LDPE／CPE／炭黑三相复合导电体系的电学性能

研究了ＬＤＰＥ／ＣＰＥ／炭黑三相复合导电体系的导性能和电流－电压特性。实验结果表明复合体系具有明显的导电渗滤效应，在共混比ＬＤＰＥ／ＣＰＥ＞５０／５０时，导电性能随ＣＰＥ含量增加而显著提高，这主要是由于炭黑粒子在ＬＤＰＥ和ＣＰＥ两组分分中的分布不均匀性所致。     

Rat liver regeneration after partial hepatectomy: effects of insulin, glucagon and epidermal growth factor.

This study evaluated the role of insulin, glucagon and the epidermal growth factor (EGF) on liver regeneration after partial hepatectomy. Male Wistar rats, weighing approximately 200 g, were used. A partial hepatectomy, with resection of the medial and left lateral lobes (67.31%), was performed on the control group and seven hormone-treated groups: insulin, glucagon, EGF, insulin plus glucagon, insulin plus EGF, glucagon plus EGF, and a combination of the three hormones. The hormones were administered subcutaneously two days prior to the partial hepatectomy. The groups administered insulin were allowed to drink 20% glucose in water. Another group of rats received simulated operations, i.e., only a laparotomy was performed. The rats were killed at six, 24, 48 and 72 hours after the operation. Remnant liver weight, deoxyribonucleic acid (DNA) content, rate of DNA synthesis, mitotic index, blood glucose and serum insulin levels were measured. The results showed that: 1) the effects of single hormone administration on posthepatectomy liver regeneration were not obvious; 2) combined administration of insulin and glucagon increased the weight of the remnant liver, the DNA content, and the rate of DNA synthesis; 3) the combined administration of insulin, glucagon, and EGF increased the regeneration based on the remnant liver weight and mitotic index; and 4) there was no concordance between the change in blood glucose levels and the effect of hormones during liver regeneration.     

Accidental ingestion of Ecstasy in a toddler.

Toddlers who ingest the drug of abuse 3,4-methylenedioxymethamphetamine (MDMA; 'Ecstasy') are at particularly high risk of serious neurological and cardiovascular side effects. We report of a 20-month-old male toddler who accidentally ingested Ecstasy. He presented with fever and seizures, tachycardia, hypertension, and hyperthermia. Urine amphetamine level was 2111 ng/mL. Treatment included rapid cooling, hydration, and support measures. Vital signs were regularly monitored. His condition became stable on day 2 and urine amphetamine level returned to normal on day 3 of hospitalization. His behavior, activity, and appetite had returned to their usual levels upon follow-up at our outpatient clinic. The incidence of drug abuse with MDMA has increased dramatically over the last decade in developed countries. It can be expected that accidental Ecstasy poisoning in children will increase as well. This case illustrates the need to consider the possibility of accidental Ecstasy ingestion in the differential diagnosis of a child suffering from convulsions with fever.     

广西毛南族农村妇女铁营养状况调查

对450名广西环江县毛南族农村育龄妇女进行血清铁蛋白(SF)、红细胞游离原卟啉(FEP)及血红蛋白(Hb)3项铁指标测定.结果发现:铁缺乏症患病率为27.8%(其中ID4.2%,IDE 7.8%,IDA 15.8%).随着孕次或产次的增加,血红蛋白水平逐渐下降,铁缺乏症患病率逐渐增高.有妊娠或分娩史的妇女与未孕或未生育的妇女血红蛋白水平与铁缺乏症患病率比较均有显著性差异(P<0.05).     

对SARS抗体动态水平的系统观察

目的应用化学发光光度分析法对SARS抗体(SARS-Ab)动态水平进行观察.方法对432例SARS病人在恢复期的不同阶段进行检测.结果显示SARS病人的抗体检出率为94.0%(404/432).病人SARS-Ab在2,3,4周和2个月时,抗体检出平均光子数值为3.79,7.71,12.31和24.17;3～8个月SARS-Ab下降率分别为92.9%,83.3%,40.0%,26.7%,13.3%和7.0%.结论病人在患病初期,SARS-Ab呈上升趋势,3个月后逐渐下降,并能动态观察不同年龄组SARS-Ab的明显差异.     

A retrospective analysis of the stability and relapse of soft and hard tissue change after bilateral sagittal split osteotomy for mandibular setback of 64 Taiwanese patients.

PURPOSE: This study was an analysis of the soft and hard tissue changes of the facial profile after bilateral sagittal splitting osteotomy for mandibular setback of Taiwanese patients. PATIENTS AND METHODS: We collected pre- and postsurgical lateral cephalographs of 64 patients (28 males, 36 females) with skeletal Class III malocclusion who received combined orthodontic-surgical treatment with bilateral sagittal splitting osteotomy mandibular setback at Taipei Veterans General Hospital between 1994 and 2000. Nineteen cephalometric parameters of (14 linear, 4 angular, and the BS index) soft and hard tissues were measured at 1 week before treatment, and 2 months and 1 year after surgery, and analyzed by paired t test. RESULTS: Mean patient age was 20.0 +/- 1.6 years. The patients underwent an average of 7 mm mandibular setback at the osseous pogonion (Pog). Average setbacks at Pog and soft tissue pogonion (pog) were 5.54 mm and 4.85 mm, respectively, at 1 year after surgery. The setback ratio of Pog/pog was 1:0.88. The hard tissue relapse at Pog was 21% at 1 year after surgery. Improvement in prognathic profile was demonstrated by significant changes in the positions of Pog and pog, ANB angle, the distance from lower lip to esthetic line (E-L lip), and the BS index after surgery. However, compared with parameters obtained from a normal Taiwanese population, the cephalometric data of Pog, pog, and BS index still indicated mild prognathism. CONCLUSION: Although mandibular prognathism could be grossly improved by bilateral sagittal splitting osteotomy mandibular setback, a significant amount of relapse occurred within 1 year after surgery. The extent of the postoperatively preserved features showing mandibular prognathism should be a concern for both patients and physicians.     

EVALUATION OF INDOCYANINE GREEN RETENTION AND AMINOPYRINE BREATH TESTS IN PATIENTS WITH MALIGNANT BILIARY OBSTRUCTION

Impaired hepatic function is a major contributory factor to the high incidence of postoperative morbidity and mortality in patients with malignant biliary obstruction. Dynamic hepatic function tests such as indocyanine green (ICG) retention and aminopyrine breath tests were evaluated in such patients to define whether they were clinically useful for prediction of postoperative morbidity and mortality. Forty-four patients with malignant biliary obstruction undergoing surgery for relief of obstructive jaundice were recruited into the study. Indocyanine green retention and aminopyrine breath tests were carried out in all patients pre-operatively and repeated in 36 patients postoperatively. The ICG retention was abnormal in all patients before surgery and there was significant improvement 2 weeks after surgery (32.8 ± 2.5%vs 18.3 ± 2.8%, P= 0.001). The change in ICG retention levels correlated with the serum bilirubin levels but the pre-operative ICG retention value could not predict postoperative morbidity and mortality. The aminopyrine breath test was abnormal in all but one patient. It correlated with pre-operative prothrombin time of the patients before surgery but it did not improve significantly after surgery and was not predictive of postoperative outcome. It is concluded that both ICG retention and aminopyrine breath tests have limited clinical value in the pre-operative evaluation of patients with malignant biliary obstruction.     

Benzo(a)pyrene inhibits epidermal growth factor binding and receptor autophosphorylation in human placental cell cultures

Studies investigated the effects of benzo(a)pyrene (BP) treatment on epidermal growth factor (EGF) receptor binding and kinase activity in human placental cell cultures. Specific binding of 125I-EGF to cells from early gestation placentae was significantly decreased by 37 and 60% following exposure to 1 and 10 microM BP, respectively, for 24 hr. In contrast, cells cultured from term placentae showed no inhibitory effect of either concentration of BP. Specific binding of 125I-labeled insulin and insulin-like growth factors-I and -II to early gestation cells was decreased only 15-18% at 10 microM BP, which indicates that loss of membrane receptors appears to be selective for EGF. Scatchard analysis of early gestation cells revealed that BP was associated with a dose-dependent loss in the number of high affinity EGF binding sites. Evidence from cross-linking and autophosphorylation experiments confirmed that the Mr 170,000 binding protein was decreased in a dose-dependent manner following BP treatment. In comparison, term placental cells exhibit a 26% loss of EGF receptor autophosphorylation without alteration in binding following exposure to 10 microM BP. Thus, early gestation cells exhibit a BP-related down-regulation of EGF receptors, whereas term placental cells show receptor desensitization. No adverse effect of BP treatment was observed on the incorporation of [35S] methionine into proteins secreted by early gestation cells. Further experiments compared the effects of BP with the related poly-cyclic compounds beta-naphthoflavone, alpha-naphthoflavone, and 3-methylcholanthrene. In early gestation cells, EGF binding and receptor autophosphorylation were measurably decreased at 10 microM concentrations of these polycyclic compounds, but to a lesser extent than observed with BP. In term placental cells, however, EGF binding was unchanged or increased, whereas receptor autophosphorylation was decreased 10-26%. Thus, exposure of term placental cells to these polycyclic compounds leads to a dissociation between EGF binding and receptor protein kinase activity. Finally, aryl hydrocarbon hydroxylase activity was induced 20- to 200-fold in early placental cells exposed to BP, beta-naphthoflavone, and 3-methylcholanthrene. In summary, the direct effects of BP and related compounds observed on placental EGF receptors may indicate altered function of EGF in the regulation of cell growth and differentiation in the human placenta.