Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “linear mixed model”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25Linked to original sources

Social support and ambulatory blood pressure: an examination of both receiving and giving.

The relationship between the social network and physical health has been studied extensively and it has consistently been shown that individuals live longer, have fewer physical symptoms of illness, and have lower blood pressure when they are a member of a social network than when they are isolated. Much of the research has focused on the benefits of receiving social support from the network and the effects of giving to others within the network have been neglected. The goal of the present research was to systematically investigate the relationship between giving and ambulatory blood pressure. Systolic blood pressure, diastolic blood pressure, mean arterial pressure, and heart rate were recorded every 30 min during the day and every 60 min at night during a 24-h period. Linear mixed models analyses revealed that lower systolic and diastolic blood pressure and mean arterial pressure were related to giving social support. Furthermore, correlational analyses revealed that participants with a higher tendency to give social support reported greater received social support, greater self-efficacy, greater self-esteem, less depression, and less stress than participants with a lower tendency to give social support to others. Structural equation modeling was also used to test a proposed model that giving and receiving social support represent separate pathways predicting blood pressure and health. From this study, it appears that giving social support may represent a unique construct from receiving social support and may exert a unique effect on health.

Adolescent↗

Left atrial structure and function after percutaneous left atrial appendage transcatheter occlusion (PLAATO): six-month echocardiographic follow-up.

OBJECTIVES: This study was designed to evaluate the effects of percutaneous left atrial appendage transcatheter occlusion (PLAATO) on the anatomic and hemodynamic properties of the mitral valve (MV) and left upper pulmonary vein (LUPV). BACKGROUND: PLAATO is a device designed to seal the neck of the left atrial (LA) appendage and reduce embolization in patients with atrial fibrillation intolerant of warfarin. The impact of deployment of this device on adjacent structures has not been reported. METHODS: Patients with atrial fibrillation participating in the ongoing study for evaluation of PLAATO were enrolled. Transesophageal echocardiographies at baseline, one, and six months were reviewed to measure LA and LUPV dimensions, degree of mitral regurgitation, stability of the device, peak MV E-wave velocity, and peak systolic and diastolic flow velocities in the LUPV. Data were analyzed by a linear mixed model for repeated measures. RESULTS: Eleven patients (mean age of 72 +/- 7 years) completed six months of follow-up. Left upper pulmonary vein diameter (mean: 1.55, 1.61, 1.54 cm, p = 0.13) and peak systolic (mean: 0.38, 0.34, 0.31 m/s, p = 0.72) and diastolic flow velocities (mean: 0.39, 0.40, 0.42 m/s, p = 0.46) did not differ over the follow-up period. Left atrial size, mitral regurgitation severity, and MV peak E-wave velocities (mean: 0.94, 0.94, 0.82 m/s, p = 0.58) showed no significant change from baseline. The devices remained stable at their sites of deployment with minimal residual flow around them. CONCLUSIONS: PLAATO achieved an adequate seal of the neck of the left atrial appendage without significant effect on the structure or function of the LA and LUPV.

Aged↗

Colchicine and Longitudinal Dynamics of Clonal Hematopoiesis: An Exploratory Substudy of the LoDoCo2 Trial.

