Nationwide surveillance of IC anterior (or dorsal) wall aneurysm: with special reference to its dissecting nature.

Two hundred and twenty-one cases of IC dorsal aneurysm (ICDA) with subarachnoid hemorrhage (SAH) from 365 cases in the nationwide surveillance of ICDA (NSICDA) data bank were studied with special reference to the dissecting type. Dissection of the internal carotid artery (ICA) was confirmed in 50 out of 221 SAH cases. In 193 surgically treated cases, 40 were of the certified dissecting type. Including those with clinical features which strongly suggests the existence of dissecting changes in the ICA wall, 97 cases (55.6% of operated) were thought to be a dissecting type. Incidence of intraoperative bleeding is significantly higher and surgical outcome is significantly worse in the dissecting type than in the non-dissecting type. Treatment options for this peculiar and formidable aneurysm (An) are described.

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.

Chemokines differentially induce matrix metalloproteinase-3 and prostaglandin E2 in human articular chondrocytes.

OBJECTIVE: To explore prostaglandin (PG) E2 production by human articular chondrocytes induced by different chemokines. METHODS: Human chondrocytes were enzymatically isolated from the articular cartilage of patients with rheumatoid arthritis (RA), osteoarthritis (OA) or traumatic fracture (N) who underwent total joint replacement. They were cultured in vitro as monolayers and then exposed to MCP-1, RANTES or SDF-1 for 24 h. Levels of PGE2 and MMP-3 in the culture supernatant were then immunoassayed. RESULTS: PGE2 production was enhanced up to 2.7-fold in a subset of samples. Responses to different chemokines were heterogeneous even within the same disease groups. As previously reported, chemokines induced MMP-3 secretion by chondrocytes, but there was no significant correlation between levels of PGE2 and MMP-3. CONCLUSION: We here document the presence of "responders" among OA, RA and normal chondrocytes that produce enhanced levels of PGE2 upon stimulation by chemokines. The relationship between chemokines and prostaglandins could differentially influence the pathogenic network responsible for cartilage degradation in arthropathy.

Muscarinic cholinergic receptors on the endothelium of human cerebral arteries.

To characterize the muscarinic cholinergic receptors on the endothelium of human cerebral arteries, isometric tension measurement and receptor autoradiographic studies were performed. Acetylcholine (ACh) induced dose-dependent relaxation of human cerebral arteries precontracted by 10(-5) M serotonin, with an EC50 of 1.9 +/- 0.6 X 10(-6) M (n = 7). The relaxation was abolished by 10(-5) M hemoglobin. Autoradiography, using the muscarinic antagonist [3H]propylbenzilycholine mustard, demonstrated the high density of muscarinic cholinergic receptors on the endothelial cells of human cerebral arteries, especially on the luminal surface of the endothelium. These findings suggest that ACh-induced relaxation mediated by muscarinic cholinergic receptors on the endothelium has a physiological function in human cerebral arteries.

Chaperonin GroE and ADP facilitate the folding of various proteins and protect against heat inactivation.

In the presence of ADP, the molecular chaperones GroEL and GroES from Escherichia coli not only facilitated the refolding of various proteins, but also prevented their irreversible heat inactivation in vitro. Without nucleotides the refolding reactions were arrested by GroEL. Addition of GroES and ADP to the reaction mixture initiated the refolding reactions and the enzyme activities were regained efficiently. The presence of GroE (GroEL and GroES) and ADP also protected against heat inactivation of native enzymes at various temperatures. These findings suggest that in the presence of GroES, nucleotide binding is an important event in the mechanism of GroEL-facilitated protein folding.

The role of ATP hydrolysis in the function of the chaperonin GroEL: dynamic complex formation with GroES.

In order to understand the role of ATP hydrolysis of the chaperonin GroEL during protein folding, we have studied GroEL-GroES complex formation in the presence of ATP or ADP by using capillary electrophoresis and surface plasmon resonance. Capillary electrophoresis analysis showed that the GroEL 14-mer and GroES 7-mer formed a 1:1 complex in the presence of ATP. In the presence of ADP, both the association and dissociation rates of the complex were slower by about one order of magnitude than the rates in the presence of ATP at 25 degrees C. The implications of such a stable complex on the overall mechanism of chaperonin function are discussed.

