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Objectives: The human oral microbiome may play a role in the development of oral squamous cell carcinoma. The aim of this scoping review was to examine microbial diversity and differences in the composition of the oral microbiome between OSCC patients and healthy controls. Methods: A literature search (in PubMed and Embase.com) was performed on January 9, 2023. The outcome variables used from the included studies of this review were alpha- and beta diversity and oral microbiome composition profiles for each taxonomic level (phylum-, class-, order-, genus- and species level). Results: Thirteen out of 423 studies were included in this review compromising 1,677 subjects, of which 905 (54.0%) were OSCC patients and 772 (46.0%) were healthy controls. Most studies found a higher alpha diversity in the OSCC patient group and significantly different beta diversities between OSCC patient samples and healthy control samples. Studies reported more abundant Fusobacteria (on phylum level), Fusobacterium (on genus level), Fusobacterium nucleatum, Porphyromonas endodontalis and Prevotella intermedia (on species level) in OSCC patients. The healthy control group had more abundant Actinobacteria (on phylum level), Streptococcus and Veilonella (on genus level) and Veilonella parvula (on species level) according to most studies. Conclusions: Our findings show differences in oral microbiome diversity and composition in OSCC patients. Clinical implications demand continuing study. Development of internationally accepted standard procedures for oral sample collection and oral microbiota analysis is needed for more conclusive and clinically relevant comparisons in future research.
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The bacterial genus Tetrasphaera encompasses abundant polyphosphate accumulating organisms (PAOs) that are responsible for enhanced biological phosphorus removal (EBPR) in wastewater treatment plants. Recent analyses of genomes from pure cultures revealed that 16S rRNA genes cannot resolve the lineage, and that Tetrasphaera spp. are from several different genera within the Dermatophilaceae. Here, we examine 14 recently recovered high-quality metagenome-assembled genomes from wastewater treatment plants containing full-length 16S rRNA genes identified as Tetrasphaera, 11 of which belong to the uncultured Tetrasphaera clade 3. We find that this clade represents two distinct genera, named here Ca. Phosphoribacter and Ca. Lutibacillus, and reveal that the widely used model organism Tetrasphaera elongata is less relevant for physiological predictions of this uncultured group. Ca. Phosphoribacter incorporates species diversity unresolved at the 16S rRNA gene level, with the two most abundant and often co-occurring species encoding identical V1-V3 16S rRNA gene amplicon sequence variants but different metabolic capabilities, and possibly, niches. Both Ca. P. hodrii and Ca. P. baldrii were visualised using fluorescence in situ hybridisation (FISH), and PAO capabilities were confirmed with FISH-Raman microspectroscopy and phosphate cycling experiments. Ca. Phosphoribacter represents the most abundant former Tetrasphaera lineage and PAO in EPBR systems in Denmark and globally.
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Actinomycetales , Purificación del Agua , Actinomycetales/genética , Actinomycetales/metabolismo , Reactores Biológicos , Fósforo/metabolismo , Polifosfatos/metabolismo , ARN Ribosómico 16S/genética , ARN Ribosómico 16S/metabolismo , Aguas del Alcantarillado/microbiología , Aguas ResidualesRESUMEN
INTRODUCTION: The web-based self-management application Oncokompas was developed to support cancer survivors to monitor health-related quality of life and symptoms (Measure) and to provide tailored information (Learn) and supportive care options (Act). In a previously reported randomised controlled trial (RCT), 68% of 655 recruited survivors were eligible, and of those 45% participated in the RCT. Among participants of the RCT that were randomised to the intervention group, 52% used Oncokompas as intended. The aim of this study was to explore reasons for not participating in the RCT, and reasons for not using Oncokompas among non-users, and the use and evaluation of Oncokompas among users. METHODS: Reasons for not participating were assessed with a study-specific questionnaire among 243 survivors who declined participation. Usage was investigated among 320 participants randomised to the intervention group of the RCT via system data and a study-specific questionnaire that was assessed during the 1 week follow-up (T1) assessment. RESULTS: Main reasons for not participating were not interested in participation in scientific research (40%) and not interested in scientific research and Oncokompas (28%). Main reasons for not being interested in Oncokompas were wanting to leave the period of being ill behind (29%), no symptom burden (23%), or lacking internet skills (18%). Out of the 320 participants in the intervention group 167 (52%) used Oncokompas as intended. Among 72 non-users, main reasons for not using Oncokompas were no symptom burden (32%) or lack of time (26%). Among 248 survivors that activated their account, satisfaction and user-friendliness were rated with a 7 (scale 0-10). Within 3 (IQR 1-4) sessions, users selected 32 (IQR 6-37) topics. Main reasons for not using healthcare options in Act were that the information in Learn was already sufficient (44%) or no supportive care needs (32%). DISCUSSION: Main reasons for not reaching or using Oncokompas were no symptom burden, no supportive care needs, or lack of time. Users selected many cancer-generic and tumour-specific topics to address, indicating added value of the wide range of available topics.
