Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Langmuir ; 34(29): 8670-8677, 2018 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-29940738

RESUMO

We demonstrate a novel charge-free reverse wormlike micelle (RWLM) consisting of a ternary mixture of a nonionic amphiphilic block copolymer, fatty acid alkyl ester oil, and water under ambient conditions. Nonionic amphiphile tetra-[poly(oxyethylene)-poly(oxybutylene)]pentaerythrityl ether (TEBPE) self-assembled into spheroid-type micelles in nonaqueous media isopropyl myristate (IPM) with viscosity comparable to that of IPM. The addition of water increases viscosity only slightly up to a certain concentration of water and then drastically, demonstrating the sphere-to-wormlike micelle transition as confirmed by small-angle X-ray scattering. Further increase in water decreases the viscosity after attaining a maximum value. The zero shear viscosity (η0) of the 10 wt % TEBPE/IPM system reached the maximum at 2.6 wt % water and ca. 56 Pa·s, which is ∼fivefold higher than that of water. Dynamic rheological measurements on the highly viscous solutions confirmed the viscoelastic behavior and could be described by the Maxwell model. Conductivity, measured in the presence of a conductive probe, 1-ethyl-3-methylimidazolium tetrafluoroborate, was found to be higher for viscous samples compared to the nonviscous samples, suggesting the static percolation caused by the RWLM formation. Decrease in η0 and conductivity beyond a maximum suggests the shortening of reverse micelles. A similar behavior has been observed in other fatty acid alkyl ester oils of different alkyl chain lengths. Note that most of the RWLM systems previously reported are based on phosphatidylcholine (PC). Formulation and structure-properties related to non-PC-based RWLMs have been rarely explored. Non-PC-based RWLMs using chemically stable and low-cost synthetic molecules can be applied not only in pharmaceuticals and cosmetics but also in a wide range of applications including drag reduction agents for nonaqueous fluids and as a template for nanomaterial synthesis.

2.
Biol Pharm Bull ; 40(4): 391-395, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28381793

RESUMO

Propolis is a bee product with various biological properties. C57BL/6 mice were fed a high-fat diet and treated with propolis for 14 weeks. Body weight in mice treated with 2% propolis was less than that in control mice from 3 weeks after the start of treatment until 14 weeks except for the 7th week. Mice treated with propolis showed significantly lower epididymal fat weight and subcutaneous fat weight. Infiltration of epididymal fat by macrophages and T cells was reduced in the propolis group. Supplementation of propolis increased feces weight and fat content in feces, suggesting that mechanisms of weight reduction by propolis partly include a laxative effect and inhibition of fat absorption.


Assuntos
Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Dieta Hiperlipídica/efeitos adversos , Própole/farmacologia , Redução de Peso/efeitos dos fármacos , Redução de Peso/fisiologia , Animais , Colesterol/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Triglicerídeos/antagonistas & inibidores , Triglicerídeos/metabolismo
3.
Appl Microbiol Biotechnol ; 99(4): 2001-8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25547843

RESUMO

Shimwellia blattae is an enteric bacterium and produces endogenous enzymes that convert 1,2-propanediol (1,2-PD) to 1-propanol, which is expected to be used as a fuel substitute and a precursor of polypropylene. Therefore, if S. blattae could be induced to generate its own 1,2-PD from sugars, it might be possible to produce 1-propanol from sugars with this microorganism. Here, two 1,2-PD production pathways were constructed in S. blattae, resulting in two methods for 1-propanol production with the bacterium. One method employed the L-rhamnose utilization pathway, in which L-rhamnose is split into dihydroxyacetone phosphate and 1,2-PD. When wild-type S. blattae was cultured with L-rhamnose, an accumulation of 1,2-PD was observed. The other method for producing 1,2-PD was to introduce an engineered 1,2-PD production pathway from glucose into S. blattae. In both cases, the produced 1,2-PD was then converted to 1-propanol by 1,2-PD converting enzymes, whose production was induced by the addition of glycerol.


