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The aim of the present research were histological analysis of regenerating structures through in vitro gynogenesis from unfertilized ovules of sugar beet (Beta vulgaris L.). The process of shoot regeneration using a novel two stage method combines the preculture in liquid medium with the culture on solid medium. The highest number of explants that formed shoots (60%) was observed on medium supplemented with BAP, sucrose and gerlite, and as regards carbohydrates used in the medium most of explants forming shoots (42%) and the largest total number of shoots (110) was observed for glucose. To accurately determine the course of shoot formation, histological analyses were performed. Careful histologic evaluation of regenerating structures revealed the presence of numerous meristematic centres. In some meristems formation of specialized tissues and organs was observed, including epidermis, apical meristem, leaf primordia and tracheal elements. The analyses showed that the regeneration of the new structures from sugar beet ovules occurred both through organogenesis as well as somatic embryogenesis since the presence of somatic embryos in the globular stage or torpedo stage were observed.
 Lung adenocarcinoma is a leading human malignancy with fatal prognosis. Ninety percent of the deaths, however, are caused by metastases. The model of subcutaneous tumor xenograft in nude mice was adopted to study the growth of control and photodynamically treated tumors derived from the human A549 lung adenocarcinoma cell line. As a side-result of the primary studies, observations on the metastasis of these tumors to the murine lungs were collected, and reported in the present paper. The metastasizing primary tumors were drained by a prominent number of lymphatic vessels. The metastatic tissue revealed the morphology of well-differentiated or trans-differentiated adenocarcinoma. Further histological and histochemical analyses demonstrated the presence of golden-brown granules in the metastatic tissue, similar to these found in the tumor tissue. In contrast to the primary tumors, the electron paramagnetic resonance spectroscopy revealed no nitric oxide - hemoglobin complexes (a source of intense paramagnetic signals), in the metastases. No metastases were found in other murine organs; however, white infarctions were identified in a single liver. Taken together, the A549-derived tumors growing subcutaneously in nude mice can metastasize and grow on site in the pulmonary tissue. Thus, they can represent an alternative for the model of induced metastatic nodule formation, following intravenous administration of the cancerous cells.
Histological analyses were conducted of the annual cycle of male gonads of spiny-cheek crayfish Orconectes limosus Raf. Although changes in the male gonads throughout the year are clearly evident, they are not uniform in all males. Spiny-cheek crayfish mate mainly in the autumn from September to November. After mating, the gonads of male crayfish can be divided into two groups according to their histological structure. In the first group there is an abundance of sperm in the gonads, while the testicular tubules in the second group are either empty or contain a small amount of sperm. This division remains until May. In May, the histological picture of the gonads is uniform, and there are either very few or no tubules containing sperm. In June O. limosus males occur in two forms. The histological pictures of first- and second-form male gonads do not differ. However, beginning in July and also in August and September, the gonads of first- and second-form males do differ. First-form male crayfish gonads contain more sperm than those of second-form males. From October onwards, all of the males are first-form, and primarily spermatids and sperm are visible in the gonads. The possibility that the spiny-cheek crayfish mates twice annually, once in autumn and again in spring, is discussed based on changes observed in the histological picture of the gonads.
The aim of the study was a histological evaluation of mucosa of the oviduct and uterus, regarding cystic ovarian degeneration in sows. Materials for the evaluation were received after the slaughtering of 294 sows at the age of two to five years. The sows were eliminated from breeding and culled due to disorders such as: anoestrus after weaning of piglets, return of oestrus, small litter size, high number of parturitions, bad condition after lactation, and age. Twenty of the 294 sows (6.8%) had cysts on the ovaries. The sows were divided into two groups: group 1 (12 sows) with polycystic ovaries and group 2 (8 sows) with simple cysts, which occurred unilaterally (3 sows) or bilaterally (5 sows). The studies demonstrated different kinds of ovarian cysts and structural changes in ovarian cortex, such as decreasing number of ovarian follicles of all generations and increase in follicular atresia. The histological state of tissues and changes of mucosa of the oviduct and uterus, regarding polycystic ovaries or single cysts on ovaries were compared. The single follicular cysts were not accompanied with important changes in the reproductive system. In the case of polycystic ovaries, the presence of cyst was connected with the occurrence of morphological changes in the endothelium of the oviduct and uterus, which could have been a reason of persistent infertility in pigs. An increase in the number of secretory cells with simultaneous decrease in ciliated ones, both in the ampulla and isthmus and covering the epithelium by secretions were observed in the oviduct. In our studies, we observed increasing proliferation of both glandular epithelium and surface epithelium. The terminal portion of the uterine glands was cystic dilated with remaining secretions. Hypersecretion of superficial epithelium was noted.
The research was carried out on a group of 119 foetuses aged from the 36th to 120th d of prenatal life. The "cross-section of population" method was used. The subjects were divided into six groups for statistical assessment. The development of the salivary glands was evaluated by using anatomo-topographical methods: skeletopy, synthopy, and holotopy. The structural characteristics of the vascularisation and innervations were examined by morphological, radiological, and histological methods. The development and morphology of the mandibular and sublingual glands was correlated with the development of the surrounding organs. The most intensive growth of salivary glands was observed in the 10th-11th week of prenatal life and was connected with the isometric phase. The histological structures of the glands changed according to the age of the foetus. The connective tissue of the glands diminished and the excretory parts increased during pregnancy. The position of the foetus in the uterus and its sex had no influence on morphology and the development of mandibular and sublingual salivary glands.
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