A surgically treated case with a ruptured bacterial aneurysm of the middle cerebral arterial bifurcation following occlusion

A 56-year-old woman with aortic regurgitation (AR) developd a high fever on April 25th, 2003, followed by the sudden onset of left hemiparesis and dysarthria on May 10th, 2003. MRI and MRA showed cerebral infarction due to occlusion of the right proximal portion of the middle cerebral artery. Streptococcus was isolated from arterial blood culture at the time of admission and cardiac examination such as echocardiography revealed active infective endocarditis. Cerebral angiography on the 31st day after the onset of symptoms demonstrated a fusiform-shaped aneurysm at the occluded M2 portion of the middle cerebral artery. Despite administration of antibiotics, a small subcortical hematoma was observed in the right temporal lobe surrounding the aneurysm on the 35th day. The direct surgery of aneurysmal trapping and resection was subsequently performed to prevent rebleeding. The sylvian fissure and perianeurysmal area were strongly adherent to granulation tissue and blood clot. After exposing the aneurysm, the dilated portion of the vessel was successfully trapped and resected. Other than residual left hemiparesis, the postoperative course was uneventful. Histological examination confirmed bacterial aneurysm due to bacterial embolization originating from infective endocarditis (IE). We report a rare case having a ruptured bacterial aneurysm of the middle cerebral arterial bifurcation requiring surgery following occlusion due to bacterial embolization after sepsis and meningitis due to infective endocarditis.     

Evaluation of the contours and perianeurysmal environment of unruptured cerebral aneurysms, using three-dimensional magnetic resonance cisternogram

To evaluate the anatomical relationship between cerebral aneurysm and the perianeurysmal environment within a cisternal space, the contours of an unruptured cerebral aneurysm and pericisternal structures were depicted on a three-dimensional (3D) MR cisternogram. By using perspective volume-rendering algorithm, the 3D MR cisternograms were reconstructed from the source axial volume data set obtained by the T2-weighted 3D fast spin-echo sequence. Those images were shown together with the coordinated 3D MR angiograms through similar visual projections, and then compared with the intraoperative findings. The outer wall configurations of cerebral aneurysms within the cisternal space were shown in conjunction with the accompanying surface veins, adjacent cranial nerves, dura mater and tentorial edge, cranial base bone, and surrounding pericisternal brain surfaces. With application of 3D MR cisternograms in the management of unruptured cerebral aneurysm, the anatomical relationship between the aneurysmal contours and the perianeurysmal environment could be evaluated the within the cisternal space. This might provide another clinical factor when considering the potential risk of growth, rupture, and symptomatic cranial nerve signs of an unruptured cerebral aneurysm.     

A successfully treated case of a ruptured anterior wall aneurysm of the internal carotid artery (C2) which changed in form from blister-like to saccular type

We successfully treated a case of ruptured anterior wall aneurysm of the ICA (C2) which changed in form from blister-like to saccular type. A 46-year-old woman developed subarachnoid hemorrhage on July 12, 2002. Cerebral angiogram demonstrated a blister-like aneurysm located in the left C2 portion of the internal carotid artery, but which didn't affect the arterial branches. Because of the risk of premature rupture during early surgery, delayed surgery was scheduled and the patient underwent serial study of the aneurysm. During 2 weeks of follow-up, the shape and size of the aneurysm changed in form blister-like to an enlarged saccular type aneurysm. On the day 18th, a left episubcombined approach, after insertion of a balloon catheter into the cervical ICA, was attempted and the aneurysm projecting antero-medially under the left carotid artery was exposed. The aneurysm had a distinct neck and its wall was not fragile. There was no macroscopic evidence of dissection of the ICA and the aneurysm was successfully clipped by conventional manipulation. Because of the difficulty in determining by angiographic evidence alone, whether an anterior wall aneurysm is a blister type or saccular type, careful follow-up is needed and if the shape or size changes, immediate appropriate treatment becomes mandatory. Intraoperative observation will determine the final diagnosis, as in this uncommon case.     

Taurine alters respiratory gas exchange and nutrient metabolism in type 2 diabetic rats

OBJECTIVE: To assess the effect of taurine supplementation on respiratory gas exchange, which might reflect the improved metabolism of glucose and/or lipid in the type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. RESEARCH METHODS AND PROCEDURES: Male OLETF rats (16 weeks of age) were randomly divided into two groups: unsupplemented group and taurine-supplemented (3% in drinking water) group. After 9 weeks of treatment, indirect calorimetry and insulin tolerance tests were conducted. The amounts of visceral fat pads, tissue glycogen, the blood concentrations of glucose, triacylglycerol, taurine, and electrolytes, and the level of hematocrit were compared between groups. A nondiabetic rat strain (Long-Evans Tokushima Otsuka) was used as the age-matched normal control. RESULTS: The indirect calorimetry showed that the treatment of OLETF rats with taurine could reduce a part of postprandial glucose oxidation possibly responsible for the increase of triacylglycerol synthesis in the body. Taurine supplementation also improved hyperglycemia and insulin resistance and increased muscle glycogen content in the OLETF rats. Supplementation with taurine increased the blood concentration of taurine and electrolyte and fluid volume, all of which were considered to be related to the improvement of metabolic disturbance in OLETF rats. DISCUSSION: Taurine supplementation may be an effective treatment for glucose intolerance and fat/lipid accumulation observed in type 2 diabetes associated with obesity. These metabolic changes might be ascribed, in part, to the alteration of circulating blood profiles, where the improved hyperglycemia and/or the blood accumulation of taurine itself would play roles.     

