Late Exposure Group Research Articles

Early-life malnutrition exposure associated with higher osteoporosis risk in adulthood: a large-scale cross-sectional study.

Evidence on the association between early-life malnutrition exposure at different developmental stages and the subsequent risk of osteoporosis and fractures in adulthood remains sparse and equivocal. This study sought to elucidate the relationship between malnutrition exposure in early life and the occurrence of osteoporosis and fractures later in life. This research is a cross-sectional analysis carried out within the framework of the China Community-based Cohort of Osteoporosis (CCCO), an ongoing community-based cohort study. Participants were stratified by birthdate into several categories: non-exposed, fetal, early childhood, mid-childhood, late childhood, and adolescence exposure groups. The non-exposure and adolescence exposure groups were consolidated into an "age-matched group" to provide a robust comparative framework for analyzing the probability of developing osteoporosis (defined as a T-score ≤ -2.5 in bone mineral density) and the frequency of self-reported fracture. Multiple logistic regression models were utilized to investigate the association between early-life malnutrition exposure and the risks of osteoporosis and fracture. Additionally, we validated our findings using the China Northwest Cohort (CNC). A total of 12,789 participants were included into the final analysis. After adjusting for various covariates, individuals exposed to malnutrition during their fetal and childhood stages (early, middle, and late) increased the likelihood of developing osteoporosis in adulthood, compared to their age-matched counterparts. In these four groups, the ORs (95% CI) for osteoporosis risk were 1.223 (1.035 to 1.445), 1.208 (1.052 to 1.386), 1.249 (1.097 to 1.421), and 1.101 (1.001 to 1.210), respectively (all P values < 0.05). Specifically, the late childhood exposure group showed a heightened risk of fracture, with an OR (95% CI) of 1.155 (1.033 to 1.291) and a P-value of 0.01127. Stratified analyses further found a significant correlation between early-life exposure to malnutrition and an elevated risk of osteoporosis in participants with lower educational attainment, overweight or obese participants. Additionally, corroborating evidence from the CNC confirmed the influence of malnutrition exposure on osteoporosis risk. Early-life exposure to malnutrition had a detrimental impact on bone health. Individuals who had experienced malnutrition during fetal and childhood stages (early, middle, and late) exhibited a high susceptibility to osteoporosis in adulthood, compared to age-matched cohorts. This susceptibility was particularly pronounced in women, and individuals who were overweight or obese, or had lower levels of education.

Effect of acupuncture intervention time on the therapeutic effect in patients with sudden hearing loss.

To observe the clinical efficacy of acupuncture intervention at different time for patients with sudden hearing loss. According to the timing of acupuncture intervention, 86 patients were divided into early exposure group (n=43) and late exposure group (n=43) . The early exposure group was given acupuncture treatment within 14 days of onset, and the late exposure group was given acupuncture treatment after 14 days of onset. After propensity score matching (PSM, a statistical matching technique for observational data) processing by using SPSS26.0 software, outcomes of 30 cases in the early exposure group and 30 cases in the late exposure group were analyzed. In addition to receiving basic treatment with drugs for vascular dilatation, thrombolysis, nourishing nerve, etc., all patients of the two groups were treated with neck acupuncture ("Neck Seven Meridian Lines" acupuncture), once every other day except Sundays, for a total of 12 time. Before, after the treatment and 3 months after the treatment, the total score of the Tinnitus Handicap Inventory (THI, 0, 2 and 4 points for each of the 25 items, total scores = 100 points) scale was used to evaluate the improvement of tinnitus symptoms caused by hearing loss. The clinical therapeutic effect was evaluated according to the efficacy grading criteria in the Guidelines for Diagnosis and Treatment of Sudden Deafness (2015) and the changes of pure tone audiometry curve. Multivariate Logistic regression was used to analyze the effect of factors that might influence efficacy before propensity score matching. The THI scores of patients in both groups decreased strikingly after the treatment and 3 months' follow-up (P<0.05). Compared with the same time-points of the late exposure group, the total THI scores of post-treatment and 3 months' follow-up were evidently lower in the early exposure group (P<0.05). The effective rate of the early exposure group (22/30, 80.00%) was significantly higher (P<0.05) than that of the late exposure group (16/30, 53.33%). The classification of sudden deafness and the application of traditional Chinese medicine in this study were not independent factors affecting the total effective rate. The time point of acupuncture intervention is an important factor affecting the effect on hearing and tinnitus disability of patients with sudden deafness. The earlier acupuncture treatment is accepted, the better the therapeutic effect is.

