Efficient oxidation of promutagenic hydroxymethylpyrenes by cDNA-expressed human alcohol dehydrogenase ADH2 and its inhibition by various agents

Alkylated polycyclic aromatic hydrocarbons can be metabolically activated via benzylic hydroxylation and sulphation to electrophilically reactive esters. However, we previously found that the predominant biotransformation route for the hepatocarcinogen 1-hydroxymethylpyrene (1-HMP) in the rat in vivo is the oxidation of the side chain by alcohol dehydrogenases (ADHs) and aldehyde dehydrogenases to the carboxylic acid. Inhibition of this pathway by ethanol (competing ADH substrate) or 4-methylpyrazole (ADH inhibitor) led to a dramatic increase in the 1-HMP-induced DNA adduct formation in rat tissues in the preceding study. In order to elucidate the role of individual ADHs in the metabolism of alkylated polycyclic aromatic hydrocarbons, we expressed the various members of the human ADH family in bacteria. Cytosolic preparations from bacteria expressing ADH2 clearly oxidized hydroxymethylpyrene isomers (1-, 2- and 4-HMP) with the highest rate. This form was purified to near homogeneity to perform detailed kinetic analyses. High catalytic efficiencies (V(max)/K(m)) were observed with HMPs. Thus, this value was 10,000-fold higher for 2-HMP than for the reference substrate, ethanol. The corresponding aldehydes were also efficiently reduced by ADH2. 4-Methylpyrazole inhibited the oxidation of the HMP isomers as well as the reverse reaction. Daidzein, cimetidine and the competing substrate ethanol were further compounds that inhibited the ADH2-mediated oxidative detoxification of 1-HMP.     

Differences in kinetics of donor lymphoid cells in response to G-CSF administration may affect the incidence and severity of acute GvHD in respective HLA-identical sibling recipients

Granulocyte-colony stimulating factor (G-CSF), in addition to myeloid and stem cells, mobilizes a large number of lymphoid cells. We examined which lymphoid populations were mobilized in 21 consecutive donors of peripheral blood stem cells (PBSC) and whether the differences in mobilization could affect the incidence of acute and chronic GvHD in respective HLA-identical recipients. G-CSF administration induced significant increases of donor B (CD3⁻CD19⁺) lymphocytes and slight increases of T (CD3⁺) and cytotoxic (CD16⁺CD56⁺) NK cells. The number of extrathymic cells (CD3⁺ cells with NK markers, or CD7⁺) remained unchanged except for an increase of CD3⁺CD57⁺CD8⁺ cells. Donors of patients without subsequent grade II–IV acute GvHD compared to donors of patients who developed significant acute GvHD were found to have in peripheral blood stable numbers of CD3⁺CD4⁺ cells producing IL2, with a concomitant increased number of CD3⁺CD4^low+CD25⁺ T regulatory cells and decreased NK-mediated cytotoxicity, together with a higher number of suppressive extrathymic CD57⁺CD3⁺ cells in the blood and G-PBMC grafts. Increasing numbers of activated T and NK cells in the blood were associated with the development of chronic GvHD. We suggest that differences in steady-state levels and kinetics of G-CSF induced mobilization of donor lymphoid cells may in addition to other well-known factors affect the incidence of GvHD in HLA-identical recipients. However, owing to the small number of donor-recipient pairs studied, our results must be verified in a larger group of patients. Both authors contributed equally to this study.     

Differently designed playgrounds and preschooler’s physical activity play

New playground concepts – favouring natural play characteristics – emerge. The aim of our free play study is to explore the relation between newly established natural playgrounds and the widely spread contemporary ones in terms of physical activity levels. The playground features differ in vegetation, topography, size and play equipment. The children’s locomotive activity was measured with the StepWatch? Activity Monitor – a pedometer. Research with known groups of preschool children on urban playgrounds should serve a future transfer of results to institutional play areas. Within this pilot study, results indicate that there is no significant difference in mean locomotive activity during free play on diverse playgrounds. However, results show high variability of activity between the playgrounds in terms of active children and rather sedentary ones. In conclusion, kindergarten environments should be more diverse incorporating elements of nature and contemporary playgrounds to serve all levels of activity.     

