Volume 115  ·   Issue 01  ·  2002

Objective To confirm the genetic relation between Giardia lamblia (G. lamblia) isolates from different geographic regions of China and other countries. Methods Genomic DNA were extracted from the trophozoites or cysts of Giardia lamblia. The triose phosphate isomerase (tim) gene was amplified using polymerase chain reaction (PCR) technique. PCR products were digested with endonuclease and sequenced. The data of sequencing were analyzed with the DNAstar software and compared with that of the isolates acquired from GenBank. Results Of nine isolates of Giardia lamblia from China (C1, C2, CH2 and CH3), Cambodia (CAM),Australia (A1 and A2) and America (BP and CDC), respectively,3 (A1, A2 and CAM) fit into Group 1(WB), 2 (CH2 and CH3)) into Group 2, and 4 (C1, C2, BP and CDC) into Group 3 (GS). The results confirmed the genetic relatedness of G. lamblia isolates from all over the world. Conclusion Genotyping isolates of G. Lamblia provides important information for establishing the phylogenetic relationship or for the epidemiological evaluation of the spreading of this organism. Chin Med J 2002; 115(1): 99-102

Objective To evaluate the efficacy and the mechanism of application of selective head cooling on neuronal morphological damage during postischemic reperfusion in a rabbit model. Methods 168 New Zealand rabbits were randomized into three groups. Group I [n=24, (38±0.5)℃,non-ischemic control]; Group Ⅱ [n=72, (38 ±0.5)℃, normothermic reperfusion]; Group Ⅲ [n=72,(28±0.5)℃, selective head cooling, initiated at the beginning of reperfusion). Animals in three subgroups(n=24, each) of Group Ⅱ and Group Ⅲ had reperfused lasting for 30, 180 and 360 min respectively. Using computerized image analysis technique on morphological changes of nucleus, the degree of neuronal damage in 12 regions were differentiated into type A (normal), type B (mild damaged), type C (severely damaged) and type D (necrotic). Fourteen biochemical parameters in brain tissues were measured. Results As compared with Group I, the counts of type A neuron decreased progressively, and those of type B. C and D increased significantly in Group Ⅱ during reperfusion (P <0.01) . In Group Ⅱ,vasoactive intestinal peptide, b-endorphine, prostacyclin, T3 and Na+, K+-ATPase were correlated with the changes of type A; b-endorphine and thromboxane with type B; glucose and vasopressin with type C;Na+, K+-ATPase, glutamic acid, T3 and vasoactive intestinal peptide with type D (P <0.05) . As compared with Group Ⅱ, the counts of type A increased, and those of type C and D significantly decreased in Group Ⅲ (P<0.01). In Group Ⅲ, Ca2+, Mg2+-ATPase were correlated with the changes of type A, C and D (P<0.01). Conclusion Selective head cooling for sex hours during postischemic reperfusion does improve neuronal morphological outcomes in terms of morphological changes. Chin Med J 2002; 115(1): 94-98

Objective To investigate the effect of D-AP5 (D-2-amino-5-phosphonopentanoate, a specific NMDA-antagonist) on the increase of intracellular free Ca2+concentration ([Ca2+]i) induced by glutamate in isolated cochlear inner hair cells (IHCs), and to detect the autoreceptors of the IHC membrane. Methods When a laser scanning confocal microscope (LSCM) was used, the exogenous glutamate(Glu)-induced changes in [Ca2+]i of isolated IHCs and OHCs of guinea pig cochlea were observed with fluo-3, a fluorescent probe for [Ca2+]i.After D-AP5 or CNQX (6--cyano--7--nitroguinoxaline--2, 3--dione,a specific AMPA- antagonist) was administrated, the exogenous glutamate (Glu)-induced changes in[Ca2+]i of isolated IHCs were recorded. Results In the presence of a low concentration Glu (3.85 μmol/L), there was an increase of [Ca2+]i in IHCs, whereas there was no change in OHCs. When 50 μmol/L of D-AP5 was administrated in advance,Glu did not induce a corresponding increase in [Ca2+]i in IHCs, and 50 μmol/L of CNQX did not completely block the increase of [Ca2+]i in IHCs. Conclusions These results suggest that the autoreceptors existing in the IHC membrane are mainly of NMDA type, while there are relatively few AMPA receptors. Exogenous Glu is capable of increasing[Ca2+]i in IHCs by acting on the NMDA autoreceptor of IHCs in a positive feedback manner. Chin Med J 2002; 115(1): 89-93

