[Development of anti cancer drugs targeted on Fas-mediated apoptosis signal]

The elimination of tumor cells by cytotoxic T lymphocytes (CTLs) is, in part, executed by inducing apoptosis through the cell surface antigen Fas on the target cells. There are many cancer cells that resist Fas-mediated apoptosis. To elucidate the mechanism of this resistance is very important to understand the process of tumor development. We focused on FAP-1 (Fas-associated phos phatase-1), a negative regulator of Fas-mediated apoptosis. The expression of FAP-1 was detected in many colon cancer cell lines. On the other hand no FAP-1 expression was detected in the normal colon tissue. We have found that the tri-peptide of Fas C-terminus inhibited the binding of Fas and FAP-1 in vitro. Microinjection of the tri peptide (Ac SLV) could induce Fas-mediated apoptosis in the DLD 1 human colon cancer cell line that was resistant to anti-Fas-antibody. These findings suggest that the interaction of Fas and FAP-1 has a very important role in Fas-mediated apoptosis signal transduction. The inhibition of the Fas/ FAP-1 binding will provide a good target to develop anti-cancer drugs.

Differentiation induction therapy with all-trans retinoic acid (ATRA) in a patient with secondary 11q23 leukemia

PURPOSE

Frequently recurrent leukemia is encountered in childhood and is usually resistant to multidrug therapy. We evaluated the efficacy of differentiation induction therapy in a child with leukemia.

PATIENT AND METHODS

We administered all-trans retinoic acid (ATRA) alone, and then a combination of low-dose 1-beta-D-arabinofuranosylcytosine (Ara-C), to a 7-year-old boy who had leukemia secondary to etoposide with chromosomal abnormality 11q23.

RESULTS

The patient exhibited a good response to ATRA and had a complete remission after combination therapy of ATRA and low-dose Ara-C.

CONCLUSION

Differentiation induction therapy with ATRA was effective in treating a patient with recurrence of leukemia without t(15;17) translocation, and which is resistant to conventional cytotoxic treatment.

Inhibition of vascular smooth muscle cell proliferation by the calcium antagonist clentiazem: role of protein kinase C

The proliferation of vascular smooth muscle cells has been implicated as a causative factor in atherogenesis. Calcium channel blockers have been shown to retard the progression of atherosclerosis. To elucidate the mechanism by which these drugs mediate such actions, we studied the effects of a new calcium antagonist, clentiazem, on the in vitro proliferation of vascular smooth muscle cells. PDGF-induced prolifertion of these cells is markedly inhibited by clentiazem. The probable involvement of protein kinase C (PKC) in this cellular response is suggested. Clentiazem appear to cause inhibition of PKC translocation that is induced by phorbol esters and PDGF-BB and the phosphorylation of the 80 kDa protein substrate of PKC in vascular smooth muscle cells. Moreover, treatment with clentiazem leads to a marked decrease in the number of specific phorbol ester binding sites. Analysis of the membrane bound isoenzymes of protein kinase C revealed that the inhibition was specific to delta enzymes. Arterial cholesterol ester hydrolysis is not significantly altered by clentiazem. Our results suggest that clentiazem may inhibit cell proliferation by regulating cytosolic PKC and preventing its membrane translocation and activation.

Analysis of Met235 to Thr variant of the angiotensinogen gene in relation to the blood pressure and family history of essential hypertension in Japanese children

A recent study reported a significant relationship between a T704-->C (Met235-->Thr) variant in exon 2 of the angiotensinogen gene in adults and essential hypertension. In the present study, this variant was detected in 131 Japanese children using a polymerase chain reaction. The allele frequency of the variant was 0.76. The genotype frequency of the homozygote for the allele was 0.59, and children who were homozygous had higher systolic blood pressure than those with the other two genotypes. No relationship was found between children's polymorphism and a family history of essential hypertension. These findings suggest that this molecular variant of the angiotensinogen gene may play some role in the regulation of blood pressure in Japanese children.