Timing of selective serotonin reuptake inhibitor use and risk for preterm birth and related adverse events: with a consideration of the COVID-19 pandemic period

Objective There is uncertainty around the safety of SSRIs for treating depression during pregnancy. Nevertheless, the use of SSRIs has been gradually increasing, especially during the COVID-19 pandemic period. We aimed to (1) characterize maternal depression rate and use of SSRIs in a recent 10-year period, (2) address confounding by indication, as well as socioeconomic and environmental factors, and (3) evaluate associations of the timing of SSRI exposure in pregnancy with risk for preterm birth (PTB), low birthweight (LBW), and small for gestational age (SGA) infants among women with depression before pregnancy. Methods We conducted propensity score-adjusted regression to calculate odds ratios (ORs) of PTB, LBW, and SGA. We accounted for maternal/pregnancy characteristics, comorbidity, depression severity, time of delivery, social vulnerability, and rural residence. Results There were 50.3% and 40.3% increases in the prevalence rate of prenatal depression and prenatal SSRI prescription rate during the pandemic. We identified women with depression ≤180 days before pregnancy (n = 8406). Women with no SSRI order during pregnancy (n = 3760) constituted the unexposed group. The late SSRI exposure group consisted of women with an SSRI order after the first trimester (n = 3759). The early-only SSRI exposure group consisted of women with SSRI orders only in the first trimester (n = 887). The late SSRI exposure group had an increased risk of PTB of OR = 1.5 ([1.2,1.8]) and LBW of OR = 1.5 ([1.2,2.0]), relative to the unexposed group. Associations between late SSRI exposure and risk of PTB/LBW were similar among a subsample of patients who delivered during the pandemic. Conclusions These findings suggest an association between PTB/LBW and SSRI exposure is dependent on exposure timing during pregnancy. Small for gestational age is not associated with SSRI exposure.

The role of exposure window and dose in determining lead toxicity in developing Zebrafish

Heavy metal contamination is recognized worldwide as a serious threat to human health and wildlife, and reducing their emissions is a priority of international and EU actions. Due to its persistence, high bioaccumulation tendency, and toxicity properties, lead (Pb) is one of the heavy metals of greatest concern. Even at low concentrations, lead induces various clinical and subclinical conditions in both humans and animals, and it has been included in the priority list of hazardous substances. In the present study, we used zebrafish's early stages as a model, given their well-acknowledged predictive value in the risk assessment of chemicals. This study was designed to investigate the morphological and morphometric alterations induced by Pb during zebrafish's early development and disclose the putative effects stage- and/or dose-dependent. We examined injuries induced by two environmentally relevant and extremely low concentrations of Pb (2.5 μg/L and 5 μg/L) during two exposure windows: early (between 1 and 7 dpf) and late (between 2 and 8 dpf). We clearly demonstrated that the incidence and severity of morphological abnormalities increased with increasing Pb dose and exposure time in both early and late-exposed groups. Furthermore, we revealed that malformation severity was significantly higher in the early exposed group than in the late exposure group at all exposure times and for both tested doses, thus highlighting the high sensitivity of zebrafish during the initial stages of development. The information presented in this paper emphasizes the effectiveness of morphological biomarkers in unveiling threatening situations and supports the role of zebrafish embryos and larvae in risk assessment and environmental monitoring.

Association between Early Life Famine Exposure and Metabolic Syndrome in Adulthood.

