The association between statistical shape modeling-defined hip morphology and features of early hip osteoarthritis in young adult football players: Data from the femoroacetabular impingement and hip osteoarthritis cohort (FORCe) study.

Objective: To explore the relationship between radiographic hip shape and features of early hip osteoarthritis (OA) on magnetic resonance imaging (MRI) in young male and female football players without radiographic hip OA. Design: We used baseline data from a cohort of symptomatic and asymptomatic football players aged 18-50 years. Hip shape was assessed on anteroposterior radiographs with statistical shape modeling (SSM) for men and women separately. Cartilage defects and labral tears were graded using the Scoring Hip Osteoarthritis with MRI (SHOMRI) system. We used logistic regression with generalized estimating equations to estimate associations between each hip shape variant, called shape modes, and cartilage defects or labral tears. Results: We included 229 participants (446 hips, 77.4% male). For each sex, 15 shape modes were analyzed. In men, three shape modes were associated with cartilage defects: adjusted odds ratios (aOR) 0.75 (95%CI 0.58-0.97) per standard deviation (SD) for mode 1; 1.34 (95%CI 1.05-1.69) per SD for mode 12; and 0.61 (95%CI 0.48-0.78) per SD for mode 15; and one also with labral tears: aOR 1.30 (95%CI 1.01-1.69) per SD for mode 12. These modes generally represented variations in the femoral neck and subtypes of cam morphology, with and without pincer morphology. For women, there was no evidence for associations with the outcomes. Conclusions: Several hip shape variants were associated with cartilage defects on MRI in young male football players. Specifically, one subtype of cam morphology was associated with both cartilage defects and labral tears. Hip shape was not associated with early OA features in women.

Contrast-Enhanced Tissue Processing of Fibrillin-Rich Elastic Fibres for 3D Visualization by Volume Scanning Electron Microscopy.

Elastic fibres constitute an important component of the extracellular matrix and currently are the subject of intensive study in order to elucidate their assembly, function and involvement in cell-matrix interactions and disease. However, few studies to date have investigated the 3D architecture of the elastic fibre system in bulk tissue. We describe a protocol for preparation of tissue samples, including primary fixation and backscatter electron contrast-enhancement steps, through dehydration into stable resin-embedded blocks for volume electron microscopy. The use of low molecular weight tannic acid and alcoholic lead staining are critical stages in this procedure. Block preparation by ultramicrotomy and evaporative metal coating prior to microscopical examination are also described. We present images acquired from serial block face scanning electron microscopy of cornea and aorta showing target structures clearly differentiated from cells and other matrix components. The processing method imparts high contrast to fibrillin-containing elastic fibres, thus facilitating their segmentation and rendering into 3D reconstructions by image analysis software from large serial image datasets.

Prevalence of early hip OA features on MRI in high-impact athletes. The femoroacetabular impingement and hip osteoarthritis cohort (FORCe) study.

OBJECTIVE: To compare early hip osteoarthritis (OA) features on magnetic resonance imaging (MRI) in high-impact athletes with and without hip and/or groin pain, and to evaluate associations between early hip OA features, the International Hip Outcome Tool (iHOT33) and Copenhagen Hip and Groin Outcome Score (HAGOS). DESIGN: This case-control study evaluated data of the femoroacetabular impingement and hip osteoarthritis cohort (FORCe). One hundred and eighty-two symptomatic (hip and/or groin pain >6 months and positive flexion-adduction-internal-rotation (FADIR) test) and 55 pain-free high-impact athletes (soccer or Australian football (AF)) without definite radiographic hip OA underwent hip MRI. The Scoring Hip Osteoarthritis with MRI (SHOMRI) method quantified and graded the severity of OA features. Each participant completed the iHOT33 and HAGOS. RESULTS: Hip and/or groin pain was associated with higher total SHOMRI (0-96) (mean difference 1.4, 95% CI: 0.7-2.2), labral score (adjusted incidence rate ratio (aIRR) 1.33, 95% CI: 1.1-1.6). Differences in prevalence of cartilage defects, labral tears and paralabral cysts between symptomatic and pain-free participants were inconclusive. There was a lower prevalence of effusion-synovitis in symptomatic participants when compared to pain-free participants (adjusted odds ratio (aOR) 0.46 (95% CI: 0.3-0.8). Early hip OA features were not associated with iHOT33 or HAGOS. CONCLUSIONS: A complex and poorly understood relationship exists between hip and/or groin pain and early hip OA features present on MRI in high-impact athletes without radiographic OA. Hip and/or groin pain was associated with higher SHOMRI and labral scores.

