Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Z Gastroenterol ; 54(3): 226-30, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27043885

RESUMO

OBJECTIVE: Organ failure and local complications contribute to morbidity and mortality in acute pancreatitis. Comorbidity is known to be related to organ failure. The impact of comorbidity on local complications has not yet been delineated. Moreover, it is not clear if the outcome of first-attacks and acute-on-chronic episodes, respectively, differs from outcome in all episodes. METHODS: Consecutive cases of confirmed acute pancreatitis in a four-year period were reviewed. Charlson comorbidity index (CCI), complications (organ failure and local complications), disease severity (according to the revised Atlanta Classification), need for intensive care, and mortality were derived from the charts. RESULTS: A total of 391 episodes of acute pancreatitis were included. Patients with organ failure were significantly older (P< 0.001) und had a higher CCI (P< 0.001) than patients without organ failure. Patients with and without local complications did not significantly differ in age or CCI. The complication rate of the entire cohort (n = 391; 47.1 %) was comparable with the complication rate of first-attacks (n = 269; 46.8 %) and acute-on-chronic episodes (n = 68; 47.1 %). The majority of the twelve deceased patients had been old and/or chronically ill. Six of these patients had an advanced malignant disease. CONCLUSIONS: Comorbidity and age clearly are contributors to organ failure and mortality. Local complications occur independently of age and concomitant diseases. The overall complication rate is not significantly influenced by preceding inflammation of the pancreas. To further improve care in patients with acute pancreatitis special attention should be given to old and multi-morbid patients.


Assuntos
Alcoolismo/mortalidade , Doença Crônica/mortalidade , Insuficiência de Múltiplos Órgãos/mortalidade , Neoplasias/mortalidade , Pancreatite/mortalidade , Doença Aguda , Distribuição por Idade , Idoso , Causalidade , Estudos de Coortes , Comorbidade , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência de Múltiplos Órgãos/diagnóstico , Neoplasias/diagnóstico , Pancreatite/diagnóstico , Fatores de Risco , Distribuição por Sexo , Taxa de Sobrevida
2.
Clin Exp Immunol ; 172(2): 280-9, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23574324

RESUMO

Antigen presentation by intestinal epithelial cells (IEC) is crucial for intestinal homeostasis. Disturbances of major histocompatibility complex class I (MHC I)- and II-related presentation pathways in IEC appear to be involved in an altered activation of CD4(+) and CD8(+) T cells in inflammatory bowel disease. However, a comprehensive analysis of MHC I- and II-enriched compartments in IEC of the small and large bowel in the healthy state as opposed to inflammatory bowel diseases is lacking. The aim of this study was to characterize the subcellular expression of MHC I and II in the endocytic pathway of IEC throughout all parts of the intestinal tract, and to identify differences between the healthy state and inflammatory bowel diseases. Biopsies were taken by endoscopy from the duodenum, jejunum, ileum and colon in healthy individuals (n = 20). In Crohn's disease (CD), biopsies were obtained from the ileum and colon and within the colon from ulcerative colitis (UC) patients (n = 15). Analysis of IEC was performed by immunoelectron microscopy. MHC I and II were identified in early endosomes and multi-vesicular, multi-lamellar, electrondense and vacuolar late endosomes. Both molecules were enriched in multi-vesicular bodies. No differences were found between the distinct parts of the gut axis. In CD and UC the expression of MHC I and II showed a shift from multi-vesicular bodies towards the basolateral membranes. Within the multi-vesicular bodies, MHC I and II moved from internal vesicles to the limiting membranes upon inflammation in CD and UC. MHC I- and II-enriched compartments in IEC were identical in all parts of the small and large bowel. CD and UC appear to modulate the MHC I- and II-related presentation pathways of exogenous antigens in IEC.


