Biomedical subjects

Tetsuya Imamura

Publications and source records attributed to Tetsuya Imamura.

4 recordsLinked to original sources

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

[Photoselective vaporization of the prostate (PVP) using 80 watt high power potassium-titanyl-phosphate (KTP) laser for benign prostatic hyperplasia: the first fifty-seven patients in Japan].

OBJECTIVE: To assess the safety and efficacy of photoselective vaporization of the prostate (PVP) using 80 watt high power potassium-titanyl-phosphate (KTP) laser for benign prostatic hyperplasia (BPH). METHODS: Fifty-seven patients with lower urinary tract symptoms secondary to benign prostatic hyperplasia underwent 80 W KTP laser vaporization of the prostate. According to their International Prostate Symptom Score Index (IPSS) and Quality of life (QOL) score as well as measurements of their peak flow rate and postvoiding residual urine volume (RUV), they fulfilled the diagnostic criteria of BPH. Vaporization was performed with the GreenLight PV ADDStat fiber, which was inserted through a 22.5Fr. continuous flow laser cystoscope, and a saline solution was used for irrigation. KTP laser energy was generated by a GreenLight PV (Minnetonka, Minnesota) generator. The end point of the procedure was to create a cavity like in TURP. Once vaporization was completed, an18Fr Foley catheter was inserted and was removed the next morning, as a rule. Patients were evaluated preoperatively, and at 2 weeks and 1, 3 and 6 months postoperatively. RESULTS: The procedure could be performed without any intraoperative complication. None of the patients required continuous bladder irrigation or blood transfusion postoperatively. The mean age was 71.0 +/- 8.3 years (range 52 to 86). The preoperative prostate volume was 41.0 +/- 24.9 (mean +/- SD, range 6.7 to 107.2) and the preoperative serum PSA was 4.5 +/- 4.1 ng/ml. Preoperative and immediate postoperative serum sodium concentration was 141.9 +/- 1.8 mEq/L and 142.2 +/- 1.8 mEq/L, respectively (p = 0.23). The hemoglobin value changed from 14.0 +/- 1.4 mg/dl preoperatively to 13.4 +/- 1.4 mg/dl postoperatively. The operating time was 68.3 +/- 35.0 minutes (range 21 to 170) and total laser energy was 171.1 +/- 80.3 kJ (range 18.1 to 484.8). The catheter indwelling time was 18.6 +/- 3.3 hrs (range 15 to 48). At 2 weeks and 1, 3 and 6 months the International Prostate Symptom Score decreased from 20.2 +/- 8.9 to 11.4 +/- 7.8, 9.3 +/- 6.0, 6.6 +/- 5.0 and 6.1 +/- 5.0, respectively. The maximum urinary flow increased from 7.2 +/- 2.9 mL/s to 13.6 +/- 7.6, 12.2 +/- 6.1, 15.3 +/- 7.4, and 15.3 +/- 7.5 mL/s, respectively. CONCLUSIONS: Photoselective vaporization of the prostate (PVP) using the high power (80 W) potassium-titanyl-phosphate laser for benign prostatic hyperplasia (BPH) proved to be an effective and safe procedure for our patients.

Aged↗

PubMed2003

A simple method for forming embryoid body from mouse embryonic stem cells.

We proposed a simple method for forming an embryoid body (EB) from mouse embryonic stem (ES) cells using a polypropylene 1.5-ml conical tube with a screw cap. An ES cell suspension containing 2 x 10(4) cells was incubated in a conical tube. After 5 d of incubation, a single EB of 440 microm average diameter was formed in the conical tube. The formation efficiency of EB, which is the ratio of the number of tubes showing EB formation to the number of tubes seeded with ES cells, was greater than 99% in the conical tube, while it was approximately 60% in a hanging drop culture. The 5-day-old EB formed by the conical tube method had a sufficient differentiation ability. The beating of the cardiac muscle was microscopically observed in the populations derived from the 5-day-old EB.

Journal Article↗

PubMedDate not supplied

Embryonic stem cell-derived embryoid bodies in three-dimensional culture system form hepatocyte-like cells in vitro and in vivo.

Pluripotent embryonic stem (ES) cells can be a source of hepatocytes for bioartificial livers or transplantation. In this study, embryoid bodies (EBs) were formed from ES cells cultured in polypropylene conical tubes. The EBs were then inserted into a collagen scaffold three-dimensional culture system and stimulated with exogenous growth factors and hormones to induce hepatic histogenesis. The EB-derived cells expressed liver-specific genes, and albumin-positive cells formed cord-like structures that were not present in two-dimensional monolayer culture systems. However, these albumin- positive cells were not cytokeratin 18 positive. Electron microscopy showed immature hepatocyte- like cells having tight junctions, rough endoplasmic reticulum, and intercellular canaliculi. The scaffold including EB-derived hepatocyte-like cells was transplanted into the median lobes of partially hepatectomized nude mice. After 7 and 14 days, cells positive for both albumin and cytokeratin 18 appeared in the transplant and formed clustered aggregates. Thus the collagen scaffold three-dimensional culture system and the liver regeneration environment induced hepatocyte-like cells and hepatic lobule-like aggregates from EBs. Therefore, differentiating EBs in the scaffold culture system may be useful in developing bioartificial livers, secondary livers, and as pharmaceutical models.

Animals↗