Impact of different physical activity types on knee joint structural degeneration assessed with 3-T MRI in overweight and obese subjects: data from the osteoarthritis initiative.

OBJECTIVE: To assess the impact of different types of physical activity types on longitudinal knee joint structural changes over 48 months in overweight and obese subjects. MATERIALS AND METHODS: We included 415 subjects with a BMI ≥ 25 kg/m2, Kellgren-Lawrence scores ≤ 3 at baseline and Whole-Organ Magnetic Resonance Imaging Score (WORMS) scores available from the Osteoarthritis Initiative cohort. Regular self-reported participation in six physical activity types was assessed: ball sports, bicycling, jogging/running, elliptical-trainer, racquet sports, and swimming. Moreover, they were classified into high- and low-impact physical activity groups. Evaluation of structural knee abnormalities was performed using WORMS obtained by two independent observers blinded to the subjects' physical activity and time point. Linear regression models were used to assess the associations between participation in different physical activity types and changes in WORMS. RESULTS: No significant differences in epidemiological data were found between the groups except for gender composition, and there were no significant differences in baseline WORMS. In the cohort as a whole and most exercise groups overall WORMS significantly increased during the observational period. Highest increases compared to the remainder of the group were found in the high impact group (increase in WORMS 4.65; [95% CI] [3.94,5.35]; p = 0.040) and the racquet sports group (6.39; [95% CI] [5.13,7.60]; p ≤ 0.001). Subjects using an elliptical-trainer showed the lowest increase in WORMS (- 1.50 [- 0.21, 3.22]; p = 0.002). CONCLUSION: Progression of knee joint degeneration was consistently higher in subjects engaging in high-impact and racquet sports while subjects using an elliptical-trainer showed the smallest changes in structural degeneration. This work was presented during the 2020 Radiological Society of North America Annual meeting.

Cross-sectional and longitudinal study of the impact of posterior meniscus horn lesions on adjacent cartilage composition, patient-reported outcomes and gait biomechanics in subjects without radiographic osteoarthritis.

OBJECTIVE: The aim of this study was to assess cross-sectional and longitudinal effects of meniscal lesions on adjacent cartilage T1ρ and T2 relaxation times, patient-reported outcomes and gait biomechanics. DESIGN: Thirty patients with no cartilage morphological defects reported by Whole Organ MRI Score (WORMS) magnetic resonance imaging (MRI) grading and no radiographic osteoarthritis (OA) (Kellgren--Lawrence (KL) ≤ 1) were selected, 15 with posterior meniscus horn lesions and 15 matched controls without meniscal lesions. All were imaged on a 3T MR scanner for three consecutive years, except those who dropped from the study. Sagittal and frontal plane kinematic gait data were acquired at baseline. The Knee Injury and Osteoarthritis Outcome Score (KOOS) survey was taken each time. All images were automatically segmented and registered to an atlas for voxel-by-voxel cross-sectional and longitudinal analyses. RESULTS: Relaxation time comparisons between groups showed elevated T1ρ of the lateral tibia (LP) and elevated T2 of the medial tibia (MT) and LT at 1 and 2 years in the lesion group. Longitudinal comparisons within each group revealed greater relaxation time elevations over one and 2 years in the group with lesions. KOOS Quality of Life (QOL) was significantly different between the groups at all time points (P < 0.05), as were other KOOS subcategories. No significant differences in the frontal or sagittal biomechanics were observed between the groups at baseline. CONCLUSIONS: Individuals with healthy cartilage and posterior meniscal horn lesions have increased relaxation times when compared to matched controls, increased relaxation time changes over 2 years, and consistently report a lower KOOS QOL, yet show no difference in gait biomechanics.

Role of thigh muscle cross-sectional area and strength in progression of knee cartilage degeneration over 48 months - data from the Osteoarthritis Initiative.