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PURPOSE: The eHealth self-management application 'Oncokompas' was developed to support cancer survivors in monitoring health-related quality of life (HRQOL) and symptoms, and obtaining personalized feedback and options for supportive care. The aim of this study was to assess the cost-utility of Oncokompas compared with care as usual (CAU) among cancer survivors. METHODS: Survivors were randomly allocated to the intervention or control group. Direct (non-)medical, indirect non-medical costs, and HRQOL were measured at 3- and 6-month follow-up, using iMTA Medical Consumption and Productivity Costs and the EuroQol-5D questionnaires. Mean cumulative costs and quality-adjusted life-years (QALYs) were compared between both groups. RESULTS: In total, 625 survivors were randomized into intervention (n = 320) or control group (n = 305). Base case analysis showed that incremental costs from a societal perspective were - 163 (95% CI, - 665 to 326), and incremental QALYs were 0.0017 (95% CI, - 0.0121 to 0.0155) in the intervention group compared with those in the control group. The probability that, compared with CAU, Oncokompas is more effective was 60%, less costly 73%, and both more effective and less costly 47%. Sensitivity analyses showed that incremental costs vary between - 40 and 69, and incremental QALYs vary between - 0.0023 and - 0.0057. CONCLUSION: Oncokompas is likely to be equally effective on utilities, and not more expensive than CAU, and will therefore contribute to sustainable cancer survivorship care in a (cost-)effective manner. IMPLICATIONS FOR CANCER SURVIVORS: Oncokompas seems to improve HRQOL and reduces the burden of several tumour-specific symptoms, while costs from a societal perspective are similar to CAU.
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Supervivientes de Cáncer , Neoplasias , Automanejo , Telemedicina , Anciano , Análisis Costo-Beneficio , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/terapia , Calidad de Vida , SobrevivientesRESUMEN
BACKGROUND: Oncokompas is a web-based self-management application that supports cancer survivors to monitor their health-related quality of life (HRQOL) and symptoms, and to obtain personalised feedback and tailored options for supportive care. In a large randomised controlled trial among survivors of head and neck cancer, colorectal cancer, and breast cancer and (non-)Hodgkin lymphoma, Oncokompas proved to improve HRQOL, and to reduce several tumour-specific symptoms. Effect sizes were however small, and no effect was observed on the primary outcome patient activation. Therefore, this study aims to explore which subgroups of cancer survivors may especially benefit from Oncokompas. MATERIALS AND METHODS: Cancer survivors (n = 625) were randomly assigned to the intervention group (access to Oncokompas, n = 320) or control group (6 months waiting list, n = 305). Outcome measures were HRQOL, tumour-specific symptoms, and patient activation. Potential moderators included socio-demographic (sex, age, marital status, education, employment), clinical (tumour type, stage, time since diagnosis, treatment modality, comorbidities), and personal factors (self-efficacy, personal control, health literacy, Internet use), and patient activation, mental adjustment to cancer, HRQOL, symptoms, and need for supportive care, measured at baseline. Linear mixed models were performed to investigate potential moderators. RESULTS: The intervention effect on HRQOL was the largest among cancer survivors with low to moderate self-efficacy, and among those with high personal control and those with high health literacy scores. Cancer survivors with higher baseline symptom scores benefitted more on head and neck (pain in the mouth, social eating, swallowing, coughing, trismus), and colorectal cancer (weight) specific symptoms. DISCUSSION: Oncokompas seems most effective in reducing symptoms in head and neck cancer and colorectal cancer survivors who report a higher burden of tumour-specific symptoms. Oncokompas seems most effective in improving HRQOL in cancer survivors with lower self-efficacy, and in cancer survivors with higher personal control, and higher health literacy.
