RESUMO
Intrabone marrow cord blood transplantation (IB-CBT) was proposed as a promising treatment modality to improve hematological recovery. However, clinical advantages of IB-CBT over conventional IV CBT have been unclear. We conducted a prospective single-center trial of IB-CBT to evaluate its safety and superiority in terms of hematological recovery. Fifteen adults with hematological malignancies were enrolled. A thawed and unwashed single cord blood unit was injected into the bilateral superior-posterior iliac crests under local anesthesia. Engraftments of neutrophils and platelets were achieved in 13 cases, with medians of 17 and 45 days, respectively. For the control, we extracted data from the Japanese nationwide database and compared the hematological recovery of contemporaneously transplanted 1135 CBT cases. Multivariate analysis revealed that IB-CBT enhanced platelet recovery (hazard ratio, 2.13; P=0.007), but neutrophil recovery did not differ significantly (hazard ratio, 1.70; P=0.19). Better donor chimerism was seen in the bone marrow of the ilium than of the sternum on day 14, suggesting that the local hematopoiesis at the injected site was established earlier than that at the remote bone marrow site. Collectively, IB-CBT was well tolerated and may enhance local engraftment, which promotes prompter platelet recovery than does IV-CBT.
Assuntos
Plaquetas/citologia , Transplante de Células-Tronco de Sangue do Cordão Umbilical/métodos , Sobrevivência de Enxerto , Neoplasias Hematológicas/terapia , Infusões Intraósseas , Neutrófilos/citologia , Adulto , Idoso , Feminino , Humanos , Ílio/citologia , Infusões Intravenosas , Japão , Masculino , Pessoa de Meia-Idade , Esterno/citologia , Adulto JovemRESUMO
In leukemogenesis, Notch signaling can be up and downregulated in a context-dependent manner. The transcription factor hairy and enhancer of split-1 (Hes1) is well-characterized as a downstream target of Notch signaling. Hes1 encodes a basic helix-loop-helix-type protein, and represses target gene expression. Here, we report that deletion of the Hes1 gene in mice promotes acute myeloid leukemia (AML) development induced by the MLL-AF9 fusion protein. We then found that Hes1 directly bound to the promoter region of the FMS-like tyrosine kinase 3 (FLT3) gene and downregulated the promoter activity. FLT3 was consequently upregulated in MLL-AF9-expressing immortalized and leukemia cells with a Hes1- or RBPJ-null background. MLL-AF9-expressing Hes1-null AML cells showed enhanced proliferation and ERK phosphorylation following FLT3 ligand stimulation. FLT3 inhibition efficiently abrogated proliferation of MLL-AF9-induced Hes1-null AML cells. Furthermore, an agonistic anti-Notch2 antibody induced apoptosis of MLL-AF9-induced AML cells in a Hes1-wild type but not a Hes1-null background. We also accessed two independent databases containing messenger RNA (mRNA) expression profiles and found that the expression level of FLT3 mRNA was negatively correlated with those of HES1 in patient AML samples. These observations demonstrate that Hes1 mediates tumor suppressive roles of Notch signaling in AML development, probably by downregulating FLT3 expression.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Regulação Leucêmica da Expressão Gênica , Proteínas de Homeodomínio/genética , Leucemia Mieloide Aguda/genética , Tirosina Quinase 3 Semelhante a fms/genética , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/deficiência , Proliferação de Células , Modelos Animais de Doenças , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/deficiência , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/genética , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/patologia , Camundongos , Camundongos Transgênicos , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Fosforilação , Regiões Promotoras Genéticas , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores Notch/genética , Receptores Notch/metabolismo , Transdução de Sinais , Análise de Sobrevida , Fatores de Transcrição HES-1 , Tirosina Quinase 3 Semelhante a fms/metabolismoRESUMO
TET2 (Ten Eleven Translocation 2) is a dioxygenase that converts methylcytosine (mC) to hydroxymethylcytosine (hmC). TET2 loss-of-function mutations are highly frequent in subtypes of T-cell lymphoma that harbor follicular helper T (Tfh)-cell-like features, such as angioimmunoblastic T-cell lymphoma (30-83%) or peripheral T-cell lymphoma, not otherwise specified (10-49%), as well as myeloid malignancies. Here, we show that middle-aged Tet2 knockdown (Tet2(gt/gt)) mice exhibit Tfh-like cell overproduction in the spleen compared with control mice. The Tet2 knockdown mice eventually develop T-cell lymphoma with Tfh-like features after a long latency (median 67 weeks). Transcriptome analysis revealed that these lymphoma cells had Tfh-like gene expression patterns when compared with splenic CD4-positive cells of wild-type mice. The lymphoma cells showed lower hmC densities around the transcription start site (TSS) and higher mC densities at the regions of the TSS, gene body and CpG islands. These epigenetic changes, seen in Tet2 insufficiency-triggered lymphoma, possibly contributed to predated outgrowth of Tfh-like cells and subsequent lymphomagenesis. The mouse model described here suggests that TET2 mutations play a major role in the development of T-cell lymphoma with Tfh-like features in humans.
