Focal Brain Lesions Causing Acquired Amusia Map to a Common Brain Network

Music is a universal human attribute. The study of amusia, a neurologic music processing deficit, has increasingly elaborated our view on the neural organization of the musical brain. However, lesions causing amusia occur in multiple brain locations and often also cause aphasia, leaving the distinct neural networks for amusia unclear. Here, we utilized lesion network mapping to identify these networks. A systematic literature search was carried out to identify all published case reports of lesion-induced amusia. The reproducibility and specificity of the identified amusia network were then tested in an independent prospective cohort of 97 stroke patients (46 female and 51 male) with repeated structural brain imaging, specifically assessed for both music perception and language abilities. Lesion locations in the case reports were heterogeneous but connected to common brain regions, including bilateral temporoparietal and insular cortices, precentral gyrus, and cingulum. In the prospective cohort, lesions causing amusia mapped to a common brain network, centering on the right superior temporal cortex and clearly distinct from the network causally associated with aphasia. Lesion-induced longitudinal structural effects in the amusia circuit were confirmed as reduction of both gray and white matter volume, which correlated with the severity of amusia. We demonstrate that despite the heterogeneity of lesion locations disrupting music processing, there is a common brain network that is distinct from the language network. These results provide evidence for the distinct neural substrate of music processing, differentiating music-related functions from language, providing a testable target for noninvasive brain stimulation to treat amusia.

Long noncoding RNA plasmacytoma variant translocation 1 is overexpressed in cutaneous squamous cell carcinoma and exon 2 is critical for its oncogenicity

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) is one of the most common and fastest increasing forms of cancer worldwide with metastatic potential. Long noncoding RNAs (lncRNAs) are a group of RNA molecules with essential regulatory functions in both physiological and pathological processes.

OBJECTIVES

To investigate the function and mode of action of lncRNA plasmacytoma variant translocation 1 (PVT1) in cSCC.

METHODS

Quantitative reverse transcriptase polymerase chain reaction and single-molecule in situ hybridization were used to quantify the expression level of PVT1 in normal skin, premalignant skin lesions, actinic keratosis (AK) and primary and metastatic cSCCs. The function of PVT1 in cSCC was investigated both in vivo (tumour xenografts) and in vitro (competitive cell growth assay, 5-ethynyl-2'-deoxyuridine incorporation assay, colony formation assay and tumour spheroid formation assay) upon CRISPR-Cas9-mediated knockout of the entire PVT1 locus, the knockout of exon 2 of PVT1, and locked nucleic acid (LNA) gapmer-mediated PVT1 knockdown. RNA sequencing analysis was conducted to identify genes and processes regulated by PVT1.

RESULTS

We identified PVT1 as a lncRNA upregulated in cSCC in situ and cSCC, associated with the malignant phenotype of cSCC. We showed that the expression of PVT1 in cSCC was regulated by MYC. Both CRISPR-Cas9 deletion of the entire PVT1 locus and LNA gapmer-mediated knockdown of PVT1 transcript impaired the malignant behaviour of cSCC cells, suggesting that PVT1 is an oncogenic transcript in cSCC. Furthermore, knockout of PVT1 exon 2 inhibited cSCC tumour growth both in vivo and in vitro, demonstrating that exon 2 is a critical element for the oncogenic role of PVT1. Mechanistically, we showed that PVT1 was localized in the cell nucleus and its deletion resulted in cellular senescence, increased cyclin-dependent kinase inhibitor 1 (p21/CDKN1A) expression and cell cycle arrest.

CONCLUSIONS

Our study revealed a previously unrecognized role for exon 2 of PVT1 in its oncogenic role and that PVT1 suppresses cellular senescence in cSCC. PVT1 may be a potential biomarker and therapeutic target in cSCC.

