RESUMO
BACKGROUND: Anti-programmed cell death protein 1 (PD-1) antibody monotherapy (PD1) has led to favorable responses in advanced non-acral cutaneous melanoma among Caucasian populations; however, recent studies suggest that this therapy has limited efficacy in mucosal melanoma (MCM). Thus, advanced MCM patients are candidates for PD1 plus anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) combination therapy (PD1 + CTLA4). Data on the efficacy of immunotherapy in MCM, however, are limited. We aimed to compare the efficacies of PD1 and PD1 + CTLA4 in Japanese advanced MCM patients. PATIENTS AND METHODS: We retrospectively assessed advanced MCM patients treated with PD1 or PD1 + CTLA4 at 24 Japanese institutions. Patient baseline characteristics, clinical responses (RECIST), progression-free survival (PFS), and overall survival (OS) were estimated using Kaplan-Meier analysis, and toxicity was assessed to estimate the efficacy and safety of PD1 and PD1 + CTLA4. RESULTS: Altogether, 329 patients with advanced MCM were included in this study. PD1 and PD1 + CTLA4 were used in 263 and 66 patients, respectively. Baseline characteristics were similar between both treatment groups, except for age (median age 71 versus 65 years; P < 0.001). No significant differences were observed between the PD1 and PD1 + CTLA4 groups with respect to objective response rate (26% versus 29%; P = 0.26) or PFS and OS (median PFS 5.9 months versus 6.8 months; P = 0.55, median OS 20.4 months versus 20.1 months; P = 0.55). Cox multivariate survival analysis revealed that PD1 + CTLA4 did not prolong PFS and OS (PFS: hazard ratio 0.83, 95% confidence interval 0.58-1.19, P = 0.30; OS: HR 0.89, 95% confidence interval 0.57-1.38, P = 0.59). The rate of ≥grade 3 immune-related adverse events was higher in the PD1 + CTLA4 group than in the PD1 group (53% versus 17%; P < 0.001). CONCLUSIONS: First-line PD1 + CTLA4 demonstrated comparable clinical efficacy to PD1 in Japanese MCM patients, but with a higher rate of immune-related adverse events.
Assuntos
Melanoma , Neoplasias Cutâneas , Idoso , Antígeno CTLA-4 , Humanos , Imunoterapia/métodos , Japão , Melanoma/tratamento farmacológico , Estudos RetrospectivosRESUMO
BACKGROUND: Maternal hypotension is a common complication during cesarean section performed under spinal anesthesia. Changes in maternal heart rate with postural changes or values of heart rate variability have been reported to predict hypotension. Therefore, we hypothesized that changes in heart rate variability due to postural changes can predict hypotension. METHODS: A total of 45 women scheduled to undergo cesarean section under spinal anesthesia were enrolled. A postural change test was performed the day before cesarean section. The ratio of the power of low and high frequency components contributing to heart rate variability was assessed in the order of supine, left lateral, and supine. Patients who exhibited a ⩾two-fold increase in the low-to-high frequency ratio when moving to supine from the lateral position were assigned to the postural change test-positive group. RESULTS: According to the findings of the postural change test, patients were assigned to the positive (n=22) and negative (n=23) groups, respectively. Hypotension occurred in 35/45 patients, of whom 21 (60%) were in the positive group and 14 (40%) were in the negative group. The incidence of hypotension was greater in the positive group (P<0.01). The total dose of ephedrine was greater in the positive group (15±11 vs. 7±7mg, P=0.005). The area under the receiver operating characteristic curve was 0.76 for the postural change test as a predictor of hypotension. CONCLUSION: The postural change test with heart rate variability analysis may be used to predict the risk of hypotension during spinal anesthesia for cesarean section.
