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Biomedical subjects

Kazuhiro Suzuki

Publications and source records attributed to Kazuhiro Suzuki.

At least 55 records · Page 3Linked to original sources
PubMed2004

Role of androgen on blood flow and capillary structure in rat seminal vesicles.

To clarify the effect of androgen on the microcirculation in seminal vesicles of adult Wistar rats, we investigated the organ blood flow and morphological features in the capillaries after castration and subsequent testosterone supplementation. Testosterone (T) was subcutaneously injected every 12 hours after castration and its doses were set to 10(-2), 10(-1), 10(0) and 10(1) mg/kg-body weight (T10(-2), T10(-1), T10(0) and T10(1) groups, respectively). Organ blood flow was measured using laser Doppler flowmetry, and the subepithelial capillaries were analyzed using transmission electron microscopy. The capillaries were morphologically classified into 3 types; oval opened (type 1), intermediate (type 2) and collapsed (type 3), and their luminal areas were measured using a computed image analyzer. The organ blood flow was significantly reduced from 36.3+/-5.1 to 21.9+/-2.7 ml x min(-1)/100 g tissue, and the luminal area of the capillaries was significantly reduced from 9.02+/-1.28 to 4.85+/-0.82 microm2 with the shift of the type 1 and type 2 to type 3 after castration. The reduction of the luminal area and the blood flow reduction, and shift of the capillary type were significantly protected by gradated testosterone supplementation. These results indicate that the maintenance of the blood flow and morphological profiles in capillaries depend on androgen-supplementation levels in seminal vesicles.

Animals↗
PubMed2004

Incidence of bladder cancer discovered by urethrocystoscopy at prostate biopsy: extraordinary high incidence of tiny bladder cancer in elderly males.

In order to clarify the incidence of bladder cancer with and without prostate cancer, we investigated bladder cancer discovered incidentally by urethrocystoscopy at prostate biopsy. Between April 1997 and December 2003, 498 patients who were suspected prostate cancer were performed prostate biopsy and urethrocystoscopy simultaneously. We investigate possible invasion of prostate cancer into the urethra or bladder mucosa as well as bladder cancer, including other benign lesions of the bladder by urethrocystoscopy. Prostate cancer was confirmed in 175 (35.1%) of the 498 patients histologically, and bladder cancer was discovered incidentally in 12 patients (2.4 %). The incidence of bladder cancer in patients with prostate cancer of 2.3% (4/175) was not significantly different from that in patients without prostate cancer, which was 2.5% (8/323). Superficial and those with a size less than 1 cm were noted in 11 patients (92%) and 10 patients (83%) respectively. High incidence rate of bladder cancer with prostate cancer was reported previously, however, there was no study to compare the incidence rate of bladder cancer between cases with and without prostate cancer. The present study suggests that asymptomatic tiny bladder cancer may be present at an unexpectedly high incidence rate in elderly males.

Adult↗
PubMed2004

[Acute scrotum from testicular involvement in acute lymphocytic leukemia: a case report].

A 8-year-old boy with acute lymphocytic leukemia (ALL) had received chemotherapy and a complete bone marrow remission was obtained. Then he underwent bone marrow transplantation. After 6 months, he suddenly got left flank-low abdominal pain. Sequentially, he had swelling and redness of left scrotum, left testicular swelling and tenderness. Incision was done and enlarged and hard testis was diagnosed as testicular tumor, left orchiectomy was performed. Histological diagnosis was involvement of ALL, so he received radiotherapy. He remains free of disease by the present after 7 months.

Bone Marrow Transplantation↗
PubMed2004

[The evaluation of bladder outlet obstruction using the bladder weight calculation nomogram].

The ultrasound estimated bladder weight (UEBW) of 15 patients (13 male, 2 female; mean age 64.7 years) who underwent pressure flow study (PFS) were evaluated using the nomogram. In the nomogram, thickness of bladder wall (T) and bladder weight (BW) were plotted on the horizontal axis and on the vertical axis, respectively. BW points calculated from various values of T by the formula were plotted on the volume-fixed bladder capacity curve. BW of each case was estimated by the nomogram from echo-measured T at maximum bladder filling and injected volume (V) into the bladder. Bladder outlet obstruction (BOO): was evaluated from obtained results, and compared with the results of PFS. The features of the distribution on Schafer's nomogram were also investigated. It was possible to estimate BW immediately after ultrasonic examination. BW was under 35 g in one patient, and over 35 g in 14 patients. Obstruction grade on the Schafer's nomogram ranged from III to VI. BOO could be evaluated quantitatively with little invasion even in patients who could not undergo PFS for urinary retention and urge incontinence. In conclusion, the bladder weight calculation nomogram immediately showed the BOO information of the patient with neither invasive technique, complicated calculation, electronic calculator nor expansive computer. This nomogram may make a breakthrough for utilizing UEBW.

