36 resultados para alignment-free methods

em BORIS: Bern Open Repository and Information System - Berna - Suiça


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Objective: In South Africa, many HIV-infected patients experience delays in accessing antiretroviral therapy (ART). We examined pretreatment mortality and access to treatment in patients waiting for ART. Design: Cohort of HIV-infected patients assessed for ART eligibility at 36 facilities participating in the Comprehensive HIV and AIDS Management (CHAM) program in the Free State Province. Methods: Proportion of patients initiating ART, pre-ART mortality and risk factors associated with these outcomes were estimated using competing risks survival analysis. Results: Forty-four thousand, eight hundred and forty-four patients enrolled in CHAM between May 2004 and December 2007, of whom 22 083 (49.2%) were eligible for ART; pre-ART mortality was 53.2 per 100 person-years [95% confidence interval (CI) 51.8–54.7]. Median CD4 cell count at eligibility increased from 87 cells/ml in 2004 to 101 cells/ml in 2007. Two years after eligibility an estimated 67.7% (67.1–68.4%) of patients had started ART, and 26.2% (25.6–26.9%) died before starting ART. Among patients with CD4 cell counts below 25 cells/ml at eligibility, 48% died before ART and 51% initiated ART. Men were less likely to start treatment and more likely to die than women. Patients in rural clinics or clinics with low staffing levels had lower rates of starting treatment and higher mortality compared with patients in urban/peri-urban clinics, or better staffed clinics. Conclusions: Mortality is high in eligible patients waiting for ART in the Free State Province. The most immunocompromised patients had the lowest probability of starting ART and the highest risk of pre-ART death. Prioritization of these patients should reduce waiting times and pre-ART mortality.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

PURPOSE: The purpose of this retrospective study was to examine the reliability of virtually estimated abdominal blood volume using segmentation from postmortem computed tomography (PMCT) data. MATERIALS AND METHODS: Twenty-one cases with free abdominal blood were investigated by PMCT and autopsy. The volume of the blood was estimated using a manual segmentation technique (Amira, Visage Imaging, Germany) and the results were compared to autopsy data. Six of 21 cases had undergone additional post-mortem computed tomographic angiography (PMCTA). RESULTS: The virtually estimated abdominal blood volumes did not differ significantly from those measured at autopsy. Additional PMCTA did not bias data significantly. CONCLUSION: Virtual estimation of abdominal blood volume is a reliable technique. The virtual blood volume estimation is a useful tool to deliver additional information in cases where autopsy is not performed or in cases where a postmortem angiography is performed.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND: The objective of this study was to link expression patterns of B-cell-specific Moloney murine leukemia virus integration site 1 (Bmi-1) and p16 to patient outcome (recurrence and survival) in a cohort of 252 patients with oral and oropharyngeal squamous cell cancer (OSCC). METHODS: Expression levels of Bmi-1 and p16 in samples from 252 patients with OSCC were evaluated immunohistochemically using the tissue microarray method. Staining intensity was determined by calculating an intensity reactivity score (IRS). Staining intensity and the localization of expression within tumor cells (nuclear or cytoplasmic) were correlated with overall, disease-specific, and recurrence-free survival. RESULTS: The majority of cancers were localized in the oropharynx (61.1%). In univariate analysis, patients who had OSCC and strong Bmi-1 expression (IRS >10) had worse outcomes compared with patients who had low and moderate Bmi-1 expression (P = .008; hazard ratio [HR], 1.82; 95% confidence interval [CI], 1.167-2.838); this correlation was also observed for atypical cytoplasmic Bmi-1 expression (P = .001; HR, 2.164; 95% CI, 1.389-3.371) and for negative p16 expression (P < .001; HR, 0.292; 95% CI, 0.178-0.477). The combination of both markers, as anticipated, had an even stronger correlation with overall survival (P < .001; HR, 8.485; 95% CI, 4.237-16.994). Multivariate analysis demonstrated significant results for patients with oropharyngeal cancers, but not for patients with oral cavity tumors: Tumor classification (P = .011; HR, 1.838; 95%CI, 1.146-2.947) and the combined marker expression patterns (P < .001; HR, 6.254; 95% CI, 2.869-13.635) were correlated with overall survival, disease-specific survival (tumor classification: P = .002; HR, 2.807; 95% CI, 1.477-5.334; combined markers: P = .002; HR, 5.386; 95% CI, 1.850-15.679), and the combined markers also were correlated with recurrence-free survival (P = .001; HR, 8.943; 95% CI, 2.562-31.220). CONCLUSIONS: Cytoplasmic Bmi-1 expression, an absence of p16 expression, and especially the combination of those 2 predictive markers were correlated negatively with disease-specific and recurrence-free survival in patients with oropharyngeal cancer. Therefore, the current results indicate that these may be applicable as predictive markers in combination with other factors to select patients for more aggressive treatment and follow-up. Cancer 2011;. © 2011 American Cancer Society.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

