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1.
Appl Radiat Isot ; 206: 111226, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38364610

RESUMEN

This study presents a method of measuring the activity of a specific radionuclide 234mPa in samples placed in bulk transport containers under changing background conditions. The method makes it possible to measure specific activity of 234 mPa in objects without the need for sampling. The change in the effective sample volume limited by the surfaces of the containers is considered depending on the density of the measured material and the energy of gamma radiation of the radionuclide. The high sensitivity of scintillation detector, supplemented by adequate Monte Carlo simulation, allows spectrum measurements to be taken in a short time (less than an hour) with subsequent determination of specific activity. A comparison of measurement results and calculation of 234mPa activity in samples with different densities and compositions using the proposed algorithm, and those obtained by an HPGe spectrometer, demonstrated the high efficiency of the proposed solution.

2.
Nano Lett ; 20(10): 7476-7481, 2020 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-32897724

RESUMEN

Magnetic Weyl semimetals attract considerable interest not only for their topological quantum phenomena but also as an emerging materials class for realizing quantum anomalous Hall effect in the two-dimensional limit. A shandite compound Co3Sn2S2 with layered kagome-lattices is one such material, where vigorous efforts have been devoted to synthesize the two-dimensional crystal. Here, we report a synthesis of Co3Sn2S2 thin flakes with a thickness of 250 nm by chemical vapor transport method. We find that this facile bottom-up approach allows the formation of large-sized Co3Sn2S2 thin flakes of high-quality, where we identify the largest electron mobility (∼2600 cm2 V-1 s-1) among magnetic topological semimetals, as well as the large anomalous Hall conductivity (∼1400 Ω-1 cm-1) and anomalous Hall angle (∼32%) arising from the Berry curvature. Our study provides a viable platform for studying high-quality thin flakes of magnetic Weyl semimetal and stimulate further research on unexplored topological phenomena in the two-dimensional limit.

3.
Methods Mol Biol ; 1868: 223-232, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30244470

RESUMEN

The diagnosis of vasculitis in rheumatoid arthritis (RV) is associated with considerable mortality; therefore, understanding the basic mechanisms underlying the pathogenesis of vasculitis is very important. Animal models of vasculitis have contributed to elucidating such mechanisms. We here introduce a Candida albicans water-soluble (CAWS) glycoprotein-induced vasculitis model and the methodological approach to evaluate inflammatory vascular change.


Asunto(s)
Vasculitis/patología , Animales , Candida albicans/fisiología , Proliferación Celular , Modelos Animales de Enfermedad , Hipoxia/patología , Ratones , Neovascularización Patológica/patología , Reacción en Cadena en Tiempo Real de la Polimerasa , Solubilidad , Coloración y Etiquetado , Agua/química
4.
Science ; 358(6368): 1311-1314, 2017 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-29217573

RESUMEN

Electronic ordering in magnetic and dielectric materials forms domains with different signs of order parameters. The control of configuration and motion of the domain walls (DWs) enables nonvolatile responses against minute external fields. Here, we realize chiral edge states (CESs) on the magnetic DWs of a magnetic topological insulator. We design and fabricate the magnetic domains in the quantum anomalous Hall state with the tip of a magnetic force microscope and prove the existence of the chiral one-dimensional edge conduction along the prescribed DWs through transport measurements. The proof-of-concept devices based on reconfigurable CESs and Landauer-Büttiker formalism are realized for multiple-domain configurations with well-defined DW channels. Our results may lead to the realization of low-power-consumption spintronic devices.

5.
J Med Entomol ; 54(6): 1615-1625, 2017 11 07.
Artículo en Inglés | MEDLINE | ID: mdl-28968769

RESUMEN

We compared climatic distribution ranges between Aedes albopictus (Skuse) (Diptera: Culicidae) and the five wild (nondomesticated) species of Albopictus Subgroup of Scutellaris Group of Aedes (Stegomyia) in southern Asia. Distribution sites of the wild species concentrate in seasonal forest and savannah climate zones in India, Indochina, and southern China. The distribution of Ae. albopictus is broader than the wild species under 1) tropical rain-forest climate, 2) steppe and temperate savannah climate, and 3) continental climate with large seasonal temperature variation (hot summer and cold winter) at temperate lowlands (northernmost sites 40°N in Ae. albopictus vs 32°N in the wild species). However, the distribution of Ae. albopictus is more limited at tropical and subtropical highlands where the climate is cool but less continental (small seasonal variation, mild summer, and winter). We discuss a possibility that the broader climate ranges of Ae. albopictus are ecological or eco-evolutionary consequences of adaptation to human habitats. We also propose a general scenario for the origin, dispersal, and adaptation of Ae. albopictus in Asia as a hypothesis for future research.