Kinetic Modeling of Brain [18-F]FDG Positron Emission Tomography Time Activity Curves with Input Function Recovery (IR) Method

Accurate positron emission tomography (PET) data quantification relies on high-quality input plasma curves, but venous blood sampling may yield poor-quality data, jeopardizing modeling outcomes. In this study, we aimed to recover sub-optimal input functions by using information from the tail (5th-100th min) of curves obtained through the frequent sampling protocol and an input recovery (IR) model trained with reference curves of optimal shape. Initially, we included 170 plasma input curves from eight published studies with clamp [18F]-fluorodeoxyglucose PET exams. Model validation involved 78 brain PET studies for which compartmental model (CM) analysis was feasible (reference (ref) + training sets). Recovered curves were compared with original curves using area under curve (AUC), max peak standardized uptake value (maxSUV). CM parameters (ref + training sets) and fractional uptake rate (FUR) (all sets) were computed. Original and recovered curves from the ref set had comparable AUC (d = 0.02, not significant (NS)), maxSUV (d = 0.05, NS) and comparable brain CM results (NS). Recovered curves from the training set were different from the original according to maxSUV (d = 3) and biologically plausible according to the max theoretical K1 (53//56). Brain CM results were different in the training set (p < 0.05 for all CM parameters and brain regions) but not in the ref set. FUR showed reductions similarly in the recovered curves of the training and test sets compared to the original curves (p < 0.05 for all regions for both sets). The IR method successfully recovered the plasma inputs of poor quality, rescuing cases otherwise excluded from the kinetic modeling results. The validation approach proved useful and can be applied to different tracers and metabolic conditions.

Incremental prognostic value of downstream positron emission tomography perfusion imaging after coronary computed tomography angiography: a study using machine learning

AIMS

To evaluate the incremental value of positron emission tomography (PET) myocardial perfusion imaging (MPI) over coronary computed tomography angiography (CCTA) in predicting short- and long-term outcome using machine learning (ML) approaches.

METHODS AND RESULTS

A total of 2411 patients with clinically suspected coronary artery disease (CAD) underwent CCTA, out of whom 891 patients were admitted to downstream PET MPI for haemodynamic evaluation of obstructive coronary stenosis. Two sets of Extreme Gradient Boosting (XGBoost) ML models were trained, one with all the clinical and imaging variables (including PET) and the other with only clinical and CCTA-based variables. Difference in the performance of the two sets was analysed by means of area under the receiver operating characteristic curve (AUC). After the removal of incomplete data entries, 2284 patients remained for further analysis. During the 8-year follow-up, 210 adverse events occurred including 59 myocardial infarctions, 35 unstable angina pectoris, and 116 deaths. The PET MPI data improved the outcome prediction over CCTA during the first 4 years of the observation time and the highest AUC was at the observation time of Year 1 (0.82, 95% confidence interval 0.804-0.827). After that, there was no significant incremental prognostic value by PET MPI.

CONCLUSION

PET MPI variables improve the prediction of adverse events beyond CCTA imaging alone for the first 4 years of follow-up. This illustrates the complementary nature of anatomic and functional information in predicting the outcome of patients with suspected CAD.

Association of tobacco smoke exposure with metabolic profile from childhood to early adulthood: the Special Turku Coronary Risk Factor Intervention Project

AIMS

To investigate the associations between passive tobacco smoke exposure and daily smoking with a comprehensive metabolic profile, measured repeatedly from childhood to adulthood.

