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1.
Nat Commun ; 12(1): 381, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33452257

RESUMO

The interplay among magnetism, electronic nematicity, and superconductivity is the key issue in strongly correlated materials including iron-based, cuprate, and heavy-fermion superconductors. Magnetic fluctuations have been widely discussed as a pairing mechanism of unconventional superconductivity, but recent theory predicts that quantum fluctuations of nematic order may also promote high-temperature superconductivity. This has been studied in FeSe1-xSx superconductors exhibiting nonmagnetic nematic and pressure-induced antiferromagnetic orders, but its abrupt suppression of superconductivity at the nematic end point leaves the nematic-fluctuation driven superconductivity unconfirmed. Here we report on systematic studies of high-pressure phase diagrams up to 8 GPa in high-quality single crystals of FeSe1-xTex. When Te composition x(Te) becomes larger than 0.1, the high-pressure magnetic order disappears, whereas the pressure-induced superconducting dome near the nematic end point is continuously found up to x(Te) ≈ 0.5. In contrast to FeSe1-xSx, enhanced superconductivity in FeSe1-xTex does not correlate with magnetism but with the suppression of nematicity, highlighting the paramount role of nonmagnetic nematic fluctuations for high-temperature superconductivity in this system.

3.
Transplant Proc ; 50(8): 2431-2435, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30316372

RESUMO

BACKGROUND: The frequency of renal transplants from elderly living donors has increased because of a shortage of donors. However, the results of renal transplantation using aged kidney grafts have yet to be determined conclusively. METHODS: We evaluated 45 patients who underwent living donor kidney transplantation at our institution. The patients were categorized according to donor age at the time of the transplant: ≥ 60 years (elderly donor group, n = 21) and <60 years (young donor group, n = 24). We reviewed the renal function of the recipients and pathologic findings of the graft including interstitial fibrosis score, tubular atrophy score, tubular atrophy and interstitial fibrosis grades, and arteriosclerosis up to 2 years posttransplantation. RESULTS: Significant differences were observed in the preoperative creatinine clearance of the donor, prevalence of hypertension in the donor, and age of the recipient. Serum creatinine levels in the elderly donor group were significantly higher from 2 months to 1 year posttransplantation, and the estimated glomerular filtration rate was significantly lower from 7 days to 1 year posttransplantation. However, the decline in estimated glomerular filtration rate from 14 days to up to 2 years posttransplantation was similar in the 2 groups. There was no significant difference in the renal biopsy findings between the 2 groups except for arteriosclerosis 1 year posttransplantation. CONCLUSION: Kidney grafts from elderly living donors were not associated with a deterioration in renal function, and their pathologic findings were comparable with those of young donors for up to 2 years posttransplantation.


Assuntos
Transplante de Rim/métodos , Rim/patologia , Doadores Vivos , Transplantes/patologia , Adulto , Fatores Etários , Idoso , Feminino , Sobrevivência de Enxerto , Humanos , Doadores Vivos/provisão & distribuição , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
4.
Transplant Proc ; 50(8): 2521-2525, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30316390

RESUMO

BACKGROUND: Kidney transplantation is performed as a useful treatment to improve the quality of life (QOL) of patients with end-stage renal failure; however, the correlation between mood status and QOL among recipients post-kidney transplantation have yet to be clarified. METHODS: Sixty-eight post-kidney transplantation patients who visited our institution between March and December 2016 were enrolled in this study. The QOL of the participants as measured by the Short Form-36 Health Survey Version 2 (SF-36v2) questionnaire was compared to results gathered from hemodialysis patients in a previous study. To identify the factors associated with QOL, a multiple regression analysis was performed, including some physical, mental, and socioeconomic characteristics as well as the Profile of Mood States as independent variables. RESULTS: The QOL of the transplantation group was significantly higher for all 8 subscales of SF-36v2 compared to the hemodialysis group. Among the factors, greater age and higher Confusion levels were related to lower physical QOL. In addition, higher Vigor and lower Fatigue levels were related to higher mental QOL, while the condition of having an occupation was related to higher role/social QOL. CONCLUSION: The QOL of recipients after kidney transplantation was better than that of hemodialysis patients. It is important to pay attention to mood status, especially confusion and fatigue, in order to maintain and improve the QOL of the recipient after kidney transplantation. Kidney transplantation can be a beneficial treatment not only physically but also psychologically and socially.


