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Biomedical subjects

K Takakura

Publications and source records attributed to K Takakura.

At least 73 records · Page 4Linked to original sources
PubMed1999

[Selective peripheral denervation for spasmodic torticollis involving the levator scapulae muscle].

Patients with laterocollis or rotatory type torticollis tend to show abnormal contraction of the levator scapulae muscle and the scalene muscles. These muscles are innervated from the anterior branches of the cervical spinal nerves. Because of this, the traditional Bertrand operation dealing with posterior branches does not adequately affect the symptoms of laterocollis. The authors report selective denervation of the levator scapulae muscle in three patients and discuss its rationale. All the three patients underwent denervation of both the C1-C6 posterior spinal rami and the branches from the C3 and C4 anterior rami to the levator scapulae muscle. We added myotomy of the scalene muscle in one patient, and denervation of the omohyoid muscle which is innervated from the ansa cervicalis and the descending branch of the hypoglossal nerve. The pre/post-operative Tsui scores were 12/4, 15/1, and 14/3 respectively. There were no complications. We conclude that selective peripheral denervation of the levator scapulae muscle is safe and effective in the treatment of laterocollic type torticollis.

Adult↗
PubMed1999

Handgrip-detachable soft tissue retractor for microsurgery: technical note

OBJECTIVE: We developed a modified soft tissue retractor for preventing problems that occur outside of the microscopic view field during microsurgery. INSTRUMENTATION AND OPERATIVE PROCEDURE: The characteristics of the modified soft tissue retractor are detachable handgrips, which can be easily released and fixed with the manipulation of an equipped button, and a new lock adjuster, which changes its form and position so that it is withdrawn into a corner space between both arms in proportion to the open angle of the arms. The retractor is used with handgrips, as in the conventional method, until the microsurgery begins. When microsurgery begins, the handgrips are released. We have used this retractor in 45 microsurgeries and 42 burr-hole surgeries, such as stereotactic or endoscopic operations. RESULTS: The detachable handgrips can resolve problems caused by handgrips and a lock lever in conventional retractors, such as interference with the free movement of the microsurgical operator's hands, restriction of operative approach angle or direction of the light axis of a microscope, and catching or tangling of instrument cords and thin thread. In addition to microsurgery, it was beneficial in burr-hole surgeries, because operators can manipulate instruments, such as a stereotactic arm or an endoscope, without having to handle the retractor handgrips. CONCLUSION: Our modified soft tissue retractor is very useful for performing steady and safe microsurgery.

Journal Article↗
PubMed1999

[Brain tumors].

The outcome of brain tumor treatment has greatly improved through the development of imaging diagnosis techniques such as CT scan or MRI, and microsurgical techniques. During the past 25 years, an efficient therapeutic modality for benign brain tumors, which constitute approximately half of all brain tumors, has been well established through early diagnosis an precise surgical manipulation. The outcome of malignant brain tumors has also improved with radiotherapy together with chemotherapy or an adjuvant treatment with biological response modifiers such as interferon. Although a complete therapeutic strategy for medulloblastoma or germ cell tumors is expected in near future, the ideal therapeutic modalities for other malignant brain tumors remain further off. On the other hand, focal radiotherapeutic equipment such as the gamma knife or photonradiosurgical system have been introduced for the treatment of brain tumors and the efficacy has been clinically proved. Even though much progress in brain tumor treatment has been made, the prognosis of malignant brain tumors in general is still poor and the lives of those patients are quite limited. The development of gene therapy or immunotherapy for brain tumors is, thus, looked forward to in the 21 st century.

Brain↗
PubMed1999

Detection of mammosomatotrophs in paraffin-embedded specimens of various pituitary adenomas.

BACKGROUND: There are various classification systems for pituitary adenomas based on whether mammosomatotroph cells, which simultaneously express both prolactin (PRL) and growth hormone (GH), can be found. Until the present, the identification of such cells required special techniques and could not be performed in paraffin-embedded specimens. This hindered large-scale studies for detection of mammosomatotrophs in various pituitary adenomas and, as a result, such classification has remained controversial. To establish a methodology for the detection of mammosomatotrophs in paraffin-embedded specimens and to propose a more logical classification for pituitary adenomas, the authors conducted this retrospective study. METHODS: We performed double immunofluorescence staining of PRL and GH in paraffin-embedded specimens of various pituitary adenomas with subsequent observation with a confocal laser-scanning microscope. RESULTS: Mammosomatotrophs were found in four of the 10 GH-secreting adenomas and one of the 10 clinically nonfunctioning adenomas. However, mammosomatotrophs were not identified in all 10 cases of prolactinoma. CONCLUSIONS: This is the first report in the literature that successfully demonstrates the presence of mammosomatotrophs in routine paraffin-embedded pituitary adenomas. The new methodology is important for future study of the function and role of these cells. A large-scale study for mammosomatotrophs in various pituitary adenomas with this method and a more logical classification of pituitary adenomas are proposed.

