Reducing dust using the electrocautery pencil with suction combined with the infusion catheter in mastectomy

The dust from the vaporized tissue released during a mastectomy presents a hazard to the patients and the operating room personnel. More dust has been noted using the conventional electrocautery pencil in dissecting breast tissue than with the metal knife used in the past. It is very important to reduce the hazardous dust released during mastectomy. For this study 80 patients undergoing mastectomy for breast cancer from March to June 2001 were divided into two groups: 1) those whose dissections were performed with a combination of an electrocautery pencil and suction with an intravenous infusion catheter (40 cases) and 2) those whose dissections were performed with the conventional method in which the electrocautery pencil was handled by the surgeon and the metal suction tube was used separately by an assistant (40 cases). During mastectomy the personal air sampler was affixed to the operator's neck to collect the dust from the vaporized tissue. The concentrations of the total dust were significantly lower in the combined electrocautery-suction method (mean 5.56 +/- 3.26 microg/m3) than in the conventional method (mean 34.81 +/- 4.83 microg/m3) during mastectomy (P < 0.05). Although the operating time and blood loss were less in the combined method than in the conventional method this difference was not statistically significant (P > 0.05). The combined method of using the electrocautery pencil for dissecting breast tissue along with the intravenous infusion catheter reduced the concentrations of the total dust from the vaporized tissue plume. Furthermore this method reduces the hazards of dust to the surgeons and operating room personnel. Additionally the cost of this combined method is lower than that of the conventional method.     

Predictive factors associated with long-term survival in patients with neuroendocrine tumors of the pancreas

Background Neuroendocrine tumors of the pancreas are rare tumors. We identified predictive factors that are associated with long-term survival (≥5 years). Methods Fifty patients with a diagnosis of neuroendocrine tumors of the pancreas were retrospectively evaluated. The following factors were evaluated for disease-specific mortality: age, sex, primary tumor location, functional status, type of primary tumor treatment, presence or absence of liver metastases, timing of liver metastases occurrence, and type of liver metastases treatment. Aggressive treatment of the liver metastases included surgery, chemoembolization, or intrahepatic arterial infusion chemotherapy. Results Twenty-three patients (47%) had tumor located in the head of the pancreas, and 29 patients (58%) had nonfunctioning tumor. Thirty-nine patients (78%) had liver metastases. The median follow-up for the entire group was 35 months (range, 76–206 months). The median survival for the entire group was 40 months, and the overall 1-, 2-, and 5-year survival rates were 84%, 69%, and 36%, respectively. Factors that had a significant favorable effect on survival included curative resection of the primary tumor, metachronous liver metastases, absence of liver metastases, and aggressive treatment of the liver metastases. Conclusions Definitive surgical resection of the primary tumor, absence of liver metastases, metachronous liver metastases, and aggressive treatment of the liver metastases were predictors of long-term survival in patients with neuroendocrine tumors of the pancreas. Presented as a poster presentation at the Society of Surgical Oncology 55th Annual Cancer Symposium, Denver, Colorado, March 14–17, 2002.     

Low-pressure laparoscopy may ameliorate intracranial hypertension and renal hypoperfusion

BACKGROUND: Increased abdominal pressure is associated with elevations in the intracranial pressure (ICP) and impaired renal function. These adverse effects are potentially important in clinical situations such as severe abdominal trauma and laparoscopic donor nephrectomy. It was hypothesized that the secondary elevation of ICP leads to release of vasoconstrictors, which may affect renal function by decreasing the renal blood flow (RBF). We investigated the effect of laparoscopy on ICP and renal blood flow in a porcine model. MATERIALS AND METHODS: The abdominal pressure of swine (N = 5; 20-25 kg) was gradually increased from baseline to 5, 15, and 25 mm Hg by insufflation of nitrogen into the abdominal cavity. The ICP was measured using a Camino monitor, and RBF was simultaneously measured using a Transonic Doppler probe placed on the renal artery. Results were analyzed using repeated measures ANOVA and the paired t-test. RESULTS: No significant change from baseline was observed in ICP and RBF when the abdominal pressure was 5 mm Hg. However, both ICP and RBF were affected by increasing the abdominal pressure to 15 and 25 mm Hg (P = 0.035 and 0.04 for ICP and P = 0.074 and 0.034 for RBF, respectively). CONCLUSIONS: Low-pressure laparoscopy may reduce the adverse effects of pneumoperitoneum on ICP and RBF. It may be advisable to use low pressures in laparoscopic surgery, especially when changes in ICP or renal perfusion may have significant clinical implications.     

