IL-10 suppresses cell surface CD23/Fc epsilon RII expression, not by enhancing soluble CD23 release, but by reducing CD23 mRNA expression in human monocytes

To examine a possible involvement of interleukin-10 (IL-10) in CD23/Fc epsilon RII expression in human monocytes, effects of IL-10 on the cell surface CD23 expression, soluble CD23 (sCD23) release, and CD23 type b mRNA expression were investigated. IL-10 suppressed IL-4-induced surface CD23 expression on monocytes in a dose-dependent manner, and this effect was completely neutralized by anti-IL-10 antibody. The suppressive effect of IL-10 on surface CD23 expression was not due to enhancement of sCD23 release from the cell surface because no increase in sCD23 in culture supernatant was detected after incubation with IL-10. Instead, the effect of IL-10 seemed to be exerted at the transcriptional level since IL-4-induced expression of CD23 type b mRNA was significantly reduced when IL-10 was present. Although IL-4 induced surface CD23 expression on both monocytes and B cells, the suppressive effect of IL-10 was observed only on monocytes, which underscores different regulatory mechanisms for CD23 expression between the two cell types.

MAGE-1 and MAGE-3 or -6 expression in neuroblastoma-related pediatric solid tumors

MAGE-1 and MAGE-3 or -6 are genes encoding melanoma-rejection antigens recognized by cytotoxic T lymphocytes in an HLA-A1 restriction manner. MAGE-1 and MAGE-3 or -6 were expressed in 5/14 (36%) and 6/14 (43%) neuroblastoma (NB) cell lines, and in 20/41 (49%) and 24/41 (59%) clinical NB-related tumors, respectively. Additionally, they were also expressed in pediatric tumors of other types such as rhabdomyosarcoma and Wilms' tumor. MAGE-1 expression at a functional level in tumor cells was confirmed by the cytotoxicity assay using MAGE-1-specific tumor-infiltrating lymphocytes (TIL). In clinical NB-related tumors, MAGE-3 or -6 expression demonstrated an inverse correlation to clinical stage. Furthermore, although the sample number was small, the incidence of MAGE-1 and/or MAGE-3 or -6 expression was significantly correlated to the absence of metastasis and a more favorable clinical outcome (p < 0.05). These results may suggest that NB cells silent for the expression of MAGE genes escape from the host anti-tumor immune response and consequently retain a growth advantage. Finally, NB-related tumors could be reliable candidates for immunotherapy targeted towards MAGE gene products.

Secondary structure and thermostability of the photosystem II manganese-stabilizing protein of the thermophilic cyanobacterium Synechococcus elongatus

The secondary structure of the manganese-stabilizing protein of the thermophilic cyanobacterium Synechococcus elongatus in solution was investigated by Fourier-transform infrared (FT-IR) and circular dichroism (CD) spectroscopies. Both methods showed a high proportion of disordered structure (40-43%) and a relatively small amount of beta-sheet (23-24%) and alpha-helix (17-19%). The conformation of the protein remained essentially unchanged at temperatures up to 70 degrees C. Unfolding of the protein occurred at higher temperatures and FT-IR spectroscopy revealed that beta-sheet was more strongly unfolded than alpha-helix at 76 degrees C. The protein largely lost the ordered secondary structures at 90 degrees C, but, when cooled down to 30 degrees C, regained its original conformation. Thus, the cyanobacterial protein is very thermostable and its denaturation at an extremely high temperature is reversible.

[Surgical treatment of pancreatic cancer and its prognosis-long-term therapeutic results after resection]

A total of 15,731 pancreatic cancer cases were registered by the Pancreatic Cancer Registration Committee of the Japan Pancreas Society (JPS) in a period of over 14 years. Tumor resection was performed in 35.4% of the total. The five-year actuarial survival rate of resected cases was 17.5%. 130 patients histologically confirmed had long-term (over 5 years) survival, among whom were only 7 patients with n3, pv3, ly3, a3 and pl (+) as histological criteria by JPS. The combined use of radiation therapy and chemotherapy after resection for Stage I, Stage II and Stage III disease proved effective. According to the National Cancer Data Base (NCDB), though the resection rate was only 14.2%, the long-term survival rate was similar to that by JPS, because Stage IV disease was only 8% of patients who received resection in NCDB's report. Selected patients seemed to be allowed to undergo resection. We concluded that it was very important to select patients to improve therapeutic results for pancreatic cancer.

