Drug abuse and dependency during pregnancy: anaesthetic issues

Drug abuse is a significant social problem that can lead to serious obstetric complications, some of which may be confused with pregnancy-related disease states. Substance abuse poses a number of challenges with respect to the management of pain and the conduct of anaesthesia in the peripartum period. This review was based on information from a literature search of epidemiological, research and review papers on substance abuse during pregnancy, obtained for the purpose of preparing a background paper for the Ministerial Council on Drug Strategy, Commonwealth Government of Australia. Given that almost 80% of substance-abusing parturients require anaesthetic services in the perinatal period, early antenatal referral for anaesthetic review is recommended. To optimise the care of these vulnerable patients, obstetricians, general practitioners and midwives should attempt to identify substance-abusing parturients and refer them to an anaesthetist. A careful anaesthetic evaluation with non-judgemental questioning is essential, with management tailored to individual patient needs and the urgency of obstetric intervention for vaginal delivery or caesarean section. Opioid-dependent women, in particular, benefit from antenatal pain management planning. Patients recovering from drug addiction should also have a well-documented analgesic strategy. A multidisciplinary approach will involve obstetricians, anaesthetists and staff of the Drug and Alcohol Service. In acute admissions of women by whom antenatal care was not accessed, a high index of suspicion for illicit drug use should arise. Because illicit substance use is so prevalent, if untoward reactions occur during an otherwise uneventful anaesthetic, the possibility of drug abuse should be considered.     

Influence of the number of basis images and projection array on caries detection using tuned aperture computed tomography (TACT).

OBJECTIVES: to determine if the number of basis images and spatial distribution of the projection array used for TACT slice generation influence observer performance in caries detection. METHODS: In the first experiment, 2, 4, 8 and 12 basis projections of each of 40 teeth were acquired using a CMOS digital radiography sensor. Projections were distributed radially in space using a 20 degree angular disparity. TACT slices were generated from the four subgroups of images, presented to eight observers, and viewed on a high-resolution monitor. Observers scored the presence/absence of caries using a 5-point confidence scale. Gold standard was histological examination of tooth sections. ROC curves measured observer diagnostic performance. ANOVA tested for significant differences between observers and experimental conditions. In the second experiment, the number of basis projections judged to be satisfactory for TACT slice generation was used. Horizontal and vertical linear arrays of projections were compared to the circular projection array. RESULTS: There was a statistically significant difference between the numbers of basis projections in the detection of both occlusal (P=0.006) and proximal caries (P=0.005). No significant difference was found between projection arrays in the detection of either occlusal (P=0.065) or proximal (P=0.515) caries. CONCLUSIONS: The number of TACT basis projections significantly influences caries detection. Eight or more images should be used. Either linear-vertical, linear-horizontal or circular arrays of basis projections may be used for TACT slice generation in caries detection tasks.     

Accuracy of quantification of mandibular condyle displacement in digitally subtracted linear tomograms.

Using a TMJ skeletal phantom, we assessed validity and reliability of digitally subtracted linear tomographic images to quantify condylar position changes. Horizontally corrected frontal and lateral tomographic images were made with the condyle in a 'centred' position and displaced by 1, 2 and 3 mm increments in two of three directions (inferior, and posterior, or lateral). Film images were sequentially subtracted and then randomized so that observers were blinded to the amount and direction of condylar movement. Averages of three measurements of the dark bands representing condylar shifts were made using a digitizing tablet. The study utilized a nested design where the series of film images was subtracted twice and each subtraction was read twice by two examiners. We repeated the study with a second series of films treated in an identical manner. Average differences from expected values were similar for frontal and lateral techniques and all directions and increments of displacement. Typical average difference for any increment was less than 0.1 mm. Standard deviations in measures were similar across techniques and increments and were typically less than 0.1 mm. Significant variation in the absolute value of differences between measured and expected values by direction of condylar displacement was attributed to greater accuracy of registration on the vertical axis for frontal images. A significant source of variation in the study design element 'film set' was attributed to errors in repositioning the phantom.(ABSTRACT TRUNCATED AT 250 WORDS)     

Plasma iron status and lipid peroxidation following thrombolytic therapy for acute myocardial infarction

