Divergent effects of ovarian steroids on neuronal survival during experimental allergic encephalitis in Lewis rats

Experimental allergic encephalitis, (EAE) a Th1-cell-dependent autoimmune disease of the central nervous system (CNS) used to study immune responses relevant to multiple sclerosis (MS) displays gender susceptibility. The underlying basis of the sexual dimorphism may reflect multiple factors including gender-specific hormones. To study the relationship between ovarian hormones and CNS inflammation, we induced EAE in susceptible female Lewis rats ovariectomized (OVX) 7 days earlier and implanted with blank capsules or capsules containing estradiol (E), progesterone (P), or both (EP). Rats were immunized with complete Freunds' adjuvant alone or combined with guinea pig myelin basic protein. Motor function was scored 0-5 on standard criteria (days 7-11 postimmunization). On day 11, the rats were euthanized and the lumbar spinal cord was analyzed for Nissl, neuron nuclear antigen, and DNA fragmentation with a TUNEL assay. Inflammation was judged qualitatively on a scale of 0-4. Our immunization protocol induced limited sensorimotor deficits in OVX rats (2.3 +/- 0.6, mean +/- SEM) with moderate inflammation (2.5 +/- 0.4). E limited both behavioral impairments (1.0 +/- 0.4) and inflammation (0.5 +/- 0.2). P-treated rats had more severe sensorimotor deficits (3.1 +/- 0.5) with increased inflammatory infiltrates (3.6 +/- 0.4) and markedly increased numbers of TUNEL(+) neurons. Neuron counts of the outer two Rexed lamina (L3-L5) showed a 20% neuron loss (P < 0.02) in P-treated rats with EAE in comparison to other groups. Coadministration of E with P prevented the consequences of P, including neuronal apoptosis (behavioral score, 0.6 +/- 0.6; inflammation, 1.4 +/- 0.5). Our results suggest a potential and novel function of P that increases the vulnerability of neurons to apoptotic injury in EAE and may have pathophysiologic implications in the progression of disability in women with MS.     

Health related quality of life in 10-year-old schoolchildren

Objective  The purpose of this study was to investigate the health related quality of life (HRQL) in a total cohort of general school children. Methods  The study population consisted of the children starting 4th grade (age 9–10) in Finnish primary schools in autumn 2004 (n = 1,346) and their parents in a city of 175,000 inhabitants. Pediatric Quality of Life Inventory™ 4.0 (PedsQL™ 4.0) was used for assessment of HRQL. The response rate was 81% for the children (n = 1,091). Most children had parents who participated (n = 999). Results  The children reported highest HRQL mean values in physical (85.00, SD 10.95) and social (84.71, SD 14.28), and lowest in school (78.89, SD 14.53) and emotional (75.43, SD 15.67), functioning scales. Girls reported significantly lower emotional (t = −2.43, P = 0.02) functioning than boys. Child self reports show lower social (t = −2.57, P = 0.01) and school (t = −3.44, P = 0.0006) functioning, and higher emotional (t = 5.82, P < 0.0001) and physical (t = 4.79, P < 0.0001) functioning than their parent-proxy assessments. Conclusions  Interventions aiming at supporting the emotional and school functioning of the school children are recommended. Parents may overestimate the social and school functioning and underestimate the physical and emotional functioning compared to their children’s own perceptions.     

Teaching subjects with type 2 diabetes how to incorporate sugar choices into their daily meal plan promotes dietary compliance and does not deteriorate metabolic profile

OBJECTIVE: To determine whether teaching free-living subjects with type 2 diabetes how to incorporate added sugars or sweets into their daily meal plan results in a greater consumption of calories (fat or sugar) and deteriorates their glycemic or lipid profiles but improves their perceived quality of life. RESEARCH DESIGN AND METHODS: In an 8-month randomized controlled trial, 48 free-living subjects with type 2 diabetes were taught either a conventional (C) meal plan (no concentrated sweets) or one permitting as much as 10% of total energy as added sugars or sweets (S). Mean individual nutrient intake was determined using the average of six 24-h telephone recalls per 4 months. Metabolic control and quality of life were evaluated every 2 months. Quality of life was assessed using the Medical Outcome Survey and the Diabetes Quality of Life questionnaire. RESULTS: The S group did not consume more calories (fat or sugar) and in fact ate significantly less carbohydrate (-15 vs. 10 g) and less starch (-7 vs. 8 g) and had a tendency to eat fewer calories (-77 vs. 81 kcal) than the C group. Weight remained stable, and there was no evidence that consuming more sugar worsened metabolic profile or improved their perceived quality of life. CONCLUSIONS: Giving individuals with type 2 diabetes the freedom to include sugar in their daily meal plan had no negative impact on dietary habits or metabolic control. Health professionals can be reassured and encouraged to teach the new "sugar guidelines," because doing so may result in a more conscientious carbohydrate consumption.     

High intra/interindividual variance ratios for energy and nutrient intakes of pregnant women in rural Malawi show that many days are required to estimate usual intake

Conventional wisdom suggests that because there is less variety in food intake, fewer days may be needed to capture "usual intake" of individuals in developing countries, but it is also known that intakes may vary considerably across seasons. Because few studies have examined the sources of variation in nutrient intake in subsistence communities, where food availability also may limit day-to-day food choices, our objective was to examine intraindividual and interindividual variability in energy and nutrient intakes in pregnant subsistence farmers in Africa. From 1988 through 1991, we collected a total of 1061 diet days (mean = 6; range; 2-12 d/woman), using the direct food weighing method, from 184 pregnant women in a farming community west of Lilongwe City, Malawi. Two or four consecutive days were collected for each of several visits during the 2nd and 3rd trimesters. Variance ratios were calculated as the error variance/variance across individuals. We found major seasonal differences in energy and nutrient intakes with greater intakes in the harvest than in the preharvest seasons. Adjustment for season and stage of pregnancy did not reduce variance ratios. To estimate true individual intakes within an error range of +/- 20% required 8-23 d for energy, protein, carbohydrates and fiber; and 95-213 d for micronutrients. Thus, despite limited dietary diversity, large within-person variation in nutrient intake demonstrated that more, rather than fewer days of dietary intake were required to correctly identify usual intake in subsistence farmers compared with previous reports for urbanized or Western populations.     