METHODS AND RESULTS

Study cohort was derived from the Special Turku Coronary Risk Factor Intervention Project (STRIP). Smoking status was obtained by questionnaire, while serum cotinine concentrations were measured using gas chromatography. Metabolic measures were quantified by nuclear magnetic resonance metabolomics at 9 (n = 539), 11 (n = 536), 13 (n = 525), 15 (n = 488), 17 (n = 455), and 19 (n = 409) years. Association of passive tobacco smoke exposure with metabolic profile compared participants who reported less-than-weekly smoking and had serum cotinine concentration <1 ng/mL (no exposure) with those whose cotinine concentration was ≥10 ng/mL (passive tobacco smoke exposure). Associations of daily smoking with metabolic profile in adolescence were analysed by comparing participants reporting daily smoking with those reporting no tobacco use and having serum cotinine concentrations <1 ng/mL. Passive tobacco smoke exposure was directly associated with the serum ratio of monounsaturated fatty acids to total fatty acids [β = 0.34 standard deviation (SD), (0.17-0.51), P < 0.0001] and inversely associated with the serum ratios of polyunsaturated fatty acids. Exposure to passive tobacco smoke was directly associated with very-low-density lipoprotein particle size [β = 0.28 SD, (0.12-0.45), P = 0.001] and inversely associated with HDL particle size {β = -0.21 SD, [-0.34 to -0.07], P = 0.003}. Daily smokers exhibited a similar metabolic profile to those exposed to passive tobacco smoke. These results persisted after adjusting for body mass index, STRIP study group allocation, dietary target score, pubertal status, and parental socio-economic status.

CONCLUSION

Both passive and active tobacco smoke exposures during childhood and adolescence are detrimentally associated with circulating metabolic measures indicative of increased cardio-metabolic risk.

Hypertension in NF1: A closer look at the primacy of essential hypertension versus secondary causes

BACKGROUND

We aimed to analyze hypertension in neurofibromatosis type 1 (NF1) in a Finnish population-based cohort in 1996-2014.

METHODS

A cohort of 1365 individuals with confirmed NF1 was compared with a control cohort of 13,923 individuals matched for age, sex, and area of residence. Diagnoses of hypertension were retrieved from the Finnish Care Register for Health Care. These registered data were separately analyzed for secondary and essential hypertension. Purchases of antihypertensive drugs were queried from the Finnish Register of Reimbursed Drug Purchases.

RESULTS

We identified 115 NF1 patients with hospital diagnosis of hypertension. Our findings revealed a hazard ratio (HR) of 1.64 (95% CI 1.34-2.00, p < 0.001) in NF1 versus controls. NF1 patients presented with a significantly increased hazard for both secondary hypertension (n = 9, HR 3.76, 95% CI 1.77-7.95, p < 0.001) and essential hypertension (n = 98, HR 1.73, 95% CI 1.39-2.14, p < 0.001). No difference in the HR of hypertension was observed between men and women, while NF1 patients with essential hypertension were, on average, younger than the controls. The proportions of individuals with antihypertensive medication did not differ between NF1 patients and controls (OR 0.85).

CONCLUSION

NF1 is a risk factor for hypertension. Despite the recognized risk for secondary hypertension, essential hypertension is the predominant type in NF1.

Association of Asthma Risk Alleles With Acute Respiratory Tract Infections and Wheezing Illnesses in Young Children

BACKGROUND

Genome-wide association studies have identified several risk alleles for early childhood asthma, particularly in the 17q21 locus and in the cadherin-related family member 3 (CDHR3) gene. Contribution of these alleles to the risk of acute respiratory tract infections (ARI) in early childhood is unclear.

METHODS

We analyzed data from the STEPS birth-cohort study of unselected children and the VINKU and VINKU2 studies on children with severe wheezing illness. Genome-wide genotyping was performed on 1011 children. We analyzed the association between 11 preselected asthma risk alleles and the risk of ARIs and wheezing illnesses of various viral etiologies.

RESULTS

The asthma risk alleles in CDHR3, GSDMA, and GSDMB were associated with an increased rate of ARIs (for CDHR3, incidence rate ratio [IRR], 1.06; 95% confidence interval [CI], 1.01-1.12; P = .02), and risk allele in CDHR3 gene with rhinovirus infections (IRR, 1.10; 95% CI, 1.01-1.20, P = .03). Asthma risk alleles in GSDMA, GSDMB, IKZF3, ZPBP2, and ORMDL3 genes were associated with wheezing illnesses in early childhood, especially rhinovirus-positive wheezing illnesses.

