Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 53
Filtrar
1.
Nano Lett ; 19(10): 6876-6885, 2019 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-31510752

RESUMO

We report and study the translation of exceptionally high catalytic oxygen electroreduction activities of molybdenum-doped octahedrally shaped PtNi(Mo) nanoparticles from conventional thin-film rotating disk electrode screenings (3.43 ± 0.35 A mgPt-1 at 0.9 VRHE) to membrane electrode assembly (MEA)-based single fuel cell tests with sustained Pt mass activities of 0.45 A mgPt-1 at 0.9 Vcell, one of the highest ever reported performances for advanced shaped Pt alloys in real devices. Scanning transmission electron microscopy with energy dispersive X-ray analysis (STEM-EDX) reveals that Mo preferentially occupies the Pt-rich edges and vertices of the element-anisotropic octahedral PtNi particles. Furthermore, by combining in situ wide-angle X-ray spectroscopy, X-ray fluorescence, and STEM-EDX elemental mapping with electrochemical measurements, we finally succeeded to realize high Ni retention in activated PtNiMo nanoparticles even after prolonged potential-cycling stability tests. Stability losses at the anodic potential limits were mainly attributed to the loss of the octahedral particle shape. Extending the anodic potential limits of the tests to the Pt oxidation region induced detectable Ni losses and structural changes. Our study shows on an atomic level how Mo adatoms on the surface impact the Ni surface composition, which, in turn, gives rise to the exceptionally high experimental catalytic ORR reactivity and calls for strategies on how to preserve this particular surface composition to arrive at performance stabilities comparable with state-of-the-art spherical dealloyed Pt core-shell catalysts.

2.
Int Endod J ; 51(2): 247-255, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28665514

RESUMO

AIM: To present a novel miniaturized and minimally invasive treatment approach for root canal localization in mandibular incisors with pulp canal calcification and apical periodontitis. SUMMARY: A 51-year-old male patient presented with pain from his mandibular incisors. The patient had a history of severe dental trauma over 30 years ago. Both mandibular central incisors (teeth 31, 41) were tender to percussion and had a yellowish discoloration. They did not respond to thermal and electrical sensitivity tests. Two periapical radiographs from different projections revealed severe pulp canal calcifications and signs of periapical periodontitis. To facilitate the 'Microguided Endodontics' technique, a CBCT and an intra-oral surface scan were aligned using special software. This allowed the virtual planning of optimal access cavities up to the apical third of the root. In this technique, a 3D-printed template guides a customized drill to the orifice of the root canal. After negotiation of the root canals, conventional root canal treatment was performed. This case report demonstrates that minimally invasive and apically extended access cavities are feasible in mandibular incisors with this technique. KEY LEARNING POINTS: The 'Microguided Endodontics' technique is a safe and minimally invasive method for root canal location and prevention of technical failures in anterior teeth with pulp canal calcification.


Assuntos
Preparo da Cavidade Dentária/métodos , Calcificações da Polpa Dentária/terapia , Cavidade Pulpar/anatomia & histologia , Incisivo , Periodontite Periapical/terapia , Humanos , Masculino , Mandíbula , Pessoa de Meia-Idade , Terapia Assistida por Computador
3.
J Intern Med ; 282(3): 241-253, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28682471

RESUMO

BACKGROUND: Inhibitory antibodies towards enzyme replacement therapy (ERT) are associated with disease progression and poor outcome in affected male patients with lysosomal disorders such as Fabry disease (FD). However, little is known about the impact of immunosuppressive therapy on ERT inhibition in these patients with FD. METHODS: In this retrospective study, we investigated the effect of long-term immunosuppression on ERT inhibition in male patients with FD (n = 26) receiving immunosuppressive therapy due to kidney (n = 24) or heart (n = 2) transplantation. RESULTS: No ERT-naïve transplanted patient (n = 8) developed antibodies within follow-up (80 ±72 months) after ERT initiation. Seven (26.9%) patients were tested ERT inhibition positive prior to transplantation. No de novo ERT inhibition was observed after transplantation (n = 18). In patients treated with high dosages of immunosuppressive medication such as prednisolone, tacrolimus and mycophenolate-mofetil/mycophenolate acid, ERT inhibition decreased after transplantation (n = 12; P = 0.0160). Tapering of immunosuppression (especially prednisolone) seemed to re-increase ERT inhibition (n = 4, median [range]: 16.6 [6.9; 36.9] %; P = 0.0972) over time. One ERT inhibition-positive patient required interventions with steroid therapy and increased doses of tacrolimus, which also lowered ERT inhibition. CONCLUSION: We conclude that the immunosuppressive maintenance therapy after transplantations seems to be sufficient to prevent de novo ERT inhibition in ERT-naïve patients. Intensified high dosages of immunosuppressive drugs are associated with decreased antibody titres and decreased ERT inhibition in affected patients, but did not result in long-term protection. Future studies are needed to establish ERT inhibition-specific immunosuppressive protocols with long-term modulating properties to warrant an improved disease course in ERT inhibition-positive males.


