Volume 116  ·   Issue 03  ·  2003

Objective To investigate the molecular events and metastasis-related genes in ACC-2 and ACC-M cells of adenoid cystic carcinoma. Methods Adenoid cystic carcinoma cell line ACC-2 and a sample of adenoic cystic carcinoma cell clones highly metastatic to the lung (ACC-M) were investigated. ACC-2 and ACC-M cells were cultured and collected. Total RNA was extracted using standard Trizol RNA isolation protocol. The poly A mRNA was purified and labeled in reverse transcription using M-MLV reverse transcriptase in the presence of Easytides deoxyadenosin 5' triphosphate [alpha-33 p]. A cDNA array was assembled with 7675 EST clones which represented the same number of independent single genes. Prepared nylon membranes were hybridized with the [alpha p33]-dATP labeled mRNA from ACC-2 and ACC-M cells. Membranes were exposed to phosphor screen. Results The high-through put analysis of gene expression pattern was obtained from ACC-2 and ACC-M cells by the hybridization of the cDNA array. The difference of parallel gene expression was analyzed. Genes were clustered according to their expression level in the ACC-M compared with ACC-2 cells. According to each gene's ratio of expression level, there were 17 genes which were upregulated with ratios over 3.0, and there were 12 genes which were downregulated with ratios below 0.33 (1/3.0 = 0.33). Conclusions Significantly different expression patterns between ACC-2 and ACC-M by cDNA array were observed. The differences lie in signal pathways, tumor antigens, immune molecular and some unknown genes. Chin Med J 2003; 116(3): 448-452

Objective To identify the characteristics of and evaluate surgical impact on idiopathic macular hole (IMH) by using an optical coherence tomography (OCT) scanner. Methods Sixty-five cases (70 eyes) experiencing IMH were examined using OCT, then graded by their clinical characteristics. Nineteen cases (19 eyes) were scanned and measured using OCT before and after surgery. Results Of the 70 eyes, the number of stage Ⅰ - Ⅳ macular holes were 11, 12, 36 and 11, respectively. For stage I holes, the OCT images revealed flattened or nonexistent fovea and minimally reflective space within or beneath the neurosensory retina; stage Ⅱ holes appeared to be full-sized with attached operculum and surrounding edema; stage Ⅲ holes were also full-sized with surrounding edema; finally, stage Ⅳ holes were full-sized and completely separated the posterior hyaloid membrane from the retina. Through quantitative measurements, OCT determined that the values for mean hole diameter, mean halo diameter and mean thickness of the hole's edge were reduced from 570.95 ± 265.59 to 337.05 ± 335.95 μm, 1043.53 ± 278.8 to 695.00 ± 483.00 μm and 389.78 ± 60.58 to 298.78 ± 109.80 μm, respectively in 19 IMH cases after surgery. In 17 eyes, the holes or halos eventually closed or were reduced in size, or the edges of the holes thinned out. The anatomic successful rate of the surgery was 89%. Conclusion OCT can exhibit the characteristics of IMH and measure the diameter of holes quantitatively. This method can also judge the surgical impacts of IMH objectively, accurately and effectively. Chin Med J 2003; 116(3): 444-447

Objective To investigate the prophylactic effect of low calcium concentration perilymph on noise-induced hearing loss. Methods Forty guinea pigs with normal hearing weighing 250 - 350 g were assigned to five groups (8 in each group): (1) Ca2+ -deficient perilymph perfusion (CDP) for 2 h; (2) white noise (120 dB SPL) exposure (WNE) only for 1 h, (3) combination of calcium-deficient perilymph perfusion and white noise (120 dB SPL) exposure (WNE + CDP); (4) normal artificial perilymph (NAP) perfusion for 2 h; and (5) white noise exposure + normal artificial perilymph perfusion (WNE + NAP) for 2 h. Compound action potentials (CAP) evoked by click was recorded from round window every 15 min. The cochleae from 5 animals in each group were examined with scanning electron microscope. Results The CAP for group 1 experienced a threshold shift (TS) of 15-26 dB, while group 2 yielded a 46 - 59 dB TS and group 3 a 37 - 45 dB TS; no threshold shift occurred in group 4. The CAP TS in group 5 was 33 - 64 dB. The CAP TS of group 3 was less than that of group 2. After one hour of noise exposure, the CAP TS of group 3 were 45.92 ± 2.90 dB and 59.30 ± 3.95dB in group 2. There were significant differences (P < 0.05) between groups 3 and 2. The CAP TS of group 3 was less than that of group 5 at the points of 1, 1.5 and 2 h after noise exposure. There was a significant difference between groups 3 and 5 (P < 0.01). Stereocilia of 89 OHC3 were in disarray in five cochleae after noise exposure in group 2. The cuticular plates of 8 OHC2,3 sank and the stereocilia became fused in only one animal cochlea after noise exposure in group 3 combined with low calcium perilymph perfusion. Conclusions Low calcium concentration appears to participate in preventing noise-induced hearing loss and the rising of calcium concentrations in inner hair cells after noise exposure, which may have been due to the opening of calcium channels in inner hair cells during noise exposure. The mechanism of the prophylactic effect might be caused by a lower calcium concentration in inner hair cells in the cochlea attenuating the influence of noise exposure on hearing loss; calcium deficient perilymph perfusion prevented calcium accumulation in inner hair cells of the cochlea. The motility of the OHCs might be partially inhibited by low calcium concentration that reduced noise-induced hearing loss in turn. Chin Med J 2003; 116(3): 440-443