Assuntos
Anestesia Obstétrica/efeitos adversos , Raquianestesia/efeitos adversos , Cesárea , Frequência Cardíaca/fisiologia , Hipotensão/diagnóstico , Postura/fisiologia , Adulto , Procedimentos Cirúrgicos Eletivos , Feminino , Humanos , Hipotensão/fisiopatologia , Complicações Intraoperatórias/diagnóstico , Complicações Intraoperatórias/fisiopatologia , GravidezRESUMO
We present fractional quantum Hall domain walls confined in a gate-defined wire structure. Our experiments utilize spatial oscillation of domain walls driven by radio frequency electric fields to cause nuclear magnetic resonance. The resulting spectra are discussed in terms of both large quadrupole fields created around the wire and hyperfine fields associated with the oscillating domain walls. This provides the experimental fact that the domain walls survive near the confined geometry despite of potential deformation, by which a localized magnetic resonance is allowed in electrical means.
Assuntos
Espectroscopia de Ressonância Magnética/métodos , Imãs/química , Nanofios/química , Eletricidade , Campos Eletromagnéticos , Nanofios/ultraestruturaRESUMO
We study nuclear spin polarization in the quantum Hall regime through the optically pumped electron spin polarization in the lowest Landau level. The nuclear spin polarization is measured as a nuclear magnetic field B(N) by means of the sensitive resistive detection. We find the dependence of B(N) on the filling factor nonmonotonic. The comprehensive measurements of B(N) with the help of the circularly polarized photoluminescence measurements indicate the participation of the photoexcited complexes, i.e., the exciton and trion (charged exciton), in nuclear spin polarization. On the basis of a novel estimation method of the equilibrium electron spin polarization, we analyze the experimental data and conclude that the filling factor dependence of B(N) is understood by the effect of electron spin polarization through excitons and trions.
RESUMO
BACKGROUND: The proteasome inhibitor bortezomib has improved the survival of patients with multiple myeloma but bortezomib-induced peripheral neuropathy (BiPN) has emerged as a serious potential complication of this therapy. Animal studies suggest that bortezomib predominantly causes pathological changes in Schwann cells. A tractable system to evaluate combination drugs for use with bortezomib is essential to enable continuing clinical benefit from this drug. METHODS: Rat schwannoma cells were pretreated with vincristine (VCR), histone deacetylase inhibitors, anticonvulsants, or a heat-shock protein 90 (HSP90) inhibitor. To then monitor aggresome formation as a result of proteasome inhibition and the activation of chaperone-mediated autophagy (CMA), we performed double-labelling immunofluorescent analyses of a cellular aggregation-prone protein marker. RESULTS: Aggresome formation was interrupted by VCR, whereas combination treatments with bortezomib involving suberoylanilide hydroxamic acid, 17-allylamino-17-demethoxy-geldanamycin, or clonazepam appear to facilitate the disposal of unfolded proteins via CMA, inducing HSP70 and lysosome-associated membrane protein type 2A (LAMP-2A). CONCLUSIONS: This schwannoma model can be used to test BiPN-reducing drugs. The present data suggest that aggresome formation in Schwann cells is a possible mechanism of BiPN, and drugs that induce HSP70 or LAMP-2A have the potential to alleviate this complication. Combination clinical trials are warranted to confirm the relevance of these observations.
Assuntos
Autofagia/fisiologia , Benzoquinonas/farmacologia , Clonazepam/farmacologia , Lactamas Macrocíclicas/farmacologia , Animais , Antineoplásicos/uso terapêutico , Autofagia/efeitos dos fármacos , Ácidos Borônicos/uso terapêutico , Bortezomib , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/patologia , Neurilemoma , Dobramento de Proteína , Deficiências na Proteostase/patologia , Pirazinas/uso terapêutico , Ratos , Células de Schwann/citologia , Células de Schwann/patologiaRESUMO
BACKGROUND: Merkel cells (MCs) exist in the epidermal basal layer, in contact with keratinocytes. This direct contact seems critical for maintaining MCs in vitro. OBJECTIVES: To estimate the effects of nerve cells on the maintenance of MCs within epidermal sheets in a new organotypic culture system of MCs. METHODS: We developed a new organotypic culture system of MCs, using MC-containing epidermal sheets embedded in collagen gel. To estimate the effects of nerve cells on the maintenance of MCs within the epidermal sheets, we cocultured nerve cells and MC-containing epidermal sheets. In these culture assemblies, cellular behaviour was analysed by histochemistry, immunohistochemistry, electron microscopy and enzyme-linked immunosorbent assay. RESULTS: This culture, even in the absence of neurotrophin (NT)-3 and nerve growth factor (NGF) (which are crucial for MC biology), retained cytokeratin (CK)-20-positive and neuroendocrine granule-containing MCs within the sheets for over 2 weeks. Coculture of MCs with PC-12 nerve cells significantly increased the number of MCs within the epidermal sheets, and the keratinocytes had almost identical expression levels of CK1, CK10, CK14 and the progenitor marker p63 to those produced by keratinocytes in vivo. Uptake of the growth marker bromodeoxyuridine by MCs and levels of NT-3 and NGF in the culture supernatants were undetectable in this system, regardless of the presence or absence of PC-12. CONCLUSIONS: The data suggest, first, that direct contact between MCs and keratinocytes may be critical for retaining MCs in vitro; second, that nerve cell-affected maintenance of keratinocyte differentiation, but not NT-3 and NGF, may contribute to MC maintenance; and third, that MCs are not able to grow, at least in our system. Our method would be useful for studying MC biology.