For nonsurgical treatment of fractures of the proximal phalanges of the triphalangeal fingers, different dynamic casts have been described. The main principle behind these casts is advancement and tightening of the extensor hood, caused by a combination of blocking the metacarpophalangeal joints in flexion and actively flexing the proximal interphalangeal joints. In contrast to established treatment protocols using functional forearm casts, the Lucerne cast allows for free mobilization of the wrist joint. The purpose of the current multicenter study was to compare the results of conservative, functional treatment using 2 different methods, either a forearm cast or a Lucerne cast.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Numerical simulations of eye globes often rely on topographies that have been measured in vivo using devices such as the Pentacam or OCT. The topographies, which represent the form of the already stressed eye under the existing intraocular pressure, introduce approximations in the analysis. The accuracy of the simulations could be improved if either the stress state of the eye under the effect of intraocular pressure is determined, or the stress-free form of the eye estimated prior to conducting the analysis. This study reviews earlier attempts to address this problem and assesses the performance of an iterative technique proposed by Pandolfi and Holzapfel [1], which is both simple to implement and promises high accuracy in estimating the eye's stress-free form. A parametric study has been conducted and demonstrated reliance of the error level on the level of flexibility of the eye model, especially in the cornea region. However, in all cases considered 3-4 analysis iterations were sufficient to produce a stress-free form with average errors in node location <10(-6)mm and a maximal error <10(-4)mm. This error level, which is similar to what has been achieved with other methods and orders of magnitude lower than the accuracy of current clinical topography systems, justifies the use of the technique as a pre-processing step in ocular numerical simulations.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