To analyze the relationship between famine exposure at different stages of early life and the risk of developing metabolic syndrome (MetS) in adulthood, 11,865 study participants from the 2015 Chinese Adult Chronic Disease and Nutrition Surveillance Program were enrolled and then divided into a non-exposed group, fetal exposure group, early childhood exposure group, middle childhood exposure group and late childhood exposure group according to their birth time and famine exposure. MetS was defined by the NCEP ATP III criteria. Using logistic regression to explore the association between famine exposure at different stages of early life and the increased risk of developing MetS in adulthood. After adjusting other factors, compared with the non-exposure group, famine exposure during the fetal period (OR = 1.23, 95% CI = 1.00–1.51), early childhood (OR = 1.44, 95% CI = 1.11–1.87), middle childhood (OR = 1.50, 95% CI = 1.13–1.99) and late childhood (OR = 1.67, 95% CI = 1.21–2.30) had a higher risk of developing MetS in adulthood. Stratified analysis found an association between early life famine exposure and the increased risk of MetS in adulthood in females, overweight or obese participants and those who lived in areas of severe famine, in city areas and in southern China. Compared with the non-exposed group, the fetal, early childhood, middle childhood and late childhood famine-exposed groups are more likely to suffer from MetS in adulthood, especially the subjects who are females, overweight or obese and had lived in severe famine areas, city areas and southern China.

Comparing Exogenous Methods to Induce Plant-Resistance Against a Bark-Feeding Insect

Exogenous application of the plant hormone methyl jasmonate (MeJA) can trigger induced plant defenses against herbivores, and has been shown to provide protection against insect herbivory in conifer seedlings. Other methods, such as mechanical damage to seedlings, can also induce plant defenses, yet few have been compared to MeJA and most studies lack subsequent herbivory feeding tests. We conducted two lab experiments to: (1) compare the efficacy of MeJA to mechanical damage treatments that could also induce seedling resistance, (2) examine if subsequent insect damage differs depending on the time since induction treatments occurred, and (3) assess if these induction methods affect plant growth. We compared Scots pine (Pinus sylvestris) seedlings sprayed with MeJA (10 or 15 mM) to seedlings subjected to four different mechanical bark damage treatments (two different bark wound sizes, needle-piercing damage, root damage) and previous pine weevil (Hylobius abietis) damage as a reference treatment. The seedlings were exposed to pine weevils 12 or 32 days after treatments (early and late exposure, hereafter), and resistance was measured as the amount of damage received by plants. At early exposure, seedlings treated with needle-piercing damage received significantly more subsequent pine weevil feeding damage than those treated with MeJA. Seedlings treated with MeJA and needle-piercing damage received 84% less and 250% more pine weevil feeding, respectively, relative to control seedlings. The other treatments did not differ statistically from control or MeJA in terms of subsequent pine weevil damage. For the late exposure group, plants in all induction treatments tended to receive less pine weevil feeding (yet this was not statistically significant) compared to control seedlings. On the other hand, MeJA significantly slowed down seedling growth relative to control and all other induction treatments. Overall, the mechanical damage treatments appeared to have no or variable effects on seedling resistance. One of the treatments, needle-piercing damage, actually increased pine weevil feeding at early exposure. These results therefore suggest that mechanical damage shows little potential as a plant protection measure to reduce feeding by a bark-chewing insect.

Effect of timing of acupuncture on limb dysfunction in patients with cerebral infarction: a multicenter prospective cohort pilot study

