RESUMO
BACKGROUND: HER2-positive (+) breast cancers, defined by HER2 overexpression and/or amplification, are often addicted to HER2 to maintain their malignant phenotype. Yet, some HER2+ tumors do not benefit from anti-HER2 therapy. We hypothesize that HER2 amplification levels and PI3K pathway activation are key determinants of response to HER2-targeted treatments without chemotherapy. PATIENTS AND METHODS: Baseline HER2+ tumors from patients treated with neoadjuvant lapatinib plus trastuzumab [with endocrine therapy for estrogen receptor (ER)+ tumors] in TBCRC006 (NCT00548184) were evaluated in a central laboratory for HER2 amplification by fluorescence in situ hybridization (FISH) (n = 56). HER2 copy number (CN) and FISH ratios, and PI3K pathway status, defined by PIK3CA mutations or PTEN levels by immunohistochemistry were available for 41 tumors. Results were correlated with pathologic complete response (pCR; no residual invasive tumor in breast). RESULTS: Thirteen of the 56 patients (23%) achieved pCR. None of the 11 patients with HER2 ratio <4 and/or CN <10 achieved pCR, whereas 13/45 patients (29%) with HER2 ratio ≥4 and/or CN ≥10 attained pCR (P = 0.0513). Of the 18 patients with tumors expressing high PTEN or wild-type (WT) PIK3CA (intact PI3K pathway), 7 (39%) achieved pCR, compared with 1/23 (4%) with PI3K pathway alterations (P = 0.0133). Seven of the 16 patients (44%) with HER2 ratio ≥4 and intact PI3K pathway achieved pCR, whereas only 1/25 (4%) patients not meeting these criteria achieved pCR (P = 0.0031). CONCLUSIONS: Our findings suggest that there is a clinical subtype in breast cancer with high HER2 amplification and intact PI3K pathway that is especially sensitive to HER2-targeted therapies without chemotherapy. A combination of HER2 FISH ratio and PI3K pathway status warrants validation to identify patients who may be treated with HER2-targeted therapy without chemotherapy.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Receptor ErbB-2/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Classe I de Fosfatidilinositol 3-Quinases/genética , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Feminino , Seguimentos , Amplificação de Genes , Humanos , Hibridização in Situ Fluorescente , Lapatinib/administração & dosagem , Terapia Neoadjuvante , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Prognóstico , Receptor ErbB-2/antagonistas & inibidores , Receptor ErbB-2/genética , Indução de Remissão , Trastuzumab/administração & dosagemRESUMO
BACKGROUND: The twin problems of severe alcohol dependence and homelessness are associated with precarious living and multiple acute, social and chronic harms. While much attention has been focused on harm reduction services for illicit drug use, there has been less attention to harm reduction for this group. Managed alcohol programs (MAPs) are harm reduction interventions that aim to reduce the harms of severe alcohol use, poverty and homelessness. MAPs typically provide accommodation, health and social supports alongside regularly administered sources of beverage alcohol to stabilize drinking patterns and replace use of non-beverage alcohol (NBA). METHODS: We examined impacts of MAPs in reducing harms and risks associated with substance use and homelessness. Using case study methodology, data were collected from five MAPs in five Canadian cities with each program constituting a case. In total, 53 program participants, 4 past participants and 50 program staff were interviewed. We used situational analysis to produce a series of "messy", "ordered" and "social arenas" maps that provide insight into the social worlds of participants and the impact of MAPs. RESULTS: Prior to entering a MAP, participants were often in a revolving world of cycling through multiple arenas (health, justice, housing and shelters) where abstinence from alcohol is often required in order to receive assistance. Residents described living in a street-based survival world characterized by criminalization, unmet health needs, stigma and unsafe spaces for drinking and a world punctuated by multiple losses and disconnections. MAPs disrupt these patterns by providing a harm reduction world in which obtaining accommodation and supports are not contingent on sobriety. MAPs represent a new arena that focuses on reducing harms through provision of safer spaces and supply of alcohol, with opportunities for reconnection with family and friends and for Indigenous participants, Indigenous traditions and cultures. Thus, MAPs are safer spaces but also potentially spaces for healing. CONCLUSIONS: In a landscape of limited alcohol harm reduction options, MAPs create a new arena for people experiencing severe alcohol dependence and homelessness. While MAPs reduce precarity for participants, programs themselves remain precarious due to ongoing challenges related to lack of understanding of alcohol harm reduction and insecure program funding.
