Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Naturwissenschaften ; 110(6): 51, 2023 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-37882886

RESUMEN

Phoresy is a passive transportation behavior where one organism (phoront) disperses to a new location by attaching to another organism. Pseudoscorpions are arthropod predators that mainly live in soil, subterranean habitats, and under tree bark. Some species also live in animal nests and engage in phoresy on small mammals, suggesting close associations with these animals. However, the relationship between phoretic pseudoscorpions and hosts as well as the ecological significance of phoresy remain largely unexplored. Here, to understand the function of phoresy of Megachernes ryugadensis, phoretic on small mammals, their phoretic behavior was investigated in a deciduous forest in northern Japan; individual-level dynamics of phoresy were examined by over 3-year mark-recapture surveys that concurrently marked the host and phoront; and host characteristics, such as sex and age class, were analyzed based on a 2-year small mammal trapping survey. The primary host species was the abundant Japanese wood mouse Apodemus speciosus. Out of 132 pseudoscorpions marked, 5 were recaptured approximately 1 month later. No pseudoscorpions were recaptured within the same census period (3-4 days) when they were marked, indicating that phoresy events last less than one night, and pseudoscorpions are unlikely to engage in phoresy again within a few weeks of their initial engagement. Furthermore, analysis of host characteristics revealed a tendency for female mice and adult individuals to have a higher probability of being hosts compared with males and subadults, respectively. Based on the findings in this and previous studies, the function of phoresy in this species is discussed.


Asunto(s)
Distribución Animal , Artrópodos , Conducta Animal , Murinae , Animales , Masculino , Ratones , Bosques , Japón , Femenino
2.
Int J Mol Sci ; 24(4)2023 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-36835411

RESUMEN

Heat stroke is a life-threatening illness caused by exposure to high ambient temperatures and relative humidity. The incidence of heat stroke is expected to increase due to climate change. Although pituitary adenylate cyclase-activating polypeptide (PACAP) has been implicated in thermoregulation, the role of PACAP on heat stress remains unclear. PACAP knockout (KO) and wild-type ICR mice were subjected to heat exposure at an ambient temperature of 36 °C and relative humidity of 99% for 30-150 min. After heat exposure, the PACAP KO mice had a greater survival rate and maintained a lower body temperature than the wild-type mice. Moreover, the gene expression and immunoreaction of c-Fos in the ventromedially preoptic area of the hypothalamus, which is known to harbor temperature-sensitive neurons, were significantly lower in PACAP KO mice than those in wild-type mice. In addition, differences were observed in the brown adipose tissue, the primary site of heat production, between PACAP KO and wild-type mice. These results suggest that PACAP KO mice are resistant to heat exposure. The heat production mechanism differs between PACAP KO and wild-type mice.


Asunto(s)
Golpe de Calor , Polipéptido Hipofisario Activador de la Adenilato-Ciclasa , Animales , Ratones , Golpe de Calor/genética , Golpe de Calor/metabolismo , Hipotálamo/metabolismo , Ratones Endogámicos ICR , Ratones Noqueados , Polipéptido Hipofisario Activador de la Adenilato-Ciclasa/genética , Polipéptido Hipofisario Activador de la Adenilato-Ciclasa/fisiología
3.
Neural Comput ; 33(5): 1234-1268, 2021 04 13.
Artículo en Inglés | MEDLINE | ID: mdl-33617743

RESUMEN

Pairwise similarities and dissimilarities between data points are often obtained more easily than full labels of data in real-world classification problems. To make use of such pairwise information, an empirical risk minimization approach has been proposed, where an unbiased estimator of the classification risk is computed from only pairwise similarities and unlabeled data. However, this approach has not yet been able to handle pairwise dissimilarities. Semisupervised clustering methods can incorporate both similarities and dissimilarities into their framework; however, they typically require strong geometrical assumptions on the data distribution such as the manifold assumption, which may cause severe performance deterioration. In this letter, we derive an unbiased estimator of the classification risk based on all of similarities and dissimilarities and unlabeled data. We theoretically establish an estimation error bound and experimentally demonstrate the practical usefulness of our empirical risk minimization method.

