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1.
J Interv Cardiol ; 2021: 8894223, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33531881

RESUMO

BACKGROUND: Physiotherapy prior to open-heart surgery lowers the rate of pneumonia and length of the hospital stay. Pneumonia is a major contributor to short-term mortality following transcatheter aortic valve replacement (TAVR). Hence, we hypothesized that pre- and intensified postprocedural physiotherapy in patients undergoing TAVR might impact the net functional and clinical outcome. METHODS AND RESULTS: The 4P-TAVR study was a prospective, monocentric, randomized trial. The study was designed to compare the efficacy and safety of intensified periprocedural physiotherapy including inspiratory muscle training versus standard postprocedural physiotherapy. Patients were randomized in a 1 : 1 fashion. 108 patients were included and followed up for 90 days after TAVR. While patients in group A (control group: 50 patients, age: 81.7 ± 5.0 years, 52% male) did not receive physiotherapy prior to TAVR, group B (intervention group: 58 patients, age: 82.2 ± 5.82 years, 47% male) participated in intensive physiotherapy. Compared to the control group, patients in the interventional group showed a lower incidence of postinterventional pneumonia (10 [20.0%] vs. 3 [5.1%], p=0.016) and had a 3-day shorter mean hospital stay (13.5 ± 6.1 days vs. 10.1 ± 4.7 days, p=0.02). The primary composite endpoint of mortality and rehospitalization was not different between the groups. CONCLUSION: Intensified physiotherapy is safe and has positive effects on clinical outcomes up to 90 days after TAVR but has no impact on the primary combined endpoint of mortality and rehospitalization. Longer follow-up, a multicenter design, and a higher number of subjects are needed to confirm these preliminary results. This trial is registered with DRKS00017239.


Assuntos
Estenose da Valva Aórtica , Modalidades de Fisioterapia , Pneumonia/prevenção & controle , Complicações Pós-Operatórias/prevenção & controle , Substituição da Valva Aórtica Transcateter , Idoso de 80 Anos ou mais , Estenose da Valva Aórtica/diagnóstico , Estenose da Valva Aórtica/fisiopatologia , Estenose da Valva Aórtica/cirurgia , Feminino , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Pneumonia/etiologia , Pneumonia/mortalidade , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/mortalidade , Estudos Prospectivos , Fatores de Risco , Substituição da Valva Aórtica Transcateter/métodos , Substituição da Valva Aórtica Transcateter/reabilitação , Resultado do Tratamento
2.
J Appl Microbiol ; 127(1): 29-46, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30955231

RESUMO

AIMS: To present antimicrobial susceptibilities for bacteria from dogs and cats with respiratory tract infection (RTI) across Europe in 2013-2014 and compare with data from 2008-2010. METHODS AND RESULTS: Minimal inhibitory concentrations were determined for 464 isolates following Clinical and Laboratory Standards Institute standards using antibiotics approved for RTI treatment. Where possible, susceptibility was calculated using predominantly human-derived breakpoints whilst some antibiotics had no breakpoints. The main pathogen from dogs was Staphylococcus pseudintermedius which was > 90% susceptible to fluoroquinolones and oxacillin (92·5%; six isolates confirmed mecA-positive) and 53·8, 80·0 and 88·8% susceptible to tetracycline, penicillin and trimethoprim/sulfamethoxazole. Streptococci, Escherichia coli, Bordetella bronchiseptica, Staphylococcus aureus and Pseudomonas aeruginosa were also present in dog RTI. Streptococci were fully susceptible to penicillin, ampicillin and pradofloxacin. None were enrofloxacin-resistant but 31·4% had intermediate susceptibility. The least active agent against streptococci was tetracycline (51·4% susceptible). For E. coli, 90·9% were amoxicillin/clavulanic acid-susceptible; susceptibility to other compounds ranged from 63·6 to 81·8%. There are no breakpoints for B. bronchiseptica and Ps. aeruginosa. For Staph. aureus, penicillin susceptibility was low (34·8%); for other compounds 87·0-100%. The main RTI pathogen from cats was Pasteurella multocida, where only pradofloxacin has breakpoints (100% susceptible). Susceptibility of coagulase-negative staphylococci ranged from 66·7% (penicillin) to 97·2% (pradofloxacin). Streptococci from cats were 100% susceptible to all antibiotics except enrofloxacin and tetracycline (both 65·2% susceptible). CONCLUSIONS: Overall, antimicrobial resistance was low to medium in RTI in dogs and cats, although susceptibility varied widely among pathogens studied. SIGNIFICANCE AND IMPACT OF THE STUDY: Responsible use of antibiotics is crucial to maintain susceptibility and continued resistance monitoring is important to support this goal. These findings support the need for the setting of RTI-specific breakpoints for pathogens of dogs and cats.


