Search PubMed⌕ Search

Biomedical subjects

I Takenaka

Publications and source records attributed to I Takenaka.

At least 19 recordsLinked to original sources
PubMed2006

Development of torsade de pointes caused by exacerbation of QT prolongation during clipping of cerebral artery aneurysm in a patient with subarachnoid haemorrhage.

We report the case of a 79-yr-old woman with subarachnoid haemorrhage (SAH) in whom torsade de pointes (TdP) caused by worsening the QT prolongation occurred during clipping of cerebral artery aneurysm. This patient shows a potential risk of occurrence of life-threatening tachyarrhythmia, TdP by prolonging the QT interval during surgery in patients with SAH even with no additional factors that predispose to TdP. Therefore, a proper monitoring of the QT interval is necessary as a predictor of TdP. When ventricular tachyarrhythmia occurs, recognition of TdP is important because antiarrhythmic drug therapy for TdP is different from that for ventricular tachyarrhythmias that is not TdP.

Aged↗
PubMed2002

Positive pressure ventilation during fibreoptic intubation: comparison of the laryngeal mask airway, intubating laryngeal mask and endoscopy mask techniques.

BACKGROUND: The efficacy of delivery of mechanical ventilation through different airway devices during fibreoptic intubation is not known. METHODS: We compared the laryngeal mask airway (LMA), intubating laryngeal mask (ILM) and endoscopy mask for positive pressure ventilation (PPV) during fibreoptic intubation. In 80 adult paralysed patients, fibreoptic intubation was performed during PPV using a combination of a size 3 or 4 LMA with a 6.0 mm nasal RAE tracheal tube (LMA3/4 group; n=22), a size 5 LMA with a 7.0 mm nasal RAE tube (LMA5 group; n=18), an ILM with an 8.0 mm special reinforced tracheal tube (ILM group; n=20) or an endoscopy mask (Patil mask) with a 7.5 mm standard tracheal tube (Patil group; n=20). The inspiratory and expiratory tidal volumes (VI and VE) with a ventilation pressure of 20 cm H2O were measured using a pneumotachograph. RESULTS: Mean VE values during fibreoptic intubation in the LMA5 [5.3 (SD 1.5) ml kg(-1)] and ILM [7.1 (2.3) ml kg(-1)] groups were greater than in the LMA3/4 group [2.6 (1.0) ml kg(-1), P<0.0001]. The mean VE was greater in the Patil group [20.6 (4.9) ml kg(-1)] than in the other three groups (P<0.0001). Gastric insufflation during intubation was more frequent in the Patil group (30%) than in the other three groups (4.5-5.6%) (P<0.05). CONCLUSION: PPV is possible with the LMA, ILM or endoscopy mask during fibreoptic intubation. With an airway pressure of 20 cm H2O, ventilation during intubation using a size 3 or 4 LMA was almost insufficient, while ventilation using a size 5 LMA or an ILM was almost acceptable. Ventilation during intubation with the endoscopy mask was greater than that with the LMA or ILM, but gastric insufflation was more frequent.

Adult↗
PubMed2001

Evaluation of cell proliferation, apoptosis, and angiogenesis in transitional cell carcinoma of the renal pelvis and ureter.

OBJECTIVES: To investigate cell proliferation, apoptosis, and angiogenesis and their roles in transitional cell carcinoma (TCC) of the renal pelvis and ureter. METHODS: Formalin-fixed and paraffin-embedded tissue blocks from 42 patients with TCC of the renal pelvis and ureter were studied. Cell proliferation was assessed by Ki-67 immunostaining, and the proliferation index (PI) was expressed as a percentage of Ki-67-positive cells. Apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), and the apoptotic index (AI) was expressed as a percentage of TUNEL positive cells. Angiogenesis was evaluated by CD31 immunostaining, and microvessel density (MVD) was expressed as the average of the microvessel count. RESULTS: The PI ranged from 5.9% to 48.0% (median 20.03%), AI from 1.0% to 4.2% (median 2.26%), and MVD from 16.0 to 146.0 (median 56.88) in TCC of the renal pelvis and ureter. Statistical analysis revealed close associations of both PI and MVD with tumor stage and of AI with tumor grade. Our study demonstrated a strong relationship between PI and MVD, but did not show associations of AI with PI or MVD in TCC of the renal pelvis and ureter. CONCLUSIONS: It is suggested that the high activity of tumor cell proliferation with rich neovascularization may be related to the high malignant potential of the cancer, and evaluation of cell proliferation combined with angiogenesis may be useful in predicting the progression of the renal pelvic and ureteral TCC.

Adult↗
PubMed2001

Apoptotic cell death and Smad4 expression in transitional cell carcinoma of the renal pelvis and ureter.

PURPOSE: To investigate the frequency of apoptosis and the expression of Smad4 protein as well as their roles in transitional cell carcinoma (TCC) of the renal pelvis and ureter. METHODS: Apoptosis was detected by using terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) technique in 34 formalin-fixed and paraffin-embedded specimens of renal pelvic and ureteral TCC. The expression of Smad4 was immunohistochemically studied. RESULTS: The incidence of apoptosis ranged from 1.10 to 3.75% with a median of 2.50% in TCC of the renal pelvis and ureter. The incidence of apoptosis was noted to be closely related to histologic grade but not to pathologic stage of the cancer. The expression of Smad4 was detected in six of 34 cases (17.6%). Regarding subcellular distribution, Smad4 protein was localized both in cytoplasm and nucleus of the cancer cells. In comparing the incidence of apoptosis with the expression of Smad4, no significant associations were seen between them. The expression of Smad4 was not related to the tumor grade nor stage of the cancer. CONCLUSIONS: The present study demonstrated close association of the incidence of apoptosis with the tumor grade of TCC of the renal pelvis and ureter. Significance of Smad4 expression was not noted in the study. It suggests that apoptotic cell death may play an important role in the tumor progression of renal pelvic and ureteral TCC.

Adult↗
PubMed2001

[Metastatic liver tumor arising from prostate cancer following transurethral resection of the prostate--a report of two cases].

We herein present a report of metastatic liver tumor arising from prostate cancer following transurethral resection of the prostate (TUR) in two patients. The two patients were diagnosed as having moderately differentiated prostate adenocarcinoma, either stage C or B2, and underwent hormonal and/or radiation therapy. TUR was performed due to the patients' complaints of urinary outlet obstruction. Liver metastasis, without evidence of bone or pulmonary metastasis, was then noted 23 and 5 months later in the patients with stage C and B2 prostate cancer, respectively. It is possible that the process of TUR is related to the release of tumor cells from the prostate into the systemic circulation and involved in the development of liver metastasis.

Adenocarcinoma↗
PubMed2000

Cell proliferation and apoptosis with BCL-2 expression in renal cell carcinoma.

OBJECTIVES: To investigate cell proliferation, apoptosis, and bcl-2 immunoreactivity in renal cell carcinoma (RCC). METHODS: Formalin-fixed and paraffin-embedded tissue blocks from 70 patients with RCC were studied. Cell proliferation activity was detected by Ki-67 immunostaining and the proliferation index (PI) was expressed as a percentage of the Ki-67-positive cells in the tumor cells. Apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), and the apoptotic index (AI) was expressed as a percentage of the TUNEL-positive cells in the tumor cells. Immunoreactivity of bcl-2 was assessed immunohistochemically and coexpression of Ki-67 with bcl-2 was examined by double immunostaining. RESULTS: The PI ranged from 5.0% to 44.0% (median 19.23%) and the AI from 0.9% to 3.4% (median 2.13%) in RCC. Statistical analysis revealed close associations between PI and tumor grade and stage, and a significant relationship between AI and the tumor grade of RCC. The expression of bcl-2 was detected in 24 (34.3%) of 70 RCCs. Coexpression of Ki-67 with bcl-2 was noted in 3 of the 24 RCCs with bcl-2 expression. The expression of bcl-2 was not related to PI, AI, or the clinicopathologic factors of RCC. CONCLUSIONS: Our observations suggest that active cell proliferation may be accompanied by frequent apoptosis and that cell proliferation as reflected by Ki-67 staining may be the most important parameter of cell turnover in RCC.

Adult↗
PubMed2000

A new method of predicting pulmonary capillary wedge pressure: the arterial pressure ratio.

The response of arterial blood pressure to an increase in intrathoracic pressure has been shown to be predictive of pulmonary capillary wedge pressure. We devised a new method, which we termed the arterial pressure ratio. We defined arterial pressure ratio as the ratio of systolic blood pressure of the final beat during the strain phase of the Valsalva manoeuvre to that during apnoea before the manoeuvre, and tested the accuracy of arterial pressure ratio in predicting pulmonary capillary wedge pressure. In 30 patients scheduled for elective abdominal aortic reconstruction, following induction of general anaesthesia and tracheal intubation, a 20-G catheter and pulmonary artery catheter were inserted through the radial artery and right internal jugular vein, respectively. Pulmonary capillary wedge pressure was then measured during a brief period of apnoea and the Valsalva manoeuvre was performed by application of pressure to the reservoir bag. Airway pressure was maintained at 30 cmH2O for 10 s and then released. Radial arterial pressure and airway pressure were recorded simultaneously, and arterial pressure ratio was calculated. There was a close linear correlation between arterial pressure ratio and pulmonary capillary wedge pressure (r = 0.88, p < 0.0001).

Aged↗
PubMed2000

Spermatogenic disturbance induced by di-(2-ethylhexyl) phthalate is significantly prevented by treatment with antioxidant vitamins in the rat.

Phthalate esters, now regarded as endocrine disruptors, are widely used in the plastics industry. In particular, di-(2-ethylhexyl) phthalate (DEHP) is produced in large quantities, and is used in blood storage bags, catheters and haemodialysis instruments. Previous studies have demonstrated that treatment of rats with DEHP induces testicular atrophy with liver enlargement, although the precise nature and mechanism of the action of DEHP on these organs remains unclear. In the present study, we produced an experimental model of DEHP-induced spermatogenic disturbance in rats by feeding them a DEHP-containing diet. Liver enlargement occurred in rats fed either a 1 or 2% DEHP-containing diet. However, testicular atrophy accompanied by aspermatogenesis was induced by feeding with the 2% but not with the 1% DEHP-containing diet. This suggests that the critical DEHP dose for gonadotoxicity is higher than that for hepatotoxicity. Using the 2% DEHP-dose, the effect of simultaneous administration of antioxidant vitamins (= vitamins C and E) was next examined. It was found that the vitamin supplementation significantly prevented the testicular injury. The results suggest that antioxidant vitamins can protect the testes from DEHP-toxicity.

Animals↗