Casein kinase II inhibitors isolated from two Brazilian plants Hymenaea parvifolia and Wulffia baccata

Two dihydroflavonol rhamnosides (1 and 2) isolated from the bark of Hymenaea parvifolia and two pentacyclic triterpenoids (3 and 6) obtained from the leaves of Wulffia baccata have been found to exhibit inhibitory effects of casein kinase II (CK-II) dose-dependently, suggesting that at higher doses more than 10 microM, these four compounds may act as potent CK-II suppressors of the CK-II-mediated activation of 60S acidic ribosomal P proteins in vitro.

Involvement of fibroblast growth factor-2 in joint destruction of rheumatoid arthritis patients

OBJECTIVE

To investigate the effect of the synovial fluid from knee joints of rheumatoid arthritis (RA) patients with different severities of joint destruction on osteoclastogenesis and bone resorption.

METHODS

Synovial fluid was harvested from the knee joints of 59 RA patients and 37 ostcoarthritis (OA) patients. RA patients with Larsen's knee grade 1-3 were classified as mild RA (n = 30) and those with grade 4 or 5 as severe RA (n = 29). Cytokine concentrations in synovial fluid were measured by ELISA. Osteoclastogenesis was measured by tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cell (MNC) formation in a co-culture of mouse osteoblastic cells and bone marrow cells, and bone resorption by 45Ca release from pre-labelled cultured neonatal mouse calvariae.

RESULTS

The synovial fluid of severe RA patients significantly stimulated TRAP-positive MNC formation and 45Ca release compared to those of mild RA and OA patients. Among the bone-resorptive cytokines fibroblast growth factor-2 (FGF-2), tumour necrosis factor alpha (TNF-alpha), interleukin-1alpha (IL-1alpha), IL-6 and soluble IL-6 receptor (sIL-6R), only FGF-2 concentration in the synovial fluid was positively correlated to Larsen's grade, and severe RA patients showed significantly higher FGF-2 concentrations than mild RA patients. Osteoclastogenesis in a co-culture system which was stimulated by the synovial fluid of severe RA patients was significantly inhibited by a neutralizing antibody against FGF-2 and this inhibition was stronger than antibodies against other cytokines.

CONCLUSION

The increase in endogenous FGF-2 levels in the synovial fluid of RA patients may play a role in the joint destruction by inducing osteoclastogenesis.

A case of thrombopoietin-producing ovarian carcinoma confirmed by immunohistochemistry

A case of ovarian carcinoma with thrombopoietin production is reported. A 49-year-old Japanese woman had serous cystadenocarcinoma of the right ovary with peritoneal spread. The platelet count was elevated to 432 x 10(9)/L. Enzyme-linked immunosorbent assay of the serum demonstrated remarkably high levels of thrombopoietin (2.96 fmol/ml). Immunohistochemical examination using an antibody specific for thrombopoietin revealed positive staining in the carcinoma cells, confirming thrombopoietin production.

Different frequencies of p53 codon-249 hot-spot mutations in hepatocellular carcinomas in Jiang-su province of China

Environmental carcinogens often induce specific mutations in the p53 gene, apparent in tumors. The relation between aflatoxin B1 (AFB1 )-related hepatocellular carcinomas (HCCs) and hot spot at codon 249 of the p53 gene has received a great deal of attention, but its significance is still controversial. To clarify this problem, we analyzed the p53-mutational status of HCCs in Jiang-su province in China, where AFB1 contamination of the staple food significantly differs between the northern and southern parts (prominent only in the latter), while other conditions are quite similar. Background liver status and mutations in exons 5 to 8 of p53 in a total of 31 cases were divided approximately equally between the 2 areas. In all, 15 tumors exhibited a total of 17 mutations in the p53 gene; 9 cases from the southern part of the province had the hot-spot mutation at codon 249 (9/16, 56%), but only one case from the northern part (1/15, 8%). These results suggest that AFB1 contamination may correlate with codon-249 mutations in HCC.

Different frequencies of p53 codon-249 hot-spot mutations in hepatocellular carcinomas in Jiang-su province of China

Environmental carcinogens often induce specific mutations in the p53 gene, apparent in tumors. The relation between aflatoxin B1 (AFB1 )-related hepatocellular carcinomas (HCCs) and hot spot at codon 249 of the p53 gene has received a great deal of attention, but its significance is still controversial. To clarify this problem, we analyzed the p53-mutational status of HCCs in Jiang-su province in China, where AFB1 contamination of the staple food significantly differs between the northern and southern parts (prominent only in the latter), while other conditions are quite similar. Background liver status and mutations in exons 5 to 8 of p53 in a total of 31 cases were divided approximately equally between the 2 areas. In all, 15 tumors exhibited a total of 17 mutations in the p53 gene; 9 cases from the southern part of the province had the hot-spot mutation at codon 249 (9/16, 56%), but only one case from the northern part (1/15, 8%). These results suggest that AFB1 contamination may correlate with codon-249 mutations in HCC.

Suppression of arthritic bone destruction by adenovirus-mediated csk gene transfer to synoviocytes and osteoclasts

Rheumatoid arthritis (RA) is characterized by a chronic inflammation of the synovial joints resulting from hyperplasia of synovial fibroblasts and infiltration of lymphocytes, macrophages, and plasma cells, all of which manifest signs of activation. Recent studies have revealed the essential role of osteoclasts in joint destruction in RA. Src family tyrosine kinases are implicated in various intracellular signaling pathways, including mitogenic response to growth factors in fibroblasts, activation of lymphocytes, and osteoclastic bone resorption. Therefore, inhibiting Src activity can be a good therapeutic strategy to prevent joint inflammation and destruction in RA. We constructed an adenovirus vector carrying the csk gene, which negatively regulates Src family tyrosine kinases. Csk overexpression in cultured rheumatoid synoviocytes remarkably suppressed Src kinase activity and reduced their proliferation rate and IL-6 production. Bone-resorbing activity of osteoclasts was strongly inhibited by Csk overexpression. Furthermore, local injection of the virus into rat ankle joints with adjuvant arthritis not only ameliorated inflammation but suppressed bone destruction. In conclusion, adenovirus-mediated direct transfer of the csk gene is useful in repressing bone destruction and inflammatory reactions, suggesting the involvement of Src family tyrosine kinases in arthritic joint breakdown and demonstrating the feasibility of intervention in the kinases for gene therapy in RA. off

Effects of lovastatin on expression of cell cycle regulatory proteins in vascular smooth muscle cells

BACKGROUND

The sequential appearance of cyclins D and E is thought to initiate subsequent DNA synthesis in proliferating cells. Previous studies have reported that DNA synthesis in cultured rat vascular smooth muscle cells (VSMCs) was suppressed by the HMG-CoA reductase inhibitor lovastatin. The effects of lovastatin on cell cycle regulatory proteins in proliferating VSMCs, however, are largely unknown. Thus, we investigated the sequential expression of cyclin D1, cyclin E, cyclin-dependent kinase (CDK) 4, CDK2, and p27Kip1 in cultured rat VSMCs stimulated by platelet-derived growth factor (PDGF)-BB in the presence or absence of lovastatin.

