The contribution of 3D quantitative meniscal and cartilage measures to variation in normal radiographic joint space width—Data from the Osteoarthritis Initiative healthy reference cohort

ObjectiveTo explore to what extent three-dimensional measures of the meniscus and femorotibial cartilage explain the variation in medial and lateral femorotibial radiographic joint space width (JSW), in healthy men and women.MethodsThe right knees of 87 Osteoarthritis Initiative healthy reference participants (no symptoms, radiographic signs or risk factors of osteoarthritis; 37 men, 50 women; age 55.0 ± 7.6; BMI 24.4 ± 3.1) were assessed. Quantitative measures of subregional femorotibial cartilage thickness and meniscal position and morphology were computed from segmented magnetic resonance images. Minimal and medial/lateral fixed-location JSW were determined from fixed-flexion radiographs. Correlation and regression analyses were used to explore the contribution of demographic, cartilage and meniscal parameters to JSW in healthy subjects.ResultsThe correlation with (medial) minimal JSW was somewhat stronger for cartilage thickness (0.54 ≤ r ≤ 0.67) than for meniscal (−0.31 ≤ r ≤ 0.50) or demographic measures (−0.15 ≤ r ≤ 0.48), in particular in men. In women, in contrast, the strength of the correlations of cartilage thickness and meniscal measures with minimal JSW were in the same range. Fixed-location JSW measures showed stronger correlations with cartilage thickness (r ≥ 0.68 medially; r ≥ 0.59 laterally) than with meniscal measures (r ≤ |0.32| medially; r ≤ |0.32| laterally). Stepwise regression models revealed that meniscal measures added significant independent information to the total variance explained in minimal JSW (adjusted multiple r² = 58%) but not in medial or lateral fixed-location JSW (r² = 60/51%, respectively).ConclusionsIn healthy subjects, minimal JSW was observed to reflect a combination of cartilage and meniscal measures, particularly in women. Fixed-location JSW, in contrast, was found to be dominated by variance in cartilage thickness in both men and women, with somewhat higher correlations between cartilage and JSW in the medial than lateral femorotibial compartment. The significant contribution of the meniscus’ position on minimal JSW reinforces concerns over validity of JSW as an indirect measure of hyaline cartilage.     

Spatial and temporal postural analysis in children born prematurely

The aim of this study was to compare postural stability in a group of preterm-born children aged 4–6 years old and in a group of age-matched full-term control children by exploring both spatial and temporal analysis of the Center of Pressure (CoP).Twenty-nine children born prematurely (mean age: 5.38 ± 0.17) and twenty-nine age-matched full-term control children participated in this study. Postural control was tested on both a stable and an unstable platform (from Framiral^®) in three different visual conditions: eyes open fixating a target, eyes closed, and with vision perturbed by optokinetic stimulation.We observed a significant increase of both surface area and mean velocity of the CoP in pre-term children compared to full-term control children, particularly in an unstable postural condition. The spectral power indices increased significantly in pre-term children with respect to full-term control children, while the cancelling time was not different between the two groups of children tested.We suggested that poor postural stability observed in preterm children could be due to immaturity of the cortical processes (the occipital parietal prefrontal cortex) involved in motor control. Preterm children could have an inappropriate compensation of sensory inputs when they are tested in difficult postural and/or visual conditions.     

Brain Electrical Source Differences between Depressed Subjects and Healthy Controls