Adenoma↗
PubMed1999

[Immunohistochemical evaluation of intracranial recurrent meningiomas: correlation of topoisomerase II alpha expression and cell proliferative potential].

Most of meningiomas belong to benign tumor. But inspite of Simpson grade I surgical resection, it had been reported that a part of these cases recurred after initial operation. In discussing tumor recurrence in meningioma, it is important to evaluate not only the extent of surgical resection and malignancy but also cell proliferative potential, which had been studied immunohistochemically by using BudR, PCNA and MIB-1. Recently, it is known that topoisomerase (Topo) II alpha expression becomes remarkable in tumorigenesis. The correlation with cell proliferative potential has been reported. In this paper we evaluated the relationship of cell proliferative potential and tumor recurrence immunohistochemically by using Topo II alpha and MIB-1 monoclonal antibody in the 21 recurrent cases of meningiomas and hemangiopericytomas. As a result, mean Topo II alpha staining index (SI) and MIB-1 SI initial surgical resection were 2.29% and 3.41%, respectively, at recurrence these SIs had risen at 4.3% and 6.25%, respectively. As to the interval from initial surgical resection to recurrence, in the cases which recurred under 3 years Topo II alpha SI and MIB-1 SI were 3.13% and 5.00%, on the other hand, in the cases which recurred later than 3 years were 1.16% and 1.30%, respectively. Topo II alpha SI and MIB-1 SI 1 of former cases were higher than latter cases. Furthermore good correlation between the Topo II alpha SI and MIB-1 SI was found. It is concluded that Topo II alpha expression was as well available for the marker of cell proliferative potential and for one of the predicting factors for tumor recurrence in meningioma and hemangiopericytoma as MIB-1 SI.

Adult↗
PubMed1998

Combined chemotherapy and radiation therapy for central nervous system germ cell tumors: preliminary results of a Phase II study of the Japanese Pediatric Brain Tumor Study Group.

The authors conducted a multiinstitutional phase II study to establish a postsurgical combined chemotherapy and radiation therapy regimen for patients with primary germ cell tumors of the brain. After surgical debulking of the tumor and histological verification, patients were divided into three therapeutic groups: good prognosis, intermediate prognosis, and poor prognosis. Patients received two kinds of chemotherapy (three courses) prior to receiving radiation therapy: carboplatin-etoposide combination ([CARB-VP]: carboplatin 450 mg/m(2) on Day 1, etoposide 150 mg/m(2) on Days 1-3) or ifosphamide-cisplatin-etoposide combination ([ICE]: ifosphamide 900 mg/m(2), cisplatin 20 mg/m(2), and etoposide 60 mg/m(2) on Days 1-5). Patients in the good prognosis group (those with germinomas) were treated with CARB-VP followed by local radiation therapy (24 Gy). Patients in the intermediate prognosis group received CARB-VP followed by local radiation therapy (50 Gy); they received five additional chemotherapy treatments. Patients in the poor prognosis group received ICE followed by whole craniospinal radiation therapy; they also received five additional chemotherapy treatments. Eighty-two patients were evaluated. For the 56 patients with germinomas, a 93% rate of complete remission after treatment was achieved. The remission rate was 76% for 21 patients in the intermediate prognosis group, and no recurrence was detected during a median follow-up period of 2.6 years. In the group of five patients with poor prognosis, the disease in three patients progressed during chemotherapy or radiation therapy and they died within 6 months. There were no serious complications in the surviving patients. The authors found their treatment protocols to be currently effective for patients with germinomas and those with an intermediate prognosis.

Journal Article↗
PubMed1998

Augmented reality visualization system for intravascular neurosurgery.