Different effects of gadolinium on I(KR), I(KS) and I(K1) in guinea-pig isolated ventricular myocytes.

1. Using the whole cell configuration of the patch clamp technique, we studied the potential blocking effects of gadolinium (1 microM to 1 mM) on potassium currents: I(KR), I(KS) and I(K1). The study was performed on guinea-pig isolated ventricular myocytes. 2. The background current, I(K1) was insensitive to Gd3+. Thus, we found that no obvious screening of surface charges was visible with concentrations of Gd3+ up to 100 microM. 3. By use of three different protocols: tail currents fitting, analysis of envelope of tails and electrophysiological dissection, we found that I(KR) was the only component of IK that was sensitive to Gd3+. The sensitivity was apparently different depending on the protocol used. 4. Comparison of the results obtained with the different protocols revealed that the rapid component of I(KR) is more sensitive to Gd3+ than the slow one. 5. Of the different protocols used to distinguish between I(KR) and I(KS), the electrophysiological dissection seems to be the more accurate.

Disappearance of clonally expanded T cells after allogeneic leukocyte immunotherapy in peripheral blood of patients with habitual abortion.

Allogeneic leukocyte immunotherapy is often used to improve fertility of patients with habitual abortion (HA), which probably acts through immune-mediated mechanisms. However, the involvement of T cells is not clear. This study examined the effect of allogeneic immunotherapy on T cells of patients with HA. Peripheral blood mononuclear cells were obtained from 5 healthy women and 14 women with HA. RNA was isolated from mononuclear blood cells. Reverse transcription-polymerase chain reaction (RT-PCR), followed by single-strand conformational polymorphism (SSCP) were used to analyze the gene segments of T-cell receptor beta chain (TCRbetaV) variable regions. Oligoclonal accumulation of T cells was identified in peripheral blood of nonpregnant patients with a history of HA. It was also revealed, however, that immunostimulation reduced the number of accumulating T-cell clones (p = 0.0004). The results, together with the clinical effectiveness of immunotherapy, suggest that accumulation of T-cell clonotypes, which probably resulted from antigenic stimulation, is involved in the pathogenesis of HA.

Establishment and application of a novel T cell clonality analysis using single-strand conformation polymorphism of T cell receptor messenger signals.

To identify the existence of antigen specific T cell responses and to follow the changes of these reactions, it is considered useful to evaluate whether certain T cells clonally accumulate in the lymphocyte population. For this purpose, we have established a novel method to analyze T cell clonality using a combination of reverse transcriptase-polymerase chain reaction of T cell receptor beta chain transcripts and single-strand conformation polymorphism (SSCP). Using this method, we obtained a smear-like pattern of electrophoresed DNA from the heterogeneous T cell population. On the other hand, a single T cell clone exhibits a band in the appropriate VP amplification and an accumulated T cell clone in a heterogeneous lymphocyte population is identified as a band in the background smear pattern. If a lymphocyte population was stimulated by an antigen either in vitro or in vivo, several distinct bands were found to be generated in the background smear. Thus, the dynamic changes of T cell clonal responses could be monitored with this method. Analyses of several immunological disorders, including autoimmune diseases, malignant disorders, and transplantations, revealed the involvement of antigen-specific T cell immune responses in these disorders. Furthermore, taking advantage of the reproducible mobility of a band of SSCP gel, we are now able to compare identities of the accumulated T cell clones in different samples without the need for nucleotide sequencing of each clone. Such information can thus elucidate the occurrence of uniform or stable immunological reactions in the host and also suggests that these reactions play an important role in vivo. Therefore, taken together, the above described novel T cell clonality analysis is considered to be useful in studying the T cell immune responses in various fields of immunology.

Role of chemokines/chemokine receptor systems in cartilage degradation.

The underlying mechanism of the degradation of articular cartilage is an imbalance between anabolic and catabolic pathways, which are under the control of cytokines. Chemokines are a novel class of small cytokines and have a wide range of effects in many different cell types, both inside and outside of the immune system. Their actions are mediated by a family of 7-transmembrane G-protein-coupled receptors. Recent studies have demonstrated that chondrocytes co-express chemokines and their receptors, and that the interaction of chemokines with their receptors results in the release of cartilage matrix-degrading proteinases, and affect proteoglycan metabolism in chondrocytes. These data reveal a catabolic pathway primed by chemokine/chemokine receptor system in articular cartilage, thus proposing a novel therapeutic approach against cartilage destruction in arthropathy.

