Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Ann R Coll Surg Engl ; 104(7): e208-e210, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35442821

RESUMO

The optimal surgical procedure for Siewert II oesophagogastric junction cancer is still debated. The minimally invasive Ivor Lewis technique can be considered the most adequate intervention from the oncological perspective but it is still contested owing to its technical difficulties. To allow an easier thoracoscopic stage during the procedure, we performed it with laparoscopic trans-hiatal oesophageal transection and transabdominal extraction. An 80-year-old man with stage 3 Siewert II oesophagogastric junction adenocarcinoma not suitable for neoadjuvant therapy underwent minimally invasive Ivor Lewis oesophagectomy with two-field lymphadenectomy, using a laparoscopic and thoracoscopic approach in prone position. The trans-hiatal oesophageal resection permitted easy extraction of a transabdominal specimen and frozen section examination. The prone position, together with the absence of the specimen in the operative field, allowed easier mediastinal node dissection and oesophagogastric anastomosis with better visualisation. The postoperative course was uneventful. Pathology showed a G3-pT3, N2 adenocarcinoma with 6/30 metastatic lymph nodes.


Assuntos
Adenocarcinoma , Neoplasias Esofágicas , Laparoscopia , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Idoso de 80 Anos ou mais , Neoplasias Esofágicas/diagnóstico , Esofagectomia/métodos , Junção Esofagogástrica/patologia , Junção Esofagogástrica/cirurgia , Humanos , Laparoscopia/métodos , Masculino , Estudos Retrospectivos
2.
J Endocrinol Invest ; 42(2): 183-197, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29790086

RESUMO

PURPOSE: Rhabdomyosarcoma (RMS), the most common soft-tissue sarcoma in childhood, rarely affects adults, preferring male. RMS expresses the receptor for androgen (AR) and responds to androgen; however, the molecular action of androgens on RMS is unknown. METHODS: Herein, testosterone (T) effects were tested in embryonal (ERMS) and alveolar (ARMS) RMS cell lines, by performing luciferase reporter assay, RT-PCR, and western blotting experiments. RNA interference experiments or bicalutamide treatment was performed to assess the specific role of AR. Radiation treatment was delivered to characterise the effects of T treatment on RMS intrinsic radioresistance. RESULTS: Our study showed that RMS cells respond to sub-physiological levels of T stimulation, finally promoting AR-dependent genomic and non-genomic effects, such as the transcriptional regulation of several oncogenes, the phosphorylation-mediated post-transductional modifications of AR and the activation of ERK, p38 and AKT signal transduction pathway mediators that, by physically complexing or not with AR, participate in regulating its transcriptional activity and the expression of T-targeted genes. T chronic daily treatment, performed as for the hormone circadian rhythm, did not significantly affect RMS cell growth, but improved RMS clonogenic and radioresistant potential and increased AR mRNA both in ERMS and ARMS. AR protein accumulation was evident in ERMS, this further developing an intrinsic T-independent AR activity. CONCLUSIONS: Our results suggest that androgens sustain and improve RMS transformed and radioresistant phenotype, and therefore, their therapeutic application should be avoided in RMS post puberal patients.


Assuntos
Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Receptores Androgênicos/metabolismo , Rabdomiossarcoma/metabolismo , Transdução de Sinais/fisiologia , Testosterona/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Rabdomiossarcoma/patologia , Transdução de Sinais/efeitos dos fármacos
3.
Knee ; 22(1): 30-5, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25480381

