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Biomedical subjects

A Miyata

Publications and source records attributed to A Miyata.

At least 19 recordsLinked to original sources
PubMed2006

Delayed L-DOPA-induced hyperalgesia.

Previously we reported on L-DOPA's antinociceptive effect on substance P-induced nociceptive behaviors in mice [Shimizu T, Iwata S, Morioka H, Masuyama T, Fukuda T, Nomoto M. Antinociceptive mechanism of L-DOPA. Pain 2004;110;246-9.]. Since significant hyperalgesia was noted following antinociception, our study was designed to investigate the mechanism of this hyperalgesia. Nociceptive behaviors were enhanced 2 h after L-DOPA administration. L-DOPA induced hyperalgesia occurred after conversion to dopamine because co-administration of benserazide, a DOPA decarboxylase inhibitor, completely abolished the L-DOPA-induced hyperalgesia. The D2 receptor agonist, quinpirole, depressed these behaviors entirely, while the D1 antagonist, SCH23390, inhibited the enhancement of these behaviors by L-DOPA. The D2 receptor antagonist, sulpiride, which induced hyperalgesia of the substance P-induced behaviors in naive mice, did not have any effects on L-DOPA-induced hyperalgesia. Spinal cord dopamine content increased rapidly after L-DOPA administration, exhibiting levels 100 times greater than baseline, and then returned to control after 1 h. These results suggested that the dopaminergic inhibitory system for pain sensation was temporarily impaired by excess amounts of exogenous dopamine that were derived from L-DOPA and both D1 and D2 receptors were involved in L-DOPA-induced hyperalgesia.

Animals↗
PubMed2005

Management of severe subarachnoid hemorrhage; significance of assessment of both neurological and systemic insults at acute stage.

In order to elucidate mutual interrelationship between neurological and systemic dysfunctions in patients with subarachnoid hemorrhage (SAH) at acute stage, neurological condition, systemic complications and plasma catecholamine (CA) level were studied in 1431 consecutive cases admitted within 72 hours after the onset. Five hundred and twenty-four cases with Glasgow Coma Scale (GCS) score 8 or less were assigned to the group of severely ill cases (G-ill), 907 cases with GCS score 9 or more to that of the less ill group (G-well). Plasma CA level was extremely high at super-acute stage within an hour after bleeding and lowered fairly quickly within 24 hours to the normal range. Assuming the value obtained from a formula of [blood sugar level (mg/dl)/serum potassium concentration (mEq/L)] as stress index (SI), SI correlates well (r = 0.4-0.6) with serum catecholamine level at acute stage. Thus, sympathetic hyperactivity after SAH can be grossly estimated with SI. SI over 40 means that patients might have considerable neurological insults as well as systemic ones. For patients in G-well, SI over 50 means that there may be risks for systemic complications even in cases with good neurological condition.

Acute Disease↗
PubMed2001

Expression of pituitary adenylate cyclase-activating polypeptide mRNA in the cochlea of rats.

Expression of mRNA for pituitary adenylate cyclase-activating polypeptide (PACAP) was detected in the cochlea of rats using a reverse transcription-polymerase chain reaction and in situ hybridization. Examination of in situ hybridization demonstrated that cells in the spiral ganglion, and marginal cells in the stria vascularis expressed mRNA for PACAP. These findings suggest that PACAP may play an important role in regulating cochlear functions.

Animals↗
PubMed2001

Concurrent Hodgkin's disease (mixed cellularity type) and T-cell chronic lymphocytic leukemia/prolymphocytic leukemia.

We describe a patient with leukopenic T-cell chronic lymphocytic leukemia/prolymphocytic leukemia (T-CLL/PLL), according to the Revised European-American Classification of Lymphoid Neoplasms. This patient simultaneously developed classic Hodgkin's disease (HD), a combination previously unreported. The leukemic cells were small and mature, did not have cytoplasmic granulation, and appeared similar to B-cell chronic lymphocytic leukemia. Immunophenotyping of the bone marrow-infiltrating cells revealed a postthymic suppressor/cytotoxic phenotype of CD2+, CD3+, CD4, CD5+, CD8+, CD25-, TCR-alpha beta. A lymph node biopsy showed the histological features of HD (mixed cellularity) with infiltrating CD8+ lymphocytes, and immunohistochemical examination revealed the following phenotype of Reed-Sternberg cells: LeuM1/CD15+, BerH2/CD30+, L26/PanB-, UCHL-1/CD45RO-, cyCD3-, CD4, CD8-, CD20-, CD79a-, EMA-, EBER-1+, LMP-1+. Southern blot analysis of the bone marrow and lymph node revealed the same rearrangement of bands of T-cell-receptor genes. Although the HD was treated with chemotherapy that resulted in complete remission, the T-PLL/CLL took an indolent course. This case may suggest the existence of a subtype of T-CLL/PLL with leukopenia and an indolent clinical course. Both diseases were believed to be independent and not a transformation of one to the other.

