Genetic analysis of Boletus edulis suggests that intra-specific competition may reduce local genetic diversity as a woodland ages.

Ectomycorrhizal fungi are key players in terrestrial ecosystems yet their mating systems and population dynamics remain poorly understood. We investigated the fine-scale relatedness structure and genetic diversity of Boletus edulis, one of the world's most commercially important wild mushrooms. Microsatellite genotyping of fruiting bodies from 14 different sites around Bielefeld in Germany revealed little in the way of population structure over a geographic scale of several kilometres. However, on a more local scale we found evidence for elevated relatedness as well as inbreeding. We also observed a significant negative association between the genetic diversity of fruit and the age of the trees under which they were sampled. Taken together, our results suggest that as genets mature, they compete and potentially create conditions under which further spores struggle to become established. By implication, even though this species is widely picked, propagules remain common enough to create strong competition when new habitats become available.

Assessment of normal erythropoiesis by flow cytometry: important considerations for specimen preparation.

INTRODUCTION: The extension of quantitative flow cytometric studies to the erythroid lineage in patients with suspected myelodysplastic syndrome has prompted a reassessment of cell surface antigen expression during normal erythropoiesis. Erythropoiesis in normal and pathologic bone marrows was studied to determine the expected antigenic relationships of maturing erythroid cells. METHODS: A total of 200 bone marrow specimens were evaluated by multidimensional flow cytometry (MDF). Samples were prepared using either NH4 Cl lysis or Ficoll density gradient separation. RESULTS: Normal erythroid development is described as a two-step process observable with the intensity relationships between CD235a, CD71, CD45, CD105, CD34, CD117, and CD36. The variability of these intensities (CV) was determined. A comparison of processing techniques determined lysis is the optimal analytic technique for the analysis of early-stage erythroid cells. Nucleic acid staining with DRAQ5 revealed that Ficoll allows for the analysis of reticulocytes and mature erythrocytes otherwise eliminated by lysis. CONCLUSION: These data demonstrate while lysis alters the light scatter characteristics of erythroid precursors, it did not alter quantitative antigen expression or nucleic acid content. The expected variability in antigen intensities is defined. These studies provide a basis for a comparison of erythroid development between normal individuals and those with erythroid dysplasia associated with myelodysplastic syndromes.

Standardization of flow cytometry in myelodysplastic syndromes: a report from an international consortium and the European LeukemiaNet Working Group.

Flow cytometry (FC) is increasingly recognized as an important tool in the diagnosis and prognosis of myelodysplastic syndromes (MDS). However, validation of current assays and agreement upon the techniques are prerequisites for its widespread acceptance and application in clinical practice. Therefore, a working group was initiated (Amsterdam, 2008) to discuss and propose standards for FC in MDS. In 2009 and 2010, representatives from 23, mainly European, institutes participated in the second and third European LeukemiaNet (ELN) MDS workshops. In the present report, minimal requirements to analyze dysplasia are refined. The proposed core markers should enable a categorization of FC results in cytopenic patients as 'normal', 'suggestive of', or 'diagnostic of' MDS. An FC report should include a description of validated FC abnormalities such as aberrant marker expression on myeloid progenitors and, furthermore, dysgranulopoiesis and/or dysmonocytopoiesis, if at least two abnormalities are evidenced. The working group is dedicated to initiate further studies to establish robust diagnostic and prognostic FC panels in MDS. An ultimate goal is to refine and improve diagnosis and prognostic scoring systems. Finally, the working group stresses that FC should be part of an integrated diagnosis rather than a separate technique.

Positioning for acute respiratory distress in hospitalised infants and children.

