Catecholaminergic nuclei of sheep encephalon. Immunocytochemical study. I. Myelencephalon and metencephalon

Using an anti-tyrosine hydroxylase antiserum, the whole of catecholaminergic perikarya of the myelencephalon and metencephalon of the sheep were visualized immunocytochemically. Compared with those of the rat, these neuronal groups in the sheep were featured, firstly, by a greater dispersion relative to their perikarya and, secondly, by the absence of A3 and A4 nuclei described by Dahlstrom and Fuxe.     

Localization of angiotensin converting enzyme (kininase II). II. Immunocytochemistry and immunofluorescence.

The cellular and subcellular sites of angiotensin converting enzyme (kininase II) in lung tissue and endothelial cells in culture were examined by immunocytochemical and immunofluorescence techniques. Converting enzyme is capable of inactivating bradykinin and of converting angiotensin I to its potent lower homolog, angiotensin II. Immunocytochemistry at the electron microscope level used goat anti- (pig lung and angiotensin converting enzyme) coupled to 11-MP (11-microperoxidase) via glutaraldehyde or to 8-MP (8-microperoxidase) via a bifunctional active ester, bis-succinyl succinate. The latter conjugate, which does not contain complex polymers, has been characterized in detail in terms of immunoreactivity and peroxidase activity.     

Immunocytochemistry of the pituitary glycoprotein hormones.

The storage sites of the pituitary glycoprotein hormones were identified with the use of electron microscopic immunocytochemical techniques and antisera to the beta (beta) chains of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and thyroid-stimulating hormone (TSH). The TSH cells in normal rats is ovoid or angular and contains small granules 60-160 nm in diameter. In TSH cells hypertrophied 45 days after thyroidectomy, staining is in globular patches in granules or diffusely distributed in the expanded profiles of dilated rough endoplasmic reticulum. The gonadotrophs (FSH and LH cells) exhibited three different morphologies. Type I cells are ovoid with a population of large granules and a population of small granules. Staining for FSHbeta or LHbeta was intense and specific only in the large granules (diameter of 400 nm or greater). Type II cells are angular or stellate and contain numerous secretory granules averaging 200-220 nm in diameter. They predominate during stages in the estrous cycle when FSH or LH secretion is high. Type III cells look like adrenocorticotropin (ACTH) cells in that they are stellate with peripherally arranged granules. They generally stain only with anti-FSHbeta and their staining can not be abolished by the addition of 100 ng ACTH. In preliminary quantitative studies of cycling females, we found that on serial sections FSH cells and LH cells show similar shifts to a more angular population of cells during stages of active secretion. However, the shifts are not in phase with one another. Furthermore, there are at least 1.5 times more FSH cells than LH cells at all stages of the cycle. Our collection of serial cells shows that some cells (usually type I or II) stain for both gonadotropic hormones, whereas others (usually type II or III) contain only one.     

Immunocytochemistry of the olfactory marker protein.

The olfactory marker protein has been localized, by means of immunohistochemical techniques in the primary olfactory neurons of mice. The olfactory marker protein is not present in the staminal cells of the olfactory neuroepithelium, and the protein may be regarded as indicative of the functional stage of the neurons. Our data indicate that the olfactory marker protein is present in the synaptic terminals of the olfactory neurons at the level of the olfactory bulb glomeruli. The postsynaptic profiles of both mitral and periglomerular cells are negative.     

Catecholaminergic regulation of the hypothalamic-pituitary-adrenocortical activity.

The significance and site of adrenergic receptors involved in the control of the hypothalamic-pituitary-adrenal axis (HPA) activity was assessed indirectly by estimation of serum corticosterone levels 1 h after drug administration to conscious rats. Adrenergic drugs were given intracerebroventricularly (icv) and intraperitoneally (ip), the antagonists 15 min prior to the agonists. Noradrenaline, adrenalin and isoproterenol given by either route increased dose-dependently the serum corticosterone levels. The corticosterone response to icv noradrenaline was almost abolished by icv pretreatment with propranolol, a beta-adrenergic antagonist, and yohimbine, and alpha 2-receptor blocker, and was also considerably reduced by prazosin, an alpha 1-adrenergic antagonist. When given ip, these antagonists did not significantly influence the noradrenaline induced corticosterone response, which suggests a suprapituitary site of action of noradrenaline in stimulation of the HPA. The corticosterone response to icv adrenalin was suppressed by prazosin given by either route. The corticosterone response to ip adrenalin was almost abolished by pretreatment with yohimbine, and also significantly diminished by propranolol given by the same route. The increase in corticosterone secretion, induced by isoproterenol given by either route, was abolished by ip injection of propranolol. These results indicate that noradrenaline stimulates the HPA via alpha- and beta-adrenergic receptors, mainly at the suprapituitary level. Adrenalin increases that activity both via central and pituitary alpha- and beta-adrenoceptors. Isoproterenol activates the HPA by stimulation of pituitary beta-receptors.     

Immunocytochemistry and DNA-image cytometry in diagnostic effusion cytology. II. Diagnostic accuracy in equivocal smears.

To determine sensitivity and specificity of different antibodies for the immunocytochemical detection of malignant cells in diagnostically equivocal effusions in comparison with those achieved by DNA-image cytometry. 65 cytologically doubtful effusions of the serous cavities were stained with twelve antibodies. Furthermore, DNA-image cytometry was performed. Data were correlated with patient follow-up. Sensitivity of cellular staining of Ber-EP4 for the identification of malignant cells was 77.8%, specificity of absent staining for benign cells was 100%. Positive predictive value for the identification of malignant cells was 100%, negative value 65.5%. Sensitivity of DNA-aneuploidy for the identification of malignancy was 82.9%, specificity of DNA-non-aneuploidy for benignity 94.7%. The positive predictive value of DNA-aneuploidy for the occurrence of malignant cells was 96.7%. Negative predictive value of DNA-non-aneuploidy was 72.0%. Combining immunocytochemistry applying Ber-EP4 only and DNA-cytometry in equivocal effusions resulted in a sensitivity of 88.9% for the identification of malignant cells associated with a 95.0% specificity. Positive predictive value was 97.7%, the negative one 79.2%.     

Immunocytochemistry of Rhamnogalacturonan II in Cell Walls of Higher Plants

A polyclonal antibody against a borate-RG-II complex is raisedin rabbits. The antibody recognized RG-II exclusively in cellwall polysaccharides. Immunocytochemical studies demonstratedthat the epitope is ubiquitous in cell walls of all the cellsin radish and rice roots, cultured tobacco cells, red cloverroot nodules, and lily growing pollen tubes. The label was denserin proximal to plasma membrane, and not detected in middle lamella,suggesting that borate may cross-link newly secreted pecticpolysaccharides at the membrane-cell wall interface. (Received October 13, 1997; Accepted February 16, 1998)     

Embryology of the sheep. II. The alimentary tract and associated glands

The day-by-day development of the alimentary system of the sheep embryo from 14 to 34 days is documented and described. This includes development of the mouth, the pharynx and its derivatives, esophagus, stomach, intestine, cecum, pancreas and liver. This work provides standards within the normal range of development of the ovine alimentary system on which studies of abnormal development can be based.     

Expression of en in the Prosencephalon Heterotopically Transplanted into the Mesencephalon

The alar plate of the prosencephalon differentiates into a tectum-like structure when transplanted and integrated into the mesencephalon around 10-somite stage. Homeobox containing gene, en , is expressed in the mesencephalon with caudorostral gradient from 7-somite stage. Here expression of en in the prosencephalic transplant in the mesencephalon was studied immunohistochemically with anti- en antibody. Transplantation was carried out between quail and chick. It was shown that the transplant was stained with anti- en antibody at the caudal part of the mesencephalon. At the rostral part, the transplant did not express en . When the transplant was not contiguous to the caudal part of the host mesencephalon, it did not express en . The present study suggests that the prosencephalic transplant differentiates into the tectum-like structure when it expresses en at the caudal part of the mesencephalon.     