METHODS

Quiescent VSMCs, with and without lovastatin (20 microM) pretreatment for nine hours, were stimulated by PDGF-BB (25 ng/ml). The incorporation of tritiated thymidine was done to assess DNA synthesis. VSMC lysates were obtained every 6 hours for up to 36 hours after stimulation and were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis using relevant polyclonal antibodies. Autoradiograms were analyzed using a densitometer.

RESULTS

The peak expression of cyclins D1 and E occurred at 18 and 30 hours of PDGF stimulation, respectively. Concomitant expression of CDK4 and CDK2 was also observed. The expression of p27Kip1, by contrast, was reduced in association with DNA synthesis. Lovastatin suppressed DNA synthesis and reduced the expression of cyclin D1 and cyclin E, whereas p27Kip1 expression was strongly induced by lovastatin pretreatment. CDK4 and CDK2 expression was unaffected by lovastatin treatment.

CONCLUSIONS

PDGF-BB induces cyclins D1 and E prior to the onset of DNA synthesis in VSMCs. Lovastatin may suppress DNA synthesis in VSMCs by inducing p27Kip1 and reducing expression of cyclins D1 and E.

In vitro examination of the safety of rotational atherectomy of side branches jailed by stents

In vitro experimental models of branch orifices jailed by various stents were created to estimate the safety and the efficacy of rotational atherectomy when rotational burrs were advanced through the struts of stents. The scaffolding structures of the stents were destroyed due to loss and deflection of the struts, and the size of ablated stent-particles differed: the maximal size was 1.7 mm in slotted stents, and 17.6 mm in coiled stents. Thus, there is a definite potential for ablating stents when rotational atherectomy of restenotic lesions of side-branch orifices jailed by stents is performed.

Recent advances in statins and the kidney

BACKGROUND

Experimental and clinical studies have suggested a correlation between the progression of renal disease and dyslipidemia. Indeed, apolipoprotein B-containing lipoproteins have been demonstrated to be an independent risk factor for the progression of renal disease in humans. Interventional strategies in experimental models of renal disease have clearly demonstrated a beneficial effect on renal structure and function in a variety of models of renal disease. Investigations into the mechanisms whereby reduction of lipids by lipid-lowering agents benefits renal disease have suggested that the 3-hydroxy-3-methylglutaryl coenzyme reductase inhibitors, the so-called statin class of lipid-lowering agents, may have additional effects on the biology of inflammation that are germane to the progression of renal disease.

METHODS

Both in vivo and in vitro studies that investigated secondary mechanisms of statin effects are reviewed. In addition, new studies that investigated the effects on novel cellular mechanisms are presented.

RESULTS

Lipid-lowering agents appear to have biologically important effects in modulating a variety of intracellular signaling systems involved in cell proliferation, inflammatory responses that involve macrophage adhesion, recruitment, and maturation. In addition, the effects on fibrogenesis have been recently defined. These latter effects may influence not only the development of glomerulosclerosis, but also interstitial fibrosis. These potentially major effects of lipid-lowering agents appear to be related to the effects on intracellular synthesis of nonsterol isoprenoids, which are involved in prenylation of critical small molecular weight proteins involved in cell signal transduction.

CONCLUSIONS

In addition to the beneficial effects of the reduction in serum lipids, statins and other lipid-lowering agents may influence important intracellular pathways that are involved in the inflammatory and fibrogenic responses, which are common components of many forms of progressive renal injury.

Importance of geranylgeranyl pyrophosphate for mesangial cell DNA synthesis

BACKGROUND

Farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP) are isoprenoid products of the intracellular mevalonate pathway used for prenylation of several low molecular weight G proteins, including Ras. It is likely that platelet-derived growth factor (PDGF) stimulation of mesangial cell proliferation requires prenylated, low molecular weight G proteins. The purpose of this study was to investigate the dependence of platelet-derived growth factor-stimulated mesangial cell DNA synthesis and cell membrane Ras incorporation on FPP and GGPP.

METHODS

Quiescent human mesangial cells were exposed to PDGF (25 ng/ml) to stimulate DNA synthesis. Some cells were also treated with the HMG-CoA reductase inhibitor lovastatin (2.5 to 10.0 microM), which inhibits isoprenoid synthesis, in the presence or absence of exogenous FPP or GGPP. DNA synthesis was assessed by thymidine incorporation, and Western blot analysis was used to measure total cell membrane Ras.

RESULTS

Stimulation of mesangial cells with PDGF did not increase total cell membrane Ras. Lovastatin reduced cell membrane Ras, and this was prevented by simultaneous exposure of mesangial cells to exogenous FPP (2.5 to 10.0 microM) or GGPP (1 to 5 microM). Lovastatin also reduced PDGF-stimulated mesangial cell DNA synthesis by 90%, and this was completely prevented by simultaneous exposure of cells to exogenous GGPP (1 microM), but not to FPP.

CONCLUSIONS

The results of this study suggest that both FPP and GGPP can provide for mesangial cell membrane Ras localization and that PDGF-stimulated mesangial cell DNA synthesis requires the isoprenoid GGPP.

Effect of lipoproteins on mesangial cell proliferation

BACKGROUND

Triglyceride (TG)-rich lipoproteins have been reported to promote atherosclerosis, but little is known about their role in kidney disease or about their effects on mesangial cells. Accordingly, the purpose of this study was to investigate which lipoproteins could influence mesangial cell proliferation in vitro. We assessed the effect of various lipoproteins [very low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), low density lipoprotein (LDL), oxidized LDL, and high-density lipoprotein (HDL)] on the proliferation of cultured human mesangial cells and also assessed the influence of these lipoproteins on cytokine production.

METHODS

We investigated the effect of various lipoproteins on cultured human mesangial cells using 3H-thymidine incorporation and cell counting assays and investigated the levels of several cytokines [interleukin (IL)-6, platelet-derived growth factor (PDGF), transforming growth factor (TGF)-beta, and tumor necrosis factor-alpha] in mesangial cell culture supernatants after stimulation by the lipoproteins.

RESULTS

Not only LDL but also TG-rich lipoproteins (VLDL and IDL) promoted the proliferation of mesangial cells up to certain concentrations, but cell growth was actually decreased at higher concentrations. Oxidized LDL caused a concentration-dependent decrease of 3H-thymidine incorporation, and HDL had no proliferative effect at any concentration. Exposure to VLDL, IDL, LDL, or a high concentration of HDL enhanced the secretion of IL-6, PDGF-AB, and TGF-beta by mesangial cells, whereas TNF-alpha secretion was stimulated by oxidized LDL.

CONCLUSIONS

TG-rich lipoproteins, LDL, and oxidized LDL may be involved in mesangial cell proliferation and injury in patients with mesangial proliferative glomerulonephritis.

Lipoprotein(a) as a risk factor for coronary artery disease in hemodialysis patients

BACKGROUND

We studied whether lipoprotein(a) [Lp(a)] is an independent risk factor for coronary artery disease (CAD) in hemodialysis (HD) patients.

