Parasite-induced IL-12 stimulates early IFN-gamma synthesis and resistance during acute infection with Toxoplasma gondii

In vitro and in vivo studies were performed to assess the involvement of IL-12 in resistance to acute and chronic infection with an avirulent strain of Toxoplasma gondii. Our previous findings implicated macrophages as a major source of parasite-induced IL-12. This finding was confirmed by showing that peritoneal macrophages exposed to either live parasites or soluble tachyzoite Ags produce IL-12 protein. In mice, increased expression of IL-12 (p40) mRNA in both spleen and peritoneal cells was detected as early as 2 days postinfection. Treatment with neutralizing mAbs against IL-12 increased the susceptibility of C57BL/6, BALB/c, and severe combined immunodeficient (SCID) mice to acute infection, which resulted in 100% mortality within the first 15 days after parasite inoculation. In contrast, neutralization of endogenously produced IL-12 had no effect when given during chronic infection. In agreement with the survival data, treatment with anti-IL-12 resulted in decreased IFN-gamma and enhanced Th2 (IL-4 and IL-10) cytokine synthesis by splenocytes when given during acute, but not chronic, toxoplasmosis. Sorting experiments on spleen cells from acutely infected mice indicated that both CD4+ lymphocytes and NK1.1+/CD3- cells contribute to the early IFN-gamma response. In contrast, CD4+ cells were found to be the major source of the cytokine during chronic disease. Together, these results suggest that the stimulation of macrophage-derived IL-12 plays a major role in both the induction of resistance and Th1 cell subset selection in acute T. gondii infection, but may not be required to maintain established immunity.

Antizyme protects against abnormal accumulation and toxicity of polyamines in ornithine decarboxylase-overproducing cells

Exposure of ornithine decarboxylase (ODC; L-ornithine carboxy-lyase, EC 4.1.1.17)-overproducing mouse FM3A cells to micromolar levels of spermine or spermidine caused abnormal accumulation and toxicity of polyamines. This was apparently due to the inefficiency of negative feedback control of polyamine transport by polyamines in ODC-overproducing cells. Since antizyme is the only protein thus far recognized that can interact with ODC, depletion of free antizyme was regarded as the reason for the abnormal accumulation of polyamines. Accordingly, ODC-overproducing cells were transfected with pMAMneoZ1 possessing rat antizyme cDNA under the control of a glucocorticoid-inducible promoter. In the transfected cells, the addition of dexamethasone caused an increase in the amount of antizyme with an apparent molecular mass of 27 kDa, a decrease in the amount of ODC, a decrease in the polyamine transport activity, and the recovery of growth inhibition or cell death. The results indicate that antizyme can regulate not only the amount of ODC but also the activity of polyamine transport.

[Color Doppler flow imaging of two newborns with subclavian steal phenomenon of the interrupted aortic arch (type B)]

Subclavian steal may occur in newborns with interrupted aortic arch (type B) as a result of collateral circulation. Color Doppler flow imaging could detect reversed blood flow images in the diastolic phase at the subclavian artery of two neonates with interrupted aortic arch (type B), indicating subclavian steal phenomenon at the left subclavian artery via the left vertebral artery. The diagnoses were confirmed by retrograde angiography from the radial artery.

Serum C-reactive protein and immune responses in dogs inoculated with Bordetella bronchiseptica (phase I cells)

