Search

In healthy humans, stroke volume ( SV) and cardiac output ( CO) do not increase with expansion of the central blood volume by head-down tilt or administration of fluid. Here, we exposed 85 patients to Trendelenburg's position about one hour after surgery while cardiovascular variables were determined non-invasively by Modelflow. In Trendelenburg's position, SV (83 ± 19 versus 89 ± 20 ml) and CO (6·2 ± 1·8 versus 6·8 ± 1·8 l/min; both P<0·05) increased, while heart rate (75 ± 15 versus 76 ± 14 b min−1) and mean arterial pressure were unaffected (84 ± 15 versus 84 ± 16 mmHg). For the 33 patients (39%) with a > 10% increase in SV (from 78 ± 16 to 90 ± 17 ml) corresponding to an increase in CO from 5·9 ± 1·5 to 6·9 ± 1·6 l min−1 ( P<0·05) when tilted head-down, administration of 250 ml Ringer's lactate solution increased SV (to 88 ± 18 ml) and CO (to 6·8 ± 1·7 l min−1). In conclusion, determination of SV and/or CO in Trendelenburg's position can be used to evaluate whether a patient is in need of IV fluid as here exemplified after surgery. [ABSTRACT FROM AUTHOR]

Immunization of single lymph nodes with various antigens led to the appearance of cells in the efferent lymph that secreted antibody specific for the antigen which induced their formation and for a number of unrelated, non-crossreacting anti-gens. Immunization of single lymph nodes with mitogens led to the appearance of cells secreting antibodies specific for an even greater number of antigens, including one (TNP) that in all probability is not present in the animals' natural environment. When the node was primed with one antigen, a subsequent challenge with an unrelated antigen 12 weeks later led to the appearance of greater numbers of cells containing and secreting antibody against the previously experienced antigen, than was the case in unprimed lymph nodes. These findings indicate that the immune response to antigen provokes the maturation of lymphocytes of specificities unrelated to that of the injected immunogen. Such a mechanism may be important in maintaining immunological memory. Mitogens may directly activate lymphocytes into maturation and expression as antibody-secreting cells, whereas antigens appear to act indirectly. [ABSTRACT FROM AUTHOR]

Experimental primary, secondary and tertiary stimulation with streptococcal vaccine of isolated lymph nodes in vivo in the sheep model induces largely persistence of anti-group polysaccharide antibody clonotype patterns with the rare occurrence of additional clonotypes demonstrable after secondary stimulation persisting during the tertiary stimulus. It is not clear whether these additional clonotypes are the products of mutants or whether the pre-existed and were demonstrable only after a secondary stimulus, because of threshold concentrations required for identification. Further, isolated contralateral popliteal and prescapular lymph nodes of individual sheep share completely overlapping clonotype patterns during experimental primary anti-polysaccharide antibody responses indicating an identical repertoire of specific clonotypes under this condition of responsiveness. [ABSTRACT FROM AUTHOR]

IgE-binding factors (IgE-BFs) were purified from the culture supernatant of RPMI-8866 cells, a human lymphoblastoid B-cell line expressing IgE receptors. The material, purified by affinity-chromatography on immunoadsorbents coupled to IgE or to monoclonal antibody against IgE receptor, was comprised of two major components with apparent molecular weight (MW) of 25,000–27,000 and 12,000, as determined by SDS-PAGE and silver staining. Only the 25,000–27,000 MW molecules were identified as IgE-BFs, as demonstrated by (i) their reactivity with MabER in the Western blot and the immunoprecipitation assays, and (ii) their ability to inhibit rosette formation of U937 cells with IgE-but not with IgG-coated erythrocytes. IgE-BFs were purified to homogeneity by combining affinity-chromatography and either DEAE-ion exchange or reverse-phase chromatography on an HPLC system. Chromatofocusing analysis demonstrated the microheterogeneity of IgE-BFs that were comprised of molecules with isoelectric points ranging from 5.0 to 4.4. IgE-BFs were sensitive to treatment with O-glycosidase but not with N-glycanase. These molecules were resistant to heat and to pH ranging from 2 to 9; their immunoreactivity was lost after treatment with trypsin and pepsin. Papain digestion of purified IgE-BFs generated 14,000–16,000 MW molecules that were still binding to IgE and to MabER. [ABSTRACT FROM AUTHOR]

This paper reviews the worldwide impact, now and in the future, of the 1963 discovery by Purdue researchers that the protein of the opaque-2 mutant contained more lysine and tryptophan than normal corn protein. Agricultural breeding, growing, harvesting, storage and distribution aspects are delineated and economics reviewed. Physical and chemical differences are discussed in relation to the foregoing aspects and implications concerning processing. Present and future roles of high lysine corn in human nutrition, particularly in lesser developed countries are discussed. Potential impact on the animal feeding industry is considered. [ABSTRACT FROM AUTHOR]

The article focuses on the investigation concerning on acute mountain sickness (AMS) in climbers with diabetes. A group of 11 climbers with Type 1 diabetes and 275 without diabetes attempting to reach the summit of Mount Kilimanjaro was focuses as the subject of the study. It relates that eight of the eleven diabetic climbers took regular acetazolamide as AMS prevention. In addition, the investigation revealed the reason of turning back were AMS symptoms of dizziness, fatigue, and nausea.

Assume mythical physiologists were taught that renal physiology and its disorders depend on "kidney cells" and their regulation by nonmechanical factors, but were taught nothing about nephrons. For decades they "knew" that idea was correct, just as Ptolemy "knew" the universe centers on our planet. But then others began to describe nephrons, their roles in renal physiology and disorders, and problems they revealed in former views, so doubts and controversies began. Today real physiologists encounter a similar situation for bone health and its disorders. A 1960 paradigm attributed such things to bone's effector cells (osteoblasts and osteoclasts) and their regulation by nonmechanical factors, without "nephron-equivalent" or biomechanical input. But both mechanical and nonmechanical factors regulate bone's nephron equivalents. Adding features of those equivalents to the 1960 views led to the Utah paradigm, which suggests problems in former views and better explanations for "osteoporosis," whole-bone strength, and other bone disorders. Such things incited controversies among current skeletal physiologists. Cybernetics concerns the relationships, mechanisms, signals, and message traffic that help to control the behavior and other features of dynamic systems. A cybernetic analysis of the bone physiology in the Utah paradigm can add many features to the 1960 paradigm that help to understand osteoporoses, other bone disorders, and whole-bone strength (and bone mass). The added features also show new and pertinent targets for the related research.