Experimental Research Model Research Articles

Modeling Stroke in Mice - Middle Cerebral Artery Occlusion with the Filament Model

Stroke is among the most frequent causes of death and adult disability, especially in highly developed countries. However, treatment options to date are very limited. To meet the need for novel therapeutic approaches, experimental stroke research frequently employs rodent models of focal cerebral ischaemia. Most researchers use permanent or transient occlusion of the middle cerebral artery (MCA) in mice or rats.Proximal occlusion of the middle cerebral artery (MCA) via the intraluminal suture technique (so called filament or suture model) is probably the most frequently used model in experimental stroke research. The intraluminal MCAO model offers the advantage of inducing reproducible transient or permanent ischaemia of the MCA territory in a relatively non-invasive manner. Intraluminal approaches interrupt the blood flow of the entire territory of this artery. Filament occlusion thus arrests flow proximal to the lenticulo-striate arteries, which supply the basal ganglia. Filament occlusion of the MCA results in reproducible lesions in the cortex and striatum and can be either permanent or transient. In contrast, models inducing distal (to the branching of the lenticulo-striate arteries) MCA occlusion typically spare the striatum and primarily involve the neocortex. In addition these models do require craniectomy. In the model demonstrated in this article, a silicon coated filament is introduced into the common carotid artery and advanced along the internal carotid artery into the Circle of Willis, where it blocks the origin of the middle cerebral artery. In patients, occlusions of the middle cerebral artery are among the most common causes of ischaemic stroke. Since varying ischemic intervals can be chosen freely in this model depending on the time point of reperfusion, ischaemic lesions with varying degrees of severity can be produced. Reperfusion by removal of the occluding filament at least partially models the restoration of blood flow after spontaneous or therapeutic (tPA) lysis of a thromboembolic clot in humans.In this video we will present the basic technique as well as the major pitfalls and confounders which may limit the predictive value of this model.

Modeling Stroke in Mice - Middle Cerebral Artery Occlusion with the Filament Model

Stroke is among the most frequent causes of death and adult disability, especially in highly developed countries. However, treatment options to date are very limited. To meet the need for novel therapeutic approaches, experimental stroke research frequently employs rodent models of focal cerebral ischaemia. Most researchers use permanent or transient occlusion of the middle cerebral artery (MCA) in mice or rats. Proximal occlusion of the middle cerebral artery (MCA) via the intraluminal suture technique (so called filament or suture model) is probably the most frequently used model in experimental stroke research. The intraluminal MCAO model offers the advantage of inducing reproducible transient or permanent ischaemia of the MCA territory in a relatively non-invasive manner. Intraluminal approaches interrupt the blood flow of the entire territory of this artery. Filament occlusion thus arrests flow proximal to the lenticulo-striate arteries, which supply the basal ganglia. Filament occlusion of the MCA results in reproducible lesions in the cortex and striatum and can be either permanent or transient. In contrast, models inducing distal (to the branching of the lenticulo-striate arteries) MCA occlusion typically spare the striatum and primarily involve the neocortex. In addition these models do require craniectomy. In the model demonstrated in this article, a silicon coated filament is introduced into the common carotid artery and advanced along the internal carotid artery into the Circle of Willis, where it blocks the origin of the middle cerebral artery. In patients, occlusions of the middle cerebral artery are among the most common causes of ischaemic stroke. Since varying ischemic intervals can be chosen freely in this model depending on the time point of reperfusion, ischaemic lesions with varying degrees of severity can be produced. Reperfusion by removal of the occluding filament at least partially models the restoration of blood flow after spontaneous or therapeutic (tPA) lysis of a thromboembolic clot in humans. In this video we will present the basic technique as well as the major pitfalls and confounders which may limit the predictive value of this model.

