Volume 113 · Issue 03 · 2000

Objective To study the effect of 8-bromo-cyclic AMP (8-Br-cAMP) on nitric oxide synthase (NOS) mRNA, NOS and nitric oxide (NO) product, heat shock protein (hsp)70 and neuron specific enolase (NSE) in human retinoblastoma HXO-Rb44 cells and the effect related to cell differentiation. Methods Cultured human retinoblastoma HXO-Rb44 cells were divided into two aliquots. One was cultured with 2 x 10-5 mol/L of 8-Br-cAMP for 24 hours as the experiment group; the other was treated with no 8-Br-cAMP as the control group. The cell suspensions in concentration of 1 x 107/ml in both groups were dropped onto the nitrocellulose membrane (NCM). The NOS mRNA was detected with the biotin-labeled NOS cDNA probe by RNA dot blot. The NOS activity was detected by protein dot blot. The immunoreactivity (IR) of hsp70 and NSE was detected by protein dot blot. The NO was detected by nitrate reductase method. NCM specimens were analyzed by a TLC scanner for detection of the dot blot signal intensity. Results The signals of NOS mRNA, NOS activity, hsp70-IR, NSE-IR, and NO content in the experiment group were higher than those in the control group (P < 0.05-0.01). Conclusions 8-Br-cAMP could increase NO product and the expression of NOS mRNA, NOS, NSE and hsp70. The results indicate that 8-Br-cAMP could facilitate synthesis of NO in the neuroblastoma HXO-Rb44 cells which could have tendency toward neuron development, suggesting that the increased hsp70, NO and NOS may involve cell differentiation of the retinoblastoma HXO-Rb44. Chin Med J 2000; 113(3): 198-200

Objective To study the possible mechanism of bilateral papilloedema associated with intraspinal tumor at the lumbo-sacral level. Methods Three cases were reported. Detailed clinical history was evaluated. Patients were followed up for 2, 3 and 5 months after resection of the tumor. Related literature was reviewed. Results Papilloedema was soon resolved and the level of protein in the cerebrospinal fluid (CSF) decreased significantly after resection of tumor. These indicated a close relationship between papilloedema, CSF protein and intraspinal tumor. Conclusion This is the first report of papilloedema associated with a lumbo-sacral intraspinal tumor in Chinese literature. The high level of protein in CSF may be the cause of both papilloedema and increased intracranial pressure. In patients with bilateral papilloedema, if no intracranial cause could be found, lumbo-sacral intraspinal tumor should be considered. Chin Med J 2000; 113(3): 201-205

Objective To assess whether and to what extent pulmonary function returns to normal after surgical correction for pectus excavatum. Methods Twenty-seven patients who could be examined in person at the outpatient department of our hospital were included in this study. Of these patients, 24 were boys and 3 were girls, with age ranging from 3 to 16 years (mean: 8.67 years). The mean age at surgery was 4 years and mean years at follow-up was 6.8. Pulmonary function measurements included inspiratory vital capacity (IVC), total lung capacity (TLC), residual volume (RV), functional residual capacity (FRC), RV/TLC ratio, maximal voluntary ventilation (MW), forced ventilatory capacity (FVC), forced expiratory volume in one second (FEV1), maximal mid-expiratory flow (MMEF), maximal expiratory flow at 75% vital capacity (V75), maximal expiratory flow at 50% vital capacity (V50), maximal expiratory flow at 25% vital capacity (V25) and breathing reserve ratio (BR). Results TLC, FRC, MW, MMEF, V75 and V50 were not different from normal values. IVC, FVC, FEV1 and V25 were significantly decreased compared with normal values. RV and RV/TLC were high in 87.5% cases. Conclusions Preoperative symptoms improved substantially after operation. Little airway obstruction was observed postoperatively, suggesting that patients with pectus excavatum should have surgery as early in life as possible, preferably by age 3. Chin Med J 2000; 113(3): 206-209

