Homing of transplanted bone marrow cells in livers of Schistosoma mansoni-infected mice.

The efficiency of differentiation of bone marrow cells (BMCs) into hepatocytes in vivo and its importance in physiopathological processes is still debated. Murine schistosomiasis was used as a liver injury model and unfractionated male mice BMCs were transplanted through intrahepatic injection into non-irradiated Schistosoma mansoni-infected female mice on their 16th week post-infection. Two weeks after bone marrow transplantation, mice were sacrificed on a weekly basis until 10 weeks. Tracing of male donor-derived cells in female recipient mice livers was carried out by the detection of Y chromosome expression by fluorescent in situ hybridization (FISH) and also of chromodomain Y-linked (CDYL) protein by indirect immunofluorescence (IF). Their transformation into hepatocytes was studied by double labelling indirect IF using antibodies directed against CDYL and mouse albumin. Histopathological and electron microscopic examinations revealed the presence of small hepatocyte-like cells in the periportal tracts and in between the hepatocytes facing the sinusoids. Donor-derived cells showing Y chromosome by FISH and expressing CDYL protein by IF were recovered in the infected transplanted livers. The initial number of these cells increased with increased post-transplantation time. Cells were mainly localized in the periphery of schistosoma granuloma. Few donor-derived cells appeared within the hepatic parenchymal tissue and showed positivity for albumin secretion by double labelling with IF. We suggest that transplanted bone marrow stem cells can repopulate the Schistosoma-infected liver of immunocompetent mice. Their differentiation is a complex event controlled by many factors and needs to be further characterized extensively. The extent and type of liver injury and the number of transplanted cells are important variables in the process of stem cell engraftment and differentiation into functioning hepatic cells that still need to be defined.

A comparative study of chemically induced DNA damage in isolated nasal mucosa cells of humans and rats assessed by the alkaline comet assay.

Single-cell microgel electrophoresis (comet) assay was used to study genotoxic effects in human nasal mucosa cells and rat nasal and ethmoidal mucosa cells in vitro. Human cells were obtained from tissue samples of 10 patients (3 females/7 males), who underwent surgery (conchotomy) for treatment of nasal airway obstruction. Rat nasal mucosa cells were derived from male Sprague-Dawley rats. Cells were exposed for 1 h to either N-nitrosodiethanolamine (NDELA), epichlorohydrin (EPI), 1,2-epoxybutane (EPB), ethylene dibromide (EDB), or 1,2-dibromo-3-chloropropane (DBCP). Dimethyl sulfoxide (DMSO) was used as negative control. Alkaline comet assay was performed according to a standard protocol and DNA damage was quantified as Olive tail moment using image analysis system. All test substances induced an increase in DNA damage in human and rat cells. The absolute amount of DNA damage in rat nasal mucosa cells was usually higher than in ethmoidal mucosa cells. Human nasal mucosa cells were found to be less sensitive than rat mucosa cells to the genotoxic activities of DBCP (lowest effective concentration in human cells [LEC(human)]: 1.5, in rat cells [LEC(rat)]: 0.01 mM) and NDELA (LEC(human): 25, LEC(rat): 12.5 mM), whereas EPB-treated cells were almost equal (LEC(human) and LEC(rat) 0.78 mM). NDELA induced a marked concomitant cytotoxicity. For EPI (LEC(human) and LEC(rat): 0.097 mM) and EDB (LEC(human): 0.195, LEC(rat): 0.048 mM), pronounced interindividual differences were observed in human samples.

Host defence peptides in human burns.

The goal of this study was to analyse expression profiles of human epithelial host defence peptides in burned and unburned skin tissue, samples of which were obtained during debridements and snap-frozen in liquid nitrogen. Total RNA was isolated, and cDNA of epithelial host defence peptides and proteins (hCAP-18/LL-37, hBD1-hBD4, dermcidin, S100A7/psoriasin and RNAse7) was quantified by qRT-PCR. In situ hybridisation and immunohistochemical staining localised gene expression of hCAP-18/LL-37, hBD2 and hBD3 in histological sections. Most of the analysed host defence peptides and proteins showed higher mRNA levels in partial-thickness burns than in unburned tissue. In situ hybridisation revealed expression of hCAP-18/LL-37, hBD2 and hBD3 at the surface of burns that was independent of burn depth. However, the finding of higher host defence peptide gene expression rates does not correlate with the incidence of wound infection in burns. We hypothesise that the epithelial innate immune response in burns is complex.

Airway responsiveness of rabbits after exposure to 2-octyl dodecanol.