May 2002: 38-year-old man and 69-year-old woman with dural based masses

The May 2002 COM. A 38-year-old man presented with new onset seizures and a 69-year-old woman presented with bilateral headaches and episodes of syncope. Both were found to have extra-axial masses that were contrast-enhancing and thought to be meningiomas. Both had complete resection. Microscopic examination revealed an inflammatory lesion composed of plasma cells, scattered lymphocytes and numerous large histocytic cells, which exhibited emperi polesis and were CD1 a negative, but positive for CD68 and S100. The diagnosis of Destombes-Rosai-Dorfman Disease (DRDD) was rendered. Both cases had good long-term outcome. The differential diagnosis of inflammatory masses in the dura (plasmacytoma, lymphomas, plasma cell fibroma, angiofollicular hyperplasia [Castleman's-disease] and Langerhan's cell histiocytosis) are discussed.     

Purification of a new manganese peroxidase of the white-rot fungus Irpex lacteus, and degradation of polycyclic aromatic hydrocarbons by the enzyme

The white-rot fungus Irpex lacteus has been reported to be an efficient degrader of polycyclic aromatic hydrocarbons, polychlorinated biphenyls and pentachlorophenol. The fungus produces ligninolytic enzymes laccase, lignin peroxidase and manganese peroxidase (MnP), the latter being the major one produced. MnP was purified using anion exchange and size exclusion chromatography. SDS-PAGE showed the purified MnP to be a monomeric protein of 37 kDa (37.5 kDa using MALDI-TOF) with an isoelectric point at 3.55. The pH optimum was relatively broad, from 4.0 to 7.0 with a peak at pH 5.5. Kinetic constants K(m) were 8 microM for H(2)O(2) and 12 or 31 microM for Mn(2+) depending on the substrate. The enzyme did not perform oxidation in the absence of H(2)O(2) or Mn(2+). MnP was active at 5-70 degrees C with an optimum between 50-60 degrees C. At temperatures above 65 degrees C the enzyme rapidly lost activity. Degradation of four representatives of PAHs (phenanthrene, anthracene, fluoranthene, and pyrene) was tested and the enzyme showed the ability to degrade them in vitro. Major degradation products of anthracene were identified. The results confirm the role of MnP in PAH degradation by I. lacteus, including cleavage of the aromatic ring.     

Risk factors for asthma in children in Lódź region

The incidence of asthma and other allergic diseases continues to increase. In addition to genetic factors, environmental influences are thought to play an important role. The aim of this study was to identify factors that influence and drive the atopic march from atopic sensitization to asthma in children from Lód?. METHODS: 800 atopic children, aged 5-18 years, were included to our study. Parents filled in questionnaires and gave interviews about their children's diseases. 405 (43%) children have diagnosis of asthma. RESULTS: A significant association was observed between asthma and male sex, parents' history of atopy, parental highest school grade, maternal smoking during pregnancy, maternal chronic disease (especially chronic renal diseases), maternal allergen-sensitizing diet during breast-feeding, increased exposure to indoor humidity and moulds. Similar effect was seen for episodes of wheeze occurring in the first 3 years of life as followed: wheezing during an airway infection, wheezing not connected with respiratory tract infection, wheezing not related with physical exercise. Child's daycare attendance (nursery school) was associated with decreased risk of asthma.     