Assuntos
Alcoolismo/reabilitação , Redução do Dano , Pessoas Mal Alojadas , Adulto , Idoso , Alcoolismo/psicologia , Atitude Frente a Saúde , Canadá , Feminino , Pacientes Domiciliares/psicologia , Humanos , Masculino , Programas de Assistência Gerenciada , Pessoa de Meia-Idade , Pobreza , Apoio Social , EstereotipagemRESUMO
MiRNAs are a class of short, endogenous, single-stranded RNA molecules that play a role in the regulation of gene expression. They have been shown to modulate a number of cellular processes including cell differentiation, growth and apoptosis and as a result have been implicated in carcinogenesis. They are detectable in tumour tissue, and altered expression levels have been identified in various cancer types. Of interest, miRNAs have recently been detected and identified to be dysregulated in the circulation of patients with breast cancer. The fact that a minimally invasive test can distinguish the presence or absence of disease illustrates the immense potential these molecules hold as predictive markers. This review serves to identify those systemic miRNAs that are upregulated or downregulated in malignancy and how treatment impacts on their circulating levels. In addition, this review questions the source of these small molecules in the bloodstream and how they may possibly play a role in the future detection of cancer as either prognostic or predictive markers.
Assuntos
Biomarcadores Tumorais/genética , MicroRNAs/genética , Neoplasias/diagnóstico , Neoplasias/genética , Biomarcadores Tumorais/sangue , Humanos , MicroRNAs/sangue , Ácidos Nucleicos/sangue , Estabilidade de RNARESUMO
OBJECTIVE: to explore views on advance care planning in care homes for older people. DESIGN: qualitative exploration of views from care home staff and the family of residents in care homes for older people. SETTING: all care homes for the elderly in two London Boroughs. PARTICIPANTS: staff (care managers, nurses and care assistants), community nurses and families. METHODS: individual semi-structured interviews. RESULTS: themes of the analysis: (i) BENEFITS: staff and family revealed positive opinions towards advance care planning. Staff felt it provided choice for residents and encouraged better planning. (ii) Barriers: staff and families perceived residents as reluctant to discuss advance care planning. Some care assistants were reluctant to be involved. Furthermore, families and staff reported prevalence of dementia among residents as another barrier. Nurses and care managers identified both family involvement and unforeseen medical circumstances as problematic. (iii) Facilitators: (a) early initiation of discussions (b) family involvement to establish preferences (c) residents and staff being well-known to each other and (d) staff training, were perceived to facilitate ACP. CONCLUSIONS: overall, staff and families support the concept of ACP. Methods to overcome the identified barriers are required to embed ACP within end of life care in care homes.
Assuntos
Planejamento Antecipado de Cuidados , Atitude do Pessoal de Saúde , Família/psicologia , Planejamento de Assistência ao Paciente , Participação do Paciente/psicologia , Idoso , Comunicação , Instituição de Longa Permanência para Idosos , Humanos , Entrevistas como Assunto , Londres , Competência Mental , Casas de Saúde , Pesquisa QualitativaRESUMO
Antiglycolipid IgM antibodies are known to induce formation of "wide spaced" or "expanded" myelin, a distinctive form of dysmyelination characterized by a repeat period approximately two or three times normal, which is seen also in diseases, including multiple sclerosis. To determine whether an antibody directed against a myelin protein would cause equivalent pathology, we implanted O10 hybridoma cells into the spinal cord of adult or juvenile rats. O10 produces an IgM directed against PLP, the major protein of CNS myelin. Subsequent examination of the cords showed focal demyelination and remyelination. In addition, however, some juvenile cords, but none of the adult cords, displayed wide-spaced myelin with lamellae separated by an extracellular material comprising elements consistent with IgM molecules in appearance. Wide spacing tended to involve the outer layers of the sheath and in some cases alternated with normally spaced lamellae. A feature not seen previously consists of multiple expanded myelin lamellae in one sector of a sheath continuous with normally spaced lamellae in another, resulting in variation in sheath thickness around the axonal circumference. This uneven distribution of wide-spaced lamellae is most simply explained based on incorporation of IgM molecules into immature sheaths during myelin formation and implies a model of CNS myelinogenesis more complex than simple spiraling. The periaxonal space never displays widening of this kind, but the interface with adjacent myelin sheaths or oligodendrocytes may. Thus, wide spacing appears to require that IgM molecules bridge between two PLP-containing membranes and does not reflect the mere presence of immunoglobulin within the extracellular space.
