Total lymphocyte count, lymphocyte cell-surface markers (OKT3, OKT4, OKT8, and B-1), serum complement factors (C3 and C4), immunoglobulins (IgG, IgA, and IgM), ceruloplasmin (Crl), and transferrin (Trf) were determined weekly for nine septic postoperative patients, all of whom had multiple organ-system failure. The peripheral blood total lymphocyte count, its subpopulation, T-cell subset, and proliferative responses of lymphocyte to phytohemagglutinin (PHA) and concanavalin A (Con A) decreased in all patients. OKT3 and B-1 decreased progressively in the four nonsurvivors compared with the five survivors. Although immunoglobulin levels were within the normal range in both groups, they tended to increase in survivors and decrease in nonsurvivors. Serial levels of C3, C4, Crl, and Trf increased in survivors but did not change in nonsurvivors. T-cell function and antibody-producing activity diminished progressively in nonsurvivors. These changes in cellular immunity may represent another manifestation of multiple organ-system failure during sepsis.

A four-year-old Polynesian girl with a two-year history of severe microcytic, hypochromic anemia (which was refractory to iron therapy) had a decreased beta-globulin fraction on serum protein electrophoresis, resulting from the absence of the transferrin (TRF) band. Subsequent assays for TRF showed a level below the detectable range. Liver biopsy revealed significant deposition of hemosiderin within hepatocytes and Kupffer cells, in addition to early fibrosis. Two bone marrow aspirates were hypercellular, with decreased myeloid-erythroid ratios. This case represents the eighth reported example of congenital atransferrinemia, a rare, apparently autosomal recessive disease.

A relationship between telomeres and radiosensitivity has been established by several studies based on non-mammalian model systems, mouse models, and few human genetic diseases. However, the relationship has not been proven in human carcinoma cells, which have more clinical significance than these other models. The present study aims to determine whether telomere length is related to radiosensitivity in human carcinoma cells, and to examine the influence of tissue or genetic background. Two HEp-2 larynx squamous carcinoma cell lines, eight hepatocellular carcinoma cell lines, and five breast cancer cell lines were used. Telomere length was determined by terminal restriction fragment (TRF) Southern blot analysis and cell survival was measured by a colony-forming assay. Our results indicated that there was a significant negative correlation of telomere length and radiosensitivity in the same tissue-derived cell lines, with or without the same genetic background. Thus, telomere length may be used as a promising tool to predict the radiosensitivity of human carcinomas.

Intravenous (i.v.) administration of TRF (1 mg/kg) increases the LD50 of pentobarbital (PB) by 25% while the same dose of somatostatin results in a 30% reduction in PB LD50. A similar increase of PB LD50 by TRF was observed in hypophysectomized rats. Mortality was completely abolished in rats receiving TRF (1 mg/kg) ten minutes after a lethal dose of PB (120 mg/kg). Somatostatin (1 mg/kg) decreases strychnine-induced seizure duration and increases strychnine LD50 by 21% while TRF lowers the strychnine LD50 by 28%. These observations are consistent with central nervous system sites of action for TRF and somatostatin.

Vitamin E is divided into two subgroups; tocopherols and tocotrienols. Both have protective roles in biological systems. The present study was conducted to compare the effect of short-term supplementation at 200 mg/d of either alpha-tocopherol or a tocotrienol-rich fraction (TRF) from palm oil on immune modulation and plasma vitamin E levels in normal healthy Asian volunteers. In a randomised, double-blind placebo-controlled trial conducted, fifty-three healthy volunteers aged 20-50 years were recruited based on the study's inclusion and exclusion criteria. They were randomly assigned into three groups, i.e. two experimental groups that received daily supplementation at 200 mg of either alpha-tocopherol or the TRF, and the control group that received a placebo. Blood was drawn on days 0, 28 and 56 for several laboratory analyses. Differences in the production of IL-4 or interferon-gamma by concanavalin A-stimulated lymphocytes isolated from these volunteers were not significant (P>0.05). There were no significant differences observed in immune parameters between the healthy volunteers who received daily supplementation with either alpha-tocopherol or the TRF. As these observations were made in the absence of any immunogenic challenge, we feel it would be of benefit to study if there would be any differences observed when an immunogenic challenge such as vaccination were introduced.