RESUMO

BACKGROUND: Different single-stage surgical approaches are currently under evaluation to repair cartilage focal lesions. To date, only little is known on even short-term clinical follow-up and almost no knowledge exists on histological results of such treatments. The present paper aims to analyze the clinical and histological results of the collagen-covered microfracture and bone marrow concentrate (C-CMBMC) technique in the treatment of focal condylar lesions of knee articular cartilage. METHODS: Nine patients with focal lesions of the condylar articular cartilage were consecutively treated with arthroscopic microfractures (MFX) covered with a collagen membrane immersed in autologous bone marrow concentrate (BMC) from the iliac crest. Patients were retrospectively assessed using several standardized outcome assessment tools and MRI scans. Four patients consented to undergo second look arthroscopy and biopsy harvest. RESULTS: Every patient was arthroscopically treated for a focal condylar lesion (mean area 2.5 SD(0.4) cm(2)). All the patients (mean age 43 SD(9) years) but one experienced a significant clinical improvement from the pre-operative condition to the latest follow-up (mean 29 SD(11) months). Cartilage macroscopic assessment at 12 months revealed that all the repairs appeared almost normal. Histological analysis showed a hyaline-like cartilage repair in one lesion, a fibrocartilaginous repair in two lesions and a mixture of both in one lesion. CONCLUSIONS: The first clinical experience with single-stage C-CMBMC for focal cartilage defects in the knee suggests that it is safe, it improves the short-term knee function and that it has the potential to recreate hyaline-like cartilage.


Assuntos
Implantes Absorvíveis , Artroplastia Subcondral/métodos , Transplante de Medula Óssea , Cartilagem Articular/cirurgia , Traumatismos do Joelho/cirurgia , Engenharia Tecidual , Alicerces Teciduais , Adulto , Cartilagem Articular/lesões , Colágeno , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Retrospectivos
4.
J Tissue Eng Regen Med ; 9(6): 691-701, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23109511

RESUMO

The osteoblast is the bone-forming cell and is derived from mesenchymal stem cells (MSCs). Osteo-inductive substances could represent a useful therapeutic approach during the fracture repair process. The aim of this work was to evaluate the effects of vitamin MK-7, alone or in association with vitamin D3, in differentiating human MSCs (hMSCs) in vitro along the osteoblastic lineage. In particular, primary endpoints of the study include gene and protein markers of osteoblast differentiation. Considering genes involved in bone formation and mineralization, our data show that vitamin MK-7 enhances vitamin D3 gene induction of osteocalcin (OC). Among genes related to cell growth and differentiation, a specific effect of vitamin MK-7 was observed for growth differentiation factor-10 (GDF10) and insulin-like growth factor 1 (IGF1), the latter being also involved in the induction of vascular endothelial growth factors (VEGFA). Accordingly, vitamin co-supplementation greatly affected VEGFA and its receptor fms-related tyrosine kinase 1 (FLT1), a key factor in both angiogenic and osteogenic processes. These results stress the relevance of MK-7 and D3 co-supplementation in the bone-healing process as able to modulate the expression of genes involved in both mineralization and angiogenesis. Moreover, at the protein level co-association of vitamins might provide an optimal balance between induction and carboxylation of osteocalcin, essential for its functionality in the extracellular matrix (ECM). Our results may provide hints for therapeutic application of hMSCs in bone disease, clarifying mechanisms involved in stem cell-mediated bone development, and they also highlight the relevance of co-supplementation strategies, since single supplementations might result in a suboptimal effect.


Assuntos
Calcificação Fisiológica/efeitos dos fármacos , Colecalciferol/farmacologia , Células-Tronco Mesenquimais/metabolismo , Neovascularização Fisiológica/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Vitamina K 2/análogos & derivados , Adulto , Biomarcadores/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Pessoa de Meia-Idade , Osteocalcina/metabolismo , Osteogênese/genética , Vitamina K 2/farmacologia
5.
Int J Immunopathol Pharmacol ; 26(4): 917-30, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24355227

