigen (PA) was compared with that of prostatic acid phosphatase (PAP). PA was determined in the serum of 2,183 patient examined by the mass screening for prostate cancer from 1987 to 1990. The serum samples of these patients were obtained from our serum bank. PA was measured by the E test "TOSOH" II (PA). The relationship of PA and PAP to prostate size estimated by digital rectal examination (DRE) and ultrasound tomography (US), and age was investigated. PA and PAP correlated with aging and prostate size estimated by DRE. However PA was more apparently related with these things. The correlation between PA and prostatic size estimated by US was relatively high (r = 0.53), but the correlation between PAP and prostate size estimated by US was low (r = 0.20). When the upper limit of normal range was set at 6.0 ng/ml, the sensitivity, specificity and efficiency was 64%, 97% and 62%, respectively. PA was more sensitive than PAP and could be more useful since none of the patients with prostate cancer was PAP positive and PA negative. We conclude that PA should be a reliable tumor marker in our mass screening system.

Acid Phosphatase↗