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Biomedical subjects

J Feinberg

Publications and source records attributed to J Feinberg.

123 records · Page 7Linked to original sources
PubMed1983

Evolution of Ca2+- and cAMP-dependent regulatory mechanisms during ram spermatogenesis.

Calmodulin level and cAMP-dependent protein kinase activity of ram germ cells at different stages of spermatogenesis have been determined. Calmodulin levels decrease during maturation. Simultaneously, calmodulin localization changes during cell differentiation. In round, elongating, and elongated spermatids, calmodulin is closely associated with the developing acrosome; in spermatozoa, it becomes present in the postacrosome, the neck region and the tail. Protein kinase activity is relatively low in testicular cells but increases dramatically during epididymal maturation of spermatozoa. A concerted regulation by cAMP and Ca2+ of biochemical events in spermatogenic cells and spermatozoa is suggested.

Animals↗
PubMed1982

Team care for patients with chronic rheumatic disease.

Team care is commonly used in the management of patients with chronic rheumatic disease. The specialization of team members can improve patient care and increase efficiency. By enhancing patient rapport and providing optimal opportunities to reinforce instructions, team integration can provide further advantages. In addition, integrated team care can reduce obstacles to compliance, improve patient attitudes, decrease conflicts between treatment goals of various team members, and increase opportunities for feedback among team members. Guidelines are offered for the formation and operation of a rheumatology team.

Attitude to Health↗
PubMed1981

Immunocytochemical and biochemical evidence for the presence of calmodulin in bull sperm flagellum. Isolation and characterization of sperm calmodulin.

Upon fluorescent staining with a goat antibody anti-ram testis calmodulin, washed bull sperm appears to contain calmodulin in the acrosome, in the post acrosomal region, in the neck region probably associated with the implantation plates and thin laminated fibers, and in a sheath around the upper part of the flagellum. Heads and midpieces + tails were separated by elutriation of sonicated sperm. Immunofluorescent labeling of fragments confirms the presence of calmodulin in implantation plates, where sonication disrupted heads from midpieces, and in a sheath around the midpiece and the upper part of the principal piece. These results were confirmed by electrophoretic and radioenzymatic assays of calmodulin in the fragments, using calmodulin-deficient Ca2+/calmodulin-dependent myosin light chain kinase. Small but significant amounts (approx. 3 micrograms per 10 (10) sperm) are found in midpieces + tails vs. approx. 280 micrograms in the same number of heads. These results are in agreement with a recent report from Jones et al. (1980) Proc. Natl. Acad. Sci. U.S.A. 77, 2772-2776. Sperm calmodulin was purified from a whole sperm 1 M KCl extract and found to exhibit the same characteristics as other mammalian calmodulins isolated so far in terms of ultraviolet absorption spectrum and amino acid composition, including one residue of epsilon-N-trimethyllysine. Its behavior upon SDS-polyacrylamide gel electrophoresis was dependent on the presence or absence of Ca2+. The high performance liquid chromatography tryptic peptide maps were similar, if not identical, to mammalian calmodulin maps (Autric et al. (1980) Biochim. Biophys. Acta 631, 139-147). Sperm calmodulin is therefore probably identical to the somatic cell protein.

Amino Acids↗
PubMed1981

Structural studies on yeast 3-phosphoglycerate kinase. Linear arrangement of the CNBr fragments, partial amino acid sequence of the inner part of the polypeptide chain, and analyses of the N-terminal domain of the protein.

The purpose of this work was to contribute to the study of the covalent structure of yeast 3-phosphoglycerate kinase. First, we undertook the complete alignment of the four fragments produced by cyanogen-bromide cleavage and which constitute the intact protein; we then established the total amino acid sequence of a 30-residue peptide and the N-terminal sequence of a 65-residue peptide. Second, we analyzed the acetylated state of the protein. The analyses of the acid fraction "P" obtained after digestion of 3-phosphoglycerate kinase by pronase enabled us to determine the N-terminal sequence of this enzyme as N-acetylserylglycine. Third, we isolated, purified and analyzed seven tryptic peptides from a fragment containing 102 amino acids coming from the N-terminal end of the protein. The peptides occupying the N- and C-terminal ends of this fragment were also identified.

