[The role of bone marrow cells immunophenotypic study by flow cytometry in diagnosing myelodysplastic syndrome]

Myelodysplastic syndromes are a heterogeneous group of clonal bone marrow disorders characterized by dysplasia, progressive bone marrow failure, and increased risk of transformation to acute myeloid leukemia. Although diagnostic criteria are well established, a diagnosis based on morphologic and cytogenetic findings is often difficult in a significant number of patients. Multiparametric flow cytometric immunophenotyping is a highly sensitive and specific method for quantitative and qualitative evaluation of hematopoietic cells. Flow cytometry is used to identify dysregulated antigen expression of myeloid cells, estimate the proportion of bone marrow blasts cells, and reveal their abnormal immunophenotype. Recent data suggest that flow cytometry adds important prognostic information to the widely accepted International Prognostic Scoring System.

The role of JAK2 mutations in RARS and other MDS

Acquired sideroblastic anemia with unilineage dysplasia (WHO RARS) is a clonal stem cell disorder characterized by erythroid dysplasia, mitochondrial accumulation of mitochondrial ferritin, defective erythroid maturation and anemia. A fraction of these patients also show elevated platelet counts; since 2001 this has been defined as RARS with marked thrombocytosis (RARS-T). It has recently been described that around half of RARS-T patients, along with a small subset of other MDS and mixed myelodysplastic/ myeloproliferative disorders, carry the JAK2 mutation, and that MPL mutations are found in single patients. Clinically, RARS-T patients show features of both RARS, essential thrombocythmia (ET) and to some extent also myelofibrosis. However, the degree of anemia and overall survival is more similar to RARS than myeloproliferative disorders. The occurrence of JAK2 mutations and features of ET in RARS is too frequent to be the result of chance only, and it is possible that this link may provide a key to an increased understanding of the genetic abnormalities causing ring sideroblast formation.

[Evaluation of the relationship between circulating nucleated red blood cells count and inborn infection in neonates]

OBJECTIVES

to determine the relationship between the initial nucleated red blood cells (nRBC) count during the first 12 hours after birth and inborn infection in neonates.

MATERIALS AND METHODS

The retrospective study comprised of 306 neonates born in the Department of Perinatology of the I Chair of Gynaecology and Obstetrics in Łódź, Poland, in the years 2002-2007, among whom the nucleated red blood cells count were calculated within the first 12 hours after birth. Two categories of nRBC count: the normal and the elevated value, were statistically elaborated by a Mann-Whitney test and a chi-square test with two clinical outcome categories: the presence and the absence of inborn infection in the analyzed neonates. Statistical significance was indicated by p value lower than 0,05.

RESULTS

Among 306 newborns, there were 127 mature neonates (41.5%) and 179 prematures (58.5%). The mean of the initial nRBC count in the analyzed newborn population was 40, 15. The mean of the nRBC count in the infected neonates was three times higher (52.56) than the mean of the nRBC count in newborns without inborn infection (16.76) - (p=0.00001). Inborn neonatal infection concerned a vast majority of cases with an elevated value of the nRBC count (86.4%), but in 13.6%, inborn infection was not observed. Among the cases with a normal nRBC count, the presence and the absence of inborn infection was diagnosed in about 50% of the analyzed babies (50.83% vs 49.17%). The elevated value of the nRBC count in infected neonates concerned mainly premature babies, rather than mature neonates, and similarly in neonates with a lower Apgar score than in babies born in good condition.

CONCLUSIONS

1. The positive association between elevated initial nucleated red blood cells count after birth and inborn infection in newborns has been revealed. 2. An elevated nucleated red blood cells count may be an auxiliary, early indicator for inborn infection in neonates. 3. Prematurity and perinatal asphyxia favour the elevation of a nucleated red blood cells count in cases with inborn infection.