Assuntos
Anticorpos Neutralizantes/efeitos dos fármacos , Terapia de Reposição de Enzimas , Doença de Fabry/tratamento farmacológico , Doença de Fabry/imunologia , Transplante de Coração , Imunossupressores/efeitos adversos , Transplante de Rim , Adolescente , Adulto , Anticorpos Neutralizantes/sangue , Humanos , Imunossupressores/uso terapêutico , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
4.
Clin Oral Implants Res ; 28(9): 1147-1151, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27460679

RESUMO

OBJECTIVES: To compare the deviation of different systems for Guided Implant Surgery (GIS) related to the specific tolerance between drills and sleeves. MATERIAL AND METHODS: Four different systems for GIS and their appropriate sleeves were used: Camlog Guide (CG), Straumann Guided Surgery (SG), SIC Guide (SIG), and NobelGuide (NG). System-appropriate metal sleeves were inserted into plexiglass boxes, and guided drilling procedure was performed (i) holding the drills in the most centric position of the sleeves and (ii) applying forces eccentrically. Digital microscope images of the plexiglass boxes were taken and axial deviations were calculated based on the Pythagorean Theorem, whereas coronal and apical deviations were measured with a corresponding software-device and calculated by subtracting the measured deviations from the original diameter of the drills. Statistically significant differences between centric and eccentric drilling were determined applying the t-test for independent data. RESULTS: The axial deviation ranged from 0° (SG) to 5.64° (CG). The apical deviations varied between 0.01 mm (SIG) and 3.2 mm (NG) and the coronal deviations ranged from 0.01 mm (SIG) to 1.60 mm (NG). In terms of angular deviation, there were statistically significant differences between centric and eccentric drilling for all four systems. Coronal and apical deviations, showed no statistical significance between centric and eccentric drilling for SIG and NG, in contrast to CG and SG. CONCLUSIONS: The clinician may have considerable impact on the accuracy of GIS when applying eccentric forces.


Assuntos
Implantação Dentária/instrumentação , Implantação Dentária/métodos , Instrumentos Odontológicos , Cirurgia Assistida por Computador/métodos , Desenho de Equipamento , Humanos
5.
J Dairy Sci ; 100(6): 5082-5096, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28434723

RESUMO

Pasture-raised milk is gaining in importance in some European countries and in the United States. The production of pasture-raised milk is linked to higher costs, as the milk is normally collected and processed separately from conventional barn milk. This could hinder the production of sustainable milk products. We discuss alternative labeling strategies that allow the mixing of pasture-raised (sustainable) and conventional milk to reduce costs and break free from the current niche market. The lower price would allow for more pasture-raised milk to be produced and enter the mainstream market. The aim of this study was to analyze consumers' willingness to pay for alternative labeling types using a discrete choice experiment with 1,065 German milk buyers. The 2 alternative labels, besides the classical labeling approach, are based on the mass balance approach (at least 50% pasture-raised milk in a package) and cause-related marketing (support of farmers who keep their cows on pasture). The discrete choice experiment was combined with a cluster analysis to get a deeper understanding of the buying behavior of the diverse consumer segments for milk. We found that all consumer groups prefer the classical label where products are segregated but also understand the benefits of cause-related marketing. The average consumer was willing to pay €0.50 more for pasture-raised milk certified with the classical label and €0.38 more for pasture-raised milk labeled with a cause-related marketing claim. However, differences between the clusters are strong: The smallest cluster of ethically involved consumers (15%) is willing to pay the highest premiums, especially for the classical label. Cause-related marketing is an interesting alternative for involved buyers under price pressure (41%), whereas the mass balance approach is little understood and thus less valued by consumers. From our results we concluded that cause-related marketing (in our case, the support of pasturing of dairy cows) can be useful for dairies for which it is not efficient to collect and process products separately. This approach is furthermore suitable for reaching consumers who are mainly interested in altruistic issues but at the same time are more price sensitive, as this labeling strategy does not need separate collection and processing and can thereby be marketed at a lower price.


