[Blepharoplasty and oculocardiac reflex]

100 patients have undergone electrocardiograph before and during blepharoplasty and after anaesthesia. The results show that the positive rate of oculocardiac reflex is 65%. The mechanism of occurrence of oculocardiac reflex is analysed. It has also been pointed out that great attention should be paid to the phenomenon and appropriate measures should be taken to prevent the occurrence of oculocardiac reflex.

Study of photon migration depths with time-resolved spectroscopy

In this study a light-shielding plate with a hole was placed in an intralipid emulsion. The probability distribution for photons emitted from a surface light source, passing through the hole at different depths, and reaching a surface detector at the other side of the plate was experimentally assessed. We provide qualitative verification for a model derived by Weiss et al. [J. Mod. Opt. 36, 349 (1989)] that the migration depths for the measured photons follow a distribution in depth and that this distribution has a maximum probability at a describable depth beneath the surface. This agreement, corroborated by a parallel study, suggests that we may have assessed the maximum migration depth distribution of photons that reached the detector and that the random walk model may describe the maximum migration depth distribution. The experimental results indicate that photons with the same path lengths within the medium reach a wide range of depths and suggest difficulties in resolving optical structure with time-resolved measurement. The results also provide experimental evidence that, for a given source-detector separation, the photons that migrate deeper have longer mean path lengths with larger variation in their path lengths.

Restriction enzyme analysis of mitochondrial DNA in colorectal tumours

Total cellular DNA samples were isolated from 15 colorectal adenocarcinomas, 8 colon adenomas and their adjacent histologically normal colon mucosa. These DNA samples were digested separately with 13 different restriction endonucleases and analysed by Southern blot hybridization using a purified 32P-labelled human mtDNA probe. The fragment patterns from tumour mtDNA were compared to those from corresponding normal mtDNA. No evidence for large deletions, insertions, rearrangements or single base mutations in the detectable regions was detected. This suggests that other mechanisms may be responsible for the changes of colorectal tumour mitochondria.

[Right ventricular volumes and ejection fraction estimated by two-dimensional echocardiography]

The right ventricular volumes and ejection fraction (RVEF) obtained from two-dimensional echocardiography and from right ventricular angiography were compared in 20 patients with congenital heart disease. Single plane area-length method of apical four-chamber view was used to estimate echocardiographic right ventricular volumes and single plane right anterior oblique projection was used to calculate angiographic right ventricular volumes. The results showed that right ventricular volumes estimated by echocardiography correlated highly with that calculated by angiography, the correlation coefficients of end-diastolic volume, end-systolic volume and stroke volume were 0.983, 0.976, 0.973 respectively. Echocardiographic RVEF also correlated strongly with angiographic RVEF (r = 0.992, P less than 0.001), and there were no significant difference between the two methods (P greater than 0.05).

CONCLUSION

two-dimensional echocardiography can be used to accurately estimate right ventricular volumes and ejection fraction.

Distribution of membrane cofactor protein of complement on human peripheral blood cells. An altered form is found on granulocytes

Membrane cofactor protein (MCP) of human complement is an iC3/C3b-binding glycoprotein with a characteristic two-band (63 kDa and 55 kDa) pattern on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Using affinity chromatography, it has been found on human mononuclear cells and platelets. MCP has been purified and shown to be a cofactor for the I-mediated cleavage of C3b. A rabbit polyclonal antibody was produced to the purified protein and this reagent employed to analyze the distribution of MCP on human peripheral blood cells. Flow cytometric analysis indicated that MCP is unimodally present on all platelets, granulocytes, T helper lymphocytes, T suppressor/cytotoxic lymphocytes, B lymphocytes, natural killer cells and monocytes but not erythrocytes. The presence of MCP on granulocytes was unexpected. To evaluate this, MCP was isolated by immunoprecipitation and analyzed by SDS-PAGE followed by autoradiography. The Mr of granulocyte MCP was that of a single broad band in which the typical two-band pattern could not be distinguished. Alterations in the conditions of the affinity column procedure increased the efficiency of the isolation of monocyte MCP and led to the reproducible isolation of granulocyte MCP. These results indicate that MCP of granulocytes has both structural and functional differences compared to MCP of plateletes and mononuclear cells. The wide distribution of MCP among peripheral blood cells supports the concept that MCP is important in the protection of host cells from complement-mediated damage.

[Photodynamic therapy (PDT) of bladder cancer in the rat]

PDT of rat bladder cancer, induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) was studied. All animals were divided at random into three groups. Group 2 and 3 were treated by hematoporphyrin derivative (HPD)-laser PDT while group 1, without treatment, served as control. The results showed that the malignant lesions could be selectively and obviously destroyed, if the whole tumor area were sufficiently exposed to the laser irradiation. However, the normal bladder epithelium and muscle layer showed no histologic change. Similar reactions were found in papilloma of bladder which was considered as precancerous lesion. Thus, PDT may be beneficial to cancer prevention. Its role in prevention and treatment of bladder cancer should be further studied experimentally and clinically.