Assuntos
Colite Ulcerativa/imunologia , Doença de Crohn/imunologia , Antígenos HLA-A/imunologia , Antígenos HLA-B/imunologia , Mucosa Intestinal/imunologia , Apresentação de Antígeno , Biópsia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Colite Ulcerativa/metabolismo , Colo/imunologia , Doença de Crohn/metabolismo , Duodeno/imunologia , Humanos , Íleo/imunologia , Mucosa Intestinal/citologia , Jejuno/imunologia
3.
Z Gastroenterol ; 50(5): 449-52, 2012 May.
Artigo em Alemão | MEDLINE | ID: mdl-22581699

RESUMO

Aneurysms within the visceral arteries are rare. Among these, aneurysms of the splenic artery occur most frequently followed by aneurysms of the hepatic arteries. An early diagnosis is easily missed and almost all patients become symptomatic with an acute rupture associated with high mortality. Here we demonstrate the case of a 76-year-old patient who presented with acute upper abdominal pain accompanied by a single episode of vomiting and pyrexia of 39 °C. Laboratory results presented the picture of an obstructive jaundice without evidence for accompanying pancreatitis. Inflammatory markers were within normal limits at onset, but increased dramatically within the next few days. An acute calculous cholecystitis was diagnosed on abdominal ultrasound whereas gastroscopy revealed no relevant changes. Computed tomography was suspicious for pancreatitis of the head with obstruction of the bile duct. Choledocholithiasis was ruled out by ERCP, but symptoms persisted despite papillotomy. Due to raising inflammatory markers and an ongoing impairment of the patients condition, an abdominal CT scan was repeated which revealed the suspicion of a ruptured aneurysm of the common hepatic artery. At the time of transferral we were able to confirm the diagnosis by contrast-enhanced ultrasound and angiography. The patient was immediately forwarded to surgery due to lack of satisfactory endovascular procedures. In summary, the patient suffered from a ruptured spurial aneurysm of the right gastric artery thereby obstructing the common bile duct. Beside CT scans and angiography, this case documents a pivotal role for contrast-enhanced ultrasound in the work-up of visceral artery aneurysms.


Assuntos
Aneurisma/complicações , Aneurisma/diagnóstico por imagem , Artéria Hepática/diagnóstico por imagem , Icterícia Obstrutiva/diagnóstico por imagem , Icterícia Obstrutiva/etiologia , Idoso , Diagnóstico Diferencial , Humanos , Masculino , Radiografia , Ultrassonografia
5.
Internist (Berl) ; 52(7): 833-40, 2011 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-21660632

RESUMO

Inflammatory bowel disease (IBD) is a non-curable disease. Although we seem to have a definitive surgical solution for ulcerative colitis, patients are at risk of suffering from acute and chronic pouchitis as well as peri- and postoperative complications. In Crohn's disease medical treatment is able to prolong surgery-free survival, but no definitive healing strategy is as yet at hand. Moreover, effective medication exposes patients to potentially life-threatening complications. The severely compromised patient in particular needs careful surveillance and requires a balanced treatment strategy endorsed by gastroenterologists and surgeons. Treatment is still aimed at suppressing immune mechanisms and is far from being causal. Nevertheless, this approach has resulted in a reduction in surgical procedures and hospitalizations. The following overview covers special issues related to strategies for severe and fulminant flares of inflammatory bowel disease.


Assuntos
Colite Ulcerativa/terapia , Cuidados Críticos/métodos , Doença de Crohn/terapia , Algoritmos , Anti-Inflamatórios/efeitos adversos , Anti-Inflamatórios/uso terapêutico , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/uso terapêutico , Colite Ulcerativa/diagnóstico , Colite Ulcerativa/mortalidade , Doença de Crohn/diagnóstico , Doença de Crohn/mortalidade , Ciclosporina/efeitos adversos , Ciclosporina/uso terapêutico , Humanos , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Infliximab , Comunicação Interdisciplinar , Equipe de Assistência ao Paciente , Tacrolimo/efeitos adversos , Tacrolimo/uso terapêutico , Fator de Necrose Tumoral alfa/antagonistas & inibidores
6.
Diabetes Obes Metab ; 12(2): 158-66, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19895638

