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Biomedical subjects

M J Green

Publications and source records attributed to M J Green.

At least 19 recordsLinked to original sources
PubMed2006

On distinguishing cause and consequence: do high somatic cell counts lead to lower milk yield or does high milk yield lead to lower somatic cell count?

Researchers have reported that as milk yield increases composite milk somatic cell count (SCC) is diluted in cattle with no intramammary infection (IMI) and as a consequence, estimates of SCC from high yields are lower than estimates of SCC from low yields in dairy cows without an IMI. To date, estimates of reduced milk yield associated with high SCC because of intramammary infection have not been adjusted for any dilution of SCC. Ignoring dilution is therefore likely to lead to an overestimate of reduction in yield with increasing SCC. This paper investigates scenarios of the possible impact of dilution and inflammation on the association between somatic cell count and yield. The data used to investigate this relationship come from 8373 monthly records of milk yield and composite somatic cell count, together with incidence of clinical mastitis, which were recorded on 850 cows from five dairy cattle farms in Gloucestershire, UK. Two sets of models were used to investigate dilution and inflammation using two-level hierarchical models. The first set of models was used to estimate the linear (dilution) and log10-linear (inflammation) impact of SCC on the outcome variable milk yield. Five general linear models with increasing inclusion of higher test day SCC values were run. The cumulative categories were test day SCC values of up to and inclusive of 30, 50, 100, 200 and 400x10(3)cells/ml. Linear and log linear SCC influences on milk yield were estimated. At low SCC values the linear SCC predictor was dominant, while at higher values the log linear predictor was dominant. Up to 100x10(3)cells/ml there was mostly a slightly negative linear relationship between SCC and yield, potentially indicating a dilution effect. In the second set of models, three approaches to adjust milk loss for dilution were compared with an unadjusted model. In general, dilution-adjusted SCC values fitted the data better and resulted in a slightly lower milk loss per SCC category compared with unadjusted SCC. In all models with a dilution term there was a significant reduction in yield with SCC>200x10(3)cells/ml.

Animals↗
PubMed2006

Investigation of risk factors for clinical mastitis in British dairy herds with bulk milk somatic cell counts less than 150,000 cells/ml.

A sample of dairy farms in Great Britain with a monthly bulk milk somatic cell count of less than 150,000 cells/ml was enrolled into a 12-month prospective study. At the end of the study, a questionnaire on milking practice and other farm management practices was sent to the 482 farmers who had collected data on the occurrence of mastitis throughout the 12 months. The response rate was 93 per cent. The reported mean incidence of clinical mastitis was 36.9 cases per 100 cow-years. Factors associated with an increase in the incidence of clinical mastitis were cleaning out the straw yard less frequently than every six weeks, more than 5 per cent of cows leaking milk outside the parlour, checking the foremilk, wearing gloves during milking, an average annual milk yield of more than 7000 litres per cow, dipping or spraying teats before milking and keeping milk with a high somatic cell count out of the bulk tank. Factors associated with a decrease in the incidence of clinical mastitis were using a cloth to dry the teats after washing them as part of premilking preparation, using calving boxes for less than 40 per cent of calvings, and using both cubicles and straw yards to house dry cows, as opposed to other housing.

Animals↗
PubMed2006

Seasonal variation of bulk milk somatic cell counts in UK dairy herds: investigations of the summer rise.

Individual cow somatic cell count (SCC) patterns were explored over a one year period in 33 dairy herds to investigate the reason for a summer rise in bulk milk somatic cell counts (BMSCC). Cow test day somatic cell counts were categorised according to the magnitude of change since the previous test day reading, to examine which categories were responsible for the summer increase. Multilevel models using Markov chain Monte Carlo methods were specified to estimate the number of somatic cells/ml produced by different cell count categories. Stage of lactation and parity were accounted for in the models. There was an increase in the proportion of cows that remained above 200,000 cells/ml for two consecutive recordings in summer and this group of cows were responsible for 70.8% of the increase in somatic cells/ml produced from May to September compared with October to March. There was no evidence that a greater new infection rate (somatic cell counts moving from below 100,000 cells/ml to over 200,000 cells/ml) contributed to the increased summer bulk milk somatic cell counts. There was no indication that a general small increase in all somatic cell counts played an important role in the increased summer somatic cell counts. Markov chain Monte Carlo methods provided a valuable and flexible platform for parameter estimation in reasonably complex multilevel models.