We aimed to construct an augmented reality-based visualization system to support intravascular neurosurgery and evaluate it in clinical environments. Three-dimensional (3D) vascular models are overlaid on motion pictures from X-ray fluoroscopy by 2D/3D registration using fiducial markers. The models are reconstructed from 3D data obtained from X-ray computed tomographic angiography or from magnetic resonance angiography using the marching-cube algorithm. Intraoperative X-ray images are mapped as texture patterns on a screen object which is displayed with the vascular models. Distortion of X-ray fluoroscopy is eliminated by a new technique of screen mesh deformation. A quantity called reprojection distance was introduced to evaluate the reliability of the displayed images. It predicts the maximum registration error around the registered objects. Analyses of reprojection distances were performed using synthetic data consisting of marker coordinates with 2D or 3D errors. The tolerance of reprojection distance for the clinical environment was determined to be 3.0 mm. The system was tested in two clinical cases in which reprojection distances of 2.6 and 2.09 mm were obtained. Construction and evaluation of our prototype system were successfully carried out. Further development is planned employing a range sensor to permit markerless registration.

Computer Graphics↗
PubMed1998

Endotracheal administration of lidocaine inhibits isoflurane-induced tachycardia.

PURPOSE: Rapid increase in inspired isoflurane concentration increases heart rate and arterial blood pressure. To investigate whether the responses to isoflurane were elicited from stimulation of lower airway and/or lungs, haemodynamic responses to isoflurane administered after tracheal intubation were measured with or without endotracheal or intravenous administration of lidocaine. METHODS: Seventy-two ASA physical status 1 patients, aged 21-50 yr, were randomly allocated to one of four groups. After tracheal intubation, anaesthesia was maintained with oxygen 100% and isoflurane 1.0% with controlled ventilation. After stabilization for 15 min, the isoflurane concentration was rapidly increased to 3.0% in three groups. An endotracheal lidocaine group received pretreatment with endotracheal 0.4 ml lidocaine 8% spray, an intravenous lidocaine group received pretreatment of 32 mg lidocaine i.v., and an isoflurane 3% group received not pre- treatment. In a control group, inspired isoflurane concentration was maintained at 1.0%. Heart rate, systolic blood pressure and end-tidal isoflurane concentration were measured every minute for 10 min. RESULTS: The rapid increase in isoflurane concentration increased heart rate (25 +/- 12% increase from baseline; P < 0.05) but the increase was reduced by endotracheal lidocaine (9 +/- 9%), but not by intravenous lidocaine (22 +/- 13%). The plasma concentration of lidocaine was lower in the endotracheal lidocaine group (0.4 +/- 0.3 microgram.ml-1) than in the i.v. lidocaine group (1.5 +/- 0.2 micrograms.ml-1). CONCLUSION: The isoflurane-induced tachycardia is reduced by pre-treatment with endotracheal lidocaine.

Administration, Inhalation↗
PubMed1998

Kabuki make-up syndrome and report of a case with hydrocephalus.

We report a 22-year-old man with hydrocephalus caused by aqueductal stenosis. The patient was diagnosed with Kabuki make-up syndrome based on associated findings such as a peculiar facies, postnatal growth deficiency, brachydactyly of the fifth fingers, undescended testes, and malrotation of the colon. Kabuki make-up syndrome, recognized in Japan in 1981, is characterized by five cardinal manifestations: a peculiar facies, skeletal anomalies, dermatoglyphic anomalies, slight to moderate mental retardation, and postnatal dwarfism. Neurological anomalies have been reported to include neonatal hypotonia, feeding problems, seizures, West syndrome, microcephaly, brain atrophy, GH deficiency, precocious puberty, delayed sexual development, and diabetes insipidus. Aqueductal stenosis may be caused by part of the series of midline anomalies. Physicians should pay attention to associated anomalous characteristics suggesting a malformation syndrome when they encounter nontumoral aqueductal stenosis in adolescents or adults.

Abnormalities, Multiple↗
PubMed1998

Thrombin activity in CSF after SAH is correlated with the degree of SAH the persistence of subarachnoid clot and the development of vasospasm.