BACKGROUND: Clonal hematopoiesis (CH) is an aging-related hematologic condition associated with increased risk for cardiovascular events. Larger CH clones associate more strongly with cardiovascular risk. Preclinical data indicate that inflammatory signaling drives expansion of CH clones and CH-associated cardiovascular disease. However, the effect of anti-inflammatory therapies on CH clonal dynamics in humans is unclear. OBJECTIVES: The goal of this study was to test the association of randomization to colchicine vs placebo with CH growth in participants with chronic coronary artery disease. It also assessed the association of colchicine use with change in inflammatory biomarkers over time according to CH status. METHODS: In this exploratory substudy of the LoDoCo2 (Low-Dose Colchicine 2) trial, high-coverage targeted sequencing was used to detect CH driver mutations and to quantify variant allele frequency at 4 timepoints: baseline, after a 30-day open-label colchicine run-in phase (0.5 mg daily), 1 year postrandomization to colchicine or placebo, and at end of study (median follow-up of 25.0 months). Clonal dynamics were assessed by using a generalized linear mixed model. High-sensitivity C-reactive protein and interleukin-6 were additionally measured at baseline, randomization, and 1 year postrandomization. RESULTS: In total, 854 participants contributed 2,047 observations across 4 timepoints, including before and after the prerandomization colchicine run-in period. Randomization to placebo was associated with a 14.9% annual increase in CH clone size (βtime = 0.14; 95% CI: 0.08 to 0.21) vs a nonsignificant 6.3% increase with colchicine (βtime on colchicine: 0.06; 95% CI: -0.01 to 0.14), although this difference between treatment arms was not statistically significant (Pinteraction = 0.13). Compared with placebo, colchicine was associated with attenuated clonal growth in TET2 CH (βtime on colchicine: 0.09 [95% CI: -0.04 to 0.22]; βtime placebo: 0.27 [95% CI: 0.16 to 0.37]; Pinteraction= 0.04). Among individuals with non-DNMT3A CH, interleukin-6 levels increased to a lesser extent in those receiving colchicine vs placebo over 1 year (30.0% vs 98.1% increase, respectively; Pinteraction = 0.01). CONCLUSIONS: In this exploratory analysis, treatment with low-dose colchicine was associated with attenuated clonal expansion in TET2 CH. These findings suggest the potential for colchicine to curb the proliferative advantage of key CH driver mutations and to mitigate their associated risk of cardiovascular disease. Further validation in prospective studies is warranted.

Humans↗

Increasing the portion size of a sandwich increases energy intake.

OBJECTIVE: This study investigated the effect on energy intake of increasing the portion size of a food served as a discrete unit. DESIGN: A within-subject design with repeated measures was used. SUBJECTS/SETTING: The sample comprised 75 young adults (37 females and 38 males) from a university community. INTERVENTION: Individuals ate lunch in the lab once a week for 4 weeks. Each week, they were served one of four sizes of a deli-style sandwich (6, 8, 10, or 12 inches), of which they could eat as much as they wanted. MAIN OUTCOME MEASURES: Energy intakes were determined for each meal, as were ratings of hunger and satiety before and after each meal. STATISTICAL ANALYSES PERFORMED: A linear mixed model with repeated measures was used. The influence of subject characteristics was examined using analysis of covariance. RESULTS: The portion size of the sandwich significantly influenced lunch intake for both males and females (P<.0001). The majority of individuals consumed the entire 6-inch sandwich. When served the 12-inch sandwich, compared with the 8-inch sandwich, females consumed 12% more energy (74 kcal) and males consumed 23% more energy (186 kcal). Despite these differences, ratings of hunger and fullness were not significantly different after eating the 12-inch and 8-inch sandwiches. APPLICATIONS/CONCLUSIONS: These results suggest that increasing the portion size of a food served as a discrete unit leads to increased energy intake at a single meal without differentially influencing ratings of hunger and satiety. Dietitians should educate their clients about strategies to moderate the effect on intake of increased portions of high-calorie foods.

Adult↗

Changes in food group consumption patterns from childhood to young adulthood: the Bogalusa Heart Study.

OBJECTIVE: The objective of this study was to assess changes in food group consumption patterns from childhood to young adulthood. DESIGN: Twenty-four-hour dietary recalls were collected on a longitudinal sample of young adults. SUBJECTS/SETTING: Dietary intake data were collected on 246 young adults (70% European American, 30% African American) aged 19 to 28 years who participated in a previous cross-sectional survey when they were 10-year-olds. STATISTICAL ANALYSES: Descriptive statistics and linear mixed models adjusting for study time (age), sex, and ethnicity. RESULTS: In childhood, consumption of fruits/fruit juice and mixed meats ( P </=.05), desserts, candy, and milk ( P </=.0001) were greater than in young adulthood. Young adulthood consumption was greater for sweetened beverages, poultry and seafood ( P </=.001), salty snacks ( P </=.05), and beef ( P </=.01) compared to childhood. Milk consumption decreased, but the decrease was greater among males ( P </=.0001). Sweetened beverage consumption increased, but the increase was greater for European Americans ( P </=.0001). Candy consumption decreased, but the decrease was greater for African Americans ( P </=.05). CONCLUSIONS: Changes occur in food group consumption patterns from childhood to young adulthood. Overall, there was a decrease in diet quality during this age transition. Understanding eating habits of children early in life is important for planning effective intervention strategies.

