Identification of dihydromyricetin as a natural DNA methylation inhibitor with rejuvenating activity in human skin

Changes in DNA methylation patterning have been reported to be a key hallmark of aged human skin. The altered DNA methylation patterns are correlated with deregulated gene expression and impaired tissue functionality, leading to the well-known skin aging phenotype. Searching for small molecules, which correct the aged methylation pattern therefore represents a novel and attractive strategy for the identification of anti-aging compounds. DNMT1 maintains epigenetic information by copying methylation patterns from the parental (methylated) strand to the newly synthesized strand after DNA replication. We hypothesized that a modest inhibition of this process promotes the restoration of the ground-state epigenetic pattern, thereby inducing rejuvenating effects. In this study, we screened a library of 1800 natural substances and 640 FDA-approved drugs and identified the well-known antioxidant and anti-inflammatory molecule dihydromyricetin (DHM) as an inhibitor of the DNA methyltransferase DNMT1. DHM is the active ingredient of several plants with medicinal use and showed robust inhibition of DNMT1 in biochemical assays. We also analyzed the effect of DHM in cultivated keratinocytes by array-based methylation profiling and observed a moderate, but significant global hypomethylation effect upon treatment. To further characterize DHM-induced methylation changes, we used published DNA methylation clocks and newly established age predictors to demonstrate that the DHM-induced methylation change is associated with a reduction in the biological age of the cells. Further studies also revealed re-activation of age-dependently hypermethylated and silenced genes in vivo and a reduction in age-dependent epidermal thinning in a 3-dimensional skin model. Our findings thus establish DHM as an epigenetic inhibitor with rejuvenating effects for aged human skin.

Testing the specificity of interpretation biases in women with eating disorder symptoms: An online experimental assessment

OBJECTIVE

Cognitive biases, such as memory, attention, and interpretation bias, are thought to play a central role in the development and maintenance of eating disorders (EDs). The aim of the present study was to investigate whether the interpretation bias is ED-specific or can be generalized to comorbid disorder-related threats in women with high levels of ED symptoms.

METHOD

In an online study, we measured interpretation bias using the modified Sentence Word Association Paradigm (SWAP), comparing women with (n = 39) and without (sub)threshold eating disorders (n = 56). We assessed endorsement and rejection rates as well as reaction times in response to a positive/neutral or a negative ED-specific, social anxiety-specific (SAD), or generalized anxiety-specific (GAD) interpretive word following an ambiguous sentence.

RESULTS

In ambiguous situations, women with high ED symptoms selected more negative (p < .001) and fewer positive/neutral ED-related interpretations (p < .001). Negative interpretations were endorsed significantly faster (p < .001), while positive interpretations were rejected faster in this group (p < .001). These women also manifested negative SAD-specific interpretation bias patterns in reaction time measures. Nevertheless, ED severity was best predicted by the endorsement of negative ED-specific stimuli, whereas ED and SAD reaction time measures seemed to have a negligible effect.

DISCUSSION

The results indicate that the interpretation bias might be ED-specific. The SWAP can be a useful tool for the further investigation of the etiological relevance of the interpretation bias as well as for the development of modification training interventions.

Fat-Phobic and Non-Fat-Phobic Anorexia Nervosa: A Conjoint Analysis on the Importance of Shape and Weight

With the introduction of new diagnostic criteria in DSM-5, fear of weight gain no longer represents a sine qua non-criterion for the diagnosis of anorexia nervosa (AN). This is of relevance as a subgroup of individuals with AN denies fear of weight gain as the reason for restrictive eating but still remain at a very low weight. As self-reports are susceptible to bias, other methods are needed to confirm the existence of the subtype in order to provide adapted treatment. Therefore, we aimed to measure fear of weight gain using a novel method in clinical psychology, the conjoint analysis (CA). Relative importance and preference scores for various life aspects, including appearance/shape and weight were assessed in women with fat-phobic AN (FP-AN, n = 30), NFP-AN (n = 7), and healthy controls (n = 29). Individuals with FP-AN showed a significant lower preference for weight gain versus weight maintenance than HC (p = 0.011, ηp2 = 0.107). Correlation between explicitly assessed drive for thinness and CA score was low. As expected, in FP-AN the explicitly endorsed fear of weight gain was confirmed by the marked preference for weight maintenance compared to HC, while for NFP-AN explicit and implicit measures diverged, indicating that against their self-report they may experience at least some fear of weight gain. The utility of CA as a tool to measure fear of weight gain — and potentially other psychopathological constructs —requires further confirmation.

