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AIM: To document satisfaction with root canal treatment procedures and outcomes among patients treated at Swedish public dental clinics. METHOD: The original material comprised 243 patients who began root canal treatment (RCT) at 20 public dental clinics in the county of Västra Götaland, Sweden. One to three years later, 236 (97.1%) were posted a questionnaire of eight items, rating patient perceptions of RCT-completion, present pain intensity and satisfaction with the RCT. To evaluate the reliability of the original responses, the first 50 respondents were mailed a follow-up questionnaire. Both descriptive and analytical statistics were used to compare respondents and non-respondents and tooth groups. RESULTS: One hundred and fifty-nine patients (67.4%) responded: 86 (54.1%) women and 73 (45.9%) men. The mean age 52.5 years, was higher than for non-respondents (P<0.001). A completed root filling was registered for the majority of the teeth (n = 112, 70.9%), but significantly fewer molars had been completed (n = 46, 59.7%, P = 0.02). Fifty percent (n = 59) of the patients reported current pain, mostly mild in intensity (n = 45, 38.1%). One hundred and twenty-three patients (80.9%) recalled experiencing pain during RCT. The highest satisfaction was registered for the item 'chewing ability' (mean = 1.6, SD = 1.9). The majority of patients (n = 114, 75.0%) stated that in retrospect they would still have chosen RCT. However, these patients belonged to the group which either registered the tooth as still present, or had not experienced much discomfort during or after RCT. Forty-four patients (88.0%) responded to the second questionnaire. The reliability of the responses was good. In summary, one to 3 years after beginning RCT at a public dental clinic, patient satisfaction was high, even though every fourth molar had been extracted or treatment had not been completed and half the patients reported persistent pain. The reliability of the patients' responses was considered to be good. CONCLUSIONS: The results indicate a need for further clinical observational studies of RCTs undertaken in general dental practice, with special reference to patient-centred outcomes.
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AIM: To study patient- and tooth-specific characteristics of teeth indicated for root canal treatment, in the public dental service of the county of Västra Götaland, Sweden. METHODOLOGY: During a designated 8-week period, general dental practitioners working at 20 different public dental clinics consecutively registered indications for undertaking root canal treatment. The patients' subjective level of pain was also registered (visual analogue scale) at the very first appointment. The following information was retrieved from computerized dental records and radiographs: gender, age, number of remaining teeth, tooth group, previous restoration, number of restored surfaces, dental caries and tooth substance loss. Gender and age were compared using both descriptive and analytical statistics. RESULTS: The material comprised 243 teeth in 243 patients: 128 (52.7%) women and 115 (47.3%) men, mean age 48.3 years. Molar teeth predominated (47.7%). Most of the teeth (83.5%) had previously been restored and exhibited significant loss of tooth substance, more than a third of the crown (71.3%). Dental caries was present in 127 teeth (62.9%). Dental trauma was implicated in only seven cases (2.9%). Initial treatment was frequently undertaken at an emergency visit, for relief of symptoms (64.9%). The most commonly registered indication was pulpal necrosis with apical periodontitis (38.1%), followed by pulpitis (37.7%). Retreatment of a root filled tooth was reported in 18 teeth (7.4%). CONCLUSIONS: In the general Public Dental Service of Sweden, root canal treatment is most frequently undertaken in molars. The primary indication is relief of symptoms. Retreatment of root filled teeth is uncommon.
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Clínicas Odontológicas/estadística & datos numéricos , Pautas de la Práctica en Odontología/estadística & datos numéricos , Tratamiento del Conducto Radicular/estadística & datos numéricos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Coronas/estadística & datos numéricos , Caries Dental/epidemiología , Caries Dental/terapia , Necrosis de la Pulpa Dental/epidemiología , Necrosis de la Pulpa Dental/terapia , Restauración Dental Permanente/estadística & datos numéricos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Diente Molar , Periodontitis Periapical/epidemiología , Periodontitis Periapical/terapia , Pulpitis/epidemiología , Pulpitis/terapia , Retratamiento/estadística & datos numéricos , Obturación del Conducto Radicular/estadística & datos numéricos , Encuestas y Cuestionarios , Suecia , Adulto JovenRESUMEN
This position statement represents a consensus of an expert committee convened by the European Society of Endodontology (ESE) on Antibiotics in Endodontics. The statement is based on current scientific evidence as well as the expertise of the committee. The goal is to provide dentists and other healthcare workers with evidence-based criteria for when to use antibiotics in the treatment of endodontic infections, traumatic injuries of the teeth, revascularization procedures in immature teeth with pulp necrosis, and in prophylaxis for medically compromised patients. It also highlights the role that dentists and others can play in preventing the overuse of antibiotics. A recent review article provides the basis for this position statement and more detailed background information (International Endodontic Journal, 2017, https://doi.org/10.1111/iej.12741). Given the dynamic nature of research in this area, this position statement will be updated at appropriate intervals.
