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1.
Nat Commun ; 15(1): 610, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38326315

RESUMO

Although the lithic cutting-edge productivity has long been recognized as a quantifiable aspect of prehistoric human technological evolution, there remains uncertainty how the productivity changed during the Middle-to-Upper Paleolithic transition. Here we present the cutting-edge productivity of eight lithic assemblages in the eastern Mediterranean region that represent a chrono-cultural sequence including the Late Middle Paleolithic, Initial Upper Paleolithic, the Early Upper Paleolithic, and the Epipaleolithic. The results show that a major increase in the cutting-edge productivity does not coincide with the conventional Middle-Upper Paleolithic boundary characterized by the increase in blades in the Initial Upper Paleolithic, but it occurs later in association with the development of bladelet technology in the Early Upper Paleolithic. Given increasing discussions on the complexity of Middle-Upper Paleolithic cultural changes, it may be fruitful to have a long-term perspective and employ consistent criteria for diachronic comparisons to make objective assessment of how cultural changes proceeded across conventional chrono-cultural boundaries.

2.
Innovation (Camb) ; 5(1): 100550, 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38204586

RESUMO

The remote forcing from land surface changes in the Sahara is hypothesized to play a pivotal role in modulating the intensity of the East Asian summer monsoon (EASM) through ocean-atmospheric teleconnections. This modulation has far-reaching consequences, particularly in facilitating societal shifts documented in northern China. Here, we present a well-dated lake-level record from the Daihai Lake Basin in northern China, providing quantitative assessments of Holocene monsoonal precipitation and the consequent migrations of the northern boundary of the EASM. Our reconstruction, informed by a water-and-energy balance model, indicates that annual precipitation reached ∼700 mm during 8-5 ka, followed by a rapid decline to ∼550 mm between 5 and 4 ka. This shift coherently aligns with a significant ∼300 km northwestward movement of the EASM northern boundary during the Middle Holocene (MH), in contrast to its current position. Our findings underscore that these changes cannot be entirely attributed to orbital forcing, as corroborated by simulation tests. Climate model simulations deployed in our study suggest that the presence of the Green Sahara during the MH significantly strengthened the EASM and led to a northward shift of the monsoon rainfall belt. Conversely, the Sahara's reversion to a desert landscape in the late Holocene was accompanied by a corresponding southward retraction of monsoon influence. These dramatic hydroclimate changes during ∼5-4 ka likely triggered or at least contributed to a shift in Neolithic cultures and societal transformation in northern China. With decreasing agricultural productivity, communities transitioned from millet farming to a mixed rainfed agriculture and animal husbandry system. Thus, our findings elucidate not only the variability of the EASM but also the profound implications of a remote forcing, such as surface transformations of the Sahara, on climatic changes and cultural evolution in northern China.

3.
Sci Rep ; 13(1): 3064, 2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36810487

RESUMO

Scour ponds from unusually large tsunamis cut across the crest of a beach ridge in Kiritappu marsh, eastern Hokkaido. No fewer than ten of these ponds were imaged by photogrammetry as elongate topographic depressions as large as 5 m by 30 m. Sediments in these ponds are underlain by unconformities that were detected with ground-penetrating radar and observed directly in cores and a slice sample. Sediment deposits in the ponds contain peat and volcanic ash layers, the ages of which suggest that the scouring occurred during tsunamis generated by spatially extensive thrust ruptures along the southern Kuril trench, most recently during the early seventeenth century and its predecessor during the thirteenth-fourteenth century. Some of the ponds appear to have been formed during one tsunami and refreshed during later successors. This evidence of recurrent erosion suggests that the shoreline may retreat as part of earthquake-related cycles of coastal uplift and subsidence.

4.
Sci Rep ; 11(1): 11040, 2021 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-34040036

RESUMO

The Ba Lai distributary channel of the Mekong River Delta was abandoned and infilled with sediment during the Late Holocene, providing a unique opportunity to investigate the sediment fill, timing and mechanisms of channel abandonment in tide-dominated deltaic systems. Based on analysis and age dating of four sediment cores, we show that the channel was active since 2.6 ka and was abandoned at 0.7 ka as marked by the abrupt disappearance of the sand fraction and increase in organic matter and sediment accumulation rate. We estimate that the channel might have been filled in a time range of 45-263 years after detachment from the deltaic network, with sediment accumulation rates of centimetres to decimetres per year, rapidly storing approximately 600 Mt of organic-rich mud. We suggest that the channel was abandoned due to a sediment buildup favoured by an increase in regional sediment supply to the delta. This study highlights that mechanisms for abandonment and infilling of tide-dominated deltaic channels do not entirely fit widely used models developed for fluvial-dominated environments. Their abandonment might be driven by autogenic factors related to the river-tidal and deltaic dynamics and favoured by allogenic factors (e.g., human impact and/or climate change).

