Influence of dental occlusion on oculomotory function-A pilot study.

The aim of this study was to examine the interaction between the oculomotory system and the stomatognathic system based on morphofunctional relationships between the corresponding cranial nerves, their core areas and the reticular formation as a "link" by means of optometric examinations. Test subjects (N = 100) were prospectively recruited and divided into two groups: a young-age (N = 53, age 6-16 years) and old-age group (N = 47, 23-78 years). We determined the horizontal range of convergence and divergence as well as the near convergence point. These optometrically measured parameters were recorded in both groups in the resting position, at maximal mouth opening and with bite-blocking via tin foils (0.5 mm and 1 mm), which were inserted occlusally of the first lower left molar. All oculomotory parameters were significantly altered by bite manipulation and maximal mouth opening. These effects could be observed regardless of age and gender and thus suggest an interaction between eye movement and the orofacial complex. Subjects with asthenopic symptoms showed no different reactions compared to healthy subjects. For a final statement on the correlation between the oculomotory and stomatognathic system, further investigations are necessary. An interdisciplinary cooperation between the different subject areas is recommended for further studies.

Genome-wide association study identifies loci associated with milk leukocyte phenotypes following experimental challenge with Streptococcus uberis.

Mastitis is a detrimental disease in the dairy industry that decreases milk quality and costs upwards of $2 billion annually. Often, mastitis results from bacteria entering the gland through the teat opening. Streptococcus uberis is responsible for a high percentage of subclinical and clinical mastitis. Following an intramammary experimental challenge with S. uberis on Holstein cows (n = 40), milk samples were collected and somatic cell counts (SCC) were determined by the Dairy Herd Improvement Association Laboratory. Traditional genome-wide association studies (GWAS) have utilized test day SCC or SCC lactation averages to identify loci of interest. Our approach utilizes SCC collected following a S. uberis experimental challenge to generate three novel phenotypes: (1) area under the curve (AUC) of SCC for 0-7 days and (2) 0-28 days post-challenge; and (3) when SCC returned to below 200,000 cells/mL post-challenge (< 21 days, 21-28 days, or > 28 days). Polymorphisms were identified using Illumina's BovineSNP50 v2 DNA BeadChip. Associations were tested using Plink software and identified 16 significant (p < 1.0 × 10-4) single-nucleotide polymorphisms (SNPs) across the phenotypes. Most significant SNPs were in genes linked to cell signaling, migration, and apoptosis. Several have been recognized in relation to infectious processes (ATF7, SGK1, and PACRG), but others less so (TRIO, GLRA1, CELSR2, TIAM2, CPE). Further investigation of these genes and their roles in inflammation (e.g., SCC) can provide potential targets that influence resolution of mammary gland infection. Likewise, further investigation of the identified SNP with mastitis and other disease phenotypes can provide greater insight to the potential of these SNP as genetic markers.

Genetic variation in CXCR1 haplotypes linked to severity of Streptococcus uberis infection in an experimental challenge model.

Mastitis, an inflammation of the mammary gland, costs the dairy industry billions of dollars in lost revenues annually. The prevalence and costs associated with mastitis has made genetic selection methods a target for research. Previous research has identified amino acid changes at positions 122, 207, 245, 327, and 332 in the IL8 receptor, CXCR1, that result in three dominant amino acid haplotypes: VWHKH, VWHRR, and AWQRR. We hypothesize different haplotype combinations influence a cow's resistance, strength, and duration of response to mastitis. To test this, Holstein dairy cows (n=40) were intramammarily challenged with Streptococcus uberis within 3 d post-calving. All cows developed mastitis based on isolation of S. uberis from the challenged quarter at least twice. All cows with the VWHRR x VWHRR (n=5) and AWQRR x VWHRR (n=6) haplotype combinations required antibiotic therapy due to clinical signs of mastitis and tended (P=0.08) to be different from cows with a VWHRR x VWHKH (n=6) haplotype combination where only 33.3% required antibiotic therapy. Cows with a VWHRR homozygous haplotype combination displayed significantly higher responses to challenge indicated by elevated S. uberis counts (4340±5,521.9CFU/mL; P=0.01), mammary scores (1.1±0.18; P=0.03), milk scores (0.9±0.17; P=0.002), and SCC (1,010,832±489,993cells/mL; P=0.03). Contrastingly, AWQRR x VWHRR cows had significantly lower S. uberis counts (15.3±16.46CFU/mL; P=0.01), mammary scores (0.3±0.16; P=0.03), milk scores (0±0.15; P=0.002), and SCC (239,261±92,264.3cells/mL; P=0.03). Cows of the VWHKH x VWHRR haplotype combination displayed responses to challenge statistically comparable to other haplotype combinations, but appeared to have an earlier peak in SCC in comparison to all other haplotype combinations. Haplotype combination did not influence milk yield (P=0.6). Our results suggest using combinations of the SNPs within the CXCR1 gene gives a better indication of a cow's ability to combat S. uberis mastitis and could resolve prior studies' conflicting results focusing on individual SNP.

Protective effect of anti-SUAM antibodies on Streptococcus uberis mastitis.

In the present study, the effect of anti-recombinant Streptococcus uberis adhesion molecule (SUAM) antibodies against S. uberis intramammary infections (IMI) was evaluated using a passive protection model. Mammary quarters of healthy cows were infused with S. uberis UT888 opsonized with affinity purified anti-rSUAM antibodies or hyperimmune sera. Non-opsonized S. uberis UT888 were used as a control. Mammary quarters infused with opsonized S. uberis showed mild-to undetectable clinical symptoms of mastitis, lower milk bacterial counts, and less infected mammary quarters as compared to mammary quarters infused with non-opsonized S. uberis. These findings suggest that anti-rSUAM antibodies interfered with infection of mammary gland by S. uberis which might be through preventing adherence to and internalization into mammary gland cells, thus facilitating clearance of S. uberis, reducing colonization, and causing less IMI.