Assuntos
Doenças Desmielinizantes/fisiopatologia , Imunoglobulina M/imunologia , Proteína Proteolipídica de Mielina/imunologia , Bainha de Mielina/fisiologia , Medula Espinal/fisiopatologia , Envelhecimento , Animais , Anticorpos , Linhagem Celular , Doenças Desmielinizantes/patologia , Hibridomas , Microscopia Eletrônica , Bainha de Mielina/ultraestrutura , Fotomicrografia , Ratos , Ratos Wistar , Medula Espinal/patologiaRESUMO
Surface markers typical of T and B lymphocytes were present on varying proportions of peripheral blood lymphocytes from three infants with severe combined immunodeficiency disease. Despite this, functions mediated by T and B cells were either absent or very minimal in all three, including cell-mediated responses in vivo; the in vitro proliferative response to mitogens, allogeneic cells, or antigens; effector cell function in lymphocyte-antibody lymphocytolytic interaction assays; and in vitro synthesis of IgG, IgA, and IgM. In contrast, mononuclear cells from one of the infants were tested and found capable of lysing both human and chicken antibody-coated erythrocyte targets normally. Co-cultivation experiments with unrelated normal control lymphocytes failed to demonstrate suppressor cell activity for immunoglobulin synthesis in these infants. Augmentations of immunoglobulin production from 310 to 560% over that expected on the basis of individual culture data were noted in co-cultures of one of the infants' cells with two different unrelated normal control cells. These findings suggest that that infant may have had a T helper cell defect or that his T cells were unable to produce soluble factors necessary for B cell differentiation. The finding of cells with differentiation markers characteristic of T and B lymphocytes in each of these patients, though in variable quantities, is further evidence for heterogeneity among patients with the clinical syndrome of severe combined immunodeficiency and argues against the concept that their immunodeficiency was due to a stem cell defect.
Assuntos
Células-Tronco Hematopoéticas/patologia , Síndromes de Imunodeficiência/imunologia , Linfócitos/imunologia , Adenosina Desaminase/imunologia , Anticorpos , Linfócitos B/imunologia , Membrana Celular/imunologia , Humanos , Reação de Imunoaderência , Imunoglobulina A , Imunoglobulina D , Imunoglobulina G , Imunoglobulina M , Lactente , Contagem de Leucócitos , Masculino , Linfócitos T/imunologiaRESUMO
Estrogen receptor α (ERα) is a master driver of a vast majority of breast cancers. Breast cancer cells often develop resistance to endocrine therapy via restoration of the ERα activity through survival pathways. Thus identifying the epigenetic activator of ERα that can be targeted to block ERα gene expression is a critical topic of endocrine therapy. Here, integrative genomic analysis identified MYST3 as a potential oncogene target that is frequently amplified in breast cancer. MYST3 is involved in histone acetylation via its histone acetyltransferase domain (HAT) and, as a result, activates gene expression by altering chromatin structure. We found that MYST3 was amplified in 11% and/or overexpressed in 15% of breast tumors, and overexpression of MYST3 correlated with worse clinical outcome in estrogen receptor+ (ER+) breast cancers. Interestingly, MYST3 depletion drastically inhibited proliferation in MYST3-high, ER+ breast cancer cells, but not in benign breast epithelial cells or in MYST3-low breast cancer cells. Importantly, we discovered that knocking down MYST3 resulted in profound reduction of ERα expression, while ectopic expression of MYST3 had the reversed effect. Chromatin immunoprecipitation revealed that MYST3 binds to the proximal promoter region of ERα gene, and inactivating mutations in its HAT domain abolished its ability to regulate ERα, suggesting MYST3 functioning as a histone acetyltransferase that activates ERα promoter. Furthermore, MYST3 inhibition with inducible MYST3 shRNAs potently attenuated breast tumor growth in mice. Together, this study identifies the first histone acetyltransferase that activates ERα expression which may be potentially targeted to block ERα at transcriptional level.
Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Epigênese Genética , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Amplificação de Genes , Regulação Neoplásica da Expressão Gênica , Histona Acetiltransferases/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células , Modelos Animais de Doenças , Feminino , Técnicas de Silenciamento de Genes , Histona Acetiltransferases/genética , Humanos , Camundongos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Although the emerging complementary DNA (cDNA) array technology holds great promise to discern complex patterns of gene expression, its novelty means that there are no well-established standards to guide analysis and interpretation of the data that it produces. We have used preliminary data generated with the CLONTECH Atlas human cDNA array to develop a practical approach to the statistical analysis of these data by studying changes in gene expression during the development of acquired tamoxifen resistance in breast cancer. METHODS: For hybridization to the array, we prepared RNA from MCF-7 human breast cell tumors, isolated from our athymic nude mouse xenograft model of acquired tamoxifen resistance during estrogen-stimulated, tamoxifen-sensitive, and tamoxifen-resistant growth. Principal components analysis was used to identify genes with altered expression. RESULTS AND CONCLUSIONS: Principal components analysis yielded three principal components that are interpreted as 1) the average level of gene expression, 2) the difference between estrogen-stimulated gene expression and the average of tamoxifen-sensitive and tamoxifen-resistant gene expression, and 3) the difference between tamoxifen-sensitive and tamoxifen-resistant gene expression. A bivariate (second and third principal components) 99% prediction region was used to identify outlier genes that exhibit altered expression. Two representative outlier genes, erk-2 and HSF-1 (heat shock transcription factor-1), were chosen for confirmatory study, and their predicted relative expression levels were confirmed in western blot analysis, suggesting that semiquantitative estimates are possible with array technology. IMPLICATIONS: Principal components analysis provides a useful and practical method to analyze gene expression data from a cDNA array. The method can identify broad patterns of expression alteration and, based on a small simulation study, will likely provide reasonable power to detect moderate-sized alterations in clinically relevant genes.
Assuntos
Antineoplásicos Hormonais/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Antagonistas de Estrogênios/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Tamoxifeno/farmacologia , Animais , Western Blotting , DNA Complementar/análise , DNA de Neoplasias/análise , Feminino , Humanos , Camundongos , Camundongos Nus , Técnicas de Sonda Molecular , Hibridização de Ácido Nucleico , Projetos Piloto , Células Tumorais CultivadasRESUMO
BACKGROUND: Most breast cancers, even those that are initially responsive to tamoxifen, ultimately become resistant. The molecular basis for this resistance, which in some patients is thought to involve stimulation of tumor growth by tamoxifen, is unclear. Tamoxifen induces cellular oxidative stress, and because changes in cell redox state can activate signaling pathways leading to the activation of activating protein-1 (AP-1), we investigated whether tamoxifen-resistant growth in vivo is associated with oxidative stress and/or activation of AP-1 in a xenograft model system where resistance is caused by tamoxifen-stimulated growth. METHODS: Control estrogen-treated, tamoxifen-sensitive, and tamoxifen-resistant MCF-7 xenograft tumors were assessed for oxidative stress by measuring levels of antioxidant enzyme (e.g., superoxide dismutase [SOD], glutathione S-transferase [GST], and hexose monophosphate shunt [HMS]) activity, glutathione, and lipid peroxidation. AP-1 protein levels, phosphorylated c-jun levels, and phosphorylated Jun NH(2)-terminal kinase (JNK) levels were examined by western blot analyses, and AP-1 DNA-binding and transcriptional activities were assessed by electrophoretic mobility shift assays and a reporter gene system. All statistical tests are two-sided. RESULTS: Compared with control estrogen-treated tumors, tamoxifen resistant tumors had statistically significantly increased SOD (more than threefold; P=.004) and GST (twofold; P=.004) activity and statistically significantly reduced glutathione levels (greater than twofold; P<.001) and HMS activity (10-fold; P<.001). Lipid peroxides were not significantly different between control and tamoxifen-resistant tumors. We observed no differences in AP-1 protein components or DNA-binding activity. However, AP-1-dependent transcription (P=.04) and phosphorylated c-Jun and JNK levels (P<.001) were statistically significantly increased in the tamoxifen-resistant tumors. CONCLUSION: Our results suggest that the conversion of breast tumors to a tamoxifen-resistant phenotype is associated with oxidative stress and the subsequent antioxidant response and with increased phosphorylated JNK and c-Jun levels and AP-1 activity, which together could contribute to tumor growth.
