Sec22b and Stx4 Depletion Has No Major Effect on Cross-Presentation of PLGA Microsphere-Encapsulated Antigen and a Synthetic Long Peptide In Vitro.

The induction of CTL responses by vaccines is important to combat infectious diseases and cancer. Biodegradable poly(lactic-co-glycolic acid) (PLGA) microspheres and synthetic long peptides are efficiently internalized by professional APCs and prime CTL responses after cross-presentation of Ags on MHC class I molecules. Specifically, they mainly use the cytosolic pathway of cross-presentation that requires endosomal escape, proteasomal processing, and subsequent MHC class I loading of Ags in the endoplasmic reticulum (ER) and/or the endosome. The vesicle SNARE protein Sec22b has been described as important for this pathway by mediating vesical trafficking for the delivery of ER-derived proteins to the endosome. As this function has also been challenged, we investigated the role of Sec22b in cross-presentation of the PLGA microsphere-encapsulated model Ag OVA and a related synthetic long peptide. Using CRISPR/Cas9-mediated genome editing, we generated Sec22b knockouts in two murine C57BL/6-derived APC lines and found no evidence for an essential role of Sec22b. Although pending experimental evidence, the target SNARE protein syntaxin 4 (Stx4) has been suggested to promote cross-presentation by interacting with Sec22b for the fusion of ER-derived vesicles with the endosome. In the current study, we show that, similar to Sec22b, Stx4 knockout in murine APCs had very limited effects on cross-presentation under the conditions tested. This study contributes to characterizing cross-presentation of two promising Ag delivery systems and adds to the discussion about the role of Sec22b/Stx4 in related pathways. Our data point toward SNARE protein redundancy in the cytosolic pathway of cross-presentation.

A telephone intervention to achieve differentiation in dietary intake: a randomized trial in paediatric primary care.

BACKGROUND: Telehealth offers opportunities to extend clinical and research interventions for paediatric obesity. OBJECTIVES: To assess utility of a telephone intervention, implemented through a national primary care paediatric research network, for promoting differentiation in dietary intake, consistent with either a low-glycemic load (Low GL) or Low Fat prescription, among overweight/obese school-age children. METHODS: Five-week telephone dietary counselling intervention for parents of overweight/obese school-age children recruited through the Slone Center Office-based Research Network. Parent-child dyads were randomized to Low GL or Low Fat diet. Primary outcomes were dietary GL and dietary fat, adjusted for energy intake and assessed by 24-h dietary recall. RESULTS: Subjects were randomized to Low GL (n = 11, 8.1 ± 1.7 years, 45.5% male) or Low Fat (n = 11, 8.2 ± 2.0 years, 36.4% male), with no baseline differences. Overall, 86% of subjects attended at least four of five counselling sessions, and study completion rate was 91% (based on completion of the final dietary recalls). Reported satisfaction was high. In adjusted analyses limited to 'recall completers,' reduction in dietary GL (g/1000 kcal) achieved within the Low GL group was significant (p = 0.01) and greater than the change in dietary GL in the Low Fat group (mean ± SE; -12.9 ± 4.4 vs. 5.1 ± 4.9, p = 0.03). Similarly, reduction in dietary fat (% of total energy) within the Low Fat group was significant (-5.6 ± 2.5, p = 0.046) but with no difference between groups (p = 0.25). CONCLUSION: A telephone-based dietary intervention for overweight/obese children, implemented through a national paediatric research network, fostered prescribed dietary changes. ClinicalTrials.gov registration: NCT00620152.

Effects of the residual ammonium concentration on NOB repression during partial nitritation with granular sludge.

Partial nitritation was stably achieved in a bench-scale airlift reactor (1.5L) containing granular sludge. Continuous operation at 20 °C treating low-strength synthetic wastewater (50 mg N-NH4+/L and no COD) achieved nitrogen loading rates of 0.8 g N-NH4+/(L·d) during partial nitritation. The switch between nitrite-oxidizing bacteria (NOB) repression and NOB proliferation was observed when ammonium concentrations in the reactor were below 2-5 mg N-NH4+/L for DO concentrations lower than 4 mg O2/L at 20 °C. Nitrospira spp. were detected to be the dominant NOB population during the entire reactor operation, whereas Nitrobacter spp. were found to be increasing in numbers over time. Stratification of the granule structure, with ammonia-oxidizing bacteria (AOB) occupying the outer shell, was found to be highly important in the repression of NOB in the long term. The pH gradient in the granule, containing a pH difference of ca. 0.4 between the granule surface and the granule centre, creates a decreasing gradient of ammonia towards the centre of the granule. Higher residual ammonium concentration enhances the ammonium oxidation rate of those cells located further away from the granule surface, where the competition for oxygen between AOB and NOB is more important, and it contributes to the stratification of both populations in the biofilm.

