Biomedical subjects
Publications and source records attributed to J Shimazaki.
Microsatellite instability (MSI) was examined at 36 loci, and found in 9 (43%) of the 21 prostatic cancers. A loss of heterozygosity had occurred in five cases (24%). MSI did not correlate with clinical stage, but might play a role in the development of a subset of prostate cancers.
To reduce the recurrence rate of or urolithiasis, dietary counseling was conducted for calcium-stone patients. Sixty-six patients received dietary counseling and were in principle instructed to use the Recommended Dietary Allowance for Japanese as their goal. Seventy-three patients did not undergo the counseling. Comparison of the dietary intake of the patients with the dietary requirements for Japanese revealed that protein intake, especially animal protein intake, was higher and calcium intake lower in the patients. As a result of the counseling, intakes of total protein, animal protein, fat, and carbohydrates were all reduced. Patients in the stone recurrence-free group excreted less oxalate than those in the recurrent one. The excretion of oxalate was then reduced and urine volume increased owing to the diet counseling program. The stone recurrence rate of the group participating in the diet counseling was lower than that of the group not taking part. The recurrence rate of the hyperoxaluric group was higher, with statistical significance, than that of the normooxaluric group among those not receiving the dietary counseling. With dietary counseling, the recurrence rate significantly decreased in the hyperoxaluric patients. Thus, the reduction in the rate of stone recurrence resulting from participation in the diet counseling program seemed to be attributable to the decrease in urinary oxalate excretion. Dietary counseling seems to be a useful measure to prevent urinary stone recurrence.
To study mutation of the CDKN2 gene in prostate cancer, samples from 51 Japanese patients and four human prostate cancer cell lines were examined by single-strand conformation polymorphism analysis and direct sequencing. Only one out of 51 (2%) patients revealed a mutation, which was a 24 bp deletion from the 5'-untranslated region to codon 3, resulting in loss of the initiation site. One of the four cell lines revealed a missense mutation, a GAC-->TAC (Asp-->Tyr) at codon 84. These results indicate that mutation of the CDKN2 gene is rare in prostate cancer and thus does not contribute significantly to the pathogenesis of human prostate cancer. Prostate cancer cell lines may acquire more frequent abnormality of the CDKN2 gene than tumor tissues.
To elucidate the role of the p53 tumor suppressor gene in prostate tumorigenesis, we probed for mutations in latent and clinical prostate cancers using single strand conformation polymorphism (SSCP) and restriction fragment length polymorphism (RFLP) analysis in combination with direct gene sequencing and immunohistochemical methodologies. Fifteen cases of subclinical and 32 cases of clinical carcinoma, the latter graded in stages A through D, were available for study. While p53 point mutations were detected in only 5 of 32 (16%) clinical cancers, no mutations were detected in latent disease. Of the carcinomas in stages B, C and D, 15% (2/13), 29% (2/7) and 9% (1/11) were positive for p53 mutations, respectively. Although no specific mutational patterns were observed, the aberrations found were predominantly single base missense substitutions. The data suggest not only an association of p53 mutation and progression of clinical prostate cancer, but also imply that some other mechanism(s) are at work in latent carcinoma.
Microsatellites are highly polymorphic, short-tandem repeat sequences dispersed throughout the genome. Instability of these repeat sequences at multiple genetic loci may result from mismatch repair errors, and occurs in hereditary nonpolyposis colorectal carcinoma and certain sporadic cancers. To examine microsatellite instability during the pathogenesis of human prostate cancer, we screened 48 prostate cancer cases (20 stage B, 10 stage C and 18 endocrine therapy-resistant cancer-death cases) for replication error at 17 microsatellite marker loci on 9 chromosomes. Microsatellite instabilities were found in 7 of 48 cases (14.6%), and all 7 cases showing the instability were poorly differentiated adenocarcinomas. Moreover, microsatellite instabilities were more frequently observed in cancer-death cases (6/18, 33%) than in stage B + C cases (1/30, 3.3%). These data suggest that microsatellite instability is an important genetic change related to the progression of a subset of human prostate cancer cases. It is suggested to be associated with extensive, concurrent molecular changes including androgen receptor gene mutations, as well as frequent loss of heterozygosity at chromosomal regions 8p, 10q, and 16q.