Assuntos
Antineoplásicos Hormonais/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Moduladores de Receptor Estrogênico/farmacologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Estresse Oxidativo , Tamoxifeno/farmacologia , Fator de Transcrição AP-1/metabolismo , Animais , Antineoplásicos Hormonais/uso terapêutico , Western Blotting , Neoplasias da Mama/enzimologia , Neoplasias da Mama/genética , Cloranfenicol O-Acetiltransferase/análise , DNA de Neoplasias/efeitos dos fármacos , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos , Moduladores de Receptor Estrogênico/uso terapêutico , Feminino , Glutationa Transferase/metabolismo , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno , Peroxidação de Lipídeos , Camundongos , Camundongos Nus , Via de Pentose Fosfato , Fenótipo , Fosforilação , Proteínas Proto-Oncogênicas c-jun/metabolismo , Superóxido Dismutase/metabolismo , Tamoxifeno/uso terapêutico , Transcrição Gênica/efeitos dos fármacos , Transplante HeterólogoRESUMO
It has been shown in previous studies that a variety of estrogen receptor (ER) beta mRNA transcripts are expressed in human breast cancer cell lines and tumors. To complement the RNA expression studies, we have developed ER-beta-specific antibodies to characterize ER-beta protein expression in breast cancer cell lines and tumors. Monoclonal antibodies were made against a peptide representing the first 18 amino acids of the longest ER-beta open reading frame reported to date, and polyclonal antibodies were made against a peptide within the ER-beta B domain. By Western blot analysis, we show that ER-beta protein is expressed in all cancer cell lines tested and in three of five breast tumor samples. The breast cancer cell lines showed variation in the size of the expressed ER-beta protein. The longest form detected was consistent with the 530-amino acid, full-length ER-beta sequence. Shorter ER-beta isoforms were detected in the ER-alpha-negative MDA-MB-231 and MDA-MB-435 breast cancer cell lines, likely corresponding to previously described COOH-terminal RNA variant isoforms.
Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Western Blotting , DNA Complementar/análise , Receptor beta de Estrogênio , Regulação Neoplásica da Expressão Gênica , Humanos , Osteossarcoma/metabolismo , Fenótipo , Isoformas de Proteínas , RNA Mensageiro/metabolismo , Células Tumorais CultivadasRESUMO
De novo resistance to endocrine therapy is a near-universal feature of oestrogen receptor (ER)- negative breast cancer. Although many ER-positive breast cancers also show no response to tamoxifen or aromatase inhibitors on objective clinical grounds the large majority show reduced proliferation indicating that some oestrogen dependence is present in almost all ER-positive breast cancer. In neoadjuvant studies HER2 positivity is associated with poor response rates to tamoxifen but not aromatase inhibitors, consistent with preclinical models. Acquired resistance to tamoxifen is associated with decreases in ER positivity but most recurrent lesions remain ER-positive. A small proportion of these show increased HER2 expression and in these patients increased phospho-p38 may contribute to the tamoxifen-resistant phenotype. There is an unfortunate paucity of clinical and biological data on acquired resistance to aromatase inhibitors.
Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias Hormônio-Dependentes/tratamento farmacológico , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Tamoxifeno/uso terapêutico , Inibidores da Aromatase/uso terapêutico , Neoplasias da Mama/metabolismo , Resistencia a Medicamentos Antineoplásicos , Estrogênios/metabolismo , Feminino , Humanos , Neoplasias Hormônio-Dependentes/metabolismo , Transdução de SinaisRESUMO
Continuous wave Doppler ultrasound was employed in 38 patients with ventricular septal defects, many with associated lesions, to measure the velocity (V) of the shunted blood. Using the modified Bernoulli equation (delta P = 4V2) the pressure difference (delta P) between the ventricles was determined. In 22 patients both right ventricular and either left ventricular or ascending aortic pressure were measured at the time shunt velocity was determined. In another 16 patients these measurements were not obtained simultaneously but in most they were done within 24 hours of each other. In the entire group, measured pressure differences between the ventricles (or aorta and right ventricle) ranged from 0 to 97 mm Hg (mean 52 +/- 24). On the basis of velocity measurements the pressure difference ranged from 7 to 112 mm Hg (mean 51 +/- 24). A close correlation was found between the two methods (r = 0.95, SEE = 7.8 mm Hg). This accuracy was not altered by associated lesions. These findings indicate that by the use of continuous wave Doppler interrogation right ventricular pressure can be accurately measured in the presence of a ventricular septal defect.
Assuntos
Defeitos dos Septos Cardíacos/fisiopatologia , Adolescente , Pressão Sanguínea , Cateterismo Cardíaco , Criança , Pré-Escolar , Ecocardiografia , Cardiopatias Congênitas/diagnóstico , Cardiopatias Congênitas/fisiopatologia , Defeitos dos Septos Cardíacos/diagnóstico , Ventrículos do Coração/fisiopatologia , Humanos , Lactente , Recém-Nascido , ReologiaRESUMO
Breast cancer development and progression are directly related to the effects of the female hormone estrogen. The nuclear receptor for estrogen (ER) functions as a transcription factor controlling estrogen-regulated genes. Receptor conformation on ligand binding, its interaction with various coregulators, and response elements in the promoter region of target genes all contribute to the net estrogenic effects in a cell. ER is an important diagnostic and therapeutic target in breast cancer. Various polypeptide growth factors and their membrane receptors also contribute to breast cancer development and progression. Pathways mediating cell survival, cell proliferation, and response to stress not only generate signals through various protein kinase pathways to enhance cell survival and proliferation, but these pathways also interact with ERs. Kinases in the growth factor cascade can phosphorylate and activate ER, and ER in turn activates and augments signaling through the growth factor pathways. Signaling through the growth factor pathways may contribute to hormonal resistance states by ligand-independent activation of ER. Targeting growth factor pathways, in addition to ER, is a developing strategy that hypothetically may represent optimal therapy by preventing the development of resistance to endocrine therapy.
Assuntos
Neoplasias da Mama/metabolismo , Receptores de Estrogênio/metabolismo , Animais , Feminino , Substâncias de Crescimento/metabolismo , Humanos , Transdução de Sinais/fisiologiaRESUMO
The detection of proenkephalin A (PEA) mRNA and encoded peptides in various regions of the female reproductive system raised the possibility that opioid peptides might act as local regulators within this system. Assignment of a specific role for locally synthesized enkephalins has been hampered, however, by the unknown identity of the cells that produce PEA. Using in situ hybridization analysis we have now identified the cell types that express PEA mRNA in the reproductive system of female mice. In the ovary, PEA mRNA was localized primarily in theca cells of preovulatory follicles, and to a lesser extent, in follicular granulosa cells. In the oviducts, where PEA mRNA is most abundant, expression was confined to the secretory and ciliated epithelium of the mucosa. In the uterus, the site of PEA mRNA expression was the deep glandular layer of the endometrium. When pregnancy ensues, and upon decidual transformation, PEA expression by the same uterine cells was dramatically elevated. Elevated levels of PEA mRNA were detected predominantly in the vicinity of the implantation site, suggesting that signaling by the implanted embryo play a role in stimulating PEA expression. Based on these results, possible physiological roles for PEA-encoded peptides as autocrine/paracrine regulators within the female reproductive system are suggested.
