Magnifying chromoendoscopy is a reliable method in the selection of rectal neoplasms for local excision.

PURPOSE: Adequate staging of early rectal neoplasms is essential for organ-preserving treatments, but magnetic resonance imaging (MRI) frequently overestimates the stage of those lesions. We aimed to compare the ability of magnifying chromoendoscopy and MRI to select patients with early rectal neoplasms for local excision. METHODS: This retrospective study in a tertiary Western cancer center included consecutive patients evaluated by magnifying chromoendoscopy and MRI who underwent en bloc resection of nonpedunculated sessile polyps larger than 20 mm, laterally spreading tumors (LSTs) [Formula: see text] 20 mm, or depressed-type lesions of any size (Paris 0-IIc). Sensitivity, specificity, accuracy, and positive and negative predictive values of magnifying chromoendoscopy and MRI to determine which lesions were amenable to local excision (i.e., [Formula: see text] T1sm1) were calculated. RESULTS: Specificity of magnifying chromoendoscopy was 97.3% (95% CI 92.2-99.4), and accuracy was 92.7% (95% CI 86.7-96.6) for predicting invasion deeper than T1sm1 (not amenable to local excision). MRI had lower specificity (60.5%, 95% CI 43.4-76.0) and lower accuracy (58.3%, 95% CI 43.2-72.4). Magnifying chromoendoscopy incorrectly predicted invasion depth in 10.7% of the cases in which the MRI was correct, while magnifying chromoendoscopy provided a correct diagnosis in 90% of the cases in which the MRI was incorrect (p = 0.001). Overstaging occurred in 33.3% of the cases in which magnifying chromoendoscopy was incorrect and 75% of the cases in which MRI was incorrect. CONCLUSION: Magnifying chromoendoscopy is reliable for predicting invasion depth in early rectal neoplasms and selecting patients for local excision.

Sleep during low-frequency repetitive transcranial magnetic stimulation is associated with functional improvement in upper limb hemiparesis after stroke.

Many studies have reported that repetitive transcranial magnetic stimulation (rTMS) is beneficial for post-stroke patients with upper limb hemiparesis. It was reported that application of rTMS during sleep could possibly strengthen neural plasticity. The purpose of this study was to investigate the relationship between sleep during low-frequency rTMS session and improvement of motor function in affected upper limb in post-stroke patients after inpatient rehabilitation combined with rTMS using the bispectral index (BIS) monitor. During 15-day hospitalization, each patient received rTMS and intensive occupational therapy. Low-frequency rTMS with 1 Hz was applied over the contralesional motor cortex. During rTMS session, adhesive sensor was put on each patient's forehead and connected to the BIS monitor. The mean score for the maximum change of BIS values during each rTMS session (ΔBIS) was calculated. We regarded the patients with and over 10 of mean ΔBIS as Asleep group and under 10 as Awake group. Fugl-Meyer assessment (FMA) and Action Research Arm Test (ARAT) were evaluated on admission and discharge. Awake group included six patients and Asleep group included seven patients. There was no significant difference in clinical characteristics and in increase of FMA between two groups. Asleep group was significantly superior to Awake group in the increase of ARAT (p < 0.05). There was a significant correlation between the mean of ΔBIS and increase of ARAT (ρ = 0.78, p = 0.002). Sleep during low-frequency rTMS may contribute to improvement of motor function in the affected upper limb.

Increase in skin perfusion pressure after maggot debridement therapy for critical limb ischaemia.

Skin perfusion pressure (SPP) is the perfusion pressure at the skin level, and it can serve as an index of peripheral circulation in the skin and subcutaneous tissue. We report a 78-year-old man with critical limb ischaemia who, despite having undergone several catheter interventions, still had severe ulcers with exposed bone on his right foot. We performed transmetatarsal amputation. The tissue around the surgical site became necrotic several days later, and did not respond to conservative therapy. Therefore, we opted for maggot debridement therapy (MDT), given that maggots favour necrotic tissue. After the therapy, SPP around the ulcer increased from 12 to 54 mmHg on the dorsal aspect, and from 17 to 44 mmHg on the plantar aspect. Wound healing was successfully activated by MDT, leading to complete healing within 2.5 months after MDT. We believe that MDT probably contributed to increase the blood supply to the ischaemic wound.

