Novel entry point for intraoperative ventricular puncture during the transsylvian approach.

OBJECTIVE: In dealing with cases of oedematous brain, relaxation during the transsylvian approach to supratentorial aneurysms has been accomplished by ventricular drainage by using the anatomic point defined by Dr. Paine. However, we have experienced patient complications when using this point. We propose a novel anatomic point to reduce catheter-related complications and facilitate adequate ventricular puncture during ruptured aneurysm operations. METHODS: Ten patients underwent aneurysmal neck clipping for ruptured aneurysm by means of the transsylvian approach. The use of a novel anatomic point for intraoperative drainage was examined using a neuronavigation system. RESULTS: Using the novel point of entry for ventricular cannulation proved to be reliable for puncture and reduced chance of malpositioning. CONCLUSION: Secure intraoperative ventricular cannulation is reliably achieved by pointing the catheter approximately 2 cm beyond a line extending from the anterior limb of the triangle described by Paine. This technique reduces injury to the deep brain and enhances preciseness and safety of ventricular cannulation.

The effects of N-methyl-N-nitrosourea and azoxymethane on focal cerebral infarction and the expression of p53, p21 proteins.

If the activity of pro-apoptotic genes can be down-regulated by certain chemicals, cells may be protected from apoptosis. To test this hypothesis in a cerebral infarction model, we used N-methyl-N-nitrosourea (MNU) and azoxymethane (AOM), which were approved gene-modulating chemicals. A focal cerebral infarction was created by coagulation of the right middle cerebral artery and ipsilateral common carotid artery (CCA) and simultaneous transient occlusion of the contralateral CCA for 30 min in 25 adult Sprague-Dawley rats that were sacrificed 24 h later. In one group (n=7), MNU (5 mg/kg) was injected intravenously 30 min before initiation of ischemia. In another group (n=7), AOM (15 mg/kg) was administered intraperitoneally before 24 h of ischemia. The infarction volumes were checked and the brains were stained for p53 and p21 proteins. The width in micrometers of the peri-infarct area containing p53 or p21 protein-positive cells, and the number of p53 or p21 protein-positive cells (cells/HPF) were measured at an adjacent peri-infarct area. The AOM-treated group showed a significantly reduced infarction volume (by 42.5%, p<0.001), a significantly greater number of p53 positive cells (by 12.0%, p<0. 05), and a significantly wider p53 protein-positive area (by 15.6%, p<0.01) than the untreated group. AOM did not show any influence on the expression pattern of the p21 protein. MNU had no effect in the expression of p53 or p21 proteins. As a result, we concluded that AOM revealed a protective effect in ischemia by suppressing the pro-apoptotic activity of the p53 gene. Safer chemicals that can modulate apoptotic genes, if any, will provide a new therapeutic modality for cerebral infarction.

Aneurysm clip motion during magnetic resonance imaging: in vivo experimental study with metallurgical factor analysis.

Because of various mechanical, metallurgical, and commercial constraints, aneurysm clips are manufactured from different alloys, including several stainless steel and cobalt alloys. Some of the steels contain volume fractions of the crystal phase known as martensite. Martensitic alloys have body-centered cubic structure, are prone to stress corrosion failure, and are ferromagnetic. Martensitic steel can be displaced like a compass needle when exposed to a magnetic field such as that generated during magnetic resonance imaging (MRI). The force exerted by the magnetic field is proportional to the volume fraction of the magnetic phase. We investigated the martensitic content and magnetic field-induced displacement of 12 common aneurysm clips. Four clips of each of the following types were examined: Sugita, Sundt-Kees Multi-Angle, Heifetz (two types), Vari-Angle McFadden, Yasargil (two types), Scoville, Mayfield, Vari-Angle, Pivot, and Kapp. Phase homogeneity and crystal structure were analyzed by x-ray diffraction using a Phillips x-ray diffractometer. Clip deflection in an Oxford Research Systems MRI spectrometer was measured in our in vivo rat abdominal aortic aneurysm model. Results showed that the volume fraction of the martensitic phase in the various clips correlated with the magnitude of the deflection. Among the clips examined, the Yasargil, Sugita, Heifetz Elgiloy, and Vari-Angle McFadden had a nonmartensitic composition and did not deflect in the magnetic field. The Scoville contained 5% martensite and deflected only marginally. Martensite comprised 35% of the Mayfield clip, which deflected 45 degrees, and 90% of the Heifetz, Vari-Angle, Pivot, and Sundt-Kees Multi-Angle clips, which deflected approximately 70 degrees or slipped off the aneurysm.(ABSTRACT TRUNCATED AT 250 WORDS)