OBJECTIVE: To compare four different implantation modalities for the repair of superficial osteochondral defects in a caprine model using autologous, scaffold-free, engineered cartilage constructs, and to describe the short-term outcome of successfully implanted constructs. METHODS: Scaffold-free, autologous cartilage constructs were implanted within superficial osteochondral defects created in the stifle joints of nine adult goats. The implants were distributed between four 6-mm-diameter superficial osteochondral defects created in the trochlea femoris and secured in the defect using a covering periosteal flap (PF) alone or in combination with adhesives (platelet-rich plasma (PRP) or fibrin), or using PRP alone. Eight weeks after implantation surgery, the animals were killed. The defect sites were excised and subjected to macroscopic and histopathologic analyses. RESULTS: At 8 weeks, implants that had been held in place exclusively with a PF were well integrated both laterally and basally. The repair tissue manifested an architecture similar to that of hyaline articular cartilage. However, most of the implants that had been glued in place in the absence of a PF were lost during the initial 4-week phase of restricted joint movement. The use of human fibrin glue (FG) led to massive cell infiltration of the subchondral bone. CONCLUSIONS: The implantation of autologous, scaffold-free, engineered cartilage constructs might best be performed beneath a PF without the use of tissue adhesives. Successfully implanted constructs showed hyaline-like characteristics in adult goats within 2 months. Long-term animal studies and pilot clinical trials are now needed to evaluate the efficacy of this treatment strategy.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Trichinellosis is an important parasitic zoonosis that is caused by the intracellular nematode Trichinella spp.. Infection of humans occurs through consumption of raw (or undercooked) meat containing infectious larvae. In Europe, meat from pork, horse, and wild boar have been identified as most important sources of Trichinella infections in humans. In Switzerland, both the domestic pig and wild boar population are considered free of Trichinella. Conversely, Swiss foxes, lynxs and recently a wolf were found to be infected, the species identified in these animals was always referred to as Trichinella britovi. Although this species rarely infects pork and, compared to Trichinella spiralis, only causes reduced pathogenic effects in humans, the basic presence of Trichinella in Switzerland cannot be neglegted. This fact has gained increasing importance since the responsible authorities in the European Union (EU) are preparing regulations for the official Trichinella-control in meat in order to improve food safety for consumers. These regulations will be implemented as a consequence of the recent association of east European countries with the EU. This new legislation particularly takes into account, that in the past by far most cases of human trichinellosis in the EU were due to consumption of imported east European meat.Within the framework of the bilateral agreements of Switzerland with the EU, the Swiss veterinary public health authorities will have to comply with the foreseen EU regulations. Although diagnostic methods for the direct demonstation of Trichinella in pork meat are already routine practice in several Swiss abattoirs, the implementation of a meat control program for Trichinella for the entire slaughter pig population of the country would lead to an enormous increase in costs for the administration and will require an increased infrastructure in veterinary services. In order to find a reduced testing format for monitoring Trichinella infections in Swiss pork, an infection risk-oriented survey strategy is currently evaluated. In the present article, this minimized survey strategy is discussed regarding its compatibility with the EU regulations laying down rules for the official control of meat for Trichinella.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

OBJECTIVE: Adequacy of organ perfusion depends on sufficient oxygen supply in relation to the metabolic needs. The aim of this study was to evaluate the relationship between gradients of free energy change, and the more commonly used parameter for the evaluation of the adequacy of organ perfusion, such as oxygen-extraction in patients undergoing valve replacement surgery using normothermic cardiopulmonary bypass (CPB). METHODS: In 43 cardiac patients, arterial, mixed venous, and hepato-venous blood samples were taken synchronously after induction of anaesthesia (preCPB), during CPB, and 2 and 7 h after admission to the intensive care unit (ICU+2, ICU+7). Blood gas analysis, cardiac output, and hepato-splanchnic blood flow were measured. Free energy change gradients between mixed venous and arterial (-deltadeltaG(v - a)) and hepato-venous and arterial (-deltadeltaG(hv - a)) compartments were calculated. MEASUREMENTS AND RESULTS: Cardiac index (CI) increased from 1.9 (0.7) to 2.8 (1.3) L/min/m (median, inter-quartile range) (p = 0.001), and hepato-splanchnic blood flow index (HBFI) from 0.6 (0.22) to 0.8 (0.53) L/min/m (p = 0.001). Despite increasing flow, systemic oxygen extraction increased after CPB from 24 (10)% to 35 (10)% at ICU+2 (p = 0.002), and splanchnic oxygen extraction increased during CPB from 37 (19)% to 52 (14)% (p = 0.001), and remained high thereafter. After CPB, high splanchnic and systemic gradients of free energy change gradients were associated with high splanchnic and systemic oxygen extraction, respectively (p = 0.001, 0.033, respectively). CONCLUSION: Gradients of free energy change may be helpful in characterising adequacy of perfusion in cardiac surgery patients independently from measurements or calculations of data from oxygen transport.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND: The aim of this study was to evaluate postoperative oral functions of patients who had undergone total or subtotal (75%) glossectomy with preservation of the larynx for oral squamous cell carcinomas. METHODS: Speech intelligibility and swallowing capacity of 17 patients who had been treated between 1992 and 2002 were scored and classified using standard protocols 6 to 36 months postoperatively. The outcomes were finally rated as good, acceptable, or poor. RESULTS: The 4-year disease-specific survival rate was 64%. Speech intelligibility and swallowing capacity were satisfactory (acceptable or good) in 82.3%. Only 3 patients were still dependent on tube feeding. Good speech perceptibility did not always go together with normal diet tolerance, however. CONCLUSIONS: Our satisfactory results are attributable to the use of large, voluminous soft tissue flaps for reconstruction, and to the instigation of postoperative swallowing and speech therapy on a routine basis and at an early juncture. (c) 2008 Wiley Periodicals, Inc. Head Neck, 2008.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This paper addresses the problem of estimating postoperative cup alignment from single standard X-ray radiograph with gonadal shielding. The widely used procedure of evaluation of cup orientation following total hip arthroplasty using single standard anteroposterior radiograph is known inaccurate, largely due to the wide variability in individual pelvic position relative to X-ray plate. 2D-3D image registration methods have been introduced to estimate the rigid transformation between a preoperative CT volume and postoperative radiograph(s) for an accurate estimation of the postoperative cup alignment relative to an anatomical reference extracted from the CT data. However, these methods require either multiple radiographs or a radiograph-specific calibration, both of which are not avaiable for most retrospective studies. Furthermore, these methods were only evaluated on X-ray radiograph(s) without gonadal shielding. In this paper, we propose to use a hybrid 2D-3D registration scheme combining an iterative landmark-to-ray registration with a 2D-3D intensity-based registration to estimate the rigid transfromation for a precise estimation of cup alignment. Quantitative and qualitative results evaluated on clinical and cadaveric datasets are given which indicate the validity of our approach.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