BACKGROUND

Despite the recent discovery of interchromosomal telomere length variation, a role for heterogeneity in telomere maintenance has yet to be established. This study investigated the significance of telomere length variation between chromosomes with respect to the association of cancer progression and telomere length regulation.

METHODS

Terminal restriction fragment (TRF) was evaluated in 20 surgically resected hepatocellular carcinoma specimens (HCC), corresponding noncancerous liver tissue specimens (NCL), and in 10 liver tissue specimens with chronic liver diseases devoid of cancer (DOC). Average TRF length (TRF-A) was defined as the point of maximum intensity. Shorter and longer TRF lengths (TRF-S and TRF-L) were defined as the length above which 90% of TRF distribution was involved. A ratio, (TRF-L-TRF-S)/TRF-A, was defined as telomere length dispersion.

RESULTS

The dispersion was significantly larger in HCC than in NCL specimens (P = 0.012) and in NCL than in DOC (P = 0.048). TRF-A and TRF-S were significantly shorter in HCC than in NCL (P = 0.0026, P = 0.0010). In seven patients in whom HCC recurred within 1 year, TRF-A and TRF-S were significantly shorter than in 10 patients in whom recurrence occurred after 1 year (P = 0.018, P = 0.0097). Telomeric repeat binding factor 1 was up-regulated in HCC with elongated TRF-L, whereas expression of human telomerase reverse transcriptase was greater in HCC with a shorter TRF-S.

CONCLUSIONS

These results suggest that telomere length varied through chronic liver diseases by preferentially increasing shorter telomeres, whose length is a good indicator for malignant potential of HCC. Telomere length variation may be a crucial code in telomere maintenance through hepatocarcinogenesis.

TRF (terminal restriction fragments) length in various tissues of non-human primates such as Macaca mulatta (rhesus monkey), Macaca fuscata (Japanese monkey), Macaca fascicularis (crab-eating monkey), Pan troglodytes (common chimpanzee), and Pongo pygmaeus (orangutan) was at least 23 kb without exception, which was quite different from that of human somatic tissues (smaller than 10 kb). The distribution pattern of telomerase activity among tissues was similar between human and non-human primates, while the activity level showed some differences such as that strong telomerase activity was observed in gastrointestinal and lymphocytic tissues from non-human primates. The human appears to be a unique species among primates in terms of telomere length.

BACKGROUND

Recent research has documented a link between attention problems at school entry and later academic achievement. Little is known about the association of change in attention problems during the early school years with subsequent change in academic achievement.

METHODS

A community-based cohort was followed up and assessed for attention problems at ages 6 and 11 (Teacher Report Form; TRF) and for academic achievement in math and reading at ages 11 and 17 (Woodcock-Johnson Psycho-Educational Battery). Complete data were available on 590 children (72% of the initial sample). Ordinary least squares regressions were used to estimate change in academic achievement from age 11 to age 17 in relation to change in TRF-attention problems from age 6 to age 11. Children's IQ and family factors were statistically controlled.

RESULTS

Change in teachers' ratings of attention problems from age 6 to age 11 was negatively associated with change in math and reading from age 11 to age 17, controlling for children's IQ and family factors. Externalizing problems had no significant association with change in math or reading, when added to the multivariable model.

CONCLUSIONS

Increases in teacher-rated attention problems from age 6 to age 11 were followed by declines in academic achievement from age 11 to age 17; decreases were followed by gains. The results underscore the need for research on the course of attention problems, the testing of interventions to address children's early attention problems and the evaluation of their effects on subsequent academic achievement.

