Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 44
Filtrar
1.
J Dairy Sci ; 104(11): 11660-11672, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34419269

RESUMEN

Pleurotus ostreatus (oyster mushroom) synthesizes enzymes that degrade lignin, cellulose, and hemicellulose. The objectives of this study were to evaluate the effect of Pleurotus ostreatus spent substrate (POSS) on whole-plant corn silage (WPCS) chemical composition, antioxidant capacity, lignin monomers, and in vitro digestibility, as well as the performance of lactating goats fed corn silage treated with different levels of POSS. In experiment 1, 4 levels of lignocellulolytic enzymes were tested in a complete randomized design: 0, 10, 20, and 30 mg of lignocellulosic enzymes per kilogram of fresh matter, 4 replicates per treatment (vacuum-sealed bags). The bags were opened 60 d after ensiling. In experiment 2, corn silage treated with 3 enzyme levels (0, 10, or 30 mg/kg of fresh matter) was fed to lactating goats as part of the total mixed ration. Nine lactating Saanen goats (62.68 ± 7.62 kg BW; 44 ± 8 d in milk; 2.91 ± 0.81 kg of milk/day, mean ± SD) were assigned to three 3 × 3 Latin squares. Data were analyzed using the GLIMMIX procedure of SAS (version 9.4, SAS Institute Inc.), and means were compared by linear and quadratic orthogonal contrast. In experiment 1, neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, and cellulose quadratically decreased in the WPCS treated with POSS. At the nadir point, POSS decreased NDF by 14.1%, ADF by 19.5%, lignin by 9.07%, and cellulose by 22.1% compared with the untreated silage. Therefore, POSS led to a quadratic increase in in vitro dry matter digestibility of WPCS (+8.88% at the vertex) compared with the untreated silage. In experiment 2, POSS quadratically increased the in vivo total-tract ADF digestibility. Also, the concentration of polyphenols in the milk of goats linearly increased with the addition of POSS, and no differences were observed among treatments for milk yield and composition. In summary, adding 10 mg of lignocellulolytic enzymes from POSS per kilogram of fresh matter of whole-plant corn at ensiling had a more evident reduction in lignin and cellulose concentration, leading to greater in vitro digestibility, as well as greater in vivo ADF digestibility; however, milk yield was not different among treatments.


Asunto(s)
Pleurotus , Ensilaje , Animales , Dieta/veterinaria , Fibras de la Dieta , Digestión , Cabras , Lactancia , Leche , Ensilaje/análisis , Zea mays
2.
Neuron ; 11(6): 1133-45, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-7903859

RESUMEN

A polyclonal antibody against myosin light chain kinase (MLCK) of chicken gizzard recognized a 130 kd peptide of bullfrog sympathetic ganglia as MLCK. MLCK immunoreactivity was confined to the neuronal cell body. A synthetic peptide corresponding to an inhibitory domain of MLCK (Ala783-Gly804) was applied intracellularly to isolated sympathetic neurons during whole-cell recordings of ionic currents. The peptide inhibitor reversibly decreased M-type potassium current (IM) while not affecting A-type of delayed rectifier-type potassium currents. Intracellular application of an active fragment of MLCK enhanced IM, whereas application of an inactive MLCK fragment did not. The results suggest that IM can be modulated by MLCK-catalyzed phosphorylation.


Asunto(s)
Ganglios Simpáticos/fisiología , Quinasa de Cadena Ligera de Miosina/metabolismo , Neuronas/fisiología , Péptidos/farmacología , Canales de Potasio/fisiología , Secuencia de Aminoácidos , Animales , Bario/farmacología , Western Blotting , Pollos , Molleja de las Aves/enzimología , Inmunohistoquímica , Potenciales de la Membrana/efectos de los fármacos , Datos de Secuencia Molecular , Muscarina/farmacología , Músculo Liso/enzimología , Quinasa de Cadena Ligera de Miosina/análisis , Neuronas/efectos de los fármacos , Neuronas/enzimología , Fragmentos de Péptidos/síntesis química , Fragmentos de Péptidos/farmacología , Péptidos/síntesis química , Canales de Potasio/efectos de los fármacos , Rana catesbeiana , Tirosina 3-Monooxigenasa/análisis
3.
Clin Obes ; 8(3): 170-175, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29377636

RESUMEN

Post-partum weight retention is relatively common and increases the risk for future obesity. Women who are overweight or obese prior to pregnancy, or who gain excessively during pregnancy, are more likely to retain weight post-partum. Much of the existing research is limited by a single post-partum body-weight measure and therefore cannot distinguish post-partum weight retention from post-partum weight accrual. This study tested the hypothesis that early pregnancy body mass index (BMI) is positively associated with post-partum weight change, independent of gestational weight gain (GWG) and breastfeeding (BF) among African-American women, a demographic group with greater risk for obesity. Healthy African-American women (n = 32) were weighed at 2 weeks and 3 months post-partum to derive post-partum weight change. Data from prenatal care records were retrieved to calculate BMI at the first prenatal care visit and GWG. BF status at 2 weeks post-partum was self-reported. Early pregnancy BMI was positively associated with post-partum weight change (partial r = 0.53, P < 0.005), independent of GWG and BF status at 2 weeks post-partum. These results extend the literature by suggesting that the association between early pregnancy BMI and post-partum weight retention may be at least partially attributable to the accrual of new weight during the post-partum period. Future research in a larger and more diverse cohort is warranted and should explore potential mechanisms contributing to post-partum weight change.