Research challenges for drug-induced birth defects.

Drug-induced birth defects (teratogenesis) represent unique adverse drug reactions (ADRs). Not only is the ADR manifest in a subject other than the one for whom treatment is intended, but most teratogens can be identified only after a drug is marketed. We know little about fetal safety for most marketed drugs, and identification of potential teratogens uniquely requires that study designs consider issues related to the effects of specific drugs, specific defects, and specific gestational timing.

Maternal hypertensive disorders, antihypertensive medication use, and the risk of birth defects: a case-control study.

OBJECTIVE: To study previously identified associations between specific maternal hypertensive disorders and/or prenatal exposure to antihypertensive medication and birth defects. DESIGN: Case-control study. SETTING: Slone Birth Defects Study, 1998-2010. POPULATION: A total of 5568 cases with birth defects and 7253 liveborn infants without malformations as controls. METHODS: Adjusted odds ratios (aORs) for birth defects associated with prenatal exposure to maternal hypertensive disorders and/or antihypertensive medication were calculated using multivariable logistic regression analyses. MAIN OUTCOME MEASURES: Specific birth defects previously linked to maternal hypertension or antihypertensive medication use during pregnancy. RESULTS: Non-pharmacologically managed chronic hypertension was associated with a three-fold risk of oesophageal atresia (95% CI 1.2-8.3), and pre-eclampsia superimposed on non-pharmacologically managed chronic hypertension was associated with ventricular septal defects (aOR 3.9, 95% CI 1.3-11.7) and atrial septal defects (aOR 6.5, 95% CI 1.8-23.7). For chronic hypertension that was pharmacologically treated early in pregnancy, increased risks were observed for first-degree hypospadias (aOR 2.9, 95% CI 1.1-7.4). Non-pharmacologically managed pre-eclampsia was related to second-/third-degree hypospadias and ventricular septal defects. Pharmacological treatment for gestational hypertension was associated with a number of congenital heart defects. CONCLUSIONS: Our results confirm some, but not all, previously identified associations between pharmacologically treated and non-pharmacologically managed hypertensive disorders and specific birth defects. They support the hypothesis that physiological changes early in pregnancy that manifest in gestational hypertension and pre-eclampsia may play a role in the aetiology of major birth defects, including congenital heart defects and hypospadias.

Adverse drug reactions in utero: perspectives on teratogens and strategies for the future.

Many think of an adverse drug reaction (ADR) as an adverse event caused by a medication intended for a given subject. However, as we learned from the thalidomide debacle 50 years ago, some of the most devastating ADRs affect not the subject who takes the medication but rather, in the case of pregnancy exposures, an innocent bystander--the fetus--and the ADRs include birth defects.

Application of pharmacogenomic strategies to the study of drug-induced birth defects.

Approximately 3% of all infants are born with one or more major birth defects, resulting in >150,000 affected babies each year in the US alone. At present, birth defects account for more than 21% of all infant deaths, making them the leading cause of infant mortality. Although the etiology and determinants of individual susceptibility are largely unknown for most congenital malformations, pharmacogenomic analyses offer promise for the future.

Signal generation and clarification: use of case-control data.

Case-control surveillance systems are useful for 'signal' generation, i.e., signaling potential previously unidentified adverse effects of drugs. Two systems currently in operation, the Slone Epidemiology Unit's Case-Control Surveillance and the Birth Defects Study, have monitored drug effects since 1976. With extensive information on the diagnoses and covariates, the systems have the capacity to carry out in-depth analyses in which the outcome measure is more specifically defined and in which confounding is controlled, thus reducing the possibility of false alarms.

Neural tube defects in relation to use of folic acid antagonists during pregnancy.