Assuntos
Epiderme/metabolismo , Células de Merkel/metabolismo , Neurotrofina 3/metabolismo , Células PC12/metabolismo , Animais , Técnicas de Cultura de Células , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Técnicas de Cocultura , Células Epidérmicas , Humanos , Imuno-Histoquímica , Queratina-20/metabolismo , Masculino , Células de Merkel/citologia , Microscopia Eletrônica , Células PC12/citologia , RatosRESUMO
Regulatory T cells (T(reg)) have an essential role in maintaining immune tolerance in the gut. The functional CD4(+) T(reg) express the transcription factor forkhead box protein 3 (FoxP3) or a CD25(high) in humans. Further, depletion of elevated granulocytes/monocytes by extracorporeal adsorption (GMA) induces immunomodulation in patients with ulcerative colitis (UC). We investigated the impact of GMA on T(reg). Thirty-one UC patients, clinical activity index (CAI) 12.1 +/- 2.97, refractory to conventional medications including intravenous corticosteroid and 13 healthy controls (HC), were included. Patients received five GMA sessions over 5 weeks. Biopsies from the rectal mucosa and blood samples at baseline and post-GMA were immunostained with anti-CD4/FoxP3 and anti-CD4/CD25 antibodies for immunohistochemistry and flow cytometry. Following GMA, 22 of 31 patients achieved remission (CAI Assuntos
Antígenos CD4/análise
, Colite Ulcerativa/imunologia
, Fatores de Transcrição Forkhead/análise
, Subunidade alfa de Receptor de Interleucina-2/análise
, Linfócitos T Reguladores/imunologia
, Adsorção
, Adulto
, Estudos de Casos e Controles
, Colite Ulcerativa/tratamento farmacológico
, Colite Ulcerativa/terapia
, Feminino
, Citometria de Fluxo
, Glucocorticoides/uso terapêutico
, Granulócitos/fisiologia
, Humanos
, Imuno-Histoquímica
, Leucaférese
, Masculino
, Pessoa de Meia-Idade
, Monócitos/fisiologia
, Estatísticas não Paramétricas
, Resultado do Tratamento
RESUMO
Computer simulation and myocardial cell models were used to evaluate a low-energy defibrillation technique. A generated spiral wave, considered to be a mechanism of fibrillation, and fibrillation were investigated using two myocardial sheet models: a two-dimensional computer simulation model and a two-dimensional experimental model. A new defibrillation technique that has few side effects, which are induced by the current passing into the patient's body, on cardiac muscle is desired. The purpose of the present study is to conduct a basic investigation into an efficient defibrillation method. In order to evaluate the defibrillation method, the propagation of excitation in the myocardial sheet is measured during the normal state and during fibrillation, respectively. The advantages of the low-energy defibrillation technique are then discussed based on the stimulation timing.