BACKGROUND: Because of the association between prone positioning and sudden infant death syndrome SIDS) it is recommended that young infants be placed on their backs (supine). However, the supine position might not be the most appropriate position for infants and children hospitalised with acute respiratory distress. Positioning patients has been proposed as a non-invasive way of increasing oxygenation in adult patients with acute respiratory distress. But, because of substantial differences in respiratory mechanics between adults and children and the risk of SIDS in young infants, a specific review of positioning for infants and young children with acute respiratory distress is warranted. OBJECTIVES: To compare the effects of different body positions in hospitalised infants and children with acute respiratory distress. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 3, 2004); MEDLINE (January 1966 to October Week 3, 2004); EMBASE (1980 to week 24, 2004); and CINAHL (1982 to October Week 3, 2004). SELECTION CRITERIA: All randomised or systematically-allocated controlled clinical trials comparing two or more positions in the management of infants and children hospitalised with acute respiratory distress. DATA COLLECTION AND ANALYSIS: Data were extracted from each study independently by two authors. Differences were resolved by consensus or referral to a third author. Continuous outcomes were analysed using a weighted mean difference and 95% confidence interval. No bivariate outcomes were available. All but one included study reported crossover data therefore this data was used for meta-analysis. Fixed-effect models were used unless heterogeneity was significant (p value equal to or less than 0.1), in which case a random-effects model was used. MAIN RESULTS: Forty-nine papers were selected for this review of which 21 studies (22 publications) were included. These studies compared prone, supine, lateral, elevated, and flat positions. Prone positioning was significantly more beneficial than supine positioning in terms of oxygen saturation, partial pressure of arterial oxygen, oxygenation index, thoraco-abdominal synchrony, and episodes of desaturation. There were no statistically significant differences between any other positions. AUTHORS' CONCLUSIONS: The prone position was significantly superior to the supine position in terms of oxygenation. However, as most patients included in the meta-analysis were ventilated, preterm infants the benefits of prone positioning may be most relevant to these infants. In addition, although placing infants and children in the prone position may improve respiratory function, the association of sudden infant death with prone positioning means that infants should only be placed in this position if continuous cardiorespiratory monitoring is used.

Thermal injury increases the number of eosinophil progenitors in rat spleen and bone marrow.

We have investigated the effects of thermal injury upon myelopoiesis. IL-3, GM-CSF, and IL-5 were used to stimulate myeloid colony formation. IL-3 induces early myeloid progenitors and a more developed myeloid progenitor, the granulocyte-macrophage colony-forming unit (GM-CFU), to multiply and develop into mature myeloid cells. GM-CSF induces GM-CFU to become mature myeloid cells, while IL-5 induces eosinophil progenitors to become mature eosinophils. Stem Cell Factor (SCF) + IL-6 and FLT3 ligand, which have no effect on colony formation by themselves, were used to enhance the effects of IL-3 and GM-CSF, respectively. We found that thermal injury increased the number of early myeloid progenitors and GM-CFU in the spleen with either IL-3 or GM-CSF as a stimulant. Thermal injury increased the number of early myeloid progenitors in the bone marrow when GM-CSF, but not IL-3, was used to stimulate colony growth. Also, thermal injury increased the numbers of eosinophil progenitors in rat spleen and bone marrow and increased splenic levels of IL-5 mRNA.

The effect of burn injury on suppressors of cytokine signalling.

The newly identified suppressors of cytokine signaling (SOCS) family of proteins act as intracellular inhibitors of several cytokine signal transduction pathways. Their expression is induced by cytokine activation of the Janus kinase/signal transducer and activator of transcription (Jak/STAT) pathway, and they act as a negative feedback loop by subsequently inhibiting the Jak/STAT pathway either by direct interaction with activated Jaks or with the receptors. In this study we investigated the expression and translation of SOCS proteins after burn injury. Thermal injury increased the expression of SOCS3 compared with sham at 4 h, 24 h, and 10 days after thermal injury in the liver. SOCS3 protein was increased at 4 and 24 h after thermal injury in the liver. Expression of SOCS1 mRNA was not detected in sham or burn liver. SOCS2 mRNA and cytokine-inducible SH2-containing protein (CIS) mRNA were detected at the same levels for both sham and burn at all time points in the liver. In the spleen there was a trend towards an increase in SOCS1 mRNA at all time points; thermal injury significantly decreased SOCS2 mRNA compared with sham at 4 h, SOCS3 mRNA was significantly increased at 24 h compared with 10 days, and CIS mRNA was detected at the same levels for both sham and burn at all time points. In conclusion, thermal injury causes elevations in SOCS3 within 4 h after a burn, reaching a maximum at 24 h post injury. Levels continue to be elevated for up to 10 days post injury. SOCS3 may be very important in regulating the balance between immunosuppression and inflammation after thermal injury.

