Nociceptin/orphanin FQ up‐regulates P2X3 receptors in primary cultures of neonatal rat trigeminal ganglion neurons

Recent evidence indicates a nociceptive role of the nociceptin/orphanin FQ–opioid receptor‐like receptor (N/OFQ‐ORL1) system in craniofacial pain; however, the mechanisms of such an effect remain unclear. We investigated whether the action of N/OFQ involves the modulation of P2X₃, a pain‐transducing ionotropic receptor. Double‐labeled immunohistochemical staining was used to determine the co‐localization of ORL1 and P2X₃ receptors in the trigeminal ganglia (TG) of neonatal Sprague‐Dawley rats. The effect of N/OFQ (at a concentration ranging from 1 pM to 10 nM) on the expression of P2X₃ receptors was detected by RT‐PCR, western blotting, and immunocytochemical staining. We found that ORL1 receptors were co‐localized with P2X₃ receptors and that the application of N/OFQ could up‐regulate, in a concentration‐dependent manner, the expression of P2X₃ receptor mRNA and P2X₃ receptor protein in TG neurons. Immunocytochemical staining also revealed enhanced P2X₃ immunoreactivity beneath the neuronal membrane and an increased percentage of P2X₃‐positive neurons after treatment with N/OFQ. Those effects were completely blocked by a specific ORL1 antagonist, UFP‐101. Our results suggest that the activation of ORL1 receptors by N/OFQ can potentiate P2X₃ receptors in primary cultures of neonatal trigeminal neurons, which may be a mechanism for the nociceptive role of N/OFQ in the modulation of craniofacial pain. Our findings may also have implications in treating craniofacial pain.     

Co-Occurring Psychiatric Symptoms in Opioid-Dependent Women: The Prevalence of Antenatal and Postnatal Depression

Background: Despite the high prevalence of psychiatric symptoms in substance-dependent women, little evidence is available on postpartum depression in this population. Objectives: To determine whether demographic variables and prenatal depression predict postpartum depression and select substance abuse treatment outcomes in a sample of pregnant women. Methods: A retrospective chart review was conducted on 125 pregnant women enrolled in a comprehensive substance abuse treatment program. Data on demographic variables, prenatal care attendance, urine drug screen (UDS) results, and psychiatric symptoms were abstracted from patient medical and substance abuse treatment charts. The Postpartum Depression Screening Scale (PDSS) was administered 6 weeks post-delivery. Multiple linear regression was conducted to identify predictors of prenatal care attendance and total PDSS scores at 6 weeks postpartum. Multiple logistic regression was used to examine predictors of positive UDS at delivery. Results: Nearly one-third (30.4%) of the sample screened positive for moderate or severe depression at treatment entry. Psychiatric symptoms did not predict either prenatal care compliance or UDS results at delivery. Almost half of the sample (43.7%) exhibited postpartum depression at 6 weeks post-delivery. No demographic variables correlated with incidence of postnatal depression. Only antenatal depression at treatment entry predicted PDSS scores. Conclusion: Prevalence of antenatal psychiatric disorders and postpartum depression was high in this sample of women seeking substance abuse treatment. Results support prior history of depression as a predictor of risk for developing postpartum depression. Scientific Significance: Routine screening for perinatal and postpartum depression is indicated for women diagnosed with substance abuse disorders.     

HIV Testing in the Nation's Opioid Treatment Programs, 2005–2011: The Role of State Regulations

ObjectiveTo identify the extent to which clients in a national sample of opioid treatment programs (OTPs) received HIV testing in 2005 and 2011; to examine relationships between state laws for informed consent and pretest counseling and rates of HIV testing among OTP clients.Data SourceData were collected from a nationally representative sample of OTPs in 2005 (n = 171) and 2011 (n = 200).Study DesignRandom-effects logit and interval regression analyses were used to examine changes in HIV testing rates and the relationship of state laws to HIV testing among OTPs.Data CollectionData on OTP provision of HIV testing were collected in phone surveys from OTP managers; data also were collected on state laws for HIV testing.Principal FindingsThe percentage of OTPs offering HIV testing decreased significantly from 93 percent in 2005 to 64 percent in 2011. Similarly, the percentage of clients tested decreased from an average of 41 percent in 2005 to 17 percent in 2011. OTPs located in states whose laws do not require pretest counseling and that use opt-out consent were more likely to provide HIV testing and to test higher percentages of clients.ConclusionsThe results show the need to increase HIV testing among OTP clients; the results also underscore the beneficial possibilities of dropping pretest counseling as a requirement for HIV testing and of using the opt-out approach to informed consent for testing.     

Book Reviews

The aims of this longitudinal study are to investigate the cognitive and verbal development of discordant twins without neurological morbidity. Twenty pairs (40 infants) of discordant twins (discordance range 15–41%) were examined. A follow‐up study was carried out of 11 selected pairs (22 infants), with biological and cognitive measures at birth, at 1 year, at 2 years and at 4 years. Results show that biological growth differences (weight, height and head circumference) tended to disappear after the age of 2 years. Significant differences were found in cognitive and verbal skills between the larger and smaller co‐twins at all ages. When the twins were small for gestational age, and were close to very low birth weight, together with severe discordance, their cognitive and verbal scores were consistently below the range of normality. In conclusion, the differences between the larger and smaller co‐twins appear to persist up to 4 years of age, with respect to cognitive and verbal skills. A possible additive effect of biological risk factors that accumulated in the severe discordances was observed, which appeared to increase the probability of smaller co‐twins suffering delayed cognitive and verbal development.     

Critical Summaries of Innovations in Palliative Care Pharmacotherapy

ABSTRACT

Timely and important studies are reviewed and commentaries provided by leading palliative care clinicians. Symptoms, interventions, and treatment-related adverse events addressed in this issue are: the effect of sorafenib on sarcopenia; defining, classifying, and assessing cancer breakthrough pain; treatment of opioid-dependent human immunodeficiency virus (HIV) patients (clinic-based versus referred treatment); the predictors and course of depression in metastatic cancer patients; and the effectiveness of treatment agreements and urine analysis for reducing opioid misuse in outpatients with chronic noncancer pain.