Asunto(s)
Negro o Afroamericano , Índice de Masa Corporal , Peso Corporal , Obesidad/etiología , Periodo Posparto , Complicaciones del Embarazo , Aumento de Peso , Adulto , Estudios de Cohortes , Femenino , Humanos , Sobrepeso , Embarazo , Factores de Riesgo , Adulto Joven
4.
Pediatr Obes ; 13(8): 485-491, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29573242

RESUMEN

BACKGROUND: Cord blood adiponectin and leptin concentrations are associated with birth weight and adiposity. Birth size and rate of infant weight gain are associated with future obesity risk. However, it is unclear whether biomarkers reflecting the intrauterine environment are predictive of infant prospective body composition change. OBJECTIVES: To examine whether cord blood adiponectin and leptin are predictive of neonatal adiposity and fat mass (FM) accrual to 3 months of age. METHODS: Participants (n = 36) were healthy African American infants. Leptin and adiponectin concentrations were measured in umbilical cord blood. At 2 weeks and 3 months, infant body composition was assessed via air displacement plethysmography. Weight-for-length z-scores (WLZ) were calculated using World Health Organization standards. Multiple linear regression was used to examine associations of cord blood adiponectin and leptin with birth WLZ; WLZ, FM and fat-free mass at 2 weeks, and the conditional change in these variables from 2 weeks to 3 months (body composition at 3 months adjusted for body composition at 2 weeks). RESULTS: Adiponectin was positively associated with FM at 2 weeks (r = 0.45, P < 0.01), but inversely associated with conditional FM change from 2 weeks to 3 months of age (r = -0.38, P < 0.05). Leptin was not significantly associated with infant body composition. CONCLUSIONS: Adiponectin may be a marker for FM accrual in African American infants, a relatively understudied population with a high long-term obesity risk. Mechanistic studies are needed to determine whether adiponectin directly influences infant growth or is simply a maker reflective of other ongoing biological changes after birth.


Asunto(s)
Adiponectina/sangre , Tejido Adiposo/fisiología , Adiposidad/fisiología , Negro o Afroamericano/estadística & datos numéricos , Composición Corporal/fisiología , Leptina/sangre , Biomarcadores/sangre , Peso al Nacer , Femenino , Sangre Fetal , Humanos , Lactante , Recién Nacido , Masculino , Pletismografía , Aumento de Peso
5.
Neurogastroenterol Motil ; 19(5): 390-400, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17509021

RESUMEN

Oil of mustard (OM), administered intracolonically, produces severe colitis in mice that is maximized within 3 days. The purpose of this study was to characterize the cytokine response, and to establish expression patterns of enteric neuronal mediators and neuronal receptors affected during active colitis. We measured the changes in the mRNA levels for neuronal receptors and mediators by real-time PCR, and cytokine and chemokine protein levels in the affected tissue. Significant increases in neuronal receptors, such as transient receptor potential A1 (TRPA1), cannabinoid type 1 receptor, neurokinin 1 receptor (NK1R) and delta-opioid receptor; prokineticin-1 receptor; and soluble mediators, such as prodynorphin, proenkephalin1, NK1, prokineticin-1 and secretory leukocyte protease inhibitor, occurred. Significant increases in cytokines, such as interleukin (IL)-1beta, IL-6 and granulocyte macrophage colony stimulating factor (GM-CSF), and in chemokines, such as macrophage chemotactic protein 1 (MCP-1), macrophage inflammatory protein 1 (MIP-1alpha) and Kupffer cell derived chemokine (KC), were detected, with no changes in T-cell-derived cytokines. Furthermore, immunodeficient C57Bl/6 RAG2(-/-) mice exhibited OM colitis of equal severity as seen in wt C57Bl/6 and CD-1 mice. The results demonstrate rapidly increased levels of mRNA for neuronal receptors and soluble mediators associated with pain and inflammation, and increases in cytokines associated with macrophage and neutrophil activation and recruitment. Collectively, the data support a neurogenic component in OM colitis coupled with a myeloid cell-related, T- and B-cell-independent inflammatory component.