Improved sample preparation method for selected persistent organochlorine pollutants in human serum using solid-phase disk extraction with gas chromatographic analysis.

An improved solid-phase extraction (SPE) method was developed to isolate and concentrate trace levels of selected POPs (persistent organochlorine pollutants) in human serum prior to GC-MS in SIM mode or GC-ECD quantitation. The extraction involves denaturation of serum proteins with formic acid, SPE using C18 Empore disk cartridges, followed by elimination of lipid interferences using a sulfuric acid wash of the eluate. Use of the SPE disk improved assay throughput and gave a cleaner analytical matrix compared with previously reported solid-phase and liquid-liquid extraction techniques. The extraction method provided consistent recoveries at three fortification levels using 13C12 PCB 149 as internal standard. Recoveries ranged from 48 to 140% for organochlorine pesticides (6.25, 12.5 and 25 ng/ml) and 71 to 126% for polychlorinated biphenyls (0.625, 1.25 and 2.5 ng/ml).

Occult B cell malignancies can be detected by three-color flow cytometry in patients with cytopenias.

Patients with unexplained cytopenias often present a diagnostic dilemma with minimal morphologic or cytogenetic changes to identify the underlying disease process. We have used multidimensional flow cytometry in a study of patients with cytopenias and found that this technology established, changed, or refined the diagnosis in 17/121 patients. Using the flow cytometric technique of CD45 and right angle light scatter (SSC) gating with two additional markers in a three-color analysis, eight of 121 patients were found to have hairy cell leukemia (HCL), in the absence of definitive morphologic findings of HCL. Two additional patients were found to have non-Hodgkin's lymphoma (NHL). Myeloid abnormalities, myelodysplasia (MDS) or acute leukemia was detected in seven of 56 patients with unexplained pancytopenia. Six of 65 patients identified with cytopenias resulting from lymphoid neoplasms had been referred for bone marrow transplantation (BMT) with a presumptive diagnosis of MDS, with subsequent deferral of BMT upon correct diagnosis. The screening technique is incorporated into an extensive immunophenotyping scheme to identify hematopoietic abnormalities using multidimensional flow cytometry (MDF). HCL cells (detected as low as 1.3%) reside in the same position as normal monocytes in the CD45 and SSC plots but could be distinguished from monocytes based on the expression of HLA-DR without CD11b, and expression of CD19. Further phenotyping of the abnormal population confirmed immunoglobulin light chain restriction, CD11c, and CD25 expression. Non-Hodgkin's lymphoma was detected as aberrant mature lymphocytes expressing B lymphoid markers, CD5 and light chain restriction. Myeloid abnormalities were identified in the myeloblast or maturing myeloid cell fractions. The flow cytometric scheme described can be used in primary diagnosis. The technique is definitive, sensitive, and stresses the importance of distinguishing lymphoid from myeloid etiology of cytopenias.

Multidimensional flow cytometry of marrow can differentiate leukemic from normal lymphoblasts and myeloblasts after chemotherapy and bone marrow transplantation.

Serial bone marrow aspirates from patients previously given a diagnosis of acute lymphoblastic leukemia (ALL) who had undergone chemotherapy, bone marrow transplantation (BMT), or both were analyzed by multidimensional flow cytometry (MDF) to detect residual disease (lower limit of detection 0.3%). Correlation between the results of morphologic examination and MDF showed concordant results on 100 of 118 specimens. The MDF-positive, morphologic examination-negative specimens were positive by cytogenetic examination or were obtained from patients in whom the ALL eventually relapsed. Similar correlations between MDF and the results of cytogenetic examination were obtained. Leukemic cells were detected in 29 of 62 patients before BMT and 12 of 52 after BMT Normal regenerating lymphoblasts were identified and quantified by MDF in patients without detectable leukemic lymphoblasts. Patients with leukemic lymphoblasts found by MDF in specimens obtained immediately before BMT were 3.28 times more likely to experience relapse after BMT compared with MDF-negative patients, even when leukemic lymphoblasts were undetectable by histopathologic examination, cytogenetic examination, or both. All patients who had undergone BMT with leukemic lymphoblasts found by MDF, with or without morphologic or cytogenetic confirmation, experienced relapse according to conventional criteria within 42 days of the MDF analysis. The detection of residual disease before overt relapse may provide information for early intervention, while definitive recognition of normal recovering blasts may prevent unnecessary treatment.