Hydrocarbon chain length-dependent antagonism of acylcarnitines to the depressant effect of lysophosphatidylcholine on cardiac sodium current

Amphiphilic lipid metabolites, including lysophosphatidylcholine (lysoPC) and long-chain acylcarnitine, accumulate in an ischemic myocardium and exert deleterious effects on membrane function. The effects of short-chain (3-carbon-chain, C3), medium-chain (C6 and C8), long-chain (C16) acylcarnitines, and lysoPC on the sodium current (INa) of isolated guinea-pig ventricular cells and on membrane fluidity and [14C]lysoPC uptake in cultured mouse embryo ventricular cells were examined. Guinea-pig ventricular cells were superfused with low-Na+(60 mM) Tyrode solution at a temperature of 32-33 degrees C. Ca2+ and K+ currents were blocked by external Co2+(3 mM) and internal Cs+(140 mM), respectively. Neither propionylcarnitine (PpC, C1) nor hexanoylcarnitine (HxoC. C6) at concentrations of 50, 100, 500 microM affected the amplitude of peak LNa, evoked by depolarizing pulses (0.5 Hz) to -20 mV from a holding potential of -100 mV. Octanoylcarnitine (OcoC, C8) (50 and 100 microM) did not alter the amplitude of peak INa while the highest concentration (500 microM) did inhibit it by 7.7 +/- 3.0% (mean +/- S.E., n = 6) significantly. Palmitoylcarnitine (PamC, C16) (1, 5, and 50 microM), decreased the amplitude of peak INa by 16.6 +/- 5.2% (n = 5), 36.1 +/- 4.3% (n = 11), and 52.7 +/- 8.8% (n = 4), respectively. LysoPC (50 microM) irreversibly depressed INa within 30 +/- 4 seconds (n = 4), and cell contracture occurred. If short- and medium-chain acylcarnitines would prevent the depressant effects of lysoPC on INa was then investigated. In the presence of PpC (100 microM) or HxoC (100 microM), the effects of lysoPC (either depression of INa or development of cell contracture) were not observed, while OcoC (100 microM) did not prevent any of these effects of lysoPC. In contrast, PpC and HxoC failed to prevent the reduction of INa caused by PamC. From these findings and membrane fluidity and [14C]lysoPC uptake studies, it was concluded that PpC exerts the protective effect by preventing the incorporation of lysoPC into phospholipid bilayers, and that short-chain acylcarnitine has a potent anti-amphiphilic effect against the amphipathic insults caused by lysoPC, whereas long-chain acylcarnitine had a potent amphiphilic effect; medium-chain acylcarnitine appeared to share both characteristics.

Study on neurotoxic shellfish poisoning involving the oyster, Crassostrea gigas, in New Zealand

Lipid-soluble polyether marine toxins were isolated from 80% methanol extract of oysters, Crassostrea gigas, harvested in 1993 at Tiki Road, Coromandel Peninsula, New Zealand, by chromatography on columns of LH-20 and ODS (C18), followed by reversed-phase high-performance liquid chromatography. They were identified as known brevetoxins, PbTx-2 and 3. PbTx-3 was also isolated from oysters collected at Rangaunu Harbour in February 1994 and June 1995, followed by the above procedures.

Endothelin-1 kinetics in plasma, urine, and blister fluid in burn patients

Endothelin-1, a peptide isolated from vascular endothelial cells, facilitates the constriction of vascular smooth muscle and various pharmacological actions including vasodilation, the proliferation of smooth muscle cells and fibroblasts, and the stimulation of arachidonic acid metabolism. In this study, plasma, urine, and blister fluid endothelin-1 concentrations were determined in burn patients and changes in vasoactive substances derived from endothelial cells secondary to burns were investigated. Plasma endothelin-1 concentrations in burn patients were significantly lower than those in healthy individuals at rest. However, extremely high blister fluid endothelin-1 concentrations were observed within 30 hours of a burn. The amounts of endothelin-1 excreted in urine by burn patients over 24 hours also were higher than those in healthy individuals. The finding of high concentrations of endothelin-1 in blister fluids suggests that endothelin-1 is produced at wound regions in burn victims. Clinically, it appears that endothelin-1 is involved in circulation at the wound surface or in the healing of burns.

