Pritchett-Corning K.R.,Research Models and Services |
Clifford C.B.,Research Models and Services |
Festing M.F.W.,C O Medical Research Council Toxicology Unit
Birth Defects Research Part B - Developmental and Reproductive Toxicology | Year: 2013
Although rats in various stages of pregnancy are routinely shipped by vendors, the effects of shipping on pregnancy outcomes have not been reported. This study examined the effects of shipping rats 1 day after mating. Two outbred stocks, (Crl:CD(SD), Crl:WI(Han)) and one inbred strain (F344/Crl) of rats (n = 300/strain) were mated in a vendor barrier room at 3-month intervals five times, and either shipped the next day (total time in transit ∼24 hr) or held in the room of origin until parturition. The pregnancy status, length of gestation, number of pups born per female, sex ratio of pups born, and neonatal mortality were compared between transported and nontransported rats. These pregnancy and litter parameters were also compared among strains and examined for seasonality; no seasonal effects were observed. Neonatal mortality was negligible at less than 2% in any of the groups. All sex ratios were normal. Transportation affected pregnancy rates only in the F344/Crl, in which 81.8% of the nontransported versus 70% of the transported rats had pups (p = 0.025). Overall, slightly fewer transported rats were pregnant, but they had larger litters (10.08 compared with 9.68, p = 0.02, pooling across all three strains) so produced the same numbers of pups. A total of 77 ± 8% of transported rats had gestation periods of 22 days or more compared with only 52 ± 10% in the nontransported rats. The reason for larger litters in transported females is unclear. Longer gestation in transported females may be due to facultative embryonic diapause, which might have implications for reproductive toxicology. © 2013 Wiley Periodicals, Inc.
News Article | February 15, 2017
WILMINGTON, Mass.--(BUSINESS WIRE)--Charles River Laboratories International, Inc. (NYSE: CRL) today reported its results for the fourth-quarter and full-year 2016 and provided guidance for 2017. For the quarter, revenue from continuing operations was $466.8 million, an increase of 31.9% from $353.9 million in the fourth quarter of 2015. Revenue growth was driven primarily by the Discovery and Safety Assessment and Manufacturing Support segments. Research Models and Services revenue also increased. The acquisitions of WIL Research, Agilux Laboratories, Blue Stream Laboratories, and Oncotest contributed 20.9% to consolidated fourth-quarter revenue growth, both on a reported basis and in constant currency. The addition of a 53rd week at the end of 2016, which is periodically required to align to a December 31st calendar year end, contributed approximately 5.1% to reported fourth-quarter revenue growth. The impact of foreign currency translation reduced reported revenue growth by 2.4%. Excluding the effect of these items, organic revenue growth was 8.3%. On a GAAP basis, net income from continuing operations attributable to common shareholders was $44.7 million for the fourth quarter of 2016, an increase of 36.4% from $32.8 million for the same period in 2015. Fourth-quarter diluted earnings per share on a GAAP basis were $0.93, an increase of 34.8% from $0.69 for the fourth quarter of 2015. On a non-GAAP basis, net income from continuing operations was $58.3 million for the fourth quarter of 2016, an increase of 23.3% from $47.3 million for the same period in 2015. Fourth-quarter diluted earnings per share on a non-GAAP basis were $1.21, an increase of 21.0% from $1.00 per share for the fourth quarter of 2015. Both the GAAP and non-GAAP earnings per share increases were driven primarily by the acquisition of new businesses, notably WIL Research, as well as higher revenue for legacy operations. A gain from the Company’s venture capital investments contributed $0.02 per share in the fourth quarter of 2016, compared to a negligible impact for the same period in 2015. James C. Foster, Chairman, President and Chief Executive Officer, said, “Our fourth-quarter results provided a strong finish to an exceptional year in which we met our long-term revenue goals for all of our businesses except Discovery, and our long-term operating margin targets for the three business segments. We were very pleased that three of our businesses, Safety Assessment, Microbial Solutions, and Biologics Testing Solutions, reported low-double-digit organic revenue growth for the full year. Client demand for our unique portfolio of essential products and services remained strong across each of our client segments, particularly for our biotechnology clients, who were the primary driver of our revenue growth in 2016.” “Our continued investments to broaden our early-stage portfolio, the scientific expertise of our staff, our focus on productivity and efficiency initiatives, and our ability to offer flexible partnership structures are the primary reasons that we are the partner of choice for many of our clients. Based on our view of the opportunities in 2017, we believe we will again deliver high single-digit organic revenue growth and earnings per share growth at a faster rate than revenue,” Mr. Foster concluded. Revenue for the RMS segment was $124.7 million in the fourth quarter of 2016, an increase of 9.5% from $113.8 million in the fourth quarter of 2015. Organic revenue growth was 5.7%. Revenue growth was driven primarily by