RESUMO

The association between microfracture of the subchondral plate and a coverage scaffold has emerged as a promising strategy to treat cartilage lesions in a one-step procedure. Between different types of scaffolds (e.g. collagen, hyaluronic acid, polyglycolic acid) currently studied, type I collagen scaffold is the most used for this purpose, and is currently adopted for humans. The aim of this study was to test a novel scaffold made of mixed type I and II collagen (I-IICS) in order to define the immunological reaction of the synovial tissue and the repair capabilities induced by the collagen membrane when associated with microfracture. Eight New Zealand White rabbits, aged 180 days, were operated on bilaterally on the medial femoral condyle. A circular cartilage lesion was performed up to the calcified layer of the medial femoral condyle, and the centre of the lesion was microfractured. Randomly, one of the two lesions was covered with the I-IICS (treated), and the other was left uncovered (control). The synovial membrane reaction and the quality of the cartilage tissue repair were investigated at 2, 90, 180 and 270 days macroscopically, histomorphologically and ultrastructurally. Expression of tumor necrosis factor-alpha (TNF-alpha) in synovial tissue by immunocytochemistry analyses was also investigated. In the control group, at 2 days gold particles were localized mainly on synoviocyte type A, less on synoviocytes type B and on collagen bundles; in the treated group the reaction is more intense in cells in the matrix, but at 180 days controls and treated joints were very similar. The synovial membranes of the joints receiving the I-IICS did not reveal significant changes compared to the age-matched controls. Signs of inflammation were present at the 90-day time-point, and became less evident at afterwards. The degradation of the scaffolds was already evident at the 90-day time-point. The quality of the cartilage repair of the rabbits treated with the I-IICS was slightly better in 5 cases out of 6 in comparison to the controls. However, a statistically significant difference was not detected (p=0.06). Scaffolds made of mixed type I and II collagen exhibited good biocompatibility properties in vivo and favoured cartilage restoration when associated with microfracture, as shown in this pilot study.


Assuntos
Cartilagem/cirurgia , Colágeno Tipo II/farmacologia , Colágeno Tipo I/farmacologia , Membrana Sinovial/ultraestrutura , Alicerces Teciduais , Animais , Projetos Piloto , Coelhos , Cicatrização
6.
Knee ; 20(6): 562-9, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23642661

RESUMO

BACKGROUND: Different single-stage surgical approaches are currently under evaluation to repair focal cartilage lesions. This study aims to analyze the clinical and histological results after treatment of focal condylar articular lesions of the knee with microfracture and subsequent covering with a resorbable polyglycolic acid/hyaluronan (PGA -HA) matrix augmented with autologous bone marrow concentrate (BMC). METHODS: Nine patients with focal lesions of the condylar articular cartilage were consecutively treated with arthroscopic PGA -HA-covered microfracture and bone marrow concentrate (PGA -HA-CMBMC). Patients were retrospectively assessed using standardized assessment tools and magnetic resonance imaging (MRI). Five patients consented to undergo second look arthroscopy and 2 consented biopsy harvest. RESULTS: All the patients but one showed improvement in clinical scoring from the pre-operative situation to the latest follow-up (average 22±2months). The mean IKDC subjective score, Lysholm score, VAS and the median Tegner score significantly increased from baseline to the latest follow-up. Cartilage macroscopic assessment at 12months revealed that one repair appeared normal, three almost normal and one appeared abnormal. Histological analysis proofed hyaline-like cartilage repair tissue formation in one case. MRI at 8 to 12months follow-up showed complete defect filling. CONCLUSIONS: The first clinical experience with single-stage treatment of focal cartilage defects of the knee with microfracture and covering with the PGA -HA matrix augmented with autologous BMC (PGA -HA-CMBMC) suggests that it is safe, it improves knee function and has the potential to regenerate hyaline-like cartilage. LEVEL OF EVIDENCE: IV, case series.


Assuntos
Implantes Absorvíveis , Artroplastia Subcondral/métodos , Transplante de Medula Óssea , Cartilagem Articular/cirurgia , Engenharia Tecidual , Alicerces Teciduais , Adulto , Biópsia por Agulha , Cartilagem Articular/lesões , Cartilagem Articular/patologia , Feminino , Humanos , Ácido Hialurônico , Imuno-Histoquímica , Traumatismos do Joelho/diagnóstico , Traumatismos do Joelho/cirurgia , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Ácido Poliglicólico , Medição de Risco , Estudos de Amostragem , Transplante Autólogo , Resultado do Tratamento
7.
Int J Immunopathol Pharmacol ; 24(1 Suppl 2): 69-72, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21669141

