Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
2.
Adv Mater ; 26(19): 2983-8, 2014 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-24464678

RESUMO

Split-gate organic field-effect transistors have been developed for high-speed operation. Owing to the combination of reduced contact resistance and minimized parasitic capacitance, the devices have fast switching characteristics. The cutoff frequencies for the vacuum-evaporated devices and the solution-processed devices are 20 and 10 MHz, respectively. A speed of 10 MHz is the fastest device reported so far among solution-processed organic transistors.

3.
J Neurosci Res ; 66(4): 601-11, 2001 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-11746380

RESUMO

Superior cervical ganglion (SCG) cells from neonatal rats underwent apoptosis upon treatment with colchicine, a microtubule-disrupting agent. Western blotting and activity measurements showed that caspase-3 was indeed activated, but its peptide inhibitor (Ac-DEVD-CHO) neither suppressed nuclear fragmentation nor rescued the neurons from cell death. z-VAD-fmk, the general inhibitor of caspases, prevented nuclear fragmentation and delayed the cell death. Moreover, N-alpha-tosyl-L-lysine chloromethyl ketone (TLCK), but not N-alpha-tosyl-L-phenylalanine chloromethyl ketone (TPCK), prevented nuclear fragmentation and provided neuronal protection as well. The combination of both z-VAD-fmk and TLCK provided a long-term neuronal protection (>4 days), whereas neither one alone could do so, suggesting that there are both caspase-dependent and -independent pathways. TLCK-sensitive serine protease is also likely to act upstream of caspase-3 in a caspase-dependent pathway. Electron microscopic observations demonstrated that z-VAD-fmk suppressed nuclear fragmentation and improved mitochondrial swelling, but failed to prevent vesicular formation, which resulted in a slowly-occurring necrosis. More importantly, TLCK effectively blocked this abundant vesicular formation along with suppressing chromatin condensation. Thus, the combination of both conferred a nearly normal morphology, which is consistent with the results of cell survival experiments. These findings clearly indicate that TLCK-sensitive serine protease plays multiple roles in caspase-dependent and -independent pathways of colchicine-induced cell death, and suggest a novel mechanism underlying a necrotic pathway involving ER swelling and vesicular formation.


Assuntos
Apoptose/fisiologia , Caspases/metabolismo , Necrose , Sistema Nervoso/enzimologia , Neurônios/enzimologia , Serina Endopeptidases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Apoptose/efeitos dos fármacos , Bucladesina/farmacologia , Caspase 3 , Caspases/efeitos dos fármacos , Células Cultivadas/efeitos dos fármacos , Células Cultivadas/enzimologia , Células Cultivadas/ultraestrutura , Colchicina/farmacologia , Inibidores Enzimáticos , Imuno-Histoquímica , Microscopia Eletrônica , Proteínas dos Microtúbulos/antagonistas & inibidores , Proteínas dos Microtúbulos/metabolismo , Sistema Nervoso/efeitos dos fármacos , Sistema Nervoso/ultraestrutura , Neurônios/efeitos dos fármacos , Neurônios/ultraestrutura , Fármacos Neuroprotetores/farmacologia , Potássio/farmacologia , Inibidores da Síntese de Proteínas/farmacologia , Ratos , Ratos Sprague-Dawley , Serina Endopeptidases/efeitos dos fármacos , Inibidores de Serina Proteinase/farmacologia , Transdução de Sinais/fisiologia , Gânglio Cervical Superior/efeitos dos fármacos , Gânglio Cervical Superior/enzimologia , Gânglio Cervical Superior/ultraestrutura , Tosilina Clorometil Cetona/farmacologia , Tosilfenilalanil Clorometil Cetona/farmacologia
4.
Arch Histol Cytol ; 63(5): 401-10, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11201198

RESUMO

Sensory innervation of the entire hard palate was investigated in the rat using serial sections immunostained for protein gene product 9.5 (PGP 9.5), a neuronal marker. PGP 9.5-immunoreactive nerve endings were widely distributed in the hard palate, but the innervation pattern and density differed among portions. They were numerous at papillary protrusions including the incisal papilla, antemolar/intermolar rugae, and postrugal filiform papillae. Immunoreactive free nerve endings gathered at the summits of the connective tissue papillae, some of them entering deeply into the epithelium. Electron microscopy demonstrated that nerves in the postrugal filiform papillae reached the stratum corneum. The atrial region, possibly the most sensitive in the hard palate, showed unique innervation: its anterior part, adjacent to incisors, developed intraepithelial networks of fine and beaded nerves, whereas its posterior part revealed cone-shaped nerve terminals formed on the connective tissue papillae of the atrial folds which comprised two lines of longitudinal flaps. Taste bud-like corpuscles gathered in the medial walls of the incisal canals and in the "Geschmacksstreifen" (taste stripes) present at the most anterior part of the soft palate. The hard palate of the rat is thus richly innervated, and is characterized by region-specific nerve endings which may be involved in mechano- and chemoreception in the oral cavity.


