Antiprotozoal and cytotoxic screening of 45 plant extracts from Democratic Republic of Congo

AIM OF THE STUDY

To evaluate in vitro the antiprotozoal and cytotoxic activities of 80% methanol extract from 45 medicinal plants collected in Sankuru (Democratic Republic of Congo) against Trypanosoma brucei brucei, Trypanosoma cruzi and the chloroquine-sensitive Ghanaian strain of Plasmodium falciparum, and MRC-5 cell lines respectively.

MATERIAL AND METHODS

Different extracts were obtained by maceration of each plant part used with 80% methanol for 24h. The mixture was filtered and evaporated in vacuo to give corresponding dried extract. The activity against Trypanosoma brucei brucei and Trypanosoma cruzi were performed in 96 well tissue plates each containing 10 microl aqueous plant extract dilutions (100 to 0.01 microg/ml) with 10 microl of the parasite suspension cultured in Hirumi medium supplemented with 10% foetal calf serum, a solution of 2% penicillin/streptomycin (2% P/S) After 4 days incubation with Almar blueâ solution, fluorescence was measured at 500 nm emission and 530 nm excitation and results expressed as percentage reduction in parasite compared to control wells. The antiplasmodial activity of was assessed in vitro against the chloroquine-sensitive Ghanaian strain of Plasmodium falciparum cultured in RPMI-1640 medium by the lactate deshydrogenase assay in the presence of plant extracts (50 to 0.01 microg/ml). Cell-lines MRC-5 were cultured in MEM medium supplemented with 20mM l-glutamine, 16.5mM NaHCO(3), 5% foetal calf serum and 2% P/S solution. After 4h incubation, cell proliferation/viability was spectrophotomecally assessed at 540 nm after addition of MTT. In each assay, the IC50 value for each sample was derived by the drug concentration-response curves.

RESULTS

The extracts from Alcornea cordifolia leaves, Momordica charantia whole plant, Omphalocarpum glomerata, root bark and Piptadia africanum stem bark showed good antiprotozoal activity against Trypanosoma brucei brucei with IC50 values from 0.7 to 7 microg/ml. Only Piptadenia africanum extract showed a pronounced antiprotozoal activity against Trypanosoma cruzi (IC50=4.0+/-06 microg/ml). The extracts from Alchornea cordifolia, Polyathia swaveleons stem bark, Sapium cornutum stem bark and Triclisia giletii stem bark exhibited a pronounced antiplasmodial activity against P. falciparum Ghanaian strain with IC50 values ranging from 0.5 to 3.0 microg/ml. Piptadenia africanum extract was the most cytotoxic sample (CC50=0.25 microg/ml) with poor selectivity against all selected protozoa (SI<10) while other active extracts did not show a significant cytotoxic effect against MCR-5 cell-lines with good selectivity according to the case.

CONCLUSION

These active plant extracts are selected for extensive studies leading to the isolation of active constituents.

Relation between telomerase activity, hTERT and telomere length for intracranial tumours

Human linear chromosomes are capped by specialized DNA-protein structures called telomeres. The present study analysed the telomerase activity, hTERT protein and telomere length in meningiomas and gliomas in relation to their WHO grading. Fifty-three freshly dissected tumour biopsies were analysed for telomerase activity, hTERT protein expression and telomere length. Telomerase activity was examined in 41 of the 53 biopsies. Telomerase activity was detected in 3 of 35 (8.6%) screened meningiomas (1 benign, 1 atypical and 1 malignant meningioma). For hTERT expression, 56.4% of meningiomas were positive with a mean labelling index (hTERT LI) of 31.3% (SD=26.5) for the hTERT positive meningiomas. The mean telomere length for meningiomas was 6.983 kb (SD=1.969). For gliomas, no active telomerase was detected in 2 low-grade astrocytomas, whereas three of the four screened glioblastomas were positive for telomerase activity. The only hTERT protein positive astrocytoma had a mean labelling index of 9.0%. On the other hand, the hTERT LI for glioblastomas was 53.6% (SD=28.0). The two low-grade astrocytomas had a telomere length of 14.310 and 9.236 kb. The anaplastic astrocytoma had a telomere length of 4.903 kb and the glioblastomas 5.767 kb (SD=2.042). The normal meningeal and neuronal tissue is negative for telomerase activity and hTERT. The length was +/-10.000 kb. These results indicate that telomere shortening may be a critical step in pathogenesis of atypical and malignant meningiomas and gliomas. Critical telomere shortening in vitro was shown to activate telomerase.

