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Biomedical subjects

Y Hayase

Publications and source records attributed to Y Hayase.

At least 19 recordsLinked to original sources
PubMed2006

Cervicothoracic malignant peripheral nerve sheath tumor in a 12-year-old girl with neurofibromatosis type 1.

We encountered a 12-year-old girl with neurofibromatosis type 1 (NF1) who developed a low-grade cervicothoracic malignant peripheral nerve sheath tumor (MPNST). Computed tomography of the neck showed an elastic firm tumor measuring 7 x 6 x 4 cm and arising from the upper mediastinum. She had no pain or neurological symptoms, but the tumor enlarged to ca. 8 x 8 x 4 cm over the following 7 months. Although we had diagnosed a neurofibroma by preoperative incisional biopsy, the resected tumor showed low-grade MPNST in the central portion of the tumor. In treating a tumor in a patient with NF1, we must recognize that partial biopsies do not necessarily establish a definitive diagnosis and that a growing tumor may indicate malignant transformation.

Child↗
PubMed2005

The influence of mycophenolate mofetil versus azathioprine and mycophenolic acid pharmacokinetics on the incidence of acute rejection and infectious complications after renal transplantation.

PURPOSE: The present retrospective study investigated the influence of mycophenolate mofetil (MMF) instead of azathioprine (AZA) as part of tacrolimus-based immunosuppression. Mycophenolic acid (MPA) pharmacokinetic (PK) parameters were used for associations with the incidence of acute rejection (AR) episodes and infectious complications after renal transplantation. METHODS: The 66 consecutive renal transplant recipients reported herein excluded ABO-incompatible transplants or cytomegalovirus (CMV)-seronegative recipients. The immunosuppressive regimen consisted of tacrolimus, steroids, and AZA 1-2 mg/kg/d in 22 patients (between February 1998 and December 2000) or MMF 2 g/d in 44 patients (since January 2001). CMV infection was defined as positive CMV-antigenemia. MPA PK was studied on day 28 after transplantation in 21 recipients. RESULTS: AR occurred in 13.6% of patients in the MMF group compared with 18.2% in the AZA group. The viral infection (CMV, varicella zoster virus, adenovirus hemorrhagic cystitis, and malignancy related to Epstein-Barr [EB] virus) rate was 22.7% in the MMF group and 0% in the AZA group (P = .015). There were no bacterial or fungal infections observed in the 2 groups. MMF dose per body weight was significantly lower among patients with AR than those without AR (25.1 vs 35.6 mg/kg; P = .026). There were no differences in MPA PK parameters between patients with and without viral infections. CONCLUSIONS: Patients treated with MMF required less treatment for AR, however, there were no significant differences. MMF dose per body weight may play an important role in the occurrence of AR. Although virus infections occurred in recipients treated with MMF, MPA PK did not influence the infectious complications after renal transplantation.

Adult↗
PubMed2002

A study of hypoxic cell radiosensitizer applied to Ehrlich ascite tumour: a comparison of FC43 emulsion and pentoxyfilline.

In this study, we examined the effects of various combinations of treatments involving radiation, injections of perfluorochemicals (FC-43 emulsion) and injections of pentoxifylline on the growth delay of Ehrlich ascite tumours. Ehrlich ascite tumour cells were transplanted into the legs of ddY-strain mice. Tumour-bearing mice were divided into seven groups: group 1, no treatment; group 2, irradiated only; group 3, injected with FC-43 emulsion and kept in a carbogen atmosphere; group 4, injected with pentoxifylline and nicotinamide; group 5, injected with FC-43 emulsion, kept in a carbogen atmosphere and irradiated; group 6, injected with pentoxifylline and nicotinamide and irradiated; and group 7, injected with FC-43 emulsion, pentoxifylline and nicotinamide, kept in a carbogen atmosphere and irradiated. When 20 Gy irradiation was applied, tumour growth delay was 11 days in group 2, 20 days in group 5, 22 days in group 6, and 24 days in group 7. For a growth delay of 20 days, the dose modifying factor was 1.95+/-0.04 (standard deviations) in group 5, 1.97+/-0.09 standard deviations in group 6, and 2.01+/-0.07 standard deviations in group 7. It was concluded that FC-43 emulsion and pentoxifylline did not have an interactive effect.