This study was performed in order to investigate the type of T cells recruited to the blood in response to an acute bout of exercise with regard to mean lengths of telomeric terminal restriction fragments (TRF) and surface activation markers and with special emphasis on age-associated differences. Ten elderly and ten young humans performed maximal bicycle exercise. There was no difference in the number of recruited CD4+ and CD8+ cells between the young and elderly group. In both age groups the immediate increases could be ascribed to recruitment of CD28- cells (CD8+ and CD4+ cells) and memory cells (only CD8+ cells). Furthermore, after exercise mean TRF lengths were significantly reduced in blood mononuclear cells and in CD8+ cells from young subjects and in CD4+ cells from elderly subjects compared with lengths pre-exercise. These findings suggest that the mobilization of T lymphocytes during acute exercise is mainly a redistribution of previously activated cells with an increased replicative story than cells isolated from the blood at rest. Furthermore, elderly humans fulfilling the Senieur protocol have a preserved ability to recruit T lymphocytes in response to acute physical stress.

OBJECTIVE

This study examined behavioral and emotional problems in Chinese adolescents.

METHODS

A sample of 1,694 adolescents aged 12 to 16 years participated in this study in 1997. Parents completed the Child Behavior Checklist (CBCL), and teachers completed the Teacher's Report Form (TRF).

RESULTS

For both parent and teacher reports, internalizing syndromes were scored higher in girls and externalizing syndromes were scored higher in boys. Scores on most of the CBCL and TRF subscales were higher for the older adolescents. The overall prevalence rates of parent- and teacher-reported behavioral problems were 23.1% and 19.2%, respectively. The eight cross-informant syndromes were highly comorbid, with a significant association across syndromes (mean odds ratio = 16.1 for CBCL and 22.5 for TRF). Correlations between parent and teacher reports were 0.51 for eight subscales and 0.68 for Total Problems.

CONCLUSIONS

These findings demonstrate that behavioral and emotional problems tend to increase with age and cluster in the same individuals. The prevalence rates of behavioral problems in Chinese adolescents are comparable to those reported in Western countries. In contrast to findings for Western samples, parent reports of behavioral problems were highly correlated with teacher reports.

The objectives of the study are (i) to describe and compare the epidemiology of emotional/behavioral problems and associated risk/protective factors among nationally representative samples of institutionally reared and similarly aged community-based adolescents brought up in their natural homes by means of youth self-reports, caregiver/parent, and teacher informants; and (ii) to identify mental health service needs and utilization. A cross-sectional survey was conducted between November 2005 through April 2006 using an equal probability cluster sample of 11-18 year old adolescents in institutional care settings (N = 350; 163 males, 187 females) and results were compared with similarly aged community sample of youth living in their natural homes (N = 2,206). The Sociodemographic Information Form, Youth Self Report (YSR), Child Behavior Checklist (CBCL) by caregivers for institutional sample and parents for the community sample, and Teacher's Report Form (TRF) were used to obtain standardized data on demographic characteristics, emotional/behavioral problems, and risk/protective factors. The prevalence of problems behaviors by YSR, caregiver/parent CBCL, and TRF were: 47, 15.1, 20.5% for the institutional versus 10.1, 7.5 and, 9.5% for the community samples, respectively (p < 0.05). Youth self-reports were fourfold, and all informant reports were twofold higher for institutional versus community comparisons. Furthermore, institutional sample had consistently higher rates, not only of Externalizing, but Internalizing, Social Problems, Attention Problems, and Thought Problems, as well as discrete DSM-oriented scales, suggesting that labeling of institutional youth as simply aggressive and delinquent contributes to their further marginalization and does not comprehensively address their mental health needs. In terms of protective factors, we found that: perceived social support, high competency scores, supportive caregiving, getting along well with peers and relatives (positive relationships), and problem solving skills were significantly protective of mental health. On the other hand fatalistic beliefs, cigarette and alcohol use were significantly associated with increased risk for problem behaviors (p < 0.05). The primary reason for institutional placement was family disruption (68.9%), poverty (15.7%), abandonment (8.4%), and physical or sexual abuse (5.4%). Only 31.2% of the youth were in fact true orphans (loss of one or both parents). It is therefore remarkable that in terms of service use, despite consistently high prevalence of problem behaviors across all informant sources, only 2.4% of the youth had received any speciality mental health services during institutional care. In conclusion, there is a pressing need to transform the social and health care policy and to provide family and community-based alternatives for youth currently in institutional care in Turkey. Before this goal is achieved, it is necessary to address their mental health needs urgently and comprehensively. The highest rates of problems by youth self-report also support the view that the youths' own voices ought to be heard and need to inform the reform process regarding their future care.