Assuntos
1-Propanol/metabolismo , Enterobacteriaceae/metabolismo , Glucose/metabolismo , Engenharia Metabólica , Ramnose/metabolismo , Biotransformação , Meios de Cultura/química , Enterobacteriaceae/crescimento & desenvolvimento , Fermentação , Glicerol/metabolismo , Propilenoglicol/metabolismo
4.
Mol Pharmacol ; 85(1): 74-82, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24132183

RESUMO

Our previous studies have shown that treatment of pregnant rats with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 1 µg/kg) at gestational day (GD) 15 reduces the pituitary synthesis of luteinizing hormone (LH) during the late fetal and early postnatal period, leading to the imprinting of defects in sexual behaviors at adulthood. However, it remains unclear how the attenuation of pituitary LH is linked to sexual immaturity. To address this issue, we performed a DNA microarray analysis to identify the gene(s) responsible for dioxin-induced sexual immaturity on the pituitary and hypothalamus of male pups, born of TCDD-treated dams, at the age of postnatal day (PND) 70. Among the reduced genes, we focused on gonadotropin-releasing hormone (GnRH) in the hypothalamus because of published evidence that it has a role in sexual behaviors. An attenuation by TCDD of GnRH expression emerged at PND4, and no subsequent return to the control level was seen. A change in neither DNA methylation nor histone acetylation accounted for the reduced expression of GnRH. Intracerebroventricular infusion of GnRH to the TCDD-exposed pups after reaching maturity restored the impairment of sexual behaviors. Supplying equine chorionic gonadotropin, an LH-mimicking hormone, to the TCDD-exposed fetuses at GD15 resulted in a recovery from the reduced expression of GnRH, as well as from the defects in sexual behavior. These results strongly suggest that maternal exposure to TCDD fixes the status of the lowered expression of GnRH in the offspring by reducing the LH-assisted steroidogenesis at the perinatal stage, and this mechanism imprints defects in sexual behaviors at adulthood.


Assuntos
Poluentes Ambientais/toxicidade , Hormônio Liberador de Gonadotropina/metabolismo , Hipotálamo/metabolismo , Exposição Materna/efeitos adversos , Dibenzodioxinas Policloradas/toxicidade , Efeitos Tardios da Exposição Pré-Natal/psicologia , Comportamento Sexual Animal , Animais , Animais Recém-Nascidos , Gonadotropina Coriônica/uso terapêutico , Metilação de DNA , Embrião de Mamíferos , Feminino , Impressão Genômica , Hormônio Liberador de Gonadotropina/genética , Hormônio Liberador de Gonadotropina/uso terapêutico , Cavalos , Masculino , Troca Materno-Fetal , Hipófise/metabolismo , Gravidez , Efeitos Tardios da Exposição Pré-Natal/tratamento farmacológico , Efeitos Tardios da Exposição Pré-Natal/etiologia , Ratos , Ratos Wistar , Comportamento Sexual Animal/efeitos dos fármacos , Testículo/metabolismo , Fatores de Tempo
5.
Toxicol Appl Pharmacol ; 281(1): 48-57, 2014 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-25220434

RESUMO

The effect of 2,3,4,7,8-pentachlorodibenzofuran (PnCDF) on the fetal pituitary-gonad axis was compared with that produced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in Wistar rats. Maternal treatment at gestational day (GD) 15 with PnCDF and TCDD reduced the fetal expression at GD20 of pituitary luteinizing hormone (LH) and the testicular proteins necessary for steroidogenesis. The relative potencies of PnCDF ranged from 1/42nd to 1/63rd of the TCDD effect. While PnCDF, at a dose sufficient to cause a reduction in fetal LH, provoked defects in sexual behavior at adulthood, a dose less than the ED50 failed to produce any abnormality. There was a loss of fetal body weight following in utero exposure to PnCDF, and the effect of PnCDF was also much less than that of TCDD. The disturbance in fetal growth was suggested to be due to a reduction in the level of fetal growth hormone (GH) by dioxins. The disorder caused by PnCDF/TCDD in the fetal pituitary-gonad axis occurred at doses less than those needed to cause wasting syndrome in pubertal rats. The harmful effect of PnCDF relative to TCDD was more pronounced in fetal rats than in pubertal rats. These lines of evidence suggest that: 1) PnCDF as well as TCDD imprints defects in sexual behavior by disrupting the fetal pituitary-gonad axis; 2) these dioxins hinder fetal growth by reducing the expression of fetal GH; and 3) the fetal effects of PnCDF/TCDD are more sensitive than sub-acute toxicity during puberty, and the relative effect of PnCDF varies markedly depending on the indices used.