A GPR18-based signalling system regulates IOP in murine eye

Background and Purpose

GPR18 is a recently deorphaned lipid receptor that is activated by the endogenous lipid N-arachidonoyl glycine (NAGly) as well the behaviourally inactive atypical cannabinoid, abnormal cannabidiol (Abn-CBD). The presence and/or function of any GPR18-based ocular signalling system remain essentially unstudied. The objectives of this research are: (i) to determine the disposition of GPR18 receptors and ligands in anterior murine eye, (ii) examine the effect of GPR18 activation on intraocular pressure (IOP) in a murine model, including knockout mice for CB₁, CB₂ and GPR55.

Experimental Approach

IOP was measured in mice following topical application of Abn-CBD, NAGly or the GPR55/GPR18 agonist O-1602, alone or with injection of the GPR18 antagonist, O-1918. GPR18 protein localization was assessed with immunohistochemistry. Endocannabinoids were measured using LC/MS-MS.

Key Results

GPR18 protein was expressed most prominently in the ciliary epithelium and the corneal epithelium and, interestingly, in the trabecular meshwork. The GPR18 ligand, NAGly, was also detected in mouse eye at a level comparable to that seen in the brain. Abn-CBD and NAGly, but not O-1602, significantly reduced IOP in all mice tested. The antagonist, O-1918, blocked the effects of Abn-CBD and NAGly.

Conclusions and Implications

We present evidence for a functional GPR18-based signalling system in the murine anterior eye, including receptors and ligands. GPR18 agonists, Abn-CBD and NAGly, reduce IOP independently of CB₁, CB₂ or GPR55. These findings suggest that GPR18 may serve as a desirable target for the development of novel ocular hypotensive medications.

Linked Articles

This article is part of a themed section on Cannabinoids. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2013.169.issue-4 & http://dx.doi.org/10.1111/bph.2012.167.issue-8     

A validated, stability-indicating HPLC method for the determination of dexamethasone related substances on dexamethasone-coated drug-eluting stents

An HPLC method was developed and validated to determine trace amounts of dexamethasone related substances on dexamethasone-coated drug-eluting stents. Separation of dexamethasone from its major process impurities and degradation products was achieved on a Zorbax Eclipse XDB C8 column using gradient elution and UV detection at 239 nm. The method was validated according to ICH guideline requirements. In addition, stent extraction efficiency, solution stability and method robustness were evaluated. The method was determined to be linear in the range of 0.01-0.30 microg ml(-1) for the quantitation of major dexamethasone related substances. Method accuracy was assessed by spiking dexamethasone acetate at three levels over the range of 0.025-0.175 microg ml(-1). The dexamethasone acetate recovery ranged from 89.6 to 105.8%. The intermediate precision over the three levels was less than 6% (n=9). The method was also shown to be repeatable at concentration levels of 0.025, 0.125 and 0.175 microg ml(-1) dexamethasone with relative standard deviation values of 4.1, 1.7 and 1.6%, respectively. The method was found to be specific, stability-indicating, and sensitive with a detection limit of 0.008 microg ml(-1) and a quantitation limit of 0.025 microg ml(-1) dexamethasone. Finally, the method was demonstrated to be robust, resistant to small variations of chromatographic variables such as pH, mobile phase organic/aqueous composition and column temperature. Identifying unknown dexamethasone degradation products in dexamethasone-coated drug-eluting stents was of critical interest to ensure product quality, since degradants have a significant impact on safety, efficacy, and product storage and handling. The developed chromatographic method was designed to be compatible with mass spectrometric detection. This paper also discusses using this chromatographic method coupled to an ion-trap LCQ mass spectrometer to elucidate proposed structures for four major dexamethasone degradants.     

Reliability of intracortical and corticomotor excitability estimates obtained from the upper extremities in chronic stroke

We estimated the trial-to-trial variability and the test-retest reliability of several intracortical and corticomotor excitability parameters for the upper extremity in chronic stroke patients. Nine patients with hemiparesis of the upper extremity were enrolled 8-17 months after a unilateral stroke. Transcranial magnetic stimulation was used to obtain repeated measures over a two week interval of motor evoked potential (MEP) recruitment curves and cortical silent periods in the first dorsal interosseus muscle of each hand. Five trials would have provided accurate estimates of the MEP amplitude and silent period duration for the unlesioned side in all patients, but 25% of the datasets from the lesioned side provided poor estimates of MEP amplitude even with 10 trials. Intraclass correlations were >0.70 for all parameters obtained from the lesioned side and for the MEP amplitude, slope of the recruitment curve, silent period, and silent period slope from the unlesioned side. MEP amplitude varied across sessions within subject by 20% on both sides, whereas other parameters showed less variability on the unlesioned side relative to the lesioned side. The Fugl-Meyer upper extremity motor score and the time to complete the 6 fine-motor items from the Wolf Motor Function Test (WMFT) were also found to be highly reliable over this interval. We conclude that the functional and most of the excitability parameters are reliable across time in patients with variable lesions due to stroke. Due to high intrasubject variability, the use of some excitability parameters as indicators of functional neuroplasticity in response to treatment may be limited to interventions with large effect sizes.