Assuntos
Imuno-Histoquímica/métodos , Neurônios/metabolismo , Tioléster Hidrolases/biossíntese , Animais , Epitélio/inervação , Epitélio/metabolismo , Microscopia Eletrônica , Microscopia Imunoeletrônica , Modelos Biológicos , Palato Duro/inervação , Palato Duro/metabolismo , Ratos , Ratos Wistar , Tioléster Hidrolases/imunologia , Ubiquitina Tiolesterase
6.
Horm Res ; 44 Suppl 2: 47-9, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7545643

RESUMO

Oxytocin (OT) has been detected in mammalian granulosa-luteal cells during the early stages. The purpose of this study was to explore gene expressions of OT and OT receptor (OTR) in human cumulus cells. Cumulus cells enclosing a mature oocyte were obtained from 6 women undergoing clinical in vitro fertilization and embryo transfer programs. OT and OTR gene expressions were investigated by employing reverse transcription polymerase chain reaction and reverse transcription polymerase chain reaction/single-strand conformation polymorphism methods. OT gene expression in the cumulus cells was positive in 5 women and weakly positive in the remaining patient. The structure of OT mRNA in the cumulus cells was equivalent to that in human hypothalamus. OTR gene expression was also observed in the cumulus cells. This study is the first to describe the simultaneous expression of both OT and OTR genes in human cumulus cells. It is suggested that local OT plays some important roles in fertility through modification of the micro-environment around the oocyte.


Assuntos
Expressão Gênica , Ovário/metabolismo , Ocitocina/genética , Receptores de Ocitocina/genética , Sequência de Bases , Transferência Embrionária , Feminino , Fertilização in vitro , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , DNA Polimerase Dirigida por RNA
7.
Gynecol Obstet Invest ; 40(1): 42-5, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7557642

RESUMO

Responses of LH, TSH, PRL, beta-endorphin-like immunoreactivity, ACTH and cortisol to metoclopramide were evaluated in hyperprolactinemic-amenorrheic women and normal women. Augmented TSH responses and blunted PRL responses to metoclopramide were found in hyperprolactinemic women compared to normal women. A significant increase in serum LH levels was found only in hyperprolactinemic women after metoclopramide. Thus, the hyperprolactinemic women showed hormonal changes compatible with increased central dopaminergic tone. A significant increase in circulating levels of beta-endorphin-like immunoreactivity, ACTH and cortisol was found in hyperprolactinemic women but not in normal women after metoclopramide administration. Thus, beta-endorphin and ACTH secretion appear to be tonically inhibited by increased central dopaminergic tone in hyperprolactinemic-amenorrheic women.


Assuntos
Hormônio Adrenocorticotrópico/efeitos dos fármacos , Amenorreia/metabolismo , Antagonistas de Dopamina/farmacologia , Hidrocortisona/metabolismo , Hiperprolactinemia/metabolismo , Metoclopramida/farmacologia , beta-Endorfina/efeitos dos fármacos , Hormônio Adrenocorticotrópico/metabolismo , Adulto , Antagonistas de Dopamina/administração & dosagem , Feminino , Humanos , Metoclopramida/administração & dosagem , beta-Endorfina/metabolismo
9.
Adv Exp Med Biol ; 395: 523-8, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8714009

RESUMO

Recently, several authors have reported the existence of oxytocin (OT) in mammalian granulosa-luteal cells after ovulation. The purpose of this study was to examine the evidence for gene expression and localization of OT and OT receptor (OTR) in the cumulus cells surrounding the oocytes. Cumulus cells with mature oocytes were obtained from experimental and clinical in vitro fertilization-embryo transfer (IVF-ET) programs. OT and OTR gene expression was analyzed with reverse transcriptase-polymerase chain reaction (RT-PCR) and RT-PCR/single strand conformation polymorphism (SSCP). OT gene expression was detected in mouse and human cumulus cells. The results of RT-PCR/SSCP showed that the structure of OT mRNA in cumulus cells was similar to that in the hypothalamus. Furthermore, OTR gene expression was clearly demonstrated in human cumulus cells, and a weak positive signal was observed in human oocytes. Immunocytochemical staining of OTR was clearly detected in human cumulus cells. The rate of mouse blastocyst development was significantly higher in the group cultured with OT than that without OT. These results are the first observations of simultaneous OT and OTR gene expression in cumulus cells, suggesting that ovarian OT might have some physiological role in the early stage of embryo development.