METHODS

A serum concentration of Lp(a) was measured in 212 patients with chronic glomerulonephritis and 56 patients with diabetic nephropathy (a total of 268 patients). The causes of death during five years of follow-up were studied and classified into either cardiovascular or noncardiovascular events.

RESULTS

The mortality of these 268 HD patients during the observation period was 26.1%. Seventy-eight percent were due to cardiovascular events. Those who died of cardiovascular events had significantly higher serum Lp(a) levels than those died of noncardiovascular events. The relative risk of death from CAD was 0.71 in HD patients with a Lp(a) concentration above 30 mg/dl.

CONCLUSIONS

This study indicates that the serum Lp(a) levels are independent indicators of the future risk of death from CAD in HD patients.

Apolipoprotein E polymorphism and renal disease

BACKGROUND

Lipid abnormalities are frequently found in end-stage renal disease (ESRD), and abnormal lipid metabolism may contribute to the progression of renal disease. Previous investigators have reported that apolipoprotein E (apoE) has an important role in lipoprotein metabolism and that the process of lipoprotein catabolism varies according to the apoE phenotype. In addition, the relative frequency of the apoE alleles is different among the races. In this study, we investigated the allele frequency of apoE phenotypes and evaluated the impact of apoE polymorphism on lipid profile in Japanese patients with renal disease.

METHODS

ApoE phenotypes were determined using isoelectric focusing and Western blotting in 592 Japanese patients with renal disease [86 out of 107 patients with glomerulonephritis had proteinuria of not less than 0.25 g per 24 hr and 485 with ESRD; 448 were on hemodialysis (HD), and 37 were on continuous ambulatory peritoneal dialysis (CAPD)]. The allele frequency and apoE phenotype distribution were estimated by the gene-counting method. Serum lipid parameters related to lipid metabolism were measured after at least a 12-hour fast.

RESULTS

The allele frequency of the three major apoE phenotypes (apoE2, apoE3, and apoE4) in 107 glomerulonephritis patients (epsilon 2; 0.037, epsilon 3; 0.860, epsilon 4; 0.103) was almost identical to that in the normal control population (epsilon 2; 0.036, epsilon 3; 0.848, epsilon 4; 0.115). However, 86 glomerulonephritis patients with proteinuria had higher allele frequency of apoE2 (epsilon 2; 0.052, P < 0.01) and apoE4 (epsilon 4; 0.140, P < 0.001) and lower allele frequency of apoE3 (epsilon 3; 0.808, P < 0.001) than the controls. Furthermore, ESRD patients had higher allele frequency of apoE2 (epsilon 2; 0.058, P < 0.01) and lower allele frequency of apoE4 (epsilon 4; 0.091, P < 0.05) than the controls. Higher prevalence of nephrotic syndrome was found in proteinuric glomerulonephritis patients with apoE2. The impact of apoE polymorphism on serum lipid profile in patients with glomerulonephritis, HD, and CAPD was different from that generally expected.

CONCLUSIONS

The higher frequency of apoE2 in ESRD patients suggests that apoE2 is a possible genetic predisposition to ESRD in a Japanese population. The impact of apoE2 and apoE4 on lipid profile in patients with renal disease was unique and different from that in the normal population.

HLA-B27 subtypes and HLA class II alleles in Japanese patients with anterior uveitis

PURPOSE

Some patients with anterior uveitis (AU) have ankylosing spondylitis (AS) and are HLA-B27 class I-positive. The purpose of this study was to investigate whether there are differences in HLA at the allele level among each group of patients with AU.

METHODS

Seventy-three patients with AU were studied. They were classified into three groups: 31 with AS-associated AU, 14 with HLA-B27-associated AU, and 28 with idiopathic AU. Three control groups without AU were used: 138 random subjects, 33 HLA-B27-positive healthy subjects, and 19 HLA-B27-positive patients with AS. DRB1 and DQB1 genotyping was performed using polymerase chain reaction (PCR)-single-strand conformation polymorphism (PCR-SSCP) and PCR-restriction fragment length polymorphism. HLA-B27 subtype was determined by PCR-SSCP.

RESULTS

There was no difference in the frequency of any class I antigen except HLA-B27 among the patients studied. The frequencies of HLA-DR12 in AS-associated AU and HLA-DR1 in HLA-B27-associated AU showed an increase. In HLA-B27-associated AU, DRB1*0101 and DQB1*0501 were increased compared with HLA-B27-positive control subjects. When HLA-B27 subtype distribution was compared among the groups, the proportion of B*2704 was significantly lower in HLA-B27-associated AU (P = 0.037), however, such a difference was not present in AS-associated groups.

CONCLUSIONS

These results indicated that B*2704 seemed to be less susceptible to AU compared with B*2705 in Japanese subjects. The increase of HLA-DR12 and HLA-DR1 in AU may be caused by linkage disequilibrium with B*2704 and B*2705, respectively.

Urinary excretion of aquaporin-2 water channel differentiates psychogenic polydipsia from central diabetes insipidus

The present study was undertaken to determine whether urinary excretion of aquaporin-2 (AQP-2) water channel under ad libitum water intake is of value to differentiate polyuria caused by psychogenic polydipsia from central diabetes insipidus. A 30-min urine collection was made at 0900 h in 3 groups of: 11 patients with central diabetes insipidus (22-68 yr old), 10 patients with psychogenic polydipsia (28-60 yr old), and 15 normal subjects (21-38 yr old). In the patients with central diabetes insipidus, the plasma arginine vasopressin level was low despite hyperosmolality, resulting in hypotonic urine. Urinary excretion of AQP-2 was 37 +/- 15 fmol/mg creatinine, a value one-fifth less than that in the normal subjects. In the patients with psychogenic polydipsia, plasma arginine vasopressin and urinary osmolality were as low as those in the patients with central diabetes insipidus. However, urinary excretion of AQP-2 of 187 +/- 45 fmol/mg creatinine was not decreased, and its excretion was equal to that in the normal subjects. These results indicate that urinary excretion of AQP-2, under ad libitum water drinking, participates in the differentiation of psychogenic polydipsia from central diabetes insipidus.

Hyperimmunoglobulin E syndrome associated with nephrotic syndrome

A 21-year-old man was admitted to Kure National Hospital with nephrotic syndrome in September 1996. He had suffered from an intractable pruritic skin rash and recurrent subcutaneous abscesses caused by the hyperimmunoglobulin E syndrome since the age of 18 months. Renal biopsy gave a diagnosis of membranoproliferative glomerulonephritis. Steroid therapy decreased urinary protein loss and hypoproteinemia, and his pruritic skin rash was improved. Patients with hyperimmunoglobulin E syndrome have a defective immune response, especially to Staphylococcus aureus infection. Continuous antigen stimulation may have caused this patient's renal histological damage as in immune complex glomerulonephritis.