4.
Brain Res ; 1736: 146779, 2020 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-32171704

RESUMEN

Inflammation plays an important role in acute and chronic cerebral ischemia. Recent reports indicate that the inflammatory response triggered by tissue damage is mediated by a multiple-protein complex called the inflammasome. The NOD-like receptor family, pyrin domain containing 3 (NLRP3) and absent in melanoma 2 (AIM2) inflammasome complex triggers caspase 1-mediated maturation of interleukin (IL)-1ß and IL-18. This study tested the hypothesis that chronic cerebral hypoperfusion activates inflammasomes in the white matter of the brain. To induce cerebral hypoperfusion, C57BL/6J mice were subjected to a sham or bilateral common carotid artery stenosis (BCAS) operation using microcoils with an internal diameter of 0.18 mm. At 2 and 4 weeks after BCAS, the mice were sacrificed (n = 5 in each group). Coronal sections were stained with anti-NLRP3 and anti-AIM2 antibodies. Activation of the inflammasome and cytokines was assessed using immunohistochemistry and cell counting. IL-18 and IL-1ß levels were determined by ELISA. Cell counting revealed an increase in NLRP3 and AIM2 inflammasomes at 2 and 4 weeks after BCAS. Immunoreactivity was observed in glial cells in the white matter and corpus callosum. IL-18 and IL-1ß concentrations were significantly increased compared with those in the sham operation group. Expression of NLRP3 and AIM2 was upregulated in glial cells in the autopsied brains of patients with cerebral infarction in the chronic phase. These results suggest that chronic cerebral hypoperfusion induces upregulation of NLRP3 and AIM2 inflammasomes; therefore, inflammasomes may play an important role in the sterile inflammatory response in astrocytes and microglia during chronic cerebral hypoperfusion.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Daño por Reperfusión/metabolismo , Animales , Encéfalo/metabolismo , Isquemia Encefálica/metabolismo , Caspasa 1/metabolismo , Proteínas de Unión al ADN/fisiología , Inflamasomas/metabolismo , Inflamación , Interleucina-18/metabolismo , Interleucina-1beta/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Microglía/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/fisiología , Perfusión/métodos , Daño por Reperfusión/fisiopatología , Sustancia Blanca/metabolismo
5.
eNeurologicalSci ; 18: 100220, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31909228

RESUMEN

New-onset refractory status epilepticus (NORSE) is a rare neurological emergency condition with poor prognosis. A 30-year-old male suddenly had tonic-clonic convulsions seven days after a preceding fever and diarrhea. MRI showed a reversible splenial lesion, and he developed refractory multifocal and generalized seizures in spite of anticonvulsant medication. He was diagnosed with NORSE and received a combination treatment with immunotherapy and targeted temperature management (TTM), which effectively decreased his seizures. This case suggests that even for patients with reversible splenial lesions, NORSE should be considered, and that treatment with immunotherapy and TTM may be effective.

6.
J Anim Ecol ; 89(2): 471-481, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31580494

RESUMEN

The foraging ecology of mammalian herbivores is regulated in part by their ability to detoxify plant secondary metabolites (PSM). Ambient temperature has been shown to alter liver function in rodents and the toxicity of some PSMs, but little is known about the physiological and nutritional consequences of consuming PSMs at different ambient temperatures. Furthermore, the effect of ambient temperature on the response of mammals to the most ubiquitous class of PSM, tannins, is unknown. We measured the effect of temperature and tannin intake on liver function, and the subsequent effect on the tannin tolerance of wild Japanese wood mice, Apodemus speciosus. The experiment involved acclimation to one of two ambient temperatures (10°C or 20°C) followed by acclimation to a diet of acorns (6.2% tannin DW). Liver function was measured both before and after acclimation to acorns by measuring the clearance time of a hypnotic agent. Finally, the mice were fed only acorns in a 5-day feeding experiment to assess their tolerance to tannin in the diet. Acclimation to acorns had a significant effect on liver function, but the direction of this effect was dependent on ambient temperature. Acorn consumption improved the liver function of wood mice at 10°C, but reduced liver function at 20°C, revealing a complex relationship between ambient temperature and tannin intake on liver function. Furthermore, mice with better liver function, indicated by faster clearance of the hypnotic agent, exhibited higher protein digestibility on an acorn-only diet, indicative of higher tannin tolerance. These results suggest that environmental temperature plays a significant role in the tolerance of A. speciosus to tannins, providing new insight into their seasonal feeding behaviour and winter ecology. We contend that cold-induced tannin tolerance may help to explain the population dynamics of mammalian herbivores with seasonal changes in the tannin content of their diet, and inform predictions about the response of these animals to a changing climate.


