Prenatal RHD gene determination and dosage analysis by PCR: clinical evaluation

BACKGROUND: Use of the polymerase chain reaction (PCR) for detection of the RHD gene can measure the RHD gene status for unborn babies at risk for hemolytic disease of the newborn (HDN). The occurrence of D gene variants has led to errors in prenatal typing. Previous reports have highlighted the danger of assigning a positive fetus as negative, resulting in intrauterine fetal deaths. OBJECTIVE: To evaluate the effectiveness of a testing strategy whereby PCR was not only performed to determine the presence/absence of the RHD gene, but also used to assess the D gene copy number (zero, one or two RHD genes) in family studies for at risk pregnancies. METHODS: Samples comprising maternal (57) and paternal (42) peripheral blood samples, amniotic fluid (64), and matching cord blood (64) were collected. Rhesus (Rh) serotyping was performed on all blood samples. For RHD genotyping, DNA was extracted from all samples except for 28 cord samples, where only serotyping was performed (total 199 DNA genotyping). RHD gene PCR amplified exon 4 and exon 7 regions of the RHD gene. The dosage of RHD gene was determined by comparing the intensity of the RHD gene to that of the RHCE gene. RESULTS: A total of 197/199 samples showed concordance between exon 4 and exon 7 PCR results. Two discrepant results occurred in one family: the father carried one normal D gene and one D gene variant where PCR was tested to be positive using exon 4 but negative using exon 7. One of a pair of dizygotic twins inherited this abnormal D gene and was mildly affected by HDN. This was correctly identified antenatally and the pregnancy successfully managed. The concordance rate between serotypes and genotypes for 135 blood samples was 100%. Amongst the family groups, 8/14 heterozygous fathers transmitted the D gene and 26/26 homozygous fathers transmitted the D gene to the babies. The concordance rate between RHD genotypes from amniotic fluid and Rh D serotypes from cord blood was also 100%. CONCLUSION: The present study demonstrates the effectiveness of using PCR in a clinical setting. It verifies the importance of testing more than one region of the gene, and also the need for a testing strategy where both maternal and paternal testing for RHD gene dosages are performed.     

Do bupropion SR and sertraline differ in their effects on anxiety in depressed patients?

OBJECTIVE: To examine the effects of bupropion sustained release (SR) and sertraline on anxiety in outpatients with recurrent DSM-IV-defined major depressive disorder. METHOD: This retrospective analysis was conducted using pooled data from 2 identical, 8-week, acute-phase, double-blind, placebo-controlled, parallel-group studies of bupropion SR (N = 234), sertraline (N = 225), and placebo (N = 233). Symptoms of anxiety and depression were measured using the 14-item Hamilton Rating Scale for Anxiety (HAM-A) and the 21-item Hamilton Rating Scale for Depression (HAM-D-21), respectively. Percentage reduction in baseline HAM-A total score for each treatment week was calculated to determine whether the time to onset of anxiolytic activity differed among antidepressant responders to each agent. Central nervous system (CNS) adverse events were tabulated. RESULTS: Bupropion SR and sertraline were comparably effective, both were superior to placebo in reducing depressive symptoms. and they did not differ in their effect on anxiety symptoms. Antidepressant responders (> 50% reduction in baseline HAM-D-21 score) in both groups showed marked and comparable reductions in HAM-A scores (baseline to exit). There were no differences between bupropion SR and sertraline in the median time (4 weeks) to reach a clinically significant anxiolytic effect (> or = 50% reduction in baseline HAM-A score). CNS adverse events were comparable for bupropion SR and sertraline, except for somnolence, which was more common in sertraline-treated patients. CONCLUSION: Bupropion SR and sertraline had comparable antidepressant and anxiolytic effects and an equally rapid onset of clinically significant anxiolytic activity. There was no difference in the activating effects between the 2 antidepressants. Selection between these 2 agents cannot be based on either anticipation of differential anxiolytic activity or differential CNS side effect profiles.     

Fetomaternal bleeding following diagnostic amniocentesis

The frequency of diagnostic amniocentesis is increasing. Fetal bleeding and trauma have long been recognized to be complications of amniocentesis. For detection of fetomaternal bleeding, efficacy of modified Kleihauer-Betke staining and alpha-fetoprotein elevation in maternal blood was assessed. Preamniocentesis ultrasound scanning was found useful in reducing the incidence of fetomaternal bleeding and bloody taps. Elevation of alpha-fetoprotein was found to be a more sensitive indicator of fetomaternal bleeding than was modified Kleihauer-Betke staining. The use of alpha-fetoprotein to detect fetomaternal bleeding associated with amniocentesis is suggested for the identification of Rh-negative patients requiring anti-D gamma-globulin to prevent sensitization.     

Affect regulation, nicotine addiction, and smoking cessation

Numerous investigators have examined the role of negative affective states and affect regulation in the initiation and development of cigarette smoking behavior, smoking cessation, and relapse prevention. Affect regulation refers to any attempt to alleviate negative mood states by means of pharmacologic-, cognitive-, behavioral- or environmental-change methods. The psychological construct/process of affect regulation is examined in relation to (1) the initiation, development, and maintenance of the cigarette smoking habit; (2) the process of quitting smoking; and (3) the long-term maintenance of smoking abstinence versus relapse. Various psychosocial factors and physiological mechanisms are explored that have been hypothesized to be links between negative mood states, nicotine addiction, and smoking cessation. Implications for smoking cessation treatment are discussed in the areas of (1) the use of pharmacologic agents, such as clonidine, in the reduction of nicotine withdrawal symptoms; (2) nicotine replacement therapy; and (3) skills-training approaches to smoking cessation and relapse prevention.     

Dural infolding during C1-2 myelography

Inward buckling of the dura at C1-2 may occasionally occur with hyperextension of the neck and can result in a difficult or unsuccessful puncture when the posterior lateral C1-2 approach is used for cervical myelography. In this circumstance, placement of the head in a neutral or slightly flexed position may widen the posterior subarachnoid space and facilitate the needle puncture.     

Opiate receptors: an introduction

Current status of opiate receptors and their agonists is reviewed--basic aspects of receptor theory, the importance of stereospecificity in drug-receptor interactions and the role of 'second messengers' in drug action. The three classes of endogenous opioids, originating from three distinct genes, are discussed: pro-opiomelanocortin, giving rise to beta-endorphin, ACTH and various MSHs; pro-enkephalin, giving methionine enkephalin and leucine enkephalin; and prodynorphin; their anatomical distribution and the main classes of receptors with which they interact, the mu-receptor, with a high affinity for met-enkephalin and beta-endorphin (as well as morphine and dynorphin A); the delta-receptor for which the primary ligand is leu-enkephalin; and the kappa-receptor which is the main target for the dynorphins. Functional roles for endogenous opioids are considered. Essentially they are inhibitory to target neurones, depressing motor reflexes, baroreflexes and nociception. They also have roles in the response to physical and psychological stress.