scholarly journals Animal models for fertility preservation in the male

Reproduction ◽  
2008 ◽  
Vol 136 (6) ◽  
pp. 717-723 ◽  
Author(s):  
Jens Ehmcke ◽  
Stefan Schlatt
Keyword(s):  
Animal Models ◽  
Fertility Preservation ◽  
Germ Cells ◽  
Rare Species ◽  
Male Fertility ◽  
Ex Vivo ◽  
Experimental Models ◽  
Special Focus ◽  
Fertility Protection ◽  
Livestock Conservation

Fertility preservation in the male is routinely focused on sperm. In clinical and veterinary settings, cryopreservation of sperm is a widely used tool. However, the goals for male fertility preservation differ between experimental models, maintenance of livestock, conservation of rare species, and fertility protection in men. Therefore very different approaches exist, which are adapted to the specialized needs for each discipline. Novel tools for male fertility preservation are explored targeting immature germ cells in embryonic or immature testes. Many options might be developed to combine germline preservation and generation of sperm ex vivo leading to interesting new perspectives. This review highlights current and future options for male fertility preservation with a special focus on animal models and a consideration of the various disciplines in need of novel tools.

scholarly journals Ex-Vivo Analysis Platforms for Amyloid Precursor Protein Cleavage.

2021 ◽  
Author(s):  
Yuji Kamikubo ◽  
Hao Jin ◽  
Kazue Niisato ◽  
Yoshie Hashimoto ◽  
Nobumasa Takasugi ◽  
...  
Keyword(s):  
Animal Models ◽  
Amyloid Precursor Protein ◽  
Ex Vivo ◽  
Senile Plaques ◽  
Amyloid Β ◽  
Experimental Models ◽  
Precursor Protein ◽  
Amyloid Β Peptide ◽  
Ex Vivo Model ◽  
Brain Disorder

Abstract Alzheimer’s disease (AD) is a progressive neurodegenerative brain disorder and the most common cause of dementia in the elderly. Large numbers of senile plaques, neurofibrillary tangles, and cerebral atrophy are characteristic features of AD. The main component of senile plaques is amyloid β peptide (Aβ), derive from the amyloid precursor protein (APP). AD has been extensively studied using cell line, primary culture of neural cells, and animal models, however, some discrepancy is observed in these results. Dissociated cultures have lost the tissue architecture of the brain including neural circuits, glial cells, and the extracellular matrix. Animal models require lengthy animal experiments and laborious monitoring of multiple parameters following manipulations. Therefore, it is necessary to connect these experimental models to understand the pathology of AD. In order to analyze long-term neuronal development and plasticity, and progressive neurodegenerative disease, experimental platform amenable to continuous observation and experimental manipulation is required. In this report, we provide a practical method to slice and cultivate rodent hippocampus to consecutively investigate the cleavage of APP and the secretion of Aβ as an ex vivo model.

scholarly journals Advanced bioengineering of male germ stem cells to preserve fertility

2021 ◽  
Vol 12 ◽  
pp. 204173142110605
Author(s):  
Hossein Eyni ◽  
Sadegh Ghorbani ◽  
Hojjatollah Nazari ◽  
Marziyeh Hajialyani ◽  
Sajad Razavi Bazaz ◽  
...  
Keyword(s):  
Fertility Preservation ◽  
Germ Cells ◽  
Male Fertility ◽  
Round Spermatid ◽  
The Body ◽  
Testicular Sperm Extraction ◽  
Male Germ Cells ◽  
Vitro Fertilization ◽  
In Vitro Spermatogenesis

In modern life, several factors such as genetics, exposure to toxins, and aging have resulted in significant levels of male infertility, estimated to be approximately 18% worldwide. In response, substantial progress has been made to improve in vitro fertilization treatments (e.g. microsurgical testicular sperm extraction (m-TESE), intra-cytoplasmic sperm injection (ICSI), and round spermatid injection (ROSI)). Mimicking the structure of testicular natural extracellular matrices (ECM) outside of the body is one clear route toward complete in vitro spermatogenesis and male fertility preservation. Here, a new wave of technological innovations is underway applying regenerative medicine strategies to cell-tissue culture on natural or synthetic scaffolds supplemented with bioactive factors. The emergence of advanced bioengineered systems suggests new hope for male fertility preservation through development of functional male germ cells. To date, few studies aimed at in vitro spermatogenesis have resulted in relevant numbers of mature gametes. However, a substantial body of knowledge on conditions that are required to maintain and mature male germ cells in vitro is now in place. This review focuses on advanced bioengineering methods such as microfluidic systems, bio-fabricated scaffolds, and 3D organ culture applied to the germline for fertility preservation through in vitro spermatogenesis.

scholarly journals Synaptic Reshaping and Neuronal Outcomes in the Temporal Lobe Epilepsy

