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1.
J Endovasc Ther ; : 15266028241230943, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38380529

RESUMO

PURPOSE: The aim of this study was to evaluate the radiation dose, image quality, and the potential of virtual monoenergetic imaging (VMI) reconstructions of high-pitch computed tomography angiography (CTA) of the thoracoabdominal aorta on a dual-source photon-counting detector-CT (PCD-CT) in comparison with an energy-integrating detector-CT (EID-CT), with a special focus on low-contrast attenuation. METHODS: Consecutive patients being referred for an electrocardiogram (ECG)-gated, high-pitch CTA of the thoracoabdominal aorta prior to transcatheter aortic valve replacement (TAVR), and examined on the PCD-CT, were included in this prospective single-center study. For comparison, a retrospective patient group with ECG-gated, high-pitch CTA examinations of the thoracoabdominal aorta on EID-CT with a comparable scan protocol was matched for gender, body mass index, height, and age. Virtual monoenergetic imaging reconstructions from 40 to 120 keV were performed. Enhancement and noise were measured in 7 vascular segments and the surrounding air as mean and standard deviation of CT values. The radiation dose was noted and signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Finally, a subgroup analysis was performed, comparing VMI reconstructions from 40 keV to 70 keV in patients with at least a 50% decrease in contrast attenuation between the ascending aorta and femoral arteries. RESULTS: Fifty patients (mean age 77.0±14.5 years; 31 women) were included. The radiation dose was significantly lower on the PCD-CT (4.2±1.4 vs. 7.2±2.2 mGy; p<0.001). With increasing keV, vascular noise, SNR, and CNR decreased. Intravascular attenuation was significantly higher on VMI at levels from 40 to 65, compared with levels of 120 keV (p<0.01 and p<0.005, respectively). On the PCD-CT, SNR was significantly higher in keV levels 40 and 70 (all p<0.001), and CNR was higher at keV levels 40 and 45 (each p<0.001), compared with scans on the EID-CT. At VMI ≤60 keV, image noise was also significantly higher than that in the control group. The subgroup analysis showed a drastically improved diagnostic performance of the low-keV images in patients with low-contrast attenuation. CONCLUSION: The ECG-gated CTA of the thoracoabdominal aorta in high-pitch mode on PCD-CT have significantly lower radiation dose and higher objective image quality than EID-CT. In addition, low-keV VMI can salvage suboptimal contrast studies, further reducing radiation dose by eliminating the need for repeat scans. CLINICAL IMPACT: ECG-gated CT-angiographies of the thoracoabdominal aorta can be acquired with a lower radtiation dose and a better image quality by using a dual-source photon-countinge detector CT. Furthermore, the inherent spectral data offers the possiblity to improve undiagnostic images and thus saves the patient from further radiation and contrast application.

2.
Clin Oral Investig ; 28(3): 192, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38438798

RESUMO

OBJECTIVES: To compare the efficacy of fiber post removal using conventional (CONV) versus guided endodontics (GE) in terms of dentin loss, residual resin material, procedural errors, and working time in vitro. MATERIAL AND METHODS: Ninety human central incisors were root-filled and scanned by micro-computed tomography (CT), then restored with fiber posts and composite. Twenty-four sets of teeth with up to four human maxillary central incisors were fabricated and divided into three groups: conventional post removal by a general dentist (CG) or endodontology specialist (CS) and guided endodontics (GE) by a general dentist, yielding 30 teeth per operator and group. After treatment, the prepared access cavities were volumetrically assessed by micro-CT. Statistical significance was evaluated by one-way analysis of variance followed by post hoc comparisons with Tukey's HSD test and Pearson's chi-squared test for independence. RESULTS: Both CONV and GE resulted in dentin loss and residual resin material. CS resulted in more dentin loss and less residual resin material than CG and GE (p < .05). All groups had some deviations from the original root canal but no perforations. The shortest working time was observed in the GE group. CONCLUSIONS: Compared to the conventional freehand technique, GE resulted in significantly less radicular dentin loss, a few deviations but no perforations. CLINICAL RELEVANCE: Guided endodontics can improve the speed and safety of fiber post removal without root perforation.


Assuntos
Endodontia , Humanos , Microtomografia por Raio-X , Assistência Odontológica , Tratamento do Canal Radicular , Dentina
3.
Clin Oral Investig ; 24(4): 1551-1560, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31414272