Assuntos
Comércio , Rotulagem de Alimentos/métodos , Marketing , Leite/economia , Poaceae , Animais , Bovinos , Custos e Análise de Custo , Europa (Continente) , Feminino , Leite/classificação , Crescimento Sustentável
6.
Clin Oral Implants Res ; 27(1): 126-9, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25682786

RESUMO

OBJECTIVES: Sinus floor augmentation using transalveolar techniques is a successful and predictable procedure. The aim of the study was to compare the performance of conventional hand instruments using mallets and osteotomes with that of piezoelectric-hydrodynamic devices for maxillary sinus floor elevation. MATERIAL AND METHODS: In 17 undamaged cadaver heads on randomly allocated sites, Schneiderian membrane elevation was carried out transcrestally using piezosurgery and a hydrodynamic device or by conventional hand instrumentation. After simulation of sinus augmentation by the use of a radiopaque impression material, a post-operative CT scan was carried out and volumes were determined. Statistic significant differences between the two methods were evaluated by nonparametric Mann-Whitney U-test with P < 0.05. RESULTS: A mean graft volume of 0.29 ± 0.18 cm(3) (0.07-0.60 cm(3)) was measured for the Summers' technique compared to 0.39 ± 0.32 cm(3) (0.05-1.04 cm(3)) for the Sinus Physiolift(®) technique. There is no statistically significant difference with regard to trauma to the Schneiderian membrane or augmented volume. CONCLUSIONS: Both techniques generate expedient augmentation volume in the posterior atrophic maxilla. The piezoelectric technique can be recommended as an alternative tool to graft the floor of human maxillary sinuses.


Assuntos
Osteotomia/instrumentação , Piezocirurgia/métodos , Levantamento do Assoalho do Seio Maxilar/métodos , Cadáver , Humanos , Mucosa Nasal/lesões , Tomografia Computadorizada por Raios X
7.
Int Endod J ; 49(10): 966-72, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26353942

RESUMO

AIM: To present a novel method utilizing 3D printed templates to gain guided access to root canals and to evaluate its accuracy in vitro. METHODOLOGY: Sixty extracted human teeth were placed into six maxillary jaw models. Preoperative CBCT scans were matched with intra-oral scans using the coDiagnostix(™) software. Access cavities, sleeves and templates for guidance were virtually planned. Templates were produced by a 3D printer. After access cavity preparation by two operators, a postoperative CBCT scan was superimposed on the virtual planning. Accuracy was measured by calculating the deviation of planned and prepared cavities in three dimensions and angle. Ninety-five per cent confidence intervals were calculated for both operators. RESULTS: All root canals were accessible after cavity preparation with 'Guided Endodontics'. Deviations of planned and prepared access cavities were low with means ranging from 0.16 to 0.21 mm for different aspects at the base of the bur and 0.17-0.47 mm at the tip of the bur. Mean of angle deviation was 1.81°. Overlapping 95% confidence intervals revealed no significant difference between operators. CONCLUSION: 'Guided Endodontics' allowed an accurate access cavity preparation up to the apical third of the root utilizing printed templates for guidance. All root canals were accessible after preparation.


