Functional modification of vascular endothelial cells by cytokines during septic shock

The function of vascular endothelial cells is to adjust blood vessel tonus, which contributes to maintaining homeostasis within blood vessels. However, inflammatory cytokines are produced in response to invasion by stimulating vascular endothelial cells and sometimes lead to shock or multiple organ failure. In the present study, we assessed cytokines in sepsis and septic shock, and various factors that are said to have a damaging effect on vascular endothelium. Endotoxin was measured by endotoxin-specific methods. Tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), and interleukin 8 (IL-8) were measured by enzyme-linked immunosorbent assay (ELISA). Endothelin-I was measured by radioimmunoassay (RIA). Nitric oxide was measured as metabolites of nitrite and nitrate oxides (NOx) by a method based on the Griess method. Thromboxane B2 (TXB2) and 6-keto-prostaglandin F1 alpha (PGF 1 alpha) were both measured by RIA. All of the factors except endotoxin were significantly higher in the septic shock group than in the non-shock group and significantly higher in the non-survivor group than in the survivor group. Significant correlations were also found between endothelin-1 and NOx and between TXB2 and PG1 alpha. Significant correlations were also found between TNF-alpha and IL-6, endothelin-1, NOx and TXB2, but no significant correlations were detected between any of them and endotoxin. In serious diseases such as septic shock, the vascular endothelial constricting factors, endothelin and TXB2, and the blood vessel relaxing factors NOx and PGF1 alpha increase almost simultaneously. This suggests that the body's regulating mechanisms are disrupted in these serious conditions. The results of this study also suggest that inflammatory cytokines may be involved in stimulating the production of these factors.

In vivo and in vitro evidence for iodide regulation of major histocompatibility complex class I and class II expression in Graves' disease

Increases in thyroid cell major histocompatibility complex (MHC) class I and class II expression have been suggested to be an important factor in the development or perpetuation of Graves' disease. It is hypothesized that elevations result in abnormal presentation of thyroid antigens to immune cells, and that iodide and/or methimazole (MMI) are effective therapeutic agents because, at least in part, of their suppression of MHC expression. In this report, we show that Graves' patients pretreated with iodide only 4 days before surgery have lower levels of MHC class I and class II RNA levels in their thyroid tissue than do patients with no iodide pretreatment (P < 0.001 and 0.03, respectively). Because patients in both groups are treated with MMI and because the change is independent of the amounts of MMI used to treat patients, the class I and class II changes cannot be ascribed to MMI. The iodide action to decrease MHC class I and class II RNA levels was duplicated using cultured human thyroid cells in vitro; the iodide effect was dependent on the iodide concentration, was not duplicated by chloride, was not associated with an alteration in cAMP levels or with a change in thyrotropin receptor RNA levels, and was evident in gamma-interferon-treated cells. The data suggest, therefore, that the therapeutic action of iodide in Graves' patients is associated with decreased MHC gene expression, that this action is a direct effect of high concentrations of iodide on the thyroid cells, and that altered MHC gene expression in the target tissue may well be associated with the development or perpetuation of Graves' disease.

Dehydroepiandrosterone markedly inhibits the accumulation of cholesteryl ester in mouse macrophage J774-1 cells