PP075. Endothelial dysfunction may be impaired by increased oxidative stress in preeclamptic women.

INTRODUCTION: The essential pathogenesis in preeclampsia is vasospasm induced by endothelial cell injury. The vascular endothelium regulates vascular smooth muscle tone by producing vasoconstrictors and vasodilators, such as nitric oxide (NO). Recently, it has been reported that the levels of oxidative stress are increased and they may impair endothelial NO production and induce endothelial dysfunction in preeclampsia. OBJECTIVES: To determine whether maternal release of oxygen free radical and antioxidants are associated with maternal vascular endothelial cell injury, we measured serum parameters of oxidative stress and endothelial function during pregnancy in women with or without preeclampsia. METHODS: We evaluated 20 participants with uncomplicated pregnancies, 15 with mild preeclampsia, and 18 with severe preeclampsia. Plasma concentrations were measured for derivatives of reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) as markers of oxygen free radicals and antioxidants, respectively. Flow-mediated vasodilation (FMD) was also assessed as a marker of endothelial function. RESULTS: D-ROMs were increased in the maternal blood of the severe preeclamptic group compared with the control group (681.0±239.0 vs 478.6±101.4 CARR U, P<0.001), but not in the mild preeclamptic group (562.0±106.5 CARR U). Plasma BAP levels did not change significant in all three groups. The proportion of d-ROMs to BAP was higher in the severe preeclamptic group than in controls (0.28±0.11 vs 0.21±0.05, P<0.01), but not in the mild preeclamptic group (0.24±0.08). FMD was significantly decreased in both preeclamptic groups (severe, 4.3±3.3%, P<0.001; mild, 6.5±3.6%, P<0.001) compared with controls (10.5±2.3%), but FMD in the severe preeclamptic group was significantly greater than in the mild preeclamptic group. A negative correlation between FMD and d-ROM concentrations was observed in all participants (r=-0.376, P<0.05), and the ratio of serum d-ROMsto BAP correlated negatively with FMD (r=-0.413, P<0.05) in all participants. CONCLUSION: We found that the production of oxygen free radicals increased, but not the production of antioxidants which decreased, as a result, an imbalance between reactive oxygen species formation and antioxidant defence mechanisms may have impaired endothelial function in preeclamptic women.

Placental oxidative DNA damage and its repair in preeclamptic women with fetal growth restriction.

