Chemical stress in a largely deformed electrode: Effects of trapping lithium.

Lithium trapping, which is associated with the immobilization of lithium and is one of key factors contributing to structural degradation of lithium-ion batteries during electrochemical cycling, can exacerbate mechanical stress and ultimately cause the capacity loss and battery failure. Currently, there are few studies focusing on how lithium trapping contributes to mechanical stress during electrochemical cycling. This study incorporates the contribution of lithium trapping in the analysis of mechanical stress and mass transport in the framework of finite deformation. Two de-lithiation scenarios are analyzed: one with a constant concentration of trapped lithium and the other with inhomogeneous distribution of trapped lithium. The results show that the constant concentration of trapped lithium increases chemical stress and the inhomogeneous distribution of trapped lithium causes the decrease of chemical stress. The findings can serve as a basis for developing effective strategies to mitigate the lithium trapping and improve the battery performance.

Effect of Previous Alkylating Agent Exposure on Follicle Numbers in Cryopreserved Prepubertal and Young Adult Ovarian Tissue after Long-Term Xenografting.

PURPOSE AND METHODS: To elucidate whether previous cancer treatment affects graft recovery and follicle numbers, morphology, and development in grafts, cryopreserved ovarian biopsies obtained from 18 cancer patients aged 1-24 years with and without exposure to chemotherapy were xenografted as 1 mm3 fragments to immunodeficient mice for 22 weeks with exogenous stimulation. RESULTS: Graft recovery showed no association with chemotherapy exposure, pubertal stage, or leukemia contamination. Total follicle number per recovered graft varied between 0 and 1031 in the chemotherapy-exposed and between 0 and 502 in the non-chemotherapy-exposed group. Atretic follicles formed the largest proportion of the follicle pool in chemotherapy-exposed grafts. Increased atresia correlated with exposure to alkylating agents (mean ± SD 8866.2 ± 9316.3 mg/m2) but not with anthracyclines, pubertal stage, or leukemia contamination. CONCLUSION: The observation confirms the harmful effects of alkylating agents on ovarian tissue. Therapy at the median cumulative dose of 8866 mg/m2 leads to the decreased quality of cryopreserved ovarian follicles in children and young adults.

Telomere length regulators are activated in young men after pediatric kidney transplantation compared to healthy controls and survivors of childhood cancer-A cross-sectional study.

Chronic diseases are known to cause premature aging and frailty. Data about telomere length and telomere length-regulating proteins after pediatric KTx are scarce. Leukocyte telomere length and gene expression level of eight telomere-binding proteins were analyzed in 20 KTx recipients, eight childhood NBL survivors, and nine healthy controls. The influence of key clinical parameters on telomere length and on regulators of telomere length was evaluated. The telomere length in the KTx recipients tended to be shorter (0.53 AU) than in the healthy controls (0.64 AU) but longer than in the NBL survivors (0.38 AU). There was no significant difference in telomere length between the NBL survivors and the KTx recipients (P = .110). The gene expression level of telomere length-preserving protein RPA1 was significantly higher in the KTx recipients than among the NBL survivors or healthy controls, while the expression of TRF2 and the tumor suppressor gene p16 was significantly higher in the KTX recipients when compared to the controls. TRF2 and TIN2 correlated significantly with hsCRP; additionally, TRF2 showed significant correlation with plasma creatinine and eGFR. KTx recipients have near to normal telomere length, but they have significantly higher gene expression levels of telomere regulatory proteins compared with healthy controls, suggesting activation of mechanisms preserving telomere length among KTx recipients. Our results suggest that declined graft function and consequent inflammatory response may have influence on telomerase activity.

LJELSR: A Strengthened Version of JELSR for Feature Selection and Clustering.

Feature selection and sample clustering play an important role in bioinformatics. Traditional feature selection methods separate sparse regression and embedding learning. Later, to effectively identify the significant features of the genomic data, Joint Embedding Learning and Sparse Regression (JELSR) is proposed. However, since there are many redundancy and noise values in genomic data, the sparseness of this method is far from enough. In this paper, we propose a strengthened version of JELSR by adding the L1-norm constraint on the regularization term based on a previous model, and call it LJELSR, to further improve the sparseness of the method. Then, we provide a new iterative algorithm to obtain the convergence solution. The experimental results show that our method achieves a state-of-the-art level both in identifying differentially expressed genes and sample clustering on different genomic data compared to previous methods. Additionally, the selected differentially expressed genes may be of great value in medical research.

PCA via joint graph Laplacian and sparse constraint: Identification of differentially expressed genes and sample clustering on gene expression data.

BACKGROUND: In recent years, identification of differentially expressed genes and sample clustering have become hot topics in bioinformatics. Principal Component Analysis (PCA) is a widely used method in gene expression data. However, it has two limitations: first, the geometric structure hidden in data, e.g., pair-wise distance between data points, have not been explored. This information can facilitate sample clustering; second, the Principal Components (PCs) determined by PCA are dense, leading to hard interpretation. However, only a few of genes are related to the cancer. It is of great significance for the early diagnosis and treatment of cancer to identify a handful of the differentially expressed genes and find new cancer biomarkers. RESULTS: In this study, a new method gLSPCA is proposed to integrate both graph Laplacian and sparse constraint into PCA. gLSPCA on the one hand improves the clustering accuracy by exploring the internal geometric structure of the data, on the other hand identifies differentially expressed genes by imposing a sparsity constraint on the PCs. CONCLUSIONS: Experiments of gLSPCA and its comparison with existing methods, including Z-SPCA, GPower, PathSPCA, SPCArt, gLPCA, are performed on real datasets of both pancreatic cancer (PAAD) and head & neck squamous carcinoma (HNSC). The results demonstrate that gLSPCA is effective in identifying differentially expressed genes and sample clustering. In addition, the applications of gLSPCA on these datasets provide several new clues for the exploration of causative factors of PAAD and HNSC.

A new method for mining information of co-expression network based on multi-cancers integrated data.

BACKGROUND: Gene co-expression network is a favorable method to reveal the nature of disease. With the development of cancer, the way to build gene co-expression networks based on cancer data has been become a hot spot. However, there are still a limited number of current node measurement methods and node mining strategies for multi-cancers network construction. METHODS: In this paper, we introduce a new method for mining information of co-expression network based on multi-cancers integrated data, named PMN. We construct the network by combining the different types of relevant measures (linear and nonlinear rules) for different nodes based on integrated gene expression data of multi-cancers from The Cancer Genome Atlas (TCGA). For mining genes, we combine different properties (local and global characteristics) of the nodes. RESULTS: We uncover more suspicious abnormally expressed genes and shared pathways of different cancers. And we have also found some proven genes and pathways; of course, there are some suspicious factors and molecules that need clinical validation. CONCLUSIONS: The results demonstrate that our method is very effective in excavating gene co-expression genes of multi-cancers.

Network analysis based on low-rank method for mining information on integrated data of multi-cancers.

The noise problem of cancer sequencing data has been a problem that can't be ignored. Utilizing considerable way to reduce noise of these cancer data is an important issue in the analysis of gene co-expression network. In this paper, we apply a sparse and low-rank method which is Robust Principal Component Analysis (RPCA) to solve the noise problem for integrated data of multi-cancers from The Cancer Genome Atlas (TCGA). And then we build the gene co-expression network based on the integrated data after noise reduction. Finally, we perform nodes and pathways mining on the denoising networks. Experiments in this paper show that after denoising by RPCA, the gene expression data tend to be orderly and neat than before, and the constructed networks contain more pathway enrichment information than unprocessed data. Moreover, learning from the betweenness centrality of the nodes in the network, we find some abnormally expressed genes and pathways proven that are associated with many cancers from the denoised network. The experimental results indicate that our method is reasonable and effective, and we also find some candidate suspicious genes that may be linked to multi-cancers.

