Overview of Session 3 Mechanisms of Decreased Erythropoiesis and Erythroid Cell Injury.

This session, held during the 41st Annual STP Symposium, focused on mechanisms of decreased erythropoiesis and erythroid cell injury. The speakers provided comprehensive overviews of physiologic and pathologic erythropoiesis, reviewed various mechanisms of erythroid cell injury, and shared innovative investigative research with the audience.

The use of emerging safety biomarkers in nonclinical and clinical safety assessment - The current and future state: An IQ DruSafe industry survey.

Pharmaceutical and biotechnology companies rarely disclose their use of translational emerging safety biomarkers (ESBs) during drug development, and the impact of ESB use on the speed of drug development remains unclear. A cross-industry survey of 20 companies of varying size was conducted to understand current trends in ESB use and future use prospects. The objectives were to: (1) determine current ESB use in nonclinical and clinical drug development and impact on asset advancement; (2) identify opportunities, gaps, and challenges to greater ESB implementation; and (3) benchmark perspectives on regulatory acceptance. Although ESBs were employed in only 5-50% of studies/programs, most companies used ESBs to some extent, with larger companies demonstrating greater nonclinical use. Inclusion of ESBs in investigational new drug applications (INDs) was similar across all companies; however, differences in clinical trial usage could vary among the prevailing health authority (HA). Broader implementation of ESBs requires resource support, cross-industry partnerships, and collaboration with HAs. This includes generating sufficient foundational data, demonstrating nonclinical to clinical translatability and practical utility, and clearly written criteria by HAs to enable qualification. If achieved, ESBs will play a critical role in the development of next-generation, translationally-tailored standard laboratory tests for drug development.

Recognizing and Reducing Analytical Errors and Sources of Variation in Clinical Pathology Data in Safety Assessment Studies.

Veterinary clinical pathologists are well positioned via education and training to assist in investigations of unexpected results or increased variation in clinical pathology data. Errors in testing and unexpected variability in clinical pathology data are sometimes referred to as "laboratory errors." These alterations may occur in the preanalytical, analytical, or postanalytical phases of studies. Most of the errors or variability in clinical pathology data occur in the preanalytical or postanalytical phases. True analytical errors occur within the laboratory and are usually the result of operator or instrument error. Analytical errors are often ≤10% of all errors in diagnostic testing, and the frequency of these types of errors has decreased in the last decade. Analytical errors and increased data variability may result from instrument malfunctions, inability to follow proper procedures, undetected failures in quality control, sample misidentification, and/or test interference. This article (1) illustrates several different types of analytical errors and situations within laboratories that may result in increased variability in data, (2) provides recommendations regarding prevention of testing errors and techniques to control variation, and (3) provides a list of references that describe and advise how to deal with increased data variability.

Deciphering Sources of Variability in Clinical Pathology.

The objectives of this session were to explore causes of variability in clinical pathology data due to preanalytical and analytical variables as well as study design and other procedures that occur in toxicity testing studies. The presenters highlighted challenges associated with such variability in differentiating test article-related effects from the effects of experimental procedures and its impact on overall data interpretation. These presentations focused on preanalytical and analytical variables and study design-related factors and their influence on clinical pathology data, and the importance of various factors that influence data interpretation including statistical analysis and reference intervals. Overall, these presentations touched upon potential effect of many variables on clinical pathology parameters, including animal physiology, sample collection process, specimen handling and analysis, study design, and some discussion points on how to manage those variables to ensure accurate interpretation of clinical pathology data in toxicity studies. This article is a brief synopsis of presentations given in a session entitled "Deciphering Sources of Variability in Clinical Pathology-It's Not Just about the Numbers" that occurred at the 35th Annual Symposium of the Society of Toxicologic Pathology in San Diego, California.

Nonclinical pharmacology and toxicology of the first biosimilar insulin glargine drug product (BASAGLAR®/ABASAGLAR®) approved in the European Union.