Assuntos
Benzofuranos/toxicidade , Feto/efeitos dos fármacos , Hipófise/efeitos dos fármacos , Dibenzodioxinas Policloradas/toxicidade , Comportamento Sexual Animal/efeitos dos fármacos , Testículo/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Poluentes Ambientais/toxicidade , Feminino , Desenvolvimento Fetal/efeitos dos fármacos , Desenvolvimento Fetal/fisiologia , Feto/metabolismo , Hormônio Luteinizante/sangue , Masculino , Exposição Materna , Hipófise/metabolismo , Gravidez , Ratos , Ratos Wistar , Comportamento Sexual Animal/fisiologia , Testículo/fisiologia
6.
J Biol Chem ; 287(22): 18440-50, 2012 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-22493514

RESUMO

Maternal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes the impairment of reproduction and development in the pups. Our previous studies have revealed that maternal treatment with TCDD attenuates the fetal production of pituitary gonadotropins (luteinizing hormone (LH) and follicle-stimulating hormone) at gestational day (GD) 20, leading to the impairment of sexual behavior in adulthood. However, the mechanism underlying such a reduction has remained unknown until now. When pregnant rats at GD15 were given an oral dose of TCDD (1 µg/kg), the testicular expression of steroidogenic proteins was reduced between GD20 and postnatal days (PND) 2. In accordance with this, the pituitary expression of gonadotropin ß-subunit and serum gonadotropin were also attenuated from GD20 to PND0 in a pup-specific fashion. To identify the target genes linked to a fetal reduction in gonadotropin ß-subunit, we performed a DNA microarray analysis using the fetal pituitary and its regulatory organ, the hypothalamus. The results obtained showed that TCDD induced histone deacetylases (HDACs) in the fetal pituitary. In support with this, TCDD markedly deacetylated histones H3 and H4 twined around the promoter of the fetal LHß gene. This effect was fetus- and LHß-specific, and this was not observed in the maternal pituitary or for other pituitary hormone genes. Finally, an LHß reduction caused by TCDD was completely restored by maternal co-treatment with valproic acid, an HDAC inhibitor. These results strongly suggest that the increased deacetylation of histone owing to HDAC induction plays a critical role in the TCDD-induced reduction in LHß in the fetal pituitary.


Assuntos
Gonadotropinas/metabolismo , Histona Desacetilases/biossíntese , Dibenzodioxinas Policloradas/farmacologia , Maturidade Sexual , Esteroides , Animais , Sequência de Bases , Imunoprecipitação da Cromatina , Metilação de DNA , Indução Enzimática , Epigênese Genética , Feminino , Masculino , Dados de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Hipófise/efeitos dos fármacos , Hipófise/embriologia , Gravidez , Ratos , Ratos Wistar , Esteroides/biossíntese
7.
Fukuoka Igaku Zasshi ; 104(4): 143-51, 2013 Apr.
Artigo em Japonês | MEDLINE | ID: mdl-23858793

RESUMO

Maternal exposure to 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) causes a number of toxic effects on development such as growth retardation and sexual immaturity in the offspring. However, the toxic mechanism remains unknown. Our previous studies have revealed that single oral administration of TCDD (1 jg/kg) to pregnant rats at gestational day (GD) 15 attenuates the fetal expression of testicular steroidogenic proteins such as steroidogenic acute-regulatory protein (StAR) and cytochrome P450 (CYP) 17 by targeting the fetal production of pituitary gonadotropins. In addition, we provided evidence that TCDD-produced damage on the fetal pituitary-gonad axis leads to imprint defects in sexual behaviors at adulthood. In this study, we investigated whether TCDD also affects fetal steroidogenesis in the adrenal gland. When pregnant Wistar rats were orally treated with TCDD, the fetal expression of CYP21, CYP11B1 and CYP11B2 mRNAs was either induced or tended to be induced in the male adrenal gland during GD17 and GD19, while the expression of mRNAs coding for StAR, CYP11A1 and 313-hydroxysteroid dehydrogenase was insensitive to TCDD treatment. The above alterations did not seem to be caused through a change in the upstream regulator, because TCDD exhibited little ability to attenuate the expression of adrenocorticotropin, a pituitary hormone stimulating adrenal steroidogenesis, in the male and female fetuses. In contrast to the males, TCDD effect on the adrenal gland was not observed in the female fetuses. These results suggest that maternal exposure to TCDD disrupts fetal steroidogenesis in adrenal as well as gonadal glands in a male specific manner, and the mechanism underlying the effect on adrenal gland is independent of the alteration of pituitary regulator.


