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Biomedical subjects

S Higashino

Publications and source records attributed to S Higashino.

6 recordsLinked to original sources

Telescience testbed for biomedical experiments in space morphological and physiological experiments of rat musculoskeletal system.

As the second telescience testbed experiment we were examined sophisticated processes of biomedical experiment, such as an implantation of a transmitter into the hamster's abdominal cavity, non-stressful blood sampling, large amount of blood collection, muscle extirpation and biopsy from the hamsters on February 6-8, 1990. To make clear the differences between successful results obtained by an experienced hand and by a non-experienced one, three operators were selected for three successive experimental days; an engineer who had never experienced any biological experiment, a non-biology student, who experienced on biological experiments, and a veterinary surgeon. Surgical procedures need much experiences on maneuvering and understanding of theory to shorten the elapse time. Especially for a non-experienced hand, graphic instructions were much helpful to understand and to maneuver the procedures. Continuous recordings of ECG from a operator and PIs were of an advantage to grasp an extent of the mental strain, which was compared with their reports requested after end of each experimental day. The mental strain was not related to degrees of scientific achievement, but showed faithfully difficulty of each experimental procedure. Training effects on PIs in successive experimental days were found in their instructions for the operator to let understand the procedures.

Animals↗

Inadequate erythroid response to hypoxia in cystic fibrosis.

An increase in hemoglobin concentration characterizes the normal compensatory response to chronic tissue hypoxia. We observed no such increase in 42 chronically hypoxic patients with cystic fibrosis, in whom the mean concentration was 12.6 gm/dl; one third of the patients were anemic. Compared with patients with cyanotic heart disease, patients with cystic fibrosis did not have a compensatory increase in P50 or 2,3-diphosphoglycerate. Despite anemia, erythropoietin levels in patients with cystic fibrosis were not significantly different from normal control values. The growth of colony-forming units-erythroid in patients with cystic fibrosis was similar to that in control subjects, and there was no inhibition of growth with the addition of autologous serum. Erythropoietin sensitivity, determined by measuring the CFUe dose response curve, was normal in both patients and controls. Results of iron studies were consistent with iron deficiency in the majority of patients. Impaired absorption of iron was observed in six of 13 iron-deficient patients with cystic fibrosis. An inverse correlation between erythrocyte sedimentation rate and peak serum iron was obtained during the iron absorption study. Eight patients who underwent a therapeutic trial of iron demonstrated a 1.8 gm/dl rise in hemoglobin concentration. Two patients with previously documented iron malabsorption responded to parenteral iron therapy after failure to respond to oral supplementation. These studies demonstrate that patients with cystic fibrosis not only have an impaired erythroid response to hypoxia, but are frequently anemic. Their inadequate erythroid response to hypoxia results in part from disturbances in erythropoietin regulation and iron availability.

2,3-Diphosphoglycerate↗

Uncoupling of an epithelial cell membrane junction by calcium-ion removal.

Calcium takes part in maintaining ion communication between salivary gland cells (Chironomus thummi). Its withdrawal from the cell systems results in virtual disconnection of ion communication, at Ca(++) concentrations which do not noticeably affect cell adhesion. The junctional membrane surfaces. which are normally quite freely permeable to ions, become as impermeable as the nonjunctional membrane surfaces; each cell seals itself off irreversibly as a unit. In maintaining ion communication Mg(++) substitutes for Ca(++)

Animals↗