Interactive toxicity of copper and cadmium in regenerating and adult planarians.

In a polluted environment, metals are present as complex mixtures. As a result, organisms are exposed to different metals at the same time, which affects both metal-specific as well as overall toxicity. Detailed information about the molecular mechanisms underlying the adverse effects of combined exposures remains limited in terms of different life stages.

Regenerative responses following DNA damage - β-catenin mediates head regrowth in the planarian .

Pluripotent stem cells hold great potential for regenerative medicine. Increased replication and division, such is the case during regeneration, concomitantly increases the risk of adverse outcomes through the acquisition of mutations. Seeking for driving mechanisms of such outcomes, we challenged a pluripotent stem cell system during the tightly controlled regeneration process in the planarian Exposure to the genotoxic compound methyl methanesulfonate (MMS) revealed that despite a similar DNA-damaging effect along the anteroposterior axis of intact animals, responses differed between anterior and posterior fragments after amputation.

Toxicity Assessment of Silver Nanoparticles in Homeostatic versus Regenerating Planarians.

Silver nanoparticles (AgNPs) belong to the most commercialized nanomaterials, used in both consumer products and medical applications. Despite its omnipresence, in-depth knowledge on the potential toxicity of nanosilver is still lacking, especially for developing organisms. Research on vertebrates is limited due to ethical concerns, and planarians are an ideal invertebrate model to study the effects of AgNPs on stem cells and developing tissues , as regeneration mimics development by triggering massive stem cell proliferation.

Applications of reflection-contrast microscopy, including the sensitive detection of the results of in situ hybridisation a review.

The observation with RCM of the reflection from reaction products produced by nonisotopic in situ hybridisation and a peroxidase staining, has recently facilitated the identification of single copy genes. RCM also reveals light microscope structures in stained ultrathin (0.1 μm) epon and lowicryl sections.

Planarians Customize Their Stem Cell Responses Following Genotoxic Stress as a Function of Exposure Time and Regenerative State.

Aiming to in vivo characterize the responses of pluripotent stem cells and regenerative tissues to carcinogenic stress, we employed the highly regenerative organism Schmidtea mediterranea. Its broad regenerative capacities are attributable to a large pool of pluripotent stem cells, which are considered key players in the lower vulnerability toward chemically induced carcinogenesis observed in regenerative organisms. Schmidtea mediterranea is, therefore, an ideal model to study pluripotent stem cell responses with stem cells residing in their natural environment.

Stem cell proliferation patterns as an alternative for in vivo prediction and discrimination of carcinogenic compounds.

One of the major challenges in the development of alternative carcinogenicity assays is the prediction of non-genotoxic carcinogens. The variety of non-genotoxic cancer pathways complicates the search for reliable parameters expressing their carcinogenicity. As non-genotoxic and genotoxic carcinogens have different cancer risks, the objective of this study was to develop a concept for an in vivo test, based on flatworm stem cell dynamics, to detect and classify carcinogenic compounds.

Molecular basis and enzymatic properties of glucose 6-phosphate dehydrogenase volendam, leading to chronic nonspherocytic anemia, granulocyte dysfunction, and increased susceptibility to infections.

We have investigated the blood cells from a woman with a low degree of chronic nonspherocytic hemolytic anemia and frequent bacterial infections accompanied by icterus and anemia. The activity of glucose 6-phosphate dehydrogenase (G6PD) in her red blood cells (RBCs) was below detection level, and in her leukocytes less than 3% of normal. In cultured skin fibroblasts, G6PD activity was approximately 15% of normal, with 4- to 5-fold increased Michaelis constant (Km) for NADP and for glucose 6-phosphate.

High DNA content and prognosis in lymph node positive breast cancer. A case control study by the University of Leiden and ECOG. (Eastern Cooperative Oncology Group).

To investigate whether breast cancer cells with unusually high nuclear DNA content are associated with an adverse outcome, Eastern Cooperative Oncology Group investigators selected breast cancer trial patients who suffered an early death (ED) within two years after diagnosis to compare with other trial patients who had a survival of at least 7.5 years. Paraffin blocks of primary breast cancers were obtained from 93 evaluable patients who had been enrolled in two surgical adjuvant trials for lymph node positive (LN+) disease (T1-3N1M0).

Laboratory test of an automated cell analysis system for cervical screening.

An automated cell analysis system (Autoplan-MIAC) for the early detection of precancerous lesions of the cervix was tested under semi-routine conditions in a clinical cytology laboratory. A set of 1500 specimens, highly enriched with abnormal cases, was analysed. Cervical scrapings were collected in suspension and processed by cytocentrifugation for microscopy.

The prognostic value of DNA content measured by image cytometry in soft tissue sarcomas.

Nuclear DNA content in soft tissue sarcoma was determined by image cytometry using archival, paraffin embedded material. In a retrospective study 138 specimens of 81 patients have been analysed. The ploidy level was correlated to clinical outcome regarding tumor volume and histological grading, the most important prognostic parameters.

Preparation and microscopic visualization of multicolor luminescent immunophosphors.

The preparation of charge-stabilized suspensions of small phosphor particles (0.1-0.3 micron) and their coupling with antibodies to immunoreactive conjugates is described.

Remission of monoclonal chronic T-cell expansion associated with severe anemia.

A 49-year-old male with an 8 year history of lowered Hb level, granulocytopenia and fatigue presented in 1986 with progressive fatigue, a dramatically reduced Hb level (45 g/l) and an increased lymphocyte count (6.6 x 10(9)/l). Clinical picture and laboratory studies led to the diagnosis of chronic T lymphocytosis with expansion of CD8+ T cells expressing CD16 IgG Fc receptors (Fc gamma RIII).

Symptomatic cytomegalovirus (CMV) infections identified by image cytometry and other parameters for CMV infection.

Thirty-eight renal transplant recipients were followed during the first 3 months after transplantation. Once weekly, cultures of urine and buffy coat for cytomegalovirus (CMV) were taken and an immunocytochemical assay for immediate early antigens of CMV (IEA assay) was performed. Thirty patients had evidence of a CMV infection and 11 had a symptomatic CMV infection.

The present state of the automated micronucleus test for lymphocytes.

This minireview presents the state of the art with respect to automated detection of micronuclei (MN) in binucleated lymphocytes. Emphasis is on an image analysis technique, based on the principles of mathematical morphology (pattern recognition), which combines a personal computer with an image processing board and a board for microscope control. The basic idea behind this procedure is that nuclei plus MN and cytoplasms are analysed separately and sequentially by capturing images from gallocyanin-stained nuclei plus MN and naphthol yellow-S stained cytoplasms from one microscope field by using different filters.

Trisomy 13 and myelodysplastic syndrome.

The clinical and cytogenetic data of a patient with myelodysplastic syndrome-refractory anemia with excess blasts (MDS-RAEB) and trisomy 13 as the sole abnormality are presented. This appears to be only the second report of such a patient. The presence of trisomy 13 is confirmed by in situ hybridization using an alphoid repeat probe L1.

Interobserver variability in the cytological diagnosis of 1500 Papanicolaou stained cervical monolayer specimens.

Cervical specimens from 1500 patients were prepared by means of a centrifugation procedure to obtain monolayer specimens suitable for automated screening using a machine. After staining according to Papanicolaou, each specimen was diagnosed by four independent cytologists from two different institutes. Within each institute, noncorresponding screening results were discussed to arrive at a conclusion diagnosis.

Multiple fluorescence in situ hybridization.

A method for multiple fluorescence in situ hybridization is described allowing the simultaneous detection of more than three target sequences with only three fluorescent dyes (FITC, TRITC, AMCA), respectively emitting in the green, red, and blue. This procedure is based on the labeling of (DNA) probes with more than one hapten and visualisation in multiple colors. The possibility to detect multiple targets simultaneously is important for prenatal diagnosis and the detection of numerical and/or structural chromosome aberrations in tumor diagnosis.

Hb J-Anatolia [alpha 61(E10)Lys----Thr]: structural characterization and gene localization of a new alpha chain variant.

We report the characterization of a new hemoglobin variant having a single amino acid substitution (Lys----Thr) at position 61 of the alpha chain. In addition to the structural analysis, we also describe the strategy used for the identification of the base substitution and the localization of the defect at the gene level using polymerase chain reaction and hybridization with allele-specific oligonucleotides.

Automated image cytometry in cytopathology.

Image cytometry is used more and more for the study of clinical cytology, notably for the determination of morphometrical and densitometrical values, the quantification of monoclonal antibody labelling and the detection of DNA probes after in situ hybridisation. Aspects of automated and interactive image cytometry are discussed, including a brief evaluation of limitations and advantages of the image technique in connection to flow cytometry. Some new technologies such as a sampling technique for paraffin embedded tissue and a new automated microscope, which are of special interest to the pathologist, are described in more detail.

Automated cell analysis for DNA studies of large cell populations using the LEYTAS image cytometry system.

Image cytometry by means of LEYTAS features analysis of both fresh and archival cellular material. Although not as accurate in ploidy determination as flow cytometry, LEYTAS cytometry incorporates extensive artefact rejection algorithms, thereby allowing detection of low frequency cells. This feature is very useful for the search of rare cells, as e.

Discrepancies in ploidy determination due to specimen sampling errors.

Two techniques are described to enhance the detection of low frequency aneuploid cells in automated cell analysis. One method concerns a cell preparation technique; the other is focused on specific cell selection at the measurement level. The cell preparation method has been designed to select and process the tumour areas in paraffin blocks and can be used for image as well as for flow cytometry.

Leptomeningeal plasmacytosis. Case report and considerations on treatment.

We describe a 68-year-old patient with a plasma cell leukaemia in haematological remission presenting with massive intracranial leptomeningeal plasmocytic infiltration (LPI) and hydrocephalus. He was treated with skull irradiation and a combination of intraventricular and lumbar intrathecal therapy with methotrexate. Neurologic improvement and clearance of plasma cells from the cerebrospinal fluid was reached after 2 weeks of treatment but prolonged follow-up was interrupted by a lethal gastro-intestinal haemorrhage, 6 weeks after starting the therapy.