Asunto(s)
Frío , Taninos , Animales , Dieta/veterinaria , Conducta Alimentaria , Ratones , Murinae , Temperatura
7.
Neurosci Lett ; 704: 133-140, 2019 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-30954605

RESUMEN

Alzheimer's disease (AD) is the most common type of dementia in aging adults. Increasing evidence has revealed that vascular risk factors influence the midlife development of AD and that diet-induced obesity accelerates tau phosphorylation in tau transgenic mice and increases the level of serum leptin receptor (leptin-R). Leptin-R is upregulated in the peri-infarct cortices after acute cerebral ischemia. Leptin may be protective against the development of AD as it can inactivate GSK-3ß through the phosphorylation of Ser-9, leading to the reduction of tau phosphorylation. Using tau transgenic mice, the present study examined whether chronic cerebral hypoperfusion affects leptin-R signaling and tau phosphorylation. Eight-month-old tau transgenic mice (T44) overexpressing the shortest human tau isoform were subjected to chronic cerebral hypoperfusion with bilateral common carotid artery stenosis (BCAS) using microcoils or sham surgery. Their brains were analyzed four weeks later to evaluate the expression of phosphorylated tau and leptin-R via immunohistochemistry and Western blot analysis. In addition, expression of leptin-R was examined in the rat primary astrocyte cultures subjected to prolonged chemical hypoxic stress, as well as in autopsied brains. BCAS upregulated leptin-R expression and promoted the expression of phosphorylated tau in T44 Tg mice. In primary astrocyte cultures, leptin-R was upregulated under hypoxic conditions via the phosphorylated AKT/pAKT pathway, possibly suppressing the expression of caspase 3. Leptin-R was also strongly expressed in autopsied brains with AD and cerebrovascular diseases. These results collectively indicate that chronic cerebral hypoperfusion promotes leptin-R signaling and tau phosphorylation.


Asunto(s)
Astrocitos/metabolismo , Isquemia Encefálica/metabolismo , Corteza Cerebral/metabolismo , Receptores de Leptina/metabolismo , Proteínas tau/metabolismo , Animales , Isquemia Encefálica/etiología , Estenosis Carotídea/complicaciones , Corteza Cerebral/irrigación sanguínea , Masculino , Ratones Transgénicos , Fosforilación , Regulación hacia Arriba
8.
In Vivo ; 32(4): 759-763, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29936456

RESUMEN

BACKGROUND/AIM: From the standpoint of cancer therapy, it is valuable to enhance the anticancer effects of chemotherapy. Our previous reports revealed that up-regulation of heat-shock protein 27 (HSP27) has been linked to gemcitabine resistance of pancreatic cancer cells. Enzyme-treated asparagus extract (ETAS) is an extract that is produced from asparagus. The purpose of this study was to investigate the effect of ETAS on the expression of HSP27 and other HSPs in the gemcitabine-resistant pancreatic cancer cell line KLM1-R. MATERIALS AND METHODS: KLM1-R cells were treated with ETAS, and expression levels of HSPs, including HSP27, were investigated by western blotting. RESULTS: ETAS down-regulated HSP27 and pHSP27 (serine 78) in KLM1-R cells, but, HSP70 and GRP78 levels were not altered. CONCLUSION: This study suggests the potential therapeutic benefit of ETAS in enhancing anticancer effects by its combination with gemcitabine for patients with pancreatic cancer.