Assuntos
Simulação por Computador , Cardioversão Elétrica , Modelos Biológicos , Miócitos Cardíacos/fisiologia , Animais , Células Cultivadas , Feto/citologia , Camundongos , Camundongos Endogâmicos ICRRESUMO
UNLABELLED: We investigated whether the stereoisomers of ropivacaine and bupivacaine exert differential effects on the cerebral microcirculation. Pentobarbital-anesthetized dogs (n = 16) were prepared for measurement of cerebral pial vessel diameters by using a closed cranial window preparation. We administered three different concentrations (10(-7), 10(-5), and 10(-3) M) of each of three drug solutions [R(+), racemic, and S(-) forms of ropivacaine (n = 8) or bupivacaine (n = 8)] under the window in a randomized manner and measured cerebral pial arteriolar diameters. Various physiologic data were obtained before and after topical application of each test solution. All three forms of ropivacaine constricted cerebral pial arterioles, each in a concentration-dependent manner. The rank order for degree of vasoconstriction was S(-) ropivacaine > racemic ropivacaine > R(+) ropivacaine. In contrast, R(+) and racemic bupivacaine dilated, but S(-) bupivacaine constricted, cerebral pial arterioles, each in a concentration-dependent manner. We could find no difference in vascular reactivity to these drugs between large (> or = microm) and small (<100 microm) arterioles. Topical application of these drugs induced no changes in mean blood pressure or heart rate. The observed differences in the microvascular alterations induced by the stereoisomers of ropivacaine and bupivacaine suggest that the vasoactive effects of these drugs on cerebral arterioles could, at least in part, depend on their chirality. IMPLICATIONS: The differential effects of the stereoisomers of ropivacaine and bupivacaine on cerebral pial vessels could, at least in part, depend on their chirality.
Assuntos
Amidas/farmacologia , Anestésicos Locais/farmacologia , Bupivacaína/farmacologia , Pia-Máter/irrigação sanguínea , Animais , Arteríolas/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Cães , Frequência Cardíaca , Ropivacaina , Estereoisomerismo , Vasoconstrição/efeitos dos fármacos , Vasodilatação/efeitos dos fármacosRESUMO
This study aimed to clarify whether spontaneous T-wave normalization (TWN) in infarct-related leads reflects improvement in left ventricular (LV) wall motion even in patients with persistent abnormal Q waves after acute myocardial infarction (AMI). Eighty-five patients were classified into the following 3 groups: patients with Q-wave regression (group A, n = 21), those with persistent abnormal Q waves and TWN (group B, n = 36), and those with persistent abnormal Q waves and absence of TWN (group C, n = 28). Groups A and B had greater improvement in LV ejection fraction and regional wall motion between 1 and 6 months after AMI than group C. In conclusion, spontaneous TWN in the healing stage of anterior AMI reflects functional recovery of viable myocardium in the infarct region even in patients with persistent abnormal Q waves.
Assuntos
Eletrocardiografia , Infarto do Miocárdio/complicações , Infarto do Miocárdio/fisiopatologia , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/fisiopatologia , Idoso , Cateterismo Cardíaco , Angiografia Coronária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Recuperação de Função Fisiológica , Remissão Espontânea , Volume Sistólico/fisiologia , Fatores de Tempo , Disfunção Ventricular Esquerda/diagnóstico por imagem , Cicatrização/fisiologiaRESUMO
UNLABELLED: We studied 160 ASA I or II patients undergoing elective otolaryngologic surgery in order to compare the anxiolytic effects of a novel 5-hydroxytryptamine-1A agonist, tandospirone, with diazepam. To monitor preoperative anxiety, the following variables were used: systolic and diastolic arterial pressure, heart rate, and the state anxiety score yielded by the Spielberger State-Trait Anxiety Inventory. We performed pretreatment evaluation on the day before surgery and posttreatment examination immediately after entry into the operating room. In a double-blinded, randomized design, four groups of 40 patients each received one of the following oral medications 90 min before entry into the operating room: 1) tandospirone 10 mg (T10 group); 2) tandospirone 30 mg (T30 group); 3) diazepam 10 mg (D group); or 4) placebo (P group). After premedication, the State-Trait Anxiety Inventory state anxiety decreased in the T10 (P < 0.02), T30 (P < 0.02), and D groups (P < 0.001), but it increased in the P group (P < 0.001). Tandospirone, 10 and 30 mg, safely reduced preoperative anxiety to a similar extent as oral diazepam 10 mg in patients undergoing elective otolaryngologic surgery. IMPLICATIONS: Oral tandospirone reduces preoperative anxiety to a similar extent as oral diazepam in patients undergoing elective otolaryngologic surgery. This finding implies that tandospirone can be used as an oral premedicant drug for relieving anxiety before surgery.