higher sales of research model services, and sales of research models also increased. In the fourth quarter of 2016, the RMS segment’s GAAP operating margin increased to 26.7% from 24.1% in the fourth quarter of 2015. On a non-GAAP basis, the operating margin increased to 27.3% from 25.4% in the fourth quarter of 2015. Both the GAAP and non-GAAP operating margin increases were due primarily to higher sales volume and the benefit of efficiency initiatives. Revenue from continuing operations for the DSA segment was $241.7 million in the fourth quarter of 2016, an increase of 50.6% from $160.5 million in the fourth quarter of 2015. Growth was driven primarily by the acquisitions of WIL Research, Agilux Laboratories, and Oncotest, which contributed 41.6% to DSA revenue growth. Organic revenue growth was 7.9%. Low-double-digit growth in the legacy Safety Assessment business was partially offset by lower revenue for the legacy Discovery Services business, which declined due primarily to softer demand from global clients for Early Discovery services. Robust demand from biotechnology clients continued to drive revenue growth in the DSA segment. In the fourth quarter of 2016, the DSA segment’s GAAP operating margin declined to 18.1% from 23.1% in the fourth quarter of 2015. The margin decline was due to costs associated with the evaluation and integration of acquisitions, including amortization of intangible assets, as well as the benefit from a tax law change in Quebec in the fourth quarter of 2015. On a non-GAAP basis, the operating margin decreased to 23.8% from 27.1% in the fourth quarter of 2015, due primarily to the tax law change in Quebec, which benefited both the GAAP and non-GAAP DSA operating margin by approximately 230 basis points in the fourth quarter of 2015. The acquisition of WIL reduced the fourth-quarter operating margin by approximately 100 basis points, and foreign exchange benefited the DSA operating margin by approximately 80 basis points due primarily to a weaker British pound. Revenue for the Manufacturing segment was $100.3 million in the fourth quarter of 2016, an increase of 26.2% from $79.5 million in the fourth quarter of 2015. The acquisitions of Blue Stream Laboratories and WIL Research’s contract development and manufacturing (CDMO) services contributed 9.2% to Manufacturing revenue growth in the fourth quarter of 2016. Organic revenue growth was 12.9%, primarily driven by robust growth in the Microbial Solutions and Biologics Testing Solutions businesses. In the fourth quarter of 2016, the Manufacturing segment’s GAAP operating margin increased to 31.0% from 23.7% in the fourth quarter of 2015. The GAAP operating margin increase was primarily driven by lower acquisition costs related to Celsis, as well as leverage from higher revenue in the Microbial Solutions business. On a non-GAAP basis, the operating margin increased to 34.2% from 33.8% in the fourth quarter of 2015, driven by operating margin improvement in the Microbial Solutions business as a result of higher revenue and the benefit of efficiency initiatives. For 2016, revenue increased by 23.3% to $1.68 billion from $1.36 billion in 2015. Organic revenue growth was 7.7%. On a GAAP basis, net income from continuing operations attributable to common shareholders was $154.5 million in 2016, an increase of 2.8% from $150.3 million in 2015. Diluted earnings per share on a GAAP basis in 2016 were $3.22, an increase of 2.2% from $3.15 in 2015. On a non-GAAP basis, net income from continuing operations was $218.9 million in 2016, an increase of 22.1% from $179.3 million in 2015. Diluted earnings per share on a non-GAAP basis in 2016 were $4.56, an increase of 21.3% from $3.76 in 2015. For 2016, RMS revenue was $494.0 million, an increase of 5.0% from $470.4 million in 2015. Organic revenue growth was 4.1%. On a GAAP basis, the RMS segment operating margin increased to 27.6% in 2016 from 25.7% in 2015. On a non-GAAP basis, the operating margin increased to 28.4% in 2016 from 27.1% in 2015. For 2016, DSA revenue was $836.6 million, an increase of 36.7% from $612.2 million in 2015. Organic revenue growth was 8.9%. On a GAAP basis, the DSA segment operating margin decreased to 16.5% in 2016 from 19.9% in 2015. On a non-GAAP basis, the operating margin decreased to 22.7% in 2016 from 23.3% in 2015. For 2016, Manufacturing revenue was $350.8 million, an increase of 25.0% from $280.7 million in 2015. Organic revenue growth was 11.3%. On a GAAP basis, the Manufacturing segment operating margin increased to 29.8% in 2016 from 26.6% in 2015. On a non-GAAP basis, the operating margin increased to 33.8% in 2016 from 32.6% in 2015. Charles River completed the divestiture of its CDMO business on February 10, 2017, to Quotient Clinical, a portfolio company of specialist healthcare investment adviser GHO Capital Partners LLP, based in London, England, for $75.0 million in cash, subject to certain post-closing adjustments. The CDMO business, which represented approximately 1% of Charles River’s 2016 consolidated revenue, provides services to support the formulation design and manufacture of oral drug dosages for biopharmaceutical clients, specializing in high-potency compounds. Charles River acquired the CDMO business in April 2016 as part of the acquisition of WIL Research. Following a strategic review, Charles River determined that the CDMO business was not optimized within Charles River’s portfolio at its current scale, and