Cryptic Leishmaniosis by Leishmania infantum, a feature of canines only? A study of natural infection in wild rabbits, humans and dogs in southeastern Spain

An epidemiological study was carried out to investigate asymptomatic Leishmania infantum infection by PCR and ELISA in wild rabbits, humans and domestic dogs in southeastern Spain. Seroprevalence was 0% (0/36) in rabbits, 2% (13/657) in humans and 7% (14/208) in dogs. The prevalence of PCR-positives was 0.6% (1/162) in rabbits tested in a wide range of tissue samples, 2% (8/392) in humans analysed in blood samples and 10% (20/193) and 67% (29/43) in dogs analysed in blood and lymphoid tissue samples, respectively. Results suggest that wild rabbits have a very low risk of becoming chronically infected with L. infantum, and provide further evidence that cryptic L. infantum infection is widespread in the domestic dog population and is also present in a comparatively smaller proportion of healthy humans. The epidemiological and clinical implications of these findings are discussed.

[Functional capacity evaluation in a clinical and ambulatory setting: new challenges of accelerometry to assessment balance and muscle power in aging population]

If we consider a population of free-living individuals, who are 65 years old and even older, a substantial proportion (in the range of 6% to 25%) suffers from many of the elements of the syndrome of frailty. Although the syndrome is complex and still lacks a standard definition, there is a growing consensus about its signs and symptoms. Patients who are afflicted with frailty typically exhibit losses of muscle strength, fatigue easily, are physically inactive, with an increased risk (and fear) of falling, have undergone a recent, unintentional loss of weight, experience impaired cognition and depression, all of which is frequently complicated by a variety of coexistent illnesses. In this context, functional tests to predict disability and frailty are needed. Accelerometry offers a practical and low cost method of objectively monitoring human movements, and has particular applicability to the monitoring of disability in an aging population. Accelerometers have been used to monitor a range of different movements, including gait, sit to stand transfers and postural sway. This review focuses on methodological concepts in the evaluation of skeletal muscle function and monitoring systems (accelerometers and gyroscopes) in each of these areas. An integrated approach is described in which a combination of accelorometry and gyroscopy can be used to monitor a range of different parameters (muscle power, gait and balance) in an aging population in a clinical or out-patient setting.

Simultaneous detection of the immunophenotypic markers and genetic aberrations on routinely processed paraffin sections of lymphoma samples by means of the FICTION technique

Disciplines such as morphology, immunophenotyping and genetics widely contributed over decades to the understanding of the cellular mechanisms of cancer. To obtain a greater insight into the complex processes of tumorigenesis, scientists have joined their efforts to combine many of the available techniques. Here, we report on the development of a FICTION (Fluorescence Immunophenotyping and Interphase Cytogenetics as a tool for the Investigation of Neoplasms) technique that allows a simultaneous detection of immunophenotypic markers and genetic aberrations on routinely processed lymphoma samples. As the antigen retrieval method seems to play an important role in the final results, we tested the pressure-cooking method at different times (2, 4 and 8 min) using three different buffers (EDTA, Tris-EDTA and citrate), resulting in improved sensitivity for the detection of both immunophenotypic markers and genetic aberrations. We also applied this method to different types of lymphoma using double immunofluorescence assays (including CD30, CD20, CD8 monoclonal antibodies) and several fluorescence in situ hybridization probes to demonstrate that the FICTION technique could be easily applied on paraffin sections in different combinations for the diagnosis and research of cancer.

Characterization of the A673 cell line (Ewing tumor) by molecular cytogenetic techniques

The A673 cell line was established from a patient with a primary rhabdomyosarcoma (RMS), which is referred to in the literature either as a Ewing tumor (ET) or as RMS. Although the two tumoral types are associated with specific and well-characterized translocations, no cytogenetic report on this cell line has been published. We characterized the A673 cell line using a combination of spectral karyotyping (SKY), fluorescence in situ hybridization (FISH), and reverse transcriptase polymerase chain reaction (RT-PCR), which revealed the presence of a complex karyotype and a translocation involving chromosomes 11 and 22 and the fusion of EWS and FLI1 genes, both events being specific to ET. Neither cytogenetics nor molecular alterations specific to RMS were found.

Complex cytogenetic abnormalities including telomeric associations and MEN1 mutation in a pediatric ependymoma

Ependymomas are neuroectodermal tumors of the brain and spinal cord. Some recurrent cytogenetic aberrations have been reported in these tumors, including alterations involving chromosomes 22, 6, and 11. However, consistent molecular alterations have not been identified in ependymal tumors. We studied a recurrent ependymoma in a 3-year-old patient by standard cytogenetic and molecular analysis of TP53 and MEN1 genes. In the present case, we found many of the cytogenetic features previously described as being recurrent in ependymomas, including unstable telomeric alterations. Furthermore, we detected a novel acquired heterozygous mutation in the MEN1 gene. The chromosomal instability produced by the telomeric alterations and the mutation in the MEN1 gene could be important events in the tumorigenesis of ependymomas.

Identification of ins(8;21) with AML1/ETO fusion in acute myelogenous leukemia M2 by molecular cytogenetics

A high percentage of cases of acute myelogenous leukemia (AML) of the M2 subtype show a rearrangement between the AML1 and ETO genes. The detection of the AML1/ETO fusion has clinical relevance because patients with this subtype have a good prognosis. We present the results of conventional and molecular cytogenetic studies in a patient with acute myelogenous leukemia French-American-British M2 classification, who had a complex karyotype involving chromosomes 8 and 21. Dual-color fluorescence in situ hybridization (FISH) using the AML1/ETO probe demonstrated a recombination of both genes on an add(8) chromosome. The use of other FISH probes (CEP8, c-myc and TEL21) and spectral karyotyping indicated that AML1/ETO fusion occurred as a consequence of a previously undescribed ins(8;21)(q22;q22.1q22.3).

Multiplex-polymerase chain reaction assay for the detection of prognostically significant translocations in acute lymphoblastic leukemia

BACKGROUND AND OBJECTIVES

The presence of specific chromosomal translocations in acute lymphoblastic leukemias (ALL) plays an important role in determining the prognosis of the patients. Our aim is to develop a highly sensitive and specific method to screen simultaneously for the four most frequent translocations in ALL: t(9;22), t(1;19), t(4;11), t(12;21).

DESIGN AND METHODS

Our approach uses a multiplex-polymerase chain reaction (PCR) method, which involves two rounds of PCR using fluorescence-labeled nested primers. The chimeric transcripts resulting from these translocations can be identified by agarose gel electrophoresis or by fluorescence analysis. To validate this method we carried out the analysis in 42 pediatric ALL samples previously studied by cytogenetic and fluorescent in situ hybridization (FISH) techniques.

RESULTS

In all samples with a known translocation detected by cytogenetic or FISH techniques, the same translocation was identified by the multiplex-PCR assay. Moreover, with this method we detected rearrangements in five patients in clinical remission and in two patients at diagnosis for whom karyotypes were normal and rearrangements had not been detected. The application of this multiplex-PCR assay was also useful in cases without cytogenetic results.

INTERPRETATION AND CONCLUSIONS

These results show that the multiplex-PCR method allows reliable, sensitive and rapid detection of the prognostically significant translocations in ALL. We believe that this assay combined with cytogenetic analysis should be the strategy of choice for the initial diagnostic phase of acute lymphoblastic leukemia, and that it could be used not only at diagnosis but also to follow-up these alterations in remission samples without previous controls.

Fluorescence in situ hybridization study of TEL/AML1 fusion and other abnormalities involving TEL and AML1 genes. Correlation with cytogenetic findings and prognostic value in children with acute lymphocytic leukemia

BACKGROUND AND OBJECTIVES

The TEL/AML1 fusion is the most common genetic abnormality found in childhood acute lymphoblastic leukemias (ALL). Although it is very difficult to identify by conventional cytogenetic techniques it can be readily detected using fluorescence in situ hybridization (FISH). We carried out cytogenetic and FISH studies on 42 children with ALL in order to know the frequency of this translocation in our population, the incidence of TEL and/or AML1 gene alterations, and their correlation with clinical evolution and prognosis. In addition, we performed reverse transcription polymerase chain reaction (RT-PCR) in some cases, confirming the feasibility of FISH techniques in the detection of this translocation.

DESIGN AND METHODS

Bone marrow samples were obtained from 42 childhood ALL patients. The copy number of AML1 and TEL genes were studied using fluorescent in situ hybridization with a dual color DNA probe specific for the AML1 and TEL genes.

RESULTS

We found a frequency of TEL/AML1 fusion of 17% in our sample. Double TEL/AML1 fusion, lack of TEL signal and extra AML1 signals were frequent additional FISH abnormalities. Duplication of a chromosomal complement, deletion of chromosome 12p arm, and polysomies of chromosome 21 are plausible explanations for these additional FISH findings. However, a relatively high proportion of our cases (9.5%) presented specific amplification of AML1. A statistically significant difference in prognosis was found between patients with and without these additional AML1 or TEL FISH alterations (p<0.02), which could be related to the presence of specific karyotypes.

INTERPRETATIONS AND CONCLUSIONS

The frequency of TEL/AML1 fusion is similar to that found in other populations (17%). We found that FISH analysis of AML and TEL is related to the evolution of the disease. The absence of alterations in these genes revealed by FISH could be indicative of bad prognosis, while the presence of alterations is related to a good evolution. Our results suggest that interphase FISH analysis to search for alterations in AML and TEL genes could be extremely useful for complementing cytogenetic studies and for providing additional information about the possible outcome of the disease in patients with ALL.

A PCR product derived from female DNA with regional localization on the Y chromosome

A 154-bp PCR product amplified from human female DNA mapped onto the Y chromosome under high-stringency in situ hybridization conditions. The female DNA sequence revealed an 89% homology with the HSDYZ1 sequence. When the same primers were used to amplify male DNA, a 154-bp DNA fragment was also obtained, showing a 98% homology with HSDYZ1. However, although the HSDYZ1 sequence is widely distributed along the long arm of the Y chromosome, both of these particular PCR products are di-regionally localized within this distal block of constitutive heterochromatin. In situ hybridization under lower stringency showed that these 154-bp sequences map both onto the autosomes and the Y chromosome. Overall, this paper shows (i) a new class of DNA sequences shared by the autosomes and the Y chromosome; and (ii) a substructured organization of some DNA repeats within the DYZ1 family that forms a large part of the constitutive heterochromatin of the Y chromosome.