Assuntos
Ansiolíticos/uso terapêutico , Ansiedade/tratamento farmacológico , Piperazinas/uso terapêutico , Pirimidinas/uso terapêutico , Agonistas do Receptor de Serotonina/uso terapêutico , Adolescente , Adulto , Ansiedade/etiologia , Ansiedade/fisiopatologia , Pressão Sanguínea/efeitos dos fármacos , Diazepam/uso terapêutico , Método Duplo-Cego , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Isoindóis , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Otorrinolaringológicos , Cuidados Pré-Operatórios , Receptores de Serotonina/fisiologia , Receptores 5-HT1 de SerotoninaRESUMO
To evaluate the effects of ketamine on cerebral arterioles, we used a closed cranial window technique in mechanically ventilated, anesthetized dogs. Fourteen dogs were assigned to one of the following two basal-anesthesia groups: pentobarbital 2 mg. kg(-1). h(-1) or isoflurane 0.5 MAC (n = 7 each). We administered three different concentrations of ketamine (10(-7), 10(-5), and 10(-3) M) under the window and measured arteriolar diameters. For comparison, in another 14 dogs we examined the effect of systemic (IV) ketamine (1 mg/kg and 5 mg/kg) using the same two basal anesthetics. We measured diameters before and after ketamine administration, and we evaluated the effect of ketamine on CO(2) reactivity of the cerebral arterioles. Neither topical nor systemic ketamine dilated pial arterioles in either basal-anesthesia group. CO(2) reactivity of pial arterioles was reduced under systemic ketamine in both basal-anesthesia groups. The results indicate that although ketamine does not dilate pial arteriolar diameters when topically or IV administered, IV ketamine does attenuate hypercapnic vasodilation in dogs under basal pentobarbital or isoflurane anesthesia. These results provide some insight that ketamine is suitable for supplementary neurosurgical anesthesia.
Assuntos
Adjuvantes Anestésicos/farmacologia , Anestésicos Dissociativos/farmacologia , Anestésicos Inalatórios/farmacologia , Artérias Cerebrais/efeitos dos fármacos , Isoflurano/farmacologia , Ketamina/farmacologia , Pentobarbital/farmacologia , Administração Tópica , Anestésicos Dissociativos/administração & dosagem , Animais , Arteríolas/efeitos dos fármacos , Gasometria , Cães , Hemodinâmica/efeitos dos fármacos , Ketamina/administração & dosagemRESUMO
In order to clarify the time course of left ventricular (LV) wall motion in patients with anterior acute myocardial infarction (AMI) showing terminal QRS distortion on the admission electrocardiogram (ECG), the present study examined 106 patients with their first anterior AMI (< or =6 h) who underwent emergency coronary arteriography and cardiac cathetherization at 1 and 6 months after the infarction. The patients were classified into 2 groups according to the presence (group A, n=23) or absence (group B, n=83) of terminal QRS distortion (emergence of the J point at > or =50% of the R-wave amplitude in leads with QR configuration and/or absence of S waves in leads with RS configuration) on the admission ECG. Group A had a lower LV ejection fraction and more reduced regional wall motion (RWM) in the infarct region at both 1 and 6 months after AMI than group B. The degree of improvement in RWM between 1 and 6 months after AMI was less in group A than in group B (-0.1+/-0.5 vs 0.4+/-0.6 SD/chord, p<0.01). This study indicates that patients with anterior AMI showing terminal QRS distortion on the admission ECG have more severely depressed LV wall motion and less improvement in RWM in the infarct region in the healing stage, suggesting that this sign is an indicator of severe myocardial damage.