Amino Acid Sequence↗
PubMed1981

Use of resting splints by patients with rheumatoid arthritis.

A follow-up evaluation of 50 patients with rheumatoid arthritis who were fitted with full bilateral wrist and hand resting splints revealed that 62 percent wore them most or all of the prescribed time. Patients deviated from the prescribed splint program when their symptoms remitted or diminished, and adhered more closely to the program when they experienced persistent inflammation. Patients splinted during a hospital stay were somewhat more compliant than those splinted as outpatients. Patients judged to be noncompliant discontinued splint usage because of a decrease of joint pain or stiffness, or both. Their decision did not appear detrimental, since, during the course of the study, there was no significant difference between compliant and noncompliant patients in range of motion of hand or wrist joints at followup evaluation and, when range of motion at the time of initial evaluation was compared with that at the follow-up examination, a higher proportion of noncompliant (37%) than compliant patients (16%) showed improvement.

Adolescent↗
PubMed1978

Structural studies on yeast 3-phosphoglycerate kinase. Isolation by affinity chromatography and characterization of the peptides produced by cyanogen bromide cleavage. Location of the single cysteinyl residue in the primary structure.

Cyanogen bromide cleavage of yeast 3-phosphoglycerate kinase yielded four fragments which account for the amino acid composition of the entire molecule. These results are consistent with a single polypeptide chain of molecular weight 42 000. Affinity chromatography on Sepharose-mercurial followed by gel filtration on Sephadex was used with success for separation of peptides. The carboxyl and N-terminal fragments were characterized. The N-terminal fragment contained the single cysteinyl residue of the protein. After cyanylation and subsequent cleavage, this cysteinyl residue was located near position 100.

Amino Acid Sequence↗
PubMedDate not supplied

Effect of surgery on the nontreated hip in severe cerebral palsy.

We studied the fate of the nonoperated hip in 35 patients with cerebral palsy who underwent surgical stabilization for unilateral hip subluxation (24 patients) or dislocation (11 patients). Review of medical records and radiographs was performed and analysis was accomplished on the effect of preoperative and radiographic variables on the radiographic outcome of the nonoperated hip. The average age at surgery was 5.5 years and at follow-up was 9.7 years, with an average follow-up of 4.2 years. Before subsequent surgery (in 15 nonoperated hips) or at follow-up, 10 of the nonoperated hips were dislocated and 16 hips were subluxated. Hips were stable and less likely to have surgery if they had a lower initial migration index and higher center edge angles. We conclude that there are few indications for unilateral hip surgery in patients with diplegia or quadriplegia undergoing initial hip stabilization surgery, especially if any degree of dysplasia is present.

Adolescent↗
PubMedDate not supplied

Correlations between biological activity and structural properties for two short homologous sequences in thymosin beta4 and gelsolin.

Gelsolin and thymosin beta4 appear to be two important actin-associated proteins involved in the regulation of actin polymerization. It has been widely demonstrated that thymosin is the major cellular actin-sequestering factor shifting the polymerization equilibrium of actin towards a monomeric state. At the same time gelsolin, a Ca2+ and inositol phosphate sensitive protein, regulates actin filament length. The interactions of these two proteins with actin are rather complex and require the participation of several complementary peptide sequences. We have identified a common motif, (I, V)EKFD, in the two proteins in the functional sequences so far examined. Gelsolin- and thymosin beta4-related peptides including the common motif were synthesized and their structural and functional properties studied. These two sequences exert a major inhibitory effect on salt-induced actin polymerization. We used circular dichroism and Fourier-transform infrared spectroscopy to show that the two synthetic peptides present some secondary structure in solution. As far as the peptide derived from the thymosin sequence was concerned, alpha-helical structure was induced by trifluoroethanol as observed with the full-length molecule. These experiments underscore the importance of the conformational state of peptide fragments in their biological activities. ELISA and fluorescence measurements have been used to identify the binding regions of these fragments to a C-terminal region (subdomain 1) of the actin sequence. Our results also emphasize the relationship between the propensity of small sequences to form secondary structures and their propensity for biological activity as related to actin interaction and inhibition of actin polymerization.

Actins↗