RESUMO

AIM: The endocannabinoid (EC) system is a major component in the control of energy homeostasis. It mediates a positive energy balance via central and peripheral pathways. Blockade of the cannabinoid type 1 receptor induces weight reduction and improves cardiovascular risk factors in overweight patients. Cannabinoid receptor type 1 (CB1R)-deficient mice are resistant to diet-induced obesity. The mechanisms responsible for these effects remain only partially elucidated. We hypothesized peripheral effects via direct modulation of adipocyte function to be an integral part of EC action on energy metabolism and insulin sensitivity. METHODS: SV40 immortalized murine white and brown adipocytes were used for all experiments. We investigated the effect of CB1R blockade by stimulating the cells acutely and chronically with rimonabant, a selective antagonist for the CB1R, or by knocking down the receptor with small interfering RNA (siRNA). Changes in thermogenic mRNA and protein expression as well as mitochondrial biogenesis and function were assessed by real-time RT-PCR, immunoblotting, fluorescent staining techniques, electron microscopy and by measuring oxygen consumption. RESULTS: Acute and chronic blockade of the CB1R with the selective antagonist rimonabant or by siRNA in murine white adipocytes strongly induced the thermogenic uncoupling protein-1 (UCP-1). UCP-1 expression was increased in a time- and dose-dependent manner both at the RNA and protein level. Furthermore, this effect was paralleled by enhanced peroxisome proliferator-activated receptor gamma coactivator 1alpha (PGC-1alpha) expression. In accordance with these findings, AMP-activated protein kinase (AMPK) phosphorylation was also increased after rimonabant treatment. Mitochondria-specific fluorescent staining demonstrated an augmentation in the number of mitochondria. This was confirmed by electron microscopy images. Moreover, rimonabant treatment enhanced the cytochrome c oxidase activity and increased cellular oxygen consumption. CONCLUSIONS: Taken together, our data demonstrate that inhibition of peripheral CB1R action in adipocytes directly promotes transdifferentiation of white adipocytes into a mitochondria-rich, thermogenic brown fat phenotype. Enhanced thermogenesis and insulin sensitivity may represent a peripheral mechanism contributing to weight loss and improved glucose homeostasis in rimonabant-treated patients.


Assuntos
Adipócitos Brancos/citologia , Tecido Adiposo Marrom , Antagonistas de Receptores de Canabinoides , Obesidade/patologia , Receptor CB1 de Canabinoide/antagonistas & inibidores , Tecido Adiposo Marrom/efeitos dos fármacos , Animais , Transdiferenciação Celular , Expressão Gênica , Camundongos , PPAR gama/genética , Fenótipo , Piperidinas/farmacologia , Pirazóis/farmacologia , Receptor CB1 de Canabinoide/genética , Receptores de Canabinoides/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rimonabanto
7.
Aliment Pharmacol Ther ; 47(5): 581-587, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29266360

RESUMO

BACKGROUND: The most common complication after ileal pouch anal anastomosis in up to 50% of patients is an acute pouchitis. The majority of patients respond to antibiotic treatment. However, 10%-15% develops chronic antibiotic-dependent or refractory pouchitis which is usually hard to treat. AIM: To evaluate the effectiveness of vedolizumab in patients with chronic pouchitis. METHODS: Patients with chronic antibiotic-dependent or refractory pouchitis were treated with vedolizumab (300 mg at week 0, 2, 6 and 10) in 10 IBD centres and retrospectively registered. Data were recorded until week 14 of vedolizumab treatment. In total 20 patients (12 male, median age 43 years) were included for analysis. The effectiveness was measured using the Oresland Score (OS) at week 2, 6, 10 and 14 and the pouch disease activity index (PDAI) at week 0 and 14. RESULTS: The mean OS declined from 6.8 (range 2-12) to 3.4 (range 0-11). Concordantly, the mean PDAI after 14 weeks of treatment dropped from 10 (range 5-18) to 3 (range 0-10). Only three patients reported moderate side effects. No serious side effects were recorded. In addition, symptomatic co-medication such as loperamide and tincture of opium could be terminated in 8 out of 12 patients as well as antibiotic treatment could be stopped in 17 out of 19 patients. CONCLUSION: Our data indicate that vedolizumab could be an option in the treatment of patients with chronic, antibiotic-dependent or refractory pouchitis.