We previously reported that the coagulation system in cerebrospinal fluid (CSF) is strongly activated in the early stage of a subarachnoid haemorrhage (SAH). We evaluated the relationship among thrombin activity, degree of SAH, amount of clearance of SAH, and vasospasm. The CSF levels of fibrinopeptide A (FPA) were measured by radio-immunoassay in 36 SAH patients, who were diagnosed by computerized tomography (CT) within 12 hours and on whom surgery was performed within 48 hours. Clearance of SAH (%) was evaluated as the size of the clot in the basal cistern visualized between the initial and postoperative CT. The mean level of FPA in the patients of Group 3 (Fisher's CT classification) (182.2 ng/ml) was significantly higher than those in the patients of Group 2 (36.2 ng/ml). There was a significant difference in the mean level of FPA between patients with (47.6 ng/ml) and without infarction (408.3 ng/ml). In 18 of the 27 patients of Group 3 for whom the clearance of the SAH was determined, the patients showing a lower clearance rate (< 50%) of SAH demonstrated a significantly higher rate of infarction and a significantly higher level of FPA (466.6 ng/ml) than did the patients with a higher clearance rate (> 50%) of SAH (79.2 ng/ml). These results suggest that, the thrombin activity in CSF is correlated with the degree of SAH, the persistence of subarachnoid clot and the development of vasospasm.

Cerebral Infarction↗
PubMed1998

Current treatment strategies and factors influencing outcome in patients with bacterial brain abscess.

We clearly determined the key to managing patients with brain abscess by retrospectively evaluating the factors affecting poor outcome in these patients. This study included 113 patients with brain abscess diagnosed in the CT era. Basic characteristics and therapeutic parameters were estimated as independent predictors of poor outcome by using univariate and multivariate logistic regression analysis. Patients with poor outcomes more frequently had deeply-located abscesses (p < 0.02), IVROBA (intraventricular rupture of brain abscess (p < 0.001) and were in a severely deteriorated neurological state (p < 0.001) than those with good outcomes. Multiple logistic regression analysis predicted that IVROBA (ORs, 24.5; 95% CI, 3.04 to 197.9) and severely deteriorated cases (ORs, 13.7; 95% CI, 2.34 to 80.8) resulting from IVROBA increased the relative risk of poor outcome. Patients with IVROBA more frequently had also deeply-located abscesses (p < 0.005), positively immunocompromised states (p < 0.05) and were in a severely deteriorated condition (p < 0.003) than those without IVROBA. Patients with metastatic abscess had also IVROBA (p < 0.006). Multiple logistic regression analysis anticipated that deeply-located abscess (ORs, 3.90; 95% CI, 1.38 to 11.04), and metastatic abscess (ORs, 12.26; 95% CI, 1.35 to 111.2) increased the relative risk of IVROBA. Patients in an obtunded state and with marked neurological deficit had IVROBA more often than patients in an alert state and/or mild neurological deficit (ORs, 3.23; 95% CI, 1.17 to 8.86, p < 0.03) before treatment. Our findings suggest that IVROBA strongly influences poor outcome in patients with brain abscess. The key to decreasing poor outcomes may be the prevention and management of IVROBA, by evaluating intracranial pressure pathophysiology. IVROBA should be aggressively treated by aspiration methods for the abscess coupled with appropriate intravenous and intrathecial administration of antibiotics.

Adolescent↗
PubMed1998

Treatment of ornithine transcarbamylase deficiency in girls by auxiliary liver transplantation: conceptual changes in a living-donor program.

BACKGROUND/PURPOSE: Ornithine transcarbamylase (OTC) deficiency is an X-chromosome-linked genetic disorder resulting in hyperammonemia hepatic dysfunction, coma, and serious neurological sequelae. This report describes an experience in treating this condition with living-related liver transplantation. METHODS: Three children with OTC were treated with a living-related liver transplantation. Potential donors were evaluated with the allopurinol loading test to exclude heterozygotes. FK506 and low-dose steroids were used for immunosuppression. Auxiliary partial orthotopic transplantation (APOLT) was used in two of the cases. RESULTS: All three children survived and are doing well without protein restriction. CONCLUSIONS: These observations suggest that in OTC removal of the native liver is not necessary because (1) a partial liver segment with normal enzyme activity corrects the hyperammonemia, (2) in case of graft failure the native liver is an available backup, and (3) the native liver has the ability to recover function. As long as living-related donors serve as the main source of donor organs, APOLT is a safer approach to liver transplantation in OTC.

Amino Acid Metabolism, Inborn Errors↗
PubMed1998

Prophylactic effect of papaverine prolonged-release pellets on cerebral vasospasm in dogs.