Animals↗
PubMed2006

Idiopathic pericarditis in dogs: no evidence for an immune-mediated aetiology.

OBJECTIVE: To ascertain whether specific immunological changes are associated with canine pericardial effusion due to idiopathic pericarditis. METHODS: In this prospective study, serum antinuclear antibody and serum and pericardial fluid immunoglobulin (Ig) G, Ig M and Ig A concentrations were measured in dogs with pericardial effusion due to idiopathic pericarditis or pericardial neoplasia. The secretory index relative to albumin concentration was calculated in order to distinguish between Ig actively secreted into the pericardial fluid and that derived from the blood accumulating within the pericardial sac. Statistical analysis was performed comparing the results obtained between the two groups of dogs. RESULTS: Only three dogs were antinuclear antibody positive; two of these dogs had idiopathic pericarditis and one had neoplasia. Mean serum Ig M and Ig A concentrations were lower than the reference values in both groups, and the secretory indices for Ig M and Ig A were greater than 1.0. However, there was no significant difference with respect to any Ig measurement between the two groups of dogs (P>0.1). CLINICAL SIGNIFICANCE: The results of the present study do not support the hypothesis that canine idiopathic pericarditis has a significant 'immune-mediated' aetiology or immunological features that distinguish it from the pericardial changes associated with local neoplastic disease.

Animals↗
PubMed2006

The innovator will prevail in glucose monitoring.

As well as the expanding diabetes market for glucose-monitoring devices, there are other applications for these products and opportunities for companies with the will to innovate. One area that is explored here is the intensive care unit.

Blood Glucose Self-Monitoring↗
PubMed2005

Anti-CCP antibodies measured at disease onset help identify seronegative rheumatoid arthritis and predict radiological and functional outcome.

OBJECTIVE: Anti-cyclic citrullinated peptide (anti-CCP) antibodies have been identified as highly specific for rheumatoid arthritis (RA). Studies suggest an association with radiographic outcome. The aims of this study were to assess the diagnostic and prognostic utility of the second-generation anti-CCP(2) test in a large cohort of early RA patients compared with connective tissue disease (CTD) controls. METHODS: One hundred and eighty-two patients with RA and 121 patients with CTD were recruited. All RA patients had less than 24 months of symptoms and had CRP, rheumatoid factor (RF), HLA typing (SE) and anti-CCP(2) antibodies measured at baseline. Function was assessed using the Health Assessment Questionnaire (HAQ) and X-rays performed at 0, 12 and 24 months. RESULTS: The anti-CCP(2) antibody test demonstrated a specificity of 91% and sensitivity of 81% for RA when compared with controls. In RF-negative patients, specificity was 92% and sensitivity 60%. Baseline demographics of the RA cohort showed mean age 57 yr, mean symptom duration 7 months, 63% RF-positive patients, 72% SE-positive, 81% CCP-positive and 21% erosive. The only predictor of change in Larsen score from 0 to 24 months in the cohort was the presence of the shared epitope (P<0.05) and in the RF-negative subgroup it was CCP(2) antibody titre >100 (P<0.05). Baseline HAQ was the only significant predictor of HAQ at 24 months, but in the RF-negative subgroup CCP(2) antibody titre >100 predicted a poor functional response at 24 months (P<0.05). CONCLUSIONS: This study confirms the diagnostic utility of anti-CCP(2) antibodies in early RA, particularly in seronegative patients, in whom anti-CCP(2) positivity also conferred prognostic utility for radiographic and functional outcomes.

