Chondrocyte hypertrophy in the growth plate promotes stress anisotropy affecting long bone development through chondrocyte column formation.

The length of long bones is determined by column formation of proliferative chondrocytes and subsequent chondrocyte hypertrophy in the growth plate during bone development. Despite the importance of mechanical loading in long bone development, the mechanical conditions of the cells within the growth plate, such as the stress field, remain unclear owing to the difficulty in investigating spatiotemporal changes within dynamically growing tissues. In this study, the mechanisms of longitudinal bone growth were investigated from a mechanical perspective through column formation of proliferative chondrocytes within the growth plate before secondary ossification center formation using continuum-based particle models (CbPMs). A one-factor model, which simply describes essential aspects of a biological signaling cascade regulating cell activities within the growth plate, was developed and incorporated into CbPM. Subsequently, the developmental process and maintenance of the growth plate structure and resulting bone morphogenesis were simulated. Thus, stress anisotropy in the proliferative zone that affects bone elongation through chondrocyte column formation was identified and found to be promoted by chondrocyte hypertrophy. These results provide further insights into the mechanical regulation of multicellular dynamics during bone development.

Hydrogen transfer reactions via organic radicals in gamma-irradiated chibaite.

Chibaite, a silica-framework structure with cage-like voids occupied by gaseous molecules, was found in marine sediments. Its formation age could be evaluated using electron spin resonance (ESR) if the radicals formed by natural radiation can be assumed to accumulate over time. To investigate whether hydrogen transfer reactions, where organic radicals withdraw hydrogen atoms from other molecules in adjacent cages, occur in chibaite and affect ESR dating, gamma-irradiated chibaite was measured by ESR. Methyl, ethyl, n-propyl, isopropyl, tert-butyl radicals and hydrogen atoms were created by gamma irradiation at 77 K. The amount of tert-butyl radicals increased around 240 K and the similar amount of the other organic radicals decreased simultaneously, implying that hydrogen transfer reactions occur between isobutane and the organic radicals in chibaite around 240 K and therefore would have no influence on ESR dating because the reactions are completed at the environmental temperature.

Preclinical Characterization of the Tau PET Tracer [18F]SNFT-1: Comparison of Tau PET Tracers.

Tau PET tracers are expected to be sufficiently sensitive to track the progression of age-related tau pathology in the medial temporal cortex. The tau PET tracer N-(4-[18F]fluoro-5-methylpyridin-2-yl)-7-aminoimidazo[1,2-a]pyridine ([18F]SNFT-1) has been successfully developed by optimizing imidazo[1,2-a]pyridine derivatives. We characterized the binding properties of [18F]SNFT-1 using a head-to-head comparison with other reported 18F-labeled tau tracers. Methods: The binding affinity of SNFT-1 to tau, amyloid, and monoamine oxidase A and B was compared with that of the second-generation tau tracers MK-6240, PM-PBB3, PI-2620, RO6958948, JNJ-64326067, and flortaucipir. In vitro binding properties of 18F-labeled tau tracers were evaluated through the autoradiography of frozen human brain tissues from patients with diverse neurodegenerative disease spectra. Pharmacokinetics, metabolism, and radiation dosimetry were assessed in normal mice after intravenous administration of [18F]SNFT-1. Results: In vitro binding assays demonstrated that [18F]SNFT-1 possesses high selectivity and high affinity for tau aggregates in Alzheimer disease (AD) brains. Autoradiographic analysis of tau deposits in medial temporal brain sections from patients with AD showed a higher signal-to-background ratio for [18F]SNFT-1 than for the other tau PET tracers and no significant binding with non-AD tau, α-synuclein, transactiviation response DNA-binding protein-43, and transmembrane protein 106B aggregates in human brain sections. Furthermore, [18F]SNFT-1 did not bind significantly to various receptors, ion channels, or transporters. [18F]SNFT-1 showed a high initial brain uptake and rapid washout from the brains of normal mice without radiolabeled metabolites. Conclusion: These preclinical data suggest that [18F]SNFT-1 is a promising and selective tau radiotracer candidate that allows the quantitative monitoring of age-related accumulation of tau aggregates in the human brain.