Animals↗
PubMed2001

Neuronal microdysgenesis and acquired lesions of the hippocampal formation connected with seizure activities in Ihara epileptic rat.

The present study was designed to examine the morphological features of the hippocampal formation in the Ihara epileptic rat (IER), and to characterize genetically programmed lesions and acquired lesions connected with seizure activities. Neuropathological investigation of the hippocampal formation was performed in four separate groups, 2-month-old IERs with neither abnormal behaviors nor any seizure activity, and 12-month-old IERs of both sexes with abnormal behaviors, circling seizures or generalized tonic-clonic convulsions. In every IER examined, there were invariable and fundamental neuropathological findings consisting of abnormal neuronal clusters in the CA1 of the hippocampal formation. Moreover, disarrangement of neuronal cells, such as dispersion and gaps in lamination of pyramidal neurons, were observed. These changes were thought to represent genetically programmed lesions, neuronal microdysgenesis, because they were common findings in 2-month-old and 12-month-old IERs of both sexes. An enlargement of the dentate gyrus was also found in rats that experienced generalized tonic-clonic convulsions or circling seizures. This enlargement of the dentate gyrus, on the other hand, was categorized as a secondary and acquired lesion connected with seizure activities. It is suggested that the neuronal microdysgenesis in the hippocampal formation of IER has an intimate relationship with epileptogenesis and/or an enhancement of seizure susceptibility.

Animals↗
PubMed2001

Transperineal 12-core systematic biopsy in the detection of prostate cancer.

BACKGROUND: The present study was designed to determine the clinical value of transperineal 12-core systematic prostate biopsy guided by transrectal ultrasonography (TRUS) in the detection of prostate cancer. METHODS: A total of 679 consecutive patients underwent systematic prostate biopsies because of abnormal results on digital rectal examination and/or TRUS and/or an elevated serum prostate-specific antigen level. Systematic six- and 12-core biopsies were taken in 138 patients between April 1994 and February 1995 and in the remaining 541 between March 1995 and February 2000, respectively. Twelve-core biopsy included two samples from the lateral portion of the peripheral zone and four from the anterior portion of the transition zone in addition to the conventional six-core biopsy. RESULTS: In the series overall, systematic biopsy revealed 156 cases of prostate cancer (23.0%). The detection rate increased by 5.2%, although this was statistically not significant, from 18.8% (26/138) by six-core biopsy to 24.0% (130/541) by 12-core biopsy. Out of 130 patients in whom prostate cancer was detected by 12-core biopsy, it was supposed that conventional six-core biopsy would have missed 18 cases (13.8%). CONCLUSIONS: Systematic 12-core biopsy might improve the detection rate for prostate cancer. However, further studies are needed to determine its clinical value in the diagnosis of the disease.

Adult↗
PubMed2001

Expansion of megakaryocyte progenitors from cryopreserved leukocyte concentrates of human placental and umbilical cord blood in short-term liquid culture.

Long-term severe thrombocytopenia following human placental and umbilical cord blood (CB) transplantation is a significant clinical problem. We studied the ex vivo expansion of megakaryocytic progenitor cells (CFU-Meg) from cryopreserved/thawed leukocyte concentrates (LC) of CB prepared by the Tokyo Cord Blood Bank protocol. The LC cells were cultured in serum-free culture medium supplemented with a combination of early-acting cytokines including thrombopoietin (TPO), flt3-ligand (FL), and stem cell factor (SCF). Combination of TPO plus FL, TPO plus SCF, and all of these cytokines together resulted in 8.9-, 7.7-, and 8.4-fold increases in CFU-Meg, respectively, by Day 5 of culture. Our results showed that this simple expansion strategy has the potential for expanding CFU-Meg from cryopreserved/thawed LC cells from CB.

Cell Culture Techniques↗
PubMed2001

[Age-related changes in lower urinary tract symptoms and urodynamic parameters in patients with benign prostatic hyperplasia treated by transurethral resection of the prostate].

PURPOSE: To characterize age-related clinical and urodynamic features of patients with benign prostatic hyperplasia (BPH) treated by transurethral resection of the prostate (TUR-P). MATERIALS AND METHODS: Between July 1994 and March 2000, a total number of 451 patients underwent TUR-P in Nagoya Urology Hospital. Out of these 451 patients, 15 (3.3%) were diagnosed as having an incidental prostate cancer on pathological examination of resected prostate tissue. The remaining 436 patients (48-92 years, 69.8 +/- 7.4 years), in whom 196 (45.0%), 208 (47.7%) and 32 (7.3%) were < or = 69, 70-79 and > or = 80 years, respectively, were subjects for the present study. Their clinical features before and after TUR-P and the therapeutic effects of the treatment were evaluated in terms of aging. RESULTS: Among preoperative variables evaluated, IPSS in patients aged < or = 69 years was significantly higher than in those aged 70-79 years (p < 0.05). The QOL index was significantly higher in patients aged > or = 80 years than in those aged 70-79 years (p < 0.05). The maximum bladder capacity decreased with age from 276 ml in patients aged < or = 69 years to 211 ml in those aged > or = 80 years. Postoperatively, both maximum and mean flow rates were significantly lower in patients aged 70-79 and > or = 80 years compared to those aged < or = 69 years. There was, however, no significant age-related difference in IPSS and QOL index. The assessment of treatment effects at 3 months following TUR-P revealed that the outcomes in function as evaluated by uroflowmetry, anatomy and ultrasonic measurement of prostate volume were significantly worse in patients aged > or = 80 years compared to those in younger patients. However, there was no significant age-related difference in outcomes in subjective symptoms and QOL. CONCLUSIONS: TUR-P could be performed safely even in patients aged > or = 80 years. It is concluded that although postoperative urinary condition might be worse in older patients, they would nevertheless be satisfied with the results of TUR-P in the same way as less aged patients. As long as subjects are selected properly based on the correct diagnosis of BPH and a sufficient evaluation of operation risks, TUR-P can be expected to be performed safely and be followed by satisfaction with the treatment effects.

Aged↗
PubMed2001

[A case of infravesical obstruction caused by prostatic stones as diagnosed by transrectal ultrasonography at voiding].

A 69-year-old patient, who had been treated using alpha 1-blocker for benign prostatic hyperplasia (BPH) at another clinic, visited our clinic due to persistent difficulty in urination. Total International Prostate Symptom Score (IPSS) was 32 points and quality of life (QOL) index was 5. Uroflowmetry demonstrated maximum urinary flow rate and average urinary flow rate to be 9.2 ml/sec and 5.1 ml/sec, respectively, with 3 ml of residual urine volume. Transrectal ultrasonography (TRUS) revealed prostatic stones but not BPH. Retrograde urethrography demonstrated nothing abnormal other than prostatic stones. TRUS at voiding phase using linear probe (voiding TRUS) revealed poor opening of the urethra surrounded by prostatic stones. As a result, the cause of urinary disturbance was diagnosed to be due to urethral obstruction caused by prostatic stones, and transurethral resection of prostatic tissue with stones was performed. Postoperatively, IPSS decreased to 10 points and QOL index to 2. Maximum urinary flow rate also improved to 18.1 ml/sec and mean urinary flow to 8.4 ml/sec. Thus, voiding TRUS is likely the best urodynamic test for clinical use in determining the etiology of obstruction at posterior urethra.

Aged↗
PubMed2000

Self-replicating pulses and sierpinski gaskets in excitable media

In our previous papers, we have shown by computer simulations that a Sierpinski gasket pattern appears in a Bonhoeffer-van der Pol type reaction-diffusion system. In this paper, we show another class of regular self-similar structure which is found in four different excitable reaction-diffusion systems. This result strongly implies that the existence of the self-similar spatiotemporal evolution is universal in excitable reaction-diffusion media.

Journal Article↗
PubMed2000

Effect of murine kidney extracts on the proliferation of hematopoietic progenitor cells in human umbilical cord blood.

We examined the effect of murine kidney extract (MKE) on the clonal growth of highly purified CD34+ hematopoietic progenitor cells from human umbilical cord blood. MKE did not affect the total number of colonies of erythroid burst-forming units (BFU-E), granulocyte-macrophage colony-forming units (CFU-GM) or granulocyte-erythroid-macrophage-megakaryocyte colony-forming units (CFU-Mix/CFU-GEMM) in a methylcellulose culture with exogenous recombinant human granulocyte colony-stimulating factor, granulocytemacrophage colony-stimulating factor, interleukin-3, stem cell factor and erythropoietin. MKE significantly increased the proportion of BFU-E- or CFU-Mix-derived colonies, and suppressed the formation CFU-GM-derived colonies depending on the MKE dose. However, because of an increase in small megakaryocyte colonies derived from mature CFU-Meg MKE increased by approximately 40% the growth of megakaryocyte colony-forming units (CFU-Meg) in plasma clot culture stimulated by recombinant human thrombopoietin. Also MKE promoted an increase in hyperploid megakaryocytes, suggesting that the active factor(s) in MKE acts on the mature CFU-Meg and promotes the maturation of megakaryocytes. Gel-filtration high performance liquid chromatography of MKE showed that the promoting factor(s) in MKE was approximately 45 kDa. These results indicate that the factor(s) detected in MKE influence human hematopoiesis in vitro, especially thrombopoiesis.

Animals↗
PubMed2000

Radiation sensitivity of megakaryocyte colony-forming cells in human placental and umbilical cord blood.

The in vitro radiation sensitivity of CFU-Meg isolated from human placental and umbilical cord blood was evaluated in plasma clot cultures stimulated by recombinant human cytokines, including thrombopoietin, the FLT3 ligand (FLT3LG), interleukin-3, interleukin-11 and stem cell factor. The CD34(+) cells were irradiated with X rays at a dose rate of 73 cGy/ min. The megakaryocyte colonies were identified by using an FITC-conjugated antibody to glycoprotein IIbIIIa and were classified into two groups based on colony size: large colonies (immature CFU-Meg) and small colonies (mature CFU-Meg). Treatment with thrombopoietin alone or in combination with FLT3LG and/or interleukin-11 gave exponential radiation survival curves (D(0) for immature CFU-Meg = 56-77 cGy, D(0) for mature CFU-Meg = 86 cGy-1.12 Gy), while marked shoulders were observed on the survival curves for colonies supported by the combination of thrombopoietin, interleukin-3 and stem cell factor (D(0) for immature CFU-Meg = 89- 98 cGy; D(0) for mature CFU-Meg = 1. 25-1.31 Gy). Our results showed that the immature CFU-Meg were more radiosensitive than the mature CFU-Meg and that the combination of cytokines, including thrombopoietin, interleukin-3 and stem cell factor, affected the radiation sensitivity of CFU-Meg to the same extent as with thrombopoietin alone or in combination with FLT3LG and/or interleukin-11.

Antigens, CD34↗
PubMed2000

Preparation and antimicrobial activity of micacocidin.

Micacocidin (3), a Zn-free derivative of micacocidin A (1), was prepared to evaluate its antimicrobial activity in comparison with 1 and to obtain a starting material for chemical modification of 1. The structure of 3, quite unlike those of any previously known antimicrobial agents, was elucidated by 1-D and 2-D homonuclear and heteronuclear NMR and mass spectroscopy. Micacocidin (3) thus prepared exhibited weak or no antibacterial activity except against Mycoplasma species, i.e. 3 showed stronger activity than 1. It is noteworthy that 3 displayed high activity against fungi such as Candida, Aspergillus and Trichophyton species.

Anti-Bacterial Agents↗
PubMed1999

Mossy fiber sprouting in the dentate gyrus in a newly developed epileptic mutant, Ihara epileptic rat.