Development of secondary mutations in wild-type and mutant EZH2 alleles cooperates to confer resistance to EZH2 inhibitors

The histone methyltransferase Enhancer of Zeste Homolog 2 (EZH2) is frequently dysregulated in cancers, and gain-of-function (GOF) EZH2 mutations have been identified in non-Hodgkin lymphomas. Small-molecule inhibitors against EZH2 demonstrated anti-tumor activity in EZH2-mutated lymphomas and entered clinical trials. Here, we developed models of acquired resistance to EZH2 inhibitor EI1 with EZH2-mutated lymphoma cells. Resistance was generated by secondary mutations in both wild-type (WT) and GOF Y641N EZH2 alleles. These EZH2 mutants retained the substrate specificity of their predecessor complexes but became refractory to biochemical inhibition by EZH2 inhibitors. Resistant cells were able to maintain a high level of H3K27Me3 in the presence of inhibitors. Interestingly, mutation of EZH2 WT alone generated an intermediate resistance phenotype, which is consistent with a previously proposed model of cooperation between EZH2 WT and Y641N mutants to promote tumorigenesis. In addition, the findings presented here have implications for the clinical translation of EZH2 inhibitors and underscore the need to develop novel EZH2 inhibitors to target potential resistance emerging in clinical settings.

Microdeletion/duplication at 15q13.2q13.3 among individuals with features of autism and other neuropsychiatric disorders

BACKGROUND

Segmental duplications at breakpoints (BP4-BP5) of chromosome 15q13.2q13.3 mediate a recurrent genomic imbalance syndrome associated with mental retardation, epilepsy, and/or electroencephalogram (EEG) abnormalities.

PATIENTS

DNA samples from 1445 unrelated patients submitted consecutively for clinical array comparative genomic hybridisation (CGH) testing at Children's Hospital Boston and DNA samples from 1441 individuals with autism from 751 families in the Autism Genetic Resource Exchange (AGRE) repository.

RESULTS

We report the clinical features of five patients with a BP4-BP5 deletion, three with a BP4-BP5 duplication, and two with an overlapping but smaller duplication identified by whole genome high resolution oligonucleotide array CGH. These BP4-BP5 deletion cases exhibit minor dysmorphic features, significant expressive language deficits, and a spectrum of neuropsychiatric impairments that include autism spectrum disorder, attention deficit hyperactivity disorder, anxiety disorder, and mood disorder. Cognitive impairment varied from moderate mental retardation to normal IQ with learning disability. BP4-BP5 covers approximately 1.5 Mb (chr15:28.719-30.298 Mb) and includes six reference genes and 1 miRNA gene, while the smaller duplications cover approximately 500 kb (chr15:28.902-29.404 Mb) and contain three reference genes and one miRNA gene. The BP4-BP5 deletion and duplication events span CHRNA7, a candidate gene for seizures. However, none of these individuals reported here have epilepsy, although two have an abnormal EEG.

CONCLUSIONS

The phenotype of chromosome 15q13.2q13.3 BP4-BP5 microdeletion/duplication syndrome may include features of autism spectrum disorder, a variety of neuropsychiatric disorders, and cognitive impairment. Recognition of this broader phenotype has implications for clinical diagnostic testing and efforts to understand the underlying aetiology of this syndrome.

Embryonic central nervous system angiogenesis does not involve blood-borne endothelial progenitors

We asked, whether, in the blood of avian embryos, endothelial precursor cells circulate that actually contribute to the growing vascular system in and around the central nervous system (CNS). We compared the morphology and distribution of QH1-positive cells after transplantation of quail paraxial mesoderm, after blood transfusion, in quail-chick parabiosis, or after quail bone-marrow transplantation. After head mesoderm transplantation from quail to chick, we observed sprouting endothelial cells (ECs), capillary tube formation, and chimeric endothelial lining of large arteries in the host brain. These QH1-positive quail cells showed EC morphologies that demonstrated three different aspects of CNS angiogenesis: invasion by means of filopodia, clonal proliferation and tube formation, and integration into preexisting EC layers. After blood transfusion or in chick-quail parabiosis, blood-borne QH1+ cells were found in the lumen of but not integrated into the wall of the host vascular system. Neither were QH1+ cells observed in the capillary walls of parabiotic chick chorioallantoic membranes. In both cases, the quail cells showed typical macrophage morphology. In chicks that had received quail bone marrow transplants onto their chorioallantoic membranes, QH1+ cells with macrophage, but not EC shape were occasionally seen near the inoculation site. We conclude that (1) blood-borne cells do not become ECs or directly contribute to angiogenesis inside, or in vascular plexuses around the CNS during embryonic development; (2) blood-borne cells do not contribute to the intraneural macrophage population of the embryonic CNS.