Industrial and occupational exposure to chromium compounds, particularly hexavalent chromium (Cr(VI))-containing compounds are often known to cause acute renal injury (ARI) in humans and animals. Its nephrotoxicity is associated with an increased formation of reactive oxygen species and lipid peroxidation in renal tissue. Recent studies suggest that antioxidants of the vitamin E family have protective effects against metal toxicity. Tocotrienols are known to have greater antioxidant activity than tocopherols and protect more efficiently against some free radical-related diseases than does tocopherols. In the present study, ARI induced by potassium dichromate (K(2)Cr(2)O(7)) has been used as a model to investigate the possible nephroprotective effect of tocotrienol-rich fraction (TRF) from palm oil. Wistar male rats having an average body weight (bw) of 210 g were divided into four groups. The first group was taken as control and injected with vehicle alone while the second group was drug control and ingested with TRF (200mg/kg, bw, orally, once daily for 21 days); the third group served as toxicant and was pre-treated with saline, followed by a single subcutaneous (SC) injection of K(2)Cr(2)O(7) (15 mg/kg bw). The fourth group was pre-treated with TRF and subsequently injected with K(2)Cr(2)O(7) (same dose as for the third group). Renal functions, oxidative and nitrosative stress were evaluated on days 0, 1, 2, 4, 7, 11 and 14 after treatment with K(2)Cr(2)O(7). The results revealed altered proximal tubular function; decreased glomerular filtration accompanied by oxidative damage 48 h after exposure to dichromate; while in the TRF-treated group proximal reabsorptive function, glomerular function and the cellular redox status were sustained. These results were further supported and confirmed by histological findings. The study suggests that TRF is effective in preventing K(2)Cr(2)O(7)-induced acute renal injury, but more studies are needed to confirm the effects of TRF as a nephroprotective agent.

An enzyme which catalyzes the deamidation of thyroliberin (TRF; less than Glu-His-Pro-NH2) has been purified 110-fold from extracts of bovine anterior pituitary by ammonium sulfate fractionation, ion exchange chromatography on DEAE-cellulose, and gel filtration. This enzyme of 76,000 molecular weight (as estimated by gel filtration) exhibits maximal activity at neutral pH (optimum pH 7.4 to 7.6) in buffers of high ionic strength supplemented with thiol-protecting agents. As indicated by the strong inhibition of the enzymatic activity by N-ethylmaleimide and Hg2+, as well as by the extreme sensitivity toward diisopropyl fluorophosphate, -SH, and -OH residues apparently represent essential functional groups of the enzyme. The stereospecific deamidation of TRF (Km = 4.1 . 10(-4) M) is inhibited competitively by TRF analogues which contain proline or by the proline containing biologically active peptides luliberin (LH-RF), oxytocin, vasopressin, angiotensin II, and Substance P. TRF analogues without proline or peptide amides without proline are ineffective. This enzyme cleaves the appropriate Pro-X bonds in luliberin, angiotensin II, pyroGlu-His-Pro-Gly-NH2, and the collagenase substrate Z-Gly-Pro-Leu-Gly-Pro. Thus, it may be characterized as a post-proline-cleaving enzyme.

BACKGROUND

Dendritic cells (DCs) have the potential for cancer immunotherapy due to their ability to process and present antigens to T-cells and also in stimulating immune responses. However, DC-based vaccines have only exhibited minimal effectiveness against established tumours in mice and humans. The use of appropriate adjuvant enhances the efficacy of DC based cancer vaccines in treating tumours.