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Neoplasias de la Mama , Supervivientes de Cáncer , Automanejo , Telemedicina , Femenino , Humanos , Calidad de VidaRESUMEN
AIMS: To assess the functional outcomes of patients treated for hypopharynx cancer and to obtain an unbiased estimate of survival difference between patients treated with chemoradiotherapy (CRT) or total laryngectomy (TL). METHODS: Retrospective cohort study of all patients treated with curative intent for T1-T4 squamous cell carcinoma of the hypopharynx in The Netherlands Cancer Institute (1990-2013). Functional outcome following radiotherapy (RT) or CRT was measured using laryngo-esophageal dysfunction free survival rate (LDFS). Using propensity score (PS) matched analysis, we compared survival outcome of TL to CRT in T2-T4 patients. RESULTS: We included 343 patients with T1T4 hypopharynx cancer. LDFS 2 and 5-years following CRT was respectively 44 and 32%. Following RT this was 39 and 30%. Patients were matched on the following variables: age, gender, TNM classification, subsite of tumor, decade of diagnosis, prior cancer, smoking, ACE27 score, BMI hemoglobin, albumin, and leukocyte level. With PS matching, we were able to match 26 TL patients with 26 CRT patients. The OS rates for TL and CRT in this matched cohort were respectively 56% and 46% at 5â¯years and 35% and 17% at 10â¯years. CONCLUSION: In conclusion, functional outcomes following RT or CRT are suboptimal and require improved treatment strategies or rehabilitation efforts. The OS results challenge the preposition that CRT and TLE are equivalent in terms of survival.
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Quimioradioterapia/métodos , Neoplasias Hipofaríngeas/terapia , Laringectomía/métodos , Tratamientos Conservadores del Órgano/métodos , Complicaciones Posoperatorias/epidemiología , Anciano , Quimioradioterapia/efectos adversos , Supervivencia sin Enfermedad , Esófago/fisiopatología , Esófago/cirugía , Femenino , Estudios de Seguimiento , Humanos , Neoplasias Hipofaríngeas/mortalidad , Neoplasias Hipofaríngeas/patología , Hipofaringe/patología , Hipofaringe/cirugía , Laringectomía/efectos adversos , Laringe/fisiopatología , Laringe/cirugía , Masculino , Persona de Mediana Edad , Países Bajos/epidemiología , Tratamientos Conservadores del Órgano/efectos adversos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/fisiopatología , Complicaciones Posoperatorias/rehabilitación , Puntaje de Propensión , Estudios Retrospectivos , Tasa de SupervivenciaRESUMEN
Non-melanoma skin cancer (NMSC) has become an epidemic disease and is predominantly located in the head and neck area. While historically auricular NMSCs are treated by means of a wedge excision, we describe a more elegant technique with excellent esthetical results. We conducted a retrospective cohort study of 43 consecutive patients with NMSC of the auricle who underwent reconstruction with a full thickness skin graft (FTSG). All grafts survived. Two patients (5%) showed crust formation, but fully recovered. One patient had an irradical resection for which he required a limited re-excision. All patients showed excellent esthetical results. When treating NMSC of the auricle, reconstruction with a FTSG demonstrates several important advantages. It is a relatively simple but oncological safe technique; it leads to excellent esthetical and functional outcomes, and shows high patient and surgeon satisfaction.
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Carcinoma de Células Escamosas , Disección/métodos , Pabellón Auricular , Procedimientos de Cirugía Plástica/métodos , Neoplasias Cutáneas , Trasplante de Piel/métodos , Anciano , Anciano de 80 o más Años , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/cirugía , Estudios de Cohortes , Investigación sobre la Eficacia Comparativa , Pabellón Auricular/patología , Pabellón Auricular/cirugía , Estética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Satisfacción del Paciente , Estudios Retrospectivos , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/cirugía , Resultado del TratamientoRESUMEN
Estimating the risk of venous thromboembolism (VTE) associated with combined hormonal contraceptives following early terminated pregnancies or birth, a Danish nationwide retrospective cohort observing a one-year follow-up was defined using three unique registries. All Danish women with confirmed pregnancies aged 15-49 during the period of 1995-2009 were included. The main outcomes were relative and absolute risks of first time venous thromboembolism in users as well as non-users of combined hormonal contraceptives. In 985,569 person-years, 598 venous thromboembolisms were recorded. After early terminated pregnancies and births, respectively, 113 and 485 events occurred in 212,552 and 773,017 person-years. After early terminated pregnancies, the crude VTE incidence ratios were similar, and the numbers needed to harm were equal between groups that did or did not use combined hormonal contraceptives throughout the follow-up year. After childbirth, individuals that used combined hormonal contraceptives were more likely than non-users to experience VTE depicted by crude incidence ratios; however, the difference was only significant after 14 weeks. This implied that the numbers needed to harm were lower for those that used compared to those that did not use combined oral contraceptives in the initial 14 weeks postpartum. In conclusion, the use of combined hormonal contraceptives after early terminated pregnancies was not detrimental, but during the puerperal period, they should be used with caution.
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Aborto Inducido/estadística & datos numéricos , Anticonceptivos Hormonales Orales/administración & dosificación , Tromboembolia Venosa/epidemiología , Adolescente , Adulto , Estudios de Cohortes , Anticonceptivos Hormonales Orales/efectos adversos , Dinamarca , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Persona de Mediana Edad , Periodo Posparto , Sistema de Registros , Estudios Retrospectivos , Riesgo , Resultado del Tratamiento , Tromboembolia Venosa/inducido químicamente , Tromboembolia Venosa/prevención & control , Adulto JovenRESUMEN
BACKGROUND: The peroxisome proliferator-activated receptors (PPAR) are ligand-activated transcription factors belonging to the nuclear receptor family. The roles of PPARalpha in fatty acid oxidation and PPARgamma in adipocyte differentiation and lipid storage have been characterized extensively. PPARs are activated by fatty acids and eicosanoids and are also targets for antidyslipidemic drugs, but the molecular interactions governing ligand selectivity for specific subtypes are unclear due to the lack of a PPARalpha ligand binding domain structure. RESULTS: We have solved the crystal structure of the PPARalpha ligand binding domain (LBD) in complex with the combined PPARalpha and -gamma agonist AZ 242, a novel dihydro cinnamate derivative that is structurally different from thiazolidinediones. In addition, we present the crystal structure of the PPARgamma_LBD/AZ 242 complex and provide a rationale for ligand selectivity toward the PPARalpha and -gamma subtypes. Heteronuclear NMR data on PPARalpha in both the apo form and in complex with AZ 242 shows an overall stabilization of the LBD upon agonist binding. A comparison of the novel PPARalpha/AZ 242 complex with the PPARgamma/AZ 242 complex and previously solved PPARgamma structures reveals a conserved hydrogen bonding network between agonists and the AF2 helix. CONCLUSIONS: The complex of PPARalpha and PPARgamma with the dual specificity agonist AZ 242 highlights the conserved interactions required for receptor activation. Together with the NMR data, this suggests a general model for ligand activation in the PPAR family. A comparison of the ligand binding sites reveals a molecular explanation for subtype selectivity and provides a basis for rational drug design.
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Receptores Citoplasmáticos y Nucleares/química , Factores de Transcripción/química , Sitios de Unión , Unión Competitiva , Cristalografía por Rayos X , Relación Dosis-Respuesta a Droga , Ácidos Grasos/metabolismo , Humanos , Enlace de Hidrógeno , Ligandos , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Unión Proteica , Estructura Terciaria de ProteínaRESUMEN
The three-dimensional structures of pepsin inhibitor-3 (PI-3) from Ascaris suum and of the complex between PI-3 and porcine pepsin at 1. 75 A and 2.45 A resolution, respectively, have revealed the mechanism of aspartic protease inhibition by this unique inhibitor. PI-3 has a new fold consisting of two domains, each comprising an antiparallel beta-sheet flanked by an alpha-helix. In the enzyme-inhibitor complex, the N-terminal beta-strand of PI-3 pairs with one strand of the 'active site flap' (residues 70-82) of pepsin, thus forming an eight-stranded beta-sheet that spans the two proteins. PI-3 has a novel mode of inhibition, using its N-terminal residues to occupy and therefore block the first three binding pockets in pepsin for substrate residues C-terminal to the scissile bond (S1'-S3'). The molecular structure of the pepsin-PI-3 complex suggests new avenues for the rational design of proteinaceous aspartic proteinase inhibitors.
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Ascaris suum/química , Pepsina A/antagonistas & inhibidores , Pepsina A/metabolismo , Pepstatinas/química , Pepstatinas/metabolismo , Proteínas/química , Proteínas/metabolismo , Porcinos , Secuencia de Aminoácidos , Animales , Sitios de Unión , Cristalografía por Rayos X , Disulfuros/metabolismo , Proteínas del Helminto , Modelos Moleculares , Datos de Secuencia Molecular , Inhibidores de Proteasas/química , Inhibidores de Proteasas/metabolismo , Unión Proteica , Estructura Secundaria de Proteína , Alineación de Secuencia , Relación Estructura-Actividad , Especificidad por SustratoRESUMEN
The crystal structure of the 2A proteinase from human rhinovirus serotype 2 (HRV2-2A(pro)) has been solved to 1.95 A resolution. The structure has an unusual, although chymotrypsin-related, fold comprising a unique four-stranded beta sheet as the N-terminal domain and a six-stranded beta barrel as the C-terminal domain. A tightly bound zinc ion, essential for the stability of HRV2-2A(pro), is tetrahedrally coordinated by three cysteine sulfurs and one histidine nitrogen. The active site consists of a catalytic triad formed by His18, Asp35 and Cys106. Asp35 is additionally involved in an extensive hydrogen-bonding network. Modelling studies reveal a substrate-induced fit that explains the specificity of the subsites S4, S2, S1 and S1'. The structure of HRV2-2A(pro) suggests the mechanism of the cis cleavage and its release from the polyprotein.
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Cisteína Endopeptidasas/química , Rhinovirus/enzimología , Proteínas Virales , Secuencia de Aminoácidos , Dominio Catalítico , Quimotripsina/química , Cristalografía por Rayos X , Cisteína Endopeptidasas/genética , Cisteína Endopeptidasas/metabolismo , Humanos , Modelos Moleculares , Datos de Secuencia Molecular , Conformación Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Rhinovirus/genética , Rhinovirus/patogenicidad , Homología de Secuencia de Aminoácido , Especificidad por Sustrato , Zinc/metabolismoRESUMEN
Well diffracting crystals of rhamnogalacturonan acetylesterase from Aspergillus aculeatus have been obtained in two polymorphic modifications despite its heterogeneous glycosylation. The best-diffracting crystals (resolution 1.55 A) are orthorhombic. The limit of the diffraction pattern of the other (trigonal) form is 2.5 A. The ability of the enzyme to crystallize appears to depend on the glycosylation of the protein sample. This aspect has been investigated by mass spectrometry, which also showed that the orthorhombic crystals have the same glycosylation as the protein sample used in the crystallization.
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Acetilesterasa/química , Aspergillus/enzimología , Proteínas Fúngicas/química , Conformación Proteica , Acetilesterasa/aislamiento & purificación , Cristalización , Cristalografía por Rayos X , Proteínas Fúngicas/aislamiento & purificación , Glicosilación , Procesamiento Proteico-PostraduccionalRESUMEN
The use of strong analgesics was continuously registered in 90 patients throughout 12 months via the public health authorities, who are responsible for the control of prescription of strong analgesics. After the 12 months, questionnaires were sent to the prescribing doctors about the treatment during that period. Twenty-five patients were excluded mainly due to incomplete data and non-responding GPs. Analysis of validity of the GPs' registration, with the public health authorities' registration used as the reference standard, showed 90% (95% confidence limits (CL):68-99%) agreement concerning continuing treatment with strong analgesics and 98% (CL:88-100%) regarding GPs' registration of patients not being treated with strong analgesics. In all, misclassification occurred in 5% (CL:1-13%) of the patients. Our study suggests that the GPs' information about prescriptions of strong analgesics is valid, and that it can be used in research.
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Analgésicos/administración & dosificación , Prescripciones de Medicamentos , Utilización de Medicamentos , Medicina Familiar y Comunitaria/estadística & datos numéricos , Dinamarca , Humanos , Registros Médicos , Estudios Prospectivos , Sistema de Registros , Encuestas y CuestionariosRESUMEN
METHODS: Efficacy and safety of the topically acting glucocorticosteroid budesonide retention enema (2.3 mg/115 mL) were compared with prednisolone disodium phosphate enema (31.25 mg/125 mL) in patients with active distal ulcerative colitis. The study was a randomized, multicentre trial, with two parallel groups and single-blind to the investigator. One hundred patients with active ulcerative colitis, not reaching beyond the splenic flexure as determined by endoscopy, were treated for up to 8 weeks. RESULTS: Forty-five patients were randomized to receive budesonide and 55 to prednisolone. Both treatment groups improved significantly in terms of endoscopic and histological scoring during the study, but there were no statistically significant differences between the two groups. Clinical remission, defined as no more than three daily bowel movements without blood and endoscopically non-inflamed mucosa, was achieved in 16% of the patients in the budesonide group after four weeks and in 24% in the prednisolone group (N.S.). After 8 weeks treatment the clinical remission rate in the groups had increased to 36% for budesonide and 47% for prednisolone (N.S.). Mean morning plasma cortisol levels were unchanged in the budesonide group, whereas they were significantly suppressed in the prednisolone group after 2, 4 and 8 weeks (P < 0.0001). Side effects were mild and rare in both groups. CONCLUSIONS: Treatment with budesonide enema in active distal ulcerative colitis was comparable, regarding efficacy, to treatment with conventional prednisolone enema. A prolongation of the treatment time from 4 to 8 weeks doubled the clinical remission rate in both groups. However, budesonide may be preferable to prednisolone since it causes less systemic effects as reflected by a lack of plasma cortisol suppression.
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Antiinflamatorios/uso terapéutico , Colitis Ulcerosa/tratamiento farmacológico , Hidrocortisona/sangre , Pregnenodionas/uso terapéutico , Adulto , Budesonida , Colitis Ulcerosa/patología , Endoscopía , Enema , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prednisolona/uso terapéutico , Pregnenodionas/administración & dosificación , Inducción de RemisiónRESUMEN
The predictive value of a urea/creatinine ratio > or = 100 for indicating upper gastrointestinal bleeding was evaluated in 78 consecutive patients with a history of gastrointestinal bleeding 24 hours or less before admission. Serum beta-2-microglobulin was measured to elucidate whether renal hypoperfusion plays a part in elevation of the urea/creatinine ratio. The predictive value of a urea/creatinine ratio > or = 100 in terms of upper gastrointestinal bleeding, was 95% (95% confidence interval (CI): 83-99%), whereas the predictive value of a urea/creatinine ratio < 100, indicating lower gastrointestinal bleeding, was 41% (CI: 25-59%). No statistically significant differences were found between serum beta-2-microglobulin levels in upper and lower gastrointestinal bleeders. We conclude that a urea/creatinine ratio > or = 100 strongly indicates an upper gastrointestinal bleeding source and that the main cause of a high ratio is not renal hypoperfusion.
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Creatinina/sangre , Hemorragia Gastrointestinal/diagnóstico , Urea/sangre , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios ProspectivosRESUMEN
The structure of a recombinant peroxidase from the ink cap, Coprinus cinereus, CiP, is reported to 2.6 A resolution and refined to a R-value of 18.1%. The structure was solved by molecular replacement using the coordinates from a newly published ligninase structure. LiP. CiP crystallizes in space group P2(1)2(1)2(1) with two independent molecules in the asymmetric unit related by the vector 0.29b + 0.5c. The two CiP molecules are structurally identical; each contains two Ca2+ ions in positions equivalent to those found in the LiP structure. Two N-acetylglucosamines and one mannose residue were fitted into the density adjacent to two of the three predicted glycosylation sites. The refinement also included 40 and 41 water molecules, respectively, in the two CiP molecules. The structure of CiP displays a folding very similar to that of LiP. The active sites are almost identical in the LiP and CiP structures. CiP has a much larger opening to the active site than LiP.