To evaluate the clinical efficacy of acupuncture at different timings in acute stage for limb dysfunction in patients with cerebral infarction. A total of 101 patients with cerebral infarction limb dysfunction were divided into an early exposure group (n=51) and a late exposure group (n=50) according to the time of first acupuncture treatment during the acute phase. SPSS 25.0 software was used to balance the baseline between the two groups, and 31 pairs of matched patients were included, including 31 cases in the early exposure group and 31 cases in the late exposure group. The two groups were treated with Xingnao Kaiqiao acupuncture at Shuigou (GV 26), Neiguan (PC 6), Sanyinjiao (SP 6), Jiquan (HT 1), Chize (LU 5), Weizhong (BL 40), etc., once a day, and the course of treatment was not limited. In the early exposure group, acupuncture was started after 1 to 3 days of onset; in the late exposure group, acupuncture was started after 11 to 14 days of onset. The modified Rankin scale (mRS) grade was recorded before treatment, 30 and 60 days after onset; Fugl-Meyer assessment (FMA) grade was observed before treatment and 30 days after onset; the effect of acupuncture timing on the patients was analyzed by logistic analysis. Compared before treatment, the mRS grade at 30 and 60 days after onset in the early exposure group was improved (P<0.05), which was superior to the late exposure group (P<0.05); compared before treatment, the FMA grade at 30 days after onset in the early exposure group was improved (P<0.05), which was superior to the late exposure group (P<0.05). The timing of acupuncture was independently correlated with the disability status and the severity of motor dysfunction at 30 days after onset, and the disability status at 60 days after onset (P<0.05). Compared with the late exposure group, the possibility of becoming non-disabled at 30 days after onset (OR=22.882, 95%CI: 4.034-129.778), normal limb motor dysfunction (OR=22.320, 95%CI: 3.454-144.213) and non-disabled at 60 days after onset (OR=8.650, 95%CI: 2.437-30.696) in the early exposure group was increased. The timing of acupuncture is an independent factor affecting the disability status and limb motor dysfunction in patients with cerebral infarction, and the effect of early intervention may be better than late intervention.

Paternal cannabis extract exposure in rats: Preconception timing effects on neurodevelopmental behavior in offspring

Maternal toxicant exposure during gestation can have deleterious effects on neurobehavioral development of the offspring. The potential risks engendered by paternal toxicant exposure prior to conception have been largely understudied. Recently, we found that chronic THC exposure prior to conception in male rats causes long-lasting behavioral impairment in their offspring. The current study examined the effects of chronic preconception exposure to cannabis smoke extract in Sprague-Dawley rats at two different phases in sperm development. One group received daily subcutaneous (sc) injections of THC in cannabis extract at 4 mg/kg/day for 28 days until three days prior to mating with untreated females (late exposure group). Another group received the same regimen except they underwent 56 days of drug abstinence prior to mating (early exposure group). These were compared with a control group treated with vehicle. The offspring underwent a battery of tests for behavioral function to assess motor, emotional and cognitive function. On the elevated plus maze test, the offspring of both paternal cannabis smoke extract (CSE) exposure groups had significantly more time on the open arms than control offspring, indicative of greater risk-taking behavior. No significant main effects of CSE exposure were seen on adolescent or adult locomotor activity in the figure-8 apparatus. In the novel object recognition test, there was a significantly greater drop-off in novel object preference across the session in the male, but not female offspring of the late exposure group. There was also a sex-selective effect of paternal CSE treatment in the 16-arm radial maze test of memory function. Female offspring of the late exposure group had significantly more working memory errors than control females in the first half of the 12-session training sequence. No significant effects were seen in the operant visual signal sustained detection test of attention. This study shows that there are long-lasting behavioral consequences of preconception CSE exposure through the paternal lineage in rats.

Investigating Antibiotic Exposure and Risk of Severe Acute Graft Versus Host Disease in Patients Undergoing Allogeneic Hematopoietic Stem Cell Transplantation