Asunto(s)
Aedes , Distribución Animal , Clima , Animales , Asia
6.
Nat Mater ; 16(5): 516-521, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28191899

RESUMEN

The axion insulator which may exhibit an exotic quantized magnetoelectric effect is one of the most interesting quantum phases predicted for the three-dimensional topological insulator (TI). The axion insulator state is expected to show up in magnetically doped TIs with magnetizations pointing inwards and outwards from the respective surfaces. Towards the realization of the axion insulator, we here engineered a TI heterostructure in which magnetic ions (Cr) are modulation-doped only in the vicinity of the top and bottom surfaces of the TI ((Bi,Sb)2Te3) film. A separation layer between the two magnetic layers weakens interlayer coupling between them, enabling the magnetization reversal of individual layers. We demonstrate the realization of the axion insulator by observing a zero Hall plateau (ZHP) (where both the Hall and longitudinal conductivity become zero) in the electric transport properties, excluding the other possible origins for the ZHP. The manifestation of the axion insulator can lead to a new stage of research on novel magnetoelectric responses in topological matter.

7.
Oral Dis ; 21(1): 97-105, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24330147

RESUMEN

OBJECTIVE: We previously reported that matrix metalloproteinase-3(MMP-3) accelerates wound healing following dental pulp injury. In this study, we tested the hypothesis that induction of MMP-3 activity by interleukin-1ß would promote proliferation and apoptosis of dental pulp cells. MATERIALS AND METHODS: Dental pulp cells were isolated from rat incisors and subjected to interleukin-1ß. Matrix metalloproteinase-3 mRNA and protein expression were assessed using reverse transcription-polymerase chain reaction and Western blotting, respectively. Matrix metalloproteinase-3 activity was measured using fluorescence. Dental pulp cell proliferation and apoptosis were determined using enzyme-linked immunosorbent assays (ELISA) for BrdU and DNA fragmentation, respectively. siRNA was used to reduce MMP-3 transcripts in these cells. RESULTS: Treatment with interleukin-1ß increased MMP-3 mRNA and protein levels as well as its activity in dental pulp cells. Cell proliferation was also markedly increased, with no changes in apoptosis observed. Treatment with siRNA against MMP-3 potently suppressed this interleukin-1ß-induced increase in MMP-3 expression and activity, and also suppressed cell proliferation but unexpectedly increased apoptosis in these cells (P < 0.05). This siRNA-mediated increase in apoptosis could be reversed with exogenous MMP-3 stimulation (P < 0.05). CONCLUSIONS: Interleukin-1ß induces MMP-3-regulated cell proliferation and suppresses apoptosis in dental pulp cells.


Asunto(s)
Proliferación Celular/fisiología , Pulpa Dental/fisiología , Interleucina-1beta/farmacología , Metaloproteinasa 3 de la Matriz/fisiología , Animales , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Western Blotting , Proliferación Celular/efectos de los fármacos , Pulpa Dental/citología , Pulpa Dental/efectos de los fármacos , Ratas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
8.
J Periodontal Res ; 50(1): 123-30, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24815103