OBJECTIVE: To determine in a 48-month longitudinal study the association of thigh muscle cross-sectional area (CSA) and strength on progression of morphologic knee cartilage degeneration using 3T magnetic resonance imaging (MRI). DESIGN: Seventy Osteoarthritis Initiative (OAI) subjects aged 50-60 years, with no radiographic evidence of osteoarthritis (OA) and constant muscle strength over 48 months as measured by isometric knee extension testing were included. Baseline right thigh muscle CSAs were assessed on axial T1-weighted magnetic resonance (MR) images, and extensor to flexor CSA ratios were calculated. Degenerative knee abnormalities at baseline and 48-months were graded on right knee 3T MRIs using a modified whole organ MRI score (WORMS). Statistical analysis employed Student's t-tests and multivariable regression models adjusted for age, body mass index and gender. RESULTS: Extension strength was significantly and positively correlated with baseline thigh muscle CSA (r = 0.65, P < 0.001). Greater baseline total thigh muscle CSA was significantly associated with increase of cartilage WORMS scores over 48 months in patellar (P = 0.027) and trochlear (P = 0.038) compartments, but not in other knee compartments. Among specific muscle groups, CSA of extensors (P = 0.021) and vastus medialis (VM) (P = 0.047) were associated with patellar cartilage increase in WORMS. Baseline E/F ratio had a significant positive association with patellar WORMS cartilage score increase over 48 months, P = 0.0015. There were no other significant associations between muscle CSA/ratios and increase in WORMS scores. CONCLUSION: Maintenance of proper extensor to flexor muscle balance about the knee through decreased E/F ratios may slow patellofemoral cartilage deterioration, while higher extensor and VM CSA may increase patellofemoral cartilage loss.

Associations between patellofemoral joint cartilage T1ρ and T2 and knee flexion moment and impulse during gait in individuals with and without patellofemoral joint osteoarthritis.

OBJECTIVE: This study aimed to investigate the associations between patellofemoral cartilage T1ρ and T2 relaxation times and knee flexion moment (KFM) and KFM impulse during gait. METHOD: Knee magnetic resonance (MR) images were obtained from 99 subjects with and without patellofemoral joint (PFJ) osteoarthritis (OA), using fast spin-echo, T1ρ and T2 relaxation time sequences. Patellar and trochlear cartilage relaxation times were computed for the whole cartilage, and superficial and deep layers (laminar analysis). Subjects also underwent three-dimensional (3D) gait analysis. Peak KFM and KFM impulse were calculated during the stance phase. Linear regressions were used to examine whether cartilage relaxation times were associated with knee kinetics during walking while adjusting age, sex, body mass index (BMI) and walking speed. RESULTS: Higher peak KFM and KFM impulse were significantly related to higher T1ρ and T2 relaxation times of the trochlear and patellar cartilage, with standardized regression coefficients ranging from 0.21 to 0.28. Laminar analysis showed that overall the superficial layer of patellofemoral cartilage showed stronger associations with knee kinetics. Subgroup analysis revealed that in subjects with PFJ OA, every standard deviation change in knee kinetics was related to greater increases in PFJ cartilage T1ρ and T2 (standardized coefficients: 0.29 to 0.41). Conversely, in subjects without OA, weaker relationships were observed between knee kinetics and PFJ cartilage T1ρ and T2. CONCLUSIONS: Our findings suggest that increased peak KFM and KFM impulse were related to worse cartilage health at the PFJ. This association is more prominent in superficial layer cartilage and cartilage with morphological lesions.

T1ρ and T2 relaxation times are associated with progression of hip osteoarthritis.

OBJECTIVE: To evaluate whether baseline T1ρ and T2 relaxation times of hip cartilage are associated with magnetic resonance imaging (MRI) based progression of hip osteoarthritis (OA) at 18 months. METHODS: 3T MRI studies of the hip were obtained at baseline and 18-month follow-up for 54 subjects without evidence of severe OA at baseline [Kellgren-Lawrence (KL) score of 0-3]. 2D fast spin-echo sequences were used for semi-quantitative morphological scoring of cartilage lesions and a combined T1ρ/T2 sequence was used to quantitatively assess cartilage composition. Progression of hip OA was defined based on incident or progression of morphological semi-quantitative grade at 18 months. Baseline T1ρ and T2 relaxation times were compared between progressors and non-progressors using one-way analysis of variance and Mann-Whitney U tests and used to predict progression with binary logistic regression after adjusting for age, gender, body mass index, and KL score. Additionally, a novel voxel-based relaxometry technique was used to compare the spatial distribution of baseline T1ρ and T2 between progressors and non-progressors. RESULTS: Significantly higher baseline T1ρ and T2 values were observed in hip OA progressors compared to non-progressors, particularly in the posterosuperior and anterior aspects of the femoral cartilage. Logistic regression showed that higher baseline T1ρ or T2 values in the femoral cartilage were significantly associated with progression of femoral cartilage lesions at 18 months. CONCLUSION: T1ρ and T2 relaxation parameters are associated with morphological cartilage degeneration at 18 months and may serve as potential imaging biomarkers for progression of cartilage lesions in hip OA.

Response of knee cartilage T1rho and T2 relaxation times to in vivo mechanical loading in individuals with and without knee osteoarthritis.

