Psychosocial correlates of organized physical activity in Portuguese urban youth

Abstract - This study aimed to explore the association between psychosocial factors and organized physical activity (PA) in urban children and adolescents. Data on organized PA, psychosocial variables, and demographic characteristics were collected via questionnaires. Logistic regression analyses were used to examine the relationship between psychosocial correlates and organized PA. Analyses were run separately for different age groups. Results showed that children and adolescents with a greater positive attitude toward PA were more likely to be involved in organized PA. Ego orientation was associated with organized PA at the age of 13-15 years. Task orientation was related to PA participation at the age of 13-15 and 16-18 years. Perception of competence was related to participation at the age of 10-12 and 13-15 years. These findings suggest that interventions to increase the level of participation in organized PA in youth should focus on increasing students' perceived physical competence, attitude toward PA, and establishing a strong motivational task/mastery climate.

Investigation and development of a measurement technique for the spatial energy distribution of home-use intense pulsed light (IPL) systems.

The current annual global market for domestic intense pulse light (IPL) hair removal has been estimated at US $1 billion and continues to grow. The five key technological parameters to consider in cutaneous photo-therapy are wavelength, energy density, pulse duration, spot size and spatial distribution. Uneven energy distribution in the treatment area can result in over or under treatment of the treated area, thus causing dissatisfaction or harmful results. This study investigates a method of measuring and analysing spatial distribution of a number of commercially available home-use IPL systems as there is no quantitative method to conduct and compare spatial distribution at the present. Using a CCD camera and a phosphorescent screen to extend the pulse duration, averaged time frames were analysed using Matlab mathematic software. 3D graphical images of the data are presented to show the spatial profile of five commercially available IPL systems. Numerical analysis of the data was completed by two methods, arithmetical mean roughness and path difference.

Suppression of intestinal polyps in Msh2-deficient and non-Msh2-deficient multiple intestinal neoplasia mice by a specific cyclooxygenase-2 inhibitor and by a dual cyclooxygenase-1/2 inhibitor.

Epidemiological studies suggest that nonsteroidal anti-inflammatory agents decrease the risk of colorectal cancer. This is believed to be mediated, at least in part, by inhibition of cyclooxygenase (COX) activity. There are two COX isoenzymes, namely the constitutively expressed COX-1 and the inducible COX-2. COX-2 is overexpressed in adenomas and colorectal cancers, and COX-2-specific inhibitors have been shown to inhibit intestinal polyps in Apc(Delta716) mice more effectively than dual COX-1/COX-2 inhibitors such as sulindac. Various Apc knockout mice, including the multiple intestinal neoplasia (Min) mouse and the Apc(Delta716) mouse, are limited by their lack of large numbers of colonic adenomas and aberrant crypt foci, the putative precursors of large-bowel polyps and cancers. Our DNA mismatch-repair-deficient Min mouse model (Apc+/-Msh2-/-) has genetic features of both familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer, and most importantly, rapidly develops numerous small- and large-bowel adenomas, as well as colonic aberrant crypt foci. The purpose of this study was to determine the effects of COX inhibitors on intestinal adenomas and colonic aberrant crypt foci in this accelerated polyposis, mismatch-repair-deficient Min mouse model, in addition to a standard Min mouse model. Weanling Apc+/-Msh2-/- and Min mice were fed diets containing no drug, sulindac, or a specific COX-2 inhibitor (MF-tricyclic). Apc+/-Msh2-/- and Min mice were sacrificed after 4 weeks and 5 months on diet, respectively. Apc+/-Msh2-/- mice treated with MF-tricyclic had significantly fewer small-bowel polyps (mean +/- SD, 178 +/- 29) compared with mice on sulindac (278 +/- 80), or control diet (341 +/- 43; P < 0.001). There was no difference in numbers of large-bowel polyps or aberrant crypt foci in mice in the three groups. MF-tricyclic was also effective in reducing both small- and large-bowel polyps in Min mice. Western analysis demonstrated COX-2 expression in both large- and small-bowel polyps from mice of both genotypes. This study demonstrates that a specific COX-2 inhibitor is effective in preventing small-bowel polyps in mismatch-repair-deficient Min mice and both small- and large-bowel polyps in standard Min mice. Therefore, specific COX-2 inhibitors may be useful as chemopreventive and therapeutic agents in humans at risk for colorectal neoplasia.

