Epithelioid hemangioendothelioma of the liver associated with thrombocytopenia and coagulopathy

Epithelioid hemangioendothelioma of the liver is a rare vascular neoplasm with intermediate malignant potential. The prognosis is highly unpredictable. We report the case of a 59-year-old woman who had the tumor radically resected, but multiple metastases of the liver developed associated with thrombocytopenia and consumption coagulopathy, as observed in Kasabach-Merritt syndrome. The patient did not respond to any treatment and the behavior of the tumor was very aggressive. The patient died 15 months after radical resection of the tumor.

In vitro and in vivo effects of 14alpha-demethylase (ERG11) depletion in Candida glabrata

Sterol 14alpha-demethylase (ERG11) is the target enzyme of azole antifungals that are widely used for the treatment of fungal infections. Candida glabrata is known to be less susceptible to fluconazole than most Candida albicans strains, and the incidence of C. glabrata infection has been increasing mostly in conjunction with the use of azole antifungals. Recently, it has been reported that C. glabrata can rescue the defect of ergosterol biosynthesis by incorporating cholesterol from serum. To explore the effect of inactivating Erg11p in C. glabrata, we generated mutant strains in which the ERG11 gene was placed under the control of tetracycline-regulatable promoters. In these mutants, expression of the ERG11 gene can be repressed by doxycycline (DOX). All mutants showed a growth defect in the presence of DOX. The numbers of CFU of the mutants were lowered by only 1/10 with DOX treatment. In these mutants, accumulation of 4,14-dimethylzymosterol, which differs from an accumulated abnormal sterol detected in C. albicans and Saccharomyces cerevisiae treated with fluconazole, was observed by DOX treatment. Although such phenotypes were also observed in serum-containing media by DOX treatment, they were alleviated. Furthermore, the mutant could grow in DOX-treated mice without a severe reduction in the number of cells. Thus, depleting the expression of the ERG11 gene lowered the number of CFU by only 1/10 due to the accumulation of 4,14-demethylzymosterol in vitro, and it did not result in the defective growth of fungal cells in mice. These results suggested that Erg11p is not an ideal target molecule of antifungals for C. glabrata.

Ethanol-induced apoptosis in hepatoma cells proceeds via intracellular Ca(2+) elevation, activation of TLCK-sensitive proteases, and cytochrome c release

Ethanol is known to induce apoptosis in hepatocytes. However, intracellular signaling events of ethanol-induced death are still only partially understood. We studied such processes in ethanol-induced apoptosis in HepG2 cells as a model system for human liver cells. We determined the incidence of apoptosis by DNA fragmentation and tested the effects of various known inhibitors. Ethanol induces apoptosis in HepG2 cells in a dose- and time-dependent manner as well as in rat primary hepatocytes. This effect was not mediated through the death receptor CD95 and the tumor necrosis factor receptors. It was efficiently inhibited by the caspase inhibitor N-benzyloxycarbonyl-Asp-Glu-Val-Asp-fluoromethylketone (zVAD-fmk), the Ca(2+) chelator EGTA, and the serine protease inhibitor N-p-tosyl-l-lysine chloromethyl ketone (TLCK). Upon ethanol treatment, the intracellular calcium ion concentration was increased and cytochrome c was released from the mitochondria, and caspases were activated. EGTA and TLCK could inhibit cytochrome c release from the mitochondria. Furthermore, overexpression of Bcl-x(L) saved cells from ethanol-induced apoptosis. These data suggest that ethanol-induced apoptosis in liver cells is initiated by the intracellular Ca(2+) elevation in the cytoplasm and activation of TLCK-sensitive serine proteases. Our data provide new insight into ethanol-induced apoptosis in liver cells and may lead to therapeutic strategies to prevent liver damage.

Intraoperative measurement of arterial blood flow using a transit time flowmeter: monitoring of hemodynamic changes during cerebrovascular surgery

BACKGROUND

The purpose of this study was to examine the utility and reliability of arterial flow measurements made with a transit time ultrasonic flowmeter for monitoring blood flow changes during intracranial and carotid surgery.

METHOD

A total of 25 patients underwent intra-operative arterial blood flow measurements. The pulsatile flow curve and mean flow values were obtained using 1- to 6-mm transit time probes with a dual channel flowmeter. Four cases underwent aneurysm clipping, 11 cases superficial temporal artery (STA)--middle cerebral artery (MCA) bypass, 2 cases external carotid artery (ECA)--radial artery--MCA bypass for aneurysm trapping, and 8 cases carotid endarterectomy. In aneurysm clipping, blood flow in the branches distal to the aneurysm was measured before and after clipping. Blood flow in the STA was measured before and after STA-MCA anastomosis, and blood flow in the internal carotid artery (ICA) cervical portion was measured during carotid endarterectomy. Blood flow in the MCA and STA was monitored during radial artery grafting.

FINDINGS

Blood flow in the STA was elevated after STA-MCA anastomosis. However, post-operative hyperperfusion syndrome was found in some cases whose flow elevation was over 50 ml/min. Also in one case of carotid stenosis, of which blood flow of ICA was elevated to 400 ml/min after carotid endarterectomy, hyperperfusion syndrome was found after surgery. In the cases of MCA aneurysm clipping, decreasing of M2 flow was detected when clipping caused bifurcation stenosis.

INTERPRETATION

We found transit time flow measurement useful for management of cerebrovascular surgery: the technique was simple to use and provided stable, reliable results. The method was able to reveal distal branch flow diminution in aneurysm clipping, or residual flow during temporary clipping in aneurysm surgery, and has the potential to predict post-operative complications such as hyperperfusion by signalling over-elevation of donor artery flow in bypass surgery or ICA flow in carotid surgery.

Pranidipine, a 1,4-dihydropyridine calcium channel blocker that enhances nitric oxide-induced vascular relaxation

Pranidipine, a long acting 1,4-dihydropyridine calcium channel blocker, prolongs nitric oxide (NO)-mediated relaxation of rat aorta; it prolongs acetylcholine-induced relaxation in presence of endothelium as well as nitroglycerin-induced relaxation in absence of endothelium. In rat aorta the effect of pranidipine on NO-mediated relaxation is cyclic guanosine monophosphate (cGMP)-independent, but in guinea pig carotid artery the same effect of pranidipine is cGMP-dependent. It has been reported that in co-cultured human endothelial and smooth muscle cells pranidipine, at a higher concentration (10(-6) M), enhances vasorelaxant effect of NO by blocking NO decomposition. The enhancement of NO action by pranidipine differs from the direct NO-releasing action of other 1,4-dihydropyridines. It is expected that enhancement of NO-induced vasodilatation will lead to a venodilator action in vivo and less peripheral edema. The target organ protective effects of pranidipine are also reviewed in this article.

