By making use of the known sequence of ovulation and fertilization in Holtzman rats, the Pontamine Blue reaction, and electron microscopy, the first stages in implantation were studied. Implantation is initiated when the blastocyst becomes clasped by the endometrium and hence assumes a fixed position (evening of day 5 ) . At this stage, the trophoblast cells are in close association with the uterine epithelial cells, with interdigitating microvilli in places, but decidualization of the fibroblasts is just beginning. In the second stage of implantation the decidualized fibroblasts form a cup around the luminal epithelium. Evidence of adhesion of the cell membranes of trophoblast cells with the cell membranes of luminal epithelial cells can be seen at this time. The layer of fibroblasts immediately surrounding the luminal epithelium becomes epithelioid, resulting in a relative isolation of the luminal epithelium from its vascularization. This stage is well-developed by the afternoon of day 6. By the morning of day 7, the luminal epithelium has disappeared from the region of the forming ectoplacental cone down to the level of the abembryonic trophoblast. The trophoblast cells on the lateral aspect of the blastocyst are directly in contact with the residual basement membrane of the luminal epithelial cells, and are separated by this structure and a small connective tissue cleft from the stromal cells. The importance of the relative isolation of the epithelium by the stromal reaction and the adhesion of the cell membrane of the trophoblast cells to the cell membranes of epithelial cells with regard to removal and phagocytosis of epithelial elements are discussed, and many of the cytological features observed during the process are described.The ready availability of the rat and mouse have made these animals favorite objects for the study of implantation. Duval (1891) took advantage of the abundance of rats in the slaughterhouses of Paris for his study materials. However, he used Lataste's collection of mouse reproductive tracts for the comparison of stages and the timing of these stages. His studies, plus those that followed in the next two decades dealing with both the mouse (Burckhard, '01; Sobotta, '03) and the rat and mouse (Melissinos, '07), established many of the essential features of implantation in these myomorph rodents. The mouse was the major subject of these studies, and little distinction was made between the mouse and rat, which were considered to be in the same genus at that time. Although these studies predated a precise knowledge of the reproductive cycle, timed implantation stages were obtained by using Sobotta's method of placing female mice that had given birth to litters 21 days previously with males, then AM. J. ANAT., 120: 185-226.examining them subsequently for copulation plugs.The most comprehensive study of implantation in the rat is that of Huber ('15). He reviewed not only the literature on implantation in the mouse mentioned above, but also the less distinguished literature on th...
This study was performed to investigate the anxiolytic efficacy of silexan, a new oral lavender oil capsule preparation, in comparison to placebo in primary care. In 27 general and psychiatric practices 221 adults suffering from anxiety disorder not otherwise specified (Diagnostic and Statistical Manual of Mental disorders-IV 300.00 or International Statistical Classification of Diseases and Related Health Problems, Tenth revision F41.9) were randomized to 80 mg/day of a defined, orally administered preparation from Lavandula species or placebo for 10 weeks with visits every 2 weeks. A Hamilton Anxiety Scale (HAMA) total score >or=18 and a total score >5 for the Pittsburgh Sleep Quality Index (PSQI) were required. The primary outcome measures were HAMA and PSQI total score decrease between baseline and week 10. Secondary efficacy measures included the Clinical Global Impressions scale, the Zung Self-rating Anxiety Scale, and the SF-36 Health Survey Questionnaire. Patients treated with silexan showed a total score decrease by 16.0+/-8.3 points (mean+/-SD, 59.3%) for the HAMA and by 5.5+/-4.4 points (44.7%) for the PSQI compared to 9.5+/-9.1 (35.4%) and 3.8+/-4.1 points (30.9%) in the placebo group (P<0.01 one-sided, intention to treat). Silexan was superior to placebo regarding the percentage of responders (76.9 vs. 49.1%, P<0.001) and remitters (60.6 vs. 42.6%, P=0.009). Lavandula oil preparation had a significant beneficial influence on quality and duration of sleep and improved general mental and physical health without causing any unwanted sedative or other drug specific effects. Lavandula oil preparation silexan is both efficacious and safe for the relief of anxiety disorder not otherwise specified. It has a clinically meaningful anxiolytic effect and alleviates anxiety related disturbed sleep.
The inner cell mass of the blastocyst has differentiated into epiblast and hypoblast (primitive endoderm) prior to implantation. Since endoderm cells extend beyond the epiblast, it can be considered that both parietal and visceral endoderm are present. At implantation, epiblast cells begin to show marked evidence of polarity. They form a spherical aggregate with their basal ends toward the basal lamina and apical ends toward the interior. The potential for an internal space is formed by this change in polarity of the cells. No cytological evidence of separation of those cells that will form amniotic epithelium from the rest of the epiblast is seen until a cavity begins to form. The amniotic epithelium is originally contiguous with overlying cytotrophoblast, and a diverticulum remains in this position during early development. Epiblast forms a pseudostratified columnar epithelium, but dividing cells are situated toward the amniotic cavity rather than basally. The first evidence of a trilaminar disc occurs when a strand of cells contiguous with epiblast is found extending toward visceral endoderm. These presumptive mesoderm cells are undifferentiated, whereas extraembryonic mesoderm cells are already a distinct population forming extracellular materials. After implantation, visceral endoderm cells proliferate forming an irregular layer one to three cells thick. Visceral endoderm cells have smooth apical surfaces, but very irregular basal surfaces, and no basal lamina. At the margins of the disc, visceral endoderm is continuous with parietal endoderm and reflects back over the apices of the marginal visceral endoderm cells. This sacculation by visceral endoderm cells precedes pinching off of the secondary yolk sac from the remaining primary yolk sac.
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