OBJECTIVE: The objective of this study was to evaluate the effects of mechanical loading on knee articular cartilage T1ρ and T2 relaxation times in patients with and without osteoarthritis (OA). DESIGN: Magnetic resonance (MR) images were acquired from 137 subjects with and without knee OA under two conditions: unloaded and loaded at 50% body weight. Three sequences were acquired: a high-resolution 3D-CUBE, a T1ρ relaxation time, and a T2 relaxation time sequences. Cartilage regions of interest included: medial and lateral femur (MF, LF); medial and lateral tibia (MT, LT), laminar analysis (superficial and deep layers), and subcompartments. Changes in relaxation times in response to loading were evaluated. RESULTS: In response to loading, we observed significant reductions in T1ρ relaxation times in the MT and LT. In both the MF and LF, loading resulted in significant decreases in the superficial layer and significant increases in the deep layer of the cartilage for T1ρ and T2. All subcompartments of the MT and LT showed significant reduction in T1ρ relaxation times. Reductions were larger for subjects with OA (range: 13-19% change) when compared to healthy controls (range: 3-13% change). CONCLUSIONS: Loading of the cartilage resulted in significant changes in relaxation times in the femur and tibia, with novel findings regarding laminar and subcompartmental variations. In general, changes in relaxation times with loading were larger in the OA group suggesting that the collagen-proteoglycan matrix of subjects with OA is less capable of retaining water, and may reflect a reduced ability to dissipate loads.

Quadriceps intramuscular fat fraction rather than muscle size is associated with knee osteoarthritis.

OBJECTIVES: To compare thigh muscle intramuscular fat (intraMF) fractions and area between people with and without knee radiographic osteoarthritis (ROA); and to evaluate the relationships of quadriceps adiposity and area with strength, function and knee magnetic resonance imaging (MRI) lesions. METHODS: Ninety six subjects (ROA: Kellgren-Lawrence (KL) > 1; n = 30, control: KL = 0, 1; n = 66) underwent 3-T MRI of the thigh muscles using chemical shift-based water/fat MRI (fat fractions) and the knee (clinical grading). Subjects were assessed for isometric/isokinetic quadriceps/hamstrings strength, function Knee injury and Osteoarthritis Outcome Score (KOOS), stair climbing test (SCT), and 6-minute walk test (6MWT). Thigh muscle intraMF fractions, muscle area and strength, and function were compared between controls and ROA subjects, adjusting for age. Relationships between measures of muscle fat/area with strength, function, KL and lesion scores were assessed using regression and correlational analyses. RESULTS: The ROA group had worse KOOS scores but SCT and 6MWT were not different. The ROA group had greater quadriceps intraMF fraction but not for other muscles. Quadriceps strength was lower in ROA group but the area was not different. Quadriceps intraMF fraction but not area predicted self-reported disability. Aging, worse KL, and cartilage and meniscus lesions were associated with higher quadriceps intraMF fraction. CONCLUSION: Quadriceps intraMF is higher in people with knee OA and is related to symptomatic and structural severity of knee OA, whereas the quadriceps area is not. Quadriceps fat fraction from chemical shift-based water/fat MR imaging may have utility as a marker of structural and symptomatic severity of knee OA disease process.

Differences between X-ray and MRI-determined knee cartilage thickness in weight-bearing and non-weight-bearing conditions.

OBJECTIVE: Determine the effect of loading upon MRI-based mean medial femorotibial cartilage thickness (mMFT_th) and radiograph-based minimum joint space width (mJSW), and determine loading's effect on the relationship between these measures. METHODS: MRI and radiographs were analyzed of 25 knees in weight-bearing and non-weight-bearing conditions. Eight subjects had a Kellgren-Lawrence (KL) grade of 0, indicating no evidence of radiographic OA. The rest were KL = 2 or KL = 3, indicating mild to moderate OA. The change from unloaded to loaded conditions was calculated. RESULTS: Joint space measures decreased from unloaded to loaded conditions for both radiographs (mJSW = 3.29 mm unloaded to 3.16 mm loaded, P < 0.05) and MRI (mMFT_th = 2.70 mm unloaded to 2.55 mm loaded P < 0.001). The mean absolute difference measured from radiographs was larger for the OA group than the control group, at -0.20 mm for OA vs +0.01 mm for control. Loaded X-ray and loaded MRI joint space values from our study were no better correlated to one another than loaded X-ray and unloaded MRI. CONCLUSION: Knee loading does not add a very significant value to the study of joint space on healthy knees, but loading may play a role in the study of OA knees. Unloaded MRI assessments of cartilage thickness are as correlated to loaded JSW as to loaded MRI measurements. More study is necessary to determine whether loaded MRI adds significant value to the study of OA progression.