Several studies have shown that alteration of the microbiota, particularly in the gastrointestinal tract, can be associated with graft-versus-host disease (GvHD). Patients undergoing allogeneic hematopoietic stem cell transplantation (allo-SCT) usually get exposed to antibiotics (ATB), mainly in the peri-transplant period. Moreover, ATB, specifically those that target anaerobic bacteria, can alter the microbiota in a variety of body organs. This, in turn, renders several organs vulnerable to injury making them more prone to developing diseases such as GvHD. In this study, we evaluate whether the use of ATB, characterized by duration, timing and type, in the peri-transplant period, is associated with an increased incidence of acute GvHD (aGvHD) and aGvHD-related mortality. In this retrospective study, we included 318 consecutive patients who underwent allo-SCT including haploidentical and cord blood transplantation between December 2012 and June 2018 at a single center. ATB exposure was collected and classified into 3 groups according to the date of initiation of ATB: from the start of conditioning to day - 1 of allo-SCT (early ATB exposure), from day 0 to neutrophil engraftment (late ATB exposure) and a third group of patients who did not receive ATB (no ATB exposure). ATB were only initiated if a patient develop fever or show signs of infection. Patients did not receive any prophylactic ATB. Exposure was further categorized as primary or adjunct. Primary exposure included the use of 4 classes of ATB: carbapenems, anti-pseudomonal penicillin, 4thand 5thgeneration cephalosporins and fluoroquinolones. Adjunct ATB comprised other ATB and was further divided into 2 groups according to anaerobic coverage. The median age at transplant was 55 years. The stem cell source was peripheral blood in 85%, bone marrow in 10% and cord blood in 5% of the patients. Ninety-nine percent of the patients received cyclosporine A as GvHD prophylaxis and 80% and 7% of the patients received (along with cyclosporine A), mycophenolate mofetil and methotrexate, respectively. In addition, 35% and 89% of the patients received post-transplant cyclophosphamide and anti-thymocyte globulin, respectively, as GvHD prophylaxis. The median time to neutrophil engraftment was 16 days post-transplant. The median follow-up was 85 months. 93.7% of the patients received ATB in the peri-transplant period with 64.5% of them in the early ATB exposure group, and 29.2% of them in the late ATB exposure group. The 2-year overall survival and progression free survival were 74.3% and 63.6% in patients with early ATB exposure, compared to 79.5% and 70.8% in patients with late ATB exposure (p=0.11 and p=0.07 respectively). The 2-year cumulative incidence of non-relapse mortality was 16.5% in patients with early ATB exposure, compared to 15.1% in patients with late ATB exposure (p=0.63). The 180-days cumulative incidence of grade 2-4 and 3-4 aGvHD were 23.8% and 12.2% in patients with early ATB exposure, compared to 27.2% and 5.4% in patients with late ATB exposure (p=0.64 and p=0.06 respectively). In multivariate analysis, including the most important parameters associated with GvHD (stem cell source and donors, conditioning regimen, sex mismatch and patients age), early ATB initiation was the only parameter associated with a significantly higher risk of severe grade 3-4 aGvHD [HR 0.51 (0.28-0.90); p=0.02]. In conclusion, in the absence of any ATB prophylaxis, early initiation of ATB, before graft infusion,is associated with a significantly higher risk of severe grade 3-4 aGvHD. Weighing risk of morbidity and mortality associated with infections versus later on risk of developing aGvHD is essential. Hence, new strategies should be developed to risk stratify patients with fever and thus to avoid early non necessary ATB exposure especially in those who develop fever during anti-thymocyte globulin infusion. Studies evaluating such strategies will be necessary in the next years. Disclosures Mohty: Jazz Pharmaceuticals: Honoraria, Research Funding. Malard:Astellas: Honoraria; JAZZ pharmaceutical: Honoraria; Sanofi: Honoraria; Keocyte: Honoraria; Janssen: Honoraria; Therakos/Mallinckrodt: Honoraria.

Cigarette smoking differentially regulates inflammatory responses in a mouse model of nonalcoholic steatohepatitis depending on exposure time point