Adolescent↗

Association Between Ratio of Triglycerides to HDL-C and Cognitive Impairment: A Longitudinal Population-Based Analysis and Mendelian Randomization Study.

OBJECTIVES: This study aimed to explore the longitudinal association between the triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio and cognitive impairment in older adults and further assess potential causality using Mendelian randomization (MR). DESIGN: Longitudinal population-based analysis combined with two-sample MR. Data from Waves 6-8 (2015-2019) of the Survey of Health, Ageing, and Retirement in Europe (SHARE) were analyzed using hierarchical regression models and mixed linear effects models. MR utilized genome-wide association studies (GWAS) summary data. PARTICIPANTS: 11,444 adults aged &#x2265;60 years from SHARE Wave 6, with longitudinal follow-up in Waves 7 (N = 2,775) and 8 (N = 5,469). MEASUREMENTS: TG/HDL-C ratio, cognitive function (orientation, immediate/delayed recall, verbal fluency, numeracy), and cognitive impairment (defined as scores >1.5 SD below age-group mean). Covariates included socio-demographics, health behaviors, comorbidities, and national-level factors. MR employed genetic variants associated with TG/HDL-C as instrumental variables. RESULTS: Higher TG/HDL-C ratios were negatively associated with total cognitive scores (&#x3b2; = -0.115, &#x3c7;&#xb2; = 15.44, df = 1, p < 0.001), immediate recall (&#x3b2; = -0.029, &#x3c7;&#xb2; = 12.34, df = 1, p < 0.001), delayed recall (&#x3b2; = -0.028, &#x3c7;&#xb2; = 7.33, df = 1, p < 0.001), verbal fluency (&#x3b2; = -0.038, &#x3c7;&#xb2; = 11.53, df = 1, p < 0.001), and numeracy (&#x3b2; = -0.019, &#x3c7;&#xb2; = 4.55, df = 1, p < 0.05) in fully adjusted models. Longitudinal analysis revealed increased cognitive impairment risk in the highest TG/HDL-C quartile (OR=1.43, 95% CI:1.01-2.03, &#x3c7;&#xb2; = 9.24, df = 1) over 4 years. MR supported a causal link between elevated TG/HDL-C and cognitive decline. CONCLUSIONS: Elevated TG/HDL-C ratios are longitudinally associated with cognitive decline in older adults. Managing lipid metabolism may mitigate cognitive impairment, highlighting the importance of TG/HDL-C as a modifiable risk factor in aging populations.

Humans↗

Cross-kingdom dynamics of the subgingival bacteriome and mycobiome: A pilot study on the effects of a novel HA-H&#x2082;O&#x2082;-Glycine formulation to treat periodontitis.

OBJECTIVES: Traditional periodontal therapy primarily focuses on bacterial biofilm control; however, recent evidence also suggests a critical role for the oral mycobiome. This study evaluated the clinical and ecological impact of a novel mouthwash formulation containing hyaluronic acid (HA), hydrogen peroxide (H2O2), and glycine on periodontal patients METHODS: This prospective, randomized split-mouth trial included 13 adult participants with periodontitis treated with HA-H2O2-glycine formula (BMG0703A) used twice a day for seven days. Subgingival plaque samples were collected from periodontal pocket and healthy control sites at baseline (T0) and one-week post-treatment (T1). Microbial and fungal communities were characterized using Next-Generation Sequencing (NGS) of the 16S rRNA and ITS2 regions. Linear Mixed Models (LMM) and Spearman correlation were used to assess taxonomic shifts and cross-kingdom relationships. RESULTS: Sequencing revealed a promising ecological shift: the bacteriome shifted from anaerobic dominance (Olsenella, Peptostreptococcus) toward a health-associated aerobic profile, with Rothia near-doubling (11.91% to 22.68%). The mycobiome underwent a "normalization" effect: Candida abundance decreased significantly (22.8% to 9.1%), while fungal Shannon diversity in pockets returned to healthy-site levels. Inter-kingdom analysis identified antagonistic relationships between expanding commensal bacteria and opportunistic fungi, suggesting that the intervention may help re-establish a protective bacterial niche. CONCLUSIONS: The HA-H2O2-glycine formulation seems to facilitate a rapid, cross-kingdom modulation of the subgingival niche. By reducing anaerobic pathogens and normalizing the mycobiome it appear to induce short-term changes, suggesting potential as adjunctive strategy in periodontal management. CLINICAL SIGNIFICANCE: The present work underlines the possible cross-Kingdom effects of a novel compound.

