The use of haemoglobin glutamer-250 (HBOC-201) as an oxygen bridge in patients with acute anaemia associated with surgical blood loss

For the treatment of substantial blood loss in surgery, allogeneic blood is transfused to maintain stability and organ perfusion and function. Continued concerns about the availability, safety, efficacy and storage-related problems of allogeneic blood products have led to an intense effort to find alternatives that can serve the same physiologic functions. Haemoglobin-based oxygen carriers (HBOCs) are compounds that can match the oxygen-carrying capacity of red blood cells (RBCs), and several HBOCs have reached advanced stages of development and clinical testing. Multi-centre, randomised, Phase III, controlled trials have demonstrated the safety and efficacy of haemoglobin glutamer-250 (bovine) (Hemopure®, Biopure Corporation, Cambridge, MA, USA), also known as HBOC-201. HBOC-201 is bovine-derived, modified haemoglobin that has been ultrapurified to remove any plasma proteins, RBC stroma and potential pathogenic material. During the manufacturing process, crosslinking and polymerisation stabilise the haemoglobin molecule, which increases its vascular persistence as well as the efficiency of oxygen transport to tissue. Results from clinical trials indicate that HBOC-201 can be used as an oxygen ‘bridge’ for patients experiencing anaemia due to surgical blood loss, until their own red blood cells are replenished or have regenerated (haematinic effect). HBOC-201 is generally well-tolerated and is approved for use in South Africa, where it is indicated for use in adult surgical patients who are acutely anaemic, and is used to eliminate, delay or reduce the need for allogeneic RBCs. A Biologics License Application for HBOC-201 is currently under review by the US FDA.     

Direct structural insight into the substrate-shuttling mechanism of yeast fatty acid synthase by electron cryomicroscopy

Yeast fatty acid synthase (FAS) is a 2.6-MDa barrel-shaped multienzyme complex, which carries out cyclic synthesis of fatty acids. By electron cryomicroscopy of single particles we obtained a three-dimensional map of yeast FAS at 5.9-Å resolution. Compared to the crystal structures of fungal FAS, the EM map reveals major differences and new features that indicate a considerably different arrangement of the complex in solution compared to the crystal structures, as well as a high degree of variance inside the barrel. Distinct density regions in the reaction chambers next to each of the catalytic domains fitted the substrate-binding acyl carrier protein (ACP) domain. In each case, this resulted in the expected distance of ∼18 Å from the ACP substrate-binding site to the active site of the catalytic domains. The multiple, partially occupied positions of the ACP within the reaction chamber provide direct structural insight into the substrate-shuttling mechanism of fatty acid synthesis in this large cellular machine.     

Carrier testing and prenatal diagnosis of haemophilia — utilisation and psychological consequences

Summary. Attitudes towards prenatal diagnosis, and abortion vary widely between different countries, religions, cultures and over time. Carrier testing and prenatal diagnosis (PD) of haemophilia have become an integrated part of the comprehensive care for haemophilia in Sweden as well as in many other countries. Almost all carriers are interested in carrier testing if they are aware of the possibility. With the development of PD by chorionic villus sampling in the first trimester, the method became acceptable for many carriers, and it has in Sweden actually had an effect on the incidence of haemophilia in the 1990s. The use of PD is more common among women who perceive haemophilia as a very serious disease and who have a positive attitude towards legal abortion. The main reason for carriers not to use PD was that they do not find haemophilia to be a sufficiently serious disorder to justify an abortion. Women and their spouses are under a great deal of psychological pressure in association with the PD procedure, and the psychological consequences of having to terminate a pregnancy are long-lasting. At follow-up, about 6 years after PD and abortion, these women, however, do not have more signs of psychological distress than women without PD experience. Nevertheless, they must be offered qualified assistance both before and after PD as well as adequate follow-up after an abortion to help them cope with the emotional strain they are under.     

血脑屏障上的转运蛋白及中药有效成分跨血脑屏障转运研究进展

本文介绍了血脑屏障的结构、功能及该部位的转运蛋白(ATP结合盒转运蛋白和溶质载体转运蛋白),以及它们在血脑屏障转运过程中的作用.通过脑微血管内皮细胞模型和在体脑微透析技术,定性定量地探讨了转运蛋白在中药有效成分跨血脑屏障中的作用.     

A convenient method for the preparation of radioiodinated meta‐iodobenzylguanidine at a no‐carrier‐added level

Radioiodinated meta‐iodobenzylguanidine (MIBG) in high effective specific activity was prepared using 3‐tributylstannylbenzylguanidine as the precursor. The labeling was carried out in aqueous solution with the insoluble and lyophilized precursor suspended in the solvent. Simply by filtration, the starting material and by‐products were readily separated from the labeled solution. Less than 1.15 ppb tin has remained in the filtrate as determined by the atom fluorescence spectrometry. By this approach, high specific activity (3.4 GBq/µmol) [¹³¹I]MIBG was obtained in 72.3 ± 3% (n = 3) radiochemical yield and 97.3 ± 2% (n = 3) radiochemical purity. The whole preparation could be finished in less than 10 min. According to this method, a kit for the preparation of ¹²³I‐MIBG and ¹³¹I‐MIBG is currently being developed.     