Cerebral revascularization for moyamoya disease in children

Ninety-four patients with moyamoya disease (56 in the pediatric age group and 38 adults) were treated by revascularization surgery in the past 21 years (1979--2000). Combined surgery of the superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis and indirect revascularization of encaphalo-duro-arterio-myo-synangiosis (EDAMS) was performed. Ischemic attacks disappeared in most patients within 1 year (mean) after surgery in pediatric cases. No morbidity or mortality was experienced in the pediatric group. Some children with cerebral infarction before the surgery, however, had mild mental retardation even after the surgery. Early diagnosis and proper prophylactic surgical treatment is indispensable for pediatric patients with moyamoya. MR angiography is an important diagnostic modality for the screening and longitudinal follow-up of moyamoya disease.

A novel chordin-like protein inhibitor for bone morphogenetic proteins expressed preferentially in mesenchymal cell lineages

Chordin is a bone morphogenetic protein (BMP) inhibitor that has been identified as a factor dorsalizing the Xenopus embryo. A novel secreted protein, CHL (for chordin-like), with significant homology to chordin, was isolated from mouse bone marrow stromal cells. Injection of CHL RNA into Xenopus embryos induced a secondary axis. Recombinant CHL protein inhibited the BMP4-dependent differentiation of embryonic stem cells in vitro and interacted directly with BMPs, similar to chordin. However, CHL also weakly bound to TGFbetas. In situ hybridization revealed that the mouse CHL gene, located on the X chromosome, was expressed predominantly in mesenchyme-derived cell types: (1) the dermatome and limb bud mesenchyme and, later, the subdermal mesenchyme and the chondrocytes of the developing skeleton during embryogenesis and (2) a layer of fibroblasts/connective tissue cells in the gastrointestinal tract, the thick straight segments of kidney tubules, and the marrow stromal cells in adults. An exception was expression in the neural cells of the olfactory bulb and cerebellum. Interestingly, the spatiotemporal expression patterns of CHL were distinct from those of chordin in many areas examined. Thus, CHL may serve as an important BMP regulator for differentiating mesenchymal cells, especially during skeletogenesis, and for developing specific neurons.

Fusarium oxysporum fatty-acid subterminal hydroxylase (CYP505) is a membrane-bound eukaryotic counterpart of Bacillus megaterium cytochrome P450BM3

The gene of a fatty-acid hydroxylase of the fungus Fusarium oxysporum (P450foxy) was cloned and expressed in yeast. The putative primary structure revealed the close relationship of P450foxy to the bacterial cytochrome P450BM3, a fused protein of cytochrome P450 and its reductase from Bacillus megaterium. The amino acid sequence identities of the P450 and P450 reductase domains of P450foxy were highest (40.6 and 35.3%, respectively) to the corresponding domains of P450BM3. Recombinant P450foxy expressed in yeast was catalytically and spectrally indistinguishable from the native protein, except most of the recombinant P450foxy was recovered in the soluble fraction of the yeast cells, in marked contrast to native P450foxy, which was exclusively recovered in the membrane fraction of the fungal cells. This difference implies that a post (or co)-translational mechanism functions in the fungal cells to target and bind the protein to the membrane. These results provide conclusive evidence that P450foxy is the eukaryotic counterpart of bacterial P450BM3, which evokes interest in the evolutionary aspects concerning the P450 superfamily along with its reducing systems. P450foxy was classified in the new family, CYP505.

Mannose-binding lectin polymorphisms in patients with hepatitis C virus infection

BACKGROUND

Persistent infection with hepatitis C virus (HCV) leads to liver cirrhosis (LC) and often to liver cancer. Little is known about host factors that determine the variable natural history. Mannose-binding lectin (MBL) is an important constituent of the innate immune system. In white patients there is an association between codon 52 mutation of the MBL gene and persistent hepatitis B virus (HBV) infection. To determine whether MBL gene polymorphisms affect the course of HCV infection, we investigated the association between MBL gene polymorphisms and HCV infection in Japanese subjects.

METHODS

Fifty-two HCV-infected Japanese patients (8 with chronic inactive hepatitis (CIH), 31 with chronic active hepatitis (CAH), 13 with LC) and 50 normal controls were studied. MBL gene mutations were determined by means of polymerase chain reaction and restriction fragment length polymorphism analyses.

RESULTS

Codon 52 and codon 57 mutations were absent in all subjects. Homozygous mutation in codon 54 was present in one (0.9%) patient. Heterozygous codon 54 mutation was present in 17 (32%) of the 52 patients and in 21 (41%) of the controls. No significant difference in the frequency of codon 54 mutation was observed between patient and control groups. However, although no significant relationship was observed between MBL polymorphisms and the levels of HCV RNA, all patients with heterozygous or homozygous codon 54 mutations had CAH or LC. In contrast, 8 of the 34 patients without codon 54 mutation remained at CIH. (P = 0.0405).

CONCLUSION

MBL may be one of the factors that influence the course of HCV infection.

Depletion of the squalene synthase (ERG9) gene does not impair growth of Candida glabrata in mice

Squalene synthase (farnesyl-diphosphate farnesyltransferase, EC 2.5. 1.21) is the first committed enzyme of the sterol biosynthesis pathway. Inhibitors of this enzyme have been intensively studied as potential antifungal agents. To assess the effect of deactivating squalene synthase on the growth of fungi in mice, we isolated the squalene synthase (ERG9) gene from the pathogenic fungus Candida glabrata and generated strains in which the CgERG9 gene was under the control of the tetracycline-regulatable promoter. Depletion of the ERG9 gene by doxycycline (DOX), a derivative of tetracycline, decreased the cell viability in laboratory media, whereas it did not affect cell growth in mice at all. The growth defect caused by DOX in laboratory media was suppressed by the addition of serum. Analyses of the sterol composition of the restored cells in serum-containing media suggest that the defect of ergosterol biosynthesis can be complemented by the incorporation of exogenous cholesterol into the cells. Thus, deactivation of squalene synthase did not affect fungal growth in mice, presumably because the cells were able to incorporate cholesterol from the serum. These results showed that squalene synthase could not be a suitable target of antifungals for the treatment of C. glabrata infection.

Effects of closed-system drain in surgery: focus on methicillin-resistant Staphylococcus aureus

OBJECTIVE

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) has made a strong impact on the strategy of peri-operative antibiotic prophylaxis, since MRSA has become one of the most common causative organisms of nosocomial infection in recent years. In this study, we conducted a bacteriological evaluation of surgical drains before and after introducing strategies to decrease MRSA infection rates.

DESIGN AND PATIENTS

Between January 1987 and December 1994, we performed a total of 2, 755 surgical operations on inpatients, including 1,635 major and 1, 120 minor operations. Almost all surgical drains were examined bacteriologically when they were removed. The number of drains examined was 460 +/- 47 (mean +/- SEM) per year. Since the increased incidence of MRSA infection, we started exclusively using a closed drainage system and first-generation cephalosporins in 1991. The strategy was evaluated by comparing the positive rates of drain cultures, changes in bacteriological features, and incidence of MRSA infection for the 4-year periods before and after 1991.