RESUMO

Chondral articular defects are a key concern in orthopaedic surgery. To overcome the disadvantages of autologous chondrocyte implantation (ACI) and to improve the outcomes of autologous matrix-induced chondrogenesis (AMIC), the latter technique is currently augmented with bone marrow concentrate injected under or seeded onto the scaffold. However, to date, only a little is known about histological outcomes of either the AMIC technique or AMIC associated with bone marrow concentrate. This study aimed to evaluate the quality of the repair tissue obtained from biopsies harvested during second-look arthroscopy after arthroscopic AMIC augmented with bone marrow concentrate. We analysed five second-look core biopsies harvested at 12 months follow-up. At the time of biopsy the surgeon reported the quality of the repair tissue using the standard ICRS Cartilage Repair Assessment (CRA). Every biopsy together with patient data was sent to our centre to undergo blind histological evaluation (ICRS II Visual Histological Assessment Scale) and data analysis. Five asymptomatic patients (mean age 43.4 years) had isolated lesions (mean size was 3.7 cm2) at the medial femoral condyle. All the implants appeared nearly normal (ICRS CRA) at arthroscopic evaluation and had a mean overall histological (ICRS II) of 59.8±14,5. Hyaline-like matrix was found in only one case, a mixture of hyaline/fibrocartilage was found in one case and fibrocartilage was found three cases. Our clinical and histological data suggest that this procedure achieved a nearly normal arthroscopic appearance and a satisfactory repair tissue, which was possibly still maturing at 12 months follow-up. Further studies are needed to understand the true potential of one-step procedures in the repair of focal chondral lesions in the knee.


Assuntos
Transplante de Medula Óssea/métodos , Cartilagem Articular/cirurgia , Colágeno , Traumatismos do Joelho/cirurgia , Alicerces Teciduais , Adulto , Artroscopia , Biópsia , Biópsia por Agulha , Cartilagem/lesões , Cartilagem/patologia , Cartilagem Articular/patologia , Feminino , Fibrocartilagem/patologia , Seguimentos , Humanos , Cartilagem Hialina/patologia , Traumatismos do Joelho/patologia , Masculino , Pessoa de Meia-Idade , Inclusão em Parafina , Resultado do Tratamento , Adulto Jovem
8.
J Biol Regul Homeost Agents ; 24(1): 51-62, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20385071

RESUMO

This report compares the effect of rhBMPs and PRG on cells derived from human non-union sites. Treatment of non-union continues to be a challenging task for the trauma surgeon often resulting in unsatisfactory results and long-term morbidity. Over the past two decades, the possibility to use growth factors in bone regeneration has been investigated. In this study we compared the in vitro capability of two recombinant human bone morphogenetic proteins (rhBMP-2 and rhBMP-7) and activated platelet-rich plasma (PRG) to stimulate proliferation and/or differentiation of cells derived from non-union patients. Cells derived from the lesion sites, osteoblasts and mesenchymal stem cells (MSCs) derived from other bone sites of the same patients were used. Treatment with rhBMP-7 or rhBMP-2 showed an improvement in the expression of osteoblastic markers (osteonectin and osteocalcin) in cells derived from human non-union sites. This enhancement was more marked in MSCs, while no significant changes were observed in osteoblast cultures. The PRG treatment produced in all analysed samples a considerable increase in cell proliferation without affecting cell differentiation. On the basis of our results, for an effective biological treatment of non-unions, small amounts of autologous bone marrow (MSCs) are necessary in the lesion site in order to provide both growth factors and a sufficient number of responsive cells. Finally, our results prove that sequential timing administration of PRG and rhBMPs may be used in new therapeutic strategy.


Assuntos
Consolidação da Fratura/efeitos dos fármacos , Fraturas não Consolidadas/tratamento farmacológico , Substâncias de Crescimento/farmacologia , Adulto , Células-Tronco Adultas/citologia , Células-Tronco Adultas/efeitos dos fármacos , Células-Tronco Adultas/metabolismo , Fosfatase Alcalina/metabolismo , Proteína Morfogenética Óssea 2/farmacologia , Proteína Morfogenética Óssea 7/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Colágeno Tipo I/metabolismo , Colágeno Tipo III/metabolismo , Feminino , Fraturas não Consolidadas/metabolismo , Fraturas não Consolidadas/patologia , Humanos , Técnicas In Vitro , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Pessoa de Meia-Idade , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteocalcina/metabolismo , Osteonectina/metabolismo , Plasma Rico em Plaquetas , Proteínas Recombinantes/farmacologia , Adulto Jovem
9.
Eur J Surg Oncol ; 33(3): 364-9, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17129703