Humans↗

Blood samples drawn from IV catheters have less hemolysis when 5-mL (vs 10-mL) collection tubes are used.

INTRODUCTION: It is common practice for emergency nurses to draw blood for laboratory analyses into vacuum tubes from newly inserted intravenous (IV) catheters, even though this technique has been associated with an increase in sample hemolysis. No clinical nursing studies have documented the effect of collection tube size on hemolysis of samples obtained via IV catheters. OBJECTIVE: To determine whether there is a difference in the hemolysis rate of blood samples drawn from IV catheters comparing 5-mL vacuum collection tubes to 10 mL vacuum collection tubes. SETTING: The study was conducted at the Emergency Department, Summa Health System, Akron, Ohio. Method This study used a 4-group, 2-period crossover design randomly assigning the order of the vacuum tube drawn. With the crossover design, each patient served as his own control. Upon receiving orders to start an IV and draw blood, each of 12 study nurses obtained an envelope with 2 vacuum tubes randomly assigned as to which tube should be drawn first and which tube should be drawn second. Samples were analyzed for hemolysis using a Hitachi automated spectrophotometer as well as by visual inspection. DATA ANALYSIS: A linear mixed model was used to test the main hypothesis of vacuum tube type effects on hemolysis. RESULTS: The 5-mL tubes showed significantly lower hemolysis than the 10 mL tubes ( P <.0001) with a substantial effect size of .6 standard deviation units. CONCLUSION: The risk of hemolyzing blood drawn from IV catheters can be significantly reduced by using 5-mL rather than 10-mL collection tubes.

Blood Specimen Collection↗

Determination of the dietary habits of a Magdalenian woman from Saint-Germain-la-Rivière in southwestern France using stable isotopes.

To obtain direct dietary information, carbon and nitrogen isotope ratios were measured from bone collagen acquired from the well-preserved skeleton of a Magdalenian woman from the site of Saint-Germain-la-Rivière in southwestern France. Comparison of delta13C and delta15N values of the human bone collagen to those of bone collagen from local herbivores and carnivores indicates that the woman's primary source of protein was the meat of large terrestrial herbivores. Application of a linear mixing model to the woman's isotopic signature indicates that (1) no significant marine-derived protein contributed to her average diet; (2) saiga antelope, which dominates the faunal remains at Saint-Germain-la-Rivière, was not the main source of terrestrial protein; and (3) her pattern of subsistence reflects a less opportunistic behavior than generally attributed to humans from this period. Dietary proportions of prey reflected by the number of identified specimens are revised using meat percentage estimates, which de-emphasize the importance of saiga antelope in human subsistence at Saint-Germain-la-Rivière during the middle Magdalenian.

Animals↗

Clusters of biochemical markers are associated with radiographic subtypes of osteoarthritis (OA) in subject with familial OA at multiple sites. The GARP study.

OBJECTIVE: To assess the relationship of biochemical markers and radiographic signs of osteoarthritis (ROA) in the subjects with symptomatic osteoarthritis (OA) at multiple sites of the Genetics osteoARthritis and Progression (GARP) study. METHODS: We have measured eight biochemical markers, representing tissue turnover of cartilage, bone, synovium, and inflammation. ROA was assessed in the knees, hips, hands, vertebral facet joints and spinal disc degeneration (DD) by using the Kellgren score. A proportionate score was subsequently made for each joint location based on the number of joints with ROA. Principal component and linear mixed model analyses were applied to analyze the data. RESULTS: Three different clusters of markers were identified that may reflect different pathophysiological processes of OA. The first component appeared to be reflected by structural markers of cartilage and bone turnover and associated especially in subjects with hip ROA. The second component was reflected by a marker of inflammation and was associated with knee ROA, high Western Ontario and McMaster Universities (WOMAC) scores and body mass index (BMI). The third component included markers of cartilage turnover and was associated with ROA at hands, spine as well as age. High familial aggregation was observed for serum cartilage oligomeric matrix protein (S-COMP) (70%) and serum N-propeptide of collagen type IIA (S-PIIANP) (62%). CONCLUSION: Using a large well-characterized study and eight biochemical markers, we were able to observe three components that may reflect different molecular mechanisms (bone, cartilage, synovium turnover and inflammation). Our data suggested that these components contribute differently to ROA at different joint sites.