Preeclampsia is frequently accompanied by fetal growth restriction (FGR). Preeclampsia increases oxygen free radical production, and the resulting oxidative stress impairs placental blood flow. To determine whether placental oxidative stress is associated with FGR in preeclamptic women, we evaluated placental oxidative DNA damage and its repair in 13 preeclamptic women with FGR, 10 preeclamptic women without FGR, and 11 healthy pregnant women without complications. We measured maternal and umbilical serum derivatives of reactive oxygen metabolites (d-ROMs), as a marker of oxygen free radicals, and pulsatility index (PI) of uterine and umbilical arteries, and performed an immunohistochemical analysis to measure the proportion of nuclei in the placental trophoblast that stained positive for 8-hydroxy-2'-deoxyguanosin (8-OHdG), an indicator of oxidative DNA damage, and redox factor-1 (ref-1), indicative of the repair function towards oxidative DNA damage. D-ROMs were increased in the maternal blood of both preeclamptic groups (with FGR, 687.3 ± 50.4 CARR U, p < 0.01; without FGR, 750.4 ± 87.2 CARR U, p < 0.001) compared with controls (504.7 ± 25.0 CARR U). In contrast, d-ROM levels in the umbilical artery were elevated in preeclamptic women with FGR (134.9 ± 13.3 CARR U, p < 0.01), but not in preeclamptic women without FGR (44.0 ± 7.3 CARR U) compared with controls (38.2 ± 5.0 CARR U). Mean PI for uterine arteries was significantly increased in both preeclamptic groups, and the PI in preeclamptic women with FGR was significantly greater than that in women without FGR (0.94 ± 0.07 vs. 1.31 ± 0.07, p < 0.001). The PI for umbilical arteries was significantly increased in preeclamptic women with FGR (0.90 ± 0.05vs. 1.19 ± 0.07, p < 0.001), but not in preeclamptic women without FGR. The proportion of nuclei positive for 8-OHdG was higher in both groups of preeclamptic women than in the control group, but was higher in preeclamptic women with FGR (0.21 ± 0.05 vs. 0.87 ± 0.01, p < 0.001). The proportion of nuclei positive for ref-1 was higher in preeclamptic women without FGR (0.54 ± 0.06, p < 0.001) than in the control group, whereas the proportion did not differ significantly between normal and preeclamptic women with FGR. Our findings indicate that increased oxidative stress and disrupted compensatory reaction against placental oxidative DNA damage may be associated with FGR in preeclamptic women.

A novel selective medium for isolation of Aggregatibacter (Actinobacillus) actinomycetemcomitans.

BACKGROUND AND OBJECTIVE: Conventional selective media have been used for the selection of Aggregatibacter (Actinobacillus) actinomycetemcomitans in clinical samples. The proportion of A. actinomycetemcomitans grown on the selective media in vitro may not reflect the true counts in vivo because of the low selectivity. A novel selective medium, designated AASM, was developed for the isolation of A. actinomycetemcomitans. MATERIAL AND METHODS: AASM was prepared by adding of 200 microg/mL of vancomycin and 10 U/mL of bacitracin to AAGM, which contains dextrose, sodium bicarbonate, trypticase soy, yeast extract and agar. Clinical efficacy was evaluated by the recovery, on AASM, of A. actinomycetemcomitans from subgingival samples of 44 periodontally healthy subjects and 76 patients with chronic periodontitis. RESULTS: All serotypes (a-f) of A. actinomycetemcomitans strains grew well, and the average growth recovery of A. actinomycetemcomitans on AASM medium was 94.4% (80.0-109.7%) of that on AAGM. The exclusive rate of other bacteria was 99.9% in clinical samples cultured on AASM. A. actinomycetemcomitans was not detected in periodontally healthy persons but was detected in 25 (32.9%) patients with chronic periodontitis. The predominant serotype was c, detected in 11 subjects. CONCLUSION: The new selective medium, AASM, was highly selective for A. actinomycetemcomitans, eliminated possible false-positive results and was useful for the isolation of A. actinomycetemcomitans from clinical samples.

[Coronary malperfusion of left main trunk due to localized dissection of the ascending aorta].

Case 1. Forty nine years woman was given a diagnosis of acute myocardial infarction. Coronary angiography and trans-esophageal echocardiography showed left main trunk dissection due to local aortic root dissection. We operated surgical repair at left main trunk by pericardium after percutaneous coronary intervention. Case 2. Forty nine years man was given a diagnosis of acute myocardial infarction caused by left main trunk dissection due to traumatic local aortic root dissection. We operated coronary artery bypass grafting after insertion of perfusion catheter to left main trunk for maintain coronary perfusion. Although local dissection of aortic aorta is relatively rare, it is potentially complicated with coronary malperfusion. We describe 2 success a cases of surgical treatment for local acute type A aortic dissection complicated with coronary malperfusion.

Mechanism by which a novel non-thiazolidinedione peroxisome proliferator-activated receptor gamma agonist, FK614, ameliorates insulin resistance in Zucker fatty rats.

