Epinephrine reduces the sedative side effects of epidural sufentanil for labour analgesia

PURPOSE: The use of opioids in labour analgesia has primarily been as an adjuvant to local anesthetics. For early labour, satisfactory analgesia with epidural sufentanil alone is possible. This study evaluates the impact of epinephrine on sedative side effects and analgesia related to the latter technique. METHODS: After Institutional Review Board approval and informed consent this prospective, randomized, double-blind study evaluated 43 nulliparous subjects requesting epidural analgesia. The study site, a tertiary care obstetric unit, accommodates 3500-4500 deliveries annually. Group selection was randomized and blinded by selection of a sealed envelope containing a number which corresponded to a premixed labelled syringe of saline or epinephrine (100 microg/mL). An epidural catheter was placed in a standardized fashion. All subjects received 40 microg of sufentanil and 0.5 mL from the premixed syringe, diluted to 10 mL with NaCl. A blinded observer collected data on maternal sedation, lightheadedness, hemodynamics, oxygenation, and fetal heart rate over a one-hour period following sufentanil injection. RESULTS: The addition of epinephrine significantly (P <0.05) reduced the incidence of sedation and lightheadedness after epidural sufentanil at all data collection points, except two. Analgesic duration was also significantly prolonged by this addition (120 +/- 56 vs 84 +/- 32 min). Maternal satisfaction was high regardless of solution. CONCLUSION: Forty micrograms of epidural sufentanil produces satisfactory analgesia in early labour. The addition of epinephrine improves the side effect profile of this technique while prolonging the duration of analgesia. Epidural sufentanil requires attention to maternal monitoring of oxygenation as maternal desaturation occurred in both groups.     

Non-isotopic hybridization assays for bacterial DNA samples

The background problem associated with the use of streptavidin in detecting biotin-labelled probes hybridized to DNA in crude bacterial extracts has been investigated. We have found that streptavidin binds specifically to a limited number of polypeptides which are difficult to remove by rapid extraction processes. Altering the hybridization and detection protocols results in a marked but not complete reduction of non-specific background in streptavidin-biotin assays. Complete elimination of non-specific background was achieved only when streptavidin was replaced with antibodies for the detection of biotinylated or sulphone-modified probes. The antibody-sulphone and streptavidin-biotin dot blot assays described here require 4.5-5 hours to perform and can detect DNA sequences in samples extracted from 2 x 10(7) cells or fewer.     

Adenocarcinomain Situof the Uterine Cervix: Management and Outcome

Objective: To retrospectively review the management of adenocarcinomain situof the uterine cervix, to determine the outcome of conization versus hysterectomy, and to compare the results achieved by different methods of conization. Methods: We performed a retrospective pathology and chart review of 46 patients with cervical adenocarcinomain situfrom January 1980 to October 1994. Results: Nine patients were managed during the first half of the study period and 37 were managed in the second half. The mean age of patients was 38.4 years (range 25–72). Forty-five of 46 patients were diagnosed as a result of an abnormal Pap smear, although only 19 smears indicated adenocarcinomain situor other glandular abnormalities. Cold knife conization resulted in a 33% rate of positive margins for adenocarcinomain situcompared to 50% for large loop excision of the transformation zone (LLETZ). Among 24 conservatively managed patients with negative conization margins, there have been 2 (8.3%) recurrences of adenocarcinomain situ.Among patients not undergoing hysterectomy as definitive treatment, 1 of 18 (6%) patients undergoing cold knife conization recurred, compared to 4 of 14 (29%) managed with LLETZ, despite a 63.4-month shorter mean follow-up interval for the LLETZ patients. Conclusions: Cold knife conization is associated with a lower rate of recurrence of cervical adenocarcinomain situcompared to LLETZ. We recommend cold knife conization for patients who are not treated with hysterectomy.     

Melatonin responses to clonidine and yohimbine challenges.

Melatonin (MT) release from the pineal gland has been used as a marker for central noradrenergic function in major depression. Norepinephrine acts at both alpha and beta adrenergic receptors on the pinealocyte membrane to mediate nocturnal MT release, but in humans the contribution of each receptor class is unclear. In order to explore the effect of alpha 2 receptors on MT release, 10 female subjects were given oral challenges, in separate placebo-controlled trials, of either 10.8 mg of yohimbine, an alpha 2 adrenergic antagonist, or clonidine, a partial alpha 2 adrenergic agonist, at doses of either 200 micrograms or 300 micrograms. Post-challenge serum melatonin was measured from 18:00 h to 22:00 h in both studies as was urinary 6-sulphatoxy-melatonin (aMT6s), the major metabolite of MT (from 18:00 h to 22:00 h, and from 22:00 h to 10:00 h). Growth hormone (GH) was also assayed following the clonidine challenge, and blood pressure, pulse rate, and side effects were monitored after both challenges. Neither yohimbine nor clonidine significantly altered nocturnal serum MT levels compared to placebo. However, there was a significant increase in urinary aMT6s between 18:00 h and 22:00 h following yohimbine ingestion. Yohimbine ingestion produced significant rises in pulse rate and the urge to urinate compared to placebo. Both doses of clonidine resulted in a significant reduction in pulse rate, systolic and diastolic blood pressure, and significant increases in drowsiness and other measures of sedation following ingestion. Only clonidine 300 micrograms produced a significant elevation in GH release. This study highlights the limitations of oral neuroendocrine challenge studies.     

Validation of computerized three-dimensional reconstruction of intravascular ultrasound: measurements of absolute luminal diameter and cross-sectional area in ex vivo human coronary arteries

Computer based 3-dimensional reconstruction transforms 2-dimensional intravascular ultrasound images into a longitudinal format facilitating analysis of luminal narrowing. To validate the accuracy of current software in measuring coronary artery diameter and cross-sectional area, in arteries with atherosclerosis, we performed 3-dimensional reconstruction in 10 human pathologic coronary arterial segments of 10-25mm length. Images were obtained using a 4.8 French catheter with pullback speed of 1mm/sec acquired at 3 frames/sec onto VHS tape. The data were digitized and intraluminal 3-dimensional reconstruction performed using a voxel-based program. Pathologic sections were obtained every 3mm, and dimensions were measured with a resolution of 0.01 mm. Maximum, minimum, and 3 other representative diameters were recorded by an observer blinded to the ultrasound diameters. Average histo-pathologic diameters were reported, and specimen cross-sectional area was then calculated. Results: In 53 sections, pathological diameters ranged from 1.4-4.5mm (mean 2.7 +/- 0.68mm) while 3-dimensional reconstructed diameters were 1.9 to 3.8mm (mean 2.6 +/- 0.54mm). Pathologic and ultrasound derived 3-dimensional reconstruction diameters had an excellent correlation (r=0.86, SEE=+/-0.36). Pathology and 3-dimensional reconstruction cross-sectional area also correlated closely (r=0.88, SEE=+/-1.50). Diameters less than 2.0mm were systematically overestimated and diameters greater than 3.5mm underestimated by 3-dimensional reconstruction. Most 3 dimensional reconstruction values were within +/- 10% of pathology, but diverged at each diameter extreme, approaching +/- 20%. Thus, computerized 3-dimensional reconstruction of ultrasound images shows excellent quantification of luminal size in the 2.0-3.5mm range, suggesting important investigative and clinical applications.     

Pre- and postoperative evaluation of plasma creatine kinase in 142 children subjected to "uncomplicated" anesthesia in muscle biopsy

Pre- and postoperative serum CK activity is evaluated in 142 children submitted, "uneventfully", to diagnostic muscle biopsy under halothane (77 patients), ketamine (50 patients) or "local" (15 patients) anaesthesia. The purpose was to ascertain whether or not anaesthesia-induced-rhabdomyolysis (AR) was an asymptomatic (and unrecognized) complication of "uneventful" anaesthesia. The majority of patients with low preoperative CK values showed a slight increase of serum CK activity on the first postoperative day. On the contrary, a postoperative decrease was observed in the majority of patients with high preoperative values (namely in almost all ketamine patients and in 2/3 of halothane-patients). In no case postoperative increase reached a value suggesting the occurrence of AR even though a postoperative value of 16480 U/I was observed in a patient with Duchenne muscular dystrophy after halothane anaesthesia. Sudden interruption of motor activity induced by general anaesthesia seems to be the most important factor in reducing the release of CK from muscle. When preoperative release is low, any further postoperative reduction is not sufficient to balance the moderate increase of CK produced by the surgical procedure; the opposite should happen in patients presenting with high preoperative release. So far as anaesthetics are concerned, our data seem to suggest that ketamine has a higher "protective" role compared to halothane.     

Polymorphisms of the equine major histocompatibility complex class II DRA locus

The full extent of the polymorphism of ELA-DRA in Equidae is not yet known. Given the apparent differences in DRA polymorphisms between Equidae and other species, the aims of this study were to more fully characterize ELA-DRA, determine the extent of gene polymorphism and establish the allele-frequency distribution. An allele reference panel for the second exon of ELA-DRA was established by sequence-based typing of 69 equine DNA samples consisting of various breeds of domestic horse (Equus caballus), together with donkeys (Equus asinus), Grant's zebras (Equus boehmi) and one onager (Equus hemionus). Five of the six previously reported alleles detected using single-strand conformation polymorphism were found: ELA-DRA*0101, ELA-DRA*0201, ELA-DRA*0301, ELA-DRA*0501 (Albright-Fraser DG et al. Polymorphism of DRA among equids. Immunogenetics 1996: 43: 315-7) and ELA-DRA*0601 (GenBank accession number AF5419361). In addition to the previously reported alleles, five novel ELA-DRA alleles were detected within the ELA-DRA allele reference panel. One of these was identified in E. caballus (ELA-DRA*JBH11), one in E. boehmi and E. hemionus (ELA-DRA*JBZ185) and three in E. asinus (ELA-DRA*JBD3, ELA-DRA*JBD17 and ELA-DRA*JBH45). A total of 565 equine DNA samples were screened using reference-strand-mediated conformation analysis, a double-stranded conformation-based mutation detection system that can be used to type existing ELA-DRA alleles and identify new variants. Based on our findings, at least 11 ELA-DRA alleles are now known to exist, and this level of polymorphism at the DRA locus appears to be unique to the genus Equus. Both the previously reported alleles and the new alleles displayed a species-specific distribution.