Assuntos
Transformação Celular Neoplásica/metabolismo , Proteínas de Ligação a DNA/biossíntese , Linfoma Folicular/metabolismo , Linfoma de Células T/metabolismo , Neoplasias Experimentais/metabolismo , Proteínas Proto-Oncogênicas/biossíntese , Linfócitos T Auxiliares-Indutores/metabolismo , Animais , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Proteínas de Ligação a DNA/genética , Dioxigenases , Técnicas de Silenciamento de Genes , Humanos , Linfoma Folicular/genética , Linfoma Folicular/patologia , Linfoma de Células T/genética , Linfoma de Células T/patologia , Camundongos , Camundongos Transgênicos , Mutação , Neoplasias Experimentais/genética , Neoplasias Experimentais/patologia , Proteínas Proto-Oncogênicas/genética , Linfócitos T Auxiliares-Indutores/patologiaRESUMO
When identical soft ferromagnetic particles are suspended at some water-air interface, capillary attraction is balanced by magnetic repulsion induced by a vertical magnetic field. By adjusting the magnetic field strength, the equilibrium interdistance between particles can be tuned. The aim of this paper is to study the ordering of particles for large assemblies. We have found an upper size limit above which the assembly collapses due to capillary effects. Before reaching this critical number of particles, defects are always present and limit the perfect ordering expected for that system. This is due to the curvature of the interface induced by the weight of the self-assembly.
RESUMO
To investigate the efficacy of long-term lamivudine (3TC) and adefovir dipivoxil (ADV) combination therapy in 3TC-resistant chronic hepatitis B virus (HBV) infected patients, we analysed 28 3TC-resistant patients treated with the combination therapy during 47 months (range, 9-75). At 12, 24, 36, and 48 months, the rates of virological response with undetectable HBV DNA (≤ 2.6 log copies/mL) were 56, 80, 86, and 92%, respectively. Among 17 hepatitis B e antigen (HBeAg)-positive patients, HBeAg disappeared in 24% at 12 months, 25% at 24 months, 62% at 36 months, and 88% at 48 months. When HBV genotypes were compared, patients with genotype B achieved virological response significantly more rapidly than those with genotype C (P=0.0496). One patient developed virological breakthrough after 54 months, and sequence analysis of HBV obtained from the patient was performed. An rtA200V mutation was present in the majority of HBV clones, in addition to the 3TC-resistant mutations of rtL180M+M204V. The rtN236T ADV-resistant mutation was observed in only 25% clones. In vitro analysis showed that the rtA200V mutation recovered the impaired replication capacity of the clone with the rtL180M+M204V mutations and induced resistance to ADV. Moreover, rtT184S and rtS202C, which are known entecavir-resistant mutations, emerged in some rtL180M+M204V clones without rtA200V or rtN236T. In conclusion, 3TC+ADV combination therapy was effective for most 3TC-resistant patients, especially with genotype B HBV, but the risk of emergence of multiple drug-resistant strains with long-term therapy should be considered. The mutation rtA200V with rtL180M+M204V may be sufficient for failure of 3TC+ADV therapy.