Development of continuum-based particle models of cell growth and proliferation for simulating tissue morphogenesis.

Biological tissues acquire various characteristic shapes through morphogenesis. Tissue shapes result from the spatiotemporally heterogeneous cellular activities influenced by mechanical and biochemical environments. To investigate multicellular tissue morphogenesis, this study aimed to develop a novel multiscale method that can connect each cellular activity to the mechanical behaviors of the whole tissue by constructing continuum-based particle models of cellular activities. This study proposed mechanical models of cell growth and proliferation that are expressed as volume expansion and cell division by extending the material point method. By simulating cell hypertrophy and proliferation under both free and constraint conditions, the proposed models demonstrated potential for evaluating the mechanical state and tracing cells throughout tissue morphogenesis. Moreover, the effect of a cell size checkpoint was incorporated into the cell proliferation model to investigate the mechanical behaviors of the whole tissue depending on the condition of cellular activities. Consequently, the accumulation of strain energy density was suppressed because of the influence of the checkpoint. In addition, the whole tissues acquired different shapes depending on the influence of the checkpoint. Thus, the models constructed herein enabled us to investigate the change in the mechanical behaviors of the whole tissue according to each cellular activity depending on the mechanical state of the cells during morphogenesis.

Rapid, simple, and cost-effective plaque assay for murine norovirus using microcrystalline cellulose.

Murine norovirus (MNV) is used widely as a practical alternative to human norovirus (HuNoV). Plaque-forming assays for MNV are important for developing therapeutic agents against HuNoV infections. Although agarose-overlay MNV assays have been reported, recent improvements in cellulose derivatives suggest that they could be optimized further, particularly with respect to improving the overlay material. To determine which overlay material is optimal for the MNV plaque assay, we compared four typical cellulose derivatives [microcrystalline cellulose (MCC), hydroxyethyl cellulose (HEC), hydroxypropyl methylcellulose (HPMC), and carboxymethyl cellulose (CMC)] with conventional agarose. We found that 3.5% (w/v) MCC-containing medium provided clear round-shaped plaques on RAW 264.7 cells 1 day after inoculation; the visibility of plaques was comparable with that of the original agarose-overlay assay. Removing residual MCC powder from the MCC-overlay assay before fixing was important for obtaining distinct plaques that are clearly countable. Finally, after calculating the plaque diameter as a percentage of well diameter, we found that 12- and 24-well plates were better than other plates for accurate plaque counting. The MCC-based MNV plaque assay is cost-effective and rapid, and produces plaques that are easy to count. Accurate virus quantification using this optimized plaque assay will enable reliable estimation of norovirus titers.

Adverse Events Associated With Long-term Treatment of Epithelial Ovarian Cancer With Bevacizumab and Chemotherapy.

BACKGROUND/AIM: Adverse events associated with long-term bevacizumab administration for ovarian cancer have been poorly documented in Japan. This study aimed to evaluate the adverse events of bevacizumab combined with chemotherapy for treating primary and recurrent epithelial ovarian cancer in Japan. PATIENTS AND METHODS: In this single-center retrospective study, we analyzed data of patients with advanced and recurrent epithelial ovarian cancer treated with bevacizumab and chemotherapy between January 2013 and November 2019. Statistical analyses were performed using the Fisher's exact test and Kaplan-Meier method. RESULTS: A total of 46 patients were included and the follow-up time was 30 months. The median duration of bevacizumab treatment was 14 months, and the median total dose of bevacizumab was 247.5 mg/kg. The most common adverse events were hypertension (n=30; 65.2%) and proteinuria (n=24; 49%) in all grades. The onset of hypertension and proteinuria occurred at a median of 2 months and 14 months after treatment initiation in all grades, respectively. Gastrointestinal perforation occurred significantly more frequently in patients with a history of radiation therapy. CONCLUSION: This study included cases of primary advanced and recurrent epithelial ovarian cancer, and had a longer observation period and reported more adverse events of bevacizumab with chemotherapy than previous reports. The administration of bevacizumab therapy in patients with a history of radiation should be carefully considered due to increased chances of gastrointestinal perforation.

