Epidemiology, Patient Characteristics, and Treatment Patterns of Myasthenia Gravis in Taiwan: A Population-Based Study

INTRODUCTION

Myasthenia gravis (MG) is a chronic neuromuscular disease leading to significant disease burden. This study aimed to investigate the epidemiology of MG in Taiwan.

METHODS

A retrospective study was conducted using the Taiwan National Health Insurance Research Database. Prevalent patients with MG diagnosis (either ocular or generalized MG) from 2013 to 2019 were identified, and 2813 patients with initial MG diagnosis from 2014 to 2019 were further defined as the incident cohort. Patient characteristics, treatment patterns, and the occurrence of MG-related events were analyzed.

RESULTS

The number of prevalent patients with MG increased from 4476 in 2013 to 5752 in 2019, with the prevalence rate increasing from 19 to 24 per 100,000 population. The incidence rate also slightly increased from 1.9 to 2.3 per 100,000 population during the study period. Almost all incident patients (99%, n = 2791) received MG-related treatment during the follow-up period. Among 1876 patients who received monotherapy as their initial treatment in the outpatient setting, the mean time from the index date to initial treatment was 48.8 (standard deviation 164.3) days, and most patients received acetylcholinesterase inhibitors (88.5%, n = 1661) as their initial treatment. During the first year after the index date, 133 (4.7%) incident patients experienced their first myasthenic crisis, and 96.2% of these events occurred within 3 months.

CONCLUSION

The prevalence of MG increased steadily in Taiwan, and the treatment of patients with MG was consistent with guidelines. Despite a high treatment rate, patients still experienced MG-related events, highlighting the limitation of current treatments and emphasizing the need for early intervention and novel treatment approaches.

Childhood-Onset Lupus Nephritis in the Childhood Arthritis and Rheumatology Research Alliance Registry: Short-Term Kidney Status and Variation in Care

OBJECTIVE

The goal was to characterize short-term kidney status and describe variation in early care utilization in a multicenter cohort of patients with childhood-onset systemic lupus erythematosus (cSLE) and nephritis.

METHODS

We analyzed previously collected prospective data from North American patients with cSLE with kidney biopsy-proven nephritis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry from March 2017 through December 2019. We determined the proportion of patients with abnormal kidney status at the most recent registry visit and applied generalized linear mixed models to identify associated factors. We also calculated frequency of medication use, both during induction and ever recorded.

RESULTS

We identified 222 patients with kidney biopsy-proven nephritis, with 64% class III/IV nephritis on initial biopsy. At the most recent registry visit at median (interquartile range) of 17 (8-29) months from initial kidney biopsy, 58 of 106 patients (55%) with available data had abnormal kidney status. This finding was associated with male sex (odds ratio [OR] 3.88, 95% confidence interval [95% CI] 1.21-12.46) and age at cSLE diagnosis (OR 1.23, 95% CI 1.01-1.49). Patients with class IV nephritis were more likely than class III to receive cyclophosphamide and rituximab during induction. There was substantial variation in mycophenolate, cyclophosphamide, and rituximab ever use patterns across rheumatology centers.

CONCLUSION

In this cohort with predominately class III/IV nephritis, male sex and older age at cSLE diagnosis were associated with abnormal short-term kidney status. We also observed substantial variation in contemporary medication use for pediatric lupus nephritis between pediatric rheumatology centers. Additional studies are needed to better understand the impact of this variation on long-term kidney outcomes.

Intraarticular steroids as DMARD-sparing agents for juvenile idiopathic arthritis flares: Analysis of the Childhood Arthritis and Rheumatology Research Alliance Registry

BACKGROUND

Children with juvenile idiopathic arthritis (JIA) who achieve a drug free remission often experience a flare of their disease requiring either intraarticular steroids (IAS) or systemic treatment with disease modifying anti-rheumatic drugs (DMARDs). IAS offer an opportunity to recapture disease control and avoid exposure to side effects from systemic immunosuppression. We examined a cohort of patients treated with IAS after drug free remission and report the probability of restarting systemic treatment within 12 months.

METHODS

We analyzed a cohort of patients from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry who received IAS for a flare after a period of drug free remission. Historical factors and clinical characteristics and of the patients including data obtained at the time of treatment were analyzed.