Assuntos
Adenina/análogos & derivados , Vírus da Hepatite B/genética , Hepatite B Crônica/tratamento farmacológico , Lamivudina/administração & dosagem , Organofosfonatos/administração & dosagem , Inibidores da Transcriptase Reversa/administração & dosagem , Adenina/administração & dosagem , Adolescente , Adulto , Idoso , DNA Viral/química , DNA Viral/genética , Farmacorresistência Viral/genética , Quimioterapia Combinada , Feminino , Genótipo , Hepatite B Crônica/enzimologia , Hepatite B Crônica/genética , Hepatite B Crônica/virologia , Humanos , Concentração Inibidora 50 , Estimativa de Kaplan-Meier , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Mutação Puntual , Reação em Cadeia da Polimerase , DNA Polimerase Dirigida por RNA/genética , Análise de Sequência de DNA , Adulto JovemAssuntos
Transplante de Medula Óssea , Linfoma de Células T/terapia , Adulto , Antígenos CD/análise , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Terapia Combinada , Humanos , Linfoma de Células T/tratamento farmacológico , Linfoma de Células T/imunologia , Masculino , Transplante HomólogoRESUMO
BACKGROUND: In previous studies, significantly elevated levels of vascular endothelial growth factor (VEGF) have been reported in patients with severe obstructive sleep apnea-hypopnea syndrome (OSAHS). On the other hand, plasma tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) have been significantly higher in mild sleep apneics than in normal controls. However, this study included a small number of patients and milder cases of OSAHS. OBJECTIVES AND METHODS: To assess the involvement of IL-6 and TNF-alpha in VEGF increases in patients with severe OSAHS, serum levels of IL-6 and TNF-alpha were determined in patients with severe OSAHS (n=110) and compared to those of controls (n=45) using an enzyme-linked immunosorbent assay. RESULTS: No significant increase in IL-6 or TNF-alpha was detected in the present study cohort. However, the body mass index was significantly correlated with the severity of the apnea-hypopnea index. CONCLUSIONS: These data suggest that the elevation in VEGF is not directly related to IL-6 or TNF-alpha levels. However, the question of whether VEGF is the cause or the result of OSAHS remains to be determined. Further studies are needed to clarify the role of IL-6 and TNF-alpha in the pathogenesis of OSAHS, in which obesity should be entered as an independent factor.
Assuntos
Interleucina-6/metabolismo , Síndromes da Apneia do Sono/diagnóstico , Apneia Obstrutiva do Sono/diagnóstico , Fator de Necrose Tumoral alfa/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Adulto , Idoso , Índice de Massa Corporal , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Mediadores da Inflamação/análise , Interleucina-6/análise , Masculino , Pessoa de Meia-Idade , Polissonografia , Probabilidade , Prognóstico , Valores de Referência , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Síndromes da Apneia do Sono/sangue , Apneia Obstrutiva do Sono/sangue , Fator de Necrose Tumoral alfa/análise , Fator A de Crescimento do Endotélio Vascular/análiseRESUMO
Our previous study has shown that ddY mice have special patches of nasal epithelium in the posterior roof of the nasal cavity that exclusively consists of olfactory supporting cells and horizontal basal cells. Here, we extend this finding to Balb/c and DBA/2 mice, Wistar and Sprague-Dawley rats, hamsters, and guinea pigs. In the mice, rats, and hamsters studied, the patches lacked olfactory cells and their precursor, globose basal cells. In rats and hamsters, the supporting cells were arranged in a single layer, in mice as three or four layers. Horizontal basal cells were located in a single layer in these species. In the guinea pigs, the specialized roof structure was less clear and could be seen at the level of ultrastructure as an olfactory neuron-lacking area. Distinct populations of transforming growth factor (TGF)-alpha-like immunoreactive olfactory cells occupied an area close to the epithelial patches. In this region, the TGF-alpha-like immunoreactive neurons were negative for the usual olfactory markers, either OMP or protein gene product (PGP) 9.5 or beta-tubulin. These cells are suggested to project to the so-called 'necklace glomeruli' and use a different cGMP-driven, transduction pathway. Three-dimensional analysis of double-labeled (TGF-alpha, PGP9.5) serial sections revealed a unique relation among the epithelial patches, TGF-alpha-like immunoreactive neurons and olfactory epithelium.