Expression and differential intracellular localization of two major forms of human 8-oxoguanine DNA glycosylase encoded by alternatively spliced OGG1 mRNAs

We identified seven alternatively spliced forms of human 8-oxoguanine DNA glycosylase (OGG1) mRNAs, classified into two types based on their last exons (type 1 with exon 7: 1a and 1b; type 2 with exon 8: 2a to 2e). Types 1a and 2a mRNAs are major in human tissues. Seven mRNAs are expected to encode different polypeptides (OGG1-1a to 2e) that share their N terminus with the common mitochondrial targeting signal, and each possesses a unique C terminus. A 36-kDa polypeptide, corresponding to OGG1-1a recognized only by antibodies against the region containing helix-hairpin-helix-PVD motif, was copurified from the nuclear extract with an activity introducing a nick into DNA containing 8-oxoguanine. A 40-kDa polypeptide corresponding to a processed form of OGG1-2a was detected in their mitochondria using antibodies against its C terminus. Electron microscopic immunocytochemistry and subfractionation of the mitochondria revealed that OGG1-2a locates on the inner membrane of mitochondria. Deletion mutant analyses revealed that the unique C terminus of OGG1-2a and its mitochondrial targeting signal are essential for mitochondrial localization and that nuclear localization of OGG1-1a depends on the NLS at its C terminus.

Expression of E2A-HLF chimeric protein induced T-cell apoptosis, B-cell maturation arrest, and development of acute lymphoblastic leukemia

The E2A-HLF fusion gene, generated by t(17;19)(q22;p13) in acute lymphoblastic leukemia (ALL), encodes a chimeric transcription factor in which the trans-activating domains of E2A are fused to the DNA-binding and dimerization domains of hepatic leukemic factor (HLF). To investigate its biological role, we generated transgenic mice expressing E2A-HLF using Ig enhancer and promoter, which direct transgene expression in cells committed to the lymphoid lineage. The transgenic mice exhibited abnormal development in the thymus and spleen and were susceptible to infection. The thymus contained small numbers of thymocytes, and TUNEL staining showed that higher population of thymocytes were undergoing apoptosis. The spleen exhibited a marked reduction in splenic lymphocytes and the flow cytometric analyses and the in vitro colony formation assays showed that the B-cell maturation was blocked at a very early developmental stage. These findings indicated that the expression of E2A-HLF induced T-cell apoptosis and B-cell maturation arrest in vivo and that the susceptibility of the transgenic mice to infection was due to immunodeficiency. Moreover, several transgenic mice developed acute leukemia, classified as T-ALL based on the surface marker analysis and DNA rearrangements, suggesting that an additional event is required for malignant transformation of lymphoid cells expressing E2A-HLF. Our findings provide insight into the biological function of E2A-HLF in lymphoid development and also its role in leukemogenesis.

Dynamic features of adherens junctions during Drosophila embryonic epithelial morphogenesis revealed by a Dalpha-catenin-GFP fusion protein

Cell-cell adherens junctions (AJs), comprised of the cadherin-catenin adhesion system, contribute to cell shape changes and cell movements in epithelial morphogenesis. However, little is known about the dynamic features of AJs in cells of the developing embryo. In this study, we constructed Dalpha-catenin fused with a green fluorescent protein (Dalpha-catenin-GFP), and found that it targeted apically located AJ-based contacts but not other lateral contacts in epithelial cells of living Drosophila embryos. Using time-lapse fluorescence microscopy, we examined the dynamic performance of AJs containing Dalpha-catenin-GFP in epithelial morphogenetic movements. In the ventral ectoderm of stage 11 embryos, concentration and deconcentration of Dalpha-catenin-GFP occurred concomitantly with changes in length of AJ contacts. In the lateral ectoderm of embryos at the same stage, dynamic behaviour of AJs was concerted with division and delamination of sensory organ precursor (SOP) cells. Moreover, changes in patterns of AJ networks during tracheal extension could be followed. Finally, we utilized Dalpha-catenin-GFP to precisely observe the defects in tracheal fusion in shotgun mutants. Thus, the Dalpha-catenin-GFP fusion protein is a helpful tool to simultaneously observe morphogenetic movements and AJ dynamics at high spatio-temporal resolution.

Uptake of 10 polar organic solvents during short-term respiration

Respiratory uptake was investigated for 10 polar organic solvents with high blood/air partition coefficients (lambda(blood/air)): ethyl acetate (lambda(blood/air), 77), methyl iso-butyl ketone (90), methyl acetate (90), methyl propyl ketone (150), acetone (245), iso-pentyl alcohol (381), iso-propyl alcohol (848), methyl alcohol (2590), ethylene glycol monobutyl ether (EGBE, 7970), and propylene glycol monomethyl ether (PGME, 12380). Test-air concentrations (Cinh) were 25 to 200 ppm. Four healthy male volunteers inhaled the test air for 10 min at rest and then room air for 5 min. The percentage of solvent in the end-exhaled air and in the mixed-exhaled air increased after the start of the test-air respiration, and reached a quasi-steady-state level within a few min. The speeds of these increases at the start of the test-air respiration became lower as lambda(blood/air) increased. The mean uptakes (U) for the last five min of the test air respiration were 67.3, 52.9, 60.4, 53.0, 52.6, 63.0, 60.3, 60.8, 79.7, and 81.3%, respectively, for ethyl acetate, methyl iso-butyl ketone, methyl acetate, methyl propyl ketone, acetone, iso-pentyl alcohol, iso-propyl alcohol, methyl alcohol, EGBE and PGME. Thus, U values of the alcohols were higher than those of the ketones and lower than the glycol ethers. The overall view, except for esters, showed that U increased with lambda(water/air) increases. This tendency can be explained by a hypothesis that solvent absorbed in the mucus layer of the respiratory tract is removed by the bronchial blood circulation. U values of ethyl acetate and methyl acetate were higher than those of methyl iso-butyl ketone and methyl propyl ketone, though the lambda(blood/air) values of these esters were nearly equal to those of the ketones. For the respiration of the esters, their metabolites, ethyl alcohol and methyl alcohol, were detected in the exhaled air. The exhalation percentage of the metabolites increased after the start of test-air respiration and reached a quasi-steady-state level of 2 and 3%, respectively, by the 5th min. These data suggest that removal of the solvent via metabolism in the wall tissue of the respiratory tract plays an important role for the esters.

Actin dynamics in lamellipodia of migrating border cells in the Drosophila ovary revealed by a GFP-actin fusion protein

Directional migration of border cells in the Drosophila egg chambers is a developmentally regulated event that requires dynamic cellular functions. In this study, the electron microscopic observation of migrating border cells revealed loose actin bundles in forepart lamellipodia and numerous microvilli extending from nurse cells and providing multiple adhesive contacts with border cells. To analyze the dynamics of actin in migrating border cells in vivo, we constructed a green fluorescent protein-actin fusion protein and induced its expression in Drosophila using the GAL4/UAS system. The green fluorescent protein-actin was incorporated into the actin bundles and it enabled visualization of the rapid cytoskeletal changes in border cell lamellipodia. During the growth of the lamellipodia, the actin bundles that increased in number and size radiated from the bundle-organizing center. Quantification of the fluorescence intensity showed that an accumulation of bundle-associated and spotted green fluorescent protein-actin signals took place during their centripetal movement. Our results favored a treadmilling model for actin behavior in border cell lamellipodia.

