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Biomedical subjects

T Nakada

Publications and source records attributed to T Nakada.

At least 289 records · Page 16Linked to original sources
PubMed1994

Modulation of the urethral pressure by high-frequency block stimulus in dogs.

Nerve conduction block by high-frequency stimulus has been used as a method to modulate the contractile force of skeletal muscles. This paper describes the effect of block stimulus on the modulation of urethral closure pressure in dogs. Tetanic stimulus was applied through a pair of electrodes wrapped about the bilateral pudendal nerves and high-frequency stimulus was superimposed through another pair of electrodes wrapped about 1 cm distalward along the nerves. Urethral closure pressure was measured through a transurethral UPP catheter. High-frequency stimulus over 300 Hz reduced elevated urethral closure pressure, which was induced by tetanic stimulus, up to 30-45%.

Animals↗
PubMed1994

Alveolar fluid clearance in the resected human lung.

Although the mechanisms responsible for alveolar liquid clearance have been studied in several species, there has not been any information regarding the effect of ion transport agonists or antagonists on alveolar liquid clearance in the human lung. Therefore, we studied alveolar liquid clearance in the recently resected human lung from patients who underwent surgery for lung cancer. A test solution of 40 ml of isosmolar albumin solution was instilled into one segment of a resected lobe within 10 min of resection. Because protein leaves the air spaces very slowly, the concentration of alveolar protein over 4 h was used to quantify alveolar liquid clearance. Basal alveolar liquid clearance was 12 +/- 2% over 4 h. Amiloride (10(-5) M), an inhibitor of apical Na+ uptake, and ouabain (10(-3) M), an inhibitor of Na,K-ATPase activity, reduced alveolar liquid clearance by 40 and 49%, respectively (p < 0.005). Terbutaline (10(-3) or 10(-4) M) doubled alveolar liquid clearance to 28 +/- 9% over 4 h (p < 0.05). Propranolol (10(-4) M) and amiloride (10(-5) M) inhibited the terbutaline-induced increase in alveolar liquid clearance. In conclusion, (1) alveolar liquid clearance in the human lung can be markedly reduced by inhibition of apical sodium channel uptake or Na,K-ATPase activity, and (2) beta-adrenergic stimulation markedly increases the rate of alveolar liquid clearance in the resected human lung without pulmonary perfusion.

Aged↗
PubMed1994

Syalil-SSEA1(SLX) levels in supernatant of cultured human lung carcinoma cell lines.

SLX levels in the culture supernatant of the following 50 cell lines were measured by RIA: pulmonary carcinoma cell lines derived from 46 patients, cell lines of other human cancers derived from 4 patients, and 2 passaged human fibroblast cells as control. Of the 46 pulmonary carcinoma cell lines, 17 (37%) were SLX positive. When the SLX-positive rate was analyzed in relation to the histological type of pulmonary carcinoma, the positive rate was 71% (10/14) for adenocarcinoma, 27% (3/11) for squamous cell carcinoma, 33% (2/6) for large cell carcinoma, 0% (0/11) for small cell carcinoma and 50% (2/4) for adenosquamous cell carcinoma. Analysis of the relationship between tumor cell proliferation and SLX level in 20 patients revealed that the SLX level in the supernatant of SLX-producing cell lines becomes higher in proportion to the increase in the number of these cells. The SLX-positive rate did not differ significantly among different stages of pulmonary carcinoma at the time of tissue collection. There was no significant correlation between SLX production and prognosis. SLX production by each cell line was not correlated with the doubling time of the same cell line in vitro or in vivo (in nude mice). SLX production also showed no correlation with the duration of tumor cell passage.

Adult↗
PubMed1994

Electrical pelvic floor stimulation by percutaneous implantable electrode.

OBJECTIVE: To describe a clinical experience of chronic pelvic floor stimulation using a percutaneous implantable electrode for the treatment of urinary incontinence. PATIENTS AND METHODS: Pelvic floor stimulation using a percutaneous procedure was performed in 10 patients who were suffering from urinary incontinence due to overactive detrusor function. After implantation of the electrode chronic stimulation was instituted with a portable external electrical stimulator. RESULTS: Four to 16 weeks of maximal electrical stimulation improved urinary incontinence in eight of 10 patients. In two of these eight patients incontinence disappeared as measured subjectively. Urodynamic investigations demonstrated a significantly increased volume at the first unstable contraction (P < 0.01) in all patients. One of 30 electrodes migrated during the follow-up period. CONCLUSION: Inhibition of detrusor overactivity was obtained using this procedure. Response appeared to be constant during chronic stimulation. This procedure appears to provide stable and reliable stimulation for chronic treatment of urinary incontinence and may be an alternative to electrical pelvic floor stimulation.

Adult↗
PubMed1994

[Effects of Pseudomonas aeruginosa on transport of protein and liquid from alveolar spaces in anesthetized rabbits].