Suprathreshold repetitive transcranial magnetic stimulation elevates thyroid-stimulating hormone in healthy male subjects

Repetitive transcranial magnetic stimulation (rTMS) has been introduced as a new antidepressive treatment strategy. The mode of action by which the antidepressive effect is brought about is not yet clear. Other antidepressive treatment strategies such as sleep deprivation are associated with an increase of plasma thyroid-stimulating hormone (TSH) levels that correlate with clinical improvement. In the present study, the effect of left prefrontal suprathreshold (120% of motor threshold) rTMS on TSH plasma levels of 19 healthy male subjects was investigated in comparison with subthreshold (80% of motor threshold) and sham stimulation. Suprathreshold rTMS was followed by a significant relative increase of TSH levels 10 and 60 minutes after stimulation in comparison with subthreshold and sham stimulation. The more pronounced effect of suprathreshold rTMS on TSH plasma levels might be important for the determination of optimal stimulation parameters in the treatment of depressed patients.

Results of a phase-I/II randomized, masked, placebo-controlled trial of recombinant human interleukin-11 (rhIL-11) in the treatment of subjects with active rheumatoid arthritis

Interleukin-11 (IL-11) is a pleiotropic cytokine that regulates the growth and development of hematopoietic stem cells and decreases the proinflammatory mediators of cytokine and nitric oxide production. In animal models of arthritis, treatment with recombinant human IL-11 (rhIL-11) reduces both the level of synovitis and the histologic lesion scores in the joints. The goal of this phase-I/II study in adults with rheumatoid arthritis (RA) was to evaluate the safety and clinical activity of different doses and schedules of rhIL-11 in patients with active RA for whom treatment with at least one disease-modifying antirheumatic drug had failed. This was a multicenter, randomized, placebo-controlled trial that evaluated the safety and tolerability of rhIL-11 in 91 patients with active RA. rhIL-11 was administered subcutaneously; patients were randomized into one of five treatment groups (ratio of rhIL-11 to placebo, 4:1). Patients were treated for 12 weeks with either 2.5 or 7.5 microg/kg of rhIL-11 or placebo twice per week or 5 or 15 microg/kg of rhIL-11 or placebo once per week. The status of each subject's disease activity in accordance with the American College of Rheumatology (ACR) criteria was assessed before, during, and after completion of administration of the study drug. Administration of rhIL-11 was well tolerated at all doses and schedules. The most frequent adverse event was a reaction at the injection site. The data suggest a statistically significant reduction in the number of tender joints (P < 0.008) at the 15 microg/kg once-weekly dose schedule but showed no overall significant benefit at the ACR criterion of a 20% response. The trial showed rhIL-11 to be safe and well tolerated at a variety of doses and schedules over a 12-week treatment period in patients with active RA. The only adverse event clearly associated with rhIL-11 administration was reaction at the injection site.

Experiments on the induction of antibody dependent macrophage-mediated cellular cytotoxicity in mixed brain cell cultures

These examinations were based on the discussion whether in demyelinating diseases anti-lipid antibody associated with brain macrophages could have a cytotoxic effect on oligodendrocytes. We used mixed brain cell cultures of newborn rats where, among others, both oligodendrocytes and vacuolated macrophage-like cells were found. On these macrophage-like cells, the presence of Fc-receptors was proven. Besides Fc-receptor-dependent phagocytosis, these cells showed an Fc-receptor-independent type of phagocytosis. The Fc-receptor-bearing cells moved within the culture and adhered to glass fibers. In the cytoplasm of these cells, unspecific esterase, acid phosphatase and peroxidase could be visualized. The vacuolated cells showed strong autofluorescence, expressed a surface marker found on all types of rat leukocytes and were marked by Griffonia simplicifolia lectin. These results definitely characterized the vacuolised cells as macrophages. We saw globular and pleomorphic macrophages. After incubation of anti-GC serum in a highly diluted solution, significantly more macrophages bound to oligodendrocytes than in the controls. In these cases, we found target cell lysis. It could be shown in vitro that anti-GC serum together with macrophages of neonatal brains can induce a cytotoxic effect on oligodendrocytes.

Observation of optical pumping of mesospheric sodium

We have observed a large variation with laser polarization in the amount of laser light resonantly backscattered from the Earth's mesospheric sodium layer located at a 90-km altitude. This variation is evidence of optical pumping of mesospheric sodium atoms.

Continuous-wave operation of a diode-pumped rotating Nd:glass disk laser

A diode-laser end-pumped cw rotating Nd:glass disk laser that operates in the TEM(00) mode with a slope efficiency of 37% has been demonstrated to have an output power dependent on both the pumping rate and the rotation rate. As the rotation rate increases, the power increases from zero to an optimum and thereafter decreases. The initial increase is due to the lessening of the effect of medium heating on laser operation, while the decrease is due to decreased laser gain caused by sweeping of the excited-state population out of the laser cavity. At the optimum rotation rate of 2.5 Hz we obtained a cw output power of 0.55 W with 2 W of absorbed pump power; the output power was limited by the available pump power as opposed to thermal damage or thermo-optic distortion.

