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Epidemiologic research suggests that youth cannabis use is associated with psychotic disorders. However, current evidence is based heavily on 20th-century data when cannabis was substantially less potent than today.
Methods
We linked population-based survey data from 2009 to 2012 with records of health services covered under universal healthcare in Ontario, Canada, up to 2018. The cohort included respondents aged 12–24 years at baseline with no prior psychotic disorder (N = 11 363). The primary outcome was days to first hospitalization, ED visit, or outpatient visit related to a psychotic disorder according to validated diagnostic codes. Due to non-proportional hazards, we estimated age-specific hazard ratios during adolescence (12–19 years) and young adulthood (20–33 years). Sensitivity analyses explored alternative model conditions including restricting the outcome to hospitalizations and ED visits to increase specificity.
Results
Compared to no cannabis use, cannabis use was significantly associated with psychotic disorders during adolescence (aHR = 11.2; 95% CI 4.6–27.3), but not during young adulthood (aHR = 1.3; 95% CI 0.6–2.6). When we restricted the outcome to hospitalizations and ED visits only, the strength of association increased markedly during adolescence (aHR = 26.7; 95% CI 7.7–92.8) but did not change meaningfully during young adulthood (aHR = 1.8; 95% CI 0.6–5.4).
Conclusions
This study provides new evidence of a strong but age-dependent association between cannabis use and risk of psychotic disorder, consistent with the neurodevelopmental theory that adolescence is a vulnerable time to use cannabis. The strength of association during adolescence was notably greater than in previous studies, possibly reflecting the recent rise in cannabis potency.
Psychiatric mother and baby units (MBUs) are recommended for severe perinatal mental illness, but effectiveness compared with other forms of acute care remains unknown.
Aims
We hypothesised that women admitted to MBUs would be less likely to be readmitted to acute care in the 12 months following discharge, compared with women admitted to non-MBU acute care (generic psychiatric wards or crisis resolution teams (CRTs)).
Method
Quasi-experimental cohort study of women accessing acute psychiatric care up to 1 year postpartum in 42 healthcare organisations across England and Wales. Primary outcome was readmission within 12 months post-discharge. Propensity scores were used to account for systematic differences between MBU and non-MBU participants. Secondary outcomes included assessment of cost-effectiveness, experience of services, unmet needs, perceived bonding, observed mother–infant interaction quality and safeguarding outcome.
Results
Of 279 women, 108 (39%) received MBU care, 62 (22%) generic ward care and 109 (39%) CRT care only. The MBU group (n = 105) had similar readmission rates to the non-MBU group (n = 158) (aOR = 0.95, 95% CI 0.86–1.04, P = 0.29; an absolute difference of −5%, 95% CI −14 to 4%). Service satisfaction was significantly higher among women accessing MBUs compared with non-MBUs; no significant differences were observed for any other secondary outcomes.
Conclusions
We found no significant differences in rates of readmission, but MBU advantage might have been masked by residual confounders; readmission will also depend on quality of care after discharge and type of illness. Future studies should attempt to identify the effective ingredients of specialist perinatal in-patient and community care to improve outcomes.
To characterize and compare severe acute respiratory coronavirus virus 2 (SARS-CoV-2)–specific immune responses in plasma and gingival crevicular fluid (GCF) from nursing home residents during and after natural infection.
Design:
Prospective cohort.
Setting:
Nursing home.
Participants:
SARS-CoV-2–infected nursing home residents.
Methods:
A convenience sample of 14 SARS-CoV-2–infected nursing home residents, enrolled 4–13 days after real-time reverse transcription polymerase chain reaction diagnosis, were followed for 42 days. After diagnosis, plasma SARS-CoV-2–specific pan-Immunoglobulin (Ig), IgG, IgA, IgM, and neutralizing antibodies were measured at 5 time points, and GCF SARS-CoV-2–specific IgG and IgA were measured at 4 time points.