CONCLUSIONS

Asthma risk alleles were associated with an increased rate of ARIs and an increased risk of viral wheezing illnesses. Nonwheezing and wheezing ARIs and asthma may have shared genetic risk factors. Clinical Trials Registration. NCT00494624 and NCT00731575.

Large-scale activation likelihood estimation meta-analysis of parkinsonian disorders

Parkinsonism is a feature of several neurodegenerative disorders, including Parkinson's disease, progressive supranuclear palsy, corticobasal syndrome and multiple system atrophy. Neuroimaging studies have yielded insights into parkinsonian disorders; however, due to variability in results, the brain regions consistently implicated in these disorders remain to be characterized. The aim of this meta-analysis was to identify consistent brain abnormalities in individual parkinsonian disorders (Parkinson's disease, progressive supranuclear palsy, corticobasal syndrome and multiple system atrophy) and to investigate any shared abnormalities across disorders. A total of 44 591 studies were systematically screened following searches of two databases. A series of whole-brain activation likelihood estimation meta-analyses were performed on 132 neuroimaging studies (69 Parkinson's disease; 23 progressive supranuclear palsy; 17 corticobasal syndrome; and 23 multiple system atrophy) utilizing anatomical MRI, perfusion or metabolism PET and single-photon emission computed tomography. Meta-analyses were performed in each parkinsonian disorder within each imaging modality, as well as across all included disorders. Results in progressive supranuclear palsy and multiple system atrophy aligned with current imaging markers for diagnosis, encompassing the midbrain, and brainstem and putamen, respectively. PET imaging studies of patients with Parkinson's disease most consistently reported abnormality of the middle temporal gyrus. No significant clusters were identified in corticobasal syndrome. When examining abnormalities shared across all four disorders, the caudate was consistently reported in MRI studies, whilst the thalamus, inferior frontal gyrus and middle temporal gyri were commonly implicated by PET. To our knowledge, this is the largest meta-analysis of neuroimaging studies in parkinsonian disorders and the first to characterize brain regions implicated across parkinsonian disorders.

Timing of symptomatic venous thromboembolism after surgery: meta-analysis

BACKGROUND

The timing at which venous thromboembolism (VTE) occurs after major surgery has major implications for the optimal duration of thromboprophylaxis. The aim of this study was to perform a systematic review and meta-analysis of the timing of postoperative VTE up to 4 weeks after surgery.

METHODS

A systematic search of MEDLINE, Scopus, and CINAHL databases was performed between 1 January 2009 and 1 April 2022. Prospective studies that recruited patients who underwent a surgical procedure and reported at least 20 symptomatic, postoperative VTE events by time were included. Two reviewers independently selected studies according to the eligibility criteria, extracted data, and evaluated risk of bias. Data were analysed with a Poisson regression model, and the GRADE approach was used to rate the certainty of evidence.

RESULTS

Some 6258 studies were evaluated, of which 22 (11 general, 5 urological, 4 mixed, and 2 orthopaedic postoperative surgical populations; total 1 864 875 patients and 24 927 VTE events) were eligible. Pooled evidence of moderate certainty showed that 47.1 per cent of the VTE events occurred during the first, 26.9 per cent during the second, 15.8 per cent during the third, and 10.1 per cent during the fourth week after surgery. The timing of VTE was consistent between individual studies.

CONCLUSION

Although nearly half of symptomatic VTE events in first 4 weeks occur during the first postoperative week, a substantial number of events occur several weeks after surgery. These data will inform clinicians and guideline developers about the duration of postoperative thromboprophylaxis.

Reproductive Markers of Testicular Function and Size During Puberty in Boys With and Without a History of Cryptorchidism

CONTEXT

Longitudinal data on levels of hypothalamic-pituitary-gonadal axis hormones and insulin-like growth factor I (IGF-I) during puberty in boys with a history of cryptorchidism are largely missing.