A new colorimetric microtitre model for the detection of Staphylococcus aureus biofilms

AIMS

Research on biofilms requires validated quantitative models that focus both on matrix and viable bacterial mass. In this study, a new microplate model for the detection of Staphylococcus aureus biofilms was developed.

METHODS AND RESULTS

Dimethyl methylene blue (DMMB) dye was used to quantify biofilm matrix colorimetrically. Initially developed for the detection of glycosaminoglycans, the DMMB protocol was optimized for S. aureus biofilm research. In addition, the redox indicator resazurin was used to determine the viable bacterial biofilm burden.

CONCLUSION

A new, simple and reproducible microplate test system based on DMMB and resazurin, offering a reliable differentiation between biofilm matrix and cellular activity, was developed and validated for the detection of S. aureus biofilms.

SIGNIFICANCE AND IMPACT OF THE STUDY

The DMMB-resazurin microtitre plate model is a valuable tool for high capacity screening of biocides and for the development of synergistic mixtures of biocides, destroying both biofilm matrix and bacteria.

Explaining the effect of a 1-year intervention promoting physical activity in middle schools: a mediation analysis

Objective

The aim of the present study was to examine the mediation effects of changes in psychosocial determinants of physical activity (attitude, social support, self-efficacy, perceived benefits and barriers) on changes in physical activity.

Design

One-year intervention study with baseline and 1-year post measures of physical activity habits and psychosocial correlates.

Setting

Fifteen middle schools.

Subjects

Boys and girls (n = 2840) aged 11–15 years completed the validated questionnaires during class hours.

Results

The product-of-coefficients test was used to asses the mediating effects. Self-efficacy for physical activity at school was found to be the only significant mediator of physical activity change. Specifically, self-efficacy for physical activity at school partly mediated the effect of the intervention on total and school-related physical activity change in the intervention group with parental support (P < 0.05). None of the other potential mediators, attitudes, social support, perceived benefits and perceived barriers, seemed to have had a positive effect. Even a suppressor effect was found for attitudes. Given that the effects of self-efficacy and attitudes were of opposite direction, the total mediated/suppressed effects of the intervention were not statistically significant.

Conclusions

Positive changes in total and school-related physical activity in adolescents could be partly explained by increases in self-efficacy for physical activity at school through a physical activity intervention in middle schools with parental support. However, the suppressor effect of attitudes decreased this effect. As this is one of the first true mediation analyses in this age group, further research is needed to replicate the importance of these mediators.

Physical activity and endurance in normal weight versus overweight boys and girls

AIM

Some studies found lower levels of physical activity and fitness in overweight children, compared to normal weight children, while others have failed to observe any difference. Therefore, the purpose of the present study was to reinvestigate the differences in physical activity and running capacity between overweight and normal weight children.

METHODS

A random sample of 121 males and 101 females, 11 to 13 years old, was selected. Children were divided into overweight/fat and normal weight/fat groups based on measures of body mass index and percentage of body fat. Physical activity level was assessed by accelerometers and a Physical Activity Questionnaire. Running capacity was measured by the Cooper Test.

RESULTS

Accelerometer data revealed that overweight/fat children were less moderate to vigorous physically active when compared to normal weight/fat children. They also performed worse on the running capacity test (P<0.001). Overweight children reported to be less active in leisure time (P<0.05) compared to normal weight children. Overfat girls reported to participate less in sports activities compared to normal fat girls (P<0.05).

CONCLUSION

The present study found clear differences in physical activity and running capacity between overweight/fat and normal weight/fat 11- to 13-year olds. A major strength of the present study is that similar results were shown based on different estimates of overweight and activity in a relatively large sample of children.

Smoking in young people with asthma

BACKGROUND

Modern guidelines for the management of asthma state that asthmatic patients should be strongly advised not to smoke. However, it remains unclear to what extend young people with asthma actually behave like this. This study compares the prevalence of daily smoking between 15-year adolescents with diagnosed asthma and without asthma, and evaluates to what extent risk factors for smoking play a comparable role in the smoking behaviour of these two groups.

METHODS

The study is part of the 2001-2002 international HBSC study. Besides questions about health behaviour, individual and social resources, a set of asthma questions were included in six countries.

