Biomedical subjects

O Sato

Publications and source records attributed to O Sato.

At least 37 records · Page 2Linked to original sources

PubMed2001

Myosin assembly critical for the enzyme activity of smooth muscle myosin phosphatase: effects of MgATP, ionic strength, and Mg(2+).

We suggested that an assembled form of phosphorylated myosin (P-myosin) might exhibit higher affinity for smooth muscle myosin phosphatase (SMMP) than dissociated P-myosin on the basis of the effect of MgATP [Sato and Ogawa (1999) J. Biochem. 126, 787-797]. To further deepen our understanding, we examined the SMMP activity and P-myosin assembly with various ionic strengths and Mg(2+) concentrations, with and without MgATP, all of which are well known to be critical for myosin assembly. The structure of myosin molecules was directly observed by electron microscopy using a rotary shadowing procedure, which was found to be consistent with the sedimentation assay. We found that the SMMP activity was always high when P-myosin was assembled. MgATP, which disassembled P-myosin mostly into a folded conformation, in contrast, decreased the enzyme activity. We also found that glycerol had a dissociating action on P-myosin, primarily dissociating it into an extended conformation, resulting in reduced SMMP activity, and that increases in the ionic strength and Mg(2+) (>5 mM) inhibited SMMP. These results indicate that myosin assembly is essential for SMMP activity.

Adenosine Triphosphate↗

PubMed2001

Fluence to effective dose conversion coefficients for electrons with energy from 1 MeV to 100 GeV.

Fluence to organ dose and effective dose conversion coefficients have been calculated for electrons from 1 MeV to 100 GeV using an anthropomorphic phantom and the EGS4 code. The conversion coefficients were calculated for six typical irradiation geometries taking electromagnetic cascade shower and photonuclear reactions into account. The contribution to the absorbed dose due to the photonuclear reactions in energies up to 140 MeV was evaluated to be less than 0.2%. Even at energies above 140 MeV the dose contributions of the photonuclear reactions were insignificant.

Electrons↗

PubMed2001

Value of intraarterial prostaglandin E(1) injection during CT hepatic arteriography.

OBJECTIVE: The purpose of our investigation was to determine if injection of prostaglandin E(1) during CT hepatic arteriography could help physicians to distinguish tumors from nonportal venous flow-related pseudolesions in the region of the gallbladder fossa. SUBJECTS AND METHODS: In 34 patients who underwent CT during arterial portography to detect liver tumors, CT hepatic arteriography was performed before and after prostaglandin E(1) injection via the superior mesenteric artery. Between each study, an interval of 10 minutes was set. On CT hepatic arteriogram obtained 15 to 20 sec after prostaglandin E(1) injection, we distinguished changes in the size and shape of pseudolesions in the liver around the gallbladder as well as those of 42 tumorous lesions. In addition, we measured the change in CT attenuation of pseudolesions. RESULTS: The size of the enhanced area of pseudolesions visible on CT hepatic arteriography decreased in 69% (25/36) of the pseudolesions after intraarterial prostaglandin E(1) injection, with the mean diameter diminishing from 14.1 mm to 8.8 mm. Notably, in 11 pseudolesions, the enhanced area disappeared. In 86% (31/36), the CT attenuation decreased with the mean attenuation, diminishing from 211.3 H to 163.8 H. However, the size and shape of the enhanced area of tumorous lesions did not change. CONCLUSION: The hemodynamic features of pseudolesions on angiographically assisted helical CT scans caused by cholecystic venous inflow are easily influenced by increased portal venous flow. Consequently, pseudolesions around the gallbladder usually can be distinguished from tumorous lesions by adding prostaglandin E(1) injection via the superior mesenteric artery during CT hepatic arteriography.

Alprostadil↗

PubMed2000

Inhibition of smooth-muscle myosin-light-chain phosphatase by Ruthenium Red.

Ruthenium Red (RuR) is widely used as an inhibitor of ryanodine receptor Ca(2+) release channels, but has additional effects such as the induction of Ca(2+) sensitization of contraction of permeabilized smooth muscles. To address the mechanism underlying this process, we examined the effects of RuR on contractility in permeabilized guinea-pig ileum and on the activity of myosin-light-chain phosphatase (MP). RuR increased the force at submaximal [Ca(2+)] (pCa 6.3) approx. 4-fold. This effect was not observed after thiophosphorylation of MP. RuR also seemed capable of preventing the thiophosphorylation of MP, suggesting a direct interaction of RuR with MP. Consistent with this possibility, smooth-muscle MP was inhibited by RuR in a concentration-dependent manner (IC(50) 23 microM). Exogenous calmodulin significantly increased RuR-induced contraction at pCa 6.3 but had little effect on contraction induced by microcystin at this [Ca(2+)]. Ca(2+)-independent contraction was induced by RuR (EC(50) 843 microM) and by microcystin (EC(50) 59 nM) but the maximal force induced by RuR was smaller than that induced by microcystin. The addition of 300 microM RuR enhanced the contraction induced by 30 nM microcystin but markedly decreased that induced by 1 microM microcystin. Such a dual action of RuR on microcystin-induced effects was not observed in experiments using purified MP. We conclude that the RuR-induced Ca(2+) sensitization of smooth-muscle contraction is due to the direct inhibition of MP by RuR.

Adenosine Triphosphate↗

PubMed2000

Malignant islet cell tumor projecting into the main pancreatic duct.

We report herein a rare case of islet cell tumor showing a unique growth pattern in a patient who developed repeated acute pancreatitis as the tumor's initial symptom. Preoperative imaging examinations showed dilatation of the main pancreatic duct (MPD) and cysts around the pancreatic tail. A distal pancreatectomy with splenectomy was performed because the pancreatitis was localized in the distal pancreas and was not controlled by various drug therapies. Grossly, the tumor consisted of two component parts: a markedly infiltrative part in the pancreatic parenchyma, and a papillary elevated part in the MPD. The MPD was obstructed by the tumor spreading widely along the distal MPD. Microscopically, the tumor was composed entirely of islet cell tumors (nonfunctioning), with several foci of venous and lymphatic involvement. Based on its growth behavior, we assumed that the tumor may have arisen from the MPD or from islet cells closely adjacent to the MPD. The patient's postoperative course was uneventful and he is doing well 2 years after the operation. We discuss the growth pattern of the tumor and the cause of the pancreatitis.

Acute Disease↗

PubMed2000

Ten years' experience of aortic aneurysm associated with systemic lupus erythematosus.

BACKGROUND: aortic aneurysm is a rare but life-threatening cardiovascular complication in patients with systemic lupus erythematosus (SLE). The purpose of this study was to clarify the characteristic clinical features and the pathological mechanism of aneurysmal formation in these patients. METHODS: among 429 patients operated on for abdominal aortic aneurysm (AAA) during the past 10 years, five cases with SLE were treated surgically. Their clinical data were reviewed, and the resected aneurysmal wall of the five patients was also examined histologically. RESULTS: the mean age of the patients with SLE was 55 years, which was statistically younger than that of the other patients (mean 77 years, s.d. 7.9, p <0.05). They had received long-term corticosteroid therapy for the treatment of SLE for a mean of 23 years. Histologically, destruction of the medial elastic lamina was characteristic. Four patients had no complications in the postoperative follow-up period (mean 4 years), while the remaining patient died of rupture of a dissecting aneurysm two years after operation. CONCLUSION: prolonged steroid therapy may play a major role in accelerating atherosclerosis, which can result in aortic aneurysmal enlargement, possibly together with primary aortic wall involvement and/or vasculitic damage in patients with SLE.

Adrenal Cortex Hormones↗

PubMed2000

In vivo retention of endothelial cells adenovirally transduced with tissue-type plasminogen activator and seeded onto expanded polytetrafluoroethylene.

PURPOSE: Seeding a prosthetic graft with genetically engineered vascular endothelial cells (ECs) has the potential to enhance the graft's antithrombotic properties. However, it has been reported that ECs transduced with tissue-type plasminogen activator (tPA) have very low levels of retention on grafts, probably because of increased proteolytic activity. We examined the retention of human tPA (htPA)-transduced ECs after the cells were seeded onto expanded polytetrafluoroethylene (ePTFE) grafts and implanted into dogs. We also examined the function of secreted htPA in this model. METHODS AND RESULTS: Canine jugular venous ECs were transduced with adenoviral vectors encoding htPA (Adex1CAhtPA) and beta-galactosidase (Adex1CALacZ). There was a positive relationship between the percentage of X-gal ECs staining and the multiplicity of infection (MOI) of Adex1CALacZ. The level of htPA production in vitro increased with the increasing MOI of Adex1CAhtPA, but decreased gradually 4 days after infection. ECs coinfected with Adex1CAhtPA and Adex1CALacZ (htPAEC) or ECs infected with Adex1CALacZ alone (LacZEC) were seeded onto ePTFE grafts at densities equivalent to confluence to visualize retained ECs in an in vivo flow study. The grafts were implanted into canine carotid arteries and harvested after 5 hours of exposure to blood flow. The harvested grafts showed patchy defects in ECs, most of which were covered with mural thrombi. There was no significant difference in retention between htPAEC (29.3% +/- 8.7%) and LacZEC (19.5% +/- 3. 6%). There was a significant negative correlation between the in vivo EC retention on the grafts and the in vitro cellular passage level of ECs (P =.041; r = -.40). htPAEC produced 210.3 +/- 22.2 ng htPA antigen/10(6) cells per 6 hours in vitro and continued to secrete htPA on the harvested graft. CONCLUSIONS: We demonstrated that a large amount of functional htPA was produced by adenovirally modified canine ECs. The results of the in vivo study may suggest that overexpression of tPA has little effect on the short-term retention of early passage ECs seeded onto ePTFE grafts.

Adenoviridae↗

PubMed2000

Pathophysiology of long-standing overt ventriculomegaly in adults.

OBJECT: Long-standing overt ventriculomegaly in adults (LOVA) is a unique form of hydrocephalus that develops during childhood and manifests symptoms during adulthood. The aim of the present study was to analyze the specific pathophysiological characteristics of LOVA. METHODS: The specific diagnostic criteria for LOVA include severe ventriculomegaly in adults that is associated with macrocephalus measuring more than two standard deviations in head circumference and/or neuroradiological evidence of a significantly expanded or destroyed sella turcica. Twenty patients who fulfilled these criteria, 14 males and six females, were retrospectively studied. These patients' ages at diagnosis ranged from 15 to 61 years (mean 39.4 years). All had symptoms and/or signs indicating that hydrocephalus first occurred at birth or during infancy in the absence of any known underlying disease. The authors performed a pathophysiological study that included specific variations of magnetic resonance (MR) imaging, such as fluid-attenuated inversion recovery and cardiac-gated cine-mode imaging; intracranial pressure (ICP) monitoring; three-dimensional computerized tomography (CT) scanning; and other techniques. Hydrocephalus was caused by aqueductal stenosis in all patients. Severe ventriculomegaly involving the lateral and third ventricles was associated with a marked expansion or destruction of the sella turcica in 17 cases. Cardiac-gated cine-MR imaging did not reveal any significant movements of cerebrospinal fluid in the aqueduct. Three-dimensional CT ventriculography confirmed that the expanded third ventricle protruded into the sella and, sometimes, extended a diverticulum. Fourteen patients revealed symptoms and signs that indicated increased ICP with prominent pressure waves. Dementia or mental retardation was seen in 11 patients, gait disturbance in 12, and urinary incontinence in eight; all three of these symptoms were observed in seven patients. Thirteen patients experienced visual disturbance. Nine patients underwent ventriculoperitoneal shunt implantation as the initial treatment, leading to postoperative subdural hematoma in all seven cases in which a differential pressure valve was used. Nine patients, three of whom were initially treated by shunt placement, underwent a neuroendoscopic procedure, mainly for third ventriculostomy. Postoperatively, ICP returned to normal, and marked to-and-fro pulsatile movements at the site of ventriculostomy were recognized on cine-MR imaging in patients treated endoscopically. However, the ventriculomegaly was little improved. Consequently, all patients eventually demonstrated improvement in response to either a shunt equipped with a pressure-programmable valve or an endoscopic procedure; however, depression appeared in six patients, who required psychiatric consultation or medication. CONCLUSIONS: Such remarkably decreased intracranial compliance but relatively high ICP dynamics are the pathophysiological characteristics of LOVA. The therapeutic regimen should be determined based on the individual's specific pathophysiological makeup.

Adolescent↗

PubMed2000

Efficacy of neuroendoscopic procedures in minimally invasive preferential management of pineal region tumors: a prospective study.

OBJECT: This prospective study is based on a consecutive series of 20 patients with pineal region tumors who underwent minimally invasive preferential management. The purpose of this report is to discuss the role of neuroendoscopic procedures in the management of pineal region tumors. METHODS: If the tumor markers alpha-fetoprotein and human chorionic gonadotropin were not detected in serum and there was significant ventricular dilation visualized on neuroimages, neuroendoscopic surgery was first applied for tumor debulking with tissue diagnosis and gross morphological analysis of the tumor and the intraventricular structures, followed by third ventriculostomy. Subsequent procedures were determined on the basis of verified individual tumors. For treatment of germinomas and pineoblastomas, if no tumor dissemination was confirmed by pre-, intra-, or postoperative findings, stereotactic radiotherapy or radiosurgery was performed after one course of chemotherapy with the ICE regimen (isofomid, cisplatin, and etoposide) and followed by two additional courses of chemotherapy. For treatment of malignant germ cell tumors, after extensive surgery, adjuvant chemotherapy with the ICE regimen was performed in three courses in all cases. Then radiotherapy was started using various methods, depending on the evidence of tumor dissemination. For treatment of teratomatous and neuroectodermal tumors other than pineoblastomas, extensive surgical removal was performed. As for adjuvant therapy, if the tumor was a low-grade glioma or if the patient was younger than 5 years of age, postoperative treatment did not include radiotherapy. If the tumor was a malignant teratoma or high-grade glioma, conventional focal radiotherapy was performed, followed by chemotherapy with ICE for 1 year. All but two treated patients had ventriculomegaly. Neuroendoscopic procedures were performed in six of 15 treated patients. Neuroendoscopic biopsy with tumor debulking offered enough material for tissue diagnosis, including immunohistochemical analysis and, in one case, revealed evidence of tumor dissemination undetectable on neuroimaging. With one exception, no shunt was required in any patient undergoing endoscopic third ventriculostomy. Stereotactic radiotherapy was performed in indicated cases. Favorable therapeutic outcomes were obtained in all cases of germinoma and pineoblastoma, with follow-up periods ranging from 24 months to 6.5 years. CONCLUSIONS: Our minimally invasive preferential regimen clarified the precise indication for neuroendoscopic procedures, and the majority of our patients with dilated ventricles and no evidence of tumor markers were treated satisfactorily with effective neuroendoscopic procedures as the initial procedure, avoiding unnecessary craniotomy and radiotherapy and promising excellent therapeutic outcomes. The treatment for malignant pineal region tumors remains a subject for further study.

Adolescent↗

PubMed2000

[Dental treatment for the handicapped by a combination of public community, dental association and university hospital--a system of Suginoki Dental Clinic].

Suginoki Dental Clinic, which is managed by Suginami Dental Association, financially supported by Suginami City, and technically assisted by the University Hospital, Tokyo Medical and Dental University, was established for dental treatment of handicapped persons living in Suginami City, Tokyo who are difficult to be treated by private practitioners. It has one full-time dentist, 12 part-time dentists, two dental hygienists, one nurse, and one clerk; one of the part-time dentists practices twice a week there. Since December 1994, 406 patients visited the clinic and the total cases was 9,273 in December 1999; 99 cases were mentally retarded, 36 autism, and 30 epileptic patients in the younger group; and 65 cases were cerebrovascular disease and 27 cardiac malfunction patients in the older group. Almost all the patients needed special care such as monitoring, intravenous sedation, nitrous oxide sedation, and general anesthesia. Four cases underwent general anesthesia, and no complication was seen among the cases. It was concluded that the clinic has been successful due to a good relationship among the Dental Association, Suginami City, and the dental hospital.

Community Dentistry↗

PubMed2000

Carotid artery reconstruction for Takayasu's arteritis the necessity of all-autogenous-vein graft policy and development of a new operation.

BACKGROUND: We have adopted an all-autogenous-vein-graft policy in carotid reconstruction for Takayasu arteritis, namely an ascendo-right carotid and right subclavian (axillary) arteries bypass using a pantaloon vein graft for patients all of whose arch branches are occluded, and an extra-anatomical bypass from the right subclavian artery for patients whose brachiocephalic artery is the only arch branch that remains patent. This report is to elaborate on these operations and to assess the long-term outcome. METHODS: Six patients were operated on according to this policy; (5 women, 1 man, age range: 14 to 59 years (mean: 30). The indications for surgery were severe cerebral ischaemia that significantly interfered with their daily lives. The pantaloon vein graft bypass was performed in four patients, and an extra-anatomical bypass in two. The specific management protocol to prevent the "postbypass hyperperfusion syndrome" and cerebral oedema included a shunt procedure to the internal carotid artery using one limb of the pantaloon vein graft, induced hypotension just before the completion of the carotid reconstruction and the administration of a glycerine-fructose solution. RESULTS: Cerebral ischaemic symptoms disappeared in all patients. All but one, who died of a ruptured thoraco-abdominal aneurysm on the 35th postoperative month, are living a normal life with a patent graft. No suture line complications have as yet been encountered (follow-up: 10 to 205 months, mean: 126 months). CONCLUSIONS: Carotid vein bypass for Takayasu arteritis, particularly, the pantaloon vein graft bypass is recommended for those of whom all aortic arch branches are occluded, resulting in severe brain ischaemia. Perioperative blood pressure control is important for prevention of the hyperperfusion syndrome.

Adolescent↗

PubMed2000

Patency after revision surgery for failing infrainguinal vein grafts.

BACKGROUND: Although the results of bypass surgery on arteries in the lower extremities have been greatly improved during the last decades, there are still a significant number of primary failures. In order to investigate the reasons for the failure of autogenous vein grafts after infrainguinal arterial bypass surgery and to ascertain the results of revision operations on the failing grafts, we conducted a clinical study. METHODS: Retrospective study on 104 patients who underwent infrainguinal arterial revascularisation with autogenous veins. RESULTS: One hundred and twenty-six bypasses were constructed in 121 limbs. Seventy-nine of these were for claudication and 47 for threatened limbs (rest pain or ischaemic tissue loss). Five-year primary and secondary patency rates were 69.7% and 84.9% respectively. Spliced or suture-repaired grafts had a poor outcome; five out of seven eventually becoming thrombosed. On the other hand, revision operations for failing but not yet thrombosed grafts produced good results; the five-year primary patency rate after these operations was 76.0%, whereas after single-segment primary grafting it was 72.1%. CONCLUSIONS: These results stress the importance of vigilant follow-up and active intervention for failing grafts. Poor outcome with injured vein grafts emphasizes the importance of meticulous vein harvesting.

Adult↗

PubMed2000

Aortic aneurysm in patients with autoimmune diseases treated with corticosteroids.

BACKGROUND: Aortic aneurysm is a rare but life-threatening cardiovascular complication in patients with autoimmune disorders. The purpose of this study was to clarify the characteristic clinical features and the pathological mechanism of aneurysmal formation in those patients treated with corticosteroids. METHODS: Among 429 patients operated on for abdominal aortic aneurysm during the past 10 years, six patients with autoimmune diseases treated with corticosteroids (one with progressive systemic sclerosis, one with rheumatoid arthritis and four with systemic lupus erythematosus) were reviewed retrospectively. Their data were compared with those of 391 patients with atherosclerotic aneurysms with no autoimmune disorders. The resected aneurysmal walls of the six patients were also compared histopathologically with those of the last six consecutive patients in the control group. RESULTS: The average age of the patients with autoimmune disease was younger than that of the control group (53.8+/-16.6 vs 71.8+/-7.8 years; p<0.05). Patients with autoimmune disease had received long-term corticosteroid therapy for 15-32 years; mean 22.2+/-6.5 years. Pathological examination showed that the destructive change of the medial elastic lamina in the autoimmune disease group was wider than that in the controls. Most patients had no complications in the postoperative follow-up period (5.1+/-3.2 years), while one patient died of rupture of a dissecting aneurysm two years after operation. CONCLUSIONS: Prolonged corticosteroid treatment probably plays a major role in the disintegration of connective tissue of the media, possibly together with primary aortic wall involvement and/or vasculitic damage in patients with autoimmune disorders, which can result in aortic aneurysmal enlargement.

Adrenal Cortex Hormones↗

PubMed1999

Noncatalytic Organic Synthesis Using Supercritical Water: The Peculiarity Near the Critical Point.

Pinacol and Beckmann rearrangements can be carried out effectively by using supercritical water (scH(2)O) both as an acid catalyst as well as a medium. In the near-critical region not only are the rates significantly accelerated (see picture), but the nature of supercritical water can be adjusted to give weak acidity, which opens a new reaction pathway to a Diels-Alder adduct between dehydrated products.

Journal Article↗

PubMed1999

Surgery for descending thoracic aortic anastomotic aneurysms with a temporary external bypass method.

The surgical treatment of descending thoracic aortic anastomotic aneurysms is technically challenging. The purpose of this study was to evaluate the use of a temporary external bypass method as an intraoperative measure in the surgical treatment of anastomotic aneurysms of the descending thoracic aorta. An analysis of five consecutive patients who had undergone surgery for a collective seven descending thoracic aortic anastomotic aneurysms in our university hospital over a period of 14 years was conducted. A temporary bypass technique was used as an intraoperative measure in all the operations, four of which were performed with a right axillary to left external iliac artery bypass, while other sites were used in the remaining three. Systemic heparinization was able to be avoided in six operations and was markedly reduced in the remaining one. Although the major postoperative complication was coagulated hemothorax after six procedures, all patients recovered well and are still alive after a mean follow-up period of 8.2+/-1.5 (SEM) years. The results of this analysis led us to conclude that our temporary bypass method for treating descending thoracic aortic anastomotic aneurysm prevented the risks of anticoagulant administration for circulatory support, which contributed to the success of the operation. This method can be used as adjunct treatment for anastomotic aneurysms in the descending thoracic aorta.

Adult↗

PubMed1999

Successful surgical treatment of aortogastric fistula after an esophagectomy and subsequent endovascular graft placement: report of a case.

An aortogastric fistula is a rare but fatal complication after an esophagectomy and intrathoracic esophagogastric anastomosis. A 54-year-old man underwent an esophageal resection due to carcinoma in his lower esophagus. The alimentary tract continuity was restored by intrathoracic esophagogastric anastomosis. Forty-six days later, he suffered a massive hematemesis due to an aortogastric fistula which had formed at the esophagogastric suture line. The fistula was surgically obliterated twice, but each operation was followed by pseudoaneurysm formation. The patient was finally successfully treated with an endovascular stent graft placement. This is the first report of a patient surviving after developing this complication.

Anastomosis, Surgical↗

PubMed1999

Neuroendoscopic surgery for specific forms of hydrocephalus.

Neuroendoscopic surgery was used to treat patients with various forms of hydrocephalus with specific pathophysiology, including long-standing overt ventriculomegaly in adulthood (LOVA), isolated unilateral hydrocephalus (IUH), isolated IV ventricle (IFV), disproportionately large IV ventricle (DLFV), isolated rhombencephalic ventricle (IRV), isolated quarto-ventriculomegaly (IQV), dorsal sac in holoprosencephaly (DS), and loculated ventricle (LV). A total of 26 operative procedures were performed, with neuroendoscopic surgery in 22 patients, 12 with unique forms of noncommunicating hydrocephalus and 10 with various types of postshunt isolated compartment. These procedures included III ventriculostomy, aqueductal plasty by both rostral and caudal approaches, foraminal plasty in the foramen of Monro/foramen of Magendie, septostomy, IV ventriculostomy, fenestration of septation in the loculated ventricle, fenestration of arachnoid cyst or cystic tumor obstructing a ventricle with or without tumor removal, and dorsal sac ventriculostomy. The characteristics of the cerebrospinal fluid (CSF) dynamics in the individual specific pathophysiologies were delineated by cardiac-gated cine-mode magnetic resonance imaging (MRI) before and after the endoscopic procedure. The consequent success rate (success = restoration of communication of the CSF pathway in the individual patients) was 19/22 (86.4%). The progression of ventricular dilatation was stopped in 17 of 19 patients (89.5%) in whom the endoscopic procedure was successful (radiologically arrested hydrocephalus). Improvement in the clinical symptoms and signs (clinically arrested hydrocephalus) was obtained in 15 of the patients (68.2% of all patients: 5 with LOVA, 3 with IQV, 5 with IUH and 2 with LV). Seven patients (2 LOVA, 2 IFV, 1 DS, 1 DFLV and 1 IRV) underwent a shunt procedure after the neuroendoscopic procedure(s). The postoperative changes of ventriculomegaly were complicated, reflecting the differences in the brain parenchymal compliance and postoperatively corrected CSF flow dynamics in the major CSF pathway.

Adult↗

PubMed1999

A new experimental model of obstructive hydrocephalus in the rat: the micro-balloon technique.

We used three types of specialized micro-balloons 0.7-1.35 mm in outer diameter instead of kaolin to develop a reproducible rat model of hydrocephalus with a low experimental mortality. The micro-balloon was inserted 6 mm deep into the cisterna magna via a burr hole immediately behind the lambda. The angle of introduction was 50 degrees. We also set up kaolin-induced hydrocephalic models in 25 rats as controls. The kaolin model revealed 52% mortality with an 80% induction rate of hydrocephalus, while the balloon model showed 9% mortality with a 60% induction rate. Balloon-induced hydrocephalus was maximal at 1 week and tended to decrease after 2-3 weeks. The pathological findings were not different between the two models. We concluded that the micro-balloon model for hydrocephalus is an easily reproducible model with low experimental mortality.

Animals↗