醇对SDS-CTAB-H2O体系双水相性质的影响

研究了短链一元醇(乙醇、正丁醇)和二元醇(乙二醇、1，4—丁二醇)对正负离子表面活性剂混合溶液(十二烷基硫酸钠—十六烷基三甲基溴化铵—水)双水相的影响。结果表明：一元醇的加入不但缩短了双水相的成相时间、使原水溶液双水相的区域得到扩展而且还会导致新双水相区域的出现，这种影响随着醇类链长的增长而增大。而二元醇的加入对双水相的相图影响不大，只是对形成双水相的表面活性剂最低总浓度稍有影响。实验结果也表明，出现双水相的表面活性剂最低总浓度与混合溶液的临界胶束浓度(CMC)有关，但CMC并不是决定出现双水相表面活性剂最低浓度的唯一因素。     

Role of psychologic and social variables in TMJ Pain Dysfunction Syndrome (PDS) symptoms

The aim of this study was to measure the relative importance of a number of psychologic and social variables in explaining the severity of symptoms of functional disturbances of the stomatognathic system. 261 non-care seeking patients with respect to pain and dysfunction of the stomatognathic system were examined. The total sample consisted of two subgroups: Group 1 (n = 130) with a complete natural dentition and Group 2 (n = 131) wearing complete maxillary and mandibular dentures. Symptoms of functional disturbances of the stomatognathic system were assessed using two questionnaires. One was derived from the Anamnestic Dysfunction Index and the other was an extended questionnaire which included accessory symptoms frequently mentioned in the literature. The patients also completed the Hopkins Symptom Checklist, the Dutch Personality Inventory, and a Dutch form of the Minnesota Multiphasic Personality Inventory. In both patient subgroups symptoms of functional disturbances of the stomatognathic system were significantly correlated with patient's sex and a complex of highly intercorrelated psychologic variables: psychoneurotic- and somatic symptoms, neuroticism, negativism, and somatization.     

Interrelations between anti-tumour activity, DNA breakage, and DNA binding kinetics for 9-aminoacridinecarboxamide anti-tumour agents

For a series of 9-aminoacridinecarboxamides, anti-tumour activity in vivo and cytotoxicity in vitro are correlated directly with the ability of the compounds to cause DNA single-strand breaks and with their DNA-dissociation mechanisms and residence times. It is suggested that one important consequence of long DNA residence times may be an enhanced ability to cause DNA strand breaks by a non-oxidative mechanism.     

Hip disarticulation--the evolution of a surgical technique

Introduced in the 18th century, hip disarticulation was considered to be one of the most radical operations performed for trauma or disease of the lower limb. The high morbidity and mortality associated with it ensured that it was a rarely performed procedure. It is fortunate that it remains extremely uncommon to the present day. Since the first successful hip disarticulation was described, a number of important advances have occurred. General medical care has improved dramatically and the development of anaesthesia, analgesics, antibiotics and blood transfusions has resulted in greatly decreased morbidity associated with this dramatic operation. This review on the history of hip disarticulation outlines the surgical evolution of the operation, the indications for its use and the techniques used. It draws on the early experiences and preferred techniques of the surgeons of the 19th century, with some discussion on the methods employed to reduce intraoperative haemorrhage. Further development of techniques in the 20th century is also described together with discussion on the evolution of hindquarter amputation.     

Mode and kinetics of DNA binding of the anti-tumour agent bisantrene

Viscometric measurements using covalently closed-circular DNA and sonicated rod-like fragments of calf thymus DNA show that the DNA-binding anti-cancer drug bisantrene intercalates with a helix unwinding angle of 14 degrees, and causes an increase in DNA contour length of 2.8A per bound drug molecule. Measurements of DNA affinity using the ethidium displacement method indicate binding constants of 7-8 X 10(7) M-1 for both natural and synthetic DNAs in buffer of ionic strength 0.1. The bimolecular rate constant for association with calf thymus DNA is greater than 1 X 10(7)M-1 s-1 at 20 degrees C and ionic strength 0.1, as determined by stopped-flow spectrophotometry. Surfactant sequestration studies of the dissociation of bisantrene from both calf thymus and synthetic DNAs reveal that the mechanism is complex, involving at least three distinguishable processes in all cases. The kinetic profiles are found to be essentially independent of DNA type, with average reciprocal time constants in the range 1-3 s-1 at a binding ratio of one drug molecule per 20 base pairs in buffer of ionic strength 0.1 at 20 degrees C. These results are discussed with respect to the mechanism of binding of bisantrene to DNA.