Binding affinity and particle size of LDL in subjects with moderate hypercholesterolemia: relationship with in vivo LDL metabolism

The aim of this study was to examine relationships between low density lipoprotein (LDL) metabolism, in vitro binding, and particle size. Twenty four study subjects, 17 men and 7 women, had elevated plasma total cholesterol (TC), ranging from 174 to 232 mg/dl, and LDL cholesterol (LDLC) ranging from 113 to 195 mg/dl after 12 weeks on a Step I diet. The fractional clearance rate (FCR) for LDL ranged from 0.233 to 0.619 pools/day (0.366 +/- 0.021) and was significantly correlated with plasma triglycerides (TG) (P < 0.05). Although there was no relation between FCR and binding in the study group as a whole, those subjects with an FCR within the normal range (< 0.45, n = 20), showed a significant negative correlation between FCR and the KD for LDL binding, (r = 0.52). A subset of four subjects with an elevated FCR (> 0.45) had higher production rate (PR) (P < 0.005) and a significant positive correlation between the KD for LDL binding and FCR (P < 0.05). LDL size varied from 240.0 to 265.8 A and was significantly inversely correlated with plasma TG (P < 0.001) but there was no relation between LDL size and metabolism or binding affinity. Thus, there appears to be a correlation between binding affinity and clearance for subjects who had normal LDL production and clearance rates. On the other hand, mechanisms other than binding affinity appear to influence clearance in subjects with elevated rates of production and clearance.

Apolipoprotein E polymorphism in American Indians and its relation to plasma lipoproteins and diabetes. The Strong Heart Study

Apo E is an important genetic factor in the development of cardiovascular disease, which is the leading cause of death among American Indians. We investigated the occurrence of the apo E alleles and the relation between apo E polymorphism and blood lipoproteins and apoproteins in members of 13 American Indian communities in three geographic areas. The frequencies of the epsilon 2 alleles in American Indians are significantly lower than those in white Americans, with the lowest frequencies of epsilon 2 in American Indians who reside in Arizona. Levels of LDL cholesterol and apo B were highest in those with epsilon 4 and lowest in those with epsilon 2. Concentrations of HDL cholesterol and apo A-I, however, tended to be lowest in epsilon 4 and highest in epsilon 2. Concentrations of total and VLDL triglycerides were lowest in the epsilon 3 group and higher in groups epsilon 2 and epsilon 4. Differences in concentrations of LDL cholesterol, HDL cholesterol, apo B, and apo A-I with apo E polymorphism were greater in women than in men, and differences in total and VLDL triglyceride concentrations by apo E phenotype were greater in men. Relations of total and VLDL triglycerides with apo E phenotype were stronger in women after menopause. In addition, differences in nearly all lipid and apoprotein concentrations between postmenopausal women and premenopausal women were greater if they had epsilon 2. Relations between apo E phenotype and lipoproteins were seen in individuals with diabetes mellitus as well as in nondiabetics. Apo E was significantly related to glucose control in diabetic women; those with epsilon 3 had higher glucose and hemoglobin A1C concentrations. Our findings show that (1) American Indians have low frequencies of apo epsilon 2; (2) apo E phenotype can influence levels of VLDL, LDL, HDL, apo B, and apo A-I; (3) the associations of apo E polymorphisms with lipid parameters differ between men and women; and (4) the associations in women of apo E polymorphisms with lipid parameters are modified by menopausal status.

[Cancer chemotherapy and apoptosis]

Tumor cells undergo apoptotic cell death when treated with several chemotherapeutic agents. Since these agents, acting on different cellular targets, induce a similar pattern of cell death (apoptosis), it is suggested that a common signaling pathway of apoptosis could exist and that apoptosis resistance could cause a new form of multi-drug resistance in tumor cells. Although the mechanisms of apoptosis are not fully understood, the involvement of ICE/ced-3 family proteases in chemotherapy-induced apoptosis is strongly suggested. Identification of factors directly acting on these apoptosis pathway will offer new strategies in cancer chemotherapy.

