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1.
Reprod Med Biol ; 23(1): e12560, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38249352

RESUMEN

Purpose: The primary objective of this investigation is to evaluate how morphological quality affects the pregnancy outcomes in euploid embryos determined by preimplantation genetic testing for aneuploidies (PGT-A). Concurrently, as a secondary objective, we aim to identify which specific aspects of morphological evaluation exert the most significant impact on these outcomes. Methods: A retrospective analysis of 451 single euploid embryo transfer cycles at our clinic was conducted. Embryos were evaluated based on the degree of blastocyst expansion, inner cell mass (ICM), trophectoderm (TE) morphology, and the day of blastocyst vitrification. Outcomes between morphologically low-grade and high-grade embryos were compared. Additionally, the study analyzed which morphological factors most influenced pregnancy outcomes. Results: Pregnancy outcomes were significantly lower in morphologically low-grade blastocysts compared to high-grade ones. Among the morphological evaluations, the ICM assessment was significantly associated with the live birth rate. Conclusion: Our study indicates that the morphological quality of euploid embryos, particularly the evaluation of the ICM, plays a crucial role in IVF-ET success.

2.
Reprod Med Biol ; 22(1): e12553, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38076206

RESUMEN

Purpose: To analyze whether response to the GnRH test is a predictor of empty follicle syndrome (EFS) and to analyze independent risk factors for EFS. Methods: The GnRH test results of 3765 patients from 2016 to 2018 were used to define the reference range of the GnRH test. Risk factors for EFS were estimated by multivariate logistic analysis of 5282 cycles (5247 oocyte-retrieved cycles with GnRH agonist trigger and 35 cycles of EFS) conducted from 2016 to 2019. Results: GnRH testing showed basal hormone values as follows: median LH 5.2 (95 percentile; 1.3-12.6) mIU/mL, LH 30 min 22.0 (6.8-57.1), basal FSH 7.3 (3.0-20.5), FSH 30 min 11.5 (5.1-30.4) and FSH/LH ratio 1.5 (0.6-4.1). Independent risk factors for EFS were antral follicle count (adjusted odds ratio; 0.94, 95% CI; 0.89-0.99), basal LH (0.78, 0.66-0.90), and days duration of ovarian stimulation (1.41, 1.21-1. 60). The respective thresholds were 8 for AFC, 5.0 for basal LH, and 16 days for duration. Conclusions: LH 30 min values of the GnRH test did not predict EFS. Independent risk factors for EFS were AFC, basal LH and days duration of ovarian stimulation.

3.
Commun Chem ; 6(1): 200, 2023 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-37737277

RESUMEN

Production of D-amino acids (D-AAs) on a large-scale enables to provide precursors of peptide therapeutics. In this study, we designed a novel L-amino acid oxidase, HTAncLAAO2, by ancestral sequence reconstruction, exhibiting high thermostability and long-term stability. The crystal structure of HTAncLAAO2 was determined at 2.2 Å by X-ray crystallography, revealing that the enzyme has an octameric form like a "ninja-star" feature. Enzymatic property analysis demonstrated that HTAncLAAO2 exhibits three-order larger kcat/Km values towards four L-AAs (L-Phe, L-Leu, L-Met, and L-Ile) than that of L-Trp. Through screening the variants, we obtained the HTAncLAAO2(W220A) variant, which shows a > 6-fold increase in kcat value toward L-Trp compared to the original enzyme. This variant applies to synthesizing enantio-pure D-Trp derivatives from L- or rac-forms at a preparative scale. Given its excellent properties, HTAncLAAO2 would be a starting point for designing novel oxidases with high activity toward various amines and AAs.

4.
ACS Omega ; 7(48): 44407-44419, 2022 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-36506213

RESUMEN

The flavin-dependent amine oxidase superfamily contains various l-amino acid oxidases (LAAOs) bearing different substrate specificities and enzymatic properties. LAAOs catalyze the oxidation of the α-amino group of l-amino acids (L-AAs) to produce imino acids and H2O2. In this study, an ancestral l-Lys α-oxidase (AncLLysO2) was designed utilizing genome-mined sequences from the Caulobacter species. The AncLLysO2 exhibited high specificity toward l-Lys; the k cat/K m values toward l-Lys were one and two orders larger than those of l-Arg and l-ornithine, respectively. Liquid chromatography-high resolution mass spectrometry analysis indicated that AncLLysO2 released imino acid immediately from the active site after completion of oxidation of the α-amino group. Crystal structures of the ligand-free, l-Lys- and l-Arg-bound forms of AncLLysO2 were determined at 1.4-1.6 Å resolution, indicating that the active site of AncLLysO2 kept an open state during the reaction and more likely to release products. The structures also indicated the substrate recognition mechanism of AncLLysO2; ε-amino, α-amino, and carboxyl groups of l-Lys formed interactions with Q357, A551, and R77, respectively. Biochemical and molecular dynamics simulation analysis of AncLLysO2 indicated that active site residues that indirectly interact with the substrate are also important to exhibit high activity; for example, the aromatic group of Y219 is important to ensure that the l-Lys substrate is placed in the correct position to allow the reaction to proceed efficiently. Taken together, we propose the reaction mechanism of AncLLysO2.

5.
Reprod Sci ; 27(7): 1400-1410, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32329031

RESUMEN

Endometriosis has several distinguishing features in the ectopic endometrium, including chronic inflammation and fibrosis. According to the retrograde menstruation theory, endometriotic cells are derived from eutopic endometrial cells, and adhesion of endometrial cells to the extracellular matrix can be the initial step in the development of endometriosis. Therefore, we hypothesized that cell adhesion, which mediates a sequence of events in the development of endometriosis triggering inflammatory responses and tissue fibrosis could be a possible therapeutic target for endometriosis. We found co-upregulation of focal adhesion kinase (FAK) and monocyte chemoattractant protein-1 (MCP-1) in the endometriotic tissues compared with that in the normal endometrium. MCP-1 secretion was significantly higher in the endometriotic stromal cells than in the eutopic endometrial stromal cells. Furthermore, co-culture of U937 cells and endometriotic stromal cells upregulated secretion of transforming growth factor-ß1 (TGF-ß1). A FAK inhibitor significantly inhibited the secretion of MCP-1 in the endometriotic stromal cells and TGF-ß1 in the co-culture with macrophages. FAK inhibitor treatment in the murine endometriosis model demonstrated a decrease in the formation of endometriotic lesions as well as the expression of MCP-1 and TGF-ß1. Our results suggest that the FAK-mediated sequential development of endometriosis, including inflammatory response and tissue fibrosis, can be a new therapeutic target in endometriosis.


Asunto(s)
Adhesión Celular/fisiología , Sistemas de Liberación de Medicamentos/métodos , Endometriosis/metabolismo , Endometriosis/patología , Quinasa 1 de Adhesión Focal/metabolismo , Mediadores de Inflamación/metabolismo , Animales , Adhesión Celular/efectos de los fármacos , Quimiocina CCL2/antagonistas & inhibidores , Quimiocina CCL2/metabolismo , Técnicas de Cocultivo , Endometriosis/tratamiento farmacológico , Femenino , Fibrosis , Quinasa 1 de Adhesión Focal/antagonistas & inhibidores , Humanos , Mediadores de Inflamación/antagonistas & inhibidores , Leiomioma/tratamiento farmacológico , Leiomioma/metabolismo , Leiomioma/patología , Ratones , Ratones Endogámicos BALB C , Quinolonas/administración & dosificación , Sulfonas/administración & dosificación , Células U937
6.
Reprod Sci ; 26(7): 979-987, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30270745