RESULTS

We identified 46 patients who met the inclusion criteria. Of those with follow up data available 49% had restarted systemic treatment 6 months after IAS injection and 70% had restarted systemic treatment at 12 months. The proportion of patients with prior use of a biologic DMARD was the only factor that differed between patients who restarted systemic treatment those who did not, both at 6 months (79% vs 35%, p < 0.01) and 12 months (81% vs 33%, p < 0.05).

CONCLUSION

While IAS are an option for all patients who flare after drug free remission, it may not prevent the need to restart systemic treatment. Prior use of a biologic DMARD may predict lack of success for IAS. Those who previously received methotrexate only, on the other hand, are excellent candidates for IAS.

Social determinants of health influence disease activity and functional disability in Polyarticular Juvenile Idiopathic Arthritis

BACKGROUND

Social determinants of health (SDH) greatly influence outcomes during the first year of treatment in rheumatoid arthritis, a disease similar to polyarticular juvenile idiopathic arthritis (pJIA). We investigated the correlation of community poverty level and other SDH with the persistence of moderate to severe disease activity and functional disability over the first year of treatment in pJIA patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance Registry.

METHODS

In this cohort study, unadjusted and adjusted generalized linear mixed effects models analyzed the effect of community poverty and other SDH on disease activity, using the clinical Juvenile Arthritis Disease Activity Score-10, and disability, using the Child Health Assessment Questionnaire, measured at baseline, 6, and 12 months.

RESULTS

One thousand six hundred eighty-four patients were identified. High community poverty (≥20% living below the federal poverty level) was associated with increased odds of functional disability (OR 1.82, 95% CI 1.28-2.60) but was not statistically significant after adjustment (aOR 1.23, 95% CI 0.81-1.86) and was not associated with increased disease activity. Non-white race/ethnicity was associated with higher disease activity (aOR 2.48, 95% CI: 1.41-4.36). Lower self-reported household income was associated with higher disease activity and persistent functional disability. Public insurance (aOR 1.56, 95% CI 1.06-2.29) and low family education (aOR 1.89, 95% CI 1.14-3.12) was associated with persistent functional disability.

CONCLUSION

High community poverty level was associated with persistent functional disability in unadjusted analysis but not with persistent moderate to high disease activity. Race/ethnicity and other SDH were associated with persistent disease activity and functional disability.

Promoting and preserving safe and active mobility in Istanbul during the COVID-19 pandemic

The COVID-19 pandemic severely impacted all facets of daily life, including and especially mobility within urban centres. As part of efforts to control the virus by encouraging citizens to stay at home, local governments imposed public health and social measures (PHSMs) restricting the availability and use of public transit. The result was an immediate, sharp decline in the use of public transit, and later as the pandemic was brought under control in certain geographies, a reluctance to return to using public transportation due to sustained fears of virus transmission. In Istanbul, Turkey, the use of public transportation decreased by over 90%, coupled with a significant rise in the use of private motorised transportation. To counter this trend, the Istanbul Metropolitan Municipality (IMM) joined cities around the world in implementing a two-pronged strategy to support safe and active mobility during the pandemic. IMM first launched a communication campaign to promote adherence to PHSMs, to rebuild trust in the safety of public transportation as restrictions eased, and to educate citizens on transportation alternatives. Billboards, social media and digital screens on public transportation promoted continued mask use, hand-washing and physical distancing and encouraged citizens wary of returning to public transit to consider walking or cycling as a safe and healthy alternative to private car use. IMM simultaneously enhanced their cycling infrastructure, creating new temporary and permanent bike lanes that closed connectivity gaps within the city. This talk will further elaborate on IMM's actions and the results and explore how they and other cities can sustain the focus on safe and active mobility as a longer-term strategy to reduce private car use and improve health outcomes.

COVID-19, Public Transportation, and Public Health Communication

 

