Una década de noticias de prensa sobre poliomielitis en la provincia de Guadalajara (1958–1967)

El período de más incidencia de la poliomielitis en España corresponde a los años de 1950 a 1963. La vacuna inactivada antipolio de Salk estuvo disponible a partir de 1955 y varios países la adoptaron para combatir la enfermedad. La actitud de las autoridades sanitarias españolas para abordar el problema fue tibia e ineficaz, sin dar una respuesta decidida para implementar la vacuna de modo sistemático. Hemos realizado un estudio de caso explorando las noticias sobre polio recogidas en dos semanarios de la provincia de Guadalajara durante el decenio de 1958–1967. Los resultados revelan una acumulación de informaciones sesgada y contradictoria, que refleja la incapacidad para tomar decisiones. Desde la negación de la enfermedad y las dudas sobre la vacuna Salk en el primer período, se pasa a la exaltación de la vacuna oral de Sabin, cuando ésta mostró su evidencia tras aplicarla en la campaña de 1963–1964, y que las autoridades se atribuyeron este éxito tardío con una fuerte propaganda mediática.

Valutazione sperimentale in-vitro di nuove superfici protesiche per la sostituzione totale di caviglia derivanti da un innovativo approccio morfologico

La sostituzione totale di caviglia o artroplastica totale di caviglia (Total Ankle Replacement - TAR) è un'operazione eseguita per sostituire le superfici di contatto delle ossa di tibia e astragalo mediante componenti protesiche e sta diventando una comune procedura chirurgica per il trattamento dell’ultimo stadio di osteoartrite di caviglia. La morfologia articolare della caviglia e la relativa cinematica sono molto complesse. Gli attuali dispositivi per TAR soffrono ancora di alti tassi di insoddisfazione e fallimento, probabilmente a causa dei relativi disegni protesici non pienamente rispettosi della normale morfologia di caviglia e del normale trasferimento dei carichi articolari. Recentemente, è stato proposto un nuovo disegno basato su un originale postulato che approssima la superficie articolare talare in modo maggiormente fisiologico, come un tronco di cono a sella con apice diretto lateralmente. L'obiettivo di questa tesi di laurea è di valutare sperimentalmente, mediante il supporto del navigatore chirurgico, il comportamento cinematico derivante dall’impianto del dispositivo TAR basato sul nuovo postulato e di confrontarlo con la cinematica derivante dalla caviglia intatta e derivante da modelli protesici basati sui disegni più comunemente utilizzati. Dieci arti inferiori da cadavere con caviglie intatte e normali, sono state scansionati via CT. Le immagini di caviglia sono state poi segmentate per la produzione dei modelli virtuali articolari. Questi sono stati prodotti sia basandosi sul nuovo postulato sia su quelli standard, e successivamente stampati in materiale plastico via 3D-printing. I risultati ottenuti a seguito di elaborazioni confermano che il nuovo dispositivo sembra riprodurre meglio rispetto agli altri, il fisiologico comportamento funzionale della caviglia, presentando valori prossimi a quelli della caviglia naturale.

Proton pump inhibitors and the risk of fractures in older adults: a population-based retrospective cohort study

Thesis (Master's)--University of Washington, 2016-06

Changes in joint stability with muscle contraction measured from transmission of mechanical vibration

A non-invasive in vivo technique was developed to evaluate changes in wrist joint stability properties induced by increased co-activation of the forearm muscles in a gripping task. Mechanical vibration at 45, 50 and 55 Hz was applied to the radial head in ten healthy volunteers. Vibrations of the styloid process of the radius and the distal end of the metacarpal bone of the index finger were measured with triaxial accelerometers. Joint stability properties were quantified by the transfer function gain between accelerations on either side of the wrist-joint. Gain was calculated with the muscles at rest and at five force levels ranging from 5% to 25% of maximum grip force (%MF). During contraction the gain was significantly greater than in control trial (0%MF) for all contractions levels at 45 and 50 Hz and a trend for 15%MF and higher at 55 Hz. Group means of contraction force and gain were significantly correlated at 45 (R-2 = 0.98) and 50 Hz (R-2 = 0.72), but not at 55 Hz (R-2 = 0.10). In conclusion, vibration transmission gain may provide a method to evaluate changes in joint stability properties. (c) 2005 Published by Elsevier Ltd.

Developmental Pathways in Microcerotermes turneri (Termitidae: Termitinae): Biometric Descriptors of Worker Caste and Instar

The foraging process of location and exploitation of food in complex termite societies is in part reliant upon unequal division of specific tasks amongst its members (polyethism). To conduct studies assessing the role of individuals in foraging activities it is necessary to have descriptors of worker caste and instar. Here we provide biometric descriptors of specific caste and instar for worker caste and instars of Microcerotermes turneri (Froggatt) (Termitidae: Termitinae) for the worker castes (male and female) for the identification of individuals in laboratory assays applicable across multiple nests. The use of head width for determining sex of workers was successful across multiple nests. The length of the first three flagellum segments of the antenna and tibia three could be used to determine worker instar.