Asunto(s)
Asparagus/química , Resistencia a Antineoplásicos/efectos de los fármacos , Proteínas de Choque Térmico HSP27/genética , Neoplasias Pancreáticas/dietoterapia , Extractos Vegetales/farmacología , Antimetabolitos Antineoplásicos/efectos adversos , Antimetabolitos Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Desoxicitidina/efectos adversos , Desoxicitidina/análogos & derivados , Chaperón BiP del Retículo Endoplásmico , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Proteínas del Choque Térmico HSP72/genética , Proteínas de Choque Térmico/genética , Humanos , Páncreas/metabolismo , Páncreas/patología , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Extractos Vegetales/química , Gemcitabina
9.
Biopharm Drug Dispos ; 39(5): 256-264, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29682747

RESUMEN

Hepatic arterial infusion (HAI) chemotherapy is expected to be a more effective and safer method to treat the hepatic metastasis of pancreatic cancer than intravenous (iv) administration because of higher tumor exposure and lower systemic exposure. To clarify the uptake mechanism of nucleoside anticancer drugs, including gemcitabine (GEM), in pancreatic cancer, we investigated the uptakes of radiolabeled uridine (a general substrate of nucleoside transporters) and GEM in pancreatic cancer cell lines MIA-PaCa2 and As-PC1. Uridine uptake was inhibited by non-labeled GEM and also by S-(4-nitrobenzyl)-6-thioinosine (NBMPR; an inhibitor of equilibrative nucleoside transporters, ENTs) in a concentration-dependent manner, suggesting that ENTs contribute to uridine uptake in pancreatic cancer cells. As for GEM, saturable uptake was mediated by high- and low-affinity components with Km values of micromolar and millimolar orders, respectively. Uptake was inhibited in a concentration-dependent manner by NBMPR and was sodium ion-independent. Moreover, the concentration dependence of uptake in the presence of 0.1 µM NBMPR showed a single low-affinity site. These results indicated that the high- and low-affinity sites correspond to hENT1 and hENT2, respectively. The results indicated that at clinically relevant hepatic concentrations of GEM in GEM-HAI therapy, the metastatic tumor exposure of GEM is predominantly determined by hENT2 under unsaturated conditions, suggesting that hENT2 expression in metastatic tumor would be a candidate biomarker for indicating anticancer therapy with GEM-HAI.


Asunto(s)
Antimetabolitos Antineoplásicos/farmacocinética , Desoxicitidina/análogos & derivados , Tranportador Equilibrativo 1 de Nucleósido/metabolismo , Transportador Equilibrativo 2 de Nucleósido/metabolismo , Neoplasias Pancreáticas/metabolismo , Línea Celular Tumoral , Desoxicitidina/farmacocinética , Hepatocitos/metabolismo , Humanos , Gemcitabina
10.
J Pharm Sci ; 104(9): 3162-9, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26037416

RESUMEN

Hepatic arterial infusion (HAI) chemotherapy with gemcitabine (GEM) is expected to be more effective and safer method to treat hepatic metastasis of pancreatic cancer compared with intravenous administration, because it affords higher tumor exposure with lower systemic exposure. Thus, a key issue for dose selection is the saturability of hepatic uptake of GEM. Therefore, we investigated GEM uptake in rat and human isolated hepatocytes. Hepatic GEM uptake involved high- and low-affinity saturable components with Km values of micromolar and millimolar order, respectively. The uptake was inhibited concentration dependently by S-(4-nitrobenzyl)-6-thioinosine (NBMPR) and was sodium-ion-independent, suggesting a contribution of equilibrative nucleoside transporters (ENTs). The concentration dependence of uptake in the presence of 0.1 µM NBMPR showed a single low-affinity binding site. Therefore, the high- and low-affinity sites correspond to ENT1 and ENT2, respectively. Our results indicate hepatic extraction of GEM is predominantly mediated by the low-affinity site (hENT2), and at clinically relevant hepatic concentrations of GEM, hENT2-mediated uptake would not be completely saturated. This is critical for HAI, because saturation of hepatic uptake would result in a marked increase of GEM concentration in the peripheral circulation, abrogating the advantage of HAI over intravenous administration in terms of severe adverse events.