CD30-positive lymphoma in human T-cell leukaemia virus type 1 carrier without monoclonal integration of HTLV-1

Summary. CD30, Ki-1 antigen, an activated T-cell antigen, is a member of the nerve growth factor receptor family. This antigen is expressed on the lymphoma cells of some adult T-cell leukaemia/lymphoma (ATL/L) patients and some patients with Epstein-Barr virus infection. CD30-positive large cell cutaneous T-cell lymphomas occasionally integrate a defective HTLV-1 provirus. We describe here an HTLV-1 carrier who developed Ki-1 lymphoma with no evidence of monoclonal integration of the HTLV-1 proviral sequence.     

Results of Duchenne muscular dystrophy family screening in practice: leaks rather than cascades?

McGowan R, Challoner BR, Ross S, Holloway S, Joss S, Wilcox D, Holden ST, Tolmie J, Longman C. Results of Duchenne muscular dystrophy family screening in practice: leaks rather than cascades? Duchenne muscular dystrophy (DMD) is a progressive neuromuscular disease caused by mutations in the gene that encodes the protein dystrophin. Approximately 2 of 3 affected boys inherit their mutation from their carrier mother whereupon other female relatives are at risk of carrying the mutation. Female carriers are also at risk of developing cardiomyopathy and regular cardiac screening is recommended. Clinical genetics services offer genetic counselling and carrier tests for consenting relatives of DMD patients known as ‘cascade screening’. We retrospectively analysed data from two genetics centres, West of Scotland and South East Thames where the latter centre operated a computer‐held DMD register. Over the period, 1971–2008, a total of 843 potential carriers, in 195 West of Scotland families, were tested: 16% of 1st degree relatives and 48% of 2nd degree and more distant relatives were not tested. In South East Thames, a total of 1223 potential carriers in 349 families were tested: 49% of 1st degree and 65% of 2nd degree and more distant relatives were not tested. These data are similar to Becker muscular dystrophy/DMD carrier screening results recently reported from the Netherlands. Retrospective results from three countries indicate that despite efforts to offer extended cascade screening, significant numbers of potential carriers of DMD remain unaware of their reproductive and health risks.     

Factors that influence parents’ experiences with results disclosure after newborn screening identifies genetic carrier status for cystic fibrosis or sickle cell hemoglobinopathy

Objective

Newborn screening (NBS) identifies genetic carriers for sickle cell hemoglobinopathy and cystic fibrosis. We aimed to identify factors during initial NBS carrier results disclosure by primary care providers (PCPs) that influenced parents’ experiences and reactions.

Methods

Open-ended responses from telephone interviews with 270 parents of carriers were analyzed using mixed-methods. Conventional content analysis identified influential factors; chi-square tests analyzed relationships between factors and parent-reported reactions.

Results

Parents reported positive (35%) or negative (31%) reactions to results disclosure. Parents’ experiences were influenced by specific factors: content messages (72%), PCP traits (47%), and aspects of the setting (30%). Including at least one of five specific content messages was associated (p < 0.05) with positive parental reactions; omitting at least one of four specific content messages was associated (p < 0.05) with negative parental reactions. Parents reported positive reactions when PCPs avoided jargon or were perceived as calm. Parents reported negative reactions to jargon usage and results disclosure by voicemail.

Conclusion

Parents identified aspects of PCP communication which influenced their reactions and results disclosure experiences.

Practice implications

Our findings suggest ways PCPs may improve communication of carrier results. PCPs should provide specific content messages and consider how their actions, characteristics, and setting can influence parental reactions.     

多西紫杉醇-海豹油纳米结构脂质载体的抗肿瘤活性评价

目的探讨多西紫杉醇(docetaxel,DTX)海豹油脂质体的抗肿瘤活性以及与脂肪乳的比较。方法采用正交试验设计法筛选处方,通过高压乳匀法制备多西紫杉醇海豹油脂质体。测定其粒径、电位、包封率、体外释药、血浆中稳定性等。并采用四甲基偶氮唑盐〔3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide,MTT〕进行体外抗肿瘤活性研究,以及采用荷肉瘤S180小鼠进行体内抗肿瘤活性研究,考察各组抑瘤率和存活率。结果多西紫杉醇海豹油脂质体的粒径在200 nm左右,Zeta电位为-30~-50 m V,包封率达95%以上。体外释放研究证明多西紫杉醇脂肪乳与多西紫杉醇海豹油脂质体具有一定的p H敏感性,且推测多西紫杉醇海豹油脂质体具有更强的缓释作用。血浆中稳定性研究证明多西紫杉醇脂肪乳与多西紫杉醇海豹油脂质体在血浆中较稳定,释放行为缓慢。结论由MTT法结果得多西紫杉醇海豹油脂质体、多西紫杉醇脂肪乳与DTX均表现出较强的细胞毒性作用,且多西紫杉醇海豹油脂质体具有一定的缓释作用。以荷肉瘤S180小鼠为模型的体内抗肿瘤活性研究表明多西紫杉醇脂肪乳与多西紫杉醇海豹油脂质体在血浆中12 h内累积释放量分别为(13.82±0.59)%与(12.91±0.60)%。说明剂型在血浆中较稳定,释放行为缓慢。另外,DTX组小鼠9 d存活率为0,多西紫杉醇脂肪乳组于9 d存活率为93.3%,而多西紫杉醇海豹油脂质体组小鼠9 d存活率为100%,说明多西紫杉醇海豹油脂质体使得耐受剂量提高,降低了药物的不良反应,提高用药安全性与用药的顺应性。