The uptake of selenite in calcite revealed by X-ray absorption spectroscopy and quantum chemical calculations.

Selenium (Se) is an important trace element in the environment, but the interaction of Se with calcite that may control the fate and geochemical behavior of Se is not fully understood. In this study, the molecular-scale mechanism for the uptake of selenite in calcite was investigated by a combination of laboratory experiments, extended X-ray absorption fine structure (EXAFS) spectroscopy, and quantum chemical calculations. Results showed that selenite can be largely distributed to calcite at circumneutral pH. The local structure of Se in calcite obtained from EXAFS analyses, in combination with quantum chemical calculations, demonstrated that selenite can be incorporated into calcite by substituting for the carbonate, and that the geometric incompatibility of selenite could be accommodated by a slight expansion of crystal volume. The findings from this study suggest that calcite could be a potential Se sink, providing an important insight into the understanding of the mobility and geochemical behavior of Se in the subsurface environments particularly in the groundwater system.

High-resolution image-based simulation reveals membrane strain concentration on osteocyte processes caused by tethering elements.

Osteocytes are vital for regulating bone remodeling by sensing the flow-induced mechanical stimuli applied to their cell processes. In this mechanosensing mechanism, tethering elements (TEs) connecting the osteocyte process with the canalicular wall potentially amplify the strain on the osteocyte processes. The ultrastructure of the osteocyte processes and canaliculi can be visualized at a nanometer scale using high-resolution imaging via ultra-high voltage electron microscopy (UHVEM). Moreover, the irregular shapes of the osteocyte processes and the canaliculi, including the TEs in the canalicular space, should considerably influence the mechanical stimuli applied to the osteocytes. This study aims to characterize the roles of the ultrastructure of osteocyte processes and canaliculi in the mechanism of osteocyte mechanosensing. Thus, we constructed a high-resolution image-based model of an osteocyte process and a canaliculus using UHVEM tomography and investigated the distribution and magnitude of flow-induced local strain on the osteocyte process by performing fluid-structure interaction simulation. The analysis results reveal that local strain concentration in the osteocyte process was induced by a small number of TEs with high tension, which were inclined depending on the irregular shapes of osteocyte processes and canaliculi. Therefore, this study could provide meaningful insights into the effect of ultrastructure of osteocyte processes and canaliculi on the osteocyte mechanosensing mechanism.

Local Anesthetics Inhibit Transient Receptor Potential Vanilloid Subtype 3 Channel Function in Xenopus Oocytes.

BACKGROUND: The transient receptor potential vanilloid subtype 3 (TRPV3) channel is activated by innocuous temperature and several chemical stimuli. It is proposed to be involved in pathological pain development and is therefore considered a potential target for treating pain. Local anesthetics have been used for patients with both acute and chronic pain. Although blockage of the voltage-gated sodium channel is the primary mechanism by which local anesthetics exert their effects, they cannot be explained by this mechanism alone, especially in pathologic states such as chronic pain. Indeed, the effects of local anesthetics on multiple targets involved in the pain pathway have been reported. It has also been suggested that modulating the function of transient receptor potential (TRP) channels (eg, TRPV1 and transient receptor potential ankyrin 1 [TRPA1]) is one of the mechanisms of action of local anesthetics. However, the effects of local anesthetics on TRPV3 have not been reported. METHODS: We expressed TRPV3 in Xenopus oocytes and investigated the effects of local anesthetics on 2-aminoethoxydiphenyl borate (2APB)-induced currents using 2-electrode voltage-clamp techniques. RESULTS: Clinically used local anesthetics inhibited the 2APB-activated currents from the TRPV3 channel in a concentration-dependent manner at pharmacologically relevant concentrations with half maximal inhibitory concentration (IC50) values of 2.5 (lidocaine), 1.4 (mepivacaine), 0.28 (ropivacaine), and 0.17 (bupivacaine) mmol/L, respectively. Conversely, these local anesthetics also directly induced currents at higher concentrations, although these currents were quite small compared to the 2APB-induced currents. We found that the inhibition of TRPV3 by lidocaine is noncompetitive and independent of intracellular signaling cascades. 2APB-induced TRPV3 currents were reduced by extracellular N-(2,6-dimethylphenylcarbamoylmethyl) triethylammonium bromide (QX-314) but not by intracellular QX-314 nor benzocaine. Moreover, lidocaine showed a use-dependent block in TRPV3 inhibition. Finally, QX-314 appeared to slightly permeate the activated TRPV3 channel pore based on examination of oocytes coexpressing TRPV3 and a sodium channel. These results suggest that local anesthetics could inhibit TRPV3 channel function by extracellular interactions of their charged forms with the channel pore. CONCLUSIONS: Local anesthetics inhibited TRPV3 2APB-induced currents at pharmacologically relevant concentrations when TRPV3 was expressed in Xenopus oocytes. These effects seem to occur via an extracellular interaction between the charged form of the anesthetic with the TRPV3 channel pore. These results help to elucidate the mechanisms of action of local anesthetics.