METHODS

In this study we have used tocotrienol-rich fraction (TRF), a non-toxic natural compound, as an adjuvant to enhance the effectiveness of DC vaccines in treating mouse mammary cancers. In the mouse model, six-week-old female BALB/c mice were injected subcutaneously with DC and supplemented with oral TRF daily (DC+TRF) and DC pulsed with tumour lysate from 4T1 cells (DC+TL). Experimental mice were also injected with DC pulsed with tumour lysate and supplemented daily with oral TRF (DC+TL+TRF) while two groups of animal which were supplemented daily with carrier oil (control) and with TRF (TRF). After three times vaccination, mice were inoculated with 4T1 cells in the mammary breast pad to induce tumour.

RESULTS

Our study showed that TRF in combination with DC pulsed with tumour lysate (DC+TL+TRF) injected subcutaneously significantly inhibited the growth of 4T1 mammary tumour cells as compared to control group. Analysis of cytokines production from murine splenocytes showed significant increased productions of IFN-gamma and IL-12 in experimental mice (DC+TL+TRF) compared to control, mice injected with DC without TRF, mice injected with DC pulsed with tumour lysate and mice supplemented with TRF alone. Higher numbers of cytotoxic T cells (CD8) and natural killer cells (NK) were observed in the peripheral blood of TRF adjuvanted DC pulsed tumour lysate mice.

CONCLUSIONS

Our study show that TRF has the potential to be an adjuvant to augment DC based immunotherapy.

This study evaluates the validity of two aggression scales for predicting observations of malicious or disruptive behavior at school. Subgroups of a sample of 1,560 children (age 8.6+/-1.5 years) were assessed using (a) peer nominations of aggression, (b) teacher reports on the Teacher Report Form (TRF) of the Child Behavior Checklist (CBCL) Aggression scale and the peer nomination items, or (c) self-reports on the peer nomination items. Criteria were observations of physical, verbal, initiated, retaliatory, malicious, and disruptive behaviors. Teacher report peer nominations predicted observed physical, verbal, initiated, and retaliatory aggression and disruptive behavior. Peer nominations predicted physical aggression, verbal aggression, initiation and disruptive behavior, and TRFs predicted verbal, initiated, and disruptive behavior. Self-reports did not significantly predict any behavior. Implications for assessment of aggression are discussed.

OBJECTIVE

To investigate the telomere hypothesis of cellular aging as the mechanism for cell cycle arrest in normal human corneal endothelium.

METHODS

The corneal endothelium and epithelium from 21 human corneas from 13 donors 5 weeks to 84 years of age were dissected and frozen at -70 degrees C. Purified DNA, digested with the restriction enzyme, HinfI, was run on 0.7% agarose gels, probed with radiolabeled (AATCCC)4, and exposed to a phosphor screen. The length of the terminal restriction fragment (TRF) was determined by densitometry.

RESULTS

The cells of the corneal endothelium had TRF lengths ranging from 11.0 to 14.0 kbp (mean, 12.2 +/- 0.9). Corneal epithelial specimens showed TRF lengths that were always less than (mean, 10.4 +/- 1.0; range 9.0-12.0) the corresponding endothelial TRF lengths. Human corneal endothelial cells, transformed with human papillomavirus type 16 oncogenes E6 and E7, showed decreasing TRF lengths from 11 kbp at population doubling level (PDL) 15 to 9.5 kbp at PDL 73. Neither the endothelial and epithelial cells from human donors nor the transformed pre-immortalized human endothelial cells showed evidence of telomerase activity.

CONCLUSIONS

Human corneal endothelial cells have long telomeres throughout life. Their limited replicative ability does not appear to result from critically short telomere lengths.

Progressive telomere shortening is thought to be important in the regulation of cellular senescence and that the upregulation or reactivation of telomerase activity may be a critical if not rate limiting step in the development of neoplastic cells. To obtain information about telomeres and telomerase activity in hematopoietic neoplasia at various disease stages, we evaluated 54 samples obtained from 41 patients with chronic myeloid leukemia (CML) using a combination of fluorescent-telomeric repeat amplification protocol and an internal telomerase assay standard. The terminal restriction fragment (TRF) lengths in the blast phase was reduced compared to that in the chronic phase (4.53 +/- 0.72 kb vs 6.13 +/- 1.68 kb; P = 0.0005). All samples obtained from CML in the chronic phase (n = 33) had detectable telomerase activity above background, regardless of age. In the blast phase (n = 21), a significant increase of telomerase activity was detected compared to that in the chronic phase (33.84 +/- 37.86% vs 6.08 +/- 3.21; P = 0.016). Among patients in the blastic phase, 50% of patients had moderate to high telomerase activity (>10 relative value), and the remaining patients had telomerase activity higher than that in the normal peripheral blood cells. No significant differences in hematologic findings, duration of chronic phase or blast phase, and telomere length in the blastic phase were noted between these two groups separated by telomerase activity. CML patients with moderate to high telomerase activity had a high frequency of additional cytogenetic changes (P = 0.01).

