bluuebunny/crossref_metadata_2025 huggingface dataset:
Tight and Adherens Junctions in the Ovine Uterus: Differential Regulation by Pregnancy and Progesterone
Authors: Satterfield M. Carey , Dunlap Kathrin A. , Hayashi Kanako , Burghardt Robert C. , Spencer Thomas E. , Bazer Fuller W.
Published: May 2007

In species with noninvasive implantation by conceptus trophectoderm, fetal/maternal communications occur across the endometrial epithelia. The present studies identified changes in junctional complexes in the ovine endometrium that regulate paracellular trafficking of water, ions, and other molecules, and the secretory capacity of the uterine epithelia. Distinct temporal and spatial alterations in occludin, tight junction protein 2, and claudin 1–4 proteins were observed in the endometrium of cyclic and early pregnant ewes. Dynamic changes in tight junction formation were characterized by an abundance of tight junction proteins on d 10 of the estrous cycle and pregnancy that substantially decreased by d 12. Early progesterone administration advanced conceptus development on d 9 and 12 that was associated with loss of tight-junction-associated proteins. Pregnancy increased tight-junction-associated proteins between d 14–16. Cadherin 1 and β-catenin, which form adherens junctions, were abundant in the endometrial glands, but decreased after d 10 of pregnancy in the luminal epithelium and then increased by d 16 with the onset of implantation. Results support the ideas that progesterone elicits transient decreases in tight and adherens junctions in the endometrial luminal epithelium between d 10–12 that increases selective serum and tissue fluid transudation to enhance blastocyst elongation, which is subsequently followed by an increase in tight and adherens junctions between d 14–16 that may be required for attachment and adherence of the trophectoderm for implantation. The continuous presence of tight and adherens junctions in the uterine glands would allow for vectorial secretion of trophic substances required for conceptus elongation and survival.
Flight Paths
Authors: Quesne Philippe
Published: April 2007

Interviewed and Translated by Tom Sellar
Taking Stock
Authors: Magasin Grand
Published: April 2007

Interviewed by Tom Sellar
Extrusion of earthworm coelomocytes: comparison of the cell populations recovered from the species Lumbricus terrestris, Eisenia fetida and Octolasion tyrtaeum
Authors: Diogéne J. , Dufour M. , Poirier G. G. , Nadeau D.
Published: April 2007

Coelomocytes were extruded from three earthworm species: Lumbricus terrestris, Eisenia fetida and Octolasion tyrtaeum. Featuring a simple low-vacuum holding device, the proposed methodology allows the recovery of cells with minimum risk of contamination by faecal material. The viability of O. tyrtaeum coelomocytes was highly reproducible (average 93%), with an average yield of 0.92 × 106 viable cells per earthworm. Cell viability for L. terrestris and E. fetida averaged ~68% but the cell yields were higher (respectively 1.67 × 106 and 1.28 × 106). Large inter-individual differences in cell yields were observed with L. terrestris. Flow cytometric analyses indicated species to species differences in cell populations. Coelomocytes from E. fetida were the smallest with ~57% of the total viable cells recovered being monitored between 2 and 10 µm. Large granulated cells (≥20 µm) were detected in fairly large proportions in L. terrestris and O. tyrtaeum [~52 and ~96%, respectively) while they were less abundant in E.fetida (~9%). Using the vital dye neutral red to assess functional integrity, average cellular uptakes were significantly higher for L. terrestris and O. tyrtaeum than for E. fetida (2.94, 2.66 and 0.64 µg/2 × 105 cells, respectively). In summary, the extrusion methodology herein described is applicable for the recovery of coelomocytes from a wide range of earthworm sizes and species. Moreover, this study strengthens the fact that extruded coelomocytes could be used for the evaluation of cell dysfunction and/or cell death following an in vitro and/or in vivo treatment.
Hypoxia-induced pulmonary hypertension in an optimized environment for the guineapig
Authors: Bochnowicz Steven , Osborn Ruth R. , Hay W. P. , Underwood David C.
Published: April 2007

Prolonged exposure to hypoxia elicits a variety of time-related morphologic and physiologic changes in the pulmonary vasculature of mammals, including humans. The study of hypoxia-induced changes in rodents generally requires a prolonged exposure to 9% oxygen for a minimum of 10 days in an airtight chamber, which has only been generally described in the literature as large (200-400 l), sealed acrylic chambers. To assist in the search for better therapies for diseases associated with chronic hypoxia using animal models, we have custom-built an airtight chamber for hypoxic exposure of rodents, and characterized the effect of chronic hypoxia on functional and morphologic changes in the pulmonary vasculature of the guineapig using this system. This chamber has been designed to alleviate any unnecessary stress related to food or water intake, cleanliness and excess illumination to the animals during the hypoxic-exposure period. Chronic exposure of the guineapig to hypoxia (0-21 days) produced time-related physiologic, morphologic, and haematologic changes. For example, after 10 days in hypoxia (9% oxygen), pulmonary artery pressure was significantly increased from 13±1 mmHg in normoxic controls (day 0, n=6) to 26±0 mmHg (day 10, n=4, P<0.01). Right ventricular hypertrophy in hypoxic animals, presented as a ratio of right ventricle free wall weight to body weight, showed a significant increase from 0.054±0.004 (day 0) to 0.069±0.004 on day 10 ( P<0.05), while age-matched normoxic animals showed no changes in right ventricular weight (day 0=0.059; day 10=0.058; P>0.05). Red blood cell count significantly increased over the same time period, from 5.9±0.1 (day 0) to 6.4±0.1 (day 10, P<0.05) as did haematocrit, 48±0.7 (day 0) to 61±0.9 (day 10, P<0.05) and haemoglobin, l6±0.2 (day 0) to 20±0.1 (day 10, P<0.05). It is concluded that considerations for the well-being of the test animals (i.e. continuous water, ample food supplies, burrow-like hiding places, sanitation and protection from excess illumination) can easily be incorporated into a hypoxic chamber. The purpose of the present study was to explore modifications that may provide the animal with an optimized environment which will reduce anxiety and stress, as seen in their behaviour when inside the chambers, and to thoroughly characterize the morphologic and physiologic changes associated with chronic hypoxia which develop in a consistent time-related manner.
Systemic mast cell disease in the Mongolian gerbil, Meriones unguiculatus: case report
Authors: Guzman-Silva Maria Angelica
Published: April 2007

