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Silicon detectors are widely used in space radiation dosimeter systems for measuring energetic charged particles. Calibration of such systems is usually performed with protons and heavier ions in high energy particle accelerators. For preliminary energy calibration and functional testing of silicon detectors, at any time during the development, an equipment producing a thin 212Bi-212Po alpha particle emitting source was designed and constructed. Our aim was to develop an alpha source with negligible self-shielding and short life-time in order to prevent the long-term contamination of the detectors with alpha particle emitting nuclides. In the present paper, a description of the method chosen, and the equipment developed are given. Estimates of the activity of the source produced was obtained from measurements with the RADTEL space radiation telescope under development in the Centre for Energy Research, Hungarian Academy of Sciences (MTA EK). It was also used to verify that the alpha particle emitting source is suitable for the preliminary calibration and functional testing of silicon detector systems.

The aim of the present study is to establish possible associations between Aquaporin-1, Cyclooxygenase-2 and Apoptosis Protease-Activating Factor-1 expression in breast cancers and pathological and immunohistochemical characteristics of the examined tumors. For the purpose of this study we used paraffin embedded archived tumor material of 31 breast cancer patients from the Pathology Department of the Odorheiu Secuiesc Municipal Hospital. We performed immunohistochemistry reactions ER, PR, HER2, AQP1, COX2 and APAF1, and following independent evaluation by two pathologists the obtained data was statistically analyzed. The tumors were divided into three groups based on their histological properties, and correlations were made with the examined markers. AQP1, COX2 and APAF1 immunostaining results produced significant correlations with HER2 status and histological groups. There were no statistical correlations between ER or PR status and the three examined markers. Lobular carcinomas showed AQP1 and COX2 overexpression, and loss of APAF1 expression, which all correlated with HER2 negative status. We concluded that AQP1 could be a useful marker for detecting more aggressive subtypes and also for evaluating tumor angiogenesis. COX2 and APAF1 immunoexpression, although somewhat specific to certain histological groups, needs to be further characterized in order to be a useful marker for the clinical setting.

Some characteristics of rapidly mobilized stem cells as a possible distinct subset of the murine bone marrow stem cell population are overviewed. Some of the agents that rapidly mobilize stem cells are toxic and possibly act through disrupting anchorage to the microenvironment. The mobilization occurring days after cytostatics and/or colony-stimulating factors (CSF), however, is a consequence of increased production or differentiation. While stem cells (colony-forming units-spleen; CFU-S) circulating normally in blood have low self-renewal capacity (SRC), SRC of rapidly mobilized CFU-S is closer to that of bone marrow stem cells and is similar to that of the late mobilized stem cells. The survival rate of mice after transplantation of rapidly mobilized stem cells did not differ from that of bone marrow stem cells. One year after transplantation of rapidly mobilized stem cells, the SRC value of bone marrow did not differ from those transplanted with bone marrow cells. Replacement of a rapidly mobilizable stem cell pool requires 48 h under physiological conditions and a longer time after damage to hemopoiesis (irradiation, hydroxyurea injection). Possible physiological mechanisms in the anchorage of stem cells are discussed.

In the frame of the European Space Agency (ESA) project called “Biology and Physics in Space”, the returning satellite, Foton-M2, carried an open-to-space exposure platform outside of the satellite body, called as BIOPAN-5, loaded with exo-biological experiments and facilities for radiation dosimetry (RADO). One of the RADO experiments was dedicated to the detection of the primary galactic cosmic rays (GCR) and secondary neutrons by a track etch detector stack. The daily absorbed dose (D) and dose equivalent (H) were calculated from the experimental LET spectra (LET > 10 keV/μm). Under a shielding of ∼2.8 g/cm2 the averaged H was found to be 658 ± 8 μSv/d, with a quality factor (Q) of 6.2 ± 1.2. The LET spectra showed a local peak at ∼105 keV/μm suggesting that the majority of tracks were created by trapped protons as it has been predicted by calculations. The low LET dose of the cosmic radiation was determined by 4 TLD stacks, and the total dose was found to be 795 ± 14 μSv/d.

In the framework of “Biology and Physics in Space” project of the European Space Agency (ESA), a returning satellite, Foton-M2, carried an open-to-space sample holder outside of the satellite body, called as BIOPAN-5, loaded with exo-biological experiments and dosemeters for RA diation DO simetry (RADO). One of the RADO experiments (Teflon – TLD) was dedicated to dose distribution measurements of the cosmic radiation by thermo-luminescent (TL) technique. It was found that the maximum surface absorbed dose rate, averaged over the first ∼8 mg/cm 2 thickness, was ∼2 Gy/d and showed a location dependence due the shading effect of the satellite construction elements. The dose rate decreased nearly by 3 orders of magnitude below 500 mg/cm 2 .

