Biomedical subjects

C L Chang

Publications and source records attributed to C L Chang.

At least 181 records · Page 10Linked to original sources

PubMed1987

Differential inotropic effects of halothane and isoflurane in dog ventricular tissues.

The differential effects of halothane (0.25-0.75%) and isoflurane (0.5-1.25%) on the electromechanical activity of canine ventricular tissues were compared in vitro. In Purkinje fibres, halothane but not isoflurane could induce an initial increase of contractile force which was not blocked by diltiazem or propranolol. In ventricular muscles, halothane decreased the resting state contraction more markedly than isoflurane. The results suggest that halothane induces a greater negative inotropy than isoflurane through a differential alteration of intracellular Ca2+ stores.

Action Potentials↗

PubMed1987

An alternative approach to tract dilation using optic urethrotome in percutaneous nephrolithotomy.

Percutaneous removal of renal or ureteral calculi requires fluoroscopic guidance of nephrostomy tube insertion, tract dilation and stone manipulation. We introduce an effective method of nephrostomy tract dilation with optic urethrotomy under direct visual control, which protects the patient and medical personnel from fluoroscopic exposure without further increasing the incidence of immediate and delayed vascular complications. In our series of 70 patients (73 kidneys) only 1 (1.4 per cent) had hypovolemic shock, with no kidney loss or operative mortality encountered. Of the kidneys 69 were operated on in 1 and 4 in 2 sessions. There was only 1 failure, for a success rate of 98.6 per cent and the stones were reached in all cases.

Adult↗

PubMed1987

Microbial dysbiosis in rabbit mucoid enteropathy.

The cecal contents of normal rabbits and rabbits with mucoid enteropathy (ME) were examined microscopically. Rabbits with ME consistently had dramatic cecal dysbiosis characterized by a loss of protozoa, large metachromatic bacilli and other gram-positive organisms and an increase in the size and stain retention of gram-negative organisms. Experimentally induced cecal hyperacidity in fistulated rabbits produced dysbiosis similar to that observed in natural cases of ME. Cecal pH measurements in normal young and adult rabbits revealed that pH values consistently were lower in young rabbits and frequently were low enough to induce microbial changes. Spontaneous cecal hyperacidity in young rabbits, therefore, appears to account for the cecal distention and diarrhea seen initially in ME. Late manifestations such as mucus hypersecretion and impaction, on the other hand, appear to be the result of specific microbial factors which develop when dysbiosis persists. The gradual change in the dysbiotic flora to one which closely resembles that of the normal rabbit colon appears to be the stimulus that permits these late manifestations to develop.

Animals↗

PubMed1987