5.
Sci Rep ; 10(1): 8085, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32415150

RESUMO

Since the 1990s the Mekong River delta has suffered a large decline in sediment supply causing coastal erosion, following catchment disturbance through hydropower dam construction and sand extraction. However, our new geological reconstruction of 2500-years of delta shoreline changes show that serious coastal erosion actually started much earlier. Data shows the sandy coast bounding river mouths accreted consistently at a rate of +2 to +4 km2/year. In contrast, we identified a variable accretion rate of the muddy deltaic protrusion at Camau; it was < +1 km2/year before 1400 years ago but increased drastically around 600 years ago, forming the entire Camau Peninsula. This high level of mud supply had sharply declined by the early 20th century after a vast canal network was built on the delta. Since then the Peninsula has been eroding, promoted by the conjunction of mud sequestration in the delta plain driven by expansion of rice cultivation, and hysteresis of long-term muddy sedimentation that left the protrusion exposed to wave erosion. Natural mitigation would require substantial increases in sediment supply well above the pre-1990s levels.

6.
J Hum Evol ; 135: 102646, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31450172

RESUMO

The Initial Upper Paleolithic (IUP) temporally overlaps with the range expansion of Homo sapiens populations in various parts of Eurasia and is often considered a key archaeological phase for investigating behavioral changes from the Middle Paleolithic. This paper reports upon new data from IUP occupations at Wadi Aghar, a rock shelter site in the southern Levant. In combining the results of radiometric dates and lithic analyses, we clarify the chronological and cultural position of Wadi Aghar assemblages in the Levantine IUP. As for the records about mobility, on-site activities, and resource procurement behaviors, we present analyses of lithic use-wear, tool-type composition, soil micromorphology, and marine shells. The lithic analyses and the optically stimulated luminescence (and subsidiary radiocarbon) dating of the Wadi Aghar materials suggest their chronocultural position in the IUP (45-40 ka for Layers C-D1; 39-36 ka for Layer B; possibly 50 ka for Layer D2), providing the southernmost location for the IUP in Eurasia. In the Levant, Wadi Aghar represents one of the few IUP sites in the inland areas. The results also indicate that the timing and technological sequences from the IUP to the following bladelet industries differed between the inland and coastal zones, likely reflecting geographically variable adaptive behaviors and/or cultural transmissions. One of the behavioral characteristics of IUP foragers at Wadi Aghar is the procurement of remote resources, represented by the transportation of marine shells from the Red Sea: Canarium fusiforme and Canarium cf. mutabile. Whether it was a direct procurement with increased mobility or a result of intergroup exchanges, it was not part of behavioral repertoires during the late MP in the same area. This can be understood as the expansion of resource procurement range, functioning as additional buffers from risk in the semiarid environments in the inland Levant.


Assuntos
Fósseis , Tecnologia , Exoesqueleto , Animais , Arqueologia , Humanos , Jordânia
7.
J Med Virol ; 90(12): 1834-1840, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30016555

RESUMO

BACKGROUND: Sustained virological response (SVR) rates for the treatment of chronic hepatitis C virus (HCV)-infected patients have drastically improved with the use of direct-acting antiviral (DAA) therapies; however, a small minority of patients still fails to eradicate the virus. We analyzed factors associated with SVR in DAA therapy and the effect of age and liver fibrosis on treatment response. METHODS: Nine hundred and eighteen patients with chronic HCV infection were treated with 24 weeks of daclatasvir plus asunaprevir (DCV + ASV) or 12 weeks of sofosbuvir plus ledipasvir (SOF + LDV), ombitasvir, paritaprevir plus ritonavir (OMB + PTV + r) or sofosbuvir plus ribavirin (SOF + RBV). Multivariate logistic regression analysis was used to identify factors associated with SVR. The effect of age and liver fibrosis on SVR was analyzed. RESULTS: The overall SVR rate was 95.4% (876 of 918 patients), and rates by DAA regimen were 93.4%, 95.7%, 100%, and 95.0% in DCV + ASV-treated, SOF + LDV-treated, OMB + PTV + r-treated, and SOF + RBV-treated patients, respectively. Patients older than 75 years achieved a similar SVR rate with those aged 75 years or younger (96.4% and 94.8%, respectively). Multivariate logistic regression analysis identified absence of DAA therapy history (odds ratio [OR], 3.868 for presence; P = 0.002) and FIB-4 index of less than 3.25 (OR, 5.042 for ≥3.25; P = 0.001) as independent predictors for SVR. SVR rates were significantly lower in patients with FIB4 index of 3.25 or more compared with those with less than 3.25, especially in sofosbuvir-based therapies such as SOF + LDV-treated or SOF + RBV-treated patients. CONCLUSION: Both older and younger patients respond similarly to DAA therapy. Advanced liver fibrosis affects the virological response to sofosbuvir-based therapy.