[A case of Borrmann type 4 gastric cancer successfully treated with MTX and 5-FU therapy through the hepatic artery]

A 73-year-old male was diagnosed as having a Borrmann type 4 gastric cancer with multiple liver metastases. Total gastrectomy (D2) with hepatic arterial cannulation was performed. Hepatic arterial infusion therapy of MTX (50 mg or 100 mg/body) and 5-FU (500 mg or 750 mg/body) was started postoperatively. A total dose of 1,150 mg of MTX and 6,250 mg of 5-FU caused a marked decrease in the volume of liver metastases and the effect remained for 8 months (partial response). Regarding drug concentrations, serum MTX levels rapidly decreased after bolus injection through hepatic artery and corresponded to those of intravenous injection as reported elsewhere. Serum 5-FU levels were maintained as low as 1.2 micrograms/ml during 2-hr continuous infusion and rapidly decreased after the end of the infusion. These results indicate that hepatic arterial infusion therapy of MTX and 5-FU may be safe and feasible for multiple liver metastases of Borrmann type 4 gastric cancer.

Novel 5-aminoflavone derivatives as specific antitumor agents in breast cancer

In the course of our search for new antitumor agents in breast cancer, novel amino-substituted flavone derivatives were synthesized and examined for antitumor activities. Among them, 5,4'-diaminoflavone and some of its congeners showed remarkable antiproliferative activity against the estrogen receptor (ER)-positive and estrogen-responsive human breast cancer cell line MCF-7. The activity was observed irrespective of the presence or absence of estrogen. The 5-aminoflavone derivatives (5-AFs) are not classical anti-estrogens because they did not compete with [3H]estradiol to bind the estrogen receptor. Moreover, 5-AFs showed antitumor activity highly selective to the ER-positive breast cancer cell line, and they showed no effects against the ER-negative human cancer cell lines HeLa S3, WiDr, and MDA-MB-453. Although the mechanism of their selective antitumor activity to ER-positive breast cancer cells is unclear, 5-AFs are expected to be a new type of antitumor agents in breast cancer.

Regulation of phosphorylation of Gi2 alpha protein controls the secretory response to isoproterenol in rat parotid tissues

Treatment of rat parotid tissues with 1 microM isoproterenol (IPR) for 10 min caused a 60% decrease in pertussis toxin (IAP)-catalyzed ADP-ribosylation of Gi alpha and resulted in supersensitivity of amylase secretion from the tissues. However, conversely, IPR treatment for 30 min caused a 40% increase in IAP-catalyzed ADP-ribosylation of Gi alpha, coupled with desensitization of amylase secretion. No changes in Gs function were observed in IPR-induced phenomena. Pretreatment with okadaic acid induced enhancement of the supersensitivity of amylase secretion and disappearance of the desensitization. These phenomena were accompanied with decreases in IAP-catalyzed ADP-ribosylation of Gi alpha. IPR treatment for 30 min caused a 50% decrease in phosphorylation of Gi2 alpha immunoprecipitated with anti-G protein antiserum (AS/7) from [32P]Pi-labeled cells, but such treatment for 10 min caused a 40% increase in phosphorylation in the cells pretreated with okadaic acid. Phosphorylation and dephosphorylation of immunoprecipitates with AS/7 by protein kinase A (PKA) and alkaline phosphatase caused decreases and increases in IAP-catalyzed ADP-ribosylation, respectively, indicating the presence of PKA-mediated phosphorylation sites on Gi2 alpha. Thus, the control of the phosphorylation of Gi2 alpha is of importance and relevance in the regulation of biological processes and cellular responses.