Eight Beagle dogs were inoculated intrabronchially with 5 x 10(9) live, avirulent cells of Bordetella bronchiseptica L-414 strain (phase I cells) (B. bronchiseptica) to investigate the serum levels of their C-reactive protein, the white blood cell counts, the antibody responses to B. bronchiseptica in the sera and tracheal secretions, and the effects of prednisolone given to four of the dogs on C-reactive protein (CRP), white blood cells (WBC) and immune responses. In two Beagle dogs inoculated intrabronchially with sterile physiological saline, the concentrations of CRP and the WBC counts did not increase. CRP was markedly increased one day after inoculation in the dogs inoculated with B. bronchiseptica to 385.0-720.0 micrograms/ml (mean 498 +/- 132 micrograms/ml) in the group given the B. bronchiseptica inoculation only, and to 372.0-649.0 micrograms/ml (mean 551 +/- 106 micrograms/ml) in the group treated with prednisolone following inoculation of B. bronchiseptica, as determined by an enzyme-linked immunosorbent assay (ELISA). The CRP levels were 23-95 times the pre-inoculation values, which indicated that prednisolone had no effect on the production of CRP. In the prednisolone-treated group, the WBC count increased and stayed at an increased level for approximately 12 days. An indirect fluorescent antibody test led to the detection of anti-B. bronchiseptica IgM and IgG antibodies in the sera from 5 days after B. bronchiseptica inoculation and S-IgA and IgG anti-B. bronchiseptica antibodies in the tracheal secretions on the day after the challenge exposure to B. bronchiseptica. The increase in CRP after challenge exposure to B. bronchiseptica was significantly (p < 0.05) smaller than that found after the first inoculation of B. bronchiseptica.

[Organ xenotransplantation using human complement regulatory factor gene]

For the success of xenotransplantation, hyperacute rejection must be controlled. Hyperacute rejection is induced by the activation of complement system via alternative pathway and/or classical pathway. Complement regulatory factors can inhibit activation of complement system via the both pathways. To overcome hyperacute rejection in organ xenotransplantation, gene engineering in the establishment of xeno-endothelial cells and transgenic animals (mouse and pig) using human complement regulatory factors are studied. In the near future, transgenic pig using human complement regulatory factor genes can be used as a potential donor in organ xenotransplantation.

Growth and/or acid production of Candida albicans on soft lining materials in vitro

Effects of soft lining materials on the growth and/or acid production of Candida albicans were investigated using a simplified method monitoring the pH change in the growth medium. Reverse sigmoidal pH curves were observed with all samples and, as compared with acrylic, all soft lining materials inhibited fungal growth or acid production in the following way, i.e. delay of the beginning of a rapid and linear decline in pH, decreases in the rate of linear change in pH and increases in minimum pH. Further examinations using a surface-modified glass tube revealed that the order of Candida growth agreed with the relative hydrophobicity and adherence capacity of substrates, suggesting that this adherence capacity affected the yeast growth on their surfaces. Besides adherence capacities of substrates, the powder, liquid and plasticizer of some soft lining materials directly inhibited Candida growth. Thus, the results obtained here revealed that several factors within soft lining materials affected Candida growth and/or acid production.

Molecular cloning of the human AH receptor gene promoter

A lambda phage clone containing a promoter region of the human Ah receptor gene was isolated. This clone spanned 13.8 kb and contained the 1st exon, the sequence of which completely matched the reported Ah receptor cDNA. Using RNase protection assay and primer extension analysis, the transcription initiation sites were determined to be 643 and 615 bp upstream of the translational initiation codon ATG. This promoter did not contain a TATA box, while multiple GC boxes were present close to the determined transcription initiation sites. Comparison of the 5' flank sequence of the human Ah receptor with its murine equivalent showed several well conserved regions, containing binding sites for known transcription factors, such as Sp1. The promoter activity was confirmed by transient transfection of chimeric constructs of the Ah receptor gene and reporter gene luciferase into hepatoma HepG2 cells.

Expression of insulin receptor substrate-1 in hepatocytes: an investigation using monoclonal antibodies

To investigate the expression and subcellular distribution of insulin receptor substrate-1 in hepatocytes, which are major targets of insulin along with muscle and adipose tissue, we obtained monoclonal antibodies by immunizing mice with a fusion protein consisting of the C-terminal portion of the human insulin receptor substrate-1 and glutathione-S-transferase. Two of the monoclonal antibodies (designated as 7B3 and 6G5) were found to be useful for immunohistochemical studies. Using 6G5 we demonstrate a high level of expression of insulin receptor substrate-1 in liver cirrhosis hepatocytes and variable expression in hepatocellular carcinoma cells. These results suggest that insulin receptor substrate-1 may play a role in liver regeneration during cirrhosis and that an insulin signaling cascade may be involved in hepatocarcinogenesis.

