Global myocardial blood flow and global flow reserve measurements by MRI and PET are comparable

Coronary flow reserve (CFR) measurements have been widely used in assessing the functional significance of coronary artery stenosis because they are more sensitive in predicting major cardiac events than angiographically detected reductions of coronary arteries. Myocardial blood flow can be determined by measuring coronary sinus (CS) flow with velocity-encoded cine magnetic resonance imaging (VEC-MRI). The purpose of this study was to compare global myocardial blood flow (MBF) and CFR measured using VEC-MRI with MBF and CFR measured using positron emission tomography (PET). We measured MBF at baseline and after dipyridamole-induced hyperemia in 12 male volunteers with VEC-MRI and PET. With VEC-MRI, MBF was 0.64 +/- 0.09 (ml/min/g) at baseline and 1.59 +/- 0.79 (ml/min/g) at hyperemia, which yielded an average CFR of 2.51 +/- 1.29. With PET, MBF was 0.65 +/- 0.20 (ml/min/g) at baseline and 1.78 +/- 0.72 (ml/min/g) at hyperemia, which yielded an average CFR of 2.79 +/- 0.97. The correlation of MBFs between these two methods was good (r = 0.82, P < 0.001). The CFRs measured by MRI correlated well with those measured using PET (r = 0.76, P < 0.004). These results suggest that MRI is a useful and accurate method to measure global MBF and CFR. Therefore, it would be suitable for studying risk factor modifications of vascular function at an early stage in healthy volunteers.     

Screening of mutations in the PHF8 gene and identification of a novel mutation in a Finnish family with XLMR and cleft lip/cleft palate

We investigated the prevalence of mutations in the PHD finger protein 8 (PHF8) gene in X-linked mental retardation (XLMR) and facial cleft starting from the original cohort of 7712 patients operated on since 1 January 1950 for cleft lip/cleft palate in the Cleft Centre at the Helsinki University Hospital. From this nationwide material, 18 patients including one family with two male patients with cleft lip/cleft palate and unknown cause of mental retardation (MR) were sequenced for the coding regions and splice sites of the PHF8 gene. A novel missense mutation c.836C>T of the PHF8 gene was identified in a Finnish family with multiple-affected male patients. The mutation resides in exon 8 and changes phenylalanine to serine (F279S) in the functionally important Jmonji C domain of the protein. The clinical phenotype of the male patients was characterized by mild MR, mild dysmorphic features, unilateral cleft lip and cleft palate in one and bilateral cleft lip and cleft palate in the other sibling. The mutation was not present in 200 anonymous blood donors (approximately 300 X-chromosomes). To our knowledge, F279S is the third mutation of the PHF8 gene identified so far.     

Effect of antenatal growth on brain white matter maturation in preterm infants at term using tract-based spatial statistics

Background

White matter maturation of infants can be studied using diffusion tensor imaging (DTI). DTI of the white matter of the infant brain provides the best available clinical measures of brain tissue organisation and integrity.

Objective

The purpose of this study was to compare white matter maturation between preterm infants born small for gestational age (SGA) and preterms with weight appropriate for gestational age (AGA) at birth.

Materials and methods

A total of 36 preterm infants were enrolled in the study (SGA, n?=?9). A rater-independent method called tract-based spatial statistics (TBSS) was used to assess white matter maturation.

Results

When measured by TBSS, the AGA infants showed higher fractional anisotrophy values in several white matter tracts than the SGA infants. Areas with significant differences included anterior thalamic radiation, corticospinal tract, forceps major and minor, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, superior longitudinal fasciculus, uncinate fasciculus, and superior longitudinal fasciculus (temporal part). No significant difference was found for mean diffusivity.

Conclusion

As an objective and user-independent method, TBSS confirmed that preterm infants with impaired antenatal growth have impaired white matter maturation compared to preterm infants with normal antenatal growth. The differences were mainly detected in radiations that are myelinated first.     

Depression and discrimination in the lives of women,transgender and gender liminal people in Ontario,Canada

This article uses an intersectionality lens to explore how experiences of race, gender, sexuality, class and their intersections are associated with depression and unmet need for mental healthcare in a population of 704 women and transgender/gender liminal people from Ontario, Canada. A survey collecting demographic information, information about mental health and use of mental healthcare services, and data for the Everyday Discrimination Scale and the PHQ‐9 Questionnaire for Depression was completed by 704 people via Internet or pen‐and‐paper between June 2011 and June 2012. Bivariate and regression analyses were conducted to assess group differences in depression and discrimination experiences, and predictors of depression and unmet need for mental healthcare services. Analyses revealed that race, gender, class and sexuality all corresponded to significant differences in exposure to discrimination, experiences of depression and unmet needs for mental healthcare. Use of interaction terms to model intersecting identities and exclusion contributed to explained variance in both outcome variables. Everyday discrimination was the strongest predictor of both depression and unmet need for mental healthcare. The results suggest lower income and intersections of race with other marginalised identities are associated with more depression and unmet need for mental healthcare; however, discrimination is the factor that contributes the most to those vulnerabilities. Future research can build on intersectionality theory by foregrounding the role of structural inequities and discrimination in promoting poor mental health and barriers to healthcare.     

Barbiturate anesthesia and brain proton spectroscopy.

BACKGROUND AND PURPOSE: Thiopentone reduces CBF and metabolic rate. Still, it is widely used for sedation during MR spectroscopy. We investigated whether barbiturate anesthesia and preanesthetic fasting have an effect on metabolic ratios in proton MR spectroscopy of the brain. METHODS: Eight healthy, consenting, male volunteers were studied twice in a random, crossover fashion. The study sessions were conducted during fasting (F) and nonfasting (nonF), with glucose infusion mimicking the fed state. During both sessions, two sets of spectroscopic data were collected, one during the awake state (F or nonF) and one under barbiturate anesthesia (F+B or nonF+B), using TEs of 135 and 270. Spectral areas of N-acetylaspartate (NAA), choline-containing compounds (Cho), and creatine plus phosphocreatine (Cr) were calculated, and the presence of lactate or lipid was noted. Venous blood samples for glucose, beta-hydroxybutyrate, lactate, and electrolytes were collected. RESULTS: Barbiturate anesthesia caused a 42% reduction in blood lactate levels during fasting, but not during glucose infusion. There were no differences in NAA/Cho, NAA/Cr, or in Cho/Cr between the groups F, nonF, F+B, or nonF+B. No lactate or lipid resonances were detected. CONCLUSION: Barbiturate anesthesia with preanesthetic fasting can be used for proton spectroscopy at TEs of 135 or 270 without interference from NAA/Cho, NAA/Cr, or Cho/Cr or from the appearance of lactate or lipid.     

MR imaging of patellar cartilage degeneration at 0.02 T. Study of 23 cadaveric patellae.

MR imaging with a 0.02 T resistive magnet was used to establish the correlation between the histologic grading of patellar cartilage degeneration and fat water separation images or T1- and T2-relaxation times. We examined 23 cadaveric patellae. There was a positive correlation between histologically graded cartilage degeneration and T1-relaxation time. Patellar cartilage was well differentiated from surrounding structures on chemical shift water proton images, and an evaluation of cartilage degeneration was possible. No correlation was found between cartilage damage and T2-relaxation time. Chemical shift imaging at 0.02 T is easy to perform and gives further information of cartilage disorders.     

Lactase non-persistence and milk consumption in Estonia

INTRODUCTION Lactase enzyme hydrolyses lactose to glucose and galactose facilitating their absorption through the gut wall. Adult- type hypolactasia (lactase non-persistence, primary lactose malabsorption) is the most common enzyme def iciency in the worl…