RESUMO

AIMS: Cutaneous squamous cell carcinoma (SCC) is the second most common skin cancer. The metastatic potential is generally low. However, there are subgroups of patients at higher risk, for whom sentinel lymph node biopsy (SLNB) might be useful. SLNB might allow the timely inclusion of high risk patients in more aggressive treatment protocols, sparing at the same time node-negative patients the morbidity of potentially unnecessary therapy. Our aim was to introduce the concept of SLNB for patients with high risk cutaneous SCC. PATIENTS AND METHODS: We examined a consecutive series of high risk cutaneous SCC patients undergoing SLNB at our large dermatological hospital, and performed a literature review and pooled analysis of all published cases of SLNB for cutaneous SCC. RESULTS: Among the 22 clinically node-negative patients undergoing SLNB at our hospital, one patient (4.5%) showed a histologically positive sentinel node and developed recurrences during follow-up. Sentinel node-negative patients showed no metastases at a median follow-up of 17 months (range: 6-64). The incidence of positive sentinel nodes in previous reports ranged between 12.5% and 44.4%. Pooling together patients from the present and previous studies (total 83 patients), we calculated an Odds Ratio of 2.76 (95% CI 1.2-6.5; p=0.02) of finding positive sentinel nodes for an increase in tumor size from <2 cm to 2.1-3 cm to >3 cm. CONCLUSIONS: Our case series and the pooled analysis support the concept that SLNB can be performed for high risk cutaneous SCC. Prospective multicenter studies are needed to examine the role, utility and cost-effectiveness of SLNB for this population.


Assuntos
Carcinoma de Células Escamosas/patologia , Biópsia de Linfonodo Sentinela , Neoplasias Cutâneas/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/cirurgia , Feminino , Humanos , Modelos Logísticos , Excisão de Linfonodo , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Neoplasias Cutâneas/cirurgia
10.
Ital J Anat Embryol ; 110(2 Suppl 1): 189-94, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16101038

RESUMO

In vitro growth culture systems of mammalian oocytes have been developed with the aims of studying regulative processes occurring during oogenesis and folliculogenesis, and of preserving fertility. Although in large mammals IVG technology does not still assure the co-ordinate development of both somatic and germinal cells and the production of high number of viable offspring, their improvement may represent an important therapeutic tool for restoring fertility in women undergoing premature menopause or cancer treatments. Morphological studies of in vitro grown follicles were not performed extensively, especially by means of scanning electron microscopy. In the present paper preliminary ultrastructural observations of in vitro cultured follicles are presented.


Assuntos
Técnicas de Cultura de Células/métodos , Oócitos/crescimento & desenvolvimento , Oócitos/ultraestrutura , Oogênese/fisiologia , Folículo Ovariano/crescimento & desenvolvimento , Folículo Ovariano/ultraestrutura , Animais , Células Cultivadas , Feminino , Fertilização in vitro/métodos , Células da Granulosa/fisiologia , Células da Granulosa/ultraestrutura , Camundongos , Microscopia Eletrônica de Varredura
11.
Hum Reprod ; 19(12): 2913-8, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15347598

