Feasibility of using interpolated contours of targets and organs at risk in intensity‐modulated radiation therapy treatment planning for advanced‐stage nasopharyngeal carcinoma

To assess the dosimetric effect of using interpolated contours in planning intensity‐modulated radiation therapy (IMRT) for advanced T‐stage nasopharyngeal carcinoma. The present study focused on T3–T4 tumours where the proximity of targets to neurological organs poses a stringent test on the feasibility of such an approach. Contours of targets and organs were delineated on CT images of 2.5‐mm interval and a reference IMRT plan was generated. An investigative (INV) IMRT plan was then generated with the same planning protocol, but based on interpolated contours that replaced deleted contours on alternate slices. The reference and INV plans were compared. Regarding target coverage, all targets in the INV plans met the acceptance criteria except for the PTV in one case. Regarding organs, the mean dose to 1% volume of the brainstem and spinal cord in the INV plans were kept below their dose limits. No significant differences in the mean doses to others organs were found. Satisfactory target coverage and protection of critical organs to a degree similar to full‐scale contouring could be achieved with use of interpolated contours. The saving in manpower time for contouring is expected to significantly improve the throughput of the IMRT planning process.     

An innovative training experience in public health at the Cheikh Anta Diop University of Dakar

The Institute for Health and Development (ISED) at the University of Dakar, was created in 1987. Its mission is to fulfill the public health training needs of Senegalese health care professionals. ISED is responsible for a training program entitled "Certificat d'études Spéciales" (CES), the equivalent of a Masters of Public Health degree. The "CES" is a two-year program comprised of six modules, which last four months each. The ISED training approach stresses trainee responsibility above all. It is based on the trainee's professional tasks and is oriented toward the problems identified by the trainees themselves. In this sense it is highly adaptive and flexible. Each module is implemented in the same way; initially there is a 15 day residential phase for intensive theoretical courses, followed by an application period of 75 days in the trainee's work place, and then a final residential phase of 15 days for writing and presenting a technical report on the work in the field. This model allows trainees to bring together the theoretical and the practical. The trainers directly supervise each of these three phases. The two residential phases are conducted in the ISED training center, located in Mbour, 80 Km south of Dakar. 103 trainees are enrolled in the program in seven different classes. Of these trainees, 93 are health care specialists (85 physicians 7 pharmacists, 1 dentist). Ninety percent of previous graduates have been civil servants who work for the Ministry of Health in Senegal and the remaining 10% were from Burkina Faso and Togo. The training program is considered by all stockholders, beneficiaries, and relevant financial institutions, to be appropriate, beneficial and successful.     

p53 protein accumulation and the presence of human papillomavirus dna in bronchiolo-alveolar carcinoma correlate with poor prognosis

Accumulation of the tumour suppressor gene p53 product due to a gene mutation is frequently seen in human carcinomas, including lung carcinoma. Another indirect mechanism involving p53 in malignant growth relates to the E6 protein of the human papillomavirus (HPV), which is able to bind and degrade wild-type p53 protein, thus eliminating its tumour suppressor activities. Bronchiolo-alveolar carcinoma (BAC) is a rare type of lung carcinoma. The aim of our study was to examine the occurrence of p53 accumulation and the presence of HPV DNA in BAC. Sections of 22 BACs were immunohistochemically stained using a p53 antibody, CM-1. The presence of HPV DNA in BACs was verified by in situ hybridisation for HPV types 6, 11, 16, 18, 31 and 33 and confirmed by PCR. Thirty-six percent of the tumours showed abnormal p53 nuclear accumulation, and HPV DNA, revealed by in situ hybridisation, was found in 36%. Unexpectedly, only 13% of the type 1 BACs were positive for p53, whereas 45% of the type 2 BACs were positive. During a follow-up of 12-176 months, only 10% of the patients with BACs negative for both p53 and HPV died of the disease, compared with 42% of the patients with either p53 or HPV positivity. No inverse relationship between abnormal p53 protein accumulation and the presence of HPV DNA was found. © 1995 Wiley-Liss, Inc.     

Epidemiology of pertussis in a West African community before and after introduction of a widespread vaccination program

The control of pertussis remains a worldwide concern. Little has been documented about its epidemiology in Africa. The authors have studied pertussis in a prospective cohort of children in a rural West African community over a 13-year period comprising time before and after introduction of a vaccination program. Children under age 15 years who were residents of the Niakhar study area in Senegal were followed prospectively between January 1984 and December 1996 for the occurrence of pertussis. Morbidity and mortality rates were extremely high before the launch of immunization. Crude incidence was 183 per 1,000 child-years at risk under age 5 years, with a 2.8% case-fatality rate. After the introduction of the vaccination program, overall incidence dropped rapidly and dramatically-by 27% after 3 years and 46% after 6 years. The decline in incidence involved all age groups but was most substantial in the group under age 5 years and was particularly pronounced in unvaccinated infants. The median age of acquisition of the disease rose steadily with population vaccine coverage. This study shows the tremendous magnitude of the disease burden in children and the rapid decline after vaccination, and it suggests a strong herd-immunity effect.     

