Search PubMed⌕ Search

Biomedical subjects

M Sandholm

Publications and source records attributed to M Sandholm.

At least 55 records · Page 3Linked to original sources
PubMed1986

Comparison of milk antitrypsin, albumin, n-acetyl-beta-D-glucosaminidase, somatic cells and bacteriological analysis as indicators of bovine subclinical mastitis.

Thirty-two quarters, five of which harbored subclinical mastitis, were examined daily for one month. The usefulness of milk antitrypsin, BSA (bovine serum albumin), NAGase, somatic cells and bacteriological analysis in differentiating the inflamed quarters from the healthy control quarters was analysed. Inter-quarter evaluation clearly improved each indirect mastitis parameter; NAGase and antitrypsin were better indicators of differences between infected and non-infected quarters than BSA or the somatic cell count.

Acetylglucosaminidase↗
PubMed1986

Determinants of bacterial replication rates in mastitic whey.

Bacterial growth was measured by a turbidimetric microtechnique in the whey of milk samples from quarters of cows with subclinical mastitis. Samples were grouped according to bacterial isolates recovered and the effects of bacterial species and whey on bacterial growth rates were analysed. Different strains of bacteria and different whey samples gave highly significant differences in bacterial replication rates. Except for penicillin-resistant Staphylococcus aureus, bacteria grew better in whey from mastitic milk where the inflammation was caused by the same bacterial species than in other mastitic milk samples. Inflammation caused by major pathogens generally enhanced the growth in whey of any type of major pathogen. Since mastitis pathogens showed enhanced growth in whey prepared from the same milk from which they were isolated, specific antibacterial factors in the whey did not appear to restrict bacterial growth in whey. The nutritional quality of the medium seems to be the important determinant of bacterial growth.

Animals↗
PubMed1986

Milk plasmin, N-acetyl-beta-D-glucosaminidase, and antitrypsin as determinants of bacterial replication rates in whey.

Quarter milk samples were collected monthly on a selected herd of 80 Ayrshire cows having a high frequency of subclinical mastitis. Analysis of bacterial growth rates in milk showed that whey prepared from infected or inflamed quarters stimulated bacterial growth. Milk N-acetyl-beta-D-glucosaminidase, antitrypsin, and plasmin activities all showed positive correlations with bacterial replication rates (Staphylococcus aureus and Escherichia coli) in respective whey samples as determined by a turbidometric micro-technique. Increased bacterial replication rates in mastitic whey represent an increased yield of the key nutrients for bacteria. Bacterial growth enhancement can be partly explained by proteose-peptone originating from plasmin activation and casein degradation. However, as multiple regression analysis showed that a combination of the predictor variables: antitrypsin, N-acetyl-beta-D-glucosaminidase and plasmin explained enhancement of bacterial growth better than plasmin alone, other factors connected with inflammation should be sought when searching for growth-enhancing factors in whey. Milk plasmin activities showed increasing activities toward end of lactation (before drying off) as well as during later lactation (age of cow in years minus 2). Bacterial replication was enhanced in parallel with these changes in plasmin activities.

Acetylglucosaminidase↗
PubMed1986

N-acetyl-beta-D-glucosaminidase and antitrypsin in subclinically infected quarter-milk samples: effect of bacteria and hemolysins, lactation stage, and lactation number.

Interrelationships between N-acetyl-beta-D-glucosaminidase (indicating cellular damage) and antitrypsin (indicating increased permeability between the blood and milk compartments) were evaluated in 1,411 quarter-milk samples collected during routine herd surveys. N-Acetyl-beta-D-glucosaminidase was antitrypsin, whereas, in more severe mastitis, antitrypsin had a more constant deflection. The sensitivity of both determinants was associated with the virulence of bacteria. Production of bacterial hemolytic toxins was associated with a significant increase in both determinants. Penicillinase production by staphylococci was associated with selective increases of antitrypsin.

Acetylglucosaminidase↗
PubMed1985

Milk antitrypsin as a marker of bovine mastitis--correlation with bacteriology.

Milk antitrypsin reflects leakage of protein of blood plasma into milk. Mastitis detection can be based on measurement of the trypsin-inhibitor capacity in milk; the "Eflab Mastitis Test" procedure is based on this principle. The procedure was developed to screen for subclinical mastitis; high capacity and sensitivity permits whole herds to be analyzed on a quarter basis to identify inflamed quarters during a single sampling. Milk antitrypsin was measured on 2174 quarter milk samples by a colorimetric procedure. The Multiskan MC reader was hooked to desk computer to interpolate antitrypsin from the standard curve and to analyze results. The analysis of inflammation was based on antitrypsin as well as computerized interquarter evaluation. These measures were compared with bacteriologic study of milk to set criteria for automatic identification of mastitis in individual quarters. The comparison against the lowest teat antitrypsin gave better indication of infection than antitrypsin as such. By strict criteria that identified inflammations caused by major pathogens, 18.8% of uninfected quarters were identified as false positive. The explanation is that a single bacteriological culture is not reliable for detecting mastitis, because there are temporary causes of tissue irritation other than bacteria that may be identified during standard bacteriologic examination.

