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Tissue Stroma (tissue + stroma)
Kinds of Tissue Stroma Selected AbstractsGerminal epithelium, folliculogenesis, and postovulatory follicles in ovaries of rainbow trout, Oncorhynchus mykiss (Walbaum, 1792) (Teleostei, protacanthopterygii, salmoniformes)JOURNAL OF MORPHOLOGY, Issue 4 2007Harry J. Grier Abstract The rainbow trout, Oncorhynchus mykiss (Walbaum, 1792), is a salmoniform fish that spawns once per year. Ripe females that had ovulated naturally, and those induced to ovulate using salmon gonadotropin-releasing hormone, were studied to determine whether follicles were forming at the time of spawning and to describe the process of folliculogenesis. After ovulation, the ovaries of postspawned rainbow trout were examined histologically, using the periodic acid-Schiff procedure, to stain basement membranes that subtend the germinal epithelium and to interpret and define the activity of the germinal epithelium. After spawning, the ovary contained a few ripe oocytes that did not ovulate, numerous primary growth oocytes including oocytes with cortical alveoli, and postovulatory follicles. The germinal epithelium was active in postspawned rainbow trout, as determined by the presence of numerous cell nests, composed of oogonia, mitotic oogonia, early diplotene oocytes, and prefollicle cells. Cell nests were separated from the stroma by a basement membrane continuous with that subtending the germinal epithelium. Furthermore, follicles containing primary growth oocytes were connected to the germinal epithelium; the basement membrane surrounding the follicle joined that of the germinal epithelium. After ovulation, the basement membrane of the postovulatory follicle was continuous with that of the germinal epithelium. We observed consistent separation of the follicle, composed of an oocyte and surrounding follicle cells, from the ovarian stroma by a basement membrane. The follicle is derived from the germinal epithelium. As with the germinal epithelium, follicle cells derived from it never contact those of the connective tissue stroma. As with epithelia, they are always separated from connective tissue by a basement membrane. J. Morphol., 2007. © 2007 Wiley-Liss, Inc. [source] Odontogenic ghost cell tumour with clear cell components: clear cell odontogenic ghost cell tumour?JOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 6 2004Jung Hoon Yoon A case of odontogenic ghost cell tumour (OGCT) with clear cell components was encountered in the mandible of a 63-year-old man. The tumour revealed ameloblastomatous-type epithelial components accompanied by clusters of ghost cells and dentinoid juxtaposed to the odontogenic epithelium. In addition, some areas of the tumour tissue showed sheets and islands of clear, glycogen containing epithelial cells, which were separated by a thin fibrous connective tissue stroma. Both ameloblastic and clear cells exhibited positive immunoreactivities for cytokeratin 19 and AE1/3. It is not known whether this tumour represents a clear cell change of a pre-existing OGCT or a separate and distinct neoplasm derived de novo from the odontogenic epithelium. This tumour was given the term ,clear cell OGCT' because it captures the clear cell components, which is one of the most prominent distinguishing features of the tumour. [source] Cyclooxygenase-2 Expression in Murine and Human Nonmelanoma Skin Cancers: Implications for Therapeutic Approaches,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 1 2002Kathy P. An ABSTRACT Inflammatory stimuli result in the production of cutaneous eicosanoids, which are known to contribute to the process of tumor promotion. Cyclooxygenase (COX), the rate-limiting enzyme for the production of prostaglandins (PG) from arachidonic acid, exists in at least two isoforms, COX-1 and COX-2. COX-1 is constitutively expressed in most tissues and plays various physiological roles, whereas increased COX-2 expression is known to occur in several types of epithelial neoplasms. Enhanced PG synthesis is a potential contributing factor in UVB-induced nonmelanoma skin cancers (NMSC). Increased COX-2 staining occurs in murine skin neoplasms after chronic exposure to carcinogenic doses of UVB. In this study, immunohistochemical and Western blot analyses were employed to assess longitudinally COX-2 expression in a standard mouse UVB complete carcinogenesis protocol and in human basal cell carcinomas (BCC) and squamous cell carcinomas (SCC). During UVB irradiation of mice, COX-2 expression consistently increased in the hyperplastic skin, the benign papillomas and the SCC. COX-2 expression was also increased in human actinic keratoses, SCC and BCC as well as in murine SCC and BCC. The pattern of COX-2 expression was quite variable, occurring in a patchy distribution in some lesions with staining confined mainly to suprabasal cell layers. In general, COX-2 expression progressively became more extensive in benign papillomas and well-differentiated murine SCC. The staining was predominantly cytoplasmic and perinuclear in some focal areas in tissue stroma around both murine and human tumors. Western blot analysis confirmed negative COX-2 expression in normal skin, whereas acute UVB exposure resulted in increased enzyme expression, which continued to increase in developing papillomas and SCC. Because of the evidence indicating a pathogenic role for eicosanoids in murine and human skin neoplasms, we performed studies to assess the anti-inflammatory and anticarcinogenic effects of green tea extracts, which are potent antioxidants. Acute exposure of the human skin to UVB (minimum erythema dose × 4) caused a transient enhancement of the COX-2 expression, which reverted to baseline within hours; however, in murine skin the expression persisted for several days. Pretreatment with the topically applied green tea extract (1 mg/cm2) largely abrogated the acute COX-2 response to UVB in mice or humans. In summary, enhanced COX-2 expression serves as a marker of epidermal UVB exposure for murine and human NMSC. These results suggest that COX-2 inhibitors could have potent anticarcinogenic effects in UVB-induced skin cancer. [source] Immunohistochemical Studies on Oestrogen Receptor Alpha (ER,) and the Proliferative Marker Ki-67 in the Sow Uterus at Different Stages of the Oestrous CycleREPRODUCTION IN DOMESTIC ANIMALS, Issue 1 2003S Sukjumlong Contents In order to better understand physiological changes during the different stages of the oestrous cycle, immunohistochemistry was used in the present study to investigate the distribution of oestrogen receptor alpha (ER,) as well as the proliferative marker Ki-67, in the sow uterus during the oestrous cycle. Uterine samples were collected from multiparous sows with normal reproductive performance at selected stages of the oestrous cycle: at late dioestrus (d 17), prooestrus (d 19), oestrous (d 1), early dioestrus (d 4) and dioestrus (d 11,12), respectively. The tissue samples were fixed in 10% formaldehyde, embedded in paraffin and subjected to immunohistochemistry using monoclonal antibodies against ER, (C-311) and Ki-67 (MM-1). In general, the immunostaining of both ER, and Ki-67 was confined to nuclei of the target cells. Variations were seen, not only at the different stages of the oestrous cycle, but also in the different tissue compartments of the uterus. In the epithelia, the strongest ER, staining and highest amount of positive Ki-67 cells were found at early dioestrus. In the myometrium, the highest levels of staining of both ER, and Ki-67 positive cells were found at pro-oestrus and oestrus. For the proliferative marker, Ki-67, no positive cells were found at dioestrus and late dioestrus in the epithelium and myometrium. In the connective tissue stroma (subepithelial layer), the highest number of ER, positive cells were found at oestrus, which was significantly different compared with other stages (p,0.05), whereas the levels of Ki-67 positive cells were relatively low and did not differ between the stages examined. Significant correlations between the number of ER, positive cells in the stroma and Ki-67 positive cells in the epithelia were observed. This suggests indirect regulatory mechanisms on epithelial proliferation via ER, in the stroma. In conclusion, these findings in the sow uterus show that the presence of ER, as well as Ki-67 protein varies not only between different stages of the oestrous cycle but also between different tissue compartments of the uterus. These findings indicate various regulatory mechanisms and stress the importance of localising ER, and proliferating cells in different uterine tissues. [source] China rose (Hibiscus rosasinensis) petals: a potent natural carotenoid source for goldfish (Carassius auratus L.)AQUACULTURE RESEARCH, Issue 11 2007Archana Sinha Abstract Goldfish (Carassius auratus) are in demand in world markets due to their attractive golden colour. Carotenoids are the primary source of colour in the skin of fish. To optimize the colour in captivity, fish must obtain an adequate level of carotenoids in their feed. With this objective, four natural colour enhancers were tested. A common batch of feed was divided into five equal portions and colour ingredients, spirulina (D-S), china rose petals (D-C), marigold petals (D-M) and Lactobacil, a commercial probiotic (D-L), were added at 5 mg kg,1 to four portions of feed; one portion (D-O) was kept as a control without any additive. A feeding trial was conducted for 8 weeks. Each 70 L aquarium was stocked with 10 fish (average weight 1.6 g) and feed was given at 5% of the body weight. Growth rate, survival, biochemical composition and pigmentation in the skin of fish were measured. Histological studies of gonads were also conducted. Growth of fish in different treatments was significantly different. There was no difference in the proximate composition of the fish at the start of the experiment but after 8 weeks of feeding, fish fed the diet supplemented with china rose petals had a lower moisture content (70.48%) and higher protein (17.7%) and lipid (5.25%) levels than the group fed the control diet. Pigmentation was the highest (4.01 ,g g,1) in D-C, followed by D-M (3.16 ,g g,1), D-S (2.92 ,g g,1) and D-L (2.84 ,g g,1) and the lowest (0.24 ,g g,1) in D-O. Gonad development of fish fed with the D-C diet was better compared with the gonads of control (D-O) fish, followed by D-M-, D-L- and D-S-fed fish. Gonads of fish, fed D-C, showed well-marked changes in the testis where a large number of seminiferous tubules bound together by means of a thin layer of connective tissue were observed. These tubules were highly convoluted and were separated from each other by thin connective tissue stroma. The intra space contained connective tissue, blood capillaries and interstitial cells. The spermatogonia could be seen as a large spherical cell containing a large central nucleus with a distinct nucleolus. The study shows that the china rose (Hibiscus rosasinensis) petal is a potent natural carotenoid source for goldfish to enhance its colour and also accelerate gonadal development. [source] The effect of enamel matrix proteins and deproteinized bovine bone mineral on heterotopic bone formationCLINICAL ORAL IMPLANTS RESEARCH, Issue 4 2006Nikolaos Donos Abstract Aim: To evaluate the osteoinductive potential of deproteinized bovine bone mineral (DBBM) and an enamel matrix derivative (EMD) in the muscle of rats. Material and methods: Sixteen rats were used in this study. The animals were divided in three groups. Group A: a pouch was created in one of the pectoralis profundis muscles of the thorax of the rats and DBBM particles (Bio-Oss®) were placed into the pouch. Healing: 60 days. Group B: a small pouch was created on both pectoralis profundis muscles at each side of the thorax midline. In one side, a mixture of EMD (Emdogain®) mixed with DBBM was placed into one of the pouches, whereas in the contralateral side of the thorax the pouch was implanted with DBBM mixed with the propylene glycol alginate (PGA , carrier for enamel matrix proteins of EMD). Healing: 60 days. Group C: the same procedure as group B, but with a healing period of 120 days. Qualitative histological analysis of the results was performed. Results: At 60 days, the histological appearance of the DBBM particles implanted alone was similar to that of the particles implanted together with EMD or PGA at both 60 and 120 days. The DBBM particles were encapsulated into a connective tissue stroma and an inflammatory infiltrate. At 120 days, the DBBM particles implanted together with EMD or PGA exhibited the presence of resorption lacunae in some cases. Intramuscular bone formation was not encountered in any group. Conclusion: The implantation of DBBM particles alone, combined with EMD or its carrier (PGA) failed to exhibit extraskeletal, bone-inductive properties. [source] | |||||||||||||