Influence of Feeding Paradigm in Rats on Temporal Pattern of: II. Brain Serotoninergic and Catecholaminergic Systems

The relationship between the feeding paradigm (single diet versus food selection) and central idoleamines and catecholamines was studied. Temporal patterns of the brain parameters in response to presentation of a single diet of fixed composition (20% casein) or a choice between two isocaloric diets (0% and 60% casein) for 2 weeks under 8-h feeding cycles during the dark phase were measured in adult Sprague-Dawley rats. Groups of animals were then killed at the beginning and at 2-h intervals throughout the feeding period. The distribution and the temporal pattern of variation of the serotoninergic and the catecholaminergic parameters studied were significantly affected by the diet paradigms used. A different neurochemical equilibrium was observed before food intake and was characterized by a central serotoninergic predominance in subjects having a dietary selection experience but a central catecholaminergic predominance in animals adapted to a single diet. Hypothalamic and extrahypothalamic serotoninergic and catecholaminergic systems were found to intervene in an interdependent way, sometimes antagonistic according to the feeding paradigm and the related temporal changes in energy intake and macronutrient selection. These results suggest that central serotoninergic and catecholaminergic systems are influenced by the diet paradigm and display characteristic patterns of temporal variations during the feeding cycle. The feeding paradigm, per se, should then be considered as a potential synchronizer of central biological rhythms of monoamines, which in turn may affect food intake and appetite for macronutrients.     

Organization of diencephalon of the sturgeons. Preoptic area

Cytoarchitectonics of preoptic area of diencephalon of chondroid ganoid fish (the sturgeons) was studied in serial sections using Nissl and Bilschowski techniques, the latter in Viktorov’s modification). The preoptic area of the hausen, Huso huso L., Kura sturgeon, Acipenser guldenstaedtii persicus n. kurensis Belyaeff, Caspian sturgeon, Acipenser stellatus Pall. and the sturgeon Acipenser nudioventris Lov. was shown to be one of the largest parts of diencephalon. It is located along the rostral excess of the third ventricle and the anterior third of the ventricle thalamic part. Eight nuclei are identified in the preoptic area: (1) anterior microcellular preoptic nucleus, (2) suprachiasmatic nucleus, (3) accessory preoptic nucleus, (4) intrachiasmatic nucleus, (5) magnocellular preoptic nucleus, (6) posterior microcellular preoptic nucleus, (7) caudal preoptic nucleus, (8) entopeduncular nucleus. Besides, microcellular, magnocellular, and gigantocellular parts are identified in the magnocellular preoptic nucleus. The obtained results indicate high differentiation of this area of the sturgeons among Actinopterygii.     

Properties of inactive Photosystem II centers

A fraction (usually in the range of 10–25%) of PS II centers is unable to transfer electrons from the primary quinone acceptor Q_A to the secondary acceptor Q_B. These centers are inactive with respect to O₂ evolution since their reopening after photochemical charge separation to the S₂O_A^- state involves predominantly a back reaction to S₁Q_A in the few seconds time range (slower phases are also occurring). Several properties of these centers are analyzed by fluorescence and absorption change experiments. The initial rise phase F_o-F_pl of fluorescence induction under weak illumination reflects both the closure of inactive centers and the modulation of the fluorescence yield by the S-states of the oxygen-evolving system: We estimate typical relative amplitudes of these contributions as, respectively, 65 and 35% of the F_o-F_pl amplitude. The half-rise time of this phase is significantly shorter than for the fluorescence induction in the presence of DCMU (in which all centers are involved). This finding is shown to be consistent with inactive centers sharing the same light-harvesting antenna as normal centers, a view which is also supported by comparing the dependence of the fluorescence yield on the amount of closed active or inactive centers estimated through absorption changes. It is argued that the exponential kinetics of the F_o-F_pl phase does not indicate absence of excitation energy transfer between the antennas of inactive and active centers. We show that the acceptor dichlorobenzoquinone does not restore electron transfer in inactive centers, in disagreement with previous suggestions. We confirm, however, the enhancement of steady-state electron flow caused by this quinone and suggest that it acts by relieving a blocking step involved in the reoxidation of a fraction of the plastoquinone pool. Part of the discrepancies between the present results and those from previous literature may arise from the confusion of inactive centers characterized on a single turnover basis and PS II centers that become blocked under steady-state conditions because of deficient reoxidation of their secondary acceptors.Abbreviations DCBQ 2,6-dichloro-p-benzoquinone - DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea - DMQ 2,5-dimethyl-p-benzoquinone - PS photosystem