Performance evaluation of a rapid immunochromatographic test kit in detecting bovine mastitis-causing streptococci.

Mastitis causes significant economic losses to the dairy industry due to decreased milk production in infected cows. Identification of mastitis-causing pathogens, such as streptococci, is necessary for selecting an effective antibiotic for treating mastitis. Although bacterial cultivation is widely used for pathogen identification, it requires more than 24 hr to complete. Contrarily, Lateral flow assays are simple, rapid, and inexpensive testing procedures. In this study, the effectiveness of an immunochromatographic test kit for detecting streptococci in milk samples from cows with clinical mastitis was evaluated as an alternative to bacterial cultivation. The performance of the immunochromatographic test kit for detecting mastitis-causing pathogens was compared with that of bacterial cultivation and real-time quantitative polymerase chain reaction (qPCR). The sensitivity and specificity of the immunochromatographic test kit were 0.800 and 0.875, respectively, compared with bacterial cultivation. Additionally, the κ statistic values of the immunochromatographic test kit was 0.667, indicating substantial agreement with the results of bacterial cultivation. Statistically, sensitivity and specificity of the immunochromatographic kit and real-time qPCR did not differ significantly; thus, the immunochromatographic test kit detected mastitis-causing streptococci as effectively as real-time qPCR. Therefore, the immunochromatographic kit is a rapid, inexpensive, and simple method for detecting streptococci and contributes to the timely selection of appropriate antibiotics for treatment and promotes early recovery from mastitis.

A novel vaccine strategy using quick and easy conversion of bacterial pathogens to unnatural amino acid-auxotrophic suicide derivatives.

We propose a novel strategy for quick and easy preparation of suicide live vaccine candidates against bacterial pathogens. This method requires only the transformation of one or more plasmids carrying genes encoding for two types of biological devices, an unnatural amino acid (uAA) incorporation system and toxin-antitoxin systems in which translation of the antitoxins requires the uAA incorporation. Escherichia coli BL21-AI laboratory strains carrying the plasmids were viable in the presence of the uAA, whereas the free toxins killed these strains after the removal of the uAA. The survival time after uAA removal could be controlled by the choice of the uAA incorporation system and toxin-antitoxin systems. Multilayered toxin-antitoxin systems suppressed escape frequency to less than 1 escape per 109 generations in the best case. This conditional suicide system also worked in Salmonella enterica and E. coli clinical isolates. The S. enterica vaccine strains were attenuated with a >105 fold lethal dose. Serum IgG response and protection against the parental pathogenic strain were confirmed. In addition, the live E. coli vaccine strain was significantly more immunogenic and provided greater protection than a formalin-inactivated vaccine. The live E. coli vaccine was not detected after inoculation, presumably because the uAA is not present in the host animals or the natural environment. These results suggest that this strategy provides a novel way to rapidly produce safe and highly immunogenic live bacterial vaccine candidates. IMPORTANCE: Live vaccines are the oldest vaccines with a history of more than 200 years. Due to their strong immunogenicity, live vaccines are still an important category of vaccines today. However, the development of live vaccines has been challenging due to the difficulties in achieving a balance between safety and immunogenicity. In recent decades, the frequent emergence of various new and old pathogens at risk of causing pandemics has highlighted the need for rapid vaccine development processes. We have pioneered the use of uAAs to control gene expression and to conditionally kill host bacteria as a biological containment system. This report proposes a quick and easy conversion of bacterial pathogens into live vaccine candidates using this containment system. The balance between safety and immunogenicity can be modulated by the selection of the genetic devices used. Moreover, the uAA-auxotrophy can prevent the vaccine from infecting other individuals or establishing the environment.

Bovine neutrophils stimulated with Streptococcus uberis induce neutrophil extracellular traps, and cause cytotoxicity and transcriptional upregulation of inflammatory cytokine genes in bovine mammary epithelial cells.

This study aimed to understand the response of neutrophils stimulated by Streptococcus uberis, a major cause of mastitis. It was found that the production of neutrophil extracellular traps (NETs) was induced in milk clots from mastitic milk produced by S. uberis-infected bovine udders. The release of NETs from neutrophils stimulated by S. uberis was investigated. Bovine neutrophils cocultured with S. uberis in vitro released the components of NETs, which contained extracellular DNA and elastase. Bovine mammary epithelial cells (BMECs) incubated in coculture supernatants containing components of NETs, caused cytotoxicity and transcriptional upregulation of inflammatory cytokines, including of interleukin (IL) -1ß, tumor necrosis factor (TNF)-α, IL-6, and IL-8, in BMECs. These findings suggest that bovine neutrophils stimulated by S. uberis induce responses that cause exacerbated inflammation, such as NET formation, cytotoxicity against BMECs, and increased production of inflammatory cytokines. Bovine neutrophil responses stimulated by S. uberis could be involved in the progression of S. uberis-induced mastitis.

