The spectrum of vascular anomalies in patients with PTEN mutations: implications for diagnosis and management

Background

Mutations in the PTEN gene cause two disorders that predispose to cancer, Bannayan–Riley–Ruvalcaba and Cowden syndromes. Some patients with a PTEN mutation have only macrocephaly and autism, but they may still be at risk for neoplasms. Vascular anomalies occur in patients with a PTEN mutation, but they have not been systematically studied or precisely defined.

Method

We analysed the clinical and radiological features of the vascular anomalies in 26 patients with PTEN mutations who were either seen or had their medical records reviewed at Children''s Hospital Boston.

Results

All 23 patients who had their head circumference measured were macrocephalic, and all 13 male patients who were fully examined had penile freckling. Vascular anomalies were found in 14/26 (54%) of patients: 8/14 (57%) had multiple lesions and 11/13 (85%) who had cross‐sectional imaging had intramuscular vascular lesions. Radiographic studies showed that 12/14 (86%) were fast‐flow vascular anomalies, and angiography typically showed focal segmental dilatation of draining veins. Excessive ectopic fat in the vascular anomalies was present in 11/12 (92%) of patients on CT or MRI. Intracranial developmental venous anomalies (DVAs) were found in 8/9 (89%) of patients who had brain MRI with contrast.

Conclusions

Vascular anomalies in patients with a PTEN mutation are typically multifocal intramuscular combinations of fast‐flow channels and ectopic fat. Cerebral DVAs are very common. PTEN mutational analysis should be considered for all macrocephalic patients with fast‐flow vascular anomalies or multiple intracranial DVAs.     

Using entropy balancing to strengthen an observational cohort study design: lessons learned from an evaluation of a complex multi-state federal demonstration

We conducted an evaluation of a patient-centered medical home demonstration sponsored by the Centers for Medicare & Medicaid Services. We implemented a quasi-experimental pre-post with a comparison group design. Traditional propensity score weighting failed to achieve balance (exchangeability) between the two groups on several critical characteristics. In response, we incorporated a relatively new alternative known as entropy balancing. Our objective is to share lessons learned from using entropy balancing in a quasi-experimental study design. We document the advantages and challenges with using entropy balancing. We also describe a set of best practices, and we present a series of illustrative analyses that empirically demonstrate the performance of entropy balancing relative to traditional propensity score weighting. We compare alternative approaches based on: (i) covariate balance (e.g., standardized differences); (ii) overlap in conditional treatment probabilities; and (iii) the distribution of weights. Our comparison of overlap is based on a novel approach we developed that uses entropy balancing weights to calculate a pseudo-propensity score. In many situations, entropy balancing provides remarkably superior covariate balance compared to traditional propensity score weighting methods. Entropy balancing is also preferred because it does not require extensive iterative manual searching for an optimal propensity score specification. However, we demonstrate that there are some situations where entropy balancing “fails”. Specifically, there are instances where entropy balancing achieves adequate covariate balance only by using a distribution of weights that dramatically up-weights a small set of observations, giving them a disproportionately large and undesirable influence.     

Exploring Lactation Consultant Views on Infant Safe Sleep

Objectives The purpose of this qualitative study was to explore the infant safe sleep beliefs and occupational practices of lactation consultants and to determine if lactation consultants give advice to clients that is consistent with the American Academy of Pediatrics’ recommendations on this topic. Methods Focus groups were conducted with certified lactation consultants in two cities in Ohio. Participants discussed the role of lactation consultants, the infant sleep advice they provide to women, their views on the American Academy of Pediatrics’ infant safe sleep recommendations and related policies, and perceived benefits and barriers associated with providing infant safe sleep education as part of their work. A member-checking session was held to ensure the credibility of the findings. Results Four focus groups were conducted with 22 certified lactation consultants between September and November 2015. Major themes that emerged included: lactation consultants’ beliefs regarding the importance of bedsharing for supporting breastfeeding success; their disagreement with the infant safe sleep recommendations of the American Academy of Pediatrics; their frustration with policies that restrict consultants’ ability to discuss bedsharing; and the impact of infant safe sleep policies on their work and the advice they provide. Conclusions for Practice Lactation consultants interact with mothers of newborns at a critical time for infant safe sleep decision-making and may influence a woman’s choices related to this topic. Women may not be receiving messages from lactation consultants that are consistent with the infant safe sleep recommendations of the American Academy of Pediatrics.     

Hydrophobic sodium fluoride‐based nanocrystals doped with lanthanide ions: assessment of in vitro toxicity to human blood lymphocytes and phagocytes

In vitro immunotoxicity of hydrophobic sodium fluoride‐based nanocrystals (NCs) doped with lanthanide ions was examined in this study. Although there is already a significant amount of optical and structural data on NaYF₄ NCs, data on safety assessment are missing. Therefore, peripheral whole blood from human volunteers was used to evaluate the effect of 25 and 30 nm hydrophobic NaYF₄ NCs dissolved in cyclohexane (CH) on lymphocytes, and of 10 nm NaYF₄ NCs on phagocytes. In the concentration range 0.12–75 µg cm^?2 (0.17–106 µg ml^?1), both 25 and 30nm NaYF₄ NCs did not induce cytotoxicity when measured as incorporation of [³H]‐thymidine into DNA. Assessment of lymphocyte function showed significant suppression of the proliferative activity of T‐lymphocytes and T‐dependent B‐cell response in peripheral blood cultures (n = 7) stimulated in vitro with mitogens phytohemagglutinin (PHA) and pokeweed (PWM) (PHA > PWM). No clear dose–response effect was observed. Phagocytic activity and respiratory burst of leukocytes (n = 5–8) were generally less affected. A dose‐dependent suppression of phagocytic activity of granulocytes in cultures treated with 25 nm NCs was observed (vs. medium control). A decrease in phagocytic activity of monocytes was found in cells exposed to higher doses of 10 and 30 nm NCs. The respiratory burst of phagocytes was significantly decreased by exposure to the middle dose of 30 nm NCs only. In conclusion, our results demonstrate immunotoxic effects of hydrophobic NaYF₄ NCs doped with lanthanide ions to lymphocytes and to lesser extent to phagocytes. Further research needs to be done, particularly faze transfer of hydrophobic NCs to hydrophilic ones, to eliminate the solvent effect. Copyright © 2014 John Wiley & Sons, Ltd.     

