VALIDATION OF A SUBENDOCARDIAL ISCHAEMIC SHEEP MODEL BY INTRACORONARY FLUORESCENT MICROSPHERES

1. We evaluated the use of non-radioactive fluorescent-labelled microspheres (FM) for the measurement of regional myocardial blood flow (RMBF) in an ischaemic sheep model. 2. Injection of FM directly into the coronary artery was compared with left atrial injection. There was a good correlation in the measurement of RMBF between these two injection methods (r = 0.92; n= 107 data points). Injection into the coronary artery requires less FM (one twentieth of that required by atrial injection) and is more economical. 3. The use of a fluorescent technique without filtering myocardial tissue was investigated. Calibration curves from the fluorescence plus myocardial tissue samples were similar to those of the pure fluorescence samples and both showed a linear relationship between fluorescent intensity and the number of microspheres (r > 0.97). These results indicate that the extraction of six fluorescent dyes (blue-green, yellow-green, green, orange, red and crimson) directly from the aqueous solution using ethyl acetate is effective. 4. A subendocardial ischaemic model was produced by partially occluding the circumflex artery (CxA) with concomitant left atrium (LA) pacing. During ischaemia, the endocardium/epicardium (Endo/Epi) flow ratios in the ischaemic area changed from 1.04 ± 0.12 to 0.47 ± 0.17 (P < 0.05; CxA injection) and from 1.08 ± 0.12 to 0.51 ± 0.05 (P < 0.05; LA injection). The ratio in the non-ischaemic area remained unchanged (1.12 ± 0.26 to 1.01 ± 0.22; not significant). 5. RMBF calculation using coronary inflow as the reference flow was also compared with that using the traditional method. We found that, in this study in which a non-filtering technique was applied, using coronary inflow as the reference flow was superior to the conventional distal sampling method.     

Bacterial meningitis in infants: sonographic findings

A retrospective study was performed on 78 patients (newborn to 2 years old) with clinically proved bacterial meningitis. Sonograms were obtained during the acute illness and medical records were reviewed. The spectrum of sonographic features of meningitis included normal scans (30 patients), ventriculomegaly (11 patients), echogenic sulci (31 patients), extra-axial fluid collections (26 patients), abnormal parenchymal echogenicity (9 patients), evidence of ventriculitis (5 patients), and brain abscess (1 patient). In 46 patients, correlation between the sonographic findings and neurologic outcome on clinical follow-up (6 months to 4 years) was made. Findings of abnormal parenchymal echogenicity and/or moderate-to-marked ventriculomegaly were associated with significant neurologic sequelae; however, echogenic sulci and small extra-axial fluid collections did not appear to have any prognostic significance. Twenty-nine of the 78 patients had sonography without clinical indication of complications of meningitis, and in no patient was a significant abnormality found. Our study suggests that sonography is indicated only when there is clinical suspicion of complications.     

The operative technique of the transverse abdominal island flap for breast reconstruction

Meticulous attention to operative details is essential to the success of the transverse abdominal island flap in each phase of the procedure: raising the flap, transfer to the anterior chest wall, molding the flap, and repair of the donor site. This will culminate in a rewarding procedure for reconstruction of the breast by autogenous tissue.     

变价态唐松草新碱—PVC膜离子选择电极的研制及解离常数的测定

本文研制了以四苯硼—唐松草新碱缔合物为电活性物质的变价态唐松草新碱—PVC膜电极。电极膜按电活性物质:PVC:DBP为1:8:8组成。该电极在pH 5.0～6.0,Ⅰ=0.05的NaCl—HCl溶液中Nernst响应范围为1×10^-3～1×10^-5mol/L。电极斜率为58.2 mV/logc。检测限为2.5×10^-6mol/L。用直接电位法考察了TDH⁺,TDH₂CF⁺⁺共存时溶液pH和电极斜率S的关系。用S—pH关系,测定了25℃,Ⅰ=0.05时的Ka₁值为(2.5±0.2)×10^-4,用E—pH关系,测定了25℃,Ⅰ=0.05时的Ka₂值为(8.1±0.9)×10^-8。