Objective To evaluate the changes in near infrared spectroscopy (NIRS) absorptive properties induced by cerebral ischemia. Methods A dual wavelength (760 nm and 850 nm) NIRS system measuring total hemoglobin concentration changes was constructed. Twenty Sprague-Dawley rats were used to set up middle cerebral artery occlusion (MCAO) model that had a stable ischemia focus on the cortex. We used NIRS to localize the ischemia focus that was confirmed with magnetic resonance imaging (MRI) and triphenyltetrazonlium chloride brain staining. The cortical ischemia area and the geometric configuration of the NIRS topograms were compared with those from MRI and the anatomical samples for the same rat. Results The reconstructed NIRS topograms showed that there was an optical density decreased area on the left cortex of the rats with MCAO model. The mean ischemia area as shown in NIRS images was 19.50 mm2 (19.50 ±0.35 mm2, n=20). Anatomical samples showed that the mean ischemic area located in the NIRS measurement area was 18.46 mm2 (18.46 ±0.38 mm2, n=20) . For MRI, the mean ischemia area located in the NIRS measurement area was 20.71 mm2 (20.71 ±0.27 mm2, n=20). There were no significant differences among NIRS, MRI and anatomical samples (F(2,57)=2.47, P> 0.05) for defining the ischemia area. The results showed that there was a significant correlation among NIRS, MRI(r=0.782, P <0.05) and anatomical sample (r=0.851, P <0.05) for the same cortical ischemia area . Meanwhile, the location and geometric configuration of the ischemia focus shown by NIRS were identified by MRI and anatomical samples, though the NIRS images had worse spatial resolution. Conclusions NIRS showed a good agreement with MRI and anatomical samples in the ischemic area and location determination of the infarction focus for the rat MCAO model. The study suggests that NIRS can non-invasively trace cortical hemodynamic changes induced by ischemia in real time. Chin Med J 2002; 115(1): 84-88

Objective To assess the effect of tetrandrine (Tet) pulmonary targeting microspheres on hypoxic pulmonary hypertension and evaluate its selective action on pulmonary circulation. Methods Twenty rats were exposed to hypoxic conditions for 3 weeks. Ten rats were used as normoxic controls. We administered Tet pulmonary targeting microspheres to 10 hypoxic rats and Tet aqueous solution to 10 hypoxic rats and the 10 control rats. Mean pulmonary arterial pressure (mPAP) was measured by a right cardiac catheterization, and mean systemic blood pressure (mSBP) was measured by left femoral catheterization. Results Rats exposed to hypoxia developed pulmonary hypertension. The decrease in mPAP in rats treated with Tet pulmonary targeting microspheres was significantly greater than that in rats receiving Tet aqueous solution (P <0.05), and the effects were longer with Tet pulmonary targeting microspheres. Moreover, Tet pulmonary targeting microspheres, unlike Tet aqueous solution, did not decrease mSBP. Conclusion Tet pulmonary targeting microspheres were more effective than Tet aqueous solution in treating hypoxic pulmonary hypertension and acted selectively on the pulmonary circulation. Chin Med J 2002; 115(1): 81-83

