1999年 · 第112卷第09期

OBJECTIVE To determine the usefulness of vectorcardiography (VCG) in assessing myocardial infarct size. METHODS The correlation of spatial and scalar parameters of VCG with the percent defect volume (%DV) of thallium myocardial single photon emission computed tomography (SPECT) was investigated in 63 patients with first-onset myocardial infarction (MI). VCG parameters included: (1) spatial parameters: magnitude, azimuth and elevation of the maximal vector, vectors at 20 ms and 30 ms, and (2) scalar parameters: amplitudes of 20 ms and 30 ms vectors at X, Y, and Z scalar leads abbreviated as X20, Y20, Z20, X30, Y30 and Z30, respectively. RESULTS For anteroseptal MI, the azimuth of 30 ms vector and Z20 showed a significant correlation with %DV (r = 0.572, P<0.05 and r = 0.832, P<0.001) while in anteroseptal MI with involvement of lateral wall, the azimuth of 30 ms vector and X30 were correlated with %DV significantly (r = 0.775, and r = 0.780, P<0.01). For inferior and inferoposterior MI, the elevation of 30 ms vector and Y30 were correlated well with %DV (r = 0.871, P<0.01, r = 0.928, P<0.001 for inferior MI and r = 0.678, P<0.01, r = 0.760, P<0.001 for inferoposterior MI). CONCLUSIONS VCG parameters, especially scalar parameters, can be used to evaluate myocardial infarct size easily and non-invasively with remarkable accuracy.

OBJECTIVE To identify whether Puerarin (Puer) has blocking effects on L-type calcium channel. METHODS We used whole-cell recording of patch-clamp techniques to analyse calcium channel current in ventricular myocytes isolated from Langendorff guinea pig hearts by collagenase. RESULTS In control group, peak calcium channel current was decreased by 10.6% and 29.8% at 5, 10 min of recording time, respectively. For the same period, 0.1 mmol/L Puer reduced calcium current by 23.9% and 72.4%. 0.1 and 1 mmol/L Puer inhibited the amplitude of peak Calcium channel current by 40.6% and 63.2% after perfusing for 10 min. Compared with control group in which "rundown" phenomenon was observed, Puer also demonstrated its blocking effect on L-type channel. While washout of Puer with perfusing solution, calcium channel current went down further instead of recovery. Current-voltage (I-V) curves showed that the levels of calcium channel current were obviously decreased by Puer (both 0.1 mmo/L and 1 mmo/L) form -40 mV to +10 mV. CONCLUSIONS Puer has blocking effect on L-type calcium channel in a concentration dependent manner.

OBJECTIVE To investigate the effects of endothelin-1 (ET-1) on mesangial cell proliferation in vitro. METHODS Antisense oligodeoxynucleotide (As-ODN) and its control sequences, sense (Se-ODN) and mismatch (Mis-ODN) oligodeoxynucleotides, targeting preproendothelin-1 (ppET-1) mRNA were delivered into cultured human mesangial cells (HMC) with lipofectin-mediated gene transfer method. The cytotoxicity of lipofectin was determined with lactate dehydrogenase (LDH) release assay. The efficiency of ODNs transfer into HMC was examined with biotinylated As-ODN staining. The effect of As-ODN on expression of ppET-1 mRNA was analyzed with semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). The action of As-ODN on HMC ET-1 secretion was tested by radioimmunoassay (RIA). The influence of As-ODN on HMC proliferation was evaluated with MTT method. RESULTS As-ODN was transferred into HMC with lipofectin without any impairment of cell viability. The ppET-1 mRNA expression, the ET-1 secretion and the cell proliferation were inhibited by As-ODN transferred into HMC, while Se-ODN and Mis-ODN transferred into HMC did not show any effects on all of these. CONCLUSIONS Decrease of ET-1 secretion by HMC, caused by the down-regulation of ppET-1 mRNA expression after As-ODN transfer, led to inhibition of HMC proliferation. These results suggest ET-1 is one of the autocrine growth factors of HMC, and may play an important role in the pathogenesis of proliferative glomerulonephritis.