Objective To elucidate the airway responsiveness and its relative factors in asthma with natural remission at puberty. Method The airway responsiveness was evaluated by provocation of methacholine (PC20). Blood sIL-2R, IL4 and IFN-γ values in the cultural supernatant of mononuclear cells, eosinophil count, basophil count and basophil releasability were detected in 18 asthmatic cases with remission at puberty (group Ⅰ), in 20 asthmatics without remission at puberty (group Ⅱ), and in 30 healthy controls (group Ⅲ). Result The mean value of PC20 in group I was significantly lower than that in group Ⅲ (P < 0.01), but still higher than that in group Ⅱ (P < 0.01). The blood sIL-2R, and eosinophil counts dropped almost to those of group Ⅲ, significantly lower than those of group Ⅱ. IL-4 in the culture supernatant of mononuclear cells was similar to group Ⅲ, but significantly lower than that in group Ⅱ. However IFN-γ was also similar to group Ⅲ, significantly higher than that of group Ⅱ. The basophil count and positive rate of human basophil degranulation test stimulated by mannitol with hyper-osmolarity were still abnormal, significantly higher than those of group Ⅲ, and the basophil level was significantly related to the airway responsiveness. Conclusion The asthmatics with remission at puberty have a certain degree of airway hyper-responsiveness that is related to the abnormality of basophil. Chin Med J 2000; 113(3): 210-212

Objective To establish rat models of chronic obstructive pulmonary disease (COPD) and study the pathological characteristics of airflow obstruction. Method S02 inhalation method was used to establish rat models. After exposure to S02 for 7 weeks, peak expiratory flow (PEF), peak inspiratory flow (PIF), intratracheal pressure (IP) and IP slope in rat were measured by Maclab data recording and analysis system. Experimental rats with PEF less than 80% of the mean of the normal rats were classified as airflow obstructed, while those with PEF greater than 80% of mean of normal rats were non-obstructed. Pathological changes in airway and lung tissue were compared between these two groups. Result In experimental animals, PEF was significantly decreased (P < 0.005) and IP slope increased (P < 0.001) as compared with normal rats. Epithelial damage, goblet cell hyperplasia and inflammatory cell infiltration in cartilaginous bronchi were more remarkable in experimental rats with airflow obstruction than those without airflow obstruction (P < 0.001, < 0.01, < 0.001, respectively). Furthermore, pathological changes in airway lumen, epithelium and airway wall in membranous and respiratory bronchioles were more marked in experimental rats with airflow obstruction than those without airflow obstruction (P < 0.001 or P < 0.05).There was a negative correlation between PEF values and epithelial hyperplasia, goblet cell hyperplasia, inflammatory cell infiltration, smooth muscle hyperplasia and mucous plug in membranous and respiratory bronchioles (P < 0.001 or P < 0. 05). Conclusion S02 inhalation may cause chronic bronchitis with airflow obstruction, i. e. COPD in rats. COPD was induced in 64% (16 of 25) of the experimental group rats. Chin Med J 2000; 113(3): 213-216

Objective To explore the role of endothelin (ET) in the pathogenesis of exercise-induced asthma (EIA), we investigated the effects of ETB receptor antagonists, ET-111-21 fragment and N-cis-2, 6-dimethylpi-peridinocardonyl-L-γ-methylleucyl-D-l-methoxycarbonyl tryptophanyl-D-norleucine (BQ788) on bronchoconstriction elicited by isocapnic hyperpnea in guinea pigs. Methods Eighteen pathogen-free Hartley guinea pigs were randomly divided into three groups. A: normal saline (NS) inhalation control group (n = 6), B: BQ788 group (n = 6), and C: ET-111-21 fragment group (n = 6). Guinea pigs were anesthetized with pentobarbital sodium. After measuring the basal value of lung resistance (RL) and dynamic compliance of the respiratory system (Cdyn), NS (0.96 ml), BQ788 (9 nmol) and ET-111-21 fragment (9 nmol) were inhaled. A rodent respirator with a dry 5%C02 - 95%02 mixture at room temperature provided mechanical ventilation (VT 8 ml/animal, 100 breaths/min) for 5 min. RL and Cdyn of the 3 groups were measured again after isocapnic hyperpnea challenge. Results In the control group, isocapnic hyperpnea of dry gas elicited a marked increase in RL and decrease in Cdyn. RL and Cdyn of the guinea pigs from BQ788 group and ET-111-21 fragment group did not change significantly. Conclusion It was demonstrated that selective ETB receptor antagonists, ET-111-21 fragment and BQ788, inhibited the bronchoconstriction induced by isocapnic hyperpnea in guinea pigs. The data showed that ETs are potent constrictors of guinea pig airway smooth muscle via a direct effect on ET receptors. It was suggested that ET receptor antagonists, especially ETB receptor antagonist, might be beneficial in preventing EIA. Chin Med J 2000; 113(3): 217-221

Objective To investigate the short- and long-term clinicam and angiographic outcome of stenting or angioplasty for chronic total coronary artery occlusion. Methods A total of 95 patients with successful percutaneous transluminal coronary angioplasty (PTCA) for total occlusion coronary artery were identified out of 358 patients undergoing PTCA for chronic total occlusion. Patients were classified into two groups: Group A had selective stenting after successful PTCA and Group B only had PTCA. Clinical cardiac events including acute myocardial infarction (AMI) angina, death, repeat revascularization and angiographic variables were followed and analyzed. Results A total of 85 of 95 patients (89%) completed clinical and angiographic follow-up. In group A (n = 42), 1 patient experienced an AMI while in group B, 2 patients experienced AMI and 1 died. In group A, the restenosis rate was 29%, reocclusion rate was 12% and recanularization rate was 19%, as compared to 58%, 22% and 45% respectively in group B (P < 0.001, P < 0.05 and P < 0.001, respectively). Conclusions Selective stent improves short- and long-term clinical and angiographic outcomes and is recommended in cases of chronic total occlusion independent of the primary PTCA results. Chin Med J 2000; 113(3): 222-224

Objective To observe the effect of endovascular brachytherapy on the prevention of restenosis after interveneional therapy and to investigate its possible mechanisms. Methods In the balloon-injuried rabbit model, pathological sections of iliac arteries were observed and the changes of vascular histomorphology were estimated by computer analysis of photomicrograms. Using immunohistochemical techniques, proliferating cell nuclear antigen (PCNA) was quantified to assess the proliferation of vascular smooth muscle cells. Results After rabbit iliac arteries were injured by balloon overstretch angioplasty, neointima were shown to be less proliferative in the irradiated group than in the control group, from PCNA scores. The formation of neointima was suppressed with the external elastic laminar area increasing and without the luminal area decreasing in the irradiation group. Conclusion Endovascular brachytherapy using a liquid 32 P filled balloon catheter system could prevent restenosis possibly by inhibiting the formation of neointima and improving positive vascular remodeling. Chin Med J 2000; 113(3): 225-227

Objective To investigate the retrovirus-mediated transfer and expression of multidrug resistance gene (mdr1) in hematopoietic cells and to develop a model for studying the possible reversal of the MDR-mediated phenotype. Methods A retroviral vector HaMDR expressing the human mdr1 gene was packaged by PA317 cells with a titer of up to 8.5 x 105CFU/ml. K562 leukemia cells were infected with MDR retrovirus, and transfectant K562/MDR cells were generated. The integration and expression of the exogenous mdr1 gene in K562/MDR cells were determined by polymerase chain reaction and flow cytometry. The reversal ability of P-glycoprotein (P-gp) antagonists was analyzed by in vitro drug sensitivity, accumulation and efflux of rhodamine 123 (Rh123) in this model. Results Transduction with amphotropic MDR retrovirus resulted in integration and expression of the mdr1 gene in the resistant cells, where an aberrant splicing transcript of the mdr1 gene was found. The K562/MDR cells displayed a classic MDR phenotype with a 41-78 fold resistance to vincristine and colchicine in comparison with parental K562 cells. The drug sensitivity of K562/MDR cells to vincristine can be completely restored by cyclosporin A (CsA, 2 mg/L) and Cremophor EL (CRE 132 mg/L), either individually or in combination (P < 0.05). CsA (3 mg/L) can block the efflux pump function of P-gp shown by the significantly increased accumulation and efflux reduction of Rh123 in K562/MDR cells. Conclusions Retroviral vector HaMDR allows transfection with high-level expression of the mdr1 gene in human myeloid progenitor cells K562. The transfected K562/MDR provides a simple, sensitive model for developing antagonists of P-gp and studying their mechanism of action. Chin Med J 2000; 113(3): 228-231

Objective To evaluate the function of T cells in chronic myeloid leukemia (CML). Methods Interleukin-1β (IL-1β), interleukin-2 (IL-2), interleukin-3 (IL-3), interleukin-4 (IL-4), interleukin-6 (IL-6), tumor necrosis factor alpha (TNFα), and granulocyte macrophage-colony stimulating factor (GM-CSF) gene expressions were investigated by reverse transcription polymerase chain reaction (RT-PCR) assay in fluorescence active cell sorter (FACS) sorted peripheral blood CD2 + /CD56-T cells from 12 CML patients, 10 meylodysplastic syndrome (MDS) patients and 7 normal individuals. Results TNFα mRNA was transcribed in T cells from all of the CML, MDS and normal individuals. IL-1β mRNA was transcribed in T cells from 10 CML, 9 MDS and 6 normal individuals. Low levels of IL-2 and IL-4 mRNA were detected in 5 CML patients. IL-3, IL-6 and GM-CSF mRNA were undetectable in all samples. Conclusion IL-4 and IL-2 were expressed abnormally in T cells of CML. Chin Med J 2000; 113(3): 232-235

Objective To get the knowledge about between patients' compliance and doctors’ order in China, and to observe the influence on the reactivity of peptic ulcers due to the variation between patients' compliance and doctors' orders. Methods This is a prospective, randomized, multicenter, controlled trial of the efficacy in various instructional programs upon patients' compliance with doctors' orders. Patients with active peptic ulcers diagnosed through gastroscopic and pathologic examinations and followed up at the selected 100 hospitals of ten districts in Zhejiang Province of China between January 1 to December 31, 1997 were eligible for this study. All patients were given the same medications (proton pump inhibitor and amoxycillin) and were divided into four groups (A, B, C, D) by randomly selected envelopes as follows. Group A: simple patient education, namely simple instruction about the use and the course of the medications, and the follow-up time. Group B: stressed patient education, namely detailed instruction about the use, the course, the curative and side effects, the necessity of following up as well as making appointments of being checked. Group C: supervised education, meaning that the patients were managed as Group A while their family members/friends as Group B. The family members/friends were also asked to supervise the patients in taking the medications, in following-up and giving their phone numbers to doctors. Group D: stressed patient education plus supervised education, meaning that the patients and their family members/friends were treated as both Group B and C. Results The compliance rate was 47.1% in all 11 983 patients. From high to low the compliance rates in the four groups were D (52.8%), C (46.8%), B (46.3%) and A (46.2%), but statistically there were no significant differences between them. The most compliant age was under 20 years with 51.7% as the rate of compliance, and the occupation was of medical workers (57.0%), and persons graduated from secondary specialized schools also had the highest compliance (55.4%). On the contrary, the most noncompliants were young people (20 - 29 years old, 44.6%), illiterate persons (43.9%) and self-employed laborers (43.9%). Mountain areas were the lowest (40.8%) compliant areas. The main reasons for the failure of compliance included drug cost (34.9%), inconvenience to see doctor (31.8%), forgetfulness of patients (24.2%). The reactivity of each group was shown as D (91.1%), C (90.3%), B (89.4%) and A (89.2%), with also no significant difference in statistics. But a big difference and be found between compliant group with the noncompliant one because the reactivity in the compliant group was 97.4%while in the noncompliant group was only 58.8% ( x = 1449.2, P < 0.005). Conclusion Compliance with doctors' orders exerts a significant influence on the reactivity. The main reasons of noncompliance (drug costs, inconvenience to see doctor) are corresponding to the economic and social conditions in China.