Assuntos
Preparo da Cavidade Dentária/métodos , Cavidade Pulpar/diagnóstico por imagem , Periodontite Periapical/cirurgia , Preparo de Canal Radicular/métodos , Tomografia Computadorizada de Feixe Cônico , Endodontia/métodos , Humanos , Modelos Dentários , Periodontite Periapical/diagnóstico por imagem , Impressão Tridimensional
8.
Clin Oral Implants Res ; 25(2): 221-5, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23294470

RESUMO

OBJECTIVES: The aim of the study was to investigate whether bone marrow aspirates (BMA) and concentrates (BMAC) influence the grafts' stability when added to deproteinized bovine bone mineral (DBBM) within the first 6 months after maxillary sinus augmentation. MATERIAL AND METHODS: 26 CT data of 13 patients undergoing bilateral maxillary sinus augmentation in a split-mouth design were evaluated using the Voxim software by comparing the graft volumes 2 weeks after the sinus lift procedure with CT data obtained 6 months later. DBBM with (N = 6) or without tibial BMA (N = 6) and DBBM with (N = 7) and without adding iliac BMAC (N = 7) were used as grafts. Absolute and percentage changes in the graft volumes were evaluated, and the nonparametric Mann-Whitney U-test and the nonparametric Wilcoxon test were performed to determine significant differences between the graft volumes within each single split-mouth group and between the two groups. RESULTS: Overall, the volumes decreased between 15% and 21%. All single groups showed statistically significant decreases over 6 months of healing. The time-dependent changes in volumes between the different groups were not statistically significant (P = 0.818). CONCLUSIONS: An evident decrease in graft volume over the first 6 months of healing has to be expected irrespectively of graft composite. Neither BMA nor BMAC seem to have an evident impact. Overaugmentation seems recommendable in two-stage maxillary sinus surgery.


Assuntos
Transplante de Medula Óssea/métodos , Transplante Ósseo/métodos , Levantamento do Assoalho do Seio Maxilar/métodos , Animais , Bovinos , Humanos , Ílio/transplante , Seio Maxilar/diagnóstico por imagem , Seio Maxilar/cirurgia , Pessoa de Meia-Idade , Estudos Prospectivos , Interpretação de Imagem Radiográfica Assistida por Computador , Tíbia/transplante , Tomografia Computadorizada por Raios X , Resultado do Tratamento
9.
Clin Oral Implants Res ; 24(7): 763-9, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22551385

RESUMO

OBJECTIVES: The benefit in terms of higher accuracy for full guided implant surgery (template based guided cavity preparation and guided implant insertion) compared with half-guided surgery (template based guided cavity preparation and free-handed, manual implant insertion) has not been proved till now. MATERIAL AND METHODS: A total of 38 identical implants were inserted into five human cadaver jaws, after virtual implant planning with the coDiagnostiX(™) device. All cavities were drilled using templates equipped with tubes for guidance. At random, 19 implants were inserted in a free handed way (half-guided), whereas 19 implants were inserted in a guided way through the templates tubes (full guided). Postoperative cone beam computer tomographies (CBCT) were performed, and based on image fusion the total deviations between the virtual implant positions at the implants base and tip were determined and compared between both implantation modi. RESULTS: The mean difference in accuracy between both implantation modalities at the implants bases was 0.72 mm (range: 0.16-1.17 mm, SD: 0.45). The mean difference in accuracy between both modalities at the implants tips was 0.46 mm (range: 0.16-1.23 mm. SD: 0.49). Although full guided implantation showed a generally higher accuracy (mean tip: 1.54 mm, range: 0.33-3.64 mm; mean base: 1.52 mm, range: 0.4-3.54 mm) than half-guided implantation (mean tip: 1.84 mm, range: 0.84-3.22 mm; mean base: 1.56 mm, range: 0.49-3.43 mm), the differences were not statistically significant. CONCLUSIONS: The accuracy of half-guided implant surgery is comparable with full guided implant surgery.


Assuntos
Implantação Dentária Endóssea/estatística & dados numéricos , Implantes Dentários , Mandíbula/cirurgia , Planejamento de Assistência ao Paciente/estatística & dados numéricos , Cirurgia Assistida por Computador/estatística & dados numéricos , Cadáver , Tomografia Computadorizada de Feixe Cônico/métodos , Implantação Dentária Endóssea/instrumentação , Retenção em Prótese Dentária , Desenho de Equipamento , Humanos , Processamento de Imagem Assistida por Computador/métodos , Arcada Edêntula/diagnóstico por imagem , Arcada Edêntula/cirurgia , Arcada Parcialmente Edêntula/diagnóstico por imagem , Arcada Parcialmente Edêntula/cirurgia , Mandíbula/diagnóstico por imagem , Osteotomia/métodos , Cirurgia Assistida por Computador/métodos , Torque , Interface Usuário-Computador
10.
Internist (Berl) ; 54(1): 121-2, 124-30, 2013 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-23250563