OBJECTIVE

We aimed to compare pubertal hormone levels between boys with a history of congenital cryptorchidism who experienced spontaneous testicular descent or underwent orchiopexy and boys without a history of cryptorchidism.

METHODS

This was a nested case-control study within a population-based birth cohort, with a prospective, longitudinal pubertal follow-up every 6 months (2005 to 2019). Participants were 109 Finnish boys, including boys with a history of unilateral cryptorchidism who underwent orchiopexy (n = 15), unilateral cryptorchidism who had spontaneous testicular descent (n = 15), bilateral cryptorchidism who underwent orchiopexy (n = 9), bilateral cryptorchidism who had spontaneous testicular descent (n = 7), and controls (n = 63). Serum reproductive hormone levels and testicular volumes were measured.

RESULTS

From around onset of puberty, boys with bilateral cryptorchidism who underwent orchiopexy had significantly higher follicle-stimulating hormone (FSH) and lower inhibin B levels than controls. Boys with unilateral cryptorchidism who underwent orchiopexy had significantly higher FSH than controls, whereas inhibin B levels were similar. Testosterone, luteinizing hormone, insulin-like factor 3, and IGF-I were generally similar between groups. Testicular volume of boys with unilateral or bilateral cryptorchidism who underwent orchiopexy was smaller than that of the controls from 1 year after pubertal onset (P < 0.05).

CONCLUSION

Cryptorchid boys, particularly those with bilateral cryptorchidism who underwent orchiopexy, had altered levels of serum biomarkers of Sertoli cells and germ cells and smaller testicular volumes compared with controls.

Sufficiency of Knowledge Processed in Patient Education in Dialysis Care

PURPOSE

Patient education improves health and treatment adherence of patients with chronic kidney disease. However, evidence about the sufficiency of patients' knowledge processed in patient education is limited. The purpose of this study was to evaluate subjective and objective sufficiency of knowledge processed in patient education in dialysis care and treatment.

PATIENTS AND METHODS

A cross-sectional study design was used. The sample (n=162) comprised patients in predialysis or home dialysis. All eligible patients during the data collection timeframe (2016-2017) in two university hospital districts in Finland were invited to participate. Subjective sufficiency was evaluated with a structured questionnaire having 34 items divided into six dimensions of empowering knowledge (bio-physiological, functional, social, experiential, ethical, and financial) on a Likert scale (1=not sufficient at all, 4=very sufficient). Objective sufficiency was evaluated with a structured knowledge test with 10 items (score range 0-10, correct=1, wrong/no knowledge=0) based on the multidimensional content of patient education emphasizing bio-physiological dimension.

RESULTS

In subjective sufficiency of knowledge, the mean was 3.27 (SD 0.54). The bio-physiological dimension of empowering knowledge was the most sufficient (mean 3.52, SD 0.49) and the experiential the least (mean 2.8, SD 0.88). In objective sufficiency, the means ranged 5.15-5.97 (SD 2.37-2.68) among patients in different modalities of dialysis care and treatment. The least sufficient objective scores were bio-physiological and functional knowledge. The subjective and objective sufficiency did not correlate with each other.

CONCLUSION

Patients' knowledge, either subjective or objective, does not seem to be sufficient. Hence, attention should be paid to supporting patients with more personalized knowledge. Furthermore, the relationship between subjective and objective sufficiency needs future consideration, as their non-correspondence was a new discovery.

Brain free fatty acid uptake is elevated in morbid obesity, and is irreversible 6 months after bariatric surgery: A positron emission tomography study

AIM

To investigate whether there are differences in brain fatty acid uptake (BFAU) between morbidly obese and lean subjects, and the effect of weight loss following bariatric surgery.

MATERIALS AND METHODS

We measured BFAU with 14(R, S)-[¹⁸ F]fluoro-6-thia-heptadecanoic acid and positron emission tomography in 24 morbidly obese and 14 lean women. Obese subjects were restudied 6 months after bariatric surgery. We also assessed whether there was hypothalamic neuroinflammation in the obese subjects using fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging.