RESUMEN

BACKGROUND AND OBJECTIVE: Although regenerative periodontal surgery with EMD or guided tissue regeneration (GTR) has been shown to enhance periodontal regeneration, there are limited data on the long-term results following these treatment modalities. The purpose of the present study was to investigate the long-term clinical outcomes in intrabony defects following regenerative periodontal surgery with EMD or GTR compared with open-flap debridement (OFD). MATERIAL AND METHODS: Data from 40 subjects (44 teeth), with no history of smoking or systemic diseases that could interfere with periodontal disease and who received one of three surgical procedures (EMD, GTR or OFD) for two- or three-wall intrabony defects, were analyzed. Postoperative reduction in probing pocket depth, gain in clinical attachment level, gingival recession and percentage bone fill were compared at 1, 3 and 5 years. RESULTS: Reduction in probing pocket depth after GTR was significantly higher than after OFD at 1 and 3 years postoperatively, but there was no difference between the groups at 5 years. The gains in clinical attachment level for EMD (at 3 and 5 years) and for GTR (at 1, 3 and 5 years) were significantly greater than for OFD. Gingival recession after treatment with EMD and GTR showed a tendency toward positive results, whereas no such tendency was observed for OFD. Postoperative percentage bone fill for EMD and GTR was significantly greater than for OFD at 3 and 5 years. CONCLUSIONS: This is a retrospective study and an exploratory report with a high risk of bias. Within the limits of the current study, it may be concluded that superior gains in clinical attachment level and improved percentage bone fill can be obtained with EMD and GTR when compared with OFD, and these can be maintained over a period of 5 years.


Asunto(s)
Pérdida de Hueso Alveolar/cirugía , Proteínas del Esmalte Dental/uso terapéutico , Regeneración Tisular Guiada Periodontal/métodos , Colgajos Quirúrgicos/cirugía , Adulto , Proceso Alveolar/patología , Materiales Biocompatibles , Regeneración Ósea/fisiología , Desbridamiento/métodos , Femenino , Estudios de Seguimiento , Recesión Gingival/cirugía , Humanos , Estudios Longitudinales , Masculino , Membranas Artificiales , Persona de Mediana Edad , Pérdida de la Inserción Periodontal/cirugía , Bolsa Periodontal/cirugía , Politetrafluoroetileno , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
9.
Oral Dis ; 20(4): 395-403, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-23731055

RESUMEN

OBJECTIVES: We examined whether mouse embryonic stem (ES) cells can differentiate into odontoblast-like cells without epithelial-mesenchymal interaction. MATERIALS AND METHODS: Cells were cultured by the 'hanging drop' method using a collagen type-I scaffold (CS) combined with bone morphogenetic protein (BMP)-4 (CS/BMP-4). Expression of odontoblast-related mRNA and protein, and cell proliferation were performed by reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence staining and WST-1 assay, respectively. RESULTS: Cells potently expressed odontoblast-related cell marker mRNAs following induction of odontoblastic differentiation. Dentin sialophosphoprotein, a marker of mature odontoblasts, was strongly expressed in differentiated ES cells. The cells also acquired an odontoblast-like functional phenotype, as evidenced by the appearance of alkaline phosphatase activity and calcification. The cell-surface expression of α2, α6, αV and αVß3 integrin proteins was rapidly upregulated in differentiated cells. Finally, anti-α2 integrin antibody suppressed the expression of odontoblastic markers in cells grown using this culture system, suggesting that α2 integrin expression in ES cells triggers their differentiation into odontoblast-like cells. CONCLUSIONS: Mouse ES cells cultured by the 'hanging drop' method are able to differentiate into cells with odontoblast-specific physiological functions and cell-surface integrin protein expression.


Asunto(s)
Diferenciación Celular , Células Madre Embrionarias/citología , Odontoblastos/citología , Animales , Células Cultivadas , Técnicas Citológicas/métodos , Ratones
10.
Oral Dis ; 20(5): 505-13, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23902456

RESUMEN

OBJECTIVES: Matrix metalloproteinase (MMP)-3 expression increases after pulpectomy and accelerates angiogenesis in rat dental pulp by an uncharacterised mechanism. Odontoblasts, a major component of dental pulp, could represent a therapeutic target. We investigated whether MMP-3 activity is induced by cytokines and/or is associated with cell proliferation and apoptosis in embryonic stem cell-derived odontoblast-like cells. MATERIALS AND METHODS: We used reverse transcriptase polymerase chain reaction, western blotting, an MMP-3 activity assay, a BrdU-cell proliferation enzyme-linked immunosorbent assay and DNA fragmentation analysis to evaluate siRNA-mediated downregulation of MMP-3 expression and activity, and any changes in the proliferative and apoptotic responses associated with this reduced expression. RESULTS: Pro-inflammatory cytokines (interleukin-1ß, tumour necrosis factor-α and interferon-γ, at relatively low concentrations) induced MMP-3 mRNA and protein expression, and increased MMP-3 activity and cell proliferation, but not apoptosis. MMP-3 silencing produced a potent and significant suppression of cytokine-induced MMP-3 expression and activity, decreased cell proliferation and increased apoptosis. These effects were rescued by application of exogenous MMP-3. CONCLUSIONS: Our results suggest that pro-inflammatory cytokines induce MMP-3-regulated cell proliferation and anti-apoptosis effects in odontoblast-like cells derived from embryonic stem cells, in addition to their well-documented destructive role in inflammation.