Assuntos
Mucosa Olfatória/ultraestrutura , Neurônios Receptores Olfatórios/ultraestrutura , Fator de Crescimento Transformador alfa/análise , Animais , Anticorpos Monoclonais , Cricetinae , Epitélio/ultraestrutura , Feminino , Cobaias , Imuno-Histoquímica , Masculino , Mesocricetus , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos DBA , Microscopia Eletrônica , Neurônios Receptores Olfatórios/química , Ratos , Ratos Sprague-Dawley , Ratos WistarRESUMO
A 29-year-old woman having acute myelogeneous leukemia-M1 subtype with the chromosomal abnormality t(16;21)(p11;q22) is presented. Complete blood count at onset showed a hemoglobin level of 7.2 g/dl, a platelet count of 48 x 10(9)/l, and a white blood cell count of 161.2 x 10(9)/l with 99% blasts and 1% lymphocytes. Bone marrow aspiration revealed massive proliferation of blasts that were positive for CD13, CD33, CD34, CD56 and myeloperoxidase, and negative for other T-cell, B-cell and monocytic markers. After achieving complete remission following conventional chemotherapy, she received an HLA-matched bone marrow transplantation (BMT) from her sibling after conditioning with busulfan, etoposide and cyclophosphamide. However, 9 months later, the leukemia relapsed as a painful extramedullary mass in her left femur. In spite of intensive re-induction chemotherapy, she died of progressive disease and sepsis. Although we could not detect the TLS/FUS-ERG fusion transcripts by reverse transcriptase-polymerase chain reaction in pre-BMT remission phase, they were clearly detectable in bone marrow cells obtained 6 months after transplantation with no translocation detected by conventional cytogenetics. We consider that even high-dose chemotherapy with BMT may not be effective in the eradication of this type of leukemia, and that the detection of minimal residual disease possibly contributes to the better planning of the therapeutic strategy.
Assuntos
Transplante de Medula Óssea , Cromossomos Humanos Par 16 , Cromossomos Humanos Par 21 , Leucemia Mieloide Aguda/genética , Neoplasia Residual/diagnóstico , Translocação Genética , Adulto , Antígenos CD/análise , Antígenos CD34/análise , Antígenos de Diferenciação Mielomonocítica/análise , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Medula Óssea/patologia , Antígenos CD13/análise , Antígeno CD56/análise , Evolução Fatal , Feminino , Hemoglobinas/análise , Humanos , Cariotipagem , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/terapia , Contagem de Leucócitos , Neoplasia Residual/patologia , Peroxidase/análise , Contagem de Plaquetas , Radioterapia , Recidiva , Indução de Remissão , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico , Transplante Homólogo , Falha de TratamentoRESUMO
The olfactory epithelium of mice generally consists of olfactory cells, progenitors of olfactory cells (globose basal cells), supporting cells, and horizontal basal cells. However, in the dorsal fossa (the roof) of the posterior nasal cavity of mice, we found seven epithelial patches consisting of only non-neuronal cell types, i.e., supporting cells and horizontal basal cells, among the normal olfactory epithelium. The supporting cells occupied three or four layers in the apical to middle regions; in the basal region, horizontal basal cells were localized in a single row adjacent to the basement membrane. Bowman's gland ducts were also present in the epithelium. Neuronal cells (olfactory cells and globose basal cells) were totally absent. The ultrastructure of the supporting cells, horizontal basal cells, and Bowman's glands was essentially similar to that in the normal olfactory epithelium. In the early postnatal period (P1-P7), cell types in the epithelium were the same as those in the normal olfactory epithelium. From P10 to P21, olfactory cells and globose basal cells had disappeared from the olfactory epithelium. At this period, the number of TUNEL-positive cells was significantly higher than that in the surrounding olfactory epithelium; ultrastructurally, many apoptotic figures were observed. This suggests that the epithelium consisting of supporting cells and horizontal basal cells is generated by the apoptotic death of olfactory cells and globose basal cells during postnatal development.
Assuntos
Células Epiteliais/ultraestrutura , Cavidade Nasal/citologia , Mucosa Olfatória/citologia , Fatores Etários , Animais , Anticorpos , Antimetabólitos/análise , Antimetabólitos/imunologia , Apoptose/fisiologia , Bromodesoxiuridina/análise , Bromodesoxiuridina/imunologia , Feminino , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Masculino , Camundongos , Microscopia Eletrônica , Cavidade Nasal/crescimento & desenvolvimento , Mucosa Olfatória/crescimento & desenvolvimentoRESUMO
Apoptotic cells in the taste buds and epithelia of mouse circumvallate papillae after colchicine treatment were examined by the methods of in situ DNA nick-end labeling, immunocytochemistry, and electron microscopy. After colchicine treatment, numerous positive cells appeared in the taste buds by DNA nick-end labeling, and some epithelial cells in the basal and suprabasal layers in and around the circumvallate papillae also revealed positive staining. Condensed and fragmented nuclei with a high density were occasionally found in the taste bud cells and in the basal and suprabasal layer epithelial cells by electron-microscopic observation. An immunocytochemical reaction for tubulin revealed weak staining in taste bud cells, because of the depolymerization of microtubules, and a decrease of the microtubules in the taste bud cells was observed by electron microscopy. These results indicate that colchicine treatment of mice induces the apoptosis of taste bud and epithelial cells in the circumvallate papillae and dorsal epithelial cells around the circumvallate papillae.
