Dynamic measurement of the force required to move a liquid drop on a solid surface.

We measured the forces required to slide sessile drops over surfaces. The forces were measured by means of a vertical deflectable capillary stuck in the drop. The drop adhesion force instrument (DAFI) allowed the investigation of the dynamic lateral adhesion force of water drops of 0.1 to 2 µL volume at defined velocities. On flat PDMS surfaces, the dynamic lateral adhesion force increases linearly with the diameter of the contact area of the solid-liquid interface and linearly with the sliding velocity. The movement of the drop relative to the surfaces enabled us to resolve the pinning of the three-phase contact line to individual defects. We further investigated a 3D superhydrophobic pillar array. The depinning of the receding part of the rim of the drop occurred almost simultaneously from four to five pillars, giving rise to peaks in the lateral adhesion force.

Involvement of microglial cells in the antinociceptive effects of metamizol in a mouse model of neuropathic pain.

Metamizol (also known as dipyrone or sulpyrine) is one of the non-opioid analgesics commonly used in clinical practice in the treatment of somatic and visceral pain. Here, our results give evidence that repeated twice daily intraperitoneal metamizol administration during 7 days diminished development of neuropathic pain symptoms in a mouse model of neuropathic pain. We observed that metamizol inhibited the activation of spinal microglia in neuropathic mice. Moreover, our findings provide evidence that pronociceptive (IL-1ß, XCL1, and CCL2), but not antinociceptive (IL-1α, IL-1RA, and IL-18BP), factors play an important role in metamizol-induced antinociception. We observed that metamizol influences the spinal levels of the nociceptin receptor (NOP) but does not alter the expression of other members of the opioid receptor family (mu (MOP), delta (DOP) and kappa (KOP)), or other important nociception receptors (transient receptor potential vanilloid 1 (TRPV1) and transient receptor potential ankyrin 1 (TRPA1)). Metamizol administration did not affect the levels of the opioid prohormones (proopiomelanocortin (POMC), proenkephalin (PENK), prodynorphin (PDYN), and pronociceptin (PNOC)). However, we observed an enhanced antinociceptive effect of oxycodone, but not buprenorphine, after metamizol treatment. In conclusion, we found that metamizol-induced analgesia in neuropathy is associated with silencing microglia activation and, consequently, with a reduction in pronociceptive cytokines. These results provide evidence that metamizol may join the modest arsenal of effective remedies for neuropathic pain and may constitute part of a multimodal pain therapy.

Surface forces between colloidal particles at high hydrostatic pressure.

It was recently suggested that the electrostatic double-layer force between colloidal particles might weaken at high hydrostatic pressure encountered, for example, in deep seas or during oil recovery. We have addressed this issue by means of a specially designed optical trapping setup that allowed us to explore the interaction of a micrometer-sized glass bead and a solid glass wall in water at hydrostatic pressures of up to 1 kbar. The setup allowed us to measure the distance between bead and wall with a subnanometer resolution. We have determined the Debye lengths in water for salt concentrations of 0.1 and 1 mM. We found that in the pressure range from 1 bar to 1 kbar the maximum variation of the Debye lengths was <1 nm for both salt concentrations. Furthermore, the magnitude of the zeta potentials of the glass surfaces in water showed no dependency on pressure.

Congenital-infantile fibrosarcoma: a clinicopathological study of five patients entered on the Prague children's tumor registry.

Five children with congenital-infantile fibrosarcoma are analyzed. The tumor was found at birth in four children: in one patient it was recognized at the age of 7 months. In three children the tumor affected the lower extremity. In one patient the inguinal region was the primary site, in another the abdominal wall. The morphology was that of a highly cellular spindle cell sarcoma with cells arranged in a fascicular pattern. Variations of this common pattern such as a cartwheel arrangement, and foci of small oval cells were observed. The immunohistochemistry revealed positivity of vimentin in four investigated tumors and muscle specific actin in three. Desmin, sarcomeric actin and myoglobin were all negative. There were scattered cells positive with KP1 (CD68), MAC 387, and in one case, with factor XIIIa antibodies which were considered to be reactive rather than tumor cells. The flow cytometry study showed DNA content in three tumors within diploid range; one tumor was hyperdiploid with the DNA index 1.2. Three children are disease-free from nine to 21 years after the diagnosis. One of them had the tumor preoperatively irradiated, and the subsequent histological examination revealed an almost complete tumor necrosis. In one patient there were six recurrences (treated by surgery only), and the child is well 25 months after the last recurrence. In one child the disease had an unusually aggressive course, and the patient died of widespread metastases to the lungs, lymph nodes and bones.

DNA ploidy in neuroblastoma.

Neuroblastoma is perhaps the most heterogeneous childhood cancer in terms of clinical behavior. Stage of disease, age at diagnosis, levels of urinary catecholamine excretion, N-myc amplification, and DNA ploidy have been found to be significant prognostic factors. The aims of this combined retrospective-prospective study are to verify the prognostic significance of DNA ploidy and to show its correlation with other prognostic signs. Thirty six fresh and thirty three paraffin embedded samples from patients with histologically confirmed neuroblastoma (41 prior to receiving any chemotherapy) were available for flow cytometry DNA analysis. Our results showed that the maturation induced during chemotherapy could give rise to aneuploidy therefore we analyzed the associations between the DNA ploidy and other prognostic markers only in patients examined before chemotherapy. There were no significant correlations between DNA ploidy and urinary catecholamine metabolites levels or tumor localization. DNA aneuploidy was significantly more frequent in patients with lower clinical stage, lower age at diagnosis, and without N-myc gene amplification. Patients with DNA aneuploid neuroblastomas died less frequently than patients with DNA diploid tumors. There were no significant associations among the S-phase or proliferation fraction and other prognostic factors.