An occupational incorporation event occurred at the Radioactive Waste Treatment and Disposal Facility in December 2013 at Puspokszilagy, Hungary. Internal contamination due to (241)Am was discovered by a regular routine whole body counting measurement at the Centre for Energy Research, Hungarian Academy of Sciences. After that, a whole body counter was calibrated for an organ counting geometry. For preliminary calibration, a home-made MIX-D chest phantom was applied simulating uniform lung activity distribution by (241)Am point sources located in different positions within the lung volume of the phantom. In order to carry out a more precise calibration, a Lawrence Livermore National Laboratory (LLNL) chest phantom was provided by the International Atomic Energy Agency. For counting efficiency over the lungs, values of 0.46±0.19 and 0.55±0.07 cps kBq(-1) were obtained for the MIX-D and the LLNL phantom, respectively; thus, the results are in good agreement.

Seventeen caddisfly species of four families (Limnephilidae, Sericostomatidae, Phryganeidae, and Leptoceridae) with a total of 1047 individuals were collected from four sampling sites in the littoral zone of Disznoskut Lakes in the Bukk Mountains. Three of these four families of Trichoptera were also recorded in the Central European lakes. From among the four substrates (sand, silt, large stones, and aquatic plants) of the littoral zone, silt and aquatic plants were dominant. Besides species of Limnephilidae found in higher than the average abundance in the silt, species of Phryganeidae and Leptoceridae also occurred. The trophic relationships of the species of these families can be considered as follows: shredders- predators- scrapers, shredders- detritivores- predators, and predators- shredders- scrapers. From the aquatic plants the species of Limnephilidae, Phryganeidae and Leptoceridae, belonging to the trophic relationships of detritivores- shredders, scrapers- predators, shredders- detritivores- predators, and predators- shredders- scrapers- detritivores were collected. The analysis (PCA) of the spatial and seasonal distribution of Trichopteran larvae at the four littoral zone sites shows that the assemblages collected near the inflow of the stream into the lake in late summer and near the inflow of the small channel into the lake in summer are very different from the others, for which Limnephilus elegans, Micropterna lateralis, and Stenophylax permistus are responsible at the previous site, while Halesus digitatus, Halesus tessellatus, and Mystacides nigra are responsible at the latter one. The other assemblages (mostly those in winter) are very similar to each other, which can be explained by the decreasing number of detectable species and their presence in low abundance. For the variance, Limnephilus rhombicus (57%) and Potamophylax nigricornis (16%) are essentially responsible. Considering the species composition of the larval assemblages, the site at the inflow of the stream into the lake was the most different (38%) from the others, and was 62% similar to them. This dissimilarity can possibly be explained by the presence of a mixed assemblage with typical stream and lake inhabitants of species of Limnephilidae present in high abundance at this silt dominated site and other caddis species that are typical stream inhabitants or common in streams and small rivers, and may have drifted into the lake.

One way of studying the risk to human health of low-level radiation exposure is to make biological experiments on living cell cultures. Two 210Po alpha-particle emitting devices, with 0.5 and 100 MBq activity, were designed and constructed to perform such experiments irradiating monolayers of cells. Estimates of dose rate at the cell surface were obtained from measurements by a PIPS alpha-particle spectrometer and from calculations by the SRIM 2000, Monte Carlo charged particle transport code. Particle fluence area distributions were measured by solid state nuclear track detectors. The design and dosimetric characterisation of the devices are discussed. c2002 Elsevier Science Ltd. All rights reserved.

Blast colony-forming cells (CFU-BL) represent a specific subpopulation of special primitive progenitors characterized by colony formation only in close contact with a preformed stromal layer. CFU-BL derived from bone marrow of chronic myeloid leukaemia (CML) patients have been proved to adhere poorly to bone marrow derived stromal layers suggesting that the appearance of progenitors and precursors in the circulation is due to a defective adhesion of these cells to the bone marrow microenvironment. In the present experiments the effect of short-term incubation of preformed normal bone marrow stroma on the adherence of CML derived CFU-BL was studied. For stroma cultures bone marrow cells were cultured in microplates in the presence of hydrocortisone. Cultures were used when stromal layers became confluent and no sign of haemopoiesis could be observed. CFU-BL were studied by panning plastic non-adherent mononuclear (PNAMNC) bone marrow or blood cells. 8.9 ± 2.4 colonies/103 PNAMNC (six experiments) were formed from normal bone marrow on stromal layers and 4.8 ± 2.1 colonies/103 PNAMNC (five experiments) from CML bone marrow. Colony formation from normal bone marrow was not increased if stromal layers were incubated with 100 ng/mL granulocyte colony-stimulating factor (G-CSF) or stem cell factor (SCF). Incubation of stroma with G-CSF or SCF, however, increased the colony formation of PNAMNC from CML bone marrow or blood significantly. These findings suggest that local concentration of haemopoietic growth factors at the time of panning may influence the attachment of CML progenitors to the stroma.