RESUMO

OBJECTIVE: To assess the impact of various local pathologies on facial alveolar bone dimensions at tooth sites. MATERIALS AND METHODS: Cone-beam computed tomography images of 60 patients were analyzed. Healthy teeth and teeth with local pathologies (i.e., endodontically treated, periodontally diseased teeth, and teeth with periapical lesions) were included. The thickness of the facial alveolar bone was measured at five locations: (1) the bone crest (W0), (2) 25% (W25), (3) 50% (W50), (4) 75% (W75) of the distance from the bone crest to the root apex (A), and (5) in the A region (W100). The results were considered statistically significant at p < 0.0008 (adjustment according to the statistical correction for multiple testing). RESULTS: A total of 1174 teeth (707 healthy and 467 with the local pathologies) were assessed. Periodontally diseased maxillary premolars and anterior teeth in the mandible in the W0 position, as well as maxillary molars in the W25 position, tended to have a lower facial bone thickness when compared to the healthy teeth (0.68 mm vs. 0.84 mm, p = 0.008; 0.47 mm vs. 0.55 mm, p = 0.004; and 1.27 mm vs. 1.72 mm; p = 0.009, respectively). In contrast, the observed tendency pointed towards thicker facial bone wall for the periodontally diseased mandibular anterior teeth in the W50 position (0.74 vs. 0.52, p = 0.001). Healthy maxillary molars tended to display a thicker facial alveolar bone compared to the teeth with local pathologies in the W25, W50, and W75 positions (p = 0.001, p = 0.005, and p = 0.004, respectively). CONCLUSIONS: The present analysis has indicated that local pathologies are commonly associated with a compromised socket morphology. CLINICAL RELEVANCE: The facial bone thickness was particularly reduced at periodontally diseased teeth, which may challenge implant therapy.


Assuntos
Processo Alveolar/diagnóstico por imagem , Tomografia Computadorizada de Feixe Cônico , Dente não Vital/diagnóstico por imagem , Dente/diagnóstico por imagem , Humanos , Maxila , Doenças Periapicais , Doenças Periodontais , Estudos Retrospectivos
4.
Clin Oral Investig ; 24(9): 3289-3298, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31980922

RESUMO

OBJECTIVE: To assess the influence of biphasic calcium phosphate materials with different surface topographies on bone formation and osseointegration of titanium implants in standardized alveolar ridge defects. MATERIALS AND METHODS: Standardized alveolar ridge defects (6 × 6 mm) were created in the mandible of 8 minipigs and filled with three biphasic calcium phosphate materials (BCP1-3, 90% tricalcium phosphate/10% hydroxyapatite) with different surface properties (micro- and macroporosities) as well as a bovine-derived natural bone mineral (NBM) as a control. At 12 weeks, implants were placed into the augmented defects. After further 8 weeks of healing, dissected blocks were processed for histological analysis (e.g., mineralized (MT), residual bone graft material (BS), bone-to-implant contact (BIC)). RESULTS: All four biomaterials showed well-integrated graft particles and new bone formation within the defect area. MT values were comparable in all groups. BS values were highest in the NBM group (21.25 ± 13.52%) and markedly reduced in the different BCP groups, reaching statistical significance at BCP1-treated sites (9.2 ± 3.28%). All test and control groups investigated revealed comparable and statistically not significant different BIC values, ranging from 73.38 ± 20.5% (BCP2) to 84.11 ± 7.84% (BCP1), respectively. CONCLUSION: All bone graft materials facilitated new bone formation and osseointegration after 12 + 8 weeks of healing.


Assuntos
Substitutos Ósseos , Implantação Dentária Endóssea , Implantes Dentários , Animais , Regeneração Óssea , Bovinos , Hidroxiapatitas , Mandíbula/cirurgia , Osseointegração , Suínos , Porco Miniatura
5.
Clin Oral Investig ; 23(12): 4263-4287, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30859329

RESUMO

AIM: The aim of this systematic review was to critically evaluate the currently existing clinical evidence on the efficacy of autogenous teeth (AT) for the reconstruction of alveolar ridge deficiencies. MATERIALS AND METHODS: A search protocol was developed to answer the focused question: "In patients exhibiting alveolar ridge deficiencies and being in need of an implant retained restoration, what is the efficacy of reconstructive procedures employing AT on changes in ridge dimensions compared with control measures?" Uncontrolled studies were also included to assess the overall efficacy of AT for specific procedures. RESULTS: A total of six studies (one randomized, one non-randomized controlled, two observational, one controlled case series, one retrospective) were identified. Two studies used AT for staged lateral augmentation, whereas four studies used AT as a demineralized dentin matrix (AutoBT) for the simultaneous grafting of dehiscence-type defects, vertical augmentation of post-extraction sockets, and lateral/transcrestal sinus floor elevation. The reported clinical outcomes following the application of either AT or AutoBT were within the range of those data noted in the respective control groups. Adverse events were commonly not observed. CONCLUSIONS: The available limited studies involved relatively small patient samples and short follow-up periods but pointed to the potential of AT to serve as an alternative material for the reconstruction of alveolar ridge deficiencies. CLINICAL RELEVANCE: AT appear to be effective in reconstructing alveolar ridge deficiencies.


