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PURPOSE OF THE REVIEW: Cardiac pacing has evolved in recent years currently culminating in the specific stimulation of the cardiac conduction system (conduction system pacing, CSP). This review aims to provide a comprehensive overview of the available literature on CSP, focusing on a critical classification of studies comparing CSP with standard treatment in the two fields of pacing for bradycardia and cardiac resynchronization therapy in patients with heart failure. The article will also elaborate specific benefits and limitations associated with CSP modalities of His bundle pacing (HBP) and left bundle branch area pacing (LBBAP). RECENT FINDINGS: Based on a growing number of observational studies for different indications of pacing therapy, both CSP modalities investigated are advantageous over standard treatment in terms of narrowing the paced QRS complex and preserving or improving left ventricular systolic function. Less consistent evidence exists with regard to the improvement of heart failure-related rehospitalization rates or mortality, and effect sizes vary between HBP and LBBAP. LBBAP is superior over HBP in terms of lead measurements and procedural duration. With regard to all reported outcomes, evidence from large scale randomized controlled clinical trials (RCT) is still scarce. CSP has the potential to sustainably improve patient care in cardiac pacing therapy if patients are appropriately selected and limitations are considered. With this review, we offer not only a summary of existing data, but also an outlook on probable future developments in the field, as well as a detailed summary of upcoming RCTs that provide insights into how the journey of CSP continues.
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Bradicardia , Estimulação Cardíaca Artificial , Terapia de Ressincronização Cardíaca , Insuficiência Cardíaca , Humanos , Insuficiência Cardíaca/terapia , Insuficiência Cardíaca/fisiopatologia , Terapia de Ressincronização Cardíaca/métodos , Estimulação Cardíaca Artificial/métodos , Bradicardia/terapia , Bradicardia/fisiopatologia , Sistema de Condução Cardíaco/fisiopatologia , Fascículo Atrioventricular/fisiopatologia , Resultado do TratamentoRESUMO
BACKGROUND: Emerging evidence indicates combination therapy with anticoagulants and antiplatelet agents for atrial fibrillation (AF) will be increasingly required. Numerous studies compare the efficacy and cost-effectiveness of anticoagulation alone in AF, i.â¯e., non-vitamin K oral anticoagulants (NOACs) vs. warfarin. However, the addition of antiplatelet agents with their potential for decreasing thromboembolic stroke counter-balanced by an increased bleeding risk has received less attention. Thus, we evaluated the cost-utility of this combination therapy. METHOD AND RESULTS: We obtained event estimates from our recent meta-analysis of four randomized clinical trials designed to compare NOACs with warfarin in patients with AF. We examined patient subgroups within each trial that received antiplatelet therapy in addition to anticoagulation. Utilities were derived from the literature and cost estimates from the German health-care system. A decision tree was constructed and populated with these parameters. We used a 1-year time horizon because combination therapy is not recommended beyond this time. We calculated the incremental cost-effectiveness ratio (ICER) per quality-adjusted life-year (QALY). The derived ICER was 13,168.50⯠per QALY. NOAC prices exerted considerable influence on the calculation. Nevertheless, there is potential for ICER shifts in favor of warfarin, e.g., if warfarin-mediated anticoagulation control is improved and thereby adverse events decrease. Conversely, if NOAC adherence decreases, adverse events could increase. CONCLUSION: The derived ICER was 13,168.50⯠per QALY, consistent with NOACs being cost-effective vs. warfarin when anticoagulation is used with antiplatelet agents. Nevertheless, country-, practice-, and patient-related factors influence the ICER. Our cost-utility calculation should be used a starting point for decision-making.
