Generation of deletion mutants by partial digestion.
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C-Reactive Protein↗
Biomedical subjects
D Zhang
Publications and source records attributed to D Zhang.
[Progress in the pathological and molecular biological study on skin aging].
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Animals↗
[Retrospects and prospects of the application of microsurgery to plastic surgery].
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Humans↗
[The evaluation of serum hormone levels (beta HCG, E2, P) and E2/P in diagnosis of early ectopic pregnancy].
27 cases of ectopic pregnancies (gestational period: 44 +/- 5d) and 33 cases of normal pregnancies (gestational period: 44 +/- 5d) as control groups were studied in our hospital from November, 1992 to May, 1994. The levels of serum hormone (beta HCG, E2, P) were measured in two groups by a radioimmunological method. The results were compared. The values of beta HCG, E2, and P in ectopic pregnancy group were significantly lower than in the control group (P < 0.01). The E2/P levels in ectopic pregnancy group were significantly higher than in the control group (P < 0.01). Our conclusion is that ectopic pregnancy may be due to the state of the higher E2 levels.
Adult↗
[Surgical treatment of esophageal carcinoma complicated with perforation--a report of nine cases].
Malignant perforation in patients with esophageal carcinoma, a catastrophic life-threatening complication, is usually treated conservatively with very poor prognosis. From December 1992 through November 1994, surgical resections was carried out in 9 patients with perforated esophageal carcinoma of these 9 cases, two received esophagogastrectomy alone and 7 received esophagogastrectomy with synchronous pulmonary resections of various types. One patient died of anostomotic leakage on the 33rd postoperative day. Eight patients recovered uneventfully. Postoperative irradiation therapy was given to two patients: one in the third month due to mediastinal lymph node metastasis and the other is still being irradiated in the first month after operation. On follow-up, six patients had been surviving for 20, 18, 11, 9.5, 8.5 and 8 months after operation, respectively. In this paper options of treatment, pre-operative diagnostic procedures, intra-operative judgement and post-operative management for the perforated esophageal carcinoma are emphasized. The authors stress that the indication of extended operation for the esophageal carcinoma complicated with perforation should be further explored.
Adult↗
[The relationship between preoperative small airway function tests and postoperative airway infection in patients with esophageal carcinoma].
The article reports the results of preoperative small airway function tests among 116 cases of esophageal carcinoma and its relationship with the postoperative airway infection. Among three main parameters reflecting narrowing of small airway, %V25/HT is the most sensitive one, %MMEF comes next, and %FEV1 the least, Eight-eight of 116 cases without any other postoperative complications were enrolled. The morbidity of postoperative airway infection in this group was 62.5%. They were divided into three groups according to %V25/HT: group I with normal small airway function (%V25/HT > 70%, 26 cases), group II with moderately deviated function (%V25/HT 46-70%, 31 cases), group III with severely deviated function (%V25/HT < 45%, 31 cases). The morbidity rate of postoperative airway infection and the average fever period in the three groups were 50%, 51.6%, 83.3% and 60, 74, 108 hours, respectively. The difference between group I and group III, between group II and group III are significant statistically both in the morbidity rate and the fever period of postoperative airway infection. If divided by different modes of operation, the average postoperative fever perioed in intrathoracic and neck anastomosis group was 79 and 105 hours. The difference between the above two groups is remarkable but not significant statistically. The results come to a conclusion that the patients undergoing larger operation and with more severe abnormal small airway function usually have longer and more severe postoperative airway infection.
Adult↗
[Estimation of configuration of F-V curve with tangent time constant and mechanism involved].