Estimation of silent phenotypes of calf antibiotic dysbiosis.

Reducing antibiotic usage among livestock animals to prevent antimicrobial resistance has become an urgent issue worldwide. This study evaluated the effects of administering chlortetracycline (CTC), a versatile antibacterial agent, on the performance, blood components, fecal microbiota, and organic acid concentrations of calves. Japanese Black calves were fed with milk replacers containing CTC at 10 g/kg (CON group) or 0 g/kg (EXP group). Growth performance was not affected by CTC administration. However, CTC administration altered the correlation between fecal organic acids and bacterial genera. Machine learning (ML) methods such as association analysis, linear discriminant analysis, and energy landscape analysis revealed that CTC administration affected populations of various types of fecal bacteria. Interestingly, the abundance of several methane-producing bacteria at 60 days of age was high in the CON group, and the abundance of Lachnospiraceae, a butyrate-producing bacterium, was high in the EXP group. Furthermore, statistical causal inference based on ML data estimated that CTC treatment affected the entire intestinal environment, potentially suppressing butyrate production, which may be attributed to methanogens in feces. Thus, these observations highlight the multiple harmful impacts of antibiotics on the intestinal health of calves and the potential production of greenhouse gases by calves.

Evaluation of a rapid coliform detection kit from clinical mastitis milk using colloidal gold nanoparticle-based immunochromatographic strips.

The accurate identification of mastitis-causing bacteria assists in effective management by both dairy farmers and veterinarians and can be used to implement the selective use of antimicrobials for treatment. The purpose of this study was to evaluate the ability of our developed anti-ribosomal protein-L7/L12 antibody-coated immunochromatographic strip (ICS) test to detect coliforms in milk by comparing the results with the bacteriological culture method. We investigated the performance of the ICS test as compared with the bacteriological culture method using 308 milk samples from clinical bovine mastitis. First, to determine the optimal ICS test cutoff point for detecting coliform mastitis, we developed a receiver-operating characteristic curve. The result showed that the cutoff point was at 0.5 of our index. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value of the ICS test were 81.3%, 84.8%, 69.2%, and 91.54%, respectively. As the clinical signs increased in severity, the F-measure, a weighted harmonic mean of the sensitivity and overall PPV performance, increased. Because it is especially important to treat clinical mastitis appropriately in the early stages of detection, the ICS test, which can be used by both dairy farmers and veterinarians on dairy farms, is considered to be a useful tool for detecting coliform mastitis, which often presents with severe signs.

Intramammary infection caused by Staphylococcus aureus increases IgA antibodies to iron-regulated surface determinant-A, -B, and -H in bovine milk.

The aim of this study was to identify virulence factors that have high immunogenicity. An in vivo-expressed Staphylococcus aureus antigen was identified by probing bacteriophage expression libraries of S. aureus with antibodies in bovine mastitis milk. Eighteen clones were isolated, and their proteins were identified as 5 characterised proteins (IsdA, Protein A, IsdB, autolysin, and imidazole glycerol phosphate dehydratase) and 13 hypothetical proteins. We focused on IsdA, IsdB, and IsdH as virulence factors that have a high immunogenicity and are capable of inducing a specific humoral immune response in S. aureus-infected quarters. The optical density (OD) values of IsdA and IsdB IgA and IgG antibodies in milk affected by naturally occurring mastitis caused by S. aureus increased significantly compared to those in healthy milk. In the experimental infection study, the OD values of IsdA- and B-specific IgA and IgG antibodies were significantly increased from 2 to 4 weeks after S. aureus infection compared to day 0 (P < 0.05). On the other hand, we demonstrated that milk from natural and experimental intramammary infections caused by S. aureus are associated with significantly higher IgA levels against IsdH (P < 0.05), but no significant change in IgG levels. Our findings facilitated our understanding of the pathogenicity of S. aureus in bovine mastitis, as well as the mechanisms by which specific humoral immune responses to S. aureus infection are induced. In addition, the results obtained could provide insight into how bovine mastitis can be controlled, for example, through vaccination.

An Incremental Sit-to-Stand Exercise for Evaluating Physical Capacity in Older Patients with Type 2 Diabetes.