AIM: The aim of this study was to examine the mechanism by which a novel non-thiazolidinedione (TZD) peroxisome proliferator-activated receptor (PPAR) gamma agonist, FK614, ameliorates insulin resistance in Zucker fatty rats. METHODS: FK614 (1, 3.2 or 10 mg/kg) and a TZD PPARgamma agonist, pioglitazone (1, 3.2 or 10 mg/kg), were orally administered to Zucker fatty rats (genetically obese and insulin resistant) once a day for 14 days, and an oral glucose tolerance test was performed. The expression levels of various genes in the white adipose tissue (WAT) of Zucker fatty rats treated with FK614 (3.2 mg/kg), pioglitazone (10 mg/kg) and another TZD PPARgamma agonist, rosiglitazone (3.2 mg/kg), were determined using a real-time reverse transcription-polymerase chain reaction method. Morphometric analysis of the WAT of Zucker fatty rats treated with FK614 (3.2 mg/kg) and pioglitazone (10 mg/kg) was performed. Glucose transport activity in the isolated soleus muscle of FK614-treated Zucker fatty rats was also investigated. RESULTS: FK614 and pioglitazone both improved glucose tolerance in Zucker fatty rats. FK614 significantly increased the expression levels of acyl CoA oxidase, a PPAR-responsive gene, and adipocyte fatty acid-binding protein (aP2), an adipocyte differentiation marker gene, in epididymal WAT. It also significantly decreased the level of gene expression of tumour necrosis factor-alpha, an insulin resistance-inducing factor in retroperitoneal WAT, as did pioglitazone and rosiglitazone. FK614 and pioglitazone both significantly increased the total number of adipocytes and decreased their average size in WAT, mainly by increasing the number of small adipocytes. Additionally, administration of FK614 to Zucker fatty rats enhanced insulin sensitivity for glucose uptake in the soleus muscle. CONCLUSION: This study suggests the possibility that FK614 induces adipocyte differentiation in Zucker fatty rats by stimulating PPARgammain vivo, thereby changing the character of WAT and improving insulin sensitivity throughout the body.

Two cases of atypical membranous aplasia cutis with hair collar sign: one with dermal melanocytosis, and the other with naevus flammeus.

We report two atypical cases of membranous aplasia cutis surrounded by a rim of hairs, one case associated with dense dermal melanocytosis and the other with naevus flammeus, with characteristic clinical features. A rim of hypertrichosis, 'hair collar' sign, is proposed to have a close association with neuroectodermal defects. A failure of the normal closure of the cranial neural tube might have affected foetal skin development, including melanoblast migration and capillary network formation. The changes in the present cases, as well as the hair collar sign may suggest a complex hamartomatous nature of membranous aplasia cutis.

[Successful surgical treatment in a nonagenarian with aortic arch aneurysm].

Surgical treatment in a nonagenarian with thoracic aortic aneurysm is challenging, and the surgical indication in such patients is controversial. A 92-year-old female patient with severe chest and back pain was transferred to our hospital because of impending rupture of an aortic arch aneurysm with normal mental activity. Physical and laboratory examinations were within normal limits. The patients underwent urgent graft replacement of the total aortic arch. Postoperative course was uneventful and the patient remains well with no disability 8 months after the operation.

[Mediastinal mature teratoma perforating into the lung with elevated serum carbohydrate antigen 19-9 (CA19-9) levels; report of a case].

A 17-year-old woman was suddenly seized with anterior chest pain and admitted to our hospital. Chest X-ray, computed tomography (CT) scan and magnetic resonance imaging (MRI) showed a mass shadow in the left middle lung field associated with the left pleural effusion and high serum carbohydrate antigen 19-9 (CA 19-9) levels (58.5 U/ml). We performed a total resection of the tumor with adherent parts of the left lung. The tumor was 6.5 x 3. 8 x 2.9 cm in size, and was made up of soft tissues, fluid and cystic components. The histological diagnosis was a mature cystic teratoma with perforation into the lung, which contained pancreatic tissues, hepatic cells, bronchial epithelium, serous glands and so on. The levels of fluid amylase and CA 19-9 were high. We report mediastinal mature teratoma perforating into the lung and discuss the mechanism of perforation.