Basaglar®/Abasaglar® (Lilly insulin glargine [LY IGlar]) is a long-acting human insulin analogue drug product granted marketing authorisation as a biosimilar to Lantus® (Sanofi insulin glargine [SA IGlar]) by the European Medicines Agency. We assessed the similarity of LY IGlar to the reference drug product, European Union-sourced SA IGlar (EU-SA IGlar), using nonclinical in vitro and in vivo studies. No biologically relevant differences were observed for receptor binding affinity at either the insulin or insulin-like growth factor-1 (IGF-1) receptors, or in assays of functional or de novo lipogenic activity. The mitogenic potential of LY IGlar and EU-SA IGlar was similar when tested in both insulin- and IGF-1 receptor dominant cell systems. Repeated subcutaneous daily dosing of rats for 4 weeks with 0, 0.3, 1.0, or 2.0 mg/kg LY IGlar and EU-SA IGlar produced mortalities and clinical signs consistent with severe hypoglycaemia. Glucodynamic profiles of LY IGlar and EU-SA IGlar in satellite animals showed comparable dose-related hypoglycaemia. Severe hypoglycaemia was associated with axonal degeneration of the sciatic nerve; the incidence and severity were low and did not differ between LY IGlar and EU-SA IGlar. These results demonstrated no biologically relevant differences in toxicity between LY IGlar and EU-SA IGlar.

[Acceptance of the Implementation of Standardised Patient Education Programmes by the Multidisciplinary Rehabilitation Team Using the Example of a Back School - A Qualitative Study]. / Akzeptanz der Einführung standardisierter Patientenschulungen durch das multidisziplinäre Reha-Team am Beispiel einer Rückenschule - Eine qualitative Studie.

AIM: The transfer of standardised patient education programmes into practice is a complex process with a multitude of influencing factors. Determinants relate among others to the organisation and individuals (e. g., practitioner, patient). Knowledge about individual factors regarding the trainers of patient education programmes in the German rehabilitation system is scarce. The aim of this study is to explore the acceptance of trainers concerning the implementation of a standardised back school and to derive facilitators and barriers to the implementation of patient education programmes. METHODS: Semi-structured guideline-based interviews were conducted in 10 rehabilitation clinics. The sample consisted of 46 trainers (25 women): 11 physicians, 11 psychologists, 21 physio-/exercise therapists and 3 occupational therapists with a mean age of 41. The opinions of the trainers regarding the central components of back schools in general, their opinions about the new curriculum, their expectations on its implementation, anticipated difficulties with implementation and requests to the project team were explored as indicators for acceptance. The data were analysed with a multi-step qualitative content analysis. RESULTS: 6 main categories comprising 136 subcategories were created and 729 quotations coded. Regarding the central components that should be covered by back schools, back-friendly behaviour was addressed most often. Opinions regarding the new curriculum were mostly positive. Trainers' approval of content and methods was highlighted and the similarity with existing offers in the clinics as well as the structure of the programme were rated positively. The trainers expected an increased patient orientation and personal development as well as a common, coherent language and interdisciplinarity. Difficulties were anticipated regarding time and personnel as well as therapy and appointment planning and also regarding the motivation/acceptance of patients. A wish for communication, education of trainers and feedback was directed at the project team. CONCLUSION: The study demonstrates high acceptance of programme implementation and central components of modern patient education programmes among trainers. The basis of individual facilitators and barriers has been investigated and might contribute to further development of implementation interventions. Communication and education considering those factors play a central role.

Major differences in organization and availability of health care and medicines for HIV/TB coinfected patients across Europe.

OBJECTIVES: The aim of the study was to investigate the organization and delivery of HIV and tuberculosis (TB) health care and to analyse potential differences between treatment centres in Eastern (EE) and Western Europe (WE). METHODS: Thirty-eight European HIV and TB treatment centres participating in the TB:HIV study within EuroCoord completed a survey on health care management for coinfected patients in 2013 (EE: 17 respondents; WE:21; 76% of all TB:HIV centres). Descriptive statistics were obtained for regional comparisons. The reported data on health care strategies were compared with actual clinical practice at patient level via data derived from the TB:HIV study. RESULTS: Respondent centres in EE comprised: Belarus (n = 3), Estonia (1), Georgia (1), Latvia (1), Lithuania (1), Poland (4), Romania (1), the Russian Federation (4) and Ukraine (1); those in WE comprised: Belgium (1), Denmark (1), France (1), Italy (7), Spain (2), Switzerland (1) and UK (8). Compared with WE, treatment of HIV and TB in EE are less often located at the same site (47% in EE versus 100% in WE; P < 0.001) and less often provided by the same doctors (41% versus 90%, respectively; P = 0.002), whereas regular screening of HIV-infected patients for TB (80% versus 40%, respectively; P = 0.037) and directly observed treatment (88% versus 20%, respectively; P < 0.001) were more common in EE. The reported availability of rifabutin and second- and third-line anti-TB drugs was lower, and opioid substitution therapy (OST) was available at fewer centres in EE compared with WE (53% versus 100%, respectively; P < 0.001). CONCLUSIONS: Major differences exist between EE and WE in relation to the organization and delivery of health care for HIV/TB-coinfected patients and the availability of anti-TB drugs and OST. Significant discrepancies between reported and actual clinical practices were found in EE.

[The Impact of 2 Interventions on Implementation Fidelity of a Standardized Back School Program in Inpatient Orthopedic Rehabilitation Facilities]. / Der Einfluss von 2 Implementierungsinterventionen auf die Implementierungsgüte einer standardisierten Rückenschulung in der orthopädischen Rehabilitation.

STUDY OBJECTIVE: Evaluation of the effectiveness of 2 implementation interventions - train-the-trainer workshops (TTT) and written implementation guideline (GL) - in terms of implementation fidelity of a back-training school within inpatient orthopedic rehabilitation. METHODS: An implementation trial was conducted using a mixed-methods approach for outcome evaluation in 10 rehabilitation clinics randomly assigned to the interventions. Data were assessed by questionnaires and observation forms. RESULTS: Trainers in the TTT condition, as compared to trainers in the GL condition, rated both their patient-oriented back school practice (d=1.37) and achievement of manual-based educational goals (W=0.18) significantly higher. Patients in the TTT condition showed significantly higher treatment satisfaction compared to patients in the GL condition (d=0.44). There were no significant group effects regarding the observed fidelity. CONCLUSIONS: An interactive TTT showed several benefits with regard to subjective outcomes compared to a written guideline.

Overview of the pancreatic toxicity and carcinogenesis session.

The theme of the Society of Toxicologic Pathology Annual Symposium 2013 was "Toxicologic Pathology of the Digestive Tract and Pancreas." The last session focused on pancreatic toxicity and carcinogenesis. This overview highlights the various presentations in this session, focusing on pancreatic toxicologic pathology, responses of the pancreas to xenobiotics, and current understanding on pancreatic carcinogenesis. The objective of this symposium overview and the subsequent articles from this session is to enable the audience to develop a better appreciation for the pancreas as a target organ in toxicological studies.

Web-based questionnaires to capture acute infections in long-term cohorts : findings of a feasibility study.

BACKGROUND: Incidence of acute respiratory infections (ARI) and gastrointestinal infections (GII) are difficult to assess due to high frequency episodes, limited severity and short duration. Retrospective assessments therefore are particularly prone to recall bias, while prospective assessment with conventional questionnaires requires high discipline from participants which is difficult to maintain over longer time periods. Web-based questionnaires (WQ) allow integration of a recall system and thus carry the potential to prospectively capture acute infections. We investigated the feasibility of a weekly WQ assessing symptoms of ARI and GII among participants of the German National Cohort (GNC). MATERIAL AND METHODS: In the study centres Hamburg and Bremen of the GNC participants of the Pretest 1 phase (September to November 2011) were invited to additionally take part in this feasibility study testing the WQ. Every Monday participants received an e-mail, containing a link to the WQ, asking for occurrence of ARI or GII symptoms during the past 7 days. The study took place from the beginning of February until mid-July 2012. We calculated the overall proportion of participation, weekly participation and the number of weekly reports per participant and we estimated incidences of ARI, ILI and GII. RESULTS: Of 200 Pretest 1 participants 171 (86 %) reported having an email address and thus were eligible for the web-based study. A total of 167 (98 %) agreed to participate. Participants of the web-based study were younger and better educated than non-participants. Access to Internet decreased with increasing age. Of the 167 participants in the feasibility study, 144 (86 %) responded at least once during the study period of 23 weeks, 5 persons (3 %) had non-functioning email addresses and 18 (11 %) did not respond at all. The weekly response varied between 62 % and 81 %, the median was 74 % (IQR: 71-77 %). Weekly median reports per person were 20 (IQR: 14-22; range 1-23). More than 90 % of participants responded during the first 3 days. The following mean incidence rates were found: ARI, 12 %; ILI, 0.49 %; and GII, 3 %. CONCLUSION: Use of WQ in prospective studies seems well possible, as Internet access is frequent among study participants and major technical problems did not occur. We observed high participation during the study period of 6 months and low drop out numbers. Participants of the web-based study were slightly younger and better educated than non-participants, so selection bias is possible and must be kept in mind when discussing generalizability of the results.

Collection of vaccination data in the German National Cohort : Findings of a feasibility study in three study centers.

BACKGROUND: Data about the vaccination status of participants are required in epidemiological cohort studies whenever infection or immunity is considered as potential exposure or outcome. Within Pretest 2 of the German National Cohort (GNC) we therefore investigated the acceptance and feasibility of extracting vaccination status from vaccination certificates provided by the participants of the study. METHODS: This study was conducted in three study centers (Bremen, n = 73; Hamburg, n = 200; Hannover, n = 193). In order to test if an additional reminder would prevent participants from forgetting their vaccination certificates at home persons willing to participate in Pretest 2 were randomly assigned to one of three invitation groups (IG). About one third of the participants received either no further reminder (IG1), a reminder card together with the appointment letter (IG2) or a separate reminder card 4 days before the appointment (IG3). At the study center, vaccination data were scanned or copied and entered into a database using a unique identification number. Participants were also asked to fill in a short questionnaire to assess the completeness of the provided vaccination data. Additionally, in one of the three participating study centers, general practitioners (GP) were asked to provide vaccination data from their records following respective participants' consent. Finally, we compared the influenza data from the vaccination certificates with the influenza data obtained from participants in Pretest 2 by use of a self-administered questionnaire (ID-Screen). RESULTS: Due to different starting dates of the study the intended reminder procedure was implemented only in Hamburg and Hannover. In Hamburg, significantly more vaccination certificates were submitted by the group which received the reminder card separately 4 days before the examination (IG3) compared to IG1 and IG2 (p = 0.04). In Hannover, in contrast, most vaccination certificates were brought by those who received the reminder card together with the appointment letter. Overall, the use of a reminder card had a positive but not significant effect as 89 % (185/209) of participants who received the reminder card submitted vaccination data versus 81 % (84/104) of participants who did not receive any reminder card (p = 0.06). Of all Pretest 2 participants in Hannover, 62 % (120/193) gave written consent for data collection by the GPs. In total, 114 practices were contacted of which 49 (43 %) sent vaccination data. All in all, 360 vaccination certificates with 5065 documented vaccinations were entered into a database, of which 4830 (95 %) were valid for analysis covering a period from 1946 to 2012. The comparison of influenza vaccination data from vaccination certificates to the remembered data from a self-completed questionnaire showed an agreement of data in 46 % (84/184) of cases (Kappa = 0.48). Influenza vaccinations were underreported in 4 % (7/170) of self-completed questionnaires. CONCLUSION: The reliable documentation of vaccinations within the context of the GNC proved to be feasible and thus recommendable at a large scale within the GNC as participants showed high willingness and compliance in providing available vaccination documents. An additional validation by means of documents provided by physicians seems to be possible for more than a quarter of participants. In order to maximize the likelyhood of participants' of bringing their vaccination certificates it would be sufficient to send a reminder card together with the appointment letter.

Comparison of stool collection on site versus at home in a population-based study : feasibility and participants' preference in Pretest 2 of the German National Cohort.