2021 ◽  
Vol 22 (8) ◽  
pp. 3860
Author(s):  
Elisa Ren ◽  
Giulia Curia
Keyword(s):  
Animal Models ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Current Knowledge ◽  
Focal Epilepsy ◽  
Ex Vivo ◽  
Hippocampal Sclerosis ◽  
Control Group ◽  
Epileptogenic Zone ◽  
Epileptiform Discharges

Temporal lobe epilepsy (TLE) is one of the most common types of focal epilepsy, characterized by recurrent spontaneous seizures originating in the temporal lobe(s), with mesial TLE (mTLE) as the worst form of TLE, often associated with hippocampal sclerosis. Abnormal epileptiform discharges are the result, among others, of altered cell-to-cell communication in both chemical and electrical transmissions. Current knowledge about the neurobiology of TLE in human patients emerges from pathological studies of biopsy specimens isolated from the epileptogenic zone or, in a few more recent investigations, from living subjects using positron emission tomography (PET). To overcome limitations related to the use of human tissue, animal models are of great help as they allow the selection of homogeneous samples still presenting a more various scenario of the epileptic syndrome, the presence of a comparable control group, and the availability of a greater amount of tissue for in vitro/ex vivo investigations. This review provides an overview of the structural and functional alterations of synaptic connections in the brain of TLE/mTLE patients and animal models.

scholarly journals Ex vivo Retrieval of Mature Oocytes for Fertility Preservation in a Patient with Bilateral Borderline Ovarian Tumor

2021 ◽  
Author(s):  
Bruno Ramalho de Carvalho ◽  
Geórgia Fontes Cintra ◽  
Taise Moura Franceschi ◽  
Íris de Oliveira Cabral ◽  
Leandro Santos de Araújo Resende ◽  
...  
Keyword(s):  
Fertility Preservation ◽  
Ovarian Stimulation ◽  
Ovarian Tumor ◽  
Ex Vivo ◽  
Oocyte Retrieval ◽  
Ovarian Response ◽  
Malignant Cell ◽  
Borderline Ovarian Tumor ◽  
Increased Risk

AbstractWe report a case of ultrasound-guided ex vivo oocyte retrieval for fertility preservation in a woman with bilateral borderline ovarian tumor, for whom conventional transvaginal oocyte retrieval was deemed unsafe because of the increased risk of malignant cell spillage. Ovarian stimulation with gonadotropins was performed. Surgery was scheduled according to the ovarian response to exogenous gonadotropic stimulation; oophorectomized specimens were obtained by laparoscopy, and oocyte retrieval was performed ∼ 37 hours after the ovulatory trigger. The sum of 20 ovarian follicles were aspirated, and 16 oocytes were obtained. We performed vitrification of 12 metaphase II oocytes and 3 oocytes matured in vitro. Our result emphasizes the viability of ex vivo mature oocyte retrieval after controlled ovarian stimulation for those with high risk of malignant dissemination by conventional approach.

scholarly journals Ocular Toxoplasmosis: Mechanisms of Retinal Infection and Experimental Models

Parasitologia ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 50-60
Author(s):  
Veronica Rodriguez Fernandez ◽  
Giovanni Casini ◽  
Fabrizio Bruschi
Keyword(s):  
Ex Vivo ◽  
Cell Damage ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Treatment Strategies ◽  
Experimental Models ◽  
Ocular Toxoplasmosis ◽  
Cell Infection

Ocular toxoplasmosis (OT) is caused by the parasite Toxoplasma gondii and affects many individuals throughout the world. Infection may occur through congenital or acquired routes. The parasites enter the blood circulation and reach both the retina and the retinal pigment epithelium, where they may cause cell damage and cell death. Different routes of access are used by T. gondii to reach the retina through the retinal endothelium: by transmission inside leukocytes, as free parasites through a paracellular route, or after endothelial cell infection. A main feature of OT is the induction of an important inflammatory state, and the course of infection has been shown to be influenced by the host immunogenetics. On the other hand, there is evidence that the T. gondii phenotype also has an impact on the distribution of the pathology in different areas. Although considerable knowledge has been acquired on OT, a deeper knowledge of its mechanisms is necessary to provide new, more targeted treatment strategies. In particular, in addition to in vitro and in vivo experimental models, organotypic, ex vivo retinal explants may be useful in this direction.

scholarly journals Ischemia-Reperfusion Injuries Assessment during Pancreas Preservation

2021 ◽  
Vol 22 (10) ◽  
pp. 5172
Author(s):  
Thomas Prudhomme ◽  
John F. Mulvey ◽  
Liam A. J. Young ◽  
Benoit Mesnard ◽  
Maria Letizia Lo Faro ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Ischemia Reperfusion ◽  
Graft Function ◽  
Impedance Analysis ◽  
Experimental Models ◽  
Caspase Activation ◽  
Pancreas Perfusion ◽  
Number Of Factors ◽  
Pancreas Preservation ◽  
Metabolite Concentrations

Maintaining organ viability between donation and transplantation is of critical importance for optimal graft function and survival. To date in pancreas transplantation, static cold storage (SCS) is the most widely practiced method of organ preservation. The first experiments in ex vivo perfusion of the pancreas were performed at the beginning of the 20th century. These perfusions led to organ oedema, hemorrhage, and venous congestion after revascularization. Despite these early hurdles, a number of factors now favor the use of perfusion during preservation: the encouraging results of HMP in kidney transplantation, the development of new perfusion solutions, and the development of organ perfusion machines for the lung, heart, kidneys and liver. This has led to a resurgence of research in machine perfusion for whole organ pancreas preservation. This review highlights the ischemia-reperfusion injuries assessment during ex vivo pancreas perfusion, both for assessment in pre-clinical experimental models as well for future use in the clinic. We evaluated perfusion dynamics, oedema assessment, especially by impedance analysis and MRI, whole organ oxygen consumption, tissue oxygen tension, metabolite concentrations in tissue and perfusate, mitochondrial respiration, cell death, especially by histology, total cell free DNA, caspase activation, and exocrine and endocrine assessment.

Biochemical and Pharmacological Properties of SANORG 34006, a Potent and Long-Acting Synthetic Pentasaccharide

Blood ◽  
1998 ◽  
Vol 91 (11) ◽  
pp. 4197-4205 ◽  
Author(s):  
J.M. Herbert ◽  
J.P. Hérault ◽  
A. Bernat ◽  
R.G.M. van Amsterdam ◽  
J.C. Lormeau ◽  
...  
Keyword(s):  
Thrombin Generation ◽  
Ex Vivo ◽  
Thrombus Formation ◽  
Factor Xa ◽  
Therapeutic Index ◽  
Inhibitory Effect ◽  
Experimental Models ◽  
Treatment And Prevention ◽  
Long Acting

Abstract SANORG 34006 is a new sulfated pentasaccharide obtained by chemical synthesis. It is an analog of the “synthetic pentasaccharide” (SR 90107/ ORG 31540) which represents the antithrombin (AT) binding site of heparin. SANORG 34006 showed a higher affinity to human AT than SR 90107/ORG 31540 (kd = 1.4 ± 0.3 v 48 ± 11 nmol/L), and it is a potent and selective catalyst of the inhibitory effect of AT on factor Xa (1,240 ± 15 anti–factor Xa U/mg v850 ± 27 anti-factor Xa U/mg for SR 90107/ORG 31540). In vitro, SANORG 34006 inhibited thrombin generation occurring via both the extrinsic and intrinsic pathway. After intravenous (IV) or subcutaneous (SC) administration to rabbits, SANORG 34006 displayed a long-lasting anti–factor Xa activity and inhibition of thrombin generation (TG) ex vivo. SANORG 34006 was slowly eliminated after IV or SC administration to rats, rabbits, and baboons, showed exceptionally long half-lives (between 9.2 hours in rats and 61.9 hours in baboons), and revealed an SC bioavailability near 100%. SANORG 34006 displayed antithrombotic activity by virtue of its potentiation of the anti–factor Xa activity of AT. It strongly inhibited thrombus formation in experimental models of thromboplastin/stasis-induced venous thrombosis in rats (IV) and rabbits (SC) (ED50values = 40.0 ± 3.4 and 105.0 ± 9.4 nmol/kg, respectively). The duration of its antithrombotic effects closely paralleled the ex vivo anti–factor Xa activity. SANORG 34006 enhanced rt-PA–induced thrombolysis and inhibited accretion of125I-fibrinogen onto a preformed thrombus in the rabbit jugular vein suggesting that concomitant use of SANORG 34006 during rt-PA therapy might be helpful in facilitating thrombolysis and preventing fibrin accretion onto the thrombus under lysis. Contrary to standard heparin, SANORG 34006 did not enhance bleeding in a rabbit ear incision model at a dose that equals 10 times the antithrombotic ED50 in this species and, therefore, exhibited a favorable therapeutic index. We suggest that SANORG 34006 is a promising compound in the treatment and prevention of various thrombotic diseases.

Reno-protective mechanisms of epoxyeicosatrienoic acids in cardiovascular disease

2012 ◽  
Vol 302 (3) ◽  
pp. R321-R330 ◽  
Author(s):  
Ahmed A. Elmarakby
Keyword(s):  
Blood Pressure ◽  
Cardiovascular Disease ◽  
Animal Models ◽  
Vascular Function ◽  
Organ Damage ◽  
Reduce Blood Pressure ◽  
Experimental Models ◽  
Epoxyeicosatrienoic Acids ◽  
Protective Effects ◽  
Protective Mechanisms

Cardiovascular disease (CVD) is the leading cause of mortality worldwide, and it is well known that end-stage renal disease (ESRD) is a profound consequence of the progression of CVD. Present treatments only slow CVD progression to ESRD, and it is imperative that new therapeutic strategies are developed to prevent the incidence of ESRD. Because epoxyeicosatrienoic acids (EETs) have been shown to elicit reno-protective effects in hypertensive animal models, the current review will focus on addressing the reno-protective mechanisms of EETs in CVD. The cytochrome P-450 epoxygenase catalyzes the oxidation of arachidonic acid to EETs. EETs have been identified as endothelium-derived hyperpolarizing factors (EDHFs) with vasodilatory, anti-inflammatory, antihypertensive, and antiplatelet aggregation properties. EETs also have profound effects on vascular migration and proliferation and promote angiogenesis. The progression of CVD has been linked to decreased EETs levels, leading to the concept that EETs should be therapeutically targeted to prevent end-organ damage associated with CVD. However, EETs are quickly degraded by the enzyme soluble epoxide hydrolase (sEH) to their less active diols, dihydroxyeicosatrienoic acids (DHETs). As such, one way to increase EETs level is to inhibit their degradation to DHETs by using sEH inhibitors. Inhibition of sEH has been shown to effectively reduce blood pressure and organ damage in experimental models of CVD. Another approach to target EETs is to develop EET analogs with improved solubility and resistance to auto-oxidation and metabolism by sEH. For example, stable ether EET analogs dilate afferent arterioles and lower blood pressure in hypertensive rodent animal models. EET agonists also improve insulin signaling and vascular function in animal models of metabolic syndrome.

scholarly journals Experimental Models to Study COVID-19 Effect in Stem Cells

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 91
Author(s):  
Rishi Man Chugh ◽  
Payel Bhanja ◽  
Andrew Norris ◽  
Subhrajit Saha
Keyword(s):  
Stem Cells ◽  
Ex Vivo ◽  
Drug Efficacy ◽  
Cell Loss ◽  
Experimental Models ◽  
Model Systems ◽  
Virus Infectivity ◽  
Ex Vivo Model ◽  
Global Pandemic ◽  
The Impact

The new strain of coronavirus (severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2)) emerged in 2019 and hence is often referred to as coronavirus disease 2019 (COVID-19). This disease causes hypoxic respiratory failure and acute respiratory distress syndrome (ARDS), and is considered as the cause of a global pandemic. Very limited reports in addition to ex vivo model systems are available to understand the mechanism of action of this virus, which can be used for testing of any drug efficacy against virus infectivity. COVID-19 induces tissue stem cell loss, resulting inhibition of epithelial repair followed by inflammatory fibrotic consequences. Development of clinically relevant models is important to examine the impact of the COVID-19 virus in tissue stem cells among different organs. In this review, we discuss ex vivo experimental models available to study the effect of COVID-19 on tissue stem cells.

Abstract 3680: Transfusion-Induced Tissue Hypoxia is Ameliorated by S -nitrosohemoglobin Repletion of Stored Red Blood Cells

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Diana L Diesen ◽  
Jonathan S Stamler
Keyword(s):  
Animal Models ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Tissue Oxygenation ◽  
Ex Vivo ◽  
Tissue Hypoxia ◽  
Mouse Blood ◽  
Mortality And Morbidity ◽  
Stored Blood ◽  
Related Mortality

Transfusion of stored red blood cells (RBCs) is associated with a decrease in tissue oxygenation in animal models and with increased mortality and morbidity in patients. Recent studies have demonstrated that stored RBCs are deficient in vasodilatory ability and depleted of S -nitrosohemoglobin (SNO-Hb), and that renitrosylation ex vivo can increase SNO-Hb levels and restore vasoactivity. We have examined in a mouse model the extent to which transfusion impairs tissue oxygenation and whether SNO-Hb repletion can ameliorate that impairment. We report here that transfusion of (mouse) RBCs stored for 1 day or 1 week results in tissue hypoxia that is largely prevented by SNO-Hb repletion prior to transfusion ( 1 day stored blood : % decrease in oxygenation 58+/−10% untreated vs. 92+/−0.7% SNO-Hb repleted, p<0.05, n=3– 6; 1 week stored blood : % decrease in oxygenation 66+/−10% untreated vs. 91+/−2.8% SNO-Hb repleted, p<0.05, n=3– 6). Storage of mouse blood beyond human expiration-equivalents (1 month) resulted in substantial lysis and the death of all mice transfused (native and SNO-Hb repleted blood, n=5). In conclusion, repletion of SNO-Hb ameliorates the decrease in tissue oxygenation that results from transfusion of untreated stored blood. Therefore, SNO-Hb repletion may provide a simple and efficacious method to reduce transfusion-related mortality and morbidity.

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