A case of pedunculated malignant melanoma of the vaginal mucosa.

We report an 84-year-old Japanese woman who presented with a pedunculated malignant melanoma of the vaginal mucosa. Mucosal melanoma is believed to be more common in Japan than other countries, but such tumors of the vulvovaginal region are quite unusual. In our patient, three tumors were connected by a narrow pedicle. Three black tumors measuring 5-10 mm in diameter with a common pedicle were seen on the vaginal mucosa at five o'clock from the cervix. The tumors were hanging from the narrow pedicle. On histologic examination, they were diagnosed as malignant melanoma. Resection was done with a distal margin of 3 cm from the tumors and a margin of 1 cm from the cervix. The patient has had no evidence of local recurrence or distant metastasis. In our patient, the three main tumors had a common pedicle, which seems to be a unique finding. Since pedunculated malignant melanomas are rare, making a clinical diagnosis is difficult. Although pedunculated melanomas are recognized as having a high malignant potential because these lesions are generally thick, a relatively good outcome is sometimes reported. In our patient, there was no tumor infiltration into the dermis of the pedicle, and this may be one reason for the good outcome at present. There has been no previous report of a mucosal melanoma consisting of three tumors like those in the present patient.

Long-term outcome of systemic cyclosporine treatment following penetrating keratoplasty.

PURPOSE: To perform a retrospective study to evaluate the long-term outcome of systemic cyclosporine treatment as an adjunct to topical corticosteroid treatment after penetrating keratoplasty (PKP). METHODS: Twenty-six high-risk patients (27 eyes) who received systemic cyclosporine following PKP for an average of 5.4 months were compared with another series of 57 patients (57 eyes) who did not receive cyclosporine after PKP. RESULTS: Endothelial rejection developed in 2 cases during cyclosporine treatment and in 6 cases after discontinuation. The rate of rejection-free graft survival was similar between the treated and the control groups. The control group showed a significantly higher rate of graft survival than the treated group. As side effects in the treatment group, transient elevation in blood urea nitrogen or creatine developed in 7 cases. Increase in glutamate oxaloacetate transaminase (GOT) or glutamate pyruvate transaminase (GPT) developed in 4 cases. Severe side effects were absent throughout the series in both groups of patients. CONCLUSION: Systemic cyclosporine treatment for several months did not reduce the incidence of rejection nor improve the rate of graft clarity in the long term in high-risk patients after PKP.

Alterations of Ca2+ mobilizing properties in migrating endothelial cells.

Endothelial migration is one of the major events of pathological neovascularization. We compared the characteristics of Ca2+ mobilization in nonconfluent, confluent, and migrating endothelial cells. Migration of endothelial cells was induced by wounding the confluent cell monolayer. The basal intracellular Ca2+ concentration was lower in migrating cells and higher in confluent cells than in nonconfluent cells. Thapsigargin (TG)-induced Ca2+ leak and TG-evoked Ca2+ entry were accelerated in migrating cells, whereas the latter was suppressed in confluent cells. The ATP-induced Ca2+ transient was also much larger in migrating cells than in confluent cells. These alterations were also observed in a cell as an intracellular polarization, i.e., the leading edge showed an acceleration of TG-evoked Ca2+ entry and an augmentation of the ATP-induced Ca2+ transient. Endothelial migration was significantly suppressed by TG or cyclopiazonic acid. These observations suggest that the alterations of Ca2+ store site-related Ca2+ mobilizations, i.e., Ca2+ sequestration, release, and TG-evoked Ca2+ entry, may be involved in the cellular mechanisms of endothelial migration.