Assuntos
Antivirais/administração & dosagem , Hepatite C Crônica/complicações , Hepatite C Crônica/tratamento farmacológico , Cirrose Hepática/patologia , Sofosbuvir/administração & dosagem , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Criança , Quimioterapia Combinada/métodos , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Resposta Viral Sustentada , Resultado do Tratamento , Adulto Jovem
8.
BMC Cancer ; 18(1): 633, 2018 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-29866075

RESUMO

BACKGROUND: In patients with advanced hepatocellular carcinoma (HCC), evidence is unclear as to whether hepatic arterial infusion chemotherapy (HAIC) or sorafenib is superior. We performed a prospective, open-label, non-comparative phase II study to assess survival with HAIC or HAIC converted to sorafenib. METHODS: Fifty-five patients were prospectively enrolled. Patients received HAIC as a second course if they had complete response, partial response, or stable disease (SD) with an alpha fetoprotein (AFP) ratio < 1 or a des-γ-carboxy prothrombin (DCP) ratio < 1. Patients were switched to sorafenib if they had SD with an AFP ratio > 1 and a DCP ratio > 1 or disease progression. The primary endpoint was the 1-year survival rate. Secondary endpoints were the 2-year survival rate, HAIC response, survival rate among HAIC responders, progression-free survival, and adverse events. RESULTS: Of the 55 patients in the intent-to-treat population, the 1-year and 2-year survival rates were 64.0 and 48.3%, respectively. After the first course of HAIC, one (1.8%) patient showed complete response, 13 (23.6%) showed partial response, 30 (54.5%) had SD, and 10 (18.1%) patients had progressive disease. Twenty-three patients (41.8%) had SD with AFP ratios < 1 or DCP ratios < 1, and 7 (12.7%) had SD with AFP ratios > 1 and DCP ratios > 1. Thirty-seven patients (68.5%) were responders and 17 (30.9%) were non-responders to HAIC. In responders, the 1-year and 2-year survival rates were 78 and 62%, respectively. CONCLUSION: Given the results of this study, this protocol deserves consideration for patients with advanced HCC. This trial was registered prospectively from December 12. 2012 to September 1. 2016.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma Hepatocelular/tratamento farmacológico , Infusões Intra-Arteriais/métodos , Neoplasias Hepáticas/tratamento farmacológico , Sorafenibe/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Cisplatino/administração & dosagem , Feminino , Fluoruracila/administração & dosagem , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Resultado do Tratamento
9.
J Gastroenterol ; 53(4): 548-556, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28815329

RESUMO

BACKGROUND: In Japan, daclatasvir (DCV) and asunaprevir (ASV) therapy was the first IFN-free treatment to be approved, and thousands of patients have since been successfully treated, with an SVR rate of around 90%. The converse, however, is that around 10% of patients fail to achieve viral eradication and must be retreated using a different approach. This study is to evaluate treatment efficacy of ledipasvir/sofosbuvir and ribavirin in patients who failed to respond to DCV and ASV therapy. METHODS: Thirty patients were treated with 12 weeks of ledipasvir/sofosbuvir and ribavirin. We evaluated the rate of sustained virological response 12 weeks after the end of treatment (SVR12) and examined the incidence of adverse events during ledipasvir/sofosbuvir and ribavirin treatment. NS5A and NS5B resistance-associated variants (RAVs) in treatment failure cases were examined. RESULTS: The overall SVR12 rate was 86.7% (26/30). Large decreases in mean log10 HCV RNA levels were observed in patients without cirrhosis, and the SVR12 rate for these patients was 100% (12/12). In cases of cirrhosis, SVR12 rate was 72.2% (13/18). The common factors in treatment failure cases were the presence of liver cirrhosis and both NS5A L31M/I and Y93H RAVs. The frequency of RAVs did not change before and after treatment among patients who relapsed. CONCLUSION: Ledipasvir/sofosbuvir with ribavirin is an effective retreatment option for patients with chronic hepatitis C who failed to respond to prior daclatasvir and asunaprevir therapy.


