Search PubMed⌕ Search

Biomedical subjects

K Shinohara

Publications and source records attributed to K Shinohara.

At least 181 records · Page 10Linked to original sources
PubMed1996

Local recurrence after radical prostatectomy: characteristics in size, location, and relationship to prostate-specific antigen and surgical margins.

OBJECTIVES: To define the sonographic characteristics of local cancer recurrence after radical prostatectomy. METHODS: in 114 patients with an elevated prostate-specific antigen (PSA) and negative bone scan, 156 ultrasound-guided prostate fossa biopsies were carried out. RESULTS: in 53.5%, biopsy proved local recurrence. More than one ultrasound-guided biopsy session was required to make the diagnosis in 33% of patients. Local recurrence was seen on ultrasound at the anastomotic site (66%), the bladder neck (16%), and posterior to the trigone (13%). in 5% of patients there was a normal-appearing anastomotic site. Transrectal ultrasound was greater than 90% sensitive in detecting local recurrence, but lacked specificity. Examination of the radical prostatectomy specimens in patients with local recurrence showed positive surgical margins in 66% and organ-confined disease in 20%. CONCLUSIONS: Transrectal ultrasonography is a useful adjunct to PSA and digital rectal examination in the detection of local recurrences following radical prostatectomy.

Biopsy, Needle↗
PubMed1996

Should cryosurgery be considered a therapeutic option in localized prostate cancer?

Cryosurgical ablation of the prostate currently is under investigation as a potential treatment for localized prostate cancer. Results to date indicate that the majority of patients have negative biopsies and a marked reduction in prostate-specific antigen levels following cryotherapy. This treatment, however, is associated with significant side effects, notably bladder outflow obstruction, impotence, and incontinence, and its long-term durability is still unknown.

Cryosurgery↗
PubMed1996

Measurement of soft X-ray absorption spectra and elemental analysis in local regions of mammalian cells using an electronic zooming tube.

Direct measurement of absorption spectra for minute areas (2 microns x 2 microns) in a dried mammalian cell was attempted using X-ray contact images of a whole cell. The wavelength region used ranged from 1.5 to 10nm covering the absorption edges of the major cellular elements. The measurements were achieved taking advantage of synchrotron radiation as a tuneable light source and an electronic zooming tube as an X-ray detector with a high spatial resolution. The spectra in every intracellular area exhibited marked absorption changes at the absorption edges of carbon, nitrogen and oxygen, while minor but significant changes for iron and calcium were observed, particularly in the cytoplasmic areas. These results reveal the different spatial distributions of the constituent elements in a cell.

Animals↗
PubMed1996

Acetyl-CoA carboxylase in higher plants: most plants other than gramineae have both the prokaryotic and the eukaryotic forms of this enzyme.

The presence and the absence of a prokaryote type and a eukaryote type of acetyl-CoA carboxylase (EC 6.4.1.2; ACCase) were examined in members of 28 plant families by two distinct methods: the detection of biotinylated subunits of ACCase with a streptavidin probe, and the detection of the accD gene, which encodes a subunit of the prokaryotic ACCase, by Southern hybridization analysis. The protein extracts of all the plants studied contained a biotinylated polypeptide of 220 kDa, which was probably the eukaryotic ACCase. All the plants but those belonging to Gramineae also contained a biotinylated polypeptide of ca. 35 kDa, which is a putative subunit of the prokaryotic ACCase. In all plants but those in Gramineae, the ca. 35 kDa polypeptide was found in the protein extracts of plastids, while the 220 kDa polypeptide was absent from these plastid extracts. The plastid extracts of the plants in Gramineae contained the 220 kDa polypeptide, as did the homogenates of the leaves. Southern hybridization analysis demonstrated that all the plants but those in the Gramineae contained the accD gene. These findings suggest that most higher plants have the prokaryotic ACCase in the plastids and the eukaryotic ACCase in the cytosol. Only Gramineae plants might contain the eukaryotic ACCases both in the plastids and in the cytosol. The origin of the plastid-located eukaryotic ACCase in Gramineae is discussed as the first possible example of substitution of a plastid gene by a nuclear gene for a non-ribosomal component.