RESULTS

Obese subjects had a higher BFAU than lean subjects (1.12 [0.61] vs. 0.72 [0.50] μmol 100 g^-1 min^-1 , P = 0.0002), driven by higher fatty acid uptake availability. BFAU correlated positively with BMI (P = 0.006, r = 0.48), whole body fatty acid oxidation (P = 0.006, r = 0.47) and leptin levels (P = 0.001, r = 0.54). When BFAU, leptin and body mass index (BMI) were included in the same model, the association between BFAU and leptin was the strongest. BFAU did not correlate with FLAIR-derived estimates of hypothalamic inflammation. Six months after bariatric surgery, obese subjects achieved significant weight loss (-10 units of BMI). BFAU was not significantly changed (1.12 [0.61] vs. 1.09 [0.39] μmol 100 g^-1 min^-1 , ns), probably because of the ongoing catabolic state. Finally, baseline BFAU predicted worse plasma glucose levels at 2 years of follow-up.

CONCLUSIONS

BFAU is increased in morbidly obese compared with lean subjects, and is unchanged 6 months after bariatric surgery. Baseline BFAU predicts worse plasma glucose levels at follow-up, supporting the notion that the brain participates in the control of whole-body homeostasis.

Neurofibromatosis type 1 of the child increases birth weight

Neurofibromatosis type 1 (NF1) is associated with reduced adult height, but there are no cohort studies on birth size. This retrospective study includes a cohort of 1,410 persons with NF1 and a matched comparison cohort from the general population. Figures for birth size were retrieved from the administrative registers of Finland, and the data were converted to standard deviation scores (SDS), defined as standard deviation difference to the reference population. The birth weight among infants with NF1 was higher than among infants without the disorder (adjusted mean difference [95% confidence interval]: 0.53 SDS [0.19–0.87]), as was the head circumference at birth (0.58 SDS [0.26–0.90]). The birth length of the NF1 infants did not differ significantly from the comparison cohort. The birth weight in the group consisting of NF1 and non‐NF1 infants of NF1 mothers was lower than among infants of mothers in the comparison cohort (−0.28 SDS [−0.51 to −0.06]), as was the birth length (−0.22 SDS [−0.45 to 0.00]). In conclusion, the birth weight and head circumference of persons with NF1 are significantly higher than those of persons without the disorder. NF1 of the mother reduces birth weight and birth length of the infant.

Craniofacial and oral alterations in patients with Neurofibromatosis 1

ABTSRACT

Neurofibromatosis type 1 (NF1) is one of the most common inherited syndromes. The literature on craniofacial alterations associated with NF1 has been limited and partially contradictory. This review is based on literature search and the results of the clinical study "Craniofacial and Oral Alterations and Speech in patients with Neurofibromatosis 1", carried out at the University of Turku and Turku University Hospital, Finland in 2006-2012. By the end of 2012, a total of 110 NF1 patients, 54 female and 56 male patients, were examined.A part of our results confirms pre-existing understanding, a part is contradictory to previous considerations based mainly on case reports, and some are entirely novel. Specifically, our results confirmed that enlargement the mandibular canal is the most common abnormality of the mandible in patients with NF1. It should be noted, however, that this finding does not require treatment. Caries was not a major problem. In fact, it was less frequent in NF1 patients compared to reference population. These findings abrogate some previous perceptions. Novel findings of our project include periapical cemental dysplasia in females; short jaws, a finding which usually does not affect bite; and immunohistological analysis of oral mucosal abnormalities. Pioneering study on speech showed that various deviations were very common: As many as 94% of the participants showed some alterations.To conclude, the awareness of craniofacial alterations common in NF1would help avoiding unnecessary and even harmful involvement, e.g. of periapical cemental dysplasia or enlarged mandibular canal which do not require treatment.

