277 research outputs found
Artroplastia unicompartimental de rodilla sin cementar: indicaciones y resultados
Desde abril de 1987 hasta octubre de 1990, 100 pacientes (81 mujeres y 19
hombres) de 69 años de edad media fueron intervenidos mediante artroplastia unicompartmental
de rodilla. El tiempo medio de seguimiento fue de 28 meses (rango: 12-48). La artroplastia
fue indicada por osteoartrosis unicompartimental en 91 casos, necrosis aséptica femoral
en 8 y destrucción post-traumática en 1. El implante utilizado era de tipo no constreñido y
fijación sin cemento. En los primeros 12 meses de evolución, murieron 4 pacientes y otros
2 casos precisaron de reintervención, uno por aflojamiento de componente tibial y otro por
luxación de ambos componentes. De los 94 pacientes restantes, 90 quedaron asintomáticos
o referían mínimo dolor tras la intervención. La valoración funcional global en la escala de
Hungerford fue de 63 puntos en el estudio preoperatorio y de 93 en la revisión postoperatoria,
lo que indica un excelente resultado. Radiológicamente, sólo se objetivó un caso de aflojamiento
del implante femoral. En 90 casos, la osteointegración a nivel tibial fue completa. Tras
2 años de seguimiento, la supervivencia del implante fue del 98%.From April 1987 to October 1990, an uncemented unicompartmental knee
arthroplasty was performed in 100 patients (81 women, 19 men) with a mean age of 69 years.
The mean follow-up period was 28 months (range, 12-48). The indication for arthroplasty was
unicompartmental osteoarthritis in 91 cases, femoral necrosis in 8, and post-traumatic femoral
destruction in one. The implant used was an uncemented non-constrained design. Four patients
died during the first 12 months after surgery. Two patients were reoperated; one had
loosening of the tibial component and the other showed dislocation of the femoral implant
backwards the tibial component. In this last patient both components were well fixed showing
no signs of loosening. Out of the 94 remained cases, 90 were either asymptomatic or complain
of very slight pain. Functional assessment according to Hungerford disclosed 63 points before
surgery and 93 at review, indicating an excellent functional outcome. In the radiographic study,
only one case who was reoperated showed loosening of the tibial component. In 90 of the 94
patients studied, and apparent good bone ingrowth was observed at the tibial component. After
2-year follow-up, the survival of the implant was found to be 98%
Relating the Time Complexity of Optimization Problems in Light of the Exponential-Time Hypothesis
Obtaining lower bounds for NP-hard problems has for a long time been an
active area of research. Recent algebraic techniques introduced by Jonsson et
al. (SODA 2013) show that the time complexity of the parameterized SAT()
problem correlates to the lattice of strong partial clones. With this ordering
they isolated a relation such that SAT() can be solved at least as fast
as any other NP-hard SAT() problem. In this paper we extend this method
and show that such languages also exist for the max ones problem
(MaxOnes()) and the Boolean valued constraint satisfaction problem over
finite-valued constraint languages (VCSP()). With the help of these
languages we relate MaxOnes and VCSP to the exponential time hypothesis in
several different ways.Comment: This is an extended version of Relating the Time Complexity of
Optimization Problems in Light of the Exponential-Time Hypothesis, appearing
in Proceedings of the 39th International Symposium on Mathematical
Foundations of Computer Science MFCS 2014 Budapest, August 25-29, 201
Immune Reconstitution During the First Year of Antiretroviral Therapy of HIV-1-Infected Adults in Rural Burkina Faso
There are no data on the outcome of highly active antiretroviral therapy (HAART) in HIV-infected adults in rural Burkina Faso. We therefore assessed CD4+ T-cell counts and HIV-1 plasma viral load (VL), the proportion of naive T-cells (co-expressing CCR7 and CD45RA) and T-cell activation (expression of CD95 or CD38) in 61 previously untreated adult patients from Nouna, Burkina Faso, at baseline and 2 weeks, 1, 3, 6, 9 and 12 months after starting therapy. Median CD4+ T-cell counts increased from 174 (10th-90th percentile: 33-314) cells/µl at baseline to 300 (114- 505) cells/µl after 3 months and 360 (169-562) cells/µl after 12 months of HAART. Median VL decreased from 5.8 (4.6- 6.6) log10 copies/ml at baseline to 1.6 (1.6-2.3) log10 copies/ml after 12 months. Early CD4+ T-cell recovery was accompanied by a