A case of spontaneous occurrence of systemic mast cell disease in a non-treated laboratory-reared gerbil is reported. This case corresponds to the form of systemic mastocytosis with bone marrow and visceral involvement associated with skin disease and displays clinically aggressive behaviour. The histopathological, histochemical and ultrastructural features are described.
Behavioural and cardiovascular responses of rats to euthanasia using carbon dioxide gas
Authors: Smith William , Harrap Stephen B.
Published: April 2007

Our results showed more rapid falls in pulse rate and blood pressure in rats euthanized in a chamber precharged with carbon dioxide (CO2), when compared with rats euthanized more slowly, but death still took over 5 min in the former group. There was no behavioural evidence of pain or distress in either group during euthanasia. Initial ataxia and dyspnoea was punctuated by a lag before death, thus separating euthanasia into three clearly defined phases. All visual signs of death preceded complete vascular collapse by about 1 min in both groups, so we recommend that gas flow be maintained for at least 1 min after apparent death.
Report on primate supply for biomedical scientific work in the UK
Authors: Owen S. , Thomas C. , West P. , Wolfensohn S. , Wood M.
Published: April 2007

A Working Party of the UK group of European Primate Resources Network (EUPREN) considered primate supply for scientific work in the UK. Through a questionnaire, which achieved a very good response, it obtained details of primate use, sources and breeding in the UK and it put forward options to ensure that animal welfare is the best possible whilst ensuring continued supply.

The questionnaire showed that contract research laboratories and pharmaceutical companies use about 80% of the 4233 primates used annually at the moment, with the rest accounted for by academic establishments and public sector laboratories. Fifty-four per cent are cynomolgus macaques ( Macaca fascicularis), of which nearly 90% are captive-bred outside the European Union (EU), the remainder being bred in the UK. Nearly 90% of cynomolgus macaques are used by only five institutions. Thirty-seven per cent of primates used are marmosets ( Callithrix jacchus jacchus), all of which are bred in the UK. Most of the rest are rhesus macaques ( Macaca mulatta), about half of which are captive-bred outside the EU, the other half being bred in the UK. Overall primate use has increased from about 3000 per year in 1990 and users predict that requirements for all species except baboons ( Papio sp.) will be maintained or increase.

Marmoset breeding in the UK is already closely matched to use, and it could be increased reasonably easily if necessary. Some of the existing breeding centres of macaques in the UK would be prepared to consider expanding to supply others, although investment and imported breeding stock would be needed and it is likely that a large investment would be needed to breed a significant fraction of the macaque use in the UK. A further problem is that the users of only about 10% of the cynomolgus macaques said that they could replace this species by rhesus macaques, which are easier to breed in the UK.

The questionnaire showed that much of the use of macaques would be transferred to other countries equally remote from the natural source countries of the animals, if constraints on primate use became more severe in the UK. Users felt that it is unlikely that much of the work could be transferred to the natural source countries themselves.

A review of the literature revealed a paucity of information on the effects of transport on primate welfare. The importance of obtaining this information before making decisions about alternative means of supply is stressed. Current schemes for the accreditation of primate breeders were reviewed.

A list of options is presented for discussion. Users vary so much in their requirements that it is unlikely that one means of supply will be applicable to all. Animal welfare will benefit and supply will be more certain if cooperation between those concerned (preferably through the UK group of EUPREN) is maintained.
Brief review of scientific studies of the welfare implications of transporting primates
Authors: Wolfensohn S. E.
Published: April 2007

The transportation of primates has become an important welfare issue and the outcome of the debate over its cost to the animal will have effects on the future of medical research using these species. There is a paucity of scientific studies on transport relating to primates and the need for gathering of further scientific evidence is highlighted.
Reporting animal use in scientific papers
Authors: Smith Jane A. , Birke Lynda , Sadler Dawn
Published: April 2007

This paper reports the results of an examination of the 'methods' sections of a range of experimental research papers in biomedical science, focusing on the descriptions of animal use and housing. Detailed descriptions in the methods should enable replication, and also enable readers to judge scientific quality. Relatively few papers sampled gave adequate descriptions of housing conditions and many failed to give details of physiologically relevant variables such as weight of animals. Thirty per cent of papers omitted the number of animals used, and the deaths of animals (whether as part of the protocol, or accidental death) were not always recorded.