Assuntos
Aumento do Rebordo Alveolar/métodos , Transplante Ósseo , Implantação Dentária Endóssea , Reconstrução Mandibular/métodos , Processo Alveolar , Humanos , Levantamento do Assoalho do Seio Maxilar
6.
Radiologe ; 59(1): 35-42, 2019 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-30552484

RESUMO

CLINICAL/METHODICAL ISSUE: Radiologic imaging for the assessment of individual cardiovascular risk. STANDARD RADIOLOGICAL METHODS: The correct estimation of the individual cardiovascular risk is prerequisite for the prevention of cardiovascular diseases. Here, extensive evidence is available for coronary calcium scans as well as coronary CT angiography (CTA). METHODICAL INNOVATIONS: Summary of the available evidence for the use of calcium score and coronary CTA. Illustration of the significance of both tests in current guidelines. PERFORMANCE: Both tests have high prognostic value, surpassing a risk-factor based assessment. In comparison with the calcium score, the CTA has higher incremental value. ACHIEVEMENTS: Results from recent trials confirm an improvement of outcomes in symptomatic patients by performing a CTA compared with standard care. PRACTICAL RECOMMENDATIONS: European and US guidelines recommend a calcium score for risk stratification of asymptomatic patients with a low to intermediate risk profile. For symptomatic patients with low to intermediate coronary artery disease pretest probability, a CTA is recommended.


Assuntos
Doenças Cardiovasculares , Angiografia Coronária/métodos , Doença da Artéria Coronariana , Doenças Cardiovasculares/diagnóstico por imagem , Humanos , Medição de Risco , Fatores de Risco
7.
Phys Rev Lett ; 121(13): 137702, 2018 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-30312054

RESUMO

The numerical renormalization group (NRG) is tailored to describe interacting impurity models in equilibrium, but it faces limitations for steady-state nonequilibrium, arising, e.g., due to an applied bias voltage. We show that these limitations can be overcome by describing the thermal leads using a thermofield approach, integrating out high energy modes using NRG, and then treating the nonequilibrium dynamics at low energies using a quench protocol, implemented using the time-dependent density matrix renormalization group. This yields quantitatively reliable results for the current (with errors ≲3%) down to the exponentially small energy scales characteristic of impurity models. We present results of benchmark quality for the temperature and magnetic field dependence of the zero-bias conductance peak for the single-impurity Anderson model.

8.
J Anim Physiol Anim Nutr (Berl) ; 99(6): 1039-46, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25846729

RESUMO

This study was performed to investigate the hypothesis that supplementation of conjugated linoleic acid (CLA) changes the concentrations of retinol and tocopherols in the milk of cows. To investigate this hypothesis, Holstein cows received daily from 3 weeks ante-partum to 14 weeks post-partum either 172 g of a CLA-free rumen-protected control fat (control group, n = 20) or the same amount of a rumen-protected CLA fat, supplying 4.3 g of cis-9, trans-11 CLA and 3.8 g of trans-10, cis-12 CLA per d (CLA group, n = 20). Milk samples (collected at weeks 1, 3, 5, 8 and 11 of lactation) were analysed for retinol, α- and γ-tocopherol concentrations. Milk of cows supplemented with CLA had higher concentrations of retinol (+34%), α-tocopherol (+44%) and γ-tocopherol (+21%) than milk of control cows (p < 0.05). The daily output of these vitamins via milk was also greater in cows of the CLA group than in cows of the control group (+36, 50 and 24% for retinol, α-tocopherol and γ-tocopherol, respectively, p < 0.05). In agreement with higher concentrations of tocopherols, concentrations of thiobarbituric acid-reactive substances, determined in milk of week 5, were lower in cows of the CLA group than in control cows, indicative of a lower susceptibility of milk lipids to peroxidation. Plasma concentrations of retinol and α-tocopherol, determined at 1 and 5 weeks post-partum, were not different between the two groups of cows. In conclusion, this study shows that supplementing dairy cows with a moderate amount of CLA causes an increase of the concentrations of vitamins A and E in the milk and results in an increased output of those vitamins via milk. These effects might be beneficial with respect to the nutritional value of dairy products and the susceptibility of milk fat to oxidative deterioration.


Assuntos
Bovinos , Ácidos Linoleicos Conjugados/farmacologia , Leite/química , Vitamina A/química , alfa-Tocoferol/química , gama-Tocoferol/química , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta/veterinária , Formas de Dosagem , Feminino , Ácidos Linoleicos Conjugados/administração & dosagem , Ácidos Linoleicos Conjugados/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/química , Vitamina A/sangue , Vitamina A/metabolismo , alfa-Tocoferol/sangue , alfa-Tocoferol/metabolismo , gama-Tocoferol/metabolismo
9.
Clin Radiol ; 69(10): 1034-8, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25017451