缺血性中风(中经络)证候分类与血脂、血压、血液流变学关系的研究

目的探讨缺血性中风证侯分类的客观量度。方法本研究对118例缺血性中风患者按中医证类进行分组,观察各证类组病例的血脂、血压及血液流变学改变。结果研究表明,风痰阻络证、痰热腑实证及气虚血瘀证组脂质变化较正常组明显升高(P<0.05～0.01),其中风痰阻络证、痰热腑实证与气虚血瘀证组存在显著差异(P<0.05);气虚血瘀证、风痰阻络证及痰热腑实证组血液流变学指标较正常组有显著差异(P<0.05～0.01);肝阳暴亢证、痰热腑实证组血压明显高于气虚血瘀证、风痰阻络证及阴虚风动证组(P<0.05～0.01)。结论血脂、血压及血液流变学指标可为缺血性中风证候分类提供客观量度。     

Factors predictive of response and survival in patients with metastatic colorectal cancer in Taiwan

5-Fluorouracil in combination with leucovorin has been shown to be active in therapeutic trials of metastatic colorectal carcinoma. In this study, we administered these drugs to 72 patients with metastatic colorectal carcinoma. Thirty-six of them without previous exposure to 5-fluorouracil were treated with weekly bolus injections of 5-fluorouracil (425 mg/m2) and leucovorin (25 mg/m2) supplemented with oral levamisole. Another 36 patients with or without prior 5-fluorouracil treatment received 5-fluorouracil 3,000 mg/m2 and leucovorin 300 mg/m2 in a 48-hour continuous infusion every two weeks. Clinical efficacy and toxicity were assessed by WHO criteria. Variables were tested for relations to response and survival by univariate and multivariate analysis. The response rate was 19.4% in weekly bolus arm and 13.9% in biweekly high-dose infusion arm (P = 0.527). Median survivals in the two arms were 18.4 months (weekly) and 21 months (biweekly) respectively (P = 0.708). Gastrointestinal side effects including nausea, vomiting, diarrhea and mucositia were the major toxicities of these regimens. By multivariate analysis, the only factor to influence response rate was the site of metastases (P = 0.009). The only factor to affect survival was performance status of the patient (P = 0.0001). We concluded that the two 5-fluorouracil based regimens are well-tolerated and shown to have a response rate comparable with previous reports of similar regimens in patients with metastatic colorectal cancer. Only liver metastases seemed to have a better response to therapy. Performance status is the most important prognostic factor in patients with metastatic colorectal cancer.      

A retrospective comparison of outcomes using three different precut needle knife techniques for biliary cannulation

GOALS: To assess the outcome differences following different precut biliary sphincterotomy needle-knife techniques. BACKGROUND: Precut biliary needle-knife sphincterotomy (NKS) allows biliary access when standard cannulation techniques fail. Little comparative data exist on the outcome of precut NKS. STUDY: Retrospective comparison of outcome differences of three NKS techniques performed by three pancreaticobiliary endoscopists at a tertiary referral center. RESULTS: A total of 139 consecutive biliary NKS were performed. In 44 cases (technique A), NKS was performed using a precut fistulotomy technique avoiding the papillary orifice, with pure cutting current, and occasional pancreatic duct (PD) stenting (6 of 44). In 47 cases (technique B), NKS was performed starting from the papillary orifice cutting upward with blended current, and no PD stenting. In 48 cases (technique C), NKS was performed as B but using pure cutting current and frequent PD stenting (15 of 48). NKS was successful in 95.5%, 95.7%, and 89.6% at initial endoscopic retrograde cholangiopancreatography and 100%, 97.8%, and 95.6% after a second endoscopic retrograde cholangiopancreatography. Total complications were not significantly different between the three groups; however, a lower incidence of pancreatitis occurred using technique A compared with techniques B and C (not significant). CONCLUSIONS: NKS techniques result in a high success rate of biliary cannulation with a similar overall complication rate. Avoiding cutting at the papillary orifice may reduce the risk of pancreatitis. When cutting at the papillary orifice, pancreatic duct stenting, pure cutting current, or both may reduce the incidence of pancreatitis.     

Effect of saliva contamination on microleakage around class-5 cavities restored with three different types of adhesive materials

The recent improvement of adhesive materials should decrease the risk related to saliva contamination. The aim of this study was to evaluate the effect of saliva contamination on the microleakage within class V cavities restored with three different types of materials: conventional glass ionomer cement, composite resin and compomer. 30 human extracted teeth were randomly divided in 3 equal groups. In each group, class V cavities were prepared on both facial and lingual surfaces (but joint for glass ionomer cement and bevelled incisal margin for composite resin and compomer). The lingual cavities were contaminated with saliva prior to restoration, while the facial cavities were not contaminated, serving as control. After water storage for 24 hours, teeth were immersed in 1% methylene blue solution for 24 hours. The axial sections were viewed under an optical microscope and the extent of dye penetration along cervical, axial and incisal margins was measured in millimetres. Statistic analysis showed that under salivary contamination, microleakage increased along the cervical margin of restoration for all three tested materials. Saliva contamination resulted in microleakage within the axial wall of the cavity only for the conventional glass ionomer cement. These data indicate that composite resin and compomer used together with new adhesives seem to be less sensitive to saliva contamination compared to conventional materials. However, under saliva contamination, cervical microleakage cannot be completely prevented and proper isolation should still be mandatory.