OBJECTIVE To investigate the relationship between the pathogenesis of Guillain-Barre syndrome (GBS) and Campylobacter jejuni (C. jejuni) in China. METHODS C. jejuni strains were isolated from fresh stools of 47 GBS patients in Beijing area from 1995 to 1997 by modified Skirrow's method. Serotyping of C. jejuni was performed with Penner's method in 47 GBS patients and 171 patients with C. jejuni enteritis in our hospital during the same period. The stools from which noC. jejuni strains could be isolated were typed by PCR-RFLP (restriction fragment length polymorphism) method. RESULTS Six C. jejuni strains were isolated by Skirrow's method, including 3 strains of Penner serotype 2, 1 Penner serotype 4, 1 Penner serotype 19 and 1 Penner serotype 26. Three strains of DNA-I, which was equal to the same type of Penner serotype 19, were found by PCR-RFLP method. CONCLUSIONS C. jejuni isolated from Beijing area are similar to those reported in literature, which once more confirms the molecular mimicry pathogenetic theory of GBS caused by C. jejuni infection in China. The similarities of serotypes between C. jejuni strains from GBS patients and those from C. jejuni enteritis patients may explain the high incidence of GBS following C. jejuni infection in China.

OBJECTIVE To investigate whether angiotensinogen (AGT) gene M235T variant is associated with non-insulin-dependent diabetes mellitus without nephropathy (DN-), and diabetic nephropathy (DN+) in Chinese non-insulin-dependent diabetes mellitus (NIDDM). METHODS The subjects in DN+ group, DN- group and control group were well matched with sex, age and duration of disease, and the two case groups were divided into two subgroups as with and without hypertension respectively. The M235T polymorphism of AGT gene of 84 cases with DN-, 96 patients with DN+ and 98 controls were determined by polymerase chain reaction (PCR) amplification and restriction fragment length polymorphism (RFLP) analysis of the region of the variant, i.e. M235T polymorphism. RESULTS The increased frequencies of T allele (0.82) and TT genotype (0.70) were observed in 96 subjects with DN+ as compared with 98 control subjects (0.63 and 0.43, respectively, P = 0.003, P = 0.0004). The odds ratio associated with TT genotype was 3.47 (95% CI: 1.51-7.94; P = 0.0033) for diabetic nephropathy in analysis adjusted for several risk factors of diabetic nephropathy, such as body-mass index, systolic and diastolic blood pressure, serum cholesterol, low density lipoprotein and high density lipoprotein. Subgroup analysis of the 67 patients in DN+ group with hypertension revealed similar distributions of M235T genotypes and alleles to those in the DN+ without hypertension subgroup. There was no difference in allele and genotype distribution between 84 DN- patients and the controls. Similarly, frequencies of the AGT M235T genotype and allele were not different between two DN- subgroups. CONCLUSIONS AGT gene M235T polymorphism is associated with diabetic nephropathy in NIDDM. TT genotype of the AGT gene might be an independent risk factor of diabetic nephropathy in Chinese NIDDM patients.

OBJECTIVE To establish normal serum leptin levels in Chinese and investigate the relationship between serum leptin levels and body fat, gender, age and androgen. METHODS Serum leptin levels were measured in 77 lean (BMI<25) and 28 overweight or obese (BMI≥ 25) subjects by a radioimmunoassay (RIA) method. RESULTS The serum leptin levels in lean Chinese were 2.15±1.46 ng/ml in male and 7.85±3.60 ng/ml in female, which are similar to those of Caucasians, while in overweight or obese ones, the levels were 4.87±3.47 ng/ml and 16.59±6.92 ng/ml respectively, lower than those in Caucasians. A 2-3 times higher leptin concentrations were found in women than in men in both conditions. Even when the number of lean males was expanded to 79 subjects aged from 17-80 years, no significant leptin-age relationship was found. Despite 25% of obese subjects manifested a relative deficiency of leptin, as a whole, leptin levels in both men and women were significantly correlated with BMI (r = 0.69, P<0.001 in male and r = 0.63, P<0.001 in female). CONCLUSIONS Serum leptin levels in Chinese lean people are similar to those in Caucasians and in both lean and obese groups, the leptin levels are correlated with BMI, suggesting that the great majority of the obese patients are resistant to endogenous leptin. Those who are relatively deficient of leptin may become a group of good candidates for leptin treatment in the future.