Prognostic implications of mandibular invasion in oral cancer.

BACKGROUND: Mandibular invasion alters the clinical staging and management of oral epidermoid carcinoma on the assumption that underresection of mandibular bone invaded by tumor can result in disease progression and poor outcome. METHODS: Cox's proportional hazard model was used to assess the effect of mandibular invasion on recurrence-free survival in 107 patients with squamous cell carcinoma of the oral cavity after controlling for the potential confounding effect of positive margins, tumor size, nodal status, and type of resection. RESULTS: Mandibular invasion was characterized as none (n = 59), focal (n = 25), or deep (n = 23). Relapse-free survival at 60 months by the Kaplan Meier product limit method for the none, focal, and deep invasion groups was 61%, 73%, and 46% respectively (p =.28). Variables influencing disease recurrence were positive margins, size >2 cm, N2 and N3 nodal disease, and marginal vs segmental mandibular resection. Mandibular invasion was not a significant risk factor for disease recurrence with an adjusted hazard ratio for deep invasion vs focal or no invasion of 1.0 (95% CI = 0.5, 2.2; p = 1.00). CONCLUSIONS: Detection of bone invasion, particularly in small tumors, may not be as critical to surgical planning as previously expected. The necessity for and extent of bone resection should be determined by the objective of achieving an adequate surgical margin and not the presence of bone invasion per se.

Chemopreventive effects of dietary folate on intestinal polyps in Apc+/-Msh2-/- mice.

Epidemiological and animal studies (reviewed in Y. I. Kim, J. Nutr. Biochemistry, 10: 66-88, 1999; J. B. Mason and T. Levesque, Oncology, 10: 1727-1743, 1996) suggest that dietary folate intake is inversely related to the risk of colorectal cancer. However, the optimal timing of folate intervention and mechanisms by which folate modulates colorectal carcinogenesis have not been clearly established. A recently developed murine model of intestinal tumorigenesis, which carries a heterozygous mutation in the Apc gene and a null mutation in the Msh2 gene (Apc+/-Msh2-/-), was used to determine the effect of dietary folate on intestinal tumorigenesis. Apc+/- Msh2-/- mice were randomized to receive either 0 or 8 mg of folate/kg diet starting at either 3 or 6 weeks of age. The 3- and 6-week diet starts represent intervention before and after the establishment of neoplastic foci, respectively. At 11 weeks of age, mice were killed, and the small intestines and colons were analyzed for adenomas and aberrant crypt foci (ACF). Serum folate concentrations were determined by a standard microbiological assay. Genomic DNA methylation was assessed by in vitro [3H]methyl incorporation into hepatic DNA and by a methyl-sensitive restriction digestion method. Microsatellite instability was determined in matched normal and polyp DNA from the small intestine and colon at 5 loci. Serum folate concentrations accurately reflected dietary folate levels (P < 0.005). Folate supplementation, started before the establishment of neoplastic foci, significantly decreased the number of small intestinal adenomas (by 2.7-fold; P = 0.004) and colonic ACF (by 2.8-fold; P = 0.028) and colonic adenomas (by 2.8-fold; P = 0.1) compared with a moderate degree of folate deficiency. In contrast, a moderately folate-deficient diet, started after the establishment of neoplastic foci, significantly reduced the number of small intestinal adenomas (by 4.2-fold; P = 0.001) but had no effect on colonic ACF and adenomas compared with folate supplementation. Genomic DNA methylation and microsatellite instability do not seem to play a major role in folate-modulated intestinal and colonic tumorigenesis in this model. In conclusion, in this murine model, dietary folate supplementation significantly protects against small intestinal and colorectal tumorigenesis if it is provided before the establishment of neoplastic foci However, if it is provided after the establishment of neoplastic foci, dietary folate seems to have an opposite effect. These data suggest that the timing of folate intervention is critical in providing an effective and safe chemopreventive effect on intestinal tumorigenesis. Notwithstanding the limitations associated with this model, our data suggest that the optimal timing of folate intervention must be established before folate supplementation can be used as a safe chemopreventive agent against colorectal cancer.

Cancer prevention education in developing countries: toward a model for nurse educators.