RESUMO

BACKGROUND: In this study, we compared the relative ability of FSH (100 mIU/ml), epidermal growth factor (EGF) (10 ng/ml), and follicular-fluid meiosis-activating sterol (FF-MAS, 10 micromol/l) to induce meiotic resumption and polar body I (PBI) extrusion in mouse oocytes. METHODS: Cumulus-enclosed oocytes (CEO) were co-incubated with meiosis-arresting agents, including 4 mmol/l hypoxanthine (Hx), 0.3 mmol/l dibutyryl cAMP (dbcAMP), and 8.5 micromol/l cilostamide, a selective inhibitor of the oocyte-specific phosphodiesterase 3 (PDE 3). RESULTS: In Hx-treated oocytes, FSH, EGF and FF-MAS induced meiosis resumption at very high rates, but only FSH and EGF also promoted PBI extrusion with high frequency. In experiments conducted in the presence of dbcAMP, FF-MAS was unable to promote an increase in germinal vesicle breakdown (GVBD) rate, whereas FSH and EGF generated a response similar to the Hx groups. Neither FSH, EGF nor FF-MAS caused any change in the meiotic status of CEO when meiotic arrest at the germinal vesicle (GV) stage was maintained by cilostamide. In the presence of Hx, naked oocytes (NkO) co-cultured with their cumulus cells were able to respond to the GVBD-inducing effect of FSH and EGF by resuming meiosis at high rate. CONCLUSIONS: Collectively, these results indicate that: (i) a signal triggered in cumulus cells by either FSH or EGF, but not necessarily coincident with FF-MAS, may contribute to meiotic maturation, supporting GVBD and extrusion of PBI; (ii) the transmission of this signal can occur in a paracrine fashion, at least with reference to the breakdown of the GV. It also appears that concomitant regulation of intra-oocyte cAMP degradation is a prerequisite for meiosis resumption.


Assuntos
Colestenos/farmacologia , Fator de Crescimento Epidérmico/farmacologia , Hormônio Foliculoestimulante/farmacologia , Meiose/efeitos dos fármacos , Oócitos/fisiologia , Animais , Bucladesina/farmacologia , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Células Cultivadas , Técnicas de Cocultura , Feminino , Hipoxantina/farmacologia , Camundongos , Oócitos/efeitos dos fármacos , Folículo Ovariano/citologia , Quinolonas/farmacologia
12.
Hum Reprod ; 15(11): 2319-25, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11056125

RESUMO

The aim of this study was to evaluate the effects of pulsed, extremely low-frequency electromagnetic fields (ELF-EMF) on in-vitro mouse pre-antral follicle development. Pre-antral follicles were cultured for 5 days and exposed to ELF-EMF at the frequencies of 33 or 50 Hz. ELF-EMF application did not affect follicular growth over a 3 day culture period, but on day 5 the growth of 33 Hz-exposed follicles was significantly reduced when compared with controls, while the 50 Hz-exposed follicles were not significantly affected. However, ELF-EMF severely impaired antrum formation at both frequencies, as 79 +/- 3% of control follicles developed antral cavities compared with 30 +/- 6% and 51.6 +/- 4% of 33 or 50 Hz-exposed follicles respectively. The follicles with failed antrum formation showed lower oestradiol release and granulosa cell DNA synthesis, but these effects were not related to granulosa cell apoptosis. Furthermore, a high percentage of the in-vitro grown oocytes obtained from exposed follicles had a reduced ability to resume meiotic maturation when compared with controls. These results suggest that ELF-EMF exposure might impair mammalian female reproductive potentiality by reducing the capacity of the follicles to reach a developmental stage that is an essential pre-requisite for reproductive success.


Assuntos
Campos Eletromagnéticos , Folículo Ovariano/fisiologia , Animais , Apoptose/fisiologia , Divisão Celular/fisiologia , Senescência Celular/fisiologia , Técnicas de Cultura , Estradiol/metabolismo , Feminino , Células da Granulosa/citologia , Células da Granulosa/fisiologia , Meiose/fisiologia , Camundongos , Muco/metabolismo , Oócitos/fisiologia , Folículo Ovariano/citologia
13.
Endocrinology ; 140(4): 1783-8, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10098516

