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1.
Ann Oncol ; 28(5): 1005-1014, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28453696

RESUMO

Background: Recent whole-genome sequencing identified four molecular subtypes of gastric cancer (GC), of which the subgroup of Epstein-Barr virus-associated GC (EBVaGC) showed a significant enrichment of PIK3CA mutations. We here aimed to validate independently the enrichment of PIK3CA mutations in EBVaGC of a Central European GC cohort, to correlate EBV status with clinico-pathological patient characteristics and to test for a major issue of GC, intratumoral heterogeneity. Patients and methods: In a first step, 484 GCs were screened for EBV and PIK3CA hot spot mutations of exon 9/20 using EBER in situ hybridization and pyrosequencing, respectively. Secondly, an extended sequencing of PIK3CA also utilizing next generation sequencing was carried out in all EBVaGCs and 96 corresponding lymph node metastases. Results: Twenty-two GCs were EBER-positive, all being of latency type I. Intratumoral heterogeneity of EBER-positivity was found in 18% of EBVaGCs. Twenty-three GCs held PIK3CA mutations in hot spot regions of exon 9 or 20, being significantly more common in EBVaGCs (P < 0.001). Subsequent extended sequencing of PIK3CA of EBVaGCs showed that 14% harvested three to five different PIK3CA genotypes (including wildtype) in the same primary tumor, albeit in histologically and spatially distinct tumor areas, and that intratumoral heterogeneity of PIK3CA was also present in the corresponding lymph node metastases. Conclusions: Our findings unravel issues of tumor heterogeneity and illustrate that the assessment of the EBV status in tissue biopsies might carry the risk of sampling errors, which may significantly hamper adequate molecular tumor classification in a more clinical setting. Moreover, this is the first report of intratumoral heterogeneity of PIK3CA mutations in GC, and our findings lead to the conclusion that PIK3CA mutant and -wildtype tumor subclones are skilled to metastasize independently to different regional lymph nodes.


Assuntos
Adenocarcinoma/genética , Classe I de Fosfatidilinositol 3-Quinases/genética , Infecções por Vírus Epstein-Barr/genética , Neoplasias Gástricas/genética , Adenocarcinoma/mortalidade , Adenocarcinoma/secundário , Adenocarcinoma/virologia , Idoso , Infecções por Vírus Epstein-Barr/mortalidade , Infecções por Vírus Epstein-Barr/patologia , Infecções por Vírus Epstein-Barr/virologia , Feminino , Frequência do Gene , Estudos de Associação Genética , Heterogeneidade Genética , Predisposição Genética para Doença , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Estimativa de Kaplan-Meier , Metástase Linfática , Masculino , Técnicas de Diagnóstico Molecular , Mutação , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Neoplasias Gástricas/virologia
2.
Br J Cancer ; 111(10): 1977-84, 2014 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-25211663

RESUMO

BACKGROUND: Anti-HER2/neu therapy is well-established in breast and gastric carcinoma. The increased understanding of this pathway led to the identification of new promising drugs in addition to trastuzumab, offering further perspectives. The role of HER2/neu in colorectal carcinoma is controversially discussed, as discrepant data has been reported. METHODS: Here, we retrospectively assessed the prevalence of HER2/neu positivity in a large series of colorectal carcinoma, testing HER2/neu status according to current recommendations. We correlated the results to clinico-pathological data and patient survival. RESULTS: Overall, in 1645 primary colorectal carcinoma cases, 1.6% of the cases were HER2/neu positive. HER2/neu positivity significantly correlated with higher UICC stages (P=0.017) and lymph node metastases (P=0.029). In the subgroup of sigmoideal and rectal carcinomas, positive HER2/neu status was associated with T-category (P=0.041) and higher UICC stages (P=0.022). Although statistically not significant, HER2/neu-positive colorectal carcinomas displayed a tendency to poorer overall survival. CONCLUSIONS: These results illustrate the importance of testing HER2/neu by approved diagnostic techniques and scoring systems. We assume that although the prevalence of HER2/neu positivity in colorectal carcinoma is low, HER2/neu testing in advanced, nodal-positive colorectal carcinoma is reasonable, offering a potential target in high risk colorectal carcinoma.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Colorretais/metabolismo , Receptor ErbB-2/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Feminino , Seguimentos , Humanos , Técnicas Imunoenzimáticas , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Análise Serial de Tecidos , Adulto Jovem
3.
Ann Oncol ; 25(1): 246-50, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24276025