Amelioration of insulin resistance in diabetic ob/ob mice by a new type of orally active insulin-mimetic vanadyl complex: bis(1-oxy-2-pyridinethiolato)oxovanadium(IV) with VO(S(2)O(2)) coordination mode.

Recently, we have shown that a newly synthesized vanadyl complex, bis(1-oxy-2-pyridinethiolato)oxovanadium(IV), VO(opt)(2), is a potent orally active insulin-mimetic in treating streptozotocin-induced diabetes in rats, with long-term action. In the present study, the anti-diabetic effect of VO(opt)(2) and its mechanism in ob/ob mice, an obese non-insulin-dependent diabetes mellitus (NIDDM) animal model, was investigated. In ob/ob mice, 15-day oral treatment with VO(opt)(2) resulted in a dose-dependent decrease in the levels of glucose, insulin and triglyceride in blood. VO(opt)(2) was also effective in ameliorating impaired glucose tolerance in ob/ob mice, when an oral glucose tolerance test was performed after treatment with VO(opt)(2). Tumor necrosis factor-alpha (TNF-alpha) is a key component of obesity-diabetes link, we therefore examined the attenuating effect of VO(opt)(2) on impaired insulin signal transduction induced by TNF-alpha. Elevated expression of TNF-alpha was observed in the epididymal and subcutaneous fat tissues of ob/ob mice. Incubation of 3T3-L1, mouse adipocytes, with TNF-alpha reduced the phosphorylation of insulin receptor substrate-1 (IRS-1), whereas VO(opt)(2) treatment resulted in an enhancement of IRS-1 phosphorylation, irrespective of the presence or absence of TNF-alpha. Overall, the present study demonstrates that VO(opt)(2) exerts an anti-diabetic effect in ob/ob mice by ameliorating impaired glucose tolerance, and furthermore, attenuates the TNF-alpha-induced decrease in IRS-1 phosphorylation in adipocytes. These results suggest that the anti-diabetic action of VO(opt)(2) is derived from an attenuation of a TNF-alpha induced impaired insulin signal transduction via inhibition of protein tyrosine phosphatase, providing a potential clinical utility for VO(opt)(2) in the treatment of NIDDM.

Complementary functions of Otx2 and Cripto in initial patterning of mouse epiblast.

The development of the mammalian antero-posterior (A-P) axis is proposed to be established by distinct anterior and posterior signaling centers, anterior visceral endoderm and primitive streak, respectively. Knock-out studies in mice have shown that Otx2 and Cripto have crucial roles in the generation and/or functions of these anterior and posterior centers, respectively. In both Otx2 and Cripto single mutants, the initial formation of the A-P axis takes place in a proximal-distal (P-D) orientation, but subsequent axis rotation fails to occur. To examine the developmental consequences of the lack of these two genes, we have analyzed the Otx2(-/-);Cripto(-/-) double homozygous mutant phenotype. In the double mutants, the expression of the A-P axis markers Cer-l, Lim1, and Wnt3 was not induced, while expression of Fgf8 and T was expanded throughout the epiblast, indicating that the double mutants could not form the A-P axis even in its initial P-D orientation. In addition, the double mutants displayed defects in differentiation of the visceral endoderm overlying the epiblast, as well as in the extraembryonic ectoderm. Furthermore, differentiation of neuroectoderm was accelerated as judged by the reduction of Oct4 expression and emergence of Sox1 and Gbx2 expression in the double mutant epiblast. The resulting ectoderm only displayed characteristics of anterior hindbrain, implicating it as a ground state in the mammalian body plan. Our results indicate that complementary functions of Otx2 and Cripto are essential for initial patterning of the A-P axis in the mouse embryo.

Prevention of secondary osteoporosis postmenopause in hemiplegia.