Objective To compare graft patency in off-pump and conventional coronary artery bypass grafting by using the transit time flow meter in the treatment of triple vessel coronary artery disease. Methods Between June 2000 and April 2001, 60 patients with triple vessel coronary artery disease underwent coronary artery bypass grafting. They were divided into two groups: off-pump and conventional coronary artery bypass. All completed grafts were tested intraoperatively using Transit Time Flow Measurement (TTFM). Preoperative and postoperative variables of the two groups were also compared. Results There were no significant differences in sex, age, weight, acute or remote myocardial infarction, hypertension, diabetes and type of bypass grafts between the two groups. The number of bypass grafts and the assisted respiratory time of the off-pump coronary artery bypass grafting (OPCAB) group were significantly less than those of the conventional coronary artery bypass grafting (CCABG) group. The flow and pulsatile index (PI) of the left anterior descending artery bypass grafts and the right coronary artery bypass grafts were not significantly different between the OPCAB and CCABG groups. The flow of OM in the CCABG group with the multiple anastomosis site of sequential grafts was higher than that in the OPCAB group. Diffused narrow coronary artery bypass grafts in both groups had less flow. Conclusion No signficant differences in graft patency were observed in patients with triple vessel coronary artery disease who had undergone OPCAB or CCABG. Chin Med J 2003; 116(3): 436-439

Objective To investigate the role of anti- interleukin-2 receptor (CD25) monoclonal antibody in the regulation of cytokine mRNA expression of IL-1β, IL-2, CD25, IL-4, IL-5, IL-6, IL-10, tumour necrosis factor-α (TNFα), and interferon-γ (IFNγ) in cardiac allografts to elucidate its immunological mechanism and role in rats that have undergone cardiac transplantation. Methods These in vivo studies were conducted using a rat MHC mismatch SD to Wistar heterotopic cardiac transplant model. Simulect, an anti-CD25 antibody, was used to prevent allograft rejection. An increase in the rate of allograft survival was observed. Rats were sacrificed on day 1, 3, 5, 7, 9, 11, 14 post-transplantation and hearts were harvested for furgher study. Cytokine mRNA expression was determined by semiquantitative RT-PCR. Results In the control group, cardiac allografts were rejected at 8.3 ± 1.7 days after transplantation (±s). The rats who received CsA rejected the cardiac allograft at 26.4 ± 5.7 days post-transplant. Allograft survival of Simulect-treated rats was 29.2 ± 7.1 days (P < 0.05 vs controls). Rats treated with simulect and CsA had the longest survival of 55.0 ± 11.6 days (P < 0.001 vs controls). CD25 mRNA expression in the heart tissue samples of treated rats was undetectable or very weak. However, the untreated group, CD25 expression increased, although anti-CD25 decreased this CD25 expression in the heart graft. Furthermore, in untreated allografts, IL-2, TNFα and IFN-γ were strongly expressed, an effect that markedly decreased after simulect treatment. Finally, IL-4, IL-5, IL-6 and IL-10 expression was strong in anti-CD25-treated allografts. Conclusions These results suggest that anti-CD25 antibody treatment may not only neutralize CD25 activity but also play a role in altering cytokine mRNA expression and prolong the survival of allografts. Chin Med J 2003; 116(3): 432-435

Objective To explore the factors which induce differentiation of embryonic neural stem cells. Methods Rat embryonic neural stem cells were co-cultured with newborn rat Schwann cells in serum-free medium. The phenotype and specific-markers including tubulin-β, glial fibrillary acidic protein (GFAP) and galactorcerebroside (GalC), were domonstrated by phase contrast microscopy and double immunofluorescence staining. Results Overall, 80% ± 5% of neural stem cells protruded several elongated processes and expressed tubulin-β antigen at high levels, while 20 ± 3% of them protruded several short processes and were GalC or GFAP positive. Conclusion The factors secreted by Schwann cells could induce rat embryonic neural stem cell to differentiate. Chin Med J 2003; 116(3): 428-431