Results:
All participants demonstrated immune responses to SARS-CoV-2 infection. Among 12 phlebotomized participants, plasma was positive for pan-Ig and IgG in all 12 participants. Neutralizing antibodies were positive in 11 participants; IgM was positive in 10 participants, and IgA was positive in 9 participants. Among 14 participants with GCF specimens, GCF was positive for IgG in 13 participants and for IgA in 12 participants. Immunoglobulin responses in plasma and GCF had similar kinetics; median times to peak antibody response were similar across specimen types (4 weeks for IgG; 3 weeks for IgA). Participants with pan-Ig, IgG, and IgA detected in plasma and GCF IgG remained positive throughout this evaluation, 46–55 days after diagnosis. All participants were viral-culture negative by the first detection of antibodies.
Conclusions:
Nursing home residents had detectable SARS-CoV-2 antibodies in plasma and GCF after infection. Kinetics of antibodies detected in GCF mirrored those from plasma. Noninvasive GCF may be useful for detecting and monitoring immunologic responses in populations unable or unwilling to be phlebotomized.
During the first wave of the severe acute respiratory syndrome-coronavirus-2 epidemic in the Netherlands, notifications consisted mostly of patients with relatively severe disease. To enable real-time monitoring of the incidence of mild coronavirus disease 2019 (COVID-19) – for which medical consultation might not be required – the Infectieradar web-based syndromic surveillance system was launched in mid-March 2020. Our aim was to quantify associations between Infectieradar participant characteristics and the incidence of self-reported COVID-19-like illness. Recruitment for this cohort study was via a web announcement. After registering, participants completed weekly questionnaires, reporting the occurrence of a set of symptoms. The incidence rate of COVID-19-like illness was estimated and multivariable Poisson regression used to estimate the relative risks associated with sociodemographic variables, lifestyle factors and pre-existing medical conditions. Between 17 March and 24 May 2020, 25 663 active participants were identified, who reported 7060 episodes of COVID-19-like illness over 131 404 person-weeks of follow-up. The incidence rate declined over the analysis period, consistent with the decline in notified cases. Male sex, age 65+ years and higher education were associated with a significantly lower COVID-19-like illness incidence rate (adjusted rate ratios (RRs) of 0.80 (95% CI 0.76–0.84), 0.77 (0.70–0.85), 0.84 (0.80–0.88), respectively) and the baseline characteristics ever-smoker, asthma, allergies, diabetes, chronic lung disease, cardiovascular disease and children in the household were associated with a higher incidence (RRs of 1.11 (1.04–1.19) to 1.69 (1.50–1.90)). Web-based syndromic surveillance has proven useful for monitoring the temporal trends in, and risk factors associated with, the incidence of mild disease. Increased relative risks observed for several patient factors could reflect a combination of exposure risk, susceptibility to infection and propensity to report symptoms.
A nationwide survey indicated that screening for asymptomatic carriers of C. difficile is an uncommon practice in US healthcare settings. Better understanding of the role of asymptomatic carriage in C. difficile transmission, and of the measures available to reduce that risk, are needed to inform best practices regarding the management of carriers.
To test the hypothesis that long-term care facility (LTCF) residents with Clostridium difficile infection (CDI) or asymptomatic carriage of toxigenic strains are an important source of transmission in the LTCF and in the hospital during acute-care admissions.
Design
A 6-month cohort study with identification of transmission events was conducted based on tracking of patient movement combined with restriction endonuclease analysis (REA) and whole-genome sequencing (WGS).
Setting
Veterans Affairs hospital and affiliated LTCF.
Participants
The study included 29 LTCF residents identified as asymptomatic carriers of toxigenic C. difficile based on every other week perirectal screening and 37 healthcare facility-associated CDI cases (ie, diagnosis >3 days after admission or within 4 weeks of discharge to the community), including 26 hospital-associated and 11 LTCF-associated cases.