RESULTS

Adolescents with diagnosed asthma are more likely to be daily smokers than non-asthmatic adolescents. In asthmatic and non-asthmatic adolescents, similar associations with risk factors are found for daily smoking (drunkenness, cannabis use, low life satisfaction, spending evenings with friends, having smoking parents and peers). Diagnosed asthmatics are more prone to score high on these factors than non-asthmatics.

CONCLUSIONS

Smoking in adolescents with asthma is a public health problem. Smoking prevention efforts directed towards young people should pay attention to young people with asthma and the curative sector should increase their efforts to motivate asthmatic adolescents not to smoke.

Personal, social and environmental predictors of daily fruit and vegetable intake in 11-year-old children in nine European countries

OBJECTIVE

To investigate potential personal, social and physical environmental predictors of daily fruit intake and daily vegetable intake in 11-year-old boys and girls in nine European countries.

SUBJECTS

The total sample size was 13 305 (90.4% participation rate).

RESULTS

Overall, 43.2% of the children reported to eat fruit every day, 46.1% reported to eat vegetables every day. Daily fruit intake and daily vegetable intake was mainly associated with knowledge of the national recommendations, positive self-efficacy, positive liking and preference, parental modeling and demand and bringing fruit to school (odds ratio between 1.40 and 2.42, P<0.02). These factors were associated fairly consistently with daily fruit intake across all nine European countries, implying that a rather uniform intervention strategy to promote fruit can be used across Europe. For vegetables, the pattern was, however, less consistent. Differences between countries in cooking and preparing vegetables might be responsible for this larger diversity.

CONCLUSIONS

This study showed that especially a combination of personal and social factors is related to daily fruit and vegetable intake in schoolchildren. This shows that a comprehensive multilevel intervention strategy based upon a series of individual and social correlates will be most promising in the promotion of daily fruit and vegetable intake in children.

Challenges and pitfalls in antioxidant research

Over the last decade, much research has focused on the potential health benefits of antioxidants and indeed many synthetic and natural compounds have been evaluated for their antioxidant profile. However, in several studies only a limited number of assays, often poorly validated, are used and the techniques available frequently lack specificity. These limitations may incorrectly influence the results. This review will therefore focus on several pitfalls that may emerge in vitro and in vivo antioxidant research. First, different in vitro techniques to determine antioxidant potential are discussed, including radical scavenging assays and fingerprinting methods. As a rule, a panel of different assays is indispensable to characterize and establish in vitro antioxidant activity. Furthermore, as problems of absorption, distribution, metabolism and excretion are only accounted for by in vivo studies, the need for in vivo antioxidant research is pointed out. Several methods to characterize the in vivo activity of antioxidants, including major drawbacks and pitfalls of some assays, have been discussed. The availability of both a representative "oxidative stress" animal model and a battery of well-validated assays to assess the broad diversity of oxidative damage and antioxidative defence parameters, are crucial for antioxidant research in vivo.

Progression of astrocytomas and meningiomas: an evaluation in vitro

OBJECTIVES/BACKGROUND

In biological terms, progression means that malignancy increases as genetic mutations accumulate leading to increased proliferation and invasion capacity. By verifying the proliferation capacity, human telomerase reverse transcriptase (hTERT) expression and in vitro invasion, in a group of highly malignant glioblastomas, benign meningiomas and astrocytomas, at the initial stage of progression, we have analysed putative progression in vitro for proliferation and telomerase expression.

MATERIALS AND METHODS

The relative proliferation status (visualized with Ki-67 antibodies) and presence of hTERT protein was analysed in 27 intracranial tumours (6 astrocytomas, 8 glioblastomas and 13 meningiomas) by immunohistochemistry on paraffin-embedded biopsy tissue, as well as on primary tumour-derived cell cultures. A confrontation model was used to analyse invasiveness in vitro.

RESULTS

The mean proliferation indices were 22.3 (SD = 18.1) for glioblastomas and 2.1 (SD = 1.9) for low-grade (LG) astrocytomas. The group of benign meningiomas had a labelling index of 2.2 (SD = 2.7). Mean percentages of staining for hTERT varied between 36.5 (SD = 28.4) for glioblastomas and 10.2 (SD = 8.6) for LG astrocytomas. The group of benign meningiomas had a labelling index of 12.4 (SD = 19.2) for hTERT. A significant difference was seen for Ki-67 (P < 0.05) and hTERT (P < 0.001) in vivo versus in vitro. No difference was seen between the group of invasive and non-invasive tumour-derived cell cultures for the histopathological markers Ki-67 and hTERT (P > 0.05) in vitro.

