Volume 119  ·   Issue 12  ·  2006

Cochlear implant is a biomedical device, which can directly stimulate the auditory nerve pass-by the damaged hair cell to recover and rebuild the hearing of deaf people. The implant can also stimulate the auditory brainstem and cortex in patients whose auditory nerve is not accessible because of acoustic tumors. Cochlear implantation can make the patients generate electrical hearing (artificial hearing).The artificial hearing can recover,improve or rebuild the hearing of deaf people through electrical stimulus。

Abstract：Background Pulmonary thromboembolism (PTE) has become a common disease that severely endangers people's health. This study analysed the changes in proportion and mortality of PTE in hospitalized patients to provide data for prevention and management of the disease.Methods The data of 763 hospitalized patients with PTE from 1974 to 2005 in Fuwai Hospital were analysed.Results During the 1970s, 0.27% of patients in a cardiovascular hospital had PTE (＜ 5 cases per year); while so far this century the proportion is 0.94% (48 to 113 per year). The mortality of hospitalized PTE patients fell from 20.00% in the 1970s to 4.10% this century. Prior to 1990, the mortality of hospitalized PTE patients was 12.50%,and in the years after 1990 only 3.40%. The difference was statistically significant (P＜0.005). People with this disease were mostly between the ages of 30 and 69 years. Men were most susceptible between the ages of 30 and 69 years, while women between the ages of 40 and 69 years. Men contracted PTE 10 years earlier than women.The mortality of male PTE patients was 4.70%, not significantly different from female patients, 5.06% (0.50＜P＜0.75). There were not any significant differences between the mortality of patients in the different age groups overall (≤39, 40-49, 50-59, and ≥60 years, P＞0.1). More people contracted the disease in winter than in other seasons (P＜0.05). There was no obvious difference between the mortality in different seasons overall (0.75＜P＜0.90).Conclusion PTE is an increasingly significant disease and deserves adequate attention。

Abstract：Background Currently anti-inflammatory therapy with steroids for allergic rhinitis need long-term repeated administration, although it is effective. Gene therapy is being suggested to substitute it. The aim of this study was to investigate nonviral vector mediated exogenous gene expression in COS-7 cells in vitro and the effect of intranasal mouse interleukin (mIL)-12 transgene expression on allergen induced eosinophil infiltration of nasal mucosa in a murine model of allergic rhinitis.Methods In vitro COS-7 cells were infected with Epstein-Barr virus (EBV)/lipoplex. The expression of IL-12 p70 in cell culture supernatant was examined by enzyme-linked immunosorbent assay (ELISA). In mice with ovalbumin (OVA) induced allergic rhinitis, EBV/lipoplex was administered by nasal drops before OVA challenge once a day from day 1 to day 10. The expression of IL-12 mRNA and protein, the change of eosinophil count in nasal mucosa and serum total IgE were measured 24 hours after the last challenge.Results EBV/lipoplex could effectively transfect COS-7 cells. The expression of IL-12 p70 in cell culture supernatant was significantly more than in blank control. IL-12 via EBV plasmid vector transduction could be overexpressed in vivo. In pGEG.mIL-12 treated models, the nasal mucosa revealed a high level of widespread mIL-12 transduction by immunohistochemistry and in situ hybridization. Histological evaluation revealed marked suppression of eosinophil infiltration in nasal mucosa. The eosinophil count in allergic rhinitis group [(26.5±9.8)/high-power field (HPF)] was significantly increased over control group [(0.40±0.52)/HPF](F=56.94, P＜0.01), while the count in IL-12 gene therapy group [(4.60±2.63)/HPF] was significantly less than that of allergic group (F=56.9, P＜0.01). Serum total IgE between in gene therapy mice [(88.83±6.71) ng/ml]and allergic rhinitis mice [(103.1 ± 5.7) ng/ml] showed a significant difference (F=1216, P＜0.05).Conclusions Nonviral EBV plasmid vector, pGEG. mIL-12 was able to overexpress exogenous gene both in vitro and in murine nasal mucosa in vivo. IL-12 overexpression via EBV/lipoplex could stem allergen induced eosinophil infiltration in nasal mucosa in murine models of allergic rhinitis, which may suggest a new cytokine immunogenetic therapy for allergic rhinitis。