Acetyl-CoA Carboxylase↗
PubMed1996

Prostate carcinoma: MR imaging findings after cryosurgery.

PURPOSE: To determine the morphologic changes in the prostate gland after cryosurgery and to assess the value of magnetic resonance (MR) imaging in detecting residual tumor. MATERIALS AND METHODS: Twenty-seven patients with prostate carcinoma underwent endorectal MR imaging after cryosurgery. Eighteen patients also underwent MR imaging before cryosurgery. MR findings were correlated with posttreatment clinical data, prostate-specific antigen level, and biopsy results. RESULTS: Mean prostate volume had decreased by 52% in patients examined 8 weeks or more after cryosurgery. Zonal differentiation was lost in 22 of 27 patients (81%). Areas of intraprostatic necrosis were identified in 14 of 27 patients (52%). A thick capsule enveloped the gland and neurovascular bundles in 24 of 27 patients (89%). Osteonecrosis of the symphysis pubis was seen in six of 27 patients (22%). Positive and negative predictive values for MR assessment of recurrent tumor were 44% and 73%, respectively. CONCLUSION: Cryosurgery-induced changes in the prostate gland preclude reliable detection of residual prostate carcinoma at MR imaging.

Aged↗
PubMed1996

Prostate cancer: metabolic response to cryosurgery as detected with 3D H-1 MR spectroscopic imaging.

PURPOSE: To determine, in patients with prostate cancer treated with cryosurgery, whether levels of choline and citrate measured at magnetic resonance (MR) spectroscopy can help discriminate regions of residual tumor from other prostatic tissues and necrosis. MATERIALS AND METHODS: Combined MR imaging and three-dimensional proton spectroscopic imaging were performed in 25 patients (mean age, 69 years) with prostate cancer who underwent cryosurgery. Volume imaging and spectroscopic data were analytically corrected for the reception profile of the endorectal and pelvic phased-array coils. Spectral data were aligned with the MR imaging data and compared with serum prostate-specific antigen levels and biopsy results. RESULTS: Histologically confirmed necrotic tissue (432 voxels) did not demonstrate any observable choline or citrate. The (choline + creatine)/ citrate values in regions of histologically confirmed benign prostatic hyperplasia (0.61 +/- 0.21 [standard deviation], 52 voxels) and cancer (2.4 +/- 1.0, 65 voxels) after cryosurgery were not statistically significantly different from those before therapy but were statistically significantly different from the ratio in necrotic tissue and from each other. The (choline + creatine)/citrate images threshold and overlaid in color on T2-weighted images yielded an estimate of the spatial extent of prostate cancer and benign prostatic hyperplasia. CONCLUSION: Volume MR imaging with MR spectroscopic imaging provided a noninvasive assessment of the presence and location of residual cancer after unsuccessful therapy and helped identify successful cryosurgery in patients who still had an elevated prostate-specific antigen level.

Aged↗
PubMed1996

Circadian rhythm and response to light of extracellular glutamate and aspartate in rat suprachiasmatic nucleus.

Extracellular concentrations of glutamate and aspartate were measured in the vicinity of rat suprachiasmatic nucleus (SCN) by means of in vivo microdialysis. The concentrations of both excitatory amino acids (EAAs) were higher during the dark phase than during the light under the light-dark cycle, showing pulsatile fluctuations throughout the day. When rats were released into the complete darkness, the 24-h pattern in the aspartate continued for at least one cycle, whereas that in the glutamate disappeared. The nocturnal increases in the EAA levels were not due to the increase of locomotor activity during the nighttime, because the 24-h rhythms were also detected in animals under urethan anesthesia. The patterns of extracellular EAA levels were changed when rats were released into the continuous light. Circadian rhythm was not detected in the glutamate, whereas the 24-h pattern was maintained in the aspartate with the levels increased to various extents. A 30-min light pulse given either at zeitgber time (ZT) 1 or ZT 13 elevated the EAA levels during the latter half of the light pulse, except glutamate by a pulse at ZT 1. The extracellular EAA levels in the vicinity of the rat SCN showed the circadian rhythm with a nocturnal peak and increased in response to the continuous light and a brief light pulse. The aspartate level is considered to be regulated by the endogenous circadian rhythm, but the glutamate levels seems to be modified by the light-dark cycle.

