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This paper reports the results of a study that aimed to assess whether liver functionality defined by liver activity index (LAI) is associated with inflammatory and immune parameters in blood and milk. LAI is an index including the average blood levels of albumin, lipoproteins and retinol-binding protein measured three times in the first month of lactation (at 5, 15 and 30 days in milk). The aim was to assess the relationship of this index with blood and udder immune and inflammatory status as a means of identifying as early as possible cows at risk of disease. The research was carried out using 10 multiparous Italian-Friesian dairy cows of average genetic merit. Cows were retrospectively ranked in three groups according the LAI level. Blood samplings were performed at different intervals before and after calving; quarter milk samples were taken only after calving with the same schedule as blood samples. Leucocytes, oxidative burst, blood lysozyme and N-acetyl-beta-d-glucosaminidase (NAGase) curves showed large overlapping among the three LAI group curves during the follow-up period. Four blood (complement, sialic acid, haptoglobin and reactive oxygen metabolites) and three milk (somatic cell count, lysozyme and NAGase) parameters showed larger and more consistent differences among LAI groups. Complement showed higher values and sialic acid showed lower values in high LAI group when compared with the other two LAI groups. Two other markers of inflammatory status (haptoglobin and reactive oxygen metabolites) showed the lowest values in high LAI cows. A consistent and significant reduction of milk NAGase and milk lysozyme in high LAI group was observed. The results suggest that cows with the highest liver functionality index have also the highest levels of some immune markers and the lowest levels for inflammatory markers at blood (already before calving) and mammary levels. Finally, cows with low LAI index, being more susceptible to metabolic and infectious diseases, should be carefully monitored to identify as early as possible the development of a disease.

Staphylococcus aureus is the most common aetiologic agent of contagious bovine mastitis. It is characterized by a wide array of virulence factors. The differences among strains jeopardize the development of effective vaccines against Staph. aureus mastitis. We tested the immunogenicity of a peptide subunit vaccine coding for three different adhesion factors, fibrinogen-binding protein (Efb), fibronectin-binding protein A (FnbpA) and clumping factor A (ClfA). Then we evaluated the influence of some virulence factors on the ability of specific anti-adhesin antibodies to react with sixteen Staph. aureus strains isolated from bovine subclinical mastitis. Immunization with the recombinant adhesins stimulated a strong humoural (IgG and IgA) and mucosal IgA immune response in all animals tested. Hyperimmune serum recognized with diverse efficiency the sixteen Staph. aureus strains and this circumstance correlated well with the level of expression of adhesins. Among the different virulence factors considered to classify strains, spa gene polymorphisms showed the strongest influence on isolate reactions to hyperimmune serum. Our results indicate the importance of a disease- and environment-specific analysis of isolates. Thus, as opposed to other pathogens to obtain an effective vaccine we should characterize multiple strains and identify the prevalent virulence factors expressed.

Cathelicidins are peptide components of the innate immune system of mammals. Apart from exerting a direct antibiotic activity, they can also trigger specific defense responses in the host. Their roles in various pathophysiological conditions have been studied, but there is a lack of published information on their expression and activities in the context of mastitis. The aims of this study were to investigate the expression of the bovine cathelicidins BMAP-27, BMAP-28, Bac5, and indolicidin in healthy and infected mammary tissue and in lipopolysaccharide (LPS)-treated cells, to determine their activities against bacteria isolated from bovine mastitis, and to examine their potentials to trigger defense responses in bovine mammary cells. The genes were found to be upregulated in LPS-stimulated neutrophils, but not in infected quarters or epithelial cells. All peptides showed a variably broad spectrum of activity against 28 bacterial isolates from bovine mastitis (MIC values, 0.5 to 32 microM), some of which were antibiotic resistant. The activity of each peptide was significantly enhanced when it was pairwise tested with the other peptides, reaching the synergy threshold when indolicidin was present. The bactericidal activity was sensitive to milk components; BMAP-27 and -28 were highly effective in mastitic bovine milk and inhibited in milk from healthy cows. Both peptides were also active in whey and in blood serum and triggered the expression of tumor necrosis factor alpha (TNF-alpha) in bovine mammary epithelial cells. Our results indicate multiple roles for the bovine cathelicidins in mastitis, with complementary and mutually enhanced antimicrobial activities against causative pathogens and the capacity to activate host cells.