Olfactory Pathology in Central Nervous System Demyelinating Diseases

Olfactory dysfunction is common in multiple sclerosis (MS). Olfactory bulb and tract pathology in MS and other demyelinating diseases remain unexplored. A human autopsy cohort of pathologically confirmed cases encompassing the spectrum of demyelinating disease (MS; n = 17), neuromyelitis optica [(NMO); n = 3] and acute disseminated encephalomyelitis [(ADEM); n = 7] was compared to neuroinflammatory [herpes simplex virus encephalitis (HSE); n = 3], neurodegenerative [Alzheimer's disease (AD); n = 4] and non‐neurologic (n = 8) controls. For each case, olfactory bulbs and/or tracts were stained for myelin, axons and inflammation. Inferior frontal cortex and hippocampus were stained for myelin in a subset of MS and ADEM cases. Olfactory bulb/tract demyelination was frequent in all demyelinating diseases [MS 12/17 (70.6%); ADEM 3/7 (42.9%); NMO 2/3 (66.7%)] but was absent in HSE, AD and non‐neurologic controls. Inflammation was greater in the demyelinating diseases compared to non‐neurologic controls. Olfactory bulb/tract axonal loss was most severe in MS where it correlated significantly with the extent of demyelination (r = 0.610, P = 0.009) and parenchymal inflammation (r = 0.681, P = 0.003). The extent of olfactory bulb/tract demyelination correlated with that found in the adjacent inferior frontal cortex but not hippocampus. We provide unequivocal evidence that olfactory bulb/tract demyelination is frequent, can occur early and is highly inflammatory, and is specific to demyelinating disease.     

Active-Passive Coping and Skin Conductance and Heart Rate Changes

Sixty subjects were administered 33 tasks, selected from the Raven Progressive Matrices, in conditions that differed by type of monetary reinforcement (reward, frustration, and control group). Subjects were tested in pairs. One subject, assigned as the active one, was asked to solve a problem while the other was only a passive observer. Heart rate level and the amplitude of evoked skin conductance responses were measured. Statistical analysis detected a higher heart rate level in active versus passive subjects at the beginning stage of the experiment, as well as a faster heart rate decrease in the former versus the latter group during subsequent blocks of four tasks. Changes in skin conductance response magnitude during the ensuing task phases exhibited a descending trend in passive subjects and an ascending trend in active subjects. The monetary reinforcement manipulation was not effective. The results support a concept put forward by Fowles (1988), who maintained that tonic heart rate and skin conductance response amplitude may serve as indices of the behavioral activation system and behavioral inhibition system, respectively, as postulated by Gray's model of arousal.     

Huntington's Disease (HD): Neurodegeneration of Brodmann's Primary Visual Area 17 (BA17)

Huntington's disease (HD), an autosomal dominantly inherited polyglutamine or CAG repeat disease along with somatomotor, oculomotor, psychiatric and cognitive symptoms, presents clinically with impairments of elementary and complex visual functions as well as altered visual‐evoked potentials (VEPs). Previous volumetric and pathoanatomical post‐mortem investigations pointed to an involvement of Brodmann's primary visual area 17 (BA17) in HD. Because the involvement of BA17 could be interpreted as an early onset brain neurodegeneration, we further characterized this potential primary cortical site of HD‐related neurodegeneration neuropathologically and performed an unbiased estimation of the absolute nerve cell number in thick gallocyanin‐stained frontoparallel tissue sections through the striate area of seven control individuals and seven HD patients using Cavalieri's principle for volume and the optical disector for nerve and glial cell density estimations. This investigation showed a reduction of the estimated absolute nerve cell number of BA17 in the HD patients (71 044 037 ± 12 740 515 nerve cells) of 32% in comparison with the control individuals (104 075 067 ± 9 424 491 nerve cells) (Mann–Whitney U‐test; P < 0.001). Additional pathoanatomical studies showed that nerve cell loss was most prominent in the outer pyramidal layer III, the inner granular layers IVa and IVc as well as in the multiform layer VI of BA17 of the HD patients. Our neuropathological results in BA17 confirm and extend previous post‐mortem, biochemical and in vivo neuroradiological HD findings and offer suitable explanations for the elementary and complex visual dysfunctions, as well as for the altered VEP observed in HD patients.