Platelet kinetics in patients with idiopathic thrombocytopenic purpura and moderate thrombocytopenia

We studied ten normal subjects and 20 patients with stable, untreated idiopathic thrombocytopenic purpura (ITP) and platelet counts in the range of 35,000 to 110,000/microL. The diagnosis was made by clinical criteria. Platelet-associated IgG was increased in all nine of the nine patients studied. Autologous platelets were labeled with chromium 51 and reinfused for measurement of mean cell life and platelet production rate. Mean cell life was calculated by two methods, weighted mean and multiple hit, with excellent agreement between the two. As expected, mean cell life was significantly reduced in ITP patients as compared to the normal subjects (2.9 days v. 8.0 days, P less than .001). However, mean platelet production rates in ITP patients and normal subjects, 3.5 and 3.8 X 10(9) platelets/k/d respectively, were not significantly different. Platelet production rate was above and below the normal range (2 to 5.6 X 10(9) platelets/k/d) in two and four patients, respectively. We conclude that the rate of platelet production is not increased in most patients with ITP who have platelet counts greater than 35,000/microL. We did find that platelet size was increased in eight of the 12 patients in whom it was measured, including two of the patients with low platelet production.     

Elastic moduli of normal and pathological human breast tissues: an inversion-technique-based investigation of 169 samples

Understanding and quantifying the mechanical properties of breast tissues has been a subject of interest for the past two decades. This has been motivated in part by interest in modelling soft tissue response for surgery planning and virtual-reality-based surgical training. Interpreting elastography images for diagnostic purposes also requires a sound understanding of normal and pathological tissue mechanical properties. Reliable data on tissue elastic properties are very limited and those which are available tend to be inconsistent, in part as a result of measurement methodology. We have developed specialized techniques to measure tissue elasticity of breast normal tissues and tumour specimens and applied them to 169 fresh ex vivo breast tissue samples including fat and fibroglandular tissue as well as a range of benign and malignant breast tumour types. Results show that, under small deformation conditions, the elastic modulus of normal breast fat and fibroglandular tissues are similar while fibroadenomas were approximately twice the stiffness. Fibrocystic disease and malignant tumours exhibited a 3-6-fold increased stiffness with high-grade invasive ductal carcinoma exhibiting up to a 13-fold increase in stiffness compared to fibrogalndular tissue. A statistical analysis showed that differences between the elastic modulus of the majority of those tissues were statistically significant. Implications for the specificity advantages of elastography are reviewed.     

An inverse problem solution for measuring the elastic modulus of intact ex vivo breast tissue tumours

Soft tissue elasticity has been a subject of interest in biomedical applications as an aid to medical diagnosis since the dawn of medicine. More recently, this has led to the concept of elastography with the aim of imaging the spatial distribution of tissue elasticity. Interpreting elastography images requires reliable information pertaining to elastic properties of normal and pathological tissues. Such information is either very limited or not available in the literature. Elastic modulus measurement techniques developed for soft tissues generally require tissue excision to prepare samples for testing. While this may be done with normal tissues, tumour tissue excision is generally not permissible because tumour pathological assessment requires that the tumour be kept intact. To address this limitation, we developed a system to measure the Young's modulus of tumour specimens. The technique consists of indenting the tumour specimen while measuring indentation force and displacements. To obtain the Young's modulus from the measured force-displacement slope, we developed an iterative inversion technique that uses a finite element model of the piecewise homogeneous tissue slice in each iteration. Preliminary elasticity measurement results of various breast tumours are presented and discussed. These results indicate that the proposed method is robust and highly accurate. Furthermore, they indicate that a benign lesion and malignant tumours are roughly five times and ten times stiffer than normal breast tissues respectively.     

Voxel based versus region of interest analysis in diffusion tensor imaging of neurodevelopment

There are two main methods of quantitative analysis in diffusion tensor imaging (DTI) studies: manual region of interest (ROI) and automated voxel based. The purpose of this study is to compare the results of each of these methods applied to the same data set. Linear correlative analysis was performed for mean diffusivity (Trace/3 ADC) and for fractional anisotropy (FA) versus age within 8-12 years (N = 32) and within 21-27 years (N = 28), as well as a group comparison. SPM analysis identified more structures changing with age, partly due to the limited regions measured with ROI analysis. In general, ROI and voxel-based analysis methods produced comparable results for widespread reductions of Trace/3 ADC and increases of FA with age, particularly for group comparison. The discrepancies (i.e., missed regions) were likely related to problems of spatial normalization for SPM analysis, and masking localized changes by averaging all the voxels within a region of interest for ROI analysis. These two analysis methods for DTI offer complementary results, but neither one yields the complete story of neurodevelopment.     

Hyperhomocysteinemia exacerbates the development of intimal hyperplasia in Sprague-Dawley rats: Alleviation by rosiglitazone

The amino acid intermediate homocysteine (Hcy) is formed during the metabolism of methionine to cysteine. Hyperhomocysteinemia (HHcy) is recognized as an independent risk factor for coronary atherosclerosis. The circulating levels of total Hcy (tHcy) can increase due to intake of foods rich in methionine or deficiencies of vitamins such as folate, pyridoxine and cyanocobalamin, which are required for the metabolism of Hcy. In addition, mutations in the genes coding for Hcy metabolizing enzymes can contribute to an increase in tHcy levels. Clinical and epidemiological studies have shown that an elevated level of tHcy measured in serum or plasma is a strong predictor of cardiovascular disease risk, which appears to be greatest in patients who have HHcy following a methionine load. Intimal hyperplasia (IH) (intima/media [I/M] ratio) is the universal response of a vessel to injury and may result in vasoconstriction when left unattended. The effect of dietary HHcy on balloon catheter-injured carotid artery and its modulation (if any) by the peroxisome proliferator-activated receptor agonist gamma rosiglitazone was evaluated in 12-week-old female Sprague-Dawley rats fed either a control diet or a diet containing 1% L-methionine. Once the rats were established on the diet, the group that was fed 1% L-methionine was further subdivided and either given an aqueous preparation of 3 mg/kg/day rosiglitazone or the vehicle via oral gavage for one week. This was followed by surgically injuring the left carotid artery using a Maverick Over-The-Wire catheter (2.0 mm × 20 mm, 3.2F; Boston Scientific, USA). The rats were continued on their respective diets and drug regimen for 21 days postsurgery. On day 22 of the procedure, the rats were sacrificed for collection of blood, the carotid arteries and liver for biochemical and histological evaluation. Compared with controls there was a significant increase in both tHcy levels and I/M ratio in the rats fed 1% L-methionine (5.4±0.28 μM versus 32.8±3.01 μM, P<0.002; and 0.175±0.05 versus 1.05±0.23, P<0.005, respectively). The effect of rosiglitazone in rats fed the control diet was not prominent. On the other hand, administration of rosiglitazone to the rats on the 1% L-methionine diet significantly reduced the levels of serum tHcy (16.6±2.1 μM versus 32.8±3.01 μM, P<0.001); however, the tHcy levels remained significantly elevated compared with animals on the control diet (P<0.002). The group receiving the L-methionine diet plus rosiglitazone had an inhibition in the development of IH compared with those receiving the L-methionine diet alone (I/M of 0.278±0.041 versus 1.05±0.23, P<0.01). Moreover, the development of IH in the group receiving the L-methionine diet plus rosiglitazone treatment was not significantly different from that observed in the group on the control diet without rosiglitazone (0.278±0.041 versus 0.175±0.05, respectively). These findings may have important implications in deciphering the molecular mechanisms involved in the augmentation of IH in HHcy and modulation of this process by rosiglitazone.     

社区医护干预预防产后抑郁症的研究

[目的]调查产后抑郁症患者的现状及需求,探讨预防措施。[方法]定性与定量研究相结合,定性采用专题小组讨论和半结构性访谈,12人参加专题讨论、9人半结构性访谈;定量研究随机抽取本市各社区产后42d的产妇776例行问卷调查。[结果]产妇月子期间常发生头疼、恶心、焦虑、恐惧、失眠以及照顾新生儿困难;半结构性访谈中有1产妇处于产后抑郁症的临界,EPDS量表测定为12分;776例产妇月子里有身心健康问题者692例,求助者91.0%,其中需要社区护理人员帮助的71.7%,实际寻求帮助仅12.7%。[结论]预防产后抑郁症应实行社区医护人员培训与产后访视人员的准入制度,采取社区医护干预的三级预防,同时拓展社区产后保健服务的内涵。     

26万女性队列人群中乳腺癌与人工流产关系的研究（上海）

目的：评估人工流产（指手术流产）对乳腺癌危险性的可能影响。方法：研究在上海267040例妇女的一项乳房自我检查随机试验的队列人群中进行，由队列研究和巢式病例对照研究两部分组成。结果：依据基线调查表采集的资料分析，人工流产不增加乳腺癌危险性。调整潜在的混淆因素后，OR=1．06（95％CI：0．91～1．25）。人工流产次数增加无危险性趋势增加。从更详细的652例乳腺癌病例和694例对照资料分析，得出相似的结果。人工流产发生在首次生育后不增加危险性；少数妇女在首次生育前人工流产以及妊娠13周后人工流产，虽然被观察到危险性有增加，但无显著性统计学意义。结论：在中国，人工流产不是乳腺癌发生的重要原因。     

Changes in energy during treatment of depression: an analysis of fluoxetine in double-blind, placebo-controlled trials

More than two thirds of patients with depression present with symptoms of fatigue, low energy, and listlessness. Because daytime sedation may be a concern in such patients, a "nonsedating" antidepressant should be considered. The authors examined the effects of fluoxetine on depression-related disturbances in energy. Data from seven double-blind, placebo-controlled clinical trials in 2,075 patients with major depression were retrospectively analyzed. The Hamilton Rating Scale for Depression (HAM-D) Retardation factor score (total of items 1, 7, 8, and 14) was used as the primary measure of energy improvement, whereas the HAM-D-17 total score was used to assess changes in overall depression. Elderly patients (aged 60 years and older) were included in the overall group and were also analyzed separately. In addition, a subgroup analysis was performed using the HAM-D Retardation factor score to categorize patients as having low (score < 8) or high (score > or = 8) levels of retardation at baseline. Beginning at week 3, fluoxetine-treated patients experienced statistically significant reductions in their HAM-D Retardation factor score compared with placebo-treated patients. The reductions for the elderly subgroup were less than those for the overall population, but they were still statistically significant beginning at week 4. Patients in both the low and high baseline retardation groups improved significantly. HAM-D-17 total scores for fluoxetine-treated patients in all groups (total, elderly, high retardation, and low retardation) improved significantly compared with placebo-treated patients. These findings demonstrate that fluoxetine-treated patients experience an improvement in energy symptoms as their overall depression improves.