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.

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.

Intraoperative protection of cranial nerves and arteries by split silicone tube.

The authors describe the usefulness of split silicone tubing to protect the cranial nerves and arteries during microneurosurgery. The inner diameter of the tube varied from 1.0 to 3.3 mm with a thickness of 0.125 mm. Application of the tube protects the nerves and arteries from mechanical trauma, electrical injury, and dryness.

Vascular compression of the medulla oblongata by the vertebral artery: report of two cases.

OBJECTIVE AND IMPORTANCE: Compression of the medulla oblongata by a tortuous vertebral artery is rare. We report two patients with this lesion who were treated with vascular decompression of the vertebral artery. CLINICAL PRESENTATION: A 36-year-old man developed right hemiparesis with lower cranial nerve deficits, and a 47-year-old man developed left lower cranial nerve deficits and left cerebellar dysfunction. In both patients, magnetic resonance imaging revealed a tortuous vertebral artery compressing the medulla oblongata. INTERVENTION: In both patients, the compressed medulla oblongata was treated by detaching the vertebral artery from the medulla oblongata, shifting it, and anchoring it to the nearby dura mater. Postoperatively, both patients are asymptomatic and have returned to their previous jobs. CONCLUSION: Although compression of the medulla oblongata by a tortuous vertebral artery is rare, it can cause brainstem dysfunction. Magnetic resonance imaging clearly revealed the vascular compression in these patients. Surgical treatment was effective. The symptoms related to a tortuous vertebral artery and some techniques for surgical treatment are discussed. Awareness of this rare lesion is necessary to ensure appropriate treatment.

The influence of experimental subarachnoid hemorrhage on the relaxation induced by vasoactive intestinal polypeptide in the cerebral arteries of the rabbit.

The influence of subarachnoid hemorrhage (SAH) on vasodilatation induced by vasoactive intestinal polypeptide (VIP) was investigated in rabbit basilar arteries. VIP-induced relaxation was measured in ring sections of the basilar arteries precontracted by 10(-5) M serotonin using an isometric tension recording method. The cyclic adenosine monophosphate (cAMP) content was measured using radioimmunoassay as an indicator of the intracellular mechanism in the arterial smooth muscle cells. VIP (10(-11)-10(-6) M) evoked dose-dependent relaxation of the basilar arteries. The relaxation achieved with 10(-6) M VIP was 85 +/- 4% (n = 7) of the initial contractile tone in control arteries and 47 +/- 5% (n = 8) in the arteries evaluated 2 days after SAH, suggesting that VIP-induced relaxation was suppressed significantly after SAH (P less than 0.01). The cAMP content was significantly higher in the basilar arteries 2 days after SAH (425 +/- 48 pmol/g of tissue, n = 7) than in the control basilar arteries (194 +/- 57 pmol/g of tissue, n = 7). In normal arteries, the cAMP content was increased to a significant degree by VIP (10(-6) M) (325 +/- 60% of control cAMP content, n = 5), whereas the increase was less in the arteries evaluated 2 days after SAH (112 +/- 16% of control cAMP content, n = 5). These results suggest that SAH has an influence on cAMP metabolism in the arteries and that SAH impairs the postsynaptic mechanism of VIP-induced dilatation of the arteries.

Pharmacological reversibility of experimental cerebral vasospasm.

Using a morphometric technique, the pharmacological reversibility of luminal narrowing after experimental subarachnoid hemorrhage (SAH) was investigated. For vasodilation, a "cocktail" consisting of 10(-4) M papaverine, 2 x 10(-4) M sodium nitroprusside, and 10(-5) M adenosine was administered intra-arterially. Forty-two rabbits were divided into six groups: control (normal animals); control plus cocktail (normal animals perfused with the cocktail before fixation); SAH (animals sacrificed 48 hours subsequent to intracisternal injection of 1.5 ml/kg of arterial blood); SAH plus cocktail (SAH plus perfusion with the cocktail); BaCl2 (animals sacrificed 10 minutes after intracisternal injection of 2 ml of 3 x 10(-3) M BaCl2); and BaCl2 plus cocktail (BaCl2 animals perfused with the cocktail). The diameter of the basilar arteries in the control and the control plus cocktail groups was not significantly different. BaCl2 reduced the diameter 44% and SAH reduced the diameter 27%. There were no significant differences between the diameter of the BaCl2 plus cocktail group and SAH plus cocktail group when compared with the control or the control plus cocktail group. Morphological examination by light and transmission electron microscopy showed luminal narrowing and corrugation of the elastic lamina with few degenerative or proliferative changes of the vessel wall in animals with SAH. These results suggest that cerebral vasospasm is caused initially by smooth muscle contraction rather than by proliferative vasculopathy and that it is not an irreversible process.