To clarify the antiatherogenic mechanism of action of dehydroepiandrosterone (DHEA), we investigated the effects of DHEA on the accumulation of cholesteryl ester (CE) in cultured mouse macrophage J774-1 cells. The accumulation of CE in J774-1 cells in the presence of acetyl low density lipoprotein (AcLDL) and 10(-5) mol/l DHEA was significantly reduced to 30% of the control values for 24 h. The marked effect of DHEA was observed as early as 6 h and continued at least for 48 h. This reduction by DHEA was dose-dependent and occurred starting at a DHEA dose of 5 x 10(-7) mol/1 for 24 h. DHEA treatment did not induced any changes in the cell surface binding, cell-association, or degradation of AcLDL. In comparison, the DHEA analogues, 8354 and 8356, which are known to be much stronger inhibitors of glucose 6-phosphate dehydrogenase than DHEA, did not show as marked an effect as DHEA on the accumulation of CE during the first 6 h. However, after 24-48 h of incubation, both 8354 and 8356 caused a marked reduction in the accumulation of CE similar to that observed with DHEA. A quantitative analysis of the cellular cholesterol content revealed that DHEA caused a marked reduction in CE with a concomitant continuous increase in free cholesterol (FC), while the DHEA analogues caused a marked reduction in CE with no change in FC. DHEA demonstrated little inhibitory effect on 25-hydroxycholesterol-driven esterification. Moreover, 10(-5) mol/1 DHEA induced a CE reduction in the foam cells induced by AcLDL. The CE-reducing capacity was also observed in the DHEA analogues. This CE-reducing capacity disappeared, however, when acyl CoA:cholesterol acyltransferase inhibitor, 58-035, was also present. Based on these findings, it can be concluded that the inhibitory effect of DHEA on the CE storage in response to AcLDL can be explained, at least in part, by two mechanisms. First, a recently published mechanism, namely, the inhibitory action of DHEA on lysosomal cholesterol transport, correlates well with the inhibition against foam cell transformation by DHEA in the early phase (at 6 h) observed in our study. With regard to the second mechanism, the CE-reducing capacity of DHEA from CE-laden foam cells, which appears to be related to a decreased cholesteryl ester cycle, may contribute to the inhibitory effect on the CE storage in the late phase (at 24 h and 48 h). These phase-specific inhibitory mechanisms of DHEA on the CE-storage may therefore partly explain the antiatherogenic action of DHEA.

Monoclonal antiidiotypic antibodies neutralize cytotoxic effects of anti-alphaGal antibodies

The aims of this study were to produce and characterize mouse monoclonal antiidiotypic antibodies (AIAs) that specifically bind human antipig (anti-alphaGal) antibodies and to select those AIAs that neutralize the cytotoxicity of human or baboon serum to pig (PK15) cells. Mice were immunized with human anti-pig antibodies, and hybridomas were produced using conventional techniques. From a total of 480 clones, 11 produced AIAs that bound with high affinity to human anti-alpha Gal IgG and F(ab')2 fragments, and individually reduced serum cytotoxicity to pig cells by 40 - 90%. Seven of the AIAs also bound to human peripheral B lymphocytes (that express the same idiotypes as the antibodies produce). Several combinations of two or three AIAs provided 100% protection of PK15 cells. Selected AIAs injected intravenously into baboons reduced the cytotoxicity of subsequently drawn sera by 50--80% for >48 hr. The cytotoxicity studies also indicated that there are at least two dominant idiotypes expressed in the human anti-alphaGal population. We conclude that AIAs against anti-alphaGal antibodies could be successfully used in 1) preoperative characterization of a recipient's anti-alphaGal profile, (2) prevention of hyperacute rejection of a pig organ, and (3) specific immunosuppression through elimination of anti-alphaGal-producing B lymphocytes.

Distribution of thromboxane A2 receptor mRNA along the mouse nephron segments

Thromboxane A2 (TXA2) receptor mRNA was semi-quantitated in microdissected mouse nephron segments by reverse transcription-polymerase chain reaction (RT-PCR). TXA2 receptor mRNA was most abundantly expressed in the glomerulus, followed by the distal convoluted tubule > proximal tubule, thick ascending limb of Henle, and outer medullary collecting duct. These results suggest the potential physiological roles of TXA2 in the entire renal tubule as well as in the glomerulus.

Amitriptyline inhibits the G protein and K+ channel in the cloned thyroid cell line

We have reported that thyroid K+ channel is activated by extracellular application of the thyroid-stimulating hormone (TSH) using single channel recording method performed on cloned normal rat thyroid cell (FRTL-5) membrane. Treatment of dibutyryladenosine cyclic monophosphate (Bt2 cAMP) also activated the TSH-dependent K+ channel. These findings indicate that the thyroid K+ channel is activated through the TSH-adenosine cyclic monophosphate (cAMP)-protein kinase A system. We examined the effects of amitriptyline on TSH-guanosine triphosphate binding protein (G protein)-adenylate cyclase-cAMP-K+ channel system in the cloned normal rat thyroid cell line FRTL-5. Amitriptyline inhibited the cAMP production induced by TSH. Amitriptyline also inhibited the cAMP production induced by cholera toxin, indicating that amitriptyline inhibited the thyroid G protein. Amitriptyline had no effect on TSH-receptor binding and cAMP production by forskolin (adenylate cyclase stimulator). Amitriptyline inhibited the K+ channel activation by cAMP, indicating that the suppressing mechanism is not the inhibition of TSH receptor or G protein but the direct suppression of K+ channel. It was concluded that amitriptyline inhibited the thyroid G protein and K+ channel.

Cobra venom factor stimulates anti-alpha-galactose antibody production in baboons. Implications for pig-to-human xenotransplantation

Cobra venom factor (CVF) depletes complement and may therefore be of use in preventing the hyperacute rejection that follows discordant organ xenotransplantation. In two baboons studied, the intramuscular injection of CVF (0.25 mg/kg) was followed by a marked reduction in serum C3 and CH50, and serum cytotoxicity to pig kidney (PK15) cells. There was, however, a very rapid rise in the level of anti-alpha-galactose (alpha Gal) antibody, and a slower rise in anti-CVF antibody. A second intramuscular injection of CVF on day 14 was ineffective in reducing C3, CH50, and serum cytotoxicity. The major oligosaccharide of CVF is known to contain alpha Gal residues, which we suggest stimulate the major increase in anti-alpha Gal antibody level seen in the present study. In the clinical situation, this might lead to an increased immune response to a concomitantly transplanted pig organ.

Adenocarcinoma in the anal canal associated with a fistula: report of a case

Adenocarcinoma in the anal canal associated with an anal fistula is extremely rare, and in most cases its origin is difficult to ascertain because the primary sites have already been destroyed before any diagnosis of malignancy is able to be made. We report herein the case of a 62-year-old man found to have papillary adenocarcinoma with partial mucinous carcinoma associated with an anal fistula. The tumor was not exposed to the mucosal surface of the anal canal or rectum and an abdominoperineal resection was carried out. Macroscopic findings suggested that the tumor had developed from the anal fistula; however, the tumor showed a positive results when tested for O-acetylated sialic acids. This test also proved positive in the mucus of normal rectal mucosa, but not in the mucus of the anal glands. We speculated that the results of these tests may indicate that this tumor could have originated from the rectal mucosa, from where it migrated into the anal fistula.

Decreased expression of a single tropomyosin isoform, TM5/TM30nm, results in reduction in motility of highly metastatic B16-F10 mouse melanoma cells

Tropomyosin is an actin-associated cytoskeletal protein expressed in muscle and non-muscle cells. There are several tropomyosin isoforms, and their cellular expression is known to be associated with transformation events caused by retroviral infection and chemical mutagens. We found that expression of a low-molecular weight tropomyosin isoform, TM5/TM30nm, was higher in a high-metastatic B16 mouse melanoma cell line, B16-F10, than in B16-F1, a low-metastatic mouse melanoma cell line. In order to determine whether this elevated level of TM5/TM30nm plays a role in malignant phenotype, B16-F10 cells were transfected with recombinant DNA containing antisense rat TM5/TM30nm cDNA linked to the human metallothioneinIIa promoter, which is inducible by heavy metals such as zinc and cadmium. When the stably transfected clones were treated with ZnSO4, decreased expression of TM5/TM30nm and reduction in cell motility, which is thought to be an indicator of cellular malignancy were observed. These findings suggest that TM5/TM30nm plays a fundamental role in regulating cell motility, which is essential for metastasis and invasion of tumor cells.