RESUMO

Fabry's disease is an X-chromosome linked lysosomal storage disorder with α-galactosidase A deficiency and subsequent multiple organ involvement. An early and common symptom also in later stages of the disease is pain. This pain depends on various precipitating factors and can severely compromise the quality of life. So-called Fabry crises can lead to the necessity for intensive care treatment. The pain can be classified as predominantly neuropathic and is difficult to treat. In addition, medication has to be adjusted to concomitant cardiac and renal involvement in Fabry's disease. This review gives guidance for pain therapy in Fabry's disease based on the available evidence and on experience.


Assuntos
Analgésicos/uso terapêutico , Doença de Fabry/complicações , Doença de Fabry/terapia , Neuralgia/etiologia , Neuralgia/terapia , Doença de Fabry/diagnóstico , Humanos , Neuralgia/diagnóstico
11.
Animal ; 17 Suppl 4: 100915, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37793712

RESUMO

In Germany (and other Organisation for Economic Co-operation and Development countries), the need for a fundamental transformation of livestock farming has become increasingly evident in recent years. Two broad-based stakeholder commissions including the German farmers' association, the meat industry, and Non-Governmental Organizations have endorsed this demand. Nevertheless, major steps towards its implementation are still missing - a circumstance we refer to in this paper as the implementation dilemma. In a globalised economy, farmers cannot solve the problem of low animal welfare standards alone although they are important actors. Moreover, consumer behaviour is changing too slowly, and possibilities for granting more subsidies are limited in the face of multiple economic crises. Against this background, we argue for a stronger focus on voluntary (private) sustainability agreements. We therefore analyse how the German meat supply chain is organised and what responsibility and power the individual actors have to push the sector's transformation. Large slaughterhouses, processors, and the retailing sector seem promising due to their high market concentration and power. Especially retailers can influence the transformation of the market through their role as gatekeepers between suppliers and consumers. Based on business ethics principles of taking responsibility, we consider the focus on sustainability obligations of the retail sector to be ethically justified. However, it is then necessary to give the four retail groups dominating the meat chain in Germany more leeway for sustainability agreements in antitrust law.


Assuntos
Agricultura , Carne , Animais , Carne/análise , Bem-Estar do Animal , Marketing , Fazendas
12.
J Mol Biol ; 235(5): 1436-46, 1994 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-8107084

RESUMO

A theory is presented to describe the coupling of the directional movement of ATPase-containing translocases (such as helicases) along polymeric lattices to the steady-state kinetic parameters of the ATPase activity that drives this movement. This theory was developed to explain the results of an experimental investigation of one such enzyme, the bacteriophage T4 gene 41 protein helicase. The salient feature of the theory is that it correctly predicts the dependence of the rate of ATP hydrolysis by ATP-driven translocases on the length of polymer lattices along which they move. In the steady-state rate equation: [formula: see text] either Vmax, or K(act), or both, may depend on the lattice length. Two translocation models are considered. The first is a simple mechanism of the type E<-->E-Lat-->E, where the E-Lat-->E step represents the sum of the translocation steps of the enzyme along, and enzyme release from, the lattice. In the second model this mechanism is expanded to add an additional kinetic step, either before or after the translocation process. Variants of this second model can be used to represent the most simple translocase mechanisms. Another method of measuring the lattice length dependence of an ATP-driven translocase, which is applicable particularly to ATPases moving along DNA lattices, involves the use of lattice-binding proteins (such as single-stranded DNA binding proteins) that can block the movement of the translocases and therefore simulate lattice ends. In this protocol the dependence of the ATPase kinetics of the translocase on lattice length can be studied by experiments on long lattices complexed with lattice-binding proteins to various binding densities. This method is not always as unambiguous as direct measurement of ATPase activity on lattices of defined length, but can help to discriminate between mechanisms. The significance of the steady-state kinetic parameters obtained in such experiments is discussed in terms of the mechanistic rate constants that define the models we have investigated.