Determination of hemoglobin A1C in normal and diabetic mice: neonatal streptozotocin-induced diabetic mice and KK-Ay mice

We have determined Hemoglobin A1C (HbA1C) in normal, neonatal streptozotocin-induced diabetic animals (NSZ), a model of lean-type non-insulin-dependent diabetes mellitus (NIDDM) with hypoinsulinaemia, and KK-Ay mice, a model of obese-type NIDDM with hyperinsulinaemia. The HbA1C of NSZ mice was slightly increased from 5 to 20 weeks while the HbA1C of KK-Ay mice was markedly increased from 5 to 10 weeks. Our findings showed a difference between experimentally-induced (NSZ) and genetically (KK-Ay) diabetic animals.

Hepatic angiomyolipoma developing during the follow-up of ulcerative colitis: report of a case and review of the literature

Hepatic angiomyolipoma is a rare tumor composed of spindle-shaped and epithelioid smooth muscle cells, adipose tissue, and proliferating blood vessels. We report the first documented case of this tumor developing in a patient with ulcerative colitis. A solitary tumor (7.5 x 7.5 x 7 cm) was detected in the left lateral segment of the liver and a left hepatic lobectomy was performed. The diagnosis of angiomyolipoma was confirmed by a pathological examination. We also review the literature on previously reported cases of hepatic angiomyolipoma.

A highly practical synthesis of the sialyl Lewis X pentasaccharide and an investigation of binding to E-, P-, and L-selectins

A practical synthesis of the sialyl Lewis X (sLex) pentasaccharide, NeuAc alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta OEt (1), as a potential blocker for E-selectin has been described. The glycosylation of a trisaccharide acceptor, Fuc alpha (1-3)GlcNAc beta (1-3)Gal beta OEt, with a disaccharide donor, NeuAc alpha (2-3)Gal beta SMe, did not yield the desired sLex pentasaccharide 1 at all. However, the glycosylation of a disaccharide acceptor, GlcNAc beta (1-3)Gal beta OEt, with a disaccharide donor, NeuAc alpha (2-3)Gal beta SMe, quantitatively yielded the tetrasaccharide NeuAc alpha (2-3)Gal beta (1-4)GlcNAc beta (1-3)Gal beta OEt. This tetrasaccharide is readily converted to the title compound in a high yield by fucosylation, followed by deprotection. The inhibitory activities of compound 1 toward the binding of the natural ligand (sLex) with the E-, P-, and L-selectins were stronger than those of the sLex tetrasaccharide.

Peroxynitrite formation from activated human leukocytes

We showed direct evidence of peroxynitrite formation from polymorphonuclear cells (PMN) with the nitration of 4-hydroxyphenylacetic acid (HPA) to 4-hydroxy-3-nitrophenylacetic acid (NO2HPA). Human PMN from healthy volunteers was stimulated with phorbol-12-myristate-13-acetate (PMA, 10 ng/ml) at 37 degrees C in 2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid-buffered Hank's balanced salt solution (pH 7.4) with HPA (1 mM). NO2HPA was detected under PMA stimulation only in the presence of myeloperoxidase inhibitor. NO2HPA was eliminated by N-monomethyl-L-arginine (100 microM). The inhibition of myeloperoxidase appears to be essential to demonstrate the production of NO2HPA since myeloperoxidase itself or its product, hypochlorite, reacted with peroxynitrite and hampered the formation of NO2HPA.

High affinity antibodies against Lex and sialyl Lex from a phage display library

Our previous studies of seven murine mAbs against the carbohydrate Lex Ag demonstrated that they were all encoded by VH441 and V kappa 24B. To obtain higher affinity Abs, and to ascertain whether their L chains could be encoded by other genes, we constructed a phage display library in a modified pComb 8 vector. The library contained random L chains, and Fd segments enriched in VH domains encoded by the VHX24 gene family. We selected phage with an Lex-BSA Ag, and obtained two Fab mAbs, clones 23 and 24, whose affinities were more than 100-fold higher than hybridoma mAb PM81. Both new mAbs were encoded by VH441, and their L chains were encoded by genes of the V kappa Ox1 and V kappa 9 families. In contrast to hybridoma mAb PM81, which binds only Lex, clones 23 and 24 bound sialyl Lex (SLex) as well as Lex, and clone 23 also binds the backbone carbohydrate structure nLacCer. Analysis of the binding of these three mAbs to synthetic glycolipids that contained structural modifications indicated that they recognize different aspects of the Lex structure, and suggested that they bind to limited regions of the oligosaccharide.