Many brain regions show metabolic and perfusion abnormalities in major depressive disorder (MDD), including anterior cingulate and prefrontal cortices. Some of these same areas also show abnormal function with low resolution electromagnetic tomography (LORETA). However, LORETA results are not always consistent across studies, nor with findings from other imaging modalities. These discrepancies may be due, among other factors, to the sensitivity of EEG source localization to different electrode montages. Thirty-six channel EEG was collected from healthy controls and age- and gender-matched unmedicated subjects with MDD (n = 74). EEGs were analyzed with LORETA to assess resting state current density at each of 2,394 cortical voxels. For comparison to previous studies, LORETA was performed using all electrodes or with specific prefrontal electrodes removed. Voxel-by-voxel differences between the depressed and healthy groups were calculated using non-parametric statistics. MDD subjects showed significantly elevated current density in delta, theta, alpha, beta1, and beta2 frequency bands relative to controls in anterior cingulate and prefrontal cortices. Removal of certain prefrontal electrodes from input to LORETA decreased or eliminated significant differences between groups. LORETA detects differences in brain activity between MDD subjects and healthy controls that are consistent with previous findings using other imaging modalities. Inconsistent findings among LORETA studies, and between LORETA studies and those using other functional imaging techniques, may result from differences in electrode montages.     

Infections and Autoimmunity: A Panorama

For more than 2,000 years, it was thought that malignant spirits caused diseases. By the end of nineteenth century, these beliefs were displaced by more modern concepts of disease, namely, the formulation of the "germ theory," which asserted that bacteria or other microorganisms caused disease. With the emergence of chronic degenerative and of autoimmune diseases in the last century, the causative role of microorganisms has been intensely debated; however, no clear explanatory models have been achieved. In this review, we examine the current available literature regarding the relationships between infections and 16 autoimmune diseases. We critically analyzed clinical, serological, and molecular associations, and reviewed experimental models of induction of and, alternatively, protection from autoimmune diseases by infection. After reviewing several studies and reports, a clinical and experimental pattern emerges: Chronic and multiple infections with viruses, such as Epstein-Barr virus and cytomegalovirus, and bacteria, such as H. pylori, may, in susceptible individuals, play a role in the evolvement of autoimmune diseases. As the vast majority of infections pertain to our resident microbiota and endogenous retroviruses and healthy carriage of infections is the rule, we propose to focus on understanding the mechanisms of this healthy carrier state and what changes its configurations to infectious syndromes, to the restoration of health, or to the sustaining of illness into a chronic state and/or autoimmune disease. It seems that in the development of this healthy carriage state, the infection or colonization in early stages of ontogenesis with key microorganisms, also called 'old friends' (lactobacilli, bifidobacteria among others), are important for the healthy living and for the protection from infectious and autoimmune syndromes.     

‘Gamma’ band oscillatory response to chromatic stimuli in volunteers and patients with idiopathic Parkinson’s disease

The signal structure of the responses to equiluminant chromatic and achromatic (contrast) stimuli was studied in normal volunteers and patients with mild to moderate idiopathic Parkinson’s disease. Visual stimuli were full-field (14 × 16 deg) achromatic or equiluminant (red-green or blue-yellow) sinusoidal gratings at 2 c/deg and 90% contrast presented in onset-offset mode. The signal was processed offline by DFT and factor analysis was performed in the frequency domain. The conventional VEPs to chromatic onset stimuli showed a monophasic negative wave, while the response to offset stimuli was comparable in shape to the on-/offset achromatic responses; latencies were longer and amplitudes higher than those of responses to contrast stimulation. In patients, latencies were longer than in controls after achromatic and (to a lesser extent) red-green stimulations, but not after blue-yellow stimulation; amplitudes were comparable in all stimulus conditions. In healthy subjects, two non-overlapping factors accounted for the ∼2-30.0 Hz and ∼25.0-50.0 Hz signal components (representative of the low-frequency VEP and gamma oscillatory responses, respectively); the frequency of the ∼25.0-50.0 Hz factor was lower after color than after contrast stimulation. The same factor structure was identified in patients, but the peak frequency of the factor on gamma activity was higher than in controls and did not vary with color-opponent stimulation. These observations indicate that stimulus-related gamma activity originates in cortex irrespective of the activated (magno-, parvo-, or konio-cellular) visual pathway, consistent with the suggested role in the phase coding of neuronal activities. Some dopaminergic modulation of gamma activity is conceivable.     