Formation of the very low density lipoprotein and metabolism of [1-14C]-oleate by perfused livers from rats treated with triiodothyronine or propylthiouracil

To gain insight into the mechanism(s) responsible for changes in plasma lipid concentrations in thyroid disease, the metabolism of [1-¹⁴C]-oleate by perfused livers from hypothyroid [propylthiouracil (PTU) treated], euthyroid and hyperthyroid (T₃ treated) rats was compared. Livers from hyperthyroid animals secreted decreased amounts of very low density lipoprotein (VLDL) and incorporated less [1-¹⁴C]-oleate into VLDL triglyceride, but produced more ketone bodies and incorporated more radioactivity from [1-¹⁴C]-oleate into ketones than did livers from euthyroid animals. Conversely, incorporation of [1-¹⁴C]-oleate into perfusate and VLDL triglyceride was increased in livers from hypothyroid animals, while rates of production of ¹⁴CO₂ were diminished. Plasma T₃ concentration was inversely correlated with VLDL triglyceride (r = ?0.70, p < 0.003) and VLDL apoprotein (r = ?0.72, p < 0.008), but directly correlated with ketogenesis (r = 0.71, p < 0.002). Thyroid hormone diminished esterification of fatty acids, and inhibited the hepatic production of triglyceride and secretion of VLDL and stimulated ketogenesis, whereas thyroid hormone deficiency increased hepatic esterification of fatty acid to triglyceride, tended to increase output of the VLDL, and diminished oxidation of fatty acid through the tricarboxylic acid cycle. The surface lipid (phospholipid, cholesterol) to apoprotein ratio was directly correlated with the output of VLDL triglyceride (r = 0.85, p < 0.0005). Furthermore, the lipid composition of the secreted VLDL particle was influenced by thyroid status. Plasma T₃ concentration was directly correlated with the molar ratios of phospholipid/triglyceride (r = 0.73, p < 0.001), cholesterol/triglyceride (r = 0.85, p < 0.0001), and cholesteryl ester/triglyceride (r = 0.80, p < 0.0002) in the VLDL particle. A direct correlation was also demonstrable between the ratio apoprotein/triglyceride and plasma T₃ concentration (r = 0.72, p < 0.0084), while the ratio was inversely correlated with output of VLDL triglyceride (r = ?0.76, p < 0.0038). The percentage of certain of the polymorphic forms of arginine-rich peptide was increased, while apo C-III₃ was decreased in VLDL produced by livers from hypothyroid rats. These data are consistent with the hypothesis that as output of VLDL diminished in the progression from hypothyroidism to hyperthyroidism, the VLDL particle secreted became smaller with a larger ratio of surface to core components.     

Higher serum leptin level in women than in men with type 1 diabetes

Leptin is the protein product of the obese (ob) gene, a lipostatic hormone that contributes to body weight regulation through suppressing appetite and/or stimulating energy expenditure in humans and/or rodents. In humans, serum leptin concentrations are increased in relation to increased body fat content. Studies have shown a higher leptin level in women compared with men. However, the gender influence on serum leptin concentrations has never been evaluated in patients with type 1 diabetes. In this study, serum leptin levels and percentage body fat mass were measured in men and women with type 1 diabetes. Fasting serum leptin levels were higher in women (16.7 + 11.6 ng/mL) than in men (3.0 +/- 1.5 ng/mL; P < 0.05) and were independent of exogenous insulin intake and of glucose control. Percentage body fat and fat mass were significant determinants of leptin concentration, whereas age and duration of diabetes were not related to leptin concentration. Subgroups of men (n = 12) and women (n = 11) with total body fat between 20 and 30% were compared. Leptin levels were also higher in women compared with men (13.5 +/- 8.3 ng/mL versus 3.2 +/- 1.7 ng/mL; P < 0.05, respectively). In conclusion, our findings indicate that gender is an important determinant of serum leptin concentration in type 1 diabetics, this gender difference is partly explained by body fat distribution and that type 1 diabetic women may be more resistant than type 1 diabetic men to leptin's alleged lipostatic actions.     

Functional health status in male patients without restenosis following successful ptca

In a prospective pilot study, subjective and objective parameters of the health status were assessed in 148 male patients (mean age 56 ± 8.4 years) before and 4 months after successful coronary angioplasty (PTCA). Restenosis was defined as residual diameter stenosis >50%. Although 96 patients (65%) had not developed restenosis at 4 months' invasive follow-up, subjective asessment of general well-being was unchanged in 26% or worse in 71%; overall anginal status and exercise performance had however improved. Of 71 men younger than 60 years who had no restenosis at follow-up, 4 men retired and 13 remained on medical leave. The striking disparity between subjective and objective parameters was not related to significant differences of age, exercise capacity, and left ventricular ejection fraction, as well as to baseline characteristics (previous myocardial infarction, extent of coronary heart disease, comorbidity) compared with 52 patients with restenosis. Thus, despite documented sustained success after PTCA, the majority of patients failed to resume the status of subjective well-being.