To evaluate amoebicidal efficacy of various disinfectants, we treated ten ocular isolates of Acanthamoeba with polyhexamethylene biguanide(PHMB), chlorhexidine and hexamidine. Acanthamoeba cysts were collected from axenic nonnutrient agar plates from 4 week culture. Cyst suspension(100microliter) was inoculated on 96-well microplate with concentration of 105 cys/ml. Each well was treated with two-fold diluted hexamidine, PHMB and chlorhexidine(100microliter each, 8 and 48hrs). Each well was examined under the inverted microscope until 7 days after treatment. Minimal cysticidal concentration(MCC) of each disinfectant qas measured after five experiments. MCC of hexamidine, chlorhexidine and PHMB against ten ocular isolates ranged 6.07-500microgram/ml, 3.12-12.50microgram/ml, 1.17-4.68microgram/ml respectively in 48hr treatment. In 8hr treatment, MCC of PHMB and chlorhexidine ranged 4.42-12.50microgram/ml and 4.67-17.71microgram/ml, but hexamidine did not demonstrate cysticidal effect. For proper disinfection of contact lens, disinfectants having cysticidal efficacy should be included in the composition of contact lens solution. Among the currently used topical amoebicidal agents, PHMB showed the greatest cysticidal activity on ten ocular strains of Acanthamoeba in invitro study.
Acanthamoeba* ; Agar ; Chlorhexidine* ; Contact Lens Solutions ; Disinfectants ; Disinfection

In order to study the effect of spinal nareotics on postoperative pulmonary function and ventilatory reserve after upper abdominal surgery, small preoperative doses of morphine were administrated into the subarachnoidal space and the changes in FVC, FEVi.e., MMEF and FEVi.e./FVC with the SC-20 spirometric computer wer evaluated. The results were as follows: 1) On the 1st day postoperatively FVC of the control group was 56% of the preperative value, 2.94+/-0.68(1/sec), and that of the morphine group was 66% of the preoperative value, 2.99+/-0.73(1/sec).(p<0.05) On the 2nd and 3rd day postoperatively the control group was 64% and 65% and that of the morphine group was 82% and 87%. (p<0.05) 2) On the 1st and 2nd postoperative day FEVi.e. of the control group was 52% and 57% of the preoperative value, 2.49+/-0.43(1/sec), and that of the morphine group was 61%, and 65% of the preoperative value, 2.42+/-0.68(1/sec). (p<0.05) On the 3rd postoperative day the FEVi.e. of the control group was 65% and that of the morphine group was 80%. (p<0.05) 3) On the 1st and 2nd postoperative day the MMEF of the control group was 56%, and 61% of the preoperative value, 2.45+/-0.77(1/sec). In the 3rd postoperative day the MMEF on the control group was 63% and that of the morphine group was 78%. (p<0.01) 4) The preoperative FEVi.e./FVC of the control group was 84.3% and that of the morphine group was 78.7%. in the postoperative period, there were no significant differences between the control and morphine group.
Morphine* ; Postoperative Period

The effect of sodium nitroprusside(SNP) on arterial oxygen tension in 20 neurosurgical patients with normal lung function was studied under general anesthesia. Blood gas, heart rate, mean arterial pressure and central venous pressure were measured before, during and after SNP infusion. The results were as follows:1) Arterial oxygen tension significantly decreased from 177+/-40.6 mmHg before SNP to 138+/-50.1 mmHg during SNP(p<0.005), and increased again to 168+/-44.4 mmHg after SNP. 2) Mixed venous oxygen tension decreased 47+/-8.2 mmHg to 40+/-7.3 mmHg(p<0.005), and increased again to 44+/-10.3 mmHg. 3) Heart rate significantly increased from 92+/-24.6 beats/min to 118+/-27.4 beats/min(p<0.005), and decreased again to 94+/-18.6 beats/min. The above findings have shown a marked reduction in PaO2 when SNP was administered during general anesthesia. After SNP, PaO2, returned to the previous values. It is suggested that the reduction in PaO2, is the result of an increased scatter of ventilation/perfusion relationships in the lung and inhibition of hypoxic pulmonary vasoconstriction by SNP. These results provide evidence that SNP induced hypotension may cause significant impairment in pulmonary gas exchange in patients with normal lung function.
Anesthesia, General ; Arterial Pressure ; Central Venous Pressure ; Heart Rate ; Humans ; Hypotension* ; Lung ; Nitroprusside* ; Oxygen* ; Pulmonary Gas Exchange ; Sodium* ; Vasoconstriction