Assuntos
Antibacterianos/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Pouchite/tratamento farmacológico , Adolescente , Adulto , Idoso , Criança , Doença Crônica , Resistência Microbiana a Medicamentos , Quimioterapia Combinada , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Pouchite/mortalidade , Pouchite/patologia , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
8.
J Crohns Colitis ; 12(6): 695-701, 2018 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-29415186

RESUMO

BACKGROUND: Intra-abdominal abscesses [IAAs] are common life-threatening complications in patients with Crohn's disease [CD]. In addition to interventional drainage and surgical therapy, empirical antibiotic therapy represents a cornerstone of treatment, but contemporary data on microbial spectra and antimicrobial resistance are scarce. METHODS: We recruited 105 patients with CD and IAAs from nine German centres for a prospective registry in order to characterize the microbiological spectrum, resistance profiles, antibiotic therapy and outcome. RESULTS: In 92 of 105 patients, microbial investigations of abscess material revealed pathogenic microorganisms. A total of 174 pathogens were isolated, with a median of 2 pathogens per culture [range: 1-6]. Most frequently isolated pathogens were E. coli [45 patients], Streptococcus spp. [28 patients], Enterococci [27 patients], Candida [13 patients] and anaerobes [12 patients]. Resistance to third-generation cephalosporins, penicillins with beta-lactamase inhibitors and quinolones were observed in 51, 36 and 35 patients, respectively. Seven patients had multiple-drug-resistant bacteria. Thirty patients received inadequate empirical treatment, and this was more frequent in patients receiving steroids or immunosuppression [37%] than in patients without immunosuppression [10%: p = 0.001] and was associated with a longer hospital stay [21 days vs 13 days, p = 0.003]. CONCLUSION: Based on antimicrobial resistance profiles, we herein report a high rate of inadequate empirical first-line therapy for IAAs in CD, especially in patients receiving immunosuppression, and this is associated with prolonged hospitalization.


Assuntos
Abscesso Abdominal/tratamento farmacológico , Abscesso Abdominal/microbiologia , Antibacterianos/uso terapêutico , Doença de Crohn/complicações , Enterobacteriaceae/isolamento & purificação , Perfuração Intestinal/complicações , Adulto , Antibacterianos/farmacologia , Antifúngicos/uso terapêutico , Candida albicans/isolamento & purificação , Carbapenêmicos/uso terapêutico , Cefalosporinas/uso terapêutico , Doença de Crohn/tratamento farmacológico , Farmacorresistência Bacteriana Múltipla , Enterobacteriaceae/efeitos dos fármacos , Enterococcus/efeitos dos fármacos , Enterococcus/isolamento & purificação , Feminino , Alemanha , Humanos , Imunossupressores/uso terapêutico , Tempo de Internação , Levofloxacino/uso terapêutico , Masculino , Penicilinas/uso terapêutico , Estudos Prospectivos , Quinolonas/uso terapêutico , Sistema de Registros , Streptococcus/efeitos dos fármacos , Streptococcus/isolamento & purificação , Adulto Jovem , Inibidores de beta-Lactamases/uso terapêutico
9.
J Crohns Colitis ; 10(1): 31-7, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26419459

RESUMO

BACKGROUND AND AIMS: Tacrolimus is recommended for the treatment of steroid-refractory ulcerative colitis (UC). Concomitantly started purine analogues (PAs) are used for the maintenance of remission, though their therapeutic relevance remains uncertain. Here we studied the role of PAs in the long-term outcome of steroid-refractory UC after tacrolimus treatment. METHODS: In five centres, charts of tacrolimus-treated UC patients with a steroid-refractory moderate to severe course were reviewed. Long-term efficacy was determined by colectomy rates and clinical remission in cases of colectomy-free survival for 3 months. RESULTS: We identified 156 patients (median age 34 years) with a median Lichtiger score of 12 (4-17) and pancolitis (E3) in 65% (101). The Kaplan-Meier curve for colectomy-free survival after month 3 showed a benefit in the PA group (p = 0.02). In patients treated with PA clinical remission was achieved in 82% (65/79) vs 67% (39/58) in those not treated with PA (p = 0.02). Time to colectomy was 2 years (median, 0.7-5.8) in the PA group and 0.8 years (0.3-4.7) in the group not treated with PAs (p = 0.02). Time to relapse was 1.2 years (median, 0.3-6.2) in patients with PA treatment and 0.5 years (0.3-3.9) in those without PA treatment (p = 0.05). Overall, clinical remission was achieved in 67% (104/156) of patients. Colectomy was performed in 29% (45/156) 0.5 years (median, 0.04-5.79) after initiation of tacrolimus. Ten (6%) patients had to stop tacrolimus due to adverse events and two (without PA treatment) died. CONCLUSIONS: Our study supports the efficacy of tacrolimus in steroid-refractory UC. Purine analogues appear to be beneficial for the long-term outcome of these patients.