Asunto(s)
Colitis/inducido químicamente , Citocinas/metabolismo , Planta de la Mostaza/toxicidad , Neuropéptidos/metabolismo , Aceites de Plantas/toxicidad , Células Receptoras Sensoriales/metabolismo , Animales , Colitis/patología , Colon/metabolismo , Colon/patología , Citocinas/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados/genética , Ratones Noqueados/metabolismo , Neuropéptidos/genética , Aceites de Plantas/administración & dosificación , Canal Catiónico TRPA1 , Canales Catiónicos TRPV/genética , Canales Catiónicos TRPV/metabolismo , Canales de Potencial de Receptor Transitorio/genética , Canales de Potencial de Receptor Transitorio/metabolismo
6.
J Leukoc Biol ; 58(5): 585-94, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7595061

RESUMEN

THP-1 myelomonocytic leukemia cells cultured with either macrophage colony-stimulating factor (M-CSF) or interferon-gamma (IFN-gamma) alone produce, at best, only low levels of interleukin-1 beta (IL-1 beta) and tumor necrosis factor alpha (TNF-alpha). However, combinations of the two factors resulted in at least 3- to 20-fold greater amounts of IL-1 beta and TNF-alpha than would have been predicted by additive mechanisms. This enhanced cytokine production was observed when M-CSF and IFN-gamma were added simultaneously or when M-CSF was added 24 h after addition of IFN-gamma to the cells. Similar results were obtained with fresh human peripheral blood cells treated with IFN-gamma + M-CSF. Cycloheximide treatment of the cultures containing M-CSF and IFN-gamma inhibited the production of IL-1 beta and TNF-alpha. Northern blotting studies revealed no effect of IFN-gamma alone on IL-1 beta or TNF-alpha mRNA production. IL-1 beta and TNF-alpha mRNA expression was observed at 2 and 6 h after treatment with M-CSF or IFN-gamma + M-CSF. Higher TNF-alpha mRNA expression was observed at 2 and 6 h after treatment with IFN-gamma + M-CSF, and higher IL-1 beta mRNA expression was observed at 2 h after treatment with IFN-gamma + M-CSF compared with mRNA levels observed for cells cultured only with M-CSF. These results suggest that the augmented cytokine production resulting from treatments with combinations of M-CSF and IFN-gamma occurs due to increased cytokine mRNA and increased cytokine protein synthesis. In addition to up-regulating cytokines, combinations of IFN-gamma and M-CSF resulted in augmented cell surface expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1. This was accompanied by morphological and functional changes that included plastic adherence, extensive homotypic aggregation, and a macrophage-like appearance. These phenotypic changes and enhancements in cytokine expression and cell surface molecule expression may be related to activation of monocytic cells to become cytotoxic effectors by M-CSF and IFN-gamma combinations. In vitro cytotoxicity against A-375 melanoma cells was greatest for cultures that contained M-CSF and IFN-gamma in combination.


Asunto(s)
Interferón gamma/administración & dosificación , Interleucina-1/administración & dosificación , Leucemia Monocítica Aguda/metabolismo , Factor de Necrosis Tumoral alfa/biosíntesis , Cicloheximida/farmacología , Citotoxicidad Inmunológica/efectos de los fármacos , Citometría de Flujo , Humanos , Inmunidad Celular , Molécula 1 de Adhesión Intercelular/metabolismo , Factor Estimulante de Colonias de Macrófagos/administración & dosificación , Inhibidores de la Síntesis de la Proteína/farmacología , Células Tumorales Cultivadas , Molécula 1 de Adhesión Celular Vascular/metabolismo
7.
J Leukoc Biol ; 52(3): 349-56, 1992 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-1522390

RESUMEN

Thioglycolate-elicited peritoneal macrophages from normal C57B1/6J mice were examined in vitro for bacterial lipopolysaccharide (LPS)-stimulated interleukin-1 (IL-1), IL-6, and tumor necrosis factor (TNF) production. Macrophages from mice administered a single oral dose of levamisole (3 mg/kg) 1 to 4 days prior to macrophage harvest demonstrated a twofold enhancement of IL-1 production compared to vehicle-treated mice. In contrast, IL-6 production and TNF production by the same macrophages were inhibited up to 36 and 62%, respectively, compared to production by macrophages harvested from vehicle-treated mice. Similar results were observed when IL-1 production and TNF production were followed in peritoneal exidate cells directly stimulated with levamisole in vitro. The ex vivo LPS-stimulated IL-1 production was enhanced 4 days after macrophage elicitation, whereas TNF and IL-6 production returned to baseline by 72 h after macrophage recruitment and augmentation. No evidence could be found for the presence of inhibitors of TNF or IL-6. The specificity of the IL-1, IL-6, and TNF bioactivities was demonstrated by neutralization with specific antisera. Immunoprecipitation studies of supernatants from biosynthetically labeled macrophages also revealed augmented IL-1 production and decreased IL-6 and TNF, indicating that levamisole may have affected cytokine production at the translational level. Kinetics studies revealed that ex vivo release of IL-6 and TNF by macrophages from levamisole-dosed mice was delayed compared to production of these cytokines by macrophages harvested from mice given vehicle only. The results may explain, in part, the reported ability of levamisole to ameliorate cases of rheumatoid arthritis or other autoimmune and inflammatory diseases by affecting the relative levels of cytokines produced by macrophages recruited to sites of injury, which are associated with inflammation and acute-phase protein synthesis.