RESUMO

In the present study we evaluated the role of T3 on the in vitro processes of mouse cumulus cell-oocyte complex expansion, oocyte meiotic maturation, and granulosa cell aromatase activity. Results obtained from cumuli oophori isolated from immature and adult mice ovaries demonstrated that T3 at all concentrations tested (0.1-100 nM) did not affect basal or FSH-induced cumulus expansion or interfere with oocyte meiotic maturation up to metaphase II stage. On the contrary, T3 inhibited in a time- and dose-dependent manner FSH-induced aromatase activity in cultured granulosa cells obtained from either adult or immature female mice. The half-maximal dose (ED50) of T3 inhibition was 0.87 +/- 0.21 nM, which is in agreement with the reported dissociation constant of T3 nuclear receptor (Kd = 0.4-5 nM) in mammalian granulosa cells. Time-course experiments demonstrated higher sensitivity to T3 of adult granulosa cells with respect to immature granulosa cells in culture. Indeed, in immature granulosa cells T3 inhibition became significantly evident only after 6 days of hormonal treatment, whereas in adult granulosa cells the inhibitory effect was present after only 2 days of treatment. (Bu)2cAMP- or 3-isobutyl-1-methyl-xanthine-stimulated aromatase activity was also significantly decreased by T3, thus suggesting that the inhibition was downstream from cAMP formation. Lastly, analysis of aromatase messenger RNA (mRNA) levels by semiquantitative RT-PCR demonstrated the ability of FSH to increase aromatase mRNA level in cultured granulosa cells by 2.4 +/- 0.5-fold. In agreement with the effect on enzyme activity, the stimulatory effect of FSH on aromatase mRNA level was greatly reduced after T3 cotreatment. In conclusion, T3 inhibition of aromatase activity may be of physiological relevance in the complex multihormonal regulation of mammalian follicle development and may contribute to explaining the alteration in female reproductive functions after thyroid hormone hypo- or hypersecretion.


Assuntos
Aromatase/metabolismo , Células da Granulosa/efeitos dos fármacos , Células da Granulosa/enzimologia , Oócitos/efeitos dos fármacos , Oócitos/fisiologia , Tri-Iodotironina/farmacologia , 1-Metil-3-Isobutilxantina/farmacologia , Animais , Aromatase/genética , Bucladesina/farmacologia , Células Cultivadas , Feminino , Hormônio Foliculoestimulante/farmacologia , Cinética , Meiose/efeitos dos fármacos , Camundongos , Oócitos/citologia , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa
14.
Biol Reprod ; 60(3): 594-601, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10026104

RESUMO

Preantral ovarian follicles isolated from prepubertal sheep ovaries were individually cultured for 6 days in the presence of increasing doses of FSH (ranging from 0.01 to 1 microg/ml) and under two different oxygen concentrations, 20% and 5% O2. Follicle development was evaluated on the basis of antral cavity formation as well as the presence of healthy cumulus oocyte complexes. Follicle growth was enhanced by FSH addition to culture medium, while the use of a low oxygen concentration slightly stimulated this process. However, when follicles were cultured in the presence of high doses of FSH (1 microgram/ml) and under low oxygen concentration, a high proportion of them showed the presence of an antral cavity and of a healthy cumulus-oocyte complex. In addition, under this specific culture condition sheep preantral follicles released higher levels of estradiol as compared to those secreted at lower FSH concentrations or under 20% O2. When the meiotic competence of oocytes derived from follicles cultured at 1 microgram/ml FSH was assessed, no significant difference was recorded between the two oxygen groups. These results show that the culture conditions here identified are beneficial to in vitro growth and differentiation of sheep preantral follicles.


Assuntos
Folículo Ovariano/crescimento & desenvolvimento , Ovinos/crescimento & desenvolvimento , Animais , Meios de Cultura , Técnicas de Cultura , Estradiol/metabolismo , Feminino , Hormônio Foliculoestimulante/administração & dosagem , Hormônio Foliculoestimulante/farmacologia , Folículo Ovariano/efeitos dos fármacos , Folículo Ovariano/metabolismo , Oxigênio/administração & dosagem
15.
Biol Reprod ; 51(1): 140-5, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7918869