RESUMEN

Several features exist that distinguish endometriotic cells from eutopic endometrial cells. Progesterone resistance is one of the main distinguishing features, although how progesterone resistance affects the phenotype of endometriotic cells is not fully elucidated. Heart and neural crest derivatives expressed 2 (HAND2) is a transcriptional factor that plays an important role in maintaining endometrial function in a progesterone-dependent manner. Therefore, we explored whether progesterone-dependent HAND2 is implicated in the progression of endometriosis. HAND2 was less expressed by endometriotic tissues compared to endometrial tissues. Suppression of HAND2 expression induced fibroblast growth factor 1 (FGF1), FGF2, and FGF9 in endometriotic stromal cells and consequently enhanced migration and invasion capacity. AZD4547, a FGF receptor inhibitor, diminished the migration and invasion of endometriotic cells in vitro. In the murine model of endometriosis, AZD4547 showed suppressive effects on the development of endometriotic lesions at a relatively low concentration. In conclusion, we demonstrated that FGF1, FGF2, and FGF9 are downstream effectors of HAND2 in endometriotic cells. Since HAND2-dependent FGFs play roles in enhancing invasive capacity of endometriotic cells, our results suggest that FGF receptor inhibitors, such as AZD4547, can be promising therapeutic targets for endometriosis.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Movimiento Celular , Endometriosis/metabolismo , Endometrio/metabolismo , Factores de Crecimiento de Fibroblastos/metabolismo , Fibroblastos/metabolismo , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Benzamidas/farmacología , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Modelos Animales de Enfermedad , Endometriosis/tratamiento farmacológico , Endometriosis/genética , Endometriosis/patología , Endometrio/efectos de los fármacos , Endometrio/patología , Femenino , Factor 1 de Crecimiento de Fibroblastos/genética , Factor 1 de Crecimiento de Fibroblastos/metabolismo , Factor 2 de Crecimiento de Fibroblastos/genética , Factor 2 de Crecimiento de Fibroblastos/metabolismo , Factor 9 de Crecimiento de Fibroblastos/genética , Factor 9 de Crecimiento de Fibroblastos/metabolismo , Factores de Crecimiento de Fibroblastos/genética , Fibroblastos/efectos de los fármacos , Fibroblastos/patología , Humanos , Ratones , Piperazinas/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Pirazoles/farmacología , Receptores de Factores de Crecimiento de Fibroblastos/antagonistas & inhibidores , Receptores de Factores de Crecimiento de Fibroblastos/metabolismo , Transducción de Señal , Regulación hacia Arriba
7.
Reprod Biol Endocrinol ; 16(1): 106, 2018 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-30368246

RESUMEN

BACKGROUND: Given the seriousness of chemotherapy-induced ovarian injury in female cancer patients, the preservation of fertility, including through the use of cryopreservation technology and pharmaceuticals, requires investigation. Previous studies have shown that damage to the ovaries is related to oxidative stress caused by anticancer drugs. Therefore, superoxide dismutase (SOD) may represent a key factor in the pharmacological protection of the ovaries. The aim of our study was to identify the effects of mangafodipir, a manganese chelate and SOD-mimetic, on suppression of apoptosis in granulosa cells and primordial follicle activation induced by anticancer drugs. METHODS: Cell viability assays using methyltrichlorosilane solutions and immunoblotting for cleaved caspase-3 were performed in in vitro experiments with the simultaneous addition of mangafodipir to human non-luteinized granulosa cell line (HGrC) cultures treated with hydrogen peroxide (H2O2), cisplatin, or paclitaxel. Count and morphological analyses of follicles at each developing stage in the ovaries and immunohistochemistry for cleaved caspase-3, Ki67 and 4-hydroxynonenal, a marker for oxidative stress, were also performed using mangafodipir-injected 6-week-old female ICR mice treated with cisplatin or paclitaxel. Further, mangafodipir was injected into 6-week-old female BALB/c mice inoculated with ES-2 to analyze whether mangafodipir inhibits the anti-tumor effects of cisplatin or paclitaxel treatment. RESULTS: Mangafodipir attenuated apoptosis induced by H2O2 and anticancer drugs in vitro. Mangafodipir also decreased the expression of 4-hydroxynonenal and reduced cisplatin- and paclitaxel-induced apoptosis in granulosa cells in vivo. In addition, mangafodipir inhibited the loss of primordial follicles. Tumor xenograft studies in mice showed that mangafodipir did not affect anticancer drug antitumor effects. CONCLUSIONS: Oxidative stress might be one of the mechanisms of cisplatin- and paclitaxel-induced the loss of primordial follicles. Mangafodipir can reduce cisplatin- and paclitaxel-induced apoptosis in granulosa cells and primordial follicle activation partially via its SOD activity. At the same time, mangafodipir might have other potential mechanisms to inhibit the activation of primordial follicles. Further, mangafodipir attenuated the ovarian damage caused by cisplatin and paclitaxel without affecting their antitumor activities. Mangafodipir, therefore, though its efficacy might be limited, may be a new option for the preservation of fertility during anticancer treatment.