Animals↗
PubMed1985

Antitrypsin and N-acetyl-beta-D-glucosaminidase as markers of mastitis in a herd of Ayshire cows.

Microplate analyzers for N-acetyl-beta-D-glucosaminidase (NAGase) and antitrypsin in milk were high-capacity systems for determination of subclinical mastitis on a mammary-quarter basis in a herd of 80 Ayshire cows. Infected quarters could be better differentiated from non-infected quarters by interquarter evaluation of milk NAGase and antitrypsin, than by adaptation of threshold values based on measured NAGase and antitrypsin values. This differentiation between healthy quarters and mastitic quarters was further improved by using absolute values and interquarter evaluations in combination. Therefore, quarter-based sample collection in combination with microplate technology and computerization is proposed as the method of choice for monitoring udder health in herds.

Acetylglucosaminidase↗
PubMed1984

Milk trypsin-inhibitor capacity as an indicator of bovine mastitis--a novel principle which can be automated.

As mastitis is associated with leakage of small molecular weight plasma proteins, such as alpha 1-antitrypsin, into milk, this antitrypsin can be used as an indicator of mastitis. A colorimetric procedure was developed for large scale monitoring of milk antitrypsin activity, using microtitration plates and the Multiskan system. The effect of stage of lactation and age of the cow on the antitrypsin concentration and its interrelationship with other mastitis indicators (bovine serum albumin (BSA), somatic cell count) was analysed by computer programs on 1029 cows. Milk antitrypsin activity was high after parturition owing to colostral inhibitors. After the first month of lactation the assay measures only blood-derived antitrypsin and is a good indicator for detecting an increased permeability between blood and milk due to mastitis. Increasing lactation number only slightly affected the antitrypsin and BSA concentrations whereas somatic cell content was markedly affected.

Animals↗
PubMed1984

Haem compounds as bacterial growth promoters in whey: a possible application to bovine mastitis.

The enhancing effect of haem compounds on the growth of Escherichia coli, Staphylococcus aureus and Streptococcus agalactiae in whey cultures was studied turbidometrically. Catalase, myoglobin and haemoglobin in concentrations 10(-5) to 10(-3) M enhanced bacterial growth. One explanation of this was the availability of iron by these haem compounds for the bacteria. However, evidence from experiments on free radical generating systems by t-BHP and hydrogen peroxide indicated that haem compounds scavenge activated oxygen products and so protect bacteria from oxygen toxicity.

Animals↗
PubMed1984

Bacterial growth in whey from mastitic and nonmastitic quarters.

Growth of Escherichia coli and Staphylococcus aureus was analyzed by turbidometry in 456 selected whey samples. The samples had been graded mastitic or nonmastitic as determined by antitrypsin assay and bacteriologic examination. Whey samples from inflamed quarters (antitrypsin increased) and infected quarters significantly promoted bacterial growth as compared with whey samples from control quarters. The growth-stimulatory effect was limited to the diseased quarters, since control quarters from the same animals did not support enhanced bacterial growth. The observations indicate that in chronic mastitis, the inflammatory process leads to changes in the whey that promote bacterial growth in vitro.

Animals↗
PubMed1983

Fat globule membrane of sow milk as a target for adhesion of K88-positive Escherichia coli.

Membrane adhesion of K88-positive Escherichia coli was studied on intestinal brush-border membranes on 237 Finnish Landrace pigs. Forty-one per cent of the brush-border membrane preparations aggregated E. coli (positive adhesion). Similar dualism of adherence/nonadherence was observed on sow milk fat globule membranes. Washed milk fat globules (washed cream) can be used as a convenient source of material for adhesion studies. Bacterial adherence on to milk fat globules is evident as agglutination of the globules (dark-field microscopy). By this procedure the sows can be typed according to their receptor phenotype. This simple principle of fat globule agglutination due to receptors for K88-positive E. coli might be complicated by SigA-mediated bacterial adherence. Fat globule membranes were shown to contain SigA, which may act as a mediator of bacterial adherence onto fat globules. The significance of this adhesive property of milk fat globule might be to provide alternative receptors for E. coli thus preventing bacterial adhesion on to gastro-intestinal epithelium of the offspring. Sow milk fat globules can be used for typing E. coli for membrane adhesiveness. The adhesiveness of the strains showed a good correlation with the presence of the K88 antigen, as well as the hydrophobicity of the bacterial strain as determined by an association on Phenyl-Sepharose beads.

Adhesiveness↗