RESUMO

BACKGROUND: Although 90% of all melanomas are of cutaneous origin, some patients present with melanoma metastases of unknown origin (MUP). Commonly, in these patients an extensive search for the primary tumor is carried out. In the past, genetic analyses have shown substantial differences in pathogenetic mutations among cutaneous, acral and mucosal melanomas. The aim of this study was to assess the mutational status of MUP in order to better characterize the putative origin of the primary tumor and to evaluate potential prognostic factors. PATIENTS AND METHODS: The medical records of 44 patients with MUP were analyzed and a survival analysis was conducted. In total, 66 paraffin samples of 44 patients were analyzed, and in 15 patients multiple metastases were tested. Mutational analysis of the BRAF, NRAS and KIT genes was carried out. RESULTS: Twenty-three patients (52.3%) had a mutation in the BRAF gene and 12 patients (23.8%) had a mutation in the NRAS gene. There were neither mutations in the KIT gene. In patients with multiple samples, there was 100% consistency regarding mutational status among the different metastases. The median overall survival (OS) was 86.4 months (39-134). The American Joint Committee on Cancer stage at first diagnosis of metastatic melanoma (stage III versus IV) was significantly associated with OS (P < 0.001), BRAF or NRAS mutation status had no significant prognostic impact on clinical outcomes. CONCLUSIONS: MUP resembles the genotype of cutaneous melanoma and not that of mucosal melanomas.


Assuntos
Melanoma/secundário , Neoplasias Primárias Desconhecidas/genética , Neoplasias Cutâneas/secundário , Idoso , Idoso de 80 Anos ou mais , Análise Mutacional de DNA , Intervalo Livre de Doença , Feminino , GTP Fosfo-Hidrolases/genética , Genótipo , Humanos , Estimativa de Kaplan-Meier , Masculino , Melanoma/genética , Melanoma/mortalidade , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Neoplasias Primárias Desconhecidas/mortalidade , Prognóstico , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas c-kit/genética , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/mortalidade
4.
Br J Cancer ; 109(8): 2217-27, 2013 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-24008668

RESUMO

BACKGROUND: We investigated the expression of members of the epithelial cell adhesion molecule (EpCAM) signalling pathway in gastric cancer (GC) testing the following hypotheses: are these molecules expressed in GC and are they putatively involved in GC biology. METHODS: The study cohort consisted of 482 patients. The following members of the EpCAM signalling pathway were analysed by immunohistochemistry and were correlated with various clinico-pathological patient characteristics: extracellular domain of EpCAM (EpEX), intracellular domain of EpCAM (EpICD), E-cadherin, ß-catenin, presenilin-2 (PSEN2), and ADAM17. RESULTS: All members of the EpCAM signalling pathway were differentially expressed in GC. The expression correlated significantly with tumour type (EpEX, EpICD, E-cadherin, ß-catenin, and PSEN2), mucin phenotype (EpEX, EpICD, ß-catenin, and ADAM17), T-category (EpEX, E-cadherin, and ß-catenin), N-category (EpEX and ß-catenin), UICC tumour stage (EpEX, EpICD, ß-catenin, and PSEN2), tumour grade (EpEX, EpICD, E-cadherin, ß-catenin, and PSEN2), and patients' survival (EpEX, EpICD, and PSEN2). A significant coincidental expression in GC was found for EpEX, EpICD, E-cadherin, ß-catenin, PSEN2, and ADAM17. Decreased immunodetection of EpEX in locally advanced GC was not associated with decreased EpCAM mRNA levels. CONCLUSION: All members of the EpCAM signalling pathway are expressed in GC. The expression correlated significantly with each other and with various clinico-pathological patient characteristics, including patients' survival. Thus, the EpCAM signalling pathway is a highly interesting putative therapeutic target in GC.