Assuntos
Adenosina Trifosfatases/metabolismo , DNA Helicases/metabolismo , Modelos Teóricos , Cinética , Matemática
13.
FASEB J ; 18(1): 203-5, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14597556

RESUMO

To rapidly respond to invading microorganisms, humans call on their innate immune system. This occurs by microbe-detecting receptors, such as CD14, that activate immune cells to eliminate the pathogens. Here, we link the lipopolysaccharide receptor CD14 with Alzheimer's disease, a severe neurodegenerative disease resulting in dementia. We demonstrate that this key innate immunity receptor interacts with fibrils of Alzheimer amyloid peptide. Neutralization with antibodies against CD14 and genetic deficiency for this receptor significantly reduced amyloid peptide induced microglial activation and microglial toxicity. The observation of strongly enhanced microglial expression of the LPS receptor in brains of animal models of Alzheimer's disease indicates a clinical relevance of these findings. These data suggest that CD14 may significantly contribute to the overall neuroinflammatory response to amyloid peptide, highlighting the possibility that the enormous progress currently being made in the field of innate immunity could be extended to research on Alzheimer's disease.


Assuntos
Peptídeos beta-Amiloides/toxicidade , Receptores de Lipopolissacarídeos/fisiologia , Doença de Alzheimer/imunologia , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Animais , Anticorpos Monoclonais/farmacologia , Imunidade Inata , Receptores de Lipopolissacarídeos/genética , Receptores de Lipopolissacarídeos/imunologia , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Microglia/efeitos dos fármacos , Microglia/imunologia , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/toxicidade
14.
Endocrinology ; 130(1): 550-2, 1992 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1309350

RESUMO

Three distinct receptor types for natriuretic peptides (NP) have been identified in human tissue. "A" and "B" receptors initiate biological actions, whereas the "C" receptor has a clearance function. It has been proposed that the natural ligand for the B receptor is c-type natriuretic peptide (CNP), rather than atrial natriuretic peptide (ANP), and that the B receptor is only found in the central nervous system (CNS) and is responsible for all NP-mediated effects in the CNS. Contrary to this hypothesis, we have identified, by means of the polymerase chain reaction (PCR), the B receptor in human kidney tissue. To detect A and C receptors, the PCR reaction was performed with primers which yielded predicted 600 and 378 base pair (bp) products, respectively. For the B receptor, 3 different primer sets were used, resulting in the expected 785, 453 and 228 bp fragments. Restriction mapping of the latter two products with Rsa I yielded the expected fragment numbers and sizes, indicating the PCR products were from B receptor mRNA. These results indicate that the human kidney has B as well as A and C receptors. Thus CNP may have a renal as well as a CNS site of action.


Assuntos
Rim/química , Proteínas do Tecido Nervoso/metabolismo , Receptores de Superfície Celular/análise , Sequência de Bases , Humanos , Dados de Sequência Molecular , Peptídeo Natriurético Encefálico , Reação em Cadeia da Polimerase , RNA Mensageiro/análise , Receptores do Fator Natriurético Atrial , Receptores de Superfície Celular/genética
15.
Gene ; 34(2-3): 219-26, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-3924739

RESUMO

A broad-host-range plasmid was constructed that allows the in vitro formation of beta-galactosidase fusions. DNA from the photosynthetic bacterium Rhodopseudomonas sphaeroides was cloned into this plasmid and a number of R. sphaeroides isolates were recovered that had varying levels of beta-galactosidase activity. beta-galactosidase antigenic activity from the fusion strains could be localized immunologically in polypeptides with an Mr of 120 000 or greater. Expression of beta-galactosidase activity under control of fusion derivatives was either very low or nonexistent in Escherichia coli relative to R. sphaeroides, indicating that R. sphaeroides promoters or translational start signals function poorly in E. coli.