Editorial The role of the immunoinflammatory response after cardiac arrest

Cardiac arrest is a good (experimental) model for research in ischaemic tolerance [1], so it has been used often during the last 20 years in animal models. The (global) ischaemic event induced by cardiac arrest is followed by a phase of ischaemic preconditioning if the initial phase was of shorter or even stroke/complete ischaemia if the initial phase was of longer duration [2]. During the last years, there has been great effort in different research groups all over the world to find out the underlying pathophysiological mechanisms involved after these events or at least to find out some risk factors either in the brain or in the whole body [3, 4]. In the present issue of Archives of Medical Science, Anna Samborska-Sablik et al. present an interesting manuscript that deals with the role of the immunoinflammatory response after cardiac arrest in humans [5]. It is one of the very few studies in humans after cardiac arrest and is therefore of special interest [6]. The authors could find a significant correlation of the post-cardiac-arrest immunoinflammatory response (hs-CRP and IL-6) with the patients’ clinical state and also with the prediction of survival [5]. Such data are in line with previous research in the brain [7, 8] and open the door to so-called “immunomodulatory therapy”. In the brain such research is advanced, but we need a better understanding of the brain and immune system after such ischaemic events [9]. For the whole body, nearly no data exist so far. However, Anna Samborska-Sablik et al. have now provided a better insight into the clinical relevance of such research [5]: They show the relevance of this immunoinflammatory response for Glasgow Coma Scale (GCS) and Acute Physiology and Chronic Health Evaluation II (APACHE II) score: two of the major scores used in clinical daily practice. Therefore the immunoinflammatory response after ischaemic events is not only an experimental phenomenon (as many others), but also of great clinical importance [10, 11]. What are now the therapeutic implications of these findings? In experimental studies, preventive antibiotic treatment dramatically improved survival and outcome after ischaemic events, and even reduced the organ’s infarct size area [9, 12]. Apart from these experimental studies there are several clinical trials with promising results in this direction [12]. Smaller events of shorter duration can be protective – for example in the postoperative period – for further ischaemic events [7]. In this context, the oxygen-conserving reflex has gained more interest [13, 14] and can explain – at least partly – why the brain is only damaged after a very long duration of cardiac arrest. Nevertheless, the article of Samborska-Sablik et al. [5] goes deep into the pathophysiology of different organs. Further clinical research on this topic will open widely the doors to interesting therapeutic modalities and will help to resolve one of the great problems in internal medicine. Let’s go on this way!

Mouse Experimental Models of Atherosclerosis in Pharmacology

The mouse has become an excellent model for experimental atherosclerosis research. Until 1992, the diet - induced atherosclerosis mouse model has been used effectively, but the lesions tended to be small and were limited to early fatty-streak stage. This model was also criticized because of the toxicity and inflammatory responses due to the diet. In 1992 the first line of gene targeted animal models, namely apolipoprotein E - knockout mice was developed. Of the genetically engineered models, the apoE - deficient model is the only one that develops extensive atherosclerotic lesions on a chow diet. It is also the model in which the lesions have been characterized most thoroughly. The lesions develop into fibrous plaques; however, there is no evidence that plaque rupture occurs in this model. The LDL receptor - deficient model has elevated LDL levels, but no lesions, or only very small lesions, form on the chow diet, however, robust lesions do form on the western type diet. The creation of apoE - knockout mice has changed the face of atherosclerosis research.

Genetic composition of laboratory stocks of the self-fertilizing fish Kryptolebias marmoratus: a valuable resource for experimental research.

The hermaphroditic Mangrove Killifish, Kryptolebias marmoratus, is the world's only vertebrate that routinely self-fertilizes. As such, highly inbred and presumably isogenic “clonal” lineages of this androdioecious species have long been maintained in several laboratories and used in a wide variety of experiments that require genetically uniform vertebrate specimens. Here we conduct a genetic inventory of essentially all laboratory stocks of the Mangrove Killifish held worldwide. At 32 microsatellite loci, these stocks proved to show extensive interline differentiation as well as some intraline variation, much of which can be attributed to post-origin de novo mutations and/or to the segregation of polymorphisms from wild progenitors. Our genetic findings also document that many of the surveyed laboratory strains are not what they have been labeled, apparently due to the rather frequent mishandling or unintended mixing of various laboratory stocks over the years. Our genetic inventory should help to clarify much of this confusion about the clonal identities and genetic relationships of laboratory lines, and thereby help to rejuvenate interest in K. marmoratus as a reliable vertebrate model for experimental research that requires or can capitalize upon “clonal” replicate specimens.

Molecular, cellular and physiological characterization of the cancer cachexia-inducing C26 colon carcinoma in mouse.

BackgroundThe majority of cancer patients experience dramatic weight loss, due to cachexia and consisting of skeletal muscle and fat tissue wasting. Cachexia is a negative prognostic factor, interferes with therapy and worsens the patients' quality of life by affecting muscle function. Mice bearing ectopically-implanted C26 colon carcinoma are widely used as an experimental model of cancer cachexia. As part of the search for novel clinical and basic research applications for this experimental model, we characterized novel cellular and molecular features of C26-bearing mice.MethodsA fragment of C26 tumor was subcutaneously grafted in isogenic BALB/c mice. The mass growth and proliferation rate of the tumor were analyzed. Histological and cytofluorometric analyses were used to assess cell death, ploidy and differentiation of the tumor cells. The main features of skeletal muscle atrophy, which were highlighted by immunohistochemical and electron microscopy analyses, correlated with biochemical alterations. Muscle force and resistance to fatigue were measured and analyzed as major functional deficits of the cachectic musculature.ResultsWe found that the C26 tumor, ectopically implanted in mice, is an undifferentiated carcinoma, which should be referred to as such and not as adenocarcinoma, a common misconception. The C26 tumor displays aneuploidy and histological features typical of transformed cells, incorporates BrdU and induces severe weight loss in the host, which is largely caused by muscle wasting. The latter appears to be due to proteasome-mediated protein degradation, which disrupts the sarcomeric structure and muscle fiber-extracellular matrix interactions. A pivotal functional deficit of cachectic muscle consists in increased fatigability, while the reported loss of tetanic force is not statistically significant following normalization for decreased muscle fiber size.ConclusionsWe conclude, on the basis of the definition of cachexia, that ectopically-implanted C26 carcinoma represents a well standardized experimental model for research on cancer cachexia. We wish to point out that scientists using the C26 model to study cancer and those using the same model to study cachexia may be unaware of each other's works because they use different keywords; we present strategies to eliminate this gap and discuss the benefits of such an exchange of knowledge.

Modeling seizure-related behavioral and endocrine phenotypes in adult zebrafish

Larval zebrafish ( Danio rerio) have recently been suggested as a high-throughput experimental model of epilepsy-related pathogenetic states. Here we use adult zebrafish to study behavioral symptoms associated with drug-evoked seizures. Experimental epilepsy-like states were evoked in zebrafish by exposure for 20 min to three chemoconvulsant drugs: caffeine (250 mg/L; 1.3 mM), pentylenetetrazole (1.5 g/L; 11.0 mM) and picrotoxin (100 mg/L; 0.17 mM). Fish behavior was analyzed using manual and video-tracking methods (Noldus Ethovision XT7). Compared to their respective controls, all three drug-treated groups showed robust seizure-like responses (hyperactivity bouts, spasms, circular and corkscrew swimming) accompanied by elevated whole-body cortisol levels (assessed by ELISA). In contrast, control fish did not display seizure-like behaviors and had significantly lower cortisol levels. Paralleling behavioral and endocrine phenotypes observed in clinical and rodent studies, our data implicates adult zebrafish as an emerging experimental model for epilepsy research.

Establishment and characterization of a human gallbladder carcinoma cell line EH-GB1 originated from a metastatic tumor

To establish a human gallbladder carcinoma cell line derived from a metastatic gallbladder carcinoma and identify its biological characteristics. Tissue samples were separated from the surgical specimen obtained from a patient with metastatic carcinoma and single-cell suspension was prepared. Then the cells were cultured in DMEM medium supplemented with 15% fetal bovine serum. The morphology of tumor cells was observed under an electron microscope. The cell growth curve was plotted. The tumorigenicity of the cell line was studied by subcutaneous inoculation in SCID mice. The cells were infected by lentiviral vector carrying fluorescent report genes (lenti-GFP and lenti-Red2) separately for expressions of GFP and Red2, respectively. A novel metastatic gallbladder carcinoma cell line was successfully established and named "EH-GB1". It could be passaged for over 20 generations with typical malignant epithelial morphology and a stable growth cycle of 24 h. Tumors were formed in all of the 10 SCID mice inoculated with EH-GB1 cells subcutaneously, and the tumor cells were tumor marker CA19-9-positive. Continuous expressions of fluorescent report genes were observed in EH-GB1 cells infected by lenti-GFP and lenti-Red2. EH-GB1 cells might be the first stable cell line of human gallbladder carcinoma established from a metastatic focus of gallbladder carcinoma. This cell line with continuous expressions of GFP and Red2 might be a novel and perfect experimental model for clinical and basic research on gallbladder carcinoma.

Lipid metabolism, adipocyte depot physiology and utilization of meat animals as experimental models for metabolic research

Meat animals are unique as experimental models for both lipid metabolism and adipocyte studies because of their direct economic value for animal production. This paper discusses the principles that regulate adipogenesis in major meat animals (beef cattle, dairy cattle, and pigs), the definition of adipose depot-specific regulation of lipid metabolism or adipogenesis, and introduces the potential value of these animals as models for metabolic research including mammary biology and the ontogeny of fatty livers.

Mitochondrial DNA Diversity among Three Subpopulations of Cynomolgus Macaques (Macaca fascicularis) Originating from the Indochinese Region

The cynomolgus macaque (Macaca fascicularis) has emerged as an important experimental animal model for biomedical research in various domains, necessitating the more extensive characterization of the genetic backgrounds influencing the macaque's response to drugs and sensitivity to experimental disease. The diversity of the variable mitochondrial DNA (mtDNA) D-loop region has been analyzed phylogenetically among geographically isolated populations or within subdivisions of the same regional population. However, the genetic differences among several substructures originating from a common population have not yet been investigated. By sequencing fragments of the mtDNA D-loop region from two subpopulations from the Indochinese region (Cambodian-Chinese and Vietnamese) along with two native Indonesian and Filipino populations, we identified 87 mtDNA D-loop haplotypes, of which 67 are new. The phylogenetic relationship suggests that the Indochinese haplotypes are intermingled in comparison to the distinct divergence of the Indonesian and Filipino lineages. The subpopulations were shown by estimation of evolutionary divergence and Wright's F-statistic (Fst) to have little genetic differentiation. Altogether, the subpopulations may be used in biomedical research, even though a slight difference is observed in haplotype frequencies among them. Therefore, genetic diversity analyses will be necessary for the elucidation of genetic differences among the populations, as well as to obtain a better understanding of genetic diversity for biomedical research. This will involve the selection of macaques and the monitoring of genetic heterogeneity among and within breeding facilities.

Metabolic and transmitter changes in core and penumbra after middle cerebral artery occlusion in mice

Middle cerebral artery occlusion (MCAO) is a popular model in experimental stroke research and causes prominent ischemic damage in the forebrain. To characterize metabolic changes induced by MCAO, we have induced permanent MCAO in mice that were implanted with a microdialysis probe in either striatum or hippocampus. Immediately after the onset of ischemia, glucose levels dropped to < 10% of basal values in the striatum while they dropped to 50%, and recovered thereafter, in hippocampus. Extracellular levels of glutamate rose 80-fold in the striatum but only 10-fold, and in a transient fashion, in hippocampus. In striatum, release of acetylcholine briefly increased, then dropped to very low values. Both glycerol and choline levels increased strongly during ischemia in the striatum reflecting membrane breakdown. In hippocampus, glycerol increased transiently while the increase of choline levels was moderate. Taken together, these observations delineate metabolic changes in ischemic mouse brain with the striatum representing the core area of ischemia. In comparison, the dorsal hippocampus was identified as a brain area suitable for monitoring metabolic responses in the penumbra region.

Establishment and Characterization of a Novel Chinese Human Lung Adenocarcinoma Cell Line CPA-Yang2 in Immunodeficient Mice.

The recurrence, metastasis and multidrug resistance (MDR) in lung cancer are the tough problems worldwide. This study was to establish a novel chinese lung adenocarcinoma cell line with high metastasis potential for exploring the mechanism of reccurrence, development and MDR in lung cancer. The cell came from the abdominal dropsy of a fifty-six years old female patient with lung adenocarcinoma and the tumor markers CA125, CYFRA21-1, CEA, NSE were detected to be higher secretion by radioimmunoassay in the abdominal dropsy. Tumorigenicity of immunodeficient mice was confirmed in 8th passage. The cell growth curve was mapped. Analysis of chromosome karyotype was tested. The gene expression was measured by real-time quantitative PCR. The tumorigenesis rate started at 8th passage in 3/10 immunodeficient mice via subcutaneously and the fully tumorigenicity was at 11th passage as well as later passages. Under the microscope, the cell showed oval-shap and adherence. The chromosome karyotype analysis of the cells was sub-triploid. Approximately 1*10(6) and 1.5*10(6) cancerous cells were injected into left cardiac ventricle and tail vein of immunodeficient mice respectively. The results showed multiorgan metastasis in the mice after three-four weeks, including mandible, scapula, humerus, vertebral column, femur, rib and brain, liver, adrenal gland, pulmonary in the mice after inoculation. The bone metastasis rate was 100% in the tumor bearing mice by bone scintigraphy and pathology. Quantitative real-time PCR was used to examined and compared with SPC-A-1 lung adenocarcinoma, ESM1, VEGF-C, IL-6, IL-8, AR genes were overexpressed. The novel cell was named CPA-Yang2 The characteristics of novel strain CPA-Yang2 is a highly metastasis cell line of Chinese lung adenocarcinoma. It has stable traits, highly metastasis ability and maybe is a MDR lung cancerous cell line. Of course, it's a good experimental model for lung cancer research.

Molecular pathology of Invasive Lobular Breast Carcinoma

Invasive lobular carcinoma (ILC) is the second most common type of breast cancer, accounting for 10%15% of breast cancer cases. As any cancer breast cancer is to be considered a multifactorial genetic disease. Whereas confounding environmental factors are involved in disease initiation, genetic risk factors also confer the possibility for its outbreak. However, within the cancer tissue, changes in different genes will mediate their transformation into cancer cells and result in different types of tumors. This is exemplified by infiltrating lobular carcinoma which is thought to arise from the same cell type as infiltrating ductal carcinoma while exhibiting distinct changes in the genome thought to result in a different phenotype of tumor cells [54]. Most studies on molecular alterations and novel breast cancer biomarkers focus on either invasive ductal carcinoma, which is the most common subtype, or analyse a non-stratified cohort of invasive breast carcinomas assuming similar biological behaviour despite the histological subtypes. However in newer studies unique different prognostic features for ILC could be shown [36, 38]. The aim and scope of this review are to provide an overview of the molecular pathology of invasive lobular carcinoma, including its molecular evolution and precursor lesions, epigenetic alterations, microRNAs, and experimental research models.

Establishment of a Novel Chinese Human Lung Adenocarcinoma Cell Line CPA-Yang1 which Produces Highly Bone Metastases in Immunodeficient Mice.

Lung cancer is a common malignancy and is the major determinant of overall cancer mortality worldwidely. Approximately 70% of lung cancer patients will die from metastatic diseases. The aim of this study is to establish a Chinese lung adenocarcinoma cell line with high metastasis potency for exploring the mechanism of occurrence and development in lung cancer. The cell came from the pericardial effusion of a fifty-year old male patient with lung adenocarcinoma and the cells in primary culture were obtained successfully. Immunodeficient mice tumorigenicity was assayed. The cell growth curve was mappinged. Analysis of chromosome karyotype was tested. Tumor marker was detected by radioimmunoassay. The gene expression was measured by real-time quantitative PCR. The first passage cells were planted in immunodeficient mice subcutaneously and the tumorigenesis rate was 100% as well as later passages. Under the microscope, the cell showed larger and semi-suspension, semi-adherence. Approximately 0.8*10(6) cancerous cells were injected into left cardiac ventricle or tail vein of immunodeficient mice resulted start to appear lower limb paralysis and spine swelling deformation in the mice after inoculation two-three weeks. The bone metastasis rate was 90% in the tumor bearing mice by bone scintigraphy and pathology and only pulmonary metastasis 10% at the same time. The chromosome karyotype analysis of the cells was sub-triploid. The tumor marker CEA was detected in higher secretion by radioimmunoassay in the cell culture suspension. Quantitative real-time PCR was used to examined and compared SPC-A-1 lung adenocarcinoma, VEGF-C, IL-6, IL-8, genes were overexpressed. The novel cell line was named CPA-Yang1. Tne novel strain CPA-Yang1 is an parental cell with characteristics of bone metastasis of Chinese lung adenocarcinoma. It has stable traits, highly metastatic ability and a good experimental model for lung cancer research.

Experimental mouse models for hepatocellular carcinoma research

Every year almost 500,000 new patients are diagnosed with hepatocellular carcinoma (HCC), a primary malignancy of the liver that is associated with a poor prognosis. Numerous experimental models have been developed to define the pathogenesis of HCC and to test novel drug candidates. This review analyses several mouse models useful for HCC research and points out their advantages and weaknesses. Chemically induced HCC mice models mimic the injury-fibrosis-malignancy cycle by administration of a genotoxic compound alone or, if necessary, followed by a promoting agent. Xenograft models develop HCC by implanting hepatoma cell lines in mice, either ectopically or orthotopically; these models are suitable for drug screening, although extrapolation should be considered with caution as multiple cell lines must always be used. The hollow fibre assay offers a solution for limiting the number of test animals in xenograft research because of the ability for implanting multiple cell lines in one mouse. There is also a broad range of genetically modified mice engineered to investigate the pathophysiology of HCC. Transgenic mice expressing viral genes, oncogenes and/or growth factors allow the identification of pathways involved in hepatocarcinogenesis.

Cancer Biology Data Curation at the Mouse Tumor Biology Database (MTB)

AbstractMany advances in the field of cancer biology have been made using mouse models of human cancer. The Mouse Tumor Biology (MTB, "http://tumor.informatics.jax.org":http://tumor.informatics.jax.org) database provides web-based access to data on spontaneous and induced tumors from genetically defined mice (inbred, hybrid, mutant, and genetically engineered strains of mice). These data include standardized tumor names and classifications, pathology reports and images, mouse genetics, genomic and cytogenetic changes occurring in the tumor, strain names, tumor frequency and latency, and literature citations.Although primary source for the data represented in MTB is peer-reviewed scientific literature an increasing amount of data is derived from disparate sources. MTB includes annotated histopathology images and cytogenetic assay images for mouse tumors where these data are available from The Jackson Laboratory’s mouse colonies and from outside contributors. MTB encourages direct submission of mouse tumor data and images from the cancer research community and provides investigators with a web-accessible tool for image submission and annotation. Integrated searches of the data in MTB are facilitated by the use of several controlled vocabularies and by adherence to standard nomenclature. MTB also provides links to other related online resources such as the Mouse Genome Database, Mouse Phenome Database, the Biology of the Mammary Gland Web Site, Festing's Listing of Inbred Strains of Mice, the JAX® Mice Web Site, and the Mouse Models of Human Cancers Consortium's Mouse Repository. MTB provides access to data on mouse models of cancer via the internet and has been designed to facilitate the selection of experimental models for cancer research, the evaluation of mouse genetic models of human cancer, the review of patterns of mutations in specific cancers, and the identification of genes that are commonly mutated across a spectrum of cancers.MTB is supported by NCI grant CA089713.

Clinical, Pathological, and Immunologic Aspects of the Multiple Sclerosis Model in Common Marmosets (Callithrix jacchus)

The efficacy of many new immunomodulatory therapies for multiple sclerosis (MS) patients has often been disappointing, reflecting our incomplete understanding of this enigmatic disease. There is a growing awareness that, at least in part, there may be limited applicability to the human disease of results obtained in the widely studied MS model experimental autoimmune encephalomyelitis in rodents. This review describes the experimental autoimmune encephalomyelitis model developed in a small neotropical primate, the common marmoset (Callithrix jacchus). The model has features including clinicopathologic correlation patterns, lesion heterogeneity, immunologic mechanisms, and disease markers that more closely mimic the human disease. Several unique features of experimental autoimmune encephalomyelitis in marmosets, together with their outbred nature and close genetic and immunologic similarities to humans, create an attractive experimental model for translational research into MS, particularly for the preclinical evaluation of new biologic therapeutic molecules that cannot be investigated in rodents because of their species specificity. Moreover, this model provides new insights into possible pathogenetic mechanisms in MS.

The effect of micro teaching application on the preservice teachers’teacher competency levels

In this study, it is aimed to examine the effect of the micro-teaching application on teacher competency level of early childhood preservice teachers who are included in the activity. Students’ teacher competency levels were measured by “Prospective Teacher Competency Sub-Scale” which was developed by Erişen and Çeliköz (2003). For the study the pretest- post-test design of experimental research model has been used without control group. The data is analyzed by the Paired Samples t test and ANOVA test for repeated measures. After the experiment of micro teaching, significant differences have been found between participants’ pre-test and post-test scores. The results show that the micro-teaching activity may affect students’ teacher competency levels positively.

The role of IGF1 in the in vivo production of bovine embryos from superovulated donors

IGF1 plays an important role in bovine follicular growth, acquisition of oocyte competence and embryo viability. Current data also indicate a critical role for IGF1 in both the ovarian response and the embryo yield following the superovulatory treatments. IGF1 can have either positive or negative effects on embryo viability which is related to the concentration of IGF1 induced by superovulation treatment. These effects impact either on oocyte competence or directly on the embryo. Concentrations in the physiological range appear to result in the production of higher quality embryos, mainly due to the mitogenic and the anti-apoptotic activities of IGF1. However, high superovulatory responses are associated with decreased embryo viability and a concomitant increase in apoptosis. Studies in mice suggest that this increase in apoptosis is related to the downregulation of the IGF1 receptor in the embryo associated with high IGF1 concentrations. Strategies capable of controlling the IGF1 concentrations could be one approach to improve superovulation responses. A range of possible approaches for research within the IGF system in gonadotrophin-stimulated cattle is discussed in this review, including the possible use of superovulated female cattle as an alternative animal experimental model for research on reproductive disorders in humans associated with abnormal IGF1 concentrations.

Detailed spectral profile analysis of penicillin-induced epileptiform activity in anesthetized rats

Penicillin model is a widely used experimental model for epilepsy research. In the present study we aimed to portray a detailed spectral analysis of penicillin-induced epileptiform activity in comparison with basal brain activity in anesthetized Wistar rats. Male Wistar rats were anesthetized with i.p. urethane and connected to an electrocorticogram setup. After a short period of basal activity recording, epileptic focus was induced by injecting 400IU/2 microl penicillin-G potassium into the left lateral ventricle while the cortical activity was continuously recorded. Basal activity, latent period and the penicillin-induced epileptiform activity periods were then analyzed using both conventional methods and spectral analysis. Spectral analyses were conducted by dividing the whole spectrum into different frequency bands including delta, theta (slow and fast), alpha-sigma, beta (1 and 2) and gamma (1 and 2) bands. Our results show that the most affected frequency bands were delta, theta, beta-2 and gamma-2 bands during the epileptiform activity and there were marked differences in terms of spectral densities between three investigated episodes (basal activity, latent period and epileptiform activity). Our results may help to analyze novel data obtained using similar experimental models and the simple analysis method described here can be used in similar studies to investigate the basic neuronal mechanism of this or other types of experimental epilepsies.