Exercise is recommended for older patients with type 2 diabetes mellitus (T2DM), and increased physical activity contributes to better management of their condition. The conventional exercise test with treadmill or cycle ergometer (CE) for assessing physical capacity, such as peak oxygen uptake (VO2) and anaerobic threshold (AT), is not always usable for older patients with T2DM. The incremental sit-to-stand (ISTS) exercise is an incremental exercise test using external signals to control the sit-to-stand rate in a given time frame and can be performed in a small space using only a chair. This study aimed to examine the validity of the physical capacity assessment during the ISTS exercise, based on the relationships between the ISTS performance, peak VO2, AT on ISTS exercise and CE test, in older patients with T2DM. Twenty-two patients with T2DM (10 men, 12 women; mean age, 68.0 years; range, 61-77 years) performed ISTS exercise (according to an existing protocol) and CE test in a randomized manner. Peak VO2, AT, and completion time were determined for the ISTS exercise and CE test. Peak VO2 during ISTS exercise was significantly associated with that during the CE test (r = 0.89, p < 0.01). The completion time on the ISTS exercise was significantly associated with peak VO2 (r = 0.80, p < 0.01) and AT on the ISTS exercise (r = 0.78, p < 0.01). The ISTS exercise is a useful tool to determine the physical capacity and estimate peak VO2 and AT in older people with T2DM.

Staphylococcus aureus-specific IgA antibody in milk suppresses the multiplication of S. aureus in infected bovine udder.

BACKGROUND: Bovine mastitis caused by Staphylococcus aureus (S. aureus) is extremely difficult to control and new methods for its prevention and management are required. Nasal vaccines may prevent initial bovine mastitis infection caused by S. aureus. However, limited information is available regarding induction of mucosal immune response through nasal immunization with antigen and its suppression of S. aureus multiplication during bovine mastitis. This study sought to investigate whether induction of immunoglobulin A (IgA) in milk by nasal immunization could suppress multiplication of S. aureus in the bovine udder. RESULTS: Nasal immunization with formalin-killed S. aureus conjugated with a cationic cholesteryl-group-bearing pullulan-nanogel was performed. Anti-S. aureus-specific IgA antibodies were significantly more abundant in the milk of immunized cows than in non-immunized animals (P < 0.05). S. aureus counts in the quarter were negative in both non-immunized and nasal-immunized cows 1 week after mock infusion. In S. aureus-infused quarters, S. aureus multiplication was significantly suppressed in immunized compared with non-immunized cows (P < 0.05). Furthermore, a significant negative correlation was found between S. aureus-specific IgA antibodies and S. aureus counts in infused quarters of both non-immunized and nasal-immunized cows (r = - 0.811, P < 0.01). CONCLUSION: In conclusion, the present study demonstrates that S. aureus-specific IgA antibodies in milk successfully suppressed the multiplication of S. aureus in infected bovine udders. Although the exact mechanism explaining such suppressive effect remains to be elucidated, nasal vaccines that can induce humoral immunity may help prevent initial infection with S. aureus and the onset of bovine mastitis.

Validity and reproducibility of an incremental sit-to-stand exercise test in healthy middle-aged individuals.

[Purpose] We aimed to evaluate the validity and reproducibility of the incremental sit-to-stand exercise test for aerobic fitness evaluation in healthy middle-aged individuals. [Participants and Methods] Thirteen healthy middle-aged individuals randomly underwent the incremental sit-to-stand exercise and cycle ergometer tests, and the peak oxygen uptake was measured during both tests. Pearson's correlation coefficients were used to assess the strength of the association between the peak oxygen uptake measured during the aforementioned tests. Intraclass correlation coefficients with 95% confidence intervals for peak oxygen uptake obtained during the first, second, and third incremental sit-to-stand exercise tests were used to determine the reproducibility of this test. [Results] The peak oxygen uptake measured during the incremental sit-to-stand exercise test was strongly associated with that measured during the cycle ergometer test (r=0.86). The intraclass correlation coefficients (95% confidence intervals) used to verify the association of the peak oxygen uptake between the first and the second incremental sit-to-stand exercise tests and between the second and third incremental sit-to-stand exercise tests were 0.92 (0.66-0.99) and 0.96 (0.82-0.99), respectively. [Conclusion] The incremental sit-to-stand exercise test is a valid and reproducible tool to evaluate aerobic fitness in healthy middle-aged individuals.

Factors associated with functional rehabilitation outcomes of non-operative treatment for hip fractures: a retrospective study.