Asunto(s)
Interleucina-1/biosíntesis , Interleucina-6/biosíntesis , Levamisol/farmacología , Macrófagos/metabolismo , Factor de Necrosis Tumoral alfa/biosíntesis , Animales , Femenino , Técnicas In Vitro , Lipopolisacáridos , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Pruebas de Precipitina
8.
Transplant Proc ; 37(2): 1243-4, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15848683

RESUMEN

UNLABELLED: The purpose of this study was to evaluate the clinical impact of methicillin-resistant Staphylococcus aureus (MRSA) infections on transplant recipients. METHODS: Liver and kidney recipients with MRSA infections were retrospectively identified and compared to an age, gender, UNOS status, organ transplanted, and transplant date matched (2:1) non-MRSA-infected recipient control group. All MRSA infections were initially treated with vancomycin, and four (33%) liver recipients were converted to linezolid therapy after failing to improve with vancomycin. RESULTS: The overall MRSA infection incidence was 1.4% (24/1770) with MRSA more common in liver (3.75%; 12/320) than kidney transplants (0.8%; 12/1450) (P < .001). The most common sites of MRSA infection were blood (42%), lung (38%), and abdomen (29%). The MRSA group had a greater percentage of prior antibiotic usage (79% vs 40%; P < .0015). The MRSA group experienced more posttransplant complications (52% vs 19%; P < .011)), and exhibited a trend toward greater length of stay in the intensive care unit (7.8 vs 4.6 days; P = .09), but not overall length of stay. Survival was similar in MRSA and non-MRSA groups (75% vs 88%; P = .17). No significant differences in mortality were noted between liver and kidney recipients infected with MRSA (P = .6). CONCLUSION: MRSA infection is associated with a higher incidence of posttransplant complications and antibiotic usage in both liver and kidney recipients compared to patients with MRSA infection.


Asunto(s)
Trasplante de Hígado , Complicaciones Posoperatorias/microbiología , Infecciones Estafilocócicas/epidemiología , Acetamidas/uso terapéutico , Femenino , Humanos , Incidencia , Unidades de Cuidados Intensivos , Tiempo de Internación , Linezolid , Masculino , Resistencia a la Meticilina , Oxazolidinonas/uso terapéutico , Complicaciones Posoperatorias/epidemiología , Estudios Retrospectivos , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/mortalidad , Análisis de Supervivencia , Vancomicina/uso terapéutico
9.
J Med Chem ; 30(8): 1433-54, 1987 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-3039136

RESUMEN

A series of pyrrolo[2,1-a]isoquinolines, and related compounds, were examined for antidepressant-like activity, by virtue of their antagonism of tetrabenazine-induced ptosis and sedation, and inhibition of biogenic amine uptake. Thus, we have identified some of the most potent antagonists of TBZ-induced ptosis and some of the most potent inhibitors of the uptake of dopamine, norepinephrine, and serotonin (in rat brain synaptosomes) ever reported. Compounds of particular note, in this regard, are 52b, 29b, 22b, and 48b, respectively. Biological activity was chiefly manifested by the trans isomeric class. Also, through resolution of four compounds, 7b, 24b, 37b, and 48b, biological activity was found to be associated with the (+) enantiomer subgroup (salts measured at 589 nm in MeOH), corresponding to the 6S, 10bR absolute configuration for 7b, 37b, and 48b, and the 6R,10bR configuration for 24b. An X-ray determination on (+)-24b X HBr established its absolute configuration; configurations for the other compounds were verified by enantiospecific synthesis starting with (+)-(R)-2-phenylpyrrolidine. Regarding the pendant phenyl ring, diverse substitution patterns were investigated. Those substitutions that were particularly unfavorable were 3',4',5'-trimethoxy (20b), 2',3',4',5',6'-pentafluoro (34b), 2'-trifluoromethyl (38b), 3',5'-bis(trifluoromethyl) (42b), 4'-n-butyl (44b), 2'-cyano (47b), 4'-methylsulfonyl (50b), and 2'-carboxy (58b). Exceedingly potent compounds, in one way or another, were 10b-12b, 22b, 23b, 25b, 28b, 29b, 33b, 45b, 48b, 51b-53b. The pattern of aromatic substitution had a strong impact on selectivity in the uptake tests (NE vs. DA vs. 5-HT). Activity was significantly diminished by methyl substitution of 7b at the 5 (65, 66), 6 (61b), or 10b (60b) position, by changing the phenyl group of 7b to cyclohexyl (67b), benzyl (68b), or H (72), by moving the phenyl group of 7b to the 5 (69) or 10b (70) position, by expansion of ring B to an azepine (78b), and by modification of ring C to an azetidine (77b), piperidine (75b), or azepine (74b). The interaction of selected analogues with various CNS receptors is reported. Little affinity was shown for the muscarinic cholinergic receptor, suggesting a lack of anticholinergic side effects. Interestingly, 24b and 33b displayed a high affinity for the serotonin-2 receptor, analogous to mianserin and clomipramine. After the body of data was reviewed, derivatives 24b and 48b were chosen for advanced development.