Although necessary for controlling the COVID-19 pandemic, public health and social measures (PHSMs) that restricted public transportation in cities diverted people to private motorized vehicle use, a trend that persisted despite evidence that public transit represented a low-risk COVID transmission environment. Mass transit and active modes of transportation in cities are key for preventing noncommunicable diseases (NCDs) and injuries and for reducing traffic-related emissions. Under the Partnership for Healthy Cities, Buenos Aires, Bangkok, Cali, Ho Chi Minh City, Istanbul, and Kyiv implemented communication campaigns to encourage and inform citizens how to safely resume use of public transportation and alternative safe, active transportation. Between July 2020 and March 2021, campaigns reinforced adherence to the 3Ws (wash hands, watch distance, wear a mask), and promoted walking and cycling as commuting alternatives. In total, the cities conducted social media campaigns, displayed posters (605), billboards (50), and videos (15) at bus, train, and bike stations, cycling lanes, and hospitals. Posters at bus stops in Buenos Aires were visible to 286,000 passengers/day, 16% of the city's passengers. Cali's social media campaign reached 1.7 million people. 70 km of new cycle lane added 1,527 cycling trips, preventing an estimated 266,920 tons of CO2 emissions. Bangkok's social media campaign reached 511,660 people and videos on television reached 1.75 million people. Ho Chi Minh City reached 48,000 passengers/day on public transport and totaled 4 million impressions on social media. Istanbul's social media campaign reached 20,000 people, promoted messaging on 50 billboards across the city's cycling network, and 4 Turkish cities replicated the campaign. Kyiv reached 800,000 transit passengers with 2,200 posters in metro stations. Simple and clear messaging is key for crisis communication and is essential to address overlapping public health and mobility priorities.

Key messages

Cities are at the forefront to use communication campaigns to promote PHSMs and transport alternatives when adapting COVID-19 responses to address negative impact on urban transport and mobility. Simple and clear messaging is key for crisis communication and is essential to address overlapping public health and mobility priorities.

A prospective, multicenter, noninterventional study in Taiwan to evaluate the safety and tolerability of lacosamide as adjunctive therapy for epilepsy in clinical practice

RATIONALE

Lacosamide (LCM) was initially approved in Taiwan in March 2014 for use as adjunctive therapy for focal impaired awareness seizures and secondarily generalized seizures (SGS) in patients with epilepsy ≥16 years of age. The efficacy and tolerability of adjunctive LCM for the treatment of patients with focal seizures have been demonstrated in randomized, placebo-controlled trials. However, the trials do not reflect a flexible dose setting. This study (EP0063) was conducted to assess the safety and tolerability of LCM in real-world clinical practice in Taiwan. Effectiveness of LCM was also assessed as an exploratory objective.

METHODS

EP0063 was a multicenter, prospective, noninterventional study with an expected observation period of 12 months ± 60 days. Eligible patients were ≥16 years of age, had focal impaired awareness seizures and/or SGS (in line with approved indication in Taiwan at the time of the study), were taking at least one concomitant antiseizure medication (ASM), and had at least one seizure in the 3 months before baseline. Patients were prescribed LCM by their treating physician in the course of routine clinical practice. The primary safety variable was treatment-emergent adverse events (TEAEs) spontaneously reported to, or observed by, the treating physician. Based on safety data from previous studies of LCM and known side effects of other ASMs, certain TEAEs (including but not limited to cardiac and electrocardiogram, suicidality, and rash related terms) were analyzed separately. Effectiveness variables included Clinical Global Impression of Change (CGIC) and change in 28-day seizure frequency from baseline to 12 months (or final visit), and freedom from focal seizures.

RESULTS

A total of 171 patients were treated with LCM, of whom 139 (81.3%) completed the study. The Kaplan-Meier estimated 12-month retention was 82.9%. Patients had a mean (standard deviation [SD], range) age of 38.5 (14.0, 16-77) years, and 96 (56.1%) were male. Patients were taking a mean (SD, range) of 2.8 (1.1, 1-6) ASMs at baseline. Mean (SD, range) duration of LCM treatment was 288.7 (111.9, 2-414) days, and the mean (SD, range) daily dosage of LCM was 205.0 (82.7, 50.0-505.2) mg/day. Overall, 95 (55.6%) patients reported at least one TEAE, most commonly dizziness (33 [19.3%] patients). Drug-related TEAEs were reported in 74 (43.3%) patients, and drug-related TEAEs leading to discontinuation of LCM were reported in 14 (8.2%) patients. Two (1.2%) patients died during LCM treatment, which were considered not related to LCM. Two (1.2%) patients had suicidality-related TEAEs; these TEAEs were considered either not related to LCM or the relationship was not recorded. Rash-related TEAEs were reported in five (2.9%) patients (considered LCM-related in two patients). Based on the CGIC, at 12 months (or final visit), 109 (63.7%) patients were considered to have improved, 54 (31.6%) had no change, and the remaining eight (4.7%) were minimally worse. At 12 months (or final visit), the median percentage change in focal seizure frequency was -50.0. During the first 6 months of the study, 21 (12.3%) patients were free from focal seizures; 37 (21.6%) patients were free from focal seizures in the last 6 months of the study; and 14 (8.2%) were free from focal seizures for the full 12 months of the study.

CONCLUSIONS

Results of this prospective, noninterventional study suggest that adjunctive LCM was generally safe and well tolerated in this patient group in real-world practice in Taiwan. Effectiveness was also favorable, with more than 60% of patients considered to be improved by their physician at 12 months (or final visit).

0834 Different Neural Circuits Were Associated With Different Parts of Relationships Among Sleep, Pain and Anxiety in Women with Primary Dysmenorrhoea

Introduction

Although the relationships amongst sleep, pain and anxiety have been evidenced, the underlying neurological mechanisms remain elusive. Primary dysmenorrhea is a good model of spontaneous pain with clear painful (menstruation, state) and pain free (e.g., peri-ovulatory phase, trait) conditions. We sought to investigate the state- and trait-related neural signatures that link sleep and anxiety in primary dysmenorrhea.

Methods

Thirty female subjects with primary dysmenorrhea and 30 healthy female controls completed resting-state functional magnetic resonance imaging, the State-Trait Anxiety Inventory and sleep quality assessments during menstruation and peri-ovulatory phases. As we have reported that there was altered default mode network in the primary dysmenorrhea, posterior parietal cortex (PPC) was therefore chosen as the seed to elucidate the functional connectivity that may correlate with sleep and anxiety.

Results

The primary dysmenorrheic subjects exhibited sleep disturbances throughout the menstrual cycle with increased state anxiety. The primary dysmenorrheic subjects demonstrated significantly higher correlations between the sleep quality and the PPC-insula and -putamen functional connectivity during the peri-ovulatory phase. During menstruation, the primary dysmenorrheic subjects demonstrated significantly lower correlations between their state-anxiety scores and the PPC-occipital cortex functional connectivity.

Conclusion

After regressing out the effects of trait anxiety, the correlation between sleep quality and the PPC-putamen functional connectivity was not significant, indicating anxiety-mediated sleep-pain relationship. The PPC-insula functional connectivity, by contrast, was remained significant. Furthermore, state anxiety was associated with the PPC-occipital cortex functional connectivity that was significantly impaired in primary dysmenorrheic subjects. These findings hinted pain and anxiety mediating sleep quality in different neurological circuits.

Support

Taipei City Goverment(10401-62-046 and 10501-62-046)

Ileal interposition surgery targets the hepatic TGF-β pathway, influencing gluconeogenesis and mitochondrial bioenergetics in the UCD-T2DM rat model of diabetes

Ileal interposition (IT) is a surgical procedure that increases the delivery of incompletely digested nutrients and biliary and pancreatic secretions to the distal intestinal mucosa. Here, we investigated the metabolic impact of this intervention in 2-mo-old prediabetic University of California, Davis type 2 diabetes mellitus rats by assessing liver gene expression at 1.5 mo post-IT surgery. Pathway analysis indicated decreased signaling via TGF-β/Smad (a family of proteins named mothers against decapentaplegic homologs), peroxisome proliferator-activated receptor (PPAR), and PI3K-Akt-AMPK-mechanistic target of rapamycin, likely targeting hepatic stellate cells because differentiation and activation of these cells is associated with decreased signaling via PPAR and TGF-β/Smad. IT surgery up-regulated the expression of genes involved in regulation of cholesterol and terpenoid syntheses and down-regulated those involved in glycerophospholipid metabolism [including cardiolipin (CL)], lipogenesis, and gluconeogenesis. Consistent with the down-regulation of the hepatic CL pathway, IT surgery produced a metabolic switch in liver, kidney cortex, and fat depots toward decreased mitochondrial fatty acid β-oxidation, the process required to fuel high energy-demanding pathways (e.g., gluconeogenesis and glyceroneogenesis), whereas opposite effects were observed in skeletal and cardiac muscles. This study demonstrates for the first time the presence of metabolic pathways that complement the effects of IT surgery to maximize its benefits and potentially identify similarly effective, durable, and less invasive therapeutic options for metabolic disease, including inhibitors of TGF-β signaling.-Hung, C., Napoli, E., Ross-Inta, C., Graham, J., Flores-Torres, A. L., Stanhope, K. L., Froment, P., Havel, P. J., Giulivi, C. Ileal interposition surgery targets the hepatic TGF-β pathway, influencing gluconeogenesis and mitochondrial bioenergetics in the UCD-T2DM rat model of diabetes.