Antiperoxidative components in Thymus vulgaris

A biphenyl compound, 3,4,3',4'-tetrahydroxy-5,5'-diisopropyl-2,2'-dimethylbiphenyl (1), and a flavonoid, eriodicytol (2), were isolated as antioxidative components from the leaves of Thymus vulgaris by bioassay-directed fractionation. These compounds inhibited superoxide anion production in the xanthine/xanthine oxidase system. Mitochondrial and microsomal lipid peroxidation induced by Fe(III)-ADP/NADH or Fe(III)-ADP/NADPH were also inhibited by these compounds. Compound 1 is an extremely potent antioxidant; complete inhibition was observed at 1 microM against both microsomal and mitochondrial peroxidation. Furthermore, compound 1 protected red cells against oxidative hemolysis. These phenolic compounds were shown to be effective to protect biological systems against various oxidative stresses.

[Clinicopathologic study of mitral regurgitation due to abnormal chordae tendineae]

Severe mitral regurgitation (MR) due to abnormal chordae tendineae as a primary cause is rare. This clinicopathologic study included four such cases which occurred among 6,500 consecutive autopsies on persons older than 60 years. This paper describes three of these cases. Case 1 was a 76-year-old woman with congestive heart failure, MR and atrial fibrillation. She died of acute myocardial infarction. The heart weighed 360 g. Mitral regurgitation was caused by a thick and long abnormal chorda originating from the posteromedial papillary muscle and protruding into the atrial surface of the middle scallop of the posterior mitral leaflet associated with prolapsed anterior mitral leaflet. Case 2 was an 81-year-old woman with MR and congestive heart failure. She died of acute myocardial infarction. The heart weighed 480 g. There were abnormal chordae tendineae with very few branches at the posterior commissure. Parts of both mitral leaflets on the sides of posterior commissure were also prolapsed. Case 3 was a 91-year-old man with MR and atrial fibrillation. He died of congestive heart failure. The heart weighed 530 g. Abnormal chordae tendineae with reticular structures originated from the anterolateral papillary muscle and protruded into the anterior mitral leaflet, which induced severe MR. These cases had abnormally protruding chordae tendineae, abnormal branching, and abnormal structures of the chordae tendineae, respectively. These abnormal chordae tendineae were considered to be congenital anomalies. Clinically all patients had a holosystolic murmur (Levine III-IV degrees), refractory congestive heart failure and atrial fibrillation. The etiology of the MR in these three patients was suspected to be ruptured chordae tendineae demonstrated on echocardiograms. These patients had heavy hearts (mean 457 g) with enlarged left atria and thickened mitral valves, which corresponded to the appearance of severe MR.

A recessive mutant of the U937 cell line acquired resistance to anti-Fas and anti-p55 tumor necrosis factor receptor antibody-induced apoptosis

Human monocytic leukemia U937 cells readily undergo apoptosis when cells are treated with various stimuli including antitumor agents, tumor necrosis factor (TNF)-alpha and anti-Fas antibody. However, the signal transduction mechanism resulting in apoptosis is unclear. To study the mechanism of apoptosis, we isolated and characterized a mutant, UK110, from U937 cells, which was resistant to TNF-alpha and anti-Fas antibody-induced apoptosis but was less resistant to etoposide-induced apoptosis. TNF-alpha induced signals are mediated by two types of TNF receptors (TNFR), p55- and p75-TNFR, and p55-TNFR is homologous to the Fas antigen. Interestingly, UK110 cells showed resistance to apoptosis by agonistic anti-p55-TNFR antibody, indicating that UK110 cells were resistant to Fas- and p55-TNFR-mediated apoptosis. Because expression of apoptosis-associated molecules, such as c-Myc, Bcl-2, and Bax, was similar between U937 and UK110 cells an undetermined pathway for apoptosis through Fas and p55-TNFR could be mutated in UK110 cells. To clarify the genetic phenotype of UK110 cells, we performed somatic cell hybridization with parental U937 and the UK110 cells. All of the hybrid clones were as sensitive as the parental U937 cells to apoptosis by both anti-Fas and anti-p55-TNFR antibodies, indicating that the apoptosis resistance in UK110 cells resulted from recessive genotype.