Asunto(s)
Encéfalo/metabolismo , Catecolaminas/metabolismo , Isoquinolinas/farmacología , Pirroles/farmacología , Tetrabenazina/antagonistas & inhibidores , Animales , Antidepresivos , Blefaroptosis/inducido químicamente , Blefaroptosis/prevención & control , Encéfalo/efectos de los fármacos , Fenómenos Químicos , Química , Dopamina/metabolismo , Isoquinolinas/síntesis química , Isoquinolinas/metabolismo , Masculino , Conformación Molecular , Actividad Motora/efectos de los fármacos , Norepinefrina/metabolismo , Pirroles/síntesis química , Pirroles/metabolismo , Ratas , Ratas Endogámicas , Receptores Adrenérgicos alfa/metabolismo , Receptores Dopaminérgicos/metabolismo , Receptores de Serotonina/metabolismo , Serotonina/metabolismo , Relación Estructura-Actividad , Sinaptosomas/metabolismo
10.
Neuroscience ; 79(4): 1219-29, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9219980

RESUMEN

Substance P is an important neuropeptide neurotransmitter in the central, autonomic and enteric nervous systems. In sympathetic ganglia, substance P is thought to play a role in modulating synaptic transmission. Release of substance P by neuronal stimulation or direct application of substance P to ganglionic neurons increases neuronal excitability. An amphibian substance P receptor complementary DNA has been cloned and characterized from bullfrog, Rana catesbeiana, sympathetic ganglion complementary DNA libraries. The deduced primary structure contains features indicative of a seven transmembrane domain G-protein-coupled receptor. The deduced protein sequence shows 69% identity to previously cloned mammalian substance P receptors. In situ hybridization analysis performed on bullfrog sympathetic ganglia using digoxigenin-labelled complementary RNA probe demonstrated that approximately 75% of the principal neurons displayed reaction product above background levels. Radioligand binding studies were performed on stably transfected cells with [(125)I]Tyr-1-substance P as the ligand. Substance P had an IC50 of 16 nM and the agonist potency profile was substance P>neurokinin A >> neurokinin B. The order of potency for three tachykinins to increase intracellular calcium when applied to a stably transfected clonal cell line was substance P>neurokinin A >> neurokinin B. This order of agonist potency also held for inhibition of the M-type potassium current in intact bullfrog sympathetic neurons. The non-peptide substance P antagonists CP-96345 and RP-67580 at concentrations that block mammalian substance P receptors had little or no effect on the responses to substance P at the bullfrog receptor. Overall, these results demonstrate that the cloned sequence has the features consistent with and characteristic of a substance P receptor. The results are discussed with reference to the established pharmacology of the bullfrog substance P receptor and known structure activity relationships of mammalian tachykinin receptors.


Asunto(s)
Ganglios Simpáticos/metabolismo , Receptores de Neuroquinina-1/efectos de los fármacos , Receptores de Neuroquinina-1/genética , Sustancia P/farmacología , Animales , Secuencia de Bases , Células CHO/efectos de los fármacos , Cricetinae , Relación Dosis-Respuesta a Droga , Ganglios Simpáticos/efectos de los fármacos , Hibridación in Situ , Masculino , Datos de Secuencia Molecular , Ensayo de Unión Radioligante , Rana catesbeiana
11.
Br J Pharmacol ; 114(2): 489-95, 1995 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7881747