Asunto(s)
Proliferación Celular , Citocinas/fisiología , Células Madre Embrionarias/citología , Metaloproteinasa 3 de la Matriz/fisiología , Odontoblastos/citología , Animales , Apoptosis/fisiología , Western Blotting , División Celular/fisiología , Línea Celular , Ratones , Odontoblastos/efectos de los fármacos , Proteínas
11.
J Neurol Sci ; 295(1-2): 41-5, 2010 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-20541774

RESUMEN

BACKGROUND: Anti-aquaporin-4 (AQP4) antibody targets perivascular astrocyte foot processes, which contain abundant angiotensinogen, a precursor of angiotensin II, angiotensin-converting enzyme (ACE) and ACE2. OBJECTIVE: To disclose any abnormality in the intrathecal angiotensin II metabolic pathway in Japanese patients with neuromyelitis optica (NMO) or NMO spectrum disorders (NMOs) and positive for anti-AQP4 antibody. METHODS: We measured CSF angiotensin II, ACE and ACE2 levels in 15 anti-AQP4 antibody-positive patients with NMO or NMOs, 21 anti-AQP4 antibody-negative multiple sclerosis (MS) patients, 32 patients with other neurological diseases (OND) and 24 non-neurologic controls, using established ELISAs. RESULTS: CSF angiotensin II levels were lower in patients with NMO/NMOs (2.01+/-1.82 pg/ml) and those with MS (3.15+/-1.67 pg/ml) than in the OND (5.41+/-2.34 pg/ml) and control groups (6.71+/-2.65 pg/ml) (P(corr)<0.005). The difference in CSF angiotensin II levels between NMO/NMOs and MS patients was nearly significant (P(uncorr)=0.052). In NMO/NMOs and MS patients, angiotensin II levels were negatively correlated with CSF/serum albumin ratio (P<0.05). ACE levels in CSF were lower in patients with NMO/NMOs (34.3+/-5.61 ng/ml) than in MS patients (42.5+/-8.19 ng/ml, P(corr)=0.035) and controls (44.7+/-4.02 ng/ml, P(corr)<0.0003) while ACE2 levels were lower in NMO/NMOs (1.13+/-0.49 ng/ml) and MS (1.75+/-0.86 ng/ml) patients than in controls (2.76+/-0.23 ng/ml, P(corr)<0.001 for both). CONCLUSION: CSF angiotensin II, ACE, and ACE2 levels are decreased in NMO/NMOs patients with anti-AQP4 antibody, reflecting severe destruction of perivascular astrocytes.


Asunto(s)
Angiotensina II/líquido cefalorraquídeo , Acuaporina 4/inmunología , Autoinmunidad/fisiología , Enfermedades Autoinmunes Desmielinizantes SNC/líquido cefalorraquídeo , Enfermedades Autoinmunes Desmielinizantes SNC/inmunología , Peptidil-Dipeptidasa A/líquido cefalorraquídeo , Adulto , Línea Celular Transformada , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Proteínas Fluorescentes Verdes/genética , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Estadística como Asunto , Transfección/métodos
12.
Mult Scler ; 15(2): 262-5, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19136547

RESUMEN

BACKGROUND: We reported a reduction in the levels of angiotensin II in cerebrospinal fluid (CSF) from patients with multiple sclerosis (MS). OBJECTIVE AND METHODS: To clarify the mechanism underlying this reduction, we assayed angiotensin-converting enzyme (ACE) and ACE2 concentrations along with angiotensin II concentrations in CSF samples from 20 patients with MS and 17 controls with non-neurological diseases. RESULTS: ACE levels were significantly elevated in patients with MS compared with controls (48.42 +/- 4.84 vs 44.71 +/- 3.9 pg/mL), whereas ACE2 levels were significantly reduced (2.56 +/- 0.26 vs 2.78 +/- 0.24 pg/mL), acting toward a normalization of angiotensin II levels. CONCLUSION: These results further indicate an alteration of the intrathecal renin-angiotensin system in patients with MS.