Whereas a recent study reported an increased risk of colorectal cancer associated with any HFE germ line mutation (C282Y or H63D), other investigators have concluded there is no increased risk, or that any increase is dependent on polymorphisms in HFE-interacting genes such as the transferrin receptor (TFR). We have established the frequency of HFE mutations in colorectal cancer patients (n = 327) with a family history of the disease and randomly selected controls (n = 322); this design increases greatly the study's power. Genotyping for the TRF S142G polymorphism was also conducted on a large proportion of the study group. Using PCR, restriction enzyme mapping, sequencing followed by data analysis with Fisher's exact test and logistic regression, we show that the presence of any HFE mutation (Y282 or D63) was not associated with colorectal cancer risk (P = 0.57). In contrast, individuals compound heterozygous for both mutations (15 cases versus 5 controls) had thrice the odds of developing colorectal cancer (odds ratio, 3.03; 95% confidence interval, 1.06-8.61) compared with those with a single mutation. This finding did not quite reach statistical significance after allowing for multiple post hoc testing (P(observed) = 0.038 versus P = 0.025, with Bonferonni correction). Overall, our data indicate that individuals with a single HFE mutation, C282Y or H63D, are unlikely predisposed to develop colorectal cancer. However, risk of colorectal cancer might be increased by compound heterozygosity for the HFE mutations in the small number of subjects studied. TFR gene polymorphism was not an independent risk factor and did not modify the disease risk associated with HFE mutation.

OBJECTIVE

This study compared the residual monomer (RM) in four hard chair-side reline resins (Duraliner II-D, Kooliner-K, Tokuso Rebase Fast-TRF and Ufi Gel hard-UGH) and one heat-polymerized denture base resin (Lucitone 550-L), which was processed using two polymerization cycles (short-LS and long-LL). It was also investigated the effect of two after polymerization treatments on this RM content.

METHODS

Specimens (n=18) of each material were produced following the manufacturers' instructions and then divided into three groups. Group I specimens were left untreated (GI-control). Specimens of group II (GII) were given post-polymerization treatment by microwave irradiation. In group III (GIII), specimens were submitted to immersion in water at 55 degrees C (reline resins-10 min; denture base resin L-60 min). The RM was analyzed using high performance liquid chromatography (HPLC) and expressed as a percentage of RM. Data were analyzed by two-way ANOVA followed by Tukey's test (alpha=0.05).

RESULTS

Comparing control specimens, statistical differences were found among all materials (p<0.05), and the results can be arranged as K (1.52%>>D (0.85%>>UGH (0.45%>>LL (0.24%>>TRF (0.14%>>LS (0.08%). Immersion in hot water (GIII) promoted a significant (p<0.05) reduction in the RM for all materials evaluated compared to control (GI), with the exception of LL specimens. Materials K, UGH and TRF exhibited significantly (p<0.05) lower values of RM after microwave irradiation (GII) than in the control specimens.

CONCLUSIONS

The reduction in RM promoted by water-bath and microwave post-polymerization treatments could improve the mechanical properties and biocompatibility of the relining and denture base materials.