Assuntos
Antivirais/uso terapêutico , Benzimidazóis/uso terapêutico , Fluorenos/uso terapêutico , Hepatite C Crônica/tratamento farmacológico , Ribavirina/uso terapêutico , Uridina Monofosfato/análogos & derivados , Idoso , Idoso de 80 Anos ou mais , Antivirais/efeitos adversos , Benzimidazóis/efeitos adversos , Carbamatos , Quimioterapia Combinada , Feminino , Fluorenos/efeitos adversos , Hepacivirus/isolamento & purificação , Hepatite C Crônica/virologia , Humanos , Imidazóis/uso terapêutico , Isoquinolinas/uso terapêutico , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Pirrolidinas , RNA Viral/sangue , Retratamento/efeitos adversos , Retratamento/métodos , Ribavirina/efeitos adversos , Sofosbuvir , Sulfonamidas/uso terapêutico , Resposta Viral Sustentada , Falha de Tratamento , Resultado do Tratamento , Uridina Monofosfato/efeitos adversos , Uridina Monofosfato/uso terapêutico , Valina/análogos & derivados
10.
J Gastroenterol ; 52(6): 746-753, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27822709

RESUMO

BACKGROUND: Polymorphisms in the inosine triphosphatase (ITPA) gene is associated with anemia induced by peg-interferon (PEG-IFN) plus ribavirin (RBV) treatment for patients with chronic hepatitis C virus (HCV) infection. However, the effect of ITPA polymorphism on sofosbuvir plus RBV treatment is unknown. METHODS: Two hundred and forty-four patients with chronic HCV genotype 2 infection without decompensated liver cirrhosis were treated with sofosbuvir plus RBV for 12 weeks. The effects of ITPA polymorphism on hemoglobin levels and RBV dose reduction and treatment response were analyzed. ITPA (rs1127354) was genotyped using the Invader assay. Multivariate regression analysis was performed to identify factors associated with sustained virological response (SVR). RESULTS: Overall, SVR12 was achieved in 231 (94.7%) patients, based on intention to treat analysis. During the therapy, reduction of hemoglobin levels was significantly greater in ITPA genotype CC patients than CA/AA patients. Therefore, the cumulative proportion of patients with RBV dose reduction was significantly higher and total dose of RBV was significantly lower in patients with CC genotype compared to CA/AA genotypes. SVR12 rates were similar between ITPA genotypes CC and CA/AA (94.7 and 94.4%, respectively, P = 0.933). Multivariate logistic regression analysis identified FIB4 index <3.25 (odds ratio [OR], 9.388 for ≥3.25; P = 0.005) and low body weight (OR, 1.059, for high body weight; P = 0.017) as independent predictors for SVR12. CONCLUSIONS: ITPA polymorphism influences hemoglobin levels and incidence of RBV dose reduction during sofosbuvir plus RBV therapy. However, ITPA genotype CC patients can expect a curative effect equivalent to CA/AA patients for chronic HCV genotype 2 infection.


Assuntos
Antivirais/administração & dosagem , Hepacivirus/genética , Hepatite C Crônica/tratamento farmacológico , Pirofosfatases/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Antivirais/uso terapêutico , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Feminino , Genótipo , Hemoglobinas/metabolismo , Hepatite C Crônica/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Ribavirina/administração & dosagem , Ribavirina/uso terapêutico , Sofosbuvir/administração & dosagem , Sofosbuvir/uso terapêutico , Resultado do Tratamento , Inosina Trifosfatase
11.
J Toxicol Pathol ; 29(2): 119-24, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27182117

RESUMO

A small mass with an ulcer was found in the skin of the dorsal cervix of a 7-month-old male Sprague-Dawley rat. Histologically, the central region of the tumor showed a high cellular density with oval-shaped tumor cells arranged in an alveolar pattern and thin collagen fiber bundles. The peripheral region of the tumor had a low cellular density with short spindle- or polygonal-shaped tumor cells surrounded by abundant collagen fiber bundles. Immunohistochemically, the tumor cells were strongly positive for vimentin and proliferating cell nuclear antigen, and a portion of the short spindle- or polygonal-shaped cells located in the peripheral region of the tumor were positive for S100A4. However, the tumor cells were negative for alpha-smooth muscle actin, desmin, S100, chromogranin A, neurofilament, CD68, Iba-1, cytokeratin 20, von Willebrand factor, melanosome, and anti-melanoma. Electron microscopically, the tumor cells had an abundance of rough endoplasmic reticulum, the Golgi apparatus, and a few intracellular collagen fibrils, showing fibroblastic features. Considering the lack of diagnostic differentiation, the tumor was diagnosed as an undifferentiated malignant mesenchymal tumor and classified as a soft tissue sarcoma with differentiation into fibroblasts in a portion of the tumor cells.