Assuntos
Colite Ulcerativa/tratamento farmacológico , Mucosa Intestinal/efeitos dos fármacos , Mercaptopurina/administração & dosagem , Tacrolimo/administração & dosagem , Adulto , Idoso , Estudos de Coortes , Colectomia/métodos , Colectomia/estatística & dados numéricos , Colite Ulcerativa/diagnóstico , Colite Ulcerativa/mortalidade , Colite Ulcerativa/cirurgia , Colonoscopia/métodos , Bases de Dados Factuais , Quimioterapia Combinada , Feminino , Seguimentos , Alemanha , Humanos , Imunossupressores/administração & dosagem , Mucosa Intestinal/patologia , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Medição de Risco , Índice de Gravidade de Doença , Estatísticas não Paramétricas , Esteroides/administração & dosagem , Esteroides/efeitos adversos , Taxa de Sobrevida , Fatores de Tempo , Resultado do Tratamento , Cicatrização/efeitos dos fármacos , Cicatrização/fisiologia , Adulto Jovem
10.
Mucosal Immunol ; 9(5): 1263-77, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-26732675

RESUMO

Inflammatory bowel disease (IBD) is characterized by chronic, uncontrolled inflammation in the intestinal mucosa. Although the etiology is poorly understood, it is widely accepted that loss of tolerance is involved in the development of IBD. Therefore, re-establishing tolerance or gut homeostasis is one of the key features in the development of new therapeutic strategies. Here we show that antigen targeting to DEC-205 on dendritic cells leads to an interleukin (IL)-10-dependent downregulation of C-X-C chemokine receptor 3 (CXCR3) expression on differentiated antigen-specific T helper type 1 (Th1) cells in vivo. This downregulation interferes with the migration of Th1 cells into the gut and protects mice against severe acute and relapsing intestinal inflammation. Moreover, CD4(+)CXCR3(+) T cells are highly enriched in the inflamed mucosa of IBD patients. Interference with this pathway may therefore be a promising approach for the treatment of IBD. In conclusion, we propose a hitherto undescribed mechanism by which IL-10 can act on effector T cells and orchestrate intestinal immune responses.


Assuntos
Antígenos CD/imunologia , Colite Ulcerativa/imunologia , Doença de Crohn/imunologia , Interleucina-10/imunologia , Lectinas Tipo C/imunologia , Antígenos de Histocompatibilidade Menor/imunologia , Receptores CXCR3/imunologia , Receptores de Superfície Celular/imunologia , Células Th1/imunologia , Animais , Antígenos CD/genética , Antígenos CD4/genética , Antígenos CD4/imunologia , Movimento Celular , Colite Ulcerativa/genética , Colite Ulcerativa/patologia , Doença de Crohn/genética , Doença de Crohn/patologia , Células Dendríticas/imunologia , Células Dendríticas/patologia , Regulação da Expressão Gênica , Humanos , Tolerância Imunológica , Interleucina-10/genética , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Lectinas Tipo C/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Antígenos de Histocompatibilidade Menor/genética , Receptores CXCR3/genética , Receptores de Superfície Celular/genética , Transdução de Sinais , Células Th1/patologia
11.
Mech Dev ; 72(1-2): 131-40, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9533964

RESUMO

Oogenesis in Drosophila is a useful model for studying cell differentiation. We have analyzed the role of the egh gene in these processes with the aid of a newly isolated viable but female sterile allele. This mutation results in diverse variable defects in oogenesis. The most frequent defect being follicles that have either more or less than the normal number of 16 germ cells. This is caused by erroneous splitting and/or fusion of correct clusters of 16 cystocytes. The entire follicle has a rather flexible structure in this allele, most obvious by a highly variable position of the oocyte within the follicle. Moreover, a second oocyte can also develop in egh clusters. This is exclusively observed in aberrant follicles that are generated by the aforementioned splitting/fusion process. Surprisingly, even a germ cell which is distinct from the two pro-oocytes can differentiate into an oocyte under these circumstances. Hence, determination of the oocyte is definitely not fixed when germ cell clusters are enveloped by prefollicular cells, and interactions between follicle cells and germ cells must play an important role in oocyte specification. Molecular analysis proves that the oocyte-specific transcript of the egh gene is drastically reduced in this viable allele.