Two-port laparoscopic cholecystectomy: initial results of a modified technique

BACKGROUND AND PURPOSE: Two-port laparoscopic cholecystectomy has been reported to be safe and feasible with a higher patient satisfaction score. However, it was technically difficult even in expert hands because of the small operating field. We have modified the operating telescope to achieve a wide field of view. PATIENTS AND METHODS: Since September 2000, 14 patients have been enrolled for two-port laparoscopic cholecystectomy. The male to female ratio was 5:9. The median age was 54.5 years (interquartile range [IQR] 45-67.75 years). RESULTS: The median operative time was 53 minutes (IQR 38-61 minutes). Two patients required one additional 5-mm port or a traction suture because of dense adhesions. There was no conversion to open surgery. The median postoperative hospital stay was 2 days (IQR 1-2.25 days). The median oral postoperative analgesia requirement was 1 dose (IQR 0-3 doses). There were no major or minor complications, and there were no deaths. CONCLUSION: The modified two-port technique greatly facilitates two-port laparoscopic cholecystectomy and improves the clinical outcome.     

Epidemiological modelling (including economic modelling) and its role in preventive drug therapy

In contrast to curative therapies, preventive therapies are administered to largely healthy individuals over long periods. The risk-benefit and cost-benefit ratios are more likely to be unfavourable, making treatment decisions difficult. Drug trials provide insufficient information for treatment decisions, as they are conducted on highly selected populations over short durations, estimate only relative benefits of treatment and offer little information on risks and costs. Epidemiological modelling is a method of combining evidence from observational epidemiology and clinical trials to assist in clinical and health policy decision-making. It can estimate absolute benefits, risks and costs of long-term preventive strategies, and thus allow their precise targeting to individuals for whom they are safest and most cost-effective. Epidemiological modelling also allows explicit information about risks and benefits of therapy to be presented to patients, facilitating informed decision-making.     

应用神经网络和遗传算法优化利福霉素B发酵培养基

对培养基进行优化时，会获得大量的实验数据，但这些实验数据往往不能被进一步利用。如果使用一些不同的方法对历史数据进一步挖掘就可能得出额外的规律。本文使用神经网络对历史数据进行处理，得到了利福霉素B培养基成份和发酵效价之间的关系；再以这个关系作为遗传算法的适应度函数，在一个相对大的空间内快速搜索最优解。优化的培养基使摇瓶发酵效价提高了17．9％，说明所建立的模型能够实现培养基优化的目的并具有数据挖掘的功能。     

在新分离的稀有放线菌群体中检测线型染色体、质粒和噬菌体

稀有放线菌属于革兰阳性细菌，具有重要的应用价值。目前对绝大多数稀有放线菌还没有合适的遗传操作系统。本文报道利用脉冲电泳技术和碱变性方法，对土壤中新分离的约200株稀有放线菌的遗传物质进行了检测。结果显示，除约20个菌株的染色体可能为环型结构外，其余染色体为线型结构。在检测到的染色体外遗传因子中，包括在诺卡菌属菌株中检测到1个线型质粒、4个环型质粒和1个噬菌体，此外，在链孢囊菌属中首次检测到1个质粒。这些遗传因子的发现，为发展稀有放线菌类群的遗传操作体系提供了基础。     

氨基酸对利用红色糖多孢菌发酵生产红霉素的产量及组分影响研究

研究红色糖多孢菌发酵生产红霉素过程中几种氨基酸对产量及组分的影响。通过摇瓶实验证实了0h时向合成培养基中分别添加数种氨基酸，对红霉素的产量与组分都有着重要的影响。本文重点研究甘氨酸在红色糖多孢菌发酵中对产量和组分的影响，试验结果表明，0h添加0．05％的甘氨酸产量明显提高（72．2％），红霉素A组分相对百分含量提高9．7％，红霉素C组分减少78．7％。通过50L FUS-50（A）发酵罐进行验证，红霉素产量达到8939u／ml，比对照提高12．2％，EMA：EMC从5．1：1提高到8.2：1。