Double aneurysms at distal basilar artery: report of nine cases.

OBJECTIVE: Double aneurysms at the basilar bifurcation and the basilar artery-superior cerebellar artery (BA-SCA) junction have not been well investigated previously. We analyzed nine patients with double basilar aneurysms to evaluate their radiological characteristics and suitable treatment. METHODS: Between 1978 and 1999, the incidence of double aneurysms was 5.3% in our 169 consecutive surgical cases of distal BA aneurysms. Seven (77.8%) of the nine patients with double aneurysms had associated aneurysms in the anterior circulation. Open surgery was performed in eight patients and coil embolization in one. The patients' radiological findings, choice of treatment, and surgical results were analyzed retrospectively. RESULTS: The size of the basilar bifurcation aneurysms ranged from 2 to 8 mm (mean, 4.4+/-2.0 mm), and the size of the BA-SCA aneurysms ranged from 2 to 12 mm (mean, 5.6+/-3.6 mm). Diagnosis of double basilar aneurysms was difficult when the basilar trunk had twisted or when size differences between the two aneurysms were apparent. The angle between the posterior cerebral artery and SCA appeared to be wider on the same side as the BA-SCA aneurysms (101+/-42 degrees) than on the opposite side (26+/-24 degrees). The P1 segment of the posterior cerebral artery originated in an upright direction from the basilar bifurcation between the two basilar aneurysms in seven patients. The pterional approach was used in eight patients; 14 basilar aneurysms were successfully clipped and 2 were wrapped. Nonstraight clips with short blades were used frequently. Coil embolization of double aneurysms was required twice in one patient because the initial angiogram was misinterpreted as a single aneurysm and its bleb. CONCLUSION: Measurement of the posterior cerebral artery-SCA angle is a simple method to estimate the presence of BA-SCA aneurysms and to differentiate double aneurysms from a bilocular aneurysm at the basilar bifurcation. The pterional approach is suitable for clipping double basilar aneurysms because anterior circulation aneurysms often coexist, and the upstanding P1 segment is an obstacle in the subtemporal approach to the basilar bifurcation aneurysm. Nonstraight clips with short blades are convenient to avoid conflicting clips in the narrow surgical space.

A study of the effectiveness of the iron-chelating agent deferoxamine as vasospasm prophylaxis in a rabbit model of subarachnoid hemorrhage.

The pathogenesis of cerebral vasospasm occurring after subarachnoid hemorrhage (SAH) is unknown. Several lines of experimentation have suggested a free radical mechanism in the etiology of vasospasm. Iron is an important catalyst in the generation of free radicals and lipid peroxides in response to tissue injury. We hypothesize that the elaboration of iron from the subarachnoid clot might result in enhanced generation of free radicals and lipid peroxidation. If so, then treatment with deferoxamine, an iron-chelating compound, might reduce the formation of free radicals and thereby ameliorate vasospasm. This hypothesis was examined in a rabbit model of experimental cerebral vasospasm. New Zealand White rabbits were divided into the following experimental groups: control (normal) animals (n = 7), control animals treated with deferoxamine (n = 3), animals subjected to SAH and killed on Day 2 (n = 7), animals subjected to SAH on Day 2 and treated with deferoxamine (n = 9), animals subjected to SAH killed on Day 3 (n = 7), and animals subjected to SAH on Day 3 and treated with deferoxamine (n = 7). Deferoxamine treatment (50 mg/kg/8 hours) was begun 16 hours before the induction of SAH and continued until the animals were killed by perfusion fixation. The basilar artery caliber was assessed using morphometric techniques. The diameter of the basilar arteries in the control animals was 0.64 +/- 0.02 mm. Deferoxamine treatment alone did not alter the artery diameter.(ABSTRACT TRUNCATED AT 250 WORDS)