CONCLUSIONS

The elevated expression of hTERT and Ki-67 in vitro provides a potential prognostic tool for early detection of the progression of brain tumours. As tumour cells require telomerase for continued proliferation, the expression of hTERT may mark immortality, leading to indefinite life span. On the other hand, hTERT expression and cell proliferation are not linked directly to invasion in vitro.

Food habits and physical activity patterns among Palestinian adolescents: findings from the national study of Palestinian schoolchildren (HBSC-WBG2004)

OBJECTIVE

To describe the food habits and physical (in)activity patterns and to investigate the relationship with sociodemographic factors among Palestinian adolescents.

DESIGN AND SUBJECTS

The Palestinian Health Behaviour in School-aged Children (HBSC) is a cross-sectional survey of grades 6, 8, 10 and 12. Students completed a modified version of the international HBSC questionnaire. A total of 8885 students were included in this analysis; 53% were from the West Bank and 47% from the Gaza Strip.

RESULTS

Adolescents in the West Bank consume more fruit, meat, chicken, sweets and soft drinks, but less vegetables than adolescents in Gaza (P<0.01). Girls reported more daily consumption of fruit, vegetables and sweets than boys (P<0.001), and less consumption of soft drinks, milk, meat and chicken (P<0.01). Boys were physically more active than girls (P<0.01), whereas girls reported doing more homework (P<0.001). Both boys and girls reported less physical activity with increasing age (P<0.001). Consumption of fruit and milk was positively associated with both parents' education, while consumption of meat, chicken and soft drinks was positively associated with mother's education only. Having breakfast on schooldays was positively associated with the father's education. Physical activity and television viewing were associated with the mother's education (P<0.01). The parents' level of education had no effect on vegetable consumption and dieting status.

CONCLUSION

This study indicated that there are problems with Palestinian adolescents' eating, dieting and physical activity. Regional, gender and parental socio-economic status differences should be taken into account in developing interventions. More detailed studies are needed with more elaborate instruments about food habits and physical activity of adolescents.

The contribution of psychosocial and home environmental factors in explaining eating behaviours in adolescents

OBJECTIVE

The present study aimed at investigating the influence of food availability, rules and television viewing habits on eating behaviours in adolescents.

DESIGN

Cross-sectional study.

SETTING

Four randomly selected middle schools.

SUBJECTS

A sample of 534 seventh and eighth graders.

INTERVENTIONS

Validated questionnaires were used to measure the family environment and fat, soft drink and fruit consumption. Hierarchical regression analyses on fat, soft drink and fruit consumption, with demographic and psychosocial variables entered as the first and environmental factors as the second block were conducted in boys and girls.

RESULTS

Boys with more unhealthy products available at home consumed more fat (P< or =0.001, 95% CI: 8.2-29.4) and more soft drinks (P< or =0.01, 95% CI: 0.2-1.4). Boys who reported better television viewing habits ate more fruit (P< or =0.001, 95% CI: -1.7 to -0.5). Girls who reported better television viewing habits consumed less fat (P< or =0.01, 95% CI: 1.4-9.0) and more fruit (P< or =0.05, 95% CI: -1.0 to -0.1). Girls who reported higher availability of healthy products at home (P< or =0.05, 95% CI: 0.3-3.1) and more food rules (P< or =0.001, 95% CI: -1.8 to -0.5), consumed more fruit. Environmental factors were poor predictors of soft drink consumption among girls.

CONCLUSION

Availability of (un)healthy food products, family food rules and TV viewing habits were related to one or more eating behaviours in boys or girls. Although home environmental factors can play an important role in influencing adolescents' eating behaviours, these factors were generally less predictive than demographic and psychosocial variables.

Evaluation of the rotatory vestibular test: exploration of stimulus parameters

OBJECTIVES

The aim of this study was to construct a rotational test protocol after exploring the stimulus parameters of the rotatory vestibular test.

METHODOLOGY

Twenty-four normal subjects were submitted to three different rotational paradigms: the sinusoidal harmonic acceleration test (SHAT), the pseudorandom rotation test (PRRT), and the velocity step test (VST). We investigated the influence of frequency and velocity on gain, phase and asymmetry values for the SHAT and the PRRT. In the case of the VST, we examined the influence of velocity and deceleration on gain, slow component velocity at deceleration, time constant, nystagmus preponderance, and time constant asymmetry.