Assuntos
Antibacterianos/farmacologia , Doenças do Gato/microbiologia , Doenças do Cão/microbiologia , Testes de Sensibilidade Microbiana , Infecções Respiratórias/veterinária , Inquéritos e Questionários , Animais , Gatos , Cães , Farmacorresistência Bacteriana/efeitos dos fármacos , Europa (Continente)/epidemiologia , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/microbiologia
3.
J Appl Microbiol ; 121(5): 1254-1267, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27593360

RESUMO

AIMS: The ComPath project is a pan-European programme dedicated to the monitoring of antimicrobial susceptibility of pathogens from diseased dogs and cats using standardized methods and centralized minimum inhibitory concentration (MIC) determination. Here, the susceptibility of major pathogens is reported from antimicrobial nontreated animals with acute clinical signs of skin, wound or ear infections in 2008-2010. METHODS AND RESULTS: MICs were determined by agar dilution for commonly used antibiotics and interpreted using CLSI breakpoints, if available. Of the 1408 strains recovered, the main canine species was Staphylococcus pseudintermedius, followed by Pseudomonas and Streptococcus. In cats, Pasteurella multocida and Staph. pseudintermedius were most prevalent. For Staph. pseudintermedius, resistance was 18·4-25·2% for penicillin, clindamycin and chloramphenicol, but below 11% for ampicillin, amoxi/clav and fluoroquinolones. For Staphylococcus aureus, beta-lactam resistance was high (26·7-62·1%) but low (0·0-4·4%) for other antibiotics. 6·3% of Staph. pseudintermedius and 5·4% of Staph. aureus were confirmed mecA-positive. Gentamicin and fluoroquinolones exhibited moderate activity against Pseudomonas aeruginosa. For streptococci, resistance was absent/very low for penicillin, ampicillin, chloramphenicol and fluoroquinolones. For Escherichia coli, resistance was low to fluoroquinolones, chloramphenicol and gentamicin. No resistance was observed in Past. multocida. CONCLUSIONS: Overall, antimicrobial resistance was low in skin and soft tissue infections in dogs and cats. The results show the need for ongoing monitoring. SIGNIFICANCE AND IMPACT OF THE STUDY: The results are a reference baseline for future surveillance. The paucity of clinical breakpoints underlines the need to set breakpoints for relevant antibiotics.


Assuntos
Infecções Bacterianas/veterinária , Doenças do Gato/microbiologia , Doenças do Cão/microbiologia , Farmacorresistência Bacteriana , Dermatopatias Bacterianas/veterinária , Animais , Antibacterianos/farmacologia , Infecções Bacterianas/microbiologia , Gatos , Cães , Farmacorresistência Bacteriana/genética , Escherichia coli/efeitos dos fármacos , Europa (Continente) , Testes de Sensibilidade Microbiana , Pasteurella multocida/isolamento & purificação , Pseudomonas aeruginosa/efeitos dos fármacos , Dermatopatias Bacterianas/microbiologia , Staphylococcus/efeitos dos fármacos , Staphylococcus/isolamento & purificação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação
5.
Nature ; 435(7040): 313-6, 2005 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-15902250

RESUMO

The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >10(20) eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within approximately 50 Mpc through interactions with the cosmic microwave background. As there are no sufficiently powerful accelerators within this distance from the Galaxy, explanations for UHECRs range from unusual astrophysical sources to exotic string physics. Also unclear is whether UHECRs consist of protons, heavy nuclei, neutrinos or gamma-rays. To resolve these questions, larger detectors with higher duty cycles and which combine multiple detection techniques are needed. Radio emission from UHECRs, on the other hand, is unaffected by attenuation, has a high duty cycle, gives calorimetric measurements and provides high directional accuracy. Here we report the detection of radio flashes from cosmic-ray air showers using low-cost digital radio receivers. We show that the radiation can be understood in terms of the geosynchrotron effect. Our results show that it should be possible to determine the nature and composition of UHECRs with combined radio and particle detectors, and to detect the ultrahigh-energy neutrinos expected from flavour mixing.