12.
Mutat Res Genet Toxicol Environ Mutagen ; 780-781: 36-40, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24731965

RESUMO

To assess the effectiveness of the multiple dose liver micronucleus (MN) assay, the induction of micronuclei by N-nitrosodi-n-propylamine (NDPA), a genotoxic rodent carcinogen, was compared in hepatocytes (HEPs) and bone marrow (BM) cells. Young adult male rats were treated orally with NDPA at 6 weeks of age for 14 days using daily doses of 10, 20 and 40mg/kg. Samples of the liver and BM tissues were harvested from each animal one day following the last treatment with NDPA and were evaluated for the frequencies of micronucleated cells. Repeated doses with 40mg/kg/day of NDPA caused systemic and hepatic toxicity, including suppressed body weight gains and histopathological hepatic lesions. The frequencies of micronucleated HEPs were significantly increased in all the NDPA-treated groups in a dose-dependent manner. In contrast, the induction of micronuclei in the BM was undetectable, even at the high dose level of 40mg/kg, for which the inhibition of hematopoiesis was observed. For the detection of micronucleated HEPs induced by NDPA treatment, a 14-day administration period is adequate. The liver MN assay using naive young adult rats may be integrated into general repeated-dose toxicity studies including histopathological examinations. Our results suggest that the liver MN assay using multiple doses is more efficient and sensitive than the BM MN assay in detecting the in vivo genotoxic potential of NDPA.


Assuntos
Carcinógenos/toxicidade , Hepatócitos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Testes para Micronúcleos , Nitrosaminas/toxicidade , Administração Oral , Fatores Etários , Animais , Peso Corporal/efeitos dos fármacos , Medula Óssea/efeitos dos fármacos , Aberrações Cromossômicas/efeitos dos fármacos , Comportamento Cooperativo , Relação Dose-Resposta a Droga , Esquema de Medicação , Hepatócitos/patologia , Humanos , Japão , Fígado/patologia , Masculino , Especificidade de Órgãos , Ratos , Ratos Sprague-Dawley , Sociedades Farmacêuticas
13.
J Toxicol Sci ; 39(2): 269-79, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24646708

RESUMO

Wistar Hannover rats have been utilized as one of major strains in regulatory toxicology studies. This study was performed to verify the appropriate age of male sexual maturity in the development and reproductive toxicity (DART) study in Wistar Hannover rats (RccHan:WIST) by comparing reproductive endpoints between 8, 10 and 12 weeks of ages. Although fertility showed a tendency toward decrease in 8-week-old males, copulation index was not different among three ages. Testis weights reached a plateau at 10 weeks of age, whereas weights of other reproductive organs developed until 12 weeks of age. Indices of spermatogenesis (sperm motility, number of sperm in the epididymis and testis and contents of morphologically abnormal sperm) showed age-related progress and did not fully develop except for 12-week-old. For histology, epididymal tubules in 8-week-old animals showed immaturity with tall epithelium. At cesarean section, dams mated with 8-week-old males showed high incidence of preimplantation loss and the number of live fetuses was less than 10. In conclusion, although reproductive performance attained maturity by age of 10 weeks, spermatogenesis was not fully established at 10-week-old, which could result in a low fertility index. Therefore, we recommend that Wistar Hannover male rats at 12-week-old or older are used to conduct DART study properly and evaluate any adverse effects on dams and embryo-fetal development.


Assuntos
Envelhecimento/fisiologia , Genitália Masculina/crescimento & desenvolvimento , Reprodução/fisiologia , Maturidade Sexual/fisiologia , Testes de Toxicidade , Toxicologia/métodos , Animais , Feminino , Fertilidade/fisiologia , Humanos , Masculino , Gravidez , Ratos , Ratos Wistar , Organismos Livres de Patógenos Específicos , Espermatogênese/fisiologia
14.
J Toxicol Pathol ; 24(4): 239-44, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22319237

RESUMO

A subcutaneous mass was noted in the abdomen of a 50-week-old male Wistar Hannover GALAS rat. Histologically, the tumor was composed of vimentin-positive small round cells with scant cytoplasm arranged in a trabecular, sheet or pericytoma-like pattern and spindle cells arranged in a bundle pattern and vimentin-negative round cells proliferating in an island-shaped pattern. Argentophilic thin fibers were observed to wrap up the individual cells, and some of the tumor cells showed coexpression of vimentin and cytokeratin that formed juxtanuclear globes in the cytoplasm by double immunohistostaining. Transmission electron microscopy did not reveal any characteristic features suggesting cellular differention toward a specific cell type. Based on these findings, it was difficult to specify the origin, and the tumor was diagnosed as a poorly differentiated mesenchymal tumor and classified as a sarcoma, NOS (not otherwise specified).