In order to quantify contaminating leukaemia inducing cells in blood or bone marrow from WEHI-3B bearing BALB/c mice (injected with 105 WEHI-3B suspension culture cells), in vitro colony forming leukaemia cells (CFU-L) and survival rate and/or survival time of mice transplanted with cells from WEHI bearing mice or suspension culture were correlated. ED50 (inoculum inducing leukaemia in 50% of the animals) was 109 CFU-L (33–361) from suspension culture cells. Three weeks after initiation of leukaemia 2 × 105 BM or 0.5–2.0 × 106 blood cells induced 100% mortality of recipients. After mobilisation with CY or CY and G-CSF, the same amount of blood or BM cells did not induce leukaemia in recipients. A significant negative correlation was found between the survival time of leukaemic mice and the log number of CFU-L inoculated from in vivosources. In terms of CFU-L cells, leukaemia induction to BM or WBC obtained 3 weeks after leukaemia induction were more potent; those from BM or WBC also obtained at 3 weeks but after mobilisation were less potent inducers than those from suspension culture. These data suggest that CFU-L and leukaemogenic cells are associated, but not identical. Bone Marrow Transplantation (2001) 28, 699–704.

A specific stroma function can be quantitatively assessed by counting the stroma-adherent blast cell colonies (CFU-BL) that are formed from normal plastic nonadherent mononuclear bone marrow cells (PNAMNC) after a short-term coincubation ("panning") with the preformed stromal layer. In order to obtain information of stroma function in myelodysplasia (MDS), the "CFU-BL-binding capacity" of stroma from normal bone marrow and from patients with MDS were compared. Stromal cell cultures were established from mononuclear bone marrow cells in microplate cultures cultured with or without 10(-6) M hydrocortisone. CFU-BL-binding capacity was studied by counting blast colonies seven days after panning, and the results were expressed as CFU-BL/10(3) PNAMNC. Normal marrow stromal layers bound CFU-BL only if they were cultured with hydrocortisone, while MDS stromal layers also bound CFU-BL in the absence of hydrocortisone. For further studies of the function of MDS stroma, the effect of growth factors (stem cell factor [SCF], G-CSF, interleukin 3 [IL-3] and their combinations) on CFU-BL binding by normal or MDS stroma has also been compared. Twenty-hour incubation of the stromal layers with a standard dose (100 ng/ml) of various hemopoietic growth factors (IL-3 alone or in combination with SCF, G-CSF alone or in combination with SCF) did not have any effect on CFU-BL binding by normal marrow stroma, but increased the CFU-BL binding by stromal layers from MDS bone marrow. These findings suggest that although stromal microenvironment in MDS is capable of supporting hemopoiesis, bone marrow stroma from MDS patients differs in some characteristics from the normal stroma.

The alterations of the argyrophil nucleolar organizer regions (AgNORs) have been studied in hyperplastic and neoplastic human liver lesions. The material studied included: 11 focal nodular hyperplasias (FNH), 3 adenomas, 19 hepatocellular carcinomas (HCC), 2 hepatoblastomas, 8 liver metastases. In 5 cases tumor-free (normal) liver was also available for study. The mean AgNOR numbers were significantly increased in all of these lesions (in FNHs 3.36 +/- 1.43, in the adenomas 2.48 +/- 1.29, in the HCCs 3.32 +/- 1.43, in the hepatoblastomas 3.33 +/- 1.33 and in the metastases 4.86 +/- 1.54) compared to those observed in normal liver (0.86 +/- 0.85). The highly increased AgNOR number in FNHs was particularly surprising and it seemed to us that based on AgNOR numbers the FNHs could be divided into two groups. With the exception of hepatoblastomas in all primary liver lesions the AgNOR counts distributed on a rather broad scale resulting in overlapping in hyperplastic and tumourous cases. The authors concluded that the AgNOR counts reflect only the proliferative activity of a given cell population and at least in the liver they cannot serve as basis for distinction between the hyperplastic, benign and malignant neoplastic lesions.

A dosimetric complex is proposed for use in long-term manned space flight on the orbital station and for the planned Mars expedition. This complex includes thermoluminescence dosimeters with on-board readout, a channel for continuous monitoring of dose rate and a channel for continuous measurement of absorbed and equivalent doses, as well as measurement of the LET spectra. The last four parameters are measured by a tissue-equivalent proportional counter.