To investigate the relationships between milk flow traits and udder health status in primiparous cows, 74 primiparous Holstein cows were randomly selected in 5 herds and monitored monthly throughout the whole lactation. A total of 2902 quarter milk samples were collected for bacteriological analyses and the determination of lysozyme, N-acetyl-beta-glucosaminidase (NAGase) and somatic cell count (SCC). Milk flow curves of the whole udder of each cow were registered with continuous electronic milk flow meters. Teat conditions and teat thickness changes during milking were assessed monthly. Quarters, udders and cows were classified as healthy, latent, inflamed and subclinical depending on SCC and the results of bacteriological analyses. Lysozyme in milk, teat apex score and teat thickness change did not vary with udder health status while NAGase in milk significantly increased as udder health status worsened (P<0.001). Milk production (P<0.001) and time of plateau phase (P<0.05) were significantly lower in subclinical cows in comparison with the others. Animals with a high frequency of bimodal curves in the first 100 days in milk showed the worst udder health status during the whole lactation (P<0.01). Moreover, cows classified as subclinical in the first 3 months of lactation had higher peak milk flow than healthy cows (3.81 v. 3.48 kg/min; P<0.05) and shorter duration of plateau phase, expressed both as minutes and as percentage of time of milk flow (pTPL; P<0.001). Multivariate logistic analysis showed udder health status to be associated with duration of plateau phase, time of milk flow, bimodality and duration of overmilking phase. With short time of plateau phase (pTPL <25%), short time of milk flow (<5 min), presence of bimodality and long overmilking phase (>0.8 min) there was an increased risk of poor udder health status. These milk flow traits can be predictive indicators of udder health status; time of plateau phase, expressed as percentage of time of milk flow, can also be a useful parameter for animal selection.

A low-dose treatment based on interleukin-2 (IL-2) was investigated for preventing mastitis in dairy cows. The treatment consisted of a single dose of IL-2 injected into the skin region drained by the supramammary lymph node 3-5 days after calving. The study included 45 cows (23 treated and 22 controls) from three commercial dairy herds. The results showed that the treatment had no side effects. The treatment with IL-2 induced the significant increase of several milk markers related to leukocyte and epithelial cell functions, i.e. SCC (somatic cell counts), serum amyloid A (SAA), lactoferrin and NAGase. The increased concentration of milk markers suggested also an activity of IL-2 on epithelial cells, resulting in a higher resistance to invading pathogens. Indeed, the increased efficiency of cells in the udder is supported by the higher frequency of healthy quarters observed in the treated group until day 17-19 after calving, in comparison with the control one.

The causative agents of avian mycobacteriosis in pet birds are rarely identified. The aim of this study is to add information about the etiology of avian mycobacteriosis. The identification of mycobacterium species in 27 cases of avian mycobacteriosis in pet birds was investigated by polymerase chain reaction (PCR) and sequencing of a rRNA hypervariable region. Avian mycobacteriosis appeared to be an infrequent diagnosis. Interestingly, a few cases of avian mycobacteriosis were recorded in very young birds. The most commonly affected species were the canary (Serinus canarius), the Eurasian goldfinch (Carduelis carduelis) and the red siskin (Spinus cucullatus). All but one bird were infected with Mycobacterium genavense. Mycobacterium avium was identified only in one case.

Knowledge of the epidemiological pattern and the potential sources of infections is important to control Staphylococcus aureus in dairy herds. This paper reports the results of a study applying both pulse field gel electrophoresis (PGFE) and the assessment of a selected number of virulence genes to investigate the role of teat skin on Staph. aureus transmission among cows and on the contamination of milk. Overall 61 isolates were considered, 23 from teat skin, 33 from milk samples and 5 from curd samples. Teat swabs were taken in five herds, but in only three of them could Staph. aureus be isolated. Curd was sampled in three herds, but Staph. aureus could be isolated in only two herds. The distribution of isolates among herds confirmed the presence of herd-specific Staph. aureus strain in most of the herds. The same pattern was observed in teat skin samples, in quarter milk samples, and in the curd samples. Our findings are consistent with other studies showing the role of teat skin as a potential reservoir. Moreover, Staph. aureus was isolated from teat skin of confirmed Staph. aureus-negative cows that were segregated from infected ones. Our findings also suggest that some strains have higher chances to survive on teat skin and therefore to increase the risk for contamination of milk and milk products due to the persistence of intramammary infections.

To support a voluntary disease control program, this study aimed to develop an integrated scoring system for the risk assessment of bovine viral diarrhoea virus (BVDV) infection in dairy herds in Northern Italy. Sixty-two dairy herds were classified according to their BVDV serological status. Farmers were interviewed using a questionnaire on potential BVDV risk factors. Scores were used to define risk levels for factors related to (1) BVDV introduction (through livestock trade, attendance of animals at shows/exhibitions and grazing common pasture), (2) within-herd spread of BVDV and (3) the results of initial serological testing. The calculated odds ratios were significant for all categories, except for livestock trade. The application of the screening test, the questionnaire and the related risk assessment showed this to be a practical approach to predicting BVDV herd status.