Biological activity and chemistry of taxoids from the Japanese yew, Taxus cuspidata

Approximately 120 taxoids have been isolated to date from the Japanese yew, Taxus cuspidata. These taxoids possess various skeletons containing 5/7/6-, 6/10/6-, 6/5/5/6-, 6/8/6-, or 6/12-membered ring systems. Among the taxoids, some non-paclitaxel-type compounds have been shown to reduce CaCl(2)-induced depolymerization of microtubules, increase cellular accumulation of vincristine in multidrug-resistant tumor cells, and exhibit potent cytotoxicity. Chemical derivatization of taxoids of T. cuspidata is also reviewed.     

Characterization of chondroitin/dermatan sulfate proteoglycans synthesized by bovine retinal pericytes in culture

Pericytes associate with the outside of endothelial cells in microvessels. Previous studies have shown that these cells synthesize glycosaminoglycans (GAGs) but the nature of the core proteins to which these GAGs are attached is unknown. In the present study, cultured bovine retinal pericytes were metabolically labeled with [(3)H]glucosamine, [(35)S]sodium sulfate or (35)S-labeled amino acids and the proteoglycans synthesized by these cells were purified by DEAE-Sephacel ion exchange and molecular sieve Sepharose CL-4B chromatography. Separated proteoglycans were digested with papain, heparitinase or chondroitin ABC lyase and the GAGs characterized by Sepharose CL-6B chromatography. Proteoglycans were also assessed by sodium dodecyl sulfate polyacrylamide gel electrophoresis before and after digestion with chondroitin ABC lyase. Pericytes predominantly synthesize and secrete chondroitin or dermatan sulfate proteoglycans (CS/DS PGs) rather than heparan sulfate proteoglycans (HSPGs). Two subclasses of CS/DS PGs are synthesized by pericytes; one is a high M(r) subclass with high charge density. This subclass eluted at the void volume of a Sepharose CL-4B molecular sieve column, was susceptible to chondroitin ABC lyase, and contained core proteins of ca. 550 and 450 kD which were recognized by antibody to versican. The other major subclass eluted at a K(av) ca. 0.45 on a Sepharose CL-4B molecular sieve column, was susceptible to chondroitin ABC lyase, and contained core proteins recognized by antibodies to either biglycan or decorin that separated as a broad band of ca. 50 kDa in SDS-PAGE. A small amount of HSPG was also synthesized by these cells and could be separated from the CS/DS PGs by DEAE-Sephacel chromatography using a linear gradient of 0.1-0.7 M NaCl. Release of GAG chains by protease digestion indicated that the length of GAG chains was approximately M(r) 45000 in biglycan and decorin, approximately M(r) 48000 in the small amount of HSPGs and approximately M(r) 66000 in versican. These proteoglycans resemble those synthesized by vascular smooth muscle cells but differ markedly from those synthesized by vascular endothelial cells.     

Bioactive taxoids from the Japanese yew Taxus cuspidata

A series of new taxoids, named taxuspines A-H and J-Z (1-25) and taxezopidines A-H and J-L (26-36), have been isolated together with 37 known taxoids (37-73) including paclitaxel (53) from the Japanese yew, Taxus cuspidata Sieb. et Zucc. (Taxaceae). These new taxoids possess various skeletons containing 5/7/6, 6/10/6, 6/5/5/6, 6/8/6, or 6/12-membered ring systems. Among the new taxoids, some non-taxol-type compounds remarkably reduced CaCl(2)-induced depolymerization of microtubules, or increased cellular accumulation of vincristine in multidrug-resistant tumor cells as potent as verapamil. On the other hand, chemical derivatization of taxinine (37), one of major taxoids obtained from this yew, led to the discovery of unusual reactions of taxinine derivatives. Here we describe our recent results on the isolation, structure elucidation, and bioactivity of these new and known taxoids and the formation of unexpected products of the unusual reactions of taxinine.     

Progesterone production and actions in the human central nervous system and neurogenic tumors

Progesterone has been suggested to be involved in the functions of the nervous system, but it has yet to be examined in humans. Progesterone has also been postulated to be involved in the biological behavior of various human neurogenic tumors via progesterone receptors A and B (PR-A and PR-B). In this study we examined the expression of PR and the enzymes responsible for progesterone biosynthesis (P450scc, 3betahydroxysteroid dehydrogenase, and steroidogenic acute regulatory protein) in human brain. We also examined the distribution of PR isoforms in neurogenic tumors using immunohistochemistry and RT-PCR analysis. The presence of PR and mRNA for P450scc, 3beta-hydroxysteroid dehydrogenase, and steroidogenic acute regulatory protein was detected in human brain. PR isoforms were detected in neurogenic tumors. PR-A and PR-B were equally expressed in meningiomas, but PR-B was the predominant isoform compared with PR-A in astrocytic tumors and Schwannomas. There was a statistically significant inverse correlation between PR-A and the proliferation index in meningiomas and astrocytic tumors. These findings suggest that progesterone is locally synthesized and exerts its actions through PR in the human central nervous system, and that progesterone may be involved in regulation of the growth and development of neurogenic tumors via PR, especially in the inhibition of tumor cell proliferation via PR-A.