Role of NKCC1 and KCC2 during hypoxia-induced neuronal swelling in the neonatal neocortex.

Neonatal hypoxia causes cytotoxic neuronal swelling by the entry of ions and water. Multiple water pathways have been implicated in neurons because these cells lack water channels, and their membrane has a low water permeability. NKCC1 and KCC2 are cation-chloride cotransporters (CCCs) involved in water movement in various cell types. However, the role of CCCs in water movement in neonatal neurons during hypoxia is unknown. We studied the effects of modulating CCCs pharmacologically on neuronal swelling in the neocortex (layer IV/V) of neonatal mice (post-natal day 8-13) during prolonged and brief hypoxia. We used acute brain slices from Clomeleon mice which express a ratiometric fluorophore sensitive to Cl- and exposed them to oxygen-glucose deprivation (OGD) while imaging neuronal size and [Cl-]i by multiphoton microscopy. Neurons were identified using a convolutional neural network algorithm, and changes in the somatic area and [Cl-]i were evaluated using a linear mixed model for repeated measures. We found that (1) neuronal swelling and Cl- accumulation began after OGD, worsened during 20 min of OGD, or returned to baseline during reoxygenation if the exposure to OGD was brief (10 min). (2) Neuronal swelling did not occur when the extracellular Cl- concentration was low. (3) Enhancing KCC2 activity did not alter OGD-induced neuronal swelling but prevented Cl- accumulation; (4) blocking KCC2 led to an increase in Cl- accumulation during prolonged OGD and aggravated neuronal swelling during reoxygenation; (5) blocking NKCC1 reduced neuronal swelling during early but not prolonged OGD and aggravated Cl- accumulation during prolonged OGD; and (6) treatment with the "broad" CCC blocker furosemide reduced both swelling and Cl- accumulation during prolonged and brief OGD, whereas simultaneous NKCC1 and KCC2 inhibition using specific pharmacological blockers aggravated neuronal swelling during prolonged OGD. We conclude that CCCs, and other non-CCCs, contribute to water movement in neocortical neurons during OGD in the neonatal period.

The Influence of Opioids on Transcutaneous Electrical Nerve Stimulation Effects in Women With Fibromyalgia.

Transcutaneous electrical nerve stimulation (TENS) uses endogenous opioids to produce analgesia, and effectiveness can be reduced in opioid-tolerant individuals'. We examined TENS effectiveness (primary aim), and differences in fibromyalgia symptoms (secondary aim), in women with fibromyalgia regularly taking opioid (RTO) medications compared with women not- regularly taking opioids (not-RTO). Women (RTO n = 79; not-RTO not-n = 222) with fibromyalgia with daily pain levels ≥4 were enrolled and categorized into RTO (taking opioids at least 5 of 7 days in last 30 days) or not-RTO groups. Participants were categorized into tramadol n = 52 (65.8%) and other opioids n = 27 (34.2%) for the RTO group. Participants were phenotyped across multiple domains including demographics, fibromyalgia characteristics pain, fatigue, sleep, psychosocial factors, and activity. Participants were randomized to active TENS (n = 101), placebo TENS (n = 99), or no TENS (n = 99) for 1-month with randomization stratified by opioid use. Active TENS was equally effective in movement-evoked pain in those in the RTO and not-RTO groups. Women with fibromyalgia in the RTO group were older (P = .002), lower-income (P = .035), more likely to smoke (P = .014), and more likely to report depression (P = .013), hypertension (P = .005) or osteoarthritis (P = .027). The RTO group demonstrated greater bodily pain on SF-36 (P = .005), lower quality of life on the physical health component of the SF-36 (P = .040), and greater fatigue (MAF-ADL P = .047; fatigue with sit to stand test (P = .047) These differences were small of and unclear clinical significance. In summary, regular use of opioid analgesics does not interfere with the effectiveness of TENS for movement-evoked pain. Clinical Trial Registration Number: NCT01888640. PERSPECTIVE: Individuals treated with mixed frequency TENS at a strong but comfortable intensity that was taking prescription opioid analgesics showed a significant reduction in movement-evoked pain and fatigue. These data support the use of TENS, using appropriate parameters of stimulation, as an intervention for individuals with fibromyalgia taking opioid analgesics.

The outcomes and experience of pregnancy in limb girdle muscular dystrophy type R9.