Assuntos
Transplante de Rim/psicologia , Qualidade de Vida , Transplantados/psicologia , Adulto , Fadiga , Feminino , Humanos , Falência Renal Crônica/psicologia , Masculino , Pessoa de Meia-Idade , Diálise Renal , Inquéritos e Questionários
5.
Nat Commun ; 8(1): 1143, 2017 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-29070845

RESUMO

A fundamental issue concerning iron-based superconductivity is the roles of electronic nematicity and magnetism in realising high transition temperature (T c). To address this issue, FeSe is a key material, as it exhibits a unique pressure phase diagram involving non-magnetic nematic and pressure-induced antiferromagnetic ordered phases. However, as these two phases in FeSe have considerable overlap, how each order affects superconductivity remains perplexing. Here we construct the three-dimensional electronic phase diagram, temperature (T) against pressure (P) and isovalent S-substitution (x), for FeSe1-x S x . By simultaneously tuning chemical and physical pressures, against which the chalcogen height shows a contrasting variation, we achieve a complete separation of nematic and antiferromagnetic phases. In between, an extended non-magnetic tetragonal phase emerges, where T c shows a striking enhancement. The completed phase diagram uncovers that high-T c superconductivity lies near both ends of the dome-shaped antiferromagnetic phase, whereas T c remains low near the nematic critical point.

6.
Transplant Proc ; 48(4): 1018-21, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27320546

RESUMO

BACKGROUND: Past studies have indicated that psychological problems in both transplant recipients and donors increase during the pre-operative period. However, few studies have evaluated the pre-operative psychological status of both the recipient and the donor. METHODS: This study included the donors and recipients of 36 adult living donor kidney transplants (LDKT) and 12 adult living donor liver transplants (LDLT) between January 2012 and December 2014. Their personalities were assessed using the Tokyo University Egogram (TEG) and the Yatabe-Guilford Personality Inventory (Y-G), while their mood states just before transplantation were evaluated via the Profile of Mood States (POMS). RESULTS: On the TEG, the mean Adapted Child (AC) score of the LDLT recipient group was significantly lower than that of the LDKT recipient group. On the Y-G, no differences in the distribution of the five personality types were recognized among the four groups. POMS depression scores in the LDLT recipient group were significantly higher compared with the other groups. CONCLUSION: LDLT recipients exhibited a depressive mood just before transplantation, and also had a low AC score. Therefore, clinicians should pay careful attention to potential medical non-adherence and post-operative depression in LDLT recipients. Based on these pre-operative assessments of personality and mood states, the transplant team should include post-operative care to support the quality of life of the recipients as well as the donors.


Assuntos
Depressão/psicologia , Transplante de Rim/métodos , Transplante de Fígado/métodos , Doadores Vivos/psicologia , Transtornos do Humor/psicologia , Adulto , Feminino , Humanos , Transplante de Rim/psicologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/psicologia , Cuidados Pré-Operatórios/métodos , Qualidade de Vida , Transplantados/psicologia , Adulto Jovem
8.
Cell Death Dis ; 5: e1148, 2014 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-24675466

RESUMO

Familial neurohypophysial diabetes insipidus (FNDI) characterized by progressive polyuria is mostly caused by mutations in the gene encoding neurophysin II (NPII), which is the carrier protein of the antidiuretic hormone, arginine vasopressin (AVP). Although accumulation of mutant NPII in the endoplasmic reticulum (ER) could be toxic for AVP neurons, the precise mechanisms of cell death of AVP neurons, reported in autopsy studies, remain unclear. Here, we subjected FNDI model mice to intermittent water deprivation (WD) in order to promote the phenotypes. Electron microscopic analyses demonstrated that, while aggregates are confined to a certain compartment of the ER in the AVP neurons of FNDI mice with water access ad libitum, they were scattered throughout the dilated ER lumen in the FNDI mice subjected to WD for 4 weeks. It is also demonstrated that phagophores, the autophagosome precursors, emerged in the vicinity of aggregates and engulfed the ER containing scattered aggregates. Immunohistochemical analyses revealed that expression of p62, an adapter protein between ubiquitin and autophagosome, was elicited on autophagosomal membranes in the AVP neurons, suggesting selective autophagy induction at this time point. Treatment of hypothalamic explants of green fluorescent protein (GFP)-microtubule-associated protein 1 light chain 3 (LC3) transgenic mice with an ER stressor thapsigargin increased the number of GFP-LC3 puncta, suggesting that ER stress could induce autophagosome formation in the hypothalamus of wild-type mice as well. The cytoplasm of AVP neurons in FNDI mice was occupied with vacuoles in the mice subjected to WD for 12 weeks, when 30-40% of AVP neurons are lost. Our data thus demonstrated that autophagy was induced in the AVP neurons subjected to ER stress in FNDI mice. Although autophagy should primarily be protective for neurons, it is suggested that the organelles including ER were lost over time through autophagy, leading to autophagy-associated cell death of AVP neurons.


