The objective of this research was to improve the techniques in processing chilled and frozen-thawed horse semen. In a preliminary experiment (Exp. I), different techniques for sperm selection and preparation [Swim-up, Glass wool (GW) filtration, Glass wool Sephadex (GWS) filtration; Percoll] were tested for their suitability for equine spermatozoa and results were compared with the routine procedure by dilution (Exp. I). In the main experiment (Exp. II), two sperm preparation techniques (GWS, Leucosorb) refering to the results of Exp. I and a previous study of our group (Pferdcheilkunde 1996 12, 773) were selected for processing complete ejaculates either for cooled-storage or cryopreservation. In a third experiment (Exp. III), pregnancy rates from inseminations with semen processed according to the techniques tested in Exp. II were compared with those obtained with semen processed according to routine procedures. In Exp. I (six stallions, six ejaculates/stallion), between 48 and 92% of spermatozoa were lost following the different sperm selection procedures (p < 0.05). Preparation of sperm increased percentage of progressively motile spermatozoa (pms) [Swim-up, GW, GWS vs dilution, Percoll (p < 0.05)] and decreased percentage of sperm head abnormalities [Swim-up, GW, GWS vs dilution, Percoll (p < 0.05)] probably by not improving the quality of individual cells, but by elimination of spermatozoa of inferior quality. In Exp. II (eight stallions, three ejaculates/stallion) Leucosorb and GWS procedures allowed the filtration of large volumes (extended ejaculates) for routine laboratory practice. GWS and Leucosorb filtration resulted in increased motility, membrane integrity and sperm viability after storage of spermatozoa until 48 h at +5 degrees C when compared with control (diluted) and centrifuged semen (p < 0.05). Significantly more spermatozoa were recovered after centrifugation (87.8 +/- 15.4%) compared with GWS (63.5 +/- 18.6%) and Leucosorb filtration (53.6 +/- 22.3%). GWS or Leucosorb procedure resulted in successful cryopreservation of stallion semen without centrifugation for removal of seminal plasma. The per cycle conception rate of inseminated mares using 200 x 106 pms transferred within 8 h after collection of semen was not affected by GWS filtration or Leucosorb separation when compared with centrifugation (n.s.; Exp. III). In conclusion, GWS and Leucosorb filtration results in the improvement of semen quality and should be considered as a method for stallion semen processing. Additional studies are needed for the evaluation of potentially higher fertilizing ability of stallion spermatozoa separated by techniques for sperm selection.
Phthalates are widely used as plasticizers in a number of daily-life products. In this study, we investigated the influence of mono-(2-ethylhexyl) phthalate (MEHP), the active metabolite of the frequently used plasticizer di-(2-ethylhexyl) phthalate (DEHP), on gonadal steroidogenesis in vitro. MEHP (25-100 mM) stimulated basal steroid synthesis in a concentration-dependent manner in immortalized mouse Leydig tumor cells (MLTC-1). The stimulatory effect was also detected in KK-1 granulosa tumor cells. MEHP exposure did not influence cAMP or StAR protein levels and induced a gene expression profile of key steroidogenic proteins different from the one induced by human chorionic gonadotropin (hCG). Simultaneous treatment with MEHP and a p450scc inhibitor (aminoglutethimide) indicated that MEHP exerts its main stimulatory effect prior to pregnenolone formation. MEHP (10-100 mM) up-regulated hormone-sensitive lipase and 3-hydroxy-3-methylglutaryl coenzyme A reductase, suggesting that MEHP increases the amount of cholesterol available for steroidogenesis. Our data suggest that MEHP, besides its known inhibitory effect on hCG action, can directly stimulate gonadal steroidogenesis in both sexes through a cAMP-and StAR-independent mechanism. The anti-steroidogenic effect of DEHP has been proposed to cause developmental disorders such as hypospadias and cryptorchidism, whereas a stimulation of steroid synthesis may prematurely initiate the onset of puberty and theoretically affect the hypothalamic-pituitary-gonadal axis. Reproduction (2008) 135 693-703
Older persons with mental disorders represent a vulnerable group of people with extensive and complex needs. The older population is rapidly increasing worldwide and, as a result of deinstitutionalization in mental health care, older persons are remaining at home to a greater extent. Although they constitute a large proportion of the population, older persons with mental disorders have been neglected in research as well as in care organizations. As there is little previous knowledge concerning older persons’ experiences of their own situations, this study aimed to illuminate the meaning of the life situation as experienced by older persons with mental disorders (excluding dementia disorders). Interviews were conducted with seven older persons and the text was analyzed using a phenomenological hermeneutical research method, inspired by the philosophy of Paul Ricoeur. “Struggling for existence” emerged as a main theme in the older persons’ narratives, understood as a loss of dignity of identity and involving being troubled and powerless as well as yearning for respect. The older persons fought to master their existence and to be seen for who they are. The study highlights the importance for caregivers, both formal and informal, to avoid focusing on the diagnoses and rather acknowledge the older persons and their lifeworld, be present in the relation and help them rebuild their dignity of identity. This study brings a new understanding about older persons with mental disorders that may help reduce stigma and contribute to planning future mental health care.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.