Association of cartilage defects, and other MRI findings with pain and function in individuals with mild-moderate radiographic hip osteoarthritis and controls.

OBJECTIVE: To evaluate the relationship of hip radiographic osteoarthritis (ROA) and MRI findings of cartilage lesions, labral tears, bone marrow edema-like lesions (BMELs) and subchondral cysts with self-reported and physical function. DESIGN: Eighty five subjects were classified as controls (n = 55, Kellgren-Lawrence (KL) 0, 1) or having mild-moderate ROA (n = 30, KL 2, 3). T2 weighted MRI images at 3-T were graded for presence of cartilage lesions, labral tears, BMELs and subchondral cysts. Posterior wall sign, cross-over sign, center-edge angle and alpha angle were also recorded. Function was assessed using Hip dysfunction and Osteoarthritis Outcome Score (HOOS), Timed-Up and Go (TUG) test and Y-Balance Test (YBT). Analysis compared function between subjects with and without ROA and those with and without femoral or acetabular cartilage lesions, adjusted for age. Non-parametric correlations were used to assess the relationship between radiographic scores, MRI scores and function. RESULTS: Subjects with acetabular cartilage lesions had worse HOOS (Difference = 5-10%, P = 0.036-0.004), but not TUG or YBT, scores. Acetabular cartilage lesions, BMELs and subchondral cysts were associated with worse HOOS scores (ρ = 0.23-0.37, P = 0.041-0.001). Differences in function between subjects with and without ROA or femoral cartilage lesions were not significant. Other radiologic findings were not associated with function. CONCLUSIONS: Acetabular cartilage defects, but not femoral cartilage defects or ROA, were associated with greater self-reported pain and disability. BMELs and subchondral cysts were related to greater hip related self-reported pain and disability. None of the radiographic or MRI features was related to physical function.

Use of enzymes in diets with different percentages of added fat for broilers / Uso de enzimas em dietas com diferentes porcentagens de adição de gordura para frangos de corte

We assessed the extent to which the removal of fat source, and consequently its compounds, such as linoleic acid, can affect the performance of broilers. We used 600 male Cobb 500 day old chicks. The birds were distributed in a completely randomized experimental design, with five treatments and six replicates of 20 birds each. The treatments were: (T1) diet - positive control (PC), which met the nutritional needs; (T2) diet - negative control (CN), a reduction of 100kcal/kg and low linoleic acid content; (T3): diet - negative control reformulated for low linoleic acid content and a set of Quantum phytase XT and Econase XT 25 (BAL + QFit-Eco), (T4): diet - negative control reformulated, with the percentage of linoleic acid adjusted to an intermediate value between the value of the diet and diet CP and CN to use a set of Quantum phytase XT and XT Econase 25 (IAL + QFit-Eco) and (T5): diet - negative control reformulated, with the percentage of linoleic acid adjusted to a value similar to that of the positive control diet and joint use of Quantum phytase XT and XT Econase 25 (AAL + QFit-Eco). The joint use of Quantum Phytase and Econase promoted improvement in the performance of broilers from 1 to 21 days. The greatest weight gain was obtained with diets containing percentages of total fat and linoleic acids. Dietary supplementation with enzymes resulted in higher levels of calcium in the tibia, whatever the percentage of linoleic studied.

Avaliou-se até que ponto a retirada de fonte de gordura e, consequentemente, de seus compostos, como o ácido linoleico, pode afetar o desempenho dos frangos de corte. Foram utilizados 600 pintos de um dia, machos da linhagem Cobb 500. As aves foram distribuídas num delineamento experimental inteiramente ao acaso, com cinco tratamentos e seis repetições de 20 aves cada. Os tratamentos foram: (T1) dieta-controle positivo (CP), que atendeu às necessidades nutricionais; (T2) dieta-controle negativo (CN), com redução de 100kcal de EM/kg e baixo teor de ácido linoleico; (T3): dieta- controle negativo reformulada, para baixo teor de ácido linoleico e com uso conjunto de Quantum fitase XT e Econase XT 25 (BAL+ Qfit-Eco); (T4): dieta-controle negativo reformulada, com porcentagem de ácido linoleico ajustada para um valor intermediário entre o valor da dieta CN e da dieta CP e com uso conjunto de Quantum fitase XT e Econase XT 25 (IAL + Qfit-Eco) e (T5): dieta-controle negativo reformulada, com porcentagem de ácido linoleico ajustada para um valor semelhante ao da dieta-controle positivo e com uso conjunto de Quantum fitase XT e Econase XT 25 (AAL+ Qfit-Eco ). O uso conjunto de Quantum Fitase e Econase promoveu melhora no desempenho dos frangos de corte de um a 21 dias. O maior ganho de peso foi obtido com dietas que continham porcentagens de gorduras totais e de ácido linoleico. A suplementação com as enzimas resultou em maior teor de cálcio nas tíbias, independentemente da porcentagem de ácido linoleico estudada.