Objective To investigate the effect of overexpression of bcl-2 on ethanol-induced apoptosis of primary hepatocellular carcinoma (HCC) cells. Methods The retrovirus expression vector pDOR-SB containing human bcl-2 cDNA was introduced into a human HCC cell line HCC-9204 by liposome-mediated transfection. pDOR-transfected and non-transfected HCC-9204 cells were used as controls. The expression of Bcl-2 protein by transfected HCC-9204 cells was detected by the immunohistochemical method. Then the cells were cloned with the limited dilution method continually until a monoclonal cell strain whose positive rate of Bcl-2 protein was 100%detected by flow cytometry was obtained. The killing rates of cells were detected by Methabenzthiazuron assay after the treatment of 6%ethanol for 6 h. The extent of apoptosis was analyzed by transferase-mediated dUTP nick end labeling (TUNEL) staining and flow cytometry. Results Most of the pDOR-SB-transfected cells demonstrated Bcl-2 positive signals, while no signal was found in the controls. The positive rate of Bcl-2 protein detected by flow cytometry in the obtained monoclonal cell strain, which was named HCC-bcl2, was 100%after the cells had been cloned 3 times continually. The killing rate, TUNEL index and the scale of sub-G1 apoptotic peak in HCC-bcl2 cells were all significantly lower than those in the control cells. Conclusion Overexpression of Bcl-2 protein suppresses ethanol-induced apoptosis of the HCC cell line HCC-9204. Chin Med J 2002; 115(1): 8-11

Objective To investigate the expression of the granulocyte-macrophage colony-stimulating factor (GM-CSF) and GM-CSF/IL-3/IL-5 receptor common beta chain (βc receptor) in an adult patient with idiopathic pulmonary alveolar proteinosis (PAP), so as to demonstrate the possible association of the GM-CSF and βc receptor with the pathogenesis of human PAP. Methods The GM-CSF levels were measured with a commercial ELISA kit (sensitivity 5 pg/ml) and the βc receptor expression on the cell surface was detected by flow cytometry analysis. Reverse transcription-polymerase chain reaction (RT-PCR) analysis was employed to detect the expression of the GM-CSF mRNA and the βc receptor mRNA in peripheral blood mononuclear cells and alveolar macrophages. The entire coding regions of the GM-CSF cDNA and the βc receptor cDNA were sequenced by the Sanger dideoxy-mediated chain termination method to detect possible mutations. Results The patient with PAP failed to release the GM-CSF protein either from circulating mononuclear cells or from alveolar macrophages. The expression of the GM-CSF mRNA was normal after the stimulation of lipopolysaccharide, whereas a point mutation at position 382 of the GM-CSF cDNA from "T" to "C" was revealed by cDNA sequencing, which caused a change in amino acid 117 of the protein from isoleucine to threonine. The βc receptor expression on the cell surface was normal, and the βc receptor mRNA expression and the sequence of the entire coding region of the βc receptor were also normal. Conclusions The decreased GM-CSF production is associated with the pathogenesis of human PAP. A point mutation of the GM-CSF cDNA may contribute to the decreased GM-CSF production in our adult PAP patient. The mutation of the βc receptor in some of paediatric patients with PAP may not be a common problem in adult patients. Chin Med J 2002; 115(1): 76-80

Objectives To evaluate the relationship between microdeletion or mutation on the Y chromosome and Chinese patients with idiopathic azoospermia and severe oligozoospermia and to establish a molecular detection method . Methods Microdeletion or mutation detection at the AZFa (sY84 and USP9Y), AZFb, AZFc/DAZ and SRY regions of the Y chromosome. Seventy-three azoospermia and 28 severe oligozoospermia patients were evaluated using PGR and PCR-SSCP techniques. Results Twelve of 101 patients (12%) with the AZFc/DAZ microdeletion were found, including 8 with azoospermia (11%) and 4 with severe oligozoospermia (14.3%), and 1 patient had a AZFb and AZFc/DAZ double deletion. No deletions in the AZFa or SRY regions were found. No deletions in AZFa,AZFb, AZFc/DAZ or SRY regions were found in 60 normal men who had produced one or more children. Conclusions Microdeletion on the Y chromosome, especially at its AZFc/DAZ regions, may be a major cause of azoospermia and severe oligozoospermia leading to male infertility in China. It is recommended that patients have genetic counseling and microdeletion detection on the Y chromosome before intracytoplasmic sperm injection. Chin Med J 2002; 115(1): 72-75