Preoperative detection of occult enterovesical fistulas in patients with Crohn's disease: efficacy of oral or rectal administration of indocyanine green solution

OBJECTIVES

Nonhazardous enteral administration of indocyanine green solution was performed to detect enterovesical occult microfistulas in patients with Crohn's disease before the fistulas had become readily apparent.

METHODS

A total of 12 patients with Crohn's disease who were suspected from their clinical manifestations of having enterovesical fistulas underwent study. For detection of the fistulas after oral or rectal administration of the indocyanine green solution, urine was collected and examined using a colorimeter to check for contamination with indocyanine green. The effectiveness of the indocyanine green test and conventional x-ray study was compared.

RESULTS

The indocyanine green test was positive after either oral or rectal administration in 11 of the 12 patients, providing a rate of accurate diagnosis of 92 percent (11/12 patients). In contrast, the rate of accurate diagnosis using the x-ray study was only 17 percent (2/12 patients). Furthermore, in eight patients with occult fistulas, accurate diagnosis could be made in none using the x-ray study, whereas all showed positive results with use of the indocyanine green test.

CONCLUSIONS

The ability to diagnose obscure fistulas using the indocyanine green test was 92 percent. This indocyanine green test was highly diagnostic, whereas conventional examinations are often complicated and much less diagnostic.

Inhibition of noradrenaline release from PC12 cells by the long-term treatment with cholera toxin

Guanine nucleotide-binding (G) proteins are required for intracellular vesicular transport and endocytosis. In this study, we investigated the effects of short-term (2 h) and long-term (24 h) treatment with cholera toxin (CTX), which ADP-ribosylates proteins having arginine residues such as the alpha subunit of Gs (G(s alpha)), on exocytosis from the neurosecretory rat pheochromocytoma PC 12 cell line. Short-term treatment with CTX stimulated the accumulation of cyclic AMP, and synergistically enhanced both extracellular Ca2+-dependent [3H]noradrenaline (NA) releases (induced by high K+ and ATP) and Ca2+-independent release (induced by mastoparan, a peptide in wasp venom). Long-term treatment with CTX for 24h inhibited Ca2+-dependent and -independent stimulated [3H]NA release. The inhibitory effect of long-term CTX treatment was not derived from a cyclic AMP-dependent system, because (1) H-89, an inhibitor of protein kinase A, had no effect on the inhibition induced by CTX, (2) the long-term treatment with forskolin did not show an inhibitory effect. [32P]ADP-ribosylation of G(s alpha) and its immunoreactivity with anti-G(s alpha) antiserum in the crude membrane fraction was inhibited in the long-term CTX-treated cells, but not in the long-term forskolin-treated cells. [32P]ADP-ribosylation of G(s alpha) in the membrane fraction of short-term CTX-treated cells was approximately 90% of the level in the control cells. These findings suggest that CTX stimulates [3H]NA release via a cyclic AMP-dependent system in the short-term, and that long-term CTX treatment inhibited its release, maybe via ADP-ribosylation of CTX-sensitive proteins such as G(s alpha).

Increased insulin sensitivity and hypoglycaemia in mice lacking the p85 alpha subunit of phosphoinositide 3-kinase

The hallmark of type 2 diabetes, the most common metabolic disorder, is a defect in insulin-stimulated glucose transport in peripheral tissues. Although a role for phosphoinositide-3-kinase (PI3K) activity in insulin-stimulated glucose transport and glucose transporter isoform 4 (Glut4) translocation has been suggested in vitro, its role in vivo and the molecular link between activation of PI3K and translocation has not yet been elucidated. To determine the role of PI3K in glucose homeostasis, we generated mice with a targeted disruption of the gene encoding the p85alpha regulatory subunit of PI3K (Pik3r1; refs 3-5). Pik3r1-/- mice showed increased insulin sensitivity and hypoglycaemia due to increased glucose transport in skeletal muscle and adipocytes. Insulin-stimulated PI3K activity associated with insulin receptor substrates (IRSs) was mediated via full-length p85 alpha in wild-type mice, but via the p50 alpha alternative splicing isoform of the same gene in Pik3r1-/- mice. This isoform switch was associated with an increase in insulin-induced generation of phosphatidylinositol(3,4,5)triphosphate (PtdIns(3,4,5)P3) in Pik3r1-/- adipocytes and facilitation of Glut4 translocation from the low-density microsome (LDM) fraction to the plasma membrane (PM). This mechanism seems to be responsible for the phenotype of Pik3r1-/- mice, namely increased glucose transport and hypoglycaemia. Our work provides the first direct evidence that PI3K and its regulatory subunit have a role in glucose homeostasis in vivo.

Comparison of complications of vaginal hysterectomy in patients with leiomyomas and in patients with adenomyosis

We reviewed 1246 vaginal hysterectomies performed at Handa City Hospital between January 1984 and December 1996. We divided the patients into 2 groups: those with leiomyomas (n = 893) and those with adenomyosis (n = 353). There was no difference in operative time and estimated blood loss between the 2 groups when analyzed by uterine weight. However, adenomyosis was associated with an increased risk of bladder injury.

Aspiration of intraspinal synovial cyst: recurrence after temporal improvement

Intraspinal synovial cyst primarily occurs in the lumbar spine and may cause back pain and compression nerve disturbance. Percutaneous aspiration has been recommended as an alternative to surgery in three cases. We report on two patients who improved after aspiration of gelatinous material and steroid injection but whose cyst recurred within a short period of time. There are reportedly two types of synovial cyst: One contains serosanguineous fluid and the other gelatinous fluid. These two types are indistinguishable on computed tomography or magnetic resonance imaging. The results of all patients whose aspirated material was gelatinous were unsuccessful, including our cases. Thus, the outcome may depend on the pathology of the cyst.

Dynamic behavior of the cadherin-based cell-cell adhesion system during Drosophila gastrulation

During Drosophila gastrulation, morphogenesis occurs as a series of cell shape changes and cell movements which probably involve adhesive interactions between cells. In the present study, we examined the dynamic aspects of cadherin-based cell-cell adhesion in the morphogenetic events to assess its contribution to morphogenesis. DE- and DN-cadherin show complementary expression patterns in the presumptive ectoderm and mesoderm at the mRNA level. We found that switching of cadherin expression from the DE- to the DN-type in the mesodermal germ layer occurred downstream of the mesoderm-determination genes twist and snail. However, examination of their protein expression patterns showed that considerable amounts of DE-cadherin remained on the surfaces of mesodermal cells during invagination, while DN-cadherin did not appear on the cell surfaces at this stage. Further immunocytochemical analysis of the localizations of DE-cadherin and its associated proteins Armadillo (beta-catenin) and Dalpha-catenin revealed dynamic changes in their distributions which were accompanied by changes in cell morphology in the neuroectoderm and mesoderm. Simultaneously, adherens junctions (AJs), based on the cadherin-catenin system, were shown to change their location, size, and morphology. These dynamic aspects of cadherin-based cell-cell adhesion appeared to be associated with the following: (1) initial establishment of the blastoderm epithelium, (2) acquisition of cell motility in the neuroectoderm, (3) cell sheet folding, and (4) epithelial to mesenchymal conversion of the mesoderm. These observations suggest that the behavior of the DE-cadherin-catenin adhesion system may be regulated in a stepwise manner during gastrulation to perform successive cell-morphology conversions. Moreover, the processes responsible for loss of epithelial cell polarity and elimination of preexisting DE-cadherin-based epithelial junctions during early mesodermal morphogenesis are discussed.