Avian paramyxoviruses: detection by transmission electron microscopy techniques / Paramixovirus aviario: detección por técnicas de microscopía electrónica de transmisión

Diseases caused by avian paramyxovirus (APMV) occur in commercial, captive and wild birds worldwide, demonstrating the significant economic and ecological importance of these agents. Paramyxoviruses belong to the paramyxoviridae family, paramyxovirinae subfamily and avulavirus genus. During the period 2000 to 2011, stool and small intestine samples of 1647 birds species were sent to the Laboratory of Electron Microscopy, Biological Institute of São Paulo, Brazil, for diagnosis of viral agents. The samples were processed by negative staining (rapid preparation) and resin embedding techniques. Under the transmission electron microscope by negative staining technique, in 294 (17.8 percent) samples of 1647 were visualized paramyxovirus particles pleomorphic, roughly spherical or filamentous, measuring 100 to 500 nm of diameter containing an envelope covered with spikes and characteristic helical herring-bone-like nucleocapsid measuring 15 to 20 nm in diameter. Ultrathin sections of the small intestine fragments revealed the presence of amorphous granular intracytoplasmic inclusions surrounded by membrane and containing viral nucleocapsid measuring 10-14 nm in diameter. Immature particles budding from cell membranes, pleomorphic, spherical and tubular particles containing viral nucleocapsid strands, and the complete particles measured up to 170 nm in diameter were seen in the cytoplasm. Intranuclear inclusions containing viral nucleocapsid were also visualized. Nuclei showed a marginalized chromatin.

Las enfermedades causadas por paramixovirus (APMV) ocurren mundialmente, tanto en aves de corral, en aquellas en vida libre o en cautiverio, lo que demuestra la importancia económica y ecológica de estos virus. El paramixovirus aviario pertenece a la familia paramyxoviridae, subfamilia paramyxovirinae y género avulavirus. Durante el periodo de 2000 a 2011, muestras de heces y fragmentos del intestino delgado de 1647 especies de aves han sido enviados al Laboratorio de Microscopía Electrónica, Instituto Biológico de São Paulo, para el diagnóstico de agentes virales. Las heces y fragmentos del intestino delgado, se procesaron por las técnicas de contraste negativo (preparación rápida) y la inclusión en resina. Al microscopio electrónico de transmisión mediante la técnica de contraste negativo se visualizaron en muestras de 294 aves, partículas de paramixovirus, pleomórficas, más o menos esféricas o filamentosas, de 100 a 500 nm de diámetro que contenían un sobre cubierto por púas que presentaban característica helicoidal, con nucleocapside tipo espiga, midiendo de 15 a 20 nm de diámetro. Secciones ultrafinas de los fragmentos del intestino delgado, revelaron en el citoplasma la presencia de inclusiones granulares amorfas rodeadas por una membrana, contiendo nucleocapside viral midiendo de 10-14 nm de diámetro, partículas inmaduras brotando de las membranas celulares, partículas virales tubulares, esféricas o pleomórficas que contenían filamentos nucleocapside. Estas partículas completas alcanzaban a los 170 nm de diámetro. Fueron observadas también, inclusiones intranucleares contiendo nucleocapside viral. Los núcleos mostraron una cromatina marginal.

Association of MR relaxation and cartilage deformation in knee osteoarthritis.