Candidemia in non-neutropenic patients with an intravenous hyperalimentation catheter: good prognosis of Candida parapsilosis infection

Positive blood cultures reported between 1986 and 1993 at the Tokyo Metropolitan Komagome Hospital were evaluated and all patients with an intravenous hyperalimentation catheter who developed candidemia, a total of 94 patients, were analyzed further, while patients with neutropenia were excluded. The primary diagnosis was malignancy in 87.2% of the cases, and Candida albicans and C. parapsilosis were the main organisms detected. A total of 17 patients died from candidemia. The patients who were positive for C. parapsilosis, however, all survived in spite of the fact that their main treatment was only removal of the catheter (20/32 cases), while eight of 25 patients who developed fungemia due to C. albicans died from the fungemia (p = 0.001). There were no significant differences in their risk factors. Because of the better outcome for the patients who developed candidemia due to C. parapsilosis, we might be able to consider less aggressive treatment for such patients.

Recognition of 2'-hydroxyl groups by Escherichia coli ribonuclease HI

In order to investigate the hydrogen-bonding interactions between Escherichia coli ribonuclease HI and the 2'-hydroxyl functions of the substrate, oligonucleotide duplexes containing 2'-amino-2'-deoxyuridine or 2'-fluoro-2'-deoxyuridine at a specific site were used, and their affinities for the enzyme were determined by kinetic analyses. The results indicate that the hydroxyl groups of the nucleoside 3'-adjacent to the cleaved phosphodiester linkage and the second nucleoside 5' to the cleaved phosphodiester act as both a proton donor and an acceptor and as a proton acceptor, respectively, in the enzyme-substrate complex. A molecular model was constructed using the interactions derived from the results.

Aspartate-based inhibitor of interleukin-1 beta-converting enzyme prevents antitumor agent-induced apoptosis in human myeloid leukemia U937 cells

We found that a novel protease inhibitor, benzyloxycarbonyl-Asp-CH2OC(O)-2,6-dichlorobenzene (Z-Asp-CH2-DCB), which can preferentially inhibit interleukin-1 beta-converting enzyme (ICE), completely blocked the apoptotic cell death of human myeloid leukemia U937 cells caused by etoposide, camptothecin, 1-beta-D-arabinofuranosyl-cytosine and Adriamycin, as well as TNF-alpha, anti-Fas antibody and staurosporine. However, Z-Asp-CH2-DCB did not block non-apoptotic cell death of U937 cells caused by etoposide during prolonged incubation periods. These results indicate that ICE or ICE-like proteases inhibited by Z-Asp-CH2-DCB are involved in a common pathway of apoptotic cell death in U937 cells.

Anti-CD40 monoclonal antibody induces the proliferation of murine B cells as a B-cell mitogen through a distinct pathway from receptors for antigens or lipopolysaccharide

To study the activation and differentiation of murine B cells, we prepared a hybridoma secreting monoclonal antibody, LB429, which can directly induce the proliferation of murine B cells in vitro. LB429 recognizes a B cell specific surface molecule of 45 kDa. It recognizes an epitope of murine CD40 produced as a soluble fusion protein with glutathione S-transferase. LB429 stains COS-7 transfectant with murine CD40 cDNA and mature B-cell lines but does not stain pre-B cell lines. Two color staining demonstrated that the epitope recognized with LB429 appears on the surface of B220+ cells of spleen and bone marrow. LB429 can induce a strong proliferation of murine B cells from spleen in the absence of initial triggering with anti-IgM antibody or with anti-IgM antibody + IL-4. LB429 induced the cell size enlargement and the cell cycle transition of resting B cells as well as lipopolysaccharide (LPS). LB429 and LPS stimulate B cells synergistically in vitro by accumulating 44.7% of cells in S/G2/M phases of cell cycle. However, stimulation of spleen B cells with LB429 resulted in the increase of sIgM high+ sIgD(high)+ B cells, in contrast LPS showed the proliferation of both sIgM(high)+ sIgD(high)+ B cells and sIgM(low)+ sIgD(high)+ B cells. These results suggested that LB429 and LPS cause the proliferation of B cells through different stimulatory pathways. This anti-mouse CD40 antibody (LB429) is a very useful reagent to study the activation and differentiation of B cells in vitro.