Abstract：Background Mitochondrial DNA mutations have been found in sensorineural deafness. The aim of this study was to compare three methods for extraction of nucleic acid from membranate inner ear tissue of rats.Methods Alkaline denaturation, a conventional phenol-chloroform method and Trizol reagent were respectively used to extract the slight nucleic acid from membranate inner ear tissue of rats. We assessed the amount and quality of nucleic acid using a UV-spectrometer and polymerase chain reaction (PCR).Results The yield and purity (OD260/OD280) of DNA from inner ear tissue using the phenol-chloroform method was the highest of the three methods. Mitochondrial DNA (mtDNA) fragment can be amplified by PCR from nucleic acid prepared by all methods, while no nuclear DNA (nDNA) fragment can be amplified by method of alkaline denaturation. Both nuclear and mitochondrial genescould be amplified by reverse transcriptional PCR from the RNA prepared by Trizol reagent.Conclusion Adequate amount and high-quality of mtDNA, nDNA and RNA were obtained from unilateral membranate inner ear tissue of rats. Method of alkaline denaturation could be chosen when mtDNA without nDNA was needed, while phenol-chloroform method was suitable for extracting total DNA (including nDNA and mtDNA); method with Trizol reagent was suitable for extracting total RNA and total DNA。

Abstract：Background After establishing a murine model of aminoglycoside antibiotic (AmAn) induced ototoxicity, the sensitivity of AmAn induced ototoxicity in three murine strains and the effect of kanamycin on the expression of Na-K-2C1 cotransporter-1 (NKCC 1) in stria vascularis were investigated.Methods C57BL/6J, CBA/CaJ, NKCC1+/- mice (24 of each strain) were randomly divided into four experimental groups: A: kanamycin alone; B: kanamycin plus 2,3-dihydroxybenzoate; C: 2,3-dihydroxybenzoate alone; and D: control group. Mice were injected with kanamycin or/and 2,3-dihydroxybenzoate twice daily for 14 days. Auditory brainstem response (ABR) was measured and morphology of cochlea delineated with succinate dehydrogenase staining. Expression of NKCC1 in stria vascularis was detected immunohistochemically.Results All three strains in groups A and B developed significant ABR threshold shifts (P＜0.01), which were accompanied by outer hair cell loss. NKCC 1 expression in stria vascularis was the weakest in group A (A cf D,P＜0.01) and the strongest in groups C and D (P＜0.05). CBA/CaJ mice had the highest sensitivity to AmAn.Conclusions Administration of kanamycin established AmAn induced ototoxicity. Kanamycin inhibited the expression of NKCC1 in stria vascularis. 2, 3-dihydroxybenzoate attenuated AmAn induced ototoxicitypossibly by enhancing the expression of NKCC1. Age related hearing loss did not show additional sensitivity to AmAn induced ototoxicity in murine model。

Abstract：Background Ouabain, a cardiac glycoside that specifically binds to Na/K-ATPase and inhibits its activity, was applied to gerbils to develop a method for studying auditory neuropathy.Methods Ouabain was applied to the round window of the cochlea in each gerbil by using a piece of gelfoam with 3 μl or 24 μl (1 mmol/L) ouabain solution. The changes of the threshold of auditory brainstem response,cochlear function round window electrocochleography, as well as the morphological changes of the spiral ganglion cells of the cochlea were observed after application of ouabain for 24 hours or 96 hours.Results:In ouabain treated gerbils, auditory brainstem response and compound action potential thresholds showed either elevation or no response at all. However, the thresholds of cochlear microphonic and distortion product otoacoustic emissions were not affected. Degeneration and necrosis of some spiral ganglion cells in ears with applications of ouabain (24 hours, 3 μl, 1 mmol/L; 96 hours, 24 μl, 1 mmol/L ouabain). The number of spiral ganglion cells was decreased (24 hours, 3 μl, 1 mmol/L ouabain) or near to a total loss (96 hours, 24 μl, 1 mmol/L ouabain).Conclusions:These results indicate a high degree of independence between the spiral ganglion cells and the outer hair cell systems in the cochlear transduction mechanism. The method used in this study would provide a valuable tool for studying auditory neuropathy。