The National Cancer Institute, United States of America, funded a series of continuing education courses in cancer prevention between 1986 and 1994 for nurses from developing countries. The purpose of this program was to stimulate interest and facilitate an increase in the participants' knowledge of primary and secondary cancer prevention. The long-term objectives were to increase the number of nurses, internationally, prepared to engage in the prevention and the early detection of cancer in their countries, to expand the international cancer nursing network, and to have these nurses ultimately play a role in reducing the incidence of cancer in developing countries. More than 50 nations were represented. Participants were chosen for their demonstrated ability to influence nursing education and practice in their country. They completed a demographic data sheet, an attitude inventory, a program evaluation and pre- and postconference activities surveys. Before and after attending the conference, participants were asked to identify anticipated problems and obstacles to their goal achievement. These problems included a lack of screening facilities and a lack of primary prevention services. Although numerous differences existed in their education, experience, and personal attributes, the participants voiced common problems with cancer prevention programs. Results from the postconference survey showed a substantial increase in cancer-related activities conducted by the participants. Activities included an increase in cancer content in nursing education programs, an increase in public and professional presentations on cancer prevention, and improvement in the delivery of cancer care.

Long-term neurotoxicity of chemotherapy in adolescents and young adults treated for bone and soft tissue sarcomas.

Purpose. To study the long-term neurotoxicity of chemotherapy in adolescents and young adults treated for bone and soft tissue sarcomas.Patients and Methods. Thirty-six adolescents and young adults (median age 17 years) were examined following chemotherapy for bone and soft tissue sarcomas. Twenty-nine (29/36) had received cisplatin (median 400 mg/m(2)), 15/36 ifosfamide (median 20 g/m(2)), and 12/36 vincristine (median 16 mg). Neurotoxicity was assessed at a median of 8 months (range, 1-54 months) after completion of chemotherapy by clinical examination, nerve conduction studies, audiograms and autonomic function tests. The same nerve conduction studies were carried out in 20 normal volunteers to define normal ranges in this age group.Results. Sixteen patients (44%) had a significant reduction in deep tendon reflexes, and this clinical parameter correlated well with abnormalities detected in nerve conduction studies. Vibration perception threshold (VPT) was raised in 20/36 patients (55%) and this was the most sensitive single test in the assessment of neuropathy. There was a significant correlation between VPT and cumulative cisplatin dose received in mg/m(-2) (r=0.607, p<0.01). Ten of 29 patients (35%) had abnormal nerve conduction studies with a pattern characteristic of sensory axonal neuropathy. No patient complained of auditory symptoms, but minor high tone hearing loss was detected by audiograms in 5/28 patients who had received cisplatin. No patients had symptoms of autonomic neuropathy, but autonomic function tests showed minor abnormalities in 4/22 patients tested, and all had received cisplatin.Conclusions. This study demonstrates significant, although asymptomatic, long-term neurotoxicity of cisplatin in adolescents and young adults receiving chemotherapy for bone and soft tissue sarcomas. Follow-up studies are planned to assess whether these neurological deficits improve with time.

The prognostic significance of DNA flow cytometry in breast cancer: results from 881 patients treated in a single centre.

In this single-centre study of 881 patients, S-phase fraction (SPF) was shown to be a significant prognostic marker in terms of overall survival (OS), relapse-free survival (RFS) and survival after relapse (SAR). Further, SPF had independent prognostic significance when considering a range of other clinicopathological variables, namely tumour grade and stage, nodal status, patient age, tumour size, menstrual status and treatment details. For OS and RFS, SPF was the second strongest predictor of the clinical course of the disease after nodal status, and for SAR it was the strongest prognostic marker. SPF correlated positively with histological grade but was the stronger predictor of survival. The distribution of SPF values was markedly different for the two ploidy classes of tumour, with DNA aneuploid tumours having a significantly higher average SPF. However, SPF retained its independent prognostic ability when DNA diploid and aneuploid tumours were analysed separately, DNA ploidy itself also proved to be an independent prognostic marker but the survival difference between the two ploidy classes was much less than that seen for different levels of SPF. Tumours with several DNA aneuploid populations (multiploid tumours) tended to have a worse prognosis than other aneuploid tumours but this trend did not reach statistical significance. In this and other studies from this centre, SPF has proved to be a robust predictor of clinical outcome in carcinoma of the breast.

A controlled trial of adjuvant tamoxifen, with or without prednisolone, in post-menopausal women with operable breast cancer.