Mechanisms of DNA breaks inductionin vivo by 5-azacytidine: paths of micronucleus induction by azaC

The aim of the present study was to correlate the time-response curves of micronucleated polychromatic erythrocyte (MN-PCE) induction by 5-azacytidine (azaC) with the possible processes involved in DNA break production; this is based on the results previously published by other authors. The MN-PCE induction at two different doses of azaC was determined by sampling blood from the tails of mice before the acute treatment and over nine periods of 8 h each afterwards. Both doses caused two peaks of MN-PCE induction, one at 32 h and another at 48 h, approximately; a shoulder was detected that remained high from 56 h up to the end of the study (72 h). These results suggest that azaC induced DNA breaks and subsequently MN (micronucleus) by three different mechanisms, and in agreement with data in the literature, these could be successively the following: (i) during excision of the large adduct comprising the DNA methyl transferase covalently linked to DNA; (ii) failure of recombination repair or mismatch repair; and (iii) persistent chromosome fragility in G-C rich sites due to DNA demethylation and chromatin decondensation.

Prognostic significance of the histomorphometric features of bone marrow trephine biopsies in patients with chronic myeloid leukemia

OBJECTIVE

To study the correlation of histomorphometric data of bone marrow trephine biopsies at the time of initial diagnosis in chronic myeloid leukemia (CML) patients with the patient prognosis.

STUDY DESIGN

A total of 40 CML patients were divided equally in group I (developed accelerated phase or blast crisis within 18 months of initial diagnosis of chronic phase of CML) and group II (developed accelerated phase or blast crisis > 30 months after initial diagnosis of chronic phase of CML). The clinical, hematologic and histomorphometric data were compared in the 2 groups of CML patients.

RESULTS

The percentage of bone marrow promyelocytes was significantly increased in group I. On morphometry, the number of blasts per square millimeter, the area of reticulin fibers per square millimeter and the percentage area occupied by reticulin fibers were statistically significant.

CONCLUSION

There seems to be grounds for hope for predicting prognosis of CML patients at initial diagnosis based on histomorphometric findings. The percentage area of reticulin fibers and the number of blasts per square millimeter are important prognostic predictors in histomorphometry data.

Hemochromatosis-associated gene mutations in patients with myelodysplastic syndromes with refractory anemia with ringed sideroblasts

We observed increased ferritin levels in newly diagnosed MDS-RARS patients without transfusional iron-overload. Hence, we hypothesized RARS patients may harbor hemochromatosis-related mutations, which could contribute to the pathophysiology of this myelodysplastic syndromes (MDS) subset. We studied a cohort of 140 MDS patients: 42 with RARS, 10 with increased ringed sideroblasts, and 96 with other forms of MDS (43 RA, 27 RAEB, 17 RAEB-T, 8 MDS/MPD, 1 CMML). Patients were genotyped using restriction fragment length polymorphism, designed to detect C282Y and H63D mutations of the HFE gene. We found significantly higher frequency of heterozygosity for C282Y mutation in RARS patients compared with a large control population of matched race individuals (21 vs. 9.8% in controls, P = 0.03); H63D genotype was not significantly increased. Frequency of HFE variation in other MDS subtypes failed to differ significantly from controls. Within this group, we included patients with a rare form of MDS, provisionally subclassified by WHO as RARS with thrombocytosis (RARSt). 10/14 RARSt patients were carriers of either C282Y or H63D allele significantly increased compared with the combined prevalence in a healthy population (71 vs. 33%, P < 0.01). We found expected distribution of mutant HFE alleles in patients with other forms of MDS (9.1 vs. 9.8%, P = 0.82). Increased prevalence of HFE gene mutations is not a generalized feature of MDS, but some subgroups of MDS, especially those characterized by excessive accumulation of ringed sideroblasts, exhibit C282Y mutations at a higher frequency than in other forms of MDS and healthy controls.

Normoblasts in pleural fluid: are they significant?

The hemopoietic cell elements in body fluids is a rare encounterance. From among the normal bone marrow inhabitants, only megakaryocytes are occasionally seen in pleural and peritoneal fluids due to extramedullary hemopoiesis as a result of myeloproliferative disorders. The finding of isolated normoblasts in body fluids with no other marrow elements is described here for the first time in pleural fluid from two patients. The normoblasts which have a close resemblance morphologically to mesothelial cells, need to be differentiated from one another. A supravital stain is of help when in doubt. Because of their close resemblance, normoblasts may get missed during evaluation. This report highlights the need for a larger number of positive cases with emphasis on their course details to understand the significance of normoblasts in body fluids.