Assuntos
Antígenos de Neoplasias/metabolismo , Moléculas de Adesão Celular/metabolismo , Neoplasias Gástricas/metabolismo , Proteínas ADAM/biossíntese , Proteínas ADAM/genética , Proteínas ADAM/metabolismo , Proteína ADAM17 , Idoso , Antígenos de Neoplasias/biossíntese , Antígenos de Neoplasias/genética , Caderinas/biossíntese , Caderinas/genética , Caderinas/metabolismo , Moléculas de Adesão Celular/biossíntese , Moléculas de Adesão Celular/genética , Linhagem Celular Tumoral , Estudos de Coortes , Molécula de Adesão da Célula Epitelial , Feminino , Células HEK293 , Humanos , Imuno-Histoquímica , Masculino , Estadiamento de Neoplasias , Presenilina-2/biossíntese , Presenilina-2/genética , Presenilina-2/metabolismo , Prognóstico , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Transdução de Sinais , Neoplasias Gástricas/patologia , beta Catenina/biossíntese , beta Catenina/genética , beta Catenina/metabolismo
5.
Ann Oncol ; 24(3): 725-33, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23139264

RESUMO

BACKGROUND: We evaluated the risk of sampling errors in specimens of biopsy size, which may be caused by heterogeneous overexpression of Her2/neu in gastric cancer (GC). PATIENTS AND METHODS: The study cohort comprised 454 gastrectomy patients with adenocarcinoma of the stomach or esophago-gastric junction. Tissue micro-arrays (TMAs) served as 'biopsy procedure' and were generated from formalin-fixed and paraffin-embedded tissue: five tissue cylinders were collected randomly from each tumor, rendering 2230 core cylinders. These were compared with 454 whole tissue sections obtained from the same paraffin blocks. Her2/neu expression and gene amplification were analyzed by immunohistochemistry and in situ hybridization. The Her2/neu status was determined according to GC scoring system by two independent observers. RESULTS: In whole tissue sections, 37 (8.1%; observer 1) and 38 (8.4%; observer 2) of the GCs, and in the corresponding TMAs, 28 (6.3%; observer 1) and 28 (6.3%; observer 2) of the GCs were classified as Her2/neu-positive (kappa value 98.5% and 96.2%; P < 0001). Comparison of whole tissue sections with corresponding TMAs showed a false-negative rate of 24% and a false-positive rate of 3% for TMAs. CONCLUSION: Assessment of the Her2/neu status in tissue biopsies carries a significant risk of sampling errors, thereby rendering patients unsuitable for treatment with trastuzumab.


Assuntos
Adenocarcinoma/metabolismo , Biomarcadores Tumorais/metabolismo , Neoplasias Esofágicas/metabolismo , Receptor ErbB-2/metabolismo , Neoplasias Gástricas/metabolismo , Adenocarcinoma/diagnóstico , Adenocarcinoma/mortalidade , Idoso , Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/mortalidade , Reações Falso-Positivas , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Risco , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/mortalidade , Análise Serial de Tecidos
6.
J Chem Phys ; 139(17): 174506, 2013 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-24206315

RESUMO

The internal friction of hydrated soda-lime-silica glasses with total water content (C(W)) up to 1.9 wt. % was studied by dynamic mechanical analysis (DMA) using temperature-frequency sweeps from 723 K to 273 K and from 1 s(-1) to 50 s(-1). Total water content and concentrations of H2O molecules (C(H2O)) and OH groups (C(OH)) in the DMA specimens were determined by infrared spectroscopy. For low water contents (C(W) ≈ C(OH) < 0.25 wt. %) two discrete internal friction peaks below the glass transition (α relaxation) were assigned to the low-temperature motion of alkali ions (γ relaxation) and cooperative movements of dissimilar mobile species under participation of OH at higher temperature (ß(OH) relaxation). For large water contents (C(W) > 1 wt. %), where significant amounts of molecular water are evident (C(H2O) > 0.15 wt. %), however, internal friction spectra change unexpectedly: the ß(OH) peak heights saturate and a low temperature shoulder appears on the ß-relaxation peak. This emerging relaxation mode (ß(H2O) relaxation) was assigned to the motions of H2O molecules. ß(H2O) relaxation was found to be faster than ß(OH) but slower than γ relaxation. Activation energy of the different relaxation modes increased in the order γ < ß(H2O) < ß(OH) < α.