The tangent time constants (tau t) of high, middle and low lung volumes tau t75, tau t50 and tau t25 were calculated with IBM PC/XT computer from the maximal expiratory flow volume (MEFV or F-V) curves of 1270 normal adolescent, middle-aged and old persons (age from 6 to 79). In the adolescents magnitude of tau t75 > 1s, and tau t75 > tau t50 > tau t25 reflected that the F-V curve had a round top and concaved towards the volume axis. In the old persons magnitude of tau t75 < 1s and tau t75 > tau t50 < tau t25 caused the curve to have a peak-shape top with its tail convex to the volume axis. In the middle-aged persons the indices were found to be intermediate between the adolescent and old persons. The configuration of F-V curve reflected by tau t was correspondent to that reflected with slope ratio (SR) by mead. The appearance of the peak-shape top on the F-V curve in the old persons was due to the reduced elasticity and increased collapsibility of the central airway. According to the wave-speed theory, the choke point (CP) occurs firstly at the least cross-sectional area of the collapsed trachea, then V75 is limited and decreases rapidly, and makes tau t75 < 1, so that a peak-shape top is developed on the F-V curve. The convex of the tail of F-V curve to the volume axis in the old persons is chiefly due to the reduced supporting force to the small airways and the decrease in the lung elastic recoil with aging. This leads to an increase in resistance and decrease in V25. Therefore, V25 can only descend slowly to the zero at RV, and tau t25 is elongated, so that the tail of the F-V curve is convex to the volume axis.
Adolescent↗
An improved simple colorimetric method for quantitation of non-transferrin-bound iron in serum.
A simple method for direct quantitation of non-transferrin-bound iron (NTBI) in serum is introduced. NTBI was separated from serum by adding excess nitrilotriacetic acid disodium salt (NTA) to serum to form an Fe-NTA complex and then ultrafiltrated using a micro-filter. The NTBI in the ultrafiltrate was quantitated using a bathophenanthroline-based method. The optimal detection condition and several potential confounding factors were investigated. The actual measurements to samples in vivo and in vitro showed that this method is very practical.
Animals↗
The regulatory effect of nucleoside diphosphate kinase on G-protein and G-protein mediated phospholipase C.
The effect of nucleoside diphosphate kinase (NDPK) on the activity of guanine nucleotide regulatory protein (G-protein) mediated phospholipase C (PLC) and on the [35S] GTPT tau S binding of G-protein was investigated in this work in order to demonstrate the mechanism behind the regulation of G-protein and its effector PLC by NDPK. The stimulation of PLC in turkey erythrocyte membrane by both GTP and GTP tau S indicated that the PLC stimulation was mediated by G-protein. NDPK alone stimulated PLC activity, as well as the stimulation in the presence of GTP and GDP, in a dose-dependent manner. However, NDPK inhibited GTP tau S-stimulated PLC. Furthermore, NDPK inhibited [35S]GTP tau S binding of purified Gi-protein in a non-competitive manner. A hypothesis implying an important role of direct interaction of G-protein and NDPK in the regulation of their functions is suggested and discussed.
Animals↗
[Thoracoscopy in persistent or recurrent spontaneous pneumothorax].
To assess the value of thoracoscopy in spontaneous pneumothorax, the procedure and results of thoracoscopy by using fiberoptic bronchoscope and rigid cold-light thoracoscope in 50 patients with persistent or recurrent pneumothorax were reported. We found subpleural blebs or bullae in 35 cases and adhesions preventing lung expansion in 10 cases. The histologic diagnosis following thoracoscopic biopsy in 13 patients showed non-specific inflammation in 12 cases and tuberculosis in one case. The overall diagnostic rate was 92% (46/50). 5 cases were cured with transendoscopical Nd-YAG laser cauterisation of the blebs or bullae not exceeding 1 cm in diameter. There were no side effects after the procedure, and no recurrence was observed in a follow-up of 24 months. 40 patients were treated with intrapleural talcum power under thoracoscopic control. The postoperative complications were transient fever and chest pain and recurrence was observed in two cases only (5%) during 2-7 years of follow-up. It is concluded that thoracoscopy enables accurate assessment of the causes of pneumothorax, talc pleurodesis is a very effective method of controlling recurrent and persistent pneumothorax, and laser therapy can play an important role in selected patients with spontaneous pneumothorax.