Adult↗
PubMed2004

Progressive and nonprogressive rheumatoid arthritis over a 10-year period in Japan.

We followed 207 patients with rheumatoid arthritis who were registered at our hospital over a 10-year period from between 1989 and 1990. The number of patients who were still treated at our hospital in 2001 was 87. Sixty patients had died, 39 had changed hospitals, 11 had interrupted treatment, and 10 had not had further followup. The patients at our hospital in 2001 were divided into 2 groups: progressive and nonprogressive disease. We compared clinical and laboratory data obtained for the 2 groups from the initial examination against data obtained from the final examination. The progressive group had a greater number of operations, used a greater variety of disease modifying antirheumatic drugs, and received higher dosages of steroids than the nonprogressive group. In the progressive group the levels of C-reactive protein, erythrocyte sedimentation rate, and IgG were significantly higher, while the levels of hemoglobin were lower at final laboratory examination. However, the initial laboratory examination revealed no significant differences between these groups that could be used to predict the likely progression of disease.

Arthritis, Rheumatoid↗
PubMed2004

[Chronological changes of incidence rates, clinical stages and pathological differentiation of prostate cancer in Gunma Prefecture, Japan].

Prostate cancer is the most common urogenital cancer, and is increasing rapidly. We performed an epidemiological study on prostate cancer in Gunma Prefecture, Japan. Registration of prostate cancer patients diagnosed at clinics and hospitals in and around Gunma Prefecture was started at Gunma University in 1985. The epidemiological characteristics of prostate cancer patients in Gunma Prefecture were analyzed by these data. The incidence and crude incidence rates have increased five-fold, from 114 and 12.0 in 1985 to 539 and 53.9 in 2000, respectively. The age-adjusted incidence rate (adjusted to the world population) was increased three-fold, from 8.3 in 1985 to 24.2 in 2000. The age-specific incidence rate showed an increase with age. The cancers in clinical stages A and D decreased, while those in stages B and C increased. No change in distribution was observed in pathological differentiation. Prostate cancer has increased rapidly during these 16 years in Gunma Prefecture. It is important to perform PSA testing aggressively in males age 50 or older, and detect prostate cancer in an early stage.

Age Factors↗
PubMed2003

Genomewide linkage analysis of familial prostate cancer in the Japanese population.

Prostate cancer (PC) is one of the most common causes of cancer mortality in Western countries, and familial aggregation of PC is well known. Multiple PC susceptibility loci have been reported in Western countries, but attempts to confirm the loci in independent data sets have proven to be inconsistent. We performed a genomewide linkage analysis with 53 affected sib pairs to identify genetic loci related to PC in a Japanese population. Two linkage analyses, GENEHUNTER-PLUS and SIBPAL, were applied and detected nominal statistical significance of linkage to PC at chromosome 1p and 8p, which were reported as being loci for PC in Caucasians. The best evidence of linkage was detected near D8S550 on 8p23 (maximum Zlr=2.25, P=0.037), and the second-best evidence of linkage was observed near D1S2667 on 1p36 (maximum Zlr=2.24, P=0.034). This is the first genetic mapping of PC in Japanese, and the results suggest that susceptibilities to PC lie close to D8S550 on 8p23 and D1S2667 on 1p36.

Chromosome Mapping↗
PubMed2003

Regulation of metallothionein and zinc transporter expression in human prostate cancer cells and tissues.

Prostate glands contain heavy metals such as zinc and cadmium, and epidemiological studies showed that both metals were associated with prostate cancer development. To understand the heavy metal metabolism in prostate glands, we investigated the regulation of metallothionein (MT), metal-responsive promoter element-binding transcription factor (MTF) and zinc transporter (ZnT) in human prostate cells and tissues. Growth of human prostate cancer cells, LNCaP and PC-3 cells, was suppressed by zinc or cadmium treatment in a dose-dependent manner. LNCaP cells expressed MT-1A, 1X and 2A mRNA, and PC-3 cells expressed MT-1X and 2A mRNA. Zinc or cadmium treatment up-regulated MTs, MTF-1 and ZnT-1 gene expression levels in both cell lines. In PC-3 cells, ZnT-1 protein was detected, and was up-regulated by the metal treatment. Human prostate cancer tissues expressed significantly lower levels of ZnT-1 gene in comparison with hyperplastic tissues. We demonstrated the ZnT-1 expression in human prostate for the first time. The present study showed that heavy metal-metabolizing proteins were involved in human prostate homeostasis, and that the metal metabolizing system might be different in malignant tissues.

