Paget disease causing intracerebral mucoceles. Case illustration.
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Humans↗
Biomedical subjects
Tetsuya Goto
Publications and source records attributed to Tetsuya Goto.
Clinical application of robotic telemanipulation system in neurosurgery. Case report.
The NeuRobot is a telecontrolled microscopic micromanipulator system designed for neurosurgical procedures. The unit houses a three-dimensional endoscope and three robot arms that the surgeon operates without direct contact with the patient. The authors have successfully performed robotics-assisted neurosurgical procedures by using the NeuRobot in a 54-year-old man who had a recurrent atypical meningioma. Following the usual preparation of craniotomy and opening of the dura mater, a portion of the tumor was removed using the NeuRobot with the aid of microscopic observation. No complication related to the use of the NeuRobot was encountered and the patient's postoperative course was uneventful. Although various kinds of robots have been developed for use in neurosurgery in recent years, a robotic telemanipulation system capable of performing several surgical tasks has not previously been introduced to clinical neurosurgery. This is the first case report in which neurosurgical manipulation by a robotics system is described.
Humans↗
Introduction to the innervation of bone.
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Animals↗
Tachykinins and tachykinin receptors in bone.
Tachykinins are neuropeptides that are widely distributed in the body and function as neurotransmitters and neuromodulators. Five tachykinin subtypes: substance P (SP), neurokinin A, neurokinin B, neuropeptide K, and neuropeptide gamma; and three receptor subtypes: neurokinin-1, -2, and -3 receptors, have been identified. SP was the first peptide of the tachykinin family to be identified. It is considered to be an important neuropeptide, and to function in the nervous system and intestine. However, recent advances in the analysis of SP receptors, particularly neurokinin-1 receptors (NK(1)-Rs) that have high affinity for SP, have demonstrated that NK(1)-Rs are distributed not only in neurons and immune cells, but also in other peripheral cells, including bone cells. This article reviews the current understanding of the distribution of SP and other tachykinins in bone, and the function of tachykinins, through neurokinin receptors. The distribution of tachykinin-immunoreactive axons and neurokinin receptors suggests that tachykinins may directly modulate bone metabolism through neurokinin receptors.
Animals↗
Identification and characterisation of known and novel transcripts expressed during the final stages of human oocyte maturation.
The final stages of oocyte maturation, from the germinal vesicle (GV) stage to metaphase II (MII) oocytes, are characterised by a series of dynamic events. These include germinal vesicle break down (GVBD), resumption of meiosis, and nuclear and cytoplasmic maturation to produce MII oocytes ready for fertilisation. To investigate the specific genes transcribed during these stages of oogenesis, we have prepared and analysed amplified cDNA representing the transcribed genes in a series of GV and MII oocytes. Differential display analysis disclosed that the overall gene expression profiles between different samples of GV oocytes are very similar, regardless of their source, while those between the MII oocytes are markedly variable. A comparison of expression profiles in oocytes and somatic (cumulus) cells identified several known genes preferentially-expressed in oocytes (e.g., a zona pellucida gene), as well as five novel sequences. Two of the five novel sequences are homologous to retrotransposon sequences, long terminal repeat (LTR) and long interspersed nuclear element (LINE) 1, and two other sequences show partial homology to known ESTs and genomic sequences. The remaining sequence, which is identical to shorter ESTs isolated from germ cell tumor cDNA libraries, was extended towards its 5' end by PCR, using the original cDNA preparation from which it was isolated as a template. Expression of the resultant 1.1-kb transcript is restricted to the testis and ovary, and its expression correlates with cell pluripotency in that it is expressed in embryonal carcinoma cells, but not in their differentiated derivative cells.
Amino Acid Sequence↗
A selective inhibitor of matrix metalloproteinases inhibits the migration of isolated osteoclasts by increasing the life span of podosomes.
The osteoclast is a unique cell that cycles between bone resorption and migration. In this study, we used KB-R7785, an inhibitor of matrix metalloproteinases (MMPs), to investigate the role of MMPs in this cycle. Osteoclasts prepared from neonatal rabbits were processed to measure: (1) migration on hydroxyapatite (HA)-coated dishes, (2) the formation of an actin band, which is a large collection of podosomes, (3) the life span of podosomes, and (4) lacunar resorption on ivory slices. KB-R7785 significantly decreased the area of the tracks formed by osteoclasts on HA-coated dishes. The percentage of actin/podosome band formation, expressed as: (total length of the actin band/circumference of the osteoclast) x 100, was significantly increased after the addition of KB-R7785, which implies that podosome disassembly in osteoclasts was decreased by the inhibition of MMPs. Time-lapse cinemicrography demonstrated that the addition of KB-R7785 increased the life span of podosomes. Several indexes (number of resorption pits, total resorption area, and mean resorption area) of osteoclast resorption activity were significantly decreased by KB-R7785, while the average depth of resorption was increased. These results indicate that decreased podosome disassembly caused by an MMP inhibitor suppresses the migration of osteoclasts and, ultimately, inhibits osteoclastic bone resorption.