Prediction of relapse of pediatric acute myeloid leukemia by use of multidimensional flow cytometry.

BACKGROUND: Most patients receiving therapy for acute myeloid leukemia (AML) enter an interval in which leukemic blast cells cannot be detected by light microscopy (i.e., morphologic remission). However, many of these patients experience a subsequent relapse. Multidimensional flow cytometry, which allows the discrimination of antigens expressed on normal and malignant cells, can detect small numbers of cancer cells in bone marrow or peripheral blood specimens. This technique enables the detection of one leukemic blast cell among 10(3) to 10(2) normal regenerating hematopoietic cells. PURPOSE: We determined whether the presence of residual leukemic blast cells, identified in the bone marrow of pediatric patients with AML by use of multidimensional flow cytometry, would be predictive of subsequent leukemic relapse. METHODS: Multidimensional flow cytometry was performed on 205 marrow specimens collected throughout the course of treatment from 39 patients who had achieved morphologic remission. The analyses employed monoclonal antibodies directed against CD45 in combination with mixed pairs of monoclonal antibodies directed against 10 other antigens. A time-varying Cox regression analysis that controlled for sample time intervals, age, sex, morphologic classification of disease, and white blood cell count at diagnosis was used to relate the multidimensional flow cytometric results to the risk of relapse after achieving remission. Reported P values are two-sided. RESULTS: Thirty-five of the 39 patients had bone marrow specimens available from the time that first morphologic remission was achieved. Leukemic blast cells were detected in the specimens from 19 (54%) of these 35 patients. Twenty-five of the 35 patients did not receive an allogeneic (i.e., from a different genetic background) bone marrow transplant during first morphologic remission, and 13 of 14 with residual leukemic cells experienced a relapse at a median time of 153 days after diagnosis (range, 48-863 days). Nine of the 11 patients who did not receive an allogeneic bone marrow transplant and lacked evidence of leukemic blast cells at first morphologic remission relapsed at a median time of 413 days after diagnosis (range, 321-794 days). Among the 10 individuals who received an allogeneic bone marrow transplant during first morphologic remission, five were positive for leukemic blast cells and five were negative; one of these patients (positive for leukemic blast cells) experienced a relapse 265 days after diagnosis, and three others died of transplant-related complications. The estimated risk of relapse during intervals of multidimensional flow cytometric positivity (i.e., intervals of remission for which the immediately preceding cytometry measurement was positive) was 2.8 times greater than that during negative intervals (95% confidence interval = 1.1-7.0; P = .02). CONCLUSIONS AND IMPLICATIONS: Multidimensional flow cytometry identifies residual leukemia in more than half of the patients with AML who are in morphologic remission. The detection of leukemic blast cells in these patients by multidimensional flow cytometry is predictive of a more rapid relapse.

Structural changes in oocyte nucleoli of Xenopus laevis during oogenesis and meiotic maturation.

Immunoelectron microscopy with anti-nucleolin defined substructures within the multiple nucleoli of biosynthetically active stage II-III oocytes and within the nucleoli of relatively quiescent stage VI oocytes of Xenopus laevis. Dense fibrillar components (DFCs) of nucleoli from stage II-III oocytes consisted of nucleolonemas that radiated from a continuous DFC sheath surrounding fibrillar centers (FCs). Discernible granular regions (GRs) were absent in these same nucleoli. Conversely, stage VI oocyte nucleoli displayed compacted DFCs and prominent GRs. Immunofluorescence microscopy then tracked fibrillarin, nucleolin, and condensed DNA through oogenesis and into progesterone-induced meiotic maturation and nuclear breakdown. In stage II-III oocyte nucleoli, fibrillarin was enriched near the FC-DFC boundaries, while nucleolin was distributed throughout these same DFCs. Both proteins were enriched within the compacted DFCs of stage VI oocyte nucleoli. Staining with (DAPI) 4',6-diamidino-2-phenylindole showed condensed DNA within nucleolar FCs of both stage II-III and stage VI oocyte. Upon nuclear breakdown, we found fibrillarin and nucleolin in small particles and in the surrounding cytoplasm. Although we saw no trace of fibrillarin or nucleolin in nuclear remnants prepared just minutes later, DAPI-stained particles remained within these preparations, thus suggesting that FCs were at least slow to disassemble.

Tumor-specific aneuploidy not detected in CD19+ B-lymphoid cells from myeloma patients in a multidimensional flow cytometric analysis.

Aneuploidy and lg light chain restriction were used as separate, independent tumor specific markers to study 26 patients with multiple myeloma to determine whether bone marrow B cells, as defined by CD19 expression, are clonally related to myeloma plasma cells. Specimens were characterized using multidimensional flow cytometry to identify the presence of clonality in both the B lymphoid and plasma cell populations using both surface and cytoplasmic staining with antibodies specific for kappa or lambda lg light chain In none of the patients with multiple myeloma were CD19+ cells found to be clonally restricted to kappa or lambda. The monoclonal plasma cells (MPC) were found to be uniformly negative for CD10, CD19, and CD34, while the CD19+ B lymphoid cells present within the samples expressed normal intensities and relationships of these antigens, which allowed them to serve as internal positive controls. Combined analysis of call surface antigen expression and DNA content allowed plasma cell populations to be characterized for aneuploidy without interference from normal bone marrow cells. The MPC, detected on the basis of bright CD38 expression (CD38+2), demonstrated DNA aneuploidy in 65% of cases (DNA index range of 0.9 to 1.3). These aneuploid DNA distributions had typical cell cycle profiles (including G1,S and G2+M) expected of a proliferating population. In all cases, DNA aneuploidy was confined almost entirely to the CD38+2, CD19- malignant plasma cells, while cells expressing CD19 were diploid. These results support the concept that myeloma is a disease process mediated by self-replicating, late compartments of B-cell ontogeny.

Management of early postdischarge adjustment reactions following psychiatric hospitalization.

Psychiatric patients frequently experience serious symptoms and demonstrate disturbed behaviors in the very early postdischarge period. Based on 25 years of clinical experience, the author reviews symptoms and behaviors that can occur and notes that they should most often be viewed as adjustment reactions rather than as exacerbations of the primary illness. A team approach to management of early postdischarge reactions that uses a psychiatrist and psychiatric nurse is effective. Interventions include forewarning inpatients that problems may occur and helping them identify potential problems. Social skills training, learning therapies, and family counseling help patients prepare to cope. Accompanying patients home on passes during hospitalization is helpful, as is inviting them to visit the hospital during their first days at home. Scheduling initial office visits within three days of discharge is another way of easing a difficult transition.

Effect of iron status on reticulocyte mean channel fluorescence.

Flow cytometric reticulocyte enumeration measures the fluorescence intensity of the reticulocyte population, the reticulocyte mean channel fluorescence. Reticulocyte mean channel fluorescence, used as an indicator of reticulocyte maturation, is directly proportional to the amount of intracellular RNA. Other factors, such as iron stores, may affect reticulocyte mean channel fluorescence. Iron status in normal controls, patients with anemia of chronic disease, and pregnant women was evaluated by hemoglobin, hematocrit, red blood cell indices, iron, total iron-binding capacity, and ferritin. Reticulocyte mean channel fluorescence was significantly elevated (P less than 0.0001) to 85.6 +/- 4.6 (mean +/- 1 standard deviation) in iron-deficient anemic patients and to 81.1 +/- 8.4 in iron-depleted patients compared to healthy individuals (69.7 +/- 2.6). The reticulocyte mean channel fluorescence in anemia of chronic disease was 71.3 +/- 5.8 and was not significantly different from that of normal controls. Reticulocyte mean channel fluorescence showed significant correlations with total iron-binding capacity (P less than 0.0001, r = 0.62) and ferritin (P less than 0.0001, r = 0.40). A possible explanation for these findings, describing differences in cytoplasmic levels of transferrin receptor mRNA, is discussed.

Major depression and amyloidosis.

Vigilance is necessary to identify psychiatric patients with significant physical illness. Amyloidosis is an uncommon disease with symptoms that overlap those of depression. A clinical and pathological review of amyloidosis is presented.

Mutagenicity and cytotoxicity of N-methyl-2-pyrrolidinone and 4-(methylamino)butanoic acid in the Salmonella/microsome assay.

The industrial solvent N-methyl-2-pyrrolidinone (NMP) and its hydrolysis product, 4-(methylamino)butanoic acid (N-MeGABA), were examined for mutagenicity and cytotoxicity in the Ames Salmonella/microsome assay. In order to detect a broad range of possible mutagenic endpoints, the following strains were used in the assay: base-pair substitution strains TA100, TA102 and TA104; frameshift strains TA97 and TA98; and repair proficient strains TA2638, UTH8413 and UTH8414. In the standard plate incorporation assay, six log-linear doses of each compound were tested; doses ranged from 0.01 to 1000 mumol/plate for NMP, and 0.01 to 316 mumol/plate for N-MeGABA. Neither compound was detectably mutagenic when tested in the presence and absence of metabolic activation by Aroclor-induced rat liver S9. NMP did show significant responses with strains TA102 and TA104 that were less than two-fold over background, but no clear dose-response relationships were evident. A preincubation modification of the assay was also performed, using strains TA98 and TA104. Mutagenic activity was not observed for NMP, while N-MeGABA showed significant responses with TA104 but dose-related mutagenicity was not established. Preincubation testing revealed both NMP and N-MeGABA to be cytotoxic to the test population of Salmonella at the highest treatment doses.

Disposition and metabolism of double-labeled [3H and 14C] N-methyl-2-pyrrolidinone in the rat.

The disposition of N-methyl-2-pyrrolidinone (NMP) was studied in the rat using tritium-labeled ([4-3H]NMP) and carbon-14-labeled ([methyl-14C]NMP and [ring-14C]NMP) radioisomers. Male Sprague-Dawley rats were administered a single intravenous dose (45 mg/kg) of 5.0 microCi of 3H or 14C for single-labeled disposition studies or 5.0 microCi of 3H and 2.5 microCi of 14C for double-labeled studies (2:1 ratio, 3H:14C). Plasma levels of intact NMP were analyzed by HPLC through 6 hr after dosing and suggested a rapid distribution phase followed by a slow elimination phase. The half-life for the terminal elimination phase from plasma was about 7 hr for both 14C-isomers and 9.9 hr for the 3H-isomer. The major route of excretion of radioactivity was via the urine and accounted for about 70% of the dose within 12 hr. After 24 hr, cumulative excretion in urine represented about 80% of the dose. The 2:1 ratio of administered 3H:14C was maintained in urine through 6 hr. Measurement of radioactivity in tissues at 6 hr showed the liver and intestines to contain the highest accumulations of radioactivity, representing approximately 2% and 3% of the dose, respectively. Tissue distribution of radioactivity was similar for all three radiolabeled isomers and showed that NMP was extensively distributed to all major organs. Radiomonitored HPLC analyses of urine revealed the presence of one major and two minor metabolites. The major metabolite, representing 70-75% of the administered dose of radioactivity, was found to retain all three radiolabeled positions.(ABSTRACT TRUNCATED AT 250 WORDS)

Disposition of [14C]povidone after oral administration to the rat.

The tissue distribution and excretion of 14C-labelled povidone (polyvinylpyrrolidone; K-30; average mol wt 40,000) was studied in male Sprague-Dawley rats given a single oral dose. The major pathway of elimination of radioactivity was in the faeces, in which 90.8% of the administered dose was recovered after 12 hr and 98.4% after 48 hr. Amounts of radioactivity in major tissues and in the blood were not significantly different from those in untreated controls. A minor amount of radioactivity, representing 0.04% of the administered dose, was detected in the urine after 6 hr. Dialysis studies of [14C]povidone suggested that the absorbed species was a low-molecular-weight (less than 3500) oligomer. It was concluded that an oral dose of [14C]povidone is not significantly absorbed in the rat.