[Hemophagocytic syndrome observed in a patient with systemic lupus erythematosus]

A 52-year-old woman was admitted to our hospital because of a skin rash, high fever and myalgia. She had been diagnosed ten years ago by a dermatologist as having MCTD (mixed connective tissue disease). At the time of admission a diagnosis of active SLE was made by fulfilling four of the 1982 ARA criteria together with increasing levels of anti-DNA antibody and low levels of complements. Prednisolone (PSL) given orally in an initial dosage of 60 mg/day was effective during the first 6 weeks. Then a high fever, skin rash and pancytopenia appeared without active findings of SLE. Infection caused by bacteria, fungus or virus was suspected, but no infectious agent was present in cultures derived from blood or other sources. Antimicrobic drugs used were not effective at all. The clinical picture was suggestive of a drug allergy, but no causative drug was found. A diagnosis of hemophagocytic syndrome (HPS) was made because of the increased number of unusual hemophagocytic cells in the bone marrow. High levels of serum ferritin and neopterin, which are known to reflect macrophage activation, supported the diagnosis of HPS. HPS is characterized by activated phagocytosis presumably induced by hypersecretion of cytokines. Malignant lymphoma and infection are the two representative diseases which may cause HPS. Recently, an acute lupus HPS was reported in patients with active SLE. Here we reported a case of reactive HPS observed in a patient with SLE who had been receiving high dose PSL. Symptoms and findings of the patient gradually disappeared in several weeks after rapid reduction of the PSL dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Different regulation and expression of the human CYP2E1 gene due to the RsaI polymorphism in the 5'-flanking region

The effects of two genetically associated polymorphisms [c1 allele: PstI -, RsaI +; c2 allele: PstI +, RsaI -] in the 5'-flanking region on the regulation and expression of the human CYP2E1 gene were investigated. DNase I footprinting and CAT activity analyses using various deletion mutants constructed with DNA segments from genotype A (c1/c1) or C (c2/c2) and SV40 or an endogenous promoter showed that the RsaI polymorphism affects the binding of a transcription factor and the transcriptional activation of CYP2E1, while the PstI polymorphism has little effect. The correlation between the genotypes and expression levels of CYP2E1 mRNA were examined in peripheral lymphocytes of 86 individuals by RT-PCR, the alcohol consumption by the subjects being taken into account. In non-drinkers, the mean ratio of the expression of CYP2E1 mRNA to that of GAPDH mRNA in genotype B (c1/c2) was 1.7-fold higher than that in genotype A (0.05 < p < 0.10). As compared to non-drinkers with genotype A, subjects with genotype B who drank alcohol on a daily basis expressed about 2.0-fold higher levels of CYP2E1 mRNA (p < 0.01). These results indicate that a RsaI polymorphism in the 5'-flanking region of CYP2E1 may lead to inter-individual differences in CYP2E1-mediated microsomal drug oxidation activities, including oxidation of N-nitrosamines.

Inhibition of the cardiac protein kinase A-dependent chloride conductance by endothelin-1

Endothelin-1 is a peptide hormone constitutively secreted by vascular and endocardial endothelial cells. Secretion of endothelin-1 is increased under certain pathophysiological conditions, including coronary vasospasm, cardiac ischaemia and myocardial infarction. We have examined the effect of endothelin-1 on the protein kinase A (PKA)-dependent chloride current in voltage-clamped guinea pig ventricular myocytes. This conductance, induced by catecholamines through beta-adrenergic receptors, counteracts the simultaneously increased L-type calcium current by shortening the action potential duration. We report here that endothelin-1, acting through ETA (endothelin-1-selective) receptors, inhibited the current through a pertussis toxin-sensitive mechanism, analogous to muscarinic receptors, by reducing the intracellular cyclic AMP concentration. This effect of endothelin-1 should help protect the ventricle against potentially arrhythmogenic shortening of the action potential during ischaemia when the circulating levels of catecholamines are increased.