MicroRNAs as Potential Mediators for Cigarette Smoking Induced Atherosclerosis.

Smoking increases the risk of atherosclerosis-related events, such as myocardial infarction and ischemic stroke. Recent studies have examined the expression levels of altered microRNAs (miRNAs) in various diseases. The profiles of tissue miRNAs can be potentially used in diagnosis or prognosis. However, there are limited studies on miRNAs following exposure to cigarette smoke (CS). The present study was designed to dissect the effects and cellular/molecular mechanisms of CS-induced atherosclerogenesis. Apolipoprotein E knockout (ApoE KO) mice were exposed to CS for five days a week for two months at low (two puffs/min for 40 min/day) or high dose (two puffs/min for 120 min/day). We measured the area of atherosclerotic plaques in the aorta, representing the expression of miRNAs after the exposure period. Two-month exposure to the high dose of CS significantly increased the plaque area in aortic arch, and significantly upregulated the expression of atherosclerotic markers (VCAM-1, ICAM-1, MCP1, p22phox, and gp91phox). Exposure to the high dose of CS also significantly upregulated the miRNA-155 level in the aortic tissues of ApoE KO mice. Moreover, the expression level of miR-126 tended to be downregulated and that of miR-21 tended to be upregulated in ApoE KO mice exposed to the high dose of CS, albeit statistically insignificant. The results suggest that CS induces atherosclerosis through increased vascular inflammation and NADPH oxidase expression and also emphasize the importance of miRNAs in the pathogenesis of CS-induced atherosclerosis. Our findings provide evidence for miRNAs as potential mediators of inflammation and atherosclerosis induced by CS.

Treatment of Recurrent Intracranial Aneurysms After Clipping: A Report of 23 Cases and a Review of the Literature.

OBJECTIVE: There are no established treatment strategies for aneurysms that recur after clipping. In this study, we present cases of patients who experienced recurrent aneurysms after clipping and subsequently underwent surgical intervention. METHODS: Between 2004 and 2015, we surgically treated 23 aneurysms that recurred at a previously clipped site. Patient characteristics and clinical history were retrospectively reviewed. RESULTS: Patients included 19 women and 4 men 45-81 years old. Aneurysms recurred 3-31 years (mean, 15.4 years) after the initial operation. For 18 cases, the first clinical presentation was a subarachnoid hemorrhage; aneurysms were incidentally diagnosed in 5 patients. Aneurysm locations were as follows: 9 on the internal carotid artery; 4 on the middle cerebral artery; 7 on the anterior communicating artery; 2 on the distal anterior cerebral artery; and 1 on the basilar artery. The reasons for retreatment included subarachnoid hemorrhage (n = 9) and aneurysm regrowth detected on follow-up examinations (n = 14). Endovascular treatment was performed in 10 cases, and direct surgery was performed in 13 cases (clipping in 8, clipping or trapping with bypass in 5). Various complex vascular reconstructions, including high-flow bypass and intracranial-intracranial in situ bypass, were performed for recurrent aneurysms. CONCLUSIONS: In our experience, coil embolization is a safe and effective procedure for treating recurrent aneurysms. When cases are unsuitable for coil embolization, surgical treatment often requires neurosurgeons not only to overcome the general technical difficulty of reoperative clipping but also to perform challenging vascular reconstruction.