Assuntos
Comunicação Celular , Proteínas de Drosophila , Indução Embrionária , Proteínas de Membrana/fisiologia , Oócitos/citologia , Folículo Ovariano/citologia , Animais , Diferenciação Celular , Drosophila melanogaster , Embrião não Mamífero/fisiologia , Feminino , Modelos Biológicos , Oogênese/genética , Fenótipo
12.
Folia Histochem Cytobiol ; 33(3): 197-200, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8612874

RESUMO

Oocytes of hymenopterans are equipped with specific organelles termed accessory nuclei (AN). These organelles are surrounded by a double envelope and contain RNA-positive inclusions. We have employed the spreading technique to analyse AN isolated from the ooplasm of the sawfly Athalia rosae. In electron microscopic spreading preparations AN appear as membranous, extensively folded structures. In their vicinity, numerous nuclear pore complexes have been found. This observation confirms the presence of pores in the envelopes of accessory nuclei.


Assuntos
Himenópteros/citologia , Membrana Nuclear/ultraestrutura , Oócitos/ultraestrutura , Animais , Núcleo Celular/ultraestrutura , Cromatina/ultraestrutura , Feminino , Microscopia Eletrônica , Microtomia , Oogênese/genética , Organelas/fisiologia , Ovário/citologia
13.
Folia Histochem Cytobiol ; 36(4): 189-95, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-10051973

RESUMO

Two entirely different types of ovaries (ovarioles) have been described in mecopterans. In the representatives of Meropeidae, Bittacidae, Panorpodidae and Panorpidae the ovarioles are of the polytrophic-meroistic type. Four regions: a terminal filament, germarium, vitellarium and ovariole stalk can be distinguished in the ovarioles. The germaria house numerous germ cell clusters. Each cluster arises as a result of 2 consecutive mitoses of a cystoblast and consists of 4 sibling cells. The oocyte always differentiates from one of the central cells of the cluster, whereas the remaining 3 cells develop into large, polyploid nurse cells. The vitellaria contain 7-12 growing egg chambers (= oocyte-nurse cell complexes). In contrast, the ovaries of the snow flea, Boreus hyemalis, are devoid of nurse cells and therefore panoistic (secondary panoistic). The ovarioles are composed of terminal filaments, vitellaria and ovariole stalks only; in adult females functional germaria are absent. Histochemical tests suggest that amplification of rDNA takes place in the oocyte nuclei. Resulting dense nucleolar masses undergo fragmentation into multiple polymorphic nucleoli. The classification of extant mecopterans as well as the phylogenetic relationships between Mecoptera and Siphonaptera are discussed in the context of presented data.


Assuntos
Insetos/anatomia & histologia , Animais , Feminino , Células Germinativas/ultraestrutura , Insetos/química , Insetos/ultraestrutura , Ovário/anatomia & histologia , Ovário/química , Ovário/ultraestrutura , Filogenia
14.
Tissue Cell ; 20(5): 783-95, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-18620245

RESUMO

Panoistic ovarioles are found in the order of fleas (Siphonaptera). Only in some species of the Hystrichopsylloidea do polytrophic meroistic ovaries occur. No stem cells and no dividing cystocytes are found in female imagines of Hystrichopsylla talpae. However, each germ cell cluster consists of 32 cells which are generated by five mitotic cycles during the pupal stage. One of the cells containing five intercellular bridges becomes the oocyte, the others serve as nurse cells. Thus, germ cell cluster formation follows the 2(n)-rule. However, no polyfusome is found and nurse cells do not form a rosette. Furthermore, nurse cells remain small and show the same ultrastructural characters as the oocytes, which became distinguishable from nurse cells only by their enhanced growth during pre-vitellogenesis. The first phase of pre-vitellogenesis is dominated by the production of an unknown cytoplasmatic component, consisting of spherical particles, clearly distinguishable from ribosomes by diameter and contrast. The next phase is characterized by a tremendous increase in the production of ribosomes. During this second phase another cytoplasmic component consisting of ball-like structures becomes prominent. During pre-vitellogenesis, germ cell nuclei undergo a pronounced structural change in which, finally, numerous extranucleolar particles predominate. Thus, H. talpae has a polytrophic meroistic ovary, but its oocyte genomes behave panoistically.