Bone marrow cells (BMC) from normal donors and from patients with acute myeloid leukaemia (AML) were cultured. Growth kinetics and the efficiency of stromal layers in supporting the adhesion of normal blast-colony forming cells (BL-CFCs) were studied. BMC from treated AML patients formed confluent stromal layers faster than normal BMCs. BL-CFC binding capacity of normal and AML stromal layers did not differ: on normal stromal layers 67.3–147, on AML stromal layers 63–117 colonies per 5 × 10 5 plastic non-adherent BMC were formed. The amount and/or binding capacity of BL-CFCs was found to be normal in two AML patients in complete remission, while a significantly reduced number and/or binding capacity of BL-CFCs was found in AML nontreated patients and in patients within 4 weeks after the last cytostatic course.

The effect of hyperthermia in vitro on the survival and leukaemogenic effectiveness of WEHI 3-B cells and on the survival and transplantation efficiency of bone marrow cells was compared in a murine model system. Normal murine clonogenic haemopoietic cells (day 9 CFU-S and CFU-GM) proved to be significantly less sensitive to 42.5°C hyperthermia (D 0 values: 54.3 and 41.1 min, respectively) than leukaemic clonogenic cells (CFU-L) derived from suspension culture or from bone marrow of leukaemic mice (D 0 : 17.8 min). Exposure for 120 min to 42.5°C reduced the surviving fraction of CFU-L to 0.002 and that of CFU-S to 0.2. If comparable graft sizes were transplanted from normal or heat exposed bone marrow, 60-day survival of supralethally irradiated mice was similar. Surviving WEHI 3-B cells were capable of inducing leukaemia in vivo . The two log difference in the surviving fraction of CFU-L and CFU-S after 120 min exposure to 42.5°C suggests that hyperthermia ex vivo may be a suitable purging method for autologous bone marrow transplantation.

The “Pille-MKS” thermoluminescent (TL) dosimeter system developed by the KFKI Atomic Energy Research Institute (KFKI AEKI) and BL-Electronics, consisting of 10 CaSO 4 :Dy bulb dosimeters and a compact reader, has been continuously operating on board the International Space Station (ISS) since October 2003. The dosimeter system is utilized for routine and extravehicular activity (EVA) individual dosimetry of astronauts/cosmonauts as part of the service system as well as for on board experiments, and is operated by the Institute for Biomedical Problems (IBMP). The system is unique in that it regularly provides accurate dose data right on board the space station, a feature that became increasingly important during the suspension of the Space Shuttle flights. Seven dosimeters are located at different places of the Russian segment of the ISS and are read out once a month. Two of these dosimeters are dedicated to EVAs and one is kept in the reader and will be read out automatically every 90 min. During coronal mass ejections impacting Earth some of the dosimeters serve for individual monitoring of the astronauts with readouts once or twice every day. In this paper we report the results of dosimetric measurements made on board the ISS during Expedition-8, -9 and -10 using the “Pille” portable thermoluminescent detector (TLD) system and we compare them with our previous measurements on different space stations.

Publisher Summary On-board personal dose measurements are mainly based on thermoluminescent dosimetry. Because of the large dimensions and big mass of the readers, the TLDs used in space activities are generally evaluated only after their return to the ground, in terrestrial laboratories. The disadvantage of on-ground evaluation is that it results in the dose accumulated since the last read-out, that is, the dose of the whole flight, whereas with the increased duration of space flights periodic and relatively frequent dose measurements would be needed. A small, portable, and space-qualified TLD reader suitable for reading out the TL dosimeters on board provides the possibility of overcoming the above-mentioned disadvantage. Such a system offers a solution for EVA dosimetry as well. KFKI Atomic Energy Research Institute (KFKI AEKI) has developed and manufactured a series of thermoluminescent dosimeter systems for measuring cosmic radiation doses in the 10 μGy to 10 Gy range, consisting of a set of bulb dosimeters and a small, compact, TLD reader suitable for on-board evaluation of the dosimeters. By means of such a system, highly accurate measurements were carried out on board the Salyut-6, -7 and Mir Space Stations as well as on the Space Shuttle and the International Space Station (ISS). A detailed description of the system is given and the comprehensive results of these measurements are summarized in this chapter.

In 1992 a living area was discovered in Hungary where the radon exhalation rate was extremely high. One of the questions asked was whether this level of concentration has existed for a long time. Because radon daughters are continuously embedded on the surface of glass sheets by alpha recoil, it means that old glass sheets can 'remember' past radon concentration levels via long-lived decay products. Traditionally 210 Po (daughter of 210 Bi) surface activity concentration is measured with an ionisation chamber or solid state nuclear track detectors (SSNTD). A new and fast radiochemical method has been developed to investigate surface beta activity concentration of 210 Bi. The new method was checked by comparing it with SSNTD. It is concluded that the radon concentrations in the radon prone area where the glass samples were analysed have not changed by more than a factor of two over the last 8-55 years.