Resistance to antitumor agent-induced apoptosis in a mutant of human myeloid leukemia U937 cells

Human monocytic leukemia U937 cells underwent apoptosis when the cells were treated with a variety of antitumor drugs. We isolated and characterized a mutant, UK711, that was resistant to apoptosis induced by antitumor agents. When U937 cells were treated with etoposide (VP-16), an inhibitor of DNA topoisomerase II, apoptosis occurred in a large number of cells, and flow-cytometric analysis revealed that the majority of cells in S phase underwent apoptosis within 2 h of the end of treatment. Such treatment, however, induced apoptosis in only a few UK711 cells. The levels of protein-DNA covalent links and DNA double-strand breaks caused by VP-16 were similar in both cell lines, indicating that the initial DNA damage caused by VP-16 were comparable, whereas the following cellular responses that resulted in apoptosis differed between these cell lines. UK711 cells also showed resistance to apoptosis induced by such antitumor agents as 1-(beta-D-arabinofuranosyl) cytosine (Ara-C), adriamycin, mitomycin C, camptothecin, and by cytotoxic stimuli such as staurosporine, cycloheximide, and uv irradiation. UK711 cells, however, were sensitive to apoptosis induced by tumor necrosis factor (TNF), as were U937 cells. In accordance with resistance to apoptosis induced by antitumor agents, UK711 cells showed significant actual drug resistance to these antitumor agents. The present results indicate that UK711 cells acquired resistance to apoptosis induced by a variety of cytotoxic stimuli resulting in actual anticancer drug resistance. This cell line may be useful in studying the mechanism of apoptosis induced by cytotoxic agents.

A novel method for concentrating urinary type IV collagen based on precipitation with polyethylene glycol: application to its measurement by enzyme immunoassay

We investigated the efficacy of polyethylene glycol (PEG) for effective and reproducible concentration of urinary type IV collagen prior to measurement by enzyme immunoassay (EIA). Human placental type IV collagen at low concentrations (5 and 10 micrograms/L) and urinary type IV collagen were readily precipitated by PEG-4000 added at a concentration of about 150 g/L in the presence of 0.5 g/L gamma-globulin. Type IV collagen measurement by EIA from PEG-concentrated urine samples showed complete recovery and good reproducibility. Analysis of size distribution by Sephacryl S-300HR gel chromatography and Western blotting following polyacrylamide gel electrophoresis confirmed that type IV collagen in PEG-concentrated urine samples was of high molecular weight comparable to that of human placental type IV collagen. After PEG concentration, type IV collagen was detectable by EIA even in the urine of healthy subjects. Significantly higher concentrations of urinary type IV collagen were found in 30 diabetic patients with nephropathy than in 20 healthy subjects [99.5 (8.9) micrograms/L, mean (SEM) versus 21.4 (2.6) micrograms/L, P < 0.0001]. Thus, urinary type IV collagen can be measured effectively by EIA following concentration with PEG. This method has potential for the assessment of the progression of diabetic nephropathy.

Antigenic phenotypes of Escherichia coli in urine from patients with urinary tract infections

Various antigenic phenotypes of Escherichia coli in urine were analysed using monoclonal antibody against pyelonephritis-associated P-pili (PAP-pili), and polyvalent O- and K1-antisera, and the results were compared with the clinical diagnosis. PAP-pili, O1- and K1-positive E. coli were isolated more frequently in urine from patients with acute pyelonephritis. E. coli found in urine from patients with recurrent pyelonephritis were frequently PAP positive. Based on the antigenic phenotypes of strains in urine, it is suggested that pyelonephritopathogenic strains may originate from a small number of clones.

Production and characterisation of monoclonal antibodies against pyelonephritis-associated P-pili of Escherichia coli

Pyelonephritis-associated P-pili (PAP) of Escherichia coli O6,H(-),K1(-),F12,haemolysin(-) were purified by salt precipitation and affinity chromatography using Synsorb P1. Purified PAP showed a single band with a molecular weight of 18 kDa by electrophoretic analysis. A monoclonal antibody (mAb) was produced by fusion of the PAI myeloma cell line with splenic lymphocytes from BALB/c mice immunised with the purified PAP. The mAb was of IgM class with kappa light chains and reacted with a 18-kDa moeity of the salt precipitate; the epitope was present near the apical part of the pilus filaments. The mAb reacted with PAP in both immunofluorescence and haemagglutination tests when 108 strains isolated from urine samples were tested; the two tests were in agreement for 202 of 204 strains isolated from faecal samples.

Multiple subcellular localization of bcl-2: detection in nuclear outer membrane, endoplasmic reticulum membrane, and mitochondrial membranes

The use of biochemical fractionation, immunofluorescence laser-scanning confocal microscopy, and immunoelectron microscopy with mouse anti-human bcl-2 monoclonal antibody to analyze the subcellular localization of the bcl-2 gene product revealed the protein prominently in the nuclear envelope, endoplasmic reticulum membrane, and mitochondrial membranes. Electron microscopy at high magnification more precisely localized bcl-2 to the nuclear outer membrane as confirmed by the biochemical fractionation, as well as to mitochondrial outer and, to a lesser degree, inner membrane. This multisite membrane distribution of bcl-2 suggests an important role for this protein in several different membrane compartments.

Apoptosis of T lymphoma cells and its inhibition by monoclonal antibodies against cell surface adhesion molecules

We previously established the malignant T lymphoma CS-21 cell line from a spontaneously developed lymphoma in a BALB/c mouse. CS-21 cells produce lymph node metastasis with a high incidence following s.c. injection. CS-21 lymphoma cells grew continuously when the cells were co-cultured under the cell-cell attached conditions with stromal cells prepared from lymph nodes. However, they were unable to proliferate by themselves and underwent apoptosis when separated from the lymph node stromal cells. To identify the cell adhesion molecules of CS-21, we developed monoclonal antibodies (mAbs) directed against CS-21 cell-surface proteins. Fourteen mAbs partially inhibited the binding of CS-21 cells to a CA-12 stromal cell monolayer. MCS-5 (mAb against CS-21 No. 5) directed against a 168-kDa cell-membrane protein and MCS-19 against a 23-kDa protein were found to suppress apoptosis and stimulate CS-21 cell growth. Soluble factors secreted from CA-12 stromal cells enhanced CS-21 cell growth but were not sufficient to prevent apoptosis. In the presence of both stromal cell-secreted factors and mAbs MCS-5 or MCS-19, CS-21 lymphoma cells resisted apoptosis and grew as quickly as in the co-culture with CA-12 stromal cells. Based on these results, we conclude that CA-12 lymph node stromal cells support CS-21 lymphoma cell growth by secreting paracrine growth factors and presenting receptors for the 168-kDa and 23-kDa cell surface adhesion molecules of CS-21 cells that transmit signals to prevent CS-21 cell apoptosis.

Simplified isoelectric focusing/immunoblotting determination of apoprotein E phenotype

We developed a rapid, accurate method for phenotyping apoprotein E that can be used for large-scale population studies. In this method, adapted from the method of Kamboh et al. (J Lipid Res 1988;29:1535-43), 10-microL plasma samples are incubated with dithiothreitol and Tween-20 for 15 min and then applied to 5% polyacrylamide gels containing ampholyte (pH 4.5-8) and urea (3 mol/L). After 2 h of isoelectric focusing, the apoprotein E bands are made visible by immunoblotting. Utilizing whole plasma, this method does not require time-consuming ultracentrifugation, delipidation of samples, or dialysis. Small amounts of plasma are required, electrofocusing time is short, and as many as 160 samples can be processed per day. Identification of phenotype is easily accomplished by noting the location and number of protein bands instead of their intensity. Because identification of phenotype is not affected by sialylation, neuraminidase treatment is not necessary. Agreement in identification of 301 individuals from blinded duplicates was 96%, and there was 98% concordance of results for 431 samples that had undergone genetic typing. This method is thus well suited for large-scale population studies.