16.
Ann Anat ; 195(1): 88-97, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22959840

RESUMO

Cartilage development is a complex process that can be analyzed using numerous model systems. We have previously shown that in vitro differentiation of murine embryonic stem (ES) cells via embryoid bodies (EBs) recapitulates the cellular differentiation steps of chondrogenesis. However, differentiated chondrocytes lose their characteristic phenotype when they are kept in monolayer culture. This dedifferentiation process is one of the main obstacles of cartilage tissue engineering and could not be analyzed using the EB model system. The aim of this study was to further characterize the chondrogenic nodules derived by in vitro-differentiation of murine ES cells for the distribution of collagen types II, IX and XI in comparison to in vitro dedifferentiating primary chondrocytes from murine embryonic ribs. Expression of cartilage collagens and other extracellular matrix proteins was analyzed using immunostaining, cytochemical stainings and quantitative RT-PCR. We show that ES cell-derived chondrocyte differentiation starts with mesenchymal condensations synthesizing high amounts of fibronectin. Later, the matrix of the mature cartilage nodules consists of type II collagen, proteoglycans and the minor collagens type IX and XI. The nodules show a three-dimensional structure with multiple layers of collagen type II-positive cells. At late differentiation stages these chondrocytes were located at lateral regions of the nodules. Similar to the distribution pattern of collagen type II positive cells, the cells staining positive for collagen type IX and XI were present in the surface regions, but not in the central areas of the chondrogenic nodules. During cultivation of the primary murine rib chondrocytes expression of chondrogenic marker genes such as collagen type II and aggrecan declined and many chondrocytes lost characteristic cartilage matrix proteins and converted to an elongated, fibroblastoid shape with prominent actin stress fibers. Chondrogenic differentiation of murine ES cells combined with monolayer culture of embryonic rib chondrocytes is a valuable tool to study changes in the expression pattern during differentiation and dedifferentiation of chondrocytes.


Assuntos
Condrogênese/genética , Condrogênese/fisiologia , Colágeno Tipo IX/biossíntese , Colágeno Tipo XI/biossíntese , Células-Tronco Embrionárias/metabolismo , Células-Tronco Embrionárias/fisiologia , Azul Alciano , Animais , Diferenciação Celular , Linhagem Celular , Separação Celular , Condrócitos/fisiologia , Colágeno Tipo IX/genética , Colágeno Tipo XI/genética , Células-Tronco Embrionárias/ultraestrutura , Feminino , Imunofluorescência , Hibridização in Situ Fluorescente , Camundongos , Microscopia Eletrônica de Transmissão , Microscopia Imunoeletrônica , Faloidina/metabolismo , Gravidez , Reação em Cadeia da Polimerase em Tempo Real
17.
Aliment Pharmacol Ther ; 37(1): 129-36, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23121200

RESUMO

BACKGROUND: Steroid-refractory ulcerative colitis (UC) remains a challenging condition warranting surgery upon failure of pharmacological treatment. Calcineurin inhibitors or infliximab are alternatives in this situation. Data on the efficacy and safety of tacrolimus in this setting are limited. AIM: To study the short-term efficacy and safety of tacrolimus in moderate-to-severe steroid-refractory UC. The role of thiopurines in this situation and predictors of colectomy were evaluated. METHODS: In three centers, all charts from tacrolimus-treated patients with steroid-refractory UC were reviewed. Efficacy was assessed by colectomy-free survival and clinical remission at 3 months. RESULTS: We identified 130 patients with pancolitis in 75 (59%), left-sided disease in 35 (27%) and proctitis in 18 patients (14%) (disease localisation not obtainable in two patients). The median age was 40 (range: 18-81). Clinical activity according to the median Lichtiger score decreased from 13 (range: 4-17) at baseline to 3 (0-14) at week 12. Eighteen patients underwent colectomy within the first 3 months of treatment with tacrolimus (14%). Clinical remission was achieved in 94 patients (72%) in this period. Thiopurines given in parallel to tacrolimus tended to limit colectomy and significantly increased remission (P = 0.002) in the short-term. No other predictors of colectomy or remission were identified. Side effects were noticed in 53% of patients and no severe events occurred. CONCLUSION: This large survey confirms the efficacy and safety of tacrolimus in patients with steroid-refractory ulcerative colitis.


