重视外科导航技术在创伤骨科的应用与研究

作为外科导航技术在创伤骨科领域中的一员,这次有幸受《中华创伤骨科杂志》邀请进行“计算机辅助骨科导航技术”专刊的组稿。除背景资料的文献回顾外,本期将介绍内地与香港在该领域中的初步临床经验体会和成果,与读者分享。随着计算机及图像技术的迅猛发展,我们可借助计算机进行越来越多的外科手术。尤其在创伤骨科,医生可借助术前或术中所获得的影像进行骨折复位与固定。在临床实践中结合使用计算机和其它信息技术将无疑是未来的发展趋势。在本期专刊中我们将着重介绍外科导航技术在创伤骨科的适应证。经过几年的探索,我们已对下列骨科手术…     

Palliative treatment of malignant ascites by intraperitoneal bleomycin after dialytic ultrafiltration with haemofilter

Dialytic ultrafiltration with haemofilter was performed in 16 patients with malignant ascites refractory to treatment with sodium restriction, diuretic and systemic chemotherapy. A continuous flow of ascitic fluid at a rate of 300–400 ml/min through a haemofilter was maintained by a blood pump. The protein-rich ascitic fluid was re-infused into the peritoneal cavity with sodium and water removed. An average of 5.2 1 of filtrate was removed over a mean interval of 3.5 h. Bleomycin (60 mg) was administered intraperitoneally following the procedure. Complete response was observed in six patients (37.25%) and partial response occurred in four (25%). The remaining patients showed no response. Complications of the dialytic ultrafiltration procedure and toxicity of intraperitoneal administration of bleomycin were minimal. The technique of dialytic ultrafiltration is simple, safe and cost-effective and could be used as an adjuvant therapy for intraperitoneal chemotherapy.     

X线透视导航技术在创伤骨科的应用

X线透视导航技术对创伤骨科尤为重要。因为术前骨折块及骨折移位的方向可发生改变,所以需在术中将骨折块整复对位后,才能进行透视图像的获取和导航手术操作。X线透视导航技术的优点包括减少X线暴露的时间、准确放置植入物、术中适时测量评估及改善创伤骨科的微创操作。随着软件和硬件的不断改进及发展,许多需要术中X线透视监控的手术操作现在都可以借助X线透视导航技术完成。我们过去四年的临床经验已证实X线透视导航技术的优点及不断扩大的应用领域。X线透视导航技术在不断进展,因此需要更多的临床实践来评价此技术的使用价值。另外,X线透视导航系统在虚拟外科环境的外科培训和评价中发挥重要作用。这一技术将不仅为年轻外科医生提供实践机会,而且也将产生设计外科技术资格客观评价系统的新领域。     

Inhibition of Human Natural Killer Cell and Lymphokine-Activated Killer Cell Cytotoxicity and Differentiation by Vitamin D3

Recent data suggest that vitamin D3 may be capable of immunoregulation after it is converted to an active metabolite, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). The effect of vitamin D3 and 1,25(OH)2D3 on human natural killer (NK) cells and their activation by interferon (IFN) and interleukin 2 (IL-2) was investigated. Vitamin D3 and 1,25(OH)2D3 inhibited NK cytotoxicity in a dose-dependent manner. Pretreatment of non-adherent (NA) cells at 37 degrees C for 18 h with the vitamins also led to inhibition of NK activity. Both the inhibition of NK lysis and pretreatment of NA cells were dependent on the concentrations of fetal calf serum (FCS) in the medium. The inhibition of NK activity was less effective in the presence of 10% FCS than with 1% FCS. Vitamin D3 inhibited both IFN and IL-2 activation of NK activity. However, increasing doses of IL-2 were able to abrogate the inhibition caused by vitamin D3. Vitamin D3 was able to inhibit NK activity of phytohaemagglutinin and IL-2-activated cells, and also inhibit the proliferation and lymphokine-activated killer activity induced by IL-2. NA cells pretreated with vitamin D3 did not respond well to IL-2. NA cells pretreated with low doses of IL-2 were sensitive to inhibition by vitamin D3 while those pretreated with high doses of IL-2 were not. The data presented suggest that vitamin D3 and 1,25(OH)2D3 inhibit NK activity and LAK cellular differentiation.     

Microsatellite instability and novel mismatch repair gene mutations in northern Chinese population with Hereditary non‐polyposis colorectal cancer

