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Biomedical subjects

J E Saunders

Publications and source records attributed to J E Saunders.

70 records · Page 4Linked to original sources
PubMed1977

Ventilation, cardiac frequency and pattern of breathing during exercise in men exposed to O-chlorobenzylidene malononitrile (CS) and ammonia gas in low concentrations.

Ventilation minute volume, tidal volume and cardiac frequency during submaximal exercise have been measured in healthy young soldier volunteers exposed to O-chlorobenzylidene malononitrile (CS) and ammonia gas in concentrations respectively of 0.16 to 4.4 mg.m(-3) and 50 to 344 mg.m(-3). The response of ventilation minute volume to the two gases is apparently similar; both gases cause a reduction of, on average 6%. With low doses this reflects a diminution in respiratory frequency whereas with higher doses it is due to a reduction in tidal volume which is accompanied by tachypnoea. The findings may result from stimulation successively of receptors in the larynx and of irritant receptors in the large airways of the lung. The pain which is a feature of exposure to CS but not to ammonia is due to stimulation of other so far unidentified receptors. Neither gas has a direct effect upon the exercise cardiac frequency.

Adolescent↗
PubMed1975

Thymidine kinase activity in human bone marrow cells.

The thymidine kinase activity per 10(6) DNA-synthesising marrow cells and the rate of incorporation of tritiated thymidine into the DNA of 10(3) DNA-synthesising marrow cells were estimated in 9 haematologically normal patients and 49 patients suffering from a variety of haematological disorders. Slight increases in thymidine kinase activity were found in 6 of the 31 patients with haematological diseases associated with normoblastic erythropoiesis and greater increases were found in 3 of the 18 patients with megaloblastic haemopoiesis due to vitamin B12 or folate deficiency. In the latter group, there was a statistically significant inverse correlation between haemoglobin levels and thymidine kinase activity. No correlation was found between thymidine kinase activity and the rate of incorporation of tritiated thymidine in either the normoblastic or megaloblastic group, suggesting that the level of thymidine kinase activity does not limit the rate of incorporation of exogenously supplied thymidine into the DNA of human bone marrow cells.

Anemia, Hypochromic↗
PubMed1975

Role of transcobalamins I, II, and III in the transfer of vitamin B12 to human bone marrow cells in vitro.

A study of the uptake of transcobalamin-bound 57Co-cyanocobalamin by suspensions of human bone marrow cells has indicated that these cells can take up vitamin B12 from all 3 transcobalamins (I, II, and III). Similar transport processes were involved in the uptake from the 3 transcobalamins; uptake was dependent on the presence of calcium ions, cellular respiration and free sulphydryl groups. These results suggest that contrary to current belief, all 3 transcobalamins play a role in the transfer of vitamin B12 to tissue cells.

Biological Transport↗
PubMedDate not supplied

The destruction of renal calculi by external shock-waves: practical operation and initial results with the Dornier lithotripter.

ESWL is now the treatment of choice for most renal calculi. Large stones (20 mm) and staghorn stones may require preliminary debulking before lithotripsy and stones in the lower part of the ureter require pushing back into the renal pelvis before treatment. Compared with open surgery and percutaneous nephrolithotomy the procedure is less traumatic for the patient and may result in a shorter hospital stay and a faster return to normal life for the patient. It has been estimated that in 10 to 20 years' time around 70% of patients with urinary stone disease will be treated by ESWL.

Contusions↗