RESULTS

The positive rate of bacteria in the drains decreased significantly (p < 0.01) from 25 +/- 2 to 16 +/- 1%. Bacteriologically, the positive rate of Staphylococcus spp. decreased significantly (p < 0.05) from 7 +/- 2 to 3 +/- 0.3%. Positive rates of MRSA decreased significantly (p < 0.05) from 2.1 +/- 0.3 to 1.3 +/- 0.3%. Streptococcus declined dramatically from 3.0 +/- 0.3 to 0.3 +/- 0.1%. Of gram-negative strains, Pseudomonas and Escherichia coli were most often isolated. They showed no significant difference in positive rates between the terms.

CONCLUSION

A closed drainage system and thorough use of the first-generation cephalosporins for prophylaxis were effective in decreasing positive bacterial culture of drains and reducing the incidence of MRSA on drains after surgery.

[A case of HTLV-1 associated myelopathy (HAM) with pseudopseudohypoparathyroidism]

We report a case of HTLV-1 associated myelopathy (HAM) with pseudopseudohypoparathyroidism (PPHP). A 57-year-old woman, without a history of blood transfusion, was admitted with numbness and pain in her legs. Pain sensation in both legs was reduced and tendon reflexes were exaggerated. She exhibited spastic gait. The diagnosis of HAM was made because of positive antibody for HTLV-1 in blood and CSF. She also had features of Albright syndrome (short stature, round face, and short fourth metatarsals) without abnormal calcium and phosphorus metabolism, leading to the diagnosis of PPHP. Brain CT revealed bilateral calcification of the basal ganglia. Although HAM rarely accompanies pseudohypoparathyroidism (PHP), there are few reported cases of HAM associated with PPHP. The exact mechanism of HAM is not known, but it is thought to involve an immune-related process. Since PHP is considered to induce a state of mild immunosuppression through reduction of 1,25-dihydroxyvitamin D3, it is possible that susceptibility to HAM could be augmented in the presence of PHP. If PPHP should be an incomplete form of PHP, a similar mechanism may be involved in the association of PPHP and HAM.

Modification of glial-neuronal cell interactions prevents photoreceptor apoptosis during light-induced retinal degeneration

Prolonged or high-intensity exposure to visible light leads to photoreceptor cell death. In this study, we demonstrate a novel pathway of light-induced photoreceptor apoptosis involving the low-affinity neurotrophin receptor p75 (p75NTR). Retinal degeneration upregulated both p75NTR and the high-affinity neurotrophin receptor TrkC in different parts of Müller glial cells. Exogenous neurotrophin-3 (NT-3) increased, but nerve growth factor (NGF) decreased basic fibroblast growth factor (bFGF) production in Müller cells, which can directly rescue photoreceptor apoptosis. Blockade of p75NTR prevented bFGF reduction and resulted in both structural and functional photoreceptor survival in vivo. Furthermore, the absence of p75NTR significantly prevented light-induced photoreceptor apoptosis. These observations implicate glial cells in the determination of neural cell survival, and suggest functional glial-neuronal cell interactions as new therapeutic targets for neurodegeneration.

Vascular endothelial growth factor synergistically enhances bone morphogenetic protein-4-dependent lymphohematopoietic cell generation from embryonic stem cells in vitro

The totipotent mouse embryonic stem (ES) cell is known to differentiate into cells expressing the beta-globin gene when stimulated with bone morphogenetic protein (BMP)-4. Here, we demonstrate that BMP-4 is essential for generating both erythro-myeloid colony-forming cells (CFCs) and lymphoid (B and NK) progenitor cells from ES cells and that vascular endothelial growth factor (VEGF) synergizes with BMP-4. The CD45(+) myelomonocytic progenitors and Ter119(+) erythroid cells began to be detected with 0.5 ng/mL BMP-4, and their levels plateaued at approximately 2 ng/mL. VEGF alone weakly elevated the CD34(+) cell population though no lymphohematopoietic progenitors were induced. However, when combined with BMP-4, 2 to 20 ng/mL VEGF synergistically augmented the BMP-4-dependent generation of erythro-myeloid CFCs and lymphoid progenitors from ES cells, which were enriched in CD34(+) CD31(lo) and CD34(+) CD45(-)cell populations, respectively, in a dose-dependent manner. Furthermore, during the 7 days of in vitro differentiation, BMP-4 was required within the first 4 days, whereas VEGF was functional after the action of BMP-4 (in the last 3 days). Thus, VEGF is a synergistic enhancer for the BMP-4-dependent differentiation processes, and it seems to be achieved by the ordered action of the 2 factors.

Differential properties of the optical-isomers of pranidipine, a 1,4-dihydropyridine calcium channel modulator

Pranidipine is an optically-active 1,4-dihydropyridine (DHP) voltage-dependent L-type calcium channel inhibitor. Certain enantiomeric pairs display opposite effects, i.e., inhibition and activation of the calcium channel while others exhibit the same qualitative actions. We investigated pranidipine, a new DHP, using a paradigm of vascular smooth muscle reactivity. In isolated rat aorta, depolarized with 80 mM KCl, both isomers of pranidipine caused a right-ward shift of the concentration-contraction curves for extracellular Ca2+. The apparent pA2, values of the S-isomer and R-isomer were 10.03 and 8.36, respectively, providing evidence that the calcium channel blocking action of the S-isomer was 50 times more potent than that of the R-isomer. Antihypertensive actions of these two isomers studied in pentobarbital-anaesthetized spontaneously hypertensive rats, revealed that the S-isomer, at doses of 3-30 microg/kg i.v. decreased blood pressure in a dose-dependent manner, while the R-isomer had no effect on blood pressure at those doses. We conclude that the pair of enantiomers of pranidipine qualitatively display the same Ca2+ channel blocking action and that neither isomer exhibits Bay K 8644-like activation. Pranidipine may be useful in studies on the architecture of the DHP receptor 'pocket'.

Pressor responses to serotonin injected into the nucleus tractus solitarius of Sprague-Dawley rats and spontaneously hypertensive rats

Previous studies in rats have shown that injection of nanomoles of serotonin (5-hydroxytryptamine; 5HT) into the nucleus tractus solitarius (NTS) acts on 5HT3 receptors to increase arterial pressure (AP). We investigated the effect of 5HT in Sprague-Dawley (SD) rats and in spontaneously hypertensive rats (SHR). Injection of nanomoles of 5HT into the NTS of chloralose-anesthetized SD rats increased AP. This effect was inhibited by prior injection of 5HT3 receptor antagonist ondansetron. The GABA(A) receptor antagonist bicuculline did not inhibit the effect of 5HT. Bilateral injection of 5HT or ondansetron did not affect the baroreflex sensitivity. Bilateral injection of ondansetron did not alter AP. The pressor effect of 5HT was exaggerated in SHR. These results suggest that stimulation of 5HT3 receptors in the NTS increases AP independently of activation of GABAA receptors and the baroreflex sensitivity. Furthermore, this serotonergic system is supersensitive in the NTS of SHR.