Assuntos
Eletrocardiografia , Infarto do Miocárdio/fisiopatologia , Função Ventricular Esquerda , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contração MiocárdicaRESUMO
STUDY OBJECTIVES: To investigate the effects of ketamine and propofol on the cerebrovascular response to carbon dioxide (CO(2)) in humans during isoflurane anesthesia. DESIGN: Randomized clinical investigation. SETTINGS: University hospital of a medical school. PATIENTS: 30 ASA physical status I and II adult, elective surgical patients. INTERVENTIONS AND MEASUREMENTS: With each patient given air/oxygen/isoflurane anesthesia, the flow velocity in the middle cerebral artery (Vmca) and pulsatility index were measured using the transcranial Doppler method under hypocapnic [arterial CO(2)tension (PaCO(2)) 28-32 mmHg], normocapnic (PaCO(2) 38-42 mmHg), and hypercapnic conditions (PaCO(2) 48-52 mmHg). PaCO(2) was altered by supplementing the inspired gas with CO(2) without changing the respiratory conditions. Patients were then randomly assigned to receive either ketamine 1 mg. kg(-1) or propofol (2 mg. kg(-1)followed by an infusion of 6-10 mg. kg(-1). hr(-1)) (n = 15 for each drug), and the measurements were repeated. MAIN RESULTS: Ketamine reduced both absolute and relative cerebrovascular reactivity to CO(2) significantly [2.9 +/- 0.8 (control) vs. 2.6 +/- 1.0 (ketamine) cm. sec(-1). mmHg(-1): p < 0.05; and 3.5 +/- 0.7 (control) vs. 2.8 +/- 0.9 (ketamine) %. mmHg(-1): p < 0.01, respectively]. However, ketamine did not reduce Vmca during hypercapnic conditions (117 +/- 29 cm. sec(-1)) compared with controls (120 +/- 28 cm. sec(-1)). Although propofol decreased Vmca during all conditions, it did not cause any change in either absolute or relative CO(2) reactivity [2.5 +/- 0.8 (control) vs. 2.5 +/- 1.0 (propofol) cm. sec(-1). mmHg(-1), and 3.3 +/- 1.3 (control) vs. 4.1 +/- 1.0 (propofol) %. mmHg(-1), respectively]. CONCLUSIONS: In humans given isoflurane anesthesia, a) ketamine reduced cerebrovascular response to CO(2), but cerebral blood flow (CBF) during hypercapnic conditions was comparable with controls, and b) although propofol decreases CBF, it maintains the cerebrovascular response to CO(2).
Assuntos
Anestesia por Inalação , Anestésicos Inalatórios , Anestésicos Intravenosos/farmacologia , Dióxido de Carbono/sangue , Circulação Cerebrovascular/efeitos dos fármacos , Isoflurano , Ketamina/farmacologia , Propofol/farmacologia , Adulto , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Artéria Cerebral Média/fisiologia , N-Metilaspartato/antagonistas & inibidoresAssuntos
Glote/fisiologia , Soluço/fisiopatologia , Intubação Intratraqueal/instrumentação , Adulto , Feminino , HumanosRESUMO
Circulating immune complex (CIC) is known to play a role in pathological glomerular alterations in malaria. However, the nature of the antigens comprising the CIC is still not fully understood. We report here the isolation of the antigen in CIC and its localisation in mice infected with Plasmodium berghei NK65. The antigen was successfully isolated from CIC extracted from the blood of mice infected with P. berghei, by using C1q-coated microplates. The molecular mass of the antigen separated from CIC bound to C1q was found to be 78 kDa. Furthermore, localisation of the antigen was examined by the fluorescent antibody technique and immunoelectron microscopy. The antigen was detected in the parasitised erythrocyte and the mesangial matrix by both methods. These results suggest that the 78 kDa protein might be associated with the glomerular alterations in malaria infection.