Periconceptional folic acid supplementation reduces the risk of neural tube defects (NTDs). To determine whether periconceptional exposure to folic acid antagonists (FAAs) might therefore increase the risk of NTDs, the authors examined data from an ongoing case-control study of birth defects (1979-1998) in the United States and Canada. They compared data on 1,242 infants with NTDs (spina bifida, anencephaly, and encephalocele) with data from a control group of 6,660 infants with malformations not related to vitamin supplementation. Mothers were interviewed within 6 months of delivery about demographic, reproductive, medical, and behavioral factors and about medication use. The adjusted odds ratios of NTDs related to exposure to FAAs (including carbamazepine, phenobarbital, phenytoin, primidone, sulfasalazine, triamterene, and trimethoprim) during the first or second months after the last menstrual period, compared with no use in either month, were 2.8 (95% confidence interval: 1.7, 4.6) for FAAs as a group, 4.8 (95% confidence interval: 1.5, 16.1) for trimethoprim (based on five exposed cases), and 6.9 (95% confidence interval: 1.9, 25.7) for carbamazepine (six exposed cases). These results are adjusted for region, interview year, periconceptional folic acid supplementation, maternal age, weight, education, and infections early in pregnancy. These findings suggest that a number of FAAs may increase NTD risk, and they provide estimates of risk for selected drugs.

Invasive group A streptococcal infection and nonsteroidal antiinflammatory drug use among children with primary varicella.

OBJECTIONS: To test the hypothesis that nonsteroidal antiinflammatory drug use increases the risk of necrotizing soft tissue infections and, secondarily, all invasive group A streptococcal (GAS) infections in children with primary varicella infection. METHODS: We conducted a prospective, multicenter case-control study among children <19 years old. Cases were children hospitalized with primary varicella complicated by invasive GAS infection or necrotizing soft tissue infection identified by a network of 45 pediatric infectious disease specialists located throughout the United States. Controls were children with uncomplicated primary varicella residing in the same communities as the cases. Data on medical history, clinical features of the varicella infection, signs and symptoms of infectious complications, and medication use were collected by structured telephone interviews. Univariate and multivariate matched odds ratios were calculated using conditional logistic regression. RESULTS: Between June 1996 and September 1998, 52 cases of invasive GAS infection, including 21 with necrotizing soft tissue infection, and 172 controls with uncomplicated primary varicella were enrolled. Risk of invasive GAS infection was increased among children who were nonwhite (multivariate odds ratio [OR] 3.8, 95% confidence interval [CI]: 1.4-11), living in low-income households (OR 5.1, 95% CI: 1.7-15), exposed to varicella at home (OR 6.4, 95% CI: 2.6-16), or had a persistent high fever (OR 9.6, 95% CI: 2.8-33). Antipyretic regimen was associated with several measures of varicella illness severity among the controls. The risk of necrotizing soft tissue infection was not associated with the use of ibuprofen before the development of signs or symptoms of this complication (OR 1.3, 95% CI: 0.33-5.3). Risk of any invasive GAS infection was increased among children who had received ibuprofen (OR 3.9, 95% CI: 1.3-12), but not acetaminophen (OR 1.2, 95% CI: 0.50-3.0). However, there was no evidence of increasing risk with increasing duration of ibuprofen use. Subgroup analyses revealed that the risk of invasive GAS infection was increased only among children who had received both acetaminophen and ibuprofen. CONCLUSIONS: These data do not support the hypothesis that nonsteroidal antiinflammatory drugs, or ibuprofen in particular, increase the risk of necrotizing GAS infections. A statistically significant association was observed between nonnecrotizing invasive GAS infection and ibuprofen use; however, because of potential confounding, the meaning of this unexpected result is unclear. Nonetheless, these data suggest that parents use ibuprofen or ibuprofen together with acetaminophen to treat high fever and severe illness, which seems to identify children at high risk for invasive GAS infection.

Folic acid antagonists during pregnancy and the risk of birth defects.

BACKGROUND: Multivitamin supplementation in pregnant women may reduce the risks of cardiovascular defects, oral clefts, and urinary tract defects in their infants. We evaluated whether the folic acid component of multivitamins is responsible for the reduction in risk by examining the associations between maternal use of folic acid antagonists and these congenital malformations. METHODS: We compared data on exposure to folic acid antagonists that act as dihydrofolate reductase inhibitors and to certain antiepileptic drugs for 3870 infants with cardiovascular defects, 1962 infants with oral clefts, and 1100 infants with urinary tract defects with data for 8387 control infants with malformations the risk of which is not reduced after vitamin supplementation. Mothers were interviewed within six months after delivery about their medication use. RESULTS: The relative risks of cardiovascular defects and oral clefts in infants whose mothers were exposed to dihydrofolate reductase inhibitors during the second or third month after the last menstrual period, as compared with infants whose mothers had no such exposure, were 3.4 (95 percent confidence interval, 1.8 to 6.4) and 2.6 (95 percent confidence interval, 1.1 to 6.1), respectively. The relative risks of cardiovascular defects, oral clefts, and urinary tract defects after maternal exposure to antiepileptic drugs were 2.2 (95 percent confidence interval, 1.4 to 3.5), 2.5 (95 percent confidence interval, 1.5 to 4.2), and 2.5 (95 percent confidence interval, 1.2 to 5.0), respectively. Use of multivitamin supplements containing folic acid diminished the adverse effects of dihydrofolate reductase inhibitors, but not that of antiepileptic drugs. CONCLUSIONS: Folic acid antagonists, which include such common drugs as trimethoprim, triamterene, carbamazepine, phenytoin, phenobarbital, and primidone, may increase the risk not only of neural-tube defects, but also of cardiovascular defects, oral clefts, and urinary tract defects. The folic acid component of multivitamins may reduce the risks of these defects.