A randomised clinical trial has been conducted to compare adjuvant tamoxifen, 20 mg daily, with tamoxifen and prednisolone, 7.5 mg daily, in post-menopausal women with operable breast cancer. There were 254 evaluable patients, of whom 128 were given tamoxifen alone and 126 received tamoxifen and prednisolone. After a median follow-up of 48 months there was no significant difference in relapse-free or overall survival of the two groups. Furthermore, with survival slightly favouring tamoxifen, confidence intervals on the hazard ratio established that a difference in favour of tamoxifen plus prednisolone of even 5% at 5 years was very unlikely (P < 0.02). Thus, despite the relatively small number of patients in this trial, the data clearly establish that prednisolone is not of value as an additional adjuvant agent.

Received dose-intensity: a randomized trial of weekly chemotherapy with and without granulocyte colony-stimulating factor in small-cell lung cancer.

PURPOSE: A prospective randomized trial to determine if granulocyte colony-stimulating factor (G-CSF) could increase the received dose-intensity (RDI) of weekly chemotherapy in patients with small-cell lung cancer (SCLC). PATIENTS AND METHODS: Forty patients with SCLC with good prognostic features (all patients with limited disease [LD], and extensive-disease [ED] patients with Eastern Cooperative Oncology Group [ECOG] 0 or 1 and plasma alkaline phosphatase levels < 1.5 times the upper limit of normal) were randomized to receive weekly chemotherapy with or without G-CSF. G-CSF (5 micrograms/kg) was self-administered subcutaneously on days when chemotherapy was not given. Chemotherapy consisted of cisplatin 50 mg/m2 intravenously (IV) on day 1 and etoposide 75 mg/m2 IV on days 1 and 2 alternating weekly with ifosfamide 2 g/m2 IV (with mesna) and doxorubicin 25 mg/m2 on day 1, for a total of 12 courses. Dose modifications (dose reductions and treatment delays) were made according to defined hematologic criteria. RESULTS: Dose reductions were made at some point during treatment in 12 of 17 patients in the control arm and in 11 of 23 patients in the G-CSF arm (P = .20). The proportion of patients experiencing dose reductions due to leukopenia was significantly higher in the control arm (nine of 17) compared with the G-CSF arm (four of 23, P < .04). Cycle delays due to leukopenia were similar in both arms of the study. The RDI was 82% of projected in the control arm (95% confidence interval [CI], 79% to 84%) and 84% in patients receiving G-CSF (95% CI, 82% to 87%) (P value not significant). CONCLUSION: In this randomized trial, G-CSF significantly decreased dose reductions due to neutropenia. However, administration of G-CSF did not decrease dose reductions or treatment delays to a level that would allow an increase in received dose-intensity. Nonhematologic toxicities such as increased creatinine concentration also prevented an increase in the RDI in the G-CSF arm.

Hearing loss and temporal bone structure in achondroplasia.

Characteristic temporal bone changes have recently been defined by high resolution CT in nine patients with achondroplasia (Cobb et al., Am J Neuroradiol 9:1195, 1988). These included narrowing of the skull base and "towering" petrous ridges resulting in abnormal orientation of the inner and middle ear structures. In order to determine whether these morphologic changes are the cause of the hearing deficit in achondroplasia, audiometric studies and ENT evaluation were performed in eight of the nine patients. All had a history of frequent otitis media and four had experienced tympanic membrane tube insertion. Three patients had significant sensorineural hearing loss, two had conductive hearing loss and one patient had combined hearing loss. None of the temporal bone morphologic changes were found to be correlated with the degree of either sensorineural or conductive hearing loss. Fusion of the ossicular chain was not present in any of our cases. Appropriate treatment of frequent acute otitis media and early awareness of middle ear effusions and conductive hearing loss in children with achondroplasia may be of great importance in preventing permanent hearing loss.

Early drain removal following modified radical mastectomy: a randomized trial.

The dilemma of increasing costs of medical care and shrinking health budgets has stimulated attempts to implement stricter control on expenditure without affecting the quality of care. This study shows that in patients with operable breast cancer, a policy of early discharge after a mastectomy did not have deleterious effects on wound healing and was well accepted by patients. In a randomized trial, drains were removed after either 3 or 6 days postmastectomy, and in both groups of patients there was no difference between the mean volumes of seromas aspirated or the number of aspirations and return visits to the hospital. This suggests that a policy of early discharge is safe, acceptable, economical, and may improve bed utilization.