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Fibrilação Atrial , Acidente Vascular Cerebral , Administração Oral , Anticoagulantes/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Humanos , Inibidores da Agregação Plaquetária/uso terapêutico , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/prevenção & controle , Vitamina K , Varfarina/uso terapêuticoRESUMO
Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown origin. Previous bile proteomic analyses in patients with PSC have revealed changes in disease activity specific to malignant transformation. In this study, we established a reference bile duct-derived bile proteome for PSC that can be used to evaluate biliary pathophysiology. Samples were collected from patients with PSC or with choledocholithiasis (control) (n=6 each). Furthermore, patients with PSC-associated cholangiocarcinoma (CC) and with CC without concomitant PSC were analyzed. None of the patients showed signs of inflammation or infection based on clinical and laboratory examinations. Proteins overexpressed in patients with PSC relative to control patients were detected by two-dimensional difference gel electrophoresis and identified by liquid chromatography-tandem mass spectrometry. Functional proteomic analysis was performed using STRING software. A total of 101 proteins were overexpressed in the bile fluid of patients with PSC but not in those of controls; the majority of these were predicted to be intracellular and related to the ribosomal and proteasomal pathways. On the other hand, 91 proteins were found only in the bile fluid of controls; most were derived from the extracellular space and were linked to cell adhesion, the complement system, and the coagulation cascade. In addition, proteins associated with inflammation and the innate immune response-e.g., cluster of differentiation 14, annexin-2, and components of the complement system-were upregulated in PSC. The most prominent pathways in PSC/CC-patients were inflammation associated cytokine and chemokine pathways, whereas in CC-patients the Wnt signaling pathway was upregulated. In PSC/CC-patients DIGE-analysis revealed biliary CD14 and Annexin-4 expression, among others, as the most prominent protein that discriminates between both cohorts. Thus, the bile-duct bile proteome of patients with PSC shows disease-specific changes associated with inflammation and the innate immune response even in the absence of obvious clinical signs of cholangitis, malignancy, or inflammation. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by Jesus Banales, Marco Marzioni and Peter Jansen.
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Neoplasias dos Ductos Biliares/metabolismo , Ductos Biliares/metabolismo , Bile/química , Colangiocarcinoma/metabolismo , Colangite Esclerosante/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Bile/imunologia , Neoplasias dos Ductos Biliares/imunologia , Neoplasias dos Ductos Biliares/patologia , Ductos Biliares/patologia , Estudos de Casos e Controles , Colangiocarcinoma/imunologia , Colangiocarcinoma/patologia , Colangite Esclerosante/imunologia , Colangite Esclerosante/patologia , Coledocolitíase/metabolismo , Coledocolitíase/patologia , Estudos de Coortes , Citocinas/análise , Citocinas/imunologia , Citocinas/metabolismo , Feminino , Humanos , Imunidade Inata , Receptores de Lipopolissacarídeos , Masculino , Pessoa de Meia-Idade , Proteômica , Regulação para Cima , Via de Sinalização Wnt/imunologiaRESUMO
How fluid resuscitation has to be performed for acute hemorrhage situations is still controversially discussed. Although the forced administration of crystalloids and colloids has been and still is practiced, nowadays there are good arguments that a cautious infusion of crystalloids may be initially sufficient. Saline should no longer be used for fluid resuscitation. The main argument for cautious fluid resuscitation is that no large prospective randomized clinical trials exist which have provided evidence of improved survival when fluid resuscitation is applied in an aggressive manner. The explanation that no positive effect has so far been observed is that fluid resuscitation is thought to boost bleeding by increasing blood pressure and dilutional coagulopathy. Nevertheless, national and international guidelines recommend that fluid resuscitation should be applied at the latest when hemorrhage causes hemodynamic instability. Consideration should be given to the fact that damage control resuscitation per se will neither improve already reduced tissue perfusion nor hemostasis. In acute and possibly rapidly progressing hypovolemic shock, colloids can be used. The third and fourth generations of hydroxyethyl starch (HES) are safe and effective if used correctly and within prescribed limits. If fluid resuscitation is applied with ongoing re-evaluation of the parameters which determine oxygen supply, it should be possible to keep fluid resuscitation restricted without causing undesirable side effects and also to administer a sufficient quantity so that survival of patients is ensured.