Asunto(s)
Proteínas Portadoras/metabolismo , Desoxicitidina/análogos & derivados , Arteria Hepática/metabolismo , Hepatocitos/metabolismo , Animales , Sitios de Unión/efectos de los fármacos , Transporte Biológico/efectos de los fármacos , Membrana Celular/metabolismo , Desoxicitidina/administración & dosificación , Desoxicitidina/metabolismo , Tranportador Equilibrativo 1 de Nucleósido , Transportador Equilibrativo 2 de Nucleósido/metabolismo , Femenino , Arteria Hepática/efectos de los fármacos , Hepatocitos/efectos de los fármacos , Humanos , Bombas de Infusión , Masculino , Proteínas de la Membrana/metabolismo , Persona de Mediana Edad , Ratas , Ratas Wistar , Tioinosina/análogos & derivados , Tioinosina/farmacología , Gemcitabina
11.
Rinsho Shinkeigaku ; 54(9): 747-50, 2014.
Artículo en Japonés | MEDLINE | ID: mdl-25283831

RESUMEN

A 43-year-old male presented with abnormal behavior and consciousness disturbance on the day after traveling abroad and was admitted to our hospital. Laboratory tests showed hyperammonemia and hypercitrullinemia. The electro-encephalogram showed frontal dominant bilateral slow δ burst. He had a peculiar taste for nuts. But he didn't take nuts during the overseas travel for 3 days. The family history revealed that his younger brother died of a status epilepticus of unknown cause at the age of 29. These findings were compatible with hepatic encephalopathy due to adult-onset type II citrullinemia (CTLN2). Gene analysis provided a definite diagnosis of CTLN2. Diet and drug therapy have improved his condition. He is due to have liver transplantation which is the only established radical treatment for CTLN2 if his condition becomes worse. The present case shows that cessation of the habitual intake of nuts only for 3 days could lead to onset of CTLN2.


Asunto(s)
Citrulinemia/etiología , Dieta , Conducta Alimentaria , Nueces , Viaje , Adulto , Aminoácidos de Cadena Ramificada/administración & dosificación , Biomarcadores/sangre , Citrulina/sangre , Citrulinemia/diagnóstico , Citrulinemia/genética , Citrulinemia/terapia , Diagnóstico Diferencial , Electroencefalografía , Encefalopatía Hepática/etiología , Humanos , Trasplante de Hígado , Masculino , Resultado del Tratamiento
12.
J Pharm Sci ; 102(10): 3678-86, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23897300

RESUMEN

Tablet characteristics of tensile strength and disintegration time were predicted using residual stress distribution, simulated by the finite element method (FEM). The Drucker-Prager Cap (DPC) model was selected as the method for modeling the mechanical behavior of pharmaceutical powders composed of lactose (LAC), cornstarch (CS), and microcrystalline cellulose (MCC). The DPC model was calibrated using a direct shear test and analysis of the hardening law of the powder. The constructed DPC model was fed into the analysis using the FEM, and the mechanical behavior of pharmaceutical powders during compaction was analyzed using the FEM. The results revealed that the residual stress distribution of the tablets was uniform when the compression force increased. In particular, the residual stress distribution of tablets composed of equal amounts of LAC, CS, and MCC was more uniform than the tablets composed of 67% LAC and 33% CS, with no MCC. The tensile strength and disintegration time were predicted accurately from the residual stress distribution of tablets using multiple linear regression analysis and partial least squares regression analysis. This suggests that the residual stress distribution of tablets is related closely to the tensile strength and disintegration time.