What does the animal model teach us about the effects of physical activity on growing bone?

Experiments to design physical activity programs that optimize their osteogenic potential are difficult to accomplish in humans. The aim of this article is to review the contributions that animal studies have made to knowledge of the loading conditions that are osteogenic to the skeleton during growth, as well as to consider to what extent animal studies fail to provide valid models of physical activity and skeletal maturation. Controlled loading studies demonstrate that static loads are ineffective, and that bone formation is threshold driven and dependent on strain rate, amplitude, and duration of loading. Only a few loading cycles per session are required, and distributed bouts are more osteogenic than sessions of long duration. Finally, animal models fail to inform us of the most appropriate ways to account for the variations in biological maturation that occur in our studies of children and adolescents, requiring the use of techniques for studying human growth and development.

3D statistical shape models to embed spatial relationship information

This paper presents the creation of 3D statistical shape models of the knee bones and their use to embed information into a segmentation system for MRIs of the knee. We propose utilising the strong spatial relationship between the cartilages and the bones in the knee by embedding this information into the created models. This information can then be used to automate the initialisation of segmentation algorithms for the cartilages. The approach used to automatically generate the 3D statistical shape models of the bones is based on the point distribution model optimisation framework of Davies. Our implementation of this scheme uses a parameterized surface extraction algorithm, which is used as the basis for the optimisation scheme that automatically creates the 3D statistical shape models. The current approach is illustrated by generating 3D statistical shape models of the patella, tibia and femoral bones from a segmented database of the knee. The use of these models to embed spatial relationship information to aid in the automation of segmentation algorithms for the cartilages is then illustrated.

Vitamin E-stabilised UHMWPE for orthopaedic implants:quantitative determination of vitamin E and characterisation of its transformation products

The fate of vitamin E and the formation and identification of its transformation products were investigated at different stages of the manufacturing process of commercially produced cross-linked (by γ-irradiation) UHMWPE stabilised with vitamin E (vitamin E infused-post irradiation) used for tibia-components (as articulating surfaces) in total knee arthroplasty (total knee replacement). Vitamin E (α-tocopherol) and its transformation products were extracted from microtomed Tibia films and the different products were separated, isolated, purified using high performance liquid chromatography (HPLC), and characterised by spectroscopic methods and LC-MS. The amount of vitamin E and that of the products formed in the different Tibia samples and in their extracts were also quantified using FTIR and HPLC analysis and calibration curves. Thorough analysis of the Tibia extracts has shown that a number of vitamin E transformation products were formed at different concentrations at two selected stages of the implant manufacturing process that is before and after sterilisation by γ-irradiation. The identified products were found to correspond mainly to different stereoisomeric forms of a small number of vitamin E transformation products. Most of the observed products were of dimeric and trimeric nature with their identity confirmed through a detailed study of their spectral and chromatographic characteristics. It was found that the products of vitamin E, prior to the sterilisation step but after the crosslinking and doping of vitamin E, were mainly the dihydroxydimers and trimers (Tibia samples at this stage are referred to as “Tibia-VEPE”). After sterilisation and completion of the manufacturing process, additional dimers of vitamin E were also formed (Tibia samples at this stage are referred to as ‘Tibia-VEPE-Sterile’), Furthermore, two tocopherol-derived aldehydes (aldehyde 5-formyl-γ-tocopherol and aldehyde 7-formyl-γ-tocopherol) were also formed but at very low concentrations especially in the Tibia-VEPE-Sterile samples. The question of whether vitamin E becomes chemically reacted (grafted) onto the polymer matrix during the manufacturing process of the Tibia is also addressed.

Stima delle forze di reazione piede-suolo durante la corsa tramite sensori inerziali

Per investigare i carichi sopportati dal corpo nella vita di tutti i giorni, è neccesario un metodo semplice per la stima delle forze di reazione piede-suolo (GRFs) . In questo studio viene presentato un modello per stimare l’andamento delle GRFs durante la corsa, a partire dalle accelerazioni misurate tramite sensori inerziali. I due soggetti che hanno partecipato all’esperimento hanno corso a 4 diverse velocità predefinite e indossato cinque sensori: uno su pelvi, due su tibia (destra e sinistra) e due su piede (destro e sinitro). A partire dai dati ottenuti è stato elaborato un modello che stima l’andamento delle GRFs (verticali e anteroposteriori) e i tempi di contatto e volo del passo tramite l’accelerazione assiale tibiale. Per la stima delle forze di reazione viene utilizzato un modello di stima basato sui tempi di contatto e volo, unito ad un modello che prevede la presenza o meno e il modulo degli impact peak sfruttando due picchi negativi individuati nelle accelerazioni assiali tibiali. Sono state utilizzate due pedane di carico come gold standard per valutare la qualità delle stime ottenute. Il modello prevede correttamente la presenza dell'impact peak nell'85% dei casi, con un errore sul modulo compreso fra il 6% e il 9%. Le GRFs verticali massime vengono approssimate con un errore fra l'1% e 5%, mentre le GRFs antero-posteriori con un errore fra l'8% e il 14% del range massimo-minimo del segnale.