Influence of a preventive care educational intervention on physician knowledge, attitudes, beliefs, and practice

We evaluated the effect of a three-part intervention on knowledge, attitudes, beliefs, and practices relevant to preventive care. A group of 13 second-year internal medicine residents (Group I) were exposed to a lecture, chart-based reminder, and biweekly feedback during a 3-month ambulatory care rotation. The remaining two groups of residents (Group II, n = 12; Group III, n = 11) were not exposed to the intervention. We performed a chart review to assess preventive care practice at a clinical site separate from the intervention and surveyed residents to assess preventive care knowledge, self-reported practice, professional attitudes, and health beliefs. Chart reviews revealed the intervention to be associated with improved performance of preventive care (0.52 vs 0.35 and 0.42, P = 0.01). In addition, the intervention was associated with improved scores for preventive care knowledge (90 vs 74 and 77, P = 0.001) and self-reported practice (85 vs 65 and 72, P = 0.007). Although attitudes toward prevention and health locus of control were not measurably influenced by the intervention, stepwise multiple linear regression analysis demonstrated these factors to be independently related to preventive practice. Our data support the notion that physician preventive practice is subject to a variety of influences involving not only knowledge, and practice environment, but also training, professional attitudes, and health beliefs.

Low-dose methotrexate treatment of rheumatoid arthritis. Long-term observations

Of 21 patients with rheumatoid arthritis who began to receive low-dose weekly methotrexate up to five years ago, 15 (71 percent) have continued to take this drug for a mean of 42 months and have received a mean total dose of 2,021 mg (range: 915 to 3,075). The clinical improvement noted at the first follow-up (11 months) was sustained throughout this follow-up period (42 months). Three patients (14 percent) have had complete clinical remission and nine others (43 percent) have had an excellent response. Methotrexate was discontinued in four patients between the first and second follow-up because of planned pregnancy (one), gastrointestinal toxicity (two), and fear of toxicity (one). Liver toxicity assessed in these 21 patients and four others receiving long-term methotrexate therapy revealed acute hepatitis in one and elevated transaminase levels in 12 (48 percent). Liver biopsy specimens in 17 patients after a mean of 1,950 mg of methotrexate (range: 915 to 3,125) revealed mild fibrosis in six and no cirrhosis. Methotrexate can continue to suppress rheumatoid synovitis over a prolonged period of time with minimal toxicity in most patients. Hepatic fibrosis and cirrhosis due to methotrexate may be less common in rheumatoid arthritis than has been reported in psoriasis.

Low dose methotrexate in rheumatoid arthritis

A systematic analysis of the efficacy of methotrexate (MTX) in severe rheumatoid arthritis (RA) was carried out. Twenty-one patients with severe classical RA resistant to conventional therapy were treated with 7.5 to 25 mg of oral or intramuscular MTX for 3-114 weeks (mean of 38 weeks). Eleven patients (52.4%) showed definite clinical improvement and a fall in sedimentation rate; some improvement was seen in 5 other patients (23.8%). Two patients were unresponsive. Three patients discontinued MTX, 1 because of acute hepatitis and the other 2 because of noncompliance and fear of toxicity. Abnormal liver function tests reversible with modification of therapy occurred frequently. Other side effects were minor. The results of this uncontrolled study indicate that MTX may be an effective drug for the treatment of severe RA. Double blind trials and longterm followup are needed prior to its widespread use in RA.

Sephadex-gel filtration (SGF) in infant and adult Gunn rats

SGF was compared in infant and adult homozygous Gunn rats. Without any drug application, the test was negative in the adult animals, whereas a remarkable percentage of positive SGF was obtained in 5-7-day-old rats, especially in those undernourished and/or intensely icteric. Unexpectedly, in infant rats the rate of positive SGF after sulfadimethoxine injection was lower than in the untreated control group. Moreover, in 9-10-day-old animals who had positive SGF before the injection, the test became negative 15-20 min after sulfadimethoxine application in vivo. No convincing explanation could be given, but drug interference with the binding capacities of the Sephadex column could be excluded by appropriate in vitro tests.

Fenmetozole in acute alcholol intoxication in man

Forty healthy adult male volunteers were studied to determine the efficacy of fenmetozole to antagonize the effects of acute alcholol intoxication. Twenty subjects receive placebo and 20 fenmetozole in dosage of 100 mg and 200 mg in a double-blind paradigm. Pretreatment with fenmetozole failed to antogonize or attenuate cognitive, perceptual, motor and affective changes associated with acute alchol intoxication.