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Biomedical subjects

J Watarai

Publications and source records attributed to J Watarai.

At least 55 records · Page 3Linked to original sources
PubMed1993

[Radiation injury of the lung following postoperative radiotherapy of breast cancer using a single large portal technique--CT study].

When postoperative radiotherapy for breast cancer is indicated, we employ a single large portal technique with electron beams using a bolus made of MIX-R (soft tissue equivalent material) for the chest wall. The entire lymph node groups as well as the chest wall are irradiated uniformly, and the total dose is 50 Gy, 2 Gy/fraction, 5 days/week. Radiation changes of the lung in 35 breast cancer patients irradiated by this technique were evaluated by computed tomographic (CT) studies. Radiation injuries were detected in 12 patients out of 35 (34%). Among patients who were irradiated by three portal techniques without bolus, radiation injuries were detected in all 4 patients (100%) by CT and in 39 patients out 72 (54%: historical control group) by plain chest film. These results indicated the superiority of the single large portal technique. Radiation injuries were identified in CT studies at 135 day after commencement of radiotherapy, and their distributions were localized to areas of 80-100% dose level. Measurements in CT revealed that the thickness of the chest wall varied extremely according to surgical procedures, so that the adequacy of the selection of energy of electron beams in each patient by CT was indispensable.

Adult↗
PubMed1993

[Experimental study on intraoperative irradiation for pancreatic cancer: histological and nutritional changes in early phase after high dose irradiation].

For the treatment of pancreatic head cancer, pancreatoduodenectomy is followed by the intraoperative radiation therapy (IORT). The present dose adopted ranged 20 to 30 Gy, however the dose is believed to be insufficient for local control of adenocarcinoma cells. In this study, high dose IORT was performed using rabbit, so histological and nutritional changes were evaluated. Rabbits were divided in three groups; 30 Gy, 50 Gy, 80 Gy. The radiation was performed with electrons focusing base of cranial mesenteric artery (SMA in human). The rabbits were sacrificed at intervals ranging from immediately after to 4 weeks following irradiation. The earliest evidence of histological changes was the loss of endothel, although it was repaired within 1 week. Fragmentation and reduplication of internal elastic lamina were observed after 1 week, however the degree was not dose dependent. Damages of the media was observed in 50 and 80 Gy groups. That is, focal degeneration of smooth muscle cell was demonstrated in 50 Gy group and medial necrosis in 80 Gy group. Degeneration of ganglion cells was observed and its severity was dose dependent. In 80 Gy group, diarrhea occurred more frequently compared with the other groups and body weight loss couldn't recover within 4 weeks. It is concluded that, since necrosis of aortic media and marked degeneration of ganglion cells are inevitable in 80 Gy group, IORT dose should be increased within 50 Gy.

Animals↗
PubMed1993

[An occlusion and stenosis of the venous drainage system in cerebral AVMs--angiographical investigation].

We investigated angiographically occlusion or stenosis of draining veins in cases of arteriovenous malformations (AVMs). The subjects were 51 cases who were diagnosed as cerebral AVMs by angiography in our hospital between April 1973 and January 1991. Those consisted of 8 dural AVMs, 3 mixed pial-dural AVMs, and 40 pial AVMs. Angiography was stereoscopically done in all cases. Angiograms obtained prior to treatment were retrospectively analyzed. Cases of dural AVMs or arteriovenous fistulae in the cavernous sinus were excluded from the subjects. Eight of 51 cases (16%) had occlusion or stenosis of draining veins; i.e., 2 dural AVMs, 1 mixed pial-dural AVM, 5 pial AVMs. One of 2 dural AVMs was located in the sigmoid sinus, and another involved the superior sagittal sinus. One mixed pial-dural AVM was a vein of Galen aneurysm. Occlusion or stenosis was recognized at the junction of the vein of Galen to the straight sinus (3 cases), in the straight sinus (2 cases), at the junction of the vein of Labbe to the transverse sinus (1 case), in the superior sagittal sinus (1 case), and in the sigmoid sinus (1 case). Two of 8 cases with occlusion or stenosis of draining vein presented with hemorrhage at the site of AVMs. In cases of pial AVMs, occlusion or stenosis of draining vein seemed be related to endothelial changes due to turbulent and irregular flow. On the other hand, in cases of dural AVM with dural sinus occlusion, sinus abnormalities may precede the formation of fistulous communications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

CT of retropharyngeal lymph node metastasis from maxillary carcinoma.

CT findings for retropharyngeal lymph node metastasis in 25 patients with histologically proven carcinoma of the maxillary sinus and with no prior treatment were evaluated retrospectively. Four lateral retropharyngeal node metastases (16%, 4/25) could be identified by CT. All retropharyngeal metastatic nodes were located between the ipsilateral internal carotid artery and the longus colli muscle at the level of the first cervical vertebral body. The metastatic nodes ranged from 8 mm to 35 mm in size at the long axis. The risk of retropharyngeal node metastasis depends on the degree of carcinoma involvement to the posterior nasal cavity, the posterior ethmoid sinuses, the sphenoid sinuses, the palate (soft and hard) and the nasopharynx. This study indicates that CT is useful for detecting these lymph node metastases.