Assuntos
Complexo Antígeno-Anticorpo/química , Antígenos de Protozoários/isolamento & purificação , Malária/imunologia , Plasmodium berghei/imunologia , Animais , Eletroforese em Gel de Poliacrilamida , Técnica Indireta de Fluorescência para Anticorpo , CamundongosRESUMO
Five immortalized brain capillary endothelial cell lines (TM-BBB1-5) were established from 3 transgenic mice harboring temperature-sensitive simian virus 40 large T-antigen gene (Tg mouse). These cell lines expressed active large T-antigen and grew well at 33 degrees C with a doubling time of about 20 to 30 hours. TM-BBBs also grew at 37 degrees C but not at 39 degrees C. However, growth was restored when the temperature of the culture was lowered to 33 degrees C. Although significant amounts of large T-antigen were shown to be present in the cell culture at 33 degrees C, there was less of this complex at 37 degrees C and 39 degrees C. TM-BBBs expressed the typical endothelial marker, von Willebrand factor, and exhibited acetylated low-density lipoprotein uptake activity. The alkaline phosphatase and gamma-glutamyltranspeptidase activity in TM-BBBs were -10% and 50% to 80% of brain capillary fraction of normal mice, respectively. D-mannitol transport in the both apical-to-basal and basal-to-apical directions across the TM-BBB was 2-fold greater than for inulin. TM-BBBs were found to express GLUT-1 but not GLUT-3, and exhibited concentration-dependent 3-O-methyl-D-glucose (3-OMG) uptake activity with a Michaelis-Menten constant of 6.59 +/- 1.16 mmol/l. Moreover, P-glycoprotein (P-gp) with a molecular weight of -170 kDa was expressed in all TM-BBBs. Both mdr1a and mdr1b mRNA were detected in TM-BBB4 using reverse transcription-polymerase chain reaction (RT-PCR) analysis. [3H]-Cyclosporin A uptake by TM-BBB was significantly increased in the presence of 100 micromol/l verapamil and vincristine, suggesting that TM-BBB exhibits efflux transport activity via P-gp. In conclusion, conditional brain capillary endothelial cell lines were established from Tg mice. This cell line expresses endothelial markers and transporters at the BBB and is able to regulate cell growth, due to the amount of active large T-antigen in the cell, by changing the culture temperature.
Assuntos
Antígenos Virais de Tumores/metabolismo , Encéfalo/irrigação sanguínea , Endotélio Vascular/citologia , Vírus 40 dos Símios/imunologia , 3-O-Metilglucose/metabolismo , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Transporte Biológico , Barreira Hematoencefálica , Capilares , Divisão Celular , Linhagem Celular , Endotélio Vascular/metabolismo , Transportador de Glucose Tipo 1 , Inulina/metabolismo , Manitol/metabolismo , Camundongos , Camundongos Transgênicos , Proteínas de Transporte de Monossacarídeos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Temperatura , gama-Glutamiltransferase/metabolismo , Fator de von Willebrand/metabolismo , Membro 4 da Subfamília B de Transportadores de Cassetes de Ligação de ATPRESUMO
UNLABELLED: Ropivacaine constricts spinal vessels. Because the CO2 response of spinal vessels is similar to that of cerebral vessels, we tested to see if hypocapnia would cause further spinal vasoconstriction during ropivacaine administration. In 12 pentobarbital-anesthetized dogs, spinal pial arteriolar diameter was measured using a closed spinal window preparation. Either ropivacaine solution (0.1%; n = 6) or artificial cerebrospinal fluid (n = 6) was infused continuously into the spinal window. After a period of hypocapnia (Paco2, 20-25 mm Hg) had been induced, inspired CO2 levels were adjusted to produce normocapnia (35-40 mm Hg) followed by hypercapnia (55-60 mm Hg). When the desired Paco2 was reached, measurements were made of the arteriolar diameter and physiological variables. During normocapnia, ropivacaine infusion produced a significant constriction of pial arterioles, whereas artificial cerebrospinal fluid caused no change. Hypocapnia induced a much smaller (almost nonexistent) additional vasoconstriction in the ropivacaine group than in the control group (P < 0.01). The final hypercapnic vasodilation was somewhat greater during ropivacaine (P < 0.05 versus control group). Topical ropivacaine induced no change in hemodynamic variables. We conclude that hypocapnia of the magnitude tested did not cause further constriction in spinal vessels during spinal ropivacaine. IMPLICATIONS: During topical application of the local anesthetic ropivacaine in dogs, hypocapnia (Paco2, 20-25 mm Hg) induced almost no additional constriction of spinal arterioles, and the hypercapnic vasodilation was maintained. These data suggest that an additional constriction in spinal vessels is unlikely when hypocapnia occurs during spinal ropivacaine.