Blast colony‐forming cells (CFU‐BL) represent a specific subpopulation of special primitive progenitors characterized by colony formation only in close contact with a preformed stromal layer. CFU‐BL derived from bone marrow of chronic myeloid leukaemia (CML) patients have been proved to adhere poorly to bone marrow derived stromal layers suggesting that the appearance of progenitors and precursors in the circulation is due to a defective adhesion of these cells to the bone marrow microenvironment. In the present experiments the effect of short‐term incubation of preformed normal bone marrow stroma on the adherence of CML derived CFU‐BL was studied. For stroma cultures bone marrow cells were cultured in microplates in the presence of hydrocortisone. Cultures were used when stromal layers became confluent and no sign of haemopoiesis could be observed. CFU‐BL were studied by panning plastic non‐adherent mononuclear (PNAMNC) bone marrow or blood cells. 8.9 ± 2.4 colonies/10(3) PNAMNC (six experiments) were formed from normal bone marrow on stromal layers and 4.8 ± 2.1 colonies/10(3) PNAMNC (five experiments) from CML bone marrow. Colony formation from normal bone marrow was not increased if stromal layers were incubated with 100 ng/mL granulocyte colony‐stimulating factor (G‐CSF) or stem cell factor (SCF). Incubation of stroma with G‐CSF or SCF, however, increased the colony formation of PNAMNC from CML bone marrow or blood significantly. These findings suggest that local concentration of haemopoietic growth factors at the time of panning may influence the attachment of CML progenitors to the stroma.

Exposure of crew, equipment, and experiments to the ambient space radiation environment in low Earth orbit poses one of the most significant problems to long-term space habitation. Accurate dose measurement has become increasingly important during the assembly (extravehicular activity (EVA)) and operation of space stations such as on Space Station Mir. Passive integrating detector systems such as thermoluminescent dosemeters (TLDs) are commonly used for dosimetry mapping and personal dosimetry on space vehicles. The well-known advantages of passive detector systems are their independence of power supply, small dimensions, high sensitivity, good stability, wide measuring range, resistance to environmental effects, and relatively low cost. Nevertheless, they have the general disadvantage that for evaluation purposes they need a laboratory or large--in mass and power consumption--terrestrial equipment, and consequently they cannot provide time-resolved dose data during long-term space flights. KFKI Atomic Energy Research Institute (KFKI AEKI) has developed and manufactured a series of thermoluminescent dosemeter systems for measuring cosmic radiation doses in the 10 microGy to 10 Gy range, consisting of a set of bulb dosemeters and a compact, self-contained, TLD reader suitable for on-board evaluation of the dosemeters. By means of such a system, highly accurate measurements were carried out on board the Salyut-6, -7 and Mir Space Stations as well as on the Space Shuttle. A detailed description of the system is given and the comprehensive results of these measurements are summarised.

A microprocessor-controlled on-board TLD system, 'Pille'96', was used during the NASA4 (1997) mission to monitor the cosmic radiation dose inside the Mir Space Station and to measure the extra dose to two astronauts in the course of their extravehicular activity (EVA). For the EVA dose measurements, CaSO4:Dy bulb dosemeters were located in specially designed pockets of the ORLAN spacesuits. During an EVA lasting 6 h, the dose ratio inside and outside Mir was measured. During the EVA, Mir crossed the South Atlantic Anomaly (SAA) three times. Taking into account the influence of these three crossings the mean EVA/internal dose rate ratio was 3.2. Internal dose mapping using CaSO4:Dy dosemeters gave mean dose rates ranging from 9.3 to 18.3 microGy h-1 at locations where the shielding effect was not the same. Evaluation results of the high temperature region of LiF dosemeters are given to estimate the mean LET.

During the Euromir'95 mission, a specially designed microprocessor-controlled thermoluminescent detector (TLD) system, called the 'Pille'95', was used by ESA astronaut Thomas Reiter to measure the cosmic radiation dose inside the Mir space station. One of the experiment's objectives was to determine the dose fraction on Mir due to the South Atlantic Anomaly (SAA) on an orbit inclined at 51.6 degrees and at an altitude of about 400 km. Using an hourly measuring period for 170 h in automatic mode, dose components both of galactic (independent of SAA) and SAA origin were determined. It was found that the maximum dose due to crossing the SAA was equal to 55 microGy. Averaging all the measurements it was calculated that the mean dose rate inside the Mir was 12-14 microGy h-1 and that half of this value was caused by the SAA.