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Antibacterianos/uso terapéutico , Endodoncia/normas , Profilaxis Antibiótica , Contraindicaciones de los Medicamentos , Humanos , Infecciones/tratamiento farmacológico , Absceso Periapical/tratamiento farmacológico , Traumatismos de los Dientes/tratamiento farmacológico , Reimplante DentalRESUMEN
Femoroacetabular impingement (FAI) is a common cause of hip pain and dysfunction. The purpose of this study was to report outcome 2 years after the arthroscopic treatment of FAI using validated outcome measurements. Two hundred and eighty-nine patients (males = 190, females = 99) with a mean age of 37 years underwent arthroscopic surgery for FAI. Patients were included consecutively in a hip arthroscopy registry. The cohort was evaluated using online web-based validated health-related patient-reported outcomes measurements, including the iHOT-12, HAGOS, EQ-5D, HSAS for physical activity level, VAS for overall hip function and overall satisfaction. The mean follow-up time was 25.4 months. Pre-operative scores compared with those obtained at follow-up revealed statistically and clinically significant improvements (P < 0.05) for all measured outcomes; iHOT-12 (43 vs 66), VAS for global hip function (50 vs 71), HSAS (2.9 vs 3.6), EQ-5D index (0.58 vs 0.75), EQ-VAS (67 vs 75) and HAGOS different subscales (56 vs 76, 51 vs 69, 60 vs 78, 40 vs 65, 29 vs 57, 33 vs 58). At the 2-year follow-up, 236 patients (82%) reported they were satisfied with the outcome of surgery. We conclude that arthroscopic treatment for FAI resulted in statistically and clinically significant improvements in outcome parameters.
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Artroscopía/métodos , Pinzamiento Femoroacetabular/cirugía , Fibrocartílago/cirugía , Articulación de la Cadera/cirugía , Sistema de Registros , Adulto , Estudios de Cohortes , Ejercicio Físico , Femenino , Pinzamiento Femoroacetabular/fisiopatología , Fibrocartílago/fisiopatología , Estudios de Seguimiento , Articulación de la Cadera/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Medición de Resultados Informados por el Paciente , Satisfacción del Paciente , Estudios Prospectivos , Resultado del Tratamiento , Escala Visual Analógica , Adulto JovenRESUMEN
AIM: Root canal treatment of teeth with necrotic pulps and apical periodontitis may be complicated by limited access to the root canals due to restorations and dystrophic calcifications. The objective of this study was to evaluate retrograde root canal as a primary treatment using a surgical approach as an alternative to conventional orthograde treatment. METHODOLOGY: Patients with apical periodontitis in the anterior region of the maxilla were consecutively recruited to the study over a period of 4 years. Fifty-seven patients met the inclusion criteria and received retrograde root canal treatment. A clinical and radiographic evaluation was made after 1 and 2 years postoperatively. RESULTS: Clinical and radiographically evaluation after 2 years revealed a successful outcome (as defined in this study) in 90% of the cases. CONCLUSION: Retrograde root canal as a primary treatment was a reliable alternative to treat apical periodontitis on single- and two-rooted teeth with limited orthograde access to the root canals in the maxilla.