Asunto(s)
Esclerosis Múltiple/líquido cefalorraquídeo , Esclerosis Múltiple/fisiopatología , Peptidil-Dipeptidasa A/líquido cefalorraquídeo , Sistema Renina-Angiotensina/fisiología , Adulto , Angiotensina II/líquido cefalorraquídeo , Enzima Convertidora de Angiotensina 2 , Volumen Sanguíneo/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad
13.
Acta Neurol Scand ; 119(5): 341-4, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-18798831

RESUMEN

BACKGROUND: Recent studies suggest that angiotensin II, a major substrate in the renin-angiotensin system, protects neurons through stimulation of its type 2 receptors. However, quite a few clinical studies of angiotensin II levels have shown their relation to disease severity in neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS). AIMS OF THE STUDY: To clarify the significance of angiotensin II in ALS. METHODS: We assayed angiotensin II concentrations in cerebrospinal fluid (CSF) samples from 23 patients with ALS, nine patients with spinocerebellar degeneration (SCD) and 24 control individuals. We evaluated the disability levels of patients with ALS using the Revised ALS Functional Rating Scale (ALSFRS-R) and calculated the disease progression rate (DPR). RESULTS: CSF angiotensin II levels were significantly lower in the ALS group compared with that in the control group (P = 0.00864), and showed a significant positive correlation with scores on the ALSFRS-R, and a significant negative correlation with the DPR. CONCLUSIONS: In the present study, we reveal for the first time that angiotensin II levels in the CSF from patients with ALS are significantly reduced and significantly associated with disease severity and progression rate. These findings suggest that reduced levels of intrathecal angiotensin II may play a role in ALS.


Asunto(s)
Esclerosis Amiotrófica Lateral/líquido cefalorraquídeo , Esclerosis Amiotrófica Lateral/diagnóstico , Angiotensina II/líquido cefalorraquídeo , Proteínas del Líquido Cefalorraquídeo/metabolismo , Citoprotección/fisiología , Adulto , Anciano , Esclerosis Amiotrófica Lateral/fisiopatología , Angiotensina II/análisis , Biomarcadores/análisis , Biomarcadores/líquido cefalorraquídeo , Proteínas del Líquido Cefalorraquídeo/análisis , Progresión de la Enfermedad , Regulación hacia Abajo/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Receptor de Angiotensina Tipo 2/metabolismo , Índice de Severidad de la Enfermedad , Médula Espinal/metabolismo , Médula Espinal/fisiopatología , Degeneraciones Espinocerebelosas/líquido cefalorraquídeo , Degeneraciones Espinocerebelosas/diagnóstico
14.
Mult Scler ; 14(4): 557-60, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18562510

RESUMEN

We previously demonstrated that angiotensin II acts as a crucial neuroprotective factor after neural injury through angiotensin II type-2 (AT2) receptor signaling. Although the pathway is known to play an important role in the development of experimental autoimmune encephalomyelitis, cerebrospinal fluid (CSF) angiotensin II levels in patients with multiple sclerosis (MS) have never been studied. To clarify the significance of angiotensin II in MS, we assayed angiotensin II concentrations using an established enzyme-linked immunoabsorbent assay in CSF samples from patients with MS (n = 21), patients with inflammatory neuropathies (IN) (n = 23) and control individuals who did not have either of the neurological diseases or any other disease that might affect the angiotensin II levels in the CSF (control) (n = 24). Angiotensin II levels in the CSF were 3.79 +/- 1.54 pg/ml in the MS group, 5.13 +/- 2.27 pg/ml in the IN group and 6.71 +/- 2.65 pg/ml in the control group. The angiotensin II levels in the CSF of the MS group were significantly lower than in the control group (p = 0.00057). Angiotensin II concentration in the CSF tended to have a negative correlation with the Kurtzke's Expanded Disability Status Scale scores during MS relapse (p = 0.0847). These findings suggest that reduced levels of intrathecal angiotensin II may be related to the abnormal neural damage and repair processes in MS.