[Condyloma acuminatum in female urethra: a case report]

A case of female intraurethral condyloma acuminata is present in this report. A 52-year-old woman visited our hospital with the chief complaint of miction pain and bloody secretions. Thirty seven years previously, she had had a pudental tumor resected which was diagnosed as condyloma acuminata. Physical examination revealed two child-finger-head sized, polypoid tumors which arose from about 5 mm inside the external urethral orifice. Laboratory findings were negative for rapid plasma reagin card test (RPR), positive for treponema pallidum hemagglutination test (TPHA) and Trichomonas vaginalis in urine and vaginal secretion. Under the clinical diagnosis of condyloma acuminata, the tumors were resected. Histological examination revealed koilocytosis with mild dysplasia. The histochemical analysis of human papillomavirus (HPV) by in situ hybridization revealed positive for HPV type 31/33/51 and negative for HPV type 6/11 and 16/18. Histological examinations confirmed that the tumors were condyloma acuminata. No recurrence was seen at the 7th post-operative month.

Clinical and angiographic characteristics of patients with multivessel coronary spasm in variant angina. Significance of progressive course of angina and disease activity

The purpose of this study was to investigate the incidence of multivessel coronary spasm and compare the clinical characteristics between patients with and without multivessel coronary spasm. In variant angina, it is controversial whether coronary hyperreactivity to vasoconstrictor stimuli is localized to a segmental lesion in only one coronary artery. Moreover, the clinical characteristics of patients with multivessel coronary spasm have never been investigated. Sixty-three patients (51 men and 12 women; mean age, 56 years; range 35-72 years) with variant angina and documented ST-segment elevation during a spontaneous attack underwent spasm provocation testing with selective intracoronary injection of ergonovine. All but 4 patients who experienced spontaneous attacks during cardiac catheterization had induced coronary spasm associated with ST-segment elevation and chest pain. Multivessel coronary spasm was found in 27 (43%) of 63 patients. By univariate analysis, a high frequency of angina (> or = 3 times/week), occurrence of a spontaneous attack within 24 hours after withdrawal of medication, a long history of angina and a progressive course of angina were significantly associated with multivessel coronary spasm. Multivariate analysis indicated a positive correlation between multivessel coronary spasm and progressive angina. Multivessel coronary spasm was found in 43% of patients with variant angina. Patients with multivessel coronary spasm have some unique clinical features. These results may increase the understanding of the pathophysiology and natural course of variant angina.

Enhancement of tumor proliferation by cyclosporine A in early phase of experimental hepatic metastasis