6.
J Exp Med ; 180(4): 1383-93, 1994 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-7931072

RESUMO

Tonsillar germinal center and immunoglobulin M+ (IgM+)IgD+ B cells as well as peripheral blood (PB) CD5+ and CD5- (conventional) B cells from a 4-yr-old child were isolated and nucleotide sequences of expressed Ig heavy chain variable regions encoded by VH4 gene family members were determined from amplified cDNA. Whereas both tonsillar IgM+IgD+ cells and the majority of IgM-expressing CD5+ and CD5- PB B cells showed no or little somatic mutation, tonsillar germinal center (GC) B cells and IgG-expressing PB B cells carried a high load of somatic mutations in their V region genes. This suggests that somatically mutated memory B cells which have switched isotype accumulate in the PB already at young age. Their frequency seems to increase with age. On the other hand, the antibody repertoire of tonsillar IgM+IgD+ B cells and the majority of IgM-expressing PB B cells is determined by germline-encoded specificities and by generation of variability in the complementary determining region III through VH-DH-JH recombination. A fraction of IgM-bearing PB B cells carries somatically mutated V region genes and probably represents GC-derived B cells which have left the GC at an early stage of the GC reaction without undergoing isotype switching. 10 VH4 germline genes were found to be expressed. Three gene segments were overrepresented in the sequence collection (35 of 50 clones): VH4.21 (30%), V71-4 (20%), and 3D279D (20%). It appears that most potentially functional VH4 germline genes are expressed in peripheral B cells. Some members of this VH gene family are clearly overrepresented over others.


Assuntos
Subpopulações de Linfócitos B/imunologia , Genes de Imunoglobulinas , Região Variável de Imunoglobulina/genética , Memória Imunológica , Mutação , Sequência de Aminoácidos , Sequência de Bases , Pré-Escolar , Clonagem Molecular , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Isotipos de Imunoglobulinas/análise , Região de Junção de Imunoglobulinas/genética , Dados de Sequência Molecular
7.
J Exp Med ; 188(9): 1679-89, 1998 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-9802980

RESUMO

Immunoglobulin (Ig)M+IgD+ B cells are generally assumed to represent antigen-inexperienced, naive B cells expressing variable (V) region genes without somatic mutations. We report here that human IgM+IgD+ peripheral blood (PB) B cells expressing the CD27 cell surface antigen carry mutated V genes, in contrast to CD27-negative IgM+IgD+ B cells. IgM+IgD+CD27(+) B cells resemble class-switched and IgM-only memory cells in terms of cell phenotype, and comprise approximately 15% of PB B lymphocytes in healthy adults. Moreover, a very small population (<1% of PB B cells) of highly mutated IgD-only B cells was detected, which likely represent the PB counterpart of IgD-only tonsillar germinal center and plasma cells. Overall, the B cell pool in the PB of adults consists of approximately 40% mutated memory B cells and 60% unmutated, naive IgD+CD27(-) B cells (including CD5(+) B cells). In the somatically mutated B cells, VH region genes carry a two- to threefold higher load of somatic mutation than rearranged Vkappa genes. This might be due to an intrinsically lower mutation rate in kappa light chain genes compared with heavy chain genes and/or result from kappa light chain gene rearrangements in GC B cells. A common feature of the somatically mutated B cell subsets is the expression of the CD27 cell surface antigen which therefore may represent a general marker for memory B cells in humans.


Assuntos
Linfócitos B/imunologia , Imunoglobulina D/metabolismo , Imunoglobulina M/metabolismo , Região Variável de Imunoglobulina/genética , Mutação , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo , Adulto , Subpopulações de Linfócitos B/imunologia , Biomarcadores , Rearranjo Gênico de Cadeia Pesada de Linfócito B , Rearranjo Gênico de Cadeia Leve de Linfócito B , Genes de Imunoglobulinas , Humanos , Memória Imunológica
8.
J Exp Med ; 194(11): 1625-38, 2001 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-11733577