OBJECTIVE To explore the mechanism of autoimmune hemolysis and establish a more sensitive test for autoimmune hemolytic anemia (AIHA). METHODS IgG subclasses were tested in 40 patients with idiopathic or secondary AIHA by Coombs test with monoclonal antibodies. Hb, TBil, RC and FHb, as hemolytic parameters, were used to analyze the clinical implications of subclasses of AIHA warm autoantibody IgG. RESULTS In most patients IgG incomplete warm autoantibody was IgG1 (27 patients), but IgG3 (20 patients), rarely IgG2 (14 patients) and IgG4 (9 patients) also occurred. Three groups were analyzed: Group A included 20 patients with IgG3; Group B included 14 patients with IgG1 bit without IgG3; Group C included 6 patients without IgG1 and IgG3. There were significant differences (P<0.01) between groups in Hb, TBil, RC and FHb. Moreover, we also found that the sensitivity of Coombs test with polyclonal antiserums was 90.0%, while that of Coombs test with monoclonal antibodies was 97.5%. The effect of treatment was worst in patients with positive IgG3 autoantibody, whose hemolysis recurred frequently. CONCLUSIONS IgG3 autoantibody was the most effective in bringing about red cell destruction, IgG1 autoantibody was less effective, IgG2 even less, whereas IgG4 autoantibody was shown to hardly affect red cell survival. Coombs test with monoclonal antibodies was more sensitive than that with polyclonal antiserums. Patients' respondence to treatment correlated with the type of IgG subclasses.

OBJECTIVE To discuss the possible role of platelets in Binswanger's disease by studying the changes of organelles and membrane glycoprotein in platelets. METHODS The organelles (dense bodies, alpha granules, and mitochondria) within platelets were measured with transmission electron microscopy in 25 patients with Binswanger's disease and matched controls, while alpha granule membrane glycoprotein CD62 and lysosomal integral membrane glycoprotein CD63 on platelet membrane were analyzed by flow cytometry. RESULTS The percentage of CD62-positive platelets was 3.6%±2.1% and 5.7%±2.4% in controls and in patients, respectively (P<0.01). The percentage of CD63 expression platelets was 3.1%±2.2% and 3.2%±2.3% in controls and patients, respectively (P>0.05). When compared with controls, platelets of patients contained fewer alpha granules (P<0.01), and had no changes in dense bodies and mitochondria (P>0.05). CD62 levels were different among patients with regarding to the degree of white matter low attenuation. CONCLUSIONS There is selective degranuation of platelets in patients with Binswanger's disease and the abnormalities of platelet secretion may play a role in the pathophysiology of this illness.

OBJECTIVE To quantitatively analyze the tremor and rigidity due to Parkinson's disease. METHODS 38 patients with Parkinson's disease (PD) ranging in age from 45 to 72 years and 211 normal subjects aged from 16 to 76 years were investigated. The frequency and range of tremor, the muscle tone of the upper limbs in elbow were detected by a computerized video motion detecting system and a new invented apparatus which can detects skeletal muscle tone. RESULTS For the PD patients, the frequency of resting tremors was detected in 4 to 6 per second. For extensor and flexor in the PD patients, the value of muscle tone was higher than that of normal subjects and the value of muscle tone in flexor was higher than that of extensor. The rigidity increased gradually with repeat passive movement. The curves of rigidity were shown on computer screen or printed out. The data of rigidity were compared with the M-A Scale. A patient who was suspected to suffer from PD above by the equipments and found the muscle tone was higher than normal. In another PD patient the rigidity was obvious at one side and the muscle tone in "normal side" was also high. These equipments were used to record changes of rigidity and tremor in one more PD patient taking with different drugs in order to see the drug effect. CONCLUSIONS Quantitative methods are useful to analyse the motion disorders due to PD.

OBJECTIVE To investigate the feasibility of our self made inferior vena cave (IVC) stent. METHODS Self-expanding, stainless steel, Z-shaped stents were deployed in the IVC of 14 dogs. They were randomly divided into four groups, four dogs in the first three groups, and 2 in the fourth group. IVC specimens were taken at 2, 4, 8 and 16 weeks following stent deployment. No anticoagulant or antiplatelet therapy was given. RESULTS All stents were widely stretched out and so was the vessel lumen. No thrombus was present and the patency was 100% in all groups. The stents were completely covered by neointima 2 weeks after stent deployment. The neointimal thickness varied significantly: the thinnest at 2 weeks, the thickest at 4 weeks and becoming thinner at 8 weeks and stable until 16 weeks. The inflammatory reaction was gradually reduced. Under scanning electronic microscopy, the neointima was covered by a layer of endothelial cells 2 weeks following stenting, which were irregularly shaped and aligned. The cells became slender, spindle-shaped and aligned parallel to the direction of bolld flow 4 weeks afterwards. CONCLUSIONS Experimental study indicated that our self-expanding IVC stent was feasible for clinical application.