[Immune adherence (C3b) receptor activity of erythrocytes in patients with esophageal cancer and cancer of the gastric cardia].

The red cell C3b receptor activity of 52 patients with esophageal cancer, 19 patients with cancer of gastric cardia and 31 age-matched normal persons was studied by the ability of forming ZC3b-rosette (rosette formation with zymosan particles treated by guinea pig complement) and IC-Z rosette (rosette formation with zymosan particles). The results showed that the ZC3b-rosette formation rate was significantly lower in cancer patients than that of the normal subjects (P less than 0.01), but the IC-Z rosette formation rate was significantly higher in the cancer patients (P less than 0.01). This suggests that the esophageal cancer and cancer of gastric cardia be associated with surface changes in the erythrocytes, especially those of the receptors which are responsible for immune adherence reaction. The methods of detecting the red cell C3b receptor are also described.

The characteristics of placental transfer and tissue concentrations of nickel in late gestational rats and fetuses.

The dynamics of nickel (Ni) uptake, transfer, retention and clearance in fetuses and late gestational rats were investigated by assessing its distributions in placenta, maternal and fetal organs and tissues during the 24 h period after a single dose of (63)Ni intraperitoneal injection on gestational day 20. Peak (63)Ni radioactivity was detected at 0.5 h in maternal blood, at 3 h in placenta, fetal membranes, fetal blood, fetal heart, maternal kidney, lung, stomach, liver and brain, at 9 h in fetal kidney, stomach, liver and brain, and lastly at 24 h in fetal lung and amniotic fluid. The maximal (63)Ni radioactivity among all samples was detected consistently in the fetal membranes and placenta. The (63)Ni radioactivity in fetal blood was higher than that in maternal blood from 3 to 24 h. The fetal liver, heart, stomach and brain exhibited higher (63)Ni radioactivity than the corresponding maternal organs from 6 to 24 h. However, maternal kidney consistently exhibited significantly higher (63)Ni radioactivity than the fetal kidney. The (63)Ni in fetal lung and amniotic fluid increased throughout the period of experimental observation. These observations corroborated previous finding that nickel is actively transferred across the blood-placenta-barrier into fetus, but hardly from fetus to mother. Moreover, these results suggest that the placenta has a high affinity for nickel and its barrier does not protect the fetus from nickel exposure. The fact that nickel concentrations are higher in most fetal organs and tissues than in corresponding maternal organs and tissues in late gestation indicates that, unlike the dam, fetuses lack effective means for getting rid of excessive nickel due to its confined environment and relatively weak kidney functions. The situation is exacerbated by mother-to-fetus unidirectional transfer. Consequently, the fetuses are particularly vulnerable to the damaging effects of nickel.

Bone marrow stromal fibroblasts secrete interleukin-6 and granulocyte-macrophage colony-stimulating factor in the absence of inflammatory stimulation: demonstration by serum-free bioassay, enzyme-linked immunosorbent assay, and reverse transcriptase polymerase chain reaction.

Bone marrow (BM) stromal fibroblasts produce hematopoietic growth factors (HGFs) in response to inflammatory mediators such as tumor necrosis factor-alpha or interleukin-1 alpha (IL-1 alpha). In the absence of such inflammatory stimuli, production of HGFs by BM stromal cells has been problematic and controversial. In vivo, however, basal hematopoiesis maintains blood counts within a normal homeostatic range even in the absence of inflammation, and HGFs are required for progenitor cell differentiation in vitro. To better ascertain the contribution of BM stromal fibroblasts to basal hematopoiesis, we therefore studied HGF production in quiescent BM stromal fibroblasts by three sensitive assays: serum-free bioassay, enzyme-linked immunosorbent assay, and reverse transcriptase polymerase chain reaction. Stromal fibroblasts were cultured in the presence or absence of normal human serum to determine if serum factor(s) present in the noninflammatory (basal) state induce secretion of HGFs. Human serum was found to induce or enhance transcription and secretion of granulocyte-macrophage colony-stimulating factor (GM-CSF) and enhance secretion of constitutively expressed IL-6. In contrast, no secretion of either granulocyte-CSF (G-CSF) or IL-3 was found. These data indicate that factors in normal human serum are active in enhancing GM-CSF and IL-6 production by stromal fibroblasts and suggest that these growth factors contribute to the maintainance of normal, basal hematopoiesis in vivo.