Radiosynthesis and Preclinical Evaluation of [18F]F-DPA, A Novel Pyrazolo[1,5a]pyrimidine Acetamide TSPO Radioligand, in Healthy Sprague Dawley Rats

PURPOSE

Many neurological conditions result in the overexpression of the translocator protein 18 kDa (TSPO), today recognized as a biomarker for microglial activation and neuroinflammation imaging. The pyrazolo[1,5-a]pyrimidine acetamides are a particularly attractive class of TSPO-specific ligands, prompting the development of several positron emission tomography (PET) radiotracers. This includes F-DPA, a recently reported fluorinated ligand (K i = 1.7 nM), wherein the fluorine atom is directly linked to the phenyl moiety without the presence of an alkyl or alkoxy spacer chain. Reported here is the preparation of [18F]F-DPA using [18F]Selectfluor bis(triflate) and the preliminary evaluation of [18F]F-DPA in healthy rats. Its metabolic profile and biodistribution in rats are compared with that of [18F]DPA-714, a closely related structure.

PROCEDURES

[18F]F-DPA was synthesized by electrophilic fluorination using [18F]Selectfluor bis(triflate), [18F]DPA-714 was synthesized by conventional nucleophilic fluorination. The biodistribution of both radiotracers was compared in Sprague Dawley rats. Radiometabolites of both radiotracers in plasma and brain homogenates were analyzed by radioTLC.

RESULTS

The radiochemical yield of [18F]F-DPA was 15 ± 3 % and the specific activity was 7.8 ± 0.4 GBq/μmol. The radiochemical purity exceeded 99 %. The in vivo time activity curves of [18F]F-DPA demonstrate rapid entry into the brain and a concentration equilibrium at 20-30 min after injection. The metabolic profiles at 90 min after radiotracer injection in the plasma show that unchanged [18F]F-DPA and [18F]DPA-714 account for 28.3 ± 6.4 and 11.1 ± 2.6 % of the remaining radioactivity, respectively. In the brain, unchanged [18F]F-DPA accounts for 93.5 ± 2.8 % of the radioactivity; whereas for [18F]DPA-714, this value is 53.6 ± 1.6 %.

CONCLUSIONS

[18F]Selectfluor bis(triflate) was successfully used to label F-DPA with fluorine-18. The labeling position on the aromatic moiety imparts a higher stability compared to [18F]DPA-714 with regard to in vivo metabolism. [18F]F-DPA is a promising new radiotracer and warrants further investigation in animal models of disease.

Daycare attendance and respiratory tract infections: a prospective birth cohort study

OBJECTIVE

We explored the burden of respiratory tract infections (RTIs) in young children with regard to day-care initiation.

DESIGN

Longitudinal prospective birth cohort study.

SETTING AND METHODS

We recruited 1827 children for follow-up until the age of 24 months collecting diary data on RTIs and daycare. Children with continuous daycare type and complete data were divided into groups of centre-based daycare (n=299), family day care (FDC) (n=245) and home care (n=350). Using repeated measures variance analyses, we analysed days per month with symptoms of respiratory tract infection, antibiotic treatments and parental absence from work for a period of 6 months prior to and 9 months after the start of daycare.

RESULTS

We documented a significant effect of time and type of daycare, as well as a significant interaction between them for all outcome measures. There was a rise in mean days with symptoms from 3.79 (95% CI 3.04 to 4.53) during the month preceding centre-based daycare to 10.57 (95% CI 9.35 to 11.79) at 2 months after the start of centre-based daycare, with a subsequent decrease within the following 9 months. Similar patterns with a rise and decline were observed in the use of antibiotics and parental absences. The start of FDC had weaker effects. Our findings were not changed when taking into account confounding factors.

CONCLUSIONS

Our study shows the rapid increase in respiratory infections after start of daycare and a relatively fast decline in the course of time with continued daycare. It is important to support families around the beginning of daycare.