In P-388 bearing BDF1 mice stem cell mobilisation was tested on the survival of lethally irradiated isologous recipients. Contamination of the graft with lymphoma cells was evaluated by the number of clonogenic lymphoma cells (CFU-L) and the ability of the graft to induce lymphoma in non-irradiated recipients. A mobilisation protocol (200 mg/kg cyclophosphamide (CY) i.p. or 200 mg/kg CY followed by 125 microg/kg G-CSF administered every 12 h for 3 consecutive days, starting 14 days after lymphoma initiation) that resulted in a substantial stem cell mobilisation in normal mice, mobilised too few CFU-L to induce lymphoma in the recipients: 50 microl of blood obtained after mobilisation protected lethally irradiated mice but did not induce lymphoma in normal recipients. A minimum graft of bone marrow (2 x 105 cells, with 5580 CFU-L) from untreated P-388 bearing donors killed irradiated recipients presumably by lymphoma and not bone marrow failure. The mobilisation protocol reduced CFU-L so much that no lymphoma-associated death occurred even after the transplantation of 10 x 105 bone marrow cells. These data suggest that, although the PBSC mobilisation protocol may also mobilise some clonogenic lymphoma cells, with the minimum graft size no lymphoma transfer can be observed.

Erythropoietin (Epo) is a hormone-like glycoprotein regulating erythropoiesis. Under normal conditions Epo stimulates mitoses of the erythroid progenitors and precursors, decreases apoptosis, decreases "ineffective erythropoiesis" and stimulates the synthesis of the specific protein, haemoglobin. Epo producing cells in the kidney sense the O2 tension of kidney tissue and react to hypoxia with increased Epo production and to O2 saturation (polycythaemia) with decreased or completely abolished Epo production. Normal level of Epo in the serum is 3-20 mU/ml. If Epo production is functioning normally there exists a strict inverse correlation between serum Epo level and hematocrit: an exponential increase in Epo level can be observed if hematocrit decreases. Any damage in Epo production lead to inadequate production (e.g. renal anaemias). This paper analyses the Epo content of 278 serum samples assayed in the Laboratory of Experimental Bone Marrow Transplantation of the National Institute of Hematology and Immunology between August 1996 and December 1997 for their diagnostic value. Those samples are primarily discussed where Epo assay was meant to decide diagnosis of polycythaemia vera or those where decision of Epo treatment of anaemic patients depended on their serum Epo level.

Proliferation and differentiation of the haemopoietic stem cell are critical for the maintenance of normal haemopoiesis, damage to haemopoiesis, onset of malignant haemopoiesis and repopulation of haemopoiesis after bone marrow transplantation. To evaluate the actual state of haemopoiesis a quantitative assay of haemopoietic stem cells would be needed. Morphology of haemopoietic stem cells cannot be detected by their microscopic morphology. In human practice no stem cell assay is available, therefore, the quantity of human pluripotent stem cells is characterised by the frequency of the progenitors differentiating into erythrocyte, granulocyte or macrophage cell lines (CFU-GEMM, BFU-E, CFU-GM, CFU-Meg). Progenitor cells, can be easily tested by their ability to form in vitro colonies in soft gel cultures in the constant presence of the specific regulator of the cell line ("colony stimulating factor" = CSF). Seven-14 days after explantation of haemopoietic cells colonies containing 40 to 1000 cells are formed. These colonies are proved to be of clonal origin. The quantitative assay of colony forming progenitors has a critical significance in haematological diseases due stem cell damage and bone marrow transplantation. The present paper deals with the diagnostic value of progenitor assays.

The case of an 11 year old girl with three line type of polycythaemia vera, with 4 cm splenomegaly and a plethoric complexion is presented. Peripheral blood values were as follows: RBC: 7.75 x 10(12)/l, Hb: 18.8 g/l, WBC: 15.2 x 10(9)/l, platelets: 920 x 10(9)/l. Serum erythropoietin level:1 mU/ml. In vitro, erythroid colonies developed from the bone marrow in the absence of added erythropoetin. For three years the haematocrit value has been controlled by regular venesections. Since extreme thrombocytosis developed, the treatment was continued with interferon alpha. Different treatment protocols are discussed.

An up-to-date microprocessor controlled thermoluminescence dosemeter (TLD) system for environmental and space dose measurements has been developed. The earlier version of the portable TLD system, Pille, was successfully used on Soviet orbital stations as well as on the US Space Shuttle, and for environmental monitoring. The new portable TLD system, Pille'95, consists of a reader and TL bulb dosemeters, and each dosemeter is provided with an EEPROM chip for automatic identification. The glow curve data are digitised and analysed by the program of the reader. The measured data and the identification number appear on the LED display of the reader. Up to several thousand measured data together with the glow curves can be stored on a removable flash memory card. The whole system is supplied either from built-in rechargeable batteries or from the mains of the space station.

Umbilical cord blood has been suggested as a potential source of haemopoietic stem cells for clinical transplantation. Assay of stroma adherent blast colony forming cells (CFU-BL), as a cell type that may predict marrow repopulation, has already been suggested to predict the outcome of bone marrow transplantation. In the present experiments the frequency of CFU-BL in plastic non adherent mononuclear cell fraction (PNAMNC) of umbilical cord blood was studied. If PNAMNC from cord blood was co-incubated with a pre-established stromal layer from normal bone marrow a strict linear correlation between panned PNAMNC and blast colonies were observed. Frequency of CFU-BL in cord blood was significantly lower than that in bone marrow. In cord blood, CFU-GEMM frequency was found to be comparable to that of bone marrow, CFU-GM and BFU-E frequency was reduced. A good correlation between CFU-BL and BFU-E frequency was found both in cord blood and bone marrow. On the other hand, irrespective of their source, correlation between CFU-BL and CFU-GEMM or CFU-GM was weak.

The aim of this study was to compare the thermal sensitivity of normal murine and human hemopoietic progenitors to that of leukemic murine and human clonogenic cells in order to assess the clinical relevance of experimental data. Colony forming units-granulocyte-macrophage (CFU-GM) from normal human bone marrow and from bone marrow of patients with acute lymphocytic leukemia (ALL), acute myelogenous leukemia (AML), and Hodgkin's disease in complete remission proved to be less sensitive to 42.5°C in vitro hyperthermia (D0: 93.9 min) than murine bone marrow CFU-GM (D0: 49.6 min). Leukemic colony forming cells (CFU-L) from HL-60 suspension culture—when compared to human CFU-GM—showed significantly increased thermal sensitivity (D0: 22.8 min). While the thermal sensitivity of CFU-L from a murine leukemia cell line (WEHI 3-B) was not statistically significant when compared to that of CFU-L from HL-60 (D0 values 17.0 versus 22.8 min), the vertical difference between the parallel regression lines suggested an approximately three-fold greater survival for human CFU-L. Although carefully controlled hyperthermia is an easy purging technique, the relevance of murine data to human clinical practice must be considered critically.

The in vitro purging effect of mafosfamide combined with hyperthermia was studied in a murine model. The survival of normal clonogenic progenitors (d-9 CFU-S and CFU-GM) and WEHI 3-B leukaemic clonogenic cells (CFU-L) were compared. At 37 degrees C, CFU-L proved to be significantly more sensitive to mafosfamide than either of the normal progenitors. When mafosfamide was combined with 42.5 degrees C hyperthermia for 1 h, an additive effect was observed: at a dose of 5 micrograms/ml mafosfamide, the survival of CFU-L was nearly two logs lower than that observed at 37 degrees C, while 37.7% of CFU-S survived the purging. The repopulating capacity of surviving bone marrow CFU-S was not altered: a similar 60 d survival of supralethally irradiated recipients transplanted with comparable graft sizes from purged or non-purged bone marrow was observed. When bone marrow suspensions containing WEHI 3-B cells were purged with 5 micrograms/ml mafosfamide at 42.5 degrees C and the minimal amount of bone marrow cells needed to protect supralethally irradiated mice were injected, leukaemia incidence was reduced to less than 10% as opposed to 100% of those injected with untreated bone marrow. Our results suggest that ex vivo hyperthermia may enhance the purging efficiency of mafosfamide.

Reversible protein-losing hypertrophic gastropathy: causal relationship with Helicobacter pylori infection, or simple coincidence?

In the aim of establishing what kind of mechanisms of steroidogenesis stimulation are put into motion in healthy males by a one-term, continual stressor influence, research was carried out concerning the influence of alcohol on the concentration of 11-OHCS and DHA in the plasma of healthy males after alcoholic stress (0.3 g/kg of body weight), by physical strain then by alcohol, with infusions of ACTH and infusions of niamide then alcohol. After a one-term alcohol stress and after physical strain followed by alcohol stress two maximums are observed during the change of 11-OHCS and DHA concentrations: in the 15th and 120th minute of stress application, while in the 60th and 240th minute the values range in the limits of basal concentrations. During the course of niamide infusions, the concentrations of 11-OHCS decrease and their increase does not occur even after subsequent stress by alcohol. In each stress test, the changes of 11-OHCS concentrations are gradual and continual. It is considered that the H-H-C system reaction to the continual stress influence develops in two phases, and first there comes to an activation of the serotoninergic system of the CNS. It is assumed that the serotoninergic system of the CNS essentially influences the function of the H-H-C system, but not the basal activity as well.

Growth kinetics of bone marrow stromal layers from normal, AML, ALL and CML patients was studied. Significantly reduced time for confluency was observed in AML patients in complete remission, in CML patients in chronic phase, or CML patients after allogenic bone marrow transplantation. The functional capacity of these stromal layers did not differ: they all bound similar amounts of blast colony forming cells (BL-CFC) from normal bone marrow. The stromal layers from bone marrow transplanted patients varied in their BL-CFC binding capacity: two CML patients (10.5 and 49 months after transplantation) showed normal values, while two ALL patients (1.5 and 3 months, respectively, after transplantation) as well as one patient transplanted for CML (19.5 months after transplantation) showed significantly reduced BL-CFC binding capacity.

A radiochemical and an SSNTD method was developed and successfully applied to estimate retrospectively the radon level in houses where recently high radon concentration was discovered.

Radioactive clouds from the atmospheric release due to the reactor accident at Chernobyl reached Hungary on April 29, 1986. During the ten days of these clouds streaming in, the radioactive concentration was highest in the first day in the northern/north-western parts of the country, and later in the southern/south-eastern regions. Considerable rainfall differences between different locations resulted in a large variation in the ground surface contamination. Accordingly, there is a variation of about one order of magnitude in external dose, and in the radioactive contamination of foodstuffs and water. A survey is given on the main results of environmental monitoring carried out in Hungary since April 29, 1986. The effects of interaction of the radioactive contamination with the human organism are also discussed. The Budapest region was subjected to the most detailed examinations according to which the median effective dose equivalent of adults in the first year after the Chernobyl accident was 105 μSv; 5% of the population was exposed to less than 64 μSv, and 95% to less than 174 μSv.

During the 3rd main expedition on board the "Salyut-6" orbital station in 1979 the integral characteristics of cosmic radiation were measured in various positions inside the manned modules (experiment "Integral"). Measurements were performed with thermoluminescent dosimeters, photographic films and solid state plastic detectors supplied for the experiment by specialists of the USSR, Bulgaria, Hungary, GDR and Romania. The dose gradient inside the manned modules of the station amounted to 70% for long intervals of time. During the experimental period the dose rate inside the station was 15 to 30 mrad per day. The mean flux of particles with Zor = 6 and LETor = 200 keV/micrometer was found to be 0.22 cm-2 or day-1.

A small, portable, vibration and shock resistant thermoluminescent dosimeter system was developed to measure cosmic radiation dose on board a spacecraft. The system consists of a small battery-operated reader and a special bulb dosimeter. Doses from 10 μGy up to 100 mGy can be measured. The electrical power consumption of the reader is about 5 W, its volume is about 1 dm 3 and its mass is about 1 kg. Details are given for the construction and technical parameters of the dosimeter and reader.

Alpha spectra of “Hot Particles” collected in Hungary after the Chernobyl accident were determined by an automated track evaluation method using CR-39 plastic track detectors with chemical etching. The presence of several transuranium elements published in the inventory of the reactor fuel was found with activity between 25 to 1000 Bq1.

The radiological consequences of a possible accident at the Paks Nuclear Power Station can be evaluated extremely rapidly by the use of tables and isodose curves prepared in advance for typical meteorological conditions.

On the basis of preliminary investigations, automatic equipment has been developed for continuous liquid chromatography. It consists of eight column sections, and four liquid streams can be introduced and four streams can be withdrawn simultaneously. By modifying the programme-disc of the switching valve, different chromatographic techniques can be accomplished. In one mode of operation, a continuous countercurrent moving bed process can be simulated by shifting the positions of the liquid inlets and outlets along the fixed bed of adsorbents. In comparison with the fixed bed system, continuous separation, higher capacity and a much lower solvent circulation can be achieved in the simulated moving bed technique. In addition, by changing the programme-disc. different elution techniques, flow programming and stepwise elution can be carried out and the semi-continuous separation of multicomponent mixtures can be achieved.

The original version of the telemetric system was constructed in 1978 and has been operating since 1982. Since that time significant improvements have been carried out: /i/ to increase the number of measuring channels, /ii/ to convert counts to physical values, /iii/ to improve peripheral units, /iv/ to display simultaneously all measured parameters for the operator.

SummaryThe radioprotective effect of 5-methoxytryptamine (Mexamin) was studied on the survival of colony-forming cells. The exogenous method was used in the dose-range 195 to 389 rads, and the endogenous method in the range 486 to 925 rads. The combination of the two methods makes possible reliable determination of the radioprotective effect of Mexamin both in the low and high dose-range. The slope of the curves suggests that the radioprotective effect of Mexamin is not a simple dose-reduction effect.