Use of a job-exposure matrix to assess occupational exposures in relation to birth defects.

Accurate exposure assessment remains a challenge in occupational epidemiology. We evaluated one approach, use of a job-exposure matrix (JEM), by applying the National Institute for Occupational Safety and Health (NIOSH) JEM to a large case-control birth defects study that included parental occupation information. We investigated the JEM exposure predictions in several ways and found that for a substantial proportion of the parents in the birth defects study, the JEM yielded either no exposure data or nonsense predictions. Among exposure predictions that were plausible, most were of low probability. The high probability exposure predictions were statistically unstable, and neither low nor high probability exposure predictions were reliable. There was considerable discrepancy between the JEM predictions and expert assessments for five exposures of interest. Application of the NIOSH JEM to the birth defects study database (and probably other databases as well) does not provide a useful means of assessing occupational exposures.

Comparison of alternative survey methods for sensitive self-reported behaviours in a follow-up study of isotretinoin.

BACKGROUND: Responses to questions on sensitive behaviours can be affected by when and how questions are asked. METHODS: Using data from an ongoing survey of women taking isotretinoin (a teratogenic drug used to treat acne), we compared answers to questions on contraceptive use during therapy among 126966 women who had begun treatment in 1990-93. 20503 were randomly assigned to a group which was surveyed by telephone at the start of treatment, during treatment and 6 months after treatment ended (DAT group). 106463 received a mail survey 6 months after treatment ended (AT group). Women who could not be contacted during treatment, along with the non-respondents in the AT group, received follow-up surveys by US mail, air courier and, if necessary, were called by telephone. RESULTS: The response rate was higher in the DAT group (96.4%) than in the AT group (84.8%). Among respondents, the odds of reported contraceptive use in the AT group compared with the DAT group (asked at 6 months after treatment) was 1.41 [95% confidence interval (CI): 1.36-1.46]. However, rates of oral contraceptive (OC) use were virtually identical in the two groups. In both groups, women surveyed by telephone reported lower rates of contraceptive use than women surveyed by mail. In the AT group, a late response was associated with a significantly lower rate of contraceptive use. CONCLUSIONS: Both mode of data collection (phone versus mail) and time to response affected reported rates of contraceptive use. Reasonable assumptions about the effect of non-response could not account for the difference between the AT and DAT groups. We found that contacting women during their treatment did not increase their reported use of contraceptives.

Adult pertussis in a general practice.

OBJECTIVE: To examine serologically the incidence of pertussis in a group of adults (> 15 years of age) presenting to their General Practitioner with symptoms which suggested the possibility of pertussis. DESIGN: One year's study of the results of testing blood samples. This was followed by a questionnaire to the General Practitioners involved, asking information on all the patients tested. SETTING: Specimens were tested as part of the normal workload in the Microbiology Department of a District General Hospital. SUBJECTS: The patients all attended a Health Centre in South Lanarkshire which caters for a population of 12,749 people. RESULTS AND CONCLUSIONS: Twenty of fifty six patients tested (35.7%) produced serological evidence of recent pertussis infection. The average age of the positive patients was 43.5, and the duration of their symptoms, before testing, was 4.2 weeks. The results suggest that pertussis in adults is not uncommon. Symptoms of "whoop" and/or vomiting were seldom reported in this series. "Paroxysmal coughing", "nocturnal coughing", and "shortness of breath" were more common in the positive cases than in the negative ones. The use of antibiotics did not appear to have any beneficial effect, probably due to them being given too late after the onset of infection. Most adults are susceptible to pertussis, as vaccine-induced immunity declines and is absent after 12 years following vaccination. In a vaccinated population, adults are now the primary source of infection for susceptible infants.

Achieving a public health recommendation for preventing neural tube defects with folic acid.

