Liver growth factor induces testicular regeneration in EDS-treated rats and increases protein levels of class B scavenger receptors

The aim of the present work was to determine the effects of liver growth factor (LGF) on the regeneration process of rat testes after chemical castration induced by ethane dimethanesulfonate (EDS) by analyzing some of the most relevant proteins involved in cholesterol metabolism, such as hormone sensitive lipase (HSL), 3β-hydroxysteroid dehydrogenase (3β-HSD), scavenger receptor SR-BI, and other components of the SR family that could contribute to the recovery of steroidogenesis and spermatogenesis in the testis. Sixty male rats were randomized to nontreated (controls) and LGF-treated, EDS-treated, and EDS + LGF-treated groups. Testes were obtained on days 10 (T1), 21 (T2), and 35 (T3) after EDS treatment, embedded in paraffin, and analyzed by immunohistochemistry and Western blot. LGF improved the recovery of the seminiferous epithelia, the appearance of the mature pattern of Leydig cell interstitial distribution, and the expression of mature SR-BI. Moreover, LGF treatment resulted in partial recovery of HSL expression in Leydig cells and spermatogonia. No changes in serum testosterone were observed in control or LGF-treated rats, but in EDS-castrated animals LGF treatment induced a progressive increase in serum testosterone levels and 3β-HSD expression. Based on the pivotal role of SR-BI in the uptake of cholesteryl esters from HDL, it is suggested that the observed effects of LGF would facilitate the provision of cholesterol for sperm cell growth and Leydig cell recovery.

Comparative epidemiologic study of skin diseases in foreign children and children of Spanish origin in Alicante, Spain

INTRODUCTION

Previous studies in Spain have shown that the foreign and immigrant populations can have different diseases to Spanish-born individuals. However, no comparative study has specifically investigated foreign children in Spain.

MATERIAL AND METHODS

The objective of the study was to compare skin diseases in foreign children with those in children born in Spain of Spanish parents. We included all patients under 15 years of age who were seen in our dermatology department between January 2007 and December 2007.

RESULTS

During the study period, 3108 pediatric patients were seen in the dermatology department. Of these, 2661 (85.6%) were Spanish and 447 (14.3%) were foreigners. Foreign children sought medical care more often (11.4%) than Spanish children (6%) (P<.001) and made less use of the specialist outpatient clinic (59.6% vs 68.8% [P<.001]) and more use of emergency care. Complaints observed more frequently in the foreign children were scabies (adjusted odds ratio [aOR], 10.6; 95% CI, 4.71-24.10), arthropod bites (aOR, 2.80; 95% CI, 1.14-6.87), hypopigmentation (aOR, 2.61; 95% CI, 1.06-6.44), and atopic dermatitis (aOR, 1.65; 95% CI, 1.19-2.31). Melanocytic nevus was observed more frequently in Spanish children (aOR, .50; 95% CI, .30-.83).

CONCLUSIONS

Differences between children born in Spain of Spanish parents and foreign children were found for type of visit and frequency of skin diseases.

[Severe adult atopic dermatitis: treatment with mycophenolate mofetil in 8 patients]

BACKGROUND

Atopic dermatitis (AD) includes severe forms that can be refractory to various systemic treatments. Mycophenolate mofetil (MMF) has been found to be useful in patients with severe forms of AD and to have fewer side effects than long-term treatment with oral corticosteroids or cyclosporine.

OBJECTIVES

To evaluate the efficacy and adverse effects of MMF in patients seen in our skin allergy unit with severe adult AD refractory to other systemic treatments.

METHODS

We performed a retrospective study of 8 patients with severe adult AD treated with MMF, analyzing the baseline characteristics, previous treatments used by the patients, and the outcome and adverse effects of treatment with MMF.

RESULTS

Five patients treated with MMF showed improvement in the fourth week of treatment. In addition, 5 of the 8 patients presented a clear, long-term improvement in their disease. Remission of AD occurred in 1 patient, making it possible to discontinue MMF; this patient remains stable with no relapses after 4 months without treatment. The other 4 patients continue on maintenance therapy. Three patients continued to have frequent acute outbreaks of AD despite treatment with MMF for 16 to 72 weeks. All patients tolerated the treatment and there were few adverse effects.