Status of microchimerism in recipients 15 years after living related kidney transplantation

To study the relevance of microchimerism to the long-term outcome of renal allografting, we analyzed the frequency of microchimerism in kidney transplant recipients who had stable graft function for 15 years or longer. Among the 104 recipients who underwent kidney transplantation between 1971 and 1980, 27 renal allografts (26%) are still functioning. Among these 27 patients, 13 recipients whose donor was still alive and cooperative were investigated for the presence of microchimerism in the peripheral blood and for their immunological status. Microchimerism was tested using the polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) method. To test the sensitivity of PCP-SSCP, the peripheral blood obtained within 5 weeks after transplantation (four kidney transplants, three liver transplants) was also examined. Microchimerism was detectable in five patients within 5 weeks of transplantation (kidney transplantation, 3/4; liver transplantation 2/3. However, in the patients studied 15 years after transplantation, microchimerism was detected in only one recipient (1/13). In this chimeric patient, mixed lymphocyte response revealed high responsiveness against donor antigen. In contrast, some patients who did not have chimerism showed donor-specific hyporesponsiveness in mixed lymphocyte response assay and did not develop antidonor antibody, according to flow cytometric analysis. Microchimerism is an infrequent state in the long-term survivors of kidney allografting, and this state is irrelevant to donor-specific unresponsiveness.

High affinity antibodies against Lex and sialyl Lex from a phage display library

Our previous studies of seven murine mAbs against the carbohydrate Lex Ag demonstrated that they were all encoded by VH441 and V kappa 24B. To obtain higher affinity Abs, and to ascertain whether their L chains could be encoded by other genes, we constructed a phage display library in a modified pComb 8 vector. The library contained random L chains, and Fd segments enriched in VH domains encoded by the VHX24 gene family. We selected phage with an Lex-BSA Ag, and obtained two Fab mAbs, clones 23 and 24, whose affinities were more than 100-fold higher than hybridoma mAb PM81. Both new mAbs were encoded by VH441, and their L chains were encoded by genes of the V kappa Ox1 and V kappa 9 families. In contrast to hybridoma mAb PM81, which binds only Lex, clones 23 and 24 bound sialyl Lex (SLex) as well as Lex, and clone 23 also binds the backbone carbohydrate structure nLacCer. Analysis of the binding of these three mAbs to synthetic glycolipids that contained structural modifications indicated that they recognize different aspects of the Lex structure, and suggested that they bind to limited regions of the oligosaccharide.

Effects of resumption of loading on stress-shielded autografts after augmentation procedures. An experimental study

An experiment was conducted to verify if resumption of loading (restressing) on autografts after augmentation procedures can recover the mechanical properties of the grafts that were deteriorated by complete stress shielding. One hundred ten Japanese White rabbits were used. After the patellar tendon in each right knee was frozen in situ, tension applied to the tendon was released for an interval in 80 rabbits. These 80 animals were divided into four groups of 20 rabbits. The patellar tendons in these groups were completely shielded from stress for 1, 2, 3, and 6 weeks, respectively. From each group, rabbits were sacrificed immediately before restressing (N = 5), and after 3 (N = 5), 6 (N = 5), and 12 (N = 5) weeks of restressing. The remaining 30 rabbits underwent sham operations. The results showed that complete stress shielding markedly decreased tensile strength of the patellar tendon. However, if restressing was applied within 3 weeks of complete stress shielding, the once-reduced strength gradually increased to the level of the sham-operated tendons by 12 weeks after the onset of restressing. Restressing applied after 6 weeks of complete stress shielding also increased the strength of the tendon; however, it reached only 65% the strength of the sham-operated tendons at 12 weeks after restressing. The timing to apply stress to grafts should be carefully determined for optimal recovery.