Murine lymphocyte function is quite sensitive to TCDD. However, in contrast to the murine model, the corresponding functional studies have not been undertaken with human lymphocytes. One laboratory has recently demonstrated that human tonsillar lymphocytes (HTL) possess the aryl hydrocarbon (Ah) receptor which mediates many of the effects of TCDD. This observation suggested that HTL may be sensitive to TCDD. In mitogen stimulated HTL, TCDD induced a dose-dependent increase in 7-ethoxyresorufin-O-deethylase (EROD) synthesis. Because we recently demonstrated that background proliferation in HTL and murine splenocytes was suppressed by TCDD, we purified human and murine B-cells into high density and low density populations. In low density human B-cells, TCDD suppressed background proliferation and IgM secretion from 0.3 to 30 nM. Interestingly, TCDD produced comparable effects on background proliferation and IgM secretion in purified low density murine B-cells. When low density human B-cells were stimulated with LPS and TRF, TCDD suppressed both proliferation and IgG secretion in a dose-dependent manner from 0.3 to 30 nM, although the suppression was modest when compared to the magnitude of suppression of the background responses. In contrast, TCDD did not alter background or stimulated proliferation in high density human B-cells. These results indicate that TCDD has a direct effect on human tonsillar lymphocyte activity and suggest that low density B-cells are a sensitive cellular target.

A vaccine against enterotoxigenic Escherichia coli (ETEC) is needed to prevent diarrheal illness among children in developing countries and at-risk travelers. Two live attenuated ETEC strains, PTL002 and PTL003, which express the ETEC colonization factor CFA/II, were evaluated for safety and immunogenicity. In a randomized, double-blind, placebo-controlled trial, 19 subjects ingested one dose, and 21 subjects ingested two doses (days 0 and 10) of PTL-002 or PTL-003 at 2 x 10(9) CFU/dose. Anti-CFA/II mucosal immune responses were determined from the number of antibody-secreting cells (ASC) in blood measured by enzyme-linked immunospot assay, the antibody in lymphocyte supernatants (ALS) measured by enzyme-linked immunosorbent assay (ELISA), and fecal immunoglobulin A (IgA) levels determined by ELISA. Time-resolved fluorescence (TRF) ELISA was more sensitive than standard colorimetric ELISA for measuring serum antibody responses to CFA/II and its components, CS1 and CS3. Both constructs were well tolerated. Mild diarrhea occurred after 2 of 31 doses (6%) of PTL-003. PTL-003 produced more sustained intestinal colonization than PTL-002 and better IgA response rates: 90% versus 55% (P = 0.01) for anti-CFA/II IgA-ASCs, 55% versus 30% (P = 0.11) for serum anti-CS1 IgA by TRF, and 65% versus 25% (P = 0.03) for serum anti-CS3 IgA by TRF. Serum IgG response rates to CS1 or CS3 were 55% in PTL-003 recipients and 15% in PTL-002 recipients (P = 0.02). Two doses of either strain were not significantly more immunogenic than one. Based on its superior immunogenicity, which was comparable to that of a virulent ETEC strain and other ETEC vaccine candidates, PTL-003 will be developed further as a component of a live, oral attenuated ETEC vaccine.

BACKGROUND

This study aims to determine the prevalence of emotional and behavioural problems in a community sample of Singaporean children aged 6-12 years, and its agreement according to parent, teacher and child reports.

METHODS

The Child Behaviour Checklist (CBCL), Teacher Rating Form (TRF) and child report questionnaires for depression and anxiety were administered to a community sample of primary school children. 60 percent of the children sampled (n = 2,139) agreed to participate. Parents of a sub-sample of 203 children underwent a structured clinical interview.

RESULTS

Higher prevalence of emotional and behavioural problems was identified by CBCL (12.5 percent) than by TRF (2.5 percent). According to parent reports, higher rates of internalising problems (12.2 percent) compared to externalising problems (4.9 percent), were found. Parent-teacher agreement was higher for externalising problems than for internalising problems. Correlations between child-reported depression and anxiety, and parent and teacher reports were low to moderate, but were better for parent reports than for teacher reports.

CONCLUSIONS

The prevalence rates of emotional and behavioural problems in Singaporean children based on CBCL ratings are comparable to those in the West, but the low response rate and exclusion of children with special needs limit the generalisability of our findings. Singaporean children have higher rates of internalising problems compared to externalising problems, while Western children have higher rates of externalising problems compared to internalising problems.