Assuntos
Desenvolvimento Embrionário e Fetal/efeitos dos fármacos , Células Lúteas/metabolismo , Ocitocina/genética , Ocitocina/farmacologia , Receptores de Ocitocina/genética , Animais , Sequência de Bases , Primers do DNA/genética , Feminino , Fertilização in vitro , Expressão Gênica , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Camundongos , Dados de Sequência Molecular , Oócitos/metabolismo , Reação em Cadeia da Polimerase
10.
Gynecol Obstet Invest ; 40(3): 162-7, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8529948

RESUMO

An immunoradiometric assay for free beta-human chorionic gonadotropin (F beta hCG) is now available. Measurement of serum F beta hCG has been shown to be valuable for the diagnosis of trophoblastic disease and for screening Down's syndrome pregnancies. Urine specimens may be preferable to blood samples since collection of urine specimens usually are less inconvenient to patients than venipuncture. We have evaluated whether the immunoradiometric assay can be applicable to urine samples. The assay was sensitive and precise. When urine samples were diluted 4-fold or more, the diluted samples gave quantitative values, and recovery of beta hCG added to urine samples was satisfactory. Creatinine corrected urinary F beta hCG levels correlated with serum F beta hCG levels. Thus, the immunoradiometric assay was considered to be applicable to urine samples. Serum F beta hCG to hCG ratio has been reported to be important to distinguish among normal pregnancies, hydatidiform mole and choriocarcinoma. However, urinary F beta hCG to hCG ratio did not significantly correlate with serum F beta hCG to hCG ratio. And therefore, the clinical value of urinary F beta hCG to hCG ratio should be further investigated.


Assuntos
Gonadotropina Coriônica Humana Subunidade beta/urina , Ensaio Imunorradiométrico/estatística & dados numéricos , Gonadotropina Coriônica/sangue , Gonadotropina Coriônica/urina , Gonadotropina Coriônica Humana Subunidade beta/sangue , Feminino , Humanos , Ensaio Imunorradiométrico/métodos , Período Pós-Parto/metabolismo , Gravidez , Valores de Referência , Sensibilidade e Especificidade
11.
Horm Res ; 41 Suppl 1: 41-7, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7522204

RESUMO

Recently, several reports have demonstrated the presence of oxytocin (OT) in the corpus luteum of mammalian species. However, the biological role of ovarian OT remains obscure. This study was performed to examine OT gene expression in cumulus cells of mice and humans, and in human corpus luteum, and the role of OT in early embryogenesis. OT gene and OT mRNA were analyzed by reverse transcription-polymerase chain reaction, with single-strand-conformation polymorphism and heteroduplex procedures. OT-treated in-vitro-fertilized mouse oocytes were cultured and the rate of blastocyst development estimated. An immunohistochemical study was also carried out to detect OT on the surface of the mouse oocytes.


Assuntos
Corpo Lúteo/metabolismo , Desenvolvimento Embrionário e Fetal/efeitos dos fármacos , Expressão Gênica , Ocitocina/genética , Ocitocina/farmacologia , Animais , Sequência de Bases , Blastocisto/fisiologia , Northern Blotting , Feminino , Humanos , Camundongos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Mensageiro/análise , DNA Polimerase Dirigida por RNA , Transcrição Gênica
12.
J Perinat Med ; 22(3): 189-94, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7823258

RESUMO

We measured cord blood levels of calcium-regulating hormones and osteocalcin in 34 premature infants of various gestational ages. 1,25(OH)2D levels were low in mid-gestation and increased with advancing gestation. Parathyroid hormone levels were low, and calcitonin levels were high in mid-gestation. Both of them declined with advancing gestation. Osteocalcin levels were high in mid-gestation. They increased from 22 weeks through 27 weeks of gestational age, and decreased thereafter. Circulating osteocalcin is considered as a clinical marker of bone turnover. However, cord blood osteocalcin decreased between 27 and 36 weeks of gestation during which period calcium accumulation by the fetus increases. Therefore, cord blood osteocalcin does not appear to reflect fetal bone formation.


Assuntos
Calcitonina/sangue , Sangue Fetal/química , Recém-Nascido Prematuro/sangue , Osteocalcina/sangue , Hormônio Paratireóideo/sangue , Cálcio/sangue , Cálcio/metabolismo , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro/metabolismo , Fósforo/sangue
13.
Obstet Gynecol ; 81(2): 189-90, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8423947

RESUMO

OBJECTIVE: To measure osteocalcin levels in fetal and maternal blood. METHODS: Osteocalcin was measured by radioimmunoassay in paired maternal and umbilical venous and arterial blood obtained at term deliveries. RESULTS: Umbilical venous osteocalcin levels (mean +/- standard deviation) were significantly higher than arterial levels (10.28 +/- 4.99 versus 3.85 +/- 2.27 micrograms/L). Umbilical venous but not arterial levels of osteocalcin were significantly higher than maternal values (2.54 +/- 1.19 micrograms/L). CONCLUSION: Higher osteocalcin levels in umbilical venous blood than in umbilical arterial blood suggest that the placenta may be the main source of osteocalcin in late fetal life.


Assuntos
Sangue Fetal/química , Osteocalcina/sangue , Gravidez/sangue , Feminino , Humanos , Recém-Nascido , Radioimunoensaio
14.
Am J Obstet Gynecol ; 164(5 Pt 1): 1248-52, 1991 May.
Artigo em Inglês | MEDLINE | ID: mdl-2035567

RESUMO

We measured serum concentrations of calcium-regulating hormones and osteocalcin in 20 women longitudinally throughout pregnancy, 1,25-Dihydroxyvitamin D levels were high early in pregnancy and increased with advancing gestation. Parathyroid hormone and osteocalcin levels were low in early pregnancy. They declined toward the middle of pregnancy, but increased in late pregnancy. The serum osteocalcin level correlated with the parathyroid hormone level. The synthesis of osteocalcin by osteoblasts is stimulated by the action of 1,25-dihydroxyvitamin D, and serum osteocalcin levels are also related to the levels of parathyroid hormone. During early and mid pregnancy, the stimulatory effect of 1,25-dihydroxyvitamin D on the synthesis of osteocalcin may be overridden by the inhibitory effect of declining parathyroid hormone levels. The increase in osteocalcin level in late pregnancy may be a consequence of increasing levels of both parathyroid hormone and 1,25-dihydroxyvitamin D.


Assuntos
Calcitonina/sangue , Calcitriol/sangue , Osteocalcina/sangue , Hormônio Paratireóideo/fisiologia , Gravidez/metabolismo , Adulto , Cálcio/sangue , Feminino , Idade Gestacional , Humanos , Estudos Longitudinais , Fósforo/sangue , Período Pós-Parto/metabolismo , Radioimunoensaio
15.
J Nutr Biochem ; 1(4): 196-9, 1990 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15539204

RESUMO

Glucose was combined covalently with the epsilon-amino groups of lysyl residues of bovine casein in the presence of sodium cyanoborohydride as a reducing reagent by reductive alkylation, forming stable secondary amine linkages. Solubility characteristics and nutritional values of the neoglycoprotein were examined. The degree of modification (%) of the glucosylated casein was 82.5. Solubility of the modified casein was increased by the attachment of glucose. The modification did not disturb the digestion of casein by pepsin or trypsin. Rat feeding experiments using 10% protein diets demonstrated that the protein efficiency ratio (PER) of the modified casein was 0.35 +/- 0.33 compared with 2.99 +/- 0.29 for the unmodified casein. When the modified casein was supplemented with L-lysine to equal the level of total lysine of unmodified casein, the PER value was increased to 2.21 +/- 0.29. Nitrogen balance experiments showed that the modified casein was digested completely. On the other hand, biological value and net protein utilization of the modified protein were shown to be considerably lower than those of the unmodified casein.

16.
Endocrinol Jpn ; 31(3): 349-53, 1984 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-6594231

RESUMO

Changes in the concentrations of progesterone, 17 beta-estradiol and 13, 14-dihydro-15-oxo-prostaglandin F2 alpha (PGFM) were evaluated in the peripheral plasma of rabbits during late pregnancy by treating trilostane, an inhibitor of 3 beta-hydroxysteroid dehydrogenase, in an attempt to obtain further insight into the involvement of progesterone and prostaglandin (PG) in the initiation of parturition. The concentrations of progesterone were 18.8 +/- 2.2 ng/ml (mean +/- SE, n = 6) before administration of the inhibitor, significantly (p less than 0.05) fell to 7.6 +/- 1.0 ng/ml (n = 6) at 30 min, and remained low until 10 h after the drug administration. The concentrations of progesterone were still low (5.4 +/- 0.5 ng/ml, n = 6) at 20-24 h after administration of the inhibitor, and were also low (4.9 +/- 2.2 ng/ml, n = 6) at delivery. Premature deliveries occurred at 28.8 +/- 2.0 h after injection of trilostane (on days 29 of gestation). Increased concentrations of PGFM were observed at delivery. However, administration of trilostane induced no discernible changes in the concentration of estradiol. These findings suggest that delivery is induced by progesterone withdrawal and that synthesis prostaglandin F2 alpha is remarkably increased at delivery in the rabbit.


Assuntos
3-Hidroxiesteroide Desidrogenases/antagonistas & inibidores , Dinoprosta/análogos & derivados , Progesterona/sangue , Prostaglandinas F/sangue , Animais , Di-Hidrotestosterona/análogos & derivados , Di-Hidrotestosterona/farmacologia , Estradiol/sangue , Feminino , Trabalho de Parto/efeitos dos fármacos , Gravidez , Coelhos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...