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Papers by eva morales

Reproduction Fertility and Development, 2003

The cellular mechanisms implicated in the atrophy of seminiferous epithelium in ageing are curren... more The cellular mechanisms implicated in the atrophy of seminiferous epithelium in ageing are currently under debate, although recent reports suggest that apoptosis may be the primary mechanism implicated in aged germ cell loss. Other investigators have suggested that changes in spermatogonial proliferation are also involved. In the present work, the changes in proliferation and apoptosis in the seminiferous epithelium of aged (24 months) Syrian hamsters were examined in concert and compared with those in young (6 months) animals. Proliferation of germ cells was studied by bromodeoxyuridine labelling and apoptosis was assessed by transmission electron microscopy and in situ TUNEL labelling. Aged animals showed a significant decrease in the numbers of total and proliferating spermatogonia plus preleptotene spermatocytes per unit volume and per testis and in the proliferative index (24.8 ± 1.6%) compared with young animals (30.8 ± 1.2%) (P < 0.05). The number of apoptotic spermatogonia plus spermatocytes per unit volume and the apoptotic index were significantly higher in aged animals (1.51 ± 0.23% v. 0.77 ± 0.04%; P < 0.05). Apoptosis was confirmed by morphological characteristics: condensation of the chromatin and nuclear fragmentation. In aged hamsters, tubular degeneration could be classified into several categories, showing an increase of apoptotic cells in tubular cross-sections characterized by maturation arrest in comparison with all other types. Spermatogonial proliferation was also diminished as seen in tubular crosssections showing hypospermatogenesis, sloughing off of germ cells and maturation arrest. The results obtained in the present study suggest that the decrease in the proliferation of spermatogonia and the increase in apoptosis constitute two consecutive mechanisms correlated with the ageing of the seminiferous epithelium.

Journal of Molecular Histology, 2005

It has been shown that there are sugars in corpora amylacea, but little attention has been focuse... more It has been shown that there are sugars in corpora amylacea, but little attention has been focused on the expression of glycoconjugates in corpora amylacea of normal and hyperplastic prostatic glands. The present study characterizes and compares the expression of glycoconjugates in corpora amylacea of normal and hyperplastic prostatic glands of elderly men by using alcian blue (AB) stain and lectin histochemistry. Corpora amylacea were larger and more numerous in hyperplastic glands compared to normal glands. The stain with AB revealed the presence of sulfated and carboxyl components in corpora amylacea. In hyperplastic prostatic glands the sulfur and acid contents of corpora amylacea were increased. Lectin affinities of corpora amylacea from normal prostatic glands demonstrated the presence of fucose, mannose, sialic acid, N-acetyl galactosamine and N-acetyl glucosamine residues. In the hyperplastic glands the lectin binding pattern of corpora amylacea was qualitatively similar to normal glands, but an increase in GalNAc, sialic acid, mannose and fucose residues was observed. Normal prostatic glands showed a weak to moderate content of mannose residues, and in contrast a strong GNA and Con-A staining was observed in hyperplastic glands. MAA and SNA affinities indicated that the content of sialic acid residues was higher in hyperplastic glands compared with normal prostatic glands. Also NAcGal residues were increased in hyperplastic glands. Luminal secretion, secretory cells and apical border of epithelium showed a similar although more intense Lectin-binding pattern as compared with corpora amylacea both in normal and hyperplastic prostatic glands. Lectin histochemistry shows that the glycoconjugates expressed in the glandular epithelium are similar to those found in corpora amylacea both in normal and hyperplastic glands. In addition, in hyperplastic glands, where the corpora amylacea are higher in size and more numerous, the reaction to lectins is more intense especially with mannose and sialic acid residues. The results suggest that corpora amylacea are originated at least in part from prostatic secretion.

International Journal of Obesity, 2010

The success of obesity therapy is dependent on the genetic background of the patient. Circadian L... more The success of obesity therapy is dependent on the genetic background of the patient. Circadian Locomotor Output Cycles Kaput (CLOCK), one of the transcription factors from the positive limb of the molecular clock, is involved in metabolic alterations. To investigate whether five candidate polymorphisms from CLOCK were associated with anthropometric, metabolic measures and weight loss in response to a behavioural weight reduction programme based on the Mediterranean diet. Five hundred overweight/obese subjects, aged 20-65 years, who attended outpatient clinics specializing in obesity, were studied. Anthropometric, biochemical and dietary intake variables were analysed. Effectiveness of the programme and weight loss progression during 28 weeks of treatment was assessed. Four of five CLOCK SNPs selected were significantly associated with obesity variables (P<0.05). The genetic variation in the rs1801260 CLOCK was associated with obesity at baseline and also affected weight loss. Patients with the variant allele (G) lost significantly less weight i(P=0.008) compared with wild type. Repeated measures analysis showed that weight loss over time was significantly different between rs1801260 CLOCK variations (P=0.038). Carriers of the G allele displayed greater difficulty in losing weight than non-carriers. In this particular polymorphism, the frequency of short-time sleepers (< or =6 h per day) was greater in minor allele carriers than in non-carriers (59% vs 41%; P<0.05). CLOCK polymorphisms were also associated with significant differences in total plasma cholesterol at the completion of dietary treatment (P<0.05). We have replicated previous studies showing a relationship between CLOCK gene polymorphisms and obesity. CLOCK rs1801260 SNP may predict the outcome of body weight reduction strategies based on low-energy diets.

Nutrition, 2009

Objetivo: Analizar cambios en la psicopatología general y específica de pacientes con obesidad mó... more Objetivo: Analizar cambios en la psicopatología general y específica de pacientes con obesidad mórbida (OM) candidatos a Cirugía Bariátrica (CB) tras aplicación de terapia cognitiva-conductual(TCC) y evaluar diferencias entre pacientes con y sin trastorno por atracón (TA y NTA respectivamente), y entre grados de obesidad III y IV; estudiando su influencia en la pérdida peso.

International Journal of Andrology, 2002

In the hamster, male reproductive quiescence is accomplished via testicular atrophy and the germi... more In the hamster, male reproductive quiescence is accomplished via testicular atrophy and the germinal epithelium is regressed to spermatogonia and spermatocytes after 8-14 weeks of short photoperiods. However, the cellular mechanisms involved in this process have not been elucidated. As it is suggested that the regulation of seasonal testicular activity is characterized by coordinated shifts in the relationships between mitosis, meiosis and apoptosis, the changes in the proliferative and apoptotic activity in the seminiferous epithelium of photoinhibited Syrian hamster were examined and compared with those maintained in natural photoperiod. The proliferative activity was studied using BrdU immunostaining, and germ cell apoptosis was assessed by in situ TUNEL labelling and transmission electron microscopy. A significant increase in the rate of apoptosis (percentage of TUNEL-positive spermatogonia + spermatocytes) was observed in photoinhibited animals (2.84 ± 0.16) compared with those exposed to natural photoperiod (0.77 ± 0.03, p < 0.05). The majority of apoptotic germ cells were spermatocytes and in some occasions spermatogonia. Germ cell apoptosis was confirmed by morphological characteristics: condensation of the chromatin and nuclear fragmentation. The rate of proliferation (percentage of BrdU-positive spermatogonia + preleptotene spermatocytes) was significantly higher in photoinhibited hamsters (42.7 ± 2.6) compared with animals exposed to natural photoperiod (31.1 ± 1.6, p < 0.05). After the exposure to a short photoperiod the apoptotic index positively correlated with the proliferative index (r ¼ 0.8150, p < 0.05). In conclusion, the seminiferous epithelium of photoinhibited Syrian hamsters is characterized by an increased rate of apoptosis associated to an enhanced rate of proliferation.

Aging and short photoperiod exposure induce germ cell apoptosis in the Syrian hamster; however, t... more Aging and short photoperiod exposure induce germ cell apoptosis in the Syrian hamster; however, the specific germ cells affected and the molecular pathways triggered have not been elucidated. We analyzed germ cell apoptosis and the expression of the Fas/Fas-L system, Bcl-2 family, and p53 in aged and photoinhibited hamsters and compared with those young maintained in natural photoperiod. Aging increased apoptosis in spermatogonia and spermatocytes, but in photoinhibited hamster testes only an increase in apoptotic spermatocytes was observed. Apoptosis was higher in aged hamsters in stages I-IV, V-VI and VII-VIII. Aging increased apoptosis of spermatogonia in stages I-IV and V-VI. Apoptotic pachytene spermatocytes were significantly higher in stages I-IV, V-VI, and VII-VIII in aging. Apoptotic preleptotene and pachytene spermatocytes were higher in aging, but no differences were observed in leptotene-zygotene. Fas-L was expressed by Sertoli cells, of young, aged, and photoinhibited hamsters. Bcl-x L was strongly expressed in germ cells on young hamsters and slightly in aging and after short photoperiod exposure. Spermatocytes of photoinhibited hamsters were intensively stained with Fas, Bax, Bcl-xs/L, and p53. In conclusion, aging increases apoptosis in spermatogonia and spermatocytes, depending on the stage of the seminiferous epithelium cycle, whereas after a short photoperiod exposure only an increase in apoptotic spermatocytes is observed. The results suggest that Fas, Bcl-x L , Bax, and p53 participate in germ cell apoptosis induction after short photoperiod exposure, whereas only Bcl-x L is involved in aging.

Journal of Andrology, 2006

Reproduction in Domestic Animals, 2010

Imbalances in the proliferation and apoptosis processes are involved in numerous epithelial alter... more Imbalances in the proliferation and apoptosis processes are involved in numerous epithelial alterations. In the seminiferous epithelium, normal spermatogenesis is regulated by spermatogonia proliferation and germ cell apoptosis, and both processes are involved in diverse pathological alterations of the seminiferous epithelium. Other physiological phenomena including aging and short photoperiod, in which apoptosis and proliferation seem to play important roles, cause testicular changes. Aging is accompanied by diminished proliferation and increased apoptosis, the latter occurring in specific states of the seminiferous cycle and considered the cause of epithelium involution. However, there is no clear evidence concerning whether proliferation decreases in the spermatogonia themselves or is due to an alteration in the cell microenvironment that surrounds them. As regards the factors that regulate the process, the data are scant, but it is considered that the diminution of c-kit expression in the spermatagonia, together with the diminution in antiapoptotic factors (Bcl-xL)) of the intrinsic molecular pathway of apoptosis play a part in epithelial regression. A short photoperiod, especially in rodents, produces a gradual involution of the seminiferous epithelium, which is related with increased apoptosis during the regression phase and a diminution of apoptosis during recrudescence. Proliferative activity varies, especially during the total regression phase, when it usually increases in the undifferentiated spermatogonia. In other species showing seasonal reproduction, however, decreased proliferation is considered the main factor in the regression of the seminiferous epithelium. Little is known about how both phenomena are regulated, although data in rodents suggest that both the intrinsic and extrinsic pathways of apoptosis contribute to the increase in this process. In conclusion, regression of the seminiferous epithelium in physiological situations, as in many pathological situations, is a result of alterations in equilibrium between the proliferation and apoptosis of germinal cell types. However, both physiological phenomena showed important differences as regard proliferation/apoptosis and their regulation pathways, probably as a result of their irreversible or reversible character.

Molecular Reproduction and Development, 2008

The glycoside residues (glycoconjugates, GC) of the zona pellucida (ZP) glycoproteins are importa... more The glycoside residues (glycoconjugates, GC) of the zona pellucida (ZP) glycoproteins are important during the first phases of fecundation. Our aim in this work was to determine the lectin affinity pattern of porcine ZP in order to analyze the changes that take place during: (a) preantral folliculogenesis, (b) the follicular atresia process, and (c) antral growth. Several prepubertal and adult pig ovaries and different sized antral follicles were used. Conventional carbohydrate histochemical techniques and peroxidase and digoxigenin (DIG) lectins were used to reveal the acid groups and the glycosidic residues of the ZP. It was seen that the ZP forms in the preantral follicles throughout their growth period. In primordial and primary follicles, ZP in the process of formation showed neutral GC. SBA, RCA-I, MAA, WGA lectins, and AAA after methylation-saponification (MS) were positive in the ZP of primordial and primary follicles. The affinity for SBA, RCA-I, MAA, and WGA increased in the multilaminar-primary follicles and new affinities for UEA-I and LFA were observed. After MS, AAA, SNA, PNA, and SBA reactivity was observed. The ZP of antral follicle oocytes of different sizes showed the same lectin pattern as multilaminar-primary follicles. The oocyte ooplasm and the follicular fluid of large antral follicles showed less affinity for WGA and LFA lectins and less intensive staining with AB (pH 2.5). Atresia did not change the antral or preantral follicle oocyte ZP lectin pattern. In conclusion, the follicles showed substantial changes in their ZP glycosidic composition as they developed, especially, during the change from primary to multilaminar-primary follicles. The ZP glycosidic composition showed no significant change during the growth of antral follicles and follicular atresia in our study. Mol. Reprod. Dev. 75: 1473–1483, 2008. © 2008 Wiley-Liss, Inc.

Acta Histochemica, 2005

Cryptorchidism is a frequent male sexual disorder in mammals, which affects the histology of the ... more Cryptorchidism is a frequent male sexual disorder in mammals, which affects the histology of the tunica propria, interstitial tissue, blood vessels, seminiferous epithelium and testis functioning. In this paper, proliferation and apoptosis were examined in the seminiferous epithelium of both testes from unaffected boars and from boars suffering unilateral and bilateral cryptorchidism. In germ cells, proliferation was studied using the immunohistochemical PCNA technique, and apoptosis was analysed by in situ TUNEL labelling. An index was obtained for the proliferation and apoptosis observed in seminiferous tubules. In abdominal testes the epithelium contained few spermatogonia and Sertoli cells. In the testes of unaffected boars, numerous spermatogonia proliferated, whereas in cryptorchid testes such proliferation was lower and the proliferation/ apoptosis ratio diminished. In the unaffected group, the TUNEL-positive germ cells were spermatogonia and spermatocytes in different phases of meiosis. In abdominal testes, the TUNEL-positive germ cells were spermatogonia alone. The apoptosis index of both abdominal and scrotal testes was similar. In conclusion, spontaneous cryptorchid testes showed a lower rate of spermatogonia proliferation in the seminiferous epithelium.

A) ¿Qué aspectos de este cuadro nos indican que está representando a un monarca absoluto?