Assuntos
Arginina Vasopressina/metabolismo , Autofagia , Diabetes Insípido Neurogênico/metabolismo , Diabetes Insípido Neurogênico/patologia , Neurônios/metabolismo , Neurônios/patologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Modelos Animais de Doenças , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/ultraestrutura , Estresse do Retículo Endoplasmático , Proteínas de Choque Térmico/metabolismo , Hipotálamo/metabolismo , Hipotálamo/patologia , Corpos de Inclusão/metabolismo , Corpos de Inclusão/ultraestrutura , Camundongos , Modelos Biológicos , Neurônios/ultraestrutura , Fagossomos/metabolismo , Fagossomos/ultraestrutura , Fenótipo , Agregados Proteicos , Proteína Sequestossoma-1 , Proteínas Ubiquitinadas/metabolismo , Privação de Água
9.
Transplant Proc ; 46(2): 552-5, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24656010

RESUMO

BACKGROUND: Monitoring cell-mediated immunity (CMI) can be used to estimate the risk of viral infections in kidney transplant recipients. The Immuknow (IMK) assay measures CD4(+) T-cell adenosine triphosphate activity, assesses patient CMI status, and assists clinicians in determining the risk of viral infection. METHODS: We retrospectively analyzed 224 IMK values in 39 kidney transplant recipients at our institution from April 2012 to January 2013. We analyzed the relationship between IMK value and viral infection during the early and late post-transplantation periods. Multiple regression analyses were performed, to determine which factors impacted the results of the IMK assay. RESULTS: Eight patients developed viral infections, including BK virus, cytomegalovirus, herpes simplex, and shingles. Five infections occurred in the early post-transplantation period (<50 d) and 3 in the late period (>120 d). The IMK levels in patients who developed an infection in the early period were within normal limits; however, those in the late period were significantly lower than 200 ng/mL (421.0 ± 062.6 for early vs 153.7 ± 72.7 for late; P = .02). Our multiple regression analyses indicated that peripheral white blood cell and neutrophil counts affected IMK values (P = .03 and P = .02, respectively). CONCLUSIONS: The IMK assay is a useful test for identifying patients at risk for post-transplantation viral infections in the late transplant period.


Assuntos
Imunidade Celular , Transplante de Rim , Viroses/complicações , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Viroses/imunologia , Adulto Jovem
10.
Neuroscience ; 247: 201-12, 2013 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-23707800

RESUMO

Central neuropathic pain (CNP) in the spinal cord, such as chronic pain after spinal cord injury (SCI), is an incurable ailment. However, little is known about the spinal cord mechanisms underlying CNP. Recently, reactive oxygen species (ROS) have been recognized to play an important role in CNP of the spinal cord. However, it is unclear how ROS affect synaptic transmission in the dorsal horn of the spinal cord. To clarify how ROS impact on synaptic transmission, we investigated the effects of ROS on synaptic transmission in rat spinal cord substantia gelatinosa (SG) neurons using whole-cell patch-clamp recordings. Administration of tert-butyl hydroperoxide (t-BOOH), an ROS donor, into the spinal cord markedly increased the frequency and amplitude of spontaneous excitatory postsynaptic currents (sEPSCs) in SG neurons. This t-BOOH-induced enhancement was not suppressed by the Na(+) channel blocker tetrodotoxin. However, in the presence of a non-N-methyl-D-aspartate glutamate receptor antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione, t-BOOH did not generate any sEPSCs. Furthermore, in the presence of a transient receptor potential ankyrin 1 (TRPA1) channel antagonist (HC-030031) or a transient receptor potential vanilloid 1 (TRPV1) channel antagonist (capsazepine or AMG9810), the t-BOOH-induced increase in the frequency of sEPSCs was inhibited. These results indicate that ROS enhance the spontaneous release of glutamate from presynaptic terminals onto SG neurons through TRPA1 and TRPV1 channel activation. Excessive activation of these ion channels by ROS may induce central sensitization in the spinal cord and result in chronic pain such as that following SCI.