OBJECTIVES: To study secondary osteoporosis postmenopause in women with hemiplegia and to show the therapeutic effects of etidronate and how osteoporotic conditions relate to the activities of daily living (ADL). DESIGN: Eighty-one postmenopausal women with hemiplegia were admitted within 6 mo of their first cerebrovascular accident. The bone mineral density (BMD) and biochemical markers of bone turnover were measured at the time of admission. Forty women (treatment group) received a 2-wk administration of etidronate. Forty-one women (control group) were not administered etidronate. RESULTS: After completing a 3-mo rehabilitation program, BMD levels were remeasured. ADL was evaluated by FIM. The low ADL group had a larger decrease in BMD than the high ADL group. For the control group, the BMD rate of change on the paretic side of the femoral neck was -9.6%/3 mo for the low ADL group. BMD loss was reduced significantly by the administration of etidronate for the low ADL group. CONCLUSIONS: Results indicate that ADL corresponds to the progression of osteoporosis in postmenopausal women with hemiplegia and that increasing the level of ADL will reduce the progression of osteoporosis. Use of etidronate has also been proven to have a suppressive effect on the BMD decrease in women.

Impairment of endothelial nitric oxide production by acute glucose overload.

We examined the effects of acute glucose overload (pretreatment for 3 h with 23 mM D-glucose) on the cellular productivity of nitric oxide (NO) in bovine aortic endothelial cells (BAEC). We had previously reported (Kimura C, Oike M, and Ito Y. Circ Res, 82: 677-685, 1998) that glucose overload impairs Ca(2+) mobilization due to an accumulation of superoxide anions (O(2)(-)) in BAEC. In control cells, ATP induced an increase in NO production, assessed by diaminofluorescein 2 (DAF-2), an NO-sensitive fluorescent dye, mainly due to Ca(2+) entry. In contrast, ATP-induced increase in DAF-2 fluorescence was impaired by glucose overload, which was restored by superoxide dismutase, but not by catalase or deferoxamine. Furthermore, pyrogallol, an O(2)(-) donor, also attenuated ATP-induced increase in DAF-2 fluorescence. In contrast, a nonspecific intracellular Ca(2+) concentration increase induced by the Ca(2+) ionophore A-23187, which depletes the intracellular store sites, elevated DAF-2 fluorescence in both control and high D-glucose-treated cells in Ca(2+)-free solution. These results indicate that glucose overload impairs NO production by the O(2)(-)-mediated attenuation of Ca(2+) entry.

Hypoxia-induced alterations in Ca(2+) mobilization in brain microvascular endothelial cells.

To investigate the possible cellular mechanisms of the ischemia-induced impairments of cerebral microcirculation, we investigated the effects of hypoxia/reoxygenation on the intracellular Ca(2+) concentration ([Ca(2+)](i)) in bovine brain microvascular endothelial cells (BBEC). In the cells kept in normal air, ATP elicited Ca(2+) oscillations in a concentration-dependent manner. When the cells were exposed to hypoxia for 6 h and subsequent reoxygenation for 45 min, the basal level of [Ca(2+)](i) was increased from 32.4 to 63.3 nM, and ATP did not induce Ca(2+) oscillations. Hypoxia/reoxygenation also inhibited capacitative Ca(2+) entry (CCE), which was evoked by thapsigargin (Delta[Ca(2+)](i-CCE): control, 62.3 +/- 3.1 nM; hypoxia/reoxygenation, 17.0 +/- 1.8 nM). The impairments of Ca(2+) oscillations and CCE, but not basal [Ca(2+)](i), were restored by superoxide dismutase and the inhibitors of mitochondrial electron transport, rotenone and thenoyltrifluoroacetone (TTFA). By using a superoxide anion (O(2)(-))-sensitive luciferin derivative MCLA, we confirmed that the production of O(2)(-) was induced by hypoxia/reoxygenation and was prevented by rotenone and TTFA. These results indicate that hypoxia/reoxygenation generates O(2)(-) at mitochondria and impairs some Ca(2+) mobilizing properties in BBEC.