Adequate reporting of the conditions of animal maintenance and use are important, both in relation to the quality of the science produced, and also because of public concerns about the ethics of animal experiments.
An immunological assessment of group-housed rabbits
Authors: Turner R. J. , Held S. D. E. , Hirst J. E. , Billinghurst G. , Wootton R. J.
Published: April 2007

Laboratory rabbits kept in barren 'traditional' cages tend to develop stereo typic behaviours and bone deformities. We have used an alternative regime, housing adult does as groups of four or five in floor pens (2.5-3 m2) supplied with hiding places and bedding. High- and low-ranking members of each group were identified, and their immunological status compared in terms of blood leucocyte function (chemiluminescence and mitogen tests), complement activity, and antibody production to soluble and cellular antigens. We found no evidence of immunosuppression, either in groups of a 'docile' breed (New Zealand White) or Dutch crosses. These results, together with the animals' general health and ease of handling, lead us to conclude that group-housed does are suitable for raising antisera and other purposes, provided that they are adequately monitored.
Analgesics in mice used in cancer research: reduction of discomfort?
Authors: van Loo P. L. P. , Everse L. A. , Bernsen M. R. , Baumans V. , Hellebrekers L. J. , Kruitwagen C. L. J. J. , den Otter W.
Published: April 2007

During the last decades, an increase is apparent in the use of analgesics for laboratory animals in situations where this was previously considered unnecessary. Mice with advanced tumours often show clear signs of discomfort which may be a result of chronic pain or a result of general ill-being. The syngeneic murine tumour model most frequently used in our experiments was used to investigate whether this discomfort can be reduced with an analgesic. Twenty DBA/2 mice bearing SL2 lymphoma were given 0.5 mg/kg buprenorphine (Temgesic®) in food gel twice daily, 20 tumour-bearing mice were given control food gel at the same times. Indicators of well-being were monitored daily. These included behavioural parameters such as exploration, grooming, and posture; food and water consumption and fur quality. All mice showed a clear increase of discomfort with time: explorative behaviours and grooming decreased, while sitting in hunched posture increased. Food and water consumption and fur quality also decreased. Major significant differences between the buprenorphine treated group and the control group were not apparent. In conclusion, we could not document a positive effect or buprenorphine on discomfort in mice as evaluated by our scoring system. It remains possible that pain itself was not the primary cause of the discomfort in mice bearing these tumours, or that the analgesic effect of buprenorphine was insufficient under these circumstances.
Portacaval shunt control animals: physiological consequences derived from the sham operation
Authors: López L. , Burgos P. , Santín L. J. , Begega A. , Arias J. , Lorente L. , Arias J. L.
Published: April 2007

The portacaval shunt in the rat is a frequently used experimental model of portosystemic encephalopathy. Among other consequences of this surgical preparation is an important decrease in hepatic and testicular volume. Different sham-operation methods including a laparotomy were used as controls in each case. Given that the liver volume varies greatly in comparison to body weight in the sham-operated animals, this paper aims to evaluate the possible consequences of the sham operation. It concludes that control animals without manipulation, in addition to the respective controls of portacaval shunt, should be used in every case.
Microbiological monitoring of laboratory pigs
Authors: Hansen Axel Kornerup , Farlov Helene , Bollen Peter
Published: April 2007

Purpose-bred minipigs, are often used as the non-rodent species in toxicology. Infections may interfere with animal experiments, and there are no scientific reasons why the non-rodent species should be of a lower microbiological quality than the rodent species. Therefore, a system for health monitoring of pigs was developed in order to raise the quality of laboratory pigs to the level of laboratory rodents. This system, which includes screening for several viruses, bacteria and ecto- and endoparasites, was used for monitoring minipigs from a barrier unit with the same standards applied to rodents units. In these pigs only rotaviruses are found, which was shown by both serological antibody detection and by detection of rotaviral antigen in faeces. In minipigs from another unit with far less hygienic protection rotaviruses were also found along with certain influenza- and coronaviruses, as well as Pasteurella spp. It is concluded, that it is possible to raise pigs of a microbiological quality comparable to the quality of rats and mice, and that advanced microbiological monitoring in pigs will reveal useful information.
Rapid increase in inspired desflurane concentration does not elicit a hyperdynamic circulatory response in the pig
Authors: Karzai Waheedullah , Haberstroh Jörg , Müller Wolfgang , Priebe Hans-Joachim
Published: April 2007

The effects of a rapid increase in inspired desflurane concentration on systemic haemodynamics and plasma catecholamines were studied in seven pigs (22-30 kg). Following premedication (flunitrazepam 0.4 mg/kg i.m.), anaesthesia was induced (propofol 2.5 mg/kg i.v., vecuronium 0.2 mg/kg i.v.), the trachea orally intubated, and ventilation controlled. Anaesthesia was maintained with N2O/O2 (70%/30%), propofol (50 μg/kg/min), desflurane 12% end-tidal concentration), and vecuronium (0.3 mg/kg/h). After cannulation of both femoral arteries for subsequent simultaneous systemic pressure measurements and blood sampling for determination of epinephrine (E) and norepinephrine (NE) plasma levels, N2O and propofol were discontinued, and FiO2 and end-tidal concentration of desflurane increased to >0.9 and 3%, respectively. Forty minutes later, the inspired concentration of desflurane was abruptly increased to 15%. Mean arterial pressure (MAP), heart rate (HR), and plasma concentrations of E and NE were determined before and 1, 2, 4, 8, 16, and 32 min after increasing the desflurane concentration. Plasma concentrations of E and NE were determined by high performance liquid chromatography (HPLC) with electrochemical detection. Data were analysed by repeated measures ANOVA (significance level P<0.05). The abrupt increase in inspired desflurane concentration caused an insignificant increase (11%) in HR at 1, 2 and 4 min. There was an immediate decrease in MAP. Plasma levels of E and NE remained unchanged throughout. In conclusion, in contrast to findings in humans, a rapid increase in inspired desflurane concentration does not cause a hyperdynamic circulatory response in the pig.
Transrectal ultrasound guided manipulation of the canine prostate with minimum intervention
Authors: Chang Stanley S. C. , Anthony Sharon , Koder Peter C. , Brown Stephen G.
Published: April 2007