[Purpose] Limited data are available regarding the outcomes of non-operative treatment for hip fractures. We investigated the factors associated with functional rehabilitation outcomes in patients undergoing non-operative treatment for hip fractures. [Participants and Methods] We investigated 57 patients with hip fractures who underwent non-operative treatment. We retrospectively analyzed medical or rehabilitation outcomes and functional outcomes (assessed using the Functional Independence Measure tool). We examined the association between functional outcomes and other factors and compared the medical and rehabilitation outcomes between mobile and immobile patients at the time of discharge. [Results] Of the 57 patients investigated, 15 (26.3%) were mobile at discharge. We observed a significant association between the Functional Independence Measure subscores (Motor and Cognitive) and serum albumin levels. Serum albumin levels and the Functional Independence Measure subscores (Motor and Cognitive) were significantly higher in mobile than in immobile patients. [Conclusion] We observed that functional outcomes at discharge in patients undergoing non-operative treatment for hip fractures were associated with serum albumin ratios and the Functional Independence Measure-Cognitive score.

Rapid Staphylococcus aureus Detection From Clinical Mastitis Milk by Colloidal Gold Nanoparticle-Based Immunochromatographic Strips.

Rapid diagnostic technologies for bovine mastitis caused by Staphylococcus aureus (S. aureus) are urgently needed. In the current study, we generated an anti-ribosomal protein-L7/L12 antibody to detect S. aureus and an anti-ribosomal protein-L7/L12 antibody-coated immune-chromatographic strip (ICS) test. Moreover, we determined the ability of the ICS test to detect S. aureus from milk samples collected from cows with clinical mastitis. The developed ICS reacted to S. aureus in a bacteria load-dependent manner with a detection limit of ~104 CFU/mL. In the evaluation of possible cross-reactivity of the ICS test, six strains of coagulase-negative Staphylococci showed slightly positive reactions, although at a lower level; however, other bacteria were completely negative. Next, we investigated the sensitivity and specificity of the ICS test compared with the bacteriological culture method using milk samples from clinical bovine mastitis. The results of the experiments demonstrated that the ICS test had high sensitivity [100%, 95% confidence interval (CI): 91.3-100%] and specificity (91.9%, CI: 90.5-91.9%) compared with culture tests. In addition, the kappa statistic demonstrated that ICS tests showed substantial agreement (k = 0.77, CI: 0.66-0.87) with culture tests. Positive correlations were observed for the statistical analysis between S. aureus (nuc gene) copy numbers and ICS test scores in mastitic milk infected by S. aureus. Therefore, we assume that this new detection method using ICS may be useful as a highly sensitive S. aureus-screening method for the diagnosis of bovine mastitis. Our findings support the ongoing effort to develop an ICS method for bovine S. aureus-induced mastitis, which can contribute to the rapid diagnosis of this disease.

The bacterial load in milk is associated with clinical severity in cases of bovine coliform mastitis.

We evaluated the relationship between the severity of coliform mastitis and bacterial load in 106 quarter milk samples. We found no significant relationship between somatic cell count and coliform bacterial load in milk in bovine clinical coliform mastitis. Results of the Cochran-Armitage test for trend in milk bacterial load proportions indicated a significant decreasing low group (P<0.001), increasing medium group (P<0.002) and increasing high group (P<0.02) with increasing clinical grade. The present study indicates that the coliform bacterial load in milk is significantly associated with clinical severity states in cases of bovine coliform mastitis, and can be a useful indicator for optimal management of this disease.

Energetics and electronic structures of perylene confined in carbon nanotubes.

The energetics and geometries of perylene encapsulated in carbon nanotubes (CNTs) have been investigated employing density functional theory using the generalized gradient approximation combined with the van der Waals correction. Our calculations show that the encapsulated perylene molecules possess two metastable molecular conformations with respect to the CNT wall, which are almost degenerate with each other. A standing conformation, with respect to the CNT wall, is the ground state conformation for a semiconducting (19,0)CNT, while a lying conformation is the ground state for a metallic (11,11)CNT. Cooperation and competition between perylene-perylene and perylene-CNT interactions cause these possible perylene conformations inside CNTs. However, the electronic structure of the CNT encapsulating the perylene molecules is found to be insensitive to the molecular conformation.

Phenotypic and functional analysis of bovine peripheral blood dendritic cells before parturition by a novel purification method.

Dendritic cells (DCs) are specialized antigen presenting cells specializing in antigen uptake and processing, and play an important role in the innate and adaptive immune response. A subset of bovine peripheral blood DCs was identified as CD172a+ /CD11c+ /MHC (major histocompatibility complex) class II+ cells. Although DCs are identified at 0.1%-0.7% of peripheral blood mononuclear cells (PBMC), the phenotype and function of DCs remain poorly understood with regard to maintaining tolerance during the pregnancy. All cattle used in this study were 1 month before parturition. We have established a novel method for the purification of DCs from PBMC using magnetic-activated cell sorting, and purified the CD172a+ /CD11c+ DCs, with high expression of MHC class II and CD40, at 84.8% purity. There were individual differences in the expressions of CD205 and co-stimulatory molecules CD80 and CD86 on DCs. There were positive correlations between expression of cytokine and co-stimulatory molecules in DCs, and the DCs maintained their immune tolerance, evidenced by their low expressions of the co-stimulatory molecules and cytokine production. These results suggest that before parturition a half of DCs may be immature and tend to maintain tolerance based on the low cytokine production, and the other DCs with high co-stimulatory molecules may already have the ability of modulating the T-cell linage.

Identification of a novel mechanism of action of bovine IgG antibodies specific for Staphylococcus aureus.

Staphylococcus aureus is a major pathogen that causes subclinical mastitis associated with huge economic losses to the dairy industry. A few vaccines for bovine mastitis are available, and they are expected to induce the production of S. aureus-specific antibodies that prevent bacterial adherence to host cells or promote opsonization by phagocytes. However, the efficacy of such vaccines are still under debate; therefore, further research focusing on improving the current vaccines by seeking additional mechanisms of action is required to reduce economic losses due to mastitis in the dairy industry. Here, we generated S. aureus-specific bovine IgG antibodies (anti-S. aureus) that directly inhibited bacterial growth in vitro. Inhibition depended on specificity for anti-S. aureus, not the interaction between Protein A and the fragment crystallizable region of the IgG antibodies or bacterial agglutination. An in vitro culture study using S. aureus strain JE2 and its deletion mutant JE2ΔSrtA, which lacks the gene encoding sortase A, revealed that the effect of anti-S. aureus was sortase-A-independent. Sortase A is involved in the synthesis of cell-wall-associated proteins. Thus, other surface molecules, such as membrane proteins, cell surface polysaccharides, or both, may trigger the inhibition of bacterial growth by anti-S. aureus. Together, our findings contribute insights into developing new strategies to further improve the available mastitis vaccine by designing a novel antigen on the surface of S. aureus to induce inhibitory signals that prevent bacterial growth.

Exfoliation rate of mammary epithelial cells in milk on bovine mastitis caused by Staphylococcus aureus is associated with bacterial load.

The exfoliation rate of mammary epithelial cells (MECs) in milk is affected by physiological, breeding and environmental factors. Little is known about the relationship between the MEC exfoliation into milk and mammary-infected Staphylococcus aureus (S. aureus) load on bovine mastitis caused by S. aureus. The aim of this study was to investigate the relationship between S. aureus load and the proportion of MEC exfoliation in milk using five substantial bovine mastitis models. In 64 randomly extracted milk samples from udders at 3-21 days after S. aureus infusion, there were various samples with different numbers of S. aureus counts and somatic cell counts. No significant correlations were found between the S. aureus counts and somatic cell count (r = 0.338). In contrast, a significant correlation was noted between S. aureus counts and the proportion of cytokeratin-positive cells in the milk from the infused udders (r = 0.734, P < 0.01). In conclusion, the increasing MEC exfoliation rate in milk from mastitis udders caused by S. aureus may contribute to reduced milk yield.

Development of an Incremental Sit-to-Stand Exercise for Aerobic Fitness Evaluation.

Incremental sit-to-stand exercise (ISTS) is an incremental exercise test using external signals to control the sit-to-stand rate in a given time frame. This study aimed to investigate the concurrent validity and reproducibility of the ISTS in aerobic fitness evaluation among healthy elderly women. Sixteen elderly women performed the ISTS and cycle ergometer test at 3-day to 2-week intervals, and six of the participants performed the ISTS twice. Peak oxygen uptake (VO2), peak heart rate and completion time on the ISTS and cycle ergometer test were determined. Measured peak VO2 on the cycle ergometer test was significantly related to the peak VO2 (r=0.80, P<0.05) and the completion time (r=0.65, P<0.05) on the ISTS. The intraclass correlation coefficients were 0.96 for peak VO2 values and 0.91 for the completion time values during the two ISTSs. In conclusion, the ISTS is a valid, reproducible and safe test for aerobic fitness evaluation in healthy elderly women.