Assuntos
Glândulas Suprarrenais/efeitos dos fármacos , Glândulas Suprarrenais/metabolismo , Feto/efeitos dos fármacos , Hormônios Esteroides Gonadais/biossíntese , Exposição Materna , Dibenzodioxinas Policloradas/toxicidade , Animais , Feminino , Feto/metabolismo , Masculino , Gravidez , Ratos , Ratos Wistar , Fatores Sexuais
8.
Fukuoka Igaku Zasshi ; 102(4): 159-66, 2011 Apr.
Artigo em Japonês | MEDLINE | ID: mdl-21706896

RESUMO

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) exposed to pregnant or lactational mother impairs the reproduction and development of the pups. The defect is a serious problem, because it is caused by TCDD at much lower doses than that needed for acute toxicity in the mother. However, the toxic mechanism underlying the defect remains to be obscure. We have previously revealed that maternal exposure to TCDD (1 microg/kg) causes a reduction in luteinizing hormone in the fetal pituitary, leading to the reduced expression of testicular steroidogenic proteins such as steroidogenic acute-regulatory protein (StAR) and cytochrome P450 (CYP) 17. In addition, we have provided evidence that such a reduction imprints defects in sexual behaviors at adulthood. In this study, we investigated TCDD effect on fetal steroidogenesis in the extra-gonadal tissues. Even when pregnant Wistar rats at gestational day (GD) 15 were orally treated with TCDD (0.25, 1 or 3 microg/kg), neither expression of StAR nor CYP17 mRNA was affected in the adrenal gland, placenta and hypothalamus of male fetuses (GD20). However, TCDD induced placental StAR (3 microg/kg) and adrenal CYP17 mRNAs (0.25 microg/kg) in female fetuses. Therefore, our study suggests that while TCDD gives damage to male fetal steroidogenesis in a testis-specific manner, the dioxin enhances the steroidogenesis of the fetal adrenal gland and placenta in females. Thus, the mechanism whereby TCDD exerts its endocrine-disrupting properties is considered to differ, at least partially, between male and female fetuses.


Assuntos
Glândulas Suprarrenais/metabolismo , Feto/metabolismo , Exposição Materna , Placenta/metabolismo , Dibenzodioxinas Policloradas/intoxicação , Esteroides/biossíntese , Animais , Feminino , Masculino , Fosfoproteínas/metabolismo , Gravidez , Ratos , Ratos Wistar , Fatores Sexuais , Esteroide 17-alfa-Hidroxilase/metabolismo
9.
Biochem Pharmacol ; 186: 114495, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33711284

RESUMO

Although dioxins and related chemicals have been suspected to disrupt child development, their toxic mechanism remains poorly understood. Our previous studies in rat fetuses revealed that maternal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a highly-toxic dioxin, suppresses fetal synthesis of pituitary growth hormone (GH) that is essential for development. This study examined the hypothesis that attenuating GH expression in fetuses triggers developmental disorders. Treating pregnant rats with 1 µg/kg TCDD reduced the circulating level of GH and its downstream factor, insulin-like growth factor-1 (IGF-1), in the offspring only during the fetal and early neonatal stages. Although maternal TCDD exposure resulted in low body weight and length at babyhood and defects in the learning and memory ability at adulthood, GH supplementation in TCDD-exposed fetuses restored or tended to restore the defects including IGF-1 downregulation. Moreover, maternal TCDD exposure decreased the number of GH-positive cells during the fetal/neonatal stage. A microarray analysis showed that TCDD reduced the expression of death-associated protein-like 1 (DAPL1), a cell cycle-dependent proliferation regulator, in the fetal pituitary gland. In addition, TCDD treatment attenuated proliferating cells and cyclin mRNA expression in the fetal pituitary gland. Aryl hydrocarbon receptor (AHR)-knockout fetuses were insensitive to TCDD treatment, indicating that the TCDD-induced reduction in DAPL1 and GH mRNAs expression was due to AHR activation. Finally, DAPL1 knockdown suppressed GH and cyclin D2 expression in fetal pituitary cells. These results provide a novel evidence that dioxin suppresses GH-producing cell proliferation and GH synthesis due to partly targeting DAPL1, thereby impairing offspring development.