Summary— Free radical species have been implicated as important agents involved in myocardial ischemic and reperfusion injuries. Superoxide is capable of mobilizing iron from ferritin and the released iron can cause hydroxyl formation from H₂O₂. The aim of this study was to evaluate the time-dependent increase in lipid peroxidation assessed by plasma thiobarbituric acid reactive substances (TBARS) and the relationship between lipid-peroxidation and the iron status. Peripheral venous blood samples were obtained from 17 men with acute myocardial infarction (AMI) before thrombolytic treatment (T0***) and 1, 2, 3, 4, 8, 12, 16, 20, 24 and 48 hours after commencing fibrinolytic treatment. The concentration of TBARS, the parameters of iron metabolism, serum myoglobin, creatine kinase, and creatine kinase-MB were measured. Early reperfusion was judged by regression of sinus tachycardia (ST) elevation and reduction of chest pain. Recanalization of coronary artery was evaluated by a late coronary angiography 24–96 hours after thrombolysis. After thrombolytic therapy, the TBARS level was raised from 2.98 ± 0.80 (T0***) to 4.57 ± 1.24 (peak), and decreased to 2.96 ± 0.40 nmol/mL plasma at T48 (T0 vs peak: P < 0.001, peak vs T48: P < 0.001, TO vs T48: NS). The mean time of the peak was observed at 9.7 ± 7.5 hours. The iron increased significantly from 0.67 ± 0.34 (T0) to 1.15 ± 0.52 mg/L (peak), and returned to the pre-reperfusion to levels: 0.53 ± 0.28 UI/L at T48 (T0 vs peak: P < 0.001, peak vs T48: P < 0.001, TO vs T48: NS). The mean time of the peak was observed at 9.4 ± 7.3 hours. In return, no correlation was found between the increase of plasma creatine-kinase activity, myoglobin and iron or between the biochemical markers and time of fibrinolytic therapy. The results confirmed the importance of the temporal relationship between lipid peroxidation and iron status after thrombolytic therapy. Our results are in agreement with the concept that antioxidant agents used in association with thrombolytic therapy might be useful.     

Direct demonstration that autologous bone marrow transplantation for solid tumors can return a multiplicity of tumorigenic cells

Patients with solid tumors are increasingly being treated by autologous bone marrow transplantation (BMT). Although response rates appear to be increased, disease recurrence is the commonest cause of treatment failure. Whether relapse is entirely due to residual disease in the patient or arises also from infiltrating malignant cells contained in the autologous marrow transplant has not been resolved. If the latter explanation is correct, then purging would be required as part of the transplantation procedure. We used retrovirally mediated transfer of the neomycin-resistance gene to mark BM harvested from eight patients with neuroblastoma in clinical remission. The marked marrow cells were subsequently reinfused as part of an autologous BMT. At relapse, we sought the marker gene in malignant cell populations. Three patients have relapsed, and in each the marker gene was detected by phenotypic and genetic analyses of resurgent malignant cells at medullary and extramedullary sites. Analysis of neuroblast DNA for discrete marker gene integration sites suggested that at least 200 malignant cells, each capable of tumor formation, were introduced with the autologous marrow transplant and contributed to relapse. Thus, autologous BMTs administered to patients with this solid tumor may contain a multiplicity of malignant cells that subsequently contribute to relapse. The marker-gene technique we describe should permit evaluation of the mechanisms of relapse and the efficacy of purging in patients receiving autologous marrow transplantation for other solid tumors that infiltrate the marrow.     

Ultrasound‐guided percutaneous tenotomy for the treatment of iliopsoas impingement: A description of technique and case study

Iliopsoas impingement is a commonly recognised source of groin pain following total hip replacement. When conservative measures fail, open or arthroscopic iliopsoas tendon release can reliably alleviate pain and improve function. This article describes an alternative ultrasound‐guided percutaneous technique, achieving iliopsoas tenotomy utilising a modified 18G coaxial needle and thus minimising the morbidity and cost associated with an open or arthroscopic procedure. This method proved successful with resultant complete resolution of patient symptoms. To the knowledge of the authors, this is the first case of ultrasound‐guided percutaneous iliopsoas tenotomy for iliopsoas impingement post total hip replacement.     

5-羟色胺对气道平滑肌细胞增生的影响及c-fos的表达

５－羟色胺对气道平滑肌细胞增生的影响及ｃ－ｆｏｓ的表达刘振千梁凤珍马军红戚好文为了探讨哮喘气道平滑肌层增厚的机制，考察哮喘的炎性介质５－羟色胺（５－ＨＴ）对兔气道平滑肌细胞（ＡＳＭＣ）增生的影响及原癌基因ｃ－ｆｏｓ的表达。新西兰大白兔，抗α－肌动蛋白...