Companion animals in comparative oncology: One Medicine in action.

Comparative oncology is poised to have a far-reaching impact on both animals and human beings with cancer. The field is gaining momentum and has repeatedly proven its utility in various aspects of oncology, including study of the genetics, development, progression, immunology and therapy of cancer. Companion animals provide many advantages over both traditional rodent models and human beings for studying cancer biology and accelerating the development of novel anti-cancer therapies. In this review, several examples of the ability of companion animals with spontaneous cancers to fill a unique niche in the field of oncology are discussed. In addition, potential caveats of the use of companion animals in research are reviewed, as well as ethical considerations and efforts to standardize veterinary clinical trials.

Extracorporeal shockwave therapy and therapeutic exercise for supraspinatus and biceps tendinopathies in 29 dogs.

Supraspinatus tendinopathy (ST) and biceps tendinopathy (BT) are common causes of forelimb lameness in large-breed dogs and have historically been treated with conservative management or surgery. Extracorporeal shockwave therapy (ESWT) and therapeutic exercise (TE) are thought to be treatment options for these conditions. The objectives of this study were to report the clinical presentations of dogs treated with ESWT for shoulder tendinopathies, to determine the association between shoulder lesion severity identified on ultrasonography or MRI and outcome, and to compare the outcomes of dogs treated with ESWT with and without TE. Medical records of 29 dogs diagnosed with shoulder tendinopathies and treated with ESWT were reviewed, and 24 dogs were diagnosed with either unilateral BT or BT and ST. None were found to have unilateral ST. Five dogs were diagnosed with bilateral disease. Eighty-five per cent of dogs had good or excellent outcomes determined by owner assessment 11-220 weeks after therapy. Outcomes were found to be better as tendon lesion severity increased (P=0.0497), regardless if ESWT was performed with or without TE (P=0.92). ESWT should be considered a safe primary therapeutic option for canine shoulder tendinopathies. Larger controlled prospective studies are needed to adequately assess these findings.

Escape from the competence state in Streptococcus mutans is governed by the bacterial population density.

Horizontal gene transfer through natural DNA transformation is an important evolutionary mechanism among bacteria. Transformation requires that the bacteria are physiologically competent to take and incorporate free DNA directly from the environment. Although natural genetic transformation is a remarkable feature of many naturally competent bacteria, the process is energetically expensive for the cells. Consequently, a tight control of the competence state is necessary. The objective of the present work was to help decipher the molecular mechanisms regulating the escape from the competence state in Streptococcus mutans, the principal etiological agent responsible for tooth decay in humans. Our results showed that the cessation of competence in S. mutans was abrupt, and did not involve the accumulation of a competence inhibitor nor the depletion of a competence activator in the extracellular environment. The competence state was repressed at high cell population density via concomitant repression of sigX gene encoding the master regulator of the competence regulon. Co-culture experiments performed with oral and non-oral bacteria showed that S. mutans assesses its own population density and also the microbial density of its surroundings to regulate its competence escape. Interestingly, neither the intra-species and extra-species quorum-sensing systems nor the other 13 two-component regulatory systems identified in S. mutans were involved in the cell-density-dependent escape of the competence state. Altogether, our results suggest a complex mechanism regulating the competence shut-off involving cell-density-dependent repression of sigX through an as yet undefined system, and possibly SigX protein stability.

Diagnostic accuracy of pre-treatment biopsy for grading soft tissue sarcomas in dogs.

Histologic grade is an important prognostic factor for both local recurrence and metastatic potential with canine soft tissue sarcoma (STS). Pre-treatment biopsy with identification of tumour grade may aid in prognostication and determination of surgical margins necessary for local control. The purpose of this study was to evaluate the grading accuracy of various pre-treatment biopsy techniques (wedge, punch, needle-core) for STS in dogs. Medical records of 68 dogs diagnosed with a STS via pre-treatment biopsy and confirmed by excisional biopsy were evaluated. The concordance in grade between excisional and pre-treatment biopsies was 59%. Of the 41% that lacked concordance, 29% of pre-treatment biopsies underestimated and 12% overestimated grade. The method of pre-treatment biopsy did not significantly effect grade concordance. Based on these data, needle-core biopsy appears to be similar in accuracy compared to open biopsy, however, grading determined by pre-treatment biopsy in general should be interpreted with caution.

Sox2 maintains self renewal of tumor-initiating cells in osteosarcomas.