Assuntos
Deficiências do Desenvolvimento/metabolismo , Dioxinas/toxicidade , Feto/metabolismo , Hormônio do Crescimento/deficiência , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Animais , Deficiências do Desenvolvimento/induzido quimicamente , Feminino , Feto/efeitos dos fármacos , Hormônio do Crescimento/antagonistas & inibidores , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Ratos , Ratos Transgênicos , Ratos Wistar
10.
Biochem Pharmacol ; 178: 114106, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32569627

RESUMO

A number of epidemiological studies have implicated environmental chemicals including dioxins in the induction of negative effects on child development. To clarify the underlying mechanisms, almost all toxicologists have concentrated on effects on the offspring themselves. We examined an alternative hypothesis that gestational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a highly-toxic dioxin, targets factors related to maternal childcare to disturb offspring development. Oral administration of TCDD (1 µg/kg) to pregnant rats on gestational day 15 suppressed maternal licking behavior, a nursing behavior, and mammary gland maturation during the lactational stage, as well as the body weight and short-term memory of postnatal offspring. In support of these findings, maternal production of prolactin, a pituitary hormone essential for nursing including milk production, was decreased during the same period. Intracerebroventricular infusion of prolactin to dioxin-exposed dams restored or tended to restore many of the above defects observed both in mothers and offspring. The TCDD-dependent defects in maternal nursing behaviors can be due to a direct action on aryl hydrocarbon receptor (AHR) of lactating dams, because they did not emerge in AHR-knockout dams or control dams with TCDD-exposed offspring. Further examinations revealed that TCDD induces transforming growth factor ß1 expression, which suppresses prolactin-producing cell proliferation, in a nursing period-specific manner. In agreement with this, the number of prolactin-positive cells in nursing dams was decreased by TCDD. These results provide novel evidence that gestational dioxin exposure attenuates prolactin-stimulated nursing in lactating dams to impair offspring development, and that immaturity of prolactin-producing cells can contribute to them.


Assuntos
Poluentes Ambientais/toxicidade , Lactação/efeitos dos fármacos , Comportamento Materno/efeitos dos fármacos , Dibenzodioxinas Policloradas/toxicidade , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Prolactina/antagonistas & inibidores , Animais , Animais Recém-Nascidos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Peso ao Nascer/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Exposição Ambiental/efeitos adversos , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Feminino , Feto , Expressão Gênica/efeitos dos fármacos , Idade Gestacional , Injeções Intraventriculares , Masculino , Memória de Curto Prazo , Gravidez , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Prolactina/biossíntese , Prolactina/genética , Prolactina/farmacologia , Ratos , Ratos Wistar , Receptores de Hidrocarboneto Arílico/genética , Receptores de Hidrocarboneto Arílico/metabolismo , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo
11.
J Orthop Sports Phys Ther ; 38(5): 257-61, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18448876

RESUMO

STUDY DESIGN: Experimental laboratory design. OBJECTIVES: To measure the strain at the proximal origin of the extensor carpi radialis brevis (ECRB), and to determine the influence of a forearm support band. BACKGROUND: A forearm support band is often used with the intent to decrease stresses around the origin of the wrist extensors. However, the influence of the location of the band has not been studied. METHODS AND MEASURES: The forearm support band was applied on 8 cadaver arms (mean +/- SD age, 78.4 +/- 10.3 years) and 2 experimental conditions were performed. First, strain measurements were made without applying tension to the distal ECRB tendon, then strain measurements were made with a traction force of 21.5 N being applied to the distal ECRB tendon. Strain of the proximal origin of the ECRB, 1.0 cm distal from the lateral epicondyle, was recorded using a strain gauge. The band was mounted on the forearm at distances equal to 80%, 70%, 60%, 50%, 40%, 30%, and 20% of the forearm length as measured from the wrist. Testing order was randomized. Tension applied to the band was 19.6 N. RESULTS: When no tension was applied to the ECRB, there was no statistically significant difference (P>.05) in strain values at the ECRB origin by mounting the band at any of the forearm positions. In the tension condition, the average (SD) strain with no band was 2.40% (1.40%). The average strain value of 0.85% (0.65%), when the band was mounted 80% of the forearm length proximal to the wrist, was statistically smaller than that obtained without the band (P<.05). CONCLUSIONS: The strain on the ECRB origin was less when the forearm support band was applied 80% proximal from the wrist joint. LEVEL OF EVIDENCE: Therapy, level 5.


Assuntos
Bandagens , Antebraço/cirurgia , Músculo Esquelético/cirurgia , Entorses e Distensões/cirurgia , Tendões/cirurgia , Idoso , Cadáver , Humanos , Articulação do Punho/cirurgia
12.
J Biosci Bioeng ; 122(4): 421-6, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27072298

RESUMO

Fermentative production of 1-propanol, which is one of the promising precursors of polypropylene production, from d-glucose, l-rhamnose and glycerol using metabolically engineered Escherichia coli was examined. To confer the ability to produce 1-propanol from 1,2-propanediol (1,2-PD) in recombinant E. coli, a part of the pdu regulon including the diol dehydratase and the propanol dehydrogenase genes together with the adenosylcobalamin (AdoCbl) regeneration enzyme genes of Klebsiella pneumoniae was cloned, and an expression vector for these genes (pRSF_pduCDEGHOQS) was constructed. Recombinant E. coli harboring pRSF_pduCDEGHOQS with 1,2-PD synthetic pathway (pKK_mde) genes, which was constructed in our previous report (Urano et al., Appl. Microbiol. Biotechnol., 99, 2001-2008, 2015), produced 16.1 mM of 1-propanol from d-glucose with a molar yield of 0.36 mol/mol after 72 h cultivation. 29.9 mM of 1-propanol was formed from l-rhamnose with a molar yield of 0.81 mol/mol using E. coli carrying only pRSF_pduCDEGHOQS. In addition, 1-propanol production from glycerol was achieved by addition of the ATP-dependent dihydroxyacetone kinase gene to E. coli harboring pKK_mde and pRSF_pduCDEGOQS. In all cases, 1-propanol production was achieved by adding only a small amount of AdoCbl.


Assuntos
1-Propanol/metabolismo , Escherichia coli/metabolismo , Fermentação , Glucose/metabolismo , Glicerol/metabolismo , Engenharia Metabólica , Ramnose/metabolismo , Cobamidas/biossíntese , Cobamidas/metabolismo , Cobamidas/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Fermentação/efeitos dos fármacos , Genes Bacterianos , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/genética , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Propanodiol Desidratase/genética , Propanodiol Desidratase/metabolismo , Propilenoglicóis/metabolismo
13.
Endocrine ; 47(2): 572-80, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24723259

RESUMO

Exposure of pregnant rats to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) at a low dose causes developmental disorders such as growth retardation and sexual immaturity in their pups. Our previous studies have demonstrated that TCDD attenuates the expression of pituitary luteinizing hormone in fetuses, resulting in the impairment of sexual behavior after they reach maturity. In this study, we focused on growth disturbance and investigated whether TCDD affects the expression of growth hormone (GH), another pituitary hormone which is essential for normal development in perinatal pups. The result showed that maternal exposure to TCDD (1 µg/kg) at gestational day (GD) 15 reduced the fetal expression of GH from the onset at GD18. In accordance with this, TCDD attenuated the pup weight during the perinatal period. We then examined the effect of TCDD on the serum concentration of corticosterone, which plays a key role in the proliferation of GH-producing cells, and found that TCDD reduces the circulating level of corticosterone in the mothers at GD18 and the male fetuses at GD19. The reduction in fetuses seems to be due to increased inactivation rather than reduced synthesis, because TCDD induces the fetal expression of hepatic enzymes participating in the metabolism of glucocorticoids without changing the expression of steroidogenic proteins in the pituitary-adrenal axis. Supplying corticosterone to TCDD-exposed mothers restored or tended to restore a TCDD-induced reduction in pup weight as well as the levels of pituitary GH mRNA and serum GH. These results suggest that TCDD lowers GH expression and growth retardation owing, at least partially, to a reduction in the circulating level of glucocorticoid in pregnant mothers and their fetuses.


Assuntos
Hormônio Adrenocorticotrópico/sangue , Corticosterona/sangue , Retardo do Crescimento Fetal/induzido quimicamente , Feto/efeitos dos fármacos , Exposição Materna , Dibenzodioxinas Policloradas , Animais , Animais Recém-Nascidos , Feminino , Retardo do Crescimento Fetal/metabolismo , Hormônio do Crescimento/sangue , Hormônio do Crescimento/metabolismo , Masculino , Hipófise/metabolismo , Gravidez , Ratos , Ratos Wistar
14.
Man Ther ; 15(1): 117-21, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19837626

RESUMO

Limitation of ankle motion is in many cases treated by joint mobilization (JM), a kind of manual physical therapy technique. Until now, the JM approach has mainly focused on the talocrural joint, with less attention to the distal tibiofibular joint. We applied cyclic loading to the lateral malleolus as in JM in order to clarify the relationship between the dorsiflexion angle and the excursion of the lateral malleolus. Seven normal, fresh-frozen cadaver legs were used. To each specimen, cyclic loading with a 30N force was applied 1000 times to the lateral malleolus at a speed of 15N/s. The displacement of the lateral malleolus was measured with a magnetic tracking system. The maximum dorsiflexion angle was measured before and after cyclic loading. After the first 100 and 1000 times of cyclic loading, the tibia was displaced 0.44+/-0.30mm and 0.75+/-0.36mm, respectively, and the fibula was displaced 0.44+/-0.28mm and 0.92+/-0.39mm, respectively. The average dorsiflexion angle increased from 14.36+/-7.51 degrees to 16.74+/-7.21 degrees after cyclic loading (P<0.05). Movement of the distal tibiofibular joint led to a significant increase in the range of ankle dorsiflexion. These results suggest that tibiofibular JM would be effective for limitation of ankle dorsiflexion.


Assuntos
Traumatismos do Tornozelo , Articulação do Tornozelo/fisiologia , Manipulações Musculoesqueléticas/métodos , Amplitude de Movimento Articular/fisiologia , Idoso , Idoso de 80 Anos ou mais , Traumatismos do Tornozelo/fisiopatologia , Traumatismos do Tornozelo/reabilitação , Cadáver , Terapia por Exercício/métodos , Feminino , Fíbula/fisiologia , Humanos , Masculino , Dinamômetro de Força Muscular , Pronação/fisiologia , Rotação , Tíbia/fisiologia
15.
J Toxicol Sci ; 35(3): 365-73, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20519845

RESUMO

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) reduces the synthesis of pituitary gonadotropins in a fetal age-specific manner. The pituitary synthesis of gonadotropins is regulated by the hypothalamus and, thus, needs the differentiation and development of the hypothalamus requiring a number of factors including energy supply and neurotransmitters. To investigate the mechanism whereby TCDD reduces fetal gonadotropins, we carried out a comparative study on the metabolomes of the hypothalamus and pituitary using fetal and mature Wistar rats. Male fetuses at gestational day (GD)20 were removed from dams treated orally with TCDD (1 microg/kg) at GD15, and the metabolome profiles were analyzed by gas chromatography-mass spectrometry (GC-MS). The principal component analysis of GC-MS data revealed that TCDD caused a change in the profile of fetal metabolome more markedly in the hypothalamus than in the pituitary. In sharp contrast, TCDD did not cause any marked alteration in hypothalamic as well as pituitary metabolomes in male rats born of untreated dams and treated with TCDD at postnatal day 49. It was also demonstrated that a number of fetal hypothalamic components, including glutamine and gamma-aminobutyric acid, are reduced by TCDD. These results demonstrate a possibility that TCDD may reduce the metabolic activity of the hypothalamus in a fetus-specific fashion, resulting in the reduced synthesis of gonadotropins.


Assuntos
Gonadotropinas/biossíntese , Hipotálamo/metabolismo , Exposição Materna/efeitos adversos , Troca Materno-Fetal , Metaboloma/efeitos dos fármacos , Dibenzodioxinas Policloradas/efeitos adversos , Animais , Depressão Química , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Glutamina/metabolismo , Masculino , Hipófise/metabolismo , Gravidez , Ratos , Ratos Wistar , Ácido gama-Aminobutírico/metabolismo
16.
Phys Ther ; 89(4): 333-41, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19246556

RESUMO

BACKGROUND AND PURPOSE: Lengthening of the pectoralis minor muscle (PMi) during passive shoulder motions and the effect of stretching techniques for this muscle are unclear. The purposes of this study were: (1) to investigate the amount and pattern of the lengthening between passive shoulder motions and (2) to determine which stretching technique effected the greatest change in PMi length. METHODS: Nine fresh cadaveric transthoracic specimens were used. Lengthening in the lateral and medial fiber group of the PMi was directly measured during 3 passive shoulder motions (flexion, scaption, and external rotation at 90 degrees of abduction) and 3 stretching techniques (scapular retraction at 0 degrees and 30 degrees of flexion and horizontal abduction) for this muscle. The measurement was conducted by using a precise displacement sensor. RESULTS: Although the length of the PMi linearly increased during all shoulder motions, lengthening during flexion and scaption was steeper and significantly larger than that during external rotation at 90 degrees of abduction. For the stretching techniques, scapular retraction at 30 degrees of flexion and horizontal abduction stretched the PMi more than scapular retraction at 0 degrees of flexion. In comparison with lengthening at 150 degrees of flexion, scapular retraction at 30 degrees of flexion significantly stretched the medial fiber group of the muscle. DISCUSSION AND CONCLUSION: The extensive lengthening of the PMi is necessary during shoulder motions, especially flexion and scaption. Scapular retraction at 30 degrees of flexion makes the greatest change in PMi length. This study suggests the importance of the PMi in shoulder motion and provides anatomical and biomechanical evidence that might guide appropriate selection of stretching techniques.


Assuntos
Exercícios de Alongamento Muscular , Músculos Peitorais/fisiologia , Amplitude de Movimento Articular/fisiologia , Ombro/fisiologia , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Cadáver , Humanos , Contração Muscular/fisiologia
17.
Man Ther ; 14(4): 427-32, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18824394

RESUMO

The ilio-femoral ligament is known to cause flexion contracture of the hip joint. Stretching positioning is intended to elongate the ilio-femoral ligaments, however, no quantitative analysis to measure the effect of stretching positions on the ligament has yet been performed. Strains on the superior and inferior ilio-femoral ligaments in 8 fresh/frozen trans-lumbar cadaveric hip joints were measured using a displacement sensor, and the range of movement of the hip joints was recorded using a 3Space Magnetic Sensor. Reference length (L(0)) for each ligament was determined to measure strain on the ligaments. Hip positions at 10 degrees adduction with maximal external rotation, 20 degrees adduction with maximal external rotation, and maximal external rotation showed larger strain for the superior ilio-femoral ligament than the value obtained from L(0), and hip positions at 20 degrees external rotation with maximal extension and maximal extension had larger strain for the inferior ilio-femoral ligament than the value obtained from L(0) (p<0.05). Superior and inferior ilio-femoral ligaments exhibited positive strain values with specific stretching positions. Selective stretching for the ilio-femoral ligaments may contribute to achieve lengthening of the ligaments to treat flexion contracture of the hip joint.


Assuntos
Articulação do Quadril , Ligamentos Articulares/fisiologia , Postura/fisiologia , Estresse Mecânico , Idoso , Idoso de 80 Anos ou mais , Cadáver , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA