Argyrophil cell carcinoma (apudoma) of the esophagus

Summary In a series of 79 cases of primary esophageal carcinoma resected at The Center for Adult Diseases, Osaka, there were six tumors with specific histopathologic features valid for the diagnosis of argyrophil cell carcinoma. Of the 6 tumors, 3 were studied electron microscopically and assay for ACTH content was performed on 4 tumors.Clinically, the ages of the 6 patients ranged from 56 to 71 years; two were women and four men. Four of the 6 patients died with widespread tumor recurrences within 9 months of operation.Microscopically, the 6 tumors were composed largely or almost entirely of small, spindle-shaped cells resembling those of oat cell carcinoma of the lung, and were characterized by the arrangement of tumor cells in solid sheets or anastomosing cords, the presence of argyrophil tumor cells, and the deposits of amyloid. Electron microscopically, the three tumors contained neurosecretory-type granules. Using bioassay or radioimmunoassay ACTH activity in the tumor tissues was detected in 3 out of the 4 tumors determined.From the light and electron microscopic characteristics and the assay evidence, it seems reasonable to conclude that the 6 tumors are endocrine polypeptide producing tumors (apudomas) that arise from argyrophil cells normally found among the basal cells of the esophageal mucosa, and that they represent a distinct histopathologic entity clearly distinguishable from other types of esophageal carcinomas.Supported in part by a Grant-in Aid for Cancer Research from the Ministry of Education, Science and Culture, and the Ministry of Health and Welfare, JapanThe authors are grateful to Prof. H. Imura and Dr. Y. Hirate, Department of Internal Medicine, Kobe University School of Medicine for their interest and performing the assays for ACTH on the tumor tissues.     

Prenatal diagnosis and characterization of an unbalanced whole arm translocation resulting in monosomy for 18p

Monosomy for the short arm of chromosome 18 is one of the most frequent autosomal deletions observed. While most cases result from terminal deletion of 18p, 16% of cases reported were as a result of an unbalanced whole arm translocation resulting in monosomy 18p. The origin and structure of these derivative chromosomes were reported in only a few cases. We report the prenatal diagnosis and characterization of a new case of monosomy 18p as a result of an unbalanced whole arm translocation. Amniocentesis was performed at 15 weeks of gestation on a 34-year-old woman initially referred for advanced maternal age. Holoprosencephaly was identified by ultrasound at the time of amniocentesis. Karyotype analysis showed an unbalanced whole arm translocation between the long arm of one chromosome 18 and the long arm of one chromosome 22, 45,XX,der(18;22)(q10;q10), in all metaphases. In effect, the fetus had monosomy for 18p. Parental karyotypes were normal, suggesting a de novo origin for the der(18;22). Fluorescence in situ hybridization (FISH) analysis was performed with alpha-satellite probes D18Z1 and D14Z1/D22Z1 to identify the origin of the centromere on the der(18;22). Signal was observed with both probes, indicating that the centromere was composed of alpha-satellite DNA from both constituent chromosomes. Genotyping of the fetus and her parents with chromosome 18p STS marker D18S391 showed only the paternal 187 bp allele was present in the fetus, indicating that it was the maternal chromosome 18 involved in the der(18;22). This case and previous reports show that de novo unbalanced whole arm translocations are more likely to retain alpha-satellite sequences from the two chromosomes involved.     

Postnatal expression of transport proteins involved in acid–base transport in mouse kidney