Shionogi Carcinoma 115 (SC 115) cells are a cloned cell line derived from androgen-dependent mouse mammary tumor. They can grow in serum-free culture if a physiological level of androgen is present in the medium, but can not proliferate in culture without testosterone. In the present study, the mechanism of cell death in SC 115 cells after androgen withdrawal was examined. Based upon the temporal sequence of DNA fragmentation, morphologic changes and loss of cell viability, androgen withdrawal induces programmed cell death (apoptosis) of SC 115 cells in serum-free culture. Northern blot analysis was used to identify a series of genes whose expression per cell is enhanced during the recruitment of cells from a nonproliferative (i.e. G0) state into G1 (i.e.,cyclins D1 and C), from G1 into the S phase of the cell cycle (i.e., cdk2), and during the programmed cell death pathway (i.e. testosterone repressed prostatic message-2 (TRPM-2), transforming growth factor-beta1 (TGF-beta1) and glucose regulated 78 kilodalton protein (GRP-78). Expression of TRPM-2, TGF-beta1, GRP-78, and calmodulin genes increases, but that of cyclins C and D1, and cdk2 genes decreases during programmed cell death of SC 115 cells. These results demonstrate that androgen-dependent SC 115 cells undergo programmed cell death induced by androgen withdrawal, and that this death does not require proliferation or progression into G1 of the proliferative cell cycle. SC 115 cells should be a good model for investigating programmed death of hormone-dependent cancer.
To study the disease progression in stage A prostate cancer, 212 patients with stage A from a group of 3370 patients who underwent transurethral resection of the prostate, or subcapsular prostatectomy during the period 1972-1991 were followed. The stage A cases were subdivided into 103 A1 patients and 109 A2 patients and their subsequent course was followed for an average of 41.7 months (6-174 months). Progression to clinical cancer was found in 12 patients, 2 from A1 and 10 from A2 groups. This progression was evident 40.5 months (14-130 months) after prostatectomy. Eight (67%) of these cases responded to endocrine therapy. The rate of expression of ras p21, and the number of argyrophilic nucleolar organizer regions in stage A cancer cells were greater in progressing than in non-progressing cases. These results indicate that stage A cancer with progression arises mainly from the A2 subgroup and exhibits a distinctly proliferative potential even at small foci.
The first case of gelatinous drop-like corneal dystrophy in one eye and band-shaped spheroidal corneal degeneration in the other eye was reported. She was a member of Japanese family with gelatinous drop-like corneal dystrophy. A close association between gelatinous drop-like corneal dystrophy and band-shaped spheroidal corneal degeneration was suggested.
We assessed the safety and effectiveness of sub-Tenon's anesthesia, a local anesthesia, for strabismus surgery. For 15 surgeries, we used anesthesia by sub-Tenon's infusion, followed by direct infusion through a transconjunctival route with a local anesthetic agent. We found the procedure was simple, it minimized complications compared with other techniques and was effective in achieving rapid anesthesia. With the ocular movement remaining, we checked eye position by the alternative cover-uncover test at the end of surgery. We obtained good eye position for all patients. This method leads to good results for strabismus surgery.
To estimate the growth rate of prostate cancer, the doubling times of prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP) were determined in 51 patients: 44 were refractory to endocrine therapy, and 7 were in an untreated state. Since an exponential increase in PSA and PAP was observed in all patients, the doubling time was calculated from a semilogarithmic plot of the respective markers. PSA doubling time was almost identical with that of PAP. The tumor marker doubling time in untreated patients was approximately 10 times greater than that in the patients who were refractory to endocrine therapy. In endocrine refractory patients, the tumor marker doubling time in patients who showed deterioration of bone lesions was less than that in patients with local regrowth and/or lymph node metastasis. The prognosis of endocrine refractory patients from the time showing tumor marker failure was examined. The group showing the longest time (> 80 days) had better prognosis than that shown by the other groups with shorter doubling times. It is concluded that the determination of tumor marker doubling time is of value for measuring the growth rates of prostate cancer, and for assessing prognosis after relapse.
