PubMed Health⌕ Search

Biomedical subjects

J Reiser

Publications and source records attributed to J Reiser.

84 records · Page 5Linked to original sources
PubMed1979

Transfer of proteins from gels to diazobenzyloxymethyl-paper and detection with antisera: a method for studying antibody specificity and antigen structure.

We describe a rapid and very sensitive method for detecting proteins as antigens after their separation in polyacrylamide/agarose composite gels, with or without sodium dodecyl sulfate. The polyacrylamide matrix is crosslinked with a reagent that can be cleaved with periodate or alkali to facilitate transfer of the protein bands to diazobenzyloxymethyl-paper, where they are coupled covalently. Specific proteins are detected by autoradiography after sequential incubation with unfractionated, unlabeled specific antiserum and 125I-labeled protein A from Staphylococcus aureus. Antibody and protein A can be removed with urea and 2-mercaptoethanol, and the same paper can be probed again with a different antiserum. An antiserum specific for the simian virus 40 virion proteins VP3 and VP2 has been prepared; it does not crossreact with VP1, as demonstrated by this method. An antiserum raised in rabbits against simian virus 40-transformed rabbit kidney cells is shown to be directed primarily against a periodate-sensitive moiety present in tumor (T) antigen from infected or transformed cells, whereas an antiserum raised in rabbits against large T antigen purified from lytically infected monkey kidney cells by electrophoresis in the presence of sodium dodecyl sulfate [Lane, D.P. & Robbins, A.K. (1978) Virology 87, 182-193] is directed primarily against determinants that are not sensitive to periodate.

Antibody Specificity↗
PubMed1978

An androgen-associated hepatic adenoma in a trans-sexual.

A case is reported of an hepatic adenoma developing in a patient who had been taking testosterone for 3 years. There appears to be an association between various steroid preparations and hepatic neoplasia. Reports of such cases with all relevant data will allow a balanced assessment of the problem to be made.

Adenoma↗
PubMed1977

Revised amino acid sequence of Qbeta coat protein between positions 1 and 60.

A reinvestigation of the primary structure of Qbeta coat protein between positions 1 and 60 was undertaken to resolve two discrepancies between the published amino acid seuqence (Maita, T., and Konigsberg, W. (1971) J. Biol. Chem. 246, 5003-5024) and the cognate nucleotide sequence recently determined in our laboratory (C. Escarmis and M. A. Billeter, unpublished results). The 22nd amino acid was asparagine rather than aspartic acid, and an additional amino acid, serine, was present between proline in position 55 and arginine in position 56. The revised structure agrees with the nucleotide sequence determined so far.

Amino Acid Sequence↗
PubMed1977

Purification and properties of the P15 specific restriction endonuclease from Escherichia coli.

The specific restriction endonuclease of the Escherichia coli plasmid, P15, has been purified to apparent homogeneity by a procedure that includes DNA-cellulose chromatography as well as a new endonuclease assay. Sedimentation on glycerol gradients showed two peaks of activity with values of 11.3 S and 15.7 S. The highly purified enzyme requires ATP and Mg2+ for activity and is stimulated by S-adenosylmethionine. A methylase activity is observed in the course of the endonucleolytic reaction which protects some of the DNA sites from cleavage.

Adenosine Triphosphatases↗
PubMed1976

Electrophysiological observations on the digitalis-potassium interaction in canine Purkinje fibers.

We studied the effects of elevating potassium concentration on the membrane potential of Purkinje cells exposed to toxic concentrations of acetylstrophanthidin or ouabain. Conventional intracellular microelectrode techniques were employed. Rapid elevation of [K+]o from 2.7 to 5.4 mEq/liter resulted in an initial increase (more negative) in membrane potential of cells demonstrating ouabain-induced phase 4 depolarization. The increase in maximal diastolic potential occurred initially without suppression of phase 4 depolarization. In cells rendered inexcitable by ouabain or acetylstrophanthidin, elevation of [K+]o consistently increased membrane potential and restored excitability. In four experiments automaticity was initiated within 2 minutes after the increase in [K]o. Although automaticity reappeared, as maximal diastolic potential increased, the automatic rate slowed and then pacemaker activity was suppressed. Studies with 3H-ouabain showed that the increase in membrane potential paralleled K+-induced release of 3H-ouabain from Purkinje cells. These studies suggest that elevation of [K+]o reverses digitalis toxic manifestations in canine Purkinje fibers by causing release of cardiac glycosides bound to the membrane. The observed increase in membrane potential of ouabain-treated Purkinje fibers that occurred after [K+]o elevation was considered to be mediated in part by restoration of the Na pump and by electrogenic pumping.

Action Potentials↗
PubMedDate not supplied

The potential value of a 750-ml spacer for the administration of inhaled corticosteroids to children.

An open, cross-over trial was conducted on 25 asthmatic children, aged 6-13 years, who required inhaled steroids. They inhaled Budesonide 200 micrograms twice daily, either directly from the metered dose inhaler or via the pear spacer (PS), for 2 months on each, in randomized order. The effects of the treatment were monitored with diary cards recording peak expiratory flow rates twice daily, symptoms and treatment taken, and with monthly clinical assessments including more sensitive lung function studies (flow-volume loops and single breath nitrogen wash-out tests). There was no specifically PS-related improvement in symptoms or in the majority of tests, but the results showed improvement with time when using either method. The improvement was more distinct in some tests reflecting proximal airway calibre (i.e., PEFR) than in tests thought to reflect predominantly peripheral airway calibre (i.e., F50, RV). The bronchodilator responsiveness, as shown by the increase in lung function tests after a beta-agonist was given, was significantly greater for FVC during the periods when the PS was used, although there was no significant improvement in FEV2 or PEFR. The improvement in tests reflecting proximal airways may have been due to optimization of the inhalation technique, greater understanding of asthma, or better compliance with medication associated with regular attendance for the study. The greater bronchodilator response whilst children were inhaling budesonide by the PS may have been due to increased deposition or better distribution of the steroid but was probably related to a difference between the two groups in initial baseline function tests.

Adolescent↗
PubMedDate not supplied

Improved pacemaker fixation and performance using a modified finned porous surfaced tip lead.

A simple method was used to modify the tip of a porous surfaced finned pacemaker lead. Comparison between the modified and the unmodified pacemaker electrodes was carried out in experimental animals and in humans. The incidence of early lead dislodgement, acute trapping and pacing thresholds was recorded. The study revealed improved overall performance with the modified pacemaker lead.

Adult↗