Cooling lubricants are used in the metal industry during drilling or turning. Vapors and aerosols of these lubricants are suspected to induce airway hyperresponsiveness (AHR) in exposed workers. In a previous study the authors demonstrated that water-soluble lubricants induce AHR after acute exposure of rabbits to concentrations near the German MAK value (10 mg/m(3)). In the present investigation the influence of a fatty alcohol as special non-water-soluble cooling lubricant was examined to determine its influence on airway responsiveness (AR). The effects of an aerosolized non-water-soluble lubricant (40, 90, and 220 mg/m(3)) on AR to acetylcholine in a rabbit model were studied. Lubricant atmosphere analysis was performed with infrared spectroscopy. Before exposure, after 2 and 4 hours of application, AR to aerosols from 0.2 and 2% acetylcholine was tested. Basal airway and cardiovascular parameters as well as blood gases did not change during exposure. Lubricant aerosol concentration of 40 and 220 mg/m(3) for 4 hours did not significantly alter AR. Inhalation of 90 mg/m(3) lubricant increased contractile response to ACH significantly. In contrast to formerly investigated water-soluble cooling lubricants, the examined non-water-soluble lubricant did not increase AR in concentrations near the MAK; however, in higher concentrations a significant (p<.05) increase was obtained.

Homozygous mutations in caveolin-3 cause a severe form of rippling muscle disease.

Heterozygous missense mutations in the caveolin-3 gene (CAV3) cause different muscle disorders. Most patients with CAV3 alterations present with rippling muscle disease (RMD) characterized by signs of increased muscle irritability without muscle weakness. In some patients, CAV3 mutations underlie the progressive limb-girdle muscular dystrophy type 1C (LGMD1C). Here, we report two unrelated patients with novel homozygous mutations (L86P and A92T) in CAV3. Both presented with a more severe clinical phenotype than usually seen in RMD. Immunohistochemical and immunoblot analyses of muscle biopsies showed a strong reduction of caveolin-3 in both homozygous RMD patients similar to the findings in heterozygous RMD. Electron microscopy studies showed a nearly complete absence of caveolae in the sarcolemma in all RMD patients analyzed. Additional plasma membrane irregularities (small plasmalemmal discontinuities, subsarcolemmal vacuoles, abnormal papillary projections) were more pronounced in homozygous than in heterozygous RMD patients. A stronger activation of nitric oxide synthase was observed in both homozygous patients compared with heterozygous RMD. Like in LGMD1C, dysferlin immunoreactivity is reduced in RMD but more pronounced in homozygous as compared with heterozygous RMD. Thus, we further extend the phenotypic variability of muscle caveolinopathies by identification of a severe form of RMD associated with homozygous CAV3 mutations.

Renal toxicity after chronic inhalation exposure of rats to trichloroethylene.

Male Long-Evans rats were exposed to 0 (controls) or 500 ppm trichloroethylene (TRI) for 6 months, 6 h daily, and 5 days a week. The TRI metabolites trichloroethanol (TCE) in blood and trichloroacetic acid (TCA) in urine were measured. Specific parameters related to the renal damage were determined in urine [biomarker for glomerular damage: high molecular weight proteins (HMW), albumin (ALB); for proximal tubular damage: N-acetyl-beta-D-glucosaminidase (NAG), low-molecular-weight-proteins (LMW)]. Significantly increased concentrations of NAG and LMW in urine of exposed rats were detected. No DNA-strand breaks in kidney cells could be detected using the comet assay, and histological examinations were performed. Histological alterations were observed in glomeruli and tubuli of exposed rats. The release of biomarkers for nephrotoxicity suggested alterations preferably in the proximal tubules of the exposed rats.

Chronic exposure to trichloroethylene affects neuronal plasticity in rat hippocampal slices.

Inhalational exposure to organic solvents is known to exert neurotoxic effects. Using the new multielectrode dish system (Panasonic) the effects of chronic exposure to trichloroethylene (TCE) on neuronal plasticity were assessed in different regions of the adult rat brain. Two groups of Long-Evans rats were exposed to 0 ppm or 500 ppm TCE, respectively, 6 h/day, 5 days/week for 6 months. Long-term potentiation (LTP) as well as paired-pulse potentiation/inhibition were assessed in slices from the visual cortex and the hippocampus. In addition, several behavioral tests were performed. Trichloroethanol concentrations were measured in blood and trichloroacetic acid concentrations were determined in urine. While TCE exposure impaired LTP as well as paired-pulse potentiation in hippocampal slices, no effects were seen in cortical slices. Our data demonstrate brain region specific functional changes following TCE exposure with the hippocampus being more vulnerable than the visual cortex. The behavioral measurements revealed no TCE related effects.