Distribution of platelet activating factor receptor mRNA along the rat nephron segments

Platelet activating factor (PAF) receptor mRNA was semi-quantitated in microdissected rat nephron segments by the reverse transcription-polymerase chain reaction (RT-PCR). PCR primers were designed from two alternative splicing isoforms of rat PAF receptor cDNA; a homologue of human leukocyte PAF receptor cDNA (p172) and the other with a unique sequence in the 5'-noncoding region upstream of the splice acceptor site (p18). Only the expression of mRNA corresponding to p172 was detectable, which was most abundant in the glomerulus, followed in order by: proximal convoluted tubule > proximal straight tubule > outer medullary and cortical collecting duct, distal convoluted tubule > thick ascending limb of Henle's loop. These results suggest the potential physiological roles of PAF in the entire renal tubule as well as in the glomerulus.

Effect of ionomycin on cell pH in isolated renal proximal tubules

In isolated rabbit proximal tubules the addition of 2.0 microM but not 0.2 microM ionomycin induced a sustained increase in cell pH ([pH]i). This [pH]i response to 2.0 microM ionomycin was shown to be independent of several transporters such as Na+/H+ exchanger, Na(+)-HCO3- cotransporter, Cl-/HCO3- exchanger, or H(+)-ATPase. On the other hand, the removal of extracellular Ca2+ abolished the [pH]i increase or even induced a transient [pH]i decrease in the presence of ionomycin. These results are consistent with the induction of Ca2+/H+ exchange by ionomycin. Therefore Ca2+ ionophores should be used with caution as probes to estimate renal tubule functions.

Post-bullous milia

A 65-year-old woman with bullous pemphigoid responded rapidly to treatment with systemic and topical corticosteroids, but subsequently developed multiple milia where the bullae had been.

Effect of unsaturated fatty acids and antioxidants on immunoglobulin production by mesenteric lymph node lymphocytes of Sprague-Dawley rats

The effect of UFA on Ig production by rat MLN lymphocytes was examined to clarify their influence on allergic reactions. A 4-h treatment at 1 mM inhibited the production of IgA, IgG, and IgM by the lymphocytes, but stimulated IgE production. The IgE production-stimulating activity became stronger with increasing number of carbon atoms and/or double bonds. However, no saturated fatty acid with carbon numbers from 12 to 18 affected IgE production by the lymphocytes. Hydrogen peroxide exerted Ig production-regulating activity similar to that of UFA, suggesting that the effect of UFA is at least partly due to oxidation products. Thus, the effect of antioxidants on the Ig production-regulating activity of arachidonic acid was examined. alpha-Tocopherol and BHT annulled the stimulation of IgE production by arachidonic acid, but ascorbic acid was not effective. The IgE production-enhancing activity of UFA was closely related to their oxidation rate in culture medium. These results suggest that UFA enhance the allergic reaction through the stimulation of IgE production and the inhibition of IgA production, and that hydrophobic antioxidants are partially effective to annul the adverse effect of UFA.

Establishment of an in vitro cell derived from human angiosarcoma

We have succeeded in the establishment of a human endothelial cell line derived from a human angiosarcoma. These cells grew as monolayers with a "cobble stone" morphology. The cells produced endothelin and showed Weibel-Palade bodies in their cytoplasm. These findings show that the cells have specific differenciated functions, and might be useful for both fundamental endothelial cell biology and biological investigation of angiosarcoma.

Effects of n-3 polyunsaturated fatty acids and lectins on immunoglobulin production by spleen lymphocytes of Sprague-Dawley rats

We examined the effects of n-3 polyunsaturated fatty acid (PUFA), such as alpha-linolenic (alpha-LA), eicosapentaenoic (EPA), and docosahexaenoic acid (DHA) on immunoglobulin (Ig) production by spleen lymphocytes of Sprague-Dawley rats. n-3 polyunsaturated fatty acid (PUFA) strongly inhibited the production of IgA and IgM and that of IgG weakly at 100 microM. When the lymphocytes were treated with n-3 PUFA in the presence of other inhibitory biomaterials such as lectins, some PUFA attenuated their inhibitory effect on Ig production. In the presence of concanavalin A (ConA), all n-3 PUFA attenuated the inhibitory effect of ConA on the production of IgM or IgG but increased its inhibition of IgA synthesis. Thus, the interaction of n-3 polyunsaturated fatty acid and lectins in spleen interfere with each other or the expression of Ig production regulating activity.