[Workers' stress after Hanshin-Awaji earthquake in 1995--symptoms related to stress after 18 months]

Stress-related symptoms were investigated in workers living in the area hit by the Hanshin-Awaji earthquake. Questionnaires were distributed among taxi and truck drivers, longshoremen, workers in factories, hospitals and local government offices 18 months after the event. Nearly 40% of them, 3,015 answered. The multiple regressive analysis showed that the degree of housing damage was the factor most relevant to the symptoms. Although the symptoms decreased as time passed, the group with seriously damaged housing still complained of severe stress-related symptoms even 18 months after the event. Symptoms related to post traumatic stress disorder (PTSD) were observed in 48.0% in the male group with seriously damaged housing immediately after the quake. The figure was 34.2% of after 3 months and 12.6% after 18 months. 21.8%, 12.9% and 3.7%, respectively, were the figures in the male group with nil or slightly damaged housing. The number of workers who complained of the recurrence and worsening of chronic diseases peaked 3 months after the event and had not changed much even after 18 months. Workers also complained of anxiety over the loss of work, job pressure, overwork, difficulty of commuting to and from the area, danger at work, decline in income and changes of job location.

Modulation of osteoclast function by adenovirus vector-induced epidermal growth factor receptor

We have explored the use of adenovirus vector-mediated gene transfer to introduce foreign genes into osteoclasts, terminally differentiated cells responsible for bone resorption. A replication-deficient adenovirus vector that contains a reporter gene encoding beta-galactosidase efficiently infected human osteoclast-like cells (OCLs) derived from human giant cell tumors and mouse OCLs formed in vitro. We then constructed an adenovirus vector carrying human epidermal growth factor receptor (EGFR) cDNA (Ax1CAhEGFR) and introduced the EGFR gene into mouse OCLs. Clear induction of EGF receptor was detected in Ax1CAhEGFR-infected OCLs (EGFR-OCLs) by immunocytochemistry and immunoblotting, and EGF stimulation induced rapid tyrosine phosphorylation of several proteins including EGF receptor itself. Large vacuoles appeared in EGFR-OCLs in response to EGF treatment, and pit-forming activity by EGFR-OCLs was dose-dependently suppressed by recombinant human EGF. In addition, survival of EGFR-OCLs was prolonged by EGF. No expression of EGF receptor or effects of EGF were observed in noninfected OCLs or control vector-infected OCLs. These results suggest that adenoviral vectors are useful for modulating osteoclast function by introducing foreign genes into osteoclasts and that they will be a good means of gene therapy of metabolic bone diseases.

[Treatment outcome on 52 patients with 53 testicular germ cell tumors]

Between August 1983 and April 1996, 53 testicular germ cell tumors in 52 patients were treated at Toranomon Hospital. The average age of the patients was 36.1 years (range 21-89). The affected side was the right side in 24, left in 27 and bilateral in 1 case. Of the 53 tumors 34 (64.2%) were seminoma and 19 (35.8%) were non-seminomatous germ cell tumor (NSGCT). High ligation orchiectomy was performed in all cases. Of 29 stage I seminomas, post-operative adjuvant radiotherapy was performed in 6 cases prior to 1991. None of these tumors recurred. Two cases of relapses (8.7%) were found among the 23 stage I seminomas followed by surveillance. Of 8 stage I NSGCTs followed by surveillance, 4 (50.0%) tumors which contained embryonal carcinoma element and vascular invasion relapsed within 12 months after orchiectomy. A case of stage IIA seminoma was treated successfully by irradiation. Seven cases of stage II (3 seminomas and 4 NSGCTs) and 8 cases of stage III (1 seminoma and 7 NSGCTs) as well as cases of 6 stage I patients who developed relapse during surveillance were treated by VAB-6 chemotherapy. Of these 21 cases, 11 (52.4%) achieved complete response (CR) and 10 (47.6%) partial response (PR). Salvage surgery and/or additional chemotherapy was successful to bring the 10 PR cases into CR condition. One NSGCT patient, however, died of electrolyte imbalance during the maintenance chemotherapy for disease progression after achieving CR. All 34 patients with seminomas and 18 of the 19 with NSGCTs were alive without evidence of disease after a mean follow up period of 61.1 months (range 4-150 months).

Tenascin expression may reflect the activity and chronicity of human IgA nephropathy

BACKGROUND

Tenascin is a large oligomeric glycoprotein component of the extracellular matrix that increases rapidly after inflammation or injury, suggesting that it may be an indicator of renal disease activity. Histological activity and chronicity indices are currently used to evaluate the activity and chronicity of IgA nephrophathy.

PATIENTS AND METHODS

We investigated whether tenascin staining could be an indicator of activity or chronicity in patients with IgA nephropathy using immunohistochemical and in situ polymerase chain reaction methods. Immunostaining for tenascin was done on 58 renal specimens, (51 from IgA nephropathy patients and 7 from normal kidneys), and the in situ polymerase chain reaction was performed on 24 renal specimens (21 from IgA nephropathy patients and 3 from normal kidneys).

RESULTS

Tenascin expression in the glomeruli was correlated with tenascin expression in the tubulointerstitium (protein; r = 0.386, p = 0.0063, mRNA; r = 0.510, p = 0.0225). Tenascin protein staining in the glomeruli was correlated with the chronicity index (r = 0.506, p = 0.0003), and glomerular tenascin mRNA positivity was correlated with the activity index (r = 0.449, p = 0.0448).

CONCLUSION

Tenascin expression was similar in the glomeruli and tubulointerstitium, but glomerular staining more closely reflected the pathological state. Tenascin protein expression may be an indicator of chronicity and tenascin mRNA expression may be an indicator of disease activity in IgA nephropathy.

Vancomycin therapy for treatment of peritonitis in outpatients on peritoneal dialysis

Vancomycin therapy is frequently used for peritonitis in patients on peritoneal dialysis, but the emergence of resistance has been reported. We evaluated the efficacy of a single intraperitoneal dose of vancomycin for peritonitis in peritoneal dialysis patients. We assessed 24 episodes of peritonitis in 16 patients, and compared clinical parameters between responders and nonresponders. Vancomycin was effective for 12 patients (18 out of 24 episodes, 75.0%). Nonresponders had a significantly higher initial C-reactive protein level and dialysis fluid leukocyte count, and the mean serum albumin over three months before onset was significantly lower than in responders. Patients with a serum albumin level 3.0 g/dl or more were significantly more likely to respond than those with a level less than 3.0 g/dl. In conclusion, it seems reasonable for peritonitis patients with a mild inflammatory response and a serum albumin 3.0 g/dl or more to receive intraperitoneal vancomycin on an outpatient basis.