Asunto(s)
Antineoplásicos/farmacología , Ácido Edético/análogos & derivados , Células de la Granulosa/efectos de los fármacos , Ovario/efectos de los fármacos , Fosfato de Piridoxal/análogos & derivados , Ensayos Antitumor por Modelo de Xenoinjerto/métodos , Animales , Apoptosis/efectos de los fármacos , Caspasa 3/metabolismo , Línea Celular , Línea Celular Tumoral , Cisplatino/farmacología , Medios de Contraste/farmacología , Ácido Edético/farmacología , Femenino , Células de la Granulosa/citología , Células de la Granulosa/metabolismo , Humanos , Ratones Endogámicos BALB C , Ratones Endogámicos ICR , Ratones Desnudos , Folículo Ovárico/efectos de los fármacos , Folículo Ovárico/metabolismo , Ovario/metabolismo , Estrés Oxidativo/efectos de los fármacos , Paclitaxel/farmacología , Sustancias Protectoras/farmacología , Fosfato de Piridoxal/farmacología
8.
Reprod Biol Endocrinol ; 14(1): 72, 2016 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-27793163

RESUMEN

BACKGROUND: Serum anti-Müllerian hormone (AMH) concentration has been used to assess ovarian reserve in patients with endometriosis, especially when endometrioma surgery is involved. Previously, we reported that decreased serum AMH levels after cystectomy for endometriomas can recover to preoperative levels in some cases. In this present study, we assessed the sequential changes in serum AMH levels before and after cystectomy in terms of the state of the mesosalpinx prior to surgery. METHODS: The retrospective cohort study recruited 53 patients from a series of prospective studies conducted from 2009 to 2015. All patients underwent laparoscopic cystectomy for endometriomas. If either mesosalpinx was involved in the endometrioma or adnexal adhesion before cystectomy, the case was defined as 'involved mesosalpinx' (n = 14). If both mesosalpinx remained anatomically correct, the case was classified as 'intact mesosalpinx' (n = 39). Blood samples were obtained from the patients 2 weeks before surgery, and at 1 month and 1 year after surgery to assess serum AMH levels. RESULTS: The serum AMH levels (the involved group vs. the intact group) were 1.92 vs. 0.98 (P = 0.552) preoperatively, 0.59 vs. 1.99 (P = 0.049) at 1 month postoperatively, and 0.48 vs. 2.37 ng/mL (P = 0.007) at 1 year postoperatively. The involved mesosalpinx group showed a further decrease in serum AMH levels at 1 year postoperatively, while serum AMH levels in the intact mesosalpinx group tended to recover. CONCLUSION: These results suggest that pre-existing mesosalpinx disturbance, in combination with adhesiolysis, may be involved in the medium- and long-term decrease in ovarian reserve after endometrioma surgery. A disturbance in ovarian blood supply via the mesosalpinx may underlie this. TRIAL REGISTRATION: UMIN-CTR UMIN000019369 . Retrospectively registered October 15, 2015.