Assuntos
Implantação do Embrião , Encefalinas/genética , Precursores de Proteínas/genética , Sistema Urogenital/metabolismo , Animais , Sequência de Bases , Encefalinas/biossíntese , Feminino , Regulação da Expressão Gênica , Camundongos , Camundongos Endogâmicos BALB C , Ovário/citologia , Ovário/metabolismo , Oviductos/citologia , Oviductos/metabolismo , Gravidez , Precursores de Proteínas/biossíntese , RNA Mensageiro/metabolismo , Sistema Urogenital/citologia , Útero/citologia , Útero/metabolismoRESUMO
Very little is known about steroidogenic capacities in the uterus during the early stages of pregnancy in rodents. Cholesterol side-chain cleavage cytochrome P450 (P450scc) is the enzyme catalizing the first and key regulatory reaction controlling the production of steroid hormones. Using a cRNA probe, we made use of in situ hybridization analysis to evaluate the spatial and temporal patterns of P450scc mRNA expression in the mouse uterus until midgestation. Unexpectedly, we found that upon implantation on day 4.5, maternal cells of both decidua capsularis and decidua basalis expressed P450scc mRNA. Only later, and no earlier than day 6.5 of gestation, were high levels of P450scc mRNA also detected in the trophoblast giant cells surrounding the embryonal cavity. Analysis of pseudopregnant mice revealed that the induction of P450scc mRNA can be coupled to the decidual reaction evoked by intrauterine injection of mineral oil. These results, therefore, unambiguously confirmed the capacity of the decidualized cells of maternal origin to express P450scc mRNA and, thus, ruled out any direct role of the blastocyst involvement in P450scc induction. The dual localization of P450scc mRNA in maternal and trophoblast cells, expressing this cytochrome earlier than the previously suspected onset of uterine steroidogenesis, suggests an unexpected role for steroid hormones locally produced at the site of implantation and the surrounding milieu of the embryo during the first half of pregnancy.
Assuntos
Enzima de Clivagem da Cadeia Lateral do Colesterol/genética , Prenhez/metabolismo , RNA Mensageiro/metabolismo , Útero/enzimologia , Animais , Northern Blotting , Feminino , Hibridização Genética , Hibridização In Situ , Fase Luteal/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Gravidez , Pseudogravidez/metabolismo , Sondas RNA , RNA Mensageiro/análise , Fatores de Tempo , Trofoblastos/metabolismoRESUMO
From May 1992 to March 1993, 50 infants with severe combined immunodeficiency (SCID) were given bone marrow transplants at Duke University Medical Center. None received chemotherapy for conditioning or for graft-versus-host disease (GVHD) prophylaxis. Forty-one received haploidentical parental marrow depleted of T cells by soybean lectin and sheep red blood cell resetting, and nine received HLA-identical marrow. Forty (80%) survived from 1 week to almost 11 years posttransplantation, including nine of nine (100%) HLA-identical marrow recipients and 31 of 41 haploidentical recipients. T-cell function was present within 2 weeks after transplantation of unfractionated HLA-identical marrow, but not until 3 to 4 months after T-cell-depleted haploidentical marrow stem cells. All 37 patients who are more than 4 months posttransplantation have good T-cell function, and all but one have 100% donor T cells. B-cell function developed slowly or not at all in some recipients of haploidentical marrow. Fourteen (four HLA-identical and 10 haploidentical recipients) have some donor B cells; 19 patients are receiving intravenous immune globulin (IVIG) therapy.
Assuntos
Haplótipos , Transplante de Células-Tronco Hematopoéticas , Imunodeficiência Combinada Severa/terapia , Linfócitos B/imunologia , Transplante de Medula Óssea , Causas de Morte , Humanos , Imunodeficiência Combinada Severa/imunologia , Síndrome , Linfócitos T/imunologiaRESUMO
Murine leukemia viruses (MuLVs) are retroviruses which induce a broad spectrum of hematopoietic malignancies. In contrast to the acutely transforming retroviruses, MuLVs do not contain transduced cellular genes, or oncogenes. Nonetheless, MuLVs can cause leukemias quickly (4 to 6 weeks) and efficiently (up to 100% incidence) in susceptible strains of mice. The molecular basis of MuLV-induced leukemia is not clear. However, the contribution of individual viral genes to leukemogenesis can be assayed by creating novel viruses in vitro using recombinant DNA techniques. These genetically engineered viruses are tested in vivo for their ability to cause leukemia. Leukemogenic MuLVs possess genetic sequences which are not found in nonleukemogenic viruses. These sequences control the histologic type, incidence, and latency of disease induced by individual MuL Vs.