Asunto(s)
Comprimidos/química , Tecnología Farmacéutica/métodos , Celulosa/química , Química Farmacéutica/métodos , Excipientes/química , Lactosa/química , Modelos Lineales , Modelos Teóricos , Polvos/química , Presión , Almidón/química , Resistencia a la Tracción
13.
Rinsho Shinkeigaku ; 52(7): 507-10, 2012.
Artículo en Japonés | MEDLINE | ID: mdl-22849995

RESUMEN

We reported a 60 year-old man with Churg-Strauss syndrome (CSS). Three months later, he presented with dysarthria, dysphagia and severe headache. We detected glossopharyngeal and vagal nerve palsy, and made a diagnosis of cranial nerve involvement comorbid with CSS. Intravenous administration of methypredonisolone was effective for alleviating clinical signs and symptoms. Two months later, he complained of headache and facial numbness, but symptoms improved with an escalating dose of prednisolon. As compared to previously reported cases, our case was characteristic because of involvement of lower cranial nerve with CSS, which has been reported previously in only one case.


Asunto(s)
Síndrome de Churg-Strauss/complicaciones , Enfermedades de los Nervios Craneales/etiología , Enfermedades de los Nervios Craneales/tratamiento farmacológico , Enfermedades del Nervio Glosofaríngeo/etiología , Humanos , Masculino , Persona de Mediana Edad , Prednisolona/uso terapéutico , Enfermedades del Nervio Vago/etiología
14.
J Chem Ecol ; 37(12): 1277-84, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22161223

RESUMEN

Mammalian herbivores adopt various countermeasures against dietary tannins, which are among the most widespread plant secondary metabolites. The large Japanese wood mouse Apodemus speciosus produces proline-rich salivary tannin-binding proteins in response to tannins. Proline-rich proteins (PRPs) react with tannins to form stable complexes that are excreted in the feces. Here, we developed a new method for estimating the tannin intake of free-living small rodents, by measuring fecal proline content, and applied the method to a field investigation. A feeding experiment with artificial diets containing various levels of tannic acid revealed that fecal proline content was clearly related to dietary tannin content in three species (A. speciosus, Apodemus argenteus, and Myodes rufocanus). We then used fecal proline content to estimate the tannin intakes of these three forest-dwelling species in a forest in Hokkaido. In the autumn, estimated tannin intakes increased significantly in the Apodemus species, but not in M. rufocanus. We speculated that an increase in tannin intake during autumn may result from consumption of tannin-rich acorns. This hypothesis was consistent with population fluctuation patterns of the three species, which were well-synchronized with acorn abundance for the Apodemus species but not for M. rufocanus.


Asunto(s)
Arvicolinae/fisiología , Heces/química , Análisis de los Alimentos/métodos , Murinae/fisiología , Prolina/análisis , Taninos/metabolismo , Animales , Dieta , Femenino , Japón , Modelos Lineales , Masculino , Prolina/metabolismo , Proteínas Salivales Ricas en Prolina/análisis , Proteínas Salivales Ricas en Prolina/metabolismo , Estaciones del Año , Especificidad de la Especie , Taninos/administración & dosificación
15.
Am J Vet Res ; 71(5): 541-6, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20433380

RESUMEN

OBJECTIVE: To evaluate effects of a high dose of methylprednisolone sodium succinate (MPSS) on function of polymorphonuclear neutrophilic leukocytes (PMNs) in dogs. ANIMALS: 7 healthy male Beagles (body weight, 10.5 to 15 kg; age, 2 to 4 years). PROCEDURES: All dogs were treated by IV administration of a high dose of MPSS (30 mg/kg). Additional doses of MPSS (15 mg/kg) were administered IV at 2 and 6 hours and then at 6-hour intervals until 48 hours after the initial dose. Blood samples were collected before and 1, 2, 4, 7, and 14 days after completion of the MPSS administrations and used for evaluation of PMN functions. Isolated PMNs were used for assessment of functions, such as adhesion, migration, phagocytosis, and oxidative burst. RESULTS: On days 1, 2, and 4 after completion of MPSS administration, there was a decrease in PMN expression of adhesion markers such as CD11b and CD18. There was a decrease in the phagocytotic ability of PMNs on days 1, 2, and 7 after completion of MPSS administration, with a reduction in the oxidative burst of PMNs detected on day 7. No significant changes were identified for migration. All functional changes returned to their pretreatment values by 14 days after completion of MPSS treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Treatment with a high dose of MPSS suppressed PMN functions in dogs. Analysis of these results suggested that treatment with a high dose of MPSS can suppress some of the major functions of PMNs for at least 7 days.