Objective To investigate the role of hypertension in the pathogenesis of cerebral aneurysms in rats. Methods Twenty spontaneous hypertensive rats (SHR) and 10 Wistar-Kyoto rats (WKY) were included in this observational study. Animals were fed with normal diet and drinking water. No experimental modifications were undertaken in either group. They were sacrificed at one year of age, the bifurcations of the circle of Willis were dissected and longitudinal serial sections were prepared for light microscopic and transmission electron microscopic study. Results In the SHR group, 2 of the 20 rats formed an aneurysm respectively at the bifurcations of the basilar artery. As revealed by electron microscopy, injury at the bifurcation of the artery first occurred on the steeper side of the intimal pad. Furthermore, loss of endothelial cells, small depressions on the intima, disruptive internal elastic lamina and lymphocytes or red blood cells infiltration were noted at the steeper side of the intimal pad. No significant changes were observed in WKY group. Conclusions Cerebral aneurysms can form spontaneously in SHR without ligation of the common carotid artery and without a diet containing β-aminoproprionitrile. Long-standing systemic arterial hypertension is one of the etiological factors that contributes to aneurysm formation in SHR rats. Chin Med J 2003; 116(3): 424-427

Objective To describe the methods which were used to develop collagen-based materials for wound dressing. Methods Fresh frozen bovine tendon was treated with 0.05 mol/L acetic acid at pH 3.2 for 48 - 72 hours, homogenized, filtered, mixed with 8% chondroitin sulphate, for creating a deaerated 1.5% - 2.5%collagen solution. The solution was lyophilized in either a pre-frozen or non-pre-frozen mould. The collagen sponge was then cross-linked with 0.25% glutaraldehyde for 24 hours. Three other types of wound dressings were developed using a similar method: collagen membrane with a polyurethane membrane onlay, polyurethane-coated collagen membrane and collagen membrane on gauze. Results It was demonstrated that the use of frozen bovine tendon was stable, and that the prepared collagen sponge contained pores of 50-400 μm in diameter. Conclusions Collagen could be used as wound dressing. Chin Med J 2003; 116(3): 419-423

Objective To investigate the effects of combination therapy with methylprednisolone (MP) and brain-derived neurotrophic factor (BDNF) on axonal remyelination and functional recovery after spinal cord injury in rats. Methods Forty-five rats were randomly divided into three groups: Group A received MP and BDNF; group B received MP and cerebrospinal fluid (CSF); and group C received CSF only. Contusion injury to adult rat spinal cord was produced at the T10 vertebra level followed by immediate intravenous MP or CSF, and was thereafter infused intrathecally with BDNF or CSF for 6 weeks. Axonal remyelination and functional recovery was observed using RT-PCR, immunohistochemistry and open field locomotion. Results An increase of 28.4% ± 2.3%in the expression of proteolipid protein (PLP) gene, an endogenous indicator of axonal remyelination, was demonstrated in group A 24 hours after injury. Ten weeks later, there were significant decreases in hematogenous inflammatory cellular infiltration in groups A and B compared to C (P < 0.05). Concomitantly, a significant amount of axonal remyelination was observed in group A compared to groups B and C (P < 0.05). Furthermore, combination therapy using MP and BDNF in group A resulted in stimulation of hindlimb activity as well as improvement in the rate of functional recovery in open field locomotion (P < 0.05). Conclusions Combined therapy of MP and BDNF can improve functional recovery through mechanisms that include attenuating inflammatory cellular infiltration and enhancing axonal remyelination at the injury site. Such a combination may be an effective approach for treatment of spinal cord injury. Chin Med J 2003; 116(3): 414-418

Objective To anatomically reconstruct the oculomotor nerve, trochlear nerve, and abducent nerve by skull base surgery. Methods Seventeen cranial nerves (three oculomotor nerves, eight trochlear nerves and six abducent nerves) were injured and anatomically reconstructed in thirteen skull base operations during a period from 1994 to 2000. Repair techniques included end-to-end neurosuture or fibrin glue adhesion, graft neurosuture or fibrin glue adhesion. The relationships between repair techniques and functional recovery and the related factors were analyzed. Results Functional recovery began from 3 to 8 months after surgery. During a follow-up period of 4 months to 6 years, complete recovery of function was observed in 6 trochlear nerves (75%) and 4 abducent nerves (67%), while partial functional recovery was observed in the other cranial nerves including 2 trochlear nerves, 2 abducent nerves, and 3 oculomotor nerves. Conclusions Complete or partial functional recovery could be expected after anatomical neurotization of an injured oculomotor, trochlear or abducent nerve. Our study demonstrated that, in terms of functional recovery, trochlear and abducent nerves are more responsive than oculomotor nerves, and that end-to-end reconstruction is more efficient than graft reconstruction. These results encourage us to perform reconstruction for a separated cranial nerve as often as possible during skull base surgery. Chin Med J 2003; 116(3): 410-413