Defective mitochondrial disulfide relay system, altered mitochondrial morphology and function in Huntington's disease

A number of studies have been conducted that link mitochondrial dysfunction (MD) to Huntington's disease (HD); however, contradicting results had resulted in a lack of a clear mechanism that links expression of mutant Huntingtin protein and MD. Mouse homozygous (HM) and heterozygous (HT) mutant striatal cells with two or one allele encoding for a mutant huntingtin protein with 111 polyGln repeats showed a significant impairment of the mitochondrial disulfide relay system (MDRS). This system (consisting of two proteins, Gfer and Mia40) is involved in the mitochondrial import of Cys-rich proteins. The Gfer-to-Mia40 ratio was significantly altered in HM cells compared with controls, along with the expression of mitochondrial proteins considered substrates of the MDRS. In progenitors and differentiated neuron-like HM cells, impairment of MDRS were accompanied by deficient oxidative phosphorylation, Complex I, IV and V activities, decreased mtDNA copy number and transcripts, accumulation of mtDNA deletions and changes in mitochondrial morphology, consistent with other MDRS-deficient biological models, thus providing a framework for the energy deficits observed in this HD model. The majority (>90%) of the mitochondrial outcomes exhibited a gene-dose dependency with the expression of mutant Htt. Finally, decreases in the mtDNA copy number, along with the accumulation of mtDNA deletions, provide a mechanism for the progressive neurodegeneration observed in HD patients.

Toxicity of the flame-retardant BDE-49 on brain mitochondria and neuronal progenitor striatal cells enhanced by a PTEN-deficient background

Polybrominated diphenyl ethers (PBDEs) represent an important group of flame retardants extensively used, tonnage of which in the environment has been steadily increasing over the past 25 years. PBDEs or metabolites can induce neurotoxicity and mitochondrial dysfunction (MD) through a variety of mechanisms. Recently, PBDEs with < 5 Br substitutions (i.e., 2,2',4,4'-tetrabromodiphenyl ether [BDE-47] and 2,2',4,5'-tetrabromodiphenyl ether [BDE-49]) have gained interest because of their high bioaccumulation. In particular, congeners such as BDE-49 arise as one of the most biologically active, with concentrations typically lower than those observed for BDE-47 in biological tissues; however, its potential to cause MD at biologically relevant concentrations is unknown. To this end, the effect of BDE-49 was studied in brain mitochondria and neuronal progenitor striatal cells (NPC). BDE-49 uncoupled mitochondria at concentrations < 0.1 nM, whereas at > 1 nM, it inhibited the electron transport at Complex V (mixed type inhibition; IC(50) = 6 nM) and Complex IV (noncompetitive inhibition; IC(50) = 40 nM). These concentrations are easily achieved in plasma concentrations considering that BDE-49 (this study, 400-fold) and other PBDEs accumulate 1-3 orders of magnitude in the cells, particularly in mitochondria and microsomes. Similar effects were observed in NPC and exacerbated with PTEN (negative modulator of the PI3K/Akt pathway) deficiency, background associated with autism-like behavior, schizophrenia, and epilepsy. PBDE-mediated MD per se or enhanced by a background that confers susceptibility to this exposure may have profound implications in the energy balance of brain.

Mitochondrial dysfunction in Pten haplo-insufficient mice with social deficits and repetitive behavior: interplay between Pten and p53