Assuntos
Colite Ulcerativa/tratamento farmacológico , Imunossupressores/administração & dosagem , Tacrolimo/administração & dosagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Colectomia , Feminino , Humanos , Imunossupressores/efeitos adversos , Masculino , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Indução de Remissão , Índice de Gravidade de Doença , Tacrolimo/efeitos adversos , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
18.
Aliment Pharmacol Ther ; 31(9): 1036-41, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20175769

RESUMO

BACKGROUND: The calcineurin inhibitor tacrolimus and the anti-TNF-antibody infliximab are established options in steroid-refractory ulcerative colitis (UC). AIM: To evaluate the efficacy of infliximab-salvage therapy in patients with refractory UC failing to respond to tacrolimus. METHODS: Twenty-four patients were enrolled in this evaluation. Reasons for tacrolimus therapy were steroid-refractory disease in 19 patients and steroid-dependency in five patients. All patients receiving infliximab had tacrolimus-refractory active disease (Lichtiger score >10) and were treated with 5 mg/kg at weeks 0, 2 and 6 and every 8 weeks thereafter, if tolerated. RESULTS: Six of 24 patients (25%) achieved remission following infliximab infusion and four of 24 (17%) had an initial response only, but underwent proctocolectomy later because of loss of response (3) or development of a delayed hypersensitivity reaction (1). Fourteen patients (58%) completely failed to respond with 10 undergoing colectomy. Eight patients experienced side effects under infliximab, including two infectious complications (herpes zoster and herpes pneumonia). CONCLUSIONS: Infliximab offers a therapeutic option as rescue therapy in about a quarter of patients with active UC after failing to respond to tacrolimus. This benefit has to be weighed against the risks of infectious complications.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Colite Ulcerativa/tratamento farmacológico , Fármacos Gastrointestinais/uso terapêutico , Adolescente , Adulto , Idoso , Resistência a Medicamentos , Feminino , Humanos , Infliximab , Masculino , Pessoa de Meia-Idade , Tacrolimo , Resultado do Tratamento , Adulto Jovem
19.
Aliment Pharmacol Ther ; 29(12): 1230-9, 2009 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-19302074

RESUMO

BACKGROUND: In severe steroid-refractory Crohn's disease (CD), established therapies fail in a relevant proportion of patients. Recent pilot studies indicated the efficacy of cyclophosphamide pulse therapy in these patients. AIM: To provide further and substantial evidence for the rationale to apply cyclophosphamide pulse therapy as therapeutic option in severe courses of CD. METHODS: Fifteen patients with steroid-refractory (n = 13) or steroid-dependent (n = 2) CD received 2-6 (median 3) monthly pulses of 750 mg cyclophosphamide in an open-label fashion. Eleven patients were on concomitant immunosuppression (azathioprine/mercaptopurine n = 9; methotrexate n = 2). RESULTS: Thirteen of 15 patients (87%) had a clinical response (CDAI decrease >100). Ten patients (67%) went into remission (CDAI <150) after 8 weeks. Steroid-free remission was achieved in eight patients (54%). Two patients (13%) failed to respond. Median CDAI decreased from 420 (245-550) to 100 (26-538) at week 8. Remission lasted 16 months (median, range 4-40). In three patients, arthritis, erythema nodosum and episcleritis completely resolved. Cyclophosphamide pulse therapy administration was well tolerated in all subjects. CONCLUSIONS: Cyclophosphamide pulse therapy is safe and highly effective for induction and maintenance of remission in steroid-refractory/-dependent CD. There is a strong need for additional experience to improve the setting of the encouraging cyclophosphamide treatment in CD.


Assuntos
Doença de Crohn/tratamento farmacológico , Ciclofosfamida/administração & dosagem , Imunossupressores/administração & dosagem , Adulto , Idoso , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Pulsoterapia , Indução de Remissão , Resultado do Tratamento , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA