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Biomedical subjects

O Watanabe

Publications and source records attributed to O Watanabe.

At least 73 records · Page 4Linked to original sources
PubMed1997

The effect of duration of muscle denervation on functional recovery in the rat model.

The effect of long-term denervation on neuromuscular recovery was studied in a rat hind limb model. The posterior tibial nerve was transected and repaired immediately or after denervation periods of 2 weeks, or 1, 3, 6, 9, or 12 months. Six months following reconstruction excellent axonal regeneration was seen across all nerve repairs irrespective of periods of denervation. However, there was a precipitous and profound decrease in the recovery of both muscle mass and integrated motor function if the reconstruction was delayed for longer than 1 month. Rather than a progressive change proportional to the length of the denervation period, significant, more discrete changes occurred sometime after 1 month of denervation that precluded a full recovery of muscle mass. Integrated motor function quantified using walking track analysis was impaired even after immediate nerve repair.

Animals↗
PubMed1997

Dissociation between semantic and autobiographic memory: a case report.

We report a patient who showed a dissociation between impaired semantic memory and preserved autobiographic memory. M.N., a 56-year-old right-handed woman, developed a supra sellar meningioma and underwent multiple operations. Following Lineac radiation, necrosis occurred in the left temporal lobe. Magnetic Resonance Imaging revealed bilateral lesions in the temporal lobes and in the right basal frontal lobe. The patient's intellectual deterioration and anterograde amnesia were mild. Language was preserved, but for a subtle anomia. Autobiographic memory remained intact, while semantic memory for public events, historical figures, cultural items, knowledge of low frequency words and technical terms related to her profession was severely impaired. We hypothesize that bilateral lesions of the anterior half of the middle region of the temporal lobe plays a crucial role in causing deficits in semantic memory.

Amnesia↗
PubMed1997

Analysis of the tumor staining obtained by preoperative IV-DSA for breast cancer patients: density and metastasis correlation.

We examined the density of tumor enhancement on intravenous digital subtraction angiography (IV-DSA) in patients with breast cancer in relation to disease-free survival. The subjects of the present study consisted of 103 patients with invasive ductal carcinoma measuring 5 cm or less treated from July 1988 to September 1993. In the 103 patients, 15 had distant metastasis. The region of interest was set in the areas enhanced by IV-DSA of the breast. The maximum density (MAX) was calculated by the time-density curve. When the patients were divided according to three classes of MAX, i.e., 0-5.0 pixels (group A, n = 23), 5.1-9.0 pixels (group B, n = 50), 9.1 pixels or more (group C, n = 30), disease-free survival was highest in group A followed by group B and C, respectively. The disease-free survival rate in group C was significantly lower than that of group A or B (p < 0.05). Thus, high values of MAX were associated with low rates of disease-free survival. Since the value of MAX was found to be independent from other prognostic factors by multivariate analysis, these results indicate that MAX has a close correlation with metastasis or recurrence of breast cancer, making IV-DSA a promising prognostic factor.

Adult↗
PubMed1997

MIB1-determined proliferative activity in intraductal components and prognosis of invasive ductal breast carcinoma.

Intraductal components of breast carcinoma may have prognostic significance. In this study, we divided 181 invasive ductal breast carcinomas into comedo and non-comedo groups based on intraductal component morphology, and differences between the two groups in clinicopathological variables, including proliferative activity and survival, were assessed. Proliferative activity was evaluated by using MIB1 antibody, which reacts with the cell-proliferation-associated Ki-67 antigen, and was expressed as the number of MIB1-positive nuclei per 1000 cancer cells in intraductal components (MIB1 labeling index). We also investigated which variables had an impact on survival. The comedo group showed a significantly higher MIB1 labeling index than the non-comedo group (P < 0.0001). The differences in disease-free and overall survival between the two groups were not significant (P = 0.2477, P = 0.2069). Multivariate analysis of the entire series showed the MIB1 labeling index to be an independent prognostic factor predicting both disease-free survival and overall survival (P = 0.0160, P = 0.0035). When multivariate analysis was repeated separately for the non-comedo and comedo groups, the MIB1 labeling index remained the most important variable predicting disease-free and overall survival in the non-comedo group (P = 0.0122, P = 0.0040). Moreover, non-comedo patients with a high MIB1 labeling index had significantly shorter disease-free and overall survival than those with a low MIB1 labeling index (P = 0.0040, P = 0.0402). These findings imply that MIB1-determined proliferative activity of intraductal components is an independent predictor of survival, and is the most important predictor in non-comedo cases.

