Volume 109  ·   Issue 03  ·  1996

OBJECTIVE Extracapsular cataract extraction (ECCE) with selective intraocular lens (IOL) implantation has been the choice of the treatment for children with cataracts. With regard to surgical technique, ECCE with anterior segment vitrectomy has shown some success in reducing complications. Formation of a secondary membrane and opacity of the posterior capsule, however, are still major postoperative complications. To reduce these complications, we modified current surgical procedures with minimal incisions and manipulations. PATIENTS AND METHODS ECCE with anterior segment vitrectomy was performed using Storz Protage's system in 84 eyes of 58 children ranging in age from 14 months to 14 years. Of 70 eyes of children aged above 3 years, IOLs were implanted simultaneously. Vision improvement and incidence of postoperative complications were compared with other standard procedures to determine the benefits of the operation for children with cataracts. After the anterior capsule was opened by continuous circular capsulorhexis or envelope-form capsulectomy, the lens cortex was excised. Subsequently, the IOL was implanted into the bag. RESULTS Nine-30 months follow-up showed that all of the central area of the posterior capsule remained clear except one eye in which a secondary membrane was partially formed on the anterior surface of vitreous. No other operative or postoperative complications occurred. CONCLUSIONS The results indicate that the modified procedure is beneficial in the prevention of secondary cataract formation and other postoperative complications in a short term follow-up, however, a long-term follow-up is warranted to evaluate its role in pediatric cataract surgery.

OBJECTIVE To evaluate the effects of low-dose aspirin on placental circulation and on the prevention of intrauterine growth retardation (IUGR). MATERIAL AND METHODS We conducted a prospective randomized, double blind, controlled clinical trial in 84 pregnant women (mainly nulliparous women) at high risk of IUGR. From the 28th-30th week of gestation onward, low dose aspirin (75 mg daily, study group, n=40) or placebo (control group, n=44) was given consecutively for 6 to 8 weeks. Pulse-wave umbilical artery Doppler velocimetry was measured before and after drug use. RESULTS The mean value of systolic/diastolic ratio of umbilical artery flow velocity waveforms in the study group was significantly lower than that in the control group after drug use, but there was no difference between the two groups before drug use. The incidences of IRGR and preeclampsia in the study group (7.5% and 10.0% respectively) were significantly lower than those in the control group (27.3% of both). No adverse effects of low dose aspirin on both mother and fetus were observed. CONCLUSIONS Low dose aspirin administration (75 mg daily) beginning at the early stage of third trimester may improve the fetoplacental circulation, and thus prevent IUGR and/or preeclampsia effectively.

OBJECTIVE To evaluate the effects of 1 MAC of enflurane or isoflurane anesthesia on the pharmacokinetics of pancuronium. METHODS Eighteen adult patients undergoing the elective plastic surgery were randomly divided equally into 3 groups, namely, Group 1 (control group), Group 2 (enflurane group) and Group 3 (isoflurane group). Anesthesia was maintained with thiopental and 67% N2O-O2 in Group 1, 1 MAC enflurane in Group 2 and 1 MAC isoflurane in Group 3. After administration of a bolus of pancuronium 100 μg/kg, an improved fluorimetric assay was used to determine the serum concentrations of pancuronium and the pharmacokinetic variables of pancuronium were calculated with a 3P87 program. RESULTS The disposition of pancuronium may be well described mathematically by a two-compartment open model. The results showed that in comparison with the control group, patients in Group 2 and Group 3 had a longer T1/2β and MRT. The patients in Group 2 had the slower K10 and lower CL than those in the control group. There were no significant differences among the three groups in T1/2α, V1, V2, Vdss, Vβ, K21, K12 and AUC. CONCLUSIONS During enflurane and isoflurane anesthesia, CL of pancuronium decreased, and T1/2β and MRT of pancuronium were prolonged in our patients, so duration of the effective plasma concentrations of pancuronium was much longer. As a result, the effects of enflurane and isoflurane of the pharmacokinetics of pancuronium may be part of reason why two drugs extended the duration of neuromuscular depression produced by pancuronium.