Efeito da geometria do implante dentário e do protocolo de fresagem óssea na estabilidade primária e na osseointegração inicial: estudo experimental em cães

CHAPTER 1 - This study histologically evaluated two implant designs: a classic thread design versus another specifically designed for healing chamber formation placed with two drilling protocols. Forty dental implants (4.1 mm diameter) with two different macrogeometries were inserted in the tibia of 10 Beagle dogs, and maximum insertion torque was recorded. Drilling techniques were: until 3.75 mm (regular-group); and until 4.0 mm diameter (overdrillinggroup) for both implant designs. At 2 and 4 weeks, samples were retrieved and processed for histomorphometric analysis. For torque and BIC (bone-to-implant contact) and BAFO (bone area fraction occupied), a general-linear model was employed including instrumentation technique and time in vivo as independent. The insertion torque recorded for each implant design and drilling group significantly decreased as a function of increasing drilling diameter for both implant designs (p<0.001). No significant differences were detected between implant designs for each drilling technique (p>0.18). A significant increase in BIC was observed from 2 to 4 weeks for both implants placed with the overdrilling technique (p<0.03) only, but not for those placed in the 3.75 mm drilling sites (p>0.32). Despite the differences between implant designs and drilling technique an intramembranous-like healing mode with newly formed woven bone prevailed. CHAPTER 2 - The objective of this preliminary histologic study was to determine whether the alteration of drilling protocols (oversized, intermediate, undersized drilling) present different biologic responses at early healing periods of 2 weeks in vivo in a beagle dog model. Ten beagle dogs were acquired and subjected to surgeries in the tibia 2 weeks before euthanasia. During surgery, 3 implants, 4 mm in diameter by 10 mm in length, were placed in bone sites drilled to 3.5 mm, 3.75 mm, and 4.0 mm in final diameter. The insertion and removal torque was recorded for all samples. Statistical significance was set to 95% level of confidence and the number of dogs was considered as the statistical unit for all comparisons. For the torque and BIC and BAFO, a general linear model was employed including instrumentation technique and time in vivo as independent. Overall, the insertion torque increased as a function of drilling diameter from 4.0 mm, to 3.75 mm, to 3.5 mm, with a significant difference in torque levels between all groups (p<0.001). Statistical assessment of BIC and BAFO showed significantly higher values for the 3.75 mm (recommended) drilling group was observed relative to the other two groups (p<0.001). Different drilling dimensions resulted in variations in insertion torque values (primary stability) and different pattern of healing and interfacial remodeling was observed for the different groups. CHAPTER 3 - The present study evaluated the effect of different drilling dimensions (undersized, regular, and oversized) in the insertion and removal torques of dental implants in a beagle dog model. Six beagle dogs were acquired and subjected to bilateral surgeries in the radii 1 and 3 weeks before euthanasia. During surgery, 3 implants, 4 mm in diameter by 10 mm in length, were placed in bone sites drilled to 3.2 mm, 3.5 mm, and 3.8 mm in final diameter. The insertion and removal torque was recorded for all samples. Statistical analysis was performed by paired t tests for repeated measures and by t tests assuming unequal variances (all at the 95% level of significance). Overall, the insertion torque and removal torque levels obtained were inversely proportional to the drilling dimension, with a significant difference detected between the 3.2 mm and 3.5 mm relative to the 3.8 mm groups (P < 0.03). Although insertion torque–removal torque paired observations was statis- tically maintained for the 3.5 mm and 3.8 mm groups, a significant decrease in removal torque values relative to insertion torque levels was observed for the 3.2 mm group. A different pattern of healing and interfacial remodeling was observed for the different groups. Different drilling dimensions resulted in variations in insertion torque values (primary stability) and stability maintenance over the first weeks of bone healing.