OBJECT: Fat suppressed 3D steady-state free precession (SSFP) sequences are of special interest in cartilage imaging due to their short repetition time in combination with high signal-to-noise ratio. At low-to-high fields (1.5-3.0 T), spectral spatial (spsp) radio frequency (RF) pulses perform superiorly over conventional saturation of the fat signal (FATSAT pulses). However, ultra-high fields (7.0 T and more) may offer alternative fat suppression techniques as a result of the increased chemical shift. MATERIALS AND METHODS: Application of a single, frequency selective, RF pulse is compared to spsp excitation for water (or fat) selective imaging at 7.0 T. RESULTS: For SSFP, application of a single frequency selective RF pulse for selective water or fat excitation performs beneficially over the commonly applied spsp RF pulses. In addition to the overall improved fat suppression, the application of single RF pulses leads to decreased power depositions, still representing one of the major restrictions in the design and application of many pulse sequences at ultra-high fields. CONCLUSION: The ease of applicability and implementation of single frequency selective RF pulses at ultra-high-fields might be of great benefit for a vast number of applications where fat suppression is desirable or fat-water separation is needed for quantification purposes.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

OBJECTIVES: Many flow-cytometric cell characterization methods require costly markers and colour reagents. We present here a novel device for cell discrimination based on impedance measurement of electrical cell properties in a microfluidic chip, without the need of extensive sample preparation steps and the requirement of labelling dyes. MATERIALS AND METHODS, RESULTS: We demonstrate that in-flow single cell measurements in our microchip allow for discrimination of various cell line types, such as undifferentiated mouse fibroblasts 3T3-L1 and adipocytes on the one hand, or human monocytes and in vitro differentiated dendritic cells and macrophages on the other hand. In addition, viability and apoptosis analyses were carried out successfully for Jurkat cell models. Studies on several species, including bacteria or fungi, demonstrate not only the capability to enumerate these cells, but also show that even other microbiological life cycle phases can be visualized. CONCLUSIONS: These results underline the potential of impedance spectroscopy flow cytometry as a valuable complement to other known cytometers and cell detection systems.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