We determined the effects of Pseudomonas aeruginosa on transport of protein and liquid across the alveolar epithelium in anesthetized rabbits. Following the injection of 3 microCi of 131I-albumin in anesthetized rabbits as a vascular marker, we instilled 3 ml/kg of 5% albumin solution with 10(7) or 10(9) CFU P. aeruginosa, 3 microCi of 125I-albumin and 3 mg of Evans blue into the alveolar spaces of the right lung. The rabbits were ventilated with 60-100% oxygen and 1-2% halothane over 8 h. We removed the lungs and aspirated the alveolar fluid 8 h after instillation. We measured protein concentration in instilled and aspirated alveolar fluid, and radioisotope counts in alveolar fluid, homogenized lung and plasma. Then we calculated the influx and efflux of radioisotope across the alveolar epithelium. Liquid clearance from the alveolar spaces and the lungs was calculated using protein concentration of alveolar fluid and extravascular lung water. In the experiments with 10(9) CFU P. aeruginosa, we found that 125I-albumin remaining in the lungs decreased and 125I-albumin in plasma increased. Lung liquid clearance decreased by 15%. However, protein and liquid clearance in the experiments with 10(7) CFU P. aeruginosa or autologous serum were not different from those in the control experiments. P. aeruginosa was cultural from blood, right pleural effusion, and liver in the experiments with 10(9) CFU P. aeruginosa, but not in the experiments with the alveolar epithelium, but decreases clearance of liquid from the alveolar spaces.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗
PubMed1994

[Growth of the hypoplastic aortic arch after arch repair for coarctation and interruption of the aorta].

Surgical treatment for a hypoplastic aortic arch associated with coarctation or interruption of the aorta is controversial. We evaluate the changes of diameter of proximal transverse aortic arch after surgery in 28 patients. Proximal transverse aortic arch in all patients was preoperatively 3.5 +/- 0.9 mm (2.5 to 7 mm), and 54 +/- 12% (36 to 84%) to the normal aortic valve dimension (n-AVD: 16.6 X BSA0.6). While postoperative proximal transverse aortic arch was 6.5 +/- 1.8 mm, and 76 +/- 12% to the n-AVD, and significantly grew more than the preoperative arch dimension (p = 0.0001). In 18 patients having two times cardiac catheterization postoperatively, proximal transverse aortic arch was 6.5 +/- 1.6 mm, and 75 +/- 13% to n-AVD on the 1st postoperative examination. On the 2nd examination, the arch was 9.9 +/- 1.9 mm, and 88 +/- 12% to n-AVD, and significantly grew with increasing years (p < or = 0.0003). We concluded that the proximal transverse aortic arch, which was more than 36% to n-AVD in diameter, if not dilated surgically, grew with increasing years after aortic arch repair.

Aorta, Thoracic↗
PubMed1994

[Subaortic stenosis in coarctation or interruption of the aorta--changes of left ventricular outflow tract dimension after aortic arch repair and pulmonary artery banding].

Left ventricular outflow tract (LVOT) dimension was measured in seven patients with coarctation (CoA) or interruption (IAA) of the aorta before and after aortic arch repair and pulmonary artery banding. The age of patients ranged 3 to 69 (mean 16) days, the weight 3.0 to 3.9 (mean 3.4) kg. Associated cardiac anomalies were VSD in 6, MA and DORV in 1. In five patients compared by ultrasound, preoperative LVOT dimension ranged from 3.5 to 5.0 (mean 4.4) mm with the ratio to the normal aortic valve dimension (n-AVD; 16.6 x BSA0.6) from 54 to 82 (mean 69)%. Postoperative dimension increased 5.0 to 7.4 (mean 5.7) mm and the ratio to the n-AVD increased 65 to 89 (mean 80)%. In three patients compared by LV graphy, preoperative LVOT dimension ranged from 4.0 to 4.5 (4.2) mm and the ratio ranged from 61 to 72 (68)%. Postoperative dimension increased from 4.5 to 6.7 (5.3) mm, and 74 to 80 (78)% to n-AVD after operation. Postoperative pressure gradients between LV and ascending aorta in each patient were 1 to 9 (mean 6) mmHg. In any patients, LVOT obstruction did not advance after aortic arch repair and pulmonary artery banding.

Aorta↗
PubMed1993

[Evaluation of the blood flow in lung disease with color Doppler flow imaging].

Blood flow within the lesions was evaluated in 6 patients of lung cancer and in 4 patients with pulmonary tuberculosis with color Doppler flow imaging. Three different signal types were noted: pulsatile signal was detected in all patients with lung cancer and in 2 patients with pulmonary tuberculosis, continuous signal was only detected in 3 patients with lung cancer, triphasic signal was detected in 4 patients with pulmonary tuberculosis and in 2 patients with lung cancer. It was seemed to be that triphasic signal was blood flow signal in peripheral vessel of pulmonary vein and color Doppler flow imaging was useful for evaluation of blood flow patterns in lung disease.

Adenocarcinoma↗
PubMed1993

[Evaluation of the blood flow in tumors before and after irradiation with color Doppler flow imaging].