The canine prostate is a widely used and well established animal model for the assessment of therapeutic effects of laser technology in the search for better options for the treatment of benign prostatic hyperplasia. Conventionally for such experiments, the canine prostate is approached by laparotomy or transperineal urethrotomy. We have demonstrated a technique involving the use of ultrasound guided biopsy of the liver and prostate, and percutaneous laser treatment of the prostate, which has proved to be effective in reducing adverse effects on the experimental animals but without compromising scientific requirements for the experiments. We conclude that state-of-the-art percutaneous procedures not only refine animal intervention significantly but are also technically feasible for most laser studies using the canine prostate as an experimental model in the live animal.
Specific detection of mousepox virus by polymerase chain reaction
Authors: Neubauer Heinrich , Pfeffer Martin , Meyer Hermann
Published: April 2007

Polymerase chain reaction was applied to the rapid identification and detection of mousepox virus. This was accomplished by selection of primers targeting the A-type inclusion body protein gene. By investigating 20 strains belonging to five different species of the genus Orthopoxvirus, amplification was achieved only with the seven mousepox virus strains examined. The size of the resulting DNA fragment accounted for 116 base pairs and contained a recognition site for the restriction enzyme HindII, thus confirming its viral origin. Amplification of mousepox virus specific sequences was also possible from infected mouse lung tissue and serum.
The morphological changes of intestinal mucosa in growing rabbits
Authors: Yu Bi , Chiou Peter W. S.
Published: April 2007

The study aimed to increase understanding of digestive function from the development of the digestive tract from suckling to maturity in rabbits. The relative weights of the digestive tract (in relation to body weight) in different segments increase linearly during the rapid growth period between 2 and 8 weeks of age; thereafter intestinal weight gain is slower. An underdeveloped mucosal histology was observed in the hindgut of suckling rabbits at 2 weeks compared with 4 weeks of age. From SEM micrographs, the small intestinal mucosal villi look more slender and finger-like in the suckling period, thereafter becoming broader or tongue-like or plate-shaped in mature rabbits. The micrographs showed a compact arrangement in the underdeveloped hindgut mucosa at 2 weeks, but after weaning as hindgut fermentation becomes significant the mucosa increased in surface area.
Outbreaks of hyperkeratotic dermatitis of athymic nude mice in northern Italy
Authors: Scanziani E. , Gobbi A. , Crippa L. , Giusti A. M. , Giavazzi R. , Cavalletti E. , Luini M.
Published: April 2007

Hyperkeratotic dermatitis of athymic nude mice is an infectious disease caused by a coryneform bacterium. During the spring of 1995, outbreaks of hyperkeratotic dermatitis were observed in several nude mice facilities in northern Italy. In this report we describe the clinical, histopathological and microbiological features of the disease in two different animal facilities. Affected animals showed a typical 'scaly' appearance with small white flakes of material adherent to the skin. In one of the outbreaks (facility 2) the lesions were less severe and involved only limited areas of the body. The infection spread very quickly and the morbidity reached more than 80% in a few days, while the mortality was about 1%. The lesions resolved spontaneously within 7-10 days. Histological examination of affected skin revealed orthokeratotic hyperkeratosis, acanthosis and dermal inflammatory infiltration which were more severe in mice from facility 1. In Gram-stained sections groups of rods consistent with coryneform bacteria were detectable in the keratin layers covering the epidermal surface. A coryneform bacterium, biochemically typed as Corynebacterium bovis, was isolated from 11 out of 11 mice from facility 1 and from 8 out of 11 mice from facility 2.
In vivo mucosal uptake, mucosal transfer and retention of iron in mice
Authors: Santos M. , Wienk K. J. H. , Schilham M. W. , Clevers H. , de Sousa M. , Marx J. J. M.
Published: April 2007

An improved and sensitive method for studying iron absorption in mice with alterations in body iron stores is described. Mice with varying iron status were given a double isotope-labelled test dose containing 59Fe and 51Cr as a non-absorbable indicator, via an oroesophageal needle. Using a whole-body counter it was possible to measure in vivo the initial mucosal iron uptake and long-term iron retention and to calculate mucosal iron transfer. A significant difference was demonstrated between normal and both anaemic and dietary iron-loaded mice with regard to the various steps of iron absorption. When mice were tested twice for iron absorption, the results were highly reproducible. In conjunction with other parameters, the method described is useful in studying the mechanism and the regulation of iron absorption in mice.
Method for long-term intestinal access in the dog
Authors: Wilsson-Rahmberg M. , Jonsson O.
Published: April 2007

A variety of devices have been used to establish long-term intestinal access in laboratory animals. Their use is complicated by infection, tissue reaction, and a frequent need for single housing to prevent implant damage.