Assuntos
Apoptose/efeitos dos fármacos , Colchicina/farmacologia , Células Epiteliais/fisiologia , Papilas Gustativas/fisiologia , Língua/citologia , Língua/inervação , Animais , Núcleo Celular/ultraestrutura , DNA/ultraestrutura , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/ultraestrutura , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Camundongos , Microscopia Eletrônica , Microtúbulos/metabolismo , Papilas Gustativas/efeitos dos fármacos , Papilas Gustativas/ultraestrutura , Língua/ultraestrutura , Tubulina (Proteína)/imunologia , Tubulina (Proteína)/metabolismoRESUMO
A rare association of der(1;7)(q10;p10) with de novo acute erythroblastic leukemia (AML-M6) in a 63-year-old male is reported. While this unbalanced 1;7 translocation, der(1;7), has been reported often in therapy-related myelodysplastic syndrome (t-MDS) or therapy-related acute myeloid leukemia (t-AML), its associations with de novo AML-FAB-M6 have rarely been reported. Although der(1;7) has been reported as a cytogenetic factor for poor prognosis in t-MDS/AML, our patient showed a good response to chemotherapy and obtained complete remission, although longer observation is required to evaluate the prognosis.
Assuntos
Cromossomos Humanos Par 1 , Cromossomos Humanos Par 7 , Leucemia Eritroblástica Aguda/genética , Translocação Genética , Idoso , Células da Medula Óssea/patologia , Humanos , Cariotipagem , Leucemia Eritroblástica Aguda/patologia , Subpopulações de Linfócitos , MasculinoRESUMO
The distribution of two cell-adhesion molecules, E- and P-cadherin, was studied in relation to morphological changes in Hertwig's epithelial root sheath Before root dentinogenesis had started, the root sheath expressed both cadherins. As dentinogenesis proceeded, the sheath fragmented and lost P-cadherin rapidly and E-cadherin slowly, whereas the intact sheath at the apical end continued to express both. These results suggest that the two cadherins play a part in root as well as in crown development, and indicate that the decrease in the amount of these molecules and the fragmentation of the epithelial root sheath are interrelated.
Assuntos
Caderinas/análise , Odontogênese/fisiologia , Germe de Dente/ultraestrutura , Raiz Dentária/ultraestrutura , Animais , Anticorpos Monoclonais , Dentinogênese/fisiologia , Órgão do Esmalte/ultraestrutura , Fluoresceína-5-Isotiocianato , Técnica Indireta de Fluorescência para Anticorpo , Corantes Fluorescentes , Imunoglobulina G , Camundongos , Rodaminas , Coroa do Dente/ultraestruturaRESUMO
Expression of the neural cell adhesion molecule (NCAM) was studied by use of an immunocytochemical technique in the taste buds of mouse circumvallate papillae after bilateral transection of the glossopharyngeal nerves. In untreated mice, innervated type-III cells reacted with anti-NCAM antibody. After denervation the taste buds gradually decreased in number and size, and were practically absent within 11 days. In parallel, NCAM-reactive cells decreased at 3 and 8 days after surgery and at 11 days they were no longer found. Three days after denervation, synaptic contacts between type-III cells and nerve fibres were not found because of the disappearance of nerve fibres. However, remaining type-III cells, characterized with dense-cored vesicles, still maintained NCAM expression on their plasma membrane until day 8.