Radical prostatectomy is the effective treatment for clinical T2 prostatic cancer. However, clinical T2 stage is often understaged preoperatively. The objective of neoadjuvant therapy is to increase the curability of surgery to understaged patients. The present study was based on patients who had had neoadjuvant endocrine therapy (LH-RH agonist) prior to radical nerve-sparing prostatectomy for T2 prostatic cancer. Sexual function were estimated before and after surgery. Ten patients with a mean age of 64.6 years (range 57-71 years) and biopsy-proven cancer received this treatment modality. No patients had evidence of lymph node metastasis by the pelvic computerized tomography and their bone scan was negative for metastasis. Clinical stage was T2a in 3 patients and T2b in 7. The grade of these tumors as assessed on prostatic biopsy before neoadjuvant endocrine treatment was well differentiated in 3 and moderately differentiated in 7. The duration of neoadjuvant endocrine therapy was 3.6 months (range 2-5 months) in average. Serum levels of prostatic specific antigen (PSA) were examined monthly and prostate volume was measured by transrectal ultrasonography before and after neoadjuvant treatment. Decrease in serum PSA values was observed from an average level of 8.6 ng/ml (range 3.1-17.5 ng/ml) determined prior to neoadjuvant treatment to an average of 1.1 ng/ml (range 0.6-3.3 ng/ml) determined after neoadjuvant treatment. An average reduction of prostatic volume was 25.3% (range 7.4-56.7%) after neoadjuvant therapy. Pathological effects of the neoadjuvant therapy by the criteria proposed by Japanese Urological Association were Grade (G) 0a in 3 patients, G0b in 4, G1 in 2 and G2 in 1. Of patients who had 10 stage T2 cancer before treatment, 4 had pT2 and 6 pT3.(ABSTRACT TRUNCATED AT 250 WORDS)
BACKGROUND: To evaluate measurement of separate renal function with Doppler ultrasound, renal blood flow velocity of interlobar and segmental arteries was examined with color Doppler echography. METHODS: Maximum blood flow velocity, minimum blood flow velocity, mean blood flow velocity, acceleration, resistive index, and pulsatility index were used as parameters of blood flow. RESULTS: In 71 patients who had undergone unilateral nephrectomy (group 1), interlobar arterial minimal blood flow velocity correlated with creatinine clearance (r = 0.59) and 15 min. PSP value (r = 0.47). In 43 patients whose separate renal functions were different each other (group 2), the separate Ccr calculated from radioisotope renogram, correlated with interlobar arterial minimal blood flow velocity (r = 0.75). As far as unilateral renal blood flow velocity showed the same value, Ccr in group 1 was larger than in one kidney of group 2. This would be account for the fact that the volume of unilateral renal parenchyma which was measured by CT scan was larger in group 1 than in one kidney of group 2. In addition, the left to right ratio of Ccr was similar to that of interlobar arterial minimal blood flow velocity. Interlobar arterial minimal blood flow velocity has been decreasing along with aging in cases with normal kidneys. CONCLUSION: Color Doppler echography is a useful technique for estimating separate renal function.
Prostate specific antigen (PSA) levels after total prostatectomy or radiation therapy to localized prostate cancer and also during endocrine therapy are within normal range. Therefore, it is necessary to use hyper sensitive PSA assay kits for early detection of relapse. The present study was undertaken to evaluate two hyper sensitive assay kits (Delfia kit, lower limit 0.1 ng/ml, Kabi Pharmacia Diagnostics Co. and Markit M kit, 0.5 ng/ml, Dainippon Pharmaceutical Co.) and to compare them with conventional PSA kit (Eiken Chemical Co., 1.0 ng/ml). Total of 291 sera were examined: patients consisted of 10 total prostatectomy+endocrine therapy, 9 radiation therapy+endocrine therapy, 5 radiation therapy alone and 44 endocrine therapy alone. Values of endocrine therapy alone were divided into two groups according to duration after start of treatment; more or less than 5 years. The following results were obtained. 1. In non-relapse patients after total prostatectomy+endocrine therapy and radiation+endocrine therapy, PSA showed under lower limit with hyper sensitive kit. On the contrary, conventional kit indicated more than 1.0 ng/ml. 2. Radiation therapy alone kept PSA in detectable range with hyper sensitive kit in spite of no sign of relapse. 3. In non-relapsed patients under endocrine therapy alone, long duration (more than 5 years after start of treatment) decreased PSA in non detectable values with hyper sensitive kits. In this case, conventional kit still showed PSA as more than 1 ng/ml. 4. Doubling time at relapse was estimated similar with Delfia kit and Markit M kit, and much longer with conventional kit. It is concluded that hyper sensitive kit is more useful to manage patients after therapy than conventional kit.
The efficacy of aspiration cytology, using Franzen method and echo-guided aspiration for prostate cancer was examined to 102 patients under saddle-block anesthesia in urological clinic of Chiba University Hospital. Between 1990 and 1993, 77 cases out of 102 patients were diagnosed histologically as prostate cancer by needle biopsy and 90% of them were coincidental with findings of aspiration cytology. Looking at histological grades, well differenciated cancer was shown to yield low positivity compared with moderately and poorly differentiated cancer. Positive rate showed similar when grade of specimens from needle biopsy was classified with Gleason pattern. Neither T category nor method of aspiration between Franzen and echo-guided methods influenced positive rate of aspiration cytology. On aspiration cytology, its grading revealed 60% of coincidence with that obtained by histological method. When counting more than 300 scattered cells, 90% of coincidence was achieved with histological grading. It is concluded that aspiration cytology is efficient for diagnosis of prostate cancer.