that the capital could be better deployed in other long-term growth opportunities. The Company is providing the following revenue growth and earnings per share guidance for 2017. This guidance reflects the divestiture of the CDMO business. Earnings per share in 2017 are expected to benefit from both higher revenue and operating margin expansion. The benefit is expected to be partially offset by foreign exchange, which is expected to reduce 2017 earnings per share by approximately $0.10, and lower gains from the Company’s venture capital investments. The Company’s 2016 earnings per share included a $0.13 gain on venture capital investments, and 2017 guidance includes an estimated $0.04 gain on these investments, consistent with the Company’s expected return on invested capital. Footnotes to Guidance Table (1) The contribution from acquisitions reflects only those acquisitions which were completed in 2016. (2) Organic revenue growth is defined as reported revenue growth adjusted for acquisitions, the divestiture of the CDMO business, the 53rd week, and foreign currency translation. (3) GAAP earnings per share guidance does not include the expected net gain and tax impact related to the divestiture of the CDMO business because the disposition accounting has not yet been finalized. (4) These charges relate primarily to the Company’s planned efficiency initiatives in 2017, including site consolidation costs, asset impairments, and severance. Other projects in support of the global productivity and efficiency initiatives are expected, but these charges reflect only the decisions that have already been finalized. (5) These adjustments are related to the evaluation and integration of acquisitions and the divestiture of the CDMO business, and primarily include transaction, advisory, and certain third-party integration costs, as well as certain costs associated with acquisition-related efficiency initiatives. Charles River has scheduled a live webcast on Tuesday, February 14, at 8:00 a.m. ET to discuss matters relating to this press release. To participate, please go to ir.criver.com and select the webcast link. You can also find the associated slide presentation and reconciliations of GAAP financial measures to non-GAAP financial measures on the website. Charles River will present at the Leerink 6th Annual Global Healthcare Conference in New York on Thursday, February 16, at 9:30 a.m. ET. Management will provide an overview of Charles River’s strategic focus and business developments. A live webcast of the presentation will be available through a link that will be posted on the Investor Relations section of the Charles River website at ir.criver.com. A webcast replay will be accessible through the same website approximately three hours after the presentation and will remain available for approximately two weeks. The Company reports non-GAAP results in this press release, which exclude often one-time charges and other items that are outside of normal operations. A reconciliation of GAAP to non-GAAP results is provided in the schedules at the end of this press release. In addition, the Company reports results from continuing operations, which exclude results of the Phase I clinical business that was divested in 2011. The Phase I business is reported as a discontinued operation. Use of Non-GAAP Financial Measures This press release contains non-GAAP financial measures, such as non-GAAP earnings per diluted share, which exclude the amortization of intangible assets, inventory purchase accounting adjustments, and other charges related to our acquisitions; expenses associated with evaluating and integrating acquisitions and divestitures, as well as fair value adjustments associated with contingent consideration; charges related to modifications of purchase options on remaining non-controlled equity interests, and re-measurement of previously held equity interests; charges, gains and losses attributable to businesses or properties we plan to close, consolidate or divest; severance and other costs associated with our efficiency initiatives; executive transition costs; a reversal of indemnification assets associated with acquisitions and corresponding interest; write-off of and adjustments to deferred financing costs and fees related to debt financing; gain on bargain purchase; and costs related to a U.S. government billing adjustment and related expenses. This press release also refers to our revenue in both a GAAP and non-GAAP basis: “constant currency,” which we define as reported revenue growth adjusted for the impact of foreign currency translation, and “organic revenue growth,” which we define as reported revenue growth adjusted for foreign currency translation, acquisitions, the divestiture of the CDMO business, and the 53rd week. We exclude these items from the non-GAAP financial measures because they are outside our normal operations. There are limitations in using non-GAAP financial measures, as they are not prepared in accordance with generally accepted accounting principles, and may be different than non-GAAP financial measures used by other companies. In particular, we believe that the inclusion of supplementary non-GAAP financial measures in this press release helps investors to gain a meaningful understanding of our core operating results and future prospects without the effect of these often-one-time charges, and is consistent with how management measures and forecasts the Company's