RESUMEN

1. The actions of wortmannin, an inhibitor of myosin light chain kinase (MLCK), on M-type potassium current of dissociated bullfrog sympathetic neurones have been examined. 2. The amplitude of M-current was measured by whole cell recordings from cells pretreated with wortmannin (0.01-10 microM) or the wortmannin vehicle, dimethylsulphoxide (0.0001-0.1 vol%), for 30 min. Internal (recording pipette) solutions having three different pCa values (6, 7 and 8) were used for the measurements. 3. Irrespective of the pCa, M-current was not detectable when the cells were pretreated with 10 microM wortmannin. Wortmannin, 3 microM, produced 85-95% inhibition of the M-current. Pretreatment with 10-30 nM wortmannin was without effect on M-current. 4. The M-current inhibition by wortmannin at concentrations of 0.1-1 microM depended on the pCa of the internal solution. Inhibition occurred only when the calcium-rich (pCa = 6) internal solution was used. 5. Pre-treatment of the cells with wortmannin (10 microM) did not affect rapidly-inactivating A-type or delayed rectifier-type potassium currents not did it alter inwardly rectifying sodium-potassium current (IH). 6. These observations show that M-current inhibition by wortmannin has two pharmacological profiles. One is calcium-dependent and occurs at lower concentrations (0.1-1 microM), and is attributed to inhibition of MLCK by wortmannin. At higher concentrations (3-10 microM), wortmannin has an additional, calcium-independent action, inhibiting the M-current by an unknown mechanism.


Asunto(s)
Androstadienos/farmacología , Inhibidores Enzimáticos/farmacología , Neuronas/metabolismo , Canales de Potasio/metabolismo , Sistema Nervioso Simpático/metabolismo , Animales , Calcio/farmacología , Calcio/fisiología , Calmodulina/farmacología , Técnicas de Cultivo , AMP Cíclico/fisiología , Potenciales de la Membrana/efectos de los fármacos , Quinasa de Cadena Ligera de Miosina/metabolismo , Neuronas/efectos de los fármacos , Técnicas de Placa-Clamp , Canales de Potasio/efectos de los fármacos , Rana catesbeiana , Sistema Nervioso Simpático/citología , Sistema Nervioso Simpático/efectos de los fármacos , Wortmanina
12.
Neurogastroenterol Motil ; 16(6): 811-8, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15601431

RESUMEN

Neurogenic mechanisms have been implicated in the induction of inflammatory bowel disease (IBD). Vanilloid receptor type 1 (TRPV1) has been visualized on nerve terminals of intrinsic and extrinsic afferent neurones innervating the gastrointestinal tract and local administration of a TRPV1 antagonist, capsazepine, reduces the severity of dextran sulphate sodium (DSS)-induced colitis in rats (Gut 2003; 52: 713-9(1)). Our aim was to test whether systemically or orally administered TRPV1 antagonists attenuate experimental colitis induced by 5% DSS in Balb/c mice. Intraperitoneal capsazepine (2.5 mg kg(-1), bid), significantly reduced the overall macroscopic damage severity compared with vehicle-treated animals (80% inhibition, P < 0.05); however, there was no effect on myeloperoxidase (MPO) levels. An experimental TRPV1 antagonist given orally was tested against DSS-induced colitis, and shown to reverse the macroscopic damage score at doses of 0.5 and 5.0 mg kg(-1). Epithelial damage assessed microscopically was significantly reduced. MPO levels were attenuated by approximately 50%, and diarrhoea scores were reduced by as much as 70%. These results suggest that pharmacological modulation of TRPV1 attenuates indices of experimental colitis in mice, and that development of orally active TRPV1 antagonists might have therapeutic potential for the treatment of IBD.


Asunto(s)
Capsaicina/análogos & derivados , Colitis/prevención & control , Canales Iónicos/antagonistas & inhibidores , Animales , Anticoagulantes/farmacología , Capsaicina/farmacología , Colitis/inducido químicamente , Colitis/patología , Sulfato de Dextran/farmacología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Femenino , Enfermedades Inflamatorias del Intestino/patología , Enfermedades Inflamatorias del Intestino/prevención & control , Canales Iónicos/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Peroxidasa/efectos de los fármacos , Peroxidasa/metabolismo , Canales Catiónicos TRPV
13.
Neurosci Lett ; 150(2): 133-6, 1993 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-7682310

RESUMEN

A peptide consisting of residues 25-35 of the amyloid beta protein was applied to single neurons while monitoring membrane current by whole cell voltage clamp recording. Within minutes of direct exposure of a neuron to the amyloid beta peptide, a paroxysmal increase in neuronal membrane conductance was observed. This conductance does not resemble previously described ionic conductances in terms of its time-dependence, voltage-dependence or sensitivity to changes in extracellular or intracellular ionic constituents. The effect of the amyloid beta peptide was not mimicked or blocked by substance P nor was it prevented by low intracellular or extracellular Ca. The increased membrane permeability elicited by the peptides may lead to the neuropathology observed in Alzheimer's disease.