RESULTS

Frequency affected the SHAT response parameters, with significant phase differences between the frequencies 0.01, 0.02, 0.05, 0.1, and 0.2 Hz, while velocity, if kept below 150 degrees/s, had no influence on the results. In the case of the VST, responses were influenced by stimulus velocity and not by stimulus deceleration, with significantly higher gain values for the velocities 50 and 250 degrees/s.

CONCLUSIONS

A velocity of 50 degrees/s tested at the frequencies 0.01, 0.02, 0.05, 0.1, and 0.2 Hz was suggested for the SHAT and PRRT protocol, whereas a velocity of 100 degrees/s with a deceleration of 200 degrees/s2 was preferred for the VST. The relevance of this rotational protocol has yet to be established from patient data.

Asthma and wheezing symptoms in young people in six Western countries

BACKGROUND

Asthma diagnosed in children shows wide geographical variations. Large scale surveys identify children with diagnosed asthma, but neglect the group of youngsters with multiple asthmatic complaints.

METHODS

A short validated asthma questionnaire was included in six national surveys of the Health Behaviour in School-Aged Children Study. Prevalence rates are presented by country, gender and age. Gender and age differences are analysed using binary and multinomial logistic regressions controlling for age and smoking.

RESULTS

Large country differences are observed in the prevalence rates of diagnosed asthma (8.6%-20.9% in boys, 6.9%-18.5% in girls) and young people with "asthma-like symptoms" (9.6%-20.2% in boys, 9.2%-23.1% in girls). When controlling for age and smoking, significant gender differences are observed (more diagnosed asthma in boys, more asthmatic symptoms in girls). Age differences were observed in adolescents with "asthma-like symptoms", but not in diagnosed asthma.

CONCLUSIONS

Using a short asthma questionnaire, large differences in diagnosed asthma and wheezing symptoms are observed between the countries. A considerable group of youngsters with "asthma-like symptoms" is detected in all countries, and may be an unrecognised risk group in health promotion.

Telomerase activity and hTERT protein expression in meningiomas: an analysis in vivo versus in vitro

BACKGROUND

Telomere length maintenance is essential for tumorigenesis. Most human tumours stabilise their chromosome ends by telomerase, a specialised reverse transcriptase that adds telomeric repeats (TTAGGG) to these ends. The main components of this telomerase complex are a reverse transcriptase (hTERT) and an integral RNA component (hTR). Most typical meningiomas, however, do not have active telomerase, although some express the hTERT component. The aim of this study was to evaluate telomerase activity and its reverse transcriptase for 33 (30 typical and three atypical) meningiomas in vivo and in vitro.

MATERIALS AND METHODS

Telomerase activity was examined by the telomeric repeat amplification protocol (TRAP) assay. The protein, telomerase reverse transcriptase, was visualised by immunohistochemistry.

RESULTS

In vivo, telomerase activity was detectable in one out of 30 typical meningiomas and in two out of three atypical meningiomas. hTERT protein expression in vivo was positive in 14 out of 33 (42%) cases. The mean percentage of positive nuclei was 12.9% (SD=21.0). In vitro, 22 out of 33 (66%) meningiomas were positive for hTERT, with a mean percentage of positive nuclei of 31.8% (SD=37.1). Only four expressed telomerase activity in vitro, from which three had expressed telomerase activity in vivo. A significant association was found for telomerase activity (p<0.001) and hTERT expression (p<0.001) in vivo versus in vitro; a significant association was found for hTERT expression and telomerase activity in vivo (p<0.05) and in vitro (p<0.05).

CONCLUSION

The results of our study suggest that hTERT expression is an early event in carcinogenesis in contrast to telomerase activity. Fast-proliferating hTERT-positive tumour cells may overgrow in vitro by clonal selection.

PCNA, Ki-67 and hTERT in residual benign meningiomas

BACKGROUND

Relapse in individual patients after incomplete/residual removal of meningiomas cannot be predicted by histology alone as re-growth occurs even in histologically benign meningiomas.

MATERIALS AND METHODS

Proliferating cell nuclear antigen (PCNA), Ki-67 and human telomerase reverse transcriptase (hTERT) labelling indices were measured in histological sections derived from residual meningiomas in 37 patients to assess their relationship to relapse. The labelling index (LI) expressed the percentage of tumour cell nuclei immunoreactive for PCNA, Ki-67 or hTERT in 1,000 tumour cells counted per section. The histological specimens comprised the following 2 groups: (i) stable for at least 10 years after initial partial resection of residual meningiomas: 20 specimens; (ii) relapsing between 11 and 145 months after initial resection of residual meningiomas: 17 specimens.