Signal intensity of normal breast tissue at MR mammography on midfield: applying a random coefficient model evaluating the effect of doubling the contrast dose

Purpose

To prospectively investigate the effect on signal intensity (SI) of healthy breast parenchyma on magnetic resonance mammography (MRM) when doubling the contrast dose from 0.1 to 0.2 mmol/kg bodyweight.

Materials and methods

Informed consent and institutional review board approval were obtained. Twenty-five healthy female volunteers (median age: 24 years (range: 21–37 years) and median bodyweight: 65 kg (51–80 kg)) completed two dynamic MRM examinations on a 0.6 T open scanner. The inter-examination time was 24 h (23.5–25 h). The following sequences were applied: axial T2W TSE and an axial dynamic T1W FFED, with a total of seven frames. At day 1, an i.v. gadolinium (Gd) bolus injection of 0.1 mmol/kg bodyweight (Omniscan) (low) was administered. On day 2, the contrast dose was increased to 0.2 mmol/kg (high). Injection rate was 2 mL/s (day 1) and 4 mL/s (day 2). Any use of estrogen containing oral contraceptives (ECOC) was recorded. Post-processing with automated subtraction, manually traced ROI (region of interest) and recording of the SI was performed. A random coefficient model was applied.

Results

We found an SI increase of 24.2% and 40% following the low and high dose, respectively (P < 0.0001); corresponding to a 65% (95% CI: 37–99%) SI increase, indicating a moderate saturation. Although not statistically significant (P = 0.06), the results indicated a tendency, towards lower maximal SI in the breast parenchyma of ECOC users compared to non-ECOC users.

Conclusion

We conclude that the contrast dose can be increased from 0.1 to 0.2 mmol/kg bodyweight, if a better contrast/noise relation is desired but increasing the contrast dose above 0.2 mmol/kg bodyweight is not likely to improve the enhancement substantially due to the moderate saturation observed. Further research is needed to determine the impact of ECOC on the relative enhancement ratio, and further studies are needed to determine if a possible use of ECOC should be considered a compromising factor, if an MRM is indicated in a young woman.     

Vaginal microflora in healthy women with Gardnerella vaginalis

In order to find the vaginal prevalence of Gardnerella vaginalis in a normal female population, we determined the incidence of G. vaginalis in relation to that of other bacterial genera and species in the vagina. Two-hundred and thirty-nine healthy women were the subjects of this study. Vaginal discharge was collected and bacteriological studies were performed. The mean total aerobe count in the G. vaginalis-positive group was 9.02 log₁₀ colony-forming units (CFU)/g, which was significantly higher (P < 0.0001) than that (6.80 log₁₀ CFU/g) in the G. vaginalis-negative group. In contrast, there was no difference in the mean total anaerobe count between the two groups of subjects (8.82 and 8.24 log₁₀ CFU/g, respectively in the case of including Lactobacillus species count). Also, the mean pH level of vaginal secretion in the G. vaginalis-positive group was 4.58, which was significantly higher (P < 0.005) than that (4.10) in the G. vaginalis-negative group. Aerobes were isolated at equal incidence in the two groups. Anaerobes were isolated at a significantly higher rate in the G. vaginalis-positive group (P < 0.005) than in the G. vaginalis-negative group. The mean count of Lactobacillus species was significantly higher (P < 0.0001) in the G. vaginalis-negative group than in the positive counterpart (7.02 vs 8.66). Elevation of vaginal pH, an increase in the anaerobe count, and decreases in the Lactobacillus species count could be good predictors of the prevalence of bacterial vaginosis in healthy women. Received: May 14, 1999 / Accepted: June 26, 2000     

室内空气质量与人体健康

本文结合我们的工作实践和国内外文献,概述了有关室内空气品质方面的研究,并对室内空气污染和病态建筑综合征及其对人体健康的危害作了论述。并从不同角度对室内空气质量及其改善做了进一步的探索。