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Hidratação/métodos , Hemorragia/terapia , Ressuscitação/métodos , Substitutos Sanguíneos , Volume Sanguíneo , Hemorragia/fisiopatologia , HumanosRESUMO
In western countries one in ten of elderly persons (> 65 years old) will develop atrial fibrillation. The main goal in atrial fibrillation therapy is the prophylaxis of thromboembolic complications through anticoagulation according to the individual risk profile (CHA2DS2-Vasc score) of patients and treatment of cardiovascular comorbidities. Symptoms during atrial fibrillation guide the further therapeutic concept. Doctors can deploy a rate control strategy with a heart rate at rest less than 110/min and/or a rhythm control strategy with cardioversion, antiarrhythmic drugs and catheter ablation to alleviate complaints. To what extent maintaining the sinus rhythm improves the prognosis of atrial fibrillation patients is part of ongoing trials.
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Antiarrítmicos/administração & dosagem , Anticoagulantes/administração & dosagem , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/prevenção & controle , Tromboembolia/etiologia , Tromboembolia/prevenção & controle , Fibrilação Atrial/complicações , Doenças das Valvas Cardíacas/complicações , HumanosRESUMO
The proinflammatory cytokine interleukin-1ß (IL-1ß) is known to be upregulated in patients suffering from metabolic syndrome. IL-1ß contributes to insulin resistance in obesity and type 2 diabetes, yet its influence on the intestinal microbiome is incompletely understood. The data presented here demonstrate that mice genetically deficient in IL-1ß show a specific alteration of intestinal colonisation of a small group of bacteria. Especially Akkermansia muciniphila, a bacterium reported to be inversely associated with obesity, diabetes, cardiometabolic diseases and low-grade inflammation, showed increased colonisation in IL-1ß knockout mice. In comparative microarray analysis from mucus scrapings of the colon mucosa of IL-1ß knockout and wildtype mice, angiogenin 4 mRNA was strongly reduced in IL-1ß knockout animals. Since the presence of angiogenin 4 in the culture medium showed a significant growth inhibition on A. muciniphila which was not detectable for other bacteria tested, IL-1ß induced expression of angiogenin 4 is a strong candidate to be responsible for the IL-1ß induced suppression of A. muciniphila colonisation. Thus, the data presented here indicate that IL-1ß might be the lacking link between inflammation and suppression of A. muciniphila abundance as observed in a variety of chronic inflammatory disorders.
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Akkermansia , Microbioma Gastrointestinal , Interleucina-1beta , Animais , Camundongos , Akkermansia/genética , Colo/microbiologia , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Mucosa Intestinal/microbiologia , Mucosa Intestinal/metabolismo , Camundongos Endogâmicos C57BL , Ribonuclease Pancreático/genética , Ribonuclease Pancreático/metabolismoRESUMO
In radiotherapy the normal tissue reaction is often a limiting factor for radiation treatment. Still there is no screening method, which predicts normal tissue reaction on radiotherapy, especially in comparison to tumor tissue, and therefore allows tailoring of the radiation dose to each patient. Here, we present a case of severe radiation-related side effects. We applied classical cytogenetic techniques (Giemsa-banding and staining of centromeric regions), the comet assay as well as multicolor fluorescence in situ hybridization on peripheral blood lymphocytes of this patient in order to determine the radio-sensitivity on the DNA level and to correlate these findings with the clinical outcome. Our investigations revealed abnormalities on chromosome 9, deficiencies in the DNA-repair capacity after radiation exposure and a high number of radiation induced chromosomal aberrations. A detected high amount of residual damage two or three hours after radiation exposure and repair as well as the high number of chromosomal aberrations (ChAs) suggests a correlation between repair capacity and radiation induced ChAs. We concluded that the detected abnormalities might serve as a genetic basis for the radio-sensitive phenotype of this patient. Taken together this report strengthens the idea that intensive DNA genomic analysis of individual patients can serve as the basis for more favourable treatment of cancer patients.
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Systemic toxicity and tumor cell resistance still limit the efficacy of chemotherapy in colorectal cancer. Therefore, alternative treatments are desperately needed. The thiazolide Nitazoxanide (NTZ) is an FDA-approved drug for the treatment of parasite-mediated infectious diarrhea with a favorable safety profile. Interestingly, NTZ and the thiazolide RM4819-its bromo-derivative lacking antibiotic activity-are also promising candidates for cancer treatment. Yet the exact anticancer mechanism(s) of these compounds still remains unclear. In this study, we systematically investigated RM4819 and NTZ in 2D and 3D colorectal cancer culture systems. Both compounds strongly inhibited proliferation of colon carcinoma cell lines by promoting G1 phase cell cycle arrest. Thiazolide-induced cell cycle arrest was independent of the p53/p21 axis, but was mediated by inhibition of protein translation via the mTOR/c-Myc/p27 pathway, likely caused by inhibition of mitochondrial respiration. While both thiazolides demonstrated mitochondrial uncoupling activity, only RM4819 inhibited the mitochondrial respiratory chain complex III. Interestingly, thiazolides also potently inhibited the growth of murine colonic tumoroids in a comparable manner with cisplatin, while in contrast to cisplatin thiazolides did not affect the growth of primary intestinal organoids. Thus, thiazolides appear to have a tumor-selective antiproliferative activity, which offers new perspectives in the treatment of colorectal cancer.
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Neoplasias Colorretais/genética , Transporte de Elétrons/genética , Pontos de Checagem da Fase G1 do Ciclo Celular/genética , Membranas Mitocondriais/metabolismo , Tiazóis/uso terapêutico , Animais , Humanos , Camundongos , Tiazóis/químicaRESUMO
To determine the extensions of cavities prepared conventionally by bur or by a fluorescence-controlled Er:YAG laser. Sixty-five human teeth with dentine caries were bisected through the caries lesion and were treated by a fluorescence-controlled Er:YAG laser in a non-contact or a contact mode or by a rotary bur. The specimens were subjected to histological staining and a quantitative evaluation of cavity area (mm(2)) by computer-assisted alignment. Data were tested for statistical significant differences by the Wilcoxon test (p < 0.05). Twenty-three out of 29 cavities were smaller after caries removal with the non-contact laser compared to the bur. For a threshold level of seven, a cavity size difference of 1.63 (1.86) mm(2) was calculated compared to a cavity size difference of 5.35 (5.05) mm(2) after bur excavation. The differences were statistically significant (p = 0.029). No significant differences were observed between the cavity size differences after excavation with the non-contact or the contact laser handpiece. Residual bacteria within the cavity floor were found only in low numbers after all treatments. The present in vitro study indicates that caries removal by a fluorescence-controlled Er:YAG laser using a threshold level of seven resulted in less dentine loss than preparations by a bur.
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Preparo da Cavidade Dentária/instrumentação , Testes de Atividade de Cárie Dentária , Preparo da Cavidade Dentária/métodos , Equipamentos Odontológicos de Alta Rotação , Dentina/microbiologia , Fluorescência , Humanos , Processamento de Imagem Assistida por Computador , Lasers de Estado SólidoRESUMO
BACKGROUND: The goal was to test the effectiveness of a structured pain management programme after invasive electrophysiological interventions in cardiology including ablation of atrial fibrillation (AF) or ventricular tachycardia (VT) and implantation, or explantation, of pacemakers or implantable cardioverter defibrillators. METHODS: This was a prospective study with a pre-/post-design where a post-intervention group (116 consecutive patients) was compared to a pre-intervention group (102 consecutive patients) after implementation of a structured pain-management programme using the numeric rating scale (NRS 0-10) and classified as moderate-to-severe if NRS > 3. Measurements were recorded every two hours during the first 24 h post-operatively. The location of the pain and the amount of analgesic used were also recorded. RESULTS: The proportion of patients who experienced moderate-to-severe pain after the procedure decreased after initiation of the pain-management program: 47% versus 61%; p = 0.048. This difference was driven primarily by reduced pain late (8-24 h) after the procedure; 16% versus 39%; p < 0.001. The risk to develop late (8-24 h) post-procedural pain was reduced approximately three-fold after implementation of the pain-management programme (OR = 0.32, 95% CI 0.16-0.64, p = 0.001). Multivariate analysis indicated chronic pain, early pain (0-6 h), and type of intervention were associated with late post-interventional pain. In contrast, age, diabetes mellitus, BMI, gender and procedure time were not related. CONCLUSION: The findings illustrate the potential value of a structured pain-management programme. The proportion of patients who experienced moderate-to-severe pain after these electrophysiological procedures decreased significantly. SIGNIFICANCE: This is the first exploratory study that evaluates the impact of a multidisciplinary pain-management programme after cardiac electrophysiological interventions. It demonstrates that significant quality improvement is achievable following simple rules together with patient and staff education. The programme reduces the proportion of patients with moderate-to-severe pain after electrophysiological procedures significantly.
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Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Ablação por Cateter/efeitos adversos , Manejo da Dor , Dor Pós-Operatória/terapia , Idoso , Idoso de 80 Anos ou mais , Analgésicos/uso terapêutico , Estudos Controlados Antes e Depois , Desfibriladores Implantáveis , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor Pós-Operatória/etiologia , Estudos Prospectivos , Resultado do TratamentoRESUMO
BACKGROUND: Coronary artery bypass grafting (CABG) using cardiopulmonary bypass (CPB) provides controlled operative conditions but induces a whole-body inflammatory response capable of initiating devastating morbidity and mortality. Although technically more demanding, deliberate avoidance of CPB in off-pump surgery attenuates the physiological insult associated with CABG. METHODS AND RESULTS: To systematically assess the molecular mechanisms underlying the better-preserved remote organ function, we studied gene expression patterns in leukocytes and plasma proteomic response to on-pump and off-pump CABG. Proteomic analysis confirmed (tumor necrosis factor-alpha, interleukin [IL]-6, IL-10) and expanded (eg, interferon [IFN]-gamma, granulocyte colony-stimulating factor [G-CSF], monocyte chemotactic protein-1, macrophage inflammatory protein-1beta) the mediators released on CPB, whereas blood leukocyte transcriptomics suggested that circulating leukocytes are not primarily responsible for this response. Interestingly, release of some cytokines (eg, IL-6, IFN-gamma, G-CSF) was observed on off-pump surgery to a similar extent but with delayed kinetics. A total of 45 of 4868 transcripts were identified to be significantly altered as a result of initiation of CPB. Systematic analysis of transcriptional activation by CPB revealed primarily genes involved in inflammation-related cell-cell communication (such as L-selectin or intercellular adhesion molecule-2) and signaling (such as IL-1, IL-8, or IL-18 receptors and toll-like receptors 4, 5, and 6), thus confirming a "primed" phenotype of circulating peripheral blood mononuclear cells. CONCLUSIONS: Gene array and multiplex protein analysis, only in concert, can illuminate the molecular mechanisms responsible for systemic sequelae of CPB and indicate that circulating leukocytes overexpress adhesion and signaling factors after contact with CPB, which potentially facilitates their trapping, eg, in the lungs and may promote a subsequent tissue-associated inflammatory response.
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Ponte de Artéria Coronária/efeitos adversos , Inflamação/genética , Proteoma/genética , Transcrição Gênica , Animais , Ponte de Artéria Coronária/métodos , Modelos Animais de Doenças , Cães , Ecocardiografia , Estimulação Elétrica , Inflamação/etiologia , Técnicas de Patch-ClampRESUMO
The existence in higher plants of an additional beta-oxidation system in mitochondria, besides the well-characterized peroxisomal system, is often considered controversial. Unequivocal demonstration of beta-oxidation activity in mitochondria should rely on identification of the enzymes specific to mitochondrial beta-oxidation. Acyl-coenzyme A dehydrogenase (ACAD) (EC 1.3.99.2,3) activity was detected in purified mitochondria from maize (Zea mays L.) root tips and from embryonic axes of early-germinating sunflower (Helianthus annuus L.) seeds, using as the enzyme assay the reduction of 2,6-dichlorophenolindophenol, with phenazine methosulfate as the intermediate electron carrier. Subcellular fractionation showed that this ACAD activity was associated with mitochondrial fractions. Comparison of ACAD activity in mitochondria and acyl-coenzyme A oxidase activity in peroxisomes showed differences of substrate specificities. Embryonic axes of sunflower seeds were used as starting material for the purification of ACADs. Two distinct ACADs, with medium-chain and long-chain substrate specificities, respectively, were separated by their chromatographic behavior, which was similar to that of mammalian ACADs. The characterization of these ACADs is discussed in relation to the identification of expressed sequenced tags corresponding to ACADs in cDNA sequence analysis projects and with the potential roles of mitochondrial beta-oxidation in higher plants.
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Whether or not adrenal medullary (chromaffin) cells which respond to nerve growth factor (NGF) both in vitro and in vivo require NGF for their normal development is controversial. Systemic deprivation of endogenous NGF by injection of anti-NGF antibodies into rat fetuses or by transfer of anti-NGF to the offspring of autoimmunized mothers has provided conflicting results. We have reinvestigated the effects of a specific antiserum to NGF on the morphology, catecholamine (CA) and neuropeptide (Met-enkephalin, Met-ENK; substance P, SP) content, and choline acetyltransferase (ChAT) activity of the rat adrenal medulla. Fetuses were injected with anti-NGF antibodies on day 17 of gestation and postnatally at daily intervals for 7 days. The histological appearance of adrenal medullae of anti-NGF injected animals was not altered as compared to controls. Ultrastructurally, no degenerative changes or developmental retardation of chromaffin cells could be detected. However, numbers of chromaffin granules per micron 2 of cytoplasmic area were greater and the mean diameters of the cores of adrenaline storage granules were smaller in antibody-treated than in control animals. CA and SP content, ratios of adrenaline to noradrenaline and ChAT activities were identical in anti-NGF-treated and control animals. Anti-NGF antibodies caused a reduction of adrenal Met-ENK by 40% as compared to controls. Superior cervical ganglia from the same animals were used to document immunosympathectomy induced by the antiserum. They displayed the well-established structural alterations and a marked reduction of the CA content. We conclude that administration of anti-NGF antibodies to embryonic and early postnatal rats induces only subtle changes in the ultramorphology of chromaffin cells without altering the development of normal CA levels. The small, yet significant effects of anti-NGF antibodies on adrenal Met-ENK, however, may suggest a role for endogenous NGF in the regulation of opioid peptide metabolism in developing chromaffin cells.
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Medula Suprarrenal/crescimento & desenvolvimento , Fatores de Crescimento Neural/fisiologia , Medula Suprarrenal/análise , Animais , Anticorpos , Colina O-Acetiltransferase/metabolismo , Encefalina Metionina/análise , Microscopia Eletrônica , Fatores de Crescimento Neural/imunologia , Ratos , Ratos Endogâmicos , Substância P/análiseRESUMO
PURPOSE: To analyse spectra of chromosome aberrations induced in vitro by low LET radiation, in order to characterize radiation damage mechanisms quantitatively. METHODS: Multiplex fluorescence in situ hybridization (mFISH) allows the simultaneous identification of each homologous chromosome pair by its own colour. mFISH data, specifying number distributions for colour junctions in metaphases of human peripheral blood lymphocytes 72 hours after exposure in vitro to a 3 Gy gamma-ray dose, were combined with similar, previously published results. Monte Carlo computer implementations of radiobiological models for chromosome aberration production guided quantitative analyses, which took into account distribution of cells among different metaphases and lethal effects or preferential elimination of some aberrations at cell division. RESULTS AND CONCLUSIONS: Standard models of DNA damage induction/repair/misrepair explain the main trends of the data as regards the fraction of metaphases having a particular number of colours involved in colour junctions. However, all standard models systematically under-predict the observed fraction of metaphases where a large number of different chromosomes participate in aberrations. An early appearance of chromosomal instability could explain most of the discrepancies.
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Aberrações Cromossômicas , Cromossomos/efeitos da radiação , Cromossomos/ultraestrutura , Hibridização in Situ Fluorescente/métodos , Dano ao DNA , Reparo do DNA , Humanos , Linfócitos/ultraestrutura , Metáfase , Modelos Genéticos , Método de Monte Carlo , Software , Fatores de TempoRESUMO
PURPOSE: Analysing chromosome aberrations induced by low linear energy transfer (LET) radiation in order to characterize systematic spatial clustering among the 22 human autosomes in human lymphocytes and to compare their relative participation in interchanges. MATERIALS AND METHODS: A multicolour fluorescence in situ hybridization (mFISH) data set, specifying colour junctions in metaphases of human peripheral blood lymphocytes 72 h after in vitro exposure to low LET radiation, was analysed separately and in combination with previously published results. Monte Carlo computer simulations and mathematical modelling guided data analysis. RESULTS AND CONCLUSIONS: Statistical tests on aberration data confirmed two clusters of chromosomes, [1, 16, 17, 19, 22] and [13, 14, 15, 21, 22], as having their members being on average closer to each other than randomness would predict. The first set has been reported previously to be near the centre of the interphase nucleus and to be formed mainly by gene-rich chromosomes, while the second set comprises the nucleolus chromosomes. The results suggest a possible interplay between chromosome positioning and transcription. A number of other clusters suggested in the literature were not confirmed and considerable randomness of chromosome-chromosome juxtapositions was present. In addition, and consistent with previous results, it was found that chromosome participation in interchanges is approximately proportional to the two-thirds power of the DNA content.
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Aberrações Cromossômicas , Cromossomos Humanos/efeitos da radiação , DNA/análise , Feminino , Humanos , Masculino , Tolerância a RadiaçãoRESUMO
BACKGROUND: A recent genome-wide association study identified the FUT2 secretor status and genotype defined by the single-nucleotide polymorphism rs601338 as potential genetic risk factor in primary sclerosing cholangitis (PSC), which significantly influences biliary bacterial composition. AIM: To determine the impact of the rs601338-FUT2 genotype on frequency of biliary infections, development of dominant stenosis and liver-transplantation-free survival in patients with PSC. METHODS: Cohort study of 215 patients with PSC treated at our tertiary care centre with respect to their rs601338-FUT2 genotype. Results of endoscopic retrograde cholangiography and bile culture were analysed; 639 biliary samples were obtained, cultured and subjected to microbial analysis. Clinical and laboratory data were analysed using chart reviews. RESULTS: For the rs601338-FUT2 genotype, 69 patients (32.1%) were found to be wildtype (GG), 97 (45.1%) patients were heterozygous (AG) and 49 patients (22.8%) were homozygous-mutated (AA). In addition to alterations in the bacterial pattern, especially in heterozygous carriers, patients with mutated alleles had a marked increase in the frequency of biliary Candida infections (P = 0.025). Further, patients with mutated alleles showed an increased frequency of episodes of cholangitis (P = 0.0025), development of dominant stenosis (P < 0.002) and a reduced actuarial transplantation-free survival (P = 0.044). Levels of biliary Ca19-9 were significantly elevated in the homozygous-mutated patients. CONCLUSIONS: The rs601338-FUT2 genotype is strongly associated with episodes of cholangitis, fungobilia and the incidence of dominant stenosis, which are three clinical hallmarks of PSC; FUT2 is thus an important genetic risk factor for host-microbial diversity and disease progression in PSC.
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Candida/isolamento & purificação , Candidíase/epidemiologia , Colangite Esclerosante/complicações , Constrição Patológica/epidemiologia , Fucosiltransferases/genética , Adulto , Alelos , Bile/microbiologia , Candidíase/etiologia , Colangiografia/métodos , Colangite Esclerosante/genética , Colangite Esclerosante/microbiologia , Estudos de Coortes , Constrição Patológica/etiologia , Constrição Patológica/genética , Progressão da Doença , Feminino , Genótipo , Heterozigoto , Humanos , Incidência , Masculino , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos , Fatores de Risco , Galactosídeo 2-alfa-L-FucosiltransferaseRESUMO
The dipole interaction model is used to investigate the effects of interactions between helices and supertwisting of helices by determining whether the predicted UV absorption and CD spectra for the three-helix bundle and coiled coil are significantly different from spectra for the single straight alpha-helix. Crystallographic data by Yan et al. for alpha-spectrin are used to construct a three-helix bundle of poly(L-alanine) modeling the protein. Backbone torsion angles represented by Fourier series are used to generate supertwisted helices and coiled coil models of poly(L-alanine) that have pitch, radius, and residue repeat similar to experimental crystallographic data on tropomyosin. Calculated CD spectra are compared with available experimental data. Theoretical spectra for the three-helix bundle and the supertwisted structures are quite similar to predictions for the straight alpha-helix of the same length with similar torsion angles, suggesting that CD is primarily dependent on the average backbone conformation and would not be a sensitive tool for distinguishing between single straight helices and closely packed or twisted alpha-helices.
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Espectrina/química , Tropomiosina/química , Dicroísmo Circular , Conformação Proteica , Estrutura Secundária de Proteína , Espectrofotometria UltravioletaRESUMO
Medium- and short-chain acyl-CoA oxidases were identified in and subsequently purified from dark-grown maize plantlets. The oxidase showing preference for medium-chain fatty acyl-CoAs (C10-C14) was purified to homogeneity. The oxidase showing preference for short-chain fatty acyl-CoAs (C4-C8) was purified over 150-fold. Various catalytic properties confirmed these enzymes to be true acyl-CoA oxidases. They produced trans-2-enoyl-CoA and H2O2 from the saturated acyl-CoA, as verified by various independent assay techniques. They also exhibited FAD-dependent activity; i.e. removal of loosely bound FAD by gel filtration markedly reduced activity, which could be restored upon re-addition of FAD. They showed apparent Km values between 2 and 10 microM for the acyl-CoA substrate giving maximal activity, no activity with the corresponding free fatty acid, high pH optima (8.3-8.6) and a peroxisomal subcellular location. The medium-chain acyl-CoA oxidase was determined to be a monomeric protein with a molecular mass of 62 kDa. The short-chain acyl-CoA oxidase was shown to have a native molecular mass of 60 kDa, but exhibited a labile multimeric structure, as indicated by the elution of multiple peaks of activity during several chromatographic steps, and ultimately by the purification of a subunit of molecular mass 15 kDa. The medium- and short-chain acyl-CoA oxidases were demonstrated to be distinct from the maize equivalent of the cucumber glyoxysomal long-chain acyl-CoA oxidase previously purified and characterized [Kirsch, Loffler and Kindl (1986) J. Biol. Chem. 261, 8570-8575]. The maize long-chain acyl-CoA oxidase was partially purified to permit determination of its substrate specificity; it showed activity with a broad range of acyl-CoAs of chain length greater than C8, and maximal activity with C16. The implications of the existence of multiple acyl-CoA oxidases in the regulation of plant peroxisomal beta-oxidation are discussed.