By use of reverse transcriptase-polymerase chain reaction, abundant expression of the mRNA of 27 kDa heat shock protein (Hsp27) was revealed in the sympathetic and parasympathetic ganglia as well as in the sensory ganglia of unstressed adult rats. In situ hybridization and immunohistochemistry further localized Hsp27 mRNA and protein to both neurons and satellite cells in all types of ganglia examined. Schwann cells in the ganglia and peripheral nerve fibers were devoid of Hsp27 signal. These results suggested that Hsp27 is constitutively expressed in neurons and satellite cells in the entire peripheral nervous system of the rat.
Retinoic acid (RA) is a meiosis-inducing factor. Primordial germ cells (PGCs) in the developing ovary are exposed to RA, resulting in entry into meiosis. In contrast, PGCs in the developing testis enter mitotic arrest to differentiate into prospermatogonia. Sertoli cells express CYP26B1, an RA-metabolizing enzyme, providing a simple explanation for why XY PGCs do not initiate meios/is. However, regulation of entry into mitotic arrest is likely more complex. To investigate the mechanisms that regulate male germ cell differentiation, we cultured XX and XY germ cells at 11.5 and 12.5 days postcoitus (dpc) with an RA receptor inhibitor. Expression of Stra8, a meiosis initiation gene, was suppressed in all groups. However, expression of Dnmt3l, a male-specific gene, during embryogenesis was elevated but only in 12.5-dpc XY germ cells. This suggests that inhibiting RA signaling is not sufficient for male germ cell differentiation but that the male gonadal environment also contributes to this pathway. To define the influence of Sertoli cells on male germ cell differentiation, Sertoli cells at 12.5, 15.5, and 18.5 dpc were aggregated with 11.5 dpc PGCs, respectively. After culture, PGCs aggregated with 12.5 dpc Sertoli cells increased Nanos2 and Dnmt3l expression. Furthermore, these PGCs established male-specific methylation imprints of the H19 differentially methylated domains. In contrast, PGCs aggregated with Sertoli cells at late embryonic ages did not commit to the male pathway. These findings suggest that male germ cell differentiation is induced both by inhibition of RA signaling and by molecule(s) production by embryonic age-specific Sertoli cells.
There is problems that an electrical rotating machine loses it’s the output and driving efficiency due to overheating during rotating. Therefore, the improvement of heat removal capacity needs to know the internal flow and heat transfer characteristics. The internal structure of the rotating machine has coaxial cylinders consisting of the inner cylinder and outer cylinder. This study produced three shapes of the rotating coaxial cylinders. By performing a visualization using Kalliroscope flakes, the effect of the shape variation on flow characteristics was investigated.
By immunolight and electron microscopy, the epithelioid, granule-containing cells within the wall of circumscribed portions of the thoracic aorta, the common carotid artery, the carotid body artery and those composing the carotid body itself of newly hatched chicks were shown to contain serotonin (5-HT), neuropeptide tyrosine (NPY) and tyrosine hydroxylase (TH). No nerve fibres immunoreactive for any of these three substances were found in relation to the granule-containing cells. All the granule-containing cells were immunoreactive for 5-HT. The proportion of 5-HT cells simultaneously immunoreactive for NPY or TH in the total cell population varied in different portions of the arteries and the carotid body: NPY-immunoreactive cells were more numerous in the thoracic and common carotid arterial walls, while TH-immunoreactive cells were much more numerous in the carotid body. Since the granule-containing cells within the arterial wall, because of similarities in their anatomical features to the carotid body, are presumed to function as the arterial chemoreceptor, the difference in content of the amines and peptides among the granule-containing cells in different locations may reflect some differences in the chemoreceptive mechanism between the cells in different locations along the thoracocervical arterial tree.
Co-localization of angiotensin II (A II) and renin in the growth hormone (GH)-containing cells of the bovine pituitary has been immunohistochemically demonstrated. A II has recently been shown to be present in the pituitary and involved in the regulation of secretion of pituitary hormones in addition to the classical physiological functions in the general circulation. To identify A II-producing cells, sections of the bovine pituitary were stained for the presence of A II and renin, an enzyme responsible for the formation of A II, using the avidin-biotin-peroxidase complex method. Anti-A II revealed a widespread distribution of moderately stained cells. Most of these A II-positive cells were also A II. Furthermore, co-localization studies indicated that the majority of A II- and reninstained cells were GH-immunoreactive. These results provide visual evidence for the intracellular formation of A II in the bovine pituitary where it helps to coordinate the secretion of other hormones.
Toward the improvement of performance of the air-cooled generator, an appropriate design for the heat removal is important. The present study numerically clarifies the flow behavior and heat transfer characteristics in rotating coaxial cylinders simulated a salient-pole rotor within the air-cooled generator. The same vortex structure as flow visualization was identified. Heat transfer coefficient on the trailing side wall near separated flow was lower than that on the leading side wall. It is implied that temperature on the wall near separated flow increased because of flow congestion at separated flow region.