Cigarette smoke (CS) is a risk factor for the development of nonalcoholic fatty liver disease. However, the role of mainstream CS (MSCS) in the pathogenesis of nonalcoholic steatohepatitis (NASH) remains unclear. During the first (early exposure) or last (late exposure) three weeks of methionine-choline deficient with high fat diet feeding (6 weeks), each diet group was exposed to MSCS (300 or 600 μg/L). Hepatic or serum biochemical analysis showed that MSCS differentially modulated hepatic injury in NASH milieu, depending on exposure time points. Consistently, NASH-related hepatocellular apoptosis and fibrosis were increased in the early exposure group, but decreased in the late exposure group, except for steatosis. Ex vivo experiments showed that CS extract differentially regulated inflammatory responses in co-cultured hepatocytes and macrophages isolated from steatohepatitic livers after 10 days or 3 weeks of diet feeding. Furthermore, CS differentially up- and down-regulated the expression levels of M1/M2 polarization markers and peroxisome proliferator-activated receptor-gamma (PPARγ) in livers (29% and 38%, respectively) or co-cultured macrophages (2 and 2.5 fold, respectively). Collectively, our findings indicate that opposite effects of MSCS on NASH progression are mediated by differential modulation of PPARγ and its-associated M1/M2 polarization in hepatic macrophages, depending on exposure time points.

Timing and Chronicity of Maternal Depression Symptoms and Children's Verbal Abilities

To test the associations between the timing and chronicity of maternal depression symptoms (MDS) and children's long-term verbal abilities. Participants were 1073 mother-child pairs from a population-based birth cohort in Canada. MDS were assessed at ages 5 months, 1.5, 3.5, and 5 years using the Center for Epidemiologic Studies Depression Scale. Verbal abilities were measured at 5, 6, and 10 years using the Peabody Picture Vocabulary Test-Revised (PPVT-R). Multiple linear regression models were used to estimate the association between timing (early: 5 months and/or 1.5 years vs late 3.5 and/or 5 years) and chronicity (5 months, 1.5, 3.5, and 5 years) of exposure to elevated MDS and children's mean PPVT-R scores. Children exposed to chronic MDS had lower PPVT-R scores than children never exposed (mean difference = 9.04 [95% CI = 2.28-15.80]), exposed early (10.08 [3.33-16.86]) and exposed late (8.69 [1.85-15.53]). There were no significant differences between scores of children in the early compared with the late exposure group. We adjusted for mother-child interactions, family functioning, socioeconomic status, PPVT-R administration language, child's birth order, and maternal IQ, psychopathology, education, native language, age at birth of child, and parenting practices. Maternal IQ, (η2 = 0.028), native language (η2 = 0.009), and MDS (η2 = 0.007) were the main predictors of children's verbal abilities. Exposure to chronic MDS in early childhood is associated with lower levels of verbal abilities in middle childhood. Further research is needed in larger community samples to test the association between MDS and children's long-term language skills.

Effects of noise exposure on neonatal auditory brainstem response thresholds in pregnant guinea pigs at different gestational periods.

Noise exposure during pregnancy has been reported to cause fetal hearing impairment. However, little is known about the effects of noise exposure during various gestational stages on postnatal hearing. In the present study, we investigated the effects of noise exposure on auditory brainstem response (ABR) at the early, mid-, and late gestational periods in newborn guinea pigs. Pregnant guinea pigs were exposed to 4-kHz pure tone at a 120-dB sound pressure level for 4 h. We divided the animals into four groups as follows: the control, early gestational exposure, mid-gestational exposure, and late gestational exposure groups. ABR thresholds and latencies in newborns were recorded using 1-, 2-, and 4-kHz tone burst on postnatal days 1, 7, 14, and 28. Changes in ABR thresholds and latencies were measured between the 4 × 4 and 4 × 3 factorial groups mentioned above (gestational periods × postnatal days, gestational periods × frequencies). The thresholds were low in the order of control group<early gestational exposure group<mid-gestational exposure group and late gestational exposure group. Noise exposure during pregnancy influenced ABR thresholds in neonatal guinea pigs. This is the first study to show that noise exposure during the early, mid-, and late gestational periods significantly elevated ABR thresholds in neonatal guinea pigs.