Asunto(s)
Hormona Antimülleriana/sangre , Ligamento Ancho/cirugía , Endometriosis/cirugía , Quistes Ováricos/cirugía , Enfermedades del Ovario/cirugía , Reserva Ovárica , Adulto , Estudios de Casos y Controles , Estudios de Cohortes , Endometriosis/sangre , Femenino , Procedimientos Quirúrgicos Ginecológicos , Humanos , Laparoscopía , Quistes Ováricos/sangre , Enfermedades del Ovario/sangre , Estudios Retrospectivos , Factores de Riesgo , Adherencias Tisulares/cirugía
9.
Free Radic Res ; 50(10): 1131-1139, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27396236

RESUMEN

Endometriosis is observed in ∼10% of reproductive age women. Ovarian endometriosis not only causes dysmenorrhea but also causes infertility and a high risk of adenocarcinoma. Due to its scattered nature, complete surgical resection is difficult. Endometriosis consists of glandular and stromal cells. Previously, we showed that endometrial stromal cells (ESCs) play a role in the protection against pathologic events caused by monthly repeated hemorrhage. Here, we undertook a preclinical study of non-thermal plasma (NTP) as a surgical treatment of endometriosis. Epithelial cells were most sensitive to NTP-activated medium in vitro, whereas ectopic ESCs were most resistant. We then transplanted excised uteruses into BALB/c mice from donors of the same strain with estradiol supplementation. Four weeks after the transplantation, we exposed NTP to each endometriotic lesion after laparotomy. Immunohistochemical analysis revealed that immediately after NTP exposure, epithelial cells exhibited significantly higher levels of nuclear immunostaining for 8-hydroxy-2'-deoxyguanosine than did stromal cells. Four weeks after NTP exposure, the total surface area consisting of endometriotic cysts was significantly smaller with less epithelial proliferative activity than the helium-exposed control, whereas the number of endometriotic lesions had not changed. Therefore, NTP exposure may be useful to prevent the progression and recurrence of endometriosis.


Asunto(s)
Endometriosis/prevención & control , Gases em Plasma/uso terapéutico , Animales , Proliferación Celular , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Femenino , Ratones , Ratones Endogámicos BALB C
10.
Gynecol Endocrinol ; 32(9): 733-736, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26965297

RESUMEN

Pentraxin 3 (PTX3) is an inflammatory mediator that is released by a wide range of tissues and cells. Elevated PTX3 levels may represent a useful diagnostic and/or prognostic marker for a number of diseases. The purpose of this study was to investigate serum PTX3 levels in benign gynecological conditions including mature cystic teratomas (MCTs), endometriomas, and uterine leiomyomas. Serum PTX3 levels of the MCT group were found to be significantly higher compared to those of the other groups, including healthy controls (p = 0.001), although carbohydrate antigen 19-9 (CA19-9) did not exhibit a significant difference. Serum PTX3 levels of the MCT, but not the endometrioma group, were also found to have significantly decreased post-operatively (mean ± standard deviation, 4.98 ± 2.10 to 3.61 ± 1.53 ng/mL). Immunohistochemical analyses demonstrated positive staining for PTX3 protein in the sebaceous glands, epidermal tissues, and hair roots of MCT specimens. PTX3 is expressed by MCTs and is associated with increased serum concentrations compared to healthy controls and patients with either endometriomas or uterine leiomyomas. We conclude that serum PTX3 levels could be used as a potential diagnostic marker for MCTs, especially helpful in differentiating them from endometriomas with elevated expression of CA19-9.