7.
J Phys Chem A ; 116(1): 309-18, 2012 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-22103350

RESUMO

In order to improve our understanding of the transport mechanisms of lithium in glasses, we have performed diffusion and ionic conductivity studies on spodumene composition (LiAlSi(2)O(6)) glasses. In diffusion couple experiments pairs of chemically identical glasses with different lithium isotopy (natural Li vs pure (7)Li) were processed at temperatures between 482 and 732 K. Profiles of lithium isotopes were measured after the diffusion runs innovatively applying femtosecond UV laser ablation combined with inductively coupled plasma mass spectrometry (LA ICP-MS). Self-diffusion coefficients of lithium in the glasses were determined by fitting the isotope profiles. During some of the diffusion experiments the electrical conductivity of the samples was intermittently measured by impedance spectrometry. Combining ionic conductivity and self-diffusivity yields a temperature-independent correlation factor of ~0.50, indicating that motions of Li ions are strongly correlated in this type of glasses. Lithium self-diffusivity in LiAlSi(2)O(6) glass was found to be very similar to that in lithium silicate glasses although Raman spectroscopy demonstrates structural differences between these glasses; that is, the aluminosilicate is completely polymerized while the lithium silicate glasses contain large fractions of nonbridging oxygen.

8.
J Cancer Res Clin Oncol ; 148(2): 387-400, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34705105

RESUMO

BACKGROUND: We explored the hypothesis that high-quality standards in diagnostic mammography can lead to an early diagnosis of breast cancers and identifies at risk populations outside screening programs. The histopathological features and distribution of the TNM classification were examined in relation to patient age in a large group of women with breast cancers participating in the Quality Assured Mamma Diagnostic (QuaMaDi) program of the state of Schleswig-Holstein. PATIENTS AND METHODS: Surgical pathological reports were studied for clinicopathological characteristics, receptor status, molecular subtype and tumor stage. The analysis was conducted by dividing the study population into three age groups: women under 50 years (pre-screening), 50-69 years (peri-screening) and over 70 years (post-screening). RESULTS: 7.111 biopsies and 2.887 resection specimens were included. Breast cancer was diagnosed in 4.241 (59.7%) cases, one fourth of them in women < 50 years. Elderly women (> 70 years) had more well-differentiated, estrogen receptor (ER)-positive and HER2-negative carcinomas, whereas younger women (< 50 years) tended to have more poorly differentiated, ER negative, and HER2-positive carcinomas. 47% of breast carcinoma were luminal B tumors and were most common regardless of age. 70.4% of resected specimen had pT1 stage. Nodal negative were 71.2%. CONCLUSION: In QuaMaDi breast cancer was diagnosed at an early and potentially curable stage of the disease due to high-quality standards in diagnostic mammography. In addition, regardless of age, an increased number of prognostically unfavorable molecular subtypes were detected. Thus, QuaMaDi helps to identify at risk populations. QuaMaDi significantly improves diagnostic mammography and complements mammography screening programs.


Assuntos
Neoplasias da Mama/diagnóstico , Neoplasias da Mama/epidemiologia , Carcinoma/diagnóstico , Carcinoma/epidemiologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/patologia , Carcinoma/patologia , Detecção Precoce de Câncer/métodos , Detecção Precoce de Câncer/normas , Feminino , Alemanha/epidemiologia , Humanos , Mamografia/normas , Mamografia/estatística & dados numéricos , Programas de Rastreamento/organização & administração , Programas de Rastreamento/normas , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Garantia da Qualidade dos Cuidados de Saúde/organização & administração , Garantia da Qualidade dos Cuidados de Saúde/normas , Sistema de Registros
9.
Eur J Cancer ; 51(5): 577-86, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25682192

RESUMO

AIM: We investigated the effect of the new tumour-, node-, metastasis- (TNM) classification on predicting and discriminating gastric cancer patient prognosis using the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) Program. PATIENTS AND METHODS: From the SEER-database we retrieved gastric cancer patients with a primary adenocarcinoma, of Caucasian or Asian ethnicity and without distant metastases (M0). The pTNM-stage was determined according to the 7th edition of the union internationale contre le cancer (UICC) guidelines. RESULTS: Spanning the period 2004-2010, 6136 patients fulfilled all inclusion criteria including 3424 (55.8%) men, 2712 (44.2%) women, 4629 (75.4%) Caucasian and 1507 (24.6%) Asian patients. 1524 (24.8%) patients underwent total gastrectomy and 4612 (75.2%) non-total gastrectomy. Only in 41.2% of the patients were >15 lymph nodes resected. 1857 (31.0%) patients received radiotherapy. Patient survival depended on ethnicity, type of surgery and radiotherapy. The discriminating value of the UICC-stage grouping could not be validated for Caucasian patients with >15 lymph nodes resected and who had not received radiotherapy: stage groups IIB, IIIA, IIIB and IIIC showed substantial overlap in survival ranges. In addition, the tumour specific survival of the different T-/N-combinations was significantly different in stage groups IIIB and IIIC, respectively. CONCLUSIONS: Our retrospective analysis of the SEER-database does not validate the discriminating value of stage grouping of the 7th edition of the UICC-stage grouping. A revision should be considered and more reliable prognostic biomarkers are urgently needed.