Impact of age of first exposure to Plasmodium falciparum on antibody responses to malaria in children: a randomized, controlled trial in Mozambique

BackgroundThe impact of the age of first Plasmodium falciparum infection on the rate of acquisition of immunity to malaria and on the immune correlates of protection has proven difficult to elucidate. A randomized, double-blind, placebo-controlled trial using monthly chemoprophylaxis with sulphadoxine-pyrimethamine plus artesunate was conducted to modify the age of first P. falciparum erythrocytic exposure in infancy and assess antibodies and malaria risk over two years.MethodsParticipants (n = 349) were enrolled at birth to one of three groups: late exposure, early exposure and control group, and were followed up for malaria morbidity and immunological analyses at birth, 2.5, 5.5, 10.5, 15 and 24 months of age. Total IgG, IgG subclasses and IgM responses to MSP-119, AMA-1, and EBA-175 were measured by ELISA, and IgG against variant antigens on the surface of infected erythrocytes by flow cytometry. Factors affecting antibody responses in relation to chemoprophylaxis and malaria incidence were evaluated.ResultsGenerally, antibody responses did not vary significantly between exposure groups except for levels of IgM to EBA-175, and seropositivity of IgG1 and IgG3 to MSP-119. Previous and current malaria infections were strongly associated with increased IgG against MSP-119, EBA-175 and AMA-1 (p < 0.0001). After adjusting for exposure, only higher levels of anti-EBA-175 IgG were significantly associated with reduced clinical malaria incidence (IRR 0.67, p = 0.0178).ConclusionsOverall, the age of first P. falciparum infection did not influence the magnitude and breadth of IgG responses, but previous exposure was critical for antibody acquisition. IgG responses to EBA-175 were the strongest correlate of protection against clinical malaria.Trial registrationClinicalTrials.gov: NCT00231452.

Abstract 3270: The effect of soy exposure in different ages on the mammary tumor development of the MMTV-ErbB-2 transgenic mice

Abstract Objective:To investigate the effect of different soy exposure timings on the mammary tumor development using MMTV-erbB-2 transgenic mice. Furthermore, the underlying mechanisms were also examined. Methods:120 MMTV-erbB-2 transgenic female mice were randomly divided into four groups:control group, early exposure group, late exposure group and lifelong exposure group. The control group mice were treated with soy free diet from week 3 to week 60, the experiment groups mice were treated with soy diet between week 3 to week 12, week 20 to week 60, week 3 to week 60, respectively. Then, the body weight change of each mice, the latency period, and the growth speed of mammary tumor were recorded. Furthermore, the mammary gland morphology was examined by whole mount at 5 weeks. In order to understand the underlying mechanisms of the mammary tumor development, the signal pathways of c-Fos, erbB2 and p-ERK were also examined in breast cancer tissue using immunohistochemistry. Results:We found that the weight in the four groups had no significant difference. Compared with the control group, the TEB numbers and the growth speed of tumors in the early exposure group and the lifelong exposure group were significantly decreased and the tumor latency periods were significantly prolonged (P&amp;lt;0.05). Furthermore, immunohistochemistry showed that the mice in the early exposure group and the lifelong exposure group displayed decreased expression of c-Fos and p-ERK (P&amp;lt;0.05). The expression of erbB-2 protein among the different groups was not statistically significant (P&amp;gt;0.05). Conclusion: Early or lifelong soy exposure affects the morphological development of mammary gland of MMTV-erbB-2 transgenic mice. Soy may display a preventive effect on the initiation of breast cancer. These obersveration may serve as a guide for soy use in the early prevention of the breast cancer. The c-Fos and and p-ERK may be involved in the development of mammary tumor in the MMTV-erbB-2 transgenic mice. The underlying mechanism warrants further studies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3270. doi:1538-7445.AM2012-3270

The Role of Age and Exposure to Plasmodium falciparum in the Rate of Acquisition of Naturally Acquired Immunity: A Randomized Controlled Trial