Etiology of aberrant social behavior consistently points to a strong polygenetic component involved in fundamental developmental pathways, with the potential of being enhanced by defects in bioenergetics. To this end, the occurrence of social deficits and mitochondrial outcomes were evaluated in conditional Pten (Phosphatase and tensin homolog) haplo-insufficient mice, in which only one allele was selectively knocked-out in neural tissues. Pten mutations have been linked to Alzheimer's disease and syndromic autism spectrum disorders, among others. By 4–6 weeks of age, Pten insufficiency resulted in the increase of several mitochondrial Complex activities (II–III, IV and V) not accompanied by increases in mitochondrial mass, consistent with an activation of the PI3K/Akt pathway, of which Pten is a negative modulator. At 8–13 weeks of age, Pten haplo-insufficient mice did not show significant behavioral abnormalities or changes in mitochondrial outcomes, but by 20–29 weeks, they displayed aberrant social behavior (social avoidance, failure to recognize familiar mouse, and repetitive self-grooming), macrocephaly, increased oxidative stress, decreased cytochrome c oxidase (CCO) activity (50%) and increased mtDNA deletions in cerebellum and hippocampus. Mitochondrial dysfunction was the result of a downregulation of p53-signaling pathway evaluated by lower protein expression of p21 (65% of controls) and the CCO chaperone SCO2 (47% of controls), two p53-downstream targets. This mechanism was confirmed in Pten-deficient striatal neurons and, HCT 116 cells with different p53 gene dosage. These results suggest a unique pathogenic mechanism of the Pten-p53 axis in mice with aberrant social behavior: loss of Pten (via p53) impairs mitochondrial function elicited by an early defective assembly of CCO and later enhanced by the accumulation of mtDNA deletions. Consistent with our results, (i) SCO2 deficiency and/or CCO activity defects have been reported in patients with learning disabilities including autism and (ii) mutated proteins in ASD have been found associated with p53-signaling pathways.

Physical activity is related to lower levels of pain, fatigue and depression in individuals with spinal-cord injury: a correlational study

STUDY DESIGN

This was a prospective cross-sectional study for people with chronic spinal cord injury (SCI).

OBJECTIVES

To (1) evaluate the intensity level and nature of physical activity in community-dwelling individuals living with SCI, and (2) explore the relation between descriptive individual variables (for example, lesion level), secondary complications and participation in physical activity.

SETTING

Urban community setting.

METHODS

A total of 49 subjects with SCI who used a manual wheelchair for primary mode of mobility (mean years since injury, 11.8; mean age, 43.7 years; 67% paraplegia) completed the physical activity recall assessment for people with SCI (PARA-SCI).

RESULTS

Approximately 50% of reported physical activity among individuals with SCI is due to activities of daily living. The amount of physical activity was not related to lesion level, age, body mass index or waistline size. Greater heavy-intensity activity was related to lower levels of pain and fatigue and higher levels of self-efficacy, whereas higher amounts of mild-intensity activity and total activity were related to less depressive symptoms.

CONCLUSIONS

Activities of daily living are a large component for physical activity among individuals with SCI. It appears that greater physical activity is associated with less secondary complications (pain, fatigue and depression) in individuals with SCI.

Factors related to primary bilateral spontaneous pneumothorax

OBJECTIVES

We studied the risk factors associated with primary bilateral spontaneous pneumothorax.

METHODS

From January 2001 to December 2002, 102 patients with primary spontaneous pneumothorax were reviewed and divided into two groups. Group A patients had primary spontaneous bilateral pneumothorax (PSBP; simultaneous or nonsimultaneous). Group B included patients with a primary spontaneous pneumothorax (PSP). We compared age, smoking habits, body weight, height, body mass index (BMI), and radiological findings between groups.

RESULTS

Twenty-four patients developed PSBP (24 %). The male-to-female ratio was 22 : 2 in group A and 73 : 5 in group B ( P = 0.106). Eleven group A patients (46 %) and 34 group B patients (44 %) were smokers ( P = 0.037). The mean BMI was 18.39 +/- 2.45 kg/m (2) in group A and 19.70 +/- 2.00 kg/m (2) in group B ( P = 0.009). High-resolution computed tomography revealed bilateral lung blebs or bullae in 63 % of group A patients and in 53 % of group B patients ( P = 0.724).

CONCLUSION

PSBP was significantly more frequent in patients with a lower BMI and among smokers. These patients require extended hospitalization and vigilant treatment.

Functional characterization of human NTRK2 mutations identified in patients with severe early-onset obesity

OBJECTIVE

The neurotrophin receptor TrkB has been implicated in the regulation of energy homeostasis in rodents. We have previously identified four rare missense mutations in the gene encoding TrkB, NTRK2, in 198 severely obese children with developmental delay. We have now undertaken a more detailed analysis of the in vitro functional consequences of the mutations identified: I98V, P660L, T821A and Y722C.

