Does the taking of biopsies affect the metastatic potential of tumours? A systematic review of reports on veterinary and human cases and animal models

Clinicians and pathologists are sporadically asked by owners whether the taking of tumour biopsies may affect the behaviour of the tumour, including its potential to metastasise. Unfortunately, systematic studies on this subject are unavailable in veterinary medicine, and the aim of this study was to estimate the risk of adverse effects of biopsy taking on tumour progression in animals. A systematic review of veterinary and human case reports and clinical studies as well as experimental animal models of biopsy-induced tumour metastasis was undertaken. There were only two veterinary case reports of needle tract metastases (NTM) following the taking of needle biopsies from urogenital and pulmonary tumours. Seventeen experimental studies found a high incidence of NTM but only a rat osteosarcoma and a hamster squamous carcinoma model showed an increased incidence of distant or regional metastases after incision or excision biopsy. In human medicine, the occurrence of NTM has been reported after the taking of biopsies from mesotheliomas (15%), melanomas (11%) and gall bladder tumours (11%), liver metastases of colon carcinomas (4%) and mammary carcinomas (4%) but an incidence of only <1% for all other tumours. Circulating tumour cells increased immediately after the taking of biopsies from human squamous cell, prostate, breast and hepatocellular carcinomas. Although no increased risk of biopsy-induced distant metastasis has been reported for any type of tumour, this is inconclusive due to a lack of non-biopsied control groups in human studies. Reports of biopsy-induced metastasis in animal tumours indicate that the taking of transcutaneous biopsies from urogenital tumours may be associated with a risk of NTM. However, there is no evidence of a general increase in risk of distant metastases in any tumour type in people or animals. The overall risk therefore appears to be negligible when compared to the valuable information obtained from biopsies in veterinary practice.     

Does surface anodisation of titanium implants change osseointegration and make their extraction from bone any easier?

OBJECTIVES: Titanium implants have a tendency for high bone-implant bonding, and, in comparison to stainless steel implants are more difficult to remove. The current study was carried out to evaluate, i) the release strength of three selected anodized titanium surfaces with increased nanohardness and low roughness, and ii) bone-implant bonding in vivo. These modified surfaces were intended to give improved anchorage while facilitating easier removal of temporary implants. MATERIAL AND METHODS: The new surfaces were referenced to a stainless steel implant and a standard titanium implant surface (TiMAX). In a sheep limb model, healing period was 3 months. Bone-implant bonding was evaluated either biomechanically or histologically. RESULTS: The new surface anodized screws demonstrated similar or slightly higher bone-implant-contact (BIC) and torque release forces than the titanium reference. The BIC of the stainless steel implants was significant lower than two of the anodized surfaces (p = 0.04), but differences between stainless steel and all titanium implants in torque release forces were not significant (p = 0.06). CONCLUSION: The new anodized titanium surfaces showed good bone-implant bonding despite a smooth surface and increased nanohardness. However, they failed to facilitate implant removal at 3 months.     

Biology and pathology of the intestinal M‐cell. A review

Summary

The literature of the intestinal M‐cell, which is part of the epithelium covering the gut‐associated lymphoid tissue (GALT), is reviewed. Attention is paid to the localization, structure, origin and function of this cell, under both normal and pathological conditions.     

A review of the off-label use of selamectin (Stronghold?/Revolution?) in dogs and cats

Since its introduction approximately seven years ago, selamectin (Stronghold^®/Revolution^®, Pfizer Inc.) has been used off-label to treat a number of ecto- and endoparasite conditions in dogs and cats. It has been used as a successful prophylactic against Dirofilaria repens and as a treatment for Aelurostrongylus abstrusus in cats. It has also been used to treat notoedric mange, infestation with the nasal mite Pneumonyssoides caninum, Cheyletiella spp. and Neotrombicula autumnalis infestations and larval Cordylobia anthropophaga infection. However, to date attempts to treat generalised canine demodicosis have not been successful. In all cases, treatment was apparently well tolerated by the host.     