RESUMO

AIM: To identify independent predictors of contrast medium-induced acute kidney injury (CI-AKI) after enhanced multidetector-row computed tomography (MDCT) prior to transcatheter aortic valve implantation (TAVI) in high-risk patients. MATERIALS AND METHODS: The present single-centre study analysed retrospectively 361 patients who were assessed using MDCT prior to TAVI. CI-AKI was defined as an increase in serum creatinine (SCr) of ≥ 25% or ≥ 0.5 mg/dl in at least one sample over baseline (24 h before MDCT) and at 24, 48, and 72 h after MDCT. RESULTS: A total of 38 patients (10.5%) experienced CI-AKI. As compared to patients without CI-AKI, they presented more frequently with estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2), (81.6% versus 64.4%, p = 0.045) and tended to receive higher volumes of iodinated contrast media (ICM; 55.3% versus 39%, p = 0.057). There was a significant interaction between baseline eGFR and the amount of intravenous ICM administered (pfor interaction = <0.001) identifying the amount of ICM >90 ml as independent predictive factor of CI-AKI only in patients with baseline eGFR <60 ml/min/1.73m(2) (OR 2.615; 95% CI: 1.21-5.64). CONCLUSION: One in ten elderly patients with aortic stenosis undergoing MDCT to plan a TAVI procedure experienced CI-AKI after intravenous ICM injection. Intravenous administration of <90 ml of ICM reduces this risk in patients with or without pre-existing impaired renal function. However, in the majority of patients renal function recovers before the TAVI procedure.


Assuntos
Injúria Renal Aguda/induzido quimicamente , Valva Aórtica/diagnóstico por imagem , Cateterismo Cardíaco/métodos , Meios de Contraste/efeitos adversos , Iopamidol/análogos & derivados , Tomografia Computadorizada Multidetectores/métodos , Idoso de 80 Anos ou mais , Valva Aórtica/cirurgia , Feminino , Próteses Valvulares Cardíacas , Implante de Prótese de Valva Cardíaca/métodos , Humanos , Iopamidol/efeitos adversos , Masculino , Estudos Retrospectivos , Fatores de Risco
10.
J Dairy Sci ; 97(3): 1535-42, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24472130

RESUMO

Adiponectin, one of the most abundant adipokines in circulation, is known for its role in regulation of body metabolism. The aim of this study was to evaluate the effects of a negative energy balance (NEB) at 2 stages of lactation (lactational NEB at the onset of lactation and an induced NEB by feed restriction near 100 d of lactation) on circulating adiponectin concentrations. We also investigated the effect of feed restriction on adiponectin concentrations in milk and the relationships of blood and milk adiponectin with selected plasma or milk variables and with measures of body condition. Plasma adiponectin was measured in 50 multiparous Holstein dairy cows throughout 3 experimental periods [i.e., period 1=3 wk antepartum up to 12 wk postpartum, period 2=3 wk of feed restriction starting at around 100 d in milk with a control (n=25) and feed-restricted group (50% of energy requirements; n=25), and period 3=subsequent realimentation period for 8 wk]. Milk adiponectin was investigated among 21 multiparous cows at wk 2 and wk 12 of period 1 and wk 2 of period 2. Adiponectin concentrations in plasma and skim milk were measured using an in-house ELISA specific for bovine adiponectin. Major changes in circulating adiponectin concentrations were observed during the periparturient period, whereas energy deficiency during established lactation at around 100 d in milk and subsequent refeeding did not affect plasma adiponectin. Together with lower adiponectin concentrations in milk (µg/mL), the reduction in milk yield led to decreased adiponectin secretion via milk (mg/d) at the second week of feed restriction. Irrespective of time and treatment, milk adiponectin represented about 0.002% of total milk protein. Mean adiponectin concentrations in milk (0.61 ± 0.03 µg/mL) were about 92% lower than the mean plasma adiponectin concentrations (32.1 ± 1.0 µg/mL). The proportion of the steady-state plasma adiponectin pool secreted daily via milk was 2.7%. In view of the similar extent of NEB in both periods of energy deficiency, decreasing adiponectin concentrations seems important for accomplishing the adaptation to the rapidly increasing metabolic rates in early lactation, whereas the lipolytic reaction toward feed restriction-induced NEB during established lactation seems to occur largely independent of changes in circulating adiponectin.


Assuntos
Adiponectina/sangue , Restrição Calórica/veterinária , Dieta/veterinária , Lactação , Leite/química , Adiponectina/química , Animais , Bovinos , Gorduras na Dieta/análise , Metabolismo Energético , Feminino , Proteínas do Leite/análise , Necessidades Nutricionais , Período Pós-Parto
11.
Clin Oral Investig ; 18(4): 1319-1328, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-23982444