Assuntos
Moléculas de Adesão de Célula Nervosa/isolamento & purificação , Papilas Gustativas/fisiologia , Animais , Denervação , Imuno-Histoquímica , Camundongos , Microscopia Imunoeletrônica , Papilas Gustativas/ultraestruturaRESUMO
A 58-year-old man was referred to our hospital because of painful swelling in the left lower leg and leukocytosis in January 1999. Moderate hepatosplenomegaly but no lymph node swelling was observed. Marked leukocytosis (leukocytes 44.9 x 10(4)/microliter with 95% morphologically prolymphocytes) and thrombocytopenia were detected. The surface phenotype of the leukemia cells was CD1-2+3+5+7+4+8+25+. Magnetic resonance imaging revealed dilated veins in the left lower leg. An abnormal 47XY, +22 karyotype was detected in 1/20 cells. Tests for HTLV-I antibody were negative. A diagnosis of T-cell prolymphocytic leukemia (T-PLL) was made on the basis of data including cytochemical and electron microscopic findings. Although 2 courses of chemotherapy comprising vincristine, cyclophosphamide, and prednisolone improved the venous thrombosis in the leg, the leukemia cells were refractory to chemotherapy. To prevent the recurrence of venous thrombosis due to leukostasis, the patient underwent repeated leukapheresis. The leukocyte count was maintained at around 20.0 x 10(4)/microliter after total 7 courses of leukapheresis, one course of which comprised 7l of extracorporeal circulation. In addition to the rare presentation of venous thrombosis, the CD4+8+25+ phenotype observed in this case is rare in patients with T-PLL.
Assuntos
Leucemia de Células T/patologia , Trombose Venosa/etiologia , Relação CD4-CD8 , Humanos , Perna (Membro) , Leucaférese , Leucemia de Células T/complicações , Leucemia de Células T/imunologia , Masculino , Pessoa de Meia-Idade , Fenótipo , Receptores de Interleucina-2 , Trombose Venosa/patologia , Trombose Venosa/terapiaRESUMO
Bulbectomy of neonatal mice induced cell migration from the olfactory epithelium in the nasal septum. We examined cell types of migrating clusters by immunohistochemistry using anti-keratin and anti-BrdU antibodies, and by electron microscopy. At 1-2 days after unilateral bulbectomy of P1 mice, cells migrated from the olfactory epithelium to the lamina propria of the septal olfactory mucosa. Horizontal basal cells that reacted specifically with anti-keratin antibody, and globose basal cells characterized by a round shape and poor content of organellae in their cytoplasm, were contained in the cluster. At 1 week, migrated clusters that contained keratin-positive horizontal basal cells were observed in both the lamina propria and olfactory bulb on the unoperated side. At 1 month, not only basal cells but also olfactory cells and presumed supporting cells were involved in the clusters in the lamina propria and olfactory bulb, suggesting that migrated cells do not transform to other phenotypes.
Assuntos
Movimento Celular/fisiologia , Neurônios/citologia , Bulbo Olfatório/citologia , Bulbo Olfatório/crescimento & desenvolvimento , Mucosa Olfatória/citologia , Animais , Animais Recém-Nascidos , Anticorpos , Bromodesoxiuridina/análise , Bromodesoxiuridina/imunologia , Denervação , Células Epiteliais/citologia , Células Epiteliais/ultraestrutura , Queratinas/análise , Queratinas/imunologia , Camundongos , Microscopia Eletrônica , Neurônios/química , Neurônios/ultraestrutura , Bulbo Olfatório/cirurgiaRESUMO
Cell-cell adhesion is fundamental in morphogenesis and is known to be mediated by several groups of cell adhesion molecules. Cadherins are a group of such molecules involved in the Ca2+-dependent cell-cell adhesion mechanism and are found in most kinds of tissue. In this study using indirect immunofluorescence microscopy, we analyzed the distribution of two kinds of cadherins, E- and P-cadherin, in developing tooth germs. In the molar tooth germs at the early bud stage, marginal cells of the epithelial tooth bud expressed both E- and P-cadherin, whereas central cells expressed only E-cadherin. At the cap stage, in addition to the cells of the inner and outer enamel epithelium, which outline the enamal organ, cells of the enamel knot, which is thought to control tooth morphogenesis, strongly expressed P-cadherin. The expression of P-cadherin was prominent in the inner enamel epithelium during the early to mid bell stage, and was also evident in the non-dividing cell masses at future cusp tips, which are the so-called secondary enamel knots. In the tooth germ at the late bell stage when the cells of the inner enamel epithelium began to polarize to differentiate into ameloblasts, the polarizing ameloblasts lost P-cadherin and strongly expressed E-cadherin. However, E-cadherin was also lost from polarized ameloblasts at later stages. The stratum intermedium and the stellate reticulum were E-cadherin positive from the bell stage onward even at the stages when the ameloblasts became E-cadherin negative again. These results suggest that the differential expression of E- and P-cadherin during morphogenetic stages plays a role in the regulation of tooth morphogenesis, whereas alteration of E-cadherin expression during later stages of tooth development is related to differentiation and function of the ameloblasts and other cells supporting amelogenesis.