Asunto(s)
Hemisuccinato de Metilprednisolona/farmacología , Neutrófilos/fisiología , Fagocitosis/efectos de los fármacos , Actinas/sangre , Actinas/efectos de los fármacos , Animales , Antígenos CD11/efectos de los fármacos , Antígenos CD11/genética , Perros , Citometría de Flujo , Luminiscencia , Masculino , Neutrófilos/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Valores de Referencia
16.
J Chem Ecol ; 32(6): 1149-63, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16770710

RESUMEN

Tannins, a diverse group of water-soluble phenolics with high affinity to proteins, are widely distributed in various parts of plants, and have negative effects in herbivores after ingestion. Some mammalian species are thought to counteract tannins by secreting tannin-binding salivary proteins (TBSPs). Several types of TBSPs are found in the saliva of laboratory animals, livestock, and wildlife. Among them, proline-rich proteins (PRPs) and histatins are effective precipitators of tannins. It is widely accepted that, at the least, PRPs act as a first line of defense against tannins. Many observations support this idea: in vitro affinity of PRPs to tannins is far higher than that of other proteins such as bovine serum albumin; complexes formed between PRPs and tannins are stable even under the conditions in the stomach and intestine; and PRP production is induced by ingesting tannins. It is believed that species that usually ingest tannins as part of their natural diets produce high levels of PRPs, whereas species not exposed to tannins produce little or no PRPs. This hypothesis is generally supported, although studies on TBSPs in wildlife are limited. This work stresses the importance of gathering basic information on such items as the characteristics of unidentified TBSPs, and seasonal and geographical variations in PRP production.


Asunto(s)
Dieta , Proteínas y Péptidos Salivales/fisiología , Taninos/antagonistas & inhibidores , Animales , Conducta Alimentaria , Insectos
17.
J Chem Ecol ; 32(6): 1165-80, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16770711

RESUMEN

We studied the defense mechanisms against the negative effects of tannins in acorns by using the Japanese wood mouse (Apodemus speciosus) and acorns of a Japanese deciduous oak Quercus crispula, which contain 9.9% tannins on a dry weight basis. For the experiment, we allocated 26 wood mice into two groups: acclimated (N = 12) and nonacclimated (N = 14). Mice in the nonacclimated group were fed only acorns for 10 d after 4 wk of receiving a tannin-free diet. In contrast, mice in the acclimated group received ca. 3 g acorns daily in addition to the tannin-free diet for the first 4 wk, then they were fed only acorns for 10 d. Body weight, food intake, and digestibility were monitored. In addition, the amount of salivary proline-rich proteins (PRPs) and abundance of tannase-producing bacteria (TPB) in the feces of mice were measured. Of the 14 mice in the nonacclimated group, 8 died, whereas only 1 of the 12 in the acclimated group died. During the first 5 d of feeding acorns only, mice in the nonacclimated group lost, on average, 17.5% of their body mass, while those in the acclimated group lost only 2.5%. Food intake, dry matter digestibility, and nitrogen digestibility were higher in the acclimated group than in the nonacclimated group. The results indicate that wood mice can mitigate the negative effects of tannins by acclimation. Path analysis revealed that increased secretion of PRPs and abundance of Lactobacillus type of TPB might explain the acclimation to tannins.


Asunto(s)
Adaptación Fisiológica/fisiología , Fenómenos Fisiológicos Bacterianos , Hidrolasas de Éster Carboxílico/biosíntesis , Murinae/fisiología , Quercus/embriología , Proteínas y Péptidos Salivales/fisiología , Semillas , Taninos/metabolismo , Animales , Peso Corporal , Digestión , Femenino , Masculino , Ratones , Proteínas y Péptidos Salivales/metabolismo , Tasa de Supervivencia
18.
J Biosci Bioeng ; 100(3): 280-7, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16243277