Assuntos
Potenciais Pós-Sinápticos Excitadores/fisiologia , Células do Corno Posterior/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transmissão Sináptica/fisiologia , Canais de Cátion TRPC/metabolismo , Canais de Cátion TRPV/metabolismo , Animais , Masculino , Técnicas de Cultura de Órgãos , Ratos , Ratos Sprague-Dawley , Canal de Cátion TRPA1
11.
Andrology ; 1(3): 505-11, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23444052

RESUMO

Great advances in tissue androgen analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) have made it possible to evaluate the tissue androgen content from a single needle prostate biopsy specimen. In this study, we investigated if pre-treatment androgen content in prostate biopsy specimens could predict their response to primary androgen deprivation therapy (ADT) and future castration-resistant prostate cancer (CRPC). One-hundred and sixty-five prostate cancer patients who received primary ADT were enrolled. They had received multiple core prostate needle biopsy at diagnosis, and an additional one needle biopsy specimen was obtained for tissue androgen determination using LC-MS/MS. The patients' prostate specific antigen (PSA) values were periodically followed during the treatment and patients were determined to have CRPC when their PSA value increased continuously to 25% above the nadir and a 2.0 ng/mL increase. A significant correlation was found between PSA value decline velocity (PSA half-time) after ADT and pre-ADT tissue androgen content. Twenty-three patients were determined to have CRPC. These CRPC patients had a significantly high concentration of tissue T (p < 0.01) and low concentration of tissue 5α-dihydrotestosterone (DHT) (p < 0.01), resulting in a higher tissue T/DHT ratio (p < 0.001). A multivariate Cox proportional hazard model revealed the pre-ADT tissue T/DHT ratio and Gleason score as independent predictors for CRPC development. By using the two statistically significant variables, the relative risk of CRPC development could be calculated. The results of this study suggest that the evaluation of prostate androgen content in a single needle biopsy specimen may be useful to predict future CRPC development after primary ADT. Further studies are required for the clinical application of T/DHT ratio evaluation.


Assuntos
Antagonistas de Androgênios/uso terapêutico , Androgênios/metabolismo , Orquiectomia , Próstata/metabolismo , Neoplasias da Próstata/etiologia , Idoso , Humanos , Masculino
12.
Exp Clin Endocrinol Diabetes ; 120(3): 139-44, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22068616

RESUMO

BACKGROUND: Angiopoietin-like protein 4 (Angptl4) is thought to cause an increase in serum triglyceride levels. In the present study, we elucidated Angptl4 expression in the mouse models of type 1 and type 2 diabetes mellitus, and investigated the possible mechanisms involved. METHODS: Type 1 diabetes was induced in C57BL/6 J mice by treating them with streptozotocin (STZ). Type 2 diabetes was induced by feeding the mice a high-fat diet (HFD) for 18 weeks. RESULTS: The levels of Angptl4 mRNA expression in liver, white adipose tissue (WAT), and brown adipose tissue (BAT) were found to increase in the STZ diabetic mice relative to control mice. This effect was attenuated by insulin administration. In the HFD diabetic mice, the Angptl4 mRNA expression levels were increased in liver, WAT, and BAT. Treatment with metformin for 4 weeks attenuated the increased levels of Angptl4 mRNA. Fatty acids (FAs) such as palmitate and linoleate induced Angptl4 mRNA expression in H4IIE hepatoma cells and 3T3-L1 adipocytes. Treatment with insulin but not metformin attenuated FA-induced Angptl4 mRNA expression in H4IIE. Both insulin and metformin did not influence the effect of FAs in 3T3-L1 cells. CONCLUSION: These observations demonstrated that Angptl4 mRNA expression was increased through the elevated free FAs in diabetic mice.