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Obturación Retrógrada/métodos , Tratamiento del Conducto Radicular/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Maxilar , Persona de Mediana Edad , Periodontitis Periapical/diagnóstico por imagen , Periodontitis Periapical/terapia , Estudios Prospectivos , Radiografía Dental , Adulto JovenRESUMEN
The overuse of antibiotics and the emergence of antibiotic-resistant bacterial strains is a global concern. This concern is also of importance in terms of the oral microbiota and the use of antibiotics to deal with oral and dental infections. The aim of this paper was to review the current literature on the indications and use of antibiotics and to make recommendations for their prescription in endodontic patients. Odontogenic infections, including endodontic infections, are polymicrobial, and in most cases, the prescription of antibiotics is empirical. This has led to the increasing use of broad-spectrum antibiotics even in cases where antibiotics are not indicated, such as symptomatic irreversible pulpitis, necrotic pulps and localized acute apical abscesses. In case of discrete and localized swelling, the primary aim is to achieve drainage without additional antibiotics. Adjunctive antibiotic treatment may be necessary in the prevention of the spread of infection, in acute apical abscesses with systemic involvement and in progressive and persistent infections. Medically compromised patients are more susceptible to complication arising from odontogenic infections and antimicrobials have a more specific role in their treatment. Therefore, antibiotics should be considered in patients having systemic diseases with compromised immunity or in patients with a localized congenital or acquired altered defence capacity, such as patients with infective endocarditis, prosthetic cardiac valves or recent prosthetic joint replacement. Penicillin VK, possibly combined with metronidazole to cover anaerobic strains, is still effective in most cases. However, amoxicillin (alone or together with clavulanic acid) is recommended because of better absorption and lower risk of side effects. In case of confirmed penicillin allergy, lincosamides such as clindamycin are the drug of choice.
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Antibacterianos/uso terapéutico , Endodoncia , Enfermedades Dentales/tratamiento farmacológico , Administración Tópica , Europa (Continente) , Infección Focal Dental/tratamiento farmacológico , Humanos , Prescripción Inadecuada/prevención & control , Prescripción Inadecuada/estadística & datos numéricos , Pautas de la Práctica en OdontologíaRESUMEN
The purpose of the present work was to optimise the filtration and dose setting for double-contrast barium enema examinations using a Philips MultiDiagnost Eleva FD system. A phantom study was performed prior to a patient study. A CDRAD phantom was used in a study where copper and aluminium filtration, different detector doses and tube potentials were examined. The image quality was evaluated using the software CDRAD Analyser and the phantom dose was determined using the Monte Carlo-based software PCXMC. The original setting [100 % detector dose (660 nGy air kerma) and a total filtration of 3.5 mm Al, at 81 kVp] and two other settings identified by the phantom study (100 % detector dose and additional filtration of 1 mm Al and 0.2 mm Cu as well as 80 % detector dose and added filtration of 1 mm Al and 0.2 mm Cu) were included in the patient study. The patient study included 60 patients and up to 8 images from each patient. Six radiologists performed a visual grading characteristics study to evaluate the image quality. A four-step scale was used to judge the fulfillment of three image quality criteria. No overall statistical significant difference in image quality was found between the three settings (P > 0.05). The decrease in the effective dose for the settings in the patient study was 15 % when filtration was added and 34 % when both filtrations was added and detector dose was reduced. The study indicates that additional filtration of 1 mm Al and 0.2 mm Cu and a decrease in detector dose by 20 % from the original setting can be used in colon examinations with Philips MultiDiagnost Eleva FD to reduce the patient dose by 30 % without significantly affecting the image quality. For 20 exposures, this corresponds to a decrease in the effective dose from 1.6 to 1.1 mSv.
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Sulfato de Bario/administración & dosificación , Colon/diagnóstico por imagen , Colonografía Tomográfica Computarizada/métodos , Enema/métodos , Intensificación de Imagen Radiográfica/métodos , Colonografía Tomográfica Computarizada/instrumentación , Medios de Contraste , Relación Dosis-Respuesta a Droga , Humanos , Fantasmas de Imagen , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
AIM: To investigate the technical feasibility and outcome of retrograde root canal treatment. SUMMARY: Endodontic access cavity preparation in abutment teeth may jeopardize the retention of the coronal restoration leading to prosthodontic failure. In such cases leaving the crown intact and performing retrograde root canal treatment might be an alternative approach. The potential to promote healing with retrograde endodontic treatment, and the technical feasibility to shape, clean and fill the canal was evaluated retrospectively. The study consisted of 21 incisors, canines and premolar teeth followed-up clinically and radiographically from 6 to 48 months. In 14 teeth the canals were completely negotiated. These cases were all judged as completely healed. In five cases no canal could be explored by files and a conventional ultrasonic root-end preparation and filling was performed. Two of these were classified as completely healed and three as 'uncertain'. In 2 two-rooted premolars a combination was performed with complete instrumentation of the buccal canal and the ultrasonic root-end preparation of the palatal root. One case was judged as a failure and the other was classified as completely healed. The results from this preliminary evaluation of retrograde root canal treatment are promising and merit a randomized clinical trial. KEY LEARNING POINTS: Abutment teeth with vital pulps may develop pulp necrosis and apical periodontitis in 10% of cases. Endodontic access preparation through an artificial crown may weaken its retention and jeopardize the longevity of a bridgework. Retrograde root canal treatment is often feasible in maxillary teeth. Results from this preliminary study suggest that treatment outcome for retrograde and orthograde root canal treatment is similar.