Role of the fibula in the stability of diaphyseal tibial fractures fixed by intramedullary nailing

Background: For tibial fractures, the decision to fix a concomitant fibular fracture is undertaken on a case-by-case basis. To aid in this clinical decision-making process, we investigated whether loss of integrity of the fibula significantly destabilises midshaft tibial fractures, whether fixation of the fibula restores stability to the tibia, and whether removal of the fibula and interosseous membrane for expediency in biomechanical testing significantly influences tibial interfragmentary mechanics. Methods: Tibia/fibula pairs were harvested from six cadaveric donors with the interosseous membrane intact. A tibial osteotomy fracture was fixed by reamed intramedullary (IM) nailing. Axial, torsion, bending, and shear tests were completed for four models of fibular involvement: intact fibula, osteotomy fracture, fibular plating, and resected fibula and interosseous membrane. Findings: Overall construct stiffness decreased slightly with fibular osteotomy compared to intact bone, but this change was not statistically significant. Under low loads, the influence of the fibula on construct stability was only statistically significant in torsion (large effect size). Fibular plating stiffened the construct slightly, but this change was not statistically significant compared to the fibular osteotomy case. Complete resection of the fibula and interosseous membrane significantly decreased construct torsional stiffness only (large effect size). Interpretation: These results suggest that fixation of the fibula may not contribute significantly to the stability of diaphyseal tibial fractures and should not be undertaken unless otherwise clinically indicated. For testing purposes, load-sharing through the interosseous membrane contributes significantly to overall construct mechanics, especially in torsion, and we recommend preservation of these structures when possible.

Systematics of African Amphicyonidae, with descriptions of new material from Napak (Uganda) and Grillental (Namibia)

The Early Miocene Napak XV locality (ca 20.5 Ma), Uganda, has yielded an interesting assemblage of fossils, including the very well represented amphicyonid Hecubides euryodon. The remarkable find of a nearly complete mandible, unfortunately with poorly preserved dentition, together with new dental remains allow us to obtain a better idea about the morphology and variability of this species. Additionally, we describe a newly discovered mandible of Hecubides euryodon from the Grillental-VI locality (Sperrgebiet, Namibia), which is the most complete and diagnostic Amphicyonidae material found in this area. Comparisons with Cynelos lemanensis from Saint Gérand le Pouy (France), the type locality, and with an updated sample of the species of amphicyonids described in Africa leads us to validate the genus Hecubides. Hecubides would be phylogenetically related to the medium and large size species of Amphicyonidae from Africa, most of them now grouped into the genera Afrocyon and Myacyon, both endemic to this continent.

Clinical and functional outcomes of acute lower extremity compartment syndrome at a Major Trauma Hospital

Background: Acute lower extremity compartment syndrome (CS) is a condition that untreated causes irreversible nerve and muscle ischemia. Treatment by decompression fasciotomy without delay prevents permanent disability. The use of intracompartmental pressure (iCP) measurement in uncertain situations aids in diagnosis of severe leg pain. As an infrequent complication of lower extremity trauma, consequences of CS include chronic pain, nerve injury, and contractures. The purpose of this study was to observe the clinical and functional outcomes for patients with lower extremity CS after fasciotomy. Methods: Retrospective chart analysis for patients with a discharge diagnosis of CS was performed. Physical demographics, employment status, activity at time of injury, injury severity score, fracture types, pain scores, hours to fasciotomy, iCP, serum creatine kinase levels, wound treatment regimen, length of hospital stay, and discharge facility were collected. Lower extremity neurologic examination, pain scores, orthopedic complications, and employment status at 30 days and 12 months after discharge were noted. Results: One hundred twenty‑four patients were enrolled in this study. One hundred and eight patients were assessed at 12 months. Eighty‑one percent were male. Motorized vehicles caused 51% of injuries in males. Forty‑one percent of injuries were tibia fractures. Acute kidney injury occurred in 2.4%. Mean peak serum creatine kinase levels were 58,600 units/ml. Gauze dressing was used in 78.9% of nonfracture patients and negative pressure wound vacuum therapy in 78.2% of fracture patients. About 21.6% of patients with CS had prior surgery. Nearly 12.9% of patients required leg amputation. Around 81.8% of amputees were male. Sixty‑seven percent of amputees had associated vascular injuries. Foot numbness occurred in 20.5% of patients and drop foot palsy in 18.2%. Osteomyelitis developed in 10.2% of patients and fracture nonunion in 6.8%. About 14.7% of patients underwent further orthopedic surgery. At long‑term follow‑up, 10.2% of patients reported moderate lower extremity pain and 69.2% had returned to work. Conclusion: Escalation in leg pain and changes in sensation are the cardinal signs for CS rather than reliance on assessing for firm compartments and pressures. The severity of nerve injury worsens with the delay in performing fasciotomy. Standardized diagnostic protocols and wound treatment strategies will result in improved outcomes from this complication.

Qual a contribuição das características antropométricas na velocidade de corrida de curta distância ?

v. 19, n. 2, abr./jun. 2016.

Hindfoot Kinematics of Healthy Subjects Using Lateral Wedge Insoles in a Biplane Fluoroscopy System

Thesis (Master's)--University of Washington, 2016-08