Biomedical subjects
J Appelbaum
Publications and source records attributed to J Appelbaum.
In vivo phosphorylation of the lamin B receptor. Binding of lamin B to its nuclear membrane receptor is affected by phosphorylation.
Previous studies have shown that the nuclear envelope of avian erythrocytes contains a 58-kDa integral membrane protein (p58) which serves as a receptor for the karyoskeletal protein lamin B (Worman, J. H., Yuan, J., Blobel, G., and Georgatos, S. D. (1988) Proc. Natl. Acad. Sci. U. S. A. 85, 8531-8534). We now demonstrate that p58 is phosphorylated in vivo at serine residues and that its phosphorylation is stimulated by isoproterenol in a dose-dependent fashion. We further show that dephosphorylation of p58 reduces significantly its binding to lamin B. These data suggest that phosphorylation may constitute one of the major mechanisms regulating the lamina-nuclear membrane interactions.
Pericarotid cluster headache.
Cluster headache is generally not associated with recognised disease, and the pathogenesis remains unclear. The onset of typical cluster headaches is reported in a patient with nasopharyngeal carcinoma. The tumor encircled the internal carotid artery but did not extend intracranially. It thus appears possible that cluster headaches may be triggered by processes involving the carotid artery.
Inhibition of the inductive activity of demineralized bone matrix by different percutaneous implants.
Teflon tubes with either Gore-Tex (PTFE) or Dacron felt sleeves were implanted percutaneously in rats, in conjunction with demineralized bone matrix. This resulted in different inflammatory reactions, as well as in chondrogenesis and osteogenesis in the subcutaneous tissues. Although induction of osteogenesis by the demineralized bone matrix in the vicinity of the foreign material was inhibited, circumferential bone formation was highly reproducible. The prospect of utilizing demineralized bone matrix in order to enhance acceptance of percutaneous tubes is discussed.
How to solder nonprecious alloys.
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Hormone receptors in breast cancer.
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Inhibition of growth of mouse ehrlich ascites by normal tissue extracts.
A dialyzable component from the aqueous extracts of mouse skeletal muscle and liver inhibited in vitro growth of a mouse Ehrlich ascites. A similar component was not detected in extracts of spleen, kidney, lung, skin, serum or small intestine. The muscle component appeared to be different from that of the liver in its resistance to heat and its stability in the culture medium. Both components however were stable on storage at 4, 23 and 37 degrees C for 72 h. Intraperitoneal injection of the muscle and liver component into mice previously innoculated with Ehrlich ascites significantly decreased tumor incidence in these animals as compared with the control.
Enolase catalyzed beta,gamma-alpha,beta isomerization of 2-phospho-3-butenoic acid to (Z)-phosphoenol-alpha-ketobutyrate.
2-Phospho-3-butenoic acid was synthesized and found to be a substrate for both yeast and rabbit muscle enolase (EC 4.2.1.11). Enolase catalyzes the isomerization of 2-phospho-3-butenoic acid to (Z)-phosphoenol-alpha-ketobutyrate, a beta,gamma-alpha,beta isomerization. Nuclear magnetic resonance studies on the product indicate only one isomer is formed. This reaction provides indirect evidence in further support of a carbanion intermediate for the enolase reaction. 2-Phospho-3-butenoic acid is also a good competitive inhibitor of both yeast and rabbit muscle pyruvate kinase (EC 2.7.1.40).
Subcellular morphological changes in the rat kidney after phosphorus burn.
Experimental phosphorus burns were performed on male rats, in order to evaluate the subcellular changes which had occurred as a result of their lesions. In addition to the external wound caused by the burn itself, pathological changes were observed macroscopically and microscopically in various body organs, mainly the kidneys. These were investigated under the electron microscope for subcellular alterations at their damaged sites, and for biochemical aberrations that were observed in those rats. In the phosphorus-burnt rats the glomeruli were ischemic, showed capillary collapse and exhibited proliferation of mesangial areas and basement membrane thickening. Many necrotic cells were observed in the proximal tubule, where large vacuoles containing myelin-like structures were identified. The lumen of the proximal tubules were completely occluded by cell debris and the cytoplasm was necrotic. Due to the damage caused to the glomeruli, high concentrations of serum urea, serum SGPT and PO-4 were assayed in the phosphorus-burnt rats. These changes may account for the high mortality rate after phosphorus burns and may further understanding of the damage as well as ways of approaching it.
Biochemistry, histopathology and treatment of phosphorus burns. An experimental study.
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Informed consent: nursing issues and ethical dilemmas.
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