BackgroundThe rate of acquisition of naturally acquired immunity (NAI) against malaria predominantly depends on transmission intensity and age, although disentangling the effects of these is difficult. We used chemoprophylaxis to selectively control exposure to P. falciparum during different periods in infancy and explore the effect of age in the build-up of NAI, measured as risk of clinical malaria.Methods and FindingsA three-arm double-blind randomized placebo-controlled trial was conducted in 349 infants born to Mozambican HIV-negative women. The late exposure group (LEG) received monthly Sulfadoxine-Pyrimethamine (SP) plus Artesunate (AS) from 2.5–4.5 months of age and monthly placebo from 5.5–9.5 months; the early exposure group (EEG) received placebo from 2.5–4.5 months and SP+AS from 5.5–9.5 months; and the control group (CG) received placebo from 2.5–9.5 months. Active and passive case detection (PCD) were conducted from birth to 10.5 and 24 months respectively. The primary endpoint was time to first or only episode of malaria in the second year detected by PCD. The incidence of malaria during the second year was of 0.50, 0.51 and 0.35 episodes/PYAR in the LEG, EEG and CG respectively (p = 0.379 for the adjusted comparison of the 3 groups). The hazard ratio of the adjusted comparison between the LEG and the CG was 1.38 (0.83–2.28, p = 0.642) and that between the EEG and the CG was 1.35 (0.81–2.24, p = 0.743).ConclusionsAfter considerably interfering with exposure during the first year of life, there was a trend towards a higher risk of malaria in the second year in children who had received chemoprophylaxis, but there was no significant rebound. No evidence was found that the age of first exposure to malaria affects the rate of acquisition of NAI. Thus, the timing of administration of antimalarial interventions like malaria vaccines during infancy does not appear to be a critical determinant.Trial Registration ClinicalTrials.gov NCT00231452

Primary Dietary Intervention Study to Reduce the Risk of Islet Autoimmunity in Children at Increased Risk for Type 1 Diabetes

OBJECTIVETo determine whether delaying the introduction of gluten in infants with a genetic risk of islet autoimmunity is feasible, safe, and may reduce the risk of type 1 diabetes–associated islet autoimmunity.RESEARCH DESIGN AND METHODSA total of 150 infants with a first-degree family history of type 1 diabetes and a risk HLA genotype were randomly assigned to a first gluten exposure at age 6 months (control group) or 12 months (late-exposure group) and were followed 3 monthly until the age of 3 years and yearly thereafter for safety (for growth and autoantibodies to transglutaminase C [TGCAs]), islet autoantibodies to insulin, GAD, insulinoma-associated protein 2, and type 1 diabetes.RESULTSAdherence to the dietary-intervention protocol was reported from 70% of families. During the first 3 years, weight and height were similar in children in the control and late-exposure groups, as was the probability of developing TGCAs (14 vs. 4%; P = 0.1). Eleven children in the control group and 13 children in the late-exposure group developed islet autoantibodies (3-year risk: 12 vs. 13%; P = 0.6). Seven children developed diabetes, including four in the late-exposure group. No significant differences were observed when children were analyzed as per protocol on the basis of the reported first gluten exposure of the children.CONCLUSIONSDelaying gluten exposure until the age of 12 months is safe but does not substantially reduce the risk for islet autoimmunity in genetically at-risk children.

Preliminary evidence of a sensitive period for olfactory learning by human newborns

To test the hypothesis that a brief window of time immediately after delivery may be a particularly sensitive period for olfactory learning by human neonates. Fifty-five vaginally delivered newborns were exposed to an odorant for 30 min beginning 4-37 min after birth (Early exposure) or 12-h post-partum (Late exposure). Several days later, newborns' head orientation responses to the exposure odour versus an unfamiliar odour or an odourless control stimulus were tested. Infants in the Early exposure group spent significantly more time oriented towards the familiar scent rather than a novel odour (Z = 2.869; n = 28; p < 0.01), or an odourless stimulus (Z = 2.550; n = 28; p < 0.01). Infants in the Late exposure condition did not respond differentially to the exposure odour versus a novel odour (Z = 1.105; n = 27, p = 0.27), and spent more time oriented towards an odourless stimulus than to the exposure odour (Z = 2.042; n = 27, p < 0.05). Infants in the Early exposure group, but not in the Late exposure group, became familiar with the exposure odour and retained a memory trace of it during the test trials.