Assuntos
Angiopoietinas/genética , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Ácidos Graxos não Esterificados/metabolismo , Insulina/metabolismo , Células 3T3-L1 , Proteína 4 Semelhante a Angiopoietina , Angiopoietinas/metabolismo , Animais , Linhagem Celular Tumoral , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/etiologia , Dieta Hiperlipídica , Regulação para Baixo/efeitos dos fármacos , Ácidos Graxos não Esterificados/sangue , Ácidos Graxos não Esterificados/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Hipoglicemiantes/farmacologia , Insulina/farmacologia , Masculino , Metformina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Estreptozocina , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética
14.
Diabetologia ; 52(5): 962-71, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19283362

RESUMO

AIMS/HYPOTHESIS: Maternal diabetes during pregnancy increases the risk of congenital malformations such as neural tube defects (NTDs). Although the mechanism of this effect is uncertain, it is known that levels of nitric oxide synthase (NOS) and nitric oxide are elevated in embryos of a mouse model of diabetes. We postulated that overproduction of nitric oxide causes diabetes-induced congenital malformations and that inhibition of inducible NOS (iNOS) might prevent diabetic embryopathy. METHODS: Mice were rendered hyperglycaemic by intraperitoneal injection of streptozotocin. The incidence of congenital malformations including NTDs was evaluated on gestational day 18.5. We assessed the involvement of iNOS in diabetes-induced malformation by administering ONO-1714, a specific inhibitor of iNOS, to pregnant mice with streptozotocin-induced diabetic mice and by screening mice with iNOS deficiency due to genetic knockout (iNos(-/-)). RESULTS: ONO-1714 markedly reduced the incidence of congenital anomalies, including NTDs, in fetuses of a mouse model of diabetes. It also prevented apoptosis in the head region of fetuses, indicating that iNOS is involved in diabetes-related congenital malformations. Indeed, no NTDs were observed in fetuses of diabetic iNos(-/-) mice and the incidence of other malformations was also markedly reduced. CONCLUSIONS/INTERPRETATION: We conclude that increased iNOS activity during organogenesis plays a crucial role in the pathogenesis of diabetes-induced malformations and suggest that inhibitors of iNOS might help prevent malformations, especially NTDs, in diabetic pregnancy.


Assuntos
Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/enzimologia , Defeitos do Tubo Neural/prevenção & controle , Óxido Nítrico Sintase Tipo II/deficiência , Amidinas/uso terapêutico , Animais , Peso Corporal , Cruzamentos Genéticos , Modelos Animais de Doenças , Feminino , Reabsorção do Feto , Feto , Compostos Heterocíclicos com 2 Anéis/uso terapêutico , Tamanho da Ninhada de Vivíparos , Camundongos , Camundongos Endogâmicos ICR , Camundongos Knockout , NG-Nitroarginina Metil Éster/farmacologia , Defeitos do Tubo Neural/etiologia , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/genética , Gravidez
15.
Diabetes Metab Res Rev ; 25(3): 287-94, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19242917

RESUMO

BACKGROUND: The mechanism of diabetes-induced congenital malformation remains to be elucidated. It has been reported that alpha-lipoic acid (LA) prevents neural tube defects (NTDs) in offsprings of rats with streptozotocin-induced diabetes. Here, we evaluate the protective effect of LA against diabetic embryopathy, including NTDs, cardiovascular malformations (CVMs), and skeletal malformations, in mice. METHODS: Female mice were rendered hyperglycemic using streptozotocin and then mated with normal male mouse. Pregnant diabetic or non-diabetic mice were treated daily with either LA (100 mg/kg body weight) or saline between gestational days 0 and 18. On day 18, fetuses were examined for congenital malformations. RESULTS: Plasma glucose levels on day 18 were not affected by LA treatment. No congenital malformations were observed either in the saline-treated or LA-treated non-diabetic group. In the saline-treated diabetic group, 39% of fetuses had external malformations and 30% had NTDs. In the LA-treated diabetic group, the corresponding proportions were 11 and 8%, respectively. LA treatment also decreased the incidence of CVMs from 30-3% and of skeletal malformations from 29-6%. CONCLUSIONS: We conclude that LA can reduce NTDs, CVMs and skeletal malformations in the offspring of diabetic mice at term delivery.


Assuntos
Anormalidades Congênitas/prevenção & controle , Defeitos do Tubo Neural/prevenção & controle , Gravidez em Diabéticas , Ácido Tióctico/farmacologia , Animais , Glicemia/metabolismo , Anormalidades Cardiovasculares/prevenção & controle , Diabetes Mellitus Experimental/sangue , Feminino , Reabsorção do Feto , Glutationa/metabolismo , Tamanho da Ninhada de Vivíparos/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Gravidez , Gravidez em Diabéticas/sangue
16.
Regul Toxicol Pharmacol ; 50(2): 226-38, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18082299

RESUMO

The safety of l-alanyl-l-glutamine (l-AG) derived by fermentation using a recombinant Escherichia coli strain containing the l-amino acid alpha-ligase gene from Bacillus subtilis, was assessed in acute and subchronic toxicity studies in the rat. l-AG was tested in vitro in a bacterial reverse mutation assay and in a chromosome aberration assay. l-AG was not acutely toxic when administered to Sprague-Dawley rats by gavage at 2000mg/kg bw. In a 14-day range-finding study, l-AG at up to 5% in the diet was without effect. In the 13-week dietary study, there were no toxicologically significant differences between the treated groups (1.0, 3.0 and 5.0% l-AG) and the controls (0% and 5% l-AG produced via a different method) with respect to body weight gain, feed consumption, feed efficiency, or the results of ophthalmological, haematological, clinical chemistry, and urinalysis evaluations. Three of 10 high-dose males had mild testicular changes, however, these were of exactly the same nature and severity as those that occur spontaneously, and were considered unlikely to be treatment-related. The NOAEL in both males and females was established as the highest dose tested at 3129 and 3601mg/kg bw/day, respectively (5.0% in the diet). There was no evidence of genotoxicity of l-AG in the Ames assay or in the in vitro CHL cell chromosome aberration study.


Assuntos
Dipeptídeos/toxicidade , Alimentos/toxicidade , Animais , Análise Química do Sangue , Linhagem Celular , Aberrações Cromossômicas/efeitos dos fármacos , Cricetinae , Cricetulus , Dipeptídeos/análise , Dipeptídeos/sangue , Relação Dose-Resposta a Droga , Feminino , Fígado/efeitos dos fármacos , Fígado/metabolismo , Pulmão/citologia , Masculino , Testes de Mutagenicidade , Tamanho do Órgão/efeitos dos fármacos , Gravidez , Ratos , Ratos Sprague-Dawley , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Caracteres Sexuais , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo
17.
J Neuroendocrinol ; 20(2): 227-32, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18088359

RESUMO

Previous studies have shown that the secretion of oxytocin and vasopressin from the posterior pituitary always accompanies systemic hyperosmotic stimuli in rats, and that oxytocin and vasopressin mRNAs consistently increase in response to prolonged hyperosmotic stimuli. Hence, it has been widely interpreted that oxytocin and vasopressin secretion and gene expression are closely coupled. In the present study, we used both vasopressin and oxytocin intron- specific probes to measure vasopressin and oxytocin heteronuclear RNA (hnRNA) levels, respectively, by in situ hybridisation in the rat supraoptic nucleus (SON) in conjunction with radioimmunoassays of vasopressin and oxytocin peptide levels in plasma and in the posterior pituitary in normally hydrated rats and after 1-5 days of salt loading. Increased oxytocin secretion in response to hyperosmotic stimuli exceeded vasopressin secretion at every time point studied. Vasopressin hnRNA in the SON increased to near maximal levels within minutes after the hyperosmotic stimulus, and was maintained throughout all 5 days of salt loading. By contrast, oxytocin hnRNA did not significantly change from control levels until approximately 2 days after hyperosmotic stimulation, and was not maximal until 3 days. In summary, increases in oxytocin gene transcription in response to osmotic stimuli are dramatically delayed compared to increases in vasopressin gene transcription under the same conditions. These data indicate that oxytocin gene transcription is not as closely correlated with pituitary peptide secretion as is vasopressin gene transcription, and suggests that there is a fundamental difference in excitation-secretion-transcription coupling mechanisms that regulate these two closely related genes in the rat magnocellular neurones in the SON.