We assessed the relationship between cartilage MR relaxation times and biomechanical response of tibiofemoral articular cartilage to physiological loading in healthy subjects and patients with osteoarthritis (OA). Female subjects above 40 years of age with (N(1) = 20) and without (N(2) = 10) OA were imaged on a 3T MR scanner using a custom made loading device. MR images were acquired with the knee flexed at 20° with and without a compressive load of 50% of the subject's bodyweight. The subjects were categorized based on the clinical MRI scoring of medial and lateral cartilage surfaces. Data were stratified twice into two equal groups (low and high) at the median value of T(1ρ) and T(2) relaxation time. The change in contact area and cartilage deformation was measured within these groups. Paired Student's t-test (α = 0.05) was used to analyze the effect of loading on contact area and deformation. The average area of the contact region in the medial compartment was significantly higher in OA subjects compared with normal subjects in both unloaded (314 ± 112 mm(2) vs. 227 ± 106 mm(2), p = 0.023) and loaded (425 ± 128 mm(2) vs. 316 ± 107 mm(2), p = 0.01) conditions. The overall relative change of cartilage thickness in the medial compartment was significantly higher than the lateral compartment (-5.3 ± 9.9% vs. -1.9 ± 9.2%, p = 0.042). When cartilage was divided into deep and superficial layers, superficial layers showed higher changes in relaxation time (T(1ρ) and T(2)) than the changes in relaxation time of whole cartilage (Normal: 12.5% vs. 6.9%; OA: 10.9% vs. 4.6%). The average T(1ρ) and T(2) times, change in area of contact region, and change in cartilage thickness in subjects with OA were higher when compared to normal subjects. This study provides support for a relationship between the mechanical response of cartilage to physiological loading (cartilage-on-cartilage contact area and cartilage deformation) and MR relaxation times (T(1ρ) and T(2)) in both OA patients and normal subjects.

Basilar artery aneurysm at a persistent trigeminal artery junction. A case report and literature review.

The trigeminal artery is an anastomosis between the embryonic precursors of the vertebrobasilar and carotid systems, and may persist into adult life. The association of the persistent primitive trigeminal artery (PTA) with cerebral aneurysm is well documented in the literature and, in general, aneurysms are located in the anterior circulation. We describe a patient who presented with a panencephalic Fisher III subarachnoid hemorrhage due to rupture of an intracranial aneurysm. Digital arteriography showed a saccular aneurysm in the middle third of the basilar artery, adjacent to the junction with a persistent trigeminal artery. She was submitted to endovascular treatment with embolization of the basilar artery aneurysm with coils. Aneurysms at the PTA junction with the basilar artery are rare. This paper describes a case of PTA associated with an aneurysm in the basilar artery at PTA junction and briefly reviews the literature.

Spatial analysis of egg distribution and geographic changes in the spawning habitat of the Brazilian sardine Sardinella brasiliensis.

This paper establishes the spawning habitat of the Brazilian sardine Sardinella brasiliensis and investigates the spatial variability of egg density and its relation with oceanographic conditions in the shelf of the south-east Brazil Bight (SBB). The spawning habitats of S. brasiliensis have been defined in terms of spatial models of egg density, temperature-salinity plots, quotient (Q) analysis and remote sensing data. Quotient curves (Q(C)) were constructed using the geographic distribution of egg density, temperature and salinity from samples collected during nine survey cruises between 1976 and 1993. The interannual sea surface temperature (SST) variability was determined using principal component analysis on the SST anomalies (SSTA) estimated from remote sensing data over the period between 1985 and 2007. The spatial pattern of egg occurrences in the SBB indicated that the largest concentration occurred between Paranaguá and São Sebastião. Spawning habitat expanded and contracted during the years, fluctuating around Paranaguá. In January 1978 and January 1993, eggs were found nearly everywhere along the inner shelf of the SBB, while in January 1988 and 1991 spawning had contracted to their southernmost position. The SSTA maps for the spawning periods showed that in the case of habitat expansion (1993 only) anomalies over the SBB were zero or slightly negative, whereas for the contraction period anomalies were all positive. Sardinella brasiliensis is capable of exploring suitable spawning sites provided by the entrainment of the colder and less-saline South Atlantic Central Water onto the shelf by means of both coastal wind-driven (to the north-east of the SBB) and meander-induced (to the south-west of the SBB) upwelling.

The effects of acute loading on T1rho and T2 relaxation times of tibiofemoral articular cartilage.