RESUMO

B cell-derived chronic lymphocytic leukemia (B-CLL) represents a common malignancy whose cell derivation and pathogenesis are unknown. Recent studies have shown that >50% of CLLs display hypermutated immunoglobulin variable region (IgV) sequences and a more favorable prognosis, suggesting that they may represent a distinct subset of CLLs which have transited through germinal centers (GCs), the physiologic site of IgV hypermutation. To further investigate the phenotype of CLLs, their cellular derivation and their relationship to normal B cells, we have analyzed their gene expression profiles using oligonucleotide-based DNA chip microarrays representative of approximately 12,000 genes. The results show that CLLs display a common and characteristic gene expression profile that is largely independent of their IgV genotype. Nevertheless, a restricted number of genes (<30) have been identified whose differential expression can distinguish IgV mutated versus unmutated cases and identify them in independent panels of cases. Comparison of CLL profiles with those of purified normal B cell subpopulations indicates that the common CLL profile is more related to memory B cells than to those derived from naive B cells, CD5(+) B cells, and GC centroblasts and centrocytes. Finally, this analysis has identified a subset of genes specifically expressed by CLL cells of potential pathogenetic and clinical relevance.


Assuntos
Linfócitos B/imunologia , Expressão Gênica , Memória Imunológica/imunologia , Leucemia Linfocítica Crônica de Células B/genética , Perfilação da Expressão Gênica , Humanos , Região Variável de Imunoglobulina/genética , Imunofenotipagem , Mutação
9.
Amino Acids ; 38(3): 753-61, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19333719

RESUMO

Influx of [(3)H]-L-proline into renal OK cells revealed that basal transport was mediated by the transporter SIT1. When cells were submitted for 8 h to amino acid deprivation, uptake of L-proline was now dominated by a low-affinity system with an apparent K (m) of 4.4 +/- 0.6 mM and a V (max) of 10.2 +/- 0.6 nmol/mg of protein/min operating in addition to the high-affinity SIT1 system with a K (m) of 0.12 +/- 0.01 mM and a V (max) of 0.28 +/- 0.04 nmol/mg of protein/min. The low- and high-affinity proline transporting systems were sensitive to inhibitors of JNK and PI-3 kinases, whereas a GSK-3 inhibitor affected only the upregulated transport system. Ion-replacement studies and experiments assessing substrate specificities for both systems provided strong evidence that SNAT2, that showed two- to threefold increased mRNA levels, is the responsible transporter mediating the increased proline influx under conditions of amino acid deprivation.


Assuntos
Sistemas de Transporte de Aminoácidos Neutros/classificação , Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Aminoácidos/deficiência , Células Epiteliais/metabolismo , Rim/metabolismo , Prolina/metabolismo , Sistema A de Transporte de Aminoácidos/genética , Sistema A de Transporte de Aminoácidos/metabolismo , Sistemas de Transporte de Aminoácidos Neutros/antagonistas & inibidores , Sistemas de Transporte de Aminoácidos Neutros/genética , Aminoácidos/metabolismo , Animais , Linhagem Celular , Permeabilidade da Membrana Celular/efeitos dos fármacos , Permeabilidade da Membrana Celular/genética , Células Epiteliais/efeitos dos fármacos , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Íons/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Rim/efeitos dos fármacos , Cinética , Gambás , Inibidores de Fosfoinositídeo-3 Quinase , Biossíntese de Proteínas/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , RNA Mensageiro/metabolismo , Especificidade por Substrato , Regulação para Cima/efeitos dos fármacos
10.
J Cell Biol ; 111(6 Pt 1): 2275-82, 1990 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2126012

RESUMO

The proteasome (MCP) is a high relative molecular mass multicatalytic proteinase complex composed of nonidentical protein subunits. We have investigated the cellular distribution of the enzyme complex during Drosophila embryogenesis using the proteasome specific antibodies N19-35 and N19-28 for immunocytology. Antibody staining of whole-mount embryos shows that during embryogenesis proteasomes are present in proliferating cells and that their accumulation and turnover is differentially regulated. Our data suggest that the proteasome may serve different proteolytic processes and that the enzyme may be involved in cell-specific proteolytic events required for cell proliferation and morphogenesis during early Drosophila development.


Assuntos
Cisteína Endopeptidases/metabolismo , Drosophila melanogaster/embriologia , Complexos Multienzimáticos/metabolismo , Animais , Cisteína Endopeptidases/biossíntese , Drosophila melanogaster/enzimologia , Embrião não Mamífero/enzimologia , Embrião não Mamífero/fisiologia , Imuno-Histoquímica , Complexos Multienzimáticos/biossíntese , Complexo de Endopeptidases do Proteassoma
11.
Poult Sci ; 88(11): 2353-9, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19834086

RESUMO

Tiamulin hydrogen fumarate is a semisynthetic derivative of the diterpene antibiotic pleuromutilin used in poultry medicine to treat mainly Mycoplasma- and Brachyspira-related diseases. Its use over 30 yr has not generally increased the development of resistance to these pathogens but occasionally resistant isolates are encountered. Tiamulin administered at therapeutic levels is relatively quickly absorbed, metabolized in the liver, and eliminated from the body of the bird after a withdrawal period of 72 h, and as a result, meat products can be safely consumed. A zero withdrawal period for eggs has been granted in several European Union states. When administered with different drugs, tiamulin has been shown to have an enhanced activity with the tetracyclines. There is a strong interaction, even death, with the ionophore anticoccidials monensin, narasin, and salinomycin when tiamulin is used at therapeutic levels, but this is dose-related and low doses do not interact. It is thought to be caused by the preferential metabolism of tiamulin in the liver resulting in a build up of the ionophore leading to clinical signs of overdosage. Tiamulin shows a milder interaction, such as temporary growth depression, with maduramicin and semduramicin but is compatible with lasalocid. Although tiamulin shows small benefits in improving performance in healthy animals, its main production benefit is in the face of infection, as a true therapeutic antibiotic.


Assuntos
Antibacterianos/uso terapêutico , Infecções Bacterianas/veterinária , Doenças das Aves Domésticas/tratamento farmacológico , Animais , Infecções Bacterianas/tratamento farmacológico , Diterpenos/química , Diterpenos/uso terapêutico , Aves Domésticas
12.
Nervenarzt ; 80(7): 833-6, 2009 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-19543699

RESUMO

The term cyberstalking appears in the media with increasing frequency. So far epidemiological studies are sparse. Since researchers have used different definitions and study samples for cyberstalking, widely varying prevalence rates have been published. We report here a case of cyberstalking and discuss available empirical data. Cyberstalking may cause psychological distress similar to that of real world stalking. The need for a scientific definition of cyberstalking and for future studies is presented. Since it is likely that psychiatrists will encounter victims of cyberstalking they should have knowledge of this phenomenon.


Assuntos
Medo/psicologia , Internet , Comportamento Social , Perseguição/prevenção & controle , Perseguição/psicologia , Estresse Psicológico/prevenção & controle , Estresse Psicológico/psicologia , Adulto , Feminino , Humanos , Masculino , Perseguição/diagnóstico , Estresse Psicológico/diagnóstico , Adulto Jovem
13.
Poult Sci ; 87(12): 2528-34, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19038809

RESUMO

In an earlier study, the continuous medication of broiler feed with a combination of tiamulin (TIA; 20 mg/kg), chlortetracycline (CTC; 60 mg/kg), and the ionophore anticoccidial salinomycin (SAL; 60 mg/kg) caused an initial increase in BW and feed efficiency (FE; g of weight gain/kg of feed intake). However, as doses increased to combinations of 30 mg/kg of TIA and 90 mg/kg of CTC or 50 mg/kg of TIA and 150 mg/kg of CTC, there was a dose-related reduction in growth rate and FE. This was thought to be due to the interaction between TIA and SAL. In this study, using a protocol similar to the previous trial, broiler chicks were administered SAL at 60 mg/kg via the feed and the same inclusion rates of TIA + CTC. However, instead of feeding the birds continuously, considering the cost of TIA and possibly to compensate for the depressed growth attributable to the interaction with SAL, they were pulse-dosed for 1 to 10 d and again at 21 to 27 d, and the whole trial lasted 35 d to see if the intermittent pulses might reduce production losses. A total of 200 straight-run 1-d-old broiler chicks (Hubbard classic) were randomly distributed into 4 groups, with each group consisting of 5 cages containing 10 birds. The 20 cages were allocated to the 4 treatment groups on a random basis. The control diet, containing only SAL at 60 mg/kg, was fed to all birds throughout the 35-d trial, including the period during the gaps between dosing (i.e., d 11 to 20 and d 28 to 35). Feed and water were available for the whole trial period. Several serum enzymes (creatine kinase, lactate dehydrogenase, and aspartate aminotransferase) were determined from blood samples taken on d 35. Blood samples were also collected at 1, 19, and 35 d of age and were examined for antibody titers to Mycoplasma gallisepticum and Mycoplasma synoviae. Necropsy and histopathology of the birds (n = >or=4) were conducted during weekly intervals. There was no significant difference in weight gain, feed intake, and FE when the groups treated with TIA + CTC were compared with the control group (P > 0.05). There was no relationship between mortality and inclusion rates of the medication. No clinical signs of an interaction were exhibited during the trial, which was supported by necropsy and serum enzyme results. Maternally derived antibodies against M. gallisepticum were identified at the start of the trial but disappeared within 19 d, and infection with M. gallisepticum or M. synoviae was found neither serologically nor clinically during the trial. The results demonstrated that intermittent pulse administration of TIA at 50 mg/kg + CTC at 150 mg/kg from d 1 to 10 and d 21 to 27, along with continuous feeding of SAL (60 mg/kg), would be possible without altering performance and while maintaining the health status of the broilers. However, further research is required on the presence of artificial infections with Mycoplasma pathogens to determine the efficacy of the combination of TIA +CTC.


Assuntos
Antibacterianos/administração & dosagem , Clortetraciclina/administração & dosagem , Piranos/administração & dosagem , Ração Animal/análise , Animais , Antibacterianos/química , Antibacterianos/uso terapêutico , Galinhas , Clortetraciclina/química , Clortetraciclina/uso terapêutico , Diterpenos/administração & dosagem , Diterpenos/química , Diterpenos/economia , Diterpenos/uso terapêutico , Relação Dose-Resposta a Droga , Esquema de Medicação , Interações Medicamentosas , Feminino , Masculino , Piranos/química , Piranos/uso terapêutico , Aumento de Peso/efeitos dos fármacos
14.
Curr Biol ; 10(19): 1221-4, 2000 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-11050393

RESUMO

Polymerase zeta (Pol zeta) is an error-prone DNA polymerase [1], which in yeast is involved in trans-lesion synthesis (TLS) and is responsible for most of the ultraviolet (UV) radiation-induced and spontaneous mutagenesis [2-4]. Pol zeta consists of three subunits: REV1, a deoxycytidyl-transferase [5]; REV7, of unclear function [6]; and REV3, the catalytic subunit. REV3 alone is sufficient to carry out TLS, but association with REV1 and REV7 enhances its activity [5, 7]. Experiments using human cells treated with UV radiation indicate also that mammalian Pol zeta is involved in TLS [7]. The peculiar mutagenic activity of Pol zeta [4,7,8] suggests a possible role in somatic hypermutation of immunoglobulin (Ig) genes [9]. Here, we report that, unlike in yeast where the REV3 gene is not essential for life [4], disruption of the mouse homologue (Rev3l) resulted in early embryonic lethality. In Rev3l(-/-) embryos, no haematopoietic cells other than erythrocytes could be identified in the yolk sac. Rev3l(-/-) haematopoietic precursors were unable to expand in vitro and no haematopoietic cells could be derived from the intraembryonic haematogenic compartment (splanchnopleura). Fibroblasts could not be derived from the Rev3l(-/-) embryos, and Rev3l(-/-) embryonic stem (ES) cells could not be obtained. This is the first evidence that an enzyme involved in TLS is critical for mammalian development.


Assuntos
DNA Polimerase Dirigida por DNA/genética , Proteínas Fúngicas/genética , Genes Letais , Proteínas de Saccharomyces cerevisiae , Animais , Domínio Catalítico , DNA Polimerase Dirigida por DNA/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
15.
J Clin Invest ; 100(7): 1667-76, 1997 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-9312164

RESUMO

B cells expressing the CD5 cell surface antigen are involved in certain B cell malignancies and autoimmune diseases. From studies in the mouse, it emerged that CD5+ B cells represent a separate lineage of B lymphocytes that, in contrast to conventional (CD5-) B cells, are not driven into T cell-dependent immune responses in which rearranged variable (V) region genes are diversified by somatic hypermutation. Against this background it came as a surprise that human disease-involved CD5-positive autoreactive B cells as well as B cell chronic lymphocytic leukemias can harbor somatically mutated V region genes. Recent V gene analyses on CD5+ B cells in healthy adults did not give rise to a clear picture about the fraction of somatically mutated among all CD5+ B cells. In this work we used a molecular single-cell analysis to determine reliably the frequency of mutated CD5+ B cells in healthy humans: single, kappa light chain-expressing CD5+ peripheral blood B cells were isolated by flow cytometry, and rearranged Vkappa genes were amplified by PCR. From one donor, CD5+CD19+ B cells were analyzed. Since CD5+ B cells were found among IgM+IgD+ and IgM+IgD- cells (but almost not among class-switched cells) from two other donors, individual cells corresponding to these IgM-expressing subsets were investigated separately. The sequence analysis of rearranged Vkappa genes revealed that most if not all CD5+ B cells in healthy humans carry unmutated V region genes. From one of the donors, a novel polymorphic Jkappa2 gene segment was identified. To explain the discrepancy between the frequent occurrence of disease-associated somatically mutated CD5+ B cells and the low incidence or absence of somatic mutation in normal CD5+ B cells, we speculate that CD5+ B cells usually do not participate in germinal center reactions, but if they occasionally do so, they may be at an increased risk to become involved in autoimmune diseases or B cell malignancies.


