Dietary omega-3 fatty acids may be associated with increased neuropathic pain in nerve-injured rats

Certain dietary proteins and oils are capable of decreasing chronic neuropathic pain levels in rats after partial sciatic nerve ligation injury. We tested, for the first time, the role of dietary polyunsaturated fatty acids in suppressing pain in partial sciatic nerve ligation-injured rats. Six groups of male Wistar rats were fed an identical casein-based, fat-free diet for 1 wk preceding partial sciatic nerve ligation injury and for 1 wk thereafter. In addition, rats received, via gavage, 1 mL/day of pure canola, corn, hemp, soy, or sunflower oil, differing significantly in their omega-3 and omega-6 polyunsaturated fatty acid content, or 1 mL of plain water. Responses to tactile and noxious heat stimuli were recorded before and after surgery and a difference score was calculated for each group by subtracting the preoperative from the post-partial sciatic nerve ligation values. Heat hyperalgesia, but not tactile allodynia, was significantly different among the dietary groups (P = 0.005). Heat hyperalgesia of rats fed hemp oil, developing the most robust response, was significantly larger compared with rats fed corn oil, developing the least pain model (difference score: 24.3 +/- 4.1 s versus 6.1 +/- 3.1 s, respectively; P < 0.001). These oils contain similar levels of omega-6 polyunsaturated fatty acids (hemp, 60%; corn, 58%) but their omega-3 levels are 28-fold different (20% versus 0.7%, respectively). A significant correlation was found among dietary levels of omega-3, but not omega-6 or the omega-3/omega-6 ratio, of the six dietary groups and heat hyperalgesia (P = 0.006). We conclude that dietary oil might predict levels of neuropathic pain in rats and that this effect may be associated with dietary omega-3 levels. IMPLICATIONS: We found that certain commonly used oils can have a significant analgesic effect in rats with persistent pain after partial nerve injury. This effect may be associated with the amounts of omega-3 fatty acids consumed by rats.     

The Preterm Prediction Study: association between maternal body mass index and spontaneous and indicated preterm birth

OBJECTIVE: The purpose of this study was to evaluate the relationship between prepregnancy maternal body mass index and spontaneous preterm birth and indicated preterm birth. STUDY DESIGN: This was a secondary analysis of the Maternal-Fetal Medicine Units Network, Preterm Prediction study. Patients were classified into categories that were based on their body mass index. Rates of indicated and spontaneous preterm birth were compared. RESULTS: Five hundred ninety-seven (20.5%) of 2910 women were obese. Obese women had fewer spontaneous preterm births at < 37 weeks of gestation (6.2% vs 11.2%; P < .001) and at < 34 weeks of gestation (1.5% vs 3.5%; P = .012). Women with a body mass index of < 19 kg/m2 had 16.6% spontaneous preterm birth, with a body mass index of 19 to 24.9 kg/m 2 had 11.3% spontaneous preterm birth, with a body mass index of 25 to 29.9 kg/m2 had 8.1% spontaneous preterm birth, with a body mass index of 30 to 34.9 kg/m2 had 7.1% spontaneous preterm birth, and with a body mass index of > or = 35 kg/m2 had 5.2% spontaneous preterm birth (P < .0001). Indicated delivery was responsible for an increasing proportion of preterm births with increasing body mass index (P = .001). Obese women had lower rates of cervical length < 25 mm (5% vs 8%; P = .012). Multivariable regression analysis confirmed a lower rate of spontaneous preterm birth in obese gravid women (odds ratio, 0.57; 95% CI, 0.39-0.83; P = .003). CONCLUSION: Obesity before pregnancy is associated with a lower rate of spontaneous preterm birth.     

CINRG randomized controlled trial of creatine and glutamine in Duchenne muscular dystrophy

We tested the efficacy and safety of glutamine (0.6 gm/kg/day) and creatine (5 gm/day) in 50 ambulant boys with Duchenne muscular dystrophy in a 6-month, double-blind, placebo-controlled clinical trial. Drug efficacy was tested by measuring muscle strength manually (34 muscle groups) and quantitatively (10 muscle groups). Timed functional tests, functional parameters, and pulmonary function tests were secondary outcome measures. Although there was no statistically significant effect of either therapy based on manual and quantitative measurements of muscle strength, a disease-modifying effect of creatine in older Duchenne muscular dystrophy and creatine and glutamine in younger Duchenne muscular dystrophy cannot be excluded. Creatine and glutamine were well tolerated.     

Development of sensitivity to texture and contour information in the human infant

Texture discrimination and bounding contour extraction are essential parts of the object segmentation and shape discrimination process. As such, successful texture and contour processing are key components underlying the development of the perception of both objects and surfaces. By recording visual-evoked potentials, we investigate whether young infants can detect orientation-defined textures and contours. We measured responses to an organized texture comprised of many Gabor patches of the same orientation, alternated with images containing the same number of patches, but all of random orientation. These responses were compared with a control condition consisting of the alternation between two independently random configurations. Significant difference potentials were found as early as 2-5 months, as were significant odd harmonics in the test conditions. Responses were also measured to Gabor patches organized either as circles (all patches tangent to an imaginary circular path) alternated with pinwheels (all patches having a fixed orientation offset from the path). Infants between 6 and 13 months also showed sensitivity to the global organization of the elements along contours. Differential responses to our texture and contour stimuli and their controls could only have been generated by mechanisms that are capable of comparing the relative orientation of 2 or more patches, as no local information at a single patch distinguished the random and organized textures or the circle and pinwheel configurations.     

