Pediatric brain tumors in Non-Hispanics,Hispanics, African Americans and Asians: differences in survival after diagnosis

Background Racial differences in survival for children with brain tumors have not been well studied, particularly in Hispanics and Asians. The objective of this study was to assess racial differences in survival of children with brain tumors, focusing on Hispanics, African Americans and Asians compared to Non-Hispanics.Methods Subjects identified through the SEER Program were 2799 children, ≤19 years old at diagnosis, newly diagnosed between 1973 and 1996 with primary, malignant brain tumors. Chi-square tests were used to evaluate prognostic variables by race. Kaplan–Meier models and Cox proportional hazards models were used to assess racial differences in overall survival and in survival by histological type of tumor.Results The distribution histological type of tumor varied significantly by race. Overall survival was similar for Hispanics, African Americans, Asians compared to Non-Hispanics, although trends of increased risk of death for the minority groups were noted when stratifying by histological type of tumor.Conclusions Racial differences in survival could exist by histological type of tumor, but further work is necessary for a more complete understanding of these differences.     

Array comparative genomic hybridisation (aCGH) analysis of premenopausal breast cancers from a nuclear fallout area and matched cases from Western New York

High-resolution array comparative genomic hybridisation (aCGH) analysis of DNA copy number aberrations (CNAs) was performed on breast carcinomas in premenopausal women from Western New York (WNY) and from Gomel, Belarus, an area exposed to fallout from the 1986 Chernobyl nuclear accident. Genomic DNA was isolated from 47 frozen tumour specimens from 42 patients and hybridised to arrays spotted with more than 3000 BAC clones. In all, 20 samples were from WNY and 27 were from Belarus. In total, 34 samples were primary tumours and 13 were lymph node metastases, including five matched pairs from Gomel. The average number of total CNAs per sample was 76 (range 35-134). We identified 152 CNAs (92 gains and 60 losses) occurring in more than 10% of the samples. The most common amplifications included gains at 8q13.2 (49%), at 1p21.1 (36%), and at 8q24.21 (36%). The most common deletions were at 1p36.22 (26%), at 17p13.2 (26%), and at 8p23.3 (23%). Belarussian tumours had more amplifications and fewer deletions than WNY breast cancers. HER2/neu negativity and younger age were also associated with a higher number of gains and fewer losses. In the five paired samples, we observed more discordant than concordant DNA changes. Unsupervised hierarchical cluster analysis revealed two distinct groups of tumours: one comprised predominantly of Belarussian carcinomas and the other largely consisting of WNY cases. In total, 50 CNAs occurred significantly more commonly in one cohort vs the other, and these included some candidate signature amplifications in the breast cancers in women exposed to significant radiation. In conclusion, our high-density aCGH study has revealed a large number of genetic aberrations in individual premenopausal breast cancer specimens, some of which had not been reported before. We identified a distinct CNA profile for carcinomas from a nuclear fallout area, suggesting a possible molecular fingerprint of radiation-associated breast cancer.     

Perceptions regarding preventive sexual practices and communication with sexual partners among Chinese college students

PURPOSE: To assess the relation between Chinese college students' perceptions and attitudes regarding preventive sexual behaviors, their sexual knowledge, and their use of protective sexual behaviors. METHODS: A subsample of 133 sexually active college students (18-25 years old) was obtained to identify factors related to protective sexual behaviors (e.g., knowledge of partner's sexual history, condom use). RESULTS: Seventy-five percent of the sexually active students were male. Significantly more females had discussed AIDS and sexually transmitted diseases (STDs) issues with their partners and had asked their partners about their sexual histories than males. Students endorsing the use of preventive behaviors were more likely to have discussed AIDS issues with their partners, used condoms, and known their partner's sexual history. CONCLUSIONS: Student perceptions about preventive behaviors have a significant impact on their knowledge of their sexual partners and their own sexual behaviors. These findings, as well as the presence of significant gender differences in perceptions and communications with their partners, have major implications for risk reduction programs.     

Qualitative teamwork issues and strategies: coordination through mutual adjustment

Multidisciplinary research teams that include faculty, students, and volunteers can be challenging and enriching for all participants. Although such teams are becoming commonplace, minimal guidance is available about strategies to enhance team effectiveness. In this article, the authors highlight strategies to guide qualitative teamwork through coordination of team members and tasks based on mutual adjustment. Using a grounded theory exemplar, they focus on issues of (a) building the team, (b) developing reflexivity and theoretical sensitivity, (c) tackling analytic and methodological procedures, and (d) developing dissemination guidelines. Sharing information, articulating project goals and elements, acknowledging variation in individual goals, and engaging in reciprocity and respectful collaboration are key elements of mutual adjustment. The authors summarize conclusions about the costs and benefits of the process.     

Dominant negative selection of vaccinia virus using a thymidine kinase/thymidylate kinase fusion gene and the prodrug azidothymidine

The Escherichia coli thymidine kinase/thymidylate kinase (tk/tmk) fusion gene encodes an enzyme that efficiently converts the prodrug 3'-azido-2',3'-dideoxythymidine (AZT) into its toxic triphosphate derivative, a substance which stops DNA chain elongation. Integration of this marker gene into vaccinia virus that normally is not inhibited by AZT allowed the establishment of a powerful selection procedure for recombinant viruses. In contrast to the conventional vaccinia thymidine kinase (tk) selection that is performed in tk-negative cell lines, AZT selection can be performed in normal (tk-positive) cell lines. The technique is especially useful for the generation of replication-deficient vaccinia viruses and may also be used for gene knock-out studies of essential vaccinia genes.     