Arsenate sorption on monohydrocalcite by coprecipitation during transformation to aragonite.

The metastability of monohydrocalcite (CaCO3·H2O: MHC) suggests high reactivity to dissolved trace elements. Using kinetic and isotherm sorption experiments with different reaction times (24h, 48h), As(V) sorption on MHC was examined to elucidate As(V) uptake by MHC. Although the MHC was transformed to aragonite with time, the MHC in higher As(V) loading conditions was able to persist longer than in lower loading conditions. Actually, As(V) uptake was negligible for samples in which the MHC remained. However, remarkable uptake of As(V) was observed for samples in which a complete transformation of MHC to aragonite occurred. Results of kinetic study confirmed that the timing of the MHC transformation coincided perfectly with that of As(V) removal from the solution. XAFS measurements showed that the local structure of As after the MHC transformation was almost identical to that of As in the As(V) coprecipitated aragonite. Sorption behavior of As(V) during the transformation is explainable theoretically by the substitution of As(V) into the aragonite structure. The distribution coefficient and (apparent) maximum sorption capacity of As(V) sorption on MHC after 48h at low-to-moderate As(V) concentrations are 500L/kg and 25µmol/g, respectively, which are much higher than those of simple adsorption of As(V) on calcite.

Idiopathic fourth ventricle outlet obstruction successfully treated by endoscopic third ventriculostomy: a case report.

INTRODUCTION: Fourth ventricle outlet obstruction (FVOO) is a rare cause of obstructive hydrocephalus. We describe a case of idiopathic FVOO that was successfully treated with endoscopic third ventriculostomy (ETV). CASE REPORT: A 3-year old boy without any remarkable medical history presented with a headache and vomiting. Computed tomography (CT) images, which had incidentally been taken 2 years previously due to a minor head injury, showed no abnormality. Magnetic resonance imaging on admission showed tetra-ventricular hydrocephalus associated with the dilatation of the fourth ventricle outlets, without any obstructive lesions. However, CT ventriculography, involving contrast medium injection through a ventricular catheter, suggested mechanical obstruction of the cerebrospinal fluid (CSF) at the fourth ventricle outlets. Thus, the patient was diagnosed with FVOO and ETV was performed; the hydrocephalus was subsequently resolved. Although hydrocephalus recurred 1 year postoperatively, re-ETV for the highly stenosed fenestration successfully resolved this condition. CONCLUSIONS: ETV should be considered for FVOO treatment, particularly in idiopathic cases without CSF malabsorption.

[Metronidazole-Induced Encephalopathy during Brain Abscess Treatment:Two Case Reports].

Metronidazole is a widely used antibiotic against anaerobic bacteria and protozoa. We report two cases of metronidazole-induced encephalopathy(MIE)during treatment of a brain abscess with metronidazole. The patients developed mental disturbance, and brain MRI showed reversible signals on DWI, FLAIR, and T2. Case 1: A 48-year-old woman was admitted to our hospital with a cerebellar abscess. We initiated treatment with oral metronidazole. After taking the medication, she developed mental disturbance, and her brain MRI showed a hyperintensity within the corpus callosum. We suspected metronidazole toxicity and discontinued metronidazole treatment. The symptoms resolved rapidly within a week, and the hyperintensity on the MRI disappeared. Case 2: A 22-year-old man was admitted to our hospital with a brain abscess. We initiated treatment with oral metronidazole. On day 38, he developed mental disturbance, and his MRI showed hyperintensities within the bilateral dentate nuclei and corpus callosum. These symptoms were consistent with MIE. After cessation of metronidazole, his symptoms and abnormal MRI signals completely disappeared.

Case Report: Trigeminal Neuralgia Caused by a Minute Meningioma with Hyperostosed Suprameatal Tubercle.