The diagnostic accuracy of serologic markers in children with IBD: the West Virginia experience

GOAL: To assess the sensitivity/specificity of the serologic markers: perinuclear antineutrophil cytoplasmic antibody (pANCA) and anti-saccharomyces cerevisiae antibody (ASCA) in children diagnosed with inflammatory bowel disease (IBD), living in West Virginia. BACKGROUND: In recent years, serologic markers have been used to differentiate between CD and UC diseases in children. The clinical usefulness of these markers in children was restricted by their low sensitivity and specificity. Racial and ethnic diversity may alter the accuracy of these markers in children. The demographic homogeneity of the West Virginia population may offer a better clinical setup to reassess the utility of those markers in children with IBD. STUDY: A retrospective analysis of all the charts of children diagnosed with IBD was performed at the gastroenterology clinics of Marshall University, Huntington, WV; and West Virginia University, Charleston Division, Charleston, WV. The diagnosis of IBD was established according to clinical, radiologic, and endoscopic data. Laboratory data and serum markers were recorded, and their accuracy to diagnose UC or CD was assessed. RESULTS: A total of 101 charts were reviewed, of which only 90 (89%) included serologic markers and were considered for further analysis. Disease distribution included: UC-41, CD-44, and indeterminate colitis (IC)-7 (2 patients changed diagnosis after colectomy). Serum antibody pANCA had a sensitivity of 73% and specificity of 84% for UC, but only 16% and 35% for CD, respectively. Serum antibody ASCA had a sensitivity of 58% and specificity of 92% for CD, but only 7% and 49% for UC, respectively. The outer membrane porin to Escherichia coli antibody (anti-OmpC) was available in 54 (59%) children and demonstrated a very poor sensitivity for both diseases (sensitivity<11%). CONCLUSION: Despite our homogeneous patient population, pANCA and ASCA antibodies had an inadequate sensitivity/specificity for children with UC or CD. Those antibodies were not useful for our small number of patients with IC.     

Enhanced excitability compensates for high-pressure-induced depression of cortical inputs to the hippocampus

High pressure (>1.0 MPa) induces the high-pressure neurological syndrome (HPNS) characterized by increased excitability of the CNS and cognitive impairments involving memory disorders. The perforant-path transfer of cortical information to the hippocampal formation is important for memory acquisition. High pressure may alter information transfer in this connection. We used rat corticohippocampal slices for studying the effect of pressure on the transfer function between synaptic inputs from the medial perforant path (MPP) and spike generation by granule cells (GC) of the dentate gyrus. High pressure (10.1 MPa) reduced single MPP field excitatory postsynaptic potential (fEPSP) amplitude and slope by nearly 50%. Field antidromic action potentials (AAPs) elicited by stimulation of GC axons, and population spike (PS) generation by the pressure-depressed MPP fEPSP were not significantly altered at hyperbaric conditions. Nevertheless the relationship PS/fEPSP increased at high pressure, indicating dendritic hyperexcitability in the GC. PSs elicited by paired-pulse MPP fEPSPs at 10- to 200-ms interstimulus intervals and PS generated by trains of five fEPSPs at 25 Hz were also not affected in spite of severe pressure-induced synaptic depression. Similarly, trains of AAPs at 25-50 Hz were not significantly changed. Trains of fEPSPs at higher frequency (50 Hz), however, induced additional spikes at high pressure, indicating pressure disruption of the regular low-pass filter properties of the DG. Such effect was closely mimicked by partial blockade of GABAA inhibition. High pressure depresses synaptic activity while increases excitability in the neuronal dendrites but not in the axons. This mechanism, allowing neuronal communication at low input signals, may partially cope with pressure effects at the low frequency range (<25 Hz) but losses reliability at higher frequencies (>50 Hz).     

Stool antigen test for diagnosis of Helicobacter pylori infection in children with symptomatic disease: a prospective study

OBJECTIVE: Noninvasive tests for the diagnosis of Helicobacter pylori (Hp) infection in children are limited by low accuracy rates and lack of validation. Existing studies indicate that the stool antigen test (HpSA) has an acceptable level of accuracy for the diagnosis of Hp infection in adults but not children. The aim of this study was to evaluate the accuracy of the HpSA test for the detection of Hp infection in U.S. children. METHODS: Children requiring upper endoscopic procedures were prospectively recruited from two pediatric gastroenterology clinics. Stool samples were collected from each participant before endoscopy. The presence of Hp infection was determined by positive histologic findings and positive rapid urease test (RUT). The presence of Hp organisms in stool was determined by an enzyme-linked immunosorbent assay using a commercially available polyclonal antibody kit (Meridian Diagnostics, Cincinnati, OH, U.S.A.). Results of the stool antigen test were compared with histology findings and RUT results. RESULTS: One hundred twenty-one children (mean age, 10.1 +/- 3.7 years) participated, of whom 9 (7.4%) had Hp infection. Histologic findings and RUT results were concordant in 95% of the children. Per study protocol, HpSA had a sensitivity, specificity, positive and negative predictive value, and accuracy rate of 67%, 99%, 86%, 97%, and 96.5%, respectively. CONCLUSION: HpSA, a polyclonal antibody test, had a low sensitivity for infection in children in the United States and at present cannot replace histologic findings as the gold standard for the diagnosis of Hp infection in the pediatric population.