[Polymyositis-induced respiratory failure in the presence of antecedent pleural effusion]

Pulmonary involvement is generally recognized to be an important determinant of the clinical course in cases of polymyositis. A patient with bilateral pleural effusion as an initial symptom developed respiratory failure due to muscle weakness. Polymyositis was diagnosed on the basis of a muscle biopsy. A chemotherapy regimen consisting of methyl prednisolone (1 g/day for 3 days) followed by prednisolone (60 mg/day) alleviated, the pleural effusion and respiratory failure. Though pleural complications in polymyositis have been described mostly in association with concomitant interstitial lung disease, our patient exhibited only bilateral pleural effusion. Given that pleural effusion can be an initial symptom of polymyositis, it seems necessary that polymyositis be taken into consideration by differential diagnoses of pleural effusion of unknown etiology.

Gonadotropin-releasing hormone-induced elevation of serum hCG in choriocarcinoma: a case report

We evaluated the effect of GnRH on the serum hCG level in gestational trophoblastic disease (GTD). Five patients with GTD were studied. Three patients had hydatidiform mole (two complete and one partial mole) and two had choriocarcinoma. Blood samples were collected immediately before and 30, 60 min after the 100 microg GnRH iv injection, followed by hCG assay. Only one case of choriocarcinoma demonstrated an hCG increase after intravenous administration of GnRH (positive GnRH test). In that case, the hCG level dropped to the normal range after eight cycles of chemotherapy but the GnRH test was still positive, suggesting the existence of viable cancer cells. Since the GnRH test became negative, no increase in hCG has been observed, indicating that the patient achieved complete remission. Although a positive GnRH test is not common in GTD, GnRH test before treatment might be useful to find a positive case where the test can be repeated to determine complete remission and the time when the chemotherapy may be discontinued.

Cardiovascular anomaly, impaired actin bundling and resistance to Src-induced transformation in mice lacking p130Cas

p130Cas (Cas), the protein encoded by the Crkas gene (also known as Cas), is an adaptor molecule with a unique structure that contains a Src homology (SH)-3 domain followed by multiple YXXP motifs and a proline-rich region. Cas was originally cloned as a highly tyrosine-phosphorylated protein in cells transformed by v-Src (refs 2,3) or v-Crk (ref. 4) and has subsequently been implicated in a variety of biological processes including cell adhesion, cell migration, growth factor stimulation, cytokine receptor engagement and bacterial infection. To determine its role in vivo, we generated mice lacking Cas. Cas-deficient embryos died in utero showing marked systemic congestion and growth retardation. Histologically, the heart was poorly developed and blood vessels were prominently dilated. Electron microscopic analysis of the heart revealed disorganization of myofibrils and disruption of Z-disks. In addition, actin stress fiber formation was severely impaired in Cas-deficient primary fibroblasts. Moreover, expression of activated Src in Cas-deficient primary fibroblasts did not induce a fully transformed phenotype, possibly owing to insufficient accumulation of actin cytoskeleton in podosomes. These findings have defined Cas function in cardiovascular development, actin filament assembly and Src-induced transformation.

[A case of primary localized amyloidosis of the urinary bladder]

A case of primary amyloidosis of the bladder is reported. A 59-year-old man visited our hospital with a complaint of gross hematuria. Cystoscopy revealed several elevated lesions with yellowish surface accompanied by proliferated vessels at the posterior wall. Transurethral mucosal biopsy was performed. Histopathological diagnosis was a primary localized amyloidosis of AL type in the bladder. Systemic amyloidosis was clinically excluded. He is followed for 38 months without symptoms but mucosal lesions persisted.

Effects of dialysis membranes on the kinetics of tumor necrosis factor-alpha production by peripheral mononuclear cells in chronic hemodialysis patients

To evaluate the biocompatibility of dialysis membranes, blood samples were collected from 10 hemodialysis patients immediately before dialysis and peripheral blood mononuclear cells were isolated. The 3.0 x 10(5) cells/ml were then passed 30 times through modules made of a polyethylene glycol-grafted cellulose membrane, a polyacrylonitrile membrane, and a polysulfone membrane. Expression of messenger RNA for tumor necrosi factor-alpha (TNF-alpha) was determined. Cells were also cultured for 2 h with and without lipopolysaccharide and TNF-alpha levels in the supernatant were measured. TNF-alpha messenger RNA expression was significantly higher immediately after passage through the polyacrylonitrile membrane compared with the other membranes. Cells cultured without lipopolysaccharide, produced significantly less TNF-alpha after passage through the polysulfone membrane, while lipopolysaccharide significantly increased TNF-alpha production by cells passed through the polyacrylonitrile membrane. These results suggest that biocompatibility differs even among dialysis membranes believed to cause no complement activation.

Long-term therapy with an ACE inhibitor, temocapril, reduces microalbuminuria in essential hypertension

The present study was conducted to prospectively evaluate whether a new ACE inhibitor, temocapril, could modify urinary microalbumin excretion rate (UAE) in a group of hypertensive outpatients who had no evidence of renal impairment. Sixty-three outpatients (32 men and 31 women; mean age, 59.9 +/- 1.5 yr) with essential hypertension entered the study, all having been treated for at least 6 mo with dihydropyridine calcium-channel blockers (CCBs: nitrendipine, nisoldipine, or amlodipine). Their blood pressures (BPs) had been controlled to adequate levels with the CCBs. None had overt proteinuria (determined by Albustix) or abnormal serum creatinine levels. After 3 mo of baseline observation under the previous treatment, the subjects were randomly divided into two groups. In group A (n = 31), the previously used CCBs were switched to temocapril, 2 to 4 mg once daily for 12 mo, and BP was controlled at a level equivalent to that during CCB treatment. In group B (n = 32), the subjects were maintained on their previous treatment for a further 12 mo. The effect of temocapril on BP appeared to be clinically similar to that of the previously used CCBs, but it significantly decreased UAE as compared with the previous therapy. In group A, UAE decreased significantly (p < 0.01) from the baseline value of 38.9 +/- 5.1 mg/g creatinine (Cr) to 22.2 +/- 4.2 and 25.3 +/- 5.6 mg/g Cr at the 6th and 12th months of temocapril therapy, respectively. In contrast, in group B UAE was unchanged (baseline 39.8 +/- 6.6 mg/g Cr; 6 mo, 44.6 +/- 6.8; 12 mo, 45.9 +/- 7.7). In group A, 17 of 31 patients (54.8%) had abnormal UAE levels (> or = 29.5 mg/g Cr) during previous therapy with CCBs, but 6 mo after switching to temocapril 25 of these patients (80.6%) had normal UAE (< 29.5 mg/g Cr). In group B, 15 of 32 patients (46.9%) had abnormal UAE levels during the observation period, and these abnormal UAE levels remained unchanged; 17 of the 32 patients (53.1%) had abnormal UAE levels after a further 6 mo of continued CCBs therapy. We conclude that long-term therapy with temocapril may provide renal protection by reducing UAE even in hypertensive patients with no evidence of renal impairment.

[Recent progress in orthopaedic managements of osteoporosis-related fractures]

Recent progress in orthopaedic treatment of osteoporosis-related fractures was reviewed. In the femoral neck fractures, the bipolar prosthesis reduces acetabular erosion or central migration, and press-fit stem or cemented stem lowers the incedence of the stem sinking. In thorocanteric fractures, compression hip screws are most commonly used, however, in the cases of unstable fractures with severe osteoporosis, it is difficult to start weight-bearing within a few weeks of surgery because varus deformites or translations at the fracture site sometimes occur. To avoid this disadvantage, the gamma nail has been found to be more effective. In paralysis due to burst fractures of the osteoporotic spine, surgical decompression and spinal instrumentation is the established response. A special orthosis named 'rucksack type orthosis' has been devised and is used for patients who have back pain due to anterior bending posture of the trunk. In distal radius fractures, external fixators are now more frequently used.

Exocytotic stimulation promotes association of the ADP-ribosylation factor with PC12 cell membranes

ADP-ribosylation factors (ARFs) are a family of small molecular, monomeric GTP-binding (G) proteins, initially identified by their ability to enhance cholera toxin (CTX) ADP-ribosyltransferase activity. ARFs have been implicated in protein transport and vesicle and endosome fusion. Although several reports show that synthetic peptides of the N-terminus of ARF inhibited Ca(2+)-dependent exocytosis in permeabilized adrenal chromaffin cells, the role of ARFs in exocytosis has not been established. In this study, we investigated the translocation of ARFs to the membrane fraction from the cytosol fraction in PC12 cells after exocytotic stimulation by measuring the immunoreactivity of ARFs (with anti-ARF anti-serum and with anti-ARF3 antibodies) and enzymatic ARF activity, which enhances the CTX effect. Both the immunoreactivity and the enzymatic activity of ARF in the membrane fraction increased about twofold, significantly, after exocytotic stimulation with ATP and KCl. The translocation of ARF and noradrenaline release was observed in the presence of extracellular CaCl2, but not in the absence of CaCl2. The ARF translocated to the membrane fraction after stimulation in intact cells seemed to be an inactive, perhaps is the GDP form, because ARF did not activate CTX in the absence of guanosine 5'-O-(thiotriphosphate) (GTP gamma S). As previously reported, ARF in the active, GTP gamma S-bound state bound to the membrane fractions. Thus ARF may have been active during translocation and inactivated later. The immunoreactivity of Gs alpha, one of the trimeric G proteins, was not changed before or after stimulation. These findings suggest that ARFs translocate to membranes from the cytosolic fraction after exocytotic stimulation in PC12 cells, and raise the possibility that ARFs regulate exocytosis.

Effect of local application of basic fibroblast growth factor on ligament healing in rabbits

OBJECTIVE

The effect of basic fibroblast growth factor (bFGF) on healing of a 4-mm defect in the medial collateral ligament of rabbits was studied.

METHODS

Fibrin gel containing 0 (vehicle only), 0.1, 1, or 10 micrograms of recombinant human bFGF was applied to the defect during the surgical procedure. Controls did not receive fibrin gel. Four rabbits in each group were sacrificed 1, 2, 3, and 6 weeks after surgery. Repair tissues were subjected to gross and histologic examinations, and expression of type I procollagen messenger RNA was evaluated using in situ hybridization after 2 and 3 weeks.

RESULTS

bFGF promoted formation of repair tissue and was associated with early filling of the ligament defect. Tissue maturation was significantly delayed after 3 and 6 weeks in the high-dose bFGF groups. In the low dose group, in contrast, tissue maturation was similar to that in controls at all time points, by both gross and histologic examination. In situ hybridization studies showed that type I procollagen mRNA expression was reduced in all bFGF groups.

CONCLUSION

Our data demonstrate that a single local application of bFGF promoted early formation of repair tissue in injured medial collateral ligaments. High doses of bFGF reduced repair tissue maturation, suggesting that in clinical uses the dose may play a significant role.

Regulation of inducible NO synthase expression by endothelin in primary cultured glial cells

Nitric oxide (NO), initially identified as an endothelium-derived relaxing factor, is a molecular mediator that has been implicated in many physiological and pathological processes. In primary cultured rat glial cells, a combination of inflammatory cytokines (tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta)) and bacterial lipopolysaccharide (LPS) stimulates production of nitrite via expression of the inducible form of nitric oxide synthase (iNOS). In these cells, simultaneous addition of endothelin (ET) markedly inhibited TNF-alpha/IL-1beta-induced and LPS-induced nitrite production and iNOS expression, although ET by itself had no effect. The inhibitory effect of ETs appears to be mediated by ET(B) receptors. Forskolin also inhibited the iNOS expression. By contrast, pretreatment with ET for 24 hours enhanced LPS-induced nitrite production and iNOS expression. This stimulatory effect of ETs was suppressed by calphostin C, a protein kinase C inhibitor, and pretreatment with phorbol ester enhanced LPS-induced iNOS expression. Our findings present the possibility that ET has dual effects on iNOS expression in glial cells.

cDNA cloning and developmental expression of the porcine homologue of WT1

Wilms' tumors occur most frequently in swines as sporadic tumors. To clarify the role of WT1 gene in the genesis of Wilms' tumors and genitourinary development, we have isolated the porcine homologue of the human WT1 gene (pWT1) and analyzed its expression in various organs including the kidney. The open reading frame of pWT1 cDNA was extremely homologous to the human counterpart: 94% identical at the nucleotide level and 98% at the polypeptide level. In particular, the zinc finger region was more than 97% similar to human WT1 gene at the nucleotide level and 100% at the polypeptide level. pWT1 mRNA was found to be expressed in new-born kidney, spleen, testis, and embryonic kidneys, suggesting a possible association of pWT1 with the development of the genitourinary system. In conclusion, the nucleotide sequence and expression patterns in organs of pWT1 were similar to those of human WT1. Therefore, swines could provide good models for analyzing the contributions of WT1 gene to genitourinary development and genesis of Wilms' tumors.

Genetic instability and mutation of the TGF-beta-receptor-II gene in ampullary carcinomas

Ampullary carcinomas are relatively rare cancers of which very little is known in terms of carcinogenetic mechanisms at the molecular level. Genetic instability caused by mutations of mismatch-repair genes has been demonstrated to be responsible for hereditary non-polyposis colorectal cancers and a sub-set of sporadic colorectal cancers. In some of those tumors showing genetic instability, the transforming-growth-factor-beta(TGF-beta)-receptor-II gene has been found to be mutated in repetitive sequences and considered to be a target of replication error. We studied the role of genetic instability and associated TGF-beta-receptor-II-gene mutations in a series of 18 sporadic cases by analyzing 5 microsatellite loci (D2S123, D3S1029, D5S409, TP53 and BAT26) and by sequencing a poly-A repeat (nucleotides 709-718) in the TGF-beta-receptor-II gene. Microsatellite instability was observed in 4 (22.2%) and gene mutations in 14 (77.8%) cases. These data indicate that the TGF-beta-receptor-II gene might be a preferential target of genetic instability whose alteration might be specifically advantageous and constitute a common step in the development of ampullary carcinomas.