Interaction between a Solute Molecule and a Fluorocarbon Bonded Layer in Reversed-Phase High-Performance Liquid Chromatography

Glassesand silica-gel packings modified with fluorocarbon and hydrocarbon silylation agents were prepared to investigate the separation mechanism of a fluorocarbon bonded layer in reversed-phase high-performance liquid chromatography (RP-HPLC). On the hydrocarbon layer the contact angles of benzene (Be) and hexafluorobenzene (FB) decreased with increasing carbon chain length of the modifier, and the mobile phase (MP) was independent of the modifier. The fluorocarbon layer gave a larger contact angle for each liquid than the hydrocarbon layer. The retention factor, k, of Be and FB on hydrocarbon packings increased with decreasing contact angle. It was demonstrated that the separation of Be and FB on hydrocarbon packings is caused by solvophobic interaction between solute molecules and the stationary layer. In contrast, k increased with increasing contact angle at the fluorocarbon layer. The retention of Be and FB on fluorocarbon packings may be attributed to the penetration of the solute molecules from the mobile phase into the fluorocarbon stationary layer. Copyright 1999 Academic Press.

Skull metastasis of Ewing's sarcoma--three case reports

Three cases of skull metastasis of Ewing's sarcoma were treated. The metastatic lesion was located at the midline of the skull above the superior sagittal sinus in all cases. Surgery was performed in two patients with solitary skull lesions involving short segments of the superior sagittal sinus without remarkable systemic metastasis, resulting in good outcome. The third patient had extensive, multiple tumors involving the superior sagittal sinus which could not be excised, and died due to intracranial hypertension. The surgical indication for skull metastasis of Ewing's sarcoma depends on the location and length of the involved superior sagittal sinus, and general condition.

[The role of discharge coordination nurses in a university hospital--changes in the role with timing of the discharge request]

We studied the role of discharge assisting nurses who coordinate discharge planning (DP). The requests for DP were ordered at different periods during the admission. The periods were mainly divided into three phases in which the DP was ordered from the wards, which were type 1: just before discharge, type 2: after the decision to discharge, and type 3: between admission and the decision to discharge. We analyzed 8 cases, DP ordered in the type 3 phase provided the most satisfactory outcome for patients' home lives, since the nurse, other medical staff and patients had sufficient time to prepare and provide the needed services.

CONCLUSION

It was clarified that type 3 provided the best outcome of discharge planning.

Clinical application of three-dimensional anisotropy contrast magnetic resonance axonography. Technical note

The utility of three-dimensional anisotropy contrast (3DAC) magnetic resonance (MR) axonography, a method sensitive to neuronal fibers and their directionality, was investigated in the clinical setting using a 3-tesla MR imaging system based on a General Electric Signa platform. The study focused on healthy volunteers and patients with common structural central nervous system disorders, namely chronic infarction, brainstem cavernous hemangioma, supratentorial meningioma, and astrocytoma. Three orthogonal anisotropic diffusion-weighted images were first obtained. Three primary colors were each assigned to a diffusion-weighted image, respectively, and the images were subsequently combined into a single-color image in full-color spectrum (3DAC MR axonography image). Fiber-tract definition in the cerebral peduncle of the midbrain of healthy volunteers showed intersubject variation, with two general patterns recognized: dispersed (60% of cases) and compact (40% of cases). Pathological alterations in the fiber tracts were readily identified in cases involving wallerian degeneration of the pyramidal tract, as illustrated in the cases of chronic infarction. Displacement of major tracts, such as the medial lemniscus or corticospinal tract, as well as fiber directionality, was also easily recognized in cases of mass lesions. As an imaging method uniquely capable of providing information regarding axonal connectivity, 3DAC MR axonography appears to have promising potential for routine clinical application.

Arteriovenous malformation in association with moyamoya disease

The authors report two rare cases of arteriovenous malformation (AVM) associated with moyamoya disease. An AVM, supplied by transdural communicating arteries, was located in the right occipital lobe in one patient who presented with ischemia. The second AVM, which was supplied by basal moyamoya vessels, was located in the posterior part of the left frontal lobe in a patient who developed intracerebral hemorrhage that occupied the left basal ganglion.

A review of the literature revealed a total of 12 AVMs in 11 patients with moyamoya disease including our cases. All AVMs were cerebral and two were supplied by normal cerebral arteries, whereas six AVMs were supplied by basal moyamoya vessels at the base of the brain and four AVMs were supplied by external carotid arteries through the transdural communicating arteries. Every AVM drained into deep or cortical cerebral veins. These findings suggest that the hyperangiogenic character of moyamoya disease occasionally induces the development of acquired arteriovenous shunts that mimic AVM.

Interleukin-6-type cytokines stimulate mesenchymal progenitor differentiation toward the osteoblastic lineage

Cytokines that transduce their signals either through glycoprotein 130 (gp130) homodimers or gp 130/leukemia inhibitory factor (LIF) receptor beta heterodimers are potent inducers of osteoclast development in vitro as well as in vivo; and interleukin (IL)-6 has been recognized as an important pathogenic factor in diseases characterized by increased bone remodeling, such as the osteoporosis of sex steroid deficiency. Based on evidence that the same cytokines can also promote committed osteoblast differentiation and stimulate bone formation in vitro and in vivo and that mesenchymal cell differentiation toward the osteoblast lineage may be a prerequisite for osteoclastogenesis, we have investigated whether gp130 activation can affect the differentiation of uncommitted mesenchymal progenitors. Using as our model murine embryonic fibroblasts (EF), we found that IL-6 or IL-11 in combination with their soluble receptors (sIL-6R or sIL-11R) increased dose-dependently the number of alkaline phosphatase (AP)-positive cells in 3-6-day-long cultures. Moreover, EF cells maintained with IL-6/sIL-6R in the presence of ascorbic acid and beta-glycerophosphate expressed osteocalcin messenger RNA (mRNA) by 2 weeks and formed a matrix containing mineralized collagen fibers by 3 weeks. This prodifferentiation effect was specific for the osteoblastic lineage, as we found no evidence for increased differentiation of chondrocytes, adipocytes, or muscle cells. Unlike IL-6/sIL-6R, LIF, oncostatin M (OSM), and ciliary neurotrophic factor (CNTF) did not promote osteoblastic differentiation of EF cells. This pattern of specificity was accounted for by the finding that EF cells express gp130, but not the ligand-binding subunit of the IL-6 receptor (gp80) nor the LIF receptor beta. These observations add credence to the contention that increased production of gp130-utilizing cytokines and their receptors in pathological conditions like sex steroid deficiency is indeed responsible for not only the increased osteoclastogenesis, but also the increased osteoblastogenesis, and thereby for the increased rate of bone remodeling.

High-resolution T2-reversed magnetic resonance imaging on a high magnetic field system. Technical note

Because of the high signal-to-noise (S/N) ratio, T2-weighted images obtained using high-field magnetic resonance (MR) imaging systems can be expected to provide high anatomical and contrast resolution. Furthermore, the improved structural and contrast resolution of these high S/N T2-weighted images can be processed for optimum perceptual resolution through the application of gray-scale reversal and expansion of the gray-scale window, known as T2-reversed (T2R) imaging. In this study, the authors investigated high-resolution T2R MR imaging performed on a high-field (3-tesla) system for its clinical utility in detecting various physiological and pathological conditions.