Introduction: Naphthalene, the most volatile polycyclic aromatic hydrocarbon (PAH), was recently classified as possible human carcinogen by International Agencies for Research on Cancer Humans may be exposed to naphthalene from a wide variety of sources, including occupation, environment, personal habits. We assessed urinary excretion of 1-naphthol (1-NAF), biomarker of naphthalene exposure, in non-occupationally exposed subjects., Materials and Methods: Urinary 1-NAF, 1-hydroxypyrene (1-OHP), biomarker of exposure to pyrene and cotinine, biomarker of smoking habits, were measured in 104 adults (53 men, 51 women)., Results: 1-NAF concentrations overlapped in males and females (median: men 0.35 Microg/g creat; women: 0.46 microg/g creat). Median concentration of 1-NAF was 6-fold higher in smokers compared to nonsmokers (respectively, 7.7 microg/g creatinine vs 1.3 microg/g creatinine). Between smokers, urinary cotinine was positively correlated to 1-naphthol (rho: 0.69; p < 0.01) and 1-OHP (rho: 0.53; p < 0.01). Higher 1-OHP concentrations were found in smokers (median: smokers 0.16 microg/g creatinine, not-smokers 0.05 microg/g creatinine;)., Conclusions: In our study population, we found that 1-NAF excretion is much higher as compared to 1-OHP excretion. This is due to the ubiquitous presence of naphthalene in the environment. Smoking considerably increase the exposure to naftalene.

Unlabelled: Chronic inflammation and reactive oxygen species (ROS) production induced by crystalline silica are involved in the development of silicosis and lung cancer pathogenesis. ROS can generate lipid peroxydation of cell membranes that can produce methylglyoxal (MG), a strong cell proliferation inhibitor and apoptosis inducer. MG is naturally removed by glyoxalase I (GI) and glyoxalase II (GII) through a glutathione (GSH) dependent mechanism. Therefore mRNA expression of glyoxalases is correlated to MG concentration and oxidative stress., Objectives: evaluate oxidative stress induced by crystalline silica by glyoxalases mRNA expression and methylglyoxal concentration, Material and Methods: In bronchial epithelial cell culture (BEAS-2B), exposed to 50 microg/cm2 crystalline silica (Min-U-Sil 5), for 2, 6, 12, and 24 hours, GI and GII mRNA levels and MG intracellular concentration were measured respectively by Real-Time PCR and HPLC., Results: Crystalline silica exposure induced a significant reduction in mRNA expression of glyoxalases and an increase of MG intracellular concentration., Conclusions: The results suggest a possible use of MG and mRNA expression of GI and GII as crystalline silica induced oxidative stress indicators.

Several milk components related to immune defences (lysozyme, lactoferrin and gamma-globulins, gamma-G) and to inflammation (somatic cell counts, SCC; N-acetyl-beta-glucosaminidase, NAGase; albumin) were considered. Forty-one quarters and 685 samples of 24 cows were included in the study; among them 534 samples were defined as negative (78.0%), 93 as diseased (13.5%) and 58 (8.5%) as subclinical. The pattern of each milk component in quarters always negative during the follow-up period was evaluated by a mixed model. Statistical analysis showed that days in milk (DIM), age (primiparous, pluriparous), herd and the interaction between herd and days in milk significantly influenced all the markers, with very few exceptions. A subset of samples including the negative quarters before the first outcome of an infection or a subclinical mastitis and the samples from quarters always negative was also selected. The analysis showed that herd, DIM and health status had a significant influence on most markers. Overall, primiparous cows were confirmed to have higher levels of most of the markers than pluriparous cows. The presence of a herd effect on non specific immune defences in fully negative quarters implies that when the mechanisms behind their release are fully elucidated, it might be possible to modulate them. Udder tissues were confirmed as an important source of some immune components, as supported by the inconsistency between SCC mean values and NAGase, lysozyme and lactoferrin values. Overall, quarters with high levels of NAGase, lysozyme and gamma-G, exposed to bacteria, did not develop subclinical mastitis. Hence, invading pathogens could induce the development of subclinical IMI when these components and gammaG are in low concentration.

Staphylococcus aureus causes different pathologies in humans and animals. In particular, it is involved in intramammary infections in cows, causing economic losses and milk-safety problems. Although it is well-known that surface components (proteins and capsular polysaccharides) and exotoxins are virulence factors involved in the pathogenesis of bovine mastitis, less is known about the precise biochemical identity of such molecules. Therefore, mapping of surface proteins using specific disease- and environment-isolates provides a benchmark for strain comparison of pathogens with different pathogenic characteristics and antibiotic resistance mechanism and can aid in defining specific vaccine and therapeutic targets. In this study, we used a proteomic approach on protein extracts of lysostaphin-treated S. aureus in isotonic conditions, to produce a reproducible and well resolved 2-D electrophoresis (2-DE) reference map of surface associated proteins of isolated S. aureus from a case of bovine mastitis. The most abundant protein components were identified by Matrix assisted laser desorption ionisation-time of flight (MALDI-TOF) mass spectrometry.