Arthritis, Rheumatoid↗
PubMed2005

Hand bone loss in early undifferentiated arthritis: evaluating bone mineral density loss before the development of rheumatoid arthritis.

OBJECTIVES: (1) To examine the change in regional bone mineral density (BMD), including the hands, and assess its role as a predictor of outcome in patients presenting with an early undifferentiated inflammatory arthritis; (2) to examine for associations with the changes in hand BMD. METHODS: 74 patients with undifferentiated hand arthritis of less than 12 months' duration were examined at baseline and then at three, six, and 12 months follow up, including BMD measurement of the femoral neck, spine (L2-4), and the whole hands using dual energy absorptiometry (DXA). RESULTS: During the study, 13 patients were diagnosed as having rheumatoid arthritis, 19 as having inflammatory non-rheumatoid joint disorders, and 42 as having non-inflammatory joint disorders. At the femoral neck and lumbar spine no significant bone loss was seen in any of the three subgroups. At the 12 months follow up the mean (95% confidence interval) hand BMD loss in the patients with rheumatoid arthritis was -4.27% (-1.41 to -7.13); in the inflammatory non-rheumatoid group, -0.49% (-1.33 to +0.35); and in the non-inflammatory joint disorder group, -0.87% (-1.51 to -0.23). In a multivariate linear regression model (including age, rheumatoid factor, mean C reactive protein, mean HAQ score, and cumulative glucocorticoid dose), only mean C reactive protein (p<0.001) and rheumatoid factor (p = 0.04) were independently associated with change in hand BMD during follow up. CONCLUSIONS: Hand DXA provides a very sensitive tool for measuring bone loss in early rheumatoid arthritis and may be useful in identifying patients at high risk of developing progressive disease. Further studies are needed to evaluate the role of hand bone loss as a prognostic factor and outcome measure in rheumatoid arthritis.

Absorptiometry, Photon↗
PubMed2005

Prevalence and associations between bacterial isolates from dry mammary glands of dairy cows.

To assess the prevalence and patterns of bacterial isolates, cultures were made from the dry mammary glands of dairy cows in six commercial dairy herds in the UK. Milk samples were taken from all four quarters of 480 cows at drying off and at weekly intervals from 14 days before to seven days after calving. A major mastitis pathogen was isolated from at least one quarter of 220 (45.8 per cent) of the cows and from more than one quarter of 90 (18.8 per cent) of them. During the late dry to calving period, of the 957 quarters with three culture results, a major mastitis pathogen was cultured from 236 (24.7 per cent) quarters of 186 (38.8 [corrected] per cent) cows. The most commonly isolated major pathogen was Escherichia coli, followed by Streptococcus uberis and coagulase-positive staphylococci. There were significant differences between the patterns of isolates from different farms and in different calving months, suggesting that the rate of infection was partially dependent on external conditions. The isolation of E. coli, S. uberis or coagulase-positive staphylococci from a cow during the late dry/periparturient period was associated with an increased risk of that cow being culled in the next lactation. Bayesian general linear mixed models were used to assess the associations between the different bacterial species. The probability of isolating either E. coli or S. uberis was significantly greater when the other organism was cultured in a milk sample; this was also true of coagulase-positive staphylococci and S. uberis. When Corynebacterium species were isolated from a milk sample, the probability of isolating coagulase-positive staphylococci or S. uberis decreased significantly, and when coagulase-negative staphylococci were isolated the probability of isolating coagulase-positive staphylococci was reduced.

Animals↗
PubMed2004

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↗
PubMed2004

Should oligoarthritis be reclassified? Ultrasound reveals a high prevalence of subclinical disease.