Adult↗
PubMed1997

End-to-side neurorrhaphy resulting in limited sensory axonal regeneration in a rat model.

This study evaluated reinnervation of an end-to-side neurorrhaphy and the resultant functional recovery in a rat model. The cut distal posterior tibial nerve was repaired to the side of an intact peroneal nerve. In one group, the epineurium of the peroneal nerve was left intact; in another group, the epineurium was stripped; in the third experimental group, a perineurial slit was created. Evaluations included walking track analysis, nerve conduction studies, muscle mass measurements, retrograde nerve tracing, and histologic evaluation. Walking tracks indicated poor functional recovery. No significant difference in nerve conduction between the experimental and control groups was seen. Gastrocnemius muscle mass measurements revealed no functional recovery in the end-to-side groups. Retrograde nerve tracing revealed minimal staining of motor neurons. However, sensory neuronal staining of the dorsal root ganglia occurred in all groups. Histology revealed minimal myelinated axonal regeneration. These results suggest that predominantly sensory neural regeneration occurs in an end-to-side neurorrhaphy at an end point of 16 weeks.

Anastomosis, Surgical↗
PubMed1997

Use of carbon dioxide microbubble-enhanced sonographic angiography for transcatheter arterial chemoembolization of hepatocellular carcinoma.

OBJECTIVE: Our objective was to determine the usefulness of sonographic angiography with carbon dioxide microbubbles during transcatheter arterial chemoembolization for hepatocellular carcinoma. SUBJECTS AND METHODS: Thirty-four patients with hepatocellular carcinoma underwent sonographic angiography during transcatheter arterial chemoembolization. Digital subtraction angiography failed to reveal tumors in 27 patients. Tumor stain became obscure on digital subtraction angiography after the catheter was inserted into distal branches in seven patients. Sonographic angiography was performed after injection of carbon dioxide microbubbles into the hepatic artery selected for transcatheter arterial chemoembolization. RESULTS: In angiographically undetectable hepatocellular carcinomas, sonographic angiography revealed tumor vascularity in 17 patients in whom transcatheter arterial chemoembolization was then performed. For the two patients who underwent a second transcatheter arterial chemoembolization, the existence of alternative feeding vessels was confirmed by sonographic angiography. In the remaining 10 patients, tumor vascularity was not seen on sonographic angiography; percutaneous ethanol injection therapy was then performed. Sonographic angiography clearly revealed tumor vascularity in patients in whom staining became obscure on digital subtraction angiography after the catheter was inserted into a peripheral branch of the hepatic artery. In all 24 patients who underwent transcatheter arterial chemoembolization, sonographic angiography was useful for determining the artery suitable for transcatheter arterial chemoembolization and for monitoring tumor perfusion in the selected artery. CONCLUSION: Sonographic angiography can be used to determine not only the therapeutic strategy for treatment of hepatocellular carcinoma but also whether the tumor is supplied by the artery selected for transcatheter arterial chemoembolization, especially when the tumor is not revealed by digital subtraction angiography.

Aged↗
PubMed1997

[Evaluation of single photon emission computed tomography of tumors in the head and neck with technetium-99m MIBI].

SPECT using 99mTc-MIBI was performed in patients with tumors in the head and neck in order to determine 99mTc-MIBI uptake in tumors and to evaluate the efficacy of 99mTc-MIBI imaging in the assessment of treatment response. A MIBI uptake index was calculated as the ratio of average counts/pixel in the tumor to average counts/pixel in the homologous contralateral side. Eighteen of 19 (95%) of the cases had increased MIBI uptake in the tumor on early images, and 8 of 14 (57%) of the cases had increased uptake of the tumor on delayed images. MIBI uptake was related to the size of the tumor. Only 6 of 25 of cervical lymph node metastases were detected by 99mTc-MIBI SPECT. In the tumors evaluated before and after radiotherapy, the superiority of 99mTc-MIBI SPECT over MRI was not obtained, but there was a tendency for MIBI-index to decrease after radiotherapy.

Adult↗
PubMed1997

[Two cases of POEMS syndrome with increased vascular endothelial growth factor (VEGF)].

We report a greatly increased amount of vascular endothelial growth factor (VEGF) in sera of two cases with POEMS syndrome. They had solitary myelomas in the cervical (case 1) and lumbar vertebrae (case 2). In both cases, serum VEGF decreased after steroid therapy. Sural nerve biopsy in case 1 showed marked subperineurial edema. The pathomechanism of polyneuropathy in POEMS syndrome may be due to involvement of the blood-nerve barrier by way of increased microvascular permeability induced by VEGF. VEGF is therefore not only a useful diagnostic marker for POEMS syndrome, but may also be a marker of clinical improvement.

Adult↗
PubMed1996

Relation between Locoregional Hyperthermic Area Detected by Contact Thermography and the Maximum Density of Tumor Stain Obtained by IV-DSA in Breast Cancer Patients.

We studied the significance of the locoregional hyperthermic area observed by contact thermography in relation to the maximum density of tumor enhancement obtained by IV-DSA. The subjects were 34 patients with primary breast cancer. The thermal difference between the locoregional hyperthermic area and the surrounding mammary tissues was obtained, and the maximum density of tumor stain on IV-DSA was calculated from the time-density curve. Twenty-three (67.6%) patients had a locoregional hyperthermic area corresponding to the tumor. The higher the degree of thermal difference between the hyperthermic area and the surrounding tissues, the higher the maximum density of tumor enhancement. As the maximum density of tumor stain is considered to reflect the vascularity of the tumor, the degee of the locoregional hyperthermic area obtained by thermography may also reflect tumor vascularity.

Journal Article↗
PubMed1996

Peripheral nerve allograft preservation improves regeneration and decreases systemic cyclosporin A requirements.

Peripheral nerve allografting is limited by the need for long-term systemic immunosuppression. The purpose of this study was to determine if nerve allograft preservation reduced the requirements for systemic Cyclosporin A (CsA) immunosuppression. One hundred twenty Lewis rats were randomized to one of seven experimental groups. Group 1 received a 2-cm Lewis posterior tibial nerve autograft. Groups 2-7 received 2-cm ACI posterior tibial nerve allografts. The allograft group was then further subdivided into three groups of two receiving daily subcutaneous injections of 0, 2.5, or 5.0 mg/kg of CsA for 12 weeks. Within each CsA dose, one group received a fresh while the other received a preserved allograft. Preserved grafts were stored in University of Wisconsin solution for 7 days at 5 degrees C prior to implantation. Animals from each group were sacrificed at 6, 12, and 20 weeks postoperatively. Evaluations included histomorphometry, electrophysiology, and serial walking track analysis. Histology revealed varying degrees of nerve regeneration in all groups at 6, 12, and 20 weeks. For a given CsA dose, the group receiving the preserved graft revealed evidence of better nerve regeneration by all histomorphometric parameters including fiber width and density, percentage neural tissue, and total fiber number. There was no statistical difference in walking track analysis between groups at 4 weeks. By 20 weeks, functional recovery statistically poorer than autograft was seen only in the fresh allograft groups receiving 0 or 2.5 mg/kg of CsA. Identical electrophysiologic findings were seen at 20 weeks. These results suggest that nerve graft preservation may decrease systemic immunosuppression requirements while improving functional recovery. As well, storage of nerve grafts is feasible and would facilitate elective surgery and less costly reconstructive repair.

Analysis of Variance↗
PubMed1996

Extraforaminal stenosis in the lumbosacral spine. Efficacy of MR imaging in the coronal plane.

PURPOSE: To review experience with MR images of extraforaminal (EF) stenosis in the lumbosacral spine. MATERIAL: MR images from 9 patients with 10 EF stenoses were reviewed. The diagnosis was confirmed in 6 patients at surgery, and in 4 on the basis of findings of nerve root injection combined with nerve block. RESULTS AND CONCLUSION: All patients had congenital lumbosacral anomalies with various degrees of fixation between the last formed level and the pelvis. In all cases, affected roots were compressed between the transverse process of the last lumbar segment and the sacral ala. MR using coronal plane imaging demonstrated the root impingement directly in the far lateral zone in all patients. However, sagittal and axial images were unable to define the EF stenoses in all patients. The results of this study show that a transitional vertebra is a cause of EF stenosis and that MR images using coronal plane are useful in the assessment of EF stenosis.

Female↗
PubMed1996

The CT findings of pulmonary sarcoidosis.

We analyzed the CT findings in 35 patients with pulmonary sarcoidosis. Twenty-seven patients had biopsy-proven sarcoidosis; in eight patients the diagnosis was made clinically. In all the 35 patients, 10-mm collimation scans were available. In seven patients, high-resolution CT was also obtained. Twenty-eight patients had lymphadenopathy associated with pulmonary infiltration, two patients had pulmonary infiltration without lymphadenpathy, five patients had lymphadenopathy alone. The most frequent parenchymal features on CT were small nodules (100%) and irregularly thickened bronchovascular bundle (90%). Other frequent CT findings were pleural or subpleural thickening (83%), septal lines (73%) and ground-glass attenuation (63%). In all cases, small nodules were associated with other lesions. The authors conclude that in patients with sarcoidosis, CT is a valuable technique to visualize the findings in the pulmonary parenchyma characteristic enough to allow confident diagnosis. While high-resolution CT is superior in the assessment of linear opacities and cysts, conventional CT is superior in demonstrating small nodular opacities. We believe that both should be combined in the examination of patients with sarcoidosis.

Adult↗
PubMed1996

Wire mesh as a post-operative physiotherapy assistive device following peripheral nerve graft repair in the rat.

Traditional methods of assessing nerve recovery following injury, including histomorphometry and electrophysiology, do not necessarily correlate with return of motor and sensory function. Accordingly, many investigators have used walking track analysis as an assessment of global functional recovery following sciatic, peroneal or tibial nerve injury. However, walking track reliability may be compromised by the development of flexion contractures secondary to neurologic loss. To prevent this, regular manual physiotherapy is recommended which is a time-consuming and often frustrating process for both the animal and investigator. We report the use of a wire mesh as a simple post-operative assistive device to provide constant physiotherapy. Twelve Lewis rats were randomized to one of two experimental groups. Each rat received a 2 cm posterior tibial nerve autograft. Postoperatively, animals in group 1 received manual physiotherapy, consisting of repeated flexion and extension exercises of the ankle, knee and hip every two weeks. Group 2 rats were permitted to climb freely on a 30 x 18 cm piece of wire mesh placed at a 45 degree angle within their cage. Group 2 rats received no manual physiotherapy throughout the course of the study. Serial walking tracks were performed every four weeks until sacrifice at sixteen weeks. There was no development of flexion contractures in the injured hind limbs of either group. There was no morbidity such as blisters associated with the use of the wire mesh. There was no statistical difference in walking track recovery between groups at any time period. However, a trend towards better functional recovery was seen in the group receiving constant physiotherapy via the wire mesh. The use of a wire mesh as a post-operative assistive device is an inexpensive, simple and reliable method to provide continuous physiotherapy to animals following denervation.

Animals↗
PubMed1995

Histopathological study of local residual carcinoma after simulated lumpectomy.