Cerebellopontine angle tumors might occasionally provoke trigeminal neuralgia but are usually large enough to be diagnosed radiographically. We present a case of trigeminal neuralgia caused by a very small meningioma covering the suprameatal tubercle that displayed hyperostosis at the entrance of Meckel's cave and was not obvious on routine magnetic resonance (MR) images. A 72-year-old woman with intractable trigeminal neuralgia in the left V3 territory was referred to our institution. Preoperative imaging studies revealed that the left trigeminal nerve was medially distorted at the entrance of Meckel's cave by a laterally seated bone bulge covered by a minute enhanced lesion. Trigeminal nerve decompression surgery was performed via a retrosigmoid intradural suprameatal approach. We found a small meningioma that had compressed and flattened the trigeminal nerve root at the entrance of Meckel's cave, which was grossly and totally removed by suprameatal tubercle resection. There was no vascular compression of the trigeminal nerve root. The trigeminal neuralgia ceased completely after the operation. Accurate preoperative determination of the causative pathologies is essential to achieve adequate surgical results after microvascular decompression for neurovascular compression syndrome. Because conventional MR sequences are inadequate for the precise interpretation of complex neurovascular anatomy in the cerebellopontine angle and such small tumors can be overlooked on routine MR studies, high-resolution thin-slice MR examinations and careful radiological interpretations are required for correct diagnosis and treatment.

Reappraisal of Microsurgical Revascularization for Anterior Circulation Ischemia in Patients with Progressive Stroke.

BACKGROUND: Intravenous thrombolysis using tissue plasminogen activator and endovascular treatment for acute ischemic stroke is becoming an established standard therapy. However, there is no consensus in the treatment of patients who are suffering from progressive neurologic symptoms in the later stages. The purpose of this study was to evaluate the safety and efficacy of microsurgical revascularization in such patients with progressive stroke. METHODS: We retrospectively reviewed the clinical and radiological records of 14 consecutive patients with progressive stroke who underwent emergency open surgery for anterior circulation occlusion within 7 days after onset. Surgical candidates were carefully selected on the basis of symptom severity, diffusion-weighted imaging, and perfusion study. Superficial temporal artery to middle cerebral artery bypass was applied for atherosclerotic occlusion, and microsurgical embolectomy was applied for embolic occlusion. RESULTS: Superficial temporal artery to middle cerebral artery bypass was performed in 12 patients, microsurgical embolectomy in 1, and the combination of these modalities in 1. As a result, complete revascularization was achieved in all patients. The National Institutes of Health Stroke Scale scores significantly improved after surgery (at third postoperative day, P < 0.05; at 14th postoperative day, P < 0.01). A favorable outcome (modified Rankin Scale 0-2) was achieved in 12 of the 14 (85.7%) patients. Minor intracerebral hemorrhage occurred in 1 patient and hyperperfusion syndrome occurred in 1 patients; however, the patients subsequently recovered without additional treatment. CONCLUSIONS: Microsurgical revascularization is a feasible treatment option for patients with progressive stroke due to anterior circulation major vessel occlusion.

[Rapid spontaneous resolution of acute epidural hematoma in an infant:a case report].

Resolution of acute epidural hematoma (AEDH) usually takes several weeks. The authors present an infantile case of AEDH that rapidly decreased within a day and review the literature. A 7-month-old boy fell from a height of approximately one meter and sustained a head injury. On presentation, a skull fracture in the right temporoparietal region was found and a small AEDH was observed on computed tomography (CT) 1 hr after the injury. He was transferred to our institute because of growing AEDH, shown by CT images taken 3 hr after the injury. We decided to treat him conservatively as he did not exhibit any neurological deficits on admission. CT images 24hr after the injury showed significant reduction of the AEDH. There was also an increase in the subcutaneous hematoma. Follow-up CT images did not show enlargement of the AEDH. The patient was discharged with no neurological deficits 3 days after admission. Rapid resolution of the AEDH might have been due to transmigration of the hematoma into the epicranial layer through the fracture gap.

Comparison of postoperative volume status and hemodynamics between surgical clipping and endovascular coiling in patients after subarachnoid hemorrhage.