OBJECTIVES: This study examined 3 approaches to achieving the public health recommendation that all women of child-bearing age ingest 0.40 mg of folic acid per day to reduce the occurrence of neural tube defects (NTDs). METHODS: A total of 1136 mothers of infants with major malformations from the Boston and Philadelphia areas, whose pregnancies began from 1993 to 1995, were interviewed within 6 months of delivery about vitamin supplementation, dietary intakes, and other factors. RESULTS: Seventy-one percent of the 1136 women in the study did not take folic acid--containing supplements daily before conception, but the proportion decreased over the years of the study. Women not taking supplements consumed an average of 0.25 mg of naturally occurring folates daily. On the basis of dietary intakes reported by women not taking folic acid supplements, a simulation of cereal grain fortification with folic acid at the level required by the US Food and Drug Administration showed that an average of only 0.13 mg of folic acid would be ingested daily. CONCLUSIONS: With consumption of folic acid only through dietary intake, sizeable portions of the childbearing population would receive less than the level of folic acid recommended for preventing NTDs. Even with food fortification, women of childbearing age should be advised to take folic acid--containing supplements on a daily basis.

Multivitamin supplementation and risk of birth defects.

It is widely accepted that supplementation with folic acid, a B vitamin, reduces the risk of neural tube defects (NTDs). This case-control study tested the hypothesis that multivitamins reduce risks of selected birth defects other than NTDs. Infants with and without birth defects and aborted fetuses with birth defects were ascertained in the greater metropolitan areas of Boston, Philadelphia, and Toronto during 1993-1996. Mothers were interviewed within 6 months after delivery about a variety of factors, including details on vitamin use. Eight case groups were included: cleft lip with or without cleft palate, cleft palate only, conotruncal defects, ventricular septal defects, urinary tract defects, limb reduction defects, congenital hydrocephaly, and pyloric stenosis (n's ranged from 31 to 186). Controls were 521 infants without birth defects (nonmalformed controls) and 442 infants with defects other than those of the cases (malformed controls). Daily multivitamin supplementation was evaluated according to gestational timing categories, including periconceptional use (28 days before through 28 days after the last menstrual period). Odds ratios (ORs) below 1.0 were observed for all case groups except cardiac defects, regardless of control type. For periconceptional use, ORs with 95% confidence intervals that excluded 1.0 were estimated for limb reduction defects using both nonmalformed controls (OR = 0.3) and malformed controls (OR = 0.2) and for urinary tract defects using both nonmalformed controls (OR = 0.6) and malformed controls (OR = 0.5). Statistically significant ORs for use that began after the periconceptional period were observed for cleft palate only and urinary tract defects. These data support the hypothesis that periconceptional vitamin supplementation may extend benefits beyond a reduction in NTD risk. However, other than folic acid's protecting against NTDs, it is not clear what nutrient or combination of nutrients might affect risk of other specific defects.

The safety of acetaminophen and ibuprofen among children younger than two years old.

BACKGROUND: Recently ibuprofen has been introduced as a nonprescription analgesic/antipyretic for use in children. OBJECTIVE: To compare the incidence of serious adverse clinical events among children <2 years old given ibuprofen and acetaminophen to control fever. STUDY DESIGN: A practitioner-based, randomized clinical trial. A total of 27 065 febrile children were randomized to receive acetaminophen (12 mg/kg), ibuprofen (5 mg/kg), or ibuprofen (10 mg/kg). Rates of hospitalization for acute gastrointestinal bleeding, acute renal failure, anaphylaxis, Reye's syndrome, asthma, bronchiolitis, and vomiting/gastritis were compared by randomization group. RESULTS: The risk of hospitalization with any diagnosis in the 4 weeks after enrollment was 1.4% (95% confidence interval, 1. 3%-1.6%) and did not vary by antipyretic assignment. No children were hospitalized for acute renal failure, anaphylaxis, or Reye's syndrome. Three children were hospitalized with gastrointestinal bleeding; all 3 had been assigned to treatment with ibuprofen. The risk of hospitalization with gastrointestinal bleeding among children randomized to ibuprofen was 17 per 100 000 (95% confidence interval, 3.5-49 per 100 000) but was not significantly greater than the risk among children given acetaminophen. The risk of hospitalization with asthma, bronchiolitis, or vomiting/gastritis did not differ by antipyretic assignment. CONCLUSIONS: The risk of serious adverse clinical events among children <2 years old receiving short-term treatment with either acetaminophen or ibuprofen suspension was small and did not vary by choice of medication. These data do not provide any information on the safety of these medications when used for prolonged periods or when used together, regardless of duration.