Anesthesia↗
PubMed1996

Local staging of prostatic carcinoma: comparison of transrectal sonography and endorectal MR imaging.

OBJECTIVE: We compared the results of transrectal sonography and endorectal MR imaging in the local staging of prostatic carcinoma. SUBJECTS AND METHODS: 56 patients (mean age, 61.1 +/- 7.3 years) with the diagnosis of prostate cancer who by transrectal sonography had no evidence of gross extracapsular extension underwent endorectal coil MR imaging prior to radical prostatectomy. Imaging findings prospectively evaluated in each patient were cancer laterality, extracapsular extension, and seminal vesicle invasion. Twenty-one of 56 (38%) patients had extracapsular extension on final pathology. A total of 100 sides and five seminal vesicles were involved with cancer, and 27 sides (21 patients, six with bilateral extracapsular extension) demonstrated extracapsular extension. Imaging results were correlated with step-sectioned, radical prostatectomy pathologic data, and statistical analysis was expressed at a p = .05 level of significance. Retrospective readings of the images were used to construct receiver operating characteristic curves for the detection of extracapsular extension. RESULTS: For tumor laterality, transrectal sonography was compared with endorectal coil MR imaging for sensitivity (70% versus 97%; p < .001), specificity (58% versus 58%), positive predictive value (93% versus 95%) and negative predictive value (18% versus 70%). For extracapsular extension, transrectal sonography was compared with endorectal coil MR imaging for the entire prostate and individually for each side of the prostate. The respective results for sensitivity (48% versus 91%, p < .01 and 37% versus 78%, p < .005), specificity (71% versus 49% and 87% versus 73%), positive predictive value (50% versus 51% and 48% versus 48%), and negative predictive value (69% versus 90% and 81% versus 91%). The receiver operating characteristic analysis of retrospective data demonstrated endorectal coil MR imaging to be superior to transrectal sonography in the detection of extracapsular extension. The small number of seminal vesicles involved by cancer (n = 5) precluded meaningful comparisons between the imaging techniques. CONCLUSIONS: Endorectal coil MR imaging is more sensitive but less specific than transrectal sonography for detecting extracapsular extension of carcinoma of the prostate. Both procedures have low positive predictive values yet similarly high negative predictive values when each side of the prostate is assessed independently for extracapsular extension.

Humans↗
PubMed1996

Detection of Auger enhancement induced in HeLa cells labeled with iododeoxyuridine and irradiated with 150 kV x-rays--Effects of cysteamine and dimethylsulfoxide.

We examined the effects of cysteamine and dimethylsulfoxide on the lethality of iododeoxyuridine-labeled HeLa cells irradiated with 150 kV x-rays (effective energy was 48 keV) and compared with those irradiated with 60Co gamma-rays. The protectable fraction was estimated from the regression lines for the reciprocal plots of the concentration of protectors, versus the degree of protection. The protectable fraction by cysteamine was 9.4% lower in iododeoxyuridine-labeled cells than in control cells when they were irradiated with x-rays, whereas no such difference was observed with dimethylsulfoxide. The slopes of the regression lines were steeper (i.e., more difficult to protect) for both protectors in iododeoxyuridine-labeled cells irradiated with x-rays. No such differences were observed in gamma-irradiated cells. The cause for these differences are attributable to Auger enhancement. The results suggest that at least a portion of Auger enhancement is not protectable by cysteamine and is hard to be protected by both protectors cysteamine and dimethylsulfoxide.

Cell Survival↗
PubMed1996

Transrectal ultrasound guided prostatic nerve blockade eases systematic needle biopsy of the prostate.