OBJECTIVE: To evaluate the effect of acute loading on healthy and osteoarthritic knee cartilage T(1ρ) and T(2) relaxation times. DESIGN: Twenty subjects with radiographic evidence of osteoarthritis (OA) and 10 age-matched controls were enrolled. Magnetic resonance imaging (MRI) acquisition, including T(1ρ) and T(2) map sequences were performed unloaded and loaded at 50% body mass. Cartilage masks were segmented semi-automatically on registered high-resolution spoiled gradient-echo (SPGR) images for each compartment (medial and lateral). Cartilage lesions were identified using a modified Whole Organ Magnetic Resonance Imaging Score (WORMS) score. Statistical differences were explored using separate two-way (group×loading condition) Analysis of Variance (ANOVA) using age as a covariate to evaluate the effects of loading on T(1ρ) and T(2) relaxation times. RESULTS: A significant decrease in T(1ρ) (44.5±3.8 vs 40.2±4.8ms for unloaded and loaded, respectively; P<0.001) and T(2) (31.8±3.8 vs 30.5±4.8ms for unloaded and loaded, respectively; P<0.001) relaxation times was observed in the medial compartment with loading while no differences were observed in the lateral compartment. This behavior occurred independent of WORMS score. Cartilage compartments with small focal lesions experienced greater T(1ρ) change scores with loading when compared to cartilage without lesions or cartilage with larger defects (P=0.05). CONCLUSIONS: Acute loading resulted in a significant decrease in T(1ρ) and T(2) relaxation times of the medial compartment, with greater change scores observed in cartilage regions with small focal lesions. These data suggest that changes of T(1ρ) values with loading may be related to cartilage biomechanical properties (i.e., tissue elasticity) and may be a valuable tool for the scientist and clinician at identifying early cartilage disease.

Cartilage and meniscus assessment using T1rho and T2 measurements in healthy subjects and patients with osteoarthritis.

OBJECTIVE: The purpose of this study was to evaluate meniscal degeneration in healthy subjects and subjects with osteoarthritis (OA) using T(1ρ) and T(2) measurements and to examine the interrelationship between cartilage and meniscus abnormalities. METHODS: Quantitative assessment of cartilage and meniscus was performed using 3T Magnetic Resonance Imaging (MRI) with a T(1ρ) and T(2) mapping technique in 19 controls and 44 OA patients. A sagittal T(2)-weighted fast spin echo (FSE) fat-saturated image was acquired for cartilage and meniscal Whole-Organ Magnetic Resonance Imaging Score (WORMS) assessment. Western Ontario and McMasters Universities Arthritis Index (WOMAC) scores were obtained to assess clinical symptoms. RESULTS: The posterior horn of the medial meniscus (PHMED) had the highest incidence of degeneration. Stratifying subjects on the basis of PHMED grade revealed that the T(1ρ) and the T(2) measurements of the PHMED and the medial tibial (MT) cartilage were higher in subjects having a meniscal tear (meniscal grade 2-4) compared to subjects with a meniscal grade of 0 or 1 (P<0.05). While not statistically significant, there was a trend for T(1ρ) and T(2) being higher in PHMED grade 1 compared to grade 0 (P=0.094, P=0.073 respectively). WOMAC scores had a stronger correlation with meniscus relaxation measures than cartilage measures. CONCLUSIONS: Magnetic Resonance (MR) T(1ρ) and T(2) measurements provide a non-invasive means of detecting and quantifying the severity of meniscal degeneration. Meniscal damage has been implicated in OA progression and is correlated with cartilage degeneration. Early detection of meniscal damage represented by elevations in meniscal relaxation measures may identify subjects at increased risk for OA.

Reduced exercise capacity in systemic sclerosis patients without pulmonary involvement.

OBJECTIVE: To evaluate the exercise capacity of women with systemic sclerosis (SSc) without pulmonary involvement using a cardiopulmonary stress test. METHODS: Thirteen consecutive female SSc patients [mean age 40.8+/-14 years, mean body mass index (BMI) 25.5+/-3.7 kg/m2] without pulmonary and cardiac involvement and 13 healthy sedentary female controls (mean age 41.6+/-9.1 years, mean BMI 23.7+/-3.8 kg/m2) matched by age and BMI underwent a maximum cardiopulmonary stress test (Bruce protocol). The following parameters were analysed: peak oxygen uptake (VO2peak), anaerobic threshold (AT), respiratory compensation point (RCP) and metabolic equivalent (MET) of the VO2peak. Comparisons between groups were analysed using the Student t-test. RESULTS: Forced vital capacity (FVC; 92.2+/-14.2% predicted) and carbon monoxide diffusion lung capacity (DL CO; 85.8+/-5.8% predicted) were within the normal range in SSc patients. VO2peak of SSc patients was significantly reduced in comparison to the control group (19.8+/-4.6 vs. 23.7+/-4.5 mL/kg/min, p = 0.04). SSc patients also had a significant reduction in MET at peak exercise (5.6+/-1.3 vs. 6.7+/-1.3 MET, p = 0.04) and a significant shorter time interval between AT and RCP compared to the control group (112.6+/-95.6 vs. 164.0+/-65.3 s, p = 0.03). CONCLUSION: SSc patients without pulmonary impairment have reduced exercise capacity. Abnormal vascular response to exercise may account for this finding, as the vascular system is one of the major target organs in this pathological condition.