RESUMEN

To investigate the therapeutical use of phage mixture for controlling gastrointestinal Escherichia coli O157:H7 cells, in vitro and in vivo experiments were conducted. Three phages, SP15, SP21, and SP22 were selected from 26 phage stock screened from feces of stock animals and sewage influent. Addition of single or binary phage to the E. coli cell batch-culture reduced the turbidity of the culture. However, reascend of the turbidity due to the appearance of phage resistance cell was observed. On the other hand, addition of three phage mixture (SP15-21-22) did not produce reascend of culture turbidity under aerobic condition. Under anaerobic condition, slight reascend of culture turbidity was observed after SP15-21-22 addition. Chemostat continuous culture was operated under anaerobic condition to optimize the titer of phage cocktail and frequency of the addition for controlling E. coli cells. Five-log decrease of E. coli cell concentration after addition of phage cocktail of 10(9) Plaque forming unit (PFU)/ml was observed. However, reascend of cell concentration was observed after 1 d incubation. Repeated addition of phage cocktail was effective to reduce the cell concentration. Suspension of phage cocktail in the buffer containing 0.25% CaCO3 neutralized 9 times much more buffer of pH 2. Based on this in vitro experiment, phage cocktail (SP15-21-22) suspended in the buffer containing 0.25% CaCO3 was orally administrated to the mice in which E. coli O157:H7 cells was administrated in 2-d advance. E. coli and phage concentration in the feces was monitored for 9 d after phage addition. High titer of phage was detected in the feces when the phage cocktail administrated daily. E. coli O157:H7 concentration in the feces has been reduced according to the time period. However, difference of E. coli concentration in the feces of mice administrates with phage and in the control mice without phage addition became slight after 9-d test period. High titer of the phage settled down in the gastrointestinal tracts and reduced the concentration of E. coli cell. Repeated oral administration of SP15-21-22 was effective for rapid evacuation of E. coli O157:H7 from the feces and gastrointestinal tract of mice.


Asunto(s)
Colifagos , Infecciones por Escherichia coli/terapia , Escherichia coli O157/virología , Tracto Gastrointestinal/microbiología , Probióticos/uso terapéutico , Administración Oral , Animales , Bacteriólisis , Bovinos , Recuento de Células , Colifagos/aislamiento & purificación , Heces/virología , Ratones , Probióticos/administración & dosificación
19.
Syst Appl Microbiol ; 28(4): 358-65, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15997709

RESUMEN

Bacteria with tannase activity were isolated from the feces of the Japanese large wood mouse, Apodemus speciosus. They were largely classified into two groups: Gram-positive cocci and Gram-positive bacilli. Genotypic analysis using a species-specific PCR assay as well as biochemical tests identified all cocci as Streptococcus gallolyticus. A PCR assay targeting a genus-specific sequence in the 16S/23S rDNA spacer region and additional 16S rDNA sequencing indicated that the bacilli belong to the genus Lactobacillus, with L. animalis and L. murinus being closely related taxa. Subsequent estimation of guanine-plus-cytosine content, amplified ribosomal DNA restriction analysis, and DNA/ DNA hybridization assay confirmed that the bacilli are homologous to each other but different from L. animalis or L. murinus. Consequently, a novel species of the genus Lactobacillus may be proposed. To date, this study is the first to report on the isolation of tannase-positive bacteria from the feces of a rodent species. These bacteria may play an essential role for the host organism in digesting tannin-rich acorns available in their natural habitats, thereby endowing them with a greater ecological advantage.


Asunto(s)
Heces/microbiología , Lactobacillus/aislamiento & purificación , Muridae/microbiología , Streptococcus/aislamiento & purificación , Taninos/metabolismo , Animales , Composición de Base , Biodegradación Ambiental , Hidrolasas de Éster Carboxílico/metabolismo , Dermatoglifia del ADN , ADN Bacteriano/análisis , ADN Bacteriano/genética , ADN Ribosómico/análisis , ADN Ribosómico/genética , ADN Espaciador Ribosómico/análisis , ADN Espaciador Ribosómico/genética , Japón , Lactobacillus/clasificación , Lactobacillus/genética , Lactobacillus/metabolismo , Ratones , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Streptococcus/clasificación , Streptococcus/genética , Streptococcus/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA