Pastor García, Luis Miguel

Person:
Pastor García, Luis Miguel

Name

Pastor García, Luis Miguel

publication.page.department

Universidad de Murcia. Departamento de Biología Celular e Histología

Full item page

Search Results

Now showing 1 - 5 of 5

Open Access
Heterogeneity of mesenchymal cells in human amniotic membrane at term
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2024) Cortés Sandoval, Salvador; Serrano Sánchez, Mª Isabel; Ferrer, Concepción; Delgado, Juan L.; Insausti, Carmen L.; Blanquer, Miguel; Beltrán Frutos, Ester; Martínez Hernández, Jesús; Pastor García, Luis Miguel; Seco Rovira, Vicente
There is increasing interest in understanding the tissue biology of human amniotic membrane (hAM) given its applications in medicine. One cellular component is mesenchymal cells, which can be extracted, cultured and differentiated "in vitro" into various cell types. These studies show that there is heterogeneity among mesenchymal cells. The aim of this work is to study the membrane "in situ" to determine whether this cellular heterogeneity exists. The hAMs were obtained from caesarean deliveries at term and analyzed by histological techniques. Types I-III mesenchymal cells and Hofbauer were distinguished by light microscopy. Histochemically, mesenchymal cell types showed successively increasing positivity to: PAS, vimentin, fibronectin, and Concanavalin-A; VGEF, TGF-β2, PDGF-C, FGF-2. By the semiquantitative point of view, the percentage of Type II cells was 60%, significantly higher than the other types. With transmission electron microscopy, an intermediate cell type between II-III was observed. Strong vesiculation of the rough endoplasmic reticulum (RER) with exocytosis was observed. In addition, an accumulation of a similar material to the extracellular matrix in the RER caused its dilation especially in type IIITEM cells. Some of this material acquired a globular structure. These structures were also found free in the extracellular matrix. In conclusion, the mesenchymal cells of the fibroblastic layer of the hAMs studied are heterogeneous, with some undifferentiated and others with a probably senescent fibroblastic phenotype with accumulation in their RER of fibronectin. These results may be of interest to extract mesenchymal cells from hAMs for use in regenerative medicine and to better understand the mechanisms of fetal membrane rupture
Open Access
Histological changes in connective tissue of rat tails after bipolar radiofrequency treatment
(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2012) Bernal-Mañas, C.M.; Navarro, S.; Zuasti Elizondo, Adelina; Ferrer Cazorla, Concepción; Canteras Jordana, Manuel; García Collado, Angel Joaquín; Beltrán Frutos, Ester; Pastor García, Luis Miguel; Seco Rovira, Vicente; Facultades, Departamentos, Servicios y Escuelas::Departamentos de la UMU::Biología Celular e Histología
Radiofrequency (RF) has been included in the techniques used in aesthetic surgery/medicine. To date, no studies have performed a histological assessment of changes in the tissue after application of bipolar radiofrequency (BRF) with low energy and frequency. The aim of this study was to examine changes that are produced in connective tissue, principally in the fibroblasts, following BRF treatment. Four groups of rats received a different number of RF sessions (1, 2, 3 and 5). The following parameters were determined: the number of fibroblasts/unit area (FA), the proliferation index (PI), the Heat shock Protein 47 index (HSPI) and the percentage of connective tissue (PC). For statistical analysis, two subgroups (A and B) were made for the variables FA, PI and PC, and another two subgroups (C and D) for the variable HSPI. Significant differences for FA, PI and PC were observed between subgroups A and B, FA and PI having higher values in A, while PC had higher values in B. The HSPI in subgroup C showed significantly higher values than in D. Low energy and frequency BRF led to an increase in the number, proliferation and biosynthetic activity of fibroblasts. The resulting stress suffered by fibroblasts as a result of heat may be associated with the phenomenon of hormesis
Open Access
Testicular histomorphometry and the proliferative and apoptotic activities of the seminiferous epithelium in Syrian hamster during spontaneous recrudescence after exposure to short photoperiod
(© 2018 Blackwell Verlag GmbH., 2018-10-01) Ferrer Cazorla, Concepción; Canteras, Manuel; Sánchez-Huertas, María del Mar; Beltrán Frutos, Ester; Martínez Hernández, Jesús; Pastor García, Luis Miguel; Seco Rovira, Vicente; Biología Celular e Histología
Syrian hamsters are photoperiodic rodents in which reproduction, including testicular function, is stimulated by long photoperiod exposure and curtailed by exposure to a short photoperiod. The objectives of this study were to characterize the testis histomorphometrically and to determine the role of the proliferation and apoptosis phenomena in the recovery of the seminiferous epithelium during spontaneous recrudescence after exposure to short photoperiod. The study was performed using conventional light microscopy, proliferating cell nuclear antigen and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP in situ nick end labelling staining, image analysis software, and transmission electron microscopy in three recrudescence groups: initial recrudescence (IR), advanced recrudescence (AR), and total recrudescence (TR). Morphometrically, the results pointed to the gradual recovery of the testicular and tubular volumes, as well as of the seminiferous epithelium. Among the IR and AR groups, the increase in testicular and tubular volumes was accompanied by an increase in tubular diameter and length, with an increase in interstitial volume. From AR to TR, there was an increase in the tubular and total volumes, but, in this case, with a gradual increase in tubular diameter. Recovery of the seminiferous epithelium was accompanied by changes in apoptosis and proliferation activities. The first decreased half way through the process and the second remained higher than the control levels throughout the recrudescence stage. Ultrastructurally, alterations in the spermatozoa were observed, which indicated that spermiogenesis was not yet completely normal. In conclusion, spontaneous testicular recrudescence in Syrian hamster comprises two histomorphometrical phases, the first related to an increase in tubular length and diameter and interstitial volume, and the second depending principally on the gradual increase in tubular diameter. The restoration of the seminiferous epithelium is due to apoptosis reaching normal values in the AR group accompanied by higher proliferative activity than that observed in the Control group.
Open Access
HSP47 expression in the hamster Sertoli cell: An immunohistochemical study
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2024) Serrano-Sánchez, María Isabel; Ferrer, Concepción; Beltrán Frutos, Ester; Martínez Hernández, Jesús; Pastor García, Luis Miguel; Seco Rovira, Vicente
HSP47, a chaperone whose main function is the maturation of collagen molecules, is considered a marker of fibrotic diseases. Increased collagen synthesis in the testis has been associated with various pathologies leading to seminiferous tubule regression. Our aim was to study whether HSP47 is expressed in hamster Sertoli cells both in the adult and in two physiological situations of seminiferous tubule atrophy: irreversible testicular ageing and testicular regression due to short photoperiod (reversible). Eighteen animals were divided as follows: a group of 6 young animals aged 6 months, a group of 6 animals aged 24 months, which were exposed to a long photoperiod, and a final group of 6 young animals subjected to a short photoperiod. Testicular samples were fixed in methacarn and an immuno-histochemical technique was used to detect HSP47. A semiquantitative study of this protein expression was performed between tubular sections of aged animals with complete spermatogenesis and arrested spermatogenesis and tubular sections with arrest spermatogenesis of photoinhibited testes. Sertoli cells were positive for HSP47, the intensity being greater in tubular sections with arrested spermatogenesis in both aged and photoinhibited animals. Semiquantitative analysis corroborated this observation in the sense that the expression of this protein differed according to the functional state of the seminiferous tubules. Thus, the ratio of immunoreactivity was significantly higher in tubular sections with arrested spermatogenesis in aged animals compared with regressed animals, and in the latter compared with those whose tubular sections showed complete spermatogenesis. In conclusion, HSP47 expression in Sertoli cells was found for the first time in mammals. Moreover, increased expression seemed to be related to the degree of seminiferous atrophy epithelium and to the reversible or nonreversible physiological state of this epithelium.
Open Access
Lectin binding pattern of glycoconjugates during spontaneous testicular recrudescence in Syrian hamster (Mesocricetus auratus) after exposure to short photoperiod
(Wiley, 2019-02-01) Ferrer Cazorla, Concepción; Serrano-Sánchez, María Isabel; Beltrán Frutos, Ester; Martínez Hernández, Jesús; Pastor García, Luis Miguel; Seco Rovira, Vicente; Biología Celular e Histología
Lectin histochemistry was used to characterize glycoconjugates and cellular apoptosis in the seminiferous epithelium and interstitium of hamster testis during spontaneous recrudescence. An increase in the LTA lectin affinity was observed in spermatids in the Golgi phase. An increase in labelling of PNA and Con-A lectin in acrosome of spermatids (acrosome phase) as well increased labelling with Con-A in spermatids (cap phase) was observed. Spermatocytes showed decreased affinity with PNA and AAA lectins and an increase in positivity for LTA and GNA lectins. Spermatogonia showed a slight decrease in positivity to WGA and an increase in labelling with Con-A, and a decreased affinity for the AAA lectin. At the end of recrudescence all these germinal cells showed a similar pattern to the control. The Sertoli cells showed a gradual decrease in labelling with the GNA lectin and the Leydig cells an increase in labelling with Con-A and GNA. Particularly unusual was the observation of apoptotic spermatocytes and spermatids positive for PNA, GNA, AAA and Con-A, together with spermatocytes positive to LTA. In conclusion the normal lectin pattern is recovered during testis recrudescence and germ cell apoptotic activity is low, as is observed by specific lectins for germ cells in apoptosis.