Asunto(s)
Biomarcadores de Tumor/sangre , Proteína C-Reactiva/metabolismo , Endometriosis/sangre , Leiomioma/sangre , Componente Amiloide P Sérico/metabolismo , Teratoma/sangre , Neoplasias Uterinas/sangre , Adolescente , Adulto , Femenino , Humanos , Leiomioma/cirugía , Persona de Mediana Edad , Teratoma/cirugía , Neoplasias Uterinas/cirugía , Adulto Joven
11.
Redox Biol ; 6: 578-586, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26498255

RESUMEN

Ovarian endometriosis is a recognized risk for infertility and epithelial ovarian cancer, presumably due to iron overload resulting from repeated hemorrhage. To find a clue for early detection and prevention of ovarian endometriosis-associated cancer, it is mandatory to evaluate catalytic (labile) ferrous iron (catalytic Fe(II)) and to study iron manipulation in ovarian endometriotic lesions. By the use of tissues from women of ovarian endometriosis as well as endometrial tissue from women with and without endometriosis, we for the first time performed histological analysis and cellular detection of catalytic Fe(II) with a specific fluorescent probe (HMRhoNox-M), and further evaluated iron transport proteins in the human specimens and in co-culture experiments using immortalized human eutopic/ectopic endometrial stromal cells (ESCs) in the presence or absence of epithelial cells (EpCs). The amounts of catalytic Fe(II) were higher in ectopic endometrial stromal cells (ecESCs) than in normal eutopic endometrial stromal cells (n-euESCs) both in the tissues and in the corresponding immortalized ESCs. ecESCs exhibited higher transferrin receptor 1 expression both in vivo and in vitro and lower ferroportin expression in vivo than n-euESCs, leading to sustained iron uptake. In co-culture experiments of ESCs with iron-loaded EpCs, ecESCs received catalytic ferrous iron from EpCs, but n-euESCs did not. These data suggest that ecESC play a protective role for cancer-target epithelial cells by collecting excess iron, and that these characteristics are retained in the immortalized ecESCs.


Asunto(s)
Endometriosis/patología , Hierro/metabolismo , Enfermedades del Ovario/patología , Células del Estroma/metabolismo , Línea Celular Tumoral , Técnicas de Cocultivo , Endometriosis/metabolismo , Femenino , Humanos , Enfermedades del Ovario/metabolismo , Ovario/metabolismo , Receptores de Transferrina
12.
Neurosci Lett ; 425(3): 137-40, 2007 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-17854993

RESUMEN

Neonicotinoid insecticides target nicotinic acetylcholine receptors (nAChRs), which, in both vertebrates and invertebrates, mediate fast-acting synaptic neurotransmission in the nervous system. Recently, Kagabu et al. synthesized bis-neonicotinoids. The neural activities of bis-neonicotinoids have been evaluated on the central nerve cord of American cockroaches. However, the action of bis-neonicotinoids on nAChRs expressed by dissociated insect neurons has not yet been studied. Thus, the actions of several alkylene-tethered bis-neonicotinoids on the terminal abdominal ganglion neurons of the American cockroach, Periplaneta americana, were investigated using whole-cell patch-clamp electrophysiology. All of the ligands tested did not induce membrane currents, but reduced the responses to ACh when bath applied prior to co-application with ACh. Of the compounds tested, HK-13, which possesses two imidacloprid units linked with a hexamethylene bridge, had the highest antagonist potency. The antagonist action was reduced, not only by elongating, but also by shortening the linker.