Assuntos
Escherichia coli/genética , Galactosidases/genética , Vetores Genéticos , Plasmídeos , Rhodobacter sphaeroides/genética , beta-Galactosidase/genética , Compartimento Celular , DNA Recombinante , Óperon Lac , Biossíntese de Proteínas , Transcrição Gênica
16.
FEMS Microbiol Lett ; 133(1-2): 21-8, 1995 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-8566708

RESUMO

Antibiotic drug-resistance cassettes (DRCs) were used to insertionally inactivate the wild-type Bordetella pertussis recA gene cloned into a suicide vector. The mutant allele was mobilized by conjugal gene transfer from Escherichia coli strain SM10 into different genetic backgrounds of B. pertussis. Southern hybridization studies of one of these mutants showed that it contained a DRC integrated within a recA gene situated within a ClaI genomic DNA fragment. Selected mutants were assayed to quantify recombinational and DNA repair deficiencies. These mutants were shown to be highly sensitive to both chemically and physically induced DNA damage. Gene transfer studies of another RecA- mutant also indicated that it was defective in intergenic recombination. No difference in hemolytic activity or production of capsule was detected between the RecA- mutants and their corresponding wild-type strains. The results of this investigation corroborate previous studies with the cloned B. pertussis recA gene, and demonstrate that the expression of the B. pertussis recA gene in the original host promotes both DNA repair and recombination.


Assuntos
Bordetella pertussis/genética , Recombinases Rec A/genética , Cápsulas Bacterianas/fisiologia , Bordetella pertussis/patogenicidade , Reparo do DNA/genética , DNA Bacteriano/genética , DNA Bacteriano/efeitos da radiação , Glicoproteínas/farmacologia , Hemólise , Metanossulfonato de Metila , Mutagênese Insercional , Mutação/genética , Recombinação Genética/genética , Raios Ultravioleta , Virulência
17.
Neurosci Lett ; 284(3): 135-8, 2000 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-10773417

RESUMO

Timing and extent of trauma-induced release of interleukin-1beta (IL-1beta) in extracellular fluid of the CNS were analyzed. In brain tissue perfusates obtained by in vivo microdialysis a marked release of IL-1beta was unexpectedly detected within less than 60 min. At such an early stage of neurotrauma, mRNA expression of IL-1beta was detected whereas immunoreactivity for the IL-1beta protein was negative. Concentrations of extracellularly secreted IL-1beta protein gradually increased, peaked at day 2 and decreased thereafter. Drugs acting on mononuclear phagocytes significantly modulated IL-1beta secretion. This so far unrecognized acuity of IL-1beta release demonstrated here, may represent a precondition for the orchestrating role of this mediator in the cascade of inflammatory host response.


Assuntos
Lesões Encefálicas/metabolismo , Interleucina-1/metabolismo , Proteínas Virais , Animais , Encéfalo/citologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Cloroquina/farmacologia , Colchicina/farmacologia , Imuno-Histoquímica , Inflamação/metabolismo , Interferon gama/farmacologia , Interleucina-1/genética , Lipopolissacarídeos/farmacologia , Masculino , Microdiálise , Microglia/efeitos dos fármacos , Microglia/metabolismo , RNA Mensageiro/análise , RNA Mensageiro/genética , Ratos , Ratos Wistar , Serpinas/farmacologia , Fatores de Tempo
18.
J Bone Joint Surg Am ; 83(7): 1062-9, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11451977

RESUMO

BACKGROUND: Although the glenohumeral joint is the most mobile articulation of the human body, it is known to exhibit ball-and-socket kinematics. Compression into the glenoid labral concavity keeps the humeral head centered. The purpose of the present study was to determine the effects of joint position on glenohumeral stability through concavity-compression. METHODS: Ten cadaveric shoulders were tested. The glenoid was mounted horizontally onto a six-component load-cell while the humerus was clamped to a vertically unconstrained slide. An x-y stage translated the load-cell with the glenoid underneath the humeral head in eight different directions. Compressive loads of 20, 40, and 60 N were applied. The tests were repeated in 0 degrees, 30 degrees, 60 degrees, and 90 degrees of glenohumeral abduction with and without the labrum. Relative translations between the glenoid and the humeral head and the forces resisting translation were recorded. Then the stability ratio, defined as the peak translational force divided by the applied compressive force, was calculated. RESULTS: The average stability ratio was higher in the hanging-arm position than it was in glenohumeral abduction. The highest stability ratio was detected in the inferior direction (59.8% 7.7%) when the labrum was intact and in the superior direction (53.3% 7.9%) when the labrum had been resected. Under both conditions, the anterior direction was associated with the lowest stability ratio (32.0% 4.4% with the labrum and 30.4% 4.1% without the labrum). Resection of the glenoid labrum resulted in an average decrease in the stability ratio of 9.6% 1.7%. With increasing compressive load, the average stability ratio slightly decreased. CONCLUSIONS: Glenohumeral stability through concavity-compression was greater in the hanging-arm position than it was in glenohumeral abduction. The average contribution of the labrum to glenohumeral stability through concavity-compression was approximately 10%, about one-half of the value previously reported. With the labrum intact, the glenohumeral joint was most stable in the inferior direction. Without the labrum, it was most stable in the superior direction. Under both conditions, it was least stable in the anterior direction. Glenohumeral joint stability through concavity-compression decreases with higher compressive loads.