Staphylococcus aureus is the most common etiologic agent of mastitis in bovines and a major cause of economic losses in the dairy industry. Since adhesins, that anchor bacteria to the extracellular matrix (ECM), are among the most important S. aureus virulence factors, we used four adhesion factors (fibrinogen binding protein, fibronectin binding protein A, clumping factor A and collagen adhesin) as target in a DNA vaccine. Intranasal immunization with a pDNA mixture coding the four adhesins, triggered significant levels of specific serum and mucosal Ig that inhibited S. aureus adhesion to cow mammary gland epithelial cells in vitro. Splenocytes of immunized mice challenged in vitro with S. aureus extracts showed a strong proliferative response. Finally, immunized mice were significantly protected against intramammary challenge with S. aureus. Our data confirm the feasibility of a genetic mucosal vaccine targeting S. aureus adhesins and prompt further study to test the efficacy in preventing cow mastitis.

High somatic cell count (SCC) affects milk quality and cheesemaking, resulting in a reduction in cheese yield and quality. In dairy cows, quarter milk samples with > 200,000 cells/ml are considered to have subclinical mastitis, while there is much uncertainty on the corresponding levels of SCC in buffalo milk. In this study 30 lactating water buffaloes were selected and SCC, differential somatic cell counts and several whey components were tested in quarter milk samples to assess the relationship between inflammation markers and milk quality. Overall 236 quarter milk samples were considered. To evaluate the relationship between cellular markers (SCC, polymorphonuclear leucocytes, PMN, and N-Acetyl-beta-glucosaminidase, NAGase) and other milk components, three classes were defined (low, medium and high). Analysis of milk yield showed a significant reduction in the high class of each of the three markers chosen. Overall, the highest class was characterized by significant changes in milk composition and a lower milk quality. The presence of an inflammatory status of the udder was frequent after the first trimester of lactation and in buffaloes with two or more parturitions. This study showed that significant changes in milk components can be observed when SCC are > 400,000 cells/ml, PMN are > 50% and NAGase is > 100 units. These thresholds could be suggested as levels to define udder health status in buffalo cows.

Staphylococcus aureus causes many serious diseases in humans and animals, and it is the most common aetiologic agent of contagious bovine mastitis. The bacteria produce several virulence factors and the importance of evaluating the combination of these virulence factors has been recently emphasized. In study, the combination of several virulence factors: coagulase gene (coa), protein A gene (spa), collagen-binding protein gene (cna), fibrinogen-binding protein gene (efb), Panton-Valentin leukocydin gene (pvl) and enterotoxins (sea,seb, sec, sed, see, seg, seh, sei, sej) was considered. The analysis of the relationship between presence/absence of the different genes and the udder inflammatory response measured by milk somatic cell counts was performed by general linear models and logistic regression. The classification of isolates in clusters by virulence genes combinations showed that at least one cluster induced a higher inflammatory response. Moreover, the analysis of the association between virulence genes and the presence of a subclinical mastitis showed the role of spa and sej gene as risk factors. These results support that the development of subclinical mastitis could be related to strains characteristics and to the expression of specific combinations of the virulence factors.

Several data from different authors show that Bovine virus diarrhoea virus (BVDV) could be a key component in multiple-etiology diseases, indeed a lower leukocytes number and their impaired functions decrease the resistance to infections. However, most of the information on the impairment of immune function during BVDV infections arise from circumstantial evidence and from experimental infection studies, and few from field data. To assess the effects of BVDV on blood cells parameters, cellular and humoral functions under field conditions, we designed a controlled study in commercial dairy herds, comparing persistent infected (PI) and healthy heifers. A total of 45 heifers were considered, the PI animals were nine, the control animals were 34, while two controls were considered as acute infected animals. The comparison of the mean values in PI calves showed a significant decrease for leukocytes and granulocytes, while platelets showed a significant increase, when compared with control animals. The total number of lymphocytes decreased not significantly in PI animals, while the proportion significantly increased. The number and proportion of monocytes was significantly reduced in PI animals, when compared with controls. The data collected on markers of cellular immunity during our study cannot be compared with the literature because there are no reference values. The presence of a persistent infection affected the cellular enzymes: NAGase, lysozyme and respiratory burst showed a large statistically significant decrease in PI animals when compared with controls. The presence of a persistent infection with BVD virus influenced blood cells number and impaired some blood cell functions. Such impairment confirms that PI animals represent a threat to the herd not only because they could spread BVDV, but also because they are more susceptible to other infectious diseases.

A practical protocol to study udder immune status in field conditions was planned with the aim to assess different non-specific immune parameters in milk samples from dairy heifers during the periparturient period. Five herds located in northern Italy were selected and overall 39 heifers were enrolled in the trial. Milk samples were taken at 7, 14, 21, 28, 45, 60, and 75 days after calving. The parameters assessed were N-acetyl-beta-glucosaminidase (NAGase), lysozyme, respiratory burst (RB), somatic cell counts (SCC) and serum protein profile. SCC and NAGase were higher in the first sampling after calving, while lysozyme showed large variations during the observation period without a definite trend. The levels of RB observed in the first two weeks after calving, even if lower, were not statistically different from the values observed in samples taken over the following weeks. This study confirmed that the levels of immune components in milk are different from what is observed at blood level in the same cow. A significant decrease in RB in milk polymorphonuclear leukocytes (PMN) post-calving was not observed; milk PMN from healthy cows showed low RB levels, while the values from infected quarters were significantly higher. Significant differences between healthy and infected animals were also observed for milk NAG, lactoglobulin and albumin. These data suggest that udder immune response could be influenced both by the cow immune status and by external factors such as pathogens and management. Therefore, the reduction in immune defences, particularly in heifers, is not unavoidable and methods to boost PMN activity should be explored.

Different protocols to evaluate teat skin status under field conditions based on scoring and on the measurement of pH and hydration of teat skin were evaluated. After determination of the teat score for all eligible animals in a commercial dairy herd, 50 of them were chosen, based on their pre-trial average teat score, and separated in two groups. Two different post-dipping products with the same amount of disinfectant, but with a different concentration of emollient were applied. All four teats were assessed with the corneometer and pH probes. A digital picture of each teat skin and teat orifice was taken with a digital camera. Hydration and pH data were analysed by anova with repeated-measurement factors, while teat skin and apex score patterns, were assessed by the means of Mann-Whitney test; between- and within-group changes were assessed by the mean of Mantel-Haenzel chi-square statistic. Data showed that teat skin pH and hydration could be assessed under field conditions and they were influenced by teat conditioning. The approach based on evaluating odds for scores, stratified for sampling and for treatment, was found to be a sensitive and informative way to compare the changes between and within treatment groups.

Staphylococcus aureus isolates produce several pathogenic factors. The combination of these products influences the pathogenic role of different isolates, but their specific effects are well known in the pathogenesis of udder infections. This study focused on the association of polymorphism of the coagulase gene, protein A gene, collagen-binding protein gene, and of fibrinogen-binding protein gene on somatic cell count (SCC) and on Staph. aureus growth rate. Fifty Staph. aureus isolates from 13 dairy cow herds, located in seven different provinces, were considered. The results showed a low frequency of cna gene, similar to the one observed in human isolates. Meanwhile, the high frequency of efb gene indirectly confirmed the role of this factor in bacterial pathogenesis, being associated with adhesion to epithelia. The association of these two single genes with SCC and growth rate showed to be not significant. The polymorphism of spa gene was confirmed to be significantly associated with inflammatory response and growth rate, albeit with a pattern different from the one suggested for human isolates. Sorting of isolates based on the clusters obtained by combining polymorphisms of spa and coa genes and the presence of cna and efb genes, showed that a single cluster (cluster V) was prevalent in the different herds and provinces, while the other six clusters identified were widely spread among the remaining 60% of the isolates. Results showed that clusters VI and VII had significantly higher growth rates at 3, 4, and 6 h in comparison with the other clusters. Meanwhile, quarters infected with these strains showed significantly lower SCC levels. The frequency of isolates from cluster V, suggested that they should possess pathogenic factors increasing their invasiveness, even if in the presence of a stronger inflammatory response. These results indirectly confirm previous findings on the different interactions between isolates and the udder immune system. They also suggest that isolates with higher growth rates and inducing a lower inflammatory response have better chances to spread among the herd. The relatively simple genomic method proposed in this study could be applied by an increasing number of diagnostic laboratories and could be useful in studying the epidemiology of Staph. aureus intra-mammary infections in dairy herds when collecting data from the field.