OBJECTIVE To evaluate the efficacy and the histologic changes caused by self-made silk segment suspension as an agent for endovascular embolization of the external carotid artery of rabbit. METHODS Three different silk suspension were used to perform selective endovascular embolization of the external carotid artery in 21 rabbits. Postembolization changes were investigated by angiography, light and electron microscopy, and behavioral and functional examination made in various groups of rabbits. RESULTS The vascular changes in the group of simple silk segment were limited. The intima became thinner, while the media and adventitia were intact. However, in groups of ethanol-or estrogen-soaked silk segments, there was evident destruction of all layers of the vascular wall, including the intima, the media and the adventitia. CONCLUSIONS Estrogen- or ethanol-soaked silk suspension is ideal and reliable for endovascular embolization, with the former being more effective than the latter. The obliteration caused by the suspension of simple silk segment was due to mechanical packing and compression plus incomplete thrombosis, which is likely to result in recurrence through compensatory collateral circulation.

OBJECTIVE To study the causes and prevention of the complications of laparoscopic cholecystectomy (LC). PATIENTS AND METHODS Based on experience with 2 428 cases, the following should be paid attention to when dissecting and separating adhesions around the gallbladder and of the Calot's triangle. The best method for the prevention of mistaking the common bile duct (CBD) for the cystic duct is to find the junction of the cystic infundibulum and duct, separate the gallbladder wall along the infundibulum, and transect the cystic duct at the junction with the infundibulum. If dense adhesions around the gallbladder or of the Calot's triangle are met with, LC should be abandoned and open the cholecystectomy (OC) should be used instead. In separating the Calot's triangle, blunt dissection should be used to avoid burning the extrahepatic bile duct (EHBD), and blind hemostasis should be avoided. If the cystic artery lies in the upper part and the back of the cystic duct, the cystic duct should be dissected out, clipped and cut first, then the cystic artery be dealt with. If the cystic artery is in the front part of the pedicle of the gallbladder, the artery should be separated, clipped and cut first. Injury to the adjacent organs may be avoided by using electric coagulating hook correctly and avoiding accidental damage to the viscera, and keeping from viscera injury due to current chemotaxis in the closed cavity of the body. RESULTS A total of 2427 patients were cured. One patient died of frequent episodes of supraventricular tachycardia and pneumonia on the 21st day after LC. CONCLUSION If LC surgeons follow the above said principles of LC technique. LC is very safe for patients with benign diseases of the gallbladder.

OBJECTIVE Craniopharyngiomas is a kind of intractable tumor in neurosurgery. Since the radical excision is very difficult and occasionally hazardous because of its deep location and close neighbouring to critical cerebral structures, it is necessary to look for a simple and effective method. PATIENTS AND METHODS Stereotactic intratumour irradiation with instillation of nuclide colloid was performed in 220 patients with craniopharyngiomas (altogether 265 times), of whom, 130 were male and 90 female. Their ages ranged from 5 to 69 years. The syndromes of optic path's impairment were present in all of the patients. CT or MRI scan showed cystic tumour in 125 patients, solid and cystic in 80 and solid in 15. No severe complications and death were related to the operation. RESULTS 150 patients were followed up for 2 months to 7 years (average 3.5 years). Tumours disappeared in 92 patients (61.4%), decreased dramatically in 20 (13.4%), decreased less than 50% in 19 (12.6%), and increased in 15 (10%); and there were 4 deaths (2.6%). CONCLUSIONS Stereotactic intratumour irradiation with instillation of nuclide colloid is effective in the patients with craniopharyngiomas. Beta-emitting isotopes (P-32 and Y-90) are the preferred internal radiation source because of their limited penetration of the energy released and the greater ease of handling. A calculated dose of 20 000 rads to the cyst wall is recommended.

OBJECTIVE To investigate whether murine recombinant interferon-gamma (IFN-γ) is capable of inhibiting antigen-induced eosinophil (EOS) infiltration into the mouse airway. MATERIALS AND METHODS BALB/c mice were sensitized and challenged repeatedly with ovalbumin (OVA) to develop an allergic airway inflammation model. The experimental mice were given injection of different doses of IFN-γ. The numbers of EOS in bronchoalveolar lavage fluid (BALF) from each group were counted, and concentrations of interleukin (IL)-5 in supernatants of cultured spleen cells were detected. RESULTS In sensitized mice challenged with OVA 20 minutes once a day for 6 days, the number of BLAF EOS was 9.53±0.84 x 105)/ml. However, no EOS could be found in BALF from mice without OVA sensitization and challenge. In mice treated with IFN-γ, doses of IFN-γ (1.0×103, 1.0×104, 1.0×105U/KG) produced 29.8% (P<0.05), 55.7% (P<0.01), and 69.0% (P<0.01) inhibition of eosinophilia, respectively. The results also showed that IFN-γ prevented antigen-induced EOS recruitment into airway accompanied be decrement of levels of IL-5 with a dose-related response. CONCLUSION IFN-γ is capable of inhibiting EOS infiltration into mouse airway by inhibiting the production of IL-5. Our RESULTS suggested that IFN-γ may be of value in treating asthma in human beings.

OBJECTIVE To study the effects of low dose γ-ray irradiation on peripheral leukocyte counts and spleen weight of mice. MATERIALS AND METHODS Two hundred male mice of ICR strain were divided into four groups. Group A served as normal control. Groups B, C and D, the experimental groups were treated with 5, 50 and 100 cGy (exposure dose in air) of whole body γ-ray irradiation respectively. The leukocyte counts and its differential counts, body weight and the spleen weight of mice were measured on days 1, 5, 12, 19, 26 and 33 after irradiation. The relative spleen weight derived from the data of body weight and spleen weight was also calculated in tested animals. RESULTS The leukocytes and its differential counts and relative spleen weight in mice decreased after 100 cGy γ-ray irradiation. Fifty cGy γ-ray irradiation could inhibit the leukocyte and its differential counts. The lowest dose, 5 cGy had no considerable damage. CONCLUSIONS One hundred cGy of 137Cs γ-ray irradiation had an inhibitory effect on counts of total leukocyte, lymphocyte, neutrophil, monocyte, spleen weight and body weight, while 50 cGy γ-ray irradiation had an evident inhibition on peripheral leukocytes and its differential counts in mice. However, 5 cGy γ-ray irradiation had no obvious inhibition in the tested mice in the period of the investigation.

OBJECTIVE To understand whether very low density lipoprotein (VLDL) and oxidatively modified very low density lipoprotein (OX-VLDL) can stimulate vascular smooth muscle cells (SMCs) to express high level of monocyte chemotactic protein (MCP-1) mRNA. METHODS LDL and VLDL were isolated from normal blood donors by density gradient ultracentrifugation and oxidatively modified by adding CuCl2 and incubation at 37 ℃ for 24 hours. Rabbit aortic SMCs were cultured by a substrate-attached explant method, and their total RNA was extracted by guanidinium isothiocyanate method. The expression of MCP-1 mRNA in SMCs was examined by dot blotting analysis using a probe of γ-22P-end-labeled 35-mer oligonucleotide. RESULTS Dot blotting analysis showed that cultured SMCs can express MCP-1 mRNA and the level of MCP-1 mRNA was increased significantly in SMCs after 24-hour coculture with VLDL (6-fold) and OX-VLDL (20-fold). CONCLUSIONS VLDL and OX-VLDL both can induce MCP-1 mRNA expression in cultured rabbit aortic SMCs and the latter is more effective than the former.

OBJECTIVE To determine the extent to which immaturity of hepatic microsomal enzyme activity might contribute to physiological jaundice. METHODS Urinary excretion of D-glucaric acid, expressed in mumol glucaric acid/ mmol creatinine, was measured in 122 Chinese full-term healthy newborn babies during the first five days of life. Among the 122 babies, 22 were born by normal spontaneous delivery at the British Military Hospital and 100 were born by caesarean section at the Prince of Wales Hospital. RESULTS In all babies the excretion of D-glucaric acid was highest on the first day of life and gradually decreased over the following 5 days. Five babies born by spontaneous delivery and six babies born by caesarean section developed jaundice during the study period. The excretion of D-glucaric acid in the jaundiced babies was significantly higher on the first two days than in the non-jaundiced babies. CONCLUSIONS D-glucaric acid excretion was increased in jaundiced newborn babies in the first few days of life. This finding does not indicate less liver microsomal enzyme activity in the jaundiced babies compared to those non-jaundiced. On the contrary, it suggests that in idiopathic neonatal jaundice compensatory mechanism might operate from a very early stage to excrete a higher bilirubin load that might be present through haemolysis.