Assuntos
Postura/fisiologia , Amplitude de Movimento Articular/fisiologia , Articulação do Ombro/fisiologia , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Cadáver , Feminino , Humanos , Instabilidade Articular , Masculino , Pressão , Sensibilidade e Especificidade , Articulação do Ombro/anatomia & histologia , Estresse Mecânico
19.
Dtsch Tierarztl Wochenschr ; 107(11): 438-43, 2000 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-11153229

RESUMO

Reference values were determined for blood plasma concentrations of albumin, total protein, glucose, total bilirubin, urea, creatinine, cholesterin, triglycerides, total calcium und anorganic phosphate as well as the activities of alkaline phosphatase, alanine-amino-transferase (ALT) and glutamate-dehydrogenase based on 109-124 healthy puppies at different times (1st-3rd, 8th-10th, 28th-33rd, and 50th-58th day of life). In addition, all the results were calculated separately for the breeds involved in this study (Beagle [n = 34-40], German Shepherd [n = 32-35] and Golden Retriever [n = 43-53]). Furthermore, male and female puppies were compared. All examined parameters showed remarkable dynamics during the suckling period. Often the values exceeded respectively fell below the reference ranges for adult dogs. Significant systematic breed influences as for instance a significantly lower glucose concentration for the German Shepherd puppies were also found for other parameters, especially for alkaline phosphatase and ALT. However, differences between male and female animals were only present sporadically and were of minor clinical relevance. The gathered breed differences show that it is worthwhile not only to acquire age specific reference ranges but also breed specific reference ranges for selected parameters. On the other hand, reference ranges without the definition of the breed can only be used for orientation.


Assuntos
Análise Química do Sangue/veterinária , Cães/sangue , Envelhecimento , Animais , Animais Recém-Nascidos , Proteínas Sanguíneas/análise , Enzimas/sangue , Lipídeos/sangue , Valores de Referência , Especificidade da Espécie
20.
J Dent Res ; 92(12 Suppl): 183S-8S, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24158338

RESUMO

For the restoration of an anterior missing tooth, implant-supported single crowns (ISCs) or fixed dental prostheses (FDPs) are indicated, but it is not clear which type of restoration is more cost-effective. A self-selected trial was performed with 15 patients with ISCs and 11 with FDPs. Patient preferences were recorded with visual analog scales before treatment, 1 month following restoration, and then annually. Quality-adjusted tooth years (QATYs) were estimated by considering the type of reconstruction for replacing the missing tooth and its effect on the adjacent teeth. A stochastic cost-effectiveness model was developed using Monte Carlo simulation. The expected costs and QATYs were summarized in cost-effectiveness acceptability curves. ISC was the dominant strategy, with a QATY increase of 0.01 over 3 years and 0.04 over 10 years with a higher probability of being cost-effective. While both treatment options provided satisfactory long-term results from the patient's perspective, the lower initial costs, particularly laboratory fees, were responsible for the dominance of ISCs over FDPs.


Assuntos
Implantes Dentários para Um Único Dente/economia , Prótese Parcial Fixa/economia , Análise Custo-Benefício , Custos e Análise de Custo , Coroas/economia , Planejamento de Prótese Dentária , Prótese Dentária Fixada por Implante/economia , Planejamento de Dentadura , Estética Dentária , Seguimentos , Humanos , Arcada Parcialmente Edêntula/economia , Arcada Parcialmente Edêntula/reabilitação , Estudos Longitudinais , Preferência do Paciente , Satisfação do Paciente , Probabilidade , Estudos Prospectivos , Anos de Vida Ajustados por Qualidade de Vida , Processos Estocásticos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA