Chronic unpredictable stress disturbs the blood-testis barrier affecting sperm parameters in mice.

RESEARCH QUESTION: Does chronic stress affect the key proteins and sperm parameters of the blood-testis barrier (BTB)? DESIGN: C57Bl/6 mice were divided into two groups: a non-treated control group and a chronic unpredictable stress (CUS) applied group. The stress status of the animals was confirmed with behavioural tests. Histopathologic evaluation was conducted by haematoxylin and eosin staining and electron microscope. Malondialdehyde, corticosterone and testosterone levels were evaluated in peripheral blood. Expression levels of BTB proteins, namely zonula occludens-1 (ZO-1), claudin-11 (CLDN11) and clathrin in Sertoli cells, were assessed by Western blotting and immunofluorescence techniques. Sperm samples were collected from cauda epididymis, and sperm parameters analysed. RESULTS: The stress model was confirmed by behavioural tests. Histopathological evaluation of the testes demonstrated a mild degeneration in seminiferous tubules. Malondialdehyde (P = 0.008) and corticosterone levels increased (P = 0.004) and testosterone levels decreased (P = 0.005) in the CUS group. Electron microscopic evaluation confirmed the damage in BTB integrity in the CUS group. Western blot analysis showed that ZO-1 and CLDN11 levels were significantly decreased, although clathrin levels were unchanged. Although sperm concentration and total motility rate were not significantly different between the groups, progressive motility (P = 0.03), normal sperm morphology (P = 0.04), chromatin integrity (toluidine blue) (P = 0.002) and the acrosomal reaction rate (P = 0.002) were significantly decreased, and acrosomal abnormality rate was dramatically increased (P = 0.04) in the CUS group. CONCLUSIONS: In mice, CUS disrupted BTB integrity and impaired sperm parameters. A decrease in ZO-1 and CLDN11 expression levels may be proposed as the causative factor.

The Use of Platelet-Rich Plasma for Storage of Surplus Harvested Skin Grafts.

BACKGROUND: There is a need for improved methods and storage media to sustain the tissue viability of autologous skin grafts. OBJECTIVE: To compare histological changes in human skin grafts stored in platelet-rich plasma (PRP) with those of grafts stored in saline. METHODS: Eight circular, 3-mm full-thickness skin graft samples were harvested from the abdominal skin of each of 5 patients scheduled to undergo an abdominoplasty procedure. Four of these graft samples were stored in saline, and the other 4 were stored in saline mixed with PRP prepared from the patient's own venous blood. Histological assessment of the microscopic appearance of the samples was performed on days 5, 8, 11, and 14. The integrity of the epidermal-dermal junction, number of keratinocytes with perinuclear halos, collagen organization, and number of fibroblasts per field were assessed. The cellular apoptosis rate was also measured on these same days. RESULTS: On day 5, significant differences were observed microscopically between the PRP- and saline-stored grafts (P < .05). The grafts preserved in saline exhibited early marked cellular and nuclear swelling with pleomorphism, as well as early nuclear halo formation. The cell viability rate of the PRP group was significantly higher than that of the saline-stored group on day 8 (P < .05). CONCLUSION: Platelet-rich plasma and its inherent growth factors supported longer graft survival; however, its effect lasted only until day 8. Platelet-rich plasma may be beneficial if grafts need to be stored for delayed application(s).

HISTORIQUE: Il faut améliorer les méthodes et les milieux de conservation pour maintenir la viabilité des greffons autologues de peau. OBJECTIF: Comparer les changements histologiques des greffons de peau humaine conservés dans du plasma riche en plaquettes (PRP) à ceux des greffons conservés dans un soluté physiologique. MÉTHODOLOGIE: Les chercheurs ont prélevé huit échantillons de greffons circulaires de trois millimètres de peau pleine épaisseur sur la peau de l'abdomen de chacun des cinq patients qui devaient subir une abdominoplastie. Quatre d'entre eux ont été conservés dans un soluté physiologique et les quatre autres, dans un soluté physiologique mélangé à du PRP préparé à partir du propre sang veineux du patient. Les chercheurs ont procédé à l'évaluation histologique de l'aspect microscopique des échantillons les cinquième, huitième, onzième et quatorzième jours après le prélèvement. Ils ont examiné l'intégrité de la jonction dermoépidermique, le nombre de kératinocytes dotés de halos périnucléaires, l'organisation du collagène et le nombre de fibroblastes par champ. Les mêmes jours, ils ont mesuré le taux d'apoptose cellulaire. RÉSULTATS: Le cinquième jour, les chercheurs ont observé des différences microscopiques significatives entre les greffons conservés dans le PRP et ceux conservés dans un soluté physiologique (P<0,05). Les greffons conservés dans le soluté physiologique présentaient une hypertrophie cellulaire et nucléaire précoce marquée accompagnée de pléomorphisme ainsi que la formation précoce de halos nucléaires. Le huitième jour, le taux de viabilité des cellules du groupe de PRP était considérablement plus élevé que celui des cellules du groupe de soluté physiologique (P<0,05). CONCLUSION: Le plasma riche en plaquettes et les facteurs de croissance inhérents favorisaient une plus longue survie, mais seulement jusqu'au huitième jour. Le plasma riche en plaquettes peut être bénéfique si les greffes doivent être conservées en vue d'être utilisées plus tard.