Platelet rescue by macrophage depletion in obese ADAMTS-13-deficient mice at risk of thrombotic thrombocytopenic purpura.

Essentials Obesity is a potential risk factor for development of thrombotic thrombocytopenic purpura (TTP). Obese ADAMTS-13-deficient mice were triggered with von Willebrand factor (VWF). Depletion of hepatic and splenic macrophages protects against thrombocytopenia in this model. VWF enhances phagocytosis of platelets by macrophages, dose-dependently. SUMMARY: Background Thrombotic thrombocytopenic purpura (TTP) is caused by the absence of ADAMTS-13 activity. Thrombocytopenia is presumably related to the formation of microthrombi rich in von Willebrand factor (VWF) and platelets. Obesity may be a risk factor for TTP; it is associated with abundance of macrophages that may phagocytose platelets. Objectives To evaluate the role of obesity and ADAMTS-13 deficiency in TTP, and to establish whether macrophages contribute to thrombocytopenia. Methods Lean or obese ADAMTS-13-deficient (Adamts-13-/- ) and wild-type (WT) mice were injected with 250 U kg-1 of recombinant human VWF (rVWF), and TTP characteristics were evaluated 24 h later. In separate experiments, macrophages were depleted in the liver and spleen of lean and obese WT or Adamts-13-/- mice by injection of clodronate-liposomes, 48 h before injection of rVWF. Results Obese Adamts-13-/- mice had a lower platelet count than their lean counterparts, suggesting that they might be more susceptible to TTP development. Lean Adamts-13-/- mice triggered with a threshold dose of rVWF did not develop TTP, whereas typical TTP symptoms developed in obese Adamts-13-/- mice, including severe thrombocytopenia and higher lactate dehydrogenase (LDH) levels. Removal of hepatic and splenic macrophages by clodronate injection in obese Adamts-13-/- mice before treatment with rVWF preserved the platelet counts measured 24 h after the trigger. In vitro experiments with cultured macrophages confirmed a VWF dose-dependent increase of platelet phagocytosis. Conclusions Obese Adamts-13-/- mice are more susceptible to the induction of TTP-related thrombocytopenia than lean mice. Phagocytosis of platelets by macrophages contributes to thrombocytopenia after rVWF injection in this model.

Prevalence and risk factors for self-reported chronic disease amongst Inuvialuit populations.

BACKGROUND: Chronic disease prevalence amongst Canadian Arctic populations is increasing, but the literature amongst Inuvialuit is limited. The present study aimed to provide baseline data that could be used to monitor changes in chronic disease risk factors and long-term health in the Arctic by determining prevalence and risk factors of self-reported chronic disease amongst adult Inuvialuit in remote communities. METHODS: Self-reported demographics and history of chronic disease (hypertension, heart disease, diabetes and cancer) were collected in three communities between July 2007 and July 2008 in the Northwest Territories. Food frequency questionnaires recorded dietary intake, International Physical Activity Questionnaires recorded physical activity and anthropometric measures of height and weight were obtained. RESULTS: Response rates ranged from 65-85%. More than 20% of the 228 participants aged 19-84 years reported having a chronic disease. Age-adjusted prevalence was 28, 9, 9 and 6 per 100 for hypertension, heart disease, diabetes and cancer, respectively. Compared with non-cases, participants reporting hypertension were more likely to have a higher body mass index and a lower level of education. Hypertension was more common amongst participants reporting heart disease and diabetes than Inuvialuit not reporting these morbidities. CONCLUSIONS: Inuvialuit participants in this study were most affected by hypertension and diabetes compared with heart disease or any cancer. Female participants had a higher prevalence of heart disease compared with the Canadian average. Primary preventive strategies are necessary to mitigate the increasing rates of chronic disease risk factors in this population. Further studies with a larger sample size and measured chronic disease are necessary to confirm the findings obtained in the present study.

Inuvialuit adults in the Canadian Arctic have a high body mass index and self-reported physical activity.

BACKGROUND: Inuvialuit in Arctic Canada are undergoing nutrition and lifestyle transitions that encourage decreased physical activity (PA) and increased body mass index (BMI), although data specific to PA and BMI within this unique population are not currently available. The present study aimed to characterise current PA and BMI levels in a sample of Inuvialuit adults. METHODS: Inuvialuit adults randomly selected from a cross-sectional survey of three communities in the Northwest Territories, Canada, completed an adapted International Physical Activity Questionnaire (IPAQ) and an anthropometric questionnaire to obtain height and weight. Data were analysed using the standardised IPAQ protocol, and the results are presented by gender and age group (≤50 and >50 years). RESULTS: One hundred and ninety-six Inuvialuit adults [148 women, 48 men; mean (standard deviation (SD)) ages 45 (14) and 41 (14) years, respectively; age range 19-84 years] completed the IPAQ (response rates 65-85%). Seventy-one percent of men and 74% of women allowed height measurements, whilst 81% and 84% allowed weight measurements, respectively; the remainder provided self-reported anthropometrics. Mean (SD) BMIs were 28.6 (7.7) kg/m(2) for males and 30.5 (8.8) kg/m(2) for females. The greatest percentage of participants in both gender and age groups fell into the obese BMI category. Self-reported PA was high, with means for men and participants ≤50 years in the high category of PA and means for women and participants >50 years in the medium category. Almost two-thirds (65%) of participants were classified as being overweight or obese, although 89% reported medium or high levels of PA. CONCLUSIONS: The results obtained in the present study indicate widespread overweight/obesity accompanying high levels of self-reported PA.

Manual method for liquid-based cytology: a demonstration using 1,000 gynecological cytologies collected directly to vial and prepared by a smear-slide technique.

We report on the formulation and use of an alcoholic-agar additive solution generally useful for rapid, inexpensive liquid-based cytology slide preparation. Gynecological cytology specimens were collected from 1,000 women. Two hundred fifty aliquots each of CytoRich, CytoRich Red (Tripath Imaging, Inc., Burlington, NC), Preservcyt (Cytyc Corp., Boxborough, MA), and DINA*TRANS (DINA*CYT Corp., Portland, OR) fixatives were used for this study. Fixed cell suspensions from 1,000 women, seen consecutively by a general obstetrics and gynecology practice, were vortex-mixed and transferred into a premeasured amount of alcoholic-agar in test tubes. Test tubes were conventionally centrifuged, cells were trapped in a spontaneously formed agar-gel, and the supernatant solutions were decanted. Vortex-mixing cell buttons caused a rapid gel-to-sol transition, affording viscous cell suspensions that were applied to slides, smeared, and stained using Papanicolaou stains. Slides showed unclumped, monolayered, uniform, random cell-spreads. All of the fixatives afforded crisp presentation of normal and abnormal cells. There was an about 3-fold increase in HSIL+ (0.7-1.8%) and LSIL diagnoses (1.3-4.4%), and a 45% reduction in ASCUS diagnoses (3.3-1.8%), as compared to our cytology laboratory's previous year's patients' statistics with a concurrent 0.2% unsatisfactory rate, due solely to inadequate sampling. This manual method makes liquid-based cytology inexpensive and does not require specialized preparative devices.

Liquid-based cervical-cell collection with brushes and wooden spatulas: a comparison of 100 conventional smears from high-risk women to liquid-fixed cytocentrifuge slides, demonstrating a cost-effective, alternative monolayer slide preparation method.

Our purpose was to demonstrate that 17.5-mm liquid-based cytocentrifuge circle-slides made using a Hettich (Andreas Hettich Co., Tuttlingen, Germany) cytocentrifuge are at least as efficacious as conventional smears for detecting cervical abnormalities. One hundred conventional smears were collected with cytobrushes and wooden spatulas from high-risk women. Both devices were then placed into CytoRich Red (AutoCyte, Inc., Burlington, NC). Cells were concentrated from CytoRich Red by centrifugation and suspended in CytoRich Yellow. Two 17.5-mm circle-slides were produced, compared to each other in order to test reproducibility of diagnoses between slides, and compared to conventional slides. Sixty-five normals, three ASCUS, three LSIL, and two HSIL matched. Overall, cytocentrifugation yielded 27 additional findings among 25 cases. Also, it downgraded one conventional ASCUS to normal (immature metaplasia and chronic inflammation) and one conventional HSIL to normal (transitional cell metaplasia). Cytocentrifugation of 14 conventional normals afforded four ASCUS and 10 LSIL. Cytocentrifugation of 11 conventional ASCUS afforded nine LSIL and two HSIL (one with AIS). One HSIL + AIS was found with a conventional HSIL. Cytobrushes and wooden spatulas can be used to collect material for liquid-based cervico-vaginal cytology if they are placed into CytoRich Red. Hettich cytocentrifuge slides were more reliable than conventional smears in presenting well-dispersed, sharply imaged cells, affording greater diagnostic sensitivity and certainty. Compared to previous split-sample studies, three different outcomes were noted: 1) the endocervical component was consistently well-represented; 2) AIS was seen more often in liquid-based slides; and 3) the liquid-based slide did not underdiagnose its conventional companion. The liquid-based preparations downgraded one ASCUS to normal and one conventional HSIL to transitional-cell metaplasia. Histology correlation of these two cases agreed with the liquid-based cytology diagnoses, which validates their specificity. These improvements are ascribed to differences in fixation and processing. The low cost, ease of operation, and reusable chambers of the Hettich cytocentrifuge make it a cost-effective liquid-based cytology instrument, especially for small to intermediate-size laboratories. The claims that this paper makes must be proven by additional studies, and test implementation needs to be scrutinized by appropriate regulatory agencies whose standards may vary from country to country. Diagn. Cytopathol. 2000;22:86-91.

Rare epithelial sheets with "cancer-like" nuclei presenting against a background of cytologically normal-appearing endometrial epithelium in endometrial brush samplings: establishing a differential diagnosis.

Liquid-fixed Tao brush samples showing small quantities (less than 10%) of endometrial epithelial sheets with cancer-like nuclei that are admixed with benign endometrium raise a concern about false-positive cytology interpretations. This paper details 7 cases along with the outcomes of three prior papers that touch on the differential diagnosis of "small amounts of atypical epithelium with cancer-like nuclei." Liquid-fixed, cytocentrifuge-processed Tao brush endometrial samples from 7 women showing "small amounts of atypical epithelium with cancer-like nuclei" were followed up by hysterectomy. Clinical presentations, diagnostic tests, surgical procedures, and tissue outcomes are detailed. Four women had hyperplastic polyps (three with focal atypical complex hyperplasia, and one with focal atypical simple hyperplasia). One had endometrial microcarcinoma. One had p53-positive endometrial intraepithelial carcinoma (EIC). One had endometrial intraepithelial neoplasia (EIN). The differential diagnosis of the index cytological finding, "small quantities of endometrial epithelial sheets with cancer-like nuclei admixed with benign endometrium," includes hyperplastic polyp, EIC, microcarcinoma/EIN, and carcinoma metastatic to the endometrium. Combining endometrial brushing, endovaginal sonography/sonohysterography, and selective immunostaining may be useful for both detecting and sorting out these lesions. Diagn. Cytopathol. 1999;21:378-386.