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Pilares Dentales , Periodontitis Periapical/cirugía , Obturación Retrógrada , Adulto , Necrosis de la Pulpa Dental/cirugía , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
BACKGROUND: Onychomycosis is a rare disorder in children. Few studies exist on the incidence or prevalence of onychomycosis in children. OBJECTIVE: To examine the epidemiology of childhood onychomycosis in Iceland during the period 1982-2000. METHODS: Results from all mycological samples taken from children in Iceland from 1982 to 2000 were examined. Information about the requesting physician, unique social security number, date of birth, sex, results of culture and microscopy were registered. Growth of a dermatophyte was taken as an indication of a case of onychomycosis. RESULTS: During the period 1982-2000 a total of 493 samples from 408 Icelandic children, aged 0-17 years, were examined. Dermatophytes were cultured from 148 (30.0%) samples. During the period 1982-85, the mean annual incidence of positive cultures was 1.65 per 100,000, increasing to 21.30 per 100,000 for the years 1996-2000. Trichophyton rubrum was the dominating organism and was found in 102/148 cases positive for the growth of a dermatophyte. The incidence of positive dermatophyte cultures increased with age and was found in eight children aged 0-4, and in 57 children aged 10-14 years. CONCLUSION: Onychomycosis is rare in children, but increases with age. It seems that onychomycosis increased during the study period, but it is not clear if this was due to a true increase in the prevalence of onychomycosis or an increased awareness of onychomycosis, or both.
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Onicomicosis/epidemiología , Adolescente , Arthrodermataceae/aislamiento & purificación , Niño , Preescolar , Femenino , Humanos , Islandia/epidemiología , Incidencia , Lactante , Masculino , PrevalenciaRESUMEN
We describe a previously unreported case of cranial arterial dolichoectasia associated with spontaneous dissection of the petrous (C2) segment of the internal carotid artery (ICA) with 2 patent lumena. Dolichoectasia of the cranial arteries and different types of double lumen of ICA are discussed. A review of previously reported cases is included.
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Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Disección de la Arteria Carótida Interna/diagnóstico por imagen , Arteria Carótida Interna/diagnóstico por imagen , Insuficiencia Vertebrobasilar/diagnóstico por imagen , Arteria Basilar/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/complicaciones , Disección de la Arteria Carótida Interna/etiología , Dilatación Patológica , Humanos , Masculino , Persona de Mediana Edad , Radiografía , Insuficiencia Vertebrobasilar/complicacionesRESUMEN
The authors present the case of a young woman, suffering from progressive tetraplegia, cranial nerve dysfunction, respiratory failure and lethargy due to radiographically demonstrated increased brainstem compression after coil embolization of an aneurysm of the midportion of the basilar artery. The patients condition improved dramatically after transclival decompression. The importance of understanding the effects of a rigid endovascular mass on adjacent neural structures is emphasized.
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Fosa Craneal Posterior/cirugía , Descompresión Quirúrgica/métodos , Embolización Terapéutica/efectos adversos , Aneurisma Intracraneal/complicaciones , Aneurisma Intracraneal/terapia , Prótesis e Implantes/efectos adversos , Adulto , Arteria Basilar/diagnóstico por imagen , Arteria Basilar/patología , Arteria Basilar/cirugía , Angiografía Cerebral , Fosa Craneal Posterior/anatomía & histología , Fosa Craneal Posterior/patología , Femenino , Humanos , Aneurisma Intracraneal/fisiopatología , Imagen por Resonancia Magnética , Hueso Occipital/anatomía & histología , Hueso Occipital/patología , Hueso Occipital/cirugía , Paresia/etiología , Paresia/fisiopatología , Paresia/cirugía , Puente/irrigación sanguínea , Puente/patología , Puente/fisiopatología , Reoperación , Insuficiencia Respiratoria/etiología , Insuficiencia Respiratoria/patología , Insuficiencia Respiratoria/cirugía , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
The discovery of toxicity related to glucose degradation products (GDP) has initiated the development of new PD fluids with low GDP concentrations and higher, more physiological, pH levels. Cell numbers, differential counts and the respiratory burst responses of peritoneal leukocytes were compared between patients treated with the low GDP, high pH fluid Gambrosol-trio (n=10) and a conventional fluid (n=12). Effluents from over-night dwells were collected and leukocytes were evaluated morphologically and by luminol-amplified chemiluminescence (CL) after stimulation with opsonized zymosan. The frequency of necrosis and early apoptosis was quantified by means of annexin V binding and propidium iodide uptake. The Gambrosol-trio group produced significantly higher (p<5%) macrophage counts and stronger CL responses (p<10%) than did the conventional fluid group. The cell compositions did not differ significantly between the groups. Necrosis was significantly more common among the cells in the conventional fluid group. The occurrence of apoptosis did not differ between the fluids.
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Soluciones para Diálisis/farmacología , Glucosa/metabolismo , Leucocitos/fisiología , Diálisis Peritoneal/métodos , Estallido Respiratorio/efectos de los fármacos , Adulto , Anciano , Apoptosis , Supervivencia Celular/efectos de los fármacos , Soluciones para Diálisis/metabolismo , Femenino , Humanos , Concentración de Iones de Hidrógeno , Enfermedades Renales/terapia , Leucocitos/metabolismo , Leucocitos/patología , Masculino , Persona de Mediana Edad , Modelos Teóricos , NecrosisRESUMEN
Heat sterilization of glucose containing peritoneal dialysis (PD) fluids induces the production of cytotoxic glucose degradation products (GDPs), some of which are still unidentified. The present study was performed to characterize the kinetics and the dose-response of the respiratory burst inhibition of GDPs and to compare different fluids in this respect. The zymosan-induced respiratory burst of rat peritoneal neutrophils and macrophages was measured by chemiluminescence (CL) after incubation in vitro for 1, 2, and 4 hours in different homemade and commercially available PD fluids, followed by one hour of recovery in Hanks' buffer. Heat sterilized fluids were compared with their filter sterilized equivalents at two different pH levels. The results revealed that the inhibitory effect of heat sterilized fluids on the respiratory burst of peritoneal neutrophils is additive to that of low pH, but more fast-acting and, in contrast to the pH effect, similar in magnitude to its in vivo equivalent. The effect developed within 1 hour and had a linear dose response. The low GDP fluid Gambrosol-Bio was less toxic than the conventional fluid Gambrosol, but the difference was smaller than expected in relation to measured concentrations of known GDPs. Macrophages were less sensitive than neutrophils to the GDP effect.
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Glucosa/toxicidad , Calor , Leucocitos/metabolismo , Diálisis Peritoneal , Estallido Respiratorio/efectos de los fármacos , Animales , Relación Dosis-Respuesta a Droga , Glucosa/metabolismo , Mediciones Luminiscentes , Masculino , Ratas , Ratas Sprague-Dawley , EsterilizaciónRESUMEN
An integrated bioprocess has been developed suitable for production of recombinant peptides using a gene multimerization strategy and site-specific cleavage of the resulting gene product. The process has been used for production in E. coli of the human proinsulin C-peptide via a fusion protein BB-C7 containing seven copies of the 31-residues C-peptide monomer. The fusion protein BB-C7 was expressed at high level, 1.8 g l(-1), as a soluble gene product in the cytoplasm. A heat treatment procedure efficiently released the BB-C7 fusion protein into the culture medium. This step also served as an initial purification step by precipitating the majority of the host cell proteins, resulting in a 70% purity of the BB-C7 fusion protein. Following cationic polyelectrolyte precipitation of the nucleic acids and anion exchange chromatography, native C-peptide monomers were obtained by enzymatic cleavage at flanking arginine residues. The released C-peptide material was further purified by reversed-phase chromatography and size exclusion chromatography. The overall yield of native C-peptide at a purity exceeding 99% was 400 mg l(-1) culture, corresponding to an overall recovery of 56%. The suitability of this process also for the production of other recombinant proteins is discussed.
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Biotecnología/métodos , Péptido C/biosíntesis , Péptido C/aislamiento & purificación , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/aislamiento & purificación , Reactores Biológicos , Péptido C/genética , Carboxipeptidasa B , Carboxipeptidasas/química , Carboxipeptidasas/metabolismo , Precipitación Química , Cromatografía Liquida/métodos , Calor , Humanos , Ácidos Nucleicos/aislamiento & purificación , Ingeniería de Proteínas/métodos , Proteínas Recombinantes de Fusión/genética , Tripsina/química , Tripsina/metabolismoRESUMEN
Recent reports have demonstrated beneficial effects of proinsulin C-peptide in the diabetic state, including improvements of kidney and nerve function. To examine the background to these effects, C-peptide binding to cell membranes has been studied by using fluorescence correlation spectroscopy. Measurements of ligand-membrane interactions at single-molecule detection sensitivity in 0.2-fl confocal volume elements show specific binding of fluorescently labeled C-peptide to several human cell types. Full saturation of the C-peptide binding to the cell surface is obtained at low nanomolar concentrations. Scatchard analysis of binding to renal tubular cells indicates the existence of a high-affinity binding process with K(ass) > 3.3 x 10(9) M(-1). Addition of excess unlabeled C-peptide is accompanied by competitive displacement, yielding a dissociation rate constant of 4.5 x 10(-4) s(-1). The C-terminal pentapeptide also displaces C-peptide bound to cell membranes, indicating that the binding occurs at this segment of the ligand. Nonnative D-C-peptide and a randomly scrambled C-peptide do not compete for binding with the labeled C-peptide, nor were crossreactions observed with insulin, insulin-like growth factor (IGF)-I, IGF-II, or proinsulin. Pretreatment of cells with pertussis toxin, known to modify receptor-coupled G proteins, abolishes the binding. It is concluded that C-peptide binds to specific G protein-coupled receptors on human cell membranes, thus providing a molecular basis for its biological effects.
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Péptido C/metabolismo , Túbulos Renales/metabolismo , Unión Competitiva , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Humanos , Túbulos Renales/citología , Túbulos Renales/efectos de los fármacos , Cinética , Microscopía Fluorescente , Toxina del Pertussis , Factores de Virulencia de Bordetella/farmacologíaRESUMEN
Hydrogen/deuterium (H/D) exchange measurements in low and moderate concentrations of GuHCI were conducted on the side chain H(N) atoms of the seven tryptophans of pseudo wild-type human carbonic anhydrase II. Tryptophans 5, 16 and 245, situated in or close to the N-terminal domain were found to have little protection against exchange. The H/D exchange results for Trp-123, Trp-192 and Trp-209 showed that a previously identified molten globule and the native state gave a similar protection against exchange. Global unfolding of the protein is necessary for the efficient exchange at Trp-97, which is located in the central part of the beta-sheet.
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Anhidrasas Carbónicas/química , Deuterio , Indoles , Resonancia Magnética Nuclear Biomolecular , Conformación Proteica , Triptófano , Deuterio/química , Humanos , Hidrógeno , Indoles/química , Resonancia Magnética Nuclear Biomolecular/métodos , Desnaturalización Proteica , Pliegue de Proteína , Triptófano/químicaRESUMEN
A multimerization strategy to improve yields upon recombinant production of the 31-aa human proinsulin C-peptide is presented. Gene fragments encoding the C-peptide were assembled using specific head-to-tail multimerization. DNA constructs encoding one, three or seven copies of the C-peptide gene, fused to a serum albumin binding affinity tag, were expressed intracellularly in Escherichia coli. The three fusion proteins were produced at similar levels (approximately 50 mg/l) and were proteolytically stable during production. Enzymatic digestion by trypsin-carboxypeptidase B treatment of the fusion proteins was shown to efficiently release native C-peptide, as determined by mass spectrometry, reverse-phase chromatography and a radioimmunoassay. The quantitative yields of C-peptide obtained from the three different fusion proteins suggest that this multimerization strategy could provide a cost-efficient production scheme for the C-peptide, and that this strategy could be useful also for production of other recombinant peptides.
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Péptido C/biosíntesis , Péptido C/genética , Clonación Molecular/métodos , Secuencia de Aminoácidos , Péptido C/aislamiento & purificación , Péptido C/metabolismo , Carboxipeptidasa B , Carboxipeptidasas/metabolismo , Cromatografía de Afinidad , ADN , Escherichia coli , Humanos , Datos de Secuencia Molecular , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/aislamiento & purificación , Proteínas Recombinantes de Fusión/metabolismo , Tripsina/metabolismoRESUMEN
OBJECTIVE: To evaluate the in vivo effects of heat-sterilized peritoneal dialysis (PD) fluids on the respiratory burst response of rat peritoneal leukocytes. DESIGN: Rats were exposed to intraperitoneal injections of a laboratory-made PD fluid that was either heat-sterilized (H-PD) or filtered (F-PD). Control groups of animals were given Hank's buffer (HBSS) or saline (NaCl). Leukocytes were harvested by intraperitoneal lavage at different times in different animals and analyzed with respect to cell numbers, differential counts, and production of superoxide (chemiluminescence) in response to opsonized zymosan. The chemiluminescence responses of the macrophage and the neutrophil populations, respectively, were obtained by curve-fitting techniques from the responses of the mixed populations. RESULTS: All fluids induced a recruitment of neutrophils, the PD fluids causing a cell number increase that was more transient than that caused by NaCl and HBSS. Macrophage numbers were only slightly influenced, but were generally higher after NaCl and HBSS injections than after PD fluid injections. The H-PD exposure induced a significant inhibition of the macrophage chemiluminescence response after 2 and 12 hours, compared with the exposure to F-PD. The neutrophil chemiluminescence response was not significantly affected. CONCLUSION: The toxins produced by heat-sterilization of glucose-containing PD fluids inhibit in vivo the respiratory burst response of peritoneal macrophages.
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Soluciones para Diálisis/efectos adversos , Glucosa/efectos adversos , Macrófagos Peritoneales/efectos de los fármacos , Esterilización/métodos , Animales , Tampones (Química) , Recuento de Células , Movimiento Celular/efectos de los fármacos , Filtración , Calor , Indicadores y Reactivos , Recuento de Leucocitos , Leucocitos/efectos de los fármacos , Leucocitos/metabolismo , Mediciones Luminiscentes , Luminol , Macrófagos Peritoneales/metabolismo , Masculino , Neutrófilos/efectos de los fármacos , Neutrófilos/metabolismo , Lavado Peritoneal , Ratas , Ratas Sprague-Dawley , Estallido Respiratorio/efectos de los fármacos , Cloruro de Sodio , Superóxidos/metabolismo , Zimosan/farmacologíaRESUMEN
The aim of this study was to characterize the morphological changes in the peritoneum following experimental peritoneal dialysis of rats, and to compare the new high-pH and low glucose-derived degradation products (GDP)-level PD fluid PD-Bio with the conventional PD fluid Gambrosol at two different exposure frequencies. Rats were subjected to 10 mL intraperitoneal injections three times per day at 3-hour intervals daytime for 9 days (2 successive weeks, excluding weekends) or once daily for 4 weeks. Untreated animals and animals exposed to Gambrosol or PD-Bio were compared. Biopsy samples were taken from the diaphragm and prepared for light microscopy. Morphometric analysis was used to compare the thickness and the cell density of the sub-mesothelial connective tissue. Intraperitoneal leukocyte numbers were counted. Both fluids induced a significant thickening of the submesothelial connective tissue and an increase in intraperitoneal leukocyte numbers. After exposure three times per day, Gambrosol induced a significantly greater submesothelial thickening than PD-Bio. The submesothelial tissue was more cell-dense after exposure to PD-Bio than after exposure to Gambrosol. The present results indicate that the structural changes of the peritoneum that follow peritoneal dialysis may be dependent upon the chemical composition of the PD fluids.
Asunto(s)
Soluciones para Diálisis/química , Glucosa/química , Diálisis Peritoneal , Peritoneo/patología , Animales , Líquido Ascítico/citología , Concentración de Iones de Hidrógeno , Recuento de Leucocitos , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
The refolding reaction of human carbonic anhydrase II has been characterized by use of seven variants in which tryptophan residues have been replaced by Phe or Cys, in each case giving proteins with six tryptophans. Intrinsic tryptophan fluorescence was used to monitor the refolding in the 2 ms-60 s time range, and kinetic traces showing the contributions from each particular tryptophan were obtained by calculation of differences between the wild-type protein and the variants. Earlier assignment [Mårtensson, L.-G., Jonasson, P., Freskgard, P.-O., Svensson, M., Carlsson, U., & Jonsson, B.-H. (1995) Biochemistry 34, 1011-1021] of specific fluorescence properties to each tryptophan, especially regarding energy transfer and intrinsic fluorescence quenching, has made it possible to use the kinetic data to describe the formation of tertiary structure at defined tryptophan residues. In summary, it was found that tertiary structure is formed earlier at those tryptophans that are associated with the central core of beta-strands than at tryptophan residues in the N-terminal minidomain.