Assuntos
Adenocarcinoma/secundário , Linfonodos/patologia , Estadiamento de Neoplasias/métodos , Neoplasias Gástricas/patologia , Adenocarcinoma/etnologia , Adenocarcinoma/mortalidade , Adenocarcinoma/terapia , Idoso , Análise Discriminante , Feminino , Gastrectomia , Humanos , Estimativa de Kaplan-Meier , Excisão de Linfonodo , Linfonodos/cirurgia , Metástase Linfática , Masculino , Valor Preditivo dos Testes , Radioterapia Adjuvante , Reprodutibilidade dos Testes , Estudos Retrospectivos , Programa de SEER , Neoplasias Gástricas/etnologia , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/terapia , Fatores de Tempo , Resultado do Tratamento , Estados Unidos/epidemiologia
10.
Obes Rev ; 16(11): 972-87, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26313354

RESUMO

Post-partum weight loss is critical to preventing and managing obesity in women, but the results from lifestyle interventions are variable and the components associated with successful outcomes are not yet clearly identified. This study aimed to identify lifestyle intervention strategies associated with weight loss in post-partum women. MEDLINE, EMBASE, PubMed, CINAHL and four other databases were searched for lifestyle intervention studies (diet or exercise or both) in post-partum women (within 12 months of delivery) published up to July 2014. The primary outcome was weight loss. Subgroup analyses were conducted for self-monitoring, individual or group setting, intervention duration, intervention types, the use of technology as a support, and home- or centre-based interventions. From 12,673 studies, 46 studies were included in systematic review and 32 randomized controlled trials were eligible for meta-analysis (1,892 women, age 24-36 years). Studies with self-monitoring had significantly greater weight lost than those without (-4.61 kg [-7.08, -2.15] vs. -1.34 kg [-1.66, -1.02], P = 0.01 for subgroup differences). Diet and physical activity when combined were significantly more effective on weight loss compared with physical activity alone (-3.24 kg [-4.59, -1.90] vs. -1.63 kg [-2.16, -1.10], P < 0.001 for subgroup differences). Lifestyle interventions that use self-monitoring and take a combined diet-and-exercise approach have significantly greater weight loss in post-partum women.


Assuntos
Dieta Redutora , Exercício Físico , Comportamentos Relacionados com a Saúde , Obesidade/prevenção & controle , Período Pós-Parto , Complicações na Gravidez/prevenção & controle , Adulto , Feminino , Humanos , Obesidade/etiologia , Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto , Comportamento de Redução do Risco , Aumento de Peso , Redução de Peso
11.
Head Neck Surg ; 10(6): 402-5, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3220780

RESUMO

Intramuscular hemangioma, a distinctive type of hemangioma occurring within skeletal muscle, accounts for approximately 1% of all hemangiomas. Most occur in the trunk and extremities, perhaps due to the relatively larger muscle mass in those areas. This report describes the first case of an intramuscular hemangioma of the prevertebral muscles. Intramuscular hemangioma is seldom diagnosed preoperatively, perhaps due to unfamiliarity with this uncommon lesion. Preoperative diagnosis is important, however, to properly evaluate feeding arterial blood supply and prevent potential operative morbidity. Surgical excision represents the treatment of choice. Intramuscular hemangioma should be considered in the differential diagnosis of deep head and neck masses.


