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Tsuyoshi Nakayama

Publications and source records attributed to Tsuyoshi Nakayama.

8 recordsLinked to original sources
PubMed2006

Circumventing air bubbles in microfluidic systems and quantitative continuous-flow PCR applications.

Polymerase chain reaction (PCR) is an essential part of research based on genomics or cell analysis. The development of a microfluidic device that would be suitable for high-temperature-based reactions therefore becomes an important contribution towards the integration of micro-total analysis systems (muTAS). However, problems associated with the generation of air bubbles in the microchannels before the introduction of the assay liquid, which we call the "initial start-up" in this study, made the flow irregular and unstable. In this report, we have tried to address these problems by adapting a novel liquid-flow method for high-temperature-based reactions. A PDMS-based microfluidic device was fabricated by soft-lithography techniques and placed on a cartridge heater. The generation of the air bubbles was prevented by introducing the fluorinated oil, an inert and highly viscous liquid, as the cap just before the introduction of the sample solutions into the microchannels. The technique was applied for continuous-flow PCR, which could perform PCR on-chip in a microfluidic system. For the evaluation of practical accuracy, plasmid DNA that serves as a reference molecule for the quantification of genetically modified (GM) maize was used as the template DNA for continuous-flow PCR. After PCR, the products were collected in a vial and analyzed by gel electrophoresis to confirm the accuracy of the results. Additionally, quantitative continuous-flow PCR was performed using TaqMan technology on our PCR device. A laser detection system was also used for the quantitative PCR method. We observed a linear relationship between the threshold cycle (Ct) and the initial DNA concentration. These results showed that it would be possible to quantify the initial copies of the template DNA on our microfluidic device. Accurate quantitative DNA analysis in microfluidic systems is required for the integration of PCR with muTAS, thus we anticipate that our device would have promising potential for applications in a wide range of research.

DNA↗
PubMed2006

Thrombolytic therapy for traumatic unilateral renal artery thrombosis.

We report a case of traumatic unilateral renal artery thrombosis that was successfully treated by thrombolytic therapy. The patient was a 17-year-old woman, who had put her left upper abdomen between a wall and the handle of a ground roller when using it. A computed tomography scan with intravenous contrast showed a lack of contrast in the left kidney. Angiography showed complete occlusion of the left renal artery, and the diagnosis was traumatic left renal artery thrombosis. Following angiography, thrombolytic therapy was performed. Urokinase was administered into the left renal artery, and 360,000 units per 1.5 h was required. Thrombus disappeared and flow of left renal artery was observed. Recovery of left renal function was seen on renoscintigraphy. Surgical maneuvers for traumatic renal artery thrombosis are autotransplantation or thrombectomy generally, but we think that thrombolytic therapy following angiography is a less invasive method and saves warm ischemic time.

Adolescent↗
PubMed2006

Alveolar soft-part sarcoma of the retroperitoneum.

A 33-year-old woman was referred to Iida Municipal Hospital because of left back pain. Computed tomography showed a tumor (17 x 11 x 10 cm) in the left retroperitoneal space. T1- and T2-weighted magnetic resonance imaging showed an inhomogeneous mass with marginal blood vessels. The tumor was resected via lumbar oblique incision with the thoraco-abdominal approach. The tumor weighed 1800 g and consisted of nests of 5-100 large, loosely arranged, polygonal cells, surrounded by capillaries, resembling alveoli. The tumor cells were rich in cytoplasm, containing periodic acid-Schiff- and diastase-positive granules and typical crystals. The pathological diagnosis was alveolar soft-part sarcoma (ASPS). Alveolar soft-part sarcoma is a rare soft-tissue tumor that accounts for approximately 0.5-1% of soft-tissue sarcomas. Such tumors originating in the retroperitoneal space are extremely rare. Herein is reported a case of ASPS of the retroperitoneum with radiological and pathological findings.

Adult↗
PubMed2006

Effects of goshajinkigan (niu-che-sen-qi-wan) for resiniferatoxin-sensitive afferents on detrusor overactivity induced by acetic acid in conscious rats.

This study was performed to investigate the effects of goshajinkigan, a traditional Chinese herbal mixture, in conscious rats undergoing continuous cystometry. Systemic resiniferatoxin (RTX) pretreatment can block resiniferatoxin-sensitive (C-fiber) nerve-mediated bladder overactivity, such as that induced by intravesical administration of acetic acid. The effects of pretreatment with goshajinkigan and RTX alone or in combination on acetic acid-induced bladder overactivity in conscious rats were also compared. Female SD rats were divided into four groups. Groups 1 and 3 received normal food for 4 weeks, while groups 2 and 4 received goshajinkigan (0.09 g/kg/day) during the same period. Two days after bladder catheterization, groups 3 and 4 received RTX (0.3 mg/kg) injection, while groups 1 and 2 received vehicle alone. Cystometric investigations were performed on all animals 24 hours after RTX or vehicle injection. The effects of intravesical instillation of acetic acid (pH = 4.0) were compared with those of intravesical saline. Goshajinkigan significantly increased threshold pressure, voiding interval, micturition volume, and bladder capacity. Intravesical instillation of acetic acid induced bladder overactivity in both normal rats and in those pretreated with goshajinkigan. However, the effects of acetic acid on voiding interval and micturition volume were significantly different between rats given normal diet and those pretreated with goshajinkigan. The effect of acetic acid was not different between goshajinkigan- and RTX-pretreated rats. The results of the present study indicated that goshajinkigan increases voiding interval, micturition volume, and bladder capacity, and pretreatment with goshajinkigan partially blocks the bladder overactivity induced by intravesical administration of acetic acid in rats.

Acetic Acid↗
PubMed2006

[The serum concentration of interleukin-2 in a hemodialysis patient--report from interleukin adjuvant therapy for local recurrent renal cancer].

We started interleukin-2 (IL-2) adjuvant therapy after resection of a repeated local recurrence of renal cell carcinoma in a hemodialysis patient. It is reported that IL-2 is mainly metabolized in proximal tubules of the kidney. To determine the IL-2 concentration, we employed the ELISA method using anti-human IL-2 antibodies. At the concentration of 350,000 Japan reference unit (JRU) in a hemodialysis patient, the change in serum IL-2 was almost the same speed compared to 700,000 JRU in normal renal function patients, which was reported previously. This report may also be a good tool to define the ideal dose of IL-2 in hemodialysis patients.

Adjuvants, Pharmaceutic↗
PubMed2005

Prostate-specific antigen, Gleason sum and clinical T stage for predicting the need for radionuclide bone scan for prostate cancer patients in Japan.

AIM: In the present study, we evaluated the relationships between prostate-specific antigen (PSA) level and bone metastasis, between Gleason sum and bone metastasis, and between clinical T stage and bone metastasis in Japanese patients. METHODS: Between November 1998 and June 2004, we performed ultrasound-guided biopsies on 709 patients (mean age: 70.5 years, range: 39-90). Prostate cancer was detected in 339 patients (47.8%), 297 (87.6%) of whom underwent a radionuclide bone scan. In close collaboration with orthopedists, bone computed tomography scans, bone magnetic resonance imaging and/or plain rentogenograms were performed for cases that were difficult to diagnose as bone metastasis through radionuclide bone scans only. RESULTS: We detected 61 (20.6%) bone metastasis cases in 296 patients. A simple linear regression analysis between log[PSA] and bone metastasis (n = 296) produced a significant relationship (P < 0.05). When we set the cut-off PSA value for the indication for a bone scan at 15 ng/mL, the possibility of bone metastasis was 10%. However, from our experience, there was no bone metastasis in the patients whose Gleason sums were less than five, and in the patients whose Gleason sum were five or more, and the PSA levels were less than 15, there was no bone metastasis. The rate of bone metastasis increased with the increase of PSA level. In the clinical T1-T2 stage cases, there were significant higher PSA levels in the cases with bone metastasis. In the T1-T2 patients whose PSA levels were less than 16, there was no bone metastasis. CONCLUSIONS: From the analysis of PSA, Gleason sum and clinical T stage, we suggest that bone scan is unnecessary for patients whose PSA level is less than 15 ng/mL or Gleason sum is less than five.

Adult↗
PubMed2002

[Hepatic arterial infusion of high-dose 5-FU to liver metastases--case reports of 6 patients with abnormal laboratory data on liver function].

Six patients with metastatic liver cancer (H3) and abnormal laboratory data for liver function underwent intra-hepatic arterial infusion (H.A.I.) therapy of high dose 5-FU (1 g/body/day, 6 days/week, 1q for 2 patients, 2q for 4 patients, with at least a one week interval). No serious side effects were observed in any case. Even in 2 cases with suspicious partial obstruction of the portal vein, no remarkable change in liver function was observed after high dose 5-FU H.A.I. therapy. Four patients who received 12 g of 5-FU showed a reduction in the abnormal data after a short transient rise in some cases. In 2 cases the reduction rate was high and the laboratory data were normalized in 3 months. A long PR was obtained in these cases. The other 2 cases, on the other hand, showed a low reduction rate and the liver function relapsed in a week. Tumor markers also returned to previous levels in a short period. These findings together imply that the reduction rate of abnormal liver function data might predict the efficacy of high dose 5-FU H.A.I. therapy.

Aged↗