Asunto(s)
Péptidos beta-Amiloides/farmacología , Neuronas/efectos de los fármacos , Animales , Calcio/fisiología , Permeabilidad de la Membrana Celular/efectos de los fármacos , Ganglios Simpáticos/citología , Ganglios Simpáticos/efectos de los fármacos , Canales Iónicos/efectos de los fármacos , Conducción Nerviosa , Péptidos/farmacología , Rana catesbeiana , Sustancia P/farmacología
14.
Neurosci Lett ; 207(2): 97-100, 1996 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-8731430

RESUMEN

The mechanism underlying the over-recovery of an M-type potassium current following the washout of muscarine (20 microM) has been examined. Whole-cell recordings were made from single neurons dissociated from bullfrog sympathetic ganglia. During over-recovery, the maximum M-conductance decreased by about 2.8 nS while the steady-state M-current activation curve was displaced in the hyperpolarizing direction by about 13 mV. These data suggest that a hyperpolarizing shift in the kinetics of M-current causes over-recovery in amphibian autonomic neurons.


Asunto(s)
Ganglios Simpáticos/efectos de los fármacos , Potenciales de la Membrana/fisiología , Muscarina/farmacología , Canales de Potasio/efectos de los fármacos , Animales , Técnicas de Placa-Clamp , Rana catesbeiana , Factores de Tiempo
15.
Public Health Rep ; 100(5): 524-30, 1985.
Artículo en Inglés | MEDLINE | ID: mdl-3931167

RESUMEN

Active transmission of intestinal schistosomiasis is currently limited to the southeastern part of the Dominican Republic. A population-based stool survey in 1980 detected 4 asymptomatic individuals among 114 selected at random in 2 towns and a rural community in El Seibo Province. The distribution of the transmitting snail, Biomphalaria glabrata, considerably exceeds that of Schistosoma mansoni, extending to the National District and capital city of Santo Domingo and well into certain central valley provinces. There is evidence that transmission sites have shifted during the past three decades because of urban development, molluscicidal activities and, perhaps, introduction of competing mollusks. In spite of intermittent control activities, the combination of domestic and recreational use of streams with consequent fecal contamination, and the extended distribution of B. glabrata indicates that the potential for new transmission foci is as great today as it was 10 years ago. This potential transmission of S. mansoni is a continuing threat to public health in the Dominican Republic.


Asunto(s)
Biomphalaria/parasitología , Esquistosomiasis mansoni/epidemiología , Adolescente , Adulto , Anciano , Animales , Niño , Preescolar , República Dominicana , Métodos Epidemiológicos , Heces/parasitología , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Schistosoma mansoni/aislamiento & purificación , Esquistosomiasis mansoni/transmisión , Contaminación del Agua
16.
Artículo en Inglés | MEDLINE | ID: mdl-1030834

RESUMEN

Human schistosomiasis has been known in Cambodia only since 1968. In 1968-1970, many cases were detected in the provincial capital of Kratié. Infection seemed to be confined to the ethnic Vietnamese fishermen who inhabited raft houses (= floating villages) on the Mekong River at Kratié. Overall prevalence in fishermen of all ages was between 7 and 10%. In the children of fishermen between the ages of 1 to 14, the prevalence was between 14 and 22%. Transmission was apparently limited to floating houses stationed more or less permanently near shore and connected to each other in a chain. It is believed that transmission occurred only in the areas of still water which were created between raft and shore. The principal focus of schistosomiasis in Cambodia appears to be Kratié. Only a few cases have been detected elsewhere in the country. The parasite is undoubtedly identical with the Schistosoma reported from humans and dogs at Khong Island, Laos. However, the transmitting snail in Laos, Lithoglyphopsis aperta, has thus far not been reported from the Mekong River in Cambodia.


Asunto(s)
Esquistosomiasis/epidemiología , Adolescente , Adulto , Anciano , Cambodia , Niño , Preescolar , Reservorios de Enfermedades , Heces/parasitología , Femenino , Geografía , Humanos , Lactante , Masculino , Persona de Mediana Edad , Recuento de Huevos de Parásitos , Esquistosomiasis/diagnóstico , Esquistosomiasis/transmisión , Pruebas Cutáneas
17.
Artículo en Inglés | MEDLINE | ID: mdl-1166350

RESUMEN

No evidence of infection with the Mekong Schistosoma was found in 12 Rattus exulans, 81 R. r. molliculus, and 10 Bandicota savilei caught in the vicinity of and downstream from the schistosomiasis transmission focus on Khong Island, South Laos, and examined by dissection and portal perfusion. Likewise, no eggs of the Mekong Schistosoma were detected in faeces of 15 domestic pigs or 43 domestic cattle examined on Khong Island both by merthiolate-iodine-formalin concentration and by the hatching technique. These results suggested that the wild rodents listed above, as well as pigs and cattle in the vicinity of Khong Town, may not contribute significantly to the transmission of the Mekong Schistosoma under present conditions.


