The acute effects of CMF-based chemotherapy on maxillary periodontal microcirculation

Purpose  A high incidence of oral complications is associated with chemotherapy (CT) treatment in cancer patients; however, while knowledge into molecular mechanisms of their pathobiology continue to evolve, the direct physiological effects of CT on oral tissue perfusion remain unexplored. The aim of this investigation was to assess the acute effects of CT on gingival microcirculation perfusion by measuring gingival capillary density. Methods  Twenty female specific-pathogen free New Zealand White rabbits were randomly divided into four groups receiving four different intravenous dose levels of cyclophosphamide, methotrexate, and fluorouracil (CMF). Noninvasive measurements of gingival capillary density were performed using sidestream dark-field (SDF) imaging prior to and 30 min after CT treatment. Four rabbits receiving saline solution were used as control animals. Results  Baseline gingival capillary density was 58 ± 11 cpll/mm², no significant differences in baseline capillary densities between the groups were found. From low to high dose CT, capillary density 30 min after CMF treatment increased in each group by 1 ± 7, 5 ± 7, 13 ± 18 and 20 ± 13 cpll/mm², respectively. Capillary density increase was significant in the high-dose group. No change in gingival capillary density was found in the control group. Conclusions  Periodontal microcirculation perfusion had increased 30 min after CT treatment as indicated by a rise in gingival capillary density. Our results support the idea that CT-induced microcirculatory response not only diligently delivers but also saturates peripheral oral tissues with antineoplastic agents by increasing surface area exposure. This functional response of the microcirculation to CT drugs may play a role in contribution to oral complications and the treatment of oral tumors.     

Which source should we use to measure quality of life in children with asthma: The children themselves or their parents?

This study compares the reproducibility, construct validity and responsiveness of self-report and parent-report quality of life questionnaires How Are You (HAY) for 8–12-year-old children with asthma. A total of 228 Dutch children with asthma and their parents completed the HAY and daily recorded the child's asthma symptoms in a diary. Additionally 296 age- and -gender matched healthy children and their parents completed the generic part of the HAY. Reproducibility and responsiveness were examined in a sub-group of 80 children with asthma. In this group, three measurements were carried out, at baseline, after one week and once during the following 6 month when the clinical asthma status had changed. The within-subject standard deviations (SD) of three dimensions (physical activities, social activities, self-management) differed significantly (p < 0.05) in favour of the parent-version, indicating that the reproducibility of the parent version was better than that of the child version. The mean score-differences between children with asthma and healthy children as reported by parents did not significantly differ from those reported by children, except for cognitive activities (e.g. be able to concentrate on school work). The mean differences with regard to children with a different actual asthma status (symptom analysis), as reported by both informants, did not differ. Compared to the child-version, the parent-version showed greater ability to detect changes in children's quality of life over time for all but one dimension, indicating better responsiveness. The results indicate that in discriminative studies child and parents reports can be substituted on a group-level. In longitudinal studies data have to be obtained from parents. Consequently, caregivers collecting quality of life data for longitudinal purposes in daily practice should collect these data simply from parents. This revised version was published online in June 2006 with corrections to the Cover Date.     

Variation in serum cholesterol level in the same person: what is the true value and when is it called a significant change?]

The blood cholesterol level is not constant over time. Changing values may be found when rechecking high values, especially in patients on a diet or receiving medication. Repeated measurements are necessary. It will then be possible to estimate the 'true mean value'. This is the theoretical average of a large number of measurements taken from one person. The study concentrated on the intra-individual variation of the serum cholesterol and the consequences for screening and follow-up. For this purpose, during a period of four weeks, cholesterol levels were measured 12 times in 33 men aged 25-40. The mean coefficient of variation was 5.7%, with wide differences between participants, ranging from 2.9% to 9.8%. The position of the 'true mean value' was estimated (with 90% confidence), after I resp. 3 determinations. These findings have consequences for the classification of subjects in the different risk categories as defined in the Dutch Cholesterol Consensus. It is also possible to determine if, after a period of intervention, there is a significant decline in the cholesterol level. Roughly, a decline of 10-12% indicates a significant difference.     

Changes in the management of patients with side effects from the treatment of hepatitis C

Since hepatitis C can be treated more and more successfully, treatment should be considered in every patient. In some of the patients infected by viral genotype I, the duration of treatment can be shortened: 24 weeks instead of 48 weeks. Maintaining the optimal dosage of ribavirin and peginterferon alpha is of great importance for successful treatment. For this purpose, new guidelines are proposed with reference to the haematological side effects, recommending more restraint with the reduction of the dosage and treatment in case of complaints. Treatment with peginterferon alpha frequently causes psychiatric problems, particularly depressive symptoms that are sometimes severe. Adequate treatment and support, including the use of antidepressants, are necessary in such cases and are often effective.     

鼠尾静脉流体力学转染技术对绿色荧光蛋白表达质粒器官靶向分布的影响

目的:观察流体力学尾静脉注射对绿色荧光蛋白基因器官靶向性的影响,为今后质粒载体的基因治疗和功能研究寻找潜在的靶器官。方法:实验于2005-12/2006-04在江西省分子医学重点实验室完成。选用健康雄性昆明鼠40只,将32只小鼠按随机数字表法分为流体力学注射和常规注射两大组,每大组再分为转染组和对照组两个小组(n=8),并设正常对照组(n=8)。①流体力学转染组将100μg/只绿色荧光蛋白表达质粒溶液2mL在5s内快速注入尾静脉;对照组仅在5s内注入林格氏液2mL。②常规注射组则将2mL林格氏液或绿色荧光蛋白表达质粒溶液在30s左右注入尾静脉。注射结束后24h采集各组小鼠血清检测转氨酶,并采集肝、脾、心、肾、肺和脑组织进行冰冻切片,部分肝组织采用多聚甲醛固定后切片,荧光显微镜下观察。结果:40只小鼠全部进入结果分析,无脱失。①流体力学注射组和常规注射组小鼠血清转氨酶与正常对照组比较差异均无显著性意义(P>0.05)。②常规尾静脉注射引起少数肾小球细胞表达绿色荧光蛋白,而肝、脾、心、肺及脑等组织未见明显绿色荧光蛋白表达。③流体力学注射引起肝内绿色荧光蛋白高水平表达,肝细胞表达率接近45%,其他组织则无绿色荧光蛋白表达。结论:流体力学方法是肝靶向性的活体基因转染方法,绿色荧光蛋白可作为该方法进行目的基因研究的一个可靠和方便的示踪剂。     

Uncoordinated expression of fibrinogen compared with thrombospondin and von Willebrand factor in maturing human megakaryocytes

The localization of three known alpha-granule proteins, thrombospondin (TSP), von Willebrand factor (vWF), and fibrinogen (Fg) has been studied in human megakaryocytes (MK) by immunofluorescence and immunoelectron microscopy. For this study, highly purified populations of MK were prepared from human bone marrow either by counterflow centrifugal elutriation or by cell culture from normal subjects and from two patients with megakaryoblastic leukemia. In normal bone marrow immature MK, TSP, and vWF were observed in the Golgi-associated vesicles and in small immature alpha-granules; in mature MK, they were found in the matrix of the mature large alpha-granules. Surprisingly, Fg was detected neither in the Golgi area, nor in the small precursors of alpha-granules; it was only found in the mature alpha-granules but this labeling was generally weaker than in blood platelets. In order to confirm these differences between the expression of Fg and vWF or TSP additional studies were performed on cultured maturing MK: immunofluorescent and ultrastructural immunogold labeling confirmed that vWF appeared early in the maturation while the same immature MK were negative for Fg. In the late maturation stage, the three proteins were detected in the alpha-granules. In order to know whether Fg was lately synthesized or endocytosed from the outside medium, normal MK were grown in the presence of either normal or afibrinogenemic plasma, and normal serum. Fg was detected only in the alpha-granules of MK grown in normal plasma. Similar results were observed with malignant MK, whose maturation was independent of the culture conditions. In conclusion, this study brings immunocytochemical evidence that vWF and TSP are synthesized by immature MK, whereas Fg appears later in the MK alpha-granules and its expression is dependent of the presence of an exogenous Fg source.     

Identification and characterization of a low-affinity granulocyte- macrophage colony-stimulating factor receptor on primary and cultured human melanoma cells

Hematopoietic growth factor receptors are present on cells of normal nonhematopoietic tissues such as endothelium and placenta. We previously demonstrated functional human granulocyte-macrophage colony- stimulating factor (GM-CSF) receptors on small cell carcinoma of the lung cell lines, and others have reported that certain solid tumor cell lines respond to GM-CSF in clonogenic assays. In the current study, we examine human melanoma cell lines and fresh specimens of melanoma to determine whether they have functional GM-CSF receptors. Scatchard analyses of 125I-GM-CSF equilibrium binding to melanoma cell lines showed a mean of 542 +/- 67 sites per cell with a kd of 0.72 +/- 0.14 nmol/L. Cross-linking studies in the melanoma cell line, M14, showed a major GM-CSF receptor species of 84,000 daltons. Under the conditions tested, the M14 cells did not have a proliferative response to GM-CSF in vitro, nor was any induction of primary response genes detected by Northern analysis in response to GM-CSF. Studies to determine internal translocation of the receptor-ligand complex indicated less than 10% of the 125I-GM-CSF internalized was specifically bound to receptors. Primary melanoma cells from five surgical specimens had GM-CSF receptors; Scatchard analysis was performed on one sample, showing 555 sites/cell with a kd of 0.23 nmol/L. These results indicate that human tumor cells may express a low-affinity GM-CSF receptor protein that localizes to the cell surface and binds ligand, but lacks functional components or accessory factors needed to transduce a signal.