Functional hyposplenism after hematopoietic stem cell transplantation.

Functional hyposplenism is associated with chronic GvHD (cGvHD) following hematopoietic stem cell transplantation (HSCT). We hypothesized that hyposplenism measured by pitted red cell counts in cGvHD was transient and related to the severity of disease. We performed a serial, retrospective review of 36 pediatric post-HSCT patients' pit counts at BC Children's Hospital from 2005 to 2013 and compared those counts with the clinical course of patients with late acute GvHD (aGvHD)/cGvHD. Of the 36 patients, 22 had late aGvHD/cGvHD based on National Institutes of Health consensus criteria. Fourteen of 22 GvHD patients had an abnormal pitted red cell count. Ten of 14 abnormal patients had late acute or overlap GvHD syndrome, primarily gastrointestinal disease. A second cohort was prospectively evaluated in a multicenter adult HSCT biomarker trial. We identified 3 out of 10 control patients who had an abnormal pitted red cell count, 3 out of 10 with classic cGvHD and 5 out of 9 patients with overlap syndrome were abnormal. In both the retrospective and prospective studies, hyposplenism was present in patients without late aGvHD/cGvHD suggesting current guidelines regarding antibiotic prophylaxis against encapsulated bacteria after HSCT need to be re-addressed and abnormal pit counts could be used to guide prophylaxis in all HSCT patients.

3-year results of a collaborative school-based oral health program in a remote First Nations community.

INTRODUCTION: Surveys of dental health among Aboriginal children in Canada, using scales such as the Decayed, Missing, and Filled Teeth (DMFT) score, indicate that Aboriginal children have 2 to 3 times poorer oral health compared with other populations. A remote First Nations community approached requested assistance in addressing the health of their children. The objective was to work with the community to improve oral health and knowledge among school children. The hypothesis formulated was that after 3 years of the program there would be a significant decrease in dmft/DMFT (primary/permanent) score. METHODS: This was a cross-sectional study of all school-aged children in a small, remote First Nations community. Pre- and post- intervention evaluation of oral health was conducted by a dentist not involved in the study. The intervention consisted of a school-based program with daily brush-ins, fluoride application, educational presentations, and a recognition/incentive scheme. RESULTS: Twenty-six children were assessed prior to the intervention, representing 45% of the 58 children then in the community. All 40 children in the community were assessed following the intervention. Prior to the intervention, 8% of children were cavity free. Following 3 years of the intervention, 32% were cavity free. Among the 13 children assessed both pre- and post-intervention, dmft/DMFT score improved significantly (p <0.005). The visiting hygienist noted increased knowledge about oral health. CONCLUSION: A community- and university-supported, school-based, collaborative oral health program improved oral health and knowledge among children in a remote First Nations community.

Diabetes screening of children in a remote First Nations community on the west coast of Canada: challenges and solutions.

Type 2 diabetes (T2D) and its precursor, impaired glucose tolerance (IGT), are now reaching epidemic proportions among Aboriginal Canadians. Of particular concern is the appearance and increasing prevalence of T2D and IGT among Aboriginal youth. At the request of three communities in the Tsimshian nation on the northern coast of British Columbia (with which the Department of Pediatrics, University of British Columbia, had a pre-existing partnership) a screening program was undertaken to determine the prevalence of T2D and IGT among the children. The long-term goal was the collaborative development of intervention programs for each community. The challenges of meeting this request included the sociological and ethical issues associated with research in First Nations communities, as well as the pragmatic issues of conducting complex research in remote communities. Three separate visits were undertaken to respect the cultural dynamics and capacity of the community to accommodate a project of this magnitude. The process began with dialogue, listening and presentations to the community. Only then began the planning of logistics and application for funding. Next, the team visited the communities to ensure understanding of exactly what was involved for the community, each child and family, and to be certain that consent was fully informed. For the diabetes screening visit, special arrangements including chartering a Beaver float plane were needed for the transport of the five-member team with all the necessary equipment, including a -20(o)C freezer to safeguard the integrity of blood samples. The 100% consent rate, successful conduct of study, and retention of community support achieved by the process, indicate that population-based clinical research is possible in remote First Nations communities. This is best achieved with appropriate dialogue, care, respect and planning to overcome the sociological, ethical and practical challenges.

Herpes simplex virus triggers and then disarms a host antiviral response.

Virus infection induces an antiviral response that is predominantly associated with the synthesis and secretion of soluble interferon. Here, we report that herpes simplex virus type 1 virions induce an interferon-independent antiviral state in human embryonic lung cells that prevents plaquing of a variety of viruses. Microarray analysis of 19,000 human expressed sequence tags revealed induction of a limited set of host genes, the majority of which are also induced by interferon. Genes implicated in controlling the intracellular spread of virus and eliminating virally infected cells were among those induced. Induction of the cellular response occurred in the absence of de novo cellular protein synthesis and required viral penetration. In addition, this response was only seen when viral gene expression was inhibited, suggesting that a newly synthesized viral protein(s) may function as an inhibitor of this response.

Growth factors and cytokines upregulate gelatinase expression in bone marrow CD34(+) cells and their transmigration through reconstituted basement membrane.

The mechanism(s) underlying the release of stem/progenitor cells from bone marrow into the circulation is poorly understood. We hypothesized that matrix metalloproteinases (MMPs), especially gelatinases, which are believed to participate in the proteolysis of basement membranes and in the migration of leukocytes, may facilitate this process. First, we investigated whether CD34(+) stem/progenitor cells express gelatinases A (MMP-2) and/or B (MMP-9) and whether growth factors and cytokines (granulocyte colony-stimulating factor [G-CSF], granulocyte-macrophage colony-stimulating factor [GM-CSF], stem cell factor [SCF], macrophage colony-stimulating factor [M-CSF], interleukin-3 [IL-3], IL-6, IL-8, and tumor necrosis factor-alpha [TNF-alpha]) are able to modulate their expression. Next, we examined the transmigration of these stem/progenitor cells through reconstituted basement membrane (Matrigel) and its modulation by growth factors and cytokines. CD34(+) cells were obtained from steady-state bone marrow and peripheral blood (from leukapheresis products collected either in steady-state hematopoiesis or after mobilization with G-CSF plus chemotherapy or G-CSF alone). We found that peripheral blood CD34(+) cells, regardless of whether they were mobilized or not, strongly expressed both gelatinases (MMP-2 and MMP-9) in contrast to steady-state bone marrow CD34(+) cells, which did not. However, all the growth factors and cytokines tested could induce MMP-2 and MMP-9 secretion by the latter cells. Moreover, the stimulatory effects of G-CSF and SCF on both MMP-2 and MMP-9 secretion were found to be significantly higher in CD34(+) cells isolated from bone marrow than in those from peripheral blood. In addition TNF-alpha, GM-CSF, and IL-6 increased the secretion of a partially active form of MMP-2. Basal transmigration of bone marrow CD34(+) cells through Matrigel was lower than that of peripheral blood CD34(+) cells (P <.0001), but growth factors and cytokines increased it by 50% to 150%. Positive correlations were established between expression of gelatinases and CD34(+) cell migration (r >.9). The stimulatory effect of G-CSF was significantly greater on the migration of CD34(+) cells from bone marrow than on those from peripheral blood (P =.004). Moreover, CD34(+) cell migration was reduced to approximately 50% by antibodies to MMP-2 and MMP-9, tissue inhibitors of metalloproteinases (rhTIMP-1 and -2), and o-phenanthroline. TNF-alpha-induced gelatinase secretion and migration of CD34(+) cells and of clonogenic progenitors (colony-forming unit-granulocyte-macrophage [CFU-GM], burst-forming unit-erythroid [BFU-E], colony-forming unit granulocyte, erythroid, monocyte, megakaryocyte [CFU-GEMM], and colony-forming unit-megakaryocyte [CFU-MK]) were dose-dependent. Therefore, this study demonstrated that CD34(+) cells that are circulating in peripheral blood express both MMP-2 and MMP-9 and transmigrate through Matrigel. In contrast, CD34(+) cells from steady-state bone marrow acquire similar properties after exposure to growth factors and cytokines, which upregulate expression of gelatinases and transmigration of these cells when they enter the bloodstream. Hence, we suggest that growth factors and cytokines induce release of stem/progenitor cells from bone marrow into peripheral blood during mobilization, as well as during steady-state hematopoiesis, by signaling through gelatinase pathways.

[New method of determination of carboxyhemoglobin by the conductometric method of extraction of carbon monoxide from the blood]. / Nowa metoda oznaczania zawartosci hemoglobiny tlenkoweglowej z pomiaru tlenku wegla we krwi.

The newly elaborated method consists in the gasometric CO determination in the blood. The extraction of CO from the blood sample (0,1-1,0 ml) is performed by means of a simple device designed by the authors. The extracted CO is determined by gas analyser ANKO-3 or Ultragas 5. The comparison between the new method and iodometric method showed very high correlation (r greater than 0,9). A discussion follows on the advantages of the new method (quick, easy, high-sensitive and precise), its use can be suggested to laboratories which are equipped with a gas analyser ANKO-3 for other purposes. The new method can be used for numerous routine analyses as well as for scientific studies.