Changes of ischemic heart disease in Utsunomiya, Japan, over 10 years: a survey of primary care physicians

A total of 502 patients presenting in Utsunomiya city and its suburbs during a 10-year period were studied to determine the clinical features of ischemic heart disease and to identify coronary risk factors. The male/female ratio was 1.21, but the ratio decreased with increasing age. The duration of chest pain showed a continuous spectrum between angina and infarction, with a short duration of chest pain not being useful for excluding the diagnosis of myocardial infarction. Hypertension was more common than hypercholesterolemia in this study, although the prevalence of the latter increased slightly with time, along with the shift towards a modernized occupational pattern. Smoking was a more important risk factor for ischemic heart disease in younger individuals than in the elderly, and diabetes mellitus was highly associated with the development of myocardial infarction. The incidence of radiologically diagnosed cardiac hypertrophy and aortic calcification decreased over time. These changes may have resulted in part from improved blood pressure control and the development of new anti-hypertensive and cholesterol-lowering agents.

[Diffusion tensor analysis with nuclear magnetic resonance in human central nervous system]

Nuclear magnetic resonance has been used to measure the diffusivity of water molecules. In central nervous system, anisotropic diffusion, which is characterized by apparent diffusion tensor Dapp zeta, is thought to be related to neuronal fiber tract orientation. For precise observation of anisotropic diffusion, it is needed to determine the diagonal and off-diagonal elements of Dapp zeta. Once Dapp zeta is estimated from a series of diffusion weighted images, a tissue's orthotropic principal axes and diffusivity of each direction are determined from eigenvalues and eigenvectors of Dapp zeta. There are several methods to represent anisotropic diffusion with Dapp zeta. Examples are diffusion ellipsoids constructed in each voxel depicting both these principal axes and the mean diffusion length in these directions, trace invariant values and its mapping image, largest eigenvalue, and ratio of largest eigenvalue to the other eigenvalue. In this study, the author investigated practical procedure to analyze diffusion tensor Dapp zeta using both of spin-echo and echo-planer diffusion weighted imagings with 3-tesla magnetic resonance machine in human brain. The ellipsoid representation provided particularly useful information about microanatomy including neuronal fiber tract orientation and molecular mobility reflective of microstructure. Furthermore, in the lesion of Wallerian degeneration, the loss of anisotropy of local apparent diffusion was observed. It is suggested that the function of axons can be observed via degree of anisotropy of apparent diffusion. Consequently, diffusion tensor analysis is expected to be a powerful, noninvasive method capable of quantitative and functional evaluation of the central nervous system.

Elevated serum levels of soluble Fas/APO-1 (CD95) in patients with hepatocellular carcinoma

Fas (APO-1/CD95)-mediated apoptosis plays an important role in liver cell destruction in viral hepatitis. Using sandwich ELISA, we measured serum levels of soluble Fas (sFas) in patients with hepatocellular carcinoma (HCC) who were positive for hepatitis B surface antigen (HBsAg) or anti-hepatitis C virus (HCV) antibody. sFas levels were significantly higher in HCC patients (median 4.07 ng/ml; range 0.14-29.18 ng/ml) than levels in age-matched healthy donors (0.29 ng/ml; 0-4.90 ng/ ml) (P < 0.0001) and HBsAg or anti-HCV antibody-positive patients with liver cirrhosis (LC) (2.16 ng/ ml; 0.24-8.39 ng/ml) (P = 0.0015). An arbitrary cut-off level of 3.03 ng/ml (mean + 3 s.d. of controls) revealed the positive frequency of sFas in each group: 1.7% in healthy subjects, 25.9% in LC, and 59.0% in HCC (sensitivity 59.0% and specificity 74.1%). All HCC sera tested contained transmembrane-deleted sFas and some contained another sFas lacking the Fas C-terminal. The positive frequency of either sFas (59.0%) or alpha-fetoprotein (AFP) (57.4%) in HCC patients reached 77.0%. HCC patients with multiple tumour foci (7.53 ng/ml; 1.40-29.18 ng/ml) had significantly higher sFas levels than did patients with a solitary tumour (2.70 ng/ml; 0.14-19.0 ng/ml) (P = 0.003). In all of the sFas-positive patients with a solitary tumour, surgical removal of the tumour reduced sFas levels to the negative in the first post-op week. These findings suggest that sFas may be closely linked with HCC and may be a candidate for a clinical parameter for HCC.

Functions of the two glutamate transporters GLAST and GLT-1 in the retina

In the retina, the glutamate transporter GLAST is expressed in Müller cells, whereas the glutamate transporter GLT-1 is found only in cones and various types of bipolar cells. To investigate the functional role of this differential distribution of glutamate transporters, we have analyzed GLAST and GLT-1 mutant mice. In GLAST-deficient mice, the electroretinogram b-wave and oscillatory potentials are reduced and retinal damage after ischemia is exacerbated, whereas GLT-1-deficient mice show almost normal electroretinograms and mild increased retinal damage after ischemia. These results demonstrate that GLAST is required for normal signal transmission between photoreceptors and bipolar cells and that both GLAST and GLT-1 play a neuroprotective role during ischemia in the retina.

Natural killer and B-lymphoid potential in CD34+ cells derived from embryonic stem cells differentiated in the presence of vascular endothelial growth factor

Differentiation of totipotent mouse embryonic stem (ES) cells to various lymphohematopoietic cells is an in vitro model of the hematopoietic cell development during embryogenesis. To understand this process at cellular levels, differentiation intermediates were investigated. ES cells generated progeny expressing CD34, which was significantly enhanced by vascular endothelial growth factor (VEGF). The isolated CD34+ cells were enriched for myeloid colony-forming cells but not significantly for erythroid colony-forming cells. When cultured on OP9 stroma cells in the presence of interleukin-2 and interleukin-7, the CD34+ cells developed two types of B220+ CD34- lymphocytes: CD3- cytotoxic lymphocytes and CD19+ pre-B cells, and such lymphoid potential was highly enriched in the CD34+ population. Interestingly, the cytotoxic cells expressed the natural killer (NK) cell markers, such as NKR-P1, perforin, and granzymes, classified into two types, one of which showed target specificity of NK cells. Thus, ES cells have potential to generate NK-type cytotoxic lymphocytes in vitro in addition to erythro-myeloid cells and pre-B cells, and both myeloid and lymphoid cells seem to be derived from the CD34+ intermediate, on which VEGF may play an important role.