[DNA cytometry analysis in childhood tumors]. / Cytometrická DNA analýza u detských nádoru.

BACKGROUND: DNA contents in cells may be determined by flow cytometry. The relationship between malignant cell aneuploidy and prognosis is known in many types of neoplasms in adults and in children. In some situations, demonstration of an aneuploid clone verifies presence of malignant cells. Aneuploidy is rare in benign diseases. This report summarizes our first experiences with cytometric DNA analysis and shows the method's abilities to other potential users. METHODS AND RESULTS: We investigated DNA contents in blood and bone marrow (BM) specimens of 25 children with leukemia, in 41 unfixed solid tumors after biopsy and in 24 specimens of paraffin embedded neuroblastoma tissue. We also investigated 5 specimens of cerebrospinal fluid (CSF) of patients with medulloblastoma, 18 specimens of CSF from patients with leukemia or lymphoma, 4 pleural exudates suspected from malignancies, and 45 specimens of possibly infiltrated BM from primary solid tumors. As the purpose of this study was to test the method on a relatively small number of specimens, we did not perform statistical analysis of our data. As reported previously, aneuploidy was frequent in CALLA + acute lymphoblastic leukemia and in types of neuroblastoma with favorable prognosis (lower clinical stages and less than 2 years of age). CONCLUSIONS: Our results show that DNA ploidy may be tested by flow cytometry in an easy and fast way. The source of the material may be unfixed tumors, deparaffinized tumors, BM, blood, CSF and pleural exudates.

Neonatal (perinatal) hemochromatosis.

Autopsy findings are described of six cases (from four families) of neonatal hemochromatosis, a defect featured by severe prenatal iron storage in the liver and in a number of visceral organs similarly as in the hereditary adult-type hemochromatosis. Genetically, the two disorders are different, however. All the cases showed a characteristic liver damage with heavy iron deposits in the liver cells, lobular disarray and intralobular fibrosis, tendency towards multinuclear hepatocyte formation, ultimately resulting in pigmented cirrhosis and liver failure. In five instances the cirrhosis present was atrophic, in one case it was hepatomegalic. Death occurred prenatally in one case (31st week), perinatally in three, and two cases died as young infants. The mechanism of the liver disorder, mainly that of iron accumulation, has remained unresolved. Extrahepatally, hemosiderosis affected various epithelia (in particular, thyreocytes, renal distal tubular epithelia and those of pancreatic acini) and myocardial cells which, however, did not show any damage. In two instances the placenta was conspicuously hyperplastic, in one case it showed prominent hydropic transformation of its villi. In one case there was simultaneous cytomegaly. Entities which must be considered in the differential diagnosis of neonatal hemochromatosis because of considerable hepatic and extrahepatic iron accumulation have been discussed.

Activation of Src family kinases by colony stimulating factor-1, and their association with its receptor.

The receptor for the macrophage colony stimulating factor-1 (CSF-1R) is a transmembrane glycoprotein with intrinsic tyrosine kinase activity. CSF-1 stimulation promotes the growth of cells of the macrophage lineage and of fibroblasts engineered to express CSF-1R. We show that CSF-1 stimulation resulted in activation of three Src family kinases, Src, Fyn and Yes. Concomitant with their activation, all three Src family kinases were found to associate with the ligand-activated CSF-1 receptor. These interactions were also demonstrated in SF9 insect cells co-infected with viruses encoding the CSF-1 receptor and Fyn, and the isolated SH2 domain of Fyn was capable of binding the CSF-1R in vitro. Analysis of mutant CSF-1Rs revealed that the 'kinase insert' (KI) domain of CSF-1R was not required for interactions with Src family kinases, but that mutation of one of the receptor autophosphorylation sites, Tyr809, reduced both their binding and enzymatic activation. Because fibroblasts expressing this receptor mutant are unable to form colonies in semi-solid medium or to grow in chemically defined medium in the presence of CSF-1, the Src family kinases may play a physiological role in the mitogenic response to CSF-1.

The human Met-ase gene (GZMM): structure, sequence, and close physical linkage to the serine protease gene cluster on 19p13.3.

Cosmid clones containing the genes for the human and murine natural killer cell serine protease Met-ase (gene symbol GZMM; granzyme M) were identified by screening human and murine cosmid libraries with rat Met-ase (RNK-Met-1) cDNA. The human gene has a size of 7.5 kb and an exon-intron structure identical to that of serine protease genes located on human chromosomes 5q11-q12, 14q11.2, and 19p13.3 that are expressed by lymphocytes, mast cells, or myelomonocyte precursors. Using cosmid DNA as a probe for fluorescence in situ hybridization, we identified the chromosomal position of human Met-ase as 19p13.3. Interphase studies with two differentially labeled probes for Met-ase and the azurocidin (AZU1), proteinase 3 (PRTN3), and neutrophil elastase (ELA2) gene cluster revealed that the distance of Met-ase from this gene cluster is in the range of 200 to 500 kb. Using differentially labeled mouse cosmid probes, we also mapped the murine gene for Met-ase to chromosomal band 10C, close to the gene for lamin B2. Thus, the Met-ase, AZU1, PRTN3, and ELA2 genes fall into an established region of homology between mouse chromosomal band 10C and human 19p13.3.