CONCLUSIONS

MMF can be an effective option in selected patients with severe forms of atopic dermatitis. Although the response is not as rapid as with oral corticosteroids or cyclosporine, it can be used for maintenance treatment with good clinical control and few adverse effects.

[Allergic contact dermatitis due to corticosteroids: a 3-year retrospective study in a hospital skin allergy unit]

BACKGROUND

Corticosteroid contact dermatitis and its patch testing are subject to certain peculiarities that we should be aware of.

MATERIALS AND METHODS

We performed a retrospective study of all patients who underwent patch tests with a corticosteroid battery in the Skin Allergy Unit of the Dermatology Department of Hospital General Universitario, Alicante, Spain, between October 2004 and June 2007.

RESULTS

During the study period, patch tests were performed on 1065 patients in our allergy unit. A corticosteroid battery was used in 34 patients (3.1 %). Fourteen patients were positive for budesonide or tixocortol in the standard battery; 20 were negative for these allergens but there was a clinical suspicion of steroid allergy. At least one positive reaction in the corticosteroid battery was observed in 15 patients (44.1 %). The substance most commonly implicated was budesonide (13 patients sensitized). The corticosteroid battery revealed sensitization to other groups of corticosteroids in 4 of the 15 patients with corticosteroid sensitization. Seventeen patients brought drugs that were also tested, obtaining positive results for 10 substances.

CONCLUSIONS

Allergens for contact dermatitis due to corticosteroids included in the standard battery (budesonide and tixocortol) detected 93 % of patients who are sensitized to steroids; there would appear to be little benefit in performing a corticosteroid battery if those markers are negative. The battery of corticosteroids and the drugs provided by patients were useful to define more exactly the corticosteroid classes that the patient should avoid.

[Perifollicular xanthomatosis as a key histological finding in Fox-Fordyce disease]

Fox-Fordyce disease is a rare skin condition characterized by the presence of multiple pruritic follicular papules in areas rich in apocrine glands, such as the axillae, mammary areolae, or genital regions. There is a high degree of variability in the histological findings seen in Fox-Fordyce disease. In addition to those described as typical of this entity, such as dilation of the infundibulum and hyperkeratosis and spongiosis of the infundibular epithelium, many other histological changes can be observed. We report the case of a 21-year-old woman with Fox-Fordyce disease and highlight the importance of perifollicular xanthomatosis as a key histological finding in the diagnosis of the disease.

Factors From Damaged Sperm Affect Its DNA Integrity and Its Ability to Promote Embryo Implantation in Mice

Endogenous nucleases in mouse sperm can be activated by freeze-thawing the spermatozoa in media without cryoprotection and cleaving spermatozoa DNA. The role of sperm chromatin integrity during intracytoplasmic sperm injection (ICSI) is of critical importance. We analyzed in the B6D2 mouse the proportion of DNA-fragmented spermatozoa (DFS) produced by incubation in conditioned medium (CM) generated by freeze-thawing sperm in the absence of cryoprotection. We then examined the subsequent development, implantation, and offspring obtained after ICSI with incubated spermatozoa. When fresh sperm cells were incubated for 90 minutes in this CM, a significant increase in the amount of DFS was detected by the terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling assay (27% vs 4.5% in fresh sperm). After ICSI of fresh and incubated spermatozoa, embryos were cultured in vitro to either the 2-cell or blastocyst stage before they were transferred into pseudopregnant CD1 females. On day 14, recipients were sacrificed, and implantation rates, estimated as the number of live fetuses plus resorptions, were determined. When ICSI was performed with sperm incubated in CM, no effects on fertilization, embryo cleavage, blastocyst rate, or blastocyst morphology were detected; however, the quality of the embryos was affected because the total implantation rate decreased significantly (P < .05) when 2-cell embryos or blastocysts were transferred. Independently of sperm pretreatment, in vitro cultures significantly affected the percentage of live fetuses present on day 14 of pregnancy. These results demonstrated that there are factors released from fragmented spermatozoa capable of inducing DNA fragmentation in intact sperm that may compromise, to some extent, birth rates after ICSI.

Scrotal heat stress effects on sperm viability, sperm DNA integrity, and the offspring sex ratio in mice

Evidence exists to suggest detrimental effects of heat stress on male fertility. This study was designed to assess the effects of scrotal heat stress on mature and developing sperm in a mouse model. After receiving shock heat treatment (42 degrees C for 30 min), mature spermatozoa were recovered from the epididymis hours (6) or Days (7, 14, 21, 28, 60) later, to determine the variables: number of spermatozoa, sperm viability, motility and progressive motility, sperm DNA integrity as established by the TUNEL method, embryo implantation rate, and sex ratio of the fetuses conceived using the heat-exposed spermatozoa. Our results indicate that transient mild heat treatment does not affect in the same way the different types of male germ cells. Spermatocytes present within the testis at the time of heat stress resulted into a lower concentration of spermatozoa with reduced viability and low motility. Even though, DNA integrity of spermatozoa resulting from spermatocytes was also compromised by heat stress, the higher degree of DNA damage was found among spermatozoa resulting from spermatids present within the testis at the time of heat stress. At last, heat shock effect on spermatozoa present in the epididymis at the time of thermal stress resulted into a sex ratio distortion. These findings point to a higher sensitivity of spermatocytes to heat exposure and also suggest a different response of X and Y chromosome-bearing spermatozoa to heat stress that warrants further investigation.

375 UNEXPECTED SEVERE ABNORMALITIES IN MOUSE ROSI OFFSPRING

Live offspring resulting from round spermatid injection (ROSI) was first accomplished in the mouse, but similar success has been obtained in rat, hamster, rabbit, mastomys, pig, monkey, and human. ROSI has received clinical attention because some infertile men have no spermatozoa or just a very few in their testes, and these are difficult to harvest and are frequently dead and deformed. Although some clinicians were able to generate healthy children by ROSI, others could not (reviewed in Yanagimachi 2004 Reprod. Biomed. Online 9). The clinical value of ROSI has been widely debated. It remains unclear if post-meiotic and pre-fertilization modifications of sperm cells are necessary to ensure normal development. In order to answer this question, we decided to study and compare mouse offspring generated by ROSI and intracytoplasmic sperm injection (ICSI). ROSI and ICSI with fresh sperm cells were carried out in the B6D2 mouse strain as described (Marh et al. 2003 Biol. Reprod. 69, 169–176; Moreira et al. 2005 Hum. Reprod. 20, 3313–3317). In vitro-produced embryos were transferred at the 2-cell stage into Day 1 pseudopregnant females. As shown in Table 1 oocyte survival after injection was significantly higher (z-test, P &lt; 0.05) with ICSI (91%) than with ROSI (68%). The proportion of live offspring obtained by ICSI was also significantly higher (26% vs. 6%; z-test, P &lt; 0.05). Moreover, fertilization with spermatozoa produced healthy offspring more efficiently than with round spermatids. Out of 30 live offspring generated by ROSI, 6 (20%) presented severe abnormalities during their first 6–8 weeks of age. One ROSI animal presented an abnormally swollen skull (hydroencephaly) with a very thin and soft cranial wall. Another developed a subcutaneous engrossment of the forehead, producing a crest-like appearance. Three others presented deviations in their vertebral columns (hyperkyphosis and scoliosis), and recently a testicular tumor was detected in another animal. These types of malformations were not observed in the control offspring. In our experience, very rarely are they observed after ICSI or in naturally mated animals. To our knowledge, and although the risks of the ROSI procedure have been extensively highlighted in human and other species, the phenotypic abnormalities observed in this study have never been reported. Presently, we keep monitoring these animals as they age, as part of an ambitious plan that is also intended to characterize and understand the origin of the possible phenotypic consequences of the ROSI procedure. Table 1. In vitro development and development to term of B6D2 mouse embryos generated by ROSI or ICSI

Differential effects of culture and nuclear transfer on relative transcript levels of genes with key roles during preimplantation

It is well known that the preimplantation culture environment to which embryos are exposed influences the expression of developmentally important genes. Recently, it has been reported that MEMα, a culture medium commonly used for somatic cells, allows high rates of preimplantation development and development to term of mouse somatic cell nuclear transfer (SCNT) embryos. The objective of this study was to compare the differential effects of this medium and of the nuclear transfer procedure on the relative mRNA abundance of several genes with key roles during preimplantation. The relative mRNA levels of nine genes (Glut 1, Glut 5, G6PDH, Bax, Survivin, Gpx 1, Oct4, mTert and IGF2bp1) were quantified at blastocyst stage on cumulus cell cloned embryos cultured in MEMα, as well as on in vivo cultured and MEMα cultured controls. Only three of the nine transcripts analysed (Glut 5, Gpx 1 and Igf2bp1) were significantly down-regulated at blastocyst stage in in vitro produced controls. However, most genes analysed in our MEMα cultured cloned embryos showed altered transcription levels. Interestingly, between cloned and in vitro produced controls only the transcription levels measured for Glut 1 were significantly different. This result suggests that Glut 1 may be a good marker for embryo quality after cumulus cell nuclear transfer.

203 EFFECT OF OXYGEN TENSION AND SUBSTRATE ON GROWTH AND DIFFERENTIATION OF MOUSE EMBRYONIC STEM CELLS

Normally the majority of mammalian cells, including murine embryonic stem (mES) cells, are immersed in a low oxygen environment (hypoxia); however, mES are generally cultured in an atmosphere containing 21% O2 (normoxia). Such conditions may not be the most appropriate for mES propagation. We have tested the effects of hypoxia and culture on either feeder fibroblasts or gelatin substrate on mES cell growth and spontaneous differentiation. Two ES cell lines (R1 129/Sv from the laboratory of A. Nagy and MAR B6D2 F1 generated in our laboratory) were cultured under two different oxygen tensions (5 and 21%), and on two different substrates, 0.1% gelatin or murine embryonic fibroblasts (mEF). Cell cycle, cell proliferation, mRNA expression of pluripotency and differentiation markers, as well as spontaneous differentiation to cardiomyocytes, were monitored. For cell proliferation measurements, mES after 7 days of culture at the different conditions were labeled with 5-(and-6)-carboxyfluorescein diacetate succinimidyl ester, and cultured for up to three more days. Cells were then harvested for flow cytometry analysis every 24 h after labeling (Cell TraceTM CFSE Cell Proliferation Kit; Molecular Probes, Inc., Eugene, OR, USA). For cell cycle analysis, cells grown on mEF under the two different oxygen tensions were fixed after 10 days of culture, and then stained with propidium iodide/Triton-X-100 for flow cytometry analysis (Current Protocols in Cytometry, Chap. 7, 2001). The spontaneous differentiation of embryoid bodies [formed by ES cells in the absence of leukemia inhibitory factor (LIF)] to cardiomyocytes was also monitored. For mRNA expression of pluripotency (Nanog, Oct-3/4, Rex1, GENESIS, FGFR-4, TERF1, Cx43, and GLUT1) and differentiation markers (GATA4, GATA2, AFP, Msx-1, Brachyury, and Myf5), RT-PCR analysis was performed on mES cells from Day 0 to Day 10. Under hypoxia conditions, the proliferation of both types of mES cells was greater than under normoxia, independent of substrate used, and a higher number of apoptotic cells was detected. Moreover, only under normoxia conditions did mES cells lose the expression of pluripotency markers GENESIS and GLUT1. In addition, under lower oxygen tension, the rate of differentiation to beating cardiomyocytes was significantly lower on the feeder layer than that under normoxia (11.9% vs. 28.1%; P = 0.012). The feeder layer supported significantly higher cardiomyocyte formation when compared to 0.1% gelatin at 21% O2 (28.1% vs. 8.3%; P < 0.001). Our results show that normoxia may not be the most appropriate condition for mES cell propagation and that hypoxic culture may be necessary to maintain full pluripotency of mES cells.

Differential sensitivity of male and female mouse embryos to oxidative induced heat-stress is mediated by glucose-6-phosphate dehydrogenase gene expression

During the preimplantation period, in vitro cultured males have a higher metabolic rate, different gene expression, and grow faster than females. It has been suggested that under some stress conditions male embryos are more vulnerable than females; however, the biological fragility of male embryos is little understood. Since many forms of stress result in the overproduction of cellular reactive oxygen species (ROS), we addressed the hypothesis that the connection between female advantage during early developmental stages and heat stress involves ROS and differential gene expression of G6PD, an X-linked gene related to oxidative stress. We have found that after compaction, female heat-stressed embryos have less relative amounts of H2O2 than males, and female embryos survive better than males under in vivo or in vitro heat stress situations. In addition, in vitro produced female embryos grow slower than male embryos, have differential mRNA transcription of G6PD and also of some genes situated on autosomal-chromosomes (Sox, Bax, and Oct-4). Moreover, by inhibiting G6PD, all differences generated by oxidative stress between male and female embryos disappear. For the first time, we provide an experimental demonstration of a mechanism that explains why following exposure to heat stress-induced ROS, female preimplantation embryos are more resistant than males.

177 GENERATION OF ES CELLS AND TRANSGENIC MICE EXPRESSING MTERT-GFP AS A MARKER OF PLURIPOTENTIAL CELLS

There is not a simple system that allows us to identify stem cells in adult tissues. Cells of adult tissues arise from dividing progenitor cells, which themselves are derived from multipotential stem cells. Telomerase is the enzyme that maintains the ends of linear chromosomes in eukaryotic cells. Recently, a segment of the promoter sequence of the reverse transcriptase of murine telomerase (mTert) has been characterized. mTert is expressed with greatest abundance during embryogenesis and becomes widely expressed in adult tissues at low levels. This low expression level in adult tissues may be due to the presence of pluripotent stem cells present in those tissues. To examine the relationship between telomerase activity and multipotential of adult cells we have generated three constructs (1k-, 2k-, and 5k-mTert-GFP) comprising different segments of the mTert promoter sequence coupled to the coding sequence of the green fluorescent protein (GFP). These constructs were electroporated into R1 and B6D2 (generated in our laboratory) ES cells and were used to produce transgenic mice. The generation and identification of transgenic mice (C57BL6 × CBA) has been previously described (Gutierrez-Adan and Pintado 2000 Trangenic Res. 9, 81–89). Transgenic founders were backcrossed to C57BL6 × CBA mice to obtain transgenic lines. The three constructs were able to mimic the mTert expression, which was coupled to green fluorescence. The mTert-GFP transfected ES cells were initially maintained in medium supplemented with LIF, which was subsequently removed to allow differentiation of embryoid bodies (EBs) and other cell types. GFP expression was higher during the first two days after LIF removal (period of enhanced cell proliferation), decreasing in the following days as a result of EB differentiation. Both ES cell lines showed reduced GFP expression upon differentiation, suggesting that mTert is the principal determinant of telomerase activity; moreover, different degrees of expression and down regulation were reported with the different constructs. Using these constructs we have also generated transgenic mice. Eight lines of transgenic mice carrying the 1kmTert-GFP transgene, four with the 2kmTert-GFP, and three with the 5kmTert-GFP, were obtained. There were no significant differences between the proportions of transgenic founder generates. The transgenic mice express and GFP during the fetal development, indicating their telomerase activity. We are now analyzing the expression of mTert-GFP in adults tissues. Our results suggest that telomerase-GFP transgenics are an important tool to assess the role of telomerase in adult multipotential cells as well as to select these pluripotent cells in adult tissue. It will be interesting to see if different levels of mTert-GFP expression are associated with different levels of pluripotency.