Adult↗

Autistic-like traits and longitudinal changes in health-related quality of life among individuals with bipolar disorder: A 12-month study.

OBJECTIVE: Autistic-like traits are common in bipolar disorder (BD) and have been linked to poor functional outcomes, yet their longitudinal impact on quality of life (QOL) remains unclear. This study examined whether autistic-like traits are associated with 12-month changes in health-related QOL in BD. METHODS: Seventy-eight outpatients with BD who completed 12-month follow-up assessments were included (mean age&#x202f;=&#x202f;34.9 years). Autistic-like traits were assessed using the Social Responsiveness Scale for Adults (SRS-A), with participants classified into elevated- and non-elevated-traits groups. Depressive and manic symptoms were evaluated using the 17-item Hamilton Depression Rating Scale (HAMD-17) and the Young Mania Rating Scale (YMRS). QOL was measured using the 36-Item Short-Form Health Survey (SF-36). Linear mixed models were used to examine longitudinal changes. RESULTS: HAMD-17 scores demonstrated significant main effects of time and group, reflecting overall improvement but persistently higher depressive symptoms in the elevated-traits group. YMRS scores indicated a significant group effect only. Physical QOL remained stable, while mental QOL improved over time without group differences. Role/social QOL showed significant main effects of time and group, with consistently lower scores in the elevated-traits group. No group&#x202f;&#xd7;&#x202f;time interactions emerged, suggesting similar rates of change between groups. CONCLUSIONS: This prospective study suggests that autistic-like traits in BD are associated with persistently poorer role/social functioning over time rather than differences in recovery trajectories. Assessing autistic-like traits may help identify patients at risk of poorer functioning and guide tailored psychosocial interventions.

Autistic-like traits↗

Soy protein and bone mineral density in older men and women: a randomized trial.

OBJECTIVE: Test the hypothesis that soy isoflavone supplementation preserves bone mineral density (BMD) in men and women. METHODS: We conducted a controlled, parallel-arm, double-blinded trial with 145 participants, 50-80 years, with random assignment to soy beverage daily for 12 months. Active treatment (+ISO) received soy protein containing 83 mg isoflavones (45.6 mg genistein, 31.7 mg daidzein), aglycone units; the comparison group (-ISO) received soy protein containing 3mg isoflavones. We measured BMD using dual-energy X-ray absorptiometry at the total hip and posterior-anterior spine (L1-L4) at baseline in 22 women and 123 men, and at 12 months in 13 women and 98 men. We used linear mixed models to test for an isoflavone effect on percentage BMD change from baseline in spine and hip. RESULTS: Among all participants, mean percent change in spine BMD (+/-S.E.) was 0.16+/-0.44 in -ISO (P=0.10) at 12 months. Treatment effects on spine BMD were significantly greater in women than men (P=0.01). At 12 months, in women, mean percent change was 0.58+/-0.70 in +ISO and -1.84+/-0.86 in -ISO (P=0.05); among men it was 1.32+/-0.53 in +ISO and 0.31+/-0.48 in -ISO (P=0.16). By comparison, percent change in hip BMD was similar in the treatment groups, and was not different between men and women. Mean percent change in hip BMD from baseline to 12 months was 0.54+/-0.38 in +ISO and -0.13+/-0.36 in -ISO (P=0.20) among all participants. CONCLUSIONS: Soy protein containing isoflavones showed a modest benefit in preserving spine, but not hip BMD in older women.

Absorptiometry, Photon↗

Use of calcium antagonists and cognitive decline in old age. The Leiden 85-plus study.

