2003年 · 第116卷第06期

Objective To summarize the clinical features of severe acute respiratory syndrome(SARS)and to discuss diagnosis and management of the disease. Methods A retrospective study was conducted on 78 cases of SARS referred to the Guangzhou Institute of Respiratory features of severe acute respiratory syndrome(SARS)and to discuss diagnosis and management of the disease. Methods A retrospective study was conducted on 78 cases of SARS referred to the Guangzhou 2003. Items reviewed cover all Institute of Respiratory Diseases(GIRD)between December 22, 2002 and near the end of March 2003. Items reviewed cover all data concerning clinical manifestations, laboratory investigation and radiology. Results The patients in the study consisted of 42 males and 36 females, aged 20-75 yrs(mean age 37. 5 ±11.6 yrs), including 44 affected health-care professionals. Clinical symptoms seen in the group were fever(100.0%), cough(88.5%), and dyspnea(79.5%).There were 12cases(15.3%)with WBCs <4.0 × 109/L,49 cases(62.8%)ranging between(4.0-10.0)x109/L(neutrophil)and 17 cases(21.8%)over 10.0 × 109/L. The average was(7.58±4.96)x109/L, with 0. 75 ±0.14(neutrophil)and 0.18 ±0.11(lymphocyte).Cheste films and CT scanning revealed changes related to pneumonia.The transmissin of the disease was likely via close contact with contagious drople.The prevalences of acute lung injury(ALI,in 37cases)and acute resplratory distress syndro developed me(ARDS, 21 out of 37 cases)were considerably high among the patients. Seven patients who developed ARDS complicated with multipe organs dysfunction sydrome(MODS)died. Conclusions A history of close contact, fever, sign of pneumonia by X-ray and normal-to-lowered WBC counts are favorable for the diagnosis of SARS. Recognition of ALI as the important index for critical SARS and comprehensive supportive management are of paramount in decreasing the mortality of the disease.Chin Med J 2003; 116(6):805-810

Objective To describe a hospital outbreak of severe acute respiratory syndrome(SARS)and summarize its clinical features and therapeutic approaches. Methods The outbreak started with a SARS patient from the community, and a total of 96 people(76 women and 20 men, mean age(29. 5 ±10. 3)years, 93. 8% of whom were health care workers)who had exposure to this source patient became infected in a short time. Clinical data in this cohort were collected prospectively as they were identified. Results (1)The incubation period ranged from 1 to 20(mean: 5. 9 ±3. 5)days. The duration of hospitalization was(17. 2 ±8. 0)days.(2)The initial temperature was(38. 3 ±0. 6)℃, while the highest was(39. 2 ±0. 6)℃(P<0. 001), with fever duration of(9. 0 ±4. 2)days.(3)Other most common symptoms included fatigue(93.8%), cough(85. 4%), mild sputum production(66. 7%), chills(55. 2%), headache(39. 6%), general malaise(35. 4%)and myalgia(21. 9%).(4)The radiographic changes were predominantly bilateral in the middle or lower lung zones. The number of affected lung fields was 1. 2 ± 0. 8 on presentation, which increased to 2. 9 ± 1. 4 after admission(P<0. 001). The interval from the beginning of fever to the onset of abnormal chest radiographs was(3. 5±2. 3)days, which increased in size, extent, and severity to the maximum(6. 7±3. 5)days later. The time before the lung opacities were basically absorbed was(14. 9±7.8)days.(5)Leukopenia was observed in 67. 7% of this cohort. The time between the onset of fever and leukopenia was(4. 4 ±2. 3)days, with the lowest white blood cell count of(2. 80 ±0. 72)x 109/L.(6)The lowest arterial oxygen saturation was(94. 8 ± 3. 1)% with supplementary oxygen.(7)Antibiotical therapies included tetracyclines(91. 0%), aminoglycosides(83. 3%), quinolones(79. 2%); 18. 8% of the patients received a combination of tetracyclines and aminoglycosides, while 11. 5% received a combination of tetracyclines and quinolones, and 63. 5% received a combination of tetracyclines, aminoglycosides and quinolones. Vancomycin was used in 13. 5% of the patients.(8)68. 8% of the patients were treated with methylprednisolones for a mean interval of(4. 9 ±2. 4)days. The initial dose was(67. 3 ±28. 2)mg/d and the maximal dose was(82. 4 ±30.5)mg/d.(9)Human y-globulin, interferon-α, antiviral drugs(oral ribavirin or oseltamivir)were used respectively in 68. 6%, 46. 9% and 92. 7% of the patients.(10)Ninety-five patients(99. 0%)had a complete clinical recovery, and only 1 patient(1. 0%)died. Conclusions SARS appears to be quickly infectious and potentially lethal among health care workers, characterized by acute onset and rapid progression, and mostly bilateral lung involvement on chest radiographs. Proper administration of glucocorticosteroids seems to be of some benefits. Antibiotics, human γ-globulin, interferon-α, and antiviral drugs, although empirically, might be useful to shorten the clinical course. Chin Med J 2003; 116(6):811-818