Aged↗
PubMed2001

T wave alternans for predicting adverse effects of amiodarone in a patient with dilated cardiomyopathy.

An implantable cardioverter defibrillator (ICD) was used in a 62-year-old man with dilated cardiomyopathy (DCM) because of hemodynamically intolerable ventricular tachycardia (VT). Amiodarone was administered after a second episode of ICD discharge. Three weeks later, incessant VT appeared, and DC discharge failed to terminate it. Microvolt T wave alternans (TWA), measured by a spectral method, was observed in this patient with and without amiodarone administration. The onset heart rate with TWA was lower and the alternans voltage was higher with amiodarone than without it. The effects of amiodarone appeared to be related to the exacerbation of VT and an increased defibrillation threshold. TWA might be useful in predicting the proarrhythmic effects of amiodarone in similar cases.

Amiodarone↗
PubMed2001

[The significance of early detection for prostate cancer in mass screening].

PURPOSE: In Mitaka city, mass screening for prostate cancer was conducted for 3 years from 1995 to 1997. Clinical stages were compared between patients found by screening and those diagnosed at our clinic during the same time. The significance of serum-free prostate specific antigen (PSA) in mass screening for prostate cancer was examined. MATERIAL AND METHODS: A prospective clinical trial was conducted on men aged 50 years or older. The primary examination consisted of taking the international prostate symptom score, quality of life score, PSA (Tandem-R) and digital rectal examination (DRE). If PSA was greater than 4.0 ng./ml and/or if DRE suggested cancer, transrectal ultrasound-guided sextant prostate biopsies were indicated. RESULTS: Of the men screened, 23.2% (320/1375) had serum PSA greater than 4.0 ng./ml. and/or suspicious findings on DRE. Biopsy was performed in 199 of 320 (62.1%). Cancer was detected in 21 (1.5%, 21/1375). Prostate cancer was found in one case among 154 males (0.65%, 1/154) who were screened twice or more. The cancer stage found by screening was significantly earlier than that diagnosed at the outpatient clinic (Wilcoxon's rank-sum test: p = 0.0047). Receiver operating characteristics analysis showed that the optimal free PSA-to-PSA ratio was 12%. Positive predictive value increased from 18% to 50% when free PSA-to-PSA ratio was combined with PSA. CONCLUSION: 1. Cancer detection rate was 1.5% in the mass screening in Mitaka City. 2. Cancer stage found by screening was significantly earlier than that diagnosed at the outpatient clinic. 3. Free PSA determination might eliminate unnecessary biopsies in men with PSA above 4.0 ng./ml with minimal loss of cancer detection.

Aged↗
PubMed2001

[Comparisons of factors affecting voiding disorders between patients with benign prostate hyperplasia and volunteers].

PURPOSE: The prostate size and motivation to visit clinics were investigated in patients with prostate hyperplasia. OBJECTS AND METHODS: One hundred ninety-five patients who had urinary symptoms and visited our outpatient clinic between September 1994 and October 1999 and 268 age-matched volunteers in Mitaka City who underwent a medical examination of the prostate in June 1997 were compared. International Prostate Symptom Score (IPSS), Quality Of Life Score (QOL score), residual urine volume, prostate volume and urinary flow rate were measured. RESULTS: The prostate volume of the volunteers was 20-25 cm3 irrespective of the age. The prostate size of the outpatients was larger than that of the volunteers for every age group. IPSS and QOL score were significantly higher in the outpatients than in the volunteers. Diurnal urinary frequency and sense of residual urine contributed to the discrimination index of the two groups more significantly than the other scores. There was a significant correlation between prostate volume and residual urine volume. The score of weak urinary steam was inversely and significantly correlated with peak urinary flow rate. CONCLUSIONS: There was no age-related enlargement of the prostate gland. The prostate gland was significantly larger in the patients than in the volunteers even in those in their fifties. Urinary frequency and sense of residual urine are important factors for men to seek and receive medical care.

Adult↗
PubMed2001

[T-cell prolymphocytic leukemia complicated by diffuse large B-cell lymphoma of the stomach].