reduction of the expression levels of CD95 and CD38 on T-cells. Out of 42 patients with complete virological follow-up under HAART, 19 (45%) achieved concordant good immunological (gain of ≥100 CD4+ T-cells/µl above baseline) and virological (undetectable VL) responses after 12 months of treatment (intention-to-treat analysis). Neither a decreased expression of the T-cell activation markers CD38 and CD95, nor an increase in the percentage of naive T-cells reliably predicted good virological treatment responses in patients with good CD4+ T-cell reconstitution. Repeated measurement of CD4+ T-cell counts during HAART remains the most important parameter for immunologic monitoring. Substitution of repeated VL testing by determination of T-cell activation levels (e.g., CD38 expression on CD8+ T-cells) should be applied with caution
Dietary cholesterol promotes repair of demyelinated lesions in the adult brain
Multiple Sclerosis (MS) is an inflammatory demyelinating disorder in which remyelination failure contributes to persistent disability. Cholesterol is rate-limiting for myelin biogenesis in the developing CNS; however, whether cholesterol insufficiency contributes to remyelination failure in MS, is unclear. Here, we show the relationship between cholesterol, myelination and neurological parameters in mouse models of demyelination and remyelination. In the cuprizone model, acute disease reduces serum cholesterol levels that can be restored by dietary cholesterol. Concomitant with blood-brain barrier impairment, supplemented cholesterol directly supports oligodendrocyte precursor proliferation and differentiation, and restores the balance of growth factors, creating a permissive environment for repair. This leads to attenuated axon damage, enhanced remyelination and improved motor learning. Remarkably, in experimental autoimmune encephalomyelitis, cholesterol supplementation does not exacerbate disease expression. These findings emphasize the safety of dietary cholesterol in inflammatory diseases and point to a previously unrecognized role of cholesterol in promoting repair after demyelinating episodes
GRS 1915+105 : High-energy Insights with SPI/INTEGRAL
We report on results of two years of INTEGRAL/SPI monitoring of the Galactic
microquasar GRS 1915+105. From September 2004 to May 2006, the source has been
observed twenty times with long (approx 100 ks) exposures. We present an
analysis of the SPI data and focus on the description of the high-energy (> 20
keV) output of the source. We found that the 20 - 500 keV spectral emission of
GRS 1915+105 was bound between two states. It seems that these high-energy
states are not correlated with the temporal behavior of the source, suggesting
that there is no direct link between the macroscopic characteristics of the
coronal plasma and the the variability of the accretion flow. All spectra are
well fitted by a thermal comptonization component plus an extra high-energy
powerlaw. This confirms the presence of thermal and non-thermal electrons
around the black hole.Comment: 7 pages, 8 figures, 2 tables; accepted (09/11/2008) for publication
in A&
Treatment of displaced intra-articular calcaneal fractures by ligamentotaxis: current concepts’ review
Introduction: A large variety of therapeutic modalities for calcaneal fractures have been described in the literature. No single treatment modality for displaced intra-articular calcaneal fractures has proven superior over the other. This review describes and compares the different percutaneous distractional approaches for intra-articular calcaneal fractures. The history, technique, anatomical and fracture considerations, limitations and the results of different distractional approaches reported in the literature are reviewed. Method: Literature review on different percutaneous distractional approaches for displaced intra-articular calcaneal fractures. Results: Eight studies in which application of a distraction technique was used for the treatment of calcaneal fractures were identified. Because of the use of different classification, techniques, and outcome scoring systems, a meta-analysis was not possible. A literature review reveals overall fair to poor result in 10-29% of patients. Ten up to 26% of patients are unable to return to work after percutaneous treatment of their fracture. A secondary arthrodesis has to be performed in 2-15% of the cases. Infectious complications occur in 2-15%. Some loss of reduction is reported in 4-67%. Conclusion: Percutaneous distractional reduction and fixation appears to be a safe technique with overall good results and an acceptable complication rate, compared with other treatment modalities for displaced intra-articular calcaneal fractures. A meta-analysis, based on Cochrane Library criteria is not possible, because of a lack of level 1 and 2 trials on this subject