PURPOSE: We assessed the effect of transrectal ultrasound guided prostatic nerve blockade on the discomfort associated with systematic needle biopsy of the prostate. MATERIALS AND METHODS: A prospective randomized double-blind study was performed of 64 patients requiring systematic biopsy of the prostate. Patients were randomly assigned to receive an injection of 5 ml. 1% lidocaine or 5 ml. saline (0.9% sodium chloride) at the vascular pedicle on 1 side of the prostate only. They were then asked to score the severity of discomfort of the injection and subsequent biopsies on each side. RESULTS: Mean pain scores were significantly lower on the side with than the side without lidocaine injection (1.6 +/- 0.9 versus 2.4 +/- 1.2, p < 0.0001) and not significantly different when saline was injected (2.9 +/- 1.2 versus 3.0 +/- 1.1, p = 0.52). Pain scores were significantly different when the lidocaine injected side was compared to the saline solution injected side (p < 0.0001) but the difference was not significant between the noninjected sides of the 2 groups (p = 0.076). Of the patients in the lidocaine group 68% reported that they would prefer to undergo biopsy with the injection compared to only 41% in the placebo group (p = 0.037). During the study no patient in either group had any adverse effect from the injection. CONCLUSIONS: Transrectal ultrasound guided nerve blockade before prostatic biopsy results in a more comfortable procedure for the patient.

Biopsy, Needle↗
PubMed1996

Cryosurgical treatment of localized prostate cancer (stages T1 to T4): preliminary results.

PURPOSE: We determined the posttreatment biopsy results, prostate specific antigen (PSA) levels and complications associated with cryosurgical ablation of the prostate performed for localized prostate cancer. MATERIALS AND METHODS: Within 18 months 102 patients underwent cryosurgery as definitive therapy for localized prostate cancer. Mean patient age was 68 years and 57% had advanced local disease (stage T3 or T4). Mean preoperative PSA was 21.8 ng./ml. RESULTS: PSA was undetectable at 6 months in 48% of patients who received no androgen deprivation therapy following cryosurgery. Of 91 patients with postoperative biopsies 77% had no evidence of cancer but 71% had benign epithelial a elements. The complication rate (excluding impotence) was 51%. Biopsy and PSA results improved with experience and changes in technique, that is double freezing, more lateral placement of cryoprobes and more aggressive freezing beyond the prostatic capsule. The most recent cohort of 77 patients had a detectable PSA rate of 23% and a positive post-cryosurgical biopsy rate of 11%. The most common serious complication encountered was bladder outflow obstruction requiring transurethral resection in 23% of the patients. Impotence occurred in 84% of patients potent preoperatively. CONCLUSIONS: Cryosurgical ablation of the prostate can result in negative posttreatment biopsies and undetectable serum PSA levels. However, it is associated with significant side effects and the long-term durability of the procedure is unknown.

Aged↗
PubMed1996

Expression of costimulatory molecules in human leukemias.

In order to determine the indication of B7 (B7-1 and B7-2) molecules-mediated immuno-gene therapy for human leukemias, we investigated 94 human leukemic samples for the expression of MHC molecules required for tumor antigen-specific signals and of B7-1, B7-2, and ICAM-1 molecules required for non-specific costimulatory signals. All samples were strongly positive for MHC class I and 84% for class II antigen. B7-1, B7-2 and ICAM-1 were expressed in 5%, 22% and 16% of the total cases, respectively. Especially in 54 AML samples, B7-1 was only expressed in one case, while B7-2 was detected in as many as 15 cases (28%). We have also examined 13 human myelo/monocytic cell lines for the expression of class II and costimulatory molecules and found that significant expression of costimulatory molecules was induced in human leukemic cells by some suitable drugs, among which interferon-gamma (IFN-gamma) was the most potent inducer. Our results indicate that when the B7-mediated immuno-gene therapy was applied to human leukemias, especially to AML, B7-1 was rather preferable to B7-2 in that the latter was more widely expressed on human leukemic cells. Furthermore, since gene-transfer systems occasionally accompany serious problems, it should be taken into account that costimulatory molecules on human myelo/monocytic leukemic cells could be induced ex vivo without the introduction of exogenous genes.

Antigens, CD↗
PubMed1996

Prospective evaluation of prostate specific antigen and prostate specific antigen density in the detection of nonpalpable and stage T1C carcinoma of the prostate.