The systolic hypertension in Europe (Syst-Eur) trial has been the only trial that has suggested a protective effect of antihypertensive treatment on incidence of dementia. It is unclear whether this protective effect has been caused by the blood pressure lowering effect of the calcium antagonist nitrendipine or by the calcium channel inhibition. From the Leiden 85-plus study, a population-based cohort study of 599 subjects aged 85 years, we selected 204 subjects who used at least one antihypertensive at baseline. Associations between use of antihypertensives at baseline and change in cognitive functioning over time were assessed with linear mixed models. After adjusting for gender, education, and use of other antihypertensives, only use of calcium antagonists was associated with a significant decelerated annual cognitive decline during follow-up (0.40 MMSE-points per year, p=0.001). Use of other antihypertensives was not associated with a decelerated annual cognitive decline (all p values >0.3). Our data support the interpretation that the reported prevention of dementia by calcium antagonists is exerted through its calcium channel inhibition rather than its blood pressure lowering properties.

Aged, 80 and over↗

Retinal venous pulsation in glaucoma and glaucoma suspects.

PURPOSE: To determine whether changes in central retinal vein pulsation characteristics occur in glaucoma, and how these are related to indices of glaucoma severity. DESIGN: A large, consecutive, prospective, case-controlled study. PARTICIPANTS: Ninety-four consecutive glaucoma patients and 105 glaucoma suspects seen in a tertiary referral clinic were examined. Forty-one age-matched normal subjects also were examined. METHODS: The presence or absence of spontaneous venous pulsation was observed in these 3 groups. The ophthalmodynamometric force (ODF) required to induce venous pulsation at the optic disc was measured in those without spontaneous pulsation. Optic disc photographs were obtained and visual field testing was performed for all subjects. MAIN OUTCOME MEASURES: The prevalence of spontaneous venous pulsation between these 3 groups was compared. The relationship between ODF and visual field mean deviation, neuroretinal rim area, age, intraocular pressure (IOP), gender, and diagnosis of glaucoma was investigated using linear mixed models fitted by Gibb's sampling. RESULTS: Significantly fewer (chi-square, 27.7; P<0.001) glaucoma patients (54%) were observed to have spontaneous venous pulsation than suspects (75%) or normals (98%). A worse visual field mean deviation was shown to be the most significant predictor of a higher ODF (P<0.000), with younger age (P<0.000) also predictive of a higher ODF. A strong relationship between ODF and mean deviation was found in the glaucoma patients (r = 0.59; n = 52; P<0.001). CONCLUSIONS: Spontaneous venous pulsation is less common in glaucoma. The ODF required to induce venous pulsation is increased in glaucoma, and this ODF is greater in those with more severe field loss.

Aged↗

Visual outcomes in children with juvenile idiopathic arthritis-associated uveitis.

PURPOSE: To analyze visual outcomes in children affected by juvenile idiopathic arthritis (JIA)-associated uveitis. DESIGN: Retrospective interventional case series. PARTICIPANTS: Eighty-nine children with JIA-associated uveitis. METHODS: Charts of children with JIA-associated uveitis were reviewed. MAIN OUTCOME MEASURE: Change in patients' visual acuities (VAs). RESULTS: Of 269 children with uveitic syndromes referred, 89 (33%) had JIA-associated uveitis. The process was bilateral in 76 children. Seventy-three patients were female, and 84% of patients were Caucasian. Mean age of onset of uveitis was 5.7 years. Mean follow-up was 2.96 years. Antinuclear antibody positivity was detected in 56 patients, 44 of them female. Patients with JIA-associated uveitis developed numerous complications in the course of their disease: of 165 affected eyes, 105 (64%) developed cataracts, 33 (20%) developed increased intraocular pressure, and 76 (46%) developed band keratopathy; posterior synechiae were present in 96 (58%). Of 89 children, 73% were treated with immunomodulators, 40% were treated with nonsteroidal antiinflammatory agents alone or in combination with immunomodulators, and 21% were treated with topical and/or systemic steroids. Of 65 children who required immunomodulation, only one chemotherapeutic agent was used in 30, two agents in 21, and > or =3 in 14. Visual acuities of 65 children (122 eyes) were documented and compared at standard intervals. By mixed-models linear regression, improvement in VA of 0.03 logarithm of the minimum angle of resolution units per year was not found to be statistically significant (standard error, 0.02, P = 0.089). CONCLUSIONS: Juvenile idiopathic arthritis-associated uveitis is a sight-threatening disease. However, much of the children's vision can be preserved if patients are treated appropriately.