Abstract：Background Renal hypertrophy has been regarded as the early feature of diabetic nephropathy (DN), which may eventually lead to proteinuria and renal fibrosis. However, the exact mechanism of renal hypertrophy is still unclear. The aim of this study was to investigate the possible association of connective tissue growth factor (CTGF) with renal hypertrophy in uninephrectomized diabetic rats.Methods Seventy-two Sprague-Dawley (SD) rats were randomly divided into two groups: control group (group C, n=32) and diabetic nephropathy (group DN, n=40). Each group was re-divided into 4 subgroups according to the experimental period. The rats were sacrificed at 1, 2, 4, and 8 weeks respectively after induction of diabetes.Diabetes was induced by intraperitoneal injection of streptozotocin (STZ) after rats had received uninephrectomy.Blood glucose (BG), body weight (BW), 24-h urinary albumin excretion (24hUalb), kidney weight (KW),KW/BW, glomerular tuft area (AG), glomerular tuft volume (VG), proximal tubular area (AT) at each time point,the width of glomerular basement membrane (GBM) and tubular basement membrane (TBM) at week 8 were measured when the rats were sacrificed. Renal expression of CTGF and p27kip1 were detected by immunohistochemical staining. The relationship between CTGF expression and increasing of VG and AT was analyzed.Results There was a significant increase of 24hUalb, KW, and KW/BW from week 1 onward in diabetic rats compared to those in group C (P＜0.05, respectively), diabetic rats also had a significant increase of AG, VG,and AT from week 1 onward. It was also shown that diabetic rats had a thickening of GBM [(245.7± 103.0) nm vs (121.8±19.1) nm, P＜0.01] and TBM [(767.7±331.1) nm vs (293.0± 110.5) nm, P＜0.01] at week 8. There was a weak expression for CTGF and p27kip1 in normal glomeruli and tubuli, while a significant increasing expression of CTGF and p27kip1 was found in glomeruli and tubuli in diabetic kidney from week 1 onward (P＜0.05, respectively), and the extent of CTGF expression was positively correlated with AG (r=0.92, P＜0.05),VG (r=0.86, P＜0.05), AT (r=0.94, P＜0.01) and positively correlated with the expression of p27kip1 (r=0.96,P＜0.01).Conclusion The expression of CTGF increases in diabetic rat kidney at the early stage, which might be an important mediator of renal hypertrophy through arresting cell cycling。

Abstract：Background Because of the lack of brain death laws in China, the proportion of cadaveric organ donation is low. Many patients with end-stage liver disease die waiting for a suitable donor. Living donor liver transplantation (LDLT) would reduce the current discrepancy between the number of patients on the transplant waiting list and the number of available organ donors. We describe the early experience of LDLT in the mainland of China based on data from five liver transplant centers.Methods Between January 2001 and October 2003, 45 patients with end-stage liver disease received LDLT at five centers in China. The indication and timing, surgical techniques and complications, nonsurgical issues including rejection, infection, and advantages of LDLT in the series were reviewed. Actuarial patient and graft survival rates were calculated by using the Kaplan-Meier product-limit estimate. Statistical analysis was completed by using SPSS 10.0.Results All LDLT recipients were cirrhotic patients, except for one man with fulminant hepatic failure. Among the 45 cases of LDLT, 35 (77.8%) were performed in one center (the First Affiliated Hospital of Nanjing Medical University). The overall 1 and 3 year survival rate of the recipients was 93.1% and 92.0%, respectively. Of the 45 LDLT donors, there were 3 cases of biliary leakage, 2 subphrenic collections, 1 fat liquefaction around the incision and 1 biliary peritonitis after T tube removal. All donors recovered completely.Conclusions LDLT provides an excellent approach to addressing the problem of donor shortage in China even though the operation is complicated, uncompromising and difficult with respect to the safety of the donors and receptors. Despite early technical hurdles having been overcome, perfection of technique is still necessarily. At present, LDLT is a good choice for the patients with irreversible liver disease。