Cadmium↗
PubMed2003

Correlation between the Banff 97 classification of renal allograft biopsies and clinical outcome.

The 1997 fourth Banff meeting revised the consensus for describing transplant biopsies. We have conducted a retrospective analysis of biopsies correlated between the Banff 97 classification and clinical outcome. The patients ( n=149), who had a total of 404 biopsy-proven rejections, were assessed and the biopsies taken from these patients were re-examined and classified according to the Banff 97 classification. Morphological changes in the glomeruli (g), interstitium (i), tubules(t), and arterial vessels (v) were scored. Severity of acute rejection was statistically associated with unresponsiveness to anti-rejection treatment ( P<0.0001) and predicted an increased risk of graft failure ( P<0.05). Each quantitative criterion (g, i, t, and v) was also statistically associated with unresponsiveness to anti-rejection treatment. Mean serum creatinine levels were significantly higher in the groups graded Banff 97 type I-III after 1 and 2 years of follow-up. The Banff 97 classification correlated with reversibility of rejection episodes and long-term graft survival.

Biopsy↗
PubMed2003

The evaluation of rat prostate blood flow using a laser speckle flowmetry: a comparative study using the microsphere method in castrated and androgen-replenished rats.

To evaluate the accuracy and reliability of laser speckle blood flowmetry in the measurement of prostate blood flow, we performed a comparative study with the ordinary intra-arterial radioactive microsphere injection method using the well-known castrate-rat model. Adult male Wistar strain rats were used for the study. The rats were either only castrated or subcutaneous testosterone replenishment was followed subcutaneously 6 h after castration. The prostate blood flow was measured at different time courses after castration. The effect of a single androgen replenishment on prostate blood flow was also evaluated. The measurement of prostate blood flow was performed by both the radioactive microsphere injection method and laser speckle blood flowmetry, and then the outcomes were compared. Rapid reduction in prostate blood flow to 30% of the normal level was observed 24 h after castration in the measurements with the microsphere injection technique. The prostate blood flow decreased gradually after 24 h post-castration to 23 and 21% of the normal level at 48 and 72 h after castration, respectively. The laser speckle blood flowmetry also detected the decrease in prostate blood flow well, but in a more gradual manner. The prostate blood flow was 70, 52 and 35% of the normal level at 24, 48 and 72 h after castration, respectively. The effect of a single administration of testosterone to castrated rats had recovered the prostate blood flow to 74 and 98% of the normal level by measurement with the microsphere injection technique and laser speckle blood flowmetry, respectively. The different outcome in blood flow rate change between the methods can be explained according to their different mechanism of measurement, thus suggesting the capillary vessels are the early and most responsive portion for hormonal manipulation. In conclusion, the laser speckle blood flowmetry is a convenient and reliable method for evaluating prostate blood flow, especially when the organ is required for other biological and molecular assays, since the method does not require the excision of the organ for the measurement.

Androgens↗
PubMed2003

Genetic polymorphisms of estrogen receptor alpha, CYP19, catechol-O-methyltransferase are associated with familial prostate carcinoma risk in a Japanese population.