Intussuscepted nipple valves have long been used in the human field of surgery for various applications where there is a need to create a reservoir without leakage. With the use of the nipple valve it was possible to establish long-term intestinal access in dogs with minimal post-operative complications, no leakage and, because no foreign material was used, no complications due to tissue rejection.

The advantages of a nipple valve over the similar technique of a straight stoma is less post-operative complications in the form of leakage as well as enhanced access due to the design of the nipple valve. Encouraging results prompted us to widen the use of nipple valves to 14 dogs in which it has been possible to establish long-term colonic or duodenal/ileal access at one or two sites. Nine of the dogs are still in use with duration of instrumentation for some animals exceeding 60 weeks.

This method requires minimal maintenance, does not prevent group housing of instrumented dogs or outdoor activities nor does it compromise the quality of life for the animals.
A serological indication of the existence of a guineapig poliovirus
Authors: Hansen Axel Kornerup , Thomsen Palle , Jensen Hans-Jørgen Skovgaard
Published: April 2007

Attempts were made to clarify whether laboratory guineapigs may harbour a poliovirus which, in 1911, was described as the cause of a disease called guineapig lameness. By the use of ELISA for antibodies against the poliovirus, Theiler's murine encephalomyelitis virus (TMEV), it was shown that two pet shop guineapigs suffering from lameness had extremely high titres against poliovirus, while healthy guineapigs from the same pet shop were negative. Clearly positive results were also found in 35 out of 152 laboratory guineapig sera. Positive results were found in only two out of six breeding centres, but in three out of three experimental units, all of which purchased guineapigs from one of the seropositive breeding colonies. The diseased guineapigs recovered fully after treatment with vitamins in the drinking water, a treatment used for guineapig lameness by small animal practitioners. A theory that vitamin C deficient guineapigs are, due to an impaired steroid secretion, predisposed to succumbing to infection and develop demyelinating disease similar to that in TMEV infected mice is discussed briefly. Guineapig sera were also tested serologically for other infections. Antibodies against lymphocytic choriomeningitis virus, Clostridium piliforme and Toxoplasma gondii were not found, but one breeding colony was infected with adenovirus, pneumonia virus of mice, reovirus type 3, Sendai virus, parainfluenza (simian) virus type 5 and Encephalitozoon cuniculi. Two other breeding colonies were infected with both reovirus type 3 and E. cuniculi. In all three experimental units infection with adenovirus was observed, and in two of these Sendai virus and E. cuniculi antibodies were also found. The pet shop guineapigs were infected with adenovirus, reovirus type 3 and E. cuniculi.
Practical role of genetic profiling and preservation stock of human tumour xenograft lines as a tool in animal experiments for antitumour drug evaluation
Authors: Ohnish Y. , Yamamoto N. , Ebukuro M. , Yoshimura M. , Sawa N. , Ueyama Y. , Nomura T. , Katoh H.
Published: April 2007

Human tumour xenografts (HTXs) are a useful tool for animal experiments especially for evaluation of new antitumour drugs. We have been establishing HTXs, and have developed tumour chemosensitivity panels for new drug evaluation using them.

With regard to quality control (problems in changes into mouse-type tumours and/or artificial cross-contamination among tumour lines), we studied genetic profiling, and effects of long-term passaging on tumour properties such as growth and chemosensitivities, and we discuss the use of cryopreservation stock of HTXs and periodic replacement in order to maintain reproducibility of the experimental results.

We examined isozyme markers and DNA fingerprinting to identify species and individuality of the tumours, respectively. Growth curves and sensitivities to antitumour drugs were examined using HTXs with different passaging in nude mice.

Among the tumours we maintained, five human tumours were found to have changed to mouse origin from their isozyme markers and were excluded. We identified the individuality of tumours which we used for the chemosensitivity panels by DNA fingerprinting, and their properties were stable for long-term passaging in nude mice. However, growth speed and chemosensitivities to drugs were altered with long-term passaging, although DNA fingerprint analysis did not show any obvious changes with passaging.

Genetic profiling, such as isozyme markers and DNA fingerprinting, is useful to identify individuality of experimental HTXs, and tumours should be renewed periodically even when there are no signs of artificial contamination when they are used in experiments which require continuous reproducibility of experimental results.
A method for long duration anaesthesia for a new hindlimb ischaemia-reperfusion model in mice
Authors: Wiersema A. M. , Dirksen R. , Oyen W. J. G. , van der Vliet J. A.
Published: April 2007