INTRODUCTION: Published information about the experiences of pregnancy in limb girdle muscular dystrophy (LGMD) is limited and does not specify LGMD type, limiting utility. We describe the experience and outcomes of pregnancy in a cohort of women with LGMD type R9 (LGMDR. METHODS: All women 18 y of age or older with a genetic and clinical diagnosis of LGMDR9 who are enrolled in the University of Iowa Wellstone dystroglycanopathy natural history study (clinicaltrials.gov NCT00313677) were invited to complete a questionnaire about their pregnancy experiences, including questions about pregnancy complications, muscle symptoms experienced during pregnancy, and post-partum course. RESULTS: A total of 22 women responded to the survey. Thirteen women reported 26 live births. The majority of pregnancies that resulted in a live birth were uncomplicated (n = 19, 73%), and most infants had no complications (n = 25, 96%). The rates of assisted vaginal delivery (n = 9, 35%) and induction of labor (n = 18, 70%) were both significantly higher than the national average. Almost half of pregnancies (n = 11, 42%) resulted in increased weakness during pregnancy; only one returned to pre-pregnancy baseline. DISCUSSION: The data presented here suggest that women with LGMDR9 who are considering a pregnancy should be counseled that they might have a higher likelihood of assisted vaginal delivery and could experience progression of weakness. These results are generally consistent with previous reports, but future studies of pregnancy in defined subtypes of LGMD will be required to confirm these findings and determine if risks vary by genotype.

Factors Associated With Frequent Opioid Use in Children With Acute Recurrent and Chronic Pancreatitis.

OBJECTIVES: The aim of the study was to understand the association of frequent opioid use with disease phenotype and pain pattern and burden in children and adolescents with acute recurrent (ARP) or chronic pancreatitis (CP). METHODS: Cross-sectional study of children <19 years with ARP or CP, at enrollment into the INSPPIRE cohort. We categorized patients as opioid "frequent use" (daily/weekly) or "nonfrequent use" (monthly or less, or no opioids), based on patient and parent self-report. RESULTS: Of 427 children with ARP or CP, 17% reported frequent opioid use. More children with CP (65%) reported frequent opioid use than with ARP (41%, P = 0.0002). In multivariate analysis, frequent opioid use was associated with older age at diagnosis (odds ratio [OR] 1.67 per 5 years, 95% confidence interval [CI] 1.13-2.47, P = 0.01), exocrine insufficiency (OR 2.44, 95% CI 1.13-5.24, P = 0.02), constant/severe pain (OR 4.14, 95% CI 2.06-8.34, P < 0.0001), and higher average pain impact score across all 6 functional domains (OR 1.62 per 1-point increase, 95% CI 1.28-2.06, P < 0.0001). Children with frequent opioid use also reported more missed school days, hospitalizations, and emergency room visits in the past year than children with no frequent use (P < 0.0002 for each). Participants in the US West and Midwest accounted for 83% of frequent opioid users but only 56% of the total cohort. CONCLUSIONS: In children with CP or ARP, frequent opioid use is associated with constant pain, more healthcare use, and higher levels of pain interference with functioning. Longitudinal and prospective research is needed to identify risk factors for frequent opioid use and to evaluate nonopioid interventions for reducing pain and disability in these children.

The use of immunohistochemistry in detection of perineural invasion in mucoepidermoid carcinoma.

OBJECTIVES: To retrospectively study the prevalence of perineural invasion (PNI) in cases of mucoepidermoid carcinoma (MEC). The study evaluated if previously assessed PNI would be increased by re-review of the original hematoxylin and eosin-stained (H&E) slides and also review of slides reacted immunohistochemically with S100 to enhance nerve visualization and whether this is associated with clinical outcome. STUDY DESIGN: Thirty-one cases were reviewed for PNI with H&E-stained slides as well as S-100-reacted slides. These results were compared with the original pathology report's PNI status when available (13 of 31). Subject demographic characteristics and clinical outcome were collected from electronic medical records. RESULTS: PNI was identified in 23% (3 of 13) of tumors in the original reports, 13% (4 of 31) of the authors' re-review of the slides, and 29% (9 of 31) by immunohistochemical assessment for S100. PNI and larger-diameter nerve involvement were significantly associated with death at 5-year follow-up. CONCLUSIONS: Immunohistochemical assessment for S100 improves the accuracy of PNI determination. PNI is a significant factor in the survival outcome of cases of MEC.

Aerobic fitness and glycemic variability in adolescents with type 1 diabetes.

OBJECTIVE: This study examines the association of fitness on glycemic variability (GV) in adolescents with type 1 diabetes mellitus (T1DM). GV has been associated with high frequency of hyper- and hypoglycemia. METHODS: Nineteen adolescents with T1DM, ages 14 to 19 years, underwent aerobic fitness testing to determine their maximal aerobic capacity (VO2 max). A continuous glucose monitoring (CGM) device was placed on each subject and worn for 3 to 5 days until a return visit when the subjects underwent a 1-hour treadmill exercise session. Mean amplitude of glycemic excursion (MAGE) was calculated from the CGM data collected between the 2 study visits. Metabolic equivalent (MET), a measure of accumulated metabolic workload during the exercise session, was also calculated. RESULTS: Mean VO2 max was 46.6 ± 6.8 mL/kg/min, with a range of 34.8 to 57.0 mL/kg/min. Mean MET during the exercise session was 577.2 ± 102.4 and ranged from 354.3 to 716.2 METs. There was an inverse association between VO2 max and MAGE (r = -0.46; 95% confidence interval [CI], -0.01 to -0.76; P = .048). MET load and MAGE also had an inverse relationship (r = -0.48; 95% CI, -0.03 to -0.77; P = .037). CONCLUSION: GV is inversely associated with fitness and MET load. Aerobic fitness should be promoted in adolescents with T1DM not only because of its multiple beneficial effects but also due to a possible association with GV, leading to fewer extremes in hypo- and hyperglycemia.

Tracking donor RBC survival in premature infants: agreement of multiple populations of biotin-labeled RBCs with Kidd antigen-mismatched RBCs.

BACKGROUND: Anemia, a common condition among critically ill premature infants, is affected by red blood cell (RBC) survival (RCS). We hypothesized that transfused allogeneic Kidd antigen-mismatched RBCs would demonstrate the same concurrent RCS tracking as RBCs multilabeled at separate, discrete low densities with biotin (BioRBCs). METHODS: Allogeneic RBCs from adult donors were labeled at four biotin densities, mixed, and transfused into 17 anemic premature infants. Nine of the donors and neonates were Kidd antigen mismatched. Serial posttransfusion blood samples were assayed for up to 8 wk by flow cytometry to track the survival of the proportions of Kidd antigen-mismatched and Kidd antigen-biotinylated RBCs. RESULTS: Using linear mixed modeling to compare results, RCS of the three lowest BioRBC densities was similar to RCS by Kidd antigen mismatch and to one another. RCS of RBCs labeled at the highest BioRBC density was shortened. CONCLUSION: RCS of different populations of RBCs can be tracked concurrently and reliably using the three lowest BioRBC densities. Although comparable RCS results can be achieved using Kidd antigen mismatches, BioRBCs are preferred for investigating neonatal anemia because biotin labeling of both allogeneic and autologous RBCs is possible.

Effects of transcutaneous electrical nerve stimulation on pain, pain sensitivity, and function in people with knee osteoarthritis: a randomized controlled trial.

BACKGROUND: Transcutaneous electrical nerve stimulation (TENS) is commonly used for the management of pain; however, its effects on several pain and function measures are unclear. OBJECTIVE: The purpose of this study was to determine the effects of high-frequency TENS (HF-TENS) and low-frequency TENS (LF-TENS) on several outcome measures (pain at rest, movement-evoked pain, and pain sensitivity) in people with knee osteoarthritis. DESIGN: The study was a double-blind, randomized clinical trial. SETTING: The setting was a tertiary care center. PARTICIPANTS: Seventy-five participants with knee osteoarthritis (29 men and 46 women; 31-94 years of age) were assessed. INTERVENTION: Participants were randomly assigned to receive HF-TENS (100 Hz) (n=25), LF-TENS (4 Hz) (n=25), or placebo TENS (n=25) (pulse duration=100 microseconds; intensity=10% below motor threshold). MEASUREMENTS: The following measures were assessed before and after a single TENS treatment: cutaneous mechanical pain threshold, pressure pain threshold (PPT), heat pain threshold, heat temporal summation, Timed "Up & Go" Test (TUG), and pain intensity at rest and during the TUG. A linear mixed-model analysis of variance was used to compare differences before and after TENS and among groups (HF-TENS, LF-TENS, and placebo TENS). RESULTS: Compared with placebo TENS, HF-TENS and LF-TENS increased PPT at the knee; HF-TENS also increased PPT over the tibialis anterior muscle. There was no effect on the cutaneous mechanical pain threshold, heat pain threshold, or heat temporal summation. Pain at rest and during the TUG was significantly reduced by HF-TENS, LF-TENS, and placebo TENS. LIMITATIONS: This study tested only a single TENS treatment. CONCLUSIONS: Both HF-TENS and LF-TENS increased PPT in people with knee osteoarthritis; placebo TENS had no significant effect on PPT. Cutaneous pain measures were unaffected by TENS. Subjective pain ratings at rest and during movement were similarly reduced by active TENS and placebo TENS, suggesting a strong placebo component of the effect of TENS.