Asunto(s)
Angiotensina II/líquido cefalorraquídeo , Esclerosis Múltiple/líquido cefalorraquídeo , Esclerosis Múltiple/fisiopatología , Evaluación de la Discapacidad , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Masculino , Neuritis/líquido cefalorraquídeo , Neuritis/fisiopatología , Índice de Severidad de la Enfermedad
15.
J Dent Res ; 85(7): 627-32, 2006 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16798863

RESUMEN

Although a recent study suggested the involvement of RANKL and osteoprotegerin (OPG) in the pathogenesis of bone-destructive disease, no study has focused on the RANKL:OPG ratio in the synovial fluid of patients with temporomandibular joint (TMJ) disorder. This communication reports on the concentrations of RANKL and OPG in synovial fluid from TMJ patients and healthy control individuals. In contrast to an unchanged concentration of RANKL, a strong decrease in the concentration of OPG was detected in the synovial fluid from patients with TMJ internal derangement. Treatment with the synovial fluid of osteoarthritis (OA) patients resulted in the high production of osteoclast-like cells from blood mononuclear cells in vitro, as well as in pit formation in dentin slices. The addition of anti-RANKL IgG or OPG attenuated OA-synovial fluid-induced osteoclast formation, suggesting that the increase in the RANKL:OPG ratio in the microenvironment of the joint has the potential to induce osteoclastogenesis in TMJ osteoarthritis.


Asunto(s)
Osteoprotegerina/metabolismo , Ligando RANK/metabolismo , Líquido Sinovial/química , Trastornos de la Articulación Temporomandibular/metabolismo , Adulto , Análisis de Varianza , Estudios de Casos y Controles , Diferenciación Celular , Células Cultivadas , Femenino , Humanos , Inmunoglobulina G , Luxaciones Articulares/metabolismo , Factor Estimulante de Colonias de Macrófagos/farmacología , Masculino , Monocitos/efectos de los fármacos , Monocitos/fisiología , Osteoartritis/metabolismo , Osteoclastos/fisiología , Osteoprotegerina/análisis , Ligando RANK/análisis , Líquido Sinovial/metabolismo
16.
Med Vet Entomol ; 18(3): 301-5, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15347399

RESUMEN

Anopheline larval habitats associated with a swamp, were examined in a highland area (1910 m elevation) of western Kenya. A significant association was found between occurrence of Anopheles gambiae Giles s.s. (Diptera: Culicidae) larvae and two factors, habitat size and vegetation type. Over 80% of An. gambiae s.s. larvae were found in small isolated pools, characterized by short plants, occurring in both swamp margins and roadside ditches. However, Anopheles gambiae s.s. was not found in habitats marked by papyrus and floating plants. The larval habitat of An. gambiae s.s. was characterized by warmer daytime temperatures of water, which were significantly affected by habitat size and plant size. The density of indoor resting An. gambiae s.s. was 0.22 per house and negatively associated with distance from the swamp. These results indicate that the practice of swamp cultivation, in populated areas of the African highlands, increases availability and enhances habitat conditions for the malaria vector.


Asunto(s)
Anopheles/crecimiento & desarrollo , Ambiente , Insectos Vectores/crecimiento & desarrollo , Altitud , Animales , Anopheles/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Femenino , Humanos , Insectos Vectores/genética , Kenia , Larva/genética , Larva/crecimiento & desarrollo , Reacción en Cadena de la Polimerasa , Ríos , Población Rural
17.
Bone ; 35(2): 507-16, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15268903