The kidney plays a major role in maintaining and controlling systemic acid–base homeostasis by reabsorbing bicarbonate and secreting protons and acid-equivalents, respectively. During postnatal kidney development and adaptation to changing diets, plasma bicarbonate levels are increasing, the capacity for urinary acidification maturates, and the final morphology and distribution of intercalated cells is achieved. In adult kidney, at least two types of intercalated cells (IC) are found along the collecting duct characterised either by the expression of AE1 (type A IC) or pendrin (non-type A IC) where non-type A IC are found only in the convoluted distal tubule, connecting tubule and cortical collecting duct. Here we investigated in mouse kidney the relative mRNA abundance, protein expression levels and distribution of several proteins involved in renal acid–base transport, namely, the Na⁺/HCO₃ ^– cotransporter NBC1 (SLC4A4), the Na⁺/H⁺-exchanger NHE3 (SLC9A3), two subunits of the vacuolar H⁺-ATPase [ATP6V0A4 (a4), ATP6V1B1 (B1)], the Cl^–/HCO₃ ^– exchangers AE1 (SLC4A1) and pendrin (SLC26A4). Relative mRNA abundance of all transport proteins was lowest at day 3 after birth and increased thereafter in parallel with protein levels. The numbers of type A and non-type A IC in the cortical collecting duct (CCD) increased from day 3 to days 18 and 24, whereas the number of IC in the CCD with apical staining for the vacuolar H⁺-ATPase subunits a4 and B1 decreased from day 3 to days 18 and 24, respectively. In addition, cells with characteristics of non-type A IC (pendrin expression, basolateral expression of vacuolar H⁺-ATPase subunits) were found in the inner and outer medulla 3 days after birth but were absent from the medulla of 24-day-old mice. Taken together, these results demonstrate massive changes in mRNA and protein expression levels of several acid–base transporters during postnatal kidney maturation and also show changes in intercalated cell phenotype in the medulla during these processes.     

Distribution and migration of angiogenic cells from grafted avascular intraembryonic mesoderm

Summary The hemangiogenic potencies of initially avascular intra-embryonic mesoderm were studied in chick and quail embryos and in chick-quail chimeras. The prechordal mesoderm, primitive streak and primitive node of quail embryos were heterospecifically grafted into limb buds of chick embryos. Hemangiopoietic quail cells in the host limb were detected by immunohistological staining with the monoclonal anti-MB-1 antibody after 3–6 days of re-incubation. The antibody is specifically directed against quail hemangiopoietic cells and their derivatives. Quail endothelial cells were found in pure quail and in chimeric vessels, inside as well as outside the graft. The main artery of the limb and the vessels inside the graft were connected by chimeric arteries. Proximal to the graft, quail endothelial cells were located predominantly within the lining of the main artery, while distally they were found mainly in the veins and the marginal sinus. The results show that, as early as stage 3 (according to Hamburger and Hamilton 1951, HH) all parts of the avascular intraembryonic mesoderm tested, give rise to endothelial cells. Both mechanisms, angiogenesis and vasculogenesis, contribute to the vascularization of the limb. Immunocytological and scanning electron microscopic studies indicate that centrifugal and centripetal migration of angiogenic cells occurs outside the vessels as well as on the inner surface of the endothelium.Supported by the Deutsche Forschungsgemeinschaft (CH 44/9-1)     

Hippocampal granule cells are necessary for normal spatial learning but not for spatially-selective pyramidal cell discharge

Summary The effects of massive destruction of granule cells of the fascia dentata on the spatial and temporal firing characteristics of pyramidal cells in the CA1 and CA3 subfields of the hippocampus were examined in freely moving rats. Microinjections of the neurotoxin colchicine were made at a number of levels along the septo-temporal axis of the dentate gyri of both hemispheres, resulting in destruction of over 75% of the granule cells. By contrast there was relatively little damage to the pyramidal cell fields. As assessed by three different behavioral tests, the colchicine treatment resulted in severe spatial learning deficits. Single units were recorded from the CA1 and CA3 subfields using the stereotrode recording method while the animals performed a forced choice behavioral task on the radial 8-arm maze. Considering the extent of damage to the dentate gyrus, which has hitherto been considered to be the main source of afferent information to the CA fields, there was remarkably little effect on the spatial selectivity of place cell discharge on the maze, as compared to recordings from control animals. There was, however, a change in the temporal firing characteristics of these cells, which was manifested primarily as an increase in the likelihood of burst discharge. The main conclusion derived from these findings is that most of the spatial information exhibited by hippocampal pyramidal cells is likely to be transmitted from the cortex by routes other than the traditional trisynaptic circuit. These routes may include the direct projections from entorhinal layers II and III to CA3 and CA1, respectively.     

Acidic ATP activates lymphocyte outwardly rectifying chloride channels via a novel pathway

Using whole-cell patch-clamp techniques we found that ATP activated an outwardly rectifying current in Daudi human B lymphoma cells under acidic conditions. The substitution of Cl^– for gluconate^– shifted the reversal potential, while Cl^– channel blockers, 4,4-diisothiocyanostibene-2,2-disulfonic acid (DIDS) and 9-anthracene carboxylic acid (9-AC), blocked the current, indicating that ATP induces this current by activating the outwardly rectifying chloride channel (ORCC). The effect of ATP on ORCC was mimicked by ADP, but not by other P2 receptor agonists such as ATPS (a poorly hydrolyzable analog of ATP), 2,3-O-benzoyl-4-benzoyl-ATP (BzATP), and UTP. The ATP-induced ORCC current was completely blocked by 100 M suramin (a P2 receptor antagonist), and was partially blocked by 100 M pyridoxal-phosphate-6-azophenyl-2,4-disulfonic acid tetrasodium (PPADS), which is another P2 receptor antagonist. Neither inactivation of G proteins nor elimination of extracellular Ca²⁺ affected the ATP-induced current, indicating that G protein-coupled P2Y receptors and Ca²⁺-permeable P2X receptors are not involved. Based on the pharmacological profile and the fact that acidic conditions are required for ATP to activate the ORCC, we suggest that acidic ATP activates the lymphocyte ORCC via a novel pathway, which is not associated with any previously described purinergic receptors.     

Assessment of HBV persistent infection in an adult population in Taiwan

In order to study the prevalence of hepatitis B virus (HBV) in the adult population of Taiwan, we screened for the presence of HBV DNA in 205 blood samples from adult (20-59-year-old) volunteers. According to the serological markers of HBV, samples were divided into three groups: group I (173 subjects) was negative for both HBsAg and HBeAg; group II (14 subjects) was positive for both HBsAg and HBeAg; and group III consisted of 18 subjects who were HBsAg-positive but HBeAg-negative. Plasma HBV DNA was not detected in group I, but it was found in 85.7% and 11.8% of samples in group II and group III, respectively. A free-form HBV DNA was found in 14.3% of the leukocyte samples in group II. Furthermore, an integrated form of HBV DNA was detected in the leukocytes of two cases of group I who remained healthy based on clinical data. HBV DNA was also detected in the spermatozoa and liver cells of one of the cases.     

Immunotherapy of mammary adenocarcinoma metastases in C3H/HeN mice with chronic administration of cyclo-oxygenase inhibitors alone or in combination with IL-2

In this study the efficacy of treatment of two cyclo-oxygenase inhibitors, ibuprofen (Ibu) and indomethacin (Indo), are compared in the immunotherapy of metastasis designed to reverse prostaglandin E₂ (PGE₂)mediated inactivation of interleukin-2 (IL-2)-dependent host killer cell lineages. These agents were tested either alone for the prevention of metastasis or in combination with IL-2 for the eradication of established metastasis. C3H/HeN mice were placed on chronic oral Ibu (CIbT; 200 and 600 ,g/ml of water) or Indo (CIT; 10 g/ml) 5 days after s.c. transplantation of 5 × 10⁵ metastatic C3L5 mammary carcinoma for the prevention of spontaneous lung metastases. They showed intolerance to Indo at a dosage of 14 g/ml, which was well tolerated by other mouse strains in previous studies, but tolerated the Ibu dosages used. Control and treated mice were killed on day 30 to score metastatic lung colonies, to evaluate killer activity in splenocytes against natural killer (NK)-sensitive YAC-1 lymphoma or NK-resistant C3L5 adenocarcinoma and 8911 lymphoma targets, and to phenotype the surface markers of killer cells. CIbT and CIT alone at the above dosage significantly reduced the number of lung colonies, retarded local tumor growth and restored NK activity of splenic killer cells expressing AGM-1⁺, Thy-1^–, Lyt-2^– phenotype. To treat established lung metastasis, mice bearing 15-day C3L5 transplants were given CIbT or CIT alone or in combination with two 4-day rounds (days 20–23, 31–34) of IL-2 (15 000 Cetus units, i.p. every 8 h) and were killed on day 35 to score lung colonies and characterize splenic killer cells. CIbT or CIT alone reduced the number of spontaneous lung metastases and restored anti-YAC-1 killer function of splenocytes with NK-like phenotype (AGM-1⁺, Thy-1^–, Lyt-2^–); some anti-C3L5 killer function was also generated in the high dose Ibu group and the killer cell showed AGM-1⁺, Thy-1⁺ and Lyt-2⁺ phenotype. Combined therapies with CIbT or CIT plus IL-2 were more effective in reducing metastases and promoting killer cell function, the best results being achieved with high dose Ibu + IL-2. All killer cells expressed AGM-1 and Thy-1. In addition, C3L5 killer cells also expressed Lyt-2, suggesting T-cell stimulation. PGE₂ synthesis in the host was inhibited by at least 50% in mice subjected to CIbT or CIT. Thus, Ibu proved to be an excellent substitute for Indo in preventing metastasis and NK cell activation when given alone, and also in ameliorating established metastasis and activating lymphokine-activated killer cells when combined with IL-2.     

