Histology and histopathology Vol.11, nº 2 (1996)
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- PublicationOpen AccessOdontogenic jaw cysts: light and electron microscopical investigations(Murcia : F. Hernández, 1996) Domenici Lombardo, L.; Amunni, F.; Bergamini, M.; Romagnoli, P.Light and electron microscopy were used to analyze the epithelial lining of odontogenic cysts excised from edentulous regions of the jaws. Clinically, three cases were identified as keratocysts, and 21 cases as cysts other than keratocysts («non-keratocysts~)T. he epithelium of the former was found to achieve keratinization over most of the surface and to never contain mucus secreting cells. The epithelium of the latter appeared to be in part stratified squamous, with cells loosely connected to each other, and in part stratified columnar, with superficial cells connected to each other by tight junctions and secreting mucus. The results suggest that cysts arising from edentulous regions of the jaws may be either keratocysts or cysts with heterogeneous, non-keratinizing epithelium; the content of keratocysts can be formed mainly by shedding of comified epithelial layers, and that of non-keratocysts by mucus secretion from columnar epithelium associated to fluid filtration through non-keratinizing squamous epithelium.
- PublicationOpen AccessStereology of human fetal adrenal medulla(Murcia : F. Hernández, 1996) Bocian-Sobkowska, J.; Woíniak, W.; Malendowicz, L.K.; Ginda, Waclaw J.Stereological studies were performed on 27 pairs of adrenal glands of human fetuses (9-38 weeks of intra-uterine development). Medullary chrornaffin cells were identified by irnrnunostaining for chromogranin-A. The volume of adrenal rnedulla, average cell volurne, and the number of chrornaffin cells were calculated. The volume of adrenal medulla increased slowly up to the 20th week and afterwards it enlarged rapidly to the 3 1 st week of the fetal period. A gradual, linear increase in the number of chromaffin cells of developing adrenal rnedulla was observed during the studied period. On the contrary, the average volurne of the adrenal medullary cells rernained quite constant until the 17th week of the development. Afterwards, a gradual, linear increase in the cell volume was observed until the 31 st week, reaching a plateau by the end of intra-uterine developrnent.
- PublicationOpen AccessA comparison of cyclosporine A and cyclosporine G in a rabbit heterotopic cardiac transplant model: graft outcome and histological findings(Murcia : F. Hernández, 1996) Fryer, J.P.; Pascoe, E.A.; Yatscoff, R.W.; Thliveris, J.A.Cervical heterotopic heart transplants were performed on 20 male New Zealand white rabbits comprising 4 treatment groups. Animals in each group were injected daily via the marginal ear vein and received one of the following regimes: Cyclosporine A, 10 mglkglday; Cyclosporine G, 15 mglkglday; cremophor-El, 3mllday; or normal saline. Measurement of 24 hour trough blood concentrations revealed no significant differences between the average concentrations of Cyclosporine A and Cyclosporine G. Animals were examined daily and the cervical allografts assessed by palpation for viabilitylrejection. The duration of the study ended for each animal when the graft stopped beating at which time the animals was euthanized and the transplanted heart and native kidneys harvested and processed for light microscopy evaluation of rejection and drug toxicity, respectively. Graft survival in the Cyclosporine A group significantly surpassed that seen in the Cyclosporine G group as well as the control groups, whereas in animals treated with Cyclosporine G, graft survival was not different from controls. In the native kidney, there were no differences in glomerular tuft area or volume density amongst drug-treated or control animals. In contrast, tubule atrophy and interstitial fibrosis were markedly greater in Cyclosporine A-treated vs Cyclosporine Gtreated animals. The results of this study indicate that, whereas Cyclosporine G is less nephrotoxic than Cyclosporine A, given equivalent blood concentrations Cyclosporine A delays rejection of a cardiac allograft significantly longer than Cyclosporine G in this animal species.
- PublicationOpen AccessMicrogravity in the STS-29 space shuttle discovery affected the vestibular system of chick embryos(Murcia : F. Hernández, 1996) Fermin, C.D.; Martin, D.; Jones, T.; Vellinge, J.; Deuser, M.; Hester, P.; Hullinger, R.Out of 32 embryos flown (16 @ E2 + 16 @ E9) for 5 days, 16 survived. Al1 sixteen E2 were dead at landing. Eight were opened and eight were incubated at 1 .OG. Autopsy showed that 4 E2 survived over 24 hours in space. Eight E14 hatched without anatomical malformations, and 8 E14 were fixed. The height of the macular epithelia was 31 ym (mean) in control and 26 pm in flight chicks. The cross-sectional area of macular nuclei of control was 17 ym2 for hair cells and 14 ym2 in supporting cells. In flight, cross-sectional area was 17 pm2 in hair cells and 15 Iim2 in supporting cells (n=250). The shape factor of cartilage cells (1.0 = perfect circle) between control (mean = 0.70) and flight (mean = 0.72), and the area of cartilaginous cells between controls (mean = 9 pm2) and flight (mean = 9 Iirn2) did not differ (n=300). The nuclei of support cells were closer to the basement membrane in flight than in control chicks. The immunoreactivity of otoconia with anti keratan, fibronectin or chrondroitin sulfate was not different between flight and control ears. There were more afferent fibers inside the macular epithelia of flight (p<0.05) than control. Three of 8 flight animals had elevated vestibular thresholds (VT), with normal mean response amplitudes and latencies. Modified afferent innervation pattems requiring weeks to compensate are sufficient to elevate VT, and should be investigated further. Other reversible (sublethal) microgravity effects on sensory epithelia (vacuoles, swelling, etc) require quantification.
- PublicationOpen AccessArchitecture of the mammalian pituitary cholinergic system with observations on a putative blood acetylcholine sensor(Murcia : F. Hernández, 1996) Caffé, A. R.Acetylcholine ( ACh) play s an important role in pituitary gland function. Little is known, however, about the source and trajectory of pituitary ACh, the location of pituitary cholinergic receptors. and the pathways along which the release of pituitary ACh is controlled. Therefore choline acetyltransferase (ChAT) immunoreactive profiles have been investigated in the rat median eminence and pituitary. Furthermore, both muscarinic- (mAChRp-L) and nicotinic receptor proteinlike (nAChRp-L) immunoreactivity have been examined in the rat, rabbit, and cat pituitary. The results have demonstrated that the rat pituitary ChAT network is composed of neurons in the hypothalamic arcuate nucleus and a great number of terminals in the median eminence. In the pituitary, ChAT immunolabeled profiles were virtually absent. This suggests that much of the ACh acting on pituitary cells is released as a humoral factor from the median eminence. Al1 the examined animals expressed mAChRp-L immunostained endocrine cells in the intermediate lobe. Apart from this, marked species differences in AChRp-L immunolabeled profiles have been found. In addition, strong mAChRp-L immunoreactive rod to cone-shaped bodies were detected associated with blood vessels of the anterior and intermediate lobes in the rat and rabbit, but not in the cat. The immunolabeling was present in particles on the body plasma membrane. These characteristics suggest that the function of these structures might be to sense pituitary blood ACh levels. Consequently the name hlood acetylcholine reading hodies (BARBs) was adopted to indicate these stmctures. It is proposed that the BARBs may play a role in the feedback control of ACh release from the median eminence.