BACKGROUND: For certain laboratory investigations it is necessary to obtain native stool samples and process them within a narrow time window at the point of contact or a nearby laboratory. However, it is not known whether it is feasible to obtain stool samples from asymptomatic individuals during an appointment in a study center (SC). We therefore compared participants' preference, feasibility and acceptance of stool sample collection during the appointment at the study center (on-site sampling) to collection at home after the appointment. METHODS: The study was conducted at two sites in Northern Germany (Bremen, n = 156; Hannover, n = 147) during the Pretest 2 phase of the German National Cohort (GNC), drawing upon a randomly selected population supplemented by a small convenience sample. In the study center, the participants were given the choice to provide a stool sample during the appointment or to collect a sample later at home and return it by mail. RESULTS: In all, 303 of the 351 participants (86 %) of Pretest 2 at these sites participated in this feasibility study. Only 7.9 % (24/303) of the participants chose on-site collection, whereas 92 % (279/303) chose at-home collection. There were significant differences between the two study sites in that 14 % (21/147) of participants in Hannover and 2 % (3/156) of participants in Bremen chose on-site collection. Compliance was high in both groups, as 100 % (24/24) and 98 % (272/279) of participants in the on-site and at-home groups, respectively, provided complete samples. Both methods were highly accepted, as 92 % of the participants in each group (22/24 and 227/248) stated that stool collection at the respective site was acceptable. CONCLUSION: When given a choice, most participants in this population-based study preferred home collection of stool samples to collection in the study center. Thus, native stool samples for immediate processing in the study center may potentially be obtained only from a subpopulation of participants, which may lead to selection bias. Home collection, on the other hand, proved to be a highly feasible method for studies that do not require freshly collected native stool.

Collaborative science in action: A 20 year perspective from the Health and Environmental Sciences Institute (HESI) Cardiac Safety Committee.

The Health and Environmental Sciences Institute (HESI) is a nonprofit organization dedicated to resolving global health challenges through collaborative scientific efforts across academia, regulatory authorities and the private sector. Collaborative science across non-clinical disciplines offers an important keystone to accelerate the development of safer and more effective medicines. HESI works to address complex challenges by leveraging diverse subject-matter expertise across sectors offering access to resources, data and shared knowledge. In 2008, the HESI Cardiac Safety Committee (CSC) was established to improve public health by reducing unanticipated cardiovascular (CV)-related adverse effects from pharmaceuticals or chemicals. The committee continues to significantly impact the field of CV safety by bringing together experts from across sectors to address challenges of detecting and predicting adverse cardiac outcomes. Committee members have collaborated on the organization, management and publication of prospective studies, retrospective analyses, workshops, and symposia resulting in 38 peer reviewed manuscripts. Without this collaboration these manuscripts would not have been published. Through their work, the CSC is actively addressing challenges and opportunities in detecting potential cardiac failure modes using in vivo, in vitro and in silico models, with the aim of facilitating drug development and improving study design. By examining past successes and future prospects of the CSC, this manuscript sheds light on how the consortium's multifaceted approach not only addresses current challenges in detecting potential cardiac failure modes but also paves the way for enhanced drug development and study design methodologies. Further, exploring future opportunities and challenges will focus on improving the translational predictability of nonclinical evaluations and reducing reliance on animal research in CV safety assessments.

Current practices in preclinical drug development: gaps in hemostasis testing to assess risk of thromboembolic injury.

The Health and Environmental Sciences Institute Cardiac Biomarkers Working Group surveyed the pharmaceutical development community to investigate practices in assessing hemostasis, including detection of hypocoagulable and hypercoagulable states. Scientists involved in discovery, preclinical, and clinical research were queried on laboratory evaluation of endothelium, platelets, coagulation, and fibrinolysis during safety assessment studies. Results indicated that laboratory assessment of hemostasis is inconsistent among institutions and not harmonized between preclinical and clinical studies. Hemostasis testing in preclinical drug safety studies primarily focuses on the risk of bleeding, whereas the clinical complication of thrombosis is seldom assessed. Our results reveal the need for broader utilization of biomarkers to detect altered hemostasis (e.g., endothelial and platelet activation) to improve preclinical safety assessments early in the drug development process. Survey respondents indicated a critical lack of validated markers of hypercoagulability and subclinical thrombosis in animal testing. Additional obstacles included limited blood volume, lack of cross-reacting antibodies for hemostasis testing in laboratory species, restricted availability of specialized hemostasis analyzers, and few centers of expertise in animal hemostasis testing. Establishment of translatable biomarkers of prothrombotic states in multiple species and strategic implementation of testing on an industry-wide basis are needed to better avert untoward drug complications in patient populations.

Integrated and translational nonclinical in vivo cardiovascular risk assessment: gaps and opportunities.

Cardiovascular (CV) safety concerns are a significant source of drug development attrition in the pharmaceutical industry today. Though current nonclinical testing paradigms have largely prevented catastrophic CV events in Phase I studies, many challenges relating to the inability of current nonclinical safety testing strategies to model patient outcomes persist. Contemporary approaches include a spectrum of evaluations of CV structure and function in a variety of laboratory animal species. These approaches might be improved with a more holistic integration of these evaluations in repeat-dose studies, addition of novel endpoints with greater sensitivity and translational application, and use of more relevant animal models. Particular opportunities present with advances in imaging capabilities applicable to rodent and non-rodent species, technical capabilities for measuring CV function in repeat-dose animal studies, detection and quantitation of microRNAs and wider use of alternative animal models. Strategic application of these novel opportunities considering putative CV risk associated with the molecular drug target as well as inherent risks present in the target patient population could tailor or 'personalize' nonclinical safety assessment as a more translational evaluation. This paper is a call to action for the clinical and nonclinical drug safety communities to assess these opportunities to determine their utility in filling potential gaps in our current cardiovascular safety testing paradigms.

Expression pattern of a 'Plus-C' class odorant binding protein in the antenna of the malaria vector Anopheles gambiae.

In the malaria mosquito Anopheles gambiae (Ag), olfaction plays a crucial role in various behaviours, most strikingly in the seeking of females after a blood meal. The first step of odorant recognition in antennal sensilla involves soluble odorant binding proteins (OBPs), which transfer odorous compounds to olfactory receptors (ORs) in the dendritic membrane of sensory neurons. A particular OBP subtype of the 'Plus-C' class, called AgOBP48, is abundantly transcribed in female antennae and partially down-regulated after a blood meal, suggesting a possible role in host detection. In the present study, we have identified the AgOBP48-expressing cells, explored their antennal topography and determined their position relative to cells that express the 'classic' AgOBP1, the AgOR co-receptor (AgOrco) and the receptor AgOR1. By means of two-colour whole-mount fluorescence in situ hybridization it was found that AgOBP48 was expressed in cells, which are closely associated with AgOrco-expressing sensory neurons. Furthermore, AgOBP48 was not expressed in the same cells as AgOBP1, but subpopulations of AgOBP48- and of AgOBP1-expressing cells were found closely associated and adjacent to sensory neurons expressing AgOR1. Together, the results indicate that cells that express either AgOBP48, AgOBP1 or AgOR1 are housed together in distinct olfactory sensilla and that an interplay of the proteins may contribute to the specific responsiveness of the sensillum to distinct odorants.

Evaluation of renal injury and function biomarkers, including symmetric dimethylarginine (SDMA), in the rat passive Heymann nephritis (PHN) model.

Symmetric dimethylarginine (SDMA) is a serum biomarker of excretory renal function which consistently correlates with glomerular filtration rate (GFR) across multiple species including rats, dogs, and humans. In human and veterinary clinical settings SDMA demonstrates enhanced sensitivity for detection of declining renal function as compared to other serum biomarkers, but application in preclinical study designs thus far has been limited. The purpose of this study was to determine the performance of serum SDMA in a rat passive Heyman nephritis model of glomerulopathy. In addition to SDMA other biomarkers of excretory renal function were measured including serum creatinine (sCr), blood urea nitrogen (BUN), and cystatin C along with creatinine clearance. Urinary renal biomarkers including microalbumin (µALB), clusterin (CLU), cystatin C, kidney injury marker-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), and osteopontin (OPN) were also measured. PHN was induced using commercial sheep anti-Fx1A serum. Tissue, serum, and urine were collected from groups of control and anti-Fx1A-treated animals for biomarker evaluation, hematology, urinalysis, serum biochemistry, and histologic examination of kidney. Over the course of a 28-day study, concentrations of the urinary biomarkers µALB, CLU, cystatin C, NGAL, KIM-1 and the serum biomarker cystatin C increased significantly in anti-Fx1A-treated rats as compared to controls but no significant increase in serum SDMA, sCr, BUN, or creatinine clearance were noted in anti-Fx1A-treated rats. Given lack of direct GFR measurement or significant change in the renal function biomarkers sCr, BUN, and creatinine clearance, it is unclear if GFR differed significantly between control and anti-Fx1A-treated rats in this study, though urinary biomarkers and histopathologic findings supported renal injury in anti-Fx1A-treated rats over the time course investigated. This study is among the first to investigate serum SDMA in a rat model relevant to preclinical safety assessment and serves to inform future experimental designs and biomarker selection when evaluation of glomerular injury is of priority.

Evaluation of Renal Biomarkers, Including Symmetric Dimethylarginine, following Gentamicin-Induced Proximal Tubular Injury in the Rat.

Symmetric dimethylarginine (SDMA) is an excretory renal function biomarker shown to correlate well with glomerular filtration rate in dogs, cats, humans, and rats. The objectives of this study were to determine utility of serum SDMA as a renal biomarker in a rat model of gentamicin-induced renal injury and to provide validation of a commercially available SDMA immunoassay for rat serum. Rats were randomly assigned to one of three dose levels of gentamicin (20, 50, or 100 mg/kg) or a vehicle control group and dosed once daily by subcutaneous injection for either four or ten days. Serum and urine renal biomarker evaluation, including serum SDMA, hematologic and serum biochemical analysis, urinalysis, and histologic examination of kidney, were performed. Before biologic validation, analytic validation of the SDMA immunoassay for rat serum was performed, including assessment of assay accuracy, precision, analytical sensitivity, linearity, analyte stability, and interference testing. Among markers of excretory renal function, SDMA and serum creatinine increased earliest and at the lowest gentamicin concentrations and were significantly increased in both the 50- and 100- mg/kg dose levels in the four- and ten-dose treatment groups compared with controls. Time- and dose-dependent increases were noted for all urinary biomarkers investigated in this study, with microalbumin being most responsive and osteopontin least responsive for detection of gentamicin-induced injury across dose levels and schedules investigated. The SDMA immunoassay met all set quality requirements assessed in analytical validation. This study is the first to investigate performance of serum SDMA compared with other excretory renal function markers in a rat gentamicin acute toxicity model. In this study, serum SDMA was an earlier biomarker for detection of gentamicin-induced toxicity than serum cystatin C, BUN, and creatinine clearance. The SDMA immunoassay provides a reliable commercially available assay for future renal investigations in rat models.

Toxicologic pathology in a multicultural world--India.

The global practice of drug development is expanding into many different continents and countries. India, in particular, is rapidly emerging as an economic force in this arena by offering ever-expanding opportunities for pharmaceutical market expansion as well as productive drug development partnerships. The key to the country's current socioeconomic success appears to be education, particularly the development of higher and professional education. Also, recent modifications to India's patent laws offer greater protections and incentives for international investment. Increasing numbers of competent contract research organizations create attractive opportunities for large Western pharmaceutical companies with a desire to gain access to burgeoning markets as well as mitigate the rising cost of drug development with less costly services. Well-trained veterinary pathologists are available, appropriate facilities are being constructed, and laboratory capabilities are expanding. Developing a productive partnership with a credible laboratory service in India, as with any new provider, requires due diligence and knowledgeable scrutiny of key elements of the work stream, such as facilities, education and training of laboratory personnel, Good Laboratory Practices, animal care, timelines, and data management. Ultimately and with appropriate management, mutually beneficial drug development partnerships are available in India.

A comparison of mortality and cardiac biomarker response between three outbred stocks of Sprague Dawley rats treated with isoproterenol.

The authors compared the mortality and cardiac biomarker responses in three outbred stocks of Sprague Dawley rats (CD/IGS, Sasco, Harlan) treated with isoproterenol hydrochloride. Cardiac injury was confirmed by histologic evaluation, and increases in cardiac troponin I concentration in serum were measured by two methods. CD/IGS rats had a higher incidence and earlier mortality compared with Sasco or Harlan rats. Harlan rats had lower severity scores for cardiomyocyte degeneration/necrosis compared with the other stocks. Post-isoproterenol treatment cardiac troponin I concentrations were greater in CD/IGS and Sasco rats compared with Harlan rats. Concentrations of cardiac troponin T followed a similar pattern to that of cardiac troponin I in rats treated with isoproterenol. Myosin, light chain 3 concentrations increased in all rats treated with isoproterenol, but there was no difference between the three stocks in the magnitude or pattern of the dose response. Increases in fatty acid binding protein 3 concentrations were detected in only the highest dose group at the earliest timepoint postdose for all three stocks of rats. Results of these studies illustrate the need for investigators to recognize the potential differences in response between stocks of Sprague Dawley rats treated with cardiotoxicants or novel chemical entities.