performance, especially when comparing such results to prior periods or forecasts. We believe that the financial impact of our acquisitions and divestitures (and in certain cases, the evaluation of such acquisitions and divestitures, whether or not ultimately consummated) is often large relative to our overall financial performance, which can adversely affect the comparability of our results on a period-to-period basis. In addition, certain activities and their underlying associated costs, such as business acquisitions, generally occur periodically but on an unpredictable basis. We calculate non-GAAP integration costs to include third-party integration costs incurred post-acquisition. Presenting revenue on a constant-currency basis allows investors to measure our revenue growth exclusive of foreign currency exchange fluctuations more clearly. Non-GAAP results also allow investors to compare the Company’s operations against the financial results of other companies in the industry who similarly provide non-GAAP results. The non-GAAP financial measures included in this press release are not meant to be considered superior to or a substitute for results of operations prepared in accordance with GAAP. The Company intends to continue to assess the potential value of reporting non-GAAP results consistent with applicable rules and regulations. Reconciliations of the non-GAAP financial measures used in this press release to the most directly comparable GAAP financial measures are set forth in this press release, and can also be found on the Company’s website at ir.criver.com. This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements may be identified by the use of words such as “anticipate,” “believe,” “expect,” “intend,” “will,” “may,” “estimate,” “plan,” “outlook,” and “project,” and other similar expressions that predict or indicate future events or trends or that are not statements of historical matters. These statements also include statements regarding our projected future financial performance including revenue (on both a reported, constant-currency, and organic growth basis), operating margins, earnings per share, the expected impact of foreign exchange rates, and the expected benefit of our life science venture capital investments; the future demand for drug discovery and development products and services, including our expectations for future revenue trends; our expectations with respect to the impact of acquisitions on the Company, our service offerings, client perception, strategic relationships, revenue, revenue growth rates, and earnings; the development and performance of our services and products; market and industry conditions including the outsourcing of services and spending trends by our clients; the potential outcome of and impact to our business and financial operations due to litigation and legal proceedings, including with respect to our ongoing investigation of inaccurate billing with respect to certain government contracts; and Charles River’s future performance as delineated in our forward-looking guidance, and particularly our expectations with respect to revenue, the impact of foreign exchange, and enhanced efficiency initiatives. Forward-looking statements are based on Charles River’s current expectations and beliefs, and involve a number of risks and uncertainties that are difficult to predict and that could cause actual results to differ materially from those stated or implied by the forward-looking statements. Those risks and uncertainties include, but are not limited to: the ability to successfully integrate businesses we acquire; the ability to execute our efficiency initiatives on an effective and timely basis (including divestitures and site closures); the timing and magnitude of our share repurchases; negative trends in research and development spending, negative trends in the level of outsourced services, or other cost reduction actions by our clients; the ability to convert backlog to revenue; special interest groups; contaminations; industry trends; new displacement technologies; USDA and FDA regulations; changes in law; continued availability of products and supplies; loss of key personnel; interest rate and foreign currency exchange rate fluctuations (including the impact of Brexit); changes in tax regulation and laws; changes in generally accepted accounting principles; and any changes in business, political, or economic conditions due to the threat of future terrorist activity in the U.S. and other parts of the world, and related U.S. military action overseas. A further description of these risks, uncertainties, and other matters can be found in the Risk Factors detailed in Charles River's Annual Report on Form 10-K as filed on February 12, 2016, as well as other filings we make with the Securities and Exchange Commission. Because forward-looking statements involve risks and uncertainties, actual results and events may differ materially from results and events currently expected by Charles River, and Charles River assumes no obligation and expressly disclaims any duty to update information contained in this news release except as required by law. Charles River provides essential products and services to help pharmaceutical and biotechnology companies, government agencies and leading academic institutions around the globe accelerate their research and drug development efforts. Our dedicated employees are focused on providing clients with