Actins↗
Malignant astrocytoma of the conus medullaris treated by spinal cordectomy.
We present a case of malignant astrocytoma of the conus medullaris in a 48-year-old man treated by spinal cordectomy. Preoperative examination revealed a tumor at the T12 to L1 level, and intraparenchymal invasion up to T8. The spinal cord was amputated caudally to the root entry zones of the T9 sensory roots. Additional cordectomies were repeated three times because of tumor infiltration at the cut end. At each procedure, the cord was segmentally transected just caudal to the root entry zones of the p reserving-aid sensory roots to minimize the neural deficit. The final transected level was between T3 and T4, and the cut end did not pathologically reveal any tumor invasion. However, the patient died from tumor recurrence and dissemination. Although the attempt to control the tumor by long segment cordectomy was unsuccessful, spinal cordectomy with wide margin may be a possible treatment for patients with malignant astrocytoma of the conus medullaris presenting with complete deficit below the lesion a nd no dissemination, if in an early stage.
Astrocytoma↗
NeuRobot: telecontrolled micromanipulator system for minimally invasive microneurosurgery-preliminary results.
OBJECTIVE: Microneurosurgery can be performed less invasively with the recent advances in neuronavigation and neuroendoscopy. For even less invasive microneurosurgery, we have developed a telecontrolled micromanipulator system. METHODS: The NeuRobot telecontrolled micromanipulator system was developed. With the use of this system, surgical simulations were performed with a human cadaveric head. RESULTS: The system consists of four main parts, i.e., a micromanipulator (slave manipulator), a manipulator-supporting device, an operation-input device (master manipulator), and a three-dimensional display monitor. Three 1-mm forceps and a three-dimensional endoscope, which could be remotely controlled with three degrees of freedom (rotation, neck swinging, and forward/backward motion), were installed in the slave manipulator. All surgical procedures were accurately performed with this system. CONCLUSION: The use of telecontrolled manipulator systems in neurosurgery is very promising, and we are convinced that this system will facilitate more accurate, less invasive microneurosurgery. The details of the NeuRobot system and preliminary results are presented.
Cadaver↗
Role of endothelial nitric oxide and smooth muscle potassium channels in cerebral arteriolar dilation in response to acidosis.
BACKGROUND AND PURPOSE: Potassium channels or nitric oxide or both are major mediators of acidosis-induced dilation in the cerebral circulation. However, these contributions depend on a variety of factors such as species and vessel location. The present study was designed to clarify whether potassium channels and endothelial nitric oxide are involved in acidosis-induced dilation of isolated rat cerebral arterioles. METHODS: Cerebral arterioles were cannulated and monitored with an inverted microscope. Acidosis (pH 6.8 to 7.4) produced by adding hydrogen ions mediated dilation of the cerebral arterioles in a concentration-dependent manner. The role of nitric oxide and potassium channels in response to acidosis was examined with several specific inhibitors and endothelial damage. RESULTS: The dilation was significantly inhibited by potassium chloride (30 mmol/L) and glibenclamide (3 micromol/L; ATP-sensitive potassium channel inhibitor). We found that 30 micromol/L BaCl2 (concentration-dependent potassium channel inhibitor) also affected the dilation; however, an additional treatment of 3 micromol/L glibenclamide did not produce further inhibition. Tetraethylammonium ion (1 mmol/L; calcium-activated potassium channel inhibitor) and 4-aminopyridine (100 micromol/L; voltage-dependent potassium channel inhibitor) as well as ouabain (10 micromol/L; Na-K ATPase inhibitor) and N-methylsulphonyl-6-(2-proparglyloxyphenyl) hexanamide (1 micromol/L; cytochrome P450 epoxygenase inhibitor) did not alter acidotic dilation. N(omega)-Monomethyl-L-arginine (10 micromol/L) and N(omega)-nitro-L-arginine (10 micromol/L) as nitric oxide synthase inhibitor blunted the dilation. Furthermore, the dilation was significantly attenuated after the endothelial impairment. Additional treatment with glibenclamide (3 micromol/L) further reduced the dilation in response to acidosis. CONCLUSIONS: Endothelial nitric oxide and smooth muscle ATP-sensitive potassium channels contribute to acidosis-induced dilation of rat cerebral arterioles. Endothelial damage caused by pathological conditions such as subarachnoid hemorrhage or traumatic brain injury may contribute to reduced blood flow despite injury-induced cerebral acidosis.