We describe a case of T-cell prolymphocytic leukemia (T-PLL) in a 76-year-old man, who developed diffuse large B-cell lymphoma (DLBL) of the stomach, a previously unreported occurrence. The patient was referred to our hospital because of marked leukocytosis (40,000/microliter) without clinical symptoms. He was diagnosed as having T-PLL on the basis of the characteristic cell morphology and immunophenotype (CD2+, CD3+, CD4+, CD5+, CD7+, CD8-, CD25-, TCR alpha/beta+), but cytogenetic analysis showed no abnormalities. Fifteen months later, he developed a gastric tumor. Biopsy of the tumor revealed DLBL without features of MALT lymphoma; Helicobacter pylori was not detected. Chemotherapy eradicated the tumor, whereas the T-PLL was resistant to the therapy. The disease showed an indolent course for about 2 years thereafter. Immunological derangement due to T-PLL might have potentiated the development of DLBL in this case.

Aged↗
PubMed2001

[Combination effect of arbekacin and cefepime on mixed culture of MRSA and P. aeruginosa].

We investigated the in vitro combination effects of arbekacin (ABK), vancomycin (VCM) or teicoplanin (TEIC) and cefepime (CFPM) on methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa isolated from various clinical specimens. Using checkerboard titration technique by agar dilution, combinations of ABK, VCM or TEIC and CFPM exhibited synergistic effects on 25 MRSA strains. The similar effects were also observed on ABK-resistant MRSA. Combination of ABK and CFPM exhibited a good effect on P. aeruginosa, but combinations of VCM or TEIC and CFPM exhibited no synergistic effect on P. aeruginosa. In vitro bactericidal activities of ABK, VCM or TEIC and CFPM against mixed cultures of MRSA with P. aeruginosa were examined at concentration of each drug that corresponds to the serum concentration at 3 hours after the usual therapeutic dosage. VCM or TEIC alone showed bacteriostatic effects against MRSA, and no enhancements were observed when combined with CFPM. ABK alone showed good bactericidal activity against MRSA and combination with CFPM enhanced the bactericidal activity. Against P. aeruginosa, ABK or CFPM alone showed the bactericidal activity, and strong bactericidal activity was induced by the combination of ABK and CFPM. VCM and TEIC showed no bactericidal activities against P. aeruginosa. When CFPM combined with VCM or TEIC, the bactericidal activity of CFPM was not enhanced against P. aeruginosa.

Aminoglycosides↗
PubMed2001

[Effect of arbekacin on the production of toxic shock syndrome toxin 1 by methicillin-resistant Staphylococcus aureus].

The effect of arbekacin (ABK), vancokmycin (VCM) and teicoplanin (TEIC) on the production of toxic shock syndrome toxin-1 (TSST-1) by methicillin-resistant Staphylococcus aureus was examined. In logarithmic-phase cultures, ABK, VCM and TEIC inhibited TSST-1 production by 85, 10 and 25%, respectively, at the concentration of one-fourth the each MIC. In stationary-phase cultures, ABK inhibited TSST-1 production by 50% or 90% compared with the control at the concentration of 4.0 micrograms/ml or 5.0 micrograms/ml respectively. VCM and TEIC did not inhibit TSST-1 production at the concentration of 8.0 micrograms/ml or lower. In human blood cultures, TSST-1 production was inhibited by ABK by 50% at 0.04 microgram/ml (1/256 of Cmax), but not inhibited by VCM and TEIC at the concentration of 1/16 of Cmax or lower. It has been already known that ABK has higher bactericidal activity than VCM and TEIC. ABK combined the inhibition of TSST-1 production with high bactericidal activity in both bacterial growth phases, and therefore ABK should be considered for the treatment of TSST-1-mediated MRSA-infection.

Aminoglycosides↗
PubMed2001

[Bactericidal activity of biapenem against various bacteria].

The bactericidal activity of biapenem (BIPM), a new carbapenem agent, against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Serratia marcescens was compared with those of imipenem (IPM), panipenem (PAPM), meropenem (MEPM) and ceftazidime (CAZ). The bactericidal activity of BIPM against S. aureus was equal to those of IPM, PAPM and MEPM. Against E. coli and K. pneumoniae, BIPM showed higher bactericidal activity than IPM and PAPM. Against P. aeruginosa, BIPM showed excellent bactericidal activity campared with IPM. The killing speeds of BIPM and IPM were obviously the most rapid among four carbapenems. BIPM showed a strong bactericidal activity against 5 species of bacteria including P. aeruginosa.