exactly what they need to improve and expedite the discovery, early-stage development and safe manufacture of new therapies for the patients who need them. To learn more about our unique portfolio and breadth of services, visit www.criver.com. (1) Charles River management believes that supplementary non-GAAP financial measures provide useful information to allow investors to gain a meaningful understanding of our core operating results and future prospects, without the effect of often-one-time charges and other items which are outside our normal operations, consistent with the manner in which management measures and forecasts the Company’s performance. The supplementary non-GAAP financial measures included are not meant to be considered superior to, or a substitute for results of operations prepared in accordance with U.S. GAAP. The Company intends to continue to assess the potential value of reporting non-GAAP results consistent with applicable rules, regulations and guidance. (2) This item includes operating losses related primarily to the Company's Shrewsbury, Massachusetts facility. (3) These adjustments are related to the evaluation and integration of acquisitions, which primarily include transaction, third-party integration, and certain compensation costs, and fair value adjustments associated with contingent consideration. (1) Charles River management believes that supplementary non-GAAP financial measures provide useful information to allow investors to gain a meaningful understanding of our core operating results and future prospects, without the effect of often-one-time charges and other items which are outside our normal operations, consistent with the manner in which management measures and forecasts the Company’s performance. The supplementary non-GAAP financial measures included are not meant to be considered superior to, or a substitute for results of operations prepared in accordance with U.S. GAAP. The Company intends to continue to assess the potential value of reporting non-GAAP results consistent with applicable rules, regulations and guidance. (2) These amounts represent the reversal of an uncertain tax position and an offsetting indemnification asset primarily related to the acquisition of BioFocus. (3) The amounts relate to the acquisition of Sunrise Farms, Inc. and represents the excess of the estimated fair value of the net assets acquired over the purchase price. (4) The amount represents a $1.5 million charge recorded in connection with the modification of the option to purchase the remaining 13% equity interest in Vital River, partially offset by a $0.7 million gain on remeasurement of previously held equity interest in an entity acquired in a step acquisition. (1) Charles River management believes that supplementary non-GAAP financial measures provide useful information to allow investors to gain a meaningful understanding of our core operating results and future prospects, without the effect of often-one-time charges and other items which are outside our normal operations, consistent with the manner in which management measures and forecasts the Company’s performance. The supplementary non-GAAP financial measures included are not meant to be considered superior to, or a substitute for results of operations prepared in accordance with U.S. GAAP. The Company intends to continue to assess the potential value of reporting non-GAAP results consistent with applicable rules, regulations and guidance. (2) The contribution from acquisitions reflects only those acquisitions which were completed during fiscal year 2016 and 2015. (3) Organic revenue growth is defined as reported revenue growth adjusted for acquisitions, the 53rd week, and foreign exchange.
PubMed | Massachusetts Institute of Technology, Research Models and Services, Michigan State University, U.S. Army and 2 more.
Type: Journal Article | Journal: Veterinary pathology | Year: 2015
A commercial diet fed to a colony of inbred strain 13 guinea pigs for approximately 6 weeks was subsequently recalled for excessive levels of vitamin D. Twenty-one of 62 animals exhibited clinical signs, including anorexia, lethargy, and poor body condition. Nine affected and 4 clinically normal animals were euthanized for further evaluation, including serum chemistry, urinalysis, and gross and/or histopathology. Macroscopic findings included white discoloration in multiple organs in 8 animals, and microscopic evaluation confirmed multiorgan mineralization in tissues from 7 animals. Serum 25-hydroxyvitamin D levels were elevated in 10 animals. Serum inorganic phosphorus and alkaline phosphatase levels were increased in all exposed animals; however, total calcium and ionized calcium levels were not significantly higher in exposed animals than in control strain 13 guinea pigs from a different institution. The data support a diagnosis of hypervitaminosis D with metastatic calcification. Following the diet recall, the remaining guinea pigs increased their food intake and regained body condition. Diagnostic testing of 8 animals euthanized approximately 3 months after returning to a normal diet demonstrated that serum parathyroid hormone remained significantly lower, and ionized calcium and ionized magnesium were significantly higher, in recovered animals compared to controls and exposed animals. These results indicate that diagnostic tests other than serum calcium are necessary for a diagnosis of hypervitaminosis D in guinea pigs.
Machholz E.,Insourcing Solutions |
Mulder G.,Research Models and Services |
Ruiz C.,Insourcing Solutions |
Corning B.F.,Insourcing Solutions |
Pritchett-Corning K.R.,Research Models and Services
Journal of Visualized Experiments | Year: 2012
Being able to safely and effectively restrain mice and rats is an important part of conducting research. Working confidently and humanely with mice and rats requires a basic competency in handling and restraint methods. This article will present the basic principles required to safely handle animals. One-handed, two-handed, and restraint with specially designed restraint objects will be illustrated. Often, another part of the research or testing use of animals is the effective administration of compounds to mice and rats. Although there are a large number of possible administration routes (limited only by the size and organs of the animal), most are not used regularly in research. This video will illustrate several of the more common routes, including intravenous, intramuscular, subcutaneous, and oral gavage. The goal of this article is to expose a viewer unfamiliar with these techniques to basic restraint and substance administration routes. This video does not replace required hands-on training at your facility, but is meant to augment and supplement that training. © 2012 Journal of Visualized Experiments.
Gaskill B.N.,Research Models and Services
Journal of visualized experiments : JoVE | Year: 2013
The minimization and alleviation of suffering has moral and scientific implications. In order to mitigate this negative experience one must be able to identify when an animal is actually in distress. Pain, illness, or distress cannot be managed if unrecognized. Evaluation of pain or illness typically involves the measurement of physiologic and behavioral indicators which are either invasive or not suitable for large scale assessment. The observation of nesting behavior shows promise as the basis of a species appropriate cage-side assessment tool for recognizing distress in mice. Here we demonstrate the utility of nest building behavior in laboratory mice as an ethologically relevant indicator of welfare. The methods presented can be successfully used to identify thermal stressors, aggressive cages, sickness, and pain. Observation of nest building behavior in mouse colonies provides a refinement to health and well-being assessment on a day to day basis.
Horn M.J.,Research Models and Services
Journal of the American Association for Laboratory Animal Science : JAALAS | Year: 2012
The objective of the current study was to evaluate the effects of cage density, sanitation frequency, and bedding type on animal growth and welfare. At weaning, Sprague-Dawley rats and C57BL/6 mice were allocated to treatment groups according to sex, bedding type (shredded aspen, cellulose, or a 50:50 mixture), and cage density and sanitation frequency (inhouse cage density standards and sanitation procedures measured against Guide recommendations) for an 8-wk period. Body weight, feed disappearance, cage ammonia, ATP concentrations, behavior, morbidity, and mortality were assessed weekly; fecal corticosterone, microbiology, and lung histopathology (rats only) were evaluated at the culmination of the trial. In both rats and mice, parameters indicative of animal health and welfare were not significantly affected by cage density and sanitation frequency or bedding type. Occasional effects of feed disappearance and cage ammonia concentrations due to density and sanitation guidelines were noted in rat cages, and bedding type affected cage ammonia and ATP concentrations. Periodic spikes of cage ammonia and ATP concentrations were recorded in mouse cages maintained according to inhouse compared with Guide standards and in cages containing aspen compared with cellulose or aspen-cellulose mixed bedding. Ongoing studies and historical data support the finding that deviations or exceptions from the cage density and sanitation frequency standards set forth in the Guide do not negatively affect animal health, welfare, or production parameters at our institution. These parameters appear to be credible measures of animal health and wellbeing and may be useful for evaluating performance standards for animal husbandry.
Pritchett-Corning K.R.,Research Models and Services |
Mulder G.B.,Research Models and Services |
Luo Y.,Research Models and Services |
White W.J.,Research Models and Services
Journal of Visualized Experiments | Year: 2010
For both scientific and animal welfare reasons, training in basic surgical concepts and techniques should be undertaken before ever seeking to perform surgery on a rodent. Students, post-doctoral scholars, and others interested in performing surgery on rodents as part of a research protocol may not have had formal surgical training as part of their required coursework. Surgery itself is a technical skill, and one that will improve with practice. The principles of aseptic technique, however, often remain unexplained or untaught. For most new surgeons, this vital information is presented in piecemeal fashion or learned on the job, neither of which is ideal. It may also make learning how to perform a particular surgery difficult, as the new surgeon is learning both a surgical technique and the principles of asepsis at the same time. This article summarizes and makes recommendations for basic surgical skills and techniques necessary for successful rodent surgery. This article is designed to supplement hands-on training by the user's institution. © 2011 Journal of Visualized Experiments.
Pritchett-Corning K.R.,Research Models and Services |
Keefe R.,Research Models and Services |
Garner J.P.,Stanford University |
Gaskill B.N.,Research Models and Services
Laboratory Animals | Year: 2013
Some laboratory mice gnaw food pellets without ingesting much of the gnawed material, resulting in the production of waste material called 'orts'. The fact that this food grinding behavior is not seen in all individuals of a particular strain suggests that it might be abnormal, and thus indicate a welfare concern. Furthermore, the increased rate of feed consumption and cage soiling is undesirable from a husbandry perspective. To try to determine possible motivations for the behavior, and identify potential treatments, outbred Crl:CD1(Icr) mice exhibiting food grinding were selected for one of three treatments placed in the feeder: no enrichment, a chewing device, or sunflower seeds. Both enrichment groups showed a significant decrease (P<0.05) in ort production when compared with baseline measurements, but only mice provided with sunflower seeds maintained the decreased rate of food wastage after the treatment was withdrawn. A relationship between body weight and ort production was also found, in that cages with greater average body weights had lower levels of ort production. This suggests that a simple need to gnaw cannot alone explain food grinding, and that a nutritional motivation may also be involved. © The Author(s) 2013.
PubMed | Research Models and Services
Type: Journal Article | Journal: Veterinary pathology | Year: 2012
A prevalent and distinctive infectious interstitial pneumonia (IIP) of immunocompetent laboratory rats was suspected to be caused by a putative virus, termed rat respiratory virus, but this was never substantiated. To study this disease, 2 isolators were independently populated with rats from colonies with endemic disease, which was perpetuated by the regular addition of naive rats. After Pneumocystis was demonstrated by histopathology and polymerase chain reaction (PCR) in the lungs of rats from both isolators and an earlier bedding transmission study, the relationship between Pneumocystis and IIP was explored further by analyzing specimens from 3 contact transmission experiments, diagnostic submissions, and barrier room breeding colonies, including 1 with and 49 without IIP. Quantitative (q) PCR and immunofluorescence assay only detected Pneumocystis infection and serum antibodies in rats from experiments or colonies in which IIP was diagnosed by histopathology. In immunocompetent hosts, the Pneumocystis concentration in lungs corresponded to the severity and prevalence of IIP; seroconversion occurred when IIP developed and was followed by the concurrent clearance of Pneumocystis from lungs and resolution of disease. Experimentally infected immunodeficient RNU rats, by contrast, did not seroconvert to Pneumocystis or recover from infection. qPCR found Pneumocystis at significantly higher concentrations and much more often in lungs than in bronchial and nasal washes and failed to detect Pneumocystis in oral swabs. The sequences of a mitochondrial ribosomal large-subunit gene region for Pneumocystis from 11 distinct IIP sources were all identical to that of P. carinii. These data provide substantial evidence that P. carinii causes IIP in immunocompetent rats.
PubMed | Research Models and Services
Type: Journal Article | Journal: Laboratory animals | Year: 2013
Some laboratory mice gnaw food pellets without ingesting much of the gnawed material, resulting in the production of waste material called orts. The fact that this food grinding behavior is not seen in all individuals of a particular strain suggests that it might be abnormal, and thus indicate a welfare concern. Furthermore, the increased rate of feed consumption and cage soiling is undesirable from a husbandry perspective. To try to determine possible motivations for the behavior, and identify potential treatments, outbred Crl:CD1(Icr) mice exhibiting food grinding were selected for one of three treatments placed in the feeder: no enrichment, a chewing device, or sunflower seeds. Both enrichment groups showed a significant decrease (P < 0.05) in ort production when compared with baseline measurements, but only mice provided with sunflower seeds maintained the decreased rate of food wastage after the treatment was withdrawn. A relationship between body weight and ort production was also found, in that cages with greater average body weights had lower levels of ort production. This suggests that a simple need to gnaw cannot alone explain food grinding, and that a nutritional motivation may also be involved.