Adolescent↗
Biotransformation of amitriptyline by Cunninghamella elegans.
A fungal biotransformation system as an in vitro model for mammalian drug metabolism was investigated. Amitriptyline, a widely used antidepressant, was effectively biotransformed within 72 hr by the filamentous fungus, Cunninghamella elegans. Eight major metabolites in HPLC elution order (11-hydroxyamitriptyline N-oxide, 11-hydroxynortriptyline, 11-hydroxyamitriptyline, 10-hydroxyamitriptyline, 3-hydroxyamitriptyline, 2-hydroxyamitriptyline, nortriptyline, and amitriptyline N-oxide) were produced at estimated molar ratios of 2:1:10:0.6:0.1:1.2.5:0.5, respectively. These metabolites were isolated by HPLC and identified by UV/MS analyses, as well as NMR spectroscopic analysis for most of these metabolites. In some cases, they were also compared with authentic standards. Glucose, culture age, and substrate concentration significantly affected the extent of amitriptyline metabolism. Kinetic studies indicated that nortriptyline and 11-hydroxyamitriptyline were produced as initial major metabolites. The hydroxylated metabolite was excreted from mycelia, but amitriptyline and its N-demethylated metabolite, nortriptyline, were not. An 18O2 labeling experiment showed that the oxygen atoms in 11-hydroxyamitriptyline and 2-hydroxyamitriptyline were derived from molecular oxygen. The cytochrome P450 inhibitors SKF 525-A (1.5 mM), metyrapone (2.0 mM), and 1-aminobenzotriazole (1.0 mM) inhibited the biotransformations of amitriptyline by 50, 75, and 95%, respectively. A microsomal preparation was shown to catalyze the 11-hydroxylation of amitriptyline, which was inhibited by SKF 525-A and carbon monoxide. The similarities of amitriptyline metabolism in C. elegans and in humans and rats are discussed.
Amitriptyline↗
[Experimental study on rapid expansion of soft tissue].
Nine white pigs weighing about 15 kg were divided into three groups: rapid expansion group (REG), conventional expansion group (CEG) and control group (CON). Expansion was carried out under monitoring of interal pressure of the expander and blood flow of the skin over the expander. After completion of expansion, hemodynamic, physical, histologic and ultrastructure changes of the expanded skin were measured and recorded. The study showed: (1) The immediate retraction ratios of skin of three groups were 41.37%, 20.82% and 10.01%, respectively (P < 0.01). (2) The thickness of the epidermis of the three groups was not statistically different, though the dermis of the expanded skin was thinner than that of the control (P < 0.01). (3) The density of collagen in the dermis of the three groups was 80.57 +/- 5.47, 79.49 +/- 6.31 and 82.72 +/- 2.69, respectively; the density of elastin of the three groups was 2.88 +/- 1.24, 2.77 +/- 0.74 and 2.56 +/- 0.63, respectively (P < 0.05). We concluded that the delay phenomenon of the expanded flap depends mainly on the intensity of expansion. The immediate retraction ratio of the rapidly expanded skin was greater than that of conventionally expanded skin. Rapid expansion also results in tissue hypertrophy but does not cause destruction of collagen. With proper calculating the size of the defect and estimating immediate skin retraction, rapid expansion is feasible in clinical applications.
Animals↗
Effects of artesunate on immune function in mice.