Negotiating Value: Comparing Human and Animal Fracture Care in Industrial Societies
At the beginning of the twentieth-century, human and veterinary surgeons faced the challenge of a medical marketplace transformed by technology. The socio-economic value ascribed to their patients – people and domestic animals – was changing, reflecting the increasing mechanisation of industry and the decreasing dependence of society upon non-human animals for labour. In human medicine, concern for the economic consequences of fractures “pathologised” any significant level of post-therapeutic disability, a productivist perspective contrary to the traditional corpus of medical values. In contrast, veterinarians adapted to the mechanisation of horse-power by shifting their primary professional interest to companion animals; a type of veterinary patient generally valued for the unique emotional attachment of the owner, and not the productive capacity of the animal. The economic rationalisation of human fracture care and the “sentimental” transformation of veterinary orthopaedic expertise indicates how these specialists utilised increasingly convergent rhetorical arguments to justify the application of innovative fracture care technologies to their humans and animal patients. Keywords: Fracture care, Industrialisation, Veterinary History, Human/animal relation
Calpeptin is a potent cathepsin inhibitor and drug candidate for SARS-CoV-2 infections
Several drug screening campaigns identified Calpeptin as a drug candidate against SARS-CoV-2. Initially reported to target the viral main protease (Mpro), its moderate activity in Mpro inhibition assays hints at a second target. Indeed, we show that Calpeptin is an extremely potent cysteine cathepsin inhibitor, a finding additionally supported by X-ray crystallography. Cell infection assays proved Calpeptin’s efficacy against SARS-CoV-2. Treatment of SARS-CoV-2-infected Golden Syrian hamsters with sulfonated Calpeptin at a dose of 1 mg/kg body weight reduces the viral load in the trachea. Despite a higher risk of side effects, an intrinsic advantage in targeting host proteins is their mutational stability in contrast to highly mutable viral targets. Here we show that the inhibition of cathepsins, a protein family of the host organism, by calpeptin is a promising approach for the treatment of SARS-CoV-2 and potentially other viral infections
Demographics of extra-articular calcaneal fractures: Including a review of the literature on treatment and outcome
Introduction: Extra-articular calcaneal fractures represent 25-40% of all calcaneal fractures and an even higher percentage of up to 60% is seen in children. A disproportionately small part of the literature on calcaneal fractures involves the extra-articular type. The aim of this study was to investigate the incidence of extra-articular calcaneal fractures in a Level 1 trauma centre, define the distribution of the various types of fractures and compare patient demographics between extra- and intra-articular calcaneal fractures. In addition the literature was reviewed for the most common types of extra-articular calcaneal fractures with regard to incidence, treatment and clinical outcome. Methods: The radiological records between 2003 and 2005 were reviewed for intra- and extra-articular calcaneal fractures. Patient gender-distribution and age were compared. A literature search was conducted for the treatment of extra-articular calcaneal fractures. Results: In this 3-year study period a total of 49 patients with 50 extra-articular calcaneal fractures and 91 patients with 101 intra-articular fractures were identified. The median age for the first group was 32.7 years, and for the second group 40.3 years; P = 0.04. Male predominance was significantly less pronounced for extra-articular (63%) compared with intra-articular fractures (79%; P = 0.04). Conclusion: One-third of all calcaneal fractures are extra-articular. Significant differences exist between the intra- and extra-articular groups, in terms of lower age and male-female ratio. The literature study shows inconsistencies in treatment options, but most extra-articular fractures are well manageable conservatively
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