BACKGROUND: Estrogen is one of the crucial hormones participating in the proliferation and carcinogenesis of the prostate glands. Genetic polymorphisms in the estrogen metabolism pathway might be involved in the risk of prostate carcinoma development. The authors evaluated the association between genetic polymorphisms in estrogen-related enzymes and receptors and the risk of developing familial prostate carcinoma. METHODS: In the current study, 101 cases with prostate carcinoma whose first-degree relatives had prostate carcinoma and 114 healthy age and residence-matched male controls were enrolled. The genotypes of estrogen receptor (ER) alpha, aromatase (CYP19), and catechol-O-methyltransferase (COMT) genes were analyzed. RESULTS: For single polymorphisms, a significant association of the T/T genotype of the PvuII site in the ER alpha gene (odds ratio [OR], 3.44; 95% confidence interval [CI], 1.97-5.99; P = 0.0028), and the C/T and T/T genotypes of the CYP19 gene (OR, 1.77; 95% CI, 1.02-3.09; P = 0.037) with prostate carcinoma risk, was observed. The G/A genotype of the COMT gene showed a weak tendency toward increased risk (OR, 1.48; 95% CI, 0.85-2.57; P = 0.18). Stratification of cases according to clinical stage and pathologic grade showed that the C/T and T/T genotypes of the CYP19 gene were associated significantly with high-grade carcinoma (OR, 2.59; 95% CI, 1.47-4.46; P = 0.048). The number of high-risk genotypes (the T/T in ER alpha, the C/T and T/T in CYP19, and the G/A in COMT) significantly increased the risk of developing prostate carcinoma (2 genotypes: OR, 3.00; 95% CI, 1.72-5.23; P = 0.008; 3 genotypes: OR, 6.30; 95% CI, 3.61-10.99; P = 0.002). CONCLUSIONS: Genetic polymorphisms of genes in the estrogen metabolism pathway were associated significantly with familial prostate carcinoma risk. Single nucleotide polymorphisms of low-penetrance genes are targets for understanding the genetic susceptibility of familial prostate carcinoma.

Adult↗
PubMed2003

Possibility of re-screening intervals of more than one year in men with PSA levels of 4.0 ng/ml or less.

BACKGROUND: The optimal re-screening interval is one of the most important issues to evaluate the effectiveness of screening for prostate cancer. METHODS: Between 1992 and 2000, 7,026 men aged 50-78 with baseline PSA levels of 4.0 ng/ml or lower underwent screening for prostate cancer twice or more. The risk of developing prostate cancer relative to elapsed years and baseline PSA levels were investigated. RESULTS: Prostate cancer was detected in a total of 127 cases (1.8%). The detection rate of prostate cancer was high between 1.6% and 5.5% at 1 year after baseline PSA measurements in men with baseline PSA levels of 2.1-4.0 ng/ml. In men with baseline PSA levels of 1.1- 2.0 ng/ml, the detection rate increased from 0.06% to 1.02% with passed years. The proportion of stage >/=T3 was high at 63% in prostate cancer cases detected between 3 and 4 years after baseline PSA levels being 1.1-2.0 ng/ml. In men with baseline PSA levels of 1.0 or lower, the cumulative detection rate of prostate cancer was low at 0.01% within 3 years, however, the detection rate increased to 0.34% after 5 or more years from baseline PSA measurements. CONCLUSIONS: The re-screening interval was recommended to be 1, 1-2, and 3-5 years for men with baseline PSA levels of 2.1-4.0 ng/ml, 1.1-2.0 ng/ml, and 1.0 ng/ml or lower, respectively.

Aged↗
PubMed2003

Regioselective synthesis of [60]fullerene eta 5-indenide R3C60- and eta 5-cyclopentadienide R5C60- bearing different R groups.

Treatment of a 1,7-diorgano[60]fullerene with Grignard reagents or organocopper reagents affords a [60]fullerene indenide or a [60]fullerene cyclopentadienide regioselectively in good to excellent yields. These reactions gave an insight into the reaction mechanism of the organocopper penta-addition reaction of [60]fullerene, giving [60]fullerene cyclopentadienide in quantitative yield.

Journal Article↗
PubMed2003

Presynaptic impairment of synaptic transmission in Drosophila embryos lacking Gs(alpha).

Gs(alpha) is a subunit of the heterotrimeric G-protein complex, expressed ubiquitously in all types of cells, including neurons. Drosophila larvae, which have mutations in the Gs(alpha) gene, are lethargic, suggesting an impairment of neuronal functions. In this study, we examined synaptic transmission at the neuromuscular synapse in Gs(alpha)-null (dgsR60) embryos shortly before they hatched. At low-frequency nerve stimulation, synaptic transmission in mutant embryos was not very different from that in controls. In contrast, facilitation during tetanic stimulation was minimal in dgsR60, and no post-tetanic potentiation was observed. Miniature synaptic currents (mSCs) were slightly smaller in amplitude and less frequent in dgsR60 embryos in normal-K+ saline. In high-K+ saline, mSCs with distinctly large amplitude occurred frequently in controls at late embryonic stages, whereas those mSCs were rarely observed in dgsR60 embryos, suggesting a developmental defect in the mutant. Using the Gal4-UAS expression system, we found that these phenotypes in dgsR60 were caused predominantly by lack of Gs(alpha) in presynaptic neurons and not in postsynaptic muscles. To test whether Gs(alpha) couples presynaptic modulator receptors to adenylyl cyclase (AC), we examined the responses of two known G-protein-coupled receptors in dgsR60 embryos. Both metabotropic glutamate and octopamine receptor responses were indistinguishable from those of controls, indicating that these receptors are not linked to AC by Gs(alpha). We therefore suggest that synaptic transmission is compromised in dgsR60 embryos because of presynaptic defects in two distinct processes; one is uncoupling between the yet-to-be-known modulator receptor and AC activation, and the other is a defect in synapse formation.