Fermentation characteristics of resistant starch,arabinoxylan, and β-glucan and their effects on the gut microbial ecology of pigs: A review

Dietary fibers (DF) contain an abundant amount of energy, although the mammalian genome does not encode most of the enzymes required to degrade them. However, a mutual dependence is developed between the host and symbiotic microbes, which has the potential to extract the energy present in these DF. Dietary fibers escape digestion in the foregut and are fermented in the hindgut, producing short-chain fatty acids (SCFA) that alter the microbial ecology in the gastrointestinal tract (GIT) of pigs. Most of the carbohydrates are fermented in the proximal part, allowing protein fermentation in the distal part, resulting in colonic diseases. The structures of resistant starch (RS), arabinoxylan (AX), and β-glucan (βG) are complex; hence, makes their way into the hindgut where these are fermented and provide energy substrates for the colonic epithelial cells. Different microbes have different preferences of binding to different substrates. The RS, AX and βG act as a unique substrate for the microbes and modify the relative composition of the gut microbial community. The granule dimension and surface area of each substrate are different, which influences the penetration capacity of microbes. Arabinose and xylan are 2 different hemicelluloses, but arabinose is substituted on the xylan backbone and occurs in the form of AX. Fermentation of xylan produces butyrate primarily in the small intestine, whereas arabinose produces butyrate in the large intestine. Types of RS and forms of βG also exert beneficial effects by producing different metabolites and modulating the intestinal microbiota. Therefore, it is important to have information of different types of RS, AX and βG and their roles in microbial modulation to get the optimum benefits of fiber fermentation in the gut. This review provides relevant information on the similarities and differences that exist in the way RS, AX, and βG are fermented, and their positive and negative effects on SCFA production and gut microbial ecology of pigs. These insights will help nutritionists to develop dietary strategies that can modulate specific SCFA production and promote beneficial microbiota in the GIT of swine.     

Does a Boar's Season of Birth Determine Semen Parameters and Reproductive Performance?

This article studies the effect of a boar's birth season and breed on semen parameters and its further reproductive performance. Research material consisted of 72 boars from three breeds (24 Polish Large White PLW, 24 Polish Landrace PL, 24 Duroc × Pietrain D×P). During the whole period of the study, selected semen parameters were analysed: semen volume, spermatozoa concentration, total number of spermatozoa, total number of motile spermatozoa, number of insemination doses and also reproductive indicators: farrowing rate, total born litter size, total number of piglets born live and still, and average piglet weight. Boars born in the winter and summer months demonstrated the highest spermatozoa concentrations (383.25 and 392.37 × 10⁶/ml), total number of spermatozoa (91.75 and 93.21 × 10⁹), total number of motile spermatozoa (76.10 and 77.99 × 10⁹) and number of insemination doses (24.53 and 24.89; p ≤0.01). Statistically lower values for these parameters were observed for boars born in the spring and especially in autumn (p ≤0.01). The significant impact of birth season on farrowing rate (p ≤ 0.05) and average piglet weight (p ≤ 0.05) was confirmed for PLW boars. For the PL breed, only the total number of piglets born live was proven to be significantly affected (p ≤ 0.05). No impact of birth season was shown on semen quality or reproductive performance for D×P boars. In our study, we showed that the birth season of a boar had a more impact on the level of semen parameters, and less on the reproductive performance indicators. The results indicated that both the quality of semen and reproductive performance varied in terms of the study factors, as well as between individual breeds of boars involved in the experiment.     

A review of viral diseases of the European wild boar: effects of population dynamics and reservoir rôle

There has been a worldwide increase in the number and geographical spread of wild boar populations in recent decades leading to an increase in both the circulation of disease agents and greater contact with domestic animals and humans. Diseases affect the population dynamics of wildlife but the effects of most viral diseases on the European wild boar are largely unknown. Many viral diseases present in domestic pig populations are also present in wild boars where they can provide a disease reservoir, as is clearly the case with classical swine fever, but little is known about other viral diseases such as porcine circovirus diseases or hepatitis E. This review considers the current scientific knowledge of the effects of viral diseases on wild boar populations and their r?le as potential disease reservoirs. The focus is on those viral diseases of domestic swine and wild boars that are included as notifiable by the Office International des Epizooties (OIE).     

Does age of hot-blade trimming impact the performance and welfare of 2 strains of White Leghorn hens?

The impact of mild hot-blade beak trimming on welfare and performance in 2 strains of White Leghorn pullets was examined. During the pullet phase, 960 pullets were designated to one of 4 trimming treatments: control (untrimmed, C), trimmed at a commercial hatchery (T0d), or trimmed on farm at 10 d (T10d) or 35 d (T35d) of age. During the hen phase, 720 of the original 960 hens were housed in conventional cages at 17 wk of age (6 replications per strain × treatment group) and data were analyzed as a 2 × 4 (performance and beak length data), 2 × 2 (behavior data, blocked by observer) factorial arrangement or a Chi-Squared analysis (beak healing). Total hen-day production tended to be lower for C birds, but hen-housed production did not differ. Feed intake was not affected by trimming treatments, but feed efficiency was poorer for C birds. Treatment did not statistically affect mortality. Cannibalism, although not significantly different among treatments, occurred in C birds only. The C pullets displayed more head/vent pecking, but no differences were noted in adult birds. There was no behavioral or histological evidence of chronic pain or neuroma formation, and healing occurred quicker when trimming occurred at zero or 10 d of age. To conclude, trimming mildly at zero, 10, or 35 d of age caused no long-term effect on welfare or performance, but trimming at younger ages resulted in faster healing.     

How do resources influence control measures during a simulated outbreak of foot and mouth disease in Australia?

An outbreak of foot and mouth disease (FMD) could seriously impact Australia's livestock sector and economy. As an FMD-free country, an outbreak would trigger a major disease control and eradication program that would include the culling of infected and at risk animals (‘stamping out’), movement restrictions and zoo-sanitary measures. Additional control measures may also include pre-emptive culling or vaccination. However, it is unclear what disease strategy would be most effective under Australian conditions and different resource levels. Using a stochastic simulation model that describes FMD transmission between farms in a livestock dense region of Australia, our results suggest that using current estimates of human resource capacity for surveillance, infected premises operations and vaccination, outbreaks were effectively controlled under a stamping out strategy. However, under more constrained resource allocations, ring vaccination was more likely to achieve eradication faster than stamping out or pre-emptive culling strategies.     

Are the material properties and matrix composition of equine flexor and extensor tendons determined by their functions?

REASONS FOR PERFORMING STUDY: Injury to the superficial digital flexor tendon (SDFT) is common in competition horses. The SDFT contributes to locomotory efficiency by storing energy; such tendons have low safety margins. Tendons which merely position the limb, including the opposing common digital extensor tendon (CDET), are rarely injured. The current failure of strategies to prevent or effectively treat injury to the SDFT indicates the importance of understanding how it differs from tendons which are not injury-prone. HYPOTHESIS: That the structural and material properties and matrix composition of the SDFT and CDET differ, reflecting their specific functional requirements in vivo. METHODS: Forelimb tendons were harvested from 26 mature horses and loaded to failure prior to matrix composition analysis of specimens. RESULTS: The SDFT had a significantly higher cross-sectional area, structural stiffness, failure load and failure strain and a lower elastic modulus than the CDET (P < 0.0001). CONCLUSIONS: The SDFT has conflicting requirements for strength and elasticity; although as a whole it is a stiffer structure than the CDET, differences in the matrix molecular composition including water and total sulphated glycosaminoglycan contents allow it to remain more elastic as a material. POTENTIAL RELEVANCE: Further information on how the two tendons attain these different properties may be of use in the development of prevention and treatment strategies for SDFT rupture.     

Is the metabolic syndrome a useful clinical concept in dogs? A review of the evidence

The metabolic syndrome is a set of risk factors for the development of type 2 diabetes, atherosclerosis, coronary heart disease and stroke in human beings. The term has recently been applied to dogs that exhibit components of the human metabolic syndrome, specifically visceral obesity, hypercholesterolaemia, hypertriglyceridaemia, hypertension and fasting hyperglycaemia. Obese dogs, like obese humans, are known to develop resistance to the glucose-lowering effects of insulin, and develop increased circulating concentrations of triglycerides, cholesterol and blood pressure. Unlike humans, however, obese dogs do not develop fasting hyperglycaemia or atherogenic hyperlipidaemia. Importantly, there is no evidence that dogs develop type 2 diabetes. Atherosclerosis, coronary heart disease and stroke are rare and not known to be associated with obesity in dogs. On the basis of current knowledge, the use of the term ‘metabolic syndrome’ in dogs does not appear to have merit.     

Leptospira interrogans serovar Hardjo: an abortifacient in New Zealand? A review of the literature

From experimental and clinical evidence, Leptospira interrogans serovar hardjo has been suspected as an abortifacient in cattle overseas. Early reports from North America and Australia described clinical disease with abortions occurring up to 12 weeks later associated with hardjo infections. Recent studies in the United Kingdom have found hardjo infections in nearly 69 percent of aborted foetuses from problem farms, and a prospective epidemiological study determined a relationship between hardjo infection and abortion on one property. In New Zealand, although the epidemiology of hardjo infections has been studied, little attention has been paid to the potential abortifacient role of this organism. In part this is due to the impracticality of using serology to diagnose infections that may have occurred months prior to the abortion. Future research to resolve this question should therefore revolve around hardjo isolation, cohort studies, and the examination of pathogenic mechanisms by which hardjo may induce abortion in cattle.     

Does the computed tomographic appearance of the lung differ between young and old dogs?

In computed tomographic (CT) images of humans, decreased lung attenuation, bronchial dilation, and/or thickening, air trapping, cysts, and thickened interlobular septa have been associated with increasing age. To determine if there are differences in the CT appearance of the lungs of young and old dogs that could affect interpretation of diagnostic studies, pulmonary CT images of dogs with conditions unrelated to the thorax were reviewed retrospectively in a case–control study. Computed tomography studies of 42 young dogs (range 0.3–4.8 years) and 47 old dogs (range 9–15.1 years) were jumbled and reviewed by an observer blinded to dog age. Computed tomography was performed under sedation in 62 (70%) dogs and under general anesthesia in 27 (30%). Heterotopic bone was more prevalent (62% vs. 14%) in old dogs. Lung collapse was significantly associated with old age, greater body weight, and anesthesia. There were no significant differences in median lung attenuation or occurrence of ground glass pattern, cysts, bronchial thickening, bronchial dilation, or degree of tracheal calcification. No examples of reticular pattern, emphysema, pleural thickening, or septal thickening were observed in any dog. Despite previous studies describing age‐related changes in the radiographic appearance of the lungs of old dogs, it appears that there are minimal observable differences in CT images. Old dogs are more likely to have visible foci of heterotopic bone and may be more prone to lung lobe collapse than young dogs, but neither of these differences should contribute to misdiagnosis of pulmonary disease.     

Effects of oral supplementation with β-carotene on concentrations of β-carotene, vitamin A and α-tocopherol in plasma, colostrum and milk of mares and plasma of their foals and on fertility in mares

In this study, effects of oral β-carotene supplementation to mares (β-carotene group: 1000 mg/day, n = 15; control group: n = 15) from 2 weeks before foaling until 6 weeks thereafter on concentrations of β-carotene, vitamin A and α-tocopherol in plasma, colostrum and milk and plasma of their foals were determined. In addition, effects on fertility were studied. Beta-carotene concentrations increased in plasma and colostrum of β-carotene-supplemented mares compared to control mares (p < 0.05). In mares of both groups, β-carotene concentrations were higher in colostrum than in milk (p < 0.05). In foals, β-carotene concentrations increased with colostrum uptake and were higher in foals born to supplemented mares (p < 0.05; control group: 0.0003 ± 0.0002 μg/ml on day 0, 0.008 ± 0.0023 μg/ml on day 1; β-carotene group: 0.0005 ± 0.0003 μg/ml on day 0, 0.048 ± 0.018 μg/ml on day 1). Concentrations of vitamin A and α-tocopherol were higher in colostrum than in milk (p < 0.05) but did not differ between groups. Concentration of α-tocopherol in plasma of mares decreased over time and in foals, increased markedly within 4 days after birth. All but one mare (control group) showed oestrus within 2 weeks post-partum. Occurrence of oestrus did not differ between groups. More mares of the control group (7/7 vs. 5/12 in the β-carotene group) became pregnant after being bred in first post-partum oestrus (p < 0.05). In conclusion, β-carotene supplementation to mares increased β-carotene concentrations in plasma, colostrum and milk of mares and plasma of their foals but had no positive effects on fertility.     

The complex role of veterinary clinical teachers: how is their role perceived and what is expected of them?

The purpose of this study was to identify personal attributes in veterinary clinical teachers that are valued most by members of their work environment (fellow faculty, clinical training scholars [CTS; residents], undergraduate students, and referring veterinary surgeons) and to determine whether the opinions of these subgroups differed. Faculty (n=50), CTS (n=35), students (n=200), and referring veterinary surgeons (n=25) were presented with a list of 15 potentially desirable attributes. Respondents were asked to rank the three most important and the three least important attributes of effective clinical teachers. Respondents were also asked to select in which of the three main activities (clinical service, teaching, or research) in which clinical teachers currently invest the most and the least effort and in which they should invest the most and the least effort. All respondent groups agreed that "competence-knowledge" was among the most desirable attributes. Faculty, undergraduate students, and referring veterinary surgeons additionally included "enthusiasm" in the top three, whereas CTS regarded "respects independence" as more important. All respondent groups consistently chose "scholarly activity" as one of the three least important characteristics. A similar number of faculty members (38%) expressed that the greatest effort should be invested in clinical service or teaching, and the greatest proportions of CTS (44%) and students (56%) felt that most emphasis should be put on teaching alone. The differences in opinion between respondent groups regarding importance of attributes and emphasis of activity indicate that what is perceived as effective performance of clinical teachers differs depending on the role of those who engage with them.