Ameliorative effects of vitamin supplementation on ethyl methane sulphonate-induced genotoxicity in a fish, Anabas testudineus

The efficacy of 0.02% vitamin C (VC; l-ascorbic acid) and 0.05% beta-carotene (BC) at the rate of 1 ml/100g of body weight in amelioration of ethyl methane sulphonate (EMS)-induced genotoxicity has been studied in an Indian endemic fish, Anabas testudineus by using several cytogenetical endpoints like chromosome aberrations, micronuclei (MN) and abnormal nuclei (AN), and sperm head anomaly at 6, 24, 48, 72 and 96 h after treatment, as compared to suitable controls (distilled water (DW)-treated control for EMS and VC-treated fish, and 1% alcohol-treated control for BC-treated fish). Both VC and BC reduced EMS-induced genotoxicity at all the fixation intervals as compared to their respective controls. Additionally, effects of two more doses of VC (0.01% and 0.05%) and BC (0.02% and 0.1%) were analyzed at 72 h after treatment (at the peak period of EMS genotoxicity) for testing their relative efficacy in amelioration of EMS-induced cytogenetical damage in this fish. All the three doses of both VC and BC appeared to reduce the EMS-induced genotoxicity in this fish to a variable extent, of which the higher dose of VC appeared to give marginally better protection while the dose-response relationship was inconclusive for BC. The results of this study can lead to future research for exploring if low doses of these vitamins may be useful in protecting fish from genotoxic damage on exposure to mutagenic agents in small confined/stagnant waters.

Extramedullary haematopoiesis in liver of sudden infant death cases

AIMS

To determine the frequency of extramedullary haematopoiesis (EMH) in sudden infant death and control cases, and to provide descriptive data on extramedullary haematopoietic islands and diffuse cells.

METHODS

The study was carried out in 51 SIDS and 102 non-SIDS cases. Liver-tissue sections were stained with haematoxylin and eosin, and immunohistochemistry was done with streptavidin-biotin-peroxidase complexes by Polyclonal Haemoglobin "A" antibody. The prevalence of data was estimated statistically by Pearson chi-square test, descriptive statistics, and Kruskal-Wallis test.

RESULTS

The Pearson chi-square values (CI: 95%; OR: 0.071-0.49; p: 0.0474) show higher frequency of EMH islands in SIDS than in controls. The number of diffuse extramedullary haematopoetic cells was higher in SIDS cases compared to non-SIDS (p=0.017).

CONCLUSIONS

EMH is a frequent finding in SIDS cases, and this may be a consequence of anaemia associated with intrauterine hypoxia, or infections.

Hypercoiling of the umbilical cord and placental maturation defect: associated pathology?

Our objective was to determine whether there is an association between hypercoiling of the umbilical cord and placental maturation defect. From a database comprising 1147 cases, containing data on all placentas examined at our institution during the study period, we selected all cases with a gestational age of at least 37 weeks that exhibited hypercoiling of the umbilical cord (coiling density above the 90th percentile, n = 42); we also examined 2 matched controls for each case, one with hypocoiling and one with normocoiling. The mean number of syncytiocapillary membranes (SCM) per terminal villus was calculated. Presence of a placental maturation defect was defined as the mean number of SCM below the 10th percentile. Correlations were assessed using Spearman's rho. Relations between dichotomous variables were tested using logistic regression. Mean number of SCM per terminal villus (+/-standard deviation) was 1.25 +/- 0.65. Difference in mean between hypo- and hypercoiled cords was 0.37 (95% confidence interval [CI], 0.07 to 0.67). The correlation coefficient between mean number of SCM and umbilical coiling index (UCI, coils/cm) was -0.28 (P = 0.002). The odds ratio (OR) for placental maturation defect in presence of hypercoiling was 2.61 (95% CI, 0.75 to 9.12). The OR for fetal death was 132 (95% CI, 13.2 to 1315) in the presence of a placental maturation defect and 5.49 (95% CI, 1.02 to 29.6) in the presence of hypercoiling. The OR for indication of fetal hypoxia/ischemia was 12.3 (95% CI, 3.0 to 50.3) in the presence of a placental maturation defect and 3.2 (95% CI, 0.95 to 10.9) in the presence of hypercoiling. We found a trend toward placental maturation defect in the presence of hypercoiling and an inverse relationship between the mean number of SCM in the terminal villi and the UCI. We confirmed associations between fetal death and both a maturation defect and hypercoiling and found an association between histological indication of fetal hypoxia/ischemia and a placental maturation defect.