Assuntos
Subpopulações de Linfócitos B/imunologia , Antígenos CD5 , Rearranjo Gênico de Cadeia Leve de Linfócito B , Região Variável de Imunoglobulina/genética , Adulto , Antígenos CD19 , Subpopulações de Linfócitos B/citologia , Citometria de Fluxo , Humanos , Imunoglobulina D/genética , Imunoglobulina M/genética , Leucemia Linfocítica Crônica de Células B/etiologia , Leucemia Prolinfocítica/etiologia , Masculino , Mutação , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
16.
Bone Marrow Transplant ; 40(11): 1033-7, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17891186

RESUMO

Lack of CD56 expression was reported to be associated with a poor prognosis in multiple myeloma (MM) patients treated with conventional chemotherapy. Aim of our retrospective study was to analyse whether CD56 expression on MM cells reveals as a prognostic factor in patients treated with high-dose chemotherapy. MM cells of 99 patients prior to treatment with high-dose chemotherapy were analysed for CD56 expression by flow cytometry. Multivariable analysis of event-free survival in these patients showed no statistically significant difference between the CD56(-) (n=28) and the CD56(+) (n=71) group. The lack of CD56 expression on MM cells of these patients correlated significantly with the presence of translocation (11;14) (t(11;14)) (estimated correlation coefficient=0.655 95%, confidence interval (0.481; 0.779)). In summary, our results indicate that lack of CD56 expression on MM cells is not a prognostic marker in patients treated with high-dose chemotherapy, but is associated with t(11;14).


Assuntos
Antígeno CD56/metabolismo , Melfalan/administração & dosagem , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Agonistas Mieloablativos/administração & dosagem , Adulto , Idoso , Biomarcadores , Antígeno CD56/genética , Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 17/genética , Intervalo Livre de Doença , Relação Dose-Resposta a Droga , Feminino , Transplante de Células-Tronco Hematopoéticas , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/patologia , Estudos Retrospectivos , Translocação Genética/genética , Transplante Autólogo
17.
Mol Cell Biol ; 18(12): 7235-42, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9819410

RESUMO

DNA supercoiling in the chloroplast of the unicellular green alga Chlamydomonas reinhardtii was found to change with a diurnal rhythm in cells growing in alternating 12-h dark-12-h light periods. Highest and lowest DNA superhelicities occurred at the beginning and towards the end of the 12-h light periods, respectively. The fluctuations in DNA supercoiling occurred concurrently and in the same direction in two separate parts of the chloroplast genome, one containing the genes psaB, rbcL, and atpA and the other containing the atpB gene. Fluctuations were not confined to transcribed DNA regions, indicating simultaneous changes in DNA conformation all over the chloroplast genome. Because the diurnal fluctuations persisted in cells kept in continuous light, DNA supercoiling is judged to be under endogenous control. The endogenous fluctuations in chloroplast DNA topology correlated tightly with the endogenous fluctuations of overall chloroplast gene transcription and with those of the pool sizes of most chloroplast transcripts analyzed. This result suggests that DNA superhelical changes have a role in the regulation of chloroplast gene expression in Chlamydomonas.


