Interferon-gamma induces differentiation of ectoplacental cone cells to phenotypically distinct trophoblasts

Maturation of the murine ectoplacental cone results in the development of the placental tissue which essentially consists of two trophoblastic zones, the spongiotrophoblast and labyrinthine trophoblast. In this study we attempted to investigate the action of cytokines on ectoplacental cone cell differentiation to mature trophoblast cells. After determining the cellular composition of the ectoplacental cone cell suspensions based on the expression of cytokeratin, vimentin, Mac-1, class I and class II MHC antigens, the cells were exposed to the differentiation-inducing cytokines IL-3, GM-CSF, CSF-1 and IFN-gamma. From the four factors employed, only IFN-gamma increased the levels of cytokeratin-positive cells without inducing Mac-1 expression. IL-3 increased the percentages of cytokeratin as well as Mac-1- and vimentin-positive cells whereas GM-CSF and CSF-1 preferentially promoted an increase of the Mac-1 and vimentin markers. For further analysis, ectoplacental cone cells were negatively selected for Mac-1, class I and class II antigens to exclude non-trophoblastic contaminants and thereafter treated with the same cytokines. We show here that only IFN-gamma leads the sorted ectoplacental cone cells to a pure trophoblastic population composed of 100% cytokeratin-positive cells. The specificity of IFN-gamma on this differentiation pathway is strengthened by the fact that murine maternal serum on the day of EC formation contains high levels of this cytokine, suggesting that its natural presence supports - at least phenotypically - the in vivo differentiation of EC cells to trophoblasts.     

Application of capillary electrophoresis in clinical chemistry: the clinical value of urinary modified nucleosides

Urinary modified nucleosides were determined by capillary electrophoresis using a 300 mM SDS-25 mM sodium tetraborate-50 mM sodium dihydrogenphosphate buffer. The nucleosides were extracted from urine by phenylboronate affinity gel chromatography. In cancer patients the levels of the modified nucleosides are generally elevated. By an artificial neural network method breast cancer patients were differentiated from normal individuals, which indicates that the modified nucleosides could be of clinical value as tumor markers.     

Serological HLA class I alleles in Senegalese blood donors detected HBs Ag positive

We analysed the HLA class I alleles in 96 blood donors HBs Ag positive compared with 93 healthy control individuals (HBs negative). The most frequent HLA-A, -B, -C alleles found were, A23 (33.6%); A2 (25%); A30 (25%); B8 (31.5%); B7 (16.3%); B58 (11.9%); B35 (11.9%); B49 (11.9%); B53 (10.8%); Cw7 (39.1%); Cw3 (36.9%); Cw4 (36.9%). Significant differences (P<0.001) were found between the blood donors and the controls for the following HLA alleles, A1; A23; B8 and Cw3. The detection of HBe antigen was positive in 26/84 blood donors. It was observed a significant difference (P<0.01; odds ratios (OR)=6.25) between positive and negative HBe antigens blood donors for HLA-A1 allele.     

In vitro evaluation of the mutagenic and carcinogenic power of high purity zirconia ceramic

Tetragonal zirconia polycrystal (TZP) is a new interesting ceramic for the manufacture of medical devices. Its wide use in orthopedic and odontoiatric implants was limited till now by the high chemical and radiochemical impurities of the raw materials. Purification processes now available allow to obtain high purity ceramic grade powders suitable for TZP ceramics manufacture, even if their possible mutagenic and transforming effects are still unclear. The aim of this work is to study in vitro the mutagenic and oncogenic effects of a new zirconia ceramic stabilized by yttria (Y-TZP). This ceramic was sintered from high purity powders obtained by a process developed under a project carried out within the Brite EuRam programme. For comparison, ceramics made from unpurified zirconia powder were also tested. Fibroblasts irradiated by a linear accelerator were used as positive control. The results obtained show that Y-TZP ceramic does not elicit either mutagenic or transforming effect on C3H/10T(1/2) (10T(1/2)) cells and demonstrate that ceramic from high purity powders can be considered suitable for biomedical applications from the point of view of the effects of its radioactive impurity content.     

Supernatants from co-cultured endothelial cells and syncytiotrophoblast microvillous membranes activate peripheral blood leukocytes in vitro

There is evidence for both endothelial cell and peripheral blood leukocyte (PBL) activation in pre-eclampsia. Syncytiotrophoblast microvillous membranes (STBM) are shed in greater quantities from the placenta in pre-eclampsia, disrupt cultured endothelial cells in vitro and may be the immediate cause of the maternal syndrome. The aim of this study was to determine if endothelial cells co-cultured with STBM release factors that can activate PBL in vitro. Flow cytometry was used to measure changes in intracellular free ionized calcium ([Ca2+]i), pH (pHi) and reactive oxygen species (iROS) as indices of leukocyte activation. PBL from male non-pregnant donors was exposed to supernatants from human umbilical vein endothelial cells (HUVEC) cultured with STBM. The time course of changes in [Ca2+]i, pHi and iROS was determined and compared with appropriate control measurements. The test supernatants caused significant activation of granulocytes and monocytes in terms of increases in [Ca2+]i and falls in pHi and release of iROS. Lymphocytes responded only with respect to increases in iROS. The results define a possible mechanism for the activation of PBL in pre-eclampsia, as being secondary to endothelial cell activation caused by circulating STBM shed in excess amounts from the placenta.     

Study on the metastatic mechanisms of human giant-cell lung carcinoma comparison between the strains C and D

The biologic characteristics of the two human giant-cell lung carcinoma strains with high (strain D) and low metastatic potential (strain C) were studied, including karyotype of chromosome, intracellular free calcium ([Ca2+]i), morphologic changes of cell surface and the expression of nm23-H1, p53, ras, c-myc, c-erbB2, bcl-2 genes and PCNA. The correlation between different biologic features and the metastatic potential of the two strains was analyzed. We found: 1) Both strains had the karyotypic abnormality of -13, -14, -15, +20, +21 with seven same marker chromosomes. Only strain D had the karyotypic abnormality of +7, -17, -18, +X, 7p+; 2) [Ca2+]i of the strain C (984.7 +/- 573.8) and D (517.6 +/- 216.6) was significantly different (p < 0.05). The amplitude of intracellular calcium oscillations of strain C was lower than the one of strain D; 3) strain C had more villous-like protrusions on the cell surface, whereas strain D had more bubble-like protrusions; 4) The expression of nm23-H1 and p53 protein of strain C was all higher than that of strain D. The expression of PCNA of strain C was lower than strain D; 5) nm23-H1 mRNA levels of strain C was lower than that of strain D. We consider that the karyotype of chromosomes, intracellular free calcium, the structure of cell membrane and the expression of nm23-H1 gene, p53 gene, PCNA could be closely related to the metastatic potential of human giant-cell lung carcinoma. They could be used as the sign for judging whether the tumor will metastasize in clinical practice as well as in judging the prognoses of patients.     

Individual differences in the effects of serotonergic anxiolytic drugs on the motivation to self-administer cocaine

Numerous clinical studies have indicated that lifetime anxiety is highly prevalent in drug addicts. In the treatment of drug abuse, dually diagnosed drug addicts may benefit from pharmacological intervention strategies that alleviate the psychiatric symptomatology. We have previously shown that rats with different coping strategies in a stressful environment show strong differences in the motivation to self-administer cocaine. That is, cocaine self-administration under a progressive ratio (PR) schedule of reinforcement was enhanced in high grooming (HG) rats as compared with low grooming (LG) rats. To identify the pharmacological basis of these differences, we tested the acute effects of several anxiolytic drugs on cocaine self-administration in HG and LG rats under a PR schedule of reinforcement. Chlordiazepoxide increased PR responding in both the HG and LG rats, while the selective corticotrophin releasing hormone 1 receptor antagonist R121919 had no effect on cocaine self-administration under the PR schedule. Interestingly, buspirone and fluoxetine decreased PR responding in HG rats only and thereby abolished the individual differences in PR responding between HG and LG rats. In support of the differential effects of the serotonergic drugs on PR responding in HG and LG rats, we found that the in vitro electrically evoked release of [3H]serotonin from mesocorticolimbic brain slices was reduced in the medial prefrontal cortex, substantia nigra and nucleus accumbens core, and increased in the nucleus accumbens shell of HG rats relative to LG rats. These findings show that serotonergic anxiolytics abolish the pre-existing individual differences in cocaine self-administration between HG and LG rats, which show differences in the reactivity of serotonergic neurons. This suggests that the effectiveness of pharmacological interference may depend on the neurochemical and motivational state of the individual.     

Human genome,race and medicine

In closing, with the new revelations of the Human Genome Project, notions on whether land-based race identity or ethnicity with genetic markers has been proven valid, with few exceptions. This has caused me to revisit the attempted effort to discard concepts on race, especially in medicine. Obviously there are outliers to this new work. But contrary to popular belief, and to some, the unthinkable, there may be, in fact, a biologic basis for our human distinctions. And I for one do not feel shame or seem perplexed by it. Moreover, it appears that Dr. Welsing in her earlier work was onto something, and was indeed ahead of her time. The problem African Americans, and other persons of color face, to some extent, has to do with the social political context of racism, and the biologic impact it has and is often expressed in the form of stress and injuries, simply put. Therefore, and more importantly, eliminating the nomenclature of how we classify ourselves in our intellectual interchange in science and other areas, will not correct our problems, but may in fact, if abandon, spell our doom. Because what we are murderously burdened by has to do with racism and its effects. Which are in effect, based on physical features, not mere classification. Further, the current thought on racism and why it is practiced by some is that racism serves an evolutionary drive to survive by humans, by forming alliances in among similar groups of people. Therefore, if that is the case, we had better be ready for the long haul in this battle as our history and ongoing struggles tell us. Besides, if not for racism, "we would not have had all of these problems over all these years." The National Medical Association and its publishing instruments must remain vigilant and stay focused.