During the periparturient period, some impairment of immune defences were observed. Reference values for the different non-specific immune parameters in cows are not generally available, thus limiting the application of these parameters in dairy practice. This paper reports the data on the measurements of different parameters in the blood, and explores the possible influence of the herd on the non-specific immune status of the cow. Five herds located in Northern Italy were selected and overall 39 heifers were enrolled in the trial. Blood samples were taken 14 and 7 days before the expected date of calving, then at 7, 14, 21, 28, 45, 60, and 75 days after calving. The parameters assessed were N-acetyl-beta-glucosaminidase (NAGase), lysozyme, nitric oxide, superoxide dismutase, haptoglobin, respiratory burst, and serum protein profile. After calving, a significant decrease of respiratory burst and nitric oxide concentration were observed in comparison with the pre-calving values but not with the post-calving samplings. Total proteins, beta- and gamma-globulins showed a progressive and significant increase in concentration after calving, in comparison with pre-calving values. The results of the study confirmed that a decrease of immune functions can be observed in commercial dairy herds in the first four weeks after calving. The amplitude of this phenomenon is not common to all animals and all herds, suggesting the possibility to reduce the impairment by improved management and genetic selection.

Objective: To determine the epidemiologic pattern of intramammary infections (IMIs) with Staphylococcus aureus during implementation of a control program in 9 commercial dairy herds., Design: Cohort study., Animals: 1,651 lactating cows and 53,098 quarter milk samples., Procedures: Nine herds located in different regions of Italy were enrolled. Control of S. aureus infections followed the general principles of contagious mastitis control and was based on precise diagnostic procedures and strict control and segregation of infected cows. All lactating cows in each herd were tested, and those free of S. aureus IMI were enrolled as the cohorts. Further additions to the cohort group were cows and heifers free of S. aureus IMI, as determined from aseptically collected milk samples taken approximately 7 and 14 days after calving., Results: After the ninth month of the program, incidence decreased to < 2 new IMIs/100 cow-months in 7 of the herds. At the end of the study, 8 of 9 herds had an incidence of < or = 1 new IMI/100 cow-months. Heifers were most at risk of developing an IMI., Conclusions and Clinical Relevance: Results suggest that control of S. aureus IMIs can be achieved by use of a control program based on segregation and use of hygienic and therapeutic protocols. Analysis of incidence and identification of risk factors in a herd could avoid the possible shortcomings of the program, maximizing the probability of success.

The teat is the main entrance for pathogens into the mammary gland. It also acts as a sensory, motor and primary defence organ. This latter function is important in preventing intramammary infections while efficiency in preventing new infections is determined by teat tissue integrity. Machine milking may evoke mechanical and circulatory impairment in teat tissues. These local metabolic disorders may decrease the efficiency of the local immune defence mechanisms. Teat tissue changes can be estimated by measuring teat thickness before and after milking. Experimental and field studies showed a high correlation between changes in thickness and infection risk. Teats with > 5% change in thickness have significantly increased teat duct colonisation rates and intramammary infection rates. The link between changes in teat thickness and infections should be found in changes in local immune defences and measurable changes in cytological and biochemical immune factors are expected. Indeed, the application of experimental milking conditions (i.e. no pulsation milking and positive pressure milking) showed to have a significant influence on some non specific immune factors in teat secretion. Positive pressure milking increases PMNs content and decreases macrophages content of teat secretion. Some enzymes such as NAGase and lysozyme were decreased by positive pressure milking, the concentration of the same enzymes were higher after no pulsation milking. A better knowledge on the interaction between the teat apex immune defense mechanisms and the machine milking process is necessary to reduce the new infection rate of the bovine mammary gland.

The distribution of Staphylococcus aureus within herds seems to be related to interactions among the shedding characteristics of the bacteria, their pathogenicity and mammary gland immune status. The aim of the present study was to investigate the relationships between selected mammary gland immune factors and intramammary infections associated with Staph. aureus. Overall, 70 cows from five commercial dairy herds were included in the study and quarter milk samples were assessed using bacteriological and cytological tests. We evaluated differential cell count, lysozyme concentration, N-acetyl-beta-glucosaminidase (NAGase) activity, cell viability and respiratory burst activity in randomly chosen quarter milk samples from each cow. Staph. aureus intramammary infection elicited different responses in the mammary gland immune defences investigated. Polymorphonuclear leucocytes (PMN) as a proportion of total somatic cells in milk, cell viability and NAGase activity were higher in infected quarters, while the proportions of macrophages and lymphocytes, respiratory burst activity and lysozyme levels were lower. Mean values differed among herds, but the differences were not significant. These changes were associated with Staph. aureus infection. The reduced respiratory burst activity together with the increase in the proportion of PMN suggests that both the number and activity of PMN could influence the susceptibility of the mammary gland to pathogens. Indeed, the logistic model adopted suggests that impairment of milk immune factors could be concurrent with the development of an infection.

The aims of this study were (a) to assess blood cadmium (B-Cd) concentrations and to establish a tentative reference interval; (b) to identify significant determinants of B-Cd, in a population from Umbria, Central Italy, which was not occupationally exposed to cadmium (Cd). Four hundred and thirty-four healthy blood-donors volunteered to answer a questionnaire and provide a blood sample for B-Cd analysis, which was performed by graphite furnace atomic absorption spectrophotometry. Blood Cd concentrations ranged from non-detectable values, i.e. below 0.1 microgram/l up to 3.4 micrograms/l and were not normally distributed. The median values and the 95th percentiles were 0.7 and 2.0 micrograms/l, respectively. Concentrations of B-Cd were more than double in smokers than in non-smokers, median values being 1.1 micrograms/l and 0.5 microgram/l, respectively. In current smokers, B-Cd values correlated with the number of cigarettes smoked daily (rs = 0.40, P = 0.0001) and with the cumulative exposure to cigarette smoke (rs = 0.35, P = 0.0001). Concentrations of B-Cd correlated with age in the non-smokers, but not in the smokers and were significantly higher in women than in men only in the non-smokers. Both in smokers and non-smokers, B-Cd concentrations were similar in subjects living in urban or in rural areas. In the whole study population the lower and the upper tentative reference limit were < 0.1 and 2.2 micrograms/l, respectively, as computed by a non-parametric rank-based method. The upper limit was approximately double in smokers than in non-smokers (3.1 micrograms/l and 1.6 micrograms/l, respectively). Our results show that B-Cd concentrations in a general population from Umbria are in the range reported for general populations in Northern Italy and other European Countries. Smoking was the strongest determinant of B-Cd concentrations and age had a lesser effect.

This report assessed lead absorption in community samples of the general population in Umbria, central Italy, in 1982 and in 1992. Each participant (128 subjects in 1982 and 479 in 1992) answered a questionnaire providing details of personal information and life style. Blood lead levels were determined by atomic absorption spectrophotometry. In 1992 hematocrit and glutamyltranspeptidase (gamma-GT) levels were also measured. In 1982 the mean blood lead level was 226 micrograms/l in males and 167 micrograms/l in females, and in 1992 it was still higher in males than in females (98 micrograms/l vs 61 micrograms/l) as were hematocrit and gamma-GT levels. Multiple regression analysis showed sex and age were the main factors accounting for 42% of the total variation in blood lead levels. They were followed by alcohol consumption, gamma-GT levels and smoking in this order. In conclusion, blood lead levels decreased significantly in central Italy in the decade 1982-92 and persistent lead absorption seems to be due to individual characteristics such as male sex, advanced age and a personal life style which includes alcohol consumption and smoking.

Objectives: The paper describes the results of a polycentric study for the assessment of reference values of urinary chromium (U-Cr) in the Italian population., Method: A total of 890 subjects (58.3% males and 41.7% females) were selected on the basis of standardized criteria in eight different areas of Italy. Urinary chromium was determined on morning spot samples collected using standardized procedures. The U-Cr was determined independently by three laboratories using an Electrothermic atomization-Atomic Absorption Spectrometry (ETA-AAS) method with a detection limit of 0.05 microgram/l, adopting-for the statistical analysis-the median value of the results of the three laboratories. The between-laboratories within-subjects standard deviation was 0.049 microgram/l. Due to the high proportion (approx, 28%) of undetectable chromium levels, the geometric mean (GM) and geometric standard deviation (GSD) were estimated using a procedure of linear interpolation. The analysis of the effects of some variables (sex, age, center, residence, smoking and drinking habits) on the U-Cr values, was also performed, by multiple regression analysis after logarithmic transformation, using GM and SD., Results: The reference value of U-Cr was of 0.08 microgram/l as an estimated GM, whereas the expected distribution ranged from not detectable (nd) (95% CI = nd-0.06) to 0.24 microgram/l (95th percentile; 95% CI = 0.20-0.31). Among the variables studied, only geographical area and sex significantly influenced the U-Cr levels. In subjects selected in the provinces of Bari and Venice values of U-Cr were significantly lower than those determined in subjects residing in other areas., Conclusions: From our investigation the reference values for U-Cr were lower than those obtained in previous investigations. In addition it confirms a further reduction in U-Cr levels following the previous decline reported in the 1970s and 1980s. In over 20 years U-Cr values in the general population dropped from values greater than 1 microgram/l to values between 0.5 and 0.2 microgram/l. The reasons of this progressive decline cannot be attributed in our opinion to a reduced intake of the metal, but mainly to the improvement in analytical instrumentation and methods. A further decrease may be ascribed to a more accurate definition of the reference groups and to a better control of pre-analytical factors. Considering that the reference values for U-Cr are much lower than those determined some decades ago, toxicological studies in order to verify the significance of biological limit values currently suggested for chromium seem to be necessary.