Assuntos
Chlamydomonas reinhardtii/genética , Cloroplastos/genética , DNA Super-Helicoidal/química , Conformação de Ácido Nucleico , Animais , Ritmo Circadiano/fisiologia , Reagentes de Ligações Cruzadas/metabolismo , Regulação da Expressão Gênica/genética , Genes de Protozoários/genética , Genes Reporter/genética , Luz , RNA Mensageiro/genética , Transcrição Gênica/genética
19.
Rofo ; 179(10): 1009-15, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17879173

RESUMO

PURPOSE: Mesenchymal stem cells (MSC) seem to be a promising cell source for cellular cardiomyoplasty. We recently developed a new aptamer-based specific selection of MSC to provide "ready to transplant" cells directly after isolation. We evaluated MRI tracking of newly isolated and freshly transplanted MSC in the heart using one short ex vivo selection step combining specific aptamer-based isolation and labeling of the cells. MATERIALS AND METHODS: Bone marrow (BM) was collected from healthy pigs. The animals were euthanized and the heart was placed in a perfusion model. During cold ischemia, immunomagnetic isolation of MSC from the BM by MSC-specific aptamers labeled with Dynabeads was performed within 2 h. For histological identification the cells were additionally stained with PKH26. Approx. 3 x 10(6) of the freshly aptamer-isolated cells were injected into the ramus interventricularis anterior (RIVA) and 5 x 10(5) cells were injected directly into myocardial tissue after damaging the respective area by freezing (cryo-scar). 3 x 10(6) of the aptamer-isolated cells were kept for further characterization (FACS and differentiation assays). 20 h after cell transplantation, MRI of the heart using a clinical 3.0 Tesla whole body scanner (Magnetom Trio, Siemens, Germany) was performed followed by histological examinations. RESULTS: The average yield of sorted cells from 120 ml BM was 7 x 10(6) cells. The cells were cultured and showed MSC-like properties. MRI showed reproducible artifacts within the RIVA-perfusion area and the cryo-scar with surprisingly excellent quality. The histological examination of the biopsies showed PKH26-positive cells within the areas which were positive in the MRI in contrast to the control biopsies. CONCLUSION: Immunomagnetic separation of MSC by specific aptamers linked to magnetic particles is feasible, effective and combines a specific separation and labeling technique to a "one stop shop" strategy.


Assuntos
Aptâmeros de Nucleotídeos , Cardiomioplastia , Imageamento por Ressonância Magnética , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Animais , Células da Medula Óssea , Cardiomioplastia/métodos , Separação Celular , Estudos de Viabilidade , Corantes Fluorescentes , Separação Imunomagnética , Células-Tronco Mesenquimais/citologia , Isquemia Miocárdica , Compostos Orgânicos , Coloração e Rotulagem , Suínos , Fatores de Tempo
20.
Psychoneuroendocrinology ; 86: 134-143, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28957772

RESUMO

To study pathogenic stress-effects in health and disease, it is paramount to define easy access parameters for non-invasive analysis of biological change in response to stress. Hair samples successfully provide this access for the study of hypothalamus-pituitary-adrenal axis (HPA) changes. In this study, we assess the hair expression and corresponding epigenetic changes of a neurotrophin essential for autonomic nervous system function and mental health: brain derived neurotrophic factor (BDNF). In three independent studies in healthy academic volunteers (study I: German students, N=36; study II, German academic population sample, N=28; study III: Mexican students, N=115), BDNF protein expression or BDNF gene (BDNF) histone acetylation was determined. Simultaneously, mental distress and distress-associated somatic complaints were assessed by self-report. In study I, we found a negative correlation between hair-BDNF protein level and hair-cortisol as well as between hair-BDNF and somatic complaints, while hair-cortisol correlated positively with mental distress. In study II, we found a negative correlation between H4 histone acetylation at the BDNF gene P4-promoter and somatic complaints. Regression analysis confirmed confounder stability of associations in both studies. In study III, we confirmed study I and found lower hair-BDNF protein level in volunteers with high somatic complaints, who also reported higher mental distress during the end of term exams. The results indicate that BDNF protein levels can be detected in clipped hair and are associated with somatic complaints and stress in life. In addition, we concluded that plucked hair can provide material for the study of epigenetic changes in stress-affected tissues. These tools can prove valuable for future studies on distress, both under experimental and field conditions.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/análise , Estresse Fisiológico/fisiologia , Acetilação , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Epigênese Genética , Feminino , Cabelo/química , Cabelo/metabolismo , Hipocampo/metabolismo , Histonas/metabolismo , Humanos , Hidrocortisona/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Masculino , Dor Nociceptiva , Projetos Piloto , Sistema Hipófise-Suprarrenal/metabolismo , Regiões Promotoras Genéticas/genética
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