OBJECTIVE: A drug delivery system using copoly(lactic/glycolic acid) was developed for the intracranial administration of papaverine. A rod-shaped implant prepared by a heat compression method was tested to determine its efficacy in preventing cerebral vasospasm in dogs. METHODS: Sixteen dogs were randomly assigned to one of two groups, i.e., placebo or papaverine. Control angiography was performed, followed by right craniectomy and the induction of subarachnoid hemorrhage by the placement of a clot in the Sylvian fissure. Two pellets, containing either 25 mg of papaverine or no papaverine, were placed in the cistern. In in vitro studies, 56% of the actual papaverine loading was released in the first 4 days and 78% within 8 days. On Day 7, angiography was repeated and the animals were killed. A similar experiment using low-dose pellets containing 5 mg of papaverine, half of which was released within 7 days, was performed with 16 mongrel dogs. RESULTS: There were significant differences between the papaverine- and placebo-treated groups in the reductions of vessel diameters of the internal carotid, middle cerebral, and anterior cerebral arteries on the clot side. The mean concentration of papaverine in the clot was 4.5 x 10(-4) mol/L. The low-dose pellet failed to prevent cerebral vasospasm, although the mean concentration of papaverine in the clot was 2.3 x 10(-5) mol/L. CONCLUSION: A prolonged-release preparation of papaverine that could be implanted intracranially at the time of surgery prevented vasospasm significantly while maintaining an appropriate concentration of papaverine in the cistern.

Animals↗
PubMed1998

Neuroprotective effect of an antioxidant, ebselen, in patients with delayed neurological deficits after aneurysmal subarachnoid hemorrhage.

OBJECTIVE: The effect of ebselen, a seleno-organic compound with antioxidant activity through a glutathione peroxidase-like action, on the outcome of subarachnoid hemorrhage was evaluated in a multicenter placebo-controlled double-blind clinical trial. METHODS: Patients who suffered aneurysmal subarachnoid hemorrhages of Hunt and Kosnik Grades II through IV at admission and were able to start drug treatment within 96 hours of the ictus were enrolled. Early surgery was performed whenever possible. Oral administration of ebselen granules suspended in water (150 mg, twice a day) or placebo was started immediately after admission and continued for 2 weeks. The major end points were the Glasgow Outcome Scale at 2 weeks, 1 month, and 3 months after the start of treatment. The incidence of delayed ischemic neurological deficits clinically diagnosed as resulting from vasospasm and the incidence and extent of low-density areas on postoperative computed tomographic scans were also studied as secondary outcome measures. RESULTS: Intent-to-treat analysis of the 286 patients enrolled in the trial (145 patients administered ebselen and 141 administered placebo) revealed that the incidence of clinically diagnosed delayed ischemic neurological deficits was unaltered. There were 52 (receiving ebselen) and 58 (receiving placebo) patients with delayed deficits; however, a significantly better outcome was observed after ebselen treatment than after placebo (P = 0.005, chi2 test). There was a corresponding decrease in the incidence and extent of low-density areas (P = 0.032, Wilcoxon rank sum test). CONCLUSION: Ebselen reduced brain damage in patients with delayed neurological deficits after subarachnoid hemorrhage and may be a promising neuroprotective agent.

Aged↗
PubMed1998

Metabolic profiles of patients with subarachnoid hemorrhage treated by early surgery.

OBJECTIVE: This study was conducted to evaluate the metabolic response of patients with subarachnoid hemorrhage (SAH) and to determine whether the severity of hemorrhage influenced the response. METHODS: Resting energy expenditure, nitrogen balance, and serum rapid-turnover proteins were studied for 3-day periods at Day 4, Day 10, and before discharge in patients with SAH who underwent surgical clipping within 2 days after the onset. The patients were divided into two groups according to the Hunt and Hess classification system; there were 17 patients with Grade I or II (mild group) and 19 patients with Grade III, IV, or V (severe group). RESULTS: The mean resting energy expenditures (mean+/-standard deviation) were highest on Day 10, which were 146+/-24% and 198+/-78% of basal energy expenditure in the mild and severe groups, respectively. The nitrogen balance levels of the mild group on Days 4 and 10 were -3.0+/-3.5 g per day and -4.5+/-2.9 g per day, and those of the severe group were -7.5+/-3.2 g per day and -9.2+/-4.1 g per day, respectively. There was a significant difference in the nitrogen balance over time between the two groups (P=0.0037). Serum transferrin, prealbumin, and retinol-binding protein levels were lowest on Day 4 and gradually increased. There were no significant differences in these parameters between the two groups. CONCLUSION: SAH treated by surgery induces a profound stress response. A significant difference of increased catabolism but not decreased anabolism between the mild and severe groups was noted.

Aged↗