DESIGN

Wild-type and mutant TrkB receptor constructs were stably transfected into PC12 cells and the signaling responses to the endogenous ligand, brain-derived neurotrophic factor (BDNF), were examined by Western blotting of cell lysates. In the case of Y722C, PC12 cells stably expressing this mutant were studied for their ability to respond to BDNF by promoting neurite outgrowth and cell survival.

RESULTS

Further functional characterization of the previously reported Y722C TrkB mutation reveals impaired activation of mitogen-activated protein kinase, phospholipase C-gamma and Akt, as well as reduced BDNF-induced neurite outgrowth and cell survival in stably transfected PC12 cell lines. However, the signaling properties of I98V, P660L and T821A were all indistinguishable from wild type.

CONCLUSION

We provide further evidence for the impairment in signaling by Y722C and show that as well as a loss of signaling, this mutation affects the ability of TrkB to promote neurite outgrowth in response to BDNF. Thus, impaired hypothalamic neurogenesis may contribute to the severe hyperphagia and obesity seen in the individual harboring the Y722C variant. The other three rare TrkB variants do not show reduced autophosphorylation or impaired downstream signaling in vitro and, as yet, it is unclear whether these variants contribute to obesity in these patients.

Differential expression of Hox A5 in human colon cancer cell differentiation: a quantitative study using real-time RT-PCR

Fifteen different homeobox genes were identified from normal colon mucosa, untreated COLO 205 and herbimycin A treated COLO 205 cells in a degenerate primer RT-PCR screen. Several of the homeobox genes, including Cdx-1, Cdx-2, Pdx-1 and Hox A5, showed a trend toward differential expression in normal colon mucosa, and undifferentiated COLO 205 cells. Hox A5 was recently shown to suppress growth and induce p53-dependent apoptosis. To determine if Hox A5 was differentially expressed in differentiation of colon epithelial cells, we quantified Hox A5 expression by real-time quantitative RT-PCR. Expression of Hox A5 was 5.3- and 4.8-fold higher in normal colon mucosa compared to COLO 205 and HT-29 cells, respectively, suggesting that Hox A5 expression was higher in differentiated compared to undifferentiated colon epithelial cells. To avoid the complexity of tissue specimens and the influence of individual variation in Hox A5 expression, the effect of differentiation on Hox A5 expression was studied in COLO 205 cells treated with herbimycin A. The quantitative study showed that Hox A5 expression was increased when COLO 205 cells were induced to differentiate. The expression of Hox A5 was about 2-fold higher in the cells treated for 48 h compared to the untreated poorly-differentiated cells. The present study shows that Hox A5 may be involved in intestinal cell differentiation, in addition to its role in apoptosis.

Platelet angiotensin II receptor status during pregnancy in Chinese women at high-risk of developing pregnancy-induced hypertension

OBJECTIVES

The aims of this prospective study were to explore the changes in platelet angiotensin II (A-II) binding in pregnancy amongst Chinese women at high risk of developing pregnancy-induced hypertension (PIH) and the effects of low-dose aspirin and calcium supplementation on A-II binding.

METHODS

Platelet A-II binding was assayed in 15 non-pregnant women and in 63 pregnant women determined to be at risk of PIH on the basis of 2nd-trimester mean arterial pressure (MAP). The pregnant patients were randomized into three groups: control, low-dose aspirin, and calcium supplementation. A-II binding was assayed again during the 3rd trimester in half the women and 8 weeks after delivery.

RESULTS

A-II binding was negatively correlated with MAP measured in the left lateral position (p < 0.05) but not with MAP measured in the supine position. There were no significant differences between A-II binding in non-pregnant and pregnant women. Neither low-dose aspirin nor calcium supplementation caused significant reductions in A-II binding.

CONCLUSION

The measurement of platelet A-II binding is unlikely to provide significant information regarding the risk of PIH over and above that obtained from measurement of 2nd-trimester MAP.

Human T-cell lymphotropic virus (HTLV)-related endogenous sequence, HRES-1, encodes a 28-kDa protein: a possible autoantigen for HTLV-I gag-reactive autoantibodies

The presence of a human T-cell lymphotropic virus (HTLV)-related endogenous sequence, HRES-1, in the human genome has been documented. The HRES-1 genomic locus is transcriptionally active and contains open reading frames. Antibodies 232 and 233, specific for synthetic peptides pep14-24 and pep117-127, corresponding to two nonoverlapping HTLV-related regions in the longer open reading frame of HRES-1, recognize an identical 28-kDa protein in H9 human T cells. Thus, HRES-1 is a human endogenous retroviral sequence capable of protein expression. HRES-1/p28 is localized to the cytoplasm and nuclear bodies. While HTLV-I-specific antibodies react with HRES-1 peptides, antibody 233 cross-reacts with HTLV-I gag p24 protein. Three consecutive highly charged amino acid residues, Arg-Arg-Glu, present in both HRES-1 pep117-127 and HTLV-I gag p24 are likely to be the core of cross-reactive epitopes. The prevalence of antibodies to HRES-1 peptides pep14-24 and pep117-127 was determined in 65 normal blood donors and 146 patients with immunological disorders. Sera of patients with multiple sclerosis (19 out of 65, 29%), progressive systemic sclerosis (4 out of 17, 23%), systemic lupus erythematosus (4 out of 19, 21%), and Sjogren syndrome (2 out of 19, 10%) contained significantly higher HRES-1 peptide binding activity than sera of normal donors. Sera of patients with AIDS showed no specific binding to HRES-1 peptides. Nine of 30 HRES-1-seropositive patients showed immunoreactivity to HTLV-I gag p24. The data indicate that HRES-1/p28 may serve as an autoantigen eliciting autoantibodies cross-reactive with HTLV-I gag antigens.

The morphogenesis of hindbrain crowding associated with lumbosacral myeloschisis

The teratogenicity of ethylenethiourea (ETU) was investigated in Sprague-Dawley rats and Landrace pigs. Pregnant rats each received a single intragastric dose of ETU on a given day from day 8 to day 19 of gestation, and pregnant pigs were given a single dose of ETU from day 15 to day 19. Control animals received an ETU-free vehicle. The newborn pigs were all normal, whereas there were high incidences of specific types of congenital malformation of the central nervous and other systems in the rats. A high incidence of lumbosacral myeloschisis associated with hindbrain crowding was observed in rat fetuses exposed to ETU on day 11 of gestation. This abnormality is considered comparable to Chiari type II malformation associated with spinal dysraphism (Arnold-Chiari malformation) in humans. Morphogenetic fetuses were examined by light and scanning electron microscopy and interactive image analysis. At gestational days 12 and 13, the volume of the caudal end of the neural tube from the anterior border of the hindlimb bud to the most caudal portion of the fetus was significantly greater in ETU-exposed than in control rat embryos. Experimental rat embryos also exhibited disturbance in closure of the posterior neuropore, with extrusion of neural tissue through the opening. An apparently unrelated abnormality in ETU-exposed rat fetuses was underdevelopment of the cranium, leading to hindbrain crowding.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibody reactivity with HBLV (HHV-6) in U.S. populations

500 sera representing healthy blood donors and a random representation of the U.S. population collected 10 years ago were screened by ELISA for antibody reactivity with purified, disrupted HBLV virions. In each group, the ELISA results were normally distributed with no evidence of bimodality. All sera were subsequently retested after preincubation of each with well-characterized preparations of disrupted HSB-2 cells or HBLV-infected HSB-2 cells. Sera showing significant levels of HBLV-specific neutralization (50% or more) were found in Minneapolis, Kansas City, and in a random population survey (81, 88 and 97% of donors, respectively). Mean ELISA test values were the same for all groups and for males and females within the same group. Sera from these normal donors reacted preferentially with viral antigens of 120 and 58 kDa by Western blot. In a hospital-based prevalence study, frequent IgM and IgG seroconversions were apparent among infants less than 1 year old, and mean ELISA test values reached the adult level before school age. Antigen preparations used in blocking experiments showed no competitive cross-reactivity with antisera against EBV, CMV, HSV, VZV, HIV, or adenovirus type 2 at levels which reduced antibody binding to HBLV by more than 90%. Antibody cross-reactivities towards HBLV and other human herpesviruses were assessed by cross-correlation of viral antibody titers against all of the viruses and by cross-absorptions of antisera against the other viruses with HBLV. In these experiments no antibody cross-reactivity between HBLV and other human herpesviruses were detected. The significance of these findings with respect to health/disease status is presently unknown. Further seroepidemiologic studies of quantitative levels of HBLV antibody reactivity to measure the age of primary infection and progressive changes in healthy and selected disease populations are needed to determine the risk of disease associated with HBLV infection.