15.
Endocr Res ; 35(4): 174-82, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20722489

RESUMO

INTRODUCTION: The effect of beta3-adrenergic receptor agonists on beta cells in the islets of Langerhans is not yet clear. This study examined the beta3-adrenergic receptor agonist on beta cells in the islets of Langerhans. METHODS: Obese diabetic C57BL/KsJ-db/db mice were treated with KTO-7924, a newly-developed beta3-adrenergic receptor agonist for 28-day. We analyzed plasma parameters, insulin resistance, and insulin-positive areas among beta-cells in the islets of Langerhans. RESULTS AND CONCLUSION: After a 28-day oral administration period, plasma levels of hemoglobin (Hb) A1c, glucose, triglyceride (TG), and free fatty acid (FFA) were all significantly reduced in KTO-7924 treatment groups compared with controls. Plasma adiponectin levels decreased with age in the control group, but were significantly higher in a treatment group throughout the study period. Furthermore, sequential administration of KTO-7924 led to an improvement in insulin resistance in the OGTT (Oral glucose tolerance test (OGTT)), and an increase in the percentage of insulin-positive areas among beta-cells in the islets of Langerhans compared with controls. This is the first study to show islet histology after treatment of a beta3-adrenergic receptor agonist, and reveals that KTO-7924 reduces hyperglycemia, and protects beta-cells in the islets of Langerhans of db/db mice.


Assuntos
Agonistas Adrenérgicos/farmacologia , Hiperglicemia/sangue , Hiperglicemia/tratamento farmacológico , Células Secretoras de Insulina/efeitos dos fármacos , Adiponectina/sangue , Adiponectina/genética , Animais , Glicemia/metabolismo , Ácidos Graxos não Esterificados/sangue , Teste de Tolerância a Glucose , Hemoglobinas Glicadas/metabolismo , Hiperglicemia/patologia , Insulina/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , RNA/química , RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Triglicerídeos/sangue
16.
Arzneimittelforschung ; 59(2): 79-85, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19338138

RESUMO

The renoprotective effect of cilnidipine ((+/-)-2-methoxyethyl 3-phenyl-2(E)-propenyl 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylate, CAS 132203-70-4), a L/N-type calcium channel antagonist, on puromycin aminonucleoside (PAN)-induced nephrosis was investigated in rats. In the Experiment I, rats were given an intravenous injection of PAN (70 mg/kg). Cilnidipine (3 mg/kg/day) and enalapril (CAS 75847-73-3, 5 mg/kg/day) were administered orally from 6 days after treatment with PAN (day 6) to day 26, and urinary analysis was performed on days 9, 15, 20 and 27. In the Experiment II, nephrosis was also induced by intravenous injection of PAN (70 or 100 mg/kg) in rats which were treated with cilnidipine and enalapril from days 6 to 10. Systolic blood pressure was measured on day 7 and urinary analysis was performed on day 10. On day 11, serum was collected and the kidneys were removed for immunofluorescence staining for nephrin and podocin proteins. In PAN-treated rats, the daily urinary protein excretion was dramatically elevated on day 5, reached a peak on day 9 and gradually returned to a normal level from days 15 to 27. Cilnidipine (3 mg/kg/ day) significantly suppressed the increase in proteinuria on day 9 and also improved the decrease in creatinine clearance without evident effect on the blood pressure. Furthermore, the elevations in serum total cholesterol and triglyceride tended to be suppressed by cilnidipine. The expression of nephrin and podocin proteins in PAN-treated rats showed the granular pattern in the glomeruli, while the intensity of staining seemed to be dependent on the urinary protein excretion level in the cilnidipine-treated rats. The results obtained in this study suggest a renoprotective effect of cilnidipine in PAN-induced nephrosis in rats.


Assuntos
Antimetabólitos Antineoplásicos/toxicidade , Bloqueadores dos Canais de Cálcio/uso terapêutico , Di-Hidropiridinas/uso terapêutico , Nefrose/induzido quimicamente , Nefrose/prevenção & controle , Substâncias Protetoras , Puromicina Aminonucleosídeo/toxicidade , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Animais , Pressão Sanguínea/efeitos dos fármacos , Canais de Cálcio Tipo L/efeitos dos fármacos , Canais de Cálcio Tipo N/efeitos dos fármacos , Creatinina/sangue , Creatinina/urina , Enalapril/uso terapêutico , Imunofluorescência , Masculino , Proteínas de Membrana/biossíntese , Nefrose/patologia , Proteinúria/prevenção & controle , Ratos , Ratos Sprague-Dawley
17.
J Toxicol Sci ; 34 Suppl 1: SP31-42, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19265287

RESUMO

In order to assess ovarian pathological changes and their relationship to changes in female fertility parameters, mifepristone, a progesterone receptor antagonist, was selected as the test article and was administered orally to female rats at dose levels of 0, 0.8, 4, 20 and 100 mg/kg for 2 or 4 weeks in repeated dose-toxicity studies and in a female fertility study at dose levels of 0, 0.8, 4 and 20 mg/kg from > 2 weeks before copulation to postcoital day 7. In the repeated dose toxicity studies, persistent estrus was seen in the vaginal smears, and multiple cysts in the ovaries at necropsy, increases in luteinized cysts and hypertrophy of previously formed corpora lutea were observed in the histopathological examination of ovaries in rats receiving 20 mg/kg or more for 2 or 4 weeks. In female fertility studies, persistent vaginal cornification was also observed at 20 mg/kg and the precoital interval was significantly shortened. All of the animals were completely infertile when dosed with 20 mg/kg during the post-coital period. An increase in pre-implantation losses was observed in the animals treated with 20 mg/kg during the pre-coital phase, while treatment with 4 mg/kg mifepristone during the post-coital phase induced an increase in post-implantation losses. These results suggested that a 2-week administration period would be sufficient to detect the ovarian toxicity of mifepristone in repeated dose toxicity study and the pathological findings in the ovaries would reflect the alterations in female reproductive endpoints in the female fertility study.


Assuntos
Fertilidade/efeitos dos fármacos , Antagonistas de Hormônios/toxicidade , Mifepristona/toxicidade , Ovário/efeitos dos fármacos , Testes de Toxicidade/métodos , Administração Oral , Animais , Esquema de Medicação , Desenvolvimento Embrionário/efeitos dos fármacos , Ciclo Estral/efeitos dos fármacos , Ciclo Estral/fisiologia , Feminino , Fertilidade/fisiologia , Antagonistas de Hormônios/administração & dosagem , Infertilidade Feminina/induzido quimicamente , Infertilidade Feminina/fisiopatologia , Japão , Masculino , Mifepristona/administração & dosagem , Cistos Ovarianos/induzido quimicamente , Cistos Ovarianos/patologia , Ovário/metabolismo , Ovário/patologia , Gravidez , Parcerias Público-Privadas , Ratos , Ratos Sprague-Dawley , Sociedades Científicas , Organismos Livres de Patógenos Específicos , Vagina/efeitos dos fármacos , Vagina/patologia
18.
J Toxicol Sci ; 33(5): 585-98, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19043280

RESUMO

Embryonic mortality and intrauterine growth retardation (IUGR) are induced by exposure of rodents to xenobiotic agents during the pregastrulation period of development. We examined the time course of the effects of methyl methanesulfonate (MMS), an alkylating agent, on conceptus development in order to clarify the relative roles of the embryo and the placenta in their induction. Pregnant rats were treated orally with a single dose of MMS (200 mg/kg) in the morning of gestation day (GD) 6 (peri-implantation stage). Embryonic mortality was increased on GD12 and thereafter by MMS treatment, with newly dead embryos showing placental hypoplasia at GD12. Embryo or fetal weight was also smaller for MMS-treated dams than for control dams from GD14 to GD20. The labyrinth zone and junctional zone (JZ) of the placenta were thinner in MMS-treated rats from GD12 to GD17 and from GD12 to GD20 (except for GD17), respectively. Furthermore, MMS-treated dams showed a smaller number of glycogen cells in the JZ on GD14. In contrast, the placental glycogen concentration was higher and the expression of glucose transporter 1 in the JZ remained at GD20. These results indicate that exposure of pregnant rats to MMS at the peri-implantation stage of embryogenesis affects placental development and growth. The placental impairment induced by MMS was likely responsible for the embryonic death observed 6 days after exposure of dams to this agent as well as for the IUGR of surviving embryos or fetuses throughout the gestation period.