Objective To explore the clinical and radiological features of severe acute respiratory syndrome(SARS). Methods Analysis of the clinical presentation, chest radiographs, course of disease and features of severe pneumonia in 45 SARS patients diagnosed at our hospital in Beijing between April 5-20, 2003. Also included is a summation of the clinical features of SARS. Results (1)SARS appears to have high infectivity;(2)the most common symptom is fever;(3)the count of leukocyte is normal or decreased;(4)most patients(35/45, 77.8%)had experienced a 24-hour fever prior to the abnormal chest X-ray changes which showed progression of pulmonary infiltrates within 48 hours in 71.1 %(32/45)of the patients and,(5)the percentage of patients who developed severe pneumonia(24. 4%)is higher than those who developed typical pneumonia. Conclusion SARS is a disease with high infectivity and has its own clinical and radiological features. Early recognition, prompt isolation, and appropriate therapy are the key to combate this infection. Chin Med J 2003; 116(6): 819-822

Objective To study the early X-ray and CT findings of patients with severe acute respiratory syndrome(SARS). Methods Chest radiography and CT were performed in 28 patients with SARS within one to three days after onset of the disease. CT examinations includedt conventional spiral CT and high-resolution CT(HRCT). The radiographic and CT findings of these patients were analyzed retrospectively. Results Abnormal CT findings were noted in all the patients, but abnormal chest radiographic findings in 17 cases(60.7%, 17/28). CT showed single small focal patchy opacities in 23 patients(82.1%, 23/28), including oval ground-glass opacities in 20 patients, lobular distribution ground-glass opacities in 2 and small patchy consolidation in one. Multi-focal ground-glass opacities were found in 2 patients and extensive opacities in three. In the 28 patients, a total of 31 lesions were found in the upper(7, 22.6%), middle(3, 9. 7%), and lower lobes(21, 67.7%). The diameter of the lesions ranged from 20 to 35 mm. Conclusion The dominant feature of early SARS patients is focal patchy opacity in the lung, and oval small ground-glass opacities are the common morphological findings on CT. Chin Med J 2003; 116(6):823-826