To study the relationship between ischaemia-reperfusion and multiple organ dysfunction syndrome (MODS), a new anaesthesia method was required to be applied to C57BL/6 mice. These mice are also used in a well accepted, standardized model for MODS using intraperitoneally administered zymosan (zymosan induced general inflammation, ZIGI). The aim was to develop a new model for ischaemia-reperfusion with 6 h of anaesthesia. This and further specific requirements for the combination of ischaemia-reperfusion and the ZIGI method, made us select inhalational anaesthesia using isoflurane in oxygen. This study evaluates whether long-term anaesthesia confounds the results of ischaemia-reperfusion and the ZIGI model. In addition the benefits of using the analgesic buprenorphine were evaluated. Ischaemia was induced with a tourniquet around the hindlimb. Ischaemia and reperfusion were verified by imaging a radioactive tracer with a gamma-camera. It was established that anaesthesia with isoflurane in oxygen caused little perturbation of body temperature and respiratory rate. A survival rate of 89% without noteworthy influence on organs was obtained. Buprenorphine proved to provide adequate analgesia and had no influence on measured parameters. In our experimental setting, this model with long duration anaesthesia allowed us to induce ischaemia and reperfusion of the hindlimb without perturbation of measurements. It also allowed good exposure of the abdomen and facilitated combination with the ZIGI model.
Effective streptokinase treatment of blocked catheters in pigs and sheep
Authors: Leuvenink H. G. D. , Dierx J. A. J.
Published: April 2007

Sheep and pigs with chronic silastic catheters with a partial blockage of the catheter were treated locally with streptokinase. After one week of treatment all affected catheters were patent again for many weeks. In sheep it proved necessary to use the enzyme treatment as a maintenance tool by contrast with pigs. This treatment may reduce the number of animals used in long-term trials requiring vascular access.
Enterotropic mouse hepatitis virus
Authors: Homberger Felix R.
Published: April 2007

Mouse hepatitis virus (MHV), the coronavirus of the mouse, is the most common viral pathogen in contemporary laboratory mouse colonies throughout the world. It is highly contagious with variable clinical manifestations. The majority of infections are subclinical, but can still significantly influence biological responses, thus interfering with research, mainly in the field of immunology. MHV has been intensively studied from a number of research perspectives and has become the prototype for studying the molecular biology of coronaviruses. MHV contains a single-stranded, positive-sense RNA genome ranging from 27 to 31 kb, which is divided into seven genes. Virions consist of four to five structural proteins. There are many MHV strains that vary in virulence, organotropism and cell tropism, and are constantly evolving by naturally occurring mutation and recombination. Based on pathogenesis studies MHV strains are usually grouped according to their primary tissue tropism into two biotypes: polytropic and enterotropic. Enterotropic strains of MHV replicate in the intestinal mucosa and only rarely spread to other tissues. No morphological structure of the virion has as yet been identified that is responsible for enterotropism. The course of an MHV infection is dependent on the virus strain and host factors. Generally, MHV causes an acute, self-limiting infection which is inapparent in adult mice. Neonates are highly susceptible to disease and show high mortality. In an enzootically infected colony, however, they are protected by maternally derived passive immunity. Detection of MHV infections depends on serological screening of colonies. MHV is controlled by culling and rederivation of the affected colony using hysterectomy or embryo transfer or by elimination through cessation of breeding.
Ophthalmologic examination in systemic toxicity studies: an overview
Authors: Kuiper B. , Boevé M. H. , Jansen T. , Roelofs-van Emden M. E. , Thuring J. W. G. M. , Wijnands M. V. W.
Published: April 2007

The procedures of ophthalmologic examination used by the authors during systemic toxicity studies in laboratory animals are presented in this paper. The present international guidelines with respect to the requirements for ophthalmological examination are given in an overview. A list of proposed keywords is included which may be used in describing ocular changes.
A comparison between medetomidine-ketamine and medetomidine-propofol anaesthesia in rabbits
Authors: Hellebrekers Ludo J. , de Boer Evert-Jan W. , van Zuylen Michiel A. , Vosmeer Hans
Published: April 2007

We investigated the effects of combinations of the α2-agonist medetomidine with either ketamine or propofol for their overall quality of anaesthesia, including the possible concomitant changes in respiratory and circulatory function in New Zealand White rabbits.

Medetomidine was administered at 0.35 mg/kg, intramuscularly. Following sedation, ketamine (5 mg/kg) or propofol (2 and 3 mg/kg) were administered intravenously via the ear vein.

Data on reflexes (palpebral, corneal, ear-pinch and toe-pinch), jaw muscle tone and physiologic parameters (heart rate, blood pressure, respiration rate, body temperature) were recorded before and after administration of drugs. Intermittent arterial blood sampling was performed at predetermined intervals before and after anaesthesia.

The results show that the ear-pinch and toe-pinch reflexes and the jaw muscle tone are reliable indices to determine surgical anaesthetic depth. A surgical level of anaesthesia could be obtained reliably with the combination medetomidine-ketamine and medetomidine-propofol (3 mg/kg) with a duration of 19 min (variation 10 to 40 min, n=6) and 11 min (variation 5 to 15 min, n=6), respectively. Propofol administered at 2 mg/kg did not produce an adequate anaesthetic level.

The data from this study demonstrate a high degree of predictability in achieving a fast induction and adequate anaesthetic depth together with a low incidence of untoward side-effects and a zero mortality with the combinations investigated.

The data from the medetomidine-ketamine group show that, although adequate anaesthetic depth of medium duration is achieved, the arterial oxygen tension is reduced to hypoxemic levels. With the use of this combination, the supplemental administration of oxygen is advised.

With the combination of medetomidine-propofol (3 mg/kg) a short duration anaesthesia of adequate depth was achieved, whereby physiological variables all remained within acceptable ranges. The use of medetomidine-propofol, in combination with the α2-antagonist atipamezole to shorten recovery time, will provide reliable and very versatile anaesthesia in rabbits.
A technique of chronic intravascular catheterization for monitoring haemodynamic and laboratory values in conscious swine
Authors: Haberstroh J. , Mand U. , Lücke I. , Breuer H. , Ahrens M. , von Specht B. U.
Published: April 2007

In human and small animal intensive care medicine percutaneous sheath introducer (PSI) sets are commonly used for repeated insertion of an arterial or a venous catheter with only one vascular puncture.

We used PSI for chronic catheterization of swine with a Swan-Ganz thermodilution catheter via a surgically exposed external jugular vein. In this way we were able to change defective catheters or correct the position of the catheter tip without renewed surgical intervention.
Co-variance of chemically and histologically analysed severity of dystrophic cardiac calcification in mice
Authors: van den Broek F. A. R. , Beems R. B. , vanTintelen G. , Lemmens A. G. , Fielmich-Bouwman A. X. M. , Beynen A. C.
Published: April 2007

Dystrophic cardiac calcification (DCC) is a post-mortem finding in mice of various strains frequently used in biomedical research. The major aim of this study was to see whether DCC severity can be assessed by chemical analysis of calcium in the heart. Histological examination was used as the method of reference. Hearts of mice of four strains (BALB/c, C3H, C57BL/6 and DBA/2) were halved and the two resulting parts were subsequently subjected to histology or chemical analysis. Within hearts, the halves generally yielded similar results. The DCC scores and calcium contents were directly correlated within hearts. Thus, calcium analysis could serve as an alternative to histological examination in the assessment of DCC severity in mice.

DBA/2 and C3H mice were found to be affected by DCC. Plasma magnesium concentrations were lower in these strains than in the DCC-free C57BL/6 and BALB/c strains. The tongue, lungs and diaphragm were also found to be calcified in DCC positive animals. Possibly, DCC is just one component of a generalized soft tissue calcification.
Fungus Paecilomyces: a new agent in laboratory animals
Authors: Kunstýř I. , Jelínek F. , Bitzenhofer U. , Pittermann W.
Published: April 2007

The fungus Paecilomyces has not yet been considered a health problem in laboratory animals. However, this agent known as a 'spoiler' of fruit beverages and other foodstuffs is an opportunistic pathogen especially in immunocompromised humans. Since 1985, we have isolated Paecilomyces, most probably P. variotti, from six laboratory animal species, mainly rats. In about 90% of cases the organism was localized in the respiratory tract and there are some other findings favouring the hypothesis of an airborne infection. During this long observation period no consequences for the health of rats in one closed 'infected' SPF breeding unit (A) could be observed. In a controlled histological study on five infected rats, no lesions attributable to this mycotic agent could be detected. However, a self-limiting spontaneous outbreak of papular skin lesions associated with Paecilomyces was observed in a breeding colony (F) of hairless mice. The role of this fungus in an acute outbreak of respiratory signs in another colony of conventional rats (B) was considered to be secondary. Bearing in mind its occasionally harmful role in humans, relatively high resistance to disinfectants and toxigenicity, this new agent should be monitored and considered a potential health risk for laboratory animals.
Rabbit haemorrhagic disease: the new scourge of Oryctolagus cuniculus
Authors: Chasey David
Published: April 2007

A new, widespread and important disease of rabbits, rabbit haemorrhagic disease (RHD), is concisely reviewed and discussed. RHD is an acute, infectious condition of adult rabbits and morbidity and mortality, after a relatively short incubation period, can be very high. The disease appears typically as a necrotizing hepatitis with associated haemorrhaging, and death occurs as a result of generalized organ dysfunction. RHD is caused by a calicivirus, antigenically related to a similar virus found in brown hares but distinct from other known caliciviruses, and is spread to susceptible rabbits by a number of routes and vectors. The disease is easily identified and can be effectively controlled in commercial and domestic rabbit populations by slaughter and vaccination regimes. The occurrence of pre-existing cross-reacting antibody in a proportion of rabbits unchallenged by the disease implies the presence of non-pathogenic strains of the virus. This antibody protects against disease on subsequent exposure to RHD. Uniquely, pre-existing antibody does not occur in rabbits in Australia where, after accidental release, the virus is currently spreading rapidly.
The response of group-housed baboons to three enrichment toys
Authors: Brent L. , Belik M.
Published: April 2007

The behaviour of group-housed baboons was compared before and after the provision of durable cage toys. One adult male hamadryas baboon and 13 adult female olive baboons living in a large enclosure were observed after they were given seven nylon bones, seven KongTM toys and seven Plaque AttackersTM. Observations were conducted four times per week on each subject over a 6-week period. Abnormal, cage-directed, inactive and self-directed behaviours all significantly decreased after the provision of the toys, while enrichment-directed activities significantly increased. Aggression did not differ between the no toy and toy conditions. Approximately 26% of the baboons were using the toys at anyone time, and use of the KongTM toys and the bones was higher than that of the Plaque AttackersTM. Individuals who used enrichment structures already present were also those who used the new toys the most.
The influence of dietary phosphorus and magnesium concentrations on the calcium content of heart and kidneys of DBA/2 and NMRI mice
Authors: van den Broek F. A. R. , Beynen A. C.
Published: April 2007

Dystrophic cardiac calcification (DCC) is often found in DBA/2 mice, reportedly in association with low plasma magnesium levels in this mouse strain. It was hypothesized that high-phosphorus diets and low-magnesium diets that are known to lower plasma magnesium concentrations would promote the development of DCC. DBA/2 mice were fed diets with either low-magnesium (0.02%, w/w) or high-phosphorus (0.8%) concentrations or a combination of the two variables. NMRI mice were given either a low-(0.2%) or high-(0.6%) phosphorus diet.

Female, but not male, NMRI mice accumulated calcium in the heart when fed the high-phosphorus diet; neither gender developed kidney calcification. DBA/2 mice with either a low-magnesium or a high-phosphorus intake developed marked cardiac calcifications. The combination of low-magnesium and high-phosphorus intake caused severe calcification of the heart, kidney and tongue'. Increasing the dietary magnesium content (0.08%) and reducing phosphorus (0.2%) did not fully prevent cardiac calcification, but reduced heart calcium concentrations in male DBA/2 mice. It is concluded that diets for DCC-susceptib1e mice should contain adequate amounts of magnesium and low, but sufficient amounts of phosphorus in order not to additionally stimulate cardiac calcification.
Reference database of the main physiological parameters in Sprague-Dawley rats from 6 to 32 months
Authors: Alemáan C. L. , Más R. M. , Rodeiro I. , Noa M. , Hernández C. , Menéndez R. , Gámez R.
Published: April 2007

A reference database comprising body weight gain, exploratory activity, hot plate response, serum biochemistry, haematology, organ weight (%) and a complete anatomopathological study containing non-neoplastic and neoplastic lesions over 1200 Sprague-Dawley rats from 6 to 32 months is described. Comparisons between age and sex were analysed.
Adverse effects of tribromoethanol as used in the production of transgenic mice
Authors: Zeller Walter , Meier Gabriele , Bürki Kurt , Panoussis Basile
Published: April 2007

Tribromoethanol is widely used as an anaesthetic agent for embryo-transfer surgery for the generation of transgenic mice. Potential side effects such as local irritation, fibrous adhesions in the abdominal cavity, and mortalities of unknown cause have been reported. Mice of three different strains (CD-1, OF-1, NMRI) received intraperitoneal injections of pentobarbiturate (60 mg/kg, 0.4%), tribromoethanol (240 mg/kg, 1.2%), tribromoethanol (450 mg/kg, 2.5%), ketamine/xylazine (120 mg/kg, 1.2%/16 mg/kg, 0.16%) or saline (NaCl, 0.9%). After 24 h the animals were sacrificed and blinded histopathological examination of abdominal organs was performed by light microscopy. Tribromoethanol caused focal to diffuse necrosis primarily of subperitoneal muscle fibres of the abdominal wall, and, occasionally, necrotic changes on the surface of abdominal organs. These changes were associated with acute peritoneal inflammation and fibrinous serositis of the abdominal organs. The severity of the findings increased with the concentration of tribromoethanol. The use of ketamine/xylazine yielded a comparable success rate in embryo transfer without undesirable side effects. Further use of tribromoethanol is not recommended.
Sampling of interstitial fluid and measurement of colloid osmotic pressure (COPi) in pigs: evaluation of the wick method
Authors: Heltne J. K. , Husby P. , Koller M.-E. , Lund T.
Published: April 2007

The wick method for sampling of interstitial fluid from subcutis was applied in fluid balance studies in young pigs. Colloid osmotic pressure was measured in serum (COPs) and interstitial fluid (COPi) using a membrane colloid osmometer. Our aims were to determine the 'true' COPi, and to find the optimal duration of wick implantation. In series I ( n=6) a 'crossover' experiment was performed using wicks soaked in different priming solutions (nondiluted and diluted serum protein solutions or isotonic salt solution). Circulatory arrest was induced just before wick insertion in order to eliminate the vascular part of the acute inflammation. In series II ( n=6) wicks were removed in sequence after 60, 90, 120 and 180 min sampling time in anaesthetized pigs in vivo. COPs, COPi and haematocrit (HCT) together with haemoglobin (Hgb), serum albumin and total protein concentrations were determined in the same animals.

In series I average COPs and COPi were 13.7 (1.4) and 7.2 (1.4) mmHg respectively (SD). In series II the optimal wick implantation times were estimated to be 60–90 min for wicks soaked in diluted protein solution, and 90–120 min for dry and saline-soaked wicks. COPs averaged 13.0 (0.7) mmHg, HCT 30.0 (1.6)%, Hgb 8.3 (0.9) g/dl, s-albumin 22.7 (0.6) g/l and s-protein 47.3 (2.3) g/l.

Compared to commonly reported reference values, we found surprisingly low values for most of the measured variables. This may be related to the fact that we used immature pigs. An analysis of the validity of the wick method based on our own results and published reports is presented. We conclude that sampling of interstitial fluid with subcutaneous wicks is easy to perform in young pigs. However, the COP-values measured in wick fluid have to be carefully evaluated especially when sampling is performed in vivo.
Saphenous vein puncture for blood sampling of the mouse, rat, hamster, gerbil, guineapig, ferret and mink
Authors: Hem Annelise , Smith Adrian J. , Solberg Per
Published: April 2007

A method is described for blood collection from the lateral saphenous vein. This enables rapid sampling, which if necessary can be repeated from the same site without a need for new puncture wounds. The method is a humane and practical alternative to cardiac and retro-orbital puncture, in species where venepuncture has traditionally been regarded as problematic.