Simplified isoelectric focusing/immunoblotting determination of apoprotein E phenotype

We developed a rapid, accurate method for phenotyping apoprotein E that can be used for large-scale population studies. In this method, adapted from the method of Kamboh et al. (J Lipid Res 1988;29:1535-43), 10-microL plasma samples are incubated with dithiothreitol and Tween-20 for 15 min and then applied to 5% polyacrylamide gels containing ampholyte (pH 4.5-8) and urea (3 mol/L). After 2 h of isoelectric focusing, the apoprotein E bands are made visible by immunoblotting. Utilizing whole plasma, this method does not require time-consuming ultracentrifugation, delipidation of samples, or dialysis. Small amounts of plasma are required, electrofocusing time is short, and as many as 160 samples can be processed per day. Identification of phenotype is easily accomplished by noting the location and number of protein bands instead of their intensity. Because identification of phenotype is not affected by sialylation, neuraminidase treatment is not necessary. Agreement in identification of 301 individuals from blinded duplicates was 96%, and there was 98% concordance of results for 431 samples that had undergone genetic typing. This method is thus well suited for large-scale population studies.

High-molecular-weight hyaluronic acids inhibit chemotaxis and phagocytosis but not lysosomal enzyme release induced by receptor-mediated stimulations in guinea pig phagocytes

The effects of high-molecular-weight (HMW) hyaluronic acids (HAs) of 1.9 x 10(6) Da, 8 x 10(5) Da and 3 x 10(5) Da on the receptor-mediated functions of guinea pig peritoneal phagocytes were studied. HMW-HAs of 1.9 x 10(6) Da (HA190) and 8 x 10(5) Da (HA80) effectively inhibited the chemotactic activity of polymorphonuclear leukocytes (PMNs) for formyl-Met-Leu-Phe (fMLP). The degree of inhibition was dose-dependent and the concentrations of HA190 and HA80 required for 50% inhibition were 0.5-1.5 mg/ml and 1.5-2.5 mg/ml, respectively. HMW-HA of 3 x 10(5) Da (HA30) hardly affected the chemotaxis within a concentration range of 0.5-5.0 mg/ml. The phagocytic activities of PMNs and macrophages (Mphis) for serum-opsonized zymosan (SOZ) and polystyrene latex particles were also inhibited by these HAs in a dose- and molecular-weight-dependent manner and HA190 was again the most inhibitory. By contrast, the release of lysosomal enzyme from Mphis stimulated with SOZ was not significantly affected by HMW-HAs at any concentration used. Furthermore, the binding of [3H]fMLP with PMNs and the rosette formation of Mphis with SOZ were not influenced by the presence of HMW-HAs. These findings suggested that the binding of HMW-HAs to the HA receptors on PMNs and M phi s might produce certain intracellular signals which would be responsible for the suppression of the chemotaxis and the phagocytosis but not for the release of lysosomal enzyme. For the generation of such signals, higher-molecular-weight HMW-HAs would be more effective than lower one.

[Clinical results of radical surgery for prostate cancer]

We reported the clinical results of radical surgeries for 44 patients with prostate cancer performed between November 1984 and December 1992. The patients were aged from 57 to 79-year-old (mean 67.2) and classified as clinical stage A2 (6 cases), B1 (7), B2 (12), C (16) and D1 (3) respectively. Radical prostatectomy was performed in 42 cases and radical cystoprostatectomy with urinary diversion in 2 patients, and thirty-nine of 44 cases underwent endocrine or chemoendocrine therapies prior to the surgeries. In all patients with stage A2-B1, the operations were curative, on the other hand, more than 80% of clinical stage B2 patients had pT3 tumors and 33.3% of them had lymph node involvements. With regard to stage C patients, the incidence of lymph node metastasis and positive margin was more frequent. Postoperative adjuvant therapies were added to the patients with pT3,4 tumors and nodal involvements. Patients without residual tumors (n = 20) remained disease-free for 8-89 months (mean 32.8). Of 24 patients who had incomplete resection of tumors, 2 died of other diseases, other 2 were alive recurrent and 20 were alive free from disease for 3-99 months (mean 33.8). The surgical indication for low-stage (A2-B2) prostate cancer has been widely accepted, however that for high-stage cancer (C,D1) has remained controversial. It was our belief that radical surgeries for high-stage cancer could become a potentially curative therapeutic modality in combination with pre- and post-operative adjuvant therapies.