Assuntos
Replicação do DNA , DNA Viral/metabolismo , Leucemia Experimental/fisiopatologia , Retroviridae/genética , Infecções Tumorais por Vírus/fisiopatologia , Replicação Viral , Animais , Sequência de Bases , Linhagem Celular , Clonagem Molecular , DNA Viral/genética , Vírus da Leucemia Murina de Friend , Genes Virais , História , Leucemia Eritroblástica Aguda , Camundongos , Recombinação Genética , Retroviridae/classificaçãoRESUMO
Fixed preparations of proteolipid protein (PLP)-null mouse spinal cord show myelin sheaths which in some regions consist of typical alternating major dense lines (MDLs) and intermediate lines (ILs) with a repeat period of 10.3 nm. More commonly, the lamellar structure consists of what appears to be a single population of dense lines, having a repeat period of 5.2 nm. These apparently equivalent lines are, however, sometimes distinguishable as MDLs or ILs based on continuity with cytoplasmic or extracellular regions. Focal separations of lamellae at the intermediate line are common. MDLs too may be replaced focally by cytoplasmic pockets, sometimes in the same quadrant over several lamellae, resembling Schmidt-Lanterman clefts. Occasional densities reminiscent of the "radial component" can be seen. Otherwise, this structure, which is prominent in wild-type myelin, is conspicuously absent. Redundant folding of some lamellae but not others may occur in the same sheath. These observations conform to those made previously on the isolated myelin segments that occur in the myelin-deficient rat central nervous system (CNS), which also lacks PLP. Thus, a compact lamellar structure can be seen in fixed PLP-null myelin, but defects in the apposition of both the extracellular and the cytoplasmic surfaces of the myelin membranes are common. The abnormalities seen suggest a lack of firm intermembrane bonding, resulting in structural instability. PLP-null myelin may therefore be more susceptible than normal myelin to disruption by mechanical or osmotic stresses. Although PLP is not essential for the formation of either major dense lines or intermediate lines, it may play a role in stabilizing the compact structure.
Assuntos
Proteína Proteolipídica de Mielina/análise , Bainha de Mielina/fisiologia , Medula Espinal/química , Animais , Genótipo , Homozigoto , Camundongos , Ratos , Manejo de Espécimes/métodosRESUMO
We adapted immunocytochemical methods for localization of laminin to examine its disposition in neural tissue at the ultrastructural level. In dorsal root ganglia, laminin was found in basal laminae of the satellite and Schwann cells ensheathing neuronal perikarya and nerve fibers, respectively, and around blood vessels. Within the basal lamina, the immunostain was found in the lamina lucida and lamina densa. Occasional immunostained coated pits were identified in satellite and Schwann cells, but virtually no intracellular label was seen even in freeze-thawed/detergent-permeabilized specimens. In the perineurium, only the basal lamina of the inward-facing surface of the inner-most cell layer was usually stained.
Assuntos
Gânglios Espinais/ultraestrutura , Laminina/análise , Animais , Invaginações Revestidas da Membrana Celular/ultraestrutura , Histocitoquímica , Microscopia Eletrônica , Fibras Nervosas/ultraestrutura , Ratos , Ratos Endogâmicos , Células de Schwann/ultraestruturaRESUMO
A 17-year-old girl presented with malaise, weakness, palpitations, dysphagia, myalgias, and weight loss of 1 month's duration. Within 24 hours of admission to the hospital, she had hypotension unresponsive to medical management, intractable congestive heart failure, and arrhythmias; she died. Several empty bottles of syrup of ipecac were later found among her belongings. Syrup of ipecac is commonly used to induce emesis in patients who had ingested toxic substances. The chief pharmacologic property of this agent is due to its alkaloid component, emetine. There have been many previous reports of death due to emetine poisoning in patients receiving ipecac fluid extract and in those treated for amoebic dysentery. However, the literature cites only three case reports of fatalities secondary to chronic ipecac use as a means of losing weight. This is the first report of a death due to chronic ipecac use in an adolescent patient with bulimia. Emetine persists in the body for long periods, and in patients who have ingested it chronically, emetine is extremely toxic, specifically to cardiac smooth and skeletal muscles. With an increased awareness of the importance of weight control in the adolescent age group, the physician must carefully evaluate these patients for the use of emetics.