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Biomedical subjects

K Hongo

Publications and source records attributed to K Hongo.

At least 19 recordsLinked to original sources
PubMed2006

Telecontrolled micromanipulator system (NeuRobot) for minimally invasive neurosurgery.

BACKGROUND: To perform less invasive neurosurgery, a telecontrolled micromanipulator system has been developed and applied to clinical situations. Basic experiments for telesurgery have also been conducted. METHOD: A cadaver head was used to carry out surgical simulation of the opening of the sylvian fissure and third ventriculostomy. After obtaining permission from the Ethical Committee of Shinshu University School of Medicine, part of the recurrent meningioma in a 45-year-old man was removed. As basic experiment for telesurgery, surgical simulation was also conducted in a rat brain with the operating console transported to a hospital 40 km distant from the University. FINDINGS: Opening of the sylvian fissure and third ventriculostomy were accurately performed. Tumour removal in a patient with recurrent meningioma was safely achieved. Surgical simulation in the rat brain was accurately and correctly carried out, operated on from a hospital 40 km distant. CONCLUSIONS: The NeuRobot, telecontrolled micromanipulator system, can be used as a tool for less invasive neurosurgery.

Animals↗
PubMed2004

Inducible expression of p57KIP2 inhibits glioma cell motility and invasion.

To examine the role of p57KIP2 in human malignant glioma cells, we studied its expression in a panel of human malignant glioma specimens by western blot and immunohistochemical analysis. To determine the effects of p57KIP2 expression on the phenotype of glioma cells, we analyzed two inducible stably transfected p57KIP2 expressing glioma cell lines. Expression of p57KIP2 was induced in U373 and U87 malignant glioma cells with doxycycline using the tetracycline repressor system. A phagokinetic track assay on gold particles was used to investigate differences in cell migration between p57KIP2 expressing and non-expressing control cells. The effects of the extracellular matrix (ECM) on U373 motility was determined in p57+ and p57-cells on surfaces coated with 5 microg/cm2 of fibronectin, laminin, type I and type IV collagens. The invasion of p57+ and p57- glioma cells across BD Biocoat Matrigel invasion chambers was then determined. p57KIP2 was weakly expressed in 4/6 glioblastoma (GBM) specimens by western blot. By immunohistochemistry, p57KIP2 immunoreactivity was positive in 8/40 GBMs, and was primarily nuclear in location. The motility of U373 glioma cells was significantly reduced after p57KIP2 induction. The presence of ECM proteins did not further alter the motility of p57+ and p57- glioma cells. The results of the invasion chamber assay showed that p57+ cells exhibited a 35% reduction in their invasive capacity as compared to p57- cells. These data suggest that p57KIP2 is expressed in at least some malignant gliomas. Inducible expression of 57KIP2 in cell lines deficient in this cyclin-dependent kinase inhibitor reduces their otility and invasiveness.

Blotting, Western↗
PubMed2001

Low anterior interhemispheric approach--a narrow corridor to aneurysms of the anterior communicating artery.

BACKGROUND: Many approaches for clipping anterior communicating artery (ACoA) aneurysms are reported in the literature. We describe here a new approach called "low anterior interhemispheric approach" for clipping of ACoA aneurysms. MATERIALS AND METHODS: A low anterior interhemispheric approach utilizing a unilateral frontal craniotomy flap with minimal unilateral frontal lobe retraction was used in treating four patients harboring an unruptured ACoA aneurysm. The approach axis is directed to the ACoA area itself with minimal exposure to the anterior cerebral vessels. FINDINGS: In all patients, complete neck clipping was possible with minimal brain retraction, without vascular damage and preserved olfaction. INTERPRETATION: This approach is preferred on anatomical grounds for cases of unruptured small and medium sized ACoA aneurysms projecting anteriorly or posteriorly because the anterior communicating artery complex area can be fully visualized with minimal manipulation of the frontal lobes and anterior cerebral arteries.

Adult↗
PubMed2001

Results of direct surgery for aneurysmal subarachnoid haemorrhage: outcome of 2055 patients who underwent direct aneurysm surgery and profile of ruptured intracranial aneurysms.

BACKGROUND AND PURPOSE: The purpose of this study is to evaluate the therapeutic value of our surgical treatment of subarachnoid haemorrhage in a large series with standardized surgical principles. METHODS: Results of 2055 direct operations on ruptured intracranial aneurysms, treated in our institutions, where surgical indications, instruments and techniques were standardized, between 1988 and 1998, were retrospectively evaluated and outcome of the patients was discussed; cases treated by intravascular procedures were excluded. RESULTS: According to the evaluation at discharge, 1083 (52.7%) patients were excellent, 324 (15.8%) good and 223 (10.9%) fair. There were 160 (7.8%) patients of poor outcome and the remaining 265 (12.9%) died. There were no differences in the outcome between pre-operative Hunt & Kosnik grade I and II, Fisher Scale 1 and 2, anterior circulation aneurysms and posterior circulation aneurysms except those at and around the basilar bifurcation, men and women, and those clipped and not clipped. CONCLUSIONS: The factors related to poor outcomes were, age of 60 years or over, pre-operative Hunt & Kosnik grade II or more, Fisher Scale 3 or more, aneurysm size over 15 mm in diameter, and location at and around the basilar artery bifurcation. The results presented in this study show the status of our direct surgical management of subarachnoid haemorrhage in a large series with standardized surgical principles and procedures.

Adolescent↗
PubMed2001

Giant basilar bifurcation aneurysm presenting as a third ventricular mass with unilateral obstructive hydrocephalus: case report.

We report a rare case of a non-ruptured basilar bifurcation aneurysm presenting as a third ventricular mass producing unilateral obstructive hydrocephalus. This is the first reported case of its kind. A 70 year old woman presented with a giant basilar bifurcation aneurysm in which the aneurysm protruded into the third ventricle as a mass causing unilateral left hydrocephalus. The patient gradually became disoriented and developed a right hemiparesis and global aphasia. The right vertebral artery was occluded by placing coils intravascularly followed by an endoscopic septostomy. The patient's neurological state dramatically improved immediately. One month after the septostomy, however, the aneurysm ruptured and the patient eventually died. Treatment of the hydrocephalus only was selected instead of direct surgery or an intravascular procedure on the aneurysm, which eventually ruptured. The mechanisms for the unilateral hydrocephalus and the rupture of the aneurysm are described. The treatment strategy for these lesions is also discussed.

Aged↗
PubMed2001

Cerebellopontine angle meningioma with a high jugular bulb.

A cerebellopontine angle meningioma originating from the skull base over a high jugular bulb is quite rare. We report a case of a 68-year-old woman who had a right cerebellopontine angle meningioma with a prominent high jugular bulb. CT and MRI revealed a round tumour which attached to a bony prominence over the high jugular bulb. The apex of the jugular bulb was 3 mm higher than the floor of the internal auditory canal. The tumour was removed via a suboccipital retrosigmoid approach. The bony projection was drilled off carefully using a diamond drill; the jugular bulb became visible through the thinned bone. When a meningioma of this type is removed including bony changes, special attention is needed to avoid injury to the jugular bulb.

Aged↗
PubMed2001

Surgical decision-making on cerebral cavernous malformations.

This study is an attempt to clarify surgical decision-making on cerebral cavernous malformations based on the data available in the literature. Using a mathematical model, we calculated the morbidity-free survival curves of the patients harboring cerebral cavernous malformations. Using these survival curves, we calculated the morbidity-free life expectancies of the patients at certain age undergoing either natural course or surgery. For superficially located lesions, permissible surgical risks were very small ranging from 0.4 to 2.8 percent of combined morbidity and mortality. The surgical gain of morbidity free life expectancy was also very small (0.0-1.1 years) irrespective of patient's age or eloquence of the location. For deep lesions, the permissible risk of surgery was very large, ranging from 64.1% for a 20-year-old and 31.4% for a 60-year-old patient. The gain of morbidity-free life expectancy was also large for younger patients (17-25 years for 20-year-old patients), but this gain rapidly decreased as the patient's age grew older, becoming 1.1 to 3.1 years for 60-year-old patients. Surgery seems to be justified for younger patients with deep lesions. There seems to be little indication for surgery of superficial lesions as far as the risk of bleeding is concerned.

Adult↗
PubMed2001

Isocentric head fixation for microscopic neurosurgery.

The significance of isocentering in head fixation during micro-neurosurgery is described. The approach angle to the lesion could be changeable without adjusting the focus and placement of the operating microscope by rotating the head holder when the lesion is fixed at the isocenter of the rotatable.

Head↗
PubMed2001

Skull base techniques for multiple aneurysms in the internal carotid juxta-dural ring region.

The aneurysm located in the internal carotid juxta-dural ring region is difficult to surgically obliterate. At surgery, careful drilling of the anterior clinoid process is mandatory, especially when a laterally projecting aneurysm protrudes to or inside the anterior clinoid process.In this paper, treatment procedures using the skull base techniques with intravascular coil embolisation are described by showing a case.

Carotid Artery, Internal↗
PubMed2001

Plate and screw technique for advancement of the supraorbital bar in surgery for craniosynostosis: a preliminary technical report.

An alternative plate and screw method of advancement of the supraorbital osteotomy bar in cranial remodelling surgery for craniosynostosis is described. The lateral orbital rim is transversely cut and using miniplates, screws are implanted into its advanced cut ends. Appropriate screws and miniplates are used to suit the size of the orbital rim in patients of different age groups. The technique was used in 12 cases and the authors have found the results extremely gratifying. It offered the advantage of providing a firm, secure and desired advancement, and height of the supraorbital bar maintaining a smooth lateral rim contour. The procedure was technically relatively straightforward. Further observation is warranted to determine whether the stabilization will last into adulthood or if there will be any problem related to the metal screws and plates.

Adolescent↗
PubMed2001

Contralateral pterional approach to a giant internal carotid-ophthalmic artery aneruysm: technical case report.

OBJECTIVE AND IMPORTANCE: The contralateral approach to internal carotid-ophthalmic artery aneurysms has been used in selected cases but has rarely been described for a giant internal carotid artery aneurysm. We report a case of giant aneurysm that was successfully clipped via the contralateral pterional approach. CLINICAL PRESENTATION: A 69-year-old woman was found to have two aneurysms: a small aneurysm at the left internal carotid-posterior communicating artery and a giant aneurysm at the right internal carotid-ophthalmic artery. INTERVENTION: A direct clipping operation was performed via the left pterional approach. After the small left internal carotid artery aneurysm was clipped, the contralateral giant aneurysm was further exposed and successfully clipped by use of the same approach via the prechiasmatic space. CONCLUSION: The contralateral pterional approach can be applied even for a giant aneurysm of the carotid-ophthalmic artery aneurysm when the neck of the aneurysm is small and when there is a space between the anterior wall of the aneurysm and the tuberculum sellae. Furthermore, such a giant aneurysm can be clipped more easily and safely via the contralateral approach without compromising visual functions. To our knowledge, this is the first reported case of a giant internal carotid-ophthalmic artery aneurysm approached contralaterally. The feasibility of this approach can be assessed preoperatively by three-dimensional computed tomographic angiography as well as by conventional cerebral angiography.

Aged↗
PubMed2001

How to make a three-dimensional surgical illustration of cerebral vessels with a personal computer: technical note.

OBJECTIVE: To introduce a method of making three-dimensional (3-D) illustrations of cerebral vessels with a personal computer. METHODS: We generated the 3-D images from only two views of conventional angiograms (anteroposterior and lateral views) with a personal computer, two commercial software programs, and an image scanner. RESULTS: This method was applied to 10 consecutive cases of cerebral aneurysms. 3-D images were made in a few hours, and they contributed to assessing vascular structures of an aneurysm complex. CONCLUSION: This method is useful for discussing surgical strategies preoperatively. Our method may be used in any facility where conventional angiography, personal computers, and 3-D software are available.

Cerebral Angiography↗
PubMed2001

Atypical pleomorphic astrocytoma in the pineal gland: case report.

OBJECTIVE AND IMPORTANCE: We report a rare case of pleomorphic astrocytoma in the pineal region that took a benign course despite pleomorphism. CLINICAL PRESENTATION: A 30-year-old woman suddenly developed right hemiparesis followed by loss of consciousness. A computed tomographic scan revealed a mass in the pineal region accompanied by obstructive hydrocephalus. Her symptoms improved after ventriculoperitoneal shunt surgery. INTERVENTION: The tumor was totally removed in an en bloc fashion using the occipital interhemispheric transtentorial route. Light microscopy revealed that the tumor had marked pleomorphism and multinucleated, bizarre giant cells, but neither mitosis nor necrosis was seen. Glial fibrillary acid protein was immunohistochemically positive in a few tumor cells. Retinal soluble antigen was negative. No reticulin network between the tumor cells was observed. A histological diagnosis of atypical pleomorphic astrocytoma was made. CONCLUSION: No signs of recurrence have been observed for 7 years after surgery without adjuvant therapy. Histologically, the tumor resembled pleomorphic xanthoastrocytoma or pleomorphic granular cell astrocytoma, but the immunohistochemical findings were not completely compatible with either diagnosis. This benign astrocytoma in the pineal gland with unique features is the first such case reported.

Adult↗
PubMed2001

Microsurgical anatomy of the ophthalmic artery and the distal dural ring for the juxta-dural ring aneurysms via the pterional approach.

Microsurgical anatomy for the pterional approach was studied regarding the origin and the course of the ophthalmic artery and the distal dural ring using human cadaveric specimens, with special reference to the surrounding bony structures. In 50 human adult formalin-fixed cadaveric cerebral hemispheres and 10 block specimens of the skull base region including the ophthalmic artery and the carotid dural ring were examined under magnification using an operating microscope. The ophthalmic artery originated from the intradural portion of the internal carotid artery (ICA), except in 5% where the ophthalmic artery originated extradurally. The extradural origin had two patterns: one was that the ophthalmic artery penetrated the bony optic strut (trans-optic strut pattern) and the other was that it coursed into the optic canal proximally to the optic strut without bone penetration (supra-optic strut pattern). The origin of the intradural ophthalmic artery was commonly located at the medial third of the superior wall of the ICA (78%). The ophthalmic artery was commonly taking an S-shaped course in the intradural portion and entered the optic canal over the optic strut. The distal dural ring was tightly adherent to the internal carotid artery; circumferential sectioning of the dural ring is required to mobilize the internal carotid artery. When approaching juxtadural ring ICA aneurysms via the pterional route, it is important to recognize the extradural origin, especially the trans-optic strut type, and to precisely understand the microsurgical anatomy around the dural ring.

Carotid Artery Diseases↗
PubMed2001

Inflammatory cytokine cascade released by leukocytes in cerebrospinal fluid after subarachnoid hemorrhage.

Subarachnoid hemorrhage (SAH) elicits an inflammatory response in the subarachnoid space, which is mediated by the release of various cytokines. To assess their involvement in post-hemorrhagic complications, we determined the source and time-course of the release of inflammatory cytokines and acute-phase proteins in cerebrospinal fluid (CSF) following SAH. Concentrations of interleukin (IL)- 1beta, IL-6, transforming growth factor-beta1 (TGF-beta1) and C-reactive protein (CRP) in CSF of 36 patients with SAH were measured by enzyme-linked immunoabsorbent assay (ELISA). Floating cells collected from the CSF were centrifuged four to six days after SAH, and examined immunohistochemically. Intracellular IL-1beta and IL-6 were examined by flow cytometric analysis. The molecular weight of TGF-beta1 in CSF of 30 patients was examined by Western blot analysis. The TGF-beta1 levels of patients who had undergone ventriculoperitoneal (VP) shunt (n = 19) was significantly higher than nonshunt group (n = 16). The CRP levels of VP shunt group was significantly higher than nonshunt group. IL-6 concentration was maximal within day 0-1 and it was secreted by neutrophils and monocytes. ELISA showed consistently low levels of IL-1beta, whereas a proportion of monocytes and lymphcytes were IL- 1beta-positive by flow cytometric analysis. TGF-beta1 levels were also maximal on day 0-1 according to ELISA, although it tended to be in the inactive form derived from platelets. A 25 kDa band of TGF-1 was detectable for at least 13 days after SAH, which may have been secreted in part by neutrophils and monocytes. CRP levels in CSF peaked on day 2-3. The present results suggest that leukocytes induced by SAH play an important role in post-hemorrhagic inflammation in the subarachnoid space by releasing IL-6 and TGF-beta1. The CRP and TGF-beta1 levels in CSF are strongly concerned with communicating hydrocephalus after SAH.

Adult↗
PubMed2001

Spread of Ca2+ in the sarcomere during fast and slow activation of mammalian cardiac myocytes.

A multi-compartment model was used to estimate Ca2+ gradients in a sarcomere of a cardiac myocyte. The mathematical model assumed Ca2+ release from the sarcoplasmic reticulum as a driving function, and calculated Ca2+ binding to myoplasmic buffers, Ca2+ uptake by the sarcoplasmic reticulum, and diffusion of Ca2+ (and the buffers). During the fast Ca2+ transient similar to those observed during a twitch, the model predicted a large Ca2+ gradient in the sarcomere. A trajectory of the instantaneous relation between spatially averaged concentrations of Ca2+ and the Ca2+-troponin complex showed a counterclockwise loop, indicating non-equilibrium Ca2+ binding to troponin. During slow changes in [Ca2+] with time to peaks of approximately 500 ms or longer, the gradient of [Ca2+] was largely dissipated and the apparent equilibrium of the Ca2+-troponin binding reaction was suggested with little hysteresis of the trajectory. We conclude that a steady-state relation between [Ca2+] and mechanical activity can be achieved uniformly in the sarcomere by slowing the rate of Ca2+ release from the sarcoplasmic reticulum.

Algorithms↗
PubMed2001

Transradial approach for diagnostic selective cerebral angiography: results of a consecutive series of 166 cases.

BACKGROUND AND PURPOSE: Diagnostic selective cerebral angiography is commonly performed via transfemoral and transbrachial approaches. With these approaches, however, patients occasionally suffer serious complications. The purpose of this study was to evaluate the feasibility, efficacy, and safety of a transradial approach as an alternative to the transfemoral and transbrachial approaches. METHODS: Between October 1998 and September 1999, transradial cerebral angiography was performed in 166 consecutive patients in a single center as a diagnostic procedure. Before the procedure, we confirmed the collateral blood supply to the hand from the ulnar artery using a modified Allen test. Regular catheterization techniques were practiced using our newly designed 120-cm-long 4F catheter. In 42 patients, anticoagulant and/or antiplatelet therapy was given perioperatively. RESULTS: Twelve of the 166 patients proved to be poor candidates for the transradial approach, owing to restlessness (n = 9), lack of collateral blood supply via the ulnar artery (n = 2), and brachial artery stenosis (n = 1). The radial artery was successfully punctured and cannulated in the remaining 154 patients. Selective catheterization of the intended vessels was obtained in all carotid and vertebral angiographic procedures with no major vascular complications. CONCLUSION: Compared with transfemoral and transbrachial approaches, the transradial approach is a less invasive and safer technique for selective cerebral angiography and may warrant consideration as a standard procedure. Anticoagulant or antiplatelet therapy need not be discontinued for this method.

Adolescent↗