Volume 108  ·   Issue 06  ·  1995

A randomized case-controlled trial of oral low-dose acyclovir (600-800 mg per day) has been conducted for the prevention of virus infections in 66 recipients of renal allografts since 1990. In comparison with the untreated controls, acyclovir could prevent herpes virus simplex (HSV), reduce morbidity of pneumonia from 10 cases (30%) to 3 cases (9%) (P<0.05) and lower CMV-IgM positive rate from 30% to 12%. Serum Cr and BUN in acyclovir group were lower than those in control group. These results strongly suggested that oral administration low-dose acyclovir could prevent virus infections after renal transplantation.

We have developed a model of coronary artery thrombosis in dog by using the method stimulating coronary adventitia with direct current. The results have shown that the thrombi are similar to human artery thrombi in composition and the model of coronary artery thrombosis is satisfactory and the time of forming thrombosis is shorter than that by other methods.

Impedance during radiofrequency (RF) catheter ablation procedures is dependent on a variety of parameters related to the catheter, cabling, reference patch, body size, and temperature. To examine the influence of body size, impedance was measured during clinical ablation procedures in 93 patients (Group I) with a wide range of body sizes. In 14 other patients (Group II), impedance was measured during variations in catheter tip size (5, 6 and 7 Fr), reference patch size (120 and 60 cm2), patch location (chest vs. thigh), and catheter tip tissue contact. The average impedance was also compared to average tip temperature in Group II patients. Impedance decreased with increasing catheter tip size, reference patch size and proximity of the patch to the heart. However, the effects of body geometry were complex. For example, using a chest patch, impedance increased with body surface area, but using a thigh patch it decreased, suggesting that lung volume may increase impedance, but body width may actually decrease it. An increase in tip tissue contact, relative to blood contact, increased the impedance, suggesting that impedance may be a useful measure of tip tissue contact. Finally impedance decreased with increasing tip temperature, suggesting that impedance may be useful as a real time measure of tissue and blood heating. The results are interpreted in terms of an electrical analog which suggests further that despite the lower total power when the same voltage is applied to a higher impedance, less voltage should be applied to achieve the same tissue effect when the measured impedance is higher.

To gain further knowledge on temporomandibular joint disturbance syndrome (TMJDS), the synovial membranes of 7 patients and 3 cadavers were examined with light microscope and transmission electron microscope. The results showed that the synoviocytes degenerated or disappeared in TMJDS. The cytoplasm contained numerous fibrils, while the organelles diminished in number. The surface of the synovial membrane was covered with a fibrinoid material. The surface of the synovial membrane was covered with a fibrinoid material. The authors consider that these pathological changes reduce or eliminate the normal functions of the synovial membrane, which may lead to damage to the articular cartilage. The articular adhesion found sometimes in TMJDS may be related to the changes in the synovial membrane.

In this study, the reexpression of nerve growth factor receptor (NGFR) on paraffin sections of the human spinal cord was examined with immunohistochemical method in 18 cases with survival periods of 2 hours to 28 months after trauma. The results were as follow: the reexpression of NGFR in motoneurons of the ventral horn began on the fourth day after trauma and decreased within 30 days after trauma. However, it could still be observed in patients who survived up to 28 months. The axons in funiculus dorsalis reexpressed NGFR 7 hours to 9 weeks after injury, which may be interpreted as axoplasmic transport effect of NGFR in the spinal ganglion cells. NGFR labelled intraspinal microvessels were present in the injured spinal cord. Reexpression of NGFR in motoneurons after injury reflects an increased demand of neurotrophic factors, and an increased access exerting the physiological effects of trophic factors mediated by NGFR.

One hundred and fifty-six children aged from 4 months to 12 years undergoing elective plastic surgery were included in this study. All children were ASA physical status I, under normal development, ranging from 64 to 140 cm in body height and from 6.0 to 41.0 kg in body weight. Following 2-minute preoxygenation, the time when SpO2 dropped to 95% and 90% in apneic period had a close correlation with age, weight and height of children by means of linear and non-linear regression analysis. The smaller the children's weight, the higher the incidence of severe arterial desaturation after reinstitution of manual ventilation with 100% oxygen at SpO2 of 90%. It is suggested that younger children are more susceptible to hypoxemia than older ones during apnea and provided no problem existing other than oxygen delivery, an SpO2 of 95% might be the safe limitation of apnea in pediatric anesthesia induction.

To assess the relationship between cochlear blood flow (CBF) and auditory function, a procedure of intravital microscopy for observations of the lateral wall vessels of the cochlea coupled with the simultaneous measurement of the endocochlear potential (EP) was established in guinea pigs with gradual ischemia of the cochlea. It was found that occlusions of both common carotid arteries and one of the vertebral arteries produced a minor reduction in CBF with no significant alteration in the EP. When intravenous infusion of ATP induced sharp and severe decreases in CBF, the EP varied only slightly from the baseline in some animals while there were no alteration in others. Furthermore, ATP infusions combined with arterial occlusions caused even more severe declines in CBF and a moderate decrease in the EP. The results indicate that not only does the CBF satisfy the basic needs of the processes of cochlear function, but also has a regulatory mechanism to ensure the normal function of the cochlea in the ischemia condition. It was also found that the changes in the stria vascularis vessels induced by decreases in blood pressure (BP) and heart rates were more severe than those of the spiral ligament vessels. This phenomenon indicated that the stria vascularis vessels were more sensitive to decreases of BP and heart rates.

Most patients lost their vocal ability after ablative surgery for the laryngeal cancer. Total laryngectomy has a history of over 100 years, hence many surgeons are accustomed to the en bloc organ resection and the loss of ability for communication after surgery. The recent advance of surgery introduces the concept and technique of radical cure and functional preservation of the cancer-afflicted-organ at the same setting. For lesions of late T categories (T3, T4), the maintenance of normal function after wide resection to ensure radicality demands a special technique to repair the crippled larynx. For this purpose a local osteomuscular flap was designed to reconstruct a functioning larynx. The surgical manoeuvre was described and the result proved to be successful. The outcome of 138 patients with T3 and T4 laryngeal carcinomas following conservation laryngectomy was analyzed. The five-year survival rate was 69% for supraglottic type and 75% for glottic type. The quality of life was much improved.

Nimodipine, produced in China, was applied to lower the blood pressure (BP) in 20 cases in craniocerebral operation. 0.02% solution of Nimodipine was dripped intravenously (by 0.02% of density), at a preliminary speed of 600-800 μg/min, and 4-12 mg of total dose. Mean arterial pressure (MAP) decreased and maintained at 7.3-8.0 kPa, and lasted 30-60 minutes. The scopes of decreasing pressure were 33.0%-37.7% of MAP, 31.6%-35.6% of systolic pressure (SP), and 36.1%-41.9% of diastolic pressure (DP). The results of lowering pressure which reduced the intraoperative bleeding were significant. After withdrawal of drug supply for 15-30 minutes, the BP raised up to the normal level. No "rebounding BP rise" occurred.

Endovascular therapeutic embolization of arteriovenous malformations (AVMs) of the brain was performed in 72 patients between October 1986 and March 1993. From October 1986 to May 1991, 38 patients in this series were treated with isobuty1-2-cyanoacrylate (IBCA) glue. After June 1991, in the remaining 34 patients the embolic materials used included surgical silk (5-0), polyvinyl alcohol (PVA), ethanol, and estrogen. After treatment, 29 patients (40.3%) had complete angiographic obliteration of AVM, 15 (21%) transient neurologic postembolization deficit, and 3 (4%) permanent deficit without death. Embolic agents and procedures are discussed as to their curative effects, safety, normal perfusion pressure breakthrough (NPPB) problem, with silk mixture fluid being considered preferable.

The main progress in the study of cardiovascular diseases in China during 1994 is reported here.

Extracorporal shock wave lithotripsy (ESWL) is a significant advancement in the treatment of urolithiasis and has now been widely used clinically in China. It has showed satisfactory efficacy and been well accepted by both doctors and patients.