OBJECTIVE: To determine the prevalence of subclinical synovitis using ultrasound (US) imaging of both painful and asymptomatic joints, in patients with early (<12 months), untreated oligoarthritis (</=5 joints). METHODS: Eighty patients underwent a detailed clinical assessment by two physicians. All painful joints were identified, which were immediately scanned by a sonographer. In the last 40 patients, an additional standard group of joints was scanned to establish the prevalence of synovitis in asymptomatic joints. RESULTS: In 80 patients, 644 painful joints (with and without clinical synovitis) were identified and each underwent a US assessment. Of these joints, 185 had clinical synovitis, of which, US detected synovitis in only 79% (147/185). In the other 38 joints US demonstrated tenosynovitis instead of synovitis in 12 joints and possible, but not definite, synovitis in 11 joints. Fifteen joints were, however, normal on US. In 459 joints that were not clinically synovitic, US detected synovitis in 33% (150/459). In 64% (51/80) of patients, US detected synovitis in more joints than clinical examination and in 36% (29/80) of patients, US detected a polyarthritis (>6 joints). Of the 826 asymptomatic (non-painful) joints scanned, 13% (107/826) had US detected synovitis. CONCLUSION: Sonography detected more synovitis than clinical examination in patients with oligoarthritis. In almost two thirds of patients there was evidence of subclinical disease while one third could be reclassified as polyarticular. These findings suggest that a definition of oligoarthritis based purely on clinical findings may be inappropriate, which may have important implications for disease management.

Adult↗
PubMed2004

Somatic cell count distributions during lactation predict clinical mastitis.

This research investigated somatic cell count (SCC) records during lactation, with the purpose of identifying distribution characteristics (mean and measures of variation) that were most closely associated with clinical mastitis. Three separate data sets were used, one containing quarter SCC (n = 1444) and two containing cow SCC (n = 933 and 11,825). Clinical mastitis was defined as a binary outcome, present or absent, for each lactation, and SCC were log (base 10) transformed. A generalized linear mixed model within a Bayesian framework was used for analysis. Parameters were estimated using Markov Chain Monte Carlo with Gibbs sampling. Results from the 3 data sets were similar. Increased maximum and standard deviation log SCC during lactation, rather than increased geometric mean, were the best overall indicators of clinical mastitis. Distributions of SCC were also investigated separately for different mastitis pathogens. Increased maximum log SCC was associated with clinical mastitis caused by all pathogen types. Increased standard deviation log SCC was associated with Staphylococcus aureus, and Streptococcus uberis clinical mastitis and increased coefficient of variation log SCC (standard deviation divided by mean) was associated with Escherichia coli clinical mastitis. Increased geometric mean lactation SCC was associated with an increased risk of Staph. aureus clinical mastitis but a reduced risk of E. coli clinical mastitis. Our results suggest that using measures of variation and maximum cow SCC would enhance the accuracy of predicting clinical mastitis, compared with geometric mean SCC, and therefore improve genetic programs that aim to select for clinical mastitis resistance. The results are also consistent with low SCC increasing susceptibility to some mastitis pathogens.

Animals↗
PubMed2003

The association between quarter somatic-cell counts and clinical mastitis in three British dairy herds.

The association between quarter somatic-cell counts (QSCCs) of milk and the risk of clinical mastitis (CM) was investigated in a 1-year study on three dairy herds in Somerset, UK. The three herds had 95-130 milking cows and an annual mean bulk milk somatic-cell count (BMSCC) of <150 x 10(3)cells/ml. The farms were visited every 4-6 weeks at morning milking when quarter-milk samples were collected. The farmers recorded all cases of CM and were trained to collect sterile milk samples from affected quarters, before treatment for bacteriology. The three herds had CM incidence rates of 25.4, 55.2, and 67.6 quarter-cases per 100 cow-years. Escherichia coli and Streptococcus uberis were cultured from approximately 50% of cases. QSCC was categorised and the risk of CM occurring in the month after the QSCC was examined using multilevel models to account for the correlated nature of the dependent data. Three models were developed: one for all cases of CM, one for those caused by coliforms and one for those caused by S. uberis. When all cases of CM were considered, quarters with somatic-cell count (SCC) 21-100 x 10(3)cells/ml had reduced odds (OR=0.60, P=0.06) and quarters with SCC >200 x 10(3)cells/ml has over three time the odds (OR=3.7, P<0.01) of CM compared with QSCC 1-20 x 10(3)cells/ml. When only coliform CM were investigated, quarters with SCC 6-200 x 10(3)cells/ml had reduced odds of coliform CM (OR=0.47, P=0.04) compared with QSCC 1-5 x 10(3)cells/ml, and SCC >200 x 10(3)cells/ml were not significantly different from the baseline. Finally, when S. uberis CM were investigated, quarters with SCC >200 x 10(3)cells/ml had more than three times the odds of S. uberis CM compared with QSCC 1-20 x 10(3)cells/ml (OR=3.73, P<0.01). QSCC <21 x 10(3) and >200 x 10(3)cells/ml are associated with increased odds of CM in the following 4-6 weeks; this association may be pathogen specific.