Bronchial asthma is a chronic inflammatory disease of the airways that is characterized by lymphocyte, eosinophil, and mast cell infiltration of the submucosa along with mucous gland hyperplasia and subepithelial fibrosis。

Nasopharyngeal carcinoma (NPC) is one of the highly prevalent malignancies in Southeast Asia.1 Chemotherapy and radiotherapy are commonly administrated to treat nasopharyngeal carcinoma, but these therapies can not prevent the recurrence and metastasis of tumor cells。

Graft-versus-host disease (GVHD) is a severe complication and a major source of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT).

There is mounting evidence that the induction of strong mucosal and cell-mediated immune responses is key element to consider in constructing efficacious HIV-1 vaccine. Therapeutic vaccines that induce high levels of CTL specific to HIV are currently being developed worldwide。

Neural stem cells (NSCs) are effective in treating Parkinsonian animals.1 Although cell transplantation is considered a promising treatment for Parkinson disease (PD), its clinical use has been limited to only a few patients. The major limiting factors of this therapy are difficulty in obtaining sufficient viable embryonic mesencephalic tissue and the controversial ethical and/or legal issues raised by the use of human fetal allografts.1 Some reports suggest that Schwann cells (SCs) can promote the proliferation of embryonic stem cells and the induction of dopaminergic neurons.2 Our research focused on potential curative effects of co-graft SCs with mesencephalic stem cells into Parkinsonian animals and elucidating the underlying mechanisms。

Mechanical injuries to the external regions of the brain including the cerebral cortex and other parts of the telencephalon are common yet relatively untreatable.1 The predicament in recovery from brain injury is that the adult central nervous system is generally thought to be incapable of replacing dead neurons. As the subventricular zone (SVZ) is now known to be neurogenic and is in close proximity to the cerebral cortex and other functionally important forebrain areas, the neurogeny of SVZ brings hope to the repair of brain injury.2,3 Because of the high frequency of injuries to the cerebral cortex and its functional importance in humans, many laboratories have studied the results of unilateral aspiration or percussion injury of the cerebral cortex.4-6 However,little is known about the response of endogenous neural stem/progenitor cells following loss of the cerebral cortex that commonly occurred in the neurosurgery. We have characterized the time course of the proliferation of neural stem/progenitor cells in the SVZ in brain to loss of cortical cells。

Catheter ablation for the treatment of atrial fibrillation (AF) has been a focal target of electrophysiological study in recent years. Up to date,circumferential pulmonary vein ablation (CPVA)guided by three-dimensional (3-D) electroanatomic mapping (Carto, USA) has been one of the most favourable procedures for the treatment of AF。

Neurilemmomas is usually a benign neoplasm which is composed of Schwann ceils, also named schwannomas and originates from the peripheral nerve sheath. It most frequently (25%-45%) occurs in the head and neck,1-3 but rarely (4%)in the nasal cavity and paranasal sinuses,2-4 especially rare in nasal vestibule. In English literature, only Alessandrini5 reported one case with the tumor originating from the nasal vestibule. Here we report two cases。

To the Editor: I read with great interest the recent article by Song et al1 who showed that green tea may play a protective role from ultraviolet B (UVB)-induced skin damage and thus may be a therapeutically effective agent against sunburn.Since excessive exposure to the sun and frequent sunburns predispose to melanoma, one wonders if green tea can also protect against melanoma。