Assuntos
Ocitocina/genética , RNA Nuclear Heterogêneo/metabolismo , Cloreto de Sódio/administração & dosagem , Núcleo Supraóptico/efeitos dos fármacos , Núcleo Supraóptico/metabolismo , Vasopressinas/genética , Animais , Sangue , Esquema de Medicação , Expressão Gênica/efeitos dos fármacos , Hibridização In Situ , Cinética , Masculino , Concentração Osmolar , Neuro-Hipófise/efeitos dos fármacos , Neuro-Hipófise/metabolismo , Radioimunoensaio , Ratos , Ratos Sprague-Dawley , Cloreto de Sódio/farmacologia , Fatores de Tempo
18.
Protoplasma ; 231(3-4): 245-8, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17922267

RESUMO

The distribution and ultrastructural features of idioblasts containing calcium oxalate crystals were studied in leaf tissues of mulberry, Morus alba L. In addition to the calcium carbonate crystals formed in epidermal idioblasts, large calcium oxalate crystals were deposited in cells adjacent to the veins and surrounded by a cell wall sheath which had immunoreactivity with an antibody recognizing a xyloglucan epitope. The wall sheath formation indicates exclusion of the mature crystal from the protoplast.


Assuntos
Oxalato de Cálcio , Parede Celular/ultraestrutura , Morus/ultraestrutura , Folhas de Planta/ultraestrutura , Estruturas Vegetais/ultraestrutura , Microscopia Eletrônica de Varredura , Microscopia Imunoeletrônica , Morus/química , Morus/citologia , Folhas de Planta/citologia , Estruturas Vegetais/citologia
19.
Protoplasma ; 228(4): 201-8, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16983487

RESUMO

Although calcium carbonate is known to be a common biomineral in plants, very little attention has been given to the biological control of calcium carbonate deposition. In mulberry leaves, a subcellular structure is involved in mineral deposition and is described here by a variety of cytological techniques. Calcium carbonate was deposited in large, rounded idioblast cells located in the upper epidermal layer of mulberry leaves. Next to the outmost region ("cap") of young idioblasts, we found that the inner cell wall layer expanded to form a peculiar outgrowth, named cell wall sac in this report. This sac grew and eventually occupied the entire apoplastic space of the idioblast. Inside the mature cell wall sac, various cellulosic membranes developed and became the major site of Ca carbonate deposition. Concentrated Ca2+ was pooled in the peripheral zone, where small Ca carbonate globules were present in large numbers. Large globules were tightly packed among multiple membranes in the central zone, especially in compartments formed by cellulosic membranes and in their neighboring membranes. The maximum Ca sink capacity of a single cell wall sac was quantified using enzymatically isolated idioblasts as approximately 48 ng. The newly formed outgrowth in idioblasts is not a pure calcareous body but a complex cell wall structure filled with substantial amounts of Ca carbonate crystals.


Assuntos
Carbonato de Cálcio/metabolismo , Parede Celular/metabolismo , Morus/metabolismo , Cálcio/metabolismo , Parede Celular/ultraestrutura , Microscopia Eletrônica/métodos , Modelos Biológicos , Morus/citologia , Morus/ultraestrutura , Estruturas Vegetais/citologia , Estruturas Vegetais/metabolismo , Estruturas Vegetais/ultraestrutura
20.
Water Sci Technol ; 53(11): 213-9, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16862792

RESUMO

Using a larval medaka (Oryzias latipes) acute toxicity assay combined with solid-phase extraction, we proposed a method for efficiently determining the fish toxicity of organic contaminants in river water. Organic toxicants were 10, 20, 50 and 100-fold concentrated from 4 L of the sample with adsorption cartridges. The lethal effect was observed by exposing every ten individuals of 48-72 h old larval medaka to 20 mL of each solution for 48h. The median lethal concentration rate (LCR50) was used as an indicator for the toxicity. With the developed toxicity test method, more than seven times difference was found in the LCR50 of the river water samples. LCR50 distribution profiles were compared with 125 samples in two typical rivers. The result revealed a lower toxicity level in the mainstream than in the confluences, and a lower toxicity level in Sagami River than in Ayase River. LCR50 proved unique as a toxicity indicator, which was impossible to speculate from the conventional water quality indicator of the dissolved organic carbon concentration. As an effective screening test for priority settings, the method can help us with an efficient planning for the environmental investigation and management.


Assuntos
Poluentes Químicos da Água/toxicidade , Animais , Bioensaio , Relação Dose-Resposta a Droga , Embrião não Mamífero/efeitos dos fármacos , Monitoramento Ambiental/métodos , Resíduos Industriais , Oryzias/embriologia , Rios , Fatores de Tempo , Testes de Toxicidade , Eliminação de Resíduos Líquidos/métodos
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