From 1989 to 1991, 24 patients with invasive ductal carcinoma underwent simulated lumpectomy at Tokyo Women's Medical College Daini Hospital. The mastectomy specimens were then examined histopathologically in serial sections for the presence of residual tumors or multicentricity. Lumpectomy specimens from cancer foci at resected margins were also examined. In this study, 23 of 24 patients demonstrated positive resection margins (95.8%). Residual tumors were found in mastectomy specimens from 16 patients (66.7%); unilateral multifocal carcinomas were found in 2 of these patients (8.3%). The incidence and severity of residual tumors did not correlate with primary tumor size or the distance between the nipple and the primary tumor but directly correlated with the severity of intraductal spread of the primary tumor. Tumors with central necrosis were associated with a higher incidence of residual tumors. Our study thus indicates that there is a high risk that some residual tumor will be left in the conserved breast when lumpectomy is performed. Multifocal carcinoma and tumors showing severe intraductal spread and central necrosis are thus associated with extensive residual tumors and are likely to cause local recurrence.

Breast Neoplasms↗
PubMed1995

Relationship between staining by digital subtraction angiography and vascularity in breast cancer: analysis of the time-density curve and the results of staining for factor VIII-related antigen/von Willebrand factor.

We performed intravenous digital subtraction angiography (IV-DSA) in 31 patients with primary invasive breast cancer, and calculated the maximum density of tumor staining from the time-density curve obtained. Specimens resected from the same patients were stained for factor VIII-related antigen/von Willebrand factor (vWF), and the amount of microvessels was calculated by image processing. A significant correlation (correlation coefficient: 0.85) was found between the maximum density of tumor staining and the vascularity determined by staining for vWF, indicating that the maximum density indirectly reflects the vascularity in the tumor.

Angiography, Digital Subtraction↗
PubMed1995

[A case of radiation neuropathy following radiation therapy for metastasis of breast cancer].

We report a 49-year-old woman with radiation neuropathy, which occurred 7 years after radiation therapy for supraclavicular lymph node metastasis of breast cancer. The patient had noticed a hard induration in the right breast twelve years previously and had a radical operation for right breast cancer. After surgery, she remained well until 7 years ago when she noted a right supraclavicular mass. Based on a diagnosis of metastasis of breast cancer at the right supraclavicular lymph node, she received radiation therapy at 50 Gy in 25 fractions to the lesion. Seven years after radiation therapy, the patient noted muscle weakness of II-V fingers of the right hand, followed by muscle atrophy of the right forearm. We diagnosed her condition as radiation neuropathy based on the absence of a mass lesion in the right supraclavicular region, no RI deposits in that region on Ga and bone scintigraphy, findings supportive of a lesion in the right brachial plexus on EMG and the history of radiation therapy for supraclavicular lymph node metastasis of breast cancer 7 years previously. We treated the patient with pulse therapy with high-dose oral prednisolone. Subsequently, the muscle weakness and atrophy of the right forearm and fingers have improved gradually. We suggest that pulse therapy with high-dose oral prednisolone for radiation neuropathy should be evaluated in a clinical trial, since few therapies are available for this condition.

Breast Neoplasms↗
PubMed1994

[Experimental chemoendocrine therapy of human breast carcinoma xenograft serially transplanted into nude mice].

The antitumor effect of combined chemoendocrine therapy with tamoxifen (TAM) and 5-fluorouracil (5-FU) on breast carcinoma xenograft (R-27), serially transplanted into the nude mice, was examined from the aspect of estrogen receptors (ER) and cytological features. The mice were given 6 intramuscular injections of TAM (5mg/kg) at 3-day intervals (TAM group), 3 intraperitoneal injections of 5-FU (60 mg/kg) at 4-day intervals ((5-FU group), or a combination of the two drugs (combined group). When the tumor was resected on 21 days after the initial treatment, the ER were assayed and %S was determined by flowcytometry. Furthermore, proliferative cell nuclear antigen (PCNA) was stained, and the stained cells were counted. A synergistic antitumor effect of TAN and 5-FU was found in mice given combined therapy. Reduction in the ER level was more marked in this group than in the others, but there were no significant differences in the %S value or the ratio of PCNA positive cells among the three treated groups. These results suggest that the combined effect of TAM and 5-FU has no relation to the inhibition of DNA synthesis.

Animals↗