AIM: To study the effects of artesunate (dihydroartemisinine-12-alpha-succinate, Art) on immune function in mice. METHODS: Hemolysin concentration was determined by colorimetric method. Serum IgG and C3 contents were measured by single immunodiffusion method. Percentage of lymphocyte transformation, phagocytosis percentage and phagocytic index were counted under microscope. RESULTS: Art im 75 mg kg-1 bid x 7 d decreased the humolysin-forming capacity and levels of serum IgG of mice sensitized with sheep red blood cell. The serum complement 3 level rose remarkably, when Art was given im to Plasmodium berghei-infected mice. Art enhanced the PHA-induced lymphocyte transformation rate (in vivo) in mice and increased the weight of spleen but reduced that of thymus in mice. Art elevated the DNFB-induced delayed-type hypersensitivity. Art im 75 mg kg-1 bid x 5 d reduced the percentage of phagocytosis of peritoneal macrophages and the phagocytic index. CONCLUSION: Art suppressed the humoral immune responses but enhanced the cell-mediated immunity.
Adjuvants, Immunologic↗
[Construction and radioimmunodetection of nude mouse xenograft of human choriocarcinoma].
Fresh tissue of human choriocarcinoma was injected subcutaneously into the BALB/C nude mouse. The xenografts had grown up with 16-68 passages. The hCG level of the ascites or intratumoral blood was 400-20,000 mIU/ml. Radioimmunodetection was performed using 131I labelled murine anti-hCG McAb. The labelled antibody could be specifically accumulated in the tumor sites and the tumor imaging was acquired. The ideal imaging time was 72-96 hours after the injection of antibody.
Animals↗
[Microwave tissue coagulation for bladder carcinoma].
47 patients with bladder carcinoma were treated by microwave tissue coagulation (MTC) through urethra. The total effective rate was 100%. Among 43 patients followed-up, 17 had recurrence of the carcinoma 6-20 months after operation and received another MTC therapy successfully. This kind of treatment is indicated for tiny, multiple, scattered and reccurred tumor. It has advantages of safety, easy operation, fast effect, mild suffering. It is an ideal treatment for the patients who are intolerable or unwilling to accept major operation.
Adult↗
[Mediastinoscopy: value in diagnosis of middle mediastinal masses].
Between 1991 and 1994 standard cervical mediastinoscopy (SCM) was performed in 22 patients with enlarged middle mediastinal nodes of unknown causes. The pathologic diagnoses were achieved in all patients. Malignancies were found in 45.5% of the patients (10/22) and benign lesions in 54.5% (12/22). An erroneous diagnosis and hence inappropriate treatment were avoided. In our experience correct diagnosis can be made by mediastinoscopy in cases of middle mediastinal nodes enlargement, which is usually impossible by routine examination.
Adolescent↗
[Surgical treatment of craniosynostosis].
Craniosynostosis is the term that designates premature fusion of one or more cranial sutures that causes severe cranial deformities. The clinical features and the operative technique were introduced and the etiology and the key points for a successful operation were discussed in this paper.
Adolescent↗
[A study on the simultaneous HPLC determination of chlorhexidine and its impurity 4-chloroaniline].
This paper reports a new RP-HPLC method using phenacetin internal standard (IS) for simultaneous determination of chlorhexidine (CH) and its impurity 4-chloroaniline (4-CA). We use the LC-3A HPLC instrument, a Zorbax-C8 column (25cm x 4.6mm id, 10 microns), a variable wave length UV detector and C-RIA chromatographic data processor. A mixture of methanol and 0.2 mol/L NaH2PO4 (50.5 : 49.5, pH 3.0) is used as mobile phase, whose flow rate is 1.0 ml/min. Sample solution of 15 microliters is injected onto the column, which is maintained at 30 degrees C. The eluent is monitored at 240nm. The retention times are 16.72 min for CH and 5.54 min for 4-CA. The standard curves of CH and 4-CA are established using peak area ratio of CH/IS and 4-CA/IS to concentration respectively. They are both linear (r = 0.9999) within 15-200 micrograms/ml for CH and 60-1200 micrograms/ml for 4-CH. The limits of detection are 1.33 micrograms/ml for CH AND 7.5 micrograms/ml for 4-CA (S/N = 3). The analytical recovery rates are 100.1% for CH and 103.1% for 4-CA. This method has been used for investigating the stability of CH preparation.
Aniline Compounds↗