RESULTS

The proliferative activity and hTERT expression do not directly correlate with every relapse. The PCNA LI significantly differed in the relapsing group (10.8%) compared to the stable group (5.5%) (p=0.08). The Ki-67 LI also was higher in the relapsing group (2.5%) than in the stable group (2.0%), but not statistically significantly (p=0.9). hTERT LI was significantly higher in the relapsing group (27.8%) than in the stable group (7.2%) (p<0.01).

CONCLUSION

The mean PCNA, Ki-67 and hTERT LI were higher in the relapsing group of residual meningiomas than in the stable group, although no statistical difference was found for PCNA and Ki-67. On the other hand, a statistical difference between the two groups of meningiomas was found for hTERT; however, it is no absolute predictor for relapse at the individual patient level.

The hTERT-protein and Ki-67 labelling index in recurrent and non-recurrent meningiomas

Meningiomas are considered as benign neoplasms affecting the coverings of the central nervous system and compromise approximately 20% of all intracranial tumours. However, a number of these tumours recur even after total resection. The aim of this study is to evaluate the prognostic significance for recurrence of the human telomerase catalytic subunit (hTERT) in the cells of meningiomas. The expression of hTERT-protein can be evaluated by immunohistochemical staining using a monoclonal antibody against hTERT (clone 44F42, NCL-L-hTERT). The interdependence between tumour recurrence and cell proliferation in this study is analysed by Ki-67 immunoreactivity (clone MIB-1). Archival material from 29 non-recurrent and 32 recurrent tumours has been evaluated, including specimens from World Health Organization (WHO) stages I (n = 73), II (n = 2) and III (n = 12). Although the tumours were categorized as benign meningiomas following the WHO classification, recurrence in 22 of 50 cases did not correlate with the tumour stage. For hTERT staining, the following results were found for nucleolar and total nuclear staining, respectively: non-recurrent meningiomas, 2.9% (+/- 7.7) and 3.0% (+/- 8.0); recurrent meningiomas at first resection, 16.8% (+/- 19.7) and 31.6% (+/- 30.2). Concerning the Ki-67 labelling index (LI): for the group of non-recurrent meningiomas, results were 2.1% (+/- 1.7) and for the recurrent group at first resection, 1.7% (+/- 2.0). A significant difference was seen for the hTERT staining (P < 0.001) between the non-recurrent and recurrent meningiomas, whereas no statistical significance was found for Ki-67. In conclusion hTERT-positive meningiomas had a high incidence for recurrence. Ki-67 was a good marker of cell proliferation status of the tumours, but did not correlate with recurrence; thus, hTERT alone seemed to be a potential predictor for recurrence.

Young adolescents' nutrition assessment on computer (YANA-C)

OBJECTIVE

To assess the relative validity and acceptability of the computerised 24-h recall 'Young Adolescent's Nutrition Assessment on Computer (YANA-C)'.

DESIGN

Food and nutrient intakes assessed with YANA-C were compared with food records (study 1) and 24-h dietary recall interviews (study 2).

MAIN OUTCOME MEASURES

Intakes of food groups (fruit, fruit juice, vegetables, potatoes, bread, cereals, milk, cheese, other milk products, soft drinks, diet soft drinks, sugar/sweets, pastry/cookies, savoury snacks, butter/sauces, eggs, fish, meat) and nutrients (energy, carbohydrates, protein, fat, fiber, calcium, vitamin C and iron).

SUBJECTS AND SETTING

A total of 237 pupils (11-14 y) from two primary and four secondary schools (study 1: n = 136; study 2: n = 101) in Belgium-Flanders.

RESULTS

YANA-C proved to agree well with both standard methods in categorizing subjects in consumers and nonconsumers (kappa(study 1) = 0.48-0.92; kappa(study 2) = 0.38-0.90). Spearman's correlations for energy and nutrient intakes ranged between 0.44 and 0.79 for study 1 and between 0.44 and 0.86 for study 2. Nutrient and energy intakes were in general (excluding calcium) significantly higher in YANA-C in comparison with the food record, but not in comparison with the interview (only fiber). Statistics used to investigate whether YANA-C agreed with the other methods in ranking portions/amounts in consumers only were fair to moderate for most of the food groups (weighted kappa study 1 = 0.11-0.55; study 2 = 0.04-0.73); amounts in consumers only, were significantly lower in YANA-C against both standards for cereals; amounts were significantly higher in YANA-C against the food record for milk, soft drinks, sugar/sweets and savoury snacks and against the interview for potatoes. Only a few pupils evaluated the program negatively.