RESUMEN

To clarify the mechanisms of osteoblastic cell death, we examined whether serum deprivation would cause activation of the apoptotic signal cascade and arrest of the cell cycle in mouse osteoblastic MC3T3-E1 cells. Serum withdrawal from osteoblastic cell cultures resulted in growth arrest and cell-cycle arrest at G0/G1, which actions were accompanied by transient and potent activation of NF-kappaB, caspase-8, caspase-2, caspase-3, and caspase-9 in this order. Apoptosis, but not necrosis, in serum-deprived cells could be detected by FACS using Annexin-V/propidium iodine double staining. Serum deprivation also resulted in transient activation of the 20S proteasome, which is an important component for regulation of the cell cycle by the ubiquitin-proteasome system. The 20S proteasome inhibitor (PSI) but not NF-kappaB inhibitor SN50 suppressed the activation of proteasomes in serum-deprived cells. Although caspase inhibitors could not prevent the G0/G1 arrest in the serum-deprived cells, SN50 and the 20S proteasome inhibitor could block it. Since SN50, 20S proteasome inhibitor and caspase inhibitor could rescue cells from serum deprivation-induced apoptosis, the pathway for NF-kappaB/caspase activation is independent of the NF-kappaB/cell-cycle pathway, and the events downstream of the NF-kappaB/caspase-9 cascade lead to apoptosis. Taken together, our present results identify a novel role for NF-kappaB in cell-cycle and apoptosis regulation and underscore the significance of each independent signal cascade in serum-deprived osteoblastic cells.


Asunto(s)
Ciclo Celular , Medio de Cultivo Libre de Suero , FN-kappa B/metabolismo , Osteoblastos/metabolismo , Células 3T3 , Animales , Western Blotting , Caspasas/metabolismo , Activación Enzimática , Ensayo de Inmunoadsorción Enzimática , Ratones , FN-kappa B/antagonistas & inhibidores , Osteoblastos/citología
18.
J Dent Res ; 83(2): 166-9, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14742657

RESUMEN

UNLABELLED: The receptor activator for NF-kappaB ligand (RANKL) plays an important role in osteoclast formation. A recent study with animal models suggests the involvement of RANKL in the pathogenesis of this periodontal disease. However, no one has examined the level of RANKL in the body fluid of human subjects. This communication reports on the in vivo concentrations of RANKL and the RANKL decoy receptor osteoprotegerin (OPG) in the gingival crevicular fluid (GCF) of periodontal subjects with severe, moderate, and mild forms of the disease. An increased concentration of RANKL and a decreased concentration of OPG were detected in GCF from patients with periodontitis (*p < 0.05 vs. control subjects). The ratio of the concentration of RANKL to that of OPG in the GCF was significantly higher for periodontal disease patients than for healthy subjects (*p < 0.01). Taken together, these data suggest that RANKL and OPG contribute to osteoclastic bone destruction in periodontal disease. ABBREVIATIONS: GCF, gingival crevicular fluid; IL, interleukin; OPG, osteoprotegerin; RANKL, receptor activator for NF-kappaB ligand.


Asunto(s)
Proteínas Portadoras/análisis , Líquido del Surco Gingival/química , Glicoproteínas/análisis , Glicoproteínas de Membrana/análisis , FN-kappa B/análisis , Periodontitis/metabolismo , Receptores Citoplasmáticos y Nucleares/análisis , Receptores del Factor de Necrosis Tumoral/análisis , Factor de Necrosis Tumoral alfa/análisis , Adulto , Resorción Ósea/metabolismo , Hemorragia Gingival/clasificación , Hemorragia Gingival/metabolismo , Humanos , Ligandos , Persona de Mediana Edad , Osteoclastos/metabolismo , Osteoprotegerina , Pérdida de la Inserción Periodontal/clasificación , Pérdida de la Inserción Periodontal/metabolismo , Bolsa Periodontal/clasificación , Bolsa Periodontal/metabolismo , Periodontitis/clasificación , Ligando RANK , Receptor Activador del Factor Nuclear kappa-B
19.
Arthritis Rheum ; 44(5): 1003-12, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11352231

