CCK-immunoreactive terminals form different types of synapses in the rat and monkey hippocampus

Electronmicroscopic immunocytochemical analysis of the types and patterns of synaptic contacts formed by cholecystokinin (CCK)-containing terminals in the CA1 and CA3 region of the rat and monkey hippocampus reveals numerous symmetric synaptic contacts on cell bodies and dendritic shafts of pyramidal cells in both species. In the monkey, however, CCK-immunoreactive terminals also form asymmetric synaptic contacts with dendritic spines, such contacts are absent or very rare in the rat hippocampus. The present finding in primate hippocampus provides evidence that the same neuropeptides can be found in both symmetric and asymmetric contacts and may be added to other evidence challenging the traditional concept that symmetric synapses mediate exclusively inhibitory and asymmetric exclusively excitatory transmission. Furthermore, although our comparative analysis confirms considerable similarities in the distribution of CCK-containing elements in primate and rodent hippocampus it also revealed a potentially important difference in synaptoarchitecture that should be taken into account in extrapolations from one species to the other.     

Catecholamine-containing neurons in the peripheral nervous system of Aplysia

Numerous green-fluorescent neurons have been revealed by means of the glyoxylic acid histochemical method in cryostat sections of several organs of two Adriatic aplysiid gastropods, Aplysia depilans and A. fasciata. Catecholamine-containing perikarya and their processes have been found to be especially abundant in the vaginal portion of the large hermaphrodite duct, in the penis and its sheath, and in the gill. In the reproductive organs, two subpopulations of catecholamine-containing neurons could be distinguished according to their size and location. Axons of larger neurons formed bundles which seemed to project at the CNS.     

Transneuronal degeneration in the Rolando substance of the primate spinal cord evoked by axotomy-induced transganglionic degenerative atrophy of central primary sensory terminals

Summary Transection of the sciatic nerve in Rhesus monkeys and the consequent transganglionic degenerative atrophy (TDA) of central terminals of primary afferents result in transneuronal degeneration of substantia gelatinosa (SG) cells. Severe degeneration is characterized by an increased electron density of the nucleus and by conspicuous shrinkage of the cytoplasm, mitochondrial swelling, dilation of cisterns of the rough-surfaced endoplasmic reticulum, accumulation of free ribosomes and an electron-dense material in the cytoplasm. In the mild form, dilation of cisternal elements of the endoplasmic reticulum, swollen mitochondria and accumulation of free ribosomes takes place. About 10% of SG cells in segment L₅ undergo the severe form whereas the rest shows signs of the mild form. Cytoplasmic alterations that occur during transneuronal degeneration seem to start at the level of subsurface cisterns. Dendrites and axons of transneuronally degenerating SG cells also show a conspicuous electron density. By analyzing the synaptic relationships of such darkened dendrites, connections in the upper dorsal horn can be deciphered. Modular units of the primary nociceptive analyzer that evaluate noxious and innocuous inputs on the basis of thin versus thick (AC/A) afferent activity and subjecting them to descending control appear to be recruited from structurally dispersed elements of synaptic glomeruli. These are arranged alongside dendritic processes of large antenna cells which relay impulses to projection cells of the spinothalamic tract.     

Structural and functional homology between the 29 kD rat liver nucleoprotein and the high mobility group 1 protein

A 29 kD soluble rat liver nucleoprotein (p29) has increased binding affinity for the hormone responsive element (RE) of the rat haptoglobin (Hp) gene during the acute-phase reaction. In this work the possibility of its structural and functional homology to the high mobility group 1 (HMG1) nonhistone protein constituent of chromatin was examined. The results of two-dimensional gel electrophoresis, Southwestern and Western immunoblot analyses, showed that p29 and HMG1 are homologous protein species. On the basis of in vitro and in vivo phosphorylation/dephosphorylation experiments, we discuss the modulatory role of phosphate groups in view of the structure and function of p29.     

Distinct functions of alpha3 and alpha(v) integrin receptors in neuronal migration and laminar organization of the cerebral cortex

Changes in specific cell-cell recognition and adhesion interactions between neurons and radial glial cells regulate neuronal migration as well as the establishment of distinct layers in the developing cerebral cortex. Here, we show that alpha3beta1 integrin is necessary for neuron-glial recognition during neuronal migration and that alpha(v) integrins provide optimal levels of the basic neuron-glial adhesion needed to maintain neuronal migration on radial glial fibers. A gliophilic-to-neurophilic switch in the adhesive preference of developing cortical neurons occurs following the loss of alpha3beta1 integrin function. Furthermore, the targeted mutation of the alpha3 integrin gene results in abnormal layering of the cerebral cortex. These results suggest that alpha3beta1 and alpha(v) integrins regulate distinct aspects of neuronal migration and neuron-glial interactions during corticogenesis.     

Influence of cytology development on frequency of pre-cancerous lesions and cervical cancer in east Croatia, 1978-2001

We analyzed the influence of cytology development to frequency of precancerosa (Cervical intraepithelial neoplasia grade 3 - CIN 3) and cervical cancer. The number of examined Pap smears increased significantly in the analyzed period. The calculated linear trend shows an average four-year increase of 17,283.35 smears. The number of detected CIN 3 increased accordingly. The calculated linear trend shows an average four-year increase by 45.03 and decrease of the rate of 0.07. A slight increase in cervical cancer was also noticed. The calculated linear trend shows an average four-year increase in cancer by 1.6 and decrease in the rate of 0.51. Analyses of cervical cancer by stages showed an increase in number of stage I and decrease of other stages. The calculated linear trend shows an average four-year increase of stage I by 4.94 or decrease in other stages of cervical cancer of 3.29 respectively. The rate of cervical cancer stage I decreased by 0.11 and of other stages by 0.39. Further analyses of the stage I showed that the linear trend of IA stage had an average four-year increase by 5.40 and decrease in stage IB of 0.48. The rate of the cervical cancer stage IA increased by 0.02, whereas the rate of IB decreased by 0.13. Cytology development in our country has resulted in detection of higher number of CIN 3 and the earliest stage (IA) of cervical cancer whereas the number of other stages (IB, II, III, IV) has decreased. However, a total number of cervical cancers haven't changed over the whole period. Thus, it is obvious that opportunistic program of detection, which has been using in Croatia, could not decrease frequency of cervical cancer. In order to achieve it, well-organized national program of detection is needed.     

Diagnostic value of cytology and colposcopy for squamous and glandular cervical intraepithelial lesions

The main objective of work was to determine a diagnostic value of cytology and colposcopy as a method of screening and differential diagnosis, as well as to determine the relative value of some colposcopic features of squamous and glandular cervical intraepithelial lesions. Cytological diagnosis and colposcopy findings is compared with histological ones for 187 patients with intraepithelial lesions (142 squamous and 45 glandular ones with or without squamous components) and determined the sensitivity and positive predictive value of cytology and colposcopy, including the types of colposcopic abnormalities associated with squamous/glandular intraepithelial lesions. The sensitivity of cytology as a screening method for SIL (squamous intraepithelial lesions) is 89% and for GIL (glandular intraepithelial lesions) 98%. Positive predictive value of differential cytology for SIL is 59% and for GIL 53%. Sensitivity of colposcopy for both lesions' type is 87%. Acetowhite epithelium occurs for more often with SIL, whereas atypical vessels and unequal, dilated gland openings with GIL (p < 0.05). Cytology and colposcopy as screening methods have a high sensitivity. Nevertheless, cytology is far more accurate in determining differential diagnosis of SIL than GIL and some colposcopy abnormalities suspicious of GIL should be further tested in praxis.     

Induction of a senescent-like phenotype does not confer the ability of bovine immortal cells to support the development of nuclear transfer embryos

Previously, we reported that cloned embryos derived from an immortalized bovine mammary epithelial cell line (MECL) failed to develop beyond 12- to 16-cell stage. To analyze whether induction of a senescent-like phenotype in MECL can improve their ability to support the development after transfer into enucleated oocytes, we treated MECL with DNA methylation inhibitor 5-aza-2-deoxycytidine (Aza-C), histone deacetylase inhibitors trichostatin A (TSA), sodium butyrate (NaBu), or 5-bromodeoxyuridine and used those cells for nuclear transfer. Primary bovine fetal fibroblasts (BFF) were used as control. All agents were capable to induce features of senescence including reduced cell proliferation, enlarged cell size with a considerable proportion of cells stained positive for acidic senescence-associated beta-galactosidase and G1/S cell cycle boundary arrest in MECL. Aza-C treatment induced genome demethylation. Acetylation of H3 and H4 was increased after TSA treatment in both MECL and BFF, whereas no obvious changes in global H3 or H4 acetylation were detected after NaBu treatment. Nuclear transfer experiments following diverse treatments demonstrated that the induced senescent-like phenotype of MECL did not confer their ability to support embryonic development, although 7.3% of reconstructed embryos derived from NaBu-treated cells developed to morula stage. Intriguingly, a much higher proportion of cloned embryos developed to blastocysts when using NaBu-treated BFF, compared with using untreated BFF (59% versus 26%). Our results suggest that the developmental failure of donor nuclei from bovine immortal cells could not be reversed by induction of senescent-like phenotype. The beneficial effect of NaBu on the developmental potential of cloned embryos reconstructed from BFF merits further studies.