Bacteria↗
PubMed2000

Clinical and Experimental Observation of Glistening in Acrylic Intraocular Lenses.

Purpose: To study whether the glistening on implanted acrylic intraocular lenses increases or not.Method: 1. Prospective study: We studied the glistening on 49 implanted acrylic intraocular lenses, particularly the time of appearance and increase after glistening appeared. 2. Experiment: We kept an intraocular lens immersed in saline solution at 50 degrees centigrade for 2 hours and then moved this lens into saline solution at 35 degrees centigrade, and observed this lens during immersion.Results: 1. Prospective study: Glistening was present in 28 eyes (57%), and appeared from 2 to 16 months postoperatively. A few months after appearance it become stable and did not increase further. 2. Experiment: On the 10th day after observation, we could see glistening on the lenses. The points of glistening were 10 µm or less in size, and did not change during 60 days of observation.Conclusion: The glistening in acrylic intraocular lenses seemed to become stable a few months after appearance. This our experimental method is useful, because it gives us glistening similar to clinical cases in a short time.

Journal Article↗
PubMed2000

Value of reverse transcription polymerase chain reaction assay in pathological stage T3N0 prostate cancer.

BACKGROUND: We tested the ability of the nested reverse transcription polymerase chain reaction (RT-PCR) assay to detect signs of biochemical recurrence of prostate cancer in the lymph nodes and peripheral blood of patients with pT3N0 prostate cancer. METHODS: Using lymph nodes and pre- and postoperative peripheral blood dissected from 30 patients with pT3N0 prostate cancer treated by radical prostatectomy, we used RT-PCR for prostate-specific membrane antigen (PSM) and serum prostate-specific antigen (PSA) to determine the presence of prostate cancer. Results of the nested RT-PCR assay were compared with pathological stages and biochemical recurrence. RESULTS: Two of 13 patients with capsular penetration (15%), 6 of 10 patients with invasion of seminal vesicles (60%), and 3 of 7 patients with a positive surgical margin (43%) were RT-PCR-positive for PSM and/or PSA in the lymph nodes. Results of preoperative RT-PCRs of peripheral blood for PSM and for PSA significantly differed between positive and negative results of RT-PCR in lymph nodes (P < 0.001 and P < 0.001, respectively). Results of postoperative RT-PCRs of peripheral blood for PSM and for PSA also significantly different between positive and negative results of RT-PCR in lymph nodes (P = 0.011 and P = 0.001, respectively). Nine of 11 patients with positive nested RT-PCR for PSM and/or PSA in the lymph nodes (82%) experienced biochemical recurrence. Significant difference in Kaplan-Meier recurrence-free actuarial curves was noted between patients who nested positive and negative on RT-PCR in the lymph nodes, pre- and postoperative peripheral blood, biopsy and prostatectomy Gleason score, and preoperative PSA values. In multivariate analysis, biopsy and prostatectomy Gleason score (P = 0.026, P = 0.020, respectively), pre- and postoperative RT-PCR for PSM in peripheral blood (P = 0.030 and P = 0.040, respectively), and RT-PCR for PSM in lymph nodes (P = 0.035) were independent prognostic factors. CONCLUSIONS: Nested RT-PCR assay of the lymph nodes or peripheral blood significantly predicted biochemical recurrence after surgery. It may help identify patients at risk for recurrence and progression of prostate cancer.

Aged↗
PubMed2000

Dominant negative isoform of the Ikaros gene in patients with adult B-cell acute lymphoblastic leukemia.

Gene targeting studies in mice have shown that the transcription factor Ikaros plays an essential role in lymphoid development and as a tumor suppressor in T cells, whereas the related gene Aiolos functions as a tumor suppressor in B cells. We analyzed the expression levels of the Ikaros gene family, Ikaros and Aiolos, in human bone marrow samples from patients with adult acute lymphoblastic leukemia [ALL (n = 46; B-cell ALL = 41; T-cell ALL = 5)]. Overexpression of the dominant negative isoform of Ikaros gene Ik-6 was observed in 14 of 41 B-cell ALL patients by reverse transcription-PCR, and the results were confirmed by sequencing analysis and immunoblotting. None of the other dominant negative isoforms of the Ikaros gene were detected by reverse transcription-PCR analysis. Southern blotting analysis with PstI digestion revealed that those patients with the dominant negative isoform Ik-6 might have small mutations in the Ikaros locus. We did not detect any overexpression of dominant negative isoforms of Aiolos in adult ALL patients. These results suggest that Ikaros plays a key role in human B-cell malignancies through the dominant negative isoform Ik-6.