RESUMEN

OBJECTIVE: To elucidate the direct role of human T cells in the induction of osteoclastogenesis in rheumatoid arthritis (RA), by studying human monocytes and the pathogenetic roles of receptor activator of nuclear factor kappaB ligand (RANKL), RANK, and osteoprotegerin (OPG). METHODS: Synovial tissue obtained at total knee replacement was stained immunohistologically using anti-RANKL, CD3, and CD4 antibodies. Synovial fluid was obtained from patients with RA, osteoarthritis (OA), gout, or trauma. Concentrations of the soluble form of RANKL (sRANKL) and OPG in the synovial fluid were measured by enzyme-linked immunosorbent assay. Activated T cells from peripheral blood mononuclear cells (PBMC) of healthy volunteers were cultured with human monocytes from PBMC. RESULTS: Immunostaining of the synovial tissue of RA patients demonstrated that RANKL-positive cells were detected in a subset of fibroblast-like synoviocytes and infiltrating mononuclear cells. Double immunostaining revealed that RANKL-positive cells were detected in a subset of CD3+ cells and CD4+ cells. An increased concentration of sRANKL and a decreased concentration of OPG were detected in synovial fluid from RA patients. The ratio of the concentration of sRANKL to that of OPG was significantly higher in synovial fluid of RA patients than in synovial fluid of patients with OA or gout. The activated T cells expressing RANKL induced osteoclastogenesis from autologous peripheral monocytes. The role of RANKL in this osteoclastogenetic process was confirmed by dose-dependent inhibition by OPG. CONCLUSION: The present study is the first to demonstrate osteoclastogenesis using human-derived T cells and monocytes. In addition, the present findings suggest that excess production of RANKL by activated T cells increases the level of sRANKL in synovial fluid and may contribute to osteoclastic bone resorption in RA patients.


Asunto(s)
Artritis Reumatoide/inmunología , Artritis Reumatoide/patología , Linfocitos T CD4-Positivos/inmunología , Monocitos/inmunología , Osteoclastos/patología , Anticuerpos , Complejo CD3/análisis , Complejo CD3/inmunología , Antígenos CD4/análisis , Antígenos CD4/inmunología , Linfocitos T CD4-Positivos/citología , Proteínas Portadoras/análisis , Proteínas Portadoras/genética , Proteínas Portadoras/inmunología , Técnicas de Cocultivo , Ensayo de Inmunoadsorción Enzimática , Femenino , Expresión Génica/inmunología , Glicoproteínas/análisis , Glicoproteínas/inmunología , Gota/inmunología , Gota/patología , Humanos , Hibridación in Situ , Activación de Linfocitos/inmunología , Masculino , Glicoproteínas de Membrana/análisis , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/inmunología , Monocitos/citología , Osteoartritis/inmunología , Osteoartritis/patología , Osteoclastos/inmunología , Osteoprotegerina , Ligando RANK , ARN Mensajero/análisis , Receptor Activador del Factor Nuclear kappa-B , Receptores Citoplasmáticos y Nucleares/análisis , Receptores Citoplasmáticos y Nucleares/inmunología , Receptores del Factor de Necrosis Tumoral , Líquido Sinovial/química , Líquido Sinovial/inmunología
20.
J Med Entomol ; 38(2): 135-46, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11296814

RESUMEN

Introduction of potential disease vectors into a new geographic area poses health risks to local human, livestock, and wildlife populations. It is therefore important to gain understanding of the dynamics of these invasions, in particular its sources, modes of spread after the introduction, and vectorial potential. We studied the population genetics of Aedes (Finlaya) japonicus japonicus (Theobald), an Asian mosquito that was recognized for the first time in the United States in 1998. We examined patterns of genetic diversity using random amplified polymorphic DNA and sequences of ND4 of mtDNA by comparing samples from populations spanning the range of this mosquito in Japan (six samples) and the United States (nine samples) as well as specimens intercepted in New Zealand in 1999. We found geographically differentiated populations in Japan, indicating limited gene flow even on small spatial scales. In the United States, we found evidence of significant genetic differentiation between samples from New York, Connecticut, and New Jersey and those from mid-Pennsylvania and Maryland. We were unable to pinpoint the source location(s) in Japan, although some of the U.S. samples are genetically close to samples from south Honshu and western Kyushu. Further studies should include samples from Korean populations. Distinct genetic signatures in U.S. populations undergoing expansion suggest the possibility of local increases in genetic diversity if and where they meet.


Asunto(s)
Aedes/genética , Variación Genética , Aedes/clasificación , Animales , ADN Mitocondrial/análisis , Técnica del ADN Polimorfo Amplificado Aleatorio , Estados Unidos
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