Clinical evaluation of TANDEM PSA which is the most frequently used prostate specific antigen (PSA) assay method in the world and a comparison with other methods were performed in Japanese cases in a cooperative research fashion. The minimum detectable level of the method was found to be 0.50 ng of PSA in one ml of serum and 1.9 ng/ml was regarded as the upper normal value in Japanese males. The distribution of serum PSA showed a significant difference between the benign prostate hypertrophy (BPH) cases and patients with stage C or D prostate cancer. The sero-diagnosis prostate cancer at an early stage with the TANDEM PSA was difficult. The correlation to other methods of PSA detection was very high. Furthermore, the clinical use of the method in following-up the clinical course of prostate cancer patients was very useful. These findings suggested that the PSA detection using TANDEM PSA is applicable even in Japanese cases although the upper cut-off level is decreased.
To assess the potential role of ras oncogene activation and p53 tumor suppressor gene mutations in the development of human prostate carcinoma, nine cases of histologically heterogeneous prostate tumors obtained from total prostatectomies were probed for these specific events. Each tumor was divided into 5 to 10 areas according to different growth or histological patterns. Targeted DNA sequences coding for ras and p53 were amplified by the polymerase chain reaction, analyzed by single-strand conformational polymorphisms, and confirmed by direct DNA sequencing. Point mutations of the ras gene were found in three of the nine tumors. Two contained K-ras codon 13 and H-ras codon 61 mutations, found in only one and three areas of each lesion, respectively. The third tumor contained two different point mutations in K-ras codons 13 and 61 in different foci of the sample. Loss of heterozygosity at the polymorphic codon 72 in the p53 gene was detected in two of four informative cases (50%) showing fragment cleavage by restriction fragment length polymorphism analysis. Mutations in p53, missense transversions, single base insertions, and two base deletions were also detected in three tumors. The present results reveal mutated ras and p53 occasionally occurring in small foci of the tumor and that genetic mutations in p53, as opposed to those in ras, are more closely associated with invasive growth of heterogeneous prostate carcinoma.
Metabolic and biochemical changes of the corneal epithelium and endothelium were studied in experimental diabetic animal models. Ocular redox fluorometry was used to noninvasively determine tissue reduction-oxidation (redox) changes in organ cultured rabbit corneas incubated in high glucose concentration media, alloxan-induced diabetic rabbits, and nonobese diabetic mice. The ratio of autofluorescence from reduced pyridine nucleotide to oxidized flavoproteins (PN/Fp) was used as the indicator of the redox state. Chemical assays for NADH and NAD+ were performed on in vitro materials. Analysis of corneal endothelial morphology using specular microscopy was performed to study possible correlations with metabolic changes. Both the PN/Fp and NADH/NAD+ ratios increased in the corneal endothelium under all experimental conditions. Changes in redox state were not observed in the corneal epithelium in any of the models. Morphologic analysis of the corneal endothelium revealed no significant changes. These results indicate that redox changes occur in the diabetic corneal endothelium, but not the corneal epithelium. Ocular redox fluorometry is capable of detecting changes in the corneal endothelial redox state noninvasively.
DNA-HLA (human leukocyte antigen) typing was performed for ocular tissues in order to determine the usefulness of the method in corneal transplantation. Each type of ocular tissue was dissected from eye bank eyes (n = 3). DNA was extracted, and HLA-DRB1, DQB1, and DPB1 genes were amplified using PCR (polymerase chain reaction) method. DNA can be extracted and amplified from each ocular tissue except for the crystalline lens, but DNA from iris and choroid can be amplified only after diluting the samples 10 to 100 times. HLA class II antigens were successfully determined in these ocular tissues by the RFLP (restriction fragment length polymorphism) method. The method was applied to the corneal tissues of donor and recipient used for the corneal transplantation (n = 7). HLA class II antigens can be determined in both the donor and recipient corneal samples, and the results of recipients' HLA typing were the same as those determined using the blood samples. These results indicate that the DNA-HLA typing can be used for ocular tissues. Since DNA-HLA typing is more accurate than the conventional serological typing, the method is promising for the study of HLA class II typing in corneal transplantation.