Effects of short-term hypoxia on platelet counts of mice

Recent studies have shown that long-term hypoxia causes decreased platelet counts in mice and short-term hypoxia increased platelet counts. In an attempt to explain the mechanism that increases platelet counts of mice after exposure to short-term hypoxia, we measured platelet counts, total circulating platelet counts (TCPC), total circulating platelet masses (TCPM), percentages of 35S incorporation, and platelet sizes. Platelet counts, as well as TCPC and TCPM of mice, increased after 1-3 days of hypoxia, but these values were decreased after 6-7 days of hypoxia. Although platelet counts were increased in hypoxic mice, the percentage 35S incorporation into platelets and platelet sizes did not show a concurrent increase. After 6 days of hypoxia, average platelet diameters began to increase as platelet counts decreased. Splenic release did not account for the increase in platelet counts of mice after short-term hypoxia. It seems possible, therefore, that megakaryocytes "shed" platelets into the circulation in response to hypoxia. The platelets that enter the circulation in response to short-term hypoxia are smaller and incorporate less 35S than platelets that are produced in response to acute thrombocytopenia.     

Dynamic exercise therapy in rheumatoid arthritis: a systematic review

The aim of this systematic review was to determine the effectiveness of dynamic exercise therapy in improving joint mobility, muscle strength, aerobic capacity and daily functioning in patients with rheumatoid arthritis (RA). In addition, possible unwanted effects such as an increase in pain, disease activity and radiological progression were studied. A computer-aided search of the MEDLINE, Embase and SCISEARCH databases was performed to identify controlled trials on the effect of exercise therapy. Randomized trials were selected on the effect of dynamic exercise therapy in RA patients with an exercise programme fulfilling the following criteria: (a) intensity level such that heart rates exceeded 60% of maximal heart rate during at least 20 min; (b) exercise frequency > or = 2 a week; and (c) duration of intervention > or = 6 weeks. Two blinded reviewers independently selected eligible studies, rated the methodological quality and extracted data. Six out of 30 identified controlled trials met the inclusion criteria. Four of the six included studies fulfilled > or = 7/10 methodological criteria. Because of heterogeneity in outcome measures, data could not be pooled. The results suggest that dynamic exercise therapy is effective in increasing aerobic capacity and muscle strength. No detrimental effects on disease activity and pain were observed. The effects of dynamic exercise therapy on functional ability and radiological progression are unclear. It is concluded that dynamic exercise therapy has a positive effect on physical capacity. Research on the long-term effect of dynamic exercise therapy on radiological progression and functional ability is needed.      

门诊与住院患者口服抗凝剂治疗的安全性指征

1 引言 英国血液标准化委员会于1998年公布了第三版口服抗凝剂治疗指南,并于2006年修订.这些指南在安全性指征方面值得称道,但对开始口服抗凝剂治疗患者和已持续进行口服抗凝剂治疗的患者来说,安全性指征和危险性是相互伴随的.并非所有的安全性指征都要被医务工作者所采纳,而是为他们提供一种选择,可根据具体情况和需求选择最有用的指标.为了医疗服务的健康发展,这些安全性指征可以用来设立各种标准和规范,并进行相应的监督和审计.     

Treatment of cluster headache in pregnancy and lactation

Cluster headache is a rare disorder in women, but has a serious impact on the affected woman's life, especially on family planning. Women with cluster headache who are pregnant need special support, including the expertise of an experienced headache centre, an experienced gynaecologist and possibly a teratology information centre. The patient should be seen through all stages of the pregnancy. A detailed briefing about the risks and safety of various treatment options is mandatory. In general, both the number of medications and the dosage should be kept as low as possible. Preferred treatments include oxygen, subcutaneous or intranasal sumatriptan for acute pain and verapamil and prednisone/prednisolone as preventatives. If there is a compelling reason to treat the patient with another preventative, gabapentin is the drug of choice. While breastfeeding, oxygen, sumatriptan and lidocaine for acute pain and prednisone/prednisolone, verapamil, and lithium as preventatives are the drugs of choice. As the individual pharmacokinetics differ substantially, adverse drug effects should be considered if unexplained symptoms occur in the newborn.     

Patient satisfaction with doctor–patient interaction in a radiotherapy centre during the severe acute respiratory syndrome outbreak

An outpatient radiotherapy department assessed how precautions implemented during the severe acute respiratory syndrome (SARS) outbreak affected patient satisfaction with doctor–patient interaction and explored variables potentially influencing satisfaction. The information obtained would help prepare us for future infectious disease outbreaks. Outpatients seen during the outbreak completed a validated questionnaire assessing satisfaction with doctor–patient interaction. Additional items assessed included patients’ perception of SARS measures and patient demographics. Of 149 patients, 97% had heard of SARS, 92% believed SARS precautions necessary, and 54% believed contracting SARS was possible despite the precautions. Patients were satisfied with doctors wearing masks (97%), temperature checks (97%), and patients wearing masks (96%). Despite the high satisfaction levels with SARS precautions, 24% believed it had adversely affected doctor–patient interaction. With regards to doctor–patient interaction, 94% of patients were satisfied. Patients were most satisfied with the ‘information exchange’ domain (mean score 3.23 out of 4) compared to other domains (P < 0.0001, 100.00% confidence) and were less satisfied with the ‘empathy’ domain compared to other domains (P < 0.0001, 100.00% confidence). Patients were most satisfied with understanding their treatment plan (100%), doctor being honest (97%) and being understood (96%). Patients were least satisfied with information about caring for their illness (61%), that the visit could be better (59%), and the doctor showing more interest (58%). On multivariate analysis, patients who were less satisfied with SARS measures were significantly less satisfied with doctor–patient interaction (P = 0.0001). Dissatisfaction with SARS measures was associated with significant dissatisfaction for questions in all domains. Older age and non‐breast cancer patients were also less satisfied with doctor–patient interaction. Most (94%) of patients were satisfied with doctor–patient interaction, despite implementation of infectious disease prevention measures. However, patients who were dissatisfied with the SARS precautions had poorer satisfaction. In particular, physician empathy appeared to be most adversely affected. The results have relevance to any radiotherapy department preparing contingency plans in the event of infectious disease outbreaks.     

Endometrial adenosarcoma with adjuvant tamoxifen therapy for primary breast carcinoma

The first documented case of endometrial adenosarcoma associated with chronic tamoxifen usage is reported.     

Sucrose density gradient analysis of erythrocyte membranes in hemolytic anemias

To investigate the membrane abnormalities that may play a pathophysiologic role in several hemolytic anemias we determined the density distribution on sucrose density gradients of human red blood cell (RBC) membranes from patients with these disorders, from normal controls, and from incubated normal RBC. We analyzed the fractions for membrane-adsorbed hemoglobin (Hb), globin, and nonglobin cytoplasmic proteins. The relationship between the cytoplasmic proteins adsorbed on the membranes and the specific gravity (SG) of the membranes was linear. An increase in SG of the entire membrane population was seen in Hb C disease due to adsorbed Hb. Subpopulations of membranes with increased SG due to adsorption of nonglobin protein were evident in the membranes from two splenectomized patients with hemolytic glucose-6- phosphate dehydrogenase (G6PD) variants. Dense membrane subpopulations found in RBC membranes from three splenectomized patients with Hb Koln were associated with adsorbed globin, while similar subpopulations in RBC membranes from three splenectomized patients with hereditary spherocytosis demonstrated increased SG due to adsorbed Hb. Splenectomized normals had no such abnormality in membrane density. Sucrose density gradients demonstrate that membrane bound cytoplasmic protein is characteristic of the RBC membranes in several hemolytic disorders. Additionally, gradients are useful for the isolation and further analysis of those subpopulations of RBC membranes with abnormal SG and exaggerated membrane protein abnormalities.     

Physics of ultrasound

Ultrasound is a form of non-ionizing radiation that uses high-frequency sound waves to image the body. It is a real-time investigation which allows assessment of moving structures and also facilitates measurement of velocity and directionality of blood flow within a vessel. It can be used for a variety of purposes in the intensive care setting, for example to aid central venous catheter and pleural drain insertion. When using this imaging modality it is vital to understand the relevant physical principles and how the images are created. This article will explain these principles, including the use of Doppler ultrasound and the interpretation of common artefacts.