We examined the correlation between seizure activity and development of mossy fiber sprouting in the hippocampal formation using Timm staining in a newly developed Ihara epileptic rat (IER). The sprouting of mossy fibers were clearly shown in the inner molecular portion of the dentate gyrus and in the stratum oriens of CA3 pyramidal cell layer with repeated seizures. A positive correlation between the frequency of generalized tonic and clonic convulsions and the Timm staining score in molecular layer of dentate gyrus was revealed. Sprouting of mossy fiber in IER seems to be linked with seizure activities resulting from epileptic bursts, not to the genetic mutation.

Animals↗
PubMed1999

Heparin-binding epidermal growth factor-like growth factor mRNA expression in neonatal rat brain with hypoxic/ischemic injury.

The neuronal expression of mRNA of heparin-binding epidermal growth factor-like growth factor (HB-EGF) was investigated in immature rat brains. Two rat models were used in this study. One was a hypoxic/ischemic (HI) brain injury model, and the other was an N-methyl-d-aspartate (NMDA) intracerebral injection model. The former model was made by permanent ligation of the left carotid artery and subsequent exposure to 2 h of hypoxia. After the HI insult, the HB-EGF mRNA was assessed by a Northern blot analysis. The levels of transcripts for HB-EGF in the cerebral cortex and the hippocampus of the ligated side were significantly higher than those of non-treated rats from 3 to 24 h after the insult. The spatial distribution of the mRNA of HB-EGF was also studied using in situ hybridization. Three to 24 h after the hypoxia, hybridization signals were intense in neuronal cytoplasm on the ligated side, but a focally decreased signal was seen in infarcted areas. Strongly increased mRNA expression was observed in the neurons surrounding the infarct. These results indicate that a neonatal HI insult induces a neuronal upregulation of HB-EGF immediately after hypoxia. In the latter model, the intracerebral NMDA injection also induced an immediate, strong upregulation of HB-EGF transcripts. Our results indicate that HB-EGF may act as a neuroprotective factor in the immature brain with HI injury by modulating the neurotoxic process which is mediated by overactivation of the NMDA receptor.

Animals↗
PubMed1999

Suppression of endothelin system in Vero cells latently infected with influenza virus B/Lee/40.

In Vero cells latently infected with influenza virus B/Lee/40 (L/V cells), the endothelin (ET) system was examined as a possible mediator in pathogenesis of latent viral infection by radioimmunoassay (RIA) and quantitative reverse transcription polymerase reaction (RT-PCR). During viral latency of more than two months, ET secretion, preproendothelin-1 (PPET-1) mRNA, and endothelin receptor subtype A (ETAR) mRNA within the cells remained suppressed. Our data indicate that not only the release of ET-1 was downregulated at the transcriptional level but also ETAR mRNA was downregulated rather than upregulated compensatively in L/V cells.

Animals↗
PubMed1999

Inhibitory effect of murine kidney extracts on the proliferation of murine mast cells.

We examined the effect of murine kidney extract (MKE) on the clonal growth of mast cells from murine peritoneal cells. Adding MKE resulted in a 40% inhibition of colony formation of mast cells in a methylcellulose culture, and a 90% decrease in mast cell numbers and histamine content in mast cells in a liquid culture containing stem cell factor and interleukin-3. The mast cell inhibitory factors in MKE were heat sensitive proteins of approximately 560 and 24 kDa. These results suggest that MKE contains regulators that suppress the growth of murine mast cells and histamine synthesis.

Animals↗
PubMed1999

[Dispersal of pollen and the variation in number of patients prescribed medicine for allergies in Otaru].

The number of patients prescribed medicine for allergies increased in May and September. Therefore, we suspected that the cause for the increase was pollen. Many kinds of pollen occur in Otaru, such as alder in April, Japanese black pine, white birch, acacia, larch in May, oak in June, and mugwort in September. The total number of pollen count of white birch was about 9 times that of mugwort, but the total number of patients prescribed Celestamine in the season of white birch pollen was about 0.8 times that of mugwort pollen. These results seen in Otaru differed from those in neighboring Sapporo. The coefficient of the correlation of the number of mugwort and white birch pollen and those of patients prescribed Celestamine were r = 0.304 and r = 0.766, respectively. We believe that making available information on pollen is very useful to improve the quality of life of patients.

Air Pollutants↗