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Coprinus/enzimología , Peroxidasa/química , Sitios de Unión , Calcio/metabolismo , Simulación por Computador , Cristalización , Cristalografía por Rayos X , Glicosilación , Modelos Moleculares , Estructura Molecular , Pliegue de Proteína , Proteínas Recombinantes/química , Especificidad por SustratoRESUMEN
BACKGROUND: The trefoil peptides are a rapidly growing family of peptides, mainly found in the gastrointestinal tract. There is circumstantial evidence that they stabilize the mucus layer, and may affect the rate of healing of the mucosal epithelium. RESULTS: We have determined the structure of porcine pancreatic spasmolytic polypeptide (PSP) to 2.5 A resolution. The polypeptide contains two trefoil domains. The domain structure is compact, and is composed of a central short antiparallel beta-sheet with one short helix above and one below it. This is a novel motif. The two domains are related by two-fold symmetry, and each domain contains a cleft. CONCLUSIONS: The cleft within each domain could accommodate a polysaccharide chain, and may therefore be responsible for binding mucin glycoproteins. We suggest that PSP may cross-link glycoproteins, explaining its ability to stabilize the mucus layer.
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Mucinas , Proteínas Musculares , Neuropéptidos , Péptidos/química , Conformación Proteica , Estructura Secundaria de Proteína , Secuencia de Aminoácidos , Animales , Cristalografía por Rayos X/métodos , Sistema Digestivo , Enlace de Hidrógeno , Péptidos y Proteínas de Señalización Intercelular , Mamíferos , Modelos Moleculares , Datos de Secuencia Molecular , Homología de Secuencia de Aminoácido , Porcinos , Simpaticolíticos , Factor Trefoil-2 , Factor Trefoil-3RESUMEN
Crystals suitable for an X-ray diffraction investigation have been obtained of recombinant Coprinus cinereus peroxidase expressed in Aspergillus oryzae. The crystals were grown by the hanging drop method with polyethylene glycol 6000 as the precipitant. A pH range from 6.2 to 8.0 and CaCl2 or MgCl2 present at a concentration of 0.35 M were essential for the crystal growth. A metastable monoclinic modification can be obtained under certain conditions, and with variations in temperature they are transformed into a stable orthorhombic modification. With CaCl2 as the additive, the unit cell dimensions were a = 74.9 A, b = 76.8 A and c = 128.2 A. With two peroxidase molecules per asymmetric unit, the solvent content is 49% (v/v). In the diffraction pattern, the reflections Okl are systematically very weak for k = 2n + 1. Combined with an analysis of the Patterson function, this showed that the two independent molecules are related by the pseudotranslational symmetry 0.29a + 0.5b. The possible space groups are P2(1)2(1)2(1) or P2(1)22(1) because of this pseudosymmetry. The crystals diffract to a resolution of 2.9 A.
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Coprinus/enzimología , Peroxidasa/química , Cristalización , Proteínas Recombinantes/química , Difracción de Rayos XRESUMEN
Crystals suitable for X-ray diffraction analysis of both glycosylated and non-glycosylated forms of a barley peroxidase have been grown. The crystals of the glycosylated peroxidase have been grown by the hanging drop vapour diffusion method using polyethylene glycol 4000 as the precipitant in the presence of n-propanol and potassium iodide at pH 8.5. The crystals are needles belonging to the orthorhombic spacegroup P2(1)2(1)2(1) with unit cell dimensions a = 62.95 A, b = 66.24 A and c = 70.78 A. There is one barley peroxidase molecule in the asymmetric unit. The crystals contain approximately 38% solvent and appear to be stable to lengthy X-ray exposure. They diffract to beyond 1.9 A.