RESUMO

The possibility that FSH stimulates the phospholipase A2 (PLA2) pathway was studied in cultured immature Sertoli cells. FSH induced [3H]-arachidonic acid (AA) release from prelabeled cells in a time- and concentration-dependent fashion (ED50 = 21.8 +/- 1.9 ng/ml). This response could be fully prevented by pretreatment of cells with the PLA2 inhibitor, mepacrine. That PLA2 was the main enzyme responsible for cleavage of AA from membrane phospholipids was directly shown by PLA2 activity assay using vesicles of radiolabeled phosphatidylcholine (PC) as substrate. Furthermore, FSH stimulated eicosanoid generation in a time-dependent manner through the cyclooxygenase but not the lipoxygenase pathway. In fact, higher levels of prostaglandin (PG) E2, F2 alpha, and the stable products of PGI2 and thromboxane A2 (6-keto PGF1 alpha and thromboxane B2, respectively) were generated by the gonadotropin-treated cells as compared to control cells. The effect was inhibited by mepacrine, further supporting the pivotal role of PLA2 in the release of the eicosanoid precursor, AA. Finally, the effect of the main product of FSH-induced AA metabolism, i.e., PGE2, was studied. Intracellular cAMP accumulation in Sertoli cells was stimulated by the prostanoid in a dose-dependent manner (ED50 = 2.3 +/- 0.37 nM). PGE2 also significantly stimulated aromatase activity, a specific marker of Sertoli cell functions, measured as 17 beta-estradiol production (ED50 = 4.7 +/- 0.8 nM). Similar results were obtained with PGF2 alpha. Our findings show that FSH, through the activation of PLA2, leads to AA release with consequent metabolism by the cyclooxygenase pathway.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Eicosanoides/biossíntese , Hormônio Foliculoestimulante/farmacologia , Fosfolipases A/metabolismo , Células de Sertoli/efeitos dos fármacos , Células de Sertoli/metabolismo , Animais , Ácido Araquidônico/metabolismo , AMP Cíclico/metabolismo , Dinoprosta/farmacologia , Dinoprostona/farmacologia , Estradiol/metabolismo , Masculino , Fosfolipases A2 , Ratos , Ratos Wistar
16.
J Exp Zool ; 258(2): 249-54, 1991 May.
Artigo em Inglês | MEDLINE | ID: mdl-2022950

RESUMO

The role of granulosa cells in the regulation of mouse ovarian oocyte metabolism was investigated. Fully grown antral oocytes, isolated from surrounding cumulus cells, were cultured on monolayers of preantral granulosa cells in the presence of dbcAMP to prevent the resumption of meiosis. Under these conditions metabolic cooperativity was established between the two cell types as early as 1 hr after seeding. Moreover, cocultured oocytes phosphorylated two polypeptides of 74 and 21 kDa which are normally phosphorylated in follicle-enclosed growing oocytes but not in cumulus cell-enclosed fully grown oocytes at the germinal vesicle stage. When cocultured oocytes were allowed to resume meiosis, the 74 and 21 kDa proteins were synthesized but no longer phosphorylated even though intercellular coupling between the two cell types was maintained during radiolabeling. It appears therefore: a) that the different protein kinase activity of growing and fully grown germinal vesicle-stage mouse oocytes is related to the differentiative state of granulosa cells, and b) that the regulation of oocyte protein phosphorylation activity by granulosa cells is dependent on the meiotic stage of the oocyte.


Assuntos
Células da Granulosa/fisiologia , Oócitos/metabolismo , Animais , Comunicação Celular , Diferenciação Celular , Separação Celular , Células Cultivadas , Eletroforese em Gel Bidimensional , Feminino , Células da Granulosa/citologia , Camundongos , Camundongos Endogâmicos , Peptídeos/metabolismo , Fosfoproteínas/metabolismo , Radioisótopos de Fósforo , Fosforilação
17.
Ann Allergy ; 38(2): 104-6, 1977 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-65929

RESUMO

To determine whether the endotoxin induced release of histamine is mediated via the mast cell c'AMP system, hamster mast cells were isolated and incubated (prior to endotoxin-serum stimulates (ET-S) with disodium cromoglycate, isoproterenol and aminophylline. All drugs caused significant inhibition of the ET-S histamine release. The authors conclude that ET-S utilizes the c'AMP system to release histamine.


Assuntos
AMP Cíclico/metabolismo , Endotoxinas/farmacologia , Liberação de Histamina , Mastócitos/metabolismo , Aminofilina/farmacologia , Animais , Atropina/farmacologia , Cricetinae , Cromolina Sódica , Técnicas In Vitro , Isoproterenol/farmacologia , Fentolamina/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA