956 resultados para SPONTANEOUS CLEARANCE
Resumo:
BACKGROUND AND OBJECTIVE: Protease inhibitors are highly bound to orosomucoid (ORM) (alpha1-acid glycoprotein), an acute-phase plasma protein encoded by 2 polymorphic genes, which may modulate their disposition. Our objective was to determine the influence of ORM concentration and phenotype on indinavir, lopinavir, and nelfinavir apparent clearance (CL(app)) and cellular accumulation. Efavirenz, mainly bound to albumin, was included as a control drug. METHODS: Plasma and cells samples were collected from 434 human immunodeficiency virus-infected patients. Total plasma and cellular drug concentrations and ORM concentrations and phenotypes were determined. RESULTS: Indinavir CL(app) was strongly influenced by ORM concentration (n = 36) (r2 = 0.47 [P = .00004]), particularly in the presence of ritonavir (r2 = 0.54 [P = .004]). Lopinavir CL(app) was weakly influenced by ORM concentration (n = 81) (r2 = 0.18 [P = .0001]). For both drugs, the ORM1 S variant concentration mainly explained this influence (r2 = 0.55 [P = .00004] and r2 = 0.23 [P = .0002], respectively). Indinavir CL(app) was significantly higher in F1F1 individuals than in F1S and SS patients (41.3, 23.4, and 10.3 L/h [P = .0004] without ritonavir and 21.1, 13.2, and 10.1 L/h [P = .05] with ritonavir, respectively). Lopinavir cellular exposure was not influenced by ORM abundance and phenotype. Finally, ORM concentration or phenotype did not influence nelfinavir (n = 153) or efavirenz (n = 198) pharmacokinetics. CONCLUSION: ORM concentration and phenotype modulate indinavir pharmacokinetics and, to a lesser extent, lopinavir pharmacokinetics but without influencing their cellular exposure. This confounding influence of ORM should be taken into account for appropriate interpretation of therapeutic drug monitoring results. Further studies are needed to investigate whether the measure of unbound drug plasma concentration gives more meaningful information than total drug concentration for indinavir and lopinavir.
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Axillary clearance in early breast cancer aims to improve locoregional control and provide staging information but is associated with undesirable morbidity. We therefore investigated whether avoiding axillary surgery in older women would result in improved quality of life (QL) with similar disease-free survival (DFS) and overall survival (OS).
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OBJECTIVE: Only a few studies have investigated variations of different markers for inflammatory processes during the physiological menstrual cycle. The results are conflicting, particularly concerning the correlation between the marker leptin and steroid hormones. The aim of the study was to investigate the inflammatory markers C-reactive protein (CRP) and leptin in the serum of healthy, normally ovulating women and to correlate these with each other and with the hormones of the gonadal axis. A cycle-dependence of the markers studied would imply an exact timing of the blood sampling for clinical needs. DESIGN: Observational study investigating the two inflammatory markers CRP and leptin in relation to the hormonal pattern of the gonadal axis during the normal cycle. METHODS: Ovulatory cycles of 36 healthy, young, normo-androgenic women, having a normal body mass index were evaluated. Serum concentrations of leptin and CRP, as well as of follicle-stimulating hormone, luteinising hormone, 17beta-oestradiol, progesterone, prolactin (PRL) and free testosterone were measured every 1-2 days during one full cycle. RESULTS: Serum levels of leptin and CRP behaved differently during ovulatory cycles, with higher concentrations for leptin only during certain phases. Significant correlations were found in the follicular phase between leptin and PRL and leptin and free testosterone. CONCLUSIONS: Leptin levels change during the menstrual cycle. Leptin levels are more stable on cycle days 1-5 than later in the cycle. For precise cycle-independent measurements, these fluctuations have to be taken into account. There is no similar cyclic pattern for CRP.
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Articular cartilage has poor reparative capacities, and once damaged cartilage lesions remain chronic and can lead to osteoarthritis. Over the last decade, several innovative therapies have been introduced to promote the regeneration of articular cartilage while sustaining sufficient mechanical stress and permitting a pain free motion. An important measure of outcome is the morphological characterization of the repair tissue in order to allow for cross-study evaluation. The International Cartilage Repair Society has developed a analogue visual scale to quantify repair tissue, which is described in this paper.
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We analyzed sex differences in 696 patients with spontaneous cervical artery dissection. There were more men (n = 399; p < 0.0001), and men showed a higher frequency of hypertension (31% vs 15%; p < 0.0001). Women were younger (42.5 +/- 9.9 vs 47.5 +/- 9.3 years; p < 0.0001), had more often multiple dissections (18 vs 10%; p = 0.001), migraine (47 vs 20%; p < 0.0001), and tinnitus (16 vs 8%; p = 0.001). Outcome and mortality were similar in both sexes.
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We examined the seasonal variability of spontaneous cervical artery dissection (sCAD) by analysing prospectively collected data from 352 patients with 380 sCAD (361 symptomatic sCAD; 305 carotid and 75 vertebral artery dissections) admitted to two university hospitals with a catchment area of 2,200,000 inhabitants between 1985 and 2004. Presenting symptoms and signs of the 380 sCAD were ischaemic stroke in 241 (63%), transient ischaemic attack in 40 (11%), retinal ischemia in seven (2%), and non-ischaemic in 73 (19%) cases; 19 (5%) were asymptomatic sCAD. A seasonal pattern, with higher frequency of sCAD in winter (31.3%; 95% confidence interval (CI): 26.5 to 36.4; p=0.021) compared to spring (25.5%; 95% CI: 21.1 to 30.3), summer (23.5%; 95% CI: 19.3 to 28.3), and autumn (19.7%; 95% CI: 15.7 to 24.1) was observed. Although the cause of seasonality in sCAD is unclear, the winter peaks of infection, hypertension, and aortic dissection suggest common underlying mechanisms.
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BACKGROUND: Peri-implantitis is associated with the presence of submarginal plaque, soft-tissue inflammation and advanced breakdown of the supporting bone. The progression of peri-implantitis following varying periods of continuing plaque accumulation has been studied in animal models. OBJECTIVE: The aim of the current experiment was to study the progression of peri-implantitis around implants with different surface roughness. MATERIAL AND METHODS: In five beagle dogs, three implants with either a sandblasted acid-etched surface (SLA) or a polished surface (P) were installed bilaterally in the edentulous premolar regions. After 3 months on a plaque control regimen, experimental peri-implantitis was induced by ligature placement and plaque accumulation was allowed to progress until about 40% of the height of the supporting bone had been lost. After this 4-month period, ligatures were removed and plaque accumulation was continued for an additional 5 months. Radiographs of all implant sites were obtained before and after 'active' experimental peri-implantitis as well as at the end of the experiment. Biopsies were harvested and the tissue samples were prepared for light microscopy. The sections were used for histometric and morphometric examinations. RESULTS: The radiographic examinations indicated that similar amounts of bone loss occurred at SLA and P sites during the active breakdown period, while the progression of bone loss was larger at SLA than at polished sites following ligature removal. The histological examination revealed that both bone loss and the size of the inflammatory lesion in the connective tissue were larger in SLA than in polished implant sites. The area of plaque was also larger at implants with an SLA surface than at implants with a polished surface. CONCLUSION: It is suggested that the progression of peri-implantitis, if left untreated, is more pronounced at implants with a moderately rough surface than at implants with a polished surface.
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BACKGROUND AND PURPOSE: Isolated Horner syndrome without associated cranial nerve palsies or ischemic symptoms is an important presentation of spontaneous internal carotid artery dissection (sICAD). Ultrasound is often used as a screening method in these patients because cervical MRI is not always available on an emergency basis. Current knowledge on ultrasound findings in patients with sICAD presenting with isolated Horner syndrome is limited. METHODS: Patients were recruited from prospective cervical artery dissection databases of 3 tertiary care centers. Diagnosis of sICAD was confirmed by cervical MRI and MR angiography or digital subtraction angiography in all patients. Data on Doppler sonography and color duplex sonography examinations performed within 30 days of symptom onset were analyzed. RESULTS: We identified 88 patients with Horner syndrome as the only sign of sICAD. Initial ultrasound examination was performed in 72 patients after a mean time interval from symptom onset to examination of 11 (SD 8) days. The overall frequency of false-negative ultrasound findings was 31% (22 of 72 patients). It showed stenosis >or=80% or occlusion in 34 (47%) patients, and stenosis
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ABSTRACT: BACKGROUND: Translocation of nanoparticles (NP) from the pulmonary airways into other pulmonary compartments or the systemic circulation is controversially discussed in the literature. In a previous study it was shown that titanium dioxide (TiO2) NP were "distributed in four lung compartments (air-filled spaces, epithelium/endothelium, connective tissue, capillary lumen) in correlation with compartment size". It was concluded that particles can move freely between these tissue compartments. To analyze whether the distribution of TiO2 NP in the lungs is really random or shows a preferential targeting we applied a newly developed method for comparing NP distributions. METHODS: Rat lungs exposed to an aerosol containing TiO2 NP were prepared for light and electron microscopy at 1 h and at 24 h after exposure. Numbers of TiO2 NP associated with each compartment were counted using energy filtering transmission electron microscopy. Compartment size was estimated by unbiased stereology from systematically sampled light micrographs. Numbers of particles were related to compartment size using a relative deposition index and chi-squared analysis. RESULTS: Nanoparticle distribution within the four compartments was not random at 1 h or at 24 h after exposure. At 1 h the connective tissue was the preferential target of the particles. At 24 h the NP were preferentially located in the capillary lumen. CONCLUSION: We conclude that TiO2 NP do not move freely between pulmonary tissue compartments, although they can pass from one compartment to another with relative ease. The residence time of NP in each tissue compartment of the respiratory system depends on the compartment and the time after exposure. It is suggested that a small fraction of TiO2 NP are rapidly transported from the airway lumen to the connective tissue and subsequently released into the systemic circulation.