The effect of cyclosporine A (CsA) on in vivo growth of hepatic metastasis was studied. Murine colon 38 tumor cells (1 x 10(5) were inoculated via the superior mesenteric vein. Mice were grouped depending on CsA dosage and time schedules: Group A: CsA 30 mg/kg body weight on the 7, 8 and 9th post tumor inoculation days by gavage; Group B: CsA 15 mg/kg body weight 30 min before tumor inoculation and 2 times more at 24 h intervals; Group C: CsA 30 mg/kg body weight at the same dose timing as Group B. Measurement of the diameter of the largest tumor serially by weekly laparotomy up to 4 weeks revealed that the tumor growth rates were significantly greater in Groups B and C than those in Group A or the control (without CsA). The mean tumor doubling times in the control, and Groups A, B and C were 2.2 +/- 1.3, 2.0 +/- 0.5, 1.5 +/- 0.4 and 1.3 +/- 0.8 days, respectively. The mean tumor numbers of hepatic metastasis were 13.2 +/- 8.3, 11.3 +/- 7.3, 19.4 +/- 8.7 and 19.6 +/- 6.8, respectively. Values of tumor proliferation index obtained by bromodeoxyuridine immunohistochemistry were 10.0 +/- 6.1%, 14.9 +/- 8.0%, 28.6 +/- 8.2% and 30.1 +/- 12.4%, respectively, with significant differences (Groups B and C vs. A or control, P < 0.05). In vitro MTT assay showed that cell viability rates were greater than 100% in the medium containing CsA concentrations of less than 10(-7) mol/liter. However, a cytostatic effect of CsA was apparent at higher concentrations. In contrast to the previous in vivo finding of a cytostatic effect of CsA on tumor cells, we found a cytoproliferative action when CsA was administered early in the course of metastatic tumor implantation in the liver. The mechanism of cytoproliferative effect of CsA is unknown but may involve multiple factors.

ATP- and antizyme-dependent endoproteolysis of ornithine decarboxylase to oligopeptides by the 26 S proteasome

Previously we reported that ornithine decarboxylase (ODC) is degraded ATP-dependently by the 26 S proteasome in the presence of antizyme (AZ), an ODC inhibitor (Murakami, Y., Matsufuji, S., Kameji, T., Hayashi, S., Igarashi, K., Tamura, T., Tanaka, K., and Ichihara, A. (1992) Nature 360, 597-599). Here we examined the cleavage of ODC by the 26 S proteasome. When ODC purified from ODC-overproducing cells was incubated with the 26 S proteasome and with AZ fused with maltose-binding protein (MBP) in the presence of ATP, ODC was degraded specifically without appreciable breakdown of MBP-AZ. The major degradation products of ODC, which were separated by high performance liquid chromatography on a reverse-phase column, were identified by N-terminal amino acid sequencing. The 26 S proteasome generated a variety of short peptides of 5-11 amino acid residues derived from regions throughout the ODC sequence. No detectable amounts of free amino acid residues were produced, indicating endoproteolytic degradation of ODC by the 26 S proteasome. Their major sites for cleavage of ODC by the 26 S proteasome were on the carboxyl sides of neutral/hydrophobic amino acid residues, but a few were on those of acidic or basic amino acid residues. These results demonstrate that the 26 S proteasome causes exhaustive endoproteolysis of the naturally occurring short-lived protein ODC in a multicatalytic and ATP-dependent manner.

The function of argos in regulating cell fate decisions during Drosophila eye and wing vein development

The Drosophila argos gene, which encodes a secreted protein with an EGF motif, is involved in several developmental processes regulating cell-cell interactions such as eye morphogenesis. Loss-of-function mutations in the argos gene cause an increase in the number of photoreceptor cells and cone cells, impaired retinal projections to the optic lobe, and the formation of extra veins. We show here that ubiquitously expressed argos product restored all these loss-of-function phenotypes. Overexpression of argos in the wild-type background resulted in the reduced number of photoreceptor cells, cone cells, and pigment cells, which are phenotypes opposite to those of the loss-of-function mutants. The argos gene is expressed in developing wing veins. Ubiquitous argos expression caused loss of veins in a dose-dependent manner. This phenotype was enhanced by the loss-of-function rhomboid mutation, implying the possibility that argos and rhomboid play key roles in a common pathway for normal wing vein formation. We propose that argos acts as an inhibitory signal for cellular differentiation in the developing eye and wing.

Partial splenic embolization for the treatment of chronic idiopathic thrombocytopenic purpura

OBJECTIVE

The purpose of this study was to assess the effectiveness of partial splenic embolization in the treatment of chronic idiopathic thrombocytopenic purpura.