Assuntos
Ameloblastos/citologia , Caderinas/metabolismo , Moléculas de Adesão Celular/metabolismo , Diferenciação Celular , Dente/embriologia , Dente/metabolismo , Animais , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Camundongos , Gravidez , Dente/citologiaRESUMO
The cytotoxic agent colchicine induced apoptotic cell death and subsequent regeneration in the mouse olfactory epithelium and vomeronasal organ. The TUNEL method revealed the presence of many apoptotic bodies in the middle to basal region of the septal olfactory epithelium and vomeronasal organ near the boundary of the respiratory epithelium at 1 day after a single i.p. injection of colchicine (4 mg/kg b.w.). In some regions of the third and the fourth nasal turbinates, massive apoptosis was observed in the olfactory epithelium. Electron micrographs of the septum showed that immature olfactory cells and globose basal cells were killed by the colchicine and had been phagocytized by the supporting cells and macrophages. In the vomeronasal organ, immature sensory cells and precursors died in response to the colchicine. In response to cell death, active proliferation of precursor cells (globose basal cells) and subsequent regeneration of olfactory cells occurred in the olfactory epithelium and vomeronasal organ. Incorporation of the mitotic tracer BrdU by precursor cells reached its peak at 4 days after colchicine treatment in the vomeronasal organ, and at 6 to 7 days in the olfactory epithelium; however, in some regions in the third and the fourth nasal turbinates, where many olfactory cells and globose basal cells had died by colchicine effect, the regeneration did not occur even in 1 month, forming the epithelium of only supporting cells and horizontal basal cells. In the next month, these regions became normal olfactory epithelium. This suggests that the globose basal cells in the surrounding normal olfactory epithelium might invade these regions to give rise to the olfactory cells.
Assuntos
Apoptose/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Colchicina/toxicidade , Mucosa Olfatória/patologia , Órgão Vomeronasal/patologia , Animais , Bromodesoxiuridina/metabolismo , Fragmentação do DNA , DNA Nucleotidilexotransferase , Epitélio/metabolismo , Epitélio/ultraestrutura , Camundongos , Microscopia Eletrônica , Bulbo Olfatório/metabolismo , Bulbo Olfatório/patologia , Mucosa Olfatória/metabolismo , Conchas Nasais/metabolismo , Conchas Nasais/patologia , Órgão Vomeronasal/metabolismoRESUMO
A novel cyclohexene compound (1), which is structurally related to theobroxide (2), was isolated from a culture filtrate of the fungus, Lasiodiplodia theobromae IFO 31059. The potato micro-tuber-inducing activity of this compound was observed at a concentration of 10(-3) M in the medium, whereas theobroxide (2) showed its activity at 10(-5) M.
RESUMO
Developmental changes in the distribution of the neural cell adhesion molecule (NCAM) were investigated in mouse incisors by means of the indirect immunofluorescence method. During the prenatal stages of development, NCAM was predominantly found in the dental follicle, but not in the dental papilla; the results were analogous to the distribution of NCAM during molar development. After birth, the expression of NCAM continued in the tissue between the enamel organ and the alveolar bone on the labial aspect. In contrast, the follicular tissue covering the lingual aspect of the incisor gradually lost NCAM immunoreactivity from its outer zone as it differentiated into the highly organized periodontal ligament. The intermediate zone of the ligament continued to express NCAM-immunoreactivity even in mice of 6 weeks of age. This pattern of NCAM expression was different from that found in molar teeth, where the organized peridontal ligament was NCAM-negative. The dental pulp, in which we previously reported that an NCAM-positive area appeared at later stages of molar tooth development, did not express NCAM immunoreactivity even at the latest stage of development covered in this study. These differences in the distribution of NCAM between the incisors and the molars might be related to the fact that rodent incisors continue to grow throughout the life of the animal.