Objective To review the relation between dietary omega-3 polyunsaturated fatty acids (ω-3 PUFA) and non-communicable diseases. Method Data were collected from scientific journals and conference publications, MEDLINE (1979 - 2002) and current content which included 68 prospective, cross-sectional, case control and dietary-intervention studies. Scientific paper selections were based on the association between ω-3 PUFA and non-communicable diseases. Results ω-3 PUFA has beneficial effects on increasing heart rate variability, decreasing the risk of stroke, reducing both systolic and diastolic blood pressure, insulin resistance and glucose metabolism. Long chain ω-3 PUFA has anti-cancer and anti-inflammatory activities, ω-3 PUFA has also been reported to have a beneficial effect on attention-deficit/hyperactivity disorder and schizophrenia, and may be effective in managing depression in adults. Conclusions Results from epidemiological and dietary intervention studies have shown that ω-3 PUFA represent powerfully a class of bioactive compounds and that dietary intake of ω-3 PUFA plays a critical role in human health in relation to non-communicable diseases. Chin Med J 2003; 116(3): 453-458

Objective To evaluate the potential role of insulin-like growth factor-1 receptor mRNA(IGF-IR mRNA) in the onset and development of retinopathy in diabetic rats. Methods A diabetic model was duplicated in Wistar rats. The early changes in the retina were examined using light and transmission electron microscopy. Expression of IGF-IR mRNA was analyzed using in situ hybridization. Results Weak expression of IGF-IR mRNA(5%) was found in retinas of normal rats, but was significantly increased (15% and 18%) in the retinas of diabetic rats after 3 and 6 months of diabetes (P < 0.01). In situ hybridization and morphological study demonstrated that there was a positive correlation between IGF-IR mRNA expression and retinal changes at various stages. Conclusion Increased IGF-IR mRNA might play an important role in the onset and development of diabetic retinopathy. Chin Med J 2003; 116(3): 478-480

Objective To measure the concentration of D-dimer (DD), tissue plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1) and plasminogen (PLG) activity in plasma and cerebrospinal fluid in patients with acute cerebral infarction and to investigate their clinical significance. Methods The concentrations of D-dimer, t-PA, and PAI-1 in plasma and cerebrospinal fluid in patients were measured by enzyme-linked immunosorbent assay (ELISA). The PLG biological activity was detected using the chromophore method. The results were compared with those of the controls. Results The concentrations of D-dimer, t-PA and PAI-1 in cerebrospinal fluid and plasma in patients with acute cerebral infarction were much higher than those of normal subjects (P < 0.01). Conversely, the level of PLG activity was significantly lower in the patients than in the controls (P < 0.01). Conclusion Hypercoagulability and secondary hyperfibrinolysis exist in patients with acute cerebral infarction. Chin Med J 2003; 116(3): 475-477

Objective To study the effects of vitamin E on the proliferation and collagen synthesis of rat hepatic stellate cells treated with interleukin-2 (IL-2 ) or tumor necrosis factor-a (TNF-α). Methods Hepatic stellate cells were isolated from male Sprague-Dawley rats by using modified Friedman' s method. Using the isolated cells cultured and treated with IL-2 or TNF-α, we studied the effects of vitamin E on their proliferation and collagen synthesis through an 3H-thymidine and 3H-proline incorporation assay, as well as through observation of these cells under a contrary phase microscope. Results Adding IL-2 increased the both proliferation and collagen synthesis of hepatic stellate cells. Their proliferation was also increased by the addition of TNF-α, although it decreased collagen synthesis. Vitamin E had marked inhibitory effects on the ability of cells treated with IL-2 or TNF-α to reproduce or synthesize collagen. Conclusion Vitamin E can inhibit the proliferation and collagen synthesis of hepatic stellate cells. It is possible that vitamin E affects liver fibrosis through these activities. Chin Med J 2003; 116(3): 472-474

