Design of an intravenous oxygenator

The aim of this study was to design a new intravenous blood–gas exchange device and to estimate the design characteristics of the device with a dimensionless function by using a substance that can be used instead of bovine blood. In addition, the characteristics of oxygen transfer were estimated using empirical formulas and the reliability of the equations was ascertained by comparing their output with an experiment performed using bovine blood. The dimensionless function was derived using distilled water and bovine blood to estimate the oxygen transfer rate. Using the derived equations, the calculated oxygen transfer rates for bovine blood and distilled water were similar for Reynolds numbers ranging from 0.7 to 7.0. Therefore, it is possible to estimate the oxygen transfer rate in bovine blood, which is a non-Newtonian fluid, using distilled water, which is a Newtonian fluid. Moreover, it was possible to verify the related equations because the oxygen transfer rate could be estimated using the derived equations, according to the diameters of the various device modules.     

Oral administration of methylergometrine shows a late and unpredictable effect on the non-pregnant human menstruating uterus

Objective: To study the pharmacodynamic and pharmacokinetic properties of oral and intravenous methylergometrine upon uterine motility during menstruation. Study-design: Intra-uterine pressure was measured in six volunteers with a fluid-filled sponge-tipped catheter during menstruation. Methylergometrine was given orally (0.5 mg) or intravenously (0.2 mg) in a cross-over design. Results: After intravenous administration, a fast increase of the frequency of uterine contractions and basal tone occurred with a decrease of amplitude, lasting at least 30 min. Oral administration had a late and less marked effect on uterine motility. An intravenous dose administered 24 h after an oral dose had no effect on uterine motility. Pharmacokinetic data, such as the maximum plasma concentration (C_max), the time at which C_max is reached (t_max) and the half-life of absorption (t_1/2abs) also demonstrated large individual variations after oral administration. Conclusion: Oral administration of methylergometrine had an unpredictable and late effect on uterine motility on the menstruating uterus, probably due to an unpredictable bioavailability, in contrast with the fast and predictable effect after intravenous administration.     

十二指肠乳头括约肌切开胆总管取石术前静注咪唑安定对麻醉及手术效果的影响

目的　探讨在十二指肠乳头括约肌切开 (EST)胆总管取石术前静注咪唑安定的可行性及价值。方法　将 71例拟行 EST胆总管取石患者随机分为咪唑安定组 (试验组 ) 5 1例和对照组 (2 0例 ) ,两组术前均给予 6 5 4 -2 (10 mg)静脉注射 ,试验组同时静脉注射咪唑安定 (3～ 5 mg)。观察两组患者的进镜时间、麻醉程度 ,患者的反应与配合程度、自身感受程度 ,同时监测患者的血压、心率、血氧饱和度。结果　试验组进镜时间缩短、镇静程度适中、患者自身感受好 ,与对照组比较 ,差异有显著性 (P<0 .0 1) ;患者心血管及呼吸参数无明显变化。结论　EST胆总管取石术前静脉注射咪唑安定可提高麻醉效果 ,有利于提高患者配合的依从性 ,对血压、心率、血氧饱和度无明显影响     

Intravenous cholangiography,ERCP, and selective operative cholangiography in the performance of laparoscopic cholecystectomy

Between March 1990 and March 1993 some 822 consecutive patients underwent an attempt at laparoscopic cholecystectomy. Intravenous cholangiography (IVC), ERCP, and selective intraoperative cholangiography (IOC) were used in the evaluation of common bile duct (CBD) stones. Two hundred thirteen patients (26%) were identified preoperatively with either abnormal liver functions or a dilated common bile duct suggestive of CBD stones. IVC was performed in 143 patients (67%). Choledocholithiasis was identified in 14 patients (10%). Preoperative therapeutic ERCP was successful in all 14 patients (100%). Diagnostic ERCP was attempted in 61 patients and successful in 59 (97%). Choledocholithiasis was identified in 25 patients (41%). Successful extraction was accomplished in 23 patients (92%). Transcystic common bile duct exploration was used effectively in the patients with an unsuccessful ERCP. IOC was attempted in 50 patients and successful in 48 (96%). Choledocholithiasis was identified in three (6%). A retained CBD stone was present in eight patients (1%). There was one level I CBD injury (0.122%). The use of IVC, selective ERCP, and selective IOC is a reasonable approach in the performance of laparoscopic cholecystectomy.     

Two deaths from intravenous nifedipine abuse

Summary An incident is reported in which 2 intravenous drug abusers died as the result of uncontrolled experimentation with intravenous injection of the common anti-hypertensive and anti-anginal drug Nifedipine (Adalatt.m. Bayer), probably in mistake for the commonly abused short-acting benzodiazepine drug Temazepam. Large quantities of Nifedipine were identified in the blood of both deceased men by gas chromatography. Apart from intense gastric mucosal congestion, pulmonary oedema and general visceral congestion, the autopsy findings were entirely nonspecific. The similarity in colour, shape and texture between capsules of Nifedipine and those of Temazepam is likely to have prompted the mistake.     

Development of the Diploma in Clinical Dentistry (Conscious Sedation and Pain Control) Faculty of Dentistry, University of Sydney

The Diploma in Clinical Dentistry (Conscious Sedation and Pain Control) of the Faculty of Dentistry, University of Sydney, is the first dedicated programme devoted to this field in Australia. Its development followed a decision by the Dental Board of New South Wales to require a formal qualification from the University of Sydney before dental practitioners could offer sedation and pain management in practice.
The programme is conducted at Westmead Hospital in conjunction with the Department of Anaesthetics, and satisfies the guidelines developed by the Royal Australasian College of Dental Surgeons and the Royal Australasian College of Surgeons.
The course is conducted either over one or two years, with block sessions requiring attendance at Westmead Hospital, together with assignments which are completed outside the block sessions. In this way, a dental practitioner enrolled in the programme is able to continue practice.
The block sessions need not be completed over one year, but must be completed within two years.     

Influence of Size, Dosage, and Surface Structure on Clearance and Tissue Distribution of Intravenous Microspheres

Intravenously injected polystyrene microspheres with functional amino groups (AP-MSs, 0.2,1.0, and 4.0 urn in diameter) were cleared from the blood very rapidly. The calculated half-lives for 0.2-, 1.0-, and 4.0-μm AP-MSs were about 55,60, and 50s; no significant differences were found with 10⁶,10⁷, and 10⁸ microspheres/rat. Loading experiments showed that the liver, spleen, lung, kidney, and heart had a very high capacity to take up AP-MSs. The AP-MSs were distributed mainly to the liver, lung, and spleen, whereas other organs contained less than 1 % of injected AP-MSs. In terms of numbers of AP-MSs per gram of tissue, the highest contents were found in spleen, liver, and lung for 0.2-, 1.0-, and 4.0-um AP-MSs, respectively. There was indication of redistribution of particles from one organ to another during the first 6 h after injection. Chondroitin sulfate A (Chon) and hyaluronic acid (Hya) adsorbed or covalently linked to AP-MSs increased uptake in the liver, with Chon AP-MSs (adsorbed or linked) showing the best effect: about 25% increase compared with unadsorbed 1-μm AP-MSs. Experiments with separated cells in vitro demonstrated that 1 um AP-MSs, intravenously injected, associated only with Kupffer cells. When the microspheres were adsorbed with Chon, there was also association with liver endothelial cells. This finding indicates that conjugation of microspheres with ligands for endothelial receptors may be a useful method for directing microspheres to specific organs, even if the receptors are not by themselves phagocytic     

Immunomodulation of autoimmune and inflammatory diseases with intravenous immunoglobulin

Abstract Intravenous immunoglobulin (IVIg) has been used in the treatment of primary and secondary antibody deficiencies for over two decades. Since the early 1980s, the therapeutic efficacy of IVIg has been established in idiopathic thrombocytopenic purpura, Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, myasthenia gravis, dermatomyositis and Kawasaki syndrome, and the prevention of graft versus host disease in recipients of allogeneic bone marrow transplants. Its use has also been reported in a large number of other autoimmune and systemic inflammatory conditions. In this review, we discuss the mechanisms by which IVIg exerts immunomodulatory effects in immune pathologies.     

Modulation of immunoglobulin production and cytokine mRNA expression in peripheral blood mononuclear cells by intravenous immunoglobulin

Intravenous immunoglobulin (IVIG) has the potential to regulate Ig production, but the mechanism(s) responsible for this effect is unknown. In experiments reported here, we examined the ability of IVIG to regulate Ig production in human peripheral blood mononuclear cells (PBMCs) stimulated with pokeweed mitogen (PWM). IVIG (2–10 mg/ml) showed a potent (80–85%) inhibition of PWM-stimulated IgG, IgM, and IgA production. To determine more precisely how IVIG mediated the inhibition of Ig production, we studied Ig promoting cytokine gene expression after PWM stimulation with or without IVIG (2 and 10 mg/ml) using dot-blot techniques. RNA was isolated from PBMCs at predetermined time points and probed with cDNAs specific for human cytokines (IL-1-, IL-2, IL-2R, IL-4, IL-5, IL-6, -IFN, and TNF-). IL-6 mRNA accumulation was maximal at 4.5 hr post-PWM stimulation and was inhibited 64–75% when IVIG (10 mg/ml) was present. -IFN mRNA levels peaked at 72 hr poststimulation and were also 68–75% inhibited by IVIG. IL-2 mRNA levels peaked at 4.5 hr and were 23–46% inhibited by IVIG. The inhibitory effect of IVIG on production of these cytokines (IL-6 and -IFN) was also observed at the protein level in sonicated PBMCs after incubation with PWM and IVIG. The mRNA levels for other cytokines were not or only minimally inhibited by IVIG. Addition of IL-6, -IFN, or IL-2 partially restored Ig production in IVIG-treated PWM-stimulated cultures, suggesting that inhibition of other cytokines or another mechanism(s) independent of cytokine inhibition might also be involved, although inhibition of IL-6, -IFN, and IL-2 may be one of the critical factors in the suppression of Ig production by IVIG.