Assuntos
Alquilantes/toxicidade , Perda do Embrião/induzido quimicamente , Desenvolvimento Embrionário/efeitos dos fármacos , Retardo do Crescimento Fetal/induzido quimicamente , Metanossulfonato de Metila/toxicidade , Placenta/efeitos dos fármacos , Animais , Glicemia/análise , Perda do Embrião/patologia , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Feminino , Desenvolvimento Fetal/efeitos dos fármacos , Retardo do Crescimento Fetal/patologia , Idade Gestacional , Masculino , Placenta/patologia , Gravidez , Ratos , Ratos Endogâmicos , Útero/efeitos dos fármacos , Útero/patologia
19.
Hepatol Res ; 38(10): 1026-39, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18513333

RESUMO

AIM: The aim of this study was to investigate the preventive actions of bezafibrate against non-alcoholic steatohepatitis (NASH), the activation of hepatic stellate cells (HSC), and fibrogenesis by using a model of NASH and an in vitro model. METHODS: Male KK-A(y)/TaJcl (KK-A(y)) mice were fed a methionine and choline-deficient (MCD) diet or a MCD diet containing bezafibrate or pioglitazone for 7 weeks, after which biochemical parameters, pathological changes, and hepatic mRNA levels were assessed. An in vitro HSC model was designed by using a previously described RI-T cell line stimulated by transforming growth factor-beta1 (TGF-beta1). RESULTS: MCD diet-fed KK-A(y) mice developed hepatic steatosis, oxidative stress, inflammation, and hepatic fibrosis. Bezafibrate markedly decreased the hepatic content of triglyceride accumulation of fatty droplets within hepatocytes, and increased the expression of hepatic fatty acid beta-oxidative genes in MCD diet-fed KK-A(y) mice. Bezafibrate markedly inhibited the increases in the plasma alanine aminotransferase level and hepatic content of thiobarbituric acid-reactive substances in this model. Moreover, it dramatically reduced hepatic inflammatory changes and fibrosis concomitantly with marked reductions in the mRNA levels for inflammatory cytokine, chemokine, and profibrogenic genes. Importantly, both bezafibrate and pioglitazone markedly reduced the mRNA levels of profibrogenic and fibrogenic genes in TGF-beta1-stimulated cells. CONCLUSION: Bezafibrate improved hepatic steatosis and potently prevented inflammation, oxidative stress, HSC activation, and fibrogenesis in the liver. Moreover, this study was the first to demonstrate that bezafibrate directly inhibits hepatic fibrogenic response induced by TGF-beta1 in vitro. Hence bezafibrate may be a new therapeutic strategy against NASH and hepatic fibrosis.

20.
J Pharmacol Sci ; 105(1): 48-56, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17827869

RESUMO

This study explores the effects of the anti-allergic and anti-fibrotic agent tranilast on adjuvant- and streptococcal cell wall-induced arthritis in rats, animal models of rheumatoid arthritis in humans. Tranilast (150 or 300 mg/kg, twice daily) or vehicle only was administered orally to the two arthritis models, from 17 days before sensitization. As a comparative control, methotrexate (0.1 mg/kg, once daily) was given to another group. Tranilast suppressed the increase in foot volumes, paw thicknesses, clinical scores, and histopathological scores of the ankle joints in both models dose-dependently. In addition, the fibrosis indices of the ankles were dramatically decreased by tranilast in both of the models. Compared to the effects of methotrexate, tranilast seemed to work more effectively in the streptococcal cell wall-induced arthritis model than in the adjuvant-induced arthritis model. From these observations, it can be concluded that tranilast suppresses the development of arthritis in multiple models and is potentially a novel therapeutic agent for human rheumatoid arthritis.


Assuntos
Articulação do Tornozelo/efeitos dos fármacos , Artrite Experimental/prevenção & controle , Parede Celular/imunologia , ortoaminobenzoatos/farmacologia , Administração Oral , Análise de Variância , Animais , Articulação do Tornozelo/patologia , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/uso terapêutico , Antirreumáticos/administração & dosagem , Antirreumáticos/farmacologia , Antirreumáticos/uso terapêutico , Artrite Experimental/imunologia , Artrite Experimental/patologia , Calcâneo/efeitos dos fármacos , Calcâneo/patologia , Parede Celular/química , Relação Dose-Resposta a Droga , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Metotrexato/administração & dosagem , Metotrexato/farmacologia , Metotrexato/uso terapêutico , Ratos , Ratos Endogâmicos Lew , Ramnose/imunologia , Índice de Gravidade de Doença , Streptococcus/química , Streptococcus/imunologia , Fatores de Tempo , ortoaminobenzoatos/administração & dosagem , ortoaminobenzoatos/uso terapêutico
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