RESUMO

AIMS: The objective of this study is to evaluate the effects of a paste-like bone substitute material with easy handling properties and improved mechanical stability on periodontal regeneration of intrabony defects in dogs. MATERIALS AND METHODS: Mandibular and maxillary first and third premolars were extracted, and three-wall intrabony defects were created on second and fourth premolars. After a healing period of 3 months, acute type defects were filled with a paste-like formulation of deproteinized bovine bone mineral (DBBM) (particle size, 0.125-0.25 mm) in a collagenous carrier matrix (T1), pulverized DBBM (particle size, 0.125-0.25 mm) without the carrier (T2), or Bio-Oss® granules (particle size, 0.25-1.00 mm) as control (C). All defects were covered with a Bio-Gide® membrane. The dogs were sacrificed after 12 weeks, and the specimens were analyzed histologically and histometrically. RESULTS: Postoperative healing of all defects was uneventful, and no histological signs of inflammation were observed in the augmented and gingival regions. New cementum, new periodontal ligament, and new bone were observed in all three groups. The mean vertical bone gain was 3.26 mm (T1), 3.60 mm (T2), and 3.81 mm (C). That of new cementum was 2.25 mm (T1), 3.88 mm (T2), and 3.53 mm (C). The differences did not reach statistical significance. The DBBM particles were both incorporated in new bone and embedded in immature bone marrow. CONCLUSIONS: The results of this preclinical study showed that the 0.125-0.25-mm DBBM particles in a powder or paste formulation resulted in periodontal regeneration comparable to the commercially available DBBM. Osteoconductivity, in particular, was not affected by DBBM size or paste formulation. CLINICAL RELEVANCE: The improved handling properties of the paste-like bone substitute consisting of small DBBM particles embedded in a collagen-based carrier hold promise for clinical applications.


Assuntos
Regeneração Óssea , Minerais , Animais , Cães , Masculino
12.
J Anim Physiol Anim Nutr (Berl) ; 98(5): 982-90, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24423073

RESUMO

The objective of this study was to determine the changes to residual plant feeding value of early- and late-maturing maize varieties. The influence of the cell wall carbohydrate composition, in terms of neutral and acid detergent fibre (NDF and ADF) content, NDF and dry matter (DM) degradability, and in vitro organic matter digestibility and gas production on the feeding value of a range of maize genotypes, was measured. The different genotypes were allotted into two maturity groups (MG I--early to mid-early: S210-S240; MG II--mid-late to late: S 250-S280) and harvested at four different harvest dates (depending on the DM content of the kernels). The maize varieties of MG I had lower NDF and ADF contents and higher ruminal DM degradability, in vitro digestibility and gas production and thus a higher feeding value than MG II at the same stage of physiological maturity. A strong negative relationship between NDF content and the ruminal DM degradability (r = -0.81) was observed. The data indicate that the early-maturing varieties permit a larger flexibility in harvesting due to a longer period of starch inclusion into the kernel whilst simultaneously maintaining a good supply of rumen-available fibre. Conclusively, the higher feeding value of the early-maturing varieties, based on lower NDF and high DM digestibility, permits more flexibility in the harvesting period over the later-maturing varieties.


Assuntos
Rúmen/fisiologia , Zea mays/química , Zea mays/genética , Animais , Fibras na Dieta , Digestão , Fermentação , Genótipo , Valor Nutritivo , Fatores de Tempo
13.
Clin Implant Dent Relat Res ; 26(2): 369-375, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38177089

RESUMO

AIM: To assess and compare the short-term clinical outcomes following a combined vertical and horizontal alveolar ridge augmentation and two-stage implant placement using either autogenous tooth roots (TR) or autogenous bone blocks (AB). MATERIALS AND METHODS: A total of n = 27 patients (TR/AB: 13/14) exhibiting n = 31 implants (TR/AB: 14/17) were available for the analysis. Each subject had been allocated to a combined vertical and horizontal alveolar ridge augmentation using either (1) healthy TR (e.g., retained wisdom teeth), or (2) monocortical AB harvested from the retromolar area (i.e. external oblique line). Clinical parameters (e.g., bleeding on probing, BOP; probing pocket depth, PD; mucosal recession, MR) were recorded after a follow-up period of 16.03 ± 4.3 months following implant placement. RESULTS: The survival rates amounted to 100% in both groups. TR and AB grafted sites were associated with similar changes in mean BOP (8.97 ± 27.73%; 11.90 ± 18.97%), PD (0.53 ± 0.49; 0.47 ± 0.67 mm), and MR (0.03 ± 0.13; 0.0 ± 0.02 mm) values. The incidence of peri-implant mucositis and peri-implantitis at the patient level amounted to 15.38% and 0.0% in the TR-, and 28.57% and 7.14% in the AB group. CONCLUSIONS: Both surgical procedures were associated with peri-implant tissue health and stability on the short-term.


Assuntos
Aumento do Rebordo Alveolar , Implantes Dentários , Humanos , Implantação Dentária Endóssea/métodos , Aumento do Rebordo Alveolar/métodos , Transplante Ósseo/métodos , Raiz Dentária
14.
J Dairy Sci ; 96(2): 1038-43, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23245956

RESUMO

In the liver of dairy cows, the production of cytokines is enhanced during the periparturient phase, which in turn leads to inflammation and an impairment of hepatic function. Nuclear factor E2-related factor 2 (Nrf2) is a redox-sensitive transcription factor that controls the transcription of genes encoding various antioxidative and cytoprotective proteins. In the present study, we investigated the hypothesis that Nrf2 is activated in the liver of dairy cows during the periparturient phase to protect the liver against the deleterious effects of cytokines and reactive oxygen species. Therefore, we determined relative mRNA abundances of TNF (encoding tumor necrosis factor-α), various acute phase proteins and several Nrf2 target genes in liver biopsy samples of 20 dairy cows at each time point from 3 wk antepartum to 1, 5, and 14 wk postpartum. We observed an increase in mRNA abundances of TNF and acute-phase proteins [serum amyloid A 3 (SAA3), haptoglobin (HP), and C-reactive protein (CRP)] from 3 wk antepartum to 1 wk postpartum, indicative of a proinflammatory condition. Messenger RNA abundances of various Nrf2 target genes with antioxidative or cytoprotective functions [glutathione peroxidase 3 (GPX3); microsomal glutathione S-transferase 3 (MGST3); superoxide dismutase (SOD1); catalase (CAT); metallothioneins 1A, 1E, and 2A (MT1A, MT1E, and MT2A, respectively); NAD(P)H dehydrogenase, quinone 1 (NQO1); heme oxygenase 2 (HMOX2); and UDP glucuronosyltransferase 1 family, polypeptide A1 (UGT1A1)] were also greatly increased from 3 wk antepartum to 1 wk postpartum. From 1 wk postpartum to later lactation, mRNA abundances of all the Nrf2-target genes considered declined but remained at levels that were higher than those in 3 wk antepartum. No correlations were found, however, between plasma concentrations of nonesterified fatty acids or ß-hydroxybutyrate and mRNA abundances of Nrf2 target genes, indicating that a negative energy balance might not have been the main factor responsible for upregulation of those genes in the liver during early lactation. In conclusion, this study provides additional evidence that the periparturient phase in dairy cows is associated with a proinflammatory condition in the liver. Moreover, it is shown for the first time that the transition from pregnancy to lactation leads to a strong upregulation of Nrf2 target genes with antioxidative or cytoprotective properties, which might be another physiologic means to prevent the liver against damage by the inflammation process and an increased generation of reactive oxygen species.


Assuntos
Lactação/metabolismo , Fígado/metabolismo , Fator 2 Relacionado a NF-E2/genética , Proteínas de Fase Aguda/metabolismo , Proteínas de Fase Aguda/fisiologia , Animais , Proteína C-Reativa/metabolismo , Proteína C-Reativa/fisiologia , Bovinos , Feminino , Regulação da Expressão Gênica/fisiologia , Haptoglobinas/metabolismo , Haptoglobinas/fisiologia , Lactação/fisiologia , Fígado/fisiologia , Fator 2 Relacionado a NF-E2/biossíntese , Fator 2 Relacionado a NF-E2/fisiologia , Período Periparto/metabolismo , Período Periparto/fisiologia , Período Pós-Parto/metabolismo , Período Pós-Parto/fisiologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/fisiologia
15.
J Dairy Sci ; 96(8): 5008-17, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23746584

RESUMO

During the transition period, the lipid metabolism of dairy cows is markedly affected by energy status. Fatty liver is one of the main health disorders after parturition. The aim of this study was to evaluate the effects of a negative energy balance (NEB) at 2 stages in lactation [NEB at the onset of lactation postpartum (p.p.) and a deliberately induced NEB by feed restriction near 100 d in milk] on liver triglyceride content and parameters of lipid metabolism in plasma and liver based on mRNA abundance of associated genes. Fifty multiparous dairy cows were studied from wk 3 antepartum to approximately wk 17 p.p. in 2 periods. According to their energy balance in period 1 (parturition to wk 12 p.p.), cows were allocated to a control (CON; n=25) or a restriction group (RES; 70% of energy requirements; n=25) for 3 wk in mid lactation starting at around 100 d in milk (period 2). Liver triglyceride (TG) content, plasma nonesterified fatty acids (NEFA), and ß-hydroxybutyrate were highest in wk 1 p.p. and decreased thereafter. During period 2, feed restriction did not affect liver TG and ß-hydroxybutyrate concentration, whereas NEFA concentration was increased in RES cows as compared with CON cows. Hepatic mRNA abundances of tumor necrosis factor α, ATP citrate lyase, mitochondrial glycerol-3-phosphate acyltransferase, and glycerol-3-phosphate dehydrogenase 2 were not altered by lactational and energy status during both experimental periods. The expression of fatty acid synthase was higher in period 2 compared with period 1, but did not differ between RES and CON groups. The mRNA abundance of acetyl-coenzyme A-carboxylase showed a tendency toward higher expression during period 2 compared with period 1. The solute carrier family 27 (fatty acid transporter), member 1 (SLC27A1) was upregulated in wk 1 p.p. and also during feed restriction in RES cows. In conclusion, the present study shows that a NEB has different effects on hepatic lipid metabolism and TG concentration in the liver of dairy cows at early and later lactation. Therefore, the homeorhetic adaptations during the periparturient period trigger excessive responses in metabolism, whereas during the homeostatic control of endocrine and metabolic systems after established lactation, as during the period of feed restriction in the present study, organs are well adapted to metabolic and environmental changes.


Assuntos
Bovinos/metabolismo , Gorduras/análise , Privação de Alimentos/fisiologia , Lactação/metabolismo , Metabolismo dos Lipídeos/fisiologia , Fígado/química , Ácido 3-Hidroxibutírico/análise , Ácido 3-Hidroxibutírico/sangue , Animais , Bovinos/fisiologia , Metabolismo Energético/fisiologia , Ácidos Graxos não Esterificados/sangue , Feminino , Lactação/fisiologia , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Triglicerídeos/análise , Triglicerídeos/sangue
16.
J Dairy Sci ; 96(7): 4568-77, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23684024

RESUMO

The objective of this study was to improve knowledge regarding the amino acid profile of the insoluble portion of ingested forage escaping rumen degradation. Six forage categories were analyzed. Categories varied in botanical composition and each contained 2 samples. Samples within categories were derived from the same parent material but differed in harvest, maturity, or conservation type. The rumen-undegradable protein of all forages was measured by incubation for 16h in the rumen of 3 nonlactating cows. All residues were corrected for microbial colonization. The AA profile of the residue was different to the original profile. Degradation trends of individual AA, in terms of increase or decrease relative to the original concentration, were similar between all forages. The AA profiles of forage residues, both within and between categories, were more similar to each other than to their respective original profile. This information may aid in improving the accuracy of estimating postruminal AA supply from forages while decreasing the number of samples required to be analyzed.


Assuntos
Aminoácidos/análise , Ração Animal/análise , Proteínas Alimentares/química , Proteínas Alimentares/metabolismo , Rúmen/metabolismo , Animais , Bovinos , Digestão , Feminino , Fermentação , Lolium/química , Lolium/metabolismo , Medicago/química , Medicago/metabolismo , Medicago sativa/química , Medicago sativa/metabolismo , Rúmen/microbiologia , Solubilidade
17.
Radiologe ; 53(1): 15-23, 2013 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-23338245

RESUMO

Hypertrophic cardiomyopathy (HCM) has a prevalence of approximately 0.2% and is clinically asymptomatic in many patients or presents with unspecific symptoms. This explains the importance of imaging for the diagnosis of HCM as well as for the assessment of the clinical course. The definitive finding in HCM is myocardial hypertrophy with thickening of the ventricular wall ≥ 15 mm. While echocardiography is an excellent screening tool magnetic resonance imaging (MRI) allows a comprehensive analysis of the heart in HCM. This includes a detailed analysis of the distribution and extent of myocardial hypertrophy, a thorough evaluation of systolic and diastolic cardiac function, the assessment of the presence and extent of dynamic outflow tract obstruction as well as the description of the systolic anterior motion (SAM) phenomenon of the mitral valve with secondary mitral insufficiency. When contrast material is administered, additional information about myocardial perfusion as well as the presence and extent of myocardial fibrosis can be obtained. This study compared systolic functional parameters as well as end systolic and end diastolic wall thickness of patients with and without diastolic dysfunction.


Assuntos
Cardiomiopatia Hipertrófica/complicações , Cardiomiopatia Hipertrófica/diagnóstico , Imagem Cinética por Ressonância Magnética/métodos , Volume Sistólico , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/etiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
18.
Schmerz ; 27(2): 129-34, 2013 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-23539274

RESUMO

Sectorally segregated healthcare structures are seen as a major reason for deficits in quality and efficiency. With the introduction of §§ 140 a ff. SGB V, the sectoral splitting into outpatient, inpatient and rehabilitative services will be eliminated. This is especially true for the requirements of state-of-the-art multidisciplinary and comprehensive pain therapy. Through this form of contract competition and competition for the best idea, incentives shall be created for economic behaviour of market participants, above all the efficient use of limited resources and allocation of healthcare resources based on need. Selective contracts are essential competition parameters for continued innovative development of the healthcare system. They enable statutory healthcare providers to offer their insurants innovative treatments which are not available in standard care. Agreements can be made concerning higher levels of quality and healthcare services, incentives for economical behaviour and success-based payment models. The key idea is the orientation on the needs of the insurant. The successful realisation of innovation in pain therapy is described using a practical example. Professional contractual partners, high quality information and communication, the taking over of responsibility for treatment and cost effectiveness are factors essential the success of innovative treatment concepts.


Assuntos
Prestação Integrada de Cuidados de Saúde/métodos , Programas Nacionais de Saúde/legislação & jurisprudência , Manejo da Dor/métodos , Terapias em Estudo/métodos , Comportamento Cooperativo , Análise Custo-Benefício/economia , Análise Custo-Benefício/legislação & jurisprudência , Prestação Integrada de Cuidados de Saúde/economia , Prestação Integrada de Cuidados de Saúde/legislação & jurisprudência , Alemanha , Alocação de Recursos para a Atenção à Saúde/economia , Alocação de Recursos para a Atenção à Saúde/legislação & jurisprudência , Setor de Assistência à Saúde/economia , Setor de Assistência à Saúde/legislação & jurisprudência , Necessidades e Demandas de Serviços de Saúde/economia , Necessidades e Demandas de Serviços de Saúde/legislação & jurisprudência , Humanos , Comunicação Interdisciplinar , Programas Nacionais de Saúde/economia , Manejo da Dor/economia , Reembolso de Incentivo/economia , Reembolso de Incentivo/legislação & jurisprudência , Terapias em Estudo/economia
19.
J Anim Physiol Anim Nutr (Berl) ; 97(5): 820-9, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22805261

RESUMO

Fibroblast growth factor 21 (FGF21) has been identified as a novel hormonal factor involved in the regulation of metabolic adaptations during energy deprivation. The present study aimed to investigate the expression of the FGF21 gene in the liver of dairy cows during the transition from pregnancy to lactation. Therefore, the relative mRNA abundance of FGF21 in liver biopsy samples of 20 dairy cows in late pregnancy (3 weeks pre-partum) and early lactation (1, 5, 14 weeks post-partum) was determined. It was observed that hepatic mRNA abundance of FGF21 at 1 week post-partum was dramatically increased (110-fold) compared to 3 weeks pre-partum (p < 0.001). With progress of lactation, mRNA concentration of FGF21 was declining; nevertheless, mRNA abundance at 5 and 14 weeks post-partum remained 25- and 10-fold increased compared to 3 weeks pre-partum (p < 0.001). Using a gene array technique, it was found that many genes involved in fatty acid oxidation, gluconeogenesis and ketogenesis were up-regulated during early lactation compared to late pregnancy. Moreover, there were positive linear correlations between hepatic mRNA concentration of FGF21 and mRNA concentrations of genes involved in ketogenesis as well as carnitine synthesis and carnitine uptake at various time-points during lactation, indicating that FGF21 could play a role in ketogenesis and carnitine metabolism in the liver of dairy cows (p < 0.05). In overall, the present study shows that expression of the FGF21 gene is strongly up-regulated during the transition period. It is assumed that the up-regulation of FGF21 might play an important role in the adaptation of liver metabolism during early lactation in dairy cows such as in other species.


Assuntos
Bovinos/fisiologia , Fatores de Crescimento de Fibroblastos/metabolismo , Lactação/fisiologia , Fígado/metabolismo , Animais , Feminino , Fatores de Crescimento de Fibroblastos/genética , Regulação da Expressão Gênica/fisiologia , Humanos , Período Pós-Parto/fisiologia , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
20.
J Anim Physiol Anim Nutr (Berl) ; 97(6): 1104-13, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23216628

RESUMO

The effects of non-starch-polysaccharide-degrading enzymes, added to a maize silage- and grass silage-based total mixed ration (TMR) at least 14 h before feeding, on the rumen bacterial population were investigated. Six non-lactating Holstein Friesian cows were allocated to three treatment groups using a duplicate 3 × 3 Latin square design with three 31-day periods (29 days of adaptation and 2 days of sampling). Treatments were control TMR [69% forage and 31% concentrates on a dry matter (DM) basis] or TMR with 13.8 or 27.7 ml/kg of feed DM of Roxazyme G2 liquid with activities (U/ml enzyme preparation) of xylanase 260 000, ß-glucanase 180 000 and cellulase 8000 (DSM Nutritional Products, Basel, Switzerland). The concentrations of 16S rDNA of Anaerovibrio lipolytica, Fibrobacter succinogenes, Prevotella ruminicola, Ruminococcus flavefaciens, Selenomonas ruminantium and Treponema bryantii, and their relative percentage of total bacteria in rumen samples obtained before feeding and 3 and 7 h after feeding and from two rumen fractions were determined using real-time PCR. Sampling time had only little influence, but bacterial numbers and the composition of the population differed between the transition layer between rumen fluid and the fibre mat (fraction A) and the rumen fluid (fraction B) highlighting the importance to standardize sampling. The 16S rDNA copies of total bacteria and the six bacterial species as well as the population composition were mainly unaffected by the high levels of exogenous enzymes supplemented at all sampling times and in both rumen fractions. Occasionally, the percentages of the non-fibrolytic species P. ruminicola and A. lipolytica changed in response to enzyme supplementation. Some increases in the potential degradability of the diet and decreases in lag time which occurred collaterally indicate that other factors than changes in numbers of non-particle-associated bacteria are mainly responsible for the effects of exogenous enzymes.


Assuntos
Ração Animal/análise , Bovinos/fisiologia , Enzimas/metabolismo , Enzimas/farmacologia , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Rúmen/microbiologia , Animais , Bovinos/microbiologia , Estudos Cross-Over , Dieta/veterinária , Suplementos Nutricionais , Enzimas/química , Feminino , Aditivos Alimentares/metabolismo , Lactação/fisiologia
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