Sodium conductance in calcium channels of guinea-pig ventricular cells induced by removal of external calcium ions

An inward current characterized by a slow inactivation, was induced when the extracellular Ca^2– concentration was reduced by EGTA. It was suppressed by replacing external Na^– with Tris⁺ or by D-600, increased by epinephrine, and was not affected by TTX. These findings suggest that this current is carried by Na⁺ ions through the Ca channels. The Na current decreased in amplitude as the concentration of external divalent cations was elevated. Blocking the Na current by divalent cations could be approximated by a bimolecular interaction between divalent cation and channel, with a dissociation constant of 1.2 M for Ca²⁺ and 60 M for Mg²⁺. Single channel currents were recorded in the cell-attached configuration. With a pipette solution of pCa=7.5 or pCa>8, the single channel I-V relationship was linear and the slope conductance was 70–75 pS. For 40 mV depolarizations from the resting potential, unitary currents were smaller at pCa=6 than at pCa=7.5. However, single channel events, which were observed after the repolarizing step to the resting potential, were much the same amplitude. The open time histogram was fitted with a single exponential having a time constant of 1.9 ms at around –40 mV (pCa>8, with 5 M Bay K 8644 in the bath solution), which was decreased with increasing the Ca²⁺ concentration in the pipette solution. Noise power spectra of patch currents at pCa=6 revealed a high-frequency component at around 1500 Hz. These results suggest that Ca binding to the sites with a high affinity for Ca²⁺ blocks the Na conductance in Ca channels. Reduction of the unitary current at higher concentrations of Ca²⁺ might be attributed to a rapid block by Ca²⁺.     

Chromosome neighborhood composition determines translocation outcomes after exposure to high-dose radiation in primary cells

Radiation exposure is an occupational hazard for military personnel, some health care professionals, airport security screeners, and medical patients, with some individuals at risk for acute, high-dose exposures. Therefore, the biological effects of radiation, especially the potential for chromosome damage, are major occupational and health concerns. However, the biophysical mechanisms of chromosome instability subsequent to radiation-induced DNA damage are poorly understood. It is clear that interphase chromosomes occupy discrete structural and functional subnuclear domains, termed chromosome territories (CT), which may be organized into ‘neighborhoods’ comprising groups of specific CTs. We directly evaluated the relationship between chromosome positioning, neighborhood composition, and translocation partner choice in primary lymphocytes, using a cell-based system in which we could induce multiple, concentrated DNA breaks via high-dose irradiation. We critically evaluated mis-rejoining profiles and tested whether breaks occurring nearby were more likely to fuse than breaks occurring at a distance. We show that CT neighborhoods comprise heterologous chromosomes, within which inter-CT distances directly relate to translocation partner choice. These findings demonstrate that interphase chromosome arrangement is a principal factor in genomic instability outcomes in primary lymphocytes, providing a structural context for understanding the biological effects of radiation exposure, and the molecular etiology of tumor-specific translocation patterns.