[Effect of Acupuncture Combined with Gavage of Rule Granule on Serum Prolactin, Estradiol and Progestone Contents and Their Receptor Expression in Breast in Mammary Gland Hyperplasia Rats].

OBJECTIVE: To observe the effect of acupuncture combined with medication (Rule Granule) on serum prolactin (PRL)，estradiol (E2) and progestone (P) contents and expressions of prolactin receptor (PRLR), estrogen receptor (ER) and progestrone receptor (PR) proteins in mammary gland (MG) tissues of MG hyperplasia (MGH) rats, so as to explore its mechanisms underlying improvement of MGH. METHODS: A total of 55 female SD rats were randomized into blank control group (n＝10), model group (n＝10), acupuncture group (n＝11), medication group (n＝10), and acupuncture plus medication group (n＝9). The MGH model was established by muscular injection of E2 benzoate(0.5 mg/kg, once daily for 20 days), followed by injection of P (5 mg/kg) into the lateral muscle of the hind-limb, once daily for 5 days, and the rats of the control group were treated by muscular injection of normal saline at the same site and in the same procedures. Acupoint group A composed of bilateral Tianzhong (SI 11), Ganshu (BL 18) and Zusanli (ST 36), and group B composed of Tanzhong (CV 17), and bilateral Wuyi (ST 15) and Hegu (LI 4) were alternatively punctured with filiform needles and stimulated swiftly by twirling the needle in each acupoint for 20－30 sec, once daily for 30 days. Rats of the medication group and acupuncture ＋medication group were treated by gavage of Rule Granule fluid containing Baishao (Paeonia Iactiflora Pall), Danggui (Angelica sinensis), etc. (1.5 mL/100 g for each rat) and those of the other groups treated by gavage of distilled water (1.5 mL/100 g). The treatment was given once daily for continuous 30 d. At the end of the experiments, the rats' abdominal aorta blood was collected for assaying the contents of serum PRL, E2 and P with ELISA, and the pathological changes of breast tissue (the left 2nd pairs) were observed under microscope after sectioning and H．E. staining. The expression of PRLR, ER and PR proteins in the breast tissue was detected by immunohistochemistry. RESULTS: After modeling, the hyperplasia of mammary gland in the model group was obvious; the serum PRL and E2 contents and the immunoactivities of PRLR, ER and PR were significantly increased (P<0.01); and the content of serum P was considerably decreased in the model group in comparison with the blank control group (P<0.01). After the treatment, the hyperplasia of mammary gland was improved; the serum PRL and E2 contents and the expression of PRLR, ER and PR were significantly decreased (P<0.05, P<0.01); and the content of P was notably increased in the acupuncture, medication and acupuncture plus medication groups relevant to the model group (P<0.05，P<0.01). The therapeutic effects of acupuncture plus medication were significantly superior to those of both simple medication and simple acupuncture in down-regulating serum PRL and E2 contents and PRLR, ER and PR immunoactivity, as well as in up-regulating serum P content (P<0.05). No significant differences were found between the medication and acupuncture groups in the above mentioned 3 serum and 3 mammary indexes (P>0.05)．. CONCLUSION: Acupuncture, Rule Granule, and acupuncture combined with Rule Granule can improve hyperplasia of mammary gland in rats, which may be related to their effects in reducing serum PRL and E2 and breast ER, PR and PRLR expression levels, and in increasing serum P level. The therapeutic effects of acupuncture plus Rule Granule are better than those of simple acupuncture and simple Rule Granule.

Knock-Out Serum Replacement and Melatonin Effects on Germ Cell Differentiation in Murine Testicular Explant Cultures.

Finding robust culture conditions for in vitro maturation (IVM) of male germ cells is still a challenge. Recently, a testis organ culture method, using Knockout Serum Replacement (KSR), was suggested as a promising approach. However, the efficiency of that model is still not optimal. Hence, we have tried to establish the culture conditions in two laboratories, and to improve the reliability of the culture system to generate mature germ cells. Male mice at three days of age were sacrificed. Testes were cut into small pieces which were cultured atop agarose stands, using Minimum Essential Medium alpha supplemented with different supplements; melatonin, Glutamax, and different concentrations of KSR. The results showed that the duration of culture beyond 18 days had an impact on the number of differentiated germ cells. Supplementation with melatonin and Glutamax revealed a positive influence on the efficiency of male germ cell differentiation in vitro. Furthermore, the results confirmed that KSR had a positive effect on germ cell maturation and testosterone production, with a concentration of at least 10%. In conclusion, this study emphasizes the beneficial role of at least 10% KSR in the IVM of germ cells.

Robust and Efficient Biomolecular Clustering of Tumor Based on ${p}$ -Norm Singular Value Decomposition.

High dimensionality has become a typical feature of biomolecular data. In this paper, a novel dimension reduction method named p-norm singular value decomposition (PSVD) is proposed to seek the low-rank approximation matrix to the biomolecular data. To enhance the robustness to outliers, the Lp-norm is taken as the error function and the Schatten p-norm is used as the regularization function in the optimization model. To evaluate the performance of PSVD, the Kmeans clustering method is then employed for tumor clustering based on the low-rank approximation matrix. Extensive experiments are carried out on five gene expression data sets including two benchmark data sets and three higher dimensional data sets from the cancer genome atlas. The experimental results demonstrate that the PSVD-based method outperforms many existing methods. Especially, it is experimentally proved that the proposed method is more efficient for processing higher dimensional data with good robustness, stability, and superior time performance.

[Effects of acupuncture combined with Rule granule on breast tissue, prolactin and receptor expression in rats with mammary gland hyperplasia].

OBJECTIVE: To observe the effects of acupuncture combined with Rule granule on breast tissue, prolactin(PRL) and prolactin receptor (PRLR) expression in rats with mammary gland hyperplasia (MGH), and to explore its action mechanism to provide reference for clinical treatment of MGH. METHODS: Fifty-five female SD rats were randomly divided into a blank group, a model group, an acupuncture group, a Rule granule group and a combination group. Except the blank group, the rats in the remaining groups were treated with combined stimulation of estrogenic and progestational hormone to establish MGH model. After model establishment, the rats in the acupuncture group were treated with acupuncture at Plan A of "Tianzong" (SI 11), "Ganshu" (BL 18), "Zusanli" (ST 36) and Plan B of "Wuyi" (ST 15), "Hegu" (LI 4), "Danzhong" (CV 17). Each plan was selected for one acupuncture treatment, and two plans were used alternately. The rats in the Rule granule group were treated with oral administration of granule, 3 mL per times. The rats in the combination group were treated with the same Rule granule, followed by acupuncture, once a day. After consecutive 30-day treatment, blood sample was collected from abdominal aorta; ELISA method was applied to measure the contents of PRL; the HE slice of mammary gland was observed under light microscope; the SABC immunohistochemical method was applied to measure the positive expression of PRLR. RESULTS: The morphology of breast tissue in the model group was consistent with MGH. Compared with the blank group, the serum PRL and the expression of PRLR were increased significantly in the model group (both P<0.01). Compared with the model group, the hyperplasia of mammary gland in each treatment group was improved, and serum PRL and expression of PRLR were significantly reduced (P<0.05, P<0.01), which were more significant in the combination group (both P<0.05). CONCLUSION: Acupuncture, Rule granule and its combination could effectively treat MGH, which is likely to reduce the level of serum PRL and inhibit the binding of PRL to PRLR, as a result, the level of E2 is indirectly inhibited, and the hyperplastic mammary gland is recovered. Compared with acupuncture or Rule granule, the combination of both has better overall efficacy.

[Experience of professor GUO Chengjie for mammary gland hyperplasia by disease-symptom diagnosis and treatment].

To introduce the experience of professor GUO Chengjie for mammary gland hyperplasia by disease-symptom diagnosis and treatment. Under disease-symptom combination and the reference of both Chinese medicine and western medicine,he took priority in diagnosis and then treated diseases by acupuncture and medicine,etc. Meanwhile,he considered the superficiality and origin of diseases and served patients based on individuals,seasons and regions. Also,regulation for mood was applied. As a result, the good effect was achieved.

Leydig cell steroidogenesis unexpectedly escapes mitochondrial dysfunction in prematurely aging mice.

Point mutations and deletions of mitochondrial DNA (mtDNA) accumulate in tissues during aging in animals and humans and are the basis for mitochondrial diseases. Testosterone synthesis occurs in the mitochondria of Leydig cells. Mitochondrial dysfunction (as induced here experimentally in mtDNA mutator mice that carry a proofreading-deficient form of mtDNA polymerase γ, leading to mitochondrial dysfunction in all cells types so far studied) would therefore be expected to lead to low testosterone levels. Although mtDNA mutator mice showed a dramatic reduction in testicle weight (only 15% remaining) and similar decreases in number of spermatozoa, testosterone levels in mtDNA mutator mice were unexpectedly fully unchanged. Leydig cell did not escape mitochondrial damage (only 20% of complex I and complex IV remaining) and did show high levels of reactive oxygen species (ROS) production (>5-fold increased), and permeabilized cells demonstrated absence of normal mitochondrial function. Nevertheless, within intact cells, mitochondrial membrane potential remained high, and testosterone production was maintained. This implies development of a compensatory mechanism. A rescuing mechanism involving electrons from the pentose phosphate pathway transferred via a 3-fold up-regulated cytochrome b5 to cytochrome c, allowing for mitochondrial energization, is suggested. Thus, the Leydig cells escape mitochondrial dysfunction via a unique rescue pathway. Such a pathway, bypassing respiratory chain dysfunction, may be of relevance with regard to mitochondrial disease therapy and to managing ageing in general.

Bortezomib treatment causes long-term testicular dysfunction in young male mice.

BACKGROUND: With increased long-term survivors of childhood cancer patients, therapy-associated infertility has become one of the most common late side-effects and significantly affects their life-quality. Therefore, evaluation of anti-cancer agents on male reproduction and infertility prevention are urgently demanding. The proteasome inhibitor bortezomib has been launched in clinical trials for childhood cancers, however, its potential side effects on reproduction have so far been neither investigated experimentally nor reported in treated children. Thus the present study is designed to explore the impact of bortezomib on male reproductive function and to gain insights into how bortezomib exerts its adverse effects on man gonad, thereby providing pediatric oncologists relevant information. METHODS: 35 day-old male mice were treated with one 11-day cycle of bortezomib and then sacrificed 2 days, 45 days, or 6 months later. A mating study was performed in the group followed for 6 months, and their pups were analyzed on postnatal day 50. Serum follicle-stimulating hormone (FSH) and testicular testosterone levels were measured. Testicular morphology was evaluated by light- and electron microscopy, and the underlying mechanisms and pathways of testis damage were investigated. RESULTS: Testicular damage was visible already 2 days after stopping bortezomib and increased in severity by day 45. Then 80% of seminiferous tubules exhibited hypospermatogenesis with arrest at the levels of spermatogonia, spermatocytes and round spermatids. Germ cells were specifically targeted by bortezomib as evidenced by increased apoptosis mediated through activation of p53 and caspases. Even six months after the bortezomib treatment, testis weight, sperm concentration and seminiferous tubule length remained at a decreased level, indicating that spermatogenesis and tubular outgrowth could not fully recover. Combined with persistently increased serum levels of FSH in these mice, our results demonstrate that bortezomib can have long-term effects on testicular function, although fertility of bortezomib-exposed males remained and their offspring looked healthy. CONCLUSION: Bortezomib treatment causes long-term gonadal dysfunction in male mice. Careful monitoring of gonadal function in male childhood cancer patients treated with bortezomib is thus strongly recommended.

Identification of an isoform of colony-stimulating factor 1 receptor mRNA in the rat testis.

Because alternative RNA splicing regulation in the testis is prevalent, we explored testes of Sprague-Dawley rats for existence of alternatively spliced colony-stimulating factor 1 receptor (CSF-1R) mRNA. Using RT-PCR and sequencing, we identified a variant of CSF-1R mRNA that was 284 bp shorter than the full-length CSF-1R transcript. This variant was present in the testis (late fetal stage to adult) and in other organs of rats (7 and 60 days old). The deletion of 284 bp disrupted the open reading frame, resulting in a noncoding mRNA product. When testicular macrophages were stimulated with CSF-1R ligand and lipopolysaccharide, proportionally increased expression of both short isoform and full-length CSF-1R mRNA was observed. Thus, the identified isoform of CSF-1R mRNA may interfere with the expression of full-length CSF-1R mRNA, thereby affecting the biological activity of the ligand/receptor signaling axis in Sprague-Dawley rats.

In vitro Spermatogenesis - Optimal Culture Conditions for Testicular Cell Survival, Germ Cell Differentiation, and Steroidogenesis in Rats.

Although three-dimensional testicular cell cultures have been demonstrated to mimic the organization of the testis in vivo and support spermatogenesis, the optimal culture conditions and requirements remain unknown. Therefore, utilizing an established three-dimensional cell culture system that promotes differentiation of pre-meiotic murine male germ cells as far as elongated spermatids, the present study was designed to test the influence of different culture media on germ cell differentiation, Leydig cell functionality, and overall cell survival. Single-cell suspensions prepared from 7-day-old rat testes and containing all the different types of testicular cells were cultured for as long as 31 days, with or without stimulation by gonadotropins. Leydig cell functionality was assessed on the basis of testosterone production and the expression of steroidogenic genes. Gonadotropins promoted overall cell survival regardless of the culture medium employed. Of the various media examined, the most pronounced expression of Star and Tspo, genes related to steroidogenesis, as well as the greatest production of testosterone was attained with Dulbecco's modified eagle medium + glutamine. Although direct promotion of germ cell maturation by the cell culture medium could not be observed, morphological evaluation in combination with immunohistochemical staining revealed unfavorable organization of tubules formed de novo in the three-dimensional culture, allowing differentiation to the stage of pachytene spermatocytes. Further differentiation could not be observed, probably due to migration of germ cells out of the cell colonies and the consequent lack of support from Sertoli cells. In conclusion, the observations reported here show that in three-dimensional cultures, containing all types of rat testicular cells, the nature of the medium per se exerts a direct influence on the functionality of the rat Leydig cells, but not on germ cell differentiation, due to the lack of proper organization of the Sertoli cells.

Mice depleted of the coxsackievirus and adenovirus receptor display normal spermatogenesis and an intact blood-testis barrier.

The coxsackievirus and adenovirus receptor (CXADR (CAR)) is a cell adhesion molecule expressed mainly in epithelial cells. Numerous evidence indicate that CXADR has an important role in testis development and function of the blood-testis barrier (BTB) in vitro. The role of CXADR in testis physiology in vivo has, however, not been addressed. We therefore constructed a conditional CXADR knockout (cKO) mouse model in which CXADR can be depleted at any chosen timepoint by the administration of tamoxifen. We report for the first time that testicular depletion of CXADR in adult and pubertal mice does not alter BTB permeability or germ cell migration across the BTB during spermatogenesis. Adult cKO mice display normal junctional ultra-structure and localization of the junctional proteins claudin-3, occludin, junction-associated molecule-A (JAM-A), and ZO1. The BTB was intact with no leakage of biotin and lanthanum tracers into the tubular lumen. Adult CXADR cKO mice were fertile with normal sperm parameters and litter size. Breeding experiments and genotyping of the pups demonstrated that CXADR-negative sperm could fertilize WT eggs. In addition, knocking down CXADR from postnatal day 9 (P9) does not affect testicular development and BTB formation. These cKO mice were analyzed at P49 and P90 and display an intact barrier and uncompromised fertility. We conclude that CXADR possesses no direct role in testicular physiology in vivo.

Telomere dysfunction induced by chemotherapeutic agents and radiation in normal human cells.

The number of long-term survivors of patients with various malignancies (>5 years) is increasing mainly owing to advances in cancer therapeutics, but long-term side effects of the cancer treatment in this population have emerged as an important health and socio-economical issue. Telomeres and telomerase are known to be essential for regulation of cellular life-span and maintenance of genomic stability, and earlier studies have demonstrated that cancer patients who receive chemotherapy have shorter telomeres in their blood cells, indicating accelerated telomere erosion and a potential contribution of telomere loss to late side-effects. Little is currently known about the effect of chemotherapeutic agents and radiation on telomere dynamics including potential effects on telomere length, structure, function, telomerase activity, and telomere shelterin proteins in normal human cells. In the present study, we had addressed this issue experimentally. The treatment of normal human T lymphocytes and fibroblasts with chemotherapeutic agents doxorubicin (DOX) or etoposide (VP16) led to significant shortening of telomeres, down-regulation of telomerase activity, and diminished expression of telomerase reverse transcriptase (hTERT) and the telomere binding proteins TPP1 and POT1. More importantly, telomere dysfunction was observed in cells treated with DOX or VP16. Furthermore, all the above alterations were similarly found in the cells receiving γ-irradiation. Taken together, both chemotherapy and radiotherapy significantly impair telomere maintenance and function in normal human cells. Conceivably telomere dysfunction causes shortened life-span and genomic instability of normal human cells, and thereby contributes to tissue/organ damage and secondary malignancies in long-term survivors of cancer.

Testicular function and fertility preservation in male cancer patients.

The testis has been shown to be highly susceptible to the toxic effects of cancer therapy at all stages of life. Young cancer survivors are approximately half as likely as their siblings to sire a pregnancy. Radiation therapy to the testes and high cumulative dose of alkylating agents are the major factors decreasing the probability of fertility. This review aims to present an overview of the current state of knowledge in mechanisms how human spermatogonia proliferate and differentiate and how cancer therapy affects germ cells, what are the options for fertility preservation and what are the clinical risks and limitations related to such procedures. This area of research is discussed in the context of the potential future options that may become available for preserving fertility in male cancer patients.

Immunomagnetic separation of normal rat testicular cells from Roser's T-cell leukaemia cells is ineffective.

Elimination of contaminating malignant cells is crucial to avoiding cancer relapse in association with transplantation of autologous spermatogonial stem cells. In the clinical setting, there is presently no effective procedure for separating testicular cells from cancer cells. Here, CD4, a selective surface marker for Roser's rat leukaemic T-cells, was utilized to eliminate cancer cells from testicular cell samples from leukaemic piebald variegated (PVG) rats by magnetic-activated cell sorting (MACS). All animals receiving MACS-selected testicular cells died within 14-15 days. Only one-third of the contaminating leukaemic cells could be removed from testicular samples. An increase in antibody concentration enhanced the proportion of leukaemic cells removed from 27 to 49%. Variations in the cell size and expression of surface antigens on testicular leukaemic cells were the major obstacles to purification based on this marker. It is concluded that MACS does not prevent transmission of leukaemia to syngenic PVG rats when cells from leukaemic testes are used for testicular cell transplantation.