SUBJECTS AND METHODS

Twenty-six patients with chronic idiopathic thrombocytopenic purpura underwent partial splenic embolization and were followed up for 6-61 months. The condition was refractory to steroids in 20 of 26 patients. The other six patients, in whom a response to steroids was shown, could not be withdrawn from steroid therapy because their platelet counts decreased with any decrease in steroid dose. Five of 26 patients underwent splenectomy after partial splenic embolization, and the other patients were followed up without medical treatment until platelet counts decreased below 3 x 10(10)/l. The therapeutic effect of partial splenic embolization was defined on the basis of the platelet count at the last follow-up after partial splenic embolization: complete response, greater than 10 x 10(10)/l; partial response, 5 x 10(10)/l to 10 x 10(10)/l; and no response, less than 5 x 10(10)/l without medication.

RESULTS

Partial splenic embolization brought a complete response in seven (33%) of 21 patients, a partial response in eight (38%), and no response in six (29%). In four of five patients, who later underwent splenectomy, response to partial splenic embolization was coincident with the response to splenectomy. No serious complications occurred, but minor complications such as abdominal pain, fever, and nausea were observed in most patients.

CONCLUSION

This study suggests that partial splenic embolization might be useful as an alternative to splenectomy in the treatment of chronic idiopathic thrombocytopenic purpura.

[Transjugular intrahepatic portosystemic shunt--early experience in eleven liver cirrhosis patients]

Eleven liver cirrhosis patients with variceal bleeding and/or ascites were treated by transjugular intrahepatic portosystemic shunt. Four of the patients were combined with hepatoma, and 2 had portal thrombosis. Ten of the patients were successfully achieved TIPS, but one patient who had portal thrombosis was failed because of portal vein occlusion; success rate of 90%. An average decrease of 14mmHg in portal vein pressure was measured in the 10 patients. All of the successful patients including 4 with hepatoma were observed the disappeared or diminished varices and ascites without technical complication. Mild encephalopathy was encountered in 2 patients but who responded well to medical therapy. Three dimension MRA before TIPS was helpful for understanding the anatomical relationship between portal vein and hepatic vein. It is concluded that TIPS is an effective and safe treatment, indicating for the patients who have uncontrollable variceal bleeding and/or ascites even with hepatoma.

Invasive growth patterns of hepatic hilar ductal carcinoma. A histologic analysis of 18 surgical cases

BACKGROUND

Postoperative recurrence of hepatic hilar ductal carcinoma usually occurs in a localized region around the surgical margin, such as the bile duct. This study was aimed at assessing the invasive patterns of the hepatic hilar ductal carcinoma by histologically examining surgical specimens obtained by extended liver resection, especially the involvement of intrahepatic duct.

METHODS

Eighteen resected specimens of hepatic hilar ductal carcinoma were histologically investigated. Multiple sections vertical to the extrahepatic and intrahepatic bile duct were made at a 5-mm interval. The extension of carcinoma was evaluated on each of three layers (mucosal, extramucosal-intramural, and extramural), and routes of the invasion were examined.

RESULTS

Extramucosal extent toward the hepatic side was observed in 14 patients (77.8%) and that toward the duodenal side in 8 patients (44.4%) (P < 0.05). The distance of extramucosal tumor extent was also significantly longer (P < 0.05) in the hepatic side than in the duodenal side. Histologic tumor margin was usually identified in the extramural layer. Two patients had discontinuous extramucosal invasion. The lymphatic invasions were observed most frequently, followed by perineural invasion, and venous invasion was rare. In the extramucosal invasion of the liver, the left dominant carcinomas had extended toward the left, whereas those right dominant had extended toward the right (P < 0.05). Well differentiated differentiated tubular adenocarcinomas extended to the liver more extensively than moderately and poorly differentiated ones, but not significantly.

CONCLUSIONS

The authors examined the extramucosal invasion of hepatic hilar ductal carcinoma. This invasion extended more frequently and further to the hepatic side than to the duodenal side, usually by the route of the extramural layer.