PURPOSE: We evaluated prospectively prostate specific antigen (PSA) and prostate specific antigen density in the detection of prostate cancer in patients with normal findings on digital rectal examination with and without normal transrectal ultrasound. MATERIALS AND METHODS: Consecutive patients (184) with an elevated serum PSA and normal digital rectal examination underwent transrectal ultrasound with lesion directed and systematic biopsies (6 if prostatic volume was 50 cc or less and 12 if volume was more than 50 cc). Receiver operating characteristic curves, predictive values and likelihood ratios were calculated for PSA and PSA density. RESULTS: Of the 184 patients 50 (27%) with a normal digital rectal examination had cancer compared to 30 of 112 (27%) with a normal digital rectal examination and transrectal ultrasound. Median PSA or PSA density did not differ between the positive and negative biopsy groups among patients with a normal digital rectal examination (8.4 versus 7.1 and 0.22 versus 0.14 ng./ml., respectively) or a normal digital rectal examination and transrectal ultrasound (8.2 versus 7.5 and 0.21 versus 0.14 ng./ml., respectively). PSA density was superior to PSA by receiver operating characteristic analysis for cancer detection when all PSA values or those between 4 and 20 ng./ml. were considered. However, the significance was lost for a PSA of 4 to 10 ng./ml. Likelihood ratios demonstrated insignificant changes in the post-test probability if PSA density was used to determine the need for biopsy and many cancers would have been missed. CONCLUSIONS: PSA density should not be used to determine the need for biopsy in patients with a normal digital rectal examination and/or transrectal ultrasound.

Biopsy↗
PubMed1996

Interleukin-2 activated lymphocytes show improved sensitivity for class 1 HLA typing.

The use of phytohemagglutinin (PHA)/interleukin-2 (IL-2) activated lymphocytes for HLA typing and the comparison with those of fresh peripheral blood lymphocytes are described. For detecting class 1 HLA antigens, PHA/IL-2 activated lymphocytes showed higher sensitivity than fresh lymphocytes of the peripheral blood in serological microcytotoxicity testing method. Their reaction specificity for the panel of alloantisera for class 1 HLA antigens was the same. On the contrary, for detecting class 2 HLA antigens, PHA/IL-2 activated lymphocytes showed lower sensitivity than those with fresh B-cells. For class 2 HLA typing, the typing with DNA methods showed the best results. Thus, we conclude that a combination of a serological typing method using PHA/IL-2 activated lymphocytes for class 1 HLA antigens with a DNA method for typing class 2 HLA antigens currently offers the best approach for the detection of HLA antigens.

Adult↗
PubMed1995

Expression of cDNA for a bark lectin of Robinia in transgenic tobacco plants.

A cDNA encoding a bark lectin of Robinia pseudoacacia was introduced into tobacco plants. The expression of the lectin cDNA under control of the 35S promoter was confirmed by Western blot analysis and a hemagglutination assay of extracts of transgenic plants. Western blot analysis revealed that the subunit of the lectin from tobacco had a molecular mass of 29 kDa. The sequence of nine amino acids from the N-terminus of the lectin from transgenic tobacco plants was identical to that of the bark lectin from Robinia, indicating that the lectin had been processed correctly at its N-terminus in tobacco. The molecular mass of the purified native lectin produced by tobacco plants was estimated to be 112 kDa by gel filtration on a column of Superdex 200. It is suggested that the lectin subunits assembled to form tetramers in transgenic tobacco plants.

Amino Acid Sequence↗
PubMed1995

Two distinct oscillators in the rat suprachiasmatic nucleus in vitro.

In the rat suprachiasmatic nucleus slice culture, circadian rhythms in the release of arginine vasopressin and vasoactive intestinal polypeptide were measured simultaneously and longitudinally. The phase relationship between the two peptide rhythms was relatively constant in the culture without a treatment of antimitotic drugs but became diverse by an introduction of antimitotics, which is generally used to reduce the number of glial cells. By monitoring the two rhythms continuously for 6 days, different periods were detected in culture with the antimitotic treatment. Furthermore, N-methyl-D-aspartate shifted the phase of the two peptide rhythms in the same culture differently. These results indicate that the arginine vasopressin and vasoactive intestinal polypeptide release are under control of different circadian oscillators.

Animals↗