Objective To investigate the changes of subgroups of peripheral blood T lymphocytes in patients with severe acute respiratory syndrome(SARS)and its clinical significance. Methods Subgroups of blood T lymphocytes in 93 patients with SARS were detected by flow cytometer. The results detected in 64 normal subjects and 50 patients with AIDS served as controls. Results The numbers of CD3+, CD4+, and CD8+ lymphocytes all significantly decreased in acute phase of patients with SARS [(722 ±533)/μl,(438 ±353)/μl,(307 ±217)/μl)] compared with those in normal controls [(1527±470)/μl,(787±257)/μl,(633 ±280)/μl, all P <0. 01)], which was different from what we observed in patients with AIDS who had decreased CD4+ [(296±298)/μl] but increased CD8+ [(818 ±566)/μl ] counts. The counts of CD3+, CD4+, and CD8+ lymphocytes decreased more apparently in patients with severe SARS. All the five patients who died had CD4+ counts less than 200/μl. As the patients' condition improved, CD3+, CD4+, and CD8+ counts gradually returned to normal ranges. Conclusion The damage of cellular immunity is probably an important mechanism of pathogenesis Of SARS. Chin Med J 2003; 116(6):827-830

Severe Acute Respiratory Syndrome(SARS), referred to as "contagious atypical pneumonia"is the fastest spreading communicable disease known in recent history. This disease is different from other kinds of respiratory contagion due to the following aspects: the syndrome happens quickly and the infectivity is high. New problems encountered by the nursing management staff are the precipitate, pestiferous, and large numbers of in-patients and the understanding of appropriate responses, within large complex hospitals, to ensure patient care is actively supported and infectivity is prevented. To deal with these problems, we implemented the following strategies: reinforcement of the management system; optimization of the nursing flow; amendments to related hospital policies; collection of relevant information; adherence to stringent disinfection protocols; isolation of areas; reallocation of hospital resources and more efficient utilization of resources. The above strategies have reinforced the nursing management system's active response, guaranteed daily operation of the hospital's nursing activities, including the quality of care provided by the nurses, and ensured the health of patients, nurses and doctors. Chin Med J 2003; 116(6):834-837

Objective To demonstrate the clinical efficacy of micronized fenofibrate on mildly-moderately elevated LDL-C levels and reduced HDL-C levels. Methods During 1998-1999, 2358 patients with type Ⅱa, Ⅱ b and IV hyperlipidemia were monitored in 16 cities in China. They were treated daily with micronized fenofibrate(micronized lipanthyl)200 mg for 8 weeks. Lipid levels before and after the treatment were measured and analyzed. Results Micronized fenofibrate significantly increased HDL-C levels by 12. 7%, the effect being inversely correlated to the baseline level of HDL-C. Out of the total patient population, a baseline level of HDL-C <1. 0 mmol/L was found in 837 patients: amongst this group, 510 patients(60. 9%)were observed to have an increase in the level of HDL-C to > 1.0 mmol/L with a mean of 1. 3 mmol/L, after 8-week micronized fenofibrate therapy. Furthermore, the mean LDL-C level decreased by 15. 9%following an 8-week treatment of micronized fenofibrate, an effect positively correlated to the baseline level of LDL. In general, all patients tolerated the drug comfortably. Conclusions Short-term treatment of micronized fenofibrate in patients with dyslipidemia significantly increases HDL-C level and reduces mildly-moderately elevated LDL-C level. As expected, it also reduces triglyceride levels. Chin Med J 2003; 116(6): 840-843

Objective To assess the immediate and late clinical outcome of left anterior descending artery ostial lesions treated with percutaneous coronary intervention. Methods Seventeen patients(6 females and 11 males)treated with percutaneous coronary intervention for ostial left anterior descending artery stenoses have had clinical follow-ups over 12 months. Clinical events were defined as an occurrence of death, myocardial infarction, recurrent angina, and reguiring repeat revascularization(either by angioplasty or by surgery). A matched population treated with coronary bypass surgery was selected based on the similarities in age, left ventricular ejection fraction and the number of diseased vessels. Kaplan-Meier event-free survival curves were generated and the matched comparison was done using the Chi-square test(Mc Neimar method). Results In the catheter-based angioplasty group, the patients' mean age was 63 ±8 years. One patient was treated with directional atherectomy plus balloon, 6 with rotational atherectomy plus balloon, 7 with stent and 3 with rotational atherectomy plus stent. Glycoprotein Ⅱ b/ III a antagonist was used in 4 cases. Initial procedural success without major complications was achieved in all cases. The mean reference diameter was 2. 90 ±0. 48 mm. The minimum lumen diameter increased from 1. 05 ±0. 30 mm to 2. 40 ±0. 45 mm, and the diameter stenosis decreased from 64% ±7% to 8% ± 13%. During the follow-up period, adverse events reguiring repeat revascularization occurred in 8 patients. The event-free probability was 0. 42 ±0. 14 in a two-year period. In a matched population treated with bypass surgery(single mammary graft), only one event occurred, and the difference in event-free survival in two-year period between the two patient groups was significant. Conclusions Percutaneous coronary intervention for left coronary descending artery ostial lesion is technically feasible and safe, leading to an optimal early success rate, but has a higher risk of late restenosis and greater need for repeat revascularization than coronary bypass surgery. Chin Med J 2003; 116(6): 844-848

Objective To establish a clinical classification of pulmonary embolism(PE), and to evaluate the optional treatment strategies for different types of PE. Methods From December 1995 to July 2001, 45 patients with acute PE were hospitalized, of which 33 received intravenous thrombolytic therapy or interventional treatment. Results Misdiagnostic rate in the 45 patients with acute PE during first visit was 62. 2% and mortality rate was 28. 9%. Misdiagnostic rate in acute PE patients who had undergone surgery was 82% and mortality rate was 73%. The effective rate of thrombolytic therapy was 77. 7%. Clinical symptoms rapidly disappeared in massive PE patients treated with interventional therapies. Conclusions Intravenous thrombolytic therapy is one of the most effective methods for treating acute PE. Application of interventional therapy for severe acute PE is also promising. Chin Med J 2003; 116(6): 849-852

Objective To investigate whether patients, who are at risk of major acute coronary events, are safe to undergo and benefit from early intervention after using simvastatin. Methods The study was a randomized, open, two-dosage-controlled trial to evaluate the safety and benefits of simvastatin administered to 197 patients(10 mg group, n =98 and 20 mg group, n =99), within 48 hours of hospitalization for a diagnosis of unstable angina or acute myocardial infarction(MI), with total cholesterol(TC)≥ 180 mg/dL or low-density lipoprotein cholesterol(LDL-C)≥ 100 mg/dL. Lipid levels were measured immediately, followed by the 3rd, 6th and 12th month after admission and all adverse events were recorded during follow-up. Results TC levels fell by 10. 15% and 14. 52% in the 10 mg and 20 mg groups(P < 0. 05), and LDL-C levels fell 13. 87% and 19. 38% in the 10 mg and 20 mg groups, respectively(P<0. 01), 12 months after using simvastatin. The rates of achieving target TC reached 26. 3% and 36. 5% in the 10 mg and 20 mg groups(P <0. 01), and that of LDL-C reached 28. 2% and 40. 3% in the 10 mg and 20 mg groups, respectively(P<0. 01). There were higher rates of Ml and re-hospitalization resulting from angina pectoris and revascularization in the 10 mg group compared with the 20 mg group. Conclusions The results suggest that early intervention with the HMG-CoA reductase inhibitor, simvastatin, in acute coronary syndromes is possible and safe. It also indicates that the clinical dosage of simvastatin are relatively smaller than that for satisfactory lipid control in patients with acute coronary syndromes. Chin Med J 2003; 116(6): 853-856

Objective To investigate the role of calcineurin(CaN)in the lung fibroblast proliferation and collagen synthesis induced by basic fibroblast growth factor(bFGF). Methods We used Western blot and immunohistochemical methods for investigating the content and distribution of calcineurin in the lung tissue. Calcineurin activity in different tissues was measured using 32P-labelled substrate. In the primary culture of lung fibroblasts, 3H-thymidine(3H-TdR)and 3H-proline incorporation methods were used to study the effect of cyclosporin A(CsA), an inhibitor of calcineurin, on the lung fibroblast DNA and collagen synthesis stimulated by bFGF. Results We found that calcineurin was expressed in lung tissue and has phosphatase activity(7. 1 ± 2. 0 pmol Pi/mg pr/min). CsA(10-8-10-8 mol/L)inhibited lung fibroblast 3H-TdR incorporation induced by bFGF in a dose-dependent manner, with the inhibitory rates by 20%, 46% and 66%(P< 0. 01). CsA(10-7-10-8 mol/L)inhibited 3H-proline incorporation in lung fibroblasts stimulated by bFGF, with the inhibitory rates by 21 % and 37%(P<0. 01). In a culture medium, CsA(10-8-10-6 mol/L)inhibited 3H-proline secretion induced by bFGF in a dose-dependent manner, with the inhibitory rates by 19%, 29%(P < 0. 05)and 56%(P < 0. 01). CsA(10-7 mol/L)could inhibit calcineurin activity by 44% in lung fibroblasts(P<0. 01). Conclusions Calcineurin is expressed in lung tissue and has phosphatase activity. It is involved in the bFGF stimulated lung fibroblast DNA and collagen synthesis. Chin Med J 2003; 116(6): 857-862

Objective To investigate the expression and role of adrenomedullin(ADM)and adrenomedullin receptor(ADMR)in patients with chronic obstructive pulmonary disease(COPD). Methods Small pulmonary artery remodeling was observed using morphometric analysis. The expression of ADM and ADMR mRNA in lung tissue was calculated by in situ hybridization in 9 COPD cases. Cardiac catheterization was performed in 22 COPD cases to monitor changes of hemodynamic parameters and patients were divided into two groups based on mean pulmonary artery pressure(mPAP). The cases without pulmonary hypertension(PH)were placed in Group A(n =12)and those with PH were placed in Group B(n =10). The levels of pulmonary arterial plasma ADM were measured by radioimmunoassay. Blood gas analysis was also conducted. Results The ratio of vascular wall thickness to external diameter(MT%)and the ratio of vascular wall area to total area(MA%)were higher in patients with COPD(P< 0. 01). In situ hybridization showed that ADM mRNA and ADMR mRNA were expressed in the pulmonary artery walls of control subjects. The expression levels were significantly higher in those of COPD sufferers(P < 0. 01). Statistically positive relationships were visible between ADM and ADMR, and the plasma ADM level of Group B was significantly higher than that of Group A(P < 0. 05). The plasma ADM level had a significantly positive correlation to mPAP and pulmonary vascular resistance(PVR), while being negatively correlated to levels of Pa02. Conclusion ADM may play an extremely protective role as a local autocrine/paracrine factor in COPD. Chin Med J 2003; 116(6): 863-867

Objective To investigate the regulation of leptin on insulin secretion and expression of ATP-sensitive potassium channel subunit sulfonulurea receptor 1(SUR1)mRNA, and to determine whether the effects of leptin are mediated through known intracellular signaling transduction. Methods Pancreatic islets were isolated by the collagenase method from male SD rats. The purified islets were incubated with different concentrations of leptin for 2 h in the presence of different concentrations of glucose. Insulin release was measured using radioimmunoassay. Expression of SUR1 mRNA was detected by RT-PCR. Results In the presence of leptin 2 nmol/L, insulin release was significantly inhibited at either 11. 1 or 16. 7 mmol/L glucose concentration(both P<0. 05), but insulin release was not altered at glucose of 5. 6 mmol/L physiological concentration. The dose-response experiment showed that the maximal effect of leptin on insulin secretion achieved at 2 nmol/L. Exposure of islets to 2 nmol/L leptin induced a significant increase of SUR1 transcription levels by 71 %(P<0. 01)at 11. 1 mmol/L glucose and by 56%(P <0. 05)at 16. 7 mmol/L glucose concentration. Selective phosphatidylinositol 3-kinase(PI 3-kinase)inhibitor wortmannin significantly prevented the leptin effect on insulin secretion and SUR1 mRNA expression. Conclusions Regulatory effects of leptin on insulin secretion could be biphasic at different concentrations of glucose and leptin. The stimulatory regulation of SUR1 transcription levels may be mediated through activation of PI 3-kinase pathway, which may be a possible mechanism of leptin in regulating insulin secretion. Chin Med J 2003; 116(6): 868-872

Objective To investigate the fluctuations in arterial leukocyte phospholipase D(PLD)activity during the perioperative period of open heart surgery under cardiopulmonary bypass(CPB), and the relationship between PLD activity and systemic inflammatory response induced by CPB. Methods Arterial blood was obtained from 26 patients undergoing open heart surgery at 8 different time points during the perioperative period, from which leukocytes were isolated for determination of PLD activity, CD11b expression and myeloperoxidase(MPO)activity. Plasma IL-6, IL-8 and C-reactive protein were also determined. The 26 cases were retrospectively divided into 3 groups according to perfusion time in order to detect the possible influences of CPB on PLD activity and IL-6 and IL-8 levels. Results When the ascending aorta was declamped, average arterial leukocyte PLD activity was 0. 305 ±0. 132 nmol choline · min-1 · mg-1, 5. 0 times higher of the pre-CPB value, and remained(5. 4 times higher of the pre-CPB level)at 72 hours after CPB. Leukocyte CD11 b expression and plasma IL-6 and IL-8 levels increased significantly at the end of CPB, while MPO activity and C-reactive protein concentration reached their peaks at 1 and 24 hours, respectively, after CPB. At the end of CPB, the arterial leukocyte PLD activity of patients whose CPB duration was longer than 90 minutes were 1. 82-and 1. 74-fold that of the other two groups with CPB lasting between 90 and 60 minutes and less than 60 minutes. Conclusions Arterial leukocyte PLD activity rises significantly in CPB and its elevation is earlier and more persistent than other inflammation-related indicators tested; longer CPB duration leads to higher leukocyte PLD activity at the end of CPB. These results imply that PLD could be a new target for prevention of systemic inflammatory response induced by CPB. Chin Med J 2003; 116(6):873-877

Objective To study the effects of dosages of total body irradiation on the healing process of cutaneous wounds and to observe the changes of wound area at different periods after injury. Methods The entire body irradiation from a 60Co y-ray source was performed on Wistar rats. The single dosage varied from 1 to 8 Gy. Within 1 h after irradiation, two whole thickness circular cutaneous wounds corresponding to 2. 5% of total body surface area(φ =22 mm)were produced on the back of the animals(combined injury groups). Same wounds were produced on rats with no irradiation(single wound group). Wound healing was observed at different points after injury. Results After total body irradiation with the dose of 1, 2, 3, 4, 5, 6, 7 or 8 Gy, the wound healing was obviously retarded as the dosages increased. The wound area remained was larger in the large dosage groups than in the small dosage groups. Seven days after injury, there was 33. 5% wound surface left unhealed in the single wound group, whereas in the combined injury groups, 35. 4%, 38.1 %, 41. 6%, 48. 8%, 53. 9%, 63. 7%, 69. 2% and 73. 9% of the wound surfaces remained unhealed, respectively. Statistical analysis showed marked correlations between the various times after total body irradiation and various dosages to the percentage of unhealed wound surface. Nine dose-effect relation formulae were deduced according to the statistical results. Conclusions In soft tissue trauma combined with radiation injury, the delay of wound healing is related to the dose of radiation inflicted. It is also related to the time between injury and time of observation. Chin Med J 2003; 116(6): 878-882

Objective To study the analgesic mechanism of gabapentin, an anticonvulsant, during antinociceptive clinical treatment. Methods Whole-cell voltage-clamp recordings were taken from adult rat spinal cord slices to investigate the effect of gabapentin on primary afferent A5-fiber evoked excitatory postsynaptic currents(EPSCs)to substantia gelatinosa(SG)neurons in normal and inflamed(established by plantar injection of carrageenan)rats. Results Gabapentin(5-20 μmol/L for 5 min)depressed dorsal root Aδ fiber evoked polysynaptic, but not monosynaptic EPSCs to SG experiencing inflammation by about 25%(n =10, P < 0. 01). However, gabapentin did not depress the evoked polysynaptic or monosynaptic EPSCs in normal rats. Gabapentin failed to block a glutamate receptor subtype, N-methyl-D-aspartate(NMDA),-induced slow excitatory currents on SG neurons. Conclusions Inflammation, at least in part, unmasks the gabapentin depression on nociception transmission in the dorsal horn, and this depression is not due to the blockade of postsynaptic NMDA receptor. Chin Med J 2003; 116(6):883-887

Objective To investigate the effects of p57kip2 and cyclinE proteins on the genesis and progression of human pancreatic cancer. Methods The expression of p57kip2 and cyclinE proteins in tumor tissues and adjacent tissues of pancreatic cancer in 32 patients was detected by SP immunohistochemical technique. Results The p57kip2 protein positive-expression rate in tumor tissues of pancreatic cancer was 46. 9%, which was lower than that in adjacent pancreatic tissue(P < 0. 05). The p57kip2 protein positive-expression correlated significantly with tumor cell differentiation(P < 0. 05)and did not correlate significantly with lymph node metastasis(P>0. 05). The cyclinE positive-expression rate in tumor tissues was 68. 8%, which was higher than that in adjacent pancreatic tissues(P <0. 05). The cyclinE positive-expression also correlated significantly with tumor cell differentiation and lymph node metastasis(P<0. 05). The cyclinE protein positive-expression rate in the tumor tissues of the p57kip2 protein positive-expression group was lower than that in the p57kip2 protein negative-expression group, and there were no significant correlation between the two groups(r=-0.112, P>0. 05). Conclusion Decreased expression of the p57kip2 protein and/or over-expression of the cyclinE protein may play an important role in the genesis and progression of human pancreatic cancer. Chin Med J 2003; 116(6): 944-946

Objective To establish hybridomas that produce anti-death receptor-5(DR5)monoclonal antibodies(mAbs)and check the surface expression of DR5(sDR5)on cell lines. Methods The cDNA of human DR5 was cloned into pGAPZa. Recombinant Pichia pastoris clones generated via homologous recombination secreted high levels of sDR5. The sDR5 was purified using a nickel ion column. BALB/c mice were immunized with sDR5 and spleen cells were fused with the SP2/0-Ag 14. Monoclonal antibodies were tested by ELISA for their abilities binding to sDR5 and by flow cytometry for the reactivities to surface DR5 of Jurkat cells. Surface expression of the TRAIL receptor was determined by flow cytometric analysis measuring the binding of anti-DR5 mAb. Results Isotypes of mAbs were determined to be IgG1 and IgM, all of which were reactive to sDR5 as observed through ELISA. It was discovered using flow cytometry that only IgG was able to bind to DR5 on the plasma membrane of Jurkat cells. sDR5 was found to completely inhibit anti-DR5 mAb binding to Jurkat cells. Approximately 95% of Jurkat cells, 98% SW480, 99% U937, 100% U87, 86% HCT116, 64% HL-60, 47% HeLa and 13% K562 cells express membrane DR5. Conclusions These results demonstrate that anti-DR5 mAb is able to specifically bind to DR5 and that DR5 is expressed at high levels on Jurkat, SW480, U87, U937 and HCT116 cell lines, and at medium levels on HL-60 and HeLa cell lines. The expression of DR5 on K562 cell line is low. Chin Med J 2003; 116(6): 947-950