CONCLUSION

YANA-C is a promising method to collect detailed dietary information from young adolescents with relatively low staff resources, useful in many nutrition research applications.

The hTERT protein as a marker for malignancy in meningiomas

The meningioma evolution remains problematic as 6 to 19% relapse after total resection. We have no criterion or marker to predict with certainty the tumour behaviour, and the WHO grading system is to a certain degree controversial. Telomerase expression seems to play an active role in conferring to the tumour cell indefinite life span. Telomerase activity has been documented via TRAP protocol and telomerase messenger expression (hTERT mRNA). In meningiomas the protein hTERT itself has not been studied directly. Thirty tumour samples of meningiomas operated in our Neurosurgical Department are reviewed with a mean follow-up of 4 years. Specifically hTERT protein, resection type, proliferation markers (Ki-67), and recurrences are evaluated. MRI is used for recurrence controls. Seven samples appeared to be hTERT-positive and all seven showed recurrence. Four patients had undergone a subtotal resection (STR). Among them two were hTERT-positive; only these showed recurrence and malignancy. Of the five macroscopically total resections (MTR), two were initially histologically benign and progressed to malignancy. A strong correlation was found between hTERT and recurrences (coefficient=0.989; p=0,01) with the Spearman's rho test, and weaker one between the Ki-67 and hTER (coefficient=0.672; p<0.0001). The hTERT staining revealed the presence of the hTERT protein not only in their nucleoli but sometime outside as nuclear speckles. The presence of nucleolar or subnuclear hTERT is directly correlated to recurrence and progression towards malignancy. Relocalisation of this protein was confirmed. A distinction is proposed between regrowth, based on normal proliferation (Ki-67) which can accompany subtotal resection and recurrence. Recurrence appears to be pathologic proliferation linked to hTERT presence. The hTERT presence predicts a sombre clinical outcome at mid-term for the individual patient.

School food policy at primary and secondary schools in Belgium-Flanders: does it influence young people's food habits?

OBJECTIVE

To describe the availability of food items at primary and secondary schools in Belgium-Flanders and to examine the influence of school food policy (availability of food items, school food rules, nutrition education programmes) and aggregated school socioeconomical status (AGG SES) on the consumption of fruit, soft drinks, crisps and sweets, using multilevel modelling.

DESIGN, SETTING AND SUBJECTS

In spring 2002, 360 schools were invited to participate in the Health Behaviour in School-aged Children survey. In January 2003, the same schools were asked to complete a short school policy questionnaire. Pupils of 197 schools participated in the pupil survey (n=16560); 247 school principals completed the school questionnaire; for 157 schools data were available for both (n=12 360).

RESULTS

Mineral water, fruit juice, chocolate milk, and soup were available in most schools. Whole fat milk was available in most primary schools; soft drinks, diet soft drinks and biscuits were available in most secondary schools. Fruit was available in 14% of primary and 26% of secondary schools. Assessment of the variation in the outcome variables revealed no significant between-school variation in primary schools, but considerable variation between secondary schools in the consumption of soft drinks, sweets and crisps (but not fruit). School characteristics explaining some of this school variance independent of pupil level characteristics were: for soft drinks: availability at the school, rules regarding the consumption of sweets and AGG SES; for sweets: AGG SES; and for crisps: rules regarding the consumption of savoury snacks and AGG SES.

CONCLUSION

The results indicate that school food policy can have an impact on adolescents' food habits.

World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines for evaluating the effectiveness of anthelmintics in chickens and turkeys

These guidelines have been prepared to assist in the planning, operation and interpretation of studies designed to assess the effectiveness of drugs against helminth parasites of chickens and turkeys. They are the first to be compiled under the auspices of the World Association for the Advancement of Veterinary Parasitology (WAAVP) for these parasites. The advantages and disadvantages of the widely used critical and controlled tests are discussed. Information is provided on the selection of animals for experiments, animal housing, feed, dose determination studies, confirmatory and field trials, record keeping and necropsy procedures. This document should help investigators and those involved in product approval and registration in conducting and evaluating studies concerned with determining the effectiveness and safety of anthelmintic drugs.

