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371.
372.
If that portion of a chick embryo destined to form the eye, the lens, part of the brain and the surrounding head region be removed from the chick before the lens has begun to develop, and placed in a liquid culture medium for four days, a structure resembling the lens will form in appropriate proximity to the presumptive retina, and the cells of the lens will synthesize proteins unique to and characteristic of the lens. The time course of morphological development of such explants is here described. In vitro the lens placode dose not invaginate to form a lens vesicle, as it does in ovo. Instead placode cells elongate directly to form fibre cells. The shape of the lens formed in this aberrant manner is remarkably similar to that of normal lens. At least one, and probably all three, of the characteristic crystallins of the lens form in these aberrant lenses, the cytological and biochemical differentiation of which proceeds normally, despite failure of the normal morphogenetic activities of the organ. 相似文献
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Thermoregulatory and motor activity circadian cycles are age-dependent. While the level of thermoregulation and motor activity remained almost at the same level during the first 1–15 months during the light portion of the 24-hr cycle, a significant decrease in the level of both rhythms was observed during the dark period. Therefore, older rats exhibited reversed cycles compared with younger rats. Treatments with d-amphetamine resulted in the enhancement of reversal of the cycles. Rats treated with α-MSH failed to exhibit a reversal of the cycles. While the effects of d-amphetamine are mediated by the brain DA mesolimbic pathway, it seems that α-MSH acts on the dopaminergic system at different sites of action. 相似文献
376.
The lethality of T-2 toxin to adult femaleAedes aegypti mosquitoes was investigated using various methods of application: Topically, by injection, and by natural feeding. The technique of topical application was found to be the most precise, whereby an LD50 of 565 ng T-2 toxin/mosquito was determined. 相似文献
377.
An auxanographic technique is described, which makes it possible to screen 2(n) combinations of nutrients on relatively few agar plates. 相似文献
378.
A 37-year-old male patient with advanced refractory plasma cell myeloma underwent T-cell depleted bone marrow transplantation (BMT) after 7 years of active disease previously treated with combination chemotherapy and irradiation. After the BMT there was marked clinical improvement and the patient is currently in good clinical condition two years after the BMT was performed. However, residual myeloma cells are still seen in the marrow and stable levels of paraprotein are still present in the serum. No GVHD was encountered after BMT. The problems of BMT in myeloma are discussed with a review of the current pertinent literature. 相似文献
379.
Hasan Ishtayeh Margarita Galves Tania T. Barnatan Yevgeny Berdichevsky Fatima Amer-Sarsour Metsada Pasmanik-Chor Itzhak Braverman Sergiu C. Blumen Avraham Ashkenazi 《Aging cell》2023,22(10):e13949
Autophagy is an intracellular degradative process with an important role in cellular homeostasis. Here, we show that the RNA binding protein (RBP), heterogeneous nuclear ribonucleoprotein Q (HNRNPQ)/SYNCRIP is required to stimulate early events in autophagosome biogenesis, in particular the induction of VPS34 kinase by ULK1-mediated beclin 1 phosphorylation. The RBPs HNRNPQ and poly(A) binding protein nuclear 1 (PABPN1) form a regulatory network that controls the turnover of distinct autophagy-related (ATG) proteins. We also show that oculopharyngeal muscular dystrophy (OPMD) mutations engender a switch from autophagosome stimulation to autophagosome inhibition by impairing PABPN1 and HNRNPQ control of the level of ULK1. The overexpression of HNRNPQ in OPMD patient-derived cells rescues the defective autophagy in these cells. Our data reveal a regulatory mechanism of autophagy induction that is compromised by PABPN1 disease mutations, and may thus further contribute to their deleterious effects. 相似文献
380.
Neutralizing Activity of Broadly Neutralizing Anti-HIV-1 Antibodies against Primary African Isolates