Asunto(s)
Esquistosomiasis/transmisión , Animales , Bovinos/parasitología , Heces/parasitología , Humanos , Laos , Ratas , Roedores/parasitología , Schistosoma/aislamiento & purificación , Porcinos/parasitología
18.
Rofo ; 185(9): 869-76, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23888470

RESUMEN

PURPOSE: To assess the feasibility of micro-CT for obtaining quantitative volumetric and morphologic information of changes in soft tissue, respiratory tracts and vascularization in fibrotic, emphysematous and non-diseased human lung specimens. MATERIALS AND METHODS: Specimens from autopsy or lung explantation with lung fibrosis of UIP pattern (n = 22) or centrilobular emphysema (n = 10) were scanned by micro-CT and compared to controls (n = 22). Imaging was performed subsequent to intravascular contrast enhancement for the assessment of the vascular volume fraction. The soft tissue and air fraction were quantified after the fixation of ventilated lungs followed by tissue contrast enhancement using osmium. Aiming an artifact-free 3 D reconstruction of lung acini, synchrotron-based micro-CT scans of specimens with emphysema (n = 5) and non-diseased tissue (n = 6) was performed. Micro-CT imaging was complemented by histology for the demonstration of comparable findings. RESULTS: Quantitative analysis showed a significant increase of the soft tissue fraction, equivalent to a decrease of the air fraction in fibrotic lungs compared to controls (p < 0.001) and a significant reduction of the vascular volume fraction compared to controls (p < 0.02). Specimens with emphysema demonstrated a significant increase of the air fraction with a decrease in soft tissue compared to controls (p < 0.001). 3 D reconstructions of lung acini worked successfully in non-diseased tissue but failed in fibrotic and emphysematous lungs. CONCLUSION: Our findings indicate micro-CT's technical feasibility to assess quantitative and morphological data from diseased and non-diseased human lung specimens.


Asunto(s)
Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Imagenología Tridimensional/métodos , Pulmón/patología , Enfisema Pulmonar/patología , Fibrosis Pulmonar/patología , Microtomografía por Rayos X/métodos , Células Acinares/patología , Tejido Conectivo/patología , Medios de Contraste , Estudios de Factibilidad , Humanos , Pulmón/irrigación sanguínea , Tamaño de los Órganos/fisiología , Alveolos Pulmonares/patología , Arteria Pulmonar/patología , Enfisema Pulmonar/diagnóstico , Fibrosis Pulmonar/diagnóstico , Venas Pulmonares/patología , Valores de Referencia , Elastómeros de Silicona
19.
Br J Pharmacol ; 167(5): 1111-25, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22671931

RESUMEN

BACKGROUND & PURPOSE: Loperamide is a selective µ opioid receptor agonist acting locally in the gastrointestinal (GI) tract as an effective anti-diarrhoeal but can cause constipation. We tested whether modulating µ opioid receptor agonism with δ opioid receptor antagonism, by combining reference compounds or using a novel compound ('MuDelta'), could normalize GI motility without constipation. EXPERIMENTAL APPROACH: MuDelta was characterized in vitro as a potent µ opioid receptor agonist and high-affinity δ opioid receptor antagonist. Reference compounds, MuDelta and loperamide were assessed in the following ex vivo and in vivo experiments: guinea pig intestinal smooth muscle contractility, mouse intestinal epithelial ion transport and upper GI tract transit, entire GI transit or faecal output in novel environment stressed mice, or four weeks after intracolonic mustard oil (post-inflammatory). Colonic δ opioid receptor immunoreactivity was quantified. KEY RESULTS: δ Opioid receptor antagonism opposed µ opioid receptor agonist inhibition of intestinal contractility and motility. MuDelta reduced intestinal contractility and inhibited neurogenically-mediated secretion. Very low plasma levels of MuDelta were detected after oral administration. Stress up-regulated δ opioid receptor expression in colonic epithelial cells. In stressed mice, MuDelta normalized GI transit and faecal output to control levels over a wide dose range, whereas loperamide had a narrow dose range. MuDelta and loperamide reduced upper GI transit in the post-inflammatory model. CONCLUSIONS AND IMPLICATIONS: MuDelta normalizes, but does not prevent, perturbed GI transit over a wide dose-range in mice. These data support the subsequent assessment of MuDelta in a clinical phase II trial in patients with diarrhoea-predominant irritable bowel syndrome.


Asunto(s)
Motilidad Gastrointestinal/fisiología , Receptores Opioides mu/fisiología , Analgésicos Opioides/farmacología , Animales , Femenino , Motilidad Gastrointestinal/efectos de los fármacos , Cobayas , Células HEK293 , Humanos , Macaca fascicularis , Masculino , Ratones , Antagonistas de Narcóticos/farmacología , Ratas , Ratas Sprague-Dawley , Ratas Wistar , Receptores Opioides mu/agonistas , Receptores Opioides mu/antagonistas & inhibidores
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda