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Volume 0 ， Issue 1 ， 2002
- Abstract：Objective. Using monoclonal antibody （mAb） Fab′ fragment to develop mAb immunoconjugates for cancer. Methods. Fab′ fragment of mAb 3A5 was prepared by digestion of the antibody with pepsin and then reduced by dithiothreitol （DTT）, while Fab′ fragment of mAb 3D6 was obtained by digestion of the antibody with ficin and subsequently reduced by β mercaptoethanol. The conjugation between Fab′ fragment and pingyangmycin （PYM）, an antitumor antibiotic, was mediated by dextran T 40. Immunoreactivity of Fab′ PYM conjugates with cancer cells was determined by ELISA, and the cytotoxicity of those conjugates to cancer cells was determined by clonogenic assay. Antitumor effects of the Fab′ PYM conjugates were evaluated by subcutaneously transplanted tumors in mice. Results. The molecular weight of Fab′ fragment was approximately 53 kD, while the average molecular weight of Fab′ PYM conjugate was 170 kD. The Fab′ PYM conjugates showed immunoreactivity with antigen relevant cancer cells and selective cytotoxicity against target cells. Administered intravenously, Fab′ PYM conjugates were more effective against the growth of tumors in mice than free PYM and PYM conjugated with intact mAb. Conclusion. Fab′ PYM conjugate may be capable of targeting cancer cells and effectively inhibiting tumor growth, suggesting its therapeutic potential in cancer treatment.Keywords：monoclonal antibody therapeutics;Fab′ fragment;immunoconjugates;antineopla stic agent4|19|5Updated：2024-04-10
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- Abstract：To clone and identify the gene encoding human ubiquitin binding enzym e 2 and study its expression pattern. Methods. According to the sequence of human EST, which is highly homologous to t he mouse ubiquitin binding/conjugating enzyme （E2）, primers were synthesized to screen the human fetal brain cDNA library. The gene was analyzed by bioinformati cs technique and its expression pattern was studied by using multiple tissue No rthern blot. Results. Two cDNA clones encoding human ubiquitin conjugating enzyme have been i solated and identified. Both containing the ubiquitin conjugating domain, the 2 cDNA clones are 88% identical in amino acid sequences and splicing isoforms to each other only with an exon excised to form the short sequence. They belong to a highly conserved and widely expressed E2 enzyme family. Northern blot shows th at they are expressed exclusively in adult human heart, placenta, and pancreas b ut no transcripts can be detected in brain, lung, liver, skeletal muscle or kidn ey. Conclusions. The gene encoding human ubiquitin binding enzyme is expressed under temporal control. As a key enzyme in the degradation of proteins, ubiquitin con jugating enzymes play a central role in the expression regulation on the level o f post translation.Keywords：ubiquitin;protein degradation;ubiquitin binding/conjugating enzyme4|12|0Updated：2024-04-10
- Abstract：To explore the association between the abnormal phosphorylation sites found in Alzheimer disease （AD） 蚲 and the inhibition of its biological activit y. Methods. Ultracentrifugation, chromatography, manual Edman degradation and autos equence techniques were used to prepare and phosphorylate human recombinant 蚲, isolate and purify 32P 蚲 peptides and determine phosphorylation sites. Results. Phosphorylation of 蚲 by casein kinase 1 （CK 1）, cyclic AMP dependent protein kinase （PKA） and glycogen synthetase kinase 3 （GSK 3） separately inhi bited its biological activity and the inhibition of this activity by GSK 3 was significantly increased if 蚲 was prephosphorylated by CK 1 or PKA. The most po tent inhibition was seen by a combined phosphorylation of 蚲 with PKA and GSK 3 . The treatment of 蚲 by PKA and GSK 3 combination induced phosphorylation of 蚲 at Ser 195, Ser 198, Ser 199, Ser 202, Thr 205, Thr 231, Ser 235, Ser 262, Ser 356, Ser 404, whereas Thr 181, Ser 184, Ser 262, Ser 356 and Se r 400 were phosphorylated by GSK 3 alone under the same condition. Conclusion. Phosphorylation of 蚲 by PKA plus GSK 3 at Thr 205 might play a ke y role in 蚲 pathology in AD.Keywords：g protein;phosphorylation;Alzheimer disease;protein kinase4|26|7Updated：2024-04-10
- Abstract：To quantitatively analyze apoptotic and secondary necrotic cells unde r apoptosis conditions. Methods. The cells of Burkitt lymphoma （BL） cell line Raji were incubated with 1 .0 μmol/L dexamethasone （DEX） for 2, 4 and 8 h respectively, then stained with Annexin V FITC （fluorescein isothiocyanate conjugated） which was used to detec t the exposed phosphatidylserine （PS） on the epimembrane resulting from a loss o f phospholipid asymmetry in the early stage of apoptosis, and also stained with propidium iodide （PI） which allows analysis of secondary necrotic cells related with cell membrane and DNA damage that probably represent late stage of apoptosi s, then apoptotic cells were quantified by flow cytometry （FCM）. Furthermore, An nexin+/PI and Annexin+/PI+ cells were sorted by fluoresence activated cell sorter （FACS）, and identified by electron microscopy （EM） and DNA gel electroph oresis. Results. The percentage of apoptotic cells was found to increase with the incuba tion time （r=0.97）. This method was sensitive with low detection limit （0.02%）, and was reproducible with low coefficient variance （CV）（4.2%）. Meanwhile, the Annexin+/PI and Annexin+/PI+ cells were identified as apoptotic and necroti c cells under EM, and DNA extracted from the Annexin+/PI cells was characteri zed by “ladder pattern”. Conclusions. Annexin V assay is a specific, sensitive, accurate, reproductive and quantitative method for analyzing apoptotic cells.Keywords：apoptosis;annexin V;flow cytometry4|20|6Updated：2024-04-10
- Abstract：To illuminate the regulating effect of all trans retinoic acid （ATRA ） on gap junctional intercellular communication （GJIC） and connexin 43 （Cx43） ge ne expression in glioma cells, which is tissue and organ specific. Method. Rat C6 glioma cells were exposed to ATRA at a concentration of 1, 10, 10 0 μmol/L respectively, and the GJIC function of the cells was examined with scr ape loading dye transfer assay 24 hours, 48 hours and 72 hours after ATRA treat ment. The effect of ATRA on Cx43 gene expression was measured with semiquantitat ive reverse transcription polymerase chain reaction （RT PCR） 24 hours after ATR A exposure. Results. The GJIC function of C6 glioma cells was significantly increased by ATR A at each concentration applied. The dye passed 4 to 5 rows of cells from the sc raping edge in ATRA treated cells, but only 1 or 2 rows in the control. The augm ent effect was observed 24 hours after each concentration ATRA treatment, and la sted till 72 hours after treatment with 1μmol/L and 10μmol/L ATRA. Forty eigh t hours after exposed to 100μmol/L ATRA, the enhancement of GJIC was less obvi ous. There was no significant increase induced by ATRA on the transcription of C x43 gene, as demonstrated by semiquantitative RT PCR. Conclusion. ATRA turned out to be a potent enhancer on GJIC function in C6 gliom a cells, and the enhancement effect was most probable at post transcriptional l evel.Keywords：all trans retinoic acid;gap junctional intercellular communication;connexin 43;glioma4|17|4Updated：2024-04-10
- Abstract：Searching for more potent and less toxic HMBA related agents. Methods. Human erythroleukemia cell K562, murine erythroleukemia cell （MEL） and its sub line MEL DS19 were used as target cells to select a cell line which is the most sensitive to HMBA, then analyzed the activity of inducing differentiati on of two new designed HMBA derivatives: HMBPA [hexamethylenebi （3 pyridin） ami de] and Co HDTA （ethylenediaminetetra acetic acid cobalt） using cell biology, c ytochemical and molecular biology techniques. Results. We found that the MEL DS19 cells were most sensitive to HMBA （benzidine positive, B+～76%）. Co HDTA can inhibit the growth of MEL DS19, but induces differentiation just in a small population （B+ 2%～4.5%）. Between 0.02～5μmo l/L, HMBPA induces 3%～8% cells committed to differentiation with little inhib ition of cell proliferation. 1μmol/L HMBPA and 2mmol/L HMBA together, can obvio usly increase the percentage of differentiated cell （B+～ 72%）, inhibit DNA sy nthesis and accelerate β globin transcription. Conclusion. The new HMBA derivatives may provide potential cancer differentiatio n inducers.Keywords：cell differentiation;HMBA;MEL cell;cell cycle6|18|3Updated：2024-04-10
- Abstract：To compare the clinical and pathological manifestations of patients with antineutrophil cytoplasmic autoantibodies （ANCA） directed against proteinas e 3 （anti PR3） or myeloperoxidase （anti MPO）. Methods. One hundred and forty patients with ANCA were detected for anti PR3 a nd anti MPO by ELISA. The clinical features at presentation, histopathological characteristics and outcome of all patients who were tested positive for anti P R3 or anti MPO were analysed.Results. In anti PR3 group （n=21）, 16 cases （76.2%） had systemic vasculitis , in which Wegener’s granulomatosis prevailed （13 cases, 61.9%）. In anti MPO g roup （n=31）, 19 cases （61.3%） were diagnosed as systemic vasculitis and 12 case s （38.7%） as microscopic angiitis. For vasculitic patients with anti PR3 and a nti MPO, the disease duration at diagnosis was 9.6±2.0m and 4.4±0.9m respecti vely, P< 0.05;vasculitis activity index （BVAS） and mean number of affected organ were 22.5±2.1, 5.0±0.4 and 25.1±1.7, 4.8±0.4 respectively, P >0.05;upper r espiratory tract, eye and joint involvements were 11（68.8%）, 7（43.8%）, 11（68.8 %） and 7（36.8%）, 2（10.5%）, 5（26.3%） respectively, P< 0.05.Although there was no statistical difference in renal involvement between these two groups, patien ts with serum creatine >500 μmol/L were more commonly seen in anti MPO group t han in anti PR3 group, which were 8（42.1%） and 2（12.5%） respectively, P< 0.05 . Ten relapses were seen in anti PR3 group and only 2 in anti MPO group, but t he acute mortality rate in anti MPO group （5/19, 27.4%） was much higher than t hat in anti PR3 group （1/16, 6.3%）. Conclusions. Anti PR3 and anti MPO occurred mainly in systemic vasculitis. A large divergence was seen in the disease spectrum between patients with anti PR 3 and those with anti MPO. In particular, upper respiratory tract, eye and join t involvements, granuloma formation and relapse were more prominent in anti PR3 patients. By contrast, the anti MPO patients had a more acute disease onset, m ore rapid progressive renal involvement and a higher acute mortality rate.Keywords：antineutrophil cytoplasmic autoantibodies;myeloperoxidase;proteina se 34|34|0Updated：2024-04-10
- Abstract：To examine the procoagulant effects of thrombolytic agent on h emostasis and study the role of hemostatic markers as predictors of clinical outcomes. Methods. In the present study, eighteen patients with acute myocardial in farction（AMI） received 1.5 or 2.0 million U nonspecific urokinase（UK）, or 70～80 mg fibrin specific recombinant tissue plasminogen activator（rt PA）and did not use heparin until 8 hours after intravenous injection of the above agents. Eig ht patients with AMI and without thrombolytic therapy were enrolled as controls. Coagulant and thrombolytic activity markers included thrombin antithrombin Ⅲ complex （TAT）, D dimer, fibrinogen （Fg）, FMPV/Amax. All markers were determined before,immediately,1,2,4 and 8 hours after the administration of thrombolytic a gents respectively. Results. Molecular marker of thrombin generation——TAT showed an activated coa gulant state immediately after thrombolytic therapy. Level of TAT showed no sign ificant changes between every two observed phases in controls. However, level of TAT increased significantly from 4.95±1.75μg/L （ 4.63±1.37μg/L） to 14.71±3 .31μg/L （ 14.25±2.53μg/L） before and immediately after administration of thro mbolytic agents UK（or rt PA）. There was significant difference between level of serum TAT of patients with and without thrombolytic therapy （P< 0.05）. Patients achieving clinical reperfusion had lower TAT level than those failing in thromb olytic therapy, and higher FMPV/Amax level than controls. D dimer, a surrogate of thrombolytic activity increased markedly and Fg significantly declined afte r thrombolytic therapy（P< 0.05）.Conclusions. Thrombin generation occurred in plasma in response to excess fibri nolysis induced by thrombolytic therapy. Both urokinase and rt PA had procoagul ant action. This transient activation of the coagulant system might contribute t o early reocclusion. These data provided the theoretical support for simultaneou s administration of anticoagulant therapy with thrombolytic agents. These result s also suggested that TAT might be useful in predicting clinical outcomes of p atients treated with thrombolytic therapy for AMI.Keywords：acute myocardial infarction;thrombolysis;urokinase;rt PA4|25|0Updated：2024-04-10
- Abstract：To assess the role of hypertension and family history of hypertensio n in the development of nephropathy in patients with non insulin dependent dia betes mellitus （NIDDM）.Methods. A retrospective analysis was done on 2 groups of NIDDM patients, one g roup without proteinuria （urine protein< 300mg/24h, n=106） and the other group w ith proteinuria （urine protein≥500mg/24h, n=106）. The 2 groups were matched by age（≤±3yrs）, sex, ethnic and resident place. Some information of these subject s including demographic; history of disease, family history of diseases, lifesty le and behavior style variables was obtained by questionnaire; some variables w ere measured, including systolic blood pressure （SBP）, diastolic blood pressure （DBP）, fasting blood glucose （FBG）, quantity of protein in 24h urine. Then condi tional logistic regression analysis was performed.Results. Some factors, including history of hypertension, longer duration of hy pertension, higher levels of the past highest SBP and DBP, were independently as sociated with the occurrence risk of diabetic nephropathy （DN）. Their correspond ing odd ratios （OR） with 95% confidence intervals （CI） were 2.00（1.17～3.43）, 1 .25（1.08～1.46）, 1.38（1.15～1.66）, and 1.33（1.09～1.62） respectively, but family history of hypertension was not significantly associated with the development o f DN. When the above mentioned relations were respectively adjusted by some pos sible confounding factors, they still existed.Conclusions. History of hypertension, longer duration of hypertension, higher l evels of the past highest SBP and DBP are independent risk factors for DN in Chi nese NIDDM patients.Keywords：hypertension;type 2 diabetes mellitus;diabetic nephropathy6|16|0Updated：2024-04-10
- Abstract：To investigate the effect of orthotopic liver transplantation on fulm inant hepatitis B and the preventive efficiency of lamivudine on recurrence of h epatitis B in China. Patients and methods. Ten patients with fulminant hepatitis B received orthotopi c liver transplantation under veno venous bypass. All patients had preoperative ly serious jaundice, ascites and coagulopathy, and of whom 7 with encephalopathy , 2 with acute renal failure, and 1 with gastro hemorrhage. Rusult. Seven of the 10 patients have survived for 3～18 months, but 3 died of m ulti organ failure or recurrence of fulminant hepatitis B. Seven survivors took lamivudine and 6 of them have survived for 3～18 months without the signs of re currence of hepatitis B. Conclusion. Orthotopic liver transplantation is an effective therapy for fulmina nt hepatitis B, and lamivudine may prevent recurrence of hepatitis B after trans plantation.Keywords：orthotopic liver transplantation;fulminant hepatitis B;lamivudine4|22|0Updated：2024-04-10
- Abstract：Electrolytic detachable coils （EDC） have been the main embolic materi als for intracranial aneurysms. Liquid aneurysmal embolic materials represented by cellulose acetate polymer （CAP） are still in controversy. In this research, t he embolization results and pathological reactions after embolization of canine aneurysmal models with EDC or CAP were observed and compared. Methods. The canine aneurysmal models constructed by anastomosis of venous pouch es were randomly grouped. The aneurysms were respectively occluded with CAP and electrolytic detachable coils that was named by Wu electrolytic detachable coil （WEDC） and made by us. Angiogram follow ups were performed at 24 hour, 2 week , and 2 month after embolization. The occluded aneurysms were dissected in each stage for light microscopic, electron microscopic, and histochemical research. Results. The effect of embolization was significantly better with WEDC than that with CAP . Post embolized complications such as aneurysm rupture and stenosis of parent arteries could only be found in CAP group. Pathol ogical research showed that CAP mass could packed the aneurysms more densely tha n coils. Acute chemical damage of aneurysmal wall and inflammatory cell infiltra tion was prominently found in early stage after CAP embolization. Organization of thrombus inside aneurysms and formation of endothelial tissue over the orific es of aneurysmal necks could be found in both groups 2 months after embolization . But parts of coils might be exposed outside endothelial layer. Conclusions. EDC are still the most safe, efficient, and reliable instruments to embolize aneurysm. CAP should be improved further to solve the problem of stron g chemical corrosion and difficulty in control before it is widely used.Keywords：intracranial aneurysm;embolism;cellulose acetate polymer;electrol ytic detachable coils4|24|0Updated：2024-04-10
- Abstract：To evaluate the results of the TRAFIX instrumentation in correcting s coliosis. Methods. Since October 1997, 47 patients with scoliosis received spinal fixation with the TRAFIX instrumentation at the Peking Union Medical College Hospital. T he average age was 14.3 years （range 10 to 38 years）. There were 27 idiopathic c ases, 16 congenital cases, 2 cases with Marfan syndrome and 2 with neurofibromat osis. Twelve of the 47 patients underwent anterior release, while 4 patients rec eived the revision approach. The average follow up time was 26 months （13～38 m onths）. Results. The measurements of primary coronal deformity before and after surgery were 74°（50°～115°） and 38.7° （11°～95°）, respectively. The average curve correction was 54%. The average number of fused segments was 12.5 （7～17） verte brae. The distance between the center of apex and the C7 plumb line was 56.8 mm before surgery （25～107mm） and 31 mm after surgery （10～87mm）. Conclusion. The TRAFIX instrumentation provides three dimensional correction wi th refinement, convenience and reliable fixation.Keywords：scoliosis;internal fixation;three dimensional correction4|26|0Updated：2024-04-10
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- Abstract：Sheng Zhiyong Burns Institute, 304th Hospital, Beijing 100037Keywords：burn;development4|9|1Updated：2024-04-10
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