Objective To investigate the distribution and clonality of T cell receptor (TCR) vβ repertoire in patients with acute monoblastic leukemia (AML-M5). Methods Expression of the TCR Vβ repertoire was analyzed using reverse transcription-polymerase chain reaction (RT-PCR), which amplified the complementarity determining region 3 of 24 TCR Vβ genes in peripheral blood from 9 cases with acute myclogenous leukemia subtype 5 or acute monoblastic leukemia(AML-M5). PCR products were further studied by genescan analysis to identify T cell clonality. Results Expression of 1-10 Vβ subfamilies was found in samples from 9 patients. Genescan analysis showed that some Vβ subfamily products from 8 of 9 cases contained an oligoclonal peak. Oligoclonal T cells of the Vβ2 subfamily could be found in 6 patients with AML-M5. Conclusions T cell clonality expansion was found in AML-M5 cases and were tendentious in the Vβ2 subfamily, suggesting a the specific immune response for leukemia cell (M5) associated antigen and may display antileukemia activity. Chin Med J 2002; 115(1): 69-71

Objective To document morphological changes in hepatic microcirculation in liver tissue with hepatitis B and the pathogenesis of hepatic microcirculatory disturbances. Methods Liver tissue samples were obtained from patients with hepatitis B by liver biopsy. These samples were examined with a light microscope and transmission electron microscope. Results Hepatic microcirculatory disturbances existed in patients with hepatitis B, including those with normal liver function, manifested by red blood cell aggregation in sinusoids seen under light microscope and sinusoidal capillarization seen under electron microscope. Weibel-Palade bodies in sinusoidal endothelial cells were seen in 26 out of 53 cases. Intimate contacts were found between lymphocyte/Kupffer cells and sinusoidal endothelial cells. Conclusions Hepatic microcirculatory disturbances exist in patients with hepatitis B. The appearance of Weibel-Palade bodies in sinusoidal endothelial cells may be a key step in the development of hepatic microcirculatory disturbances. Chin Med J 2002; 115(1): 65-68

Objective To evaluate the safety and efficacy of the Amplatzer septal occluder for transcatheter closure in patients with secundum atrial septal defect (ASD Ⅱ). Methods Patients with clinically confirmed ASD Ⅱ were recommended for transcatheter closure of ASD Ⅱ. Results 30 ASD Ⅱ patients (20 females) underwent transcatheter closure at a median age of 18.4 years(5-55 years). Both the stretched diameters of ASDs and the sizes of the devices were from 18 to 34 mm(25±7 mm). The successful placement rate was 100%. The rest shunt documented by color Doppler,was immediately after implantation in 40%of patients, in 9.9%after 24 hours, and in 3.3%trace at 3 months. No serious complications were observed. There was improvement in symptoms and in cardiac size. Septal motion abnormalities normalized in all patients after 3 months follow-up. Conclusion The Amplatzer septal occluder is a safe and effective device for transcatheter closure of ASDⅡ. Long-term follow-up is still required before widespread clinical use can be recommended. Chin Med J 2002; 115(1): 126-128

Objective To evaluate postoperative renal function in children with congenital moderate or severe hydronephrosis. Methods 99m Tc-labeled diethylenetriaminepenta-acetic acid scintigraphy was performed in 50 children with unilateral moderate or severe hydronephrosis to determine postoperative renal function. We also analyzed the factors influencing renal function recovery. Results Average postoperative renal function in 50 cases was 40.62%±10.09%. Among them, 32% of patients had nearly normal renal function and differentiated renal function reached up to 45% . Average preoperative and postoperative renal function in 25 cases was 23.89% ± 11.65% and 39.33% ± 8.59%respectively and the increase of renal function was about 15.44% ± 11.18%(P=0.0003) . Renal parenchyma thickness was negatively correlated with postoperative renal function (r= - 0.62, P= 0.0009). The follow-up period was positively correlated with postoperative renal function (r=0. 58. P= 0.0026) . The patients' age had no correlation with renal function recovery (r= -0.05, P=0.80) . Recovery of renal function in hydronephrosis with extrarenal pelvis was greater than that in hydronephrosis with intrarenal pelvis (P=0.016). Conclusions Postoperative renal function in children with moderate or severe hydronephrosis can recover to normal. Recovery of renal function was more obvious in hydronephrosis with thinner renal parenchyma,longer follow-up period and extrarenal pelvis. Chin Med J 2002; 115(1): 123-125

Objective To identify the prevalence, incidence and trend of urinary incontinence in the elderly over a two-year period. Methods We randomly selected 4187 elderly people using the State Electoral Data Base in South Australia. Questionnaire surveys were conducted in 1992 with a response rate of 53.4%. The following two surveys were conducted 12 and 24 months later. A total of 2087 elderly people completed all three surveys. Results Urge incontinence had a higher prevalence rate, with 36.6%to 41 .6%of the elderly having at least an occasional problem (with 7.5%to 9.6%having problems often), compared to 23.4%to 28.8%having at least an occasional problem with stress incontinence (with 3.3%to 5.0%having problems often). Combined incontinence and urge incontinence were more common than stress incontinence alone. The incidence rates of urge incontinence and stress incontinence were 19.8%(with 3. 1% often) and 14.5%(with 1.9% often), respectively. The trends toward incontinence during the two-year period indicated increasing trends in the elderly. Conclusion Urinary incontinence is an important health problem in the elderly and our data show that it has an increasing trend for future. Chin Med J 2002; 115(1): 119-122

Objective To evaluate the safety and effectiveness of direct gastroscopy for detecting gastric cancer. Methods Clinical screening by direct gastroscopy was performed for gastric cancer (GC from September 1985 to July 1998. 3048 elderly people were screened. Their age ranged from 60 to 93 years, and 2034 of the 3084 were followed up. Results Ninety-two patients with gastric cancer were discovered by gastroscopy, representing 3.02%of the screened population. The rate of early gastric cancer (EGC) was 63.04%(58/92) of all gastric cancers detected. The rate was up to 79.59%(39/49) on follow-up, and was 74.14%(43/51) in asymptomatic patients with gastric cancer. The excision rate was 88.89%for patients with gastric cancer,and 100%for patients with early gastric cancer. The 5-year survival rate was 91 .89%for patients with gastric cancer, and 96.30%for patients with early gastric cancer. Conclusion Clinical screening and follow-up by direct gastroscopy in persons over 60 years of age are a safe and effective method for raising the 5-year survival and detection rate of gastric cancer, especially early gastric cancer. Chin Med J 2002; 115(1): 117-118

Objective To study the efficacy and safety of cutting balloons in coronary interventions. Methods Twenty-two patients with 23 narrowed coronary arteries and 25 lesions enrolled the study, 17 of whom had 18 diseased coronary arteries and 18 lesions were in-stent restenosis. The average time from previous stenting was 7.60 ±3.53 months. The lesions were dilated with cutting balloons. Results All of the lesions were dilated successfully by 5.16 ±2.30 inflations of a cutting balloon. The mean total duration of balloon inflation was 233.96±94.83 seconds at pressures up to 9.40 ± 1 .96 bars. The severity of vascular stenosis was lessened substantially (89.64 ± 8.65% vs 17.60 ± 17.15%,P=0.000) without severe complications. Three restenotic lesions were further dilated with conventional balloons, another one was stented again because of a dissection distal to the previous stent. Three primary lesions were stented for dissection or residual stenosis. Angina pectoris reoccurred in two patients in a mean follow-up period of 7 . 42 ± 6 . 87 (range 0.5-20) months. Conclusion Cutting balloon dilation is an effective and safe choice in interventions for coronary disease especially for in-stent restenosis. Chin Med J 2002; 115(1): 114-116

