Synthetic methodology was developed for the preparation of chondrotin-4-sulfate reagents that could be specifically attached to the surface of diaspirin cross-linked hemoglobin (DCLHb), a chemically stabilized human hemoglobin. The surface-modified hemoglobin solutions had a significantly higher colloidal osmotic pressures (COP) than DCLHb. The P(50) of the modified DCLHb was dependent upon the reactive end group of the chondrotin-4-sulfate reagents that was used for the protein modification. Modification of DCLHb with the chondroitin-4-sulfate derivatives containing the maleimide end group 23 provided a hemoglobin with a P(50) value of 23 mmHg, while the P(50) of hemoglobins prepared from chondroitin-4-sulfate derivatives containing the aldehyde end group 13 and 18 remained unchanged from that of DCLHb.

Aspirin↗

PubMedDate not supplied

Synthesis of water-soluble, nonimmunogenic polyamide cross-linking agents.

Novel polyamides were developed that can be used as cross-linking agents for proteins such as hemoglobin. Water-soluble, nonimmunogenic polyamides containing oxygen and sulfur atoms in the backbone were prepared by the polycondensation of the diacids bis(carboxymethyloxyacetyl)-1,4-diaminobutane (1a) or 3, 3'-thiodipropionic acid (1b) with diethylene glycol bis(3-aminopropyl) ether (2). The resulting alpha,omega-diacids were converted to the corresponding activated esters using any of a variety of carboxylic acid activating reagents including the novel reagent diphenyl(1-methylimidazol-2-thiyl)phosphonate (9). The resulting polyamides could be activated with a broad spectrum of groups that allow for the cross-linking and surface modification of proteins.

Chromatography, Gel↗

PubMedDate not supplied

Polymerization of diaspirin cross-linked hemoglobin (DCLHb) with water-soluble, nonimmunogenic polyamide cross-linking agents.

Diaspirin cross-linked hemoglobin (DCLHb), a human hemoglobin that is intramolecularly cross-linked between the alpha chains (lysine 99(alpha)(1)-lysine 99(alpha)(2)), was polymerized with a number of water-soluble, nonimmunogenic polyamide cross-linking agents. The degree of polymerization and the oxygen-carrying capacity depended upon the polyamide reagent, the starting concentration of DCLHb, the molar ratio of the polyamide reagent to DCLHb used, the reaction pH, and whether oxy- or deoxy-DCLHb was used in the polymerization reaction.

Aspirin↗

PubMedDate not supplied

Single ionic channels observed in tissue-cultured muscle.

The extracellular patch clamp technique developed by Neher et al. to record the responses of single channels in skeletal muscle has provided firm evidence for the two-state nature of the conductance event in nicotinic endplate channels. We report here the use of the extracellular patch technique to record single-channel responses from tissue-cultured chick skeletal muscle cells. The temperature dependence of channel conductance and gating kinetics shows no evidence of discontinuous behaviour between 17 and 37 degrees C.

Animals↗

PubMedDate not supplied

Teaching small employers to buy value.

Explore the source record for details and available documents.

Decision Making, Organizational↗

PubMedDate not supplied

In-hospital cardiopulmonary resuscitation: a 30-year review.

BACKGROUND: We performed a meta-analysis to: (1) assess the disputed issue of in-hospital cardiopulmonary resuscitation (CPR) success rates among elderly patients, (2) investigate the possibility of a declining CPR success rate between 1960 and 1990, (3) provide an overview estimate of CPR effectiveness in specific patient groups, and (4) assess CPR risks. METHODS: Ninety-eight reports providing in-hospital CPR survival-to-discharge rates were included in this overview. These reports were identified from MEDLINE searches, previous reviews, and reference citations. RESULTS: A pooled analysis revealed that 2994 (15 percent) of 19,955 patients were successfully resuscitated (survival to discharge). The rate of successful CPR has not changed in 30 years (r = -0.14, P > 0.05), but there has been a steady decline in the optimism regarding its value (r = -0.29, P < 0.01). Patients younger than 70 years of age had a success rate of 16.2 percent (odds ratio = 1.36; 95 percent confidence interval, 1.20 to 1.53) versus 12.4 percent for patients older than 70 years (P < 0.001). Community hospitals had a higher CPR success rate than teaching hospitals (18.5 percent versus 13.6 percent, P < 0.001). Although 72.9 percent of the post-CPR deaths were within 72 hours, prolonged in hospital survival in a vegetative state did occur; 1.6 percent of successfully resuscitated patients had a permanent neurological impairment. CONCLUSION: The increasing pessimism about the value of CPR, specifically, its futility in the elderly patient, is not supported by this review. The results of this meta-analysis should assist both the physician and the patient in determining the probable outcome of CPR.

Age Factors↗