Adult↗
PubMed1992

[Clinical evaluation of lumbosacral nerve root and lateral stenosis using coronal MR imaging].

MR imaging is being used more frequently to study the lumbar spine and is becoming the modality of choice in the assessment of patient with low back pain. Using a new technique of coronal and half coronal scan with MR imaging, it was possible to visualize L4, L5 and S1 nerve roots accurately. We described the MR findings of lateral stenosis using this technique. Several characteristic MR findings were identified, and the most important one was nerve root impingement in the intervertebral foramen. We consider that coronal and half coronal scan with MR imaging is useful in diagnosis of lateral stenosis.

Adult↗
PubMed1992

Simultaneous recording of urethral pressure and cross sectional area profile.

A new technique for simultaneously recording urethral closure pressure and cross sectional area profile is described. The cross sectional area of the urethra could be measured using the field gradient principle. The procedure was performed readily in male patients and the recordings can be graphically presented during measurement. A high degree of reproducibility using this method was obtained. Typical recordings of control subjects was well as patients with pathology were obtained using this technique. The results of this study show that the maximum urethral closure pressure obtained was 60.8 + 3.4 mmHg and functional profile length, 4.8 + 0.4 cm. Internal meatus cross sectional area was 0.67 + 0.04 cm2 and the minimum urethral cross sectional area was 0.12 + 0.02 cm2. This method has been shown to be readily applicable in measuring urethral closure pressure in males and can potentially be used as a tool of comparing the functional parameters of pressure with the anatomical value of diameter.

Adult↗
PubMed1992

The effect of alpha-2 agonists and antagonists on the upper urinary tract of the rat.

We examined the effect of the selective alpha-2 agonist dexmedetomidine and antagonist atipamizole on the upper urinary tract, renal pelvic pressure and ureteral peristalsis. Experiments were performed on twelve Sprague-Dawley female rats weighing 275-323 grams, with administration of urethane (1.2 micrograms/kg). Ventilatory support was provided through a tracheotomy. A continuous normal saline infusion was maintained through the left iliac vein at a rate of 2.5 ml/hr. Arterial pressure was measured at the left iliac artery, which was cannulated with a PE-100 tube connected to a pressure transducer. A mid-line incision was then made from the xyphoid to the symphysis to expose the left kidney, both ureters, and the bladder. The bladder was intubated and drained to avoid bladder pressure increase. Measurements of urine output rate were made from the right ureter and renal pelvic or ureteral pressure was measured using a nephrostomy placed into the pelvis. A ureterostomy was produced by introducing another catheter, into the upper segment of the left ureter for ureteral pressure measurements. The rats were divided into two groups as follows: 1) dexmedetomidine group (n = 6); injected intravenously with 2 micrograms/kg of dexmedetomidine dissolved in 0.5 ml saline. 2) atipamizole group (n = 6); injected intravenously with 2 micrograms/kg of atipamizole dissolved in 0.5 ml saline. Ureteral peristaltic frequency, baseline pressure, and contraction amplitude were compared before, after, and between the bolus injections of 2 micrograms/kg dexmedetomidine (n = 6) or 2 micrograms/kg atipamizole (n = 6) in 0.5 ml saline. The results showed that dexmedetomidine at 2 micrograms/kg produced a significant decrease in arterial pressure and an increase in urine output from 1.2 + 0.8 to 3.6 + 1.2 ml/min. There was no effect on the baseline pelvic pressure of 6.8 + 1.2 cmH2O or amplitude of the renal pelvic contractions: 3.5 + 0.6 cmH2O. The frequency of pelvic contractions was reduced from 0.37 + 0.03 to 0.27 + 0.02 Hz. Atipamizole at 2 micrograms/kg produced a significant reduction in urine flow rate of 1.1 + 0.8 to 0.6 + 0.2 ml/min. Atipamizole also showed no significant effects on baseline pelvic pressure or frequency, but increased the amplitude of pelvic contractions from control values of 3.0 + 0.9 to 3.4 + 0.9 cmH2O. Dexmedetomidine reduced both the baseline ureteral pressure of 8.5 + 2.4 and peristaltic contraction pressure of 11.5 + 2.3 cmH2O in 4/6 rats. Atipamizole reduced base-line ureteral pressure and increased peristaltic rate.(ABSTRACT TRUNCATED AT 400 WORDS)

Adrenergic alpha-Agonists↗
PubMed1992

Locoregional control for esophageal carcinoma treated with irradiation following surgery.

Locoregional failure was analyzed in a total of 34 esophageal carcinoma patients treated with postoperative prophylactic irradiation following curative surgery. All patients had squamous cell carcinoma and no prior treatment. Twelve patients had subsequent lymph node metastasis in the follow-up period. In the 12 patients with node metastasis, there were 5 instances of supraclavicular node metastasis, 7 instances of thoracic inlet node (uppermost part of mediastinum) metastasis, and 3 instances of mediastinal node metastasis. Three patients had 2 metastatic nodes and 9 patients had 1 metastatic node. Intervals between surgery and recurrence were a median of 12 months for mediastinal nodes, 19 months for thoracic inlet nodes, and 26 months for supraclavicular nodes. Ten (52.6%) of the 19 patients treated by using a 12-MeV electron beam had metastatic involvement at the supraclavicular and thoracic inlet nodes. On the other hand, 2 (13.3%) of the 15 patients had the above-described lymph node metastases when treated by using 15-MeV electron, 18-MeV electron, or 10-MV photon beams. The difference in the metastatic rate between these two groups was statistically significant at the level of p < 0.05 (chi-square test); this seems to be attributable mainly to the dose level at deep region. Doses of over 50 Gy to the thoracic inlet and supraclavicular nodes at deep location were necessary to reduce metastasis.

Adult↗
PubMed1991

[Measurement of hematocrit of brain tumor using SPECT].

The cerebral-to-large vessel hematocrit ratio (alpha) was measured using single-photon emission computed tomography (SPECT) in patients with brain tumors. SPECT was performed following intravenous injection of 99mTc-labelled red blood cell and 99mTc-labelled human serum albumin with an interval of 72 hr. In a series of seven subjects, the mean value of "alpha" in tumor (0.74 +/- 0.13) was lower than that (0.83 +/- 0.14) in normal brain tissue. This result may be due to the increased flow of red blood cells in tumor.

Adult↗
PubMed1989

[Interstitial irradiation of carcinoma of the tongue].

From 1977 to 1988, 61 patients have received radical treatment for a carcinoma of the mobile tongue. Fifty-nine of these patients were treated in association with a BLM (or PEP), and 26 patients with external irradiation. The local tumor control rate at two years was 77%, and subsequent lymph node metastasis was 25%. The five year cumulative survival rate was 55% and the main causes of death were found to be regional node metastases and other related diseases particularly. The determinate survival for TxN0 tumors was 83%. Six percent and 26% had radio-osteonecrosis and soft tissue necrosis respectively and three patients required surgery.

Adult↗
PubMed1989

[Diagnosing the depth of esophageal carcinoma invasion by esophagography scoring].

In patients with an esophageal carcinoma, it was important to determine the depth of the carcinomatous involvement so as to decide on its resectability and prognosis. Thus four measurements of the esophagography findings involving ninety five post-esophagectomy patients were categorized into four grades and scored from point 1 to point 4, depending on the degree of severity, the measurements being the size of the tumor, the circumferential carcinomatous invasion, the degree of stenosis, and the depth of the ulcer. The sum total scores of these four esophagography findings were found to correlate well (P less than 0.01) with the depth of the invasion (submucosa, muscularis propria, adventitia, and the adjacent structures).

Adult↗
PubMed1987

[The value of follow-up bone scans in the management of postoperative breast cancer--when should it be performed?].

We have reviewed the bone scans of 106 patients with breast cancer taken after surgery, in order to determine when follow-up bone scans should be performed. The results obtained are as follows: 1. The incidence of bone metastasis was seen to be 11.6% in stage I, 39.4% in stage II, 43.5% in stage III, 57.1% in stage IV, and 30.2% overall; 2. Of 32 patients with bone metastasis, 28 patients (87.5%) developed bone metastases within the first 4 years; 3. The scan conversion rate was found to be 31.9% and the time interval to conversion ranged from 4.5 months to 28.5 months; and, 4. The period from single to multiple metastases ranged from 2 months to 37.5 months. Our findings suggest that postoperative follow-up bone scans for stage I breast cancer should be performed annually or when symptoms develop, and follow-ups for stages II, III and IV at six monthly intervals for the first 4 years after surgery and then annually.

Bone Neoplasms↗
PubMed1984

[Clinical evaluation of hypoxic cell sensitizer (Misonidazole)].

Clinical effectiveness and toxicity of Misonidazole were analyzed and discussed in 22 cases of carcinoma of uterine cervix, 17 cases of esophageal cancer and 11 with other malignancies treated by radiation. By clinical and histologic examination in the controlled trial, it was shown that radiation response of tumor was slightly sensitized in the treated group with this drug, compared with that in the control group. It was confirmed that there was no significant difference between radiation response of tumor in both groups. Peripheral neuropathy was a complication in 10% and toxicodermatitis in 12% even if the total dose administered was below 10 g/m2. From these results, it was strongly suggested that this drug is not suitable in combination with simple fractionated irradiation as a hypoxic cell sensitizer.

Aged↗