Objective To test the immunosuppressive effect of cyclosporine (Cs) in a polymer placed in the anterior chamber of corneal allograft recipients. Methods Wistar inbred rats with vascularized corneas were recipients of corneal allografts from Sprague-Dawley donor rats. Rats underwent penetrating keratoplasty and were divided randomly into four groups: untreated control animals (UCA); Cs-polymer anterior chamber recipients (CPA); co-polymer subconjunctival recipients (CPS); and Cs-olive oil drop recipients (COO). Grafts were examined by slit lamp every 3 days and clinical conditions were scored. Cs concentration in the aqueous humor was assayed at 1, 2, and 4 weeks. At 1, 2 and 4 weeks after transplantation, the operated eyes were collected for histopathological evaluation of the grafts. Results The median survival time of the allografts was 8.2 ± 1 .48 days for the UCA group, 11.4 ± 2.50 days for the CPS group, and 17.0 ±2.00 days for the CPA group. There was a statistically significant difference (P <0.05) between survival time of the allografts in the animals of the CPA group compared to the other groups of graft recipients. Significantly higher concentrations of Cs were found in the eyes given an anterior chamber implant of Cs-polymer, compared to other treatment groups or untreated rats. A transient inflammatory response in the anterior chamber was observed in the CPA group. Conclusions Cs-polymer placed in the anterior chamber significantly prolongs corneal allograft survival time in a high risk corneal graft rejection model. This intraocular delivery system may be a valuable adjunct for the suppression of immune graft rejection. Chin Med J 2002; 115(1): 110-113

Objective To evaluate the roles of Na+/H+exchanger-1 (NHE-1)in the proliferation and apoptosis of pulmonary artery smooth muscle cells in rats. Methods Twenty Wistar rats were randomized into control group and 3-week hypoxic group. Intracellular pH (pHi) of the smooth muscle was determined with fluorescence measurement of the pH-sensitive dye BCECF-AM, and the expression of NHE-1 mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR). Primary culture of pulmonary artery smooth muscle cells in vitro was performed. In situ cell death detection kit (TUNEL) was used for studying the effect of specific NHE-1 inhibitor-dimethyl amiloride (DMA) on the apoptosis of muscle cells which had intracellular acidification. Results pHi value and NHE-1 mRNA expression of pulmonary artery smooth muscle cells were significantly higher in the hypoxic group than in the control group (P<0.01, P <0.001). DMA elevated the apoptotic ratio remarkably. The effect was enhanced when DMA concentration increased and the time prolonged. Conclusions With the function of adjusting pHi, NHE-1 may play an important role in the proliferation and apoptosis of pulmonary artery smooth muscle cells. Chin Med J 2002; 115(1): 107-109

Purpose To review evidence-based management of nephropathy in patients with type 2 diabetes. Data sources A literature search (MEDLINE 1966 to 2000) was performed using the key word "diabetic nephropathy". Relevant book chapters were also reviewed. Study selection Well-controlled, prospective landmark studies and expert review articles on diabetic nephropathy were selected. Data extraction Data and conclusions from the selected articles that provide solid evidence to the optimal management of diabetic nephropathy were extracted and interpreted in light of our clinical research experience with many thousands of Hong Kong Chinese patients. Results Hypertension, long diabetes duration, poor glycaemic control and central obesity are the most important risk factors. Microalbuminuria is a practical marker to predict overt nephropathy in type 2 diabetic patients. Risk factor modification, renal function monitoring and combined therapies are the current integrated approaches to manage patients with diabetic kidney disease. Optimal glycaemic control is the mainstay of treatment but effective antihypertensive therapy is also key to delaying the progression of diabetic nephropathy. Angiotensin-converting enzyme inhibitors and angiotensin Ⅱ receptor antagonists have important renoprotective actions independent of their blood pressure lowering actions. Conclusions Diabetic nephropathy is the leading cause of end-stage renal disease worldwide. Monitoring renal function and screening for microalbuminuria will allow the identification of patients with nephropathy at a very early stage for intervention. Tight glycaemic control and aggressive antihypertensive treatment as well as the use of renin-angiotensin system inhibitors should substantially delay the progression of nephropathy. Chin Med J 2002; 115(1): 129-135