A prodrug form of a Plasmodium falciparum glutathione reductase inhibitor conjugated with a 4-anilinoquinoline

Glutathione (GSH), which is known to guard Plasmodium falciparum from oxidative damage, may have an additional protective role by promoting heme catabolism. An elevation of GSH content in parasites leads to increased resistance to chloroquine (CQ), while GSH depletion in resistant P. falciparum strains is expected to restore the sensitivity to CQ. High intracellular GSH levels depend inter alia on the efficient reduction of GSSG by glutathione reductase (GR). On the basis of this hypothesis, we have developed a new strategy for overcoming glutathione-dependent 4-aminoquinoline resistance. To direct both a 4-aminoquinoline and a GR inhibitor to the parasite, double-drugs were designed and synthesized. Quinoline-based alcohols (with known antimalarial activity) were combined with a GR inhibitor via a metabolically labile ester bond to give double-headed prodrugs. The biochemically most active double-drug 7 of this series was then evaluated as a growth inhibitor against six Plasmodium falciparum strains that differed in their degree of resistance to CQ; the ED(50) values for CQ ranged from 14 to 183 nM. While the inhibitory activity of the original 4-aminoquinoline-based alcohol followed that of CQ in these tests, the double-drug exhibited similar efficiency against all strains, the ED(50) being as low as 28 nM. For the ester 7, a dose-dependent decrease in glutathione content and GR activity and an increase in glutathione-S-transferase activity were determined in treated parasites. The drug was subsequently tested for its antimalarial action in vivo using murine malaria models infected with P. berghei. A 178% excess mean survival time was determined for the animals treated with 40 mg/kg 7 for 4 days. No cytotoxicity due to this compound was observed. Work is in progress to extend and validate the strategy outlined here.

Synthesis and in vitro and in vivo antimalarial activity of new 4-anilinoquinolines

A new series of 4-anilinoquinolines with two proton-accepting side chains has been synthesized. Antimalarial activity and levels of cytotoxicity upon both MRC-5 cells and macrophages were found to be highly dependent upon the features of these side chains. Several compounds were found to be active in the low nanomolar range, against both chloroquine-sensitive and -resistant strains of Plasmodium falciparum in vitro. From among them, a morpholino derivative cured mice infected by Plasmodium berghei and displayed a lower toxicity than amodiaquine upon mouse macrophages.

"One-pot" synthesis and antimalarial activity of formamidine derivatives of 4-anilinoquinoline

Amodiaquine (AQ) is an antimalarial which is effective against chloroquino-resistant strains of Plasmodium falciparum but whose clinical use is severely restricted because of associated hepatotoxicity and agranulocytosis. "One-pot" synthesis of formamidines likely to be transformed into AQ derivatives is reported. Compared with AQ, the new compounds were devoid of in vitro cytotoxicity upon human embryonic lung cells and mouse peritoneal macrophages. One showed a potent in vivo activity in mice infected with P berghei. Transformation of this compound by reductive amination led to a new type of AQ derivatives that displayed an in vitro activity similar to that of AQ but did not lead to toxic quinone-imines.

Antimalarial in-vivo activity of bis(9-amino-6-chloro-2-methoxyacridines)

In the fight against malaria, chemotherapy using bisacridines may represent an alternative method to overcoming chloroquine-resistance. Eight bis(9-amino-6-chloro-2-methoxyacridines), in which acridine moieties were linked by polyamines substituted with a side chain, were tested for their in-vivo activity upon mice infected by Plasmodium berghei. Three of the compounds revealed antimalarial activity but no relationship could be deduced from a comparison of in-vitro and in-vivo activities. N-alkylation of the central amino group generated toxicity and, therefore, only compounds N-acylated in this position can be selected as leads.

Antiplasmodial activity and cytotoxicity of bis-, tris-, and tetraquinolines with linear or cyclic amino linkers

Bisquinoline heteroalkanediamines were structurally modified in order to study the effects of enhanced bulkiness and rigidity on both their activity on strains of Plasmodium falciparum expressing different degrees of chloroquine (CQ) resistance and their cytotoxicity toward mammalian cells. While cyclization yielded molecules of greater rigidity that were not more active than their linear counterparts, they were characterized by an absence of cytotoxicity. Alternatively, dimerization of these compounds led to tetraquinolines that are very potent for CQ-resistant strains and noncytotoxic.