Results
Of the 37 CDI cases, 7 (18·9%) were linked to LTCF residents with LTCF-associated CDI or asymptomatic carriage, including 3 of 26 hospital-associated CDI cases (11·5%) and 4 of 11 LTCF-associated cases (36·4%). Of the 7 transmissions linked to LTCF residents, 5 (71·4%) were linked to asymptomatic carriers versus 2 (28·6%) to CDI cases, and all involved transmission of epidemic BI/NAP1/027 strains. No incident hospital-associated CDI cases were linked to other hospital-associated CDI cases.
Conclusions
Our findings suggest that LTCF residents with asymptomatic carriage of C. difficile or CDI contribute to transmission both in the LTCF and in the affiliated hospital during acute-care admissions. Greater emphasis on infection control measures and antimicrobial stewardship in LTCFs is needed, and these efforts should focus on LTCF residents during hospital admissions.
We have previously shown that the minor alleles of vascular endothelial growth factor A (VEGFA) single-nucleotide polymorphism rs833069 and superoxide dismutase 2 (SOD2) single-nucleotide polymorphism rs2758331 are both associated with improved transplant-free survival after surgery for CHD in infants, but the underlying mechanisms are unknown. We hypothesised that one or both of these minor alleles are associated with better systemic ventricular function, resulting in improved survival.
Methods
This study is a follow-up analysis of 422 non-syndromic CHD patients who underwent neonatal cardiac surgery with cardiopulmonary bypass. Echocardiographic reports were reviewed. Systemic ventricular function was subjectively categorised as normal, or as mildly, moderately, or severely depressed. The change in function was calculated as the change from the preoperative study to the last available study. Stepwise linear regression, adjusting for covariates, was performed for the outcome of change in ventricular function. Model comparison was performed using Akaike’s information criterion. Only variables that improved the model prediction of change in systemic ventricular function were retained in the final model.
Results
Genetic and echocardiographic data were available for 335/422 subjects (79%). Of them, 33 (9.9%) developed worse systemic ventricular function during a mean follow-up period of 13.5 years. After covariate adjustment, the presence of the VEGFA minor allele was associated with preserved ventricular function (p=0.011).
Conclusions
These data support the hypothesis that the mechanism by which the VEGFA single-nucleotide polymorphism rs833069 minor allele improves survival may be the preservation of ventricular function. Further studies are needed to validate this genotype–phenotype association and to determine whether this mechanism is related to increased vascular endothelial growth factor production.
Background: Transitioning from medical school to residency is difficult and stressful, necessitating innovation in easing this transition. In response, a Canadian neurosurgical Rookie Camp was designed and implemented to foster acquisition of technical, cognitive and behavioral skills among incoming Canadian post graduate year one (PGY-1) neurosurgery residents. Methods: The inaugural Rookie Camp was held in July 2012 in Halifax. The curriculum was developed based on a national needs-assessment and consisted of a pre-course manual, 7 case-based stations, 4 procedural skills stations and 2 group discussions. The content was clinically focused, used a variety of teaching methods, and addressed multiple CanMEDS competencies. Evaluation included participant and faculty surveys and a pre-course, post-course, and 3-month retention knowledge test. Results: 17 of 23 PGY-1 Canadian neurosurgical residents participated in the Camp. All agreed the course content was relevant for PGY-1 training and the experience prepared them for residency. All participants would recommend the course to future neurosurgical residents. A statistically significant improvement was observed in knowledge related to course content (F(2,32) = 7.572, p<0.002). There were no significant differences between post-test and retention-test scores at three months. Conclusion: The inaugural Canadian Neurosurgery Rookie Camp for PGY-1 residents was successfully delivered, with engagement from participants, training programs, the Canadian Neurosurgical Society, and the Royal College. In addition to providing fundamental knowledge, which was shown to be retained, the course eased junior residents’ transition to residency by fostering camaraderie and socialization within the specialty.
Mechanisms linking maternal nutrient restriction (MNR) to intra-uterine growth restriction (IUGR) and programming of adult disease remain to be established. The impact of controlled MNR on maternal and fetal amino acid metabolism has not been studied in non-human primates. We hypothesised that MNR in pregnant baboons decreases fetal amino acid availability by mid-gestation. We determined maternal and fetal circulating amino acid concentrations at 90 d gestation (90dG, term 184dG) in control baboons fed ad libitum (C, n 8) or 70 % of C (MNR, n 6). Before pregnancy, C and MNR body weights and circulating amino acids were similar. At 90dG, MNR mothers had lower body weight than C mothers (P< 0·05). Fetal and placental weights were similar between the groups. MNR reduced maternal blood urea N (BUN), fetal BUN and fetal BUN:creatinine. Except for histidine and lysine in the C and MNR groups and glutamine in the MNR group, circulating concentrations of all amino acids were lower at 90dG compared with pre-pregnancy. Maternal circulating amino acids at 90dG were similar in the MNR and C groups. In contrast, MNR fetal β-alanine, glycine and taurine all increased. In conclusion, maternal circulating amino acids were maintained at normal levels and fetal amino acid availability was not impaired in response to 30 % global MNR in pregnant baboons. However, MNR weight gain was reduced, suggesting adaptation in maternal–fetal resource allocation in an attempt to maintain normal fetal growth. We speculate that these adaptive mechanisms may fail later in gestation when fetal nutrient demands increase rapidly, resulting in IUGR.
Early detection of cervical and breast cancers is an important component of women's health strategy. Screening programmes, health professional interventions and preventive behaviours such as breast self-examination provide the means to this end. Our twin study sought to identify the relative influence of environmental and genetic factors on liability to early cancer detection behaviours, including use of cervical smear tests, mammograms, and breast examination. Additive genetic and random environmental effects models gave the best, most parsimonious fit to the data for each early cancer detection behaviour. The heritability of liability to Pap smear use was 66%, mammogram use 50%, breast examination by a doctor or nurse 38% and breast self-examination 37%. Genetic influences were behaviour-specific; there was no evidence for a common genetic influence on the four behaviours. Potential covariates investigated included age, amount of contact between co-twins, educational level and personality traits such as harm avoidance, novelty seeking, reward dependence, neuroticism, anxiety, depression, self-esteem, perceived control, interpersonal dependency and ways of coping. None were significant. The study was carried out before the implementation of national screening programmes with media campaigns to increase participation rates. Hence follow-up investigation, including data on regularity of behaviours, would be informative
This article examines the nature of oral language and representations used by teachers as they instruct young Indigenous Australian students at the beginning of formal schooling during play-based activities in mathematics. In particular, the use of Standard Australian English (SAE), the mathematical register used, and the interplay with mathematical representations during classroom instruction are analysed based upon the teachers' selfreported practices. The data are drawn from structured telephone interviews with 40 teachers in 15 schools from rural and remote or multicultural settings in Queensland at the initial stage of a large, longitudinal study. The specific aim of the study was the identification of effective pedagogical practices that may assist young Australian students from diverse ethnic and cultural backgrounds to negotiate western mathematical understanding. The findings indicate that despite experience in these settings and focused professional learning sessions, the majority of these teachers report practices which reflect a strong emphasis on literacy acquisition rather than mathematical understanding. It is the contention of the researchers that the use of oral language with a rich selection of mathematical representations strongly supports mathematical understanding.
Reduced food availability in pregnancy influences fetal growth, obstetric outcomes and offspring health in both developing and developed countries. The objective of the present study was to determine responses to moderate global maternal nutrient restriction (MNR) during pregnancy in baboons (Papio hamadryas) – an established non-human primate model for pregnancy-related research. Starting at 30 d gestation (dG), twelve pregnant baboons received 70 % of food (MNR group) consumed by twenty ad libitum-fed pregnant controls. Maternal body weight, BMI, food intake and physical activity were measured before pregnancy, at 90 dG and at 165 dG (full-term 180 dG). Fetal and placental weights were recorded at the time of Caesarean section (90 and 165 dG). Activity patterns were also evaluated in fourteen non-pregnant female baboons. Behavioural observations were made in five non-pregnant, six control and four MNR animals. Pregnant baboons decreased overall physical activity and energy-expensive behaviours compared with non-pregnant baboons. In the MNR group, maternal weight, weight gain and maternal physical activity were reduced compared with the control animals. MNR decreased placental weight and volume compared with control, while fetal weight and length were unaffected. We conclude that decreased physical activity and increased usage of maternal available body stores play an important role in the maternal response to pregnancy. Also, adaptations in maternal behaviour and energy utilisation protect fetal growth during moderate MNR.
To identify and describe the key communication and health protection issues surrounding a flooding emergency.
Methods:
A telephone questionnaire was used to assess health and safety information sources, information recalled, and behavioral responses among residents of the town of Feilding, New Zealand following a major floodin February 2004. This was supplemented by key informant interviews and a newspaper content analysis.
Results:
A total of 154 adult residents were surveyed (76% of those successfully contacted and eligible). Of the respondents, 79% recalled being provided with health and safety information from authorities. The majorsources were: radio (41%), pamphlets (23%), and newspapers (20%). The regional newspaper had extensive coverage of this flooding emergency but “health” only was mentioned in 46 (7%) of the 664 flood-related articles.
Of those who recalled receiving information from authorities, most (89%) perceived that it was adequate. Nevertheless, 18% actively sought out information (mainly about water safety and availability). In the post-flood period, 73% of all respondents boiled water; however, only 4% maintained boiling water or bottled water use for the necessary nine-week period. Some forms of emergency preparations did not change substantially from before the flood, compared to four months afterwards (e.g., having a radio with batteries increased from 62% to 68%). Perceived health concerns around the flooding were low, though 59% were concerned about the risk ofwater contamination. Actual self-reported, health consequences from the flood were rare, as only two (1%) people out of 154 reported flood-related health problems.
Conclusions:
Health and safety information generally was communicated successfully and was regarded as appropriate by the population of this floodaffected town. Nevertheless, there are further improvements needed in the emergency response by both residents and authorities.
Learning and retaining class material is not only the primary goal in many class exercises (e.g. from learning the ABC to the periodic table of the elements) but may be essential for successfully mastering more complex lessons (e.g. reading, and developing chemical compounds). Accordingly, many researchers and educators have devoted their careers to engineering techniques that will improve learning. In the present chapter, we discuss the utility of one technique for improving individuals' ability to master new materials: practice tests or self-testing. A practice test involves an individual testing their memory or comprehension of class material to evaluate whether they will succeed on a subsequent test and, as such, can be considered a metacognitive activity. That is, practice testing may inform the learner about the degree to which to-be-learned materials have been stored in memory (or have been comprehended) so that they can accurately predict future test performance. In this way, practice tests may help students to regulate their study more effectively. For instance, a student may devise a test to evaluate whether to-be-learned material can be retrieved. If the material is retrieved during the test, they can move on to study other less well-learned materials. If the material is not successfully retrieved, then more study time should be allocated. The idea is that self-testing will improve the efficiency of self-regulated learning by helping students isolate poorly learned material for restudy. This simple strategy has been included in popular learning techniques and is undoubtedly used by many students.
We examined whether responder type groups reflecting patterns of hemodynamic reactivity might also differ in recovery responses. Cardiac output (CO), total peripheral resistance (TPR), systolic and diastolic blood pressure, heart rate, and Heather index were assessed at rest and during speech and cold pressor tasks in young adults. Participants (n = 152) were classified as myocardial, vascular, or mixed-mild responders based on CO and TPR responses to speech presentation. Vascular responders exhibited slower CO and TPR speech recovery than the myocardial and/or mixed-mild groups. Responder type differences in reactivity showed limited task-generalizability. The sustained vascular response pattern of the vascular group is consistent with that seen in hypertension. In light of associations of heightened TPR with markers of disease risk, this suggests potentially negative health implications for vascular responders.