Tumors are thought to be sustained by a reservoir of self-renewing cells, termed tumor-initiating cells or cancer stem cells. Osteosarcomas are high-grade sarcomas derived from osteoblast progenitor cells and are the most common pediatric bone malignancy. In this report we show that the stem cell transcription factor Sox2 is highly expressed in human and murine osteosarcoma (mOS) cell lines as well as in the tumor samples. Osteosarcoma cells have increased ability to grow in suspension as osteospheres, that are greatly enriched in expression of Sox2 and the stem cell marker, Sca-1. Depletion of Sox2 by short-hairpin RNAs in independent mOS-derived cells drastically reduces their transformed properties in vitro and their ability to form tumors. Sox2-depleted osteosarcoma cells can no longer form osteospheres and differentiate into mature osteoblasts. Concomitantly, they exhibit decreased Sca-1 expression and upregulation of the Wnt signaling pathway. Thus, despite other mutations, these cells maintain a requirement for Sox2 for tumorigenicity. Our data indicate that Sox2 is required for osteosarcoma cell self renewal, and that Sox2 antagonizes the pro-differentiation Wnt pathway that can in turn reduce Sox2 expression. These studies define Sox2 as a survival factor and a novel biomarker of self renewal in osteosarcomas, and support a tumor suppressive role for the Wnt pathway in tumors of mesenchymal origin. Our findings could provide the basis for novel therapeutic strategies based on inhibiting Sox2 or enhancing Wnt signaling for the treatment of osteosarcomas.

Increased monocyte chemotactic protein-1 concentration and monocyte count independently associate with a poor prognosis in dogs with lymphoma.

Overexpression of the chemokine monocyte chemotactic protein-1 (MCP-1) has been associated with a poor prognosis in many human cancers. Increased MCP-1 concentrations may promote tumour progression by increasing mobilization of myeloid derived suppressor cells such as immature monocytes and neutrophils. We hypothesized that increased numbers of peripheral neutrophils or monocytes and increased MCP-1 concentrations would predict a worse outcome in dogs with multicentric lymphoma. In this retrospective study involving 26 client-owned dogs diagnosed with lymphoma, we show that peripheral neutrophil and monocyte counts as well as serum MCP-1 concentrations were significantly elevated relative to healthy control animals, and that such increases were associated with a decreased disease-free interval in dogs treated with chemotherapy based on cyclophosphamide, vincristine, doxorubicin and prednisone (CHOP). To our knowledge, this is the first study showing that pretreatment evaluation of monocyte and neutrophil counts can provide important prognostic information in dogs with lymphoma. The mechanisms underlying these observations remain to be determined.

Involvement of Streptococcus mutans regulator RR11 in oxidative stress response during biofilm growth and in the development of genetic competence.

AIMS: To identify the genes regulated by RR11, the regulator of the Streptococcus mutans HK/RR11 two-component system. METHODS AND RESULTS: The S. mutans RR11-encoding gene was inactivated, and the effects of gene disruption on the cell's ability to form biofilms under stresses and acquire extracellular DNA were tested. Biofilm was reduced in cells lacking RR11 following exposure to oxidative stress. RR11-defective cells showed approx. 20-fold reduction in transformation efficiency. Microarray used to decipher the RR11-regulated genes in biofilm showed that approx. 5% of the UA159 genome underwent a significant change in expression. RR11 was found to regulate 174 genes, including genes involved in competence, stress-response and cell division. CONCLUSIONS: Target genes controlled by RR11during biofilm growth have been identified by a comparison of transcriptional profiles between an RR11 defective mutant and the parental strain. The results demonstrated that RR11 is involved in the control of diverse cellular processes, including the formation of biofilm under oxidative stress and development of genetic competence. SIGNIFICANCE AND IMPACT OF THE STUDY: The regulator of HK/RR11 system controls a large regulon and is an important regulator involved in stress response during S. mutans biofilm growth enabling the survival and persistence of its progeny in the microbial community.

Systemic inactivation and phenotypic characterization of two-component systems in expression of Streptococcus mutans virulence properties.

AIM: To assess potential function of each two-component signal transduction system in the expression of Streptococcus mutans virulence properties. METHODS AND RESULTS: For each two-component system (TCS), the histidine kinase-encoding gene was inactivated by a polymerase chain reaction (PCR)-based deletion strategy and the effects of gene disruption on the cell's ability to form biofilms, become competent, and tolerate acid, osmotic, and oxidative stress conditions were tested. Our results demonstrated that none of the mutations were lethal for S. mutans. The TCS-2 (CiaRH) is involved in biofilm formation and tolerance to environmental stresses, the TCS-3 (ScnRK-like) participates in the survival of cells at acidic pH, and the TCS-9 affects the acid tolerance response and the process of streptococcal competence development. CONCLUSIONS: Our results confirmed the physiological role of the TCS in S. mutans cellular function, in particular the SncRK-like TCS and TCS-9 as they may represent new regulatory systems than can be involved in S. mutans pathogenesis. SIGNIFICANCE AND IMPACT OF THE STUDY: Multiple TCS govern important biological parameters of S. mutans enabling its survival and persistence in the biofilm community.

In search of effective scales for stream management: does agroecoregion, watershed, or their intersection best explain the variance in stream macroinvertebrate communities?

Our lack of understanding of relationships between stream biotic communities and surrounding landscape conditions makes it difficult to determine the spatial scale at which management practices are best assessed. We investigated these relationships in the Minnesota River Basin, which is divided into major watersheds and agroecoregions which are based on soil type, geologic parent material, landscape slope steepness, and climatic factors affecting crop productivity. We collected macroinvertebrate and stream habitat data from 68 tributaries among three major watersheds and two agroecoregions. We tested the effectiveness of the two landscape classification systems (i.e., watershed, agroecoregion) in explaining variance in habitat and macroinvertebrate metrics, and analyzed the relative influence on macroinvertebrates of local habitat versus regional characteristics. Macroinvertebrate community composition was most strongly influenced by local habitat; the variance in habitat conditions was best explained at the scale of intersection of major watershed and agroecoregion (i.e., stream habitat conditions were most homogeneous within the physical regions of intersection of these two landscape classification systems). Our results are consistent with findings of other authors that most variation in macroinvertebrate community data from large agricultural catchments is attributable to local physical conditions. Our results are the first to test the hypothesis and demonstrate that the scale of intersection best explains these variances. The results suggest that management practices adjusted for both watershed and ecoregion characteristics, with the goal of improving physical habitat characteristics of local streams, may lead to better basin-wide water quality conditions and stream biological integrity.

Seasonal eating patterns in Norway: a non-clinical population study.

Seasonal deviations in normal eating habits have been associated with seasonal affective disorder (SAD) and bulimia nervosa (BN). Two studies on seasonal variation in eating habits are reported in this paper. In Study 1, seasonal patterns of eating disturbances were measured cross-sectionally in 6313 participants using an eating disturbance scale (EDS-5) and a modified version of the Seasonal Pattern Assessment Questionnaire (SPAQ). Eating disturbance scores were predicted by seasonal sensitivity scores from the SPAQ, gender, age, and light. Study 2 used a longitudinal design in which 908 participants were given the EDS-5 every month from November 1993 to January 1995. Scores on the EDS-5 fluctuated with the season of the year, with higher EDS-5 scores in winter and lower in summer. The results suggest that seasonal fluctuations affect only a subset of the total population.

A Norwegian translation of the self-liking and competence scale.

Although global self-esteem has historically been assumed to be a unidimensional construct, recent theory and research has challenged this assumption. Instead, it has been suggested that self-esteem might more fruitfully be viewed as a two-dimensional construct composed of: (a) self-liking, based on our perceptions of feedback from our social environment; and (b) self-competence, based on our internal conceptions of success and failure in performing tasks. The Self-Liking and Competence Scale (SLCS) is a self-esteem measure that has recently been developed based on this two-dimensional conceptualization of self-esteem. The purpose of the present research was to validate a Norwegian translation of the SLCS. 372 participants were given a translated version of the SLCS, and the translated scale exhibited psychometric properties similar to those of the original English version of the scale.

Eating pattern and self-esteem in overweight women.

Recent studies have shown that the relationship between poor self-esteem and disturbed eating patterns may be more fully understood when the self-esteem concept is divided into an affective domain ('self-liking') and a cognitive domain ('self-competence'). In the present study 38 overweight women between the ages of 21 and 68 participated in an 8-week weight reduction program whereby the Self-Liking and Competence Scale [SLCS] and the Eating Disorder Scale [EDS-5] were used in order to measure self-esteem and eating patterns, respectively. An improvement in the eating patterns corresponded to an improvement in self-liking, but not in self-competence. Statistically significant weight reduction did occur, but on the average, the subjects still remained overweight. As in other studies on normal weight individuals in analogous test situations completing the same instruments, the results point only to a specific relationship between disturbed eating patterns and self-liking. The results suggest that an increased benefit from a weight reduction program could be expected if strategies for improving eating patterns and self-liking are included. This hypothesis warrants further controlled treatment studies.

Analyzing the relation between self-esteem and eating disorders: differential effects of self-liking and self-competence.

Research in the past has demonstrated an association between low self-esteem and eating disorders. Recent research on self-esteem has shown, however, that self-esteem is composed of two distinct factors--self-liking and self-competence. The present study examined the relation between these two self-esteem factors and both eating disorders and eating disturbed cognitions. A total of 51 female participants from a high-risk population were clinically interviewed to identify the eating disorder and administered a series of questionnaires that included a measure of self-liking and self-competence. A strong relationship was found between self-liking and eating disorders, but no relationship was found between self-competence and eating disorders.

A family's coming to terms with Alzheimer's disease.