Adolescent↗

Effects of a workplace physical exercise intervention on the intensity of headache and neck and shoulder symptoms and upper extremity muscular strength of office workers: a cluster randomized controlled cross-over trial.

The purpose of the study was to examine the effects of a workplace physical exercise intervention on the perceived intensity of headache and the intensity of symptoms in the neck and shoulders, as well as on the extension and flexion strength of the upper extremities. The study was a cluster randomized controlled trial. The cross-over design consisted of physical exercise intervention (15 weeks) and no-intervention (15 weeks). The subjects (n=53) were office workers (mean age 46.6 (SD 8.4)) who reported headache (n=41) symptoms in the neck (n=37) or shoulders (n=41), which had restricted their daily activities during the last 12 months. Pain symptoms were measured using the Borg CR10 scale and muscular strength with a 5RM test. Statistical analyses were based on linear mixed models. Physical exercise intervention resulted in a slight, but statistically significant, decrease in the intensity of headache and neck symptoms, as well as an increase in the extension strength of the upper extremities. The mean decrease in headache during the 5-week period was 0.64 CR10 (95% CI 0.28-1.00) (P=0.001) or 49% (95% CI 22-77), and 0.42 CR10 (95% CI 0.11-0.72) (P=0.002) or 49% (95% CI 13-85) in the intensity of neck symptoms. The mean increase in the extension strength of the upper extremities was 1.3 kg (95% CI 0.5-2.1) (P=0.001) or 4% (95% CI 1-6). The intervention had no effect on the intensity of shoulder symptoms or the flexion strength of the upper extremities. Specific exercise may be clinically important to alleviate headache and neck symptoms.

Activities of Daily Living↗

Comparison of the disease incidences of Finnish Ayrshire and Finnish Black and White dairy cows.

Finnish Ayrshire and Finnish Black and White cows were compared regarding the incidences of early and late mastitis, parturient paresis, ketosis, ovarian disorders, metritis and the risk of having a test-day somatic-cell count >200,000 cells ml(-1) at any of the first three monthly test days in lactation. In a retrospective cohort study 101,793 cows from 5844 tie stalls and 11,811 cows from 437 loose-housing systems from all over Finland were followed from calving in 2000 until the end of lactation. The observed incidences of those cows were then analysed using generalised linear mixed models. Finnish Black and White cows had higher incidences of all diseases except ovarian disorders. Although the differences were statistically significant in all models except metritis and early mastitis in loose-housing systems, they were, in our view, only important on the national level (for the breeding organisations), and of little importance for the farmers.

Animals↗

The use of Markov chain Monte Carlo for analysis of correlated binary data: patterns of somatic cells in milk and the risk of clinical mastitis in dairy cows.

Two analytical approaches were used to investigate the relationship between somatic cell concentrations in monthly quarter milk samples and subsequent, naturally occurring clinical mastitis in three dairy herds. Firstly, cows with clinical mastitis were selected and a conventional matched analysis was used to compare affected and unaffected quarters of the same cow. The second analysis included all cows, and in order to overcome potential bias associated with the correlation structure, a hierarchical Bayesian generalised linear mixed model was specified. A Markov chain Monte Carlo (MCMC) approach, that is Gibbs sampling, was used to estimate parameters. The results of both the matched analysis and the hierarchical modelling suggested that quarters with a somatic cell count (SCC) in the range 41,000-100,000 cells/ml had a lower risk of clinical mastitis during the next month than quarters <41,000 cell/ml. Quarters with an SCC >200,000 cells/ml were at the greatest risk of clinical mastitis in the next month. There was a reduced risk of clinical mastitis between 1 and 2 months later in quarters with an SCC of 81,000-150,000 cells/ml compared with quarters below this level. The hierarchical modelling analysis identified a further reduced risk of clinical mastitis between 2 and 3 months later in quarters with an SCC 61,000-150,000 cells/ml, compared to other quarters. We conclude that low concentrations of somatic cells in milk are associated with increased risk of clinical mastitis, and that high concentrations are indicative of pre-existing immunological mobilisation against infection. The variation in risk between quarters of affected cows suggests that local quarter immunological events, rather than solely whole cow factors, have an important influence on the risk of clinical mastitis. MCMC proved a useful tool for estimating parameters in a hierarchical Bernoulli model. Model construction and an approach to assessing goodness of model fit are described.

Animals↗