OBJECTIVES: Lymph node status is an important prognostic factor in patients with squamous cell carcinoma (SCC) of the vulva. Complete inguinofemoral lymph node dissection (ILND) is accompanied by a high morbidity. Sentinel lymph node biopsy (SLNB) was established for less invasive lymph node (LN) staging. The aim of this study was to evaluate safety of SLNB in terms of accuracy and outcome in a clinical routine setting. METHODS: We retrospectively reviewed the data of patients who underwent SLNB and/or ILND for vulvar SCC in the years 1990-2007. Clinical follow-up was evaluated for histological nodal-negative patients with tumor stage T1 or T2. The false negative rate of SLNB was determined in patients who underwent both SLNB and ILND. RESULTS: Preoperative sentinel lymph node (SLN) visualization by scintigraphy was successful in 95% of all patients. SLNB was false negative in 1/45 inguinae (2.2%). All SLN were detected intraoperatively. During the follow-up period (median 24 months for SLNB and 111 months for ILND), no groin recurrences in initially nodal negative patients occurred (n=34, 59 inguinae). Transient lymph edema occurred in 7/18 patients after ILND (39%) and 2/16 patients (13%) after SLNB. No persistent edemas were found after SLNB and ILND. CONCLUSION: According to our experience SLNB is feasible and accurately predicts LN status of vulvar SCC under clinical routine conditions. SLNB in vulvar cancer seems to be a safe alternative to ILND in order to reduce morbidity of surgical treatment.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

OBJECTIVE: To report our experience with the successful removal of visible tension-free vaginal tape (TVT) by standard transurethral electroresection, as intravesical tape erosion after TVT is a rare complication, and removal can be challenging, with few cases reported. PATIENTS AND METHODS: Five patients presenting with TVT erosion into the bladder were treated at our institutions from December 2004 to July 2007; all had standard transurethral electroresection. Their records were reviewed retrospectively to retrieve data on presenting symptoms, diagnostic tests, surgical procedures and outcomes. RESULTS: The median (range) interval between the TVT procedure and the onset of symptoms was 17 (1-32) months. The predominant symptoms were painful micturition, recurrent urinary tract infection (UTI), urgency and urge incontinence. There were no complications during surgery. The storage symptoms and UTI resolved completely after removing the eroded mesh in all but one patient. Cystoscopy at 1 month after surgery showed complete healing of the bladder mucosa. CONCLUSION: Although TVT erosion into the bladder is rare, persistent symptoms, particularly recurrent UTIs, must raise some suspicion for this condition. Standard transurethral electroresection seems to be a safe, simple, minimally invasive and successful treatment option for TVT removal.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

QUESTIONS UNDER STUDY: With the reduction in breast cancer mortality in recent years the aesthetic outcome after treatment has gained increasing attention. The aim of this study was to assess the outcome quality of our single institution concept of free TRAM flap breast reconstruction with the aim of providing data to assist the patient's decision-making when breast reconstruction is an option. PRINCIPLES/METHODS: Thirty-two consecutive patients receiving immediate (n = 14) or delayed (n = 18) breast reconstruction with free transverse rectus abdominis musculocutaneous (TRAM) flaps were included. The selection of patients was based on their own wish and the availability of abdominal tissue, without excluding patients at risk for wound healing complications. Patient data were assessed prospectively and the aesthetic outcome was rated after the final result had been achieved. RESULTS: Ten patients sustained wound healing complications (4 of 9 smokers, 8 of 16 patients with a BMI over 25 kg/m2), 8 of them requiring revisional surgery. An average of 1.06 corrective procedures were performed per patient. The aesthetic outcome was judged to be good by 20 patients, fair by 5 and poor by 1 patient who sustained severe tissue loss. CONCLUSIONS: Our results revealed that a large measure of satisfaction is achievable from breast reconstruction with free TRAM flaps, in spite of the invasive nature of the procedure and the inclusion of patients at risk for wound healing complications. These data may be used in the decision-making process by patients eligible for breast reconstruction after mastectomy.