Animals↗
PubMed2003

Serum MMP-3 and MMP-1 and progression of joint damage in early rheumatoid arthritis.

OBJECTIVE: Expression and activation of matrix metalloproteinases such as MMP-3 (stromelysin-1) and MMP-1 (collagenase-1) are increased in patients with rheumatoid arthritis (RA). Previous negative reports of their value as predictors of joint damage may be due to the lack of a large longitudinal study of early RA patients. This study evaluated their use in assessing early untreated patients with RA and predicting subsequent joint damage. METHODS: Ninety-eight patients with early untreated RA of less than 12 months duration and 20 normal controls had baseline serum samples tested with a double-antibody enzyme-linked immunosorbent assay for each of MMP-1 and MMP-3. The subsequent changes in Larsen score (DeltaLarsen) and Health Assessment Questionnaire (DeltaHAQ) over the first 12 months were recorded. RESULTS: Baseline serum levels of MMP-3 and MMP-1 correlated significantly with baseline C-reactive protein (CRP) (r=0.42 and 0.49, P<0.001), DeltaHAQ (r=0.32 and 0.30, P<0.01) and DeltaLarsen (r=0.23 and 0.32, P<0.05) respectively. Analysis of the group of patients with a normal CRP at presentation (n=21) showed correlation of the baseline MMP-3 and MMP-1 with the presence of erosive disease during the first 12 months (r=0.52 and 0.65 respectively, P<0.05). Logistic regression analysis, in the patients who were non-erosive at presentation, showed that the strongest correlation with progression in Larsen score was the baseline MMP-3 level (r=0.30, P=0.01). CONCLUSIONS: Baseline serum MMP-1 and MMP-3 levels correlate with disease activity and predict functional and radiographic outcome in early untreated RA. They may have a particular value in predicting the progression of erosive disease in patients who are not erosive at presentation.

Arthritis, Rheumatoid↗
PubMed2002

Study of clinical mastitis in British dairy herds with bulk milk somatic cell counts less than 150,000 cells/ml.

A 12-month prospective study of clinical mastitis was conducted in 482 British dairy herds with a bulk milk somatic cell count (BMSCC) of less than 150,000 cells/ml. The mean proportion of cows in the herd with clinical mastitis was 23.1 per cent (range 0 to 80), with a mean of 1.50 quarter cases per cow. The mean incidence rate of clinical mastitis was 36.7 quarter cases per 100 cow years (range 0 to 208.2). Twelve per cent of the quarter cases showed systemic signs, including inappetence and severe lethargy. Over 22 per cent of quarter cases occurred in the first seven days of lactation and over 50 per cent occurred in the first 90 days of lactation. Cluster analysis indicated that the main difference between herds with a low and average incidence of mastitis was the proportion of clinical cases occurring in the first seven days of lactation, 14 per cent compared with 44 per cent, respectively. The risk of severe clinical mastitis compared with mild clinical mastitis decreased significantly as the individual cow somatic cell count (SCC) in the month before clinical mastitis was diagnosed increased.

Animals↗