Acidosis↗
Endoscopic telerobotics for neurosurgery: preliminary study for optimal distance between an object lens and a target.
To overcome limited maneuverability and procedures in the endoscopic neurosurgery, and to utilize its maximum potential ability, the HUMAN (hyper-utility mechatronic assistant) system has been developed. The system has a rigid three-dimensional endoscope with built-in three guiding-manipulators completely controlled as a slave robot by a surgeon in a remote place. To use this system most efficiently, we investigated the suitable distance between an object lens of the endoscope and a target. Actual working territory (AWT) and actual working angle (AWA) of the forceps in the endoscopical operative field (EOF) were measured by changing the distance between the lens and the target. AWT ratio (AWT/EOF) and AWA ratio (AWA/360) decreased from 58% to 12% and increased from 39% to 85% respectively as the distance became longer. When the distance exceeds 13 mm, AWA did not increase more than 85%, and AWT kept decreasing. For the effective use of the system, the optimal distance between the lens and the target should be within 13 mm, and the system will demonstrate its ability to the maximum at the distance of 8mm.
Endoscopes↗
A study of the initial attachment and subsequent behavior of rat oral epithelial cells cultured on titanium.
BACKGROUND: The seal between an implant and the oral epithelium is an important factor for successful implant therapy. The purpose of this study was to evaluate the initial attachment and subsequent behavior of rat oral epithelial (OE) cells on pure titanium (Ti) used for dental implants. METHODS: OE cells derived from 4-day-old rats were cultured on Ti, polystyrene culture dishes, and glass coverslips. The number of attached cells, cell areas, number of colonies, and proliferation rates were measured. Additionally, immunostaining of vinculin and laminin-5 (LN5) was performed, and LN5-immunoreactive areas were measured. RESULTS: After 24 hours of culture, there were fewer cells attached to the Ti than to the polystyrene dishes or glass coverslips, and the area of cells was greater on the polystyrene than on the Ti or glass. OE cells reached their maximum proliferation rate after 48 hours of culture on the polystyrene and glass, and after 72 hours on Ti. LN5 was deposited behind cells as they migrated, and the LN5-immunoreactive area was smaller on Ti than on polystyrene after 96 hours of culture. CONCLUSIONS: The initial attachment of OE cells to Ti was inferior to that on polystyrene or glass, and the OE cell migration area indicated by the deposition of LN5 was smaller on Ti than on the other materials. Therefore, this study suggests that further improvement of Ti surface properties is needed for rapid attachment and spreading of oral epithelium to dental implants.
Analysis of Variance↗
Radiometric analysis of paraclinoid carotid artery aneurysms.
OBJECT: Classification of paraclinoid carotid artery (CA) aneurysms based on their associated branching arteries has been confusing because superior hypophyseal arteries (SHAs) are too fine to appear opacified on cerebral angiograms. The authors performed a retrospective radiometric analysis of surgically treated paraclinoid aneurysms to elucidate their angiographic and anatomical characteristics. METHODS: A retrospective analysis was made of 85 intradural paraclinoid aneurysms in which the presence or absence of branching arteries had been determined at the time of surgical clipping. The lesions were classified as supraclinoid, clinoid, and infraclinoid aneurysms based on their relation to the anterior clinoid process on lateral angiograms of the CA. The direction of the aneurysms were measured according to angles formed between the medial portion of the horizontal line crossing the aneurysm sac and the center of the aneurysm neck on anteroposterior angiograms. Branching arteries were associated with 68 aneurysms, of which 28 were ophthalmic artery (OphA) lesions (32.9%) and 40 were SHA ones (47.1%); associated branching arteries were absent in 17 aneurysms (20%). Twenty-five aneurysms (29.4%) were located at the supraclinoidal level, 46 (54.1%) at the clinoidal, and 14 (16.5%) at the infraclinoidal. The majority of aneurysms identified at the supraclinoidal level were OphA lesions (44%) or those unassociated with branching arteries (48%), with mean directions of 57 degrees or 67 degrees, respectively. At the clinoidal level, the mean directions of aneurysms were 76 degrees in six lesions unassociated with branching arteries (13%), 43 degrees in 16 OphA lesions (35%), and -11 degrees in 24 SHA ones (52%). All aneurysms at the infraclinoidal level arose at the origin of the SHAs, with a mean direction of -29 degrees, and most of these were embedded in the carotid cave. CONCLUSIONS: Aneurysms arising from the SHA can be distinguished from those not located at an arterial division by cerebral angiography, because SHA lesions are usually located at the medial or inferomedial wall of the internal carotid artery at the clinoidal or infraclinoidal level. Their distribution correlates well with the reported distribution of SHA origins. The carotid cave aneurysm is a kind of SHA lesion that originates at the most proximal intradural CA.
Adult↗