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1.
A 42-year-old woman with Cushing's disease was endocrinologically cured after transsphenoidal selective excision of a left-sided microadenoma. Simultaneous samplings from the bilateral inferior petrosal sinuses with ovine corticotrophin-releasing factor (CRF) stimulation were performed preoperatively to evaluate some relations between the localization of a possible microadenoma and the levels of ACTH in inferior petrosal sinuses. The data for the venous samplings were as follows:-(1) The basal levels of ACTH obtained simultaneously from both inferior petrosal sinuses and peripheral vein were about the same. (2) A significant difference, with a high level of ACTH from the ipsilateral side of the microadenoma, was demonstrated after CRF stimulation. (3) The magnitude of increase in ACTH on the contralateral side after CRF was similar to that of the peripheral response. It is recommended that all patients with ACTH dependent Cushing's syndrome and negative radiological findings should have bilateral simultaneous inferior petrosal venous sampling with CRF stimulation. 相似文献
2.
Potassium depletion and hypertonic medium reduce "non-coated" and clathrin-coated pit formation, as well as endocytosis through these two gates 总被引:3,自引:0,他引:3
J L Carpentier F Sawano D Geiger P Gorden A Perrelet L Orci 《Journal of cellular physiology》1989,138(3):519-526
Intracellular potassium depletion inhibits receptor-mediated endocytotic processes occurring through clathrin-coated pits. Besides the clathrin-coated pit route, flask-shaped invaginations that do not bear a typical clathrin coat have been recently implicated in receptor-mediated endocytosis of cholera toxin. These invaginations are called "non-coated" to distinguish them from the typical clathrin-coated pits. In the present study, we have investigated whether "non-coated" invaginations are sensitive, as are clathrin-coated pits, to potassium depletion and whether hypertonic medium, which inhibits receptor-mediated endocytosis, also affects "non-coated" invaginations. We found that 1) both potassium depletion and hypertonic medium reduce "non-coated" invaginations on the cell surface; 2) similar to potassium depletion, hypertonic medium markedly decreases the number of clathrin-coated pits; 3) these changes are accompanied by an inhibition of the internalization (measured morphologically) of cholera toxin-gold through "non-coated" invaginations, as well as of alpha 2-macroglobulin-gold taken up by clathrin-coated pits; and 4) in addition, both the hypertonic medium and potassium depletion inhibit the uptake of horseradish peroxidase, a marker of fluid-phase endocytosis. 相似文献
3.
4.
Mitsuru Iwata Shoko Iwata Mark A. Everett Bryan B. Fuller 《In vitro cellular & developmental biology. Plant》1990,26(6):554-560
Summary A human foreskin organ culture system has been developed to study the response of human skin to hormonal stimulation. Foreskins
are maintained in culture on floating plastic supports which allows the epidermal surface to be exposed to air while the dermis
is bathed in nutrient medium. Both black and white human foreskins can be maintained in organ culture for at least 1 wk with
no change in the tissue structure or cell viability as determined by histochemical staining and by dopa reaction staining.
Tyrosinase activity in both black and white human foreskin cultures decays markedly during the first 2 d of culture to a new
steady state level which remains stable throughout the culture period. Both black and white foreskin cultures consistently
demonstrate 2- to 10-fold increases in tyrosinase activity when treated with theophylline (1 mM). Approximately 90% of all skin cultures examined showed an increase in enzyme activity when treated with this phosphodiesterase
inhibitor. Dibutyryl cAMP (0.1 mM) and [Nle4, D-phe7]-alpha MSH (10−8
M), were also found to markedly stimulate tyrosinase activity in some skin cultures, whereas alpha-MSH and prostaglandin E1 produced only an inconsistent and small increase in the activity of the enzyme. Histamine (1 μM), vitamin D3 (1 μM), and retinoic acid (1μM) failed to stimulate tyrosinase activity in either white or black foreskin cultures. This hormone-responsive organ culture
system can be utilized to characterize the molecular processes responsible for the regulation of tyrosinase and pigmentation
in human skin.
This work was supported by a research contract from the Oklahoma Center for the Advancement of Science and Technology (OCAST)
and by a research grant from the Presbyterian Health Foundation. 相似文献
5.
Shoko Fujiwara Mitsuhiro Sawada Junichiro Someya Nobuhiro Minaka Masanobu Kawachi Isao Inouye 《Journal of phycology》1994,30(5):863-871
The nucleotide sequences of rbcL genes encoding the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) were determined from six species of Prymnesiophyta to clarify their phylogenetic relationships. Molecular phylogenetic trees were constructed using PAUP (Phylogenetic Analysis Using Parsimony). These analyses suggest that the Prymnesiophyta, except for the Pavlovales, area relatively stable monophyletic group. Pleurochrysis carterae, included in the Isochrysidales, is a sister species of a monophyletic group consisting of other members of the Isochrysidales, Gephyrocapsa oceanica and Emiliania huxleyi, members of the Coccosphaerales, Calyptrosphaera sphaeroidea and Umbilicosphaera sibogae var. foliosa, and a member of the Prymnesiales, Chrysochromulina hirta. The nucleotide sequence of rbcL from G. oceanica was identical to that from E. huxleyi within the region examined. Our trees show that G. oceanica and E. huxleyi are more closely related to C. hirta than to U. sibogae, C. sphaeroidea, and P. carterae. These results suggest that orders in the Prymnesiophyceae, including the above-mentioned genera, should be redefined. 相似文献
6.
Kumiko Ui Shoko Nishihara M. Sakuma S. Togashi R. Ueda Y. Miyata T. Miyake 《In vitro cellular & developmental biology. Animal》1994,30(4):209-216
Summary From the central nervous system ofDrosophila melanogaster 3rd instar larvae, eight continuous cell lines have been established (named ML-DmBG1 to 8). Using ML-DmBG2, single colony
isolation was carried out and six colonial clones were obtained. All reacted to the antibody to horseradish peroxidase, which
is a neuronal marker in insects. Acetylcholine, a known neurotransmitter inDrosophila, was detected in three of the colonial clones by high performance liquid chromatography. Therefore, it is concluded that
the established colonial clones are neural cells originating in the larval central nervous system. Among them, some variation
was observed with respect to morphology, acetylcholine content, and reactivity to anti-HRP. The variation may reflect the
heterogeneity of cells composing the central nervous system. 相似文献
7.
8.
Partial purification of growth hormone (GH)-releasing factor (GRF) by acid extraction followed by gel filtration on Sephadex G-25 has been attained from bovine hypothalami. When rat pituitaries were incubated in 2 ml Krebs Ringer-bicarbonate-glucose (KRBG) medium, a stimulatory effect of the GRF fraction on immunoreactive GH (IR-GH) release was observed, while that of the factor neither on GH synthesis nor release of the synthesized GH was demonstrated. Stimulation of the GH release was exerted maximally within 30 min of incubation. Cycloheximide and actinomycin D, at a concentration which inhibited protein and RNA synthesis to less than 5 and 20% of the control, respectively, were without effect on the stimulatory action of the factor on GH release. On the other hand, stimulation of GH synthesis was observed under incubation in 0.3 ml medium with the factor and enhancing effect of the factor on the IR-GH release was undetectable. These results suggest that stimulation of the release and synthesis of GH mediated by the hypothalamic GRF fraction is under influence of the pool size of incubation media. 相似文献
9.
Shoko Nakano Yuko Abe Kimiko Nakajima Shigetoshi Sano Osamu Yamamoto Kazumasa Wakamatsu Shosuke Ito Masahiro Hayashi Tamio Suzuki 《Pigment cell & melanoma research》2021,34(1):101-110
Post‐inflammatory hyperpigmentation (PIH) is a common cutaneous condition that can cause a disfigured appearance. However, the pathophysiology of PIH remains poorly understood, at least in part, because an appropriate animal model for research has not been established. In order to analyze the pathomechanism of PIH, we successfully induced PIH in a hairless version of transgenic mice (hk14‐SCF Tg/HRM) that have a human‐type epidermis containing melanin by repeated hapten application of 2,4‐dinitrofluorobenzene. Histopathologic observation showed epidermal hyperplasia, predominant infiltrations of inflammatory cells, and melanin‐containing cells in the dermis just after elicitation of the atopic dermatitis‐like condition. At week 2, the findings were similar to the characteristics of PIH, that is, an increase of melanin without spongiosis or liquid degeneration in the epidermis and an increase in dermal melanophages. Dynamic analysis of melanin showed that the melanin in the dermis remained for a longer duration than in the epidermis. Furthermore, immunohistochemical staining revealed that the majority of cells containing melanin were positive for the anti‐CD68 antibody, but negative for the anti‐F4/80 antibody. These data suggest that novel treatments of PIH should be targeted against macrophages and should eventually lead to the development of new treatment modalities. 相似文献
10.