OBJECTIVE: Hereditary non‐polyposis colorectal cancer (HNPCC) syndrome is the most common cause of hereditary colorectal cancer with an early age of onset. Microsatellite instability (MSI) and germline mutation in one of the DNA mismatch repair (MMR) genes are found in the majority of HNPCC families and provide an opportunity for genetic diagnosis and prophylactic screening. The MMR gene mutation spectrum may vary across different populations and be influenced by founder mutations that prevail in specific ethnic groups. China is a big and ancient nation with enormous genetic diversity, which is especially notable between the northern and southern Chinese populations. A MMR gene mutation database for the southern Chinese population based in Hong Kong has been previously established. This study compares the MMR gene mutation spectrum and the MSI of HNPCC between the northern and southern Chinese populations. METHODS: Twenty‐five HNPCC families from northern China were systematically analyzed. The MSI analysis was performed using five loci in the USA National Cancer Institute (NCI) panel (D2S123, D5S346, BAT‐25, BAT‐26 and BAT‐40) by PCR from the tumor and normal tissue. MSH2, MSH6 and MLH1 were performed using immunohistochemical staining. Two founder mutations of MSH2 and MLH1 were examined by PCR base analyses using primers flanking the two deletion sites (c.1452_1455delAATG in MSH2 and 1.8 kb deletion involving exon 11 of MLH1) . RESULTS: Of the 25 families collected, 19 met Bethesda guideline (BG) 1 and six met BG3. Twenty‐two (15.7%) were extra‐colonic cancers with gastric cancer (in seven patients) being the most common cancer type. Of the 25 tumors analyzed, 21 (84%) were high level microsatellite instability (MSI‐H) and four (16%) were microsatellite stable (MSS). Eighteen (86%) of the 21 MSI‐H tumors showed loss of either the MLH1 or the MSH2 protein. Three MSI‐H tumors and all four MSS tumors showed no loss of expression of the three MMR proteins. Out of the 21 patients with MSI‐H tumors, 12 (57%) showed pathogenic germline mutations in either MLH1 (n = 8) or MSH2 (n = 4). Overall, three novel mutations (in patients H22, H17 and H29) have been identified. One of them, c.503_4insA, caused a frameshift mutation in the MLH1 gene. The other two were found in the MSH2 gene, including a frameshift (c.899_890insAT) and a splice junction (IVS7‐1G→A, SA of Exon 8) mutation. CONCLUSIONS: The results suggest a distinctly different mutation spectrum of MMR genes between northern and southern Chinese populations and call for a systematic, nationwide study to facilitate the design of a MMR gene mutation detection strategy tailored for individual populations in China.     

LC-MS/MS测定人血浆中对乙酰氨基酚及其人体药动学和生物等效性研究

目的 建立一种快速、灵敏的高效液相色谱-串联质谱（HPLC-MS/MS）方法以测定人血浆中对乙酰氨基酚浓度,并应用于两种对乙酰氨基酚制剂的人体药代动力学和生物等效性研究。方法 以替硝唑为内标,200μL血浆样品经5倍于其体积的乙酸乙酯液液萃取,再经Waters XBridge? C18柱等度洗脱分离后导入串联质谱,以正离子多反应监测模式进行定量分析,对乙酰氨基酚和内标的选择性反应离子对分别是m/z 152→110和248→121。方法经验证后应用于19名健康受试者单剂量空腹口服两种对乙酰氨基酚制剂500mg后药代动力学和生物等效性的研究。结果 血浆中对乙酰氨基酚在0.1～8.0 μg·mL-1范围内线性良好（r2 > 0.99）,最低检测限为 0.1 μg·mL-1,提取回收率为91.0%～98.7%,日内和日间准确度分别为98.8%～111.3% （精密度：CV ? 9.03%）和94.9%～102.6% （精密度：CV ? 10.68%）。生物等效性试验中,受试制剂与参比制剂的主要药代动力学参数Cmax、AUC0-t和AUC0-∞ 几何均值比的90%置信区间分别为83.50%～105.79%,94.25%～101.54%和93.24%～101.02%,均落在生物等效可接受标准80.00%～125.00%范围内。结论 所建立测定人血浆中对乙酰氨基酚浓度的HPLC-MS/MS法具有快速灵敏、回收率高、选择性好的特点,适用于对乙酰氨基酚片人体药代动力学和生物等效性研究。受试制剂与参比制剂在人体内吸收速度和程度相似,两种制剂生物等效。     

Guided bone regeneration to reduce root migration after coronectomy of lower third molar: a randomized clinical trial

Purpose

Root migration occurs after most third molar coronectomy and a portion may be exposed in the oral cavity. This study compared the root migration rate, surgical morbidities after third molar coronectomy with or without adjunctive guided bone regeneration (GBR).

Methods

A split-mouth randomized clinical trial was conducted on patients with bilateral lower third molars close to the inferior alveolar nerve. One side of the lower third molars was randomized to receive coronectomy with adjunctive GBR (study group) and the other side received coronectomy alone (control group). The cases were followed up for 2 years. Root migration, root exposure rate, surgical morbidities, and adjacent second molar periodontal regeneration were analyzed.

Results

Forty-eight subjects (19 males, 29 females) with a mean age of 2.6 years (SD 5.8 years) were recruited. There was no root exposure in the review period. There were no statistical differences in pain and infection rate between the two groups at all time-points. The root migration was significantly less in the study group than the control group from 3 months onwards, and migrated only 1 mm (SD 1.3 mm) in 2 years (versus 3.5 mm (S.D.1.9 mm) in the control group). There were no differences in the periodontal attachment regeneration between the two groups.

Conclusions

Root migration in coronectomy with adjunctive GBR was less when compared with coronectomy alone, and with similar surgical morbidities and periodontal regeneration of adjacent second molars.

Clinical relevance

Minimal root migration occurred in coronectomy with adjunctive GBR. The chance of long-term (3 years or more) root exposure and the need of subsequent second operation to remove the exposed root would be reduced.