Asunto(s)
Anabasina/farmacología , Sistema Nervioso Central/efectos de los fármacos , Ganglios de Invertebrados/efectos de los fármacos , Neuronas/efectos de los fármacos , Periplaneta/fisiología , Receptores Nicotínicos/efectos de los fármacos , Anabasina/química , Animales , Células Cultivadas , Sistema Nervioso Central/citología , Sistema Nervioso Central/metabolismo , Interacciones Farmacológicas/fisiología , Ganglios de Invertebrados/citología , Ganglios de Invertebrados/metabolismo , Ácido Glutámico/metabolismo , Ácido Glutámico/farmacología , Insecticidas/química , Insecticidas/farmacología , Ligandos , Potenciales de la Membrana/efectos de los fármacos , Potenciales de la Membrana/fisiología , Estructura Molecular , Neuronas/metabolismo , Antagonistas Nicotínicos/química , Antagonistas Nicotínicos/farmacología , Técnicas de Placa-Clamp , Periplaneta/citología , Receptores Nicotínicos/metabolismo , Transmisión Sináptica/efectos de los fármacos , Transmisión Sináptica/fisiología , Ácido gamma-Aminobutírico/metabolismo , Ácido gamma-Aminobutírico/farmacología
13.
Bioorg Med Chem Lett ; 17(16): 4500-3, 2007 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-17583505

RESUMEN

Prodrugs of imidacloprid and the thiazolylmethyl analog masked with oxodioxolylmethyl group on the N3 site were prepared. The prodrugs decomposed in a buffer solution of pH 8.3 and in a physiological salt solution with half-lives of 10-15 h, releasing the parent insecticides. Being consistent with this, an inward current was evoked in dissociated cockroach neurons treated with the masked compound solutions, which were maintained for 24 h after preparation, as measured using patch-clamp electrophysiology, whereas no response was observed in neurons when the solutions were challenged immediately after preparation. The insecticidal test on the American cockroach showed that the minimum lethal dose for each compound at 24 h after injection was 6.4x10(-8) mol, which was similar to that for imidacloprid and the thiazolyl derivative. This result strongly suggested a regeneration of the active ingredients in vivo.


Asunto(s)
Imidazoles/química , Imidazoles/farmacología , Imidazolidinas/química , Imidazolidinas/farmacología , Insecticidas/química , Insecticidas/farmacología , Nitrocompuestos/química , Nitrocompuestos/farmacología , Animales , Cucarachas/efectos de los fármacos , Estructura Molecular , Neonicotinoides , Neuronas/efectos de los fármacos , Profármacos , Relación Estructura-Actividad
14.
Appl Environ Microbiol ; 73(10): 3404-11, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17400778

RESUMEN

An insecticidal protein produced by Bacillus sphaericus A3-2 was purified to elucidate its structure and mode of action. The active principle purified from the culture broth of A3-2 was a protein with a molecular mass of 53 kDa that rapidly intoxicated German cockroaches (Blattela germanica) at a dose of about 100 ng when injected. The insecticidal protein sphaericolysin possessed the undecapeptide motif of cholesterol-dependent cytolysins and had a unique N-terminal sequence. The recombinant protein expressed in Escherichia coli was equally as potent as the native protein. Sphaericolysin-induced hemolysis resulted from the protein's pore-forming action. This activity as well as the insecticidal activity was markedly reduced by a Y159A mutation. Also, coapplication of sphaericolysin with cholesterol abolished the insecticidal action, suggesting that cholesterol binding plays an important role in insecticidal activity. Sphaericolysin-lysed neurons dissociated from the thoracic ganglia of the German cockroaches. In addition, sphaericolysin's activity in ganglia was suppressed by the Y159A mutation. The sphaericolysin-induced damage to the cockroach ganglia was greater than the damage to the ganglia of common cutworms (Spodoptera litura), which accounts, at least in part, for the higher sensitivity to sphaericolysin displayed by the cockroaches than that displayed by cutworms.


Asunto(s)
Bacillus/genética , Toxinas Bacterianas/genética , Toxinas Bacterianas/toxicidad , Clonación Molecular , Insecticidas , Proteínas Citotóxicas Formadoras de Poros/toxicidad , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Animales , Bacillus/citología , Bacillus/metabolismo , Toxinas Bacterianas/aislamiento & purificación , Secuencia de Bases , Colesterol/metabolismo , Cucarachas/efectos de los fármacos , ADN Bacteriano/química , ADN Bacteriano/genética , Escherichia coli , Ganglios/efectos de los fármacos , Datos de Secuencia Molecular , Peso Molecular , Mutación Missense , Neuronas/efectos de los fármacos , Proteínas Citotóxicas Formadoras de Poros/genética , Proteínas Citotóxicas Formadoras de Poros/aislamiento & purificación , Estructura Terciaria de Proteína , Análisis de Secuencia de ADN , Spodoptera/efectos de los fármacos
15.
Invert Neurosci ; 7(1): 47-51, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17265057

RESUMEN

The low mammalian toxicity of neonicotinoid insecticides has been shown to be attributable, at least in part, to their selective actions on insect nicotinic acetylcholine receptors (nAChRs). There are multiple nAChRs in insects and a wealth of neonicotinoid chemicals. Studies to date have discribed a wide range of effects on nAChRs, notably partial agonist, super agonist and antagonist actions. Both the diversity of the neonicotinoid actions and their selectivity for insect over vertebrate nAChRs are the result of physicochemical and steric interactions at their molecular targets (nAChRs). In such interactions, the formation and breakage of hydrogen bond (HB) networks plays a key role. Therefore the loss or gain of even a single HB resulting from either structural changes in neonicotinoids, or the amino acid sequence of a particular nAChR subunit, could result in a drastic modification of neonicotinoid actions. In addition to the amino acid residues, the backbone carbonyl of nAChRs may also be involved in the formation of HB networks with neonicotinoids.


Asunto(s)
Anabasina/toxicidad , Insecticidas/toxicidad , Receptores Nicotínicos/efectos de los fármacos , Receptores Nicotínicos/fisiología , Secuencia de Aminoácidos , Anabasina/química , Animales , Enlace de Hidrógeno , Insectos/fisiología , Insecticidas/química , Modelos Moleculares , Conformación Molecular , Receptores Nicotínicos/química
16.
Invert Neurosci ; 5(3-4): 157-64, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16195902

RESUMEN

4'-Ethynyl-4-n-propylbicycloorthobenzoate (EBOB) has been employed extensively as a radioligand in binding assays to evaluate the pharmacology of gamma-aminobutyric acid (GABA)-gated Cl- channels (GABARs) of insects and mammals, and gamma-hexachlorocyclohexane (gamma-HCH) was used as an insecticide targeting insect GABARs. Since recent studies have shown that not only GABARs but also glutamate-gated chloride channels (GluCls) are blocked by picrotoxinin, dieldrin and fipronil, the actions of EBOB and gamma-HCH on native GABARs and GluCls of terminal abdominal ganglion neurons in American cockroach (Periplaneta americana) were tested using patch-clamp electrophysiology. A marked run-down of the GABA- and glutamate-induced responses of the cockroach neurons occurred, when a standard pipette solution was employed, but addition of pyruvate to the solution permitted stable recordings of these responses. With this solution, EBOB and gamma-HCH were found to block not only the GABA- but also glutamate-gated responses, with the actions augmented by repeated co-application with the agonists. It was also found that prolonged pre-application of EBOB and gamma-HCH prior to co-application with GABA and glutamate resulted in enhanced blocking actions, indicating resting-state actions of the blockers. The blocking actions of EBOB and gamma-HCH on the GABA- and glutamate-induced responses were compared by determining IC50 values under steady state condition. The IC50 values for the actions of EBOB on GABAR and GluCls differed less than those of gamma-HCH.


Asunto(s)
Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Hexaclorociclohexano/farmacología , Insecticidas/farmacología , Neuronas/efectos de los fármacos , Ácido gamma-Aminobutírico/metabolismo , Animales , Canales de Cloruro/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ácido Glutámico/metabolismo , Técnicas de Placa-Clamp , Periplaneta , Receptores de GABA/efectos de los fármacos , Receptores de Glutamato/efectos de los fármacos
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