Anatomic correction of transposition of the great vessels

We present a new approach for anatomic correction of transposition of the great arteries. The two coronary arteries, with a piece of the aortic wall attached, are transposed to the posterior artery. The two aortic openings are closed with a patch. The aorta and pulmonary artery are transected, contraposed, ant then anastomosed. The interventricular septal defect is closed with a patch, through a right ventriculotomy approach, because the right ventricle is no longer part of the systemic circulation. Two patients, aged 3 months and 40 days weighing 4,200 and 3,700 grams, respectively, were operated upon with deep hypothermia and total circulatory arrest. There was good recovery from the operation, with normal cardiocirculatory conditions. Renal failure developed in the first patient, and she died on the third postoperative day. During this time the cardiocirculatory conditions were good. The second patient made an uneventful recovery. Hemodynamic studies 20 days after the operation showed complete correction of the malformation. Five and one-half months after the operation, he weighs 7,500 grams, and his development is very good. We believe that this operation will be reproducible by most cardiovascular septal defect and pulmonary hypertension.     

Pancytopenia and aplastic anemia: a retrospective study

During January 1971--June 1975 we examined 195 patients with pancytopenia. The cause was bone marrow failure in 67.7% of cases (classic aplastic anaemia in 11.3%) hypersplenism in 7.7%, massive blood transfusions in 1.5%, severe infections in 9.7% (Gram-negative in 3%), and various other conditions in 7.8%. Records were insufficient for diagnosis in 5.6% of cases. Analysis of the 22 patients with aplastic anaemia showed no apparent aetiology in 16 (72.7%), previous phenylbutazone ingestion in 2, and Fanconi-type anaemia in 4 of 7 children. One-year survival was 73.7%, 2-year survival 71.4%, 3-year survival 63.6% and 4-year survival 57.1%. Marrow-investigation of the 21 available samples showed that 6 were acellular, 11 hypocellular and 4 normocellular. All patients received at least temporary therapy with anabolic steroids but its effectivity could not be satisfactorily assessed. Five patients died within 7 months and 5 patients went into remission, needing no further therapy. The initial haematological features of the 5 patients who died were not significantly different from those of the rest of the patients.     

Amoxycillin versus ampicillin in treatment of exacerbations of chronic bronchitis

To compare the efficacy and unwanted effects of amoxycillin and ampicillin in the treatment of acute exacerbations of chronic bronchitis, 199 patients were recruited from 28 centres into a double-blind between-patient comparison of four regimens: ampicillin 250 mg or 500 mg, amoxycillin 250 mg or 500 mg, each given orally three times daily for seven days. In these doses, amoxycillin and ampicillin were equally effective and there was no apparent advantage in using the higher dose of either drug in preference to the lower dose. Unwanted effects were few. Only in five patients did diarrhoea lead to withdrawal of therapy and there was no significant difference between the two drugs in this respect. Rashes occurred in four patients, all on ampicillin.     

On the question of an electrokinetic requirement for phospholipase C action

The phospholipase C of clostridium welchii (alpha toxin) has an absolute requirement for trace quantities of Ca2+. It attacks pure phosphatidylcholine particles (smectic mesophases) having a close-packed bilayer structure only when their surface zeta potential is made positive by the addition of certain divalent ions (e.g., Ca2+) to the aqueous phase or by the presence of low concentrations of long chain cations to the lipid. Alternatively, if the rotational freedom of individual phospholipid molecules is increased by the insertion of short n-alkanols (e.g., hexanol) into the bilayer or when a monolayer of the substrate at an air/water interface is expended, enzymic hydrolysis can occur without any requirement for a net postive charge on the surface.     

智能数字万用表的设计

本系统采用TI公司的单片机MSP430F2274作为系统的控制核心,由A/D数据采集、功能转换、量程自动转换以及键盘显示等模块组成。被测信号经过功能转换电路,转换成与其成比例关系的电压,再经12位AD574转换送单片机进行数据处理,结合继电器完成量程的自动转换,从而通过由MC14433组成的数字电压表头实时反映测试参数,同时本系统还具有相对误差测量、自动休眠等功能。通过实验测试,该系统满足设计要求,具有量程自动转换,具有精度高、工作稳定、交互界面友好等特色。