BACKGROUND: Recent clinical data suggest that postoperative hemodynamic profile and fluid management may differ in aneurysmal subarachnoid hemorrhage patients depending on the treatment option: surgical clipping or endovascular coiling. Our aim was to determine the differences in hemodynamic parameters between the 2 modalities using an advanced transpulmonary thermodilution technique. METHODS: We studied 73 consecutive aneurysmal subarachnoid hemorrhage patients treated with either clipping or coiling. Transpulmonary thermodilution was established for monitoring cardiac index, global end-diastolic volume index (GEDI), and extravascular lung water index (ELWI). Blood biochemical markers were sampled in parallel. RESULTS: Hypovolemia (GEDI: 656±72 vs. 713±40 mL/m; P=0.0001) and elevated plasma brain natriuretic peptide (114.0±56.7 vs. 68.6±47.4 pg/mL; P=0.0004) were evident on initial measurements in the clipping group. The number of fluid challenges until normalization of GEDI and ROC-based prediction of the responders (GEDI≥10%) during vasospasm risk period (day 4 to 14 of ictus) were less with coiling than with clipping (P<0.05). Therapy-related pulmonary edema was detected only in the clipping group (8%, n=3). Although length of intensive care unit stay was shorter in the coiling group (P=0.016), incidences of delayed ischemia (13% vs. 11%; P=0.50) and poor functional outcome on modified Rankin Scale score 4 to 6 at 1 month (37% vs. 46%; P=0.30) were not statistically different. CONCLUSIONS: Surgical clipping is associated with higher cardiac output and hypovolemia in the early postoperative stage and poorer preload responsiveness to volume therapy during the vasospasm risk period compared with endovascular coiling.

Identification of sources of lead in the atmosphere by chemical speciation using X-ray absorption near-edge structure (XANES) spectroscopy.

Sources of Pb pollution in the local atmosphere together with Pb species, major ions, and heavy metal concentrations in a size-fractionated aerosol sample from Higashi-Hiroshima (Japan) have been determined by X-ray absorption near-edge structure (XANES) spectroscopy, ion chromatography, and ICP-MS/AES, respectively. About 80% of total Pb was concentrated in fine aerosol particles. Lead species in the coarse aerosol particles were PbC2O4, 2PbCO3 Pb(OH)2, and Pb(NO3)2, whereas Pb species in the fine aerosol particles were PbC2O4, PbSO4, and Pb(NO3)2. Chemical speciation and abundance data suggested that the source of Pb in the fine aerosol particles was different from that of the coarse ones. The dominant sources of Pb in the fine aerosol particles were judged to be fly ash from a municipal solid waste incinerator and heavy oil combustion. For the coarse aerosol particles, road dust was considered to be the main Pb source. In addition to Pb species, elemental concentrations in the aerosols were also determined. The results suggested that Pb species in size-fractionated aerosols can be used to identify the origin of aerosol particles in the atmosphere as an alternative to Pb isotope ratio measurement.

[Reversible cerebral vasoconstriction syndrome associated with stroke: three case reports].

Reversible cerebral vasoconstriction syndrome(RCVS)is characterized by severe headache and diffuse segmental constriction of cerebral arteries that resolves spontaneously within a few months. Although manifestations of stroke are not included in diagnostic criteria of RCVS, it is known that some cases may be associated with stroke, including intracerebral hemorrhage, subarachnoid hemorrhage, or cerebral infarction. We present three cases of RCVS associated with various types of stroke, and then review the literature. Case 1:A 49-year-old woman presented with a headache followed by left hemiparesis and dysarthria. One month before the onset, she was transfused for severe anemia caused by uterus myoma. CT images revealed intracerebral hemorrhages in the right putamen and right occipital lobe. Angiography revealed multiple segmental constrictions of the cerebral arteries. One month after the onset, these vasoconstrictions improved spontaneously. Case 2:A postpartum 38-year-old woman who had a history of migraine presented with thunderclap headache. Imaging revealed a focal subarachnoid hemorrhage in the right postcentral sulcus and segmental vasoconstriction of the right middle cerebral artery. One week after the onset, this vasoconstriction improved spontaneously. Case 3:A 32-year-old woman who had a history of migraine presented with headache followed by left homonymous hemianopsia. Imaging revealed a cerebral infarction of the right occipital lobe and multiple constrictions of the right posterior cerebral artery. These vasoconstrictions gradually improved spontaneously.