Assuntos
Neoplasias de Cabeça e Pescoço , Hemangioma , Adulto , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/cirurgia , Hemangioma/patologia , Hemangioma/cirurgia , Humanos
12.
J Plant Physiol ; 114(3): 195-200, 1984 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11541120

RESUMO

Since gravistimulation is followed by alterations in the external current symmetry (Behrens et al., 1982), the effect of gravistimulation on cellular membrane potential was investigated using conventional glass microelectrode techniques. The resting potential of statocytes in a vertically oriented root is approx. -118 mV. Upon gravistimulation, the membrane potential is temporarily depolarized (lag time = 2 s) to a potential of approx. -93 mV. This depolarization is only observed in statocytes located on the physically lower root flank while those on the corresponding upper flank become weakly hyperpolarized (approx. -13 mV). These results reflect altered ion fluxes across the plasma membrane. The perception of gravistimulus was suggested to result from a pressure of the amyloplasts on the distal endoplasmic reticulum (ER) of the statocytes (Sievers and Volkmann, 1972). A causal relationship between changes in ER-amyloplast interactions and the rapid alterations in plasma membrane potential described above is not known. A candidate for such an intracellular messenger is Ca2+. As a first step in establishing the validity of such an assumption, we have isolated ER membranes from roots. When incubated with micromolar concentrations of Ca2+, the vesicular membrane fraction accumulates Ca2+. The accumulation is ATP-dependent and -specific and is directly coupled to ATP hydrolysis since a protonophore shows no inhibitory effect. Thus, in analogy to the sarcoplasmic reticulum of muscle, regulation of an ER-localized Ca2+ compartment might be an important step in such complex processes as stimulus-transduction in gravitropism.


Assuntos
Brassicaceae/fisiologia , Canais de Cálcio/fisiologia , Retículo Endoplasmático/fisiologia , Sensação Gravitacional/fisiologia , Raízes de Plantas/fisiologia , Sistemas do Segundo Mensageiro/fisiologia , Trifosfato de Adenosina/fisiologia , Transporte Biológico , Brassicaceae/ultraestrutura , Cálcio/metabolismo , Cálcio/farmacocinética , Cálcio/fisiologia , Retículo Endoplasmático/ultraestrutura , Potenciais da Membrana , Raízes de Plantas/ultraestrutura , Plastídeos/fisiologia , Plastídeos/ultraestrutura
13.
Acta Histochem ; 67(2): 272-82, 1980.
Artigo em Alemão | MEDLINE | ID: mdl-6782810

RESUMO

The skin of the quail embryo has been investigated microscopically with the help of freeze-etched preparations and the thin section method. On the 11th day of hatching the epidermis consists of the stratum basale and the periderm. They are not keratinized and do not differ concerning their cell junctions. Desmosomes have particles on both fracture faces with a diameter of 8 to 10 nm. Gap junctions consist of particles (5 to 8 nm) on P-face and depressions on E-face. Tight junctions are always small; they consist of spreaded ridges on the cytoplasmic face and grooves on the extracellular face. On the 14th day of hatching the stratum basale is keratinized in part in the outer layers and the periderm has been replaced by the fully keratinized stratum corneum. In the inner layers of the stratum basale cell junctions are identical with the epidermal cells on the 11th day of hatching. In the layers there are additional connexions of desmosomes and keratin fibrils. Tight junctions are absent in the stratum corneum. The size and frequency of gap junctions and desmosomes as well as the number of membrane-associated particles are reduced in comparison to the stratum basale.


Assuntos
Junções Intercelulares/ultraestrutura , Pele/ultraestrutura , Animais , Embrião de Galinha , Desmossomos/ultraestrutura , Técnica de Congelamento e Réplica , Microscopia Eletrônica
14.
J Res Natl Inst Stand Technol ; 101(3): 365-373, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-27805174

RESUMO

In the following paper the input procedures for the Inorganic Crystal Structure Database (ICSD) will be outlined. The input flow of the data is explained. Since the data have been excerpted from journal articles a bibliometric analysis of the relevant literature is presented. The types of data and the form in which they are recorded are discussed. Finally, illustrations are given of the importance of data checking and the data checking procedures are described in detail.

15.
J Phys Condens Matter ; 22(2): 025402, 2010 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-21386253

RESUMO

The evolution of the boson peak with densification at medium densification rates (up to 2.3%) in silicate glasses was followed through heat capacity measurements and low frequency Raman scattering. It is shown that the decrease of the boson peak induced by densification does not conform to that expected from a continuous medium; rather it follows a two step behaviour. The comparison of the heat capacity data with the Raman data shows that the light-vibration coupling coefficient is almost unaffected in this densification regime. These results are discussed in relation to the inhomogeneity of the glass elastic network at the nanometre scale.

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