Cigarette smoking among rural-to-urban migrants in Beijing, China

BACKGROUND: Tobacco use remains a substantial public health challenge in China. The rapidly growing rural-to-urban migrant population currently numbering approximately 121 million individuals may be especially vulnerable to tobacco use. METHODS: Cigarette smoking levels and associated factors were examined among 2,201 subjects using cross-sectional data from the Migrant Health Behavior Survey (MHBS), conducted in 2002, Beijing, China. RESULTS: Respondents (39.3% females) were 18-30 years old with a mean age of 22.7 years; 77.3% were single and 35.6% had at least attended high school for education. Migrants reported an average of 4 years of migratory experience; 28.8% had worked in at least three cities and 36.8 had held at least four jobs. Males (51.7%) and females (10.9%) reported 30-day cigarette use. Smoking levels were positively associated with age, education, income, migration years, number of cities in which the migrants had worked, living in rental properties, and number of jobs held. Smoking levels were negatively associated with job and life satisfaction and living with relatives in Beijing. Smoking levels were not associated with marital status. CONCLUSIONS: Female migrants had disproportionately high rate of cigarette smoking. Several conditions and experiences common to the migratory lifestyle were associated with increased levels of smoking. Tobacco control measures are needed to protect migrant populations in China.     

Methodological Issues in Group-Matching Designs: α Levels for Control Variable Comparisons and Measurement Characteristics of Control and Target Variables

Group-matching designs are commonly used to identify the diagnosis-specific characteristics of children with developmental disabilities. In this paper, we address three issues central to the use of this design. The first concerns the alpha level to be used for considering groups to be matched on the control variable(s). The second involves the measurement characteristics of the control and target variables. We discuss the properties of standard scores, raw scores, and age equivalents and argue against the use of age equivalents. In addition, we consider the appropriateness of the commonly made prediction that groups that are matched for a control variable such as language ability or nonverbal reasoning ability but are not matched for chronological age should perform at equivalent levels on the target variable. Finally, we discuss issues related to the interpretation of significant between-group differences on the target variable, assuming groups are well-matched on the control variables, and describe the benefits of a method that focuses on characterizing a disorder on a case-by-case basis and then aggregating the cases, using the measures of sensitivity and specificity from signal detection theory.     

Effects of buspirone and alprazolam treatment on the startle-potentiated startle response

The startle potentiated startle (SPS) paradigm has been reported to be an effective procedure for studying the conditioned enhancement of acoustic startle in the absence of electric shocks or extinction. This study examines the effects of two anxiolytic treatments, buspirone and alprazolam, on this SPS effect. Subjects were tested in the SPS paradigm 2 days a week (Monday and Thursday) for 10 weeks. Each startle test session consisted of 10 Noise Alone trials (115 dB acoustic noise burst presented for 40 ms) and 10 Light+Noise trials (115 dB acoustic stimuli presented during the latter 40 ms of a 3,540 ms period in which a 15-watt light was illuminated). Although there was no difference in startle amplitude on Noise Alone trials when compared to Light+Noise trials initially, by the end of the first test session and continuing throughout the duration of the experiment, startle amplitude on Light+Noise trials was significantly (approximately 50-75%) greater than on Noise Alone trials. After five control (i.e., no injection) SPS test sessions, once-weekly drug challenges were conducted over the course of 7 weeks. In these weekly drug challenges, subjects received acute treatment with various doses of the benzodiazepine anxiolytic alprazolam (0.25, 0.5, 1.0 mg/kg) or the novel anxiolytic buspirone (1.0, 2.0, 4.0 mg/kg); subjects also received vehicle treatment (0.5% methylcellulose) on one treatment day. All treatments were administered intraperitoneally (i.p.), 15 min before the start of startle testing. Consistent with previous reports, buspirone increased and alprazolam decreased startle amplitude on the Noise Alone trials; these effects were dose-related. Both agents reduced the magnitude of the SPS effect when it was expressed as the Light+Noise startle amplitude minus the Noise Alone startle amplitude. These findings are similar to the effects of these treatments in the traditional shock-based fear-potentiated startle paradigm.     

Gemcitabine and cisplatin chemotherapy is an active combination in the treatment of platinum-resistant ovarian and peritoneal carcinoma

The treatment of recurrent ovarian cancer with the combination of gemcitabine and cisplatin chemotherapy has recently been shown to be an active regimen. But the majority of positive responses have been observed in patients considered either platinum-sensitive or who have had extended platinum-free intervals. The purpose of our study was to review our experience with this regimen in women with platinum-resistant ovarian and peritoneal carcinoma with more recent exposure to platinum. We studied twenty-two patients who had relapsed within six months of their most recent platinum-based regimen and were treated with gemcitabine (450–600 mg/m²) and cisplatin (30 mg/m²) on days 1 and 8 of a 21-day cycle. The overall response rate was 64% (95% C.I. 42–85%) with seven (32%) complete and seven (32%) partial responses. The median progression-free interval was 6.7 months for responding patients and 3.9 months for the entire study group. Median survival for responders was 15.8 months compared to 8.8 months for non-responders. Overall survival was 11.4 months. Grade 3 or 4 toxicity was encountered in 59% of treatments. We conclude from this limited review that the combination of gemcitabine and cisplatin chemotherapy is an active regimen in platinum-resistant ovarian and peritoneal carcinoma and warrants consideration in the management of patients with recurrent disease.