Lenalidomide inhibits the malignant clone and up-regulates the SPARC gene mapping to the commonly deleted region in 5q- syndrome patients

Myelodysplastic syndromes (MDSs) are a group of hematopoietic stem cell disorders characterized by ineffective hematopoiesis and peripheral blood cytopenias. Lenalidomide has dramatic therapeutic effects in patients with low-risk MDS and a chromosome 5q31 deletion, resulting in complete cytogenetic remission in >60% of patients. The molecular basis of this remarkable drug response is unknown. To gain insight into the molecular targets of lenalidomide we investigated its in vitro effects on growth, maturation, and global gene expression in isolated erythroblast cultures from MDS patients with del(5)(q31). Lenalidomide inhibited growth of differentiating del(5q) erythroblasts but did not affect cytogenetically normal cells. Moreover, lenalidomide significantly influenced the pattern of gene expression in del(5q) intermediate erythroblasts, with the VSIG4, PPIC, TPBG, activin A, and SPARC genes up-regulated by >2-fold in all samples and many genes involved in erythropoiesis, including HBA2, GYPA, and KLF1, down-regulated in most samples. Activin A, one of the most significant differentially expressed genes between lenalidomide-treated cells from MDS patients and healthy controls, has pleiotropic functions, including apoptosis of hematopoietic cells. Up-regulation and increased protein expression of the tumor suppressor gene SPARC is of particular interest because it is antiproliferative, antiadhesive, and antiangiogenic and is located at 5q31-q32, within the commonly deleted region in MDS 5q- syndrome. We conclude that lenalidomide inhibits growth of del(5q) erythroid progenitors and that the up-regulation of SPARC and activin A may underlie the potent effects of lenalidomide in MDS with del(5)(q31). SPARC may play a role in the pathogenesis of the 5q- syndrome.

Spi-1/PU.1 participates in erythroleukemogenesis by inhibiting apoptosis in cooperation with Epo signaling and by blocking erythroid differentiation

Overexpression of the transcription factor Spi-1/PU.1 in mice leads to acute erythroleukemia characterized by a differentiation block at the proerythroblastic stage. In this study, we made use of a new cellular system allowing us to reach graded expression of Spi-1 in preleukemic cells to dissect mechanisms of Spi-1/ PU-1 in erythroleukemogenesis. This system is based on conditional production of 1 or 2 spi-1-interfering RNAs stably inserted into spi-1 transgenic proerythroblasts. We show that Spi-1 knock-down was sufficient to reinstate the erythroid differentiation program. This differentiation process was associated with an exit from the cell cycle. Evidence is provided that in the presence of erythropoietin (Epo), Spi-1 displays an antiapoptotic role that is independent of its function in blocking erythroid differentiation. Apoptosis inhibited by Spi-1 did not involve activation of the Fas/FasL signaling pathway nor a failure to activate Epo receptor (EpoR). Furthermore, we found that reducing the Spi-1 level yields to ERK dephosphorylation and increased phosphorylation of AKT and STAT5, suggesting that Spi-1 may affect major signaling pathways downstream of the EpoR in erythroid cells. These findings reveal 2 distinct roles for Spi-1 during erythroleukemogenesis: Spi-1 blocks the erythroid differentiation program and acts to impair apoptotic death in cooperation with an Epo signaling.

Candidate gene mutation analysis in idiopathic acquired sideroblastic anemia (refractory anemia with ringed sideroblasts)

BACKGROUND

For most cases of idiopathic acquired sideroblastic anemia (IASA), the molecular pathogenesis is unknown, despite the consistent morphological signature of abundant pathological ringed sideroblasts with their characteristic iron-engorged mitochondria. Moderately elevated free erythrocyte protoporphyrin (FEP) levels have been described in IASA, suggesting that the activity of ferrochelatase, the enzyme that catalyzes the final step in heme biosynthesis (incorporation of ferrous iron into protoporphyrin), might be diminished in erythroid progenitor cells from IASA patients.

METHODS

We confirmed FEP elevation in IASA, then pursued a candidate gene approach that included screening the gene encoding ferrochelatase, FECH, for promoter and coding region mutations and mRNA expression changes in bone marrow from 37 patients with IASA.

RESULTS

The analytical techniques employed detected mutations in a test cohort of previously undiagnosed patients with biochemical evidence for erythropoietic protoporphyria, a condition resulting from germline mutations in FECH, but somatic missense mutations of FECH and its promoter were not observed in IASA patients. FECH was modestly overexpressed in progenitor cells from patients with IASA, compared with MDS patients without sideroblasts and healthy controls. In addition, we analyzed ABCB7 and PUS1, genes implicated in congenital sideroblastic anemia syndromes, but again found no coding mutations in acquired cases.

CONCLUSION

We conclude that acquired mutations in the factors currently known to cause inherited sideroblastic anemias are uncommon in IASA.

Abnormalities of erythrocyte glycoconjugates are identical in two families with congenital dyserythropoietic anemia type II with different chromosomal localizations of the disease gene

We analyzed erythrocyte glycoconjugates in two families with congenital dyserythropoietic anemia type II (CDA-II): family 2 with the typical localization of the disease gene to chromosome 20q11.2 and family 1 in which this localization was excluded. Despite the different genetics, the erythrocyte glycoconjugate abnormalities in the two families were identical suggesting a complex inheritance of CDA-II. We also found that erythrocyte anion exchanger 1 protein is decreased in CDA-II homozygotes and obligate carriers alike.

Disruption of palladin leads to defects in definitive erythropoiesis by interfering with erythroblastic island formation in mouse fetal liver

Palladin was originally found up-regulated with NB4 cell differentiation induced by all-trans retinoic acid. Disruption of palladin results in neural tube closure defects, liver herniation, and embryonic lethality. Here we further report that Palld(-/-) embryos exhibit a significant defect in erythropoiesis characterized by a dramatic reduction in definitive erythrocytes derived from fetal liver but not primitive erythrocytes from yolk sac. The reduction of erythrocytes is accompanied by increased apoptosis of erythroblasts and partial blockage of erythroid differentiation. However, colony-forming assay shows no differences between wild-type (wt) and mutant fetal liver or yolk sac in the number and size of colonies tested. In addition, Palld(-/-) fetal liver cells can reconstitute hematopoiesis in lethally irradiated mice. These data strongly suggest that deficient erythropoiesis in Palld(-/-) fetal liver is mainly due to a compromised erythropoietic microenvironment. As expected, erythroblastic island in Palld(-/-) fetal liver was found disorganized. Palld(-/-) fetal liver cells fail to form erythroblastic island in vitro. Interestingly, wt macrophages can form such units with either wt or mutant erythroblasts, while mutant macrophages lose their ability to bind wt or mutant erythroblasts. These data demonstrate that palladin is crucial for definitive erythropoiesis and erythroblastic island formation and, especially, required for normal function of macrophages in fetal liver.

Unrestrained erythroblast development in Nix-/- mice reveals a mechanism for apoptotic modulation of erythropoiesis

Normal production of RBCs requires that the antiapoptotic protein Bcl-xl be induced at end stages of differentiation in response to erythropoietin (Epo) signaling. The critical proapoptotic pathways inhibited by Bcl-xl in erythroblasts are unknown. We used gene targeting in the mouse to evaluate the BH3-only factor Nix, which is transcriptionally up-regulated during Epo-stimulated in vitro erythrocyte differentiation. Nix null mice are viable and fertile. Peripheral blood counts revealed a profound reticulocytosis and thrombocytosis despite normal serum Epo levels and blood oxygen tension. Nix null mice exhibited massive splenomegaly, with splenic and bone marrow erythroblastosis and reduced apoptosis in vivo during erythrocyte maturation. Hematopoietic progenitor populations were unaffected. Cultured Nix null erythroid cells were hypersensitive to Epo and resistant to apoptosis stimulated by cytokine deprivation and calcium ionophore. Transcriptional profiling of Nix null spleens revealed increased expression of cell cycle and erythroid genes, including Bcl-xl, and diminished expression of cell death and B cell-related genes. Thus, cell-autonomous Nix-mediated apoptosis in opposition to the Epo-induced erythroblast survival pathway appears indispensable for regulation of erythrocyte production and maintenance of hematological homeostasis. These results suggest that physiological codependence and coordinated regulation of pro- and antiapoptotic Bcl2 family members may represent a general regulatory paradigm in hematopoiesis.

Chromosomal composition of micronuclei in mouse bone marrow treated with rifampicin and nicotine, analyzed by multicolor fluorescence in situ hybridization with pancentromeric DNA probe

The mechanism underlying the induction of micronuclei induced by rifampicin and nicotine in mouse bone marrow was investigated by fluorescence in situ hybridization assay using mouse minor satellite DNA probe. Colchicine and mitomycin, known to be predominantly clastogenic and aneugenic, respectively were used as positive controls and these compounds produced the expected responses. In animals treated with different doses of rifampicin (10-320 mg/kg), the frequencies of micronucleated polychromatic erythrocytes (MNPCE) increased significantly after treatment with 160 and 320 mg/kg. Furthermore, rifampicin caused a significant depression of erythroblast proliferation at the high dose. At the two highest doses of 160 and 320 mg/kg rifampicin, a total of 0.96% and 1.44% MNPCE, respectively were found. Of the rifampicin-induced signal-positive MNPCE, an average of 58.1% of them was centromere-negative, reflecting the clastogenic activity of rifampicin. Correspondingly, about 41.9% of induced MNPCE were centromere-positive, representing the aneugenic activity of rifampicin. Eight and 16 mg/kg of nicotine induced 0.84% and 1.2% MNPCE, respectively, and of these an average of 29.5% showed one or more fluorescent signals, reflecting the predominant clastogenic activity of nicotine. The results obtained demonstrate that rifampicin induced both chromosome breakage and numerical chromosomal abnormalities, whereas nicotine induced one type of MNPCE and it could be considered a clastogenic agent.

Detection of hematopoietic maturation abnormalities by flow cytometry in myelodysplastic syndromes and its utility for the differential diagnosis with non-clonal disorders

The diagnosis of myelodysplastic syndromes (MDS) is based on peripheral cytopenias, bone marrow (BM) morphology and karyotyping. This may be difficult in cases with few dysplastic elements in BM and a normal karyotype. We examined the utility of flow cytometric analysis for the differential diagnosis between MDS and non-clonal disorders (NCD) presenting peripheral cytopenias. Quantitative assessment of CD45, CD16, CD13, CD11b, CD10 and CD64 in granulocytes and monocytes, and CD71 and glycophorin A in erythroblasts besides CD34+ cell count was performed in BM of 31 consecutive newly diagnosed patients with MDS, 11 patients with NCD and 11 healthy controls (BM donors). In MDS, the median number of phenotypic abnormalities found was 3 (1-8). The WPSS score showed a correlation with the total number of changes per case (r=0.48; p=0.002). Decreased SSC in promyelocytes correlated with the peripheral neutrophil count (r=-0.46; p=0.007). In NCD, the normal variation of antigen expression along granulocytic and erythroblast maturation was always maintained. In the discriminant analysis, SSC of CD34+ cells, together with that of promyelocytes and metamyelocytes were able to correctly classify 87% of the cases as clonal or non-clonal. Our quantitative approach permitted to detect at least one abnormality in antigen expression in every case of MDS. However, the most important parameters for differential diagnosis with NCD were the analysis of the granularity in immature cells, especially of the granulocytic series.

Sox6 cell-autonomously stimulates erythroid cell survival, proliferation, and terminal maturation and is thereby an important enhancer of definitive erythropoiesis during mouse development

Erythropoiesis, the essential process of hematopoietic stem cell development into erythrocytes, is controlled by lineage-specific transcription factors that determine cell fate and differentiation and by the hormone erythropoietin that stimulates cell survival and proliferation. Here we identify the Sry-related high-mobility-group (HMG) box transcription factor Sox6 as an important enhancer of definitive erythropoiesis. Sox6 is highly expressed in proerythroblasts and erythroblasts in the fetal liver, neonatal spleen, and bone marrow. Mouse fetuses and pups lacking Sox6 develop erythroid cells slowly and feature misshapen, short-lived erythrocytes. They compensate for anemia by elevating the serum level of erythropoietin and progressively enlarging their erythropoietic tissues. Erythroid-specific inactivation of Sox6 causes the same phenotype, demonstrating cell-autonomous roles for Sox6 in erythroid cells. Sox6 potentiates the ability of erythropoietin signaling to promote proerythroblast survival and has an effect additive to that of erythropoietin in stimulating proerythroblast and erythroblast proliferation. Sox6 also critically facilitates erythroblast and reticulocyte maturation, including hemoglobinization, cell condensation, and enucleation, and ensures erythrocyte cytoskeleton long-term stability. It does not control adult globin and erythrocyte cytoskeleton genes but acts by stabilizing filamentous actin (F-actin) levels. Sox6 thus enhances erythroid cell development at multiple levels and thereby ensures adequate production and quality of red blood cells.

[A rare cause of anemia in a kidney-transplant recipient]

BACKGROUND

Anemia is a phenomenon frequently observed after kidney transplantation and differential diagnosis is broad.

CASE REPORT

A 39-year-old woman who had been transplanted a kidney of her father 11 months ago was admitted to the hospital because of severe and worsening anemia (hematocrit [Hct] 0.24). She was under a standard posttransplant immunosuppressive protocol consisting of tacrolimus, mycophenolate mofetil (MMF) and prednisolone. Kidney function was excellent (serum creatinine 118 micromol/l), clinical symptoms of anemia included vertigo, fatigue and low blood pressure. Striking laboratory features were reticulocytopenia (1 per thousand), high ferritin (3,486 microg/l) and low folic acid (4.8 nmol/l), other parameters remained in the normal or therapeutic range. Endoscopic examinations did not reveal any pathologic finding. Bone marrow biopsy, however, showed giant pronormoblasts and the missing of more mature forms as a possible hint to a lack of, e. g., vitamin B(12) (whose serum level was normal, though). After all, the most probable cause of the anemia seemed to be a toxic drug effect and MMF as a possible causative agent was significantly reduced. Nonetheless, the red blood cell count continued to fall (lowest Hct 0.18). On a later outpatient visit all of a sudden positive IgM and IgG antibodies against parvovirus B19 could be detected. Due to a high virus load short-term immunoglobulin treatment was instituted, after which Hct levels rose to normal and virus load decreased to a low degree although still detectable.

CONCLUSION

An infection with parvovirus B19 should always be taken into account as a possible cause of anemia in immunosuppressed patients. Establishing the diagnosis in the acute stage of the disease can be difficult, as antibodies are often negative in these patients and viremia remains the only proof. In most cases a substantial reduction of immunosuppressive therapy is necessary, the infection's relevance for the development of a potentially life-threatening myocarditis is still a matter of debate.

Antimutagenic effect of neem leaves extract in freshwater fish, Channa punctatus evaluated by cytogenetic tests

Neem (Azadirachta indica), an indigenous plant commonly grown in India and its sub-continent is a multipurpose plant well known for its insecticidal and biomedical properties, however, its antimutagenic effects in vertebrate organisms are lacking. The present work is therefore, focused on possible antimutagenic potential of ethanolic extract of neem leaves evaluated on the clastogenicity induced by Pentachlorophenol (PCP) and 2, 4-dichlorophenoxyacetic acid (2,4-D) in freshwater fish, Channa punctatus used as a vertebrate model, by cytogenetic endpoints: chromosome aberration (CA) and micronucleus (MN) test. In the first set of experiment, fish were exposed by medium treatment to a single treatment of each chemical (PCP, 0.6 ppm; 2,4-D, 75 ppm; neem extract, 3 ppm) along with the controls. The chromosome preparations were made after processing kidney cells and micronucleus slides were prepared from peripheral blood at multiple duration (48, 72 and 96 h). PCP and 2,4-D when used alone, induced significant CA and MN in a time dependent manner. Neem extract did not show genotoxic potential in both assays. The maximum frequency of CA were recorded as 18.58% and 15.17%, while frequency of MN reached to 8.08% and 4.62% by PCP and 2,4-D respectively, after 96 h exposure. In the second set of experiment, three concentrations of neem extract (1, 2 and 3 ppm) were run simultaneously with the same concentration of PCP (0.6 ppm) and 2,4-D (75 ppm) for antimutagenicity estimates. In mixed treatment, neem extract significantly reduced the frequency of CA and MN. The reduction in the frequency of CA ranged from 40-75% and 45.4-83.3% and similar values for MN were 40.2-75.3% and 44.1-65.8% for PCP and 2,4-D respectively. Although the reductions were significant but not dependent on concentration and time intervals employed. Results suggested that under present experimental conditions, neem extract exhibit strong antimutagenic activity in this fish model, which could further contribute to study its benefit in humans.