Adolescent↗
PubMed2000

Multi-impulsivity among bulimic patients in Japan.

OBJECTIVE: Studies in Western world patients suggest the possible existence of a subgroup of patients with bulimia nervosa (BN) who display multiple problems with impulsivity, such as suicidal attempts. We assessed impulsive behaviors among BN patients in Japan to discuss them crossculturally. METHOD: Impulsive behaviors in 64 BN patients were assessed and multi-impulsivity (MI) was defined according to the definition proposed by Fichter, Quadflieg, and Rief (Psychological Medicine, 24, 591-604,1994). RESULTS: Nineteen patients (30%) met the definition of MI. BN patients with MI had more severe clinical features, such as concurrent depressive and anxious symptoms, global functioning, and higher prevalence of borderline personality disorder than BN patients without MI. DISCUSSION: These results showed the similarities between BN patients with MI in Japan and those patients in the Western world in clinical and psychopathological characteristics and a life-time incidence of each impulsive behavior. These findings may suggest culturally free bases for linkage between BN and MI.

Adult↗
PubMed2000

Comparative study of pulsed dye laser and pneumatic lithotripters for transurethral ureterolithotripsy.

BACKGROUND: Clinical effectiveness and safety of the Swiss Lithoclast (Lithoclast) and the Candela MDL-2000 (MDL) in the treatment of lower ureteral stone were examined retrospectively. METHODS: Eighty-six stones from 66 patients and 26 stones from 20 patients were treated by Lithoclast and MDL, respectively. RESULTS: The stone-free rate on 3-month follow-up was 97% and 95% for the Lithoclast and MDL, respectively (no significant difference). The operation time was significantly shorter for the Lithoclast than for the MDL (90.2+/-50.2 vs 120.4+/-55.1 min; P<0.05). Postoperative analgesics were required significantly less frequently in Lithoclast (10/66 vs 11/20; P<0.01). Postoperative hospital stay was significantly shorter for Lithoclast (8.7+/-5.1 vs 12.1+/-4.2 days; P<0.01). CONCLUSIONS: Swiss Lithoclast is an effective and less invasive modality for endoscopic treatment of lower ureteral stones.

Adult↗
PubMed2000

The significance of the free-to-complexed prostate-specific antigen (PSA) ratio in prostate cancer detection in patients with a PSA level of 4.1-10.0 ng/mL.

OBJECTIVE: To compare the ratio of free prostate specific antigen (fPSA), total PSA (tPSA) and complexed PSA (cPSA, measured using a novel immunoassay) with other variables used to detect prostate cancer in patients with intermediate serum PSA levels of 4.1-10.0 ng/mL. PATIENTS AND METHODS: From July 1997 to August 1998, 140 consecutive patients were assessed; all had intermediate serum PSA levels and/or abnormal findings on a digital rectal examination. All patients underwent transrectal ultrasonography (TRUS)-guided biopsy, and the prostate and transition zone volumes were determined by TRUS. Free and tPSA were measured using the Tandem-R assay (Hybritech Corp., San Diego, CA). PSA complexed with alpha1-antichymotrypsin (cPSA) was measured using an appropriate assay. The ability of cPSA, free-to-total PSA ratio (f/tPSA), free-to-complexed PSA ratio (f/cPSA), tPSA density of the whole prostate (PSAD), of the transition zone (tPSATZ), and cPSA density of the whole prostate (cPSAD) and of the transition zone (cPSATZ) to improve the power of PSA in detecting prostate cancer was evaluated using receiver operating characteristic (ROC) curves. Results Of the 140 patients, 126 had histologically confirmed benign disease and 14 had prostate cancer. The cPSA alone had better specificity for detecting prostate cancer than had tPSA alone but the difference was not significant. The area under the ROC curve for f/cPSA was larger than those for all other variables. With a 93% sensitivity for detecting prostate cancer, a f/cPSA threshold of 25% would result in fewer unnecessary biopsies (40% f/cPSA specificity) than with all other PSA variables. The difference in the resolution was significant between f/cPSA and tPSA, cPSA, tPSAD and tPSATZ, but not with f/tPSA, cPSAD or cPSATZ. In patients with a prostate volume of < 30 mL, the cPSATZ showed better specificity for prostate cancer than tPSA alone. CONCLUSION: Measuring the level of cPSA and its derivatives may provide better differentiation of prostate cancer and benign disease than tPSA alone in patients with a tPSA level of 4.1-10.0 ng/mL.

Aged↗