Effect of intramammary infusion of recombinant bovine GM-CSF and IL-8 on CMT score, somatic cell count, and milk mononuclear cell populations in Holstein cows with Staphylococcus aureus subclinical mastitis.

The effect of intramammary infusion of recombinant bovine granulocyte-macrophage colony-stimulating factor (rbGM-CSF) and interleukin-8 (rbIL-8) on mononuclear cell populations in quarters, somatic cell count (SCC) and the California Mastitis Test (CMT) score were investigated. From the selected cows with naturally occurring Staphylococcus aureus subclinical mastitis, one quarter of each cow were selected for the infusions of rbGM-CSF (400 µg/5 mL/quarter, n = 9), rbIL-8 (1 mg/5 mL/quarter, n = 9), and phosphate-buffered saline (5 mL/quarter, n = 7). The CMT score of both cytokines post infusion temporarily increased between days 0 and 1 and significantly decreased between days 7 and 14 compared to the preinfusion level. The SCC on day 14 after infusions of rbGM-CSF tended to be lower than that of the control group. The percentage of CD14+ cells increased on days 1 and 2 post infusion of rbGM-CSF. The percentage of CD4+ and CD8+ cells also increased on days 2 and 3, suggesting that the infusion of rbGM-CSF enhanced cellular immunity in the mammary gland. In contrast, the percentage of CD14+ cells decreased on days 0.25 and 1 post infusion of rbIL-8. No significant changes in the percentages of CD4+ and CD8+ cells in milk after infusion of rbIL-8 were evident during the experimental period, which suggested that rbIL-8 had little effect on the function of T cells in the mammary gland. These results indicated that rbGM-CSF and rbIL-8 decreased the CMT score by a different mechanism and may have a potential as therapeutic agents for subclinical mastitis.

Effect of Different Seat Heights during an Incremental Sit-To-Stand Exercise Test on Peak Oxygen Uptake in Young, Healthy Women.

'Sit-to-stand' exercise uses the repetitive motion of standing up and sitting down in a chair, a common activity of daily living. A new assessment using an incremental sit-to-stand exercise test employs an external sound to control the speed of standing-up and allows increases in work rate. The aims of the study were to examine the effect of different seat heights on peak oxygen uptake (peak VO2) during an incremental sit-to-stand exercise and to assess any difference between peak VO2 values during incremental sit-to-stand exercise compared with a cycle ergometer test. Thirteen healthy young women (age: 23.1 ± 2.6 years, height: 1.61 ± 0.06 m, body mass: 51.9 ± 7.4 kg·m-2) participated in four incremental sit-to-stand tests with different seat heights and cycle tests in random order. The seat heights were adjusted to 100%, 80%, 120%, and 140% of knee height distance (100%, 80%, 120%, and 140% incremental sit-to-stand exercise, respectively). The peak VO2 and completion time were measured during incremental sit-to-stand and cycle ergometer tests, and repeated-measures analysis of variance and Student's paired t-test with Holm's method were used to evaluate differences between these variables. The peak VO2 values increased by about 10-12 mL·min-1·kg-1 as the seat height on the ISTS decreased over a 60% range of lower leg lengths. The peak VO2 values on the 80%, 100%, 120%, and 140% incremental sit-to-stand tests were about 11%, 25%, 40%, and 50% lower than that on the cycle ergometer test, respectively. The peak VO2 on the incremental sit-to-stand test increased as seat height decreased. These findings are useful to determine which seat height on the incremental sit-to-stand tests test is suitable for different populations.

The cell wall component lipoteichoic acid of Staphylococcus aureus induces chemokine gene expression in bovine mammary epithelial cells.

Staphylococcus aureus (SA) is a major cause of bovine mastitis, but its pathogenic mechanism remains poorly understood. To evaluate the role of lipoteichoic acid (LTA) in the immune or inflammatory response of SA mastitis, we investigated the gene expression profile in bovine mammary epithelial cells stimulated with LTA alone or with formalin-killed SA (FKSA) using cap analysis of gene expression. Seven common differentially expressed genes related to immune or inflammatory mediators were up-regulated under both LTA and FKSA stimulations. Three of these genes encode chemokines (IL-8, CXCL6 and CCL2) functioning as chemoattractant molecules for neutrophils and macrophages. These results suggest that the initial inflammatory response of SA infection in mammary gland may be related with LTA induced chemokine genes.