The blood flow in tumors of three patients with lung cancer, cancer in oral cavity and metastatic lymphnode was respectively evaluated before and after irradiation with color Doppler flow imaging. The arterial pulsating flow in lung cancer disappeared after 30 Gy irradiation and that in cancer of oral cavity disappeared after 15 Gy irradiation with intraarterial infusion chemotherapy. But the arterial pulsating flow in metastatic lymphnode was detected during irradiation and disappeared after 40 days post- irradiation. Therefore color Doppler flow imaging seemed to be useful for evaluation of the blood flow in tumors before and after irradiation.

Aged↗
PubMed1993

[Usefulness of color Doppler flow imaging for blood flow in salivary gland].

We investigated the arterial and venous blood flow response in submandibular gland to secretory stimulation using color doppler flow imaging in six normal subjects. During examination secretory stimulation by lemon juice was used. The arterial and venous flow markedly increased after secretory stimulation in all normal subject. It was seemed to be that color doppler flow imaging was of value in evaluation of the blood flow in salivary gland.

Adult↗
PubMed1993

[MR imaging during arteriography (MR arteriography) in the detection of hepatocellular carcinoma].

MR imaging during arteriography was performed to evaluate the clinical utility to patients with hepatocellular carcinoma. After a conventional hepatic arteriography, the patients were transferred to the MR unit and MR arteriography was obtained with the gradient echo technique synchronously starting manual injection of Gd-DTPA diluted with normal saline into the hepatic artery using 5-F Cobra angiographic catheter. The tumors showed high signal intensity relative to surrounding normal parenchyma and a clear liver-to-lesion contrast was obtained. Especially in one case, a conventional hepatic arteriography did not show the recurrent mass, however it was demonstrated as a high signal intensity area on MR arteriography. Therefore, this new technique seemed to be useful for the detection of hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed1993

Inhibition of human colon cancer growth by antibody-directed human LAK cells in SCID mice.

Advanced human colon cancer does not respond to lymphokine-activated killer (LAK) cells. In order to direct cytotoxic cells to the tumor, human LAK cells linked with antibodies to a tumor cell surface antigen were tested with established hepatic metastases in severe combined immunodeficient (SCID) mice. These cells had increased uptake into the tumor and suppression of tumor growth as compared with LAK cells alone, thereby improving the survival of tumor-bearing mice. Thus, tumor growth can be inhibited by targeted LAK cells, and SCID mice can be used to test the antitumor properties of human effector cells.

Animals↗
PubMed1993

[Evaluation of early MR imaging of the liver in rabbits after ethanol injection].

Seven days after ethanol injection, MR images of the liver in 5 rabbits were evaluated by T1, T2-weighted SE and TURBO-FLASH dynamic images. Necrotic area was visualized as low-intensity on T1-weighted images and high-intensity on T2-weighted images. These findings were similar to the tumor that was not treated, so it is necessary to be careful for evaluation of therapeutic efficacy. Necrotic area was not meanwhile enhanced on TURBO-FLASH dynamic images, therefore, dynamic study seemed to be useful for therapeutic efficacy after ethanol injection.

Animals↗
PubMed1993

31P localized spectroscopy of fetal brain in utero.

31-Phosphorus (31P) nuclear magnetic resonance (NMR) spectroscopy of fetal brain in utero was obtained entirely noninvasively in rat utilizing image selected in vivo spectroscopy (ISIS). The results were in excellent agreement with the data obtained using the surface coil method in the late stage fetus, namely, high phosphomonoester (PME), low phosphocreatine (PCr), and high intracellular pH. Localized spectroscopy provides unprecedented opportunities for the investigation of fetal brain metabolism in utero.

Animals↗
PubMed1993

Noninvasive analysis of aldose reductase activities in rat testis: 3-FDG NMR spectroscopy and imaging.

Noninvasive investigation of aldose reductase activities in rat testis was performed using 3-fluoro-3-deoxy-D-glucose (3-FDG) and nuclear magnetic resonance (NMR) spectroscopy/imaging. Quantitative determination of testis aldose reductase activities, expressed as the sorbitol index, showed a value similar to that of brain. Sorbitol imaging demonstrated aldose reductase activities in testis to be confined primarily to the central region of this organ. The 3-FDG 19F NMR method appears to have clinical potential in the evaluation of testicular function, especially that of spermatogenesis, noninvasively.

Aldehyde Reductase↗
PubMed1993

Therapeutic experience of hyperbaric oxygenation in radiation colitis. Report of a case.

PURPOSE: The usefulness of the hyperbaric oxygenation in a patient with radiation colitis was evaluated. METHODS: The patient had severe bleeding from the large bowel which resulted from a pelvic radiation therapy for prostatic carcinoma and was histologically diagnosed as radiation colitis. Hyperbaric oxygenation therapy consisting of 100 percent oxygen inhalation at two absolute atmospheric pressures 90 minutes daily for 30 days was performed. RESULTS: The treatment succeeded in stopping gross hemorrhage and reversed endoscopic bowel findings. CONCLUSION: The effect of the hyperbaric oxygenation therapy of radiation colitis is elucidated.

Aged↗