Adenylyl Cyclases↗
PubMed2003

Triphenyltin enhances the neutrophilic differentiation of promyelocytic HL-60 cells.

Triphenyltin (TPT) is an environmental endocrine disruptor and toxic substance, but little information is available on its immunological effects. To assess the effect of TPT on leukocyte differentiation, we investigated its effect on the neutrophilic differentiation of HL-60 cells induced by dimethyl sulfoxide and granulocyte colony-stimulating factor (G-CSF) for 6 days. At a low concentration, 10(-7)M, TPT increased superoxide production by differentiated HL-60 cells stimulated with opsonized zymosan (OZ) by about 45% and increased expression of CD18, a component of the OZ-receptor, by about 90%. Real-time PCR analysis revealed that TPT augmented the expression not only of CD18 but also of components of superoxide-generating NADPH-oxidase, p47phox, 2.7-fold, and p67phox, 2.0-fold, and of granulocyte colony-stimulating factor receptor (G-CSFR), 3.0-fold, whereas various other endocrine disruptors, including parathion, vinclozolin, and bisphenol A, had no such enhancing effects. The results of a DNA macroarray analysis showed that TPT enhanced the expression of G-CSFR and certain other neutrophil functional proteins, including CD14 and myeloid leukemia cell differentiation protein (MCL-1), and that TPT induced a decrease in expression of LC-PTP, leukocyte protein-tyrosine phosphatase, to about half the control level. The TPT-dependent suppression of LC-PTP was confirmed by real-time PCR analysis, and the results of immunoblotting indicated that TPT enhances the expression of myeloid specific tyrosine kinase hck by about 30% at the protein level, and this together with the reduction of LC-PTP may enhance tyrosine phosphorylation, in turn resulting in enhancement of superoxide production. These findings suggest that TPT may have an enhancing effect on the neutrophilic maturation of leukocytes.

CD18 Antigens↗
PubMed2003

Association of the genetic polymorphism in cytochrome P450 (CYP) 1A1 with risk of familial prostate cancer in a Japanese population: a case-control study.

Association between genetic polymorphisms of CYP1A1 and familial prostate cancer risk was examined by a case-control study of 185 individuals. Although the individual analysis of m1 or m2 genotype of CYP1A1 showed no significant association with prostate cancer risk, the presence of any mutated alleles significantly increased prostate cancer risk in comparison with wild-type genotypes by combination analysis (odds ratio [OR]=2.38; 95% confidence interval [CI]=1.72-3.29; P=0.0069). Furthermore, metastatic cancer had a significant association with mutated alleles of m1 and m2. These finding suggested that CYP1A1 polymorphisms has an association with prostate cancer risk, especially with progression of prostate cancer.

Adenocarcinoma↗
PubMed2003

Direct evidence of facilitative actions of dopamine in the medial preoptic area on reflexive and noncontact erections in male rats.

PURPOSE: We examined the effects of alterations of the extracellular dopamine level in the medial preoptic area on 2 erectile contexts, namely reflexive and noncontact erections, in male rats. MATERIALS AND METHODS: The extracellular dopamine level was measured in the medial preoptic area after administering the dopamine reuptake inhibitor bupropion hydrochloride (Sigma Chemical Co., St. Louis, Missouri) into the same area through a micro-dialysis tube. We measured the frequency and latency of reflexive erections, and the frequency of noncontact erection during infusion of bupropion. RESULTS: Administration of 10 mM. bupropion was associated with significant elevation in the extracellular dopamine level in the medial preoptic area. Bupropion (1 mM.) and Ringer's solution did not induce significant alterations in dopamine in the medial preoptic area. The number of reflexive erections significantly increased and erection latency decreased during infusion of 10 mM. bupropion into the medial preoptic area. The number of noncontact erections was also increased by administering 10 mM. of drug. CONCLUSIONS: The altered dopamine level in the medial preoptic area affected 2 distinct penile erectile contexts, suggesting that the dopamine levels in the medial preoptic area may be involved in the regulation of erection. These results may have important implications for the central regulation of penile erection.

Animals↗