Enhanced expression of hepatic acyl-coenzyme A synthetase and microsomal triglyceride transfer protein messenger RNAs in the obese and hypertriglyceridemic rat with visceral fat accumulation

The liver plays a central role in lipoprotein metabolism. In particular, very-low density lipoprotein (VLDL) is assembled in the hepatocytes and secreted into the blood circulation. The VLDL is then catabolized to low-density lipoprotein by lipoprotein lipase and hepatic triglyceride lipase. Obese subjects, especially those with visceral fat accumulation, are frequently associated with hyperlipidemia, non-insulin-dependent diabetes mellitus (NIDDM), and hypertension. The mechanism of hyperlipidemia in visceral fat obesity has not yet been elucidated. Otsuka Long-Evans Tokushima Fatty (OLETF) rat is an animal model of NIDDM, characterized by obesity with visceral fat accumulation, hyperlipidemia, and late-onset insulin resistance. To elucidate the mechanism of hyperlipidemia observed in OLETF rats, we focused on the production of VLDL by the liver and investigated hepatic messenger RNA (mRNA) levels of microsomal triglyceride transfer protein (MTP), acyl-coenzyme A synthetase (ACS), and apolipoprotein B (apo B), which play important roles in VLDL synthesis and secretion. In 6-week-old OLETF rats, in which insulin resistance had not been manifested, visceral fat weight was already higher and portal free fatty acid (FFA) and VLDL-triglyceride levels were elevated compared with the control rats. Hepatic ACS activity and mRNA levels, and MTP mRNA levels were also increased in OLETF rats, whereas apo B mRNA levels were similar; these results suggest that the enhanced expression of both ACS and MTP genes associated with visceral fat accumulation before developing insulin resistance may be involved in the pathogenesis of hyperlipidemia in obese animal models with NIDDM.

Glucose transporter levels in a male spontaneous non-insulin-dependent diabetes mellitus rat of the Otsuka Long-Evans Tokushima Fatty strain

Otsuka Long-Evans Tokushima Fatty (OLETF) rats are a new strain of spontaneous non-insulin-dependent diabetes mellitus (NIDDM) models. To evaluate the role of glucose transporters (GLUT) in the development of diabetes in this model, we examined the action of insulin on the translocation of GLUT4 and GLUT1 in isolated adipocytes, and the GLUT4 protein levels in muscles. Long-Evans Tokushima Otsuka (LETO) rats were used as a control strain. In adipocytes, the GLUT4 protein levels in OLETF rats at 30 weeks of age (diabetic stage) were considerably lower than those in LETO rats at the same age. At a pre-diabetic stage (7 weeks), there were no significant differences in GLUT4 protein levels in adipocytes between LETO and OLETF rats. However, the degree of GLUT4 translocation in OLETF rats was lower than that in LETO rats at 7 weeks of age. There were no differences in GLUT1 levels in adipocytes between the two strains. In muscles, the decrease in GLUT4 protein was observed in OLETF rats at 30 weeks of age. Whether such a difference is under the influence of hyperglycemia was also examined using rats rendered diabetic by 70% pancreatectomy. OLETF rats aged 7 weeks were subjected to partial pancreatectomy (Px) and sham pancreatectomy (sham). At 4 weeks after surgery, GLUT4 protein levels in adipose tissues and skeletal muscles were determined. GLUT4 decrease was observed for both tissues of hyperglycemic Px rats compared with euglycemic sham. Moreover, we examined the direct effect of glucose on GLUT4 protein using primary cultured adipocytes of OLETF rats at 5 weeks of age. After 7-day culture with normal (5.6 mmol/l) or high (25 mmol/l) concentrations of glucose, the GLUT4 protein levels in adipocytes decreased at 25 mmol/l glucose compared with 5.6 mmol/l glucose. These findings suggest an early defect in the insulin resistance of OLETF rats probably reflects impaired GLUT4 translocation. The GLUT4 decrease, which occurs later in the process appears to be a consequence, rather than a cause of diabetes in OLETF rats.

Surgical risks of acute cholecystitis in elderly

BACKGROUND/AIMS

For the elderly patient, an emergency biliary procedure carries a higher risk than an elective operation. Recently introduced advances in ultrasonography and critical care medicine have affected the clinical risks of surgery for acute cholecystitis in the elderly. This study evaluated the clinical risks of open cholecystectomy for the elderly with acute cholecystitis.

MATERIALS AND METHODS

During a 10 year period (1985-1994), a total of 145 patients were diagnosed with acute cholecystitis and underwent cholecystectomy. According to their age, the patients were divided into 3 groups (Group A < 59 years of age; Group B between 60-69 years of age; Group C > 70 years of age). The characteristics and the surgical risk factors in open cholecystectomy for the elderly with acute cholecystitis were evaluated.

RESULTS

The rate of acalculous cholecystitis and choledochal stones were significantly (p < 0.05) high in Group C. Septic complication, gangrenous changes, and positive bile culture were also increased parallel to the increase in age. A noteworthy finding was an incidental carcinoma found in a case in group B and in 3 cases in group C. Hospital stay was significantly longer in Group C than in the other groups due to pre-operative complications and post-operative morbidity.

CONCLUSION

With respect to increase in elderly patients with acute cholecystitis who present more frequent gangrenous changes and carcinomatous changes as well as high rate of septic complication, successful treatment of these patients is increased when early surgery can be performed on the basis of accurate and prompt diagnosis using imaging modalities and meticulous peri-operative management.

Copper concentration in hyperintense hepatocellular carcinomas of Long-Evans cinnamon rats on T1-weighted images

The Long-Evans Cinnamon (LEC) rat has abnormal intrahepatic copper accumulation and spontaneously develops hepatocellular carcinomas following hereditary hepatitis. The hepatocellular carcinomas are very similar to human well-differentiated hepatocellular carcinoma in histopathological features and on MR images. Copper is believed to be one of the causes of hyperintensity of hepatocellular carcinomas compared to surrounding non-cancerous tissues on T1-weighted MR image. Eight LEC rats were studied by MR imaging. We measured copper concentrations from the hepatocellular carcinomas and surrounding non-cancerous liver tissues. Signal intensity of hepatocellular carcinomas without cystic areas was iso- to slightly hyperintense relative to surrounding non-cancerous tissues on T1-weighted images. Histopathologically, most of the tumors resembled human highly or well-differentiated hepatocellular carcinomas. Copper concentrations of the hepatocellular carcinomas were lower than the surrounding non-cancerous liver tissues. Copper may not be the cause of increased signal intensity typically observed on T1-weighted images of hepatocellular carcinomas.

Adsorption Characteristics of Silica Gels Treated with Fluorinated Silylation Agents

Branched-chain polyfluorosilane (monochlorodimethyl[4,4-bis(trifluoromethyl)-5,5,6,6,7,7,7-heptafluoroheptyl)-bonded silica gels were prepared. The surface properties of the silica gels modified with various organic silanes were evaluated by the adsorption density of polar and nonpolar gases calculated from adsorption isotherms of nitrogen, carbon dioxide, and normal butane gases. The polyfluorocarbon-bonded silica gel surface was found to be both hydrophobic and oleophobic in nature, whereas the hydrocarbon-bonded silica gel surface was characterized only as hydrophobic. The trifunctional fluorinated silane provides the silica gel surface with a more hydrophilic nature than the monofunctional silane because of the formation of a denser polymeric coating layer with a larger number of silanols.

Hepatocyte growth factor and c-met expression in Long-Evans Cinnamon rats with spontaneous hepatitis and hepatoma

The Long-Evans Cinnamon (LEC) rat is characterized by the spontaneous onset of acute and chronic hepatitis, followed by occurrence of liver cancer, and is thus able to provide a unique experimental model for human genetical liver disease, Wilson's disease. Hepatocyte growth factor (HGF) is a potent hepatotrophic factor in liver regeneration, and its expression is up-regulated in response to liver injuries. We found that the plasma HGF level in LEC rats rose markedly during the fulminant hepatitis phase, fell during the phase of chronic/cholangiofibrosis, and fluctuated during the hepatoma phase. Immunohistological staining of the liver revealed that the number of HGF-positive cells increased remarkably during the fulminant hepatitis phase, and that many of these cells were localized at the portal triads. Fewer HGF-positive cells were observed during the phase of chronic hepatitis. The surface of the hepatocellular carcinoma (HCC) cells and the cytoplasm of the nonepithelial cells in cancerous liver tissues were HGF-positive. The HGF-messenger RNA (mRNA) level in the liver rose in the fulminant hepatitis phase, fell in the chronic hepatitis phase, and was intermediate or high during the hepatoma phase. The expression of c-met mRNA was strong in the tissues of LEC rats with fulminant hepatitis and, especially, in the cholangiofibrosis tissues. c-met mRNA was also detected in HCCs. These results suggest that the HGF-c-met system may play an important role in the regeneration of hepatocytes as well as in the development of HCC in paracrine or autocrine mechanisms.

The effect of sodium bicarbonate on CBF and intracellular pH in man: stable Xe-CT and 31P-MRS

The effects of sodium bicarbonate on cerebral blood flow (CBF) and intracellular pH were studied in five normal volunteers. CBF and intracellular pH were measured by stable xenon computed tomography and phosphorus-31 magnetic resonance spectroscopy (31P-MRS) respectively. Each patient received 7% sodium bicarbonate (3.5 ml/kg body weight) infused intravenously for 15 minutes. Before and after this injection, CBF intracellular pH and physiological parameters were measured. CBF and PaCO2 were significantly increased. On the other hand, hematocrit and intracellular pH were decreased. These result suggests that three factors are thought to contribute to increase CBF during administration of sodium bicarbonate in humans: 1) arterial dilatation in response to carbon dioxide 2) an decrease of hematocrit 3) intracellular acidosis.

[Two cases of ossified spinal meningioma]

It is generally known that meningioma has histological pleomorphism and ossification is one of them. In the cases of spinal meningioma, osteoblastic type is rare. We encountered two different types of ossified spinal meningioma. Two cases of ossified spinal meningioma are reported in this paper. One case is that of a 45-year-old male who had a sudden transient tetraparesis with a tumor located in the upper cervical spinal column. The tetraparesis was caused by the patient's head having been hit. Another case is a 74-year-old female, who had progressive paraparesis and hypesthesia in her lower extremities, with a tumor located in the 9th thoracic spinal column. The MRI findings in these cases suggested that an ossified area was included in the tumor. We performed surgical therapy in both cases, and an operative finding was that these tumors had a very hard component. Histopathological diagnosis in both cases was meningioma. The former included isolated matured bone tissue with fat marrow mixed with the tumor tissue, and the latter included scattered matured lamellar bone tissue. These tumors are considered to be osteoblastic in type.

Cytochrome P450foxy, a catalytically self-sufficient fatty acid hydroxylase of the fungus Fusarium oxysporum

We have purified membrane-bound fatty acid (omega-1-omega-3) hydroxylase of the fungus Fusarium oxysporum MT-811 and found that the activity depends on a single polypeptide with an apparent M(r) value of 118,000. The purified hydroxylase exhibited spectral characteristics of cytochrome P450 (P450), and could catalyze the hydroxylation without the aid of any other proteinaceous components, such as NADPH-P450 reductase. These properties of the fungal hydroxylase are the same as those of bacterial P450BM3 of Bacillus megaterium, a catalytically self-sufficient fused protein of P450 and its reductase. Other properties of the two enzymes, such as molecular weight, high catalytic turnover, and the regiospecificity of the hydroxylating position, were also almost identical. Further, the fungal hydroxylase reacted with the antibody to P450BM3. It was thus shown that the fungal fatty acid hydroxylase reacted with the antibody to P450BM3. It was thus shown that the fungal fatty acid hydroxylase structurally and functionally bears a close resemblance to P450BM3, although it is membrane-bound, unlike the bacterial counterpart. On the other hand, a unique phenomenon was found with the fungal hydroxylase: its NADPH-cytochrome c- or NADPH-menadione reductase activity was enhanced enormously upon binding of its substrate (fatty acid). This appears to be the first instance in which the reactivity of P450 reductase against an artificial electron acceptor was enhanced by the binding of the substrate (to be hydroxylated) to P450. These results raise interesting questions about the molecular evolution of P450. Here we term the fungal hydroxylase cytochrome P450foxy.

A fluorometric assay for measuring deamidase (lysosomal protective protein) using high-performance liquid chromatography

A rapid and sensitive assay method for the determination of deamidase activity is reported. This method is based on fluorometric detection of a dansylated dipeptide, 5-dimethylaminonaphthalene-1-sulfonyl-D-Tyr-Val (N-Dns-D-Tyr-Val), enzymatically formed from the substrate 5-dimethylaminonaphthalene-1-sulfonyl-D-Tyr-Val-NH2 (N-Dns-D-Tyr-Val-NH2), after separation by high-performance liquid chromatography (HPLC) using a C-18 reversed-phase column by isocratic elution. This method is sensitive enough to measure N-Dns-D-Tyr-Val at concentrations as low as 100 fmol, yields highly reproducible results and requires less than 8.5 min per sample for separation and quantitation. The optimum pH for deamidase activity was 4.0-4.5. Greater than 5 mM of reduced glutathione was needed for maximal enzyme activity. The Km and Vmax values were respectively 125 microM and 14.12 pmol/micrograms/h with the use of enzyme extract obtained from mouse spleen. Deamidase activity was strongly inhibited by Ag+, Cu2+, diisopropylfluorophosphate, and p-chloromercuriphenylsulfonic acid. Among the organs examined in a mouse, the highest specific activity of the enzyme was found in spleen. The sensitivity and selectivity of this method will aid in efforts to examine the physiological role of this enzyme.

[Outpatient chemotherapy with continuous infusion of 5-fluorouracil (CI 5-FU) and intravenous bolus leucovorin (IVB LV) in advanced gastrointestinal cancer: the second report]

This study was designed to evaluate the efficacy, toxicity, and quality of life (QOL) of outpatient chemotherapy with 5-FU and LV in advanced gastrointestinal cancer. Treatment consisted of CI 5-FU 450 mg/body/day, days 1-28, IVB LV 30 mg/body q wk (schedule, sch. A) and CI 5-FU 200 mg/m2/day, days 1-28, IVB LV 20 mg/m2 q wk (sch. B). 5-FU was administered with the Baxter infusor (0.5 ml/hr). Oral UFT (400-600 mg/day) was administered after these chemotherapy. Sixteen patients (pts) (sch. A 9 pts, sch. B 7 pts) with advanced gastrointestinal cancer have been treated to maintain the efficacy of prior inpatient chemotherapy. Twenty pts treated as adjuvant chemotherapy were added to evaluate toxicity and QOL. The median time to progression in sch. A was 3.0 months and sch. B was 2.4 months. Grade 3 or 4 toxicities of mucositis were seen 40% in sch. A and 0% in sch. B. Grade 1 or 2 skin toxicities were seen 100% in sch. A and 52% in sch. B. Mean score of QOL in sch. A was 78.0 +/- 11.5, sch. B was 89.5 +/- 7.8 ranked between inpatient chemotherapy (5-FU + CDDP 59.0 +/- 13.8) and UFT (91.8 +/- 6.1). In conclusion, these schedule of 5-FU and LV combination offers a high patient QOL and is suitable for advanced gastrointestinal cancer treatment.

[Marked bone marrow necrosis preceding acute monoblastic leukemia]

Bone marrow necrosis is rarely diagnosed during life but is more often seen at autopsy by accident. The prognosis of patients with bone marrow necrosis secondary to neoplastic disease is extremely poor. We described a 53-year-old man with bone marrow necrosis preceding acute monoblastic leukemia. He was admitted in June, 1994, for continuous back pain and marked elevation of serum lactate dehydrogenase. After admission, a hematologic examination showed progressive pancytopenia in peripheral blood and bone marrow necrosis. He was diagnosed as AML (M5) from the sudden appearance of leukemic blasts in the peripheral blood two months later. Induction therapy was immediately administered according to JALSG-92 protocol. The patient suffered from tumor lysis syndrome after chemotherapy, but complete remission was achieved by dialysis.

Structures of nine oxygenated 4-methylene sterols from Hachijo marine sponge Theonella swinhoei

Nine new sterols have been isolated from a marine sponge, Theonella swinhoei. Of these, seven sterols were found to be conicasterol derivatives [(24R)-4-methylene-24-methyl-8(14)-cholesten-3 beta-ol] oxygenated at carbon-7 and/or carbon-15. The other two were (24R)-7 beta,8 beta-epoxy-14 alpha-methoxy-4-methylene-24-methylcholestan- 3 beta-ol and (24R)-8,14-seco-8,14-dioxo-4-methylene-24-methylcholestan-3 beta-ol.

Monamidocin, a novel fibrinogen receptor antagonist. I. Production isolation, characterization and structural elucidation

Monamidocin, a novel fibrinogen receptor antagonist, has been isolated from the culture broth of Streptomyces sp. NR 0637 BY carbon adsorption, n-BuOH extraction, SP-Toyopearl, silica gel 60 silanised and Sephadex LH-20 column chromatographies and preparative HPLC. The molecular formula of monamidocin has been determined to be C15H22N4O4 from HRFAB-MS and 13C NMR spectral data. The structure of monamidocin has been determined to be N-[(S)-5-guanidino-2-hydroxypentanoyl]-L-phenylalanine by 2D NMR experiments.

[A case of surgical retrieve of migrated microcatheter]

This is a report of an accidental breakaway of a microcatheter during endovascular embolization for cerebral arteriovenous malformation occurring in a 48-year-old female. She had a sudden onset of cerebral herniated signs caused by a large hemorrhage in the region of the right parietal lobe. An angiogram showed a large arteriovenous malformation in the same region. 48 days after emergency evacuation of the hematoma and clipping of a feeding artery, we performed endovascular embolization using a microcatheter as assistant therapy for total removal of the nidus. However, accidentally, the microcatheter broke and migrated to the distal middle cerebral artery. Although we tried to retrieve the catheter using a loop snare, we had no success. We eventually retrieved it by open surgery next day. Fortunately the migrated catheter could be seen through a cortical artery, so after trapping it by using elastic thread and cutting off the artery we were able to extract the migrated catheter. Finally we were able to remove the nidus totally without other complications. Since breaking and migration of a microcatheter is a rare but possible accident, we should be prepared to cope with it appropriately.

Insulin resistance in skeletal muscle of the male Otsuka Long-Evans Tokushima Fatty rat, a new model of NIDDM

The Otsuka Long-Evans Tokushima Fatty rat is a new inbred obese strain with a late onset and chronic course of spontaneous hyperglycaemia in the male, and is considered to be a model of non-insulin-dependent diabetes mellitus [1, 2]. Fat distribution analysis showed a typical accumulation of intra-abdominal visceral fat in Otsuka Long-Evans Tokushima Fatty rats compared with a control strain, Long-Evans Tokushima Otsuka rats. To examine the insulin sensitivity of Otsuka Long-Evans Tokushima Fatty rats, we performed euglycaemic hyperinsulinaemic clamp experiments in vivo in rats under anaesthesia on this strain and on Long-Evans Tokushima Otsuka rats. The Otsuka Long-Evans Tokushima Fatty rats showed lower values for the glucose infusion rate (60% of the control at 12 weeks old and 20-30% of the control at 18, 24, 30 and 39 weeks old) than age-matched controls, indicating the development of insulin resistance with age. Hindlimb perfusion experiments in vitro also showed a 45% decrease of insulin-stimulated glucose uptake in Otsuka Long-Evens Tokushima Fatty rats in the diabetic stage. These results indicate that insulin resistance exists in the skeletal muscle of Otsuka Long-Evans Tokushima Fatty rats. To obtain information on the mechanism of insulin resistance in the skeletal muscle of Otsuka Long-Evans Tokushima Fatty rats, the insulin binding, autophosphorylation and tyrosine kinase activity of their partially-purified insulin receptors in vitro were compared with those from control rats. The results showed no marked differences in these insulin receptor functions between diabetic and control rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural elucidation of aculeximycin. IV. Absolute structure of aculeximycin, belonging to a new class of macrolide antibiotics

Aculeximycin (1) produced by Streptosporangium albidum possesses a 30-membered polyhydroxy macrocyclic lactone and five sugars including aculexitriose. We have described the determination of the planar structure of N-diacetylated aculeximycin (2) using degradation products, which were obtained by DBU-methanol treatment, ozonolysis and periodative oxidation. In order to determine the relative and absolute configurations of aculeximycin, first, the relative and absolute configurations of the degradation products 10, 11, 12 and 13 were determined. Rychnovsky's method was very useful to determine the relative configurations of these degradation products, and CD exciton chirality and the modified Mosher's methods were applied to determine their absolute configurations. From these results, fourteen out of the twenty asymmetric centers in aculeximycin were determined to be 5S, 17R, 20S, 21R, 23R, 24R, 29S, 30R, 31S, 34R, 35S, 36S and 37R. The absolute configurations at C-14 and C-15 on the hemiketal ring were confirmed using 12 obtained by the partial glycol bond cleavage of 9. Absolute configurations of the remaining asymmetric centers were determined by spectral analysis of 15 and NOE experiment on 1. From these results, the absolute configuration of 1 was determined to be 5S, 7R, 10S, 11R, 14R, 15S, 17R, 19R, 20S, 21R, 23R, 24R, 25S, 29S, 30R, 31S, 34R, 35S, 36S and 37R.