The aim of this study was to describe the results of teat thickness measurement applied routinely in three commercial dairy herds and to evaluate the influence of machine-induced teat thickness changes on intramammary infection and the frequency of new infection. A total of 1018 fore milk samples and the same number of teat apex measurements have been evaluated. Overall, relative teat thickness changes were normally distributed (mean -0.16%, SD 10.15%), while a specific pattern could be observed within herds. Increases in teat thickness of > 5% were significantly associated with infection and new infection (odds ratio > 1), but the association was not significant when teat thickness decreased by more than 5%. When results were classified according to aetiology, analysis showed that coagulase-negative staphylococcal infections were significantly associated with both increases and decreases in teat thickness numerically greater than 5%.

Changes in time course of blood partial pressures of oxygen (PtcO2) and carbon dioxide (PtcCO2) before, during and after challenge with ultrasonically nebulized distilled water (UNDW) were evaluated in 22 children with mild asthma in basal conditions, and after 8 weeks of therapy with inhaled nedocromil sodium at a daily dosage of 8 or 16 mg. PtcO2 and PtcCO2 were followed using transcutaneous O2 and CO2 monitoring system. All asthmatic subjects presented a significant decrease in PtcO2 and/or PtcCO2 (> 20% basal value) during or after challenge. After therapy, the decrease in PtcO2 and PtcCO2 was normalized in the group treated with 16 mg/day, whereas only a partial yet significant reduction in the decrease of O2 and CO2 was observed in the group assuming 8 mg/-day. These data indicate that inhaled nedocromil is effective in treating bronchial hyperresponsiveness in childhood and that the dose required to achieve this effect is of 16 mg/day.

Two different investigations were conducted on the chemiluminescent activity of bovine milk polymorphonuclear neutrophil leucocytes (PMN) activated by different stimuli: zymosan, derived from the wall of Saccharomyces cerevisiae (Experiment A), and Streptococcus uberis and Escherichia coli (Experiment B). In Experiment A, a quarter with a phagocytic activity of PMN < 20 mV/1000 PMN following stimulation with zymosan was found to be 23 times more likely to be a clinical mastitis case than a quarter with phagocytic activity above this threshold value. In Experiment B, calculation of the odds ratio showed similar results following stimulation with Str. uberis or Esch. coli. These results provide evidence that immunocompromisation of mammary gland defences could predispose to clinical mastitis. They also support the need to challenge phagocytic cells with appropriate stimuli, and the Esch. coli test seems to be the most sensitive.

A study was carried out on 65 male workers heavily exposed to lead in the ceramic tile manufacturing industry in order to assess the effects of alcohol on the biological indicators of lead (PbB, ALA-D, ALA-U, ZPP). All subjects selected for the study had PbB levels greater than or equal to 60 micrograms/dl, normal levels of serum iron and no haemoglobin disorders. The subjects were divided into three groups according to alcohol intake checked by anamnestic investigation, mean corpuscular volume (MCV) values and liver function parameters, as follows: Group A--27 subjects, controls, with daily alcohol intake less than 80 ml, MCV less than or equal to 95 mu 3, normal GGT, AST and ALT levels; Group B--20 subjects, heavy drinkers, with daily alcohol intake greater than or equal to 80 ml, MCV greater than 95 mu 3, occasionally high GGT, but normal AST and ALT values; Group C--18 subjects, heavy drinkers, with daily alcohol intake greater than or equal to 80 ml, MCV greater than 95 mu 3, abnormal GGT, AST and ALT levels. The length of lead exposure did not significantly differ in the three groups. The well-known effects of ethanol intake on PbB, ALA-D and ALA-U values were confirmed, with the following mean values in the three groups: Group A: PbB = 66.0 (micrograms/dl), ALA-D = 10.3 (mU/ml r.c.), ALA-U = 8.4 (mg/l); Group B: PbB = 68.3 (micrograms/dl), ALA-D = 6.7 (mU/ml r.c.), ALA-U = 9.1 (mg/l); Group C: PbB = 71.5 (micrograms/dl), ALA-D = 4.6 (mU/ml r.c.), ALA-U = 12.7 (mg/l).(ABSTRACT TRUNCATED AT 250 WORDS)

Some authors found higher lead levels in children whose parents are occupationally exposed to the metal, which is probably carried home with dirty work clothes. In order to verify the relevance of the risk in tile-workers' children we examined 3 groups of 5-7 years old children whose parents were: a) tile workers employed in lead areas; b) tile workers not employed in lead areas; c) workers not occupationally exposed to lead (control group). We found that lead workers children had PbB and PbH significantly higher than control children although all PbB values were lower than 30 micrograms/dl. Nevertheless this observation suggests that major attention must be paid to individual preventive measures, such as the change of work clothes and good personal hygiene after every work shift.