Loss of virulence in Shigella strains preserved in culture collections due to molecular alteration of the invasion plasmid.

Fifty-two Shigella strains long preserved by three Japanese culture collections were examined for virulence. All of them were avirulent when judged by the focus-plaque assay and the ability to bind Congo red. Fifteen strains had a plasmid comparable in size to that responsible for epithelial invasiveness and were positive in hybridization tests with a probe derived from a plasmid cistron, virG. Twenty-four strains had a similar plasmid but were negative in hybridization tests. The remaining 13 strains were negative in all the five criteria for virulence. Similar studies made on one hundred Shigella strains isolated from 1967 to 1985 clearly demonstrated loss of virulence with prolonged time of storage.

Antimicrobial susceptibility of bacteria isolated in 1985--with special reference to prevalence of methicillin-resistant staphylococcus aureus and activities of cefazolin, cefotaxime and piperacillin.

Antimicrobial susceptibility of nine species and one group of bacteria isolated from patients at the hospitals of Seoul National University, Severance, Hanyang University, and Kyungpuk University were tested by agar dilution method. S. aureus was most susceptible to cefazolin, methicillin and cotrimoxazole, and enterococci to ampicillin. Isolates of Enterobacteriaceae were most frequently susceptible to aminoglycosides and cefotaxime. Cefazolin susceptibility was markedly different from species to species. Aminoglycosides and piperacillin were more active than others against P. aeruginosa, and amikachin against A. anitratus. A large proportion of strains of several different species were conditionally susceptible to either tetracycline, ampicillin, cefazolin or cotrimoxazole suggesting the usefulness of these drugs for treatment of urinary tract infection. Activity of cefotaxime was highest against E. coli, and K. pneumoniae, while lowest against A. anitratus and P. aeruginosa. Decrease in the proportion of susceptible isolate was noted in E. coli and K. pneumoniae to cefazolin, K. pneumoniae, E. cloacae and S. marcescens to cotrimoxazole, and P. aeruginosa to tobramycin and gentamicin.

A co-operative study: clinical characteristics of 334 Korean patients with moyamoya disease treated at neurosurgical institutes (1976-1994). The Korean Society for Cerebrovascular Disease.

A co-operative study was conducted to determine the clinical characteristics of patients with moyamoya disease who were diagnosed and treated at neurosurgical institutes in Korea before 1995. Twenty-six hospitals contributed 505 cases and among them, the clinical characteristics of 334 patients with definite moyamoya disease were evaluated. The number of patients began to increase from the late 1980s, and after that approximately 20 patients were treated each year. There were two age peaks: from six to 15 and from 31 to 40 years of age. Haemorrhagic manifestations occurred in approximately 43% of the patients. The major clinical manifestations were haemorrhage in adults (62.4%) and ischaemia in children (61.2%). Overall 54.5% of the patients experienced decreased consciousness levels, mainly due to intracranial haemorrhage or cerebral infarction. In the patients with ischemic manifestations, the adult patients were more likely to have cerebral infarction than the pediatric patients (80% vs. 39%) and the pediatric patients were more likely to have TIA (61% vs. 25%). Thirty eight percent of the patients underwent bypass surgery and 53% of these procedures were performed bilaterally. Treatment policies, including indications for bypass surgery and commonly used drugs, were somewhat different according to the institution. Overall favorable outcome was 73%, and the most significant factor affecting poor outcome was haemorrhagic manifestation. This article describes the characteristics of 334 patients with moyamoya disease, who were diagnosed and treated at neurosurgical institutes in Korea before 1995.