Objective To determine whether the level of serum cardiac troponin T (cTnT) was increased in patients with congestive heart failure (CHF). Methods This study consisted of 265 patients with CHF and 75 healthy people. Serum cTnT was measured by electrochemiluminescence immunoassay using an Elecsys 1010 automatic analyzer. Results cTnT concentration was 0. 181 ± 0.536 ng/mL in CHF patients and 0.003 ± 0.001 ng/mL in controls (P < 0.001). Patients were categorized according to the levels of heart function and left ventricular ejection fraction (LVEF). In the first group consisting of 105 patients with LVEF≤ 35%, cTnT was 0.311 ± 0.221 ng/mL. In the second group of 106 patients with LVEF > 35%, cTnT was 0.07 ± 0.05ng/mL (P < 0.01). In patients with NYHA class Ⅰ , Ⅱ, Ⅲ and Ⅳ, cTnT values were 0.062 ± 0.022 ng/mL, 0.113 ± 0.121 mg/mL, 0.191 ± 0.231 mg/ml and 0.384 ± 0.211 mg/mL, respectively (class Ⅰ vs class Ⅱ P > 0.05, class Ⅱ vs class Ⅲ P < 0.01, class Ⅲ vs class Ⅳ P < 0.01). A negative correlation was observed between serum cTnT concentration and LVEF in 265 patients with CHF (r = -0.493, P < 0.001). Conclusions This study shows that the level of serum cTnT is increased in patients with CHF and that the increased level indicates the severity of CHF. Chin Med J 2003; 116(3): 469-471

Objective To establish a reliable approach to primary culture and identification of sinoatrial node (SAN) cells. Methods The SAN cells were cultured from SAN tissue removed from neonatal Wistar rats and purified with differential attachment and 5' -bromodeoxyuridine (BrdU) treatment. The obtained cells were morphologically observed with inverted microscopy and transmission electron microscopy. Its action potential was recorded using electrophysiological methods. Results Three distinctly different cells were observed in the cultured SAN cells: spindle, triangle and irregular. Of these, the spindle cells comprised the greatest proportion, with their shape, structure and electrophysiological characteristics consistent with those of the pacemaker cells of SAN. The triangle cells were similar in features to the similarly shaped myocytes located in the atrial myocardium. Conclusions The culture method of differential attachment combined with BrdU treatment is a reliable approach to growing SAN cells. Of the cells cultured from SAN, the spindle cells appear to function as pacemaker cells. Chin Med J 2003; 116(3): 465-468

Objective To investigate CTLA4-lg's potential role in therapy for allergic asthma by blocking B7/CD28 interactions with cytotoxic T lymphocyte antigen 4-lg (CTLA4-lg). Methods We divided BALB/C mice into the three groups: Sham/Sham (control), ovalbumin (OVA)/OVA and mCTLA4-lg. Blood, bronchoalveolar lavage, histology and determination of cytokines were performed 24 hours after airway challenge. Results In the OVA/OVA group, the number of cells, the percentage of inflamed cells and the level of IL-4 in BALF were increased. Airways in our murine model for allergic asthma underwent pathological changes, which were significantly reduced after treatment with mCTLA4-lg. Conclusion Blockage of co-stimulation with mCTLA4-lg can inhibit allergy-specific response of T cells, and asthmatic response as well. Chin Med J 2003; 116(3): 462-464

Objectives To assess the hemodynamic, oxygen-dynamic and ventilative effects of Zafirlukast in chronic obstructive pulmonary disease (COPD) induced chronic cor pulmonale at acute exacerbation stage and the mechanisms of Zafirlukast efficacy. Methods Eleven cases of chronic cor pulmonale at acute exacerbation were examinted using Swan-Ganz catheter and peripheral intra-artery catheter. The hemodynamic, oxygen-dynamic parameters and respiratory rate, plasma endothelium-1 (ET-1) level, and urea leukotriene E4(LTE4) level were measured before and at the 1st, 3rd, 5th, 7th, 9th, 12th hour after taking 40 mg Zafirlukast orally. Artarial and mixed venous blood gas analyses were done correspondingly. Results The average pulmonary arterial pressure (mPAP) and pulmonary vascular resistance index (PVRI) were lowered at the 3rd hour after taking Zafirlukast by 23% and 36.5%, respectively. They returned to the baseline around 12th hour. Respiratory rate decreased significantly within the 3rd-7th hour after taking Zafirlukast. LTE4 and ET-1 levels lowered at the 3rd hour and showed a positive correlation with change of mPAP. Conclusions Zafirlukast can reduce mPAP, pulmonary vascular resistance (PVR) and does not affect the ambulatory blood pressure monitoring (ABPM) and oxygenation in cases of chronic cor pulmonale at acute exacerbation stage. Zafirlukast may play a role as an alternative to decrease PAP in COPD patients. Chin Med J 2003; 116(3): 459-461