Findings of a qualitative analysis of several members of a family in which one member has Alzheimer's Disease (AD) support the notion that differences in how each family member defines and makes meaning of the situation have consequences for the family as a unit. Ten in-depth individual and dyadic interviews of five available family members were conducted during a period of 18 months. Data support the finding that each member of the family experienced a similar process of coming to terms with changes in the person who has AD. This process consisted of three stages: identifying how the person with AD was the same as he was before, as well as how he was different, prior to disease onset; redefining the identity of the person with AD; and rewriting one's relationship with the person with AD. This study supports both Knafl's and Deatrick's concept of family management and Patterson's concept of family meaning.

Structural and serological specificities of Pasteurella haemolytica lipopolysaccharides.

Lipopolysaccharides (LPSs) from 16 serotypes of Pasteurella haemolytica were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and examined by silver staining and immunoblotting. Silver staining of proteinase K-digested cell lysates revealed two rough LPS serotypes (serotypes 2 and 8), which lacked demonstrable O-polysaccharide, while 14 others demonstrated a ladder pattern characteristic of smooth-type LPS. Purified LPSs from several serotypes yielded O-polysaccharide in addition to low-molecular-weight core oligosaccharide components when subjected to mild acid hydrolysis. Nuclear magnetic resonance spectroscopy revealed the O-chain polysaccharides of serotypes 1, 6, and 9 to be identical. Immunoblots using hyperimmune rabbit, mouse, bovine, and ovine sera from homologous and heterologous serotypes supported this finding and suggested that most of the A biotypes share common O-chain epitopes. Immunoblotting results also supported structural data which demonstrated that the O-polysaccharides of serotypes 3 and 15 and of serotypes 4 and 10 (T biotypes) are identical. Nuclear magnetic resonance analysis indicated that the core oligosaccharides of serotypes 1, 6, 8, 9, and 12 share similar structures, but that they are distinct from those of serotypes 3, 4, 10, and 15. Immunoblots with hyperimmune antisera and monoclonal antibody having specificity for the core region of serotype 1 LPS revealed shared epitopes in the core oligosaccharides of several A biotypes. Characterization of the molecular structure and antigenic specificities of LPS has been an important consideration in the development of purity and potency assays for veterinary vaccines which contain P. haemolytica.

Sensitive trace-first liquid chromatographic determination of 4-aminopyridine in 3,4-diaminopyridine.

For the treatment of human neuromuscular diseases, 3,4-diaminopyridine (DAP) is six to ten times more effective than 4-aminopyridine (AP), but only half as convulsant and toxic. Therefore, there is a need for the determination of AP in DAP. With only conventional equipment, high-pressure liquid chromatography can be used for the extremely sensitive detection of a trace contaminant under one condition: that is, the trace must be eluted before the major component it contaminates. Prior elution presents a trace peak in a fully exploitable form that is maximally efficient and maximally observable. This has already been demonstrated with a Pirkle-concept chiral stationary phase for determination of a chiral trace. However, its application to determination of a nonchiral trace with a reversed phase has not previously been reported. Such an application is reported here. In this demonstrative study, selectivity and loading capability were iteratively improved. Ion pairing with dodecanesulfonate maximized selectivity. It was again shown that using a less concentrated sample in greater volume maximizes loading capability without obscuring the peak of the trace. Eventually, the ability to detect 0.005% AP in DAP was demonstrated. Whether that sensitivity might be improved still more, perhaps with a larger column, was not established.

The structure of the antigenic lipopolysaccharide O-chains produced by Salmonella urbana and Salmonella godesberg.

The lipopolysaccharides of Salmonella urbana and Salmonella godesberg, which belong in group N (O:30) of the Kauffmann-White system, were shown by SDS-PAGE electrophoresis, glycose analysis, periodate oxidation, methylation, and 1H- and 13C-n.m.r. analyses to have identical O-chains composed of repeating, branched pentasaccharide units having the structure: [----4)-beta-D-Glcp-(1----3)-alpha-D-GalNAcp-(1----2)-alpha-D-P erNAcp-(1----3)-alpha-L-Fucp-(1----]n 4 increases 1 beta-D-Glcp. The serological cross-reactivity of S. urbana and S. godesberg with Brucella abortus and Yersinia enterocolitica (O:9) can now be related to the presence of a 1,2-glycosylated N-acyl derivative of 4-amino-4,6-dideoxy-alpha-D-mannopyranosyl residues in their respective lipopolysaccharide O-chains.

Urinary candidiasis: a prospective study in hospital patients.

In a prospective study of 29 hospital inpatients with candiduria, yeasts were frequently isolated from the urine in the absence of symptoms and no serious deep fungal infection occurred. The prevalence of diabetes mellitus and urinary catheterisation was significantly increased in this group compared to the general hospital population. There was a high incidence of yeast species other than Candida albicans in the urine, non-albicans species constituting 39% compared with 18% from other sites (p less than 0.01).