Seventh International Conference on prostaglandins and related compounds was held in Florence, May 28-June 1, 1990. Clinical investigation of prostaglandins has been actively performed since the 1st conference held more than 20 years ago. Some of natural prostaglandins and their analogs have been launched in the obstetrical, gastrointestinal and cardiovascular areas. In addition, a thromboxane synthetase inhibitor, ozagrel·Na, has been recently launched for the prevention and treatment of cerebral vasospasms following subarachnoid heamorrhage. Prostaglandins and related compounds including thromboxane and leukotriene synthetase inhibitors and their receptor antagonists will be defined their clinical potential in the near future.
This report reviews clinical studies with those compounds.

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Using a zymosan-induced air pouch type inflammation model in rats, effects of dexamethasone, indomethacin and AA-861 on vascular permeability during a period of 30-60 min after the zymosan challenge and levels of prostaglandin (PG) E₂ and peptide leukotrienes (LTs) in the pouch fluid were examined in order to get further insight into a mechanism of anti-inflammatory action of glucocorticoids. At this period, levels of peptide LTs, PGE₂ and histamine in the pouch fluid were high.
Although AA-861 suppressed LTs production, only a weak but significant suppression of vascular permeability was obtained. PGE₂ production was also inhibited dosedependently by AA-861. Indomethacin treatment inhibited both PGE₂ production and vascular permeability response without affecting peptide LTs production. Consequently, inhibition of vascular permeability by AA-861 might be due to the inhibition of PGE₂ production. Steroidal anti-inflammatory drug dexamethasone which had been injected subcutaneously 3 hr prior to the zymosan challenge, inhibited both PGE₂ and peptide LT production. Although the inhibitory effect by dexamethasone of arachidonate metabolites production was not so potent as AA-861 and indomethacin, vascular permeability response was strongly suppressed. Combined treatment with indomethacin, pyrilamine and methysergide almost completely suppressed the vascular permeability response suggesting that histamine and serotonin released from subcutaneous mast cells are partly responsible for the vascular permeability increase. Dexamethasone treatment suppressed the vascular permeability without affecting histamine release.
These results indicate that some other mechanisms than the inhibition of arachidonate metabolism underlie for the anti-inflammatory action of the steroid.

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To clarify a role of neutrophil lysosomal proteinases in periodontal tissue breakdown, their nature in neutrophils and their levels in gingival crevicular fluid (GCF) of periodontitis patients were investigated. When the distribution of these proteinases in the neutrophil granular subfractions was analyzed, cathepsins B and H were made soluble by hypotonic shock. Cathepsins L and G were made soluble after washing the membrane with 1M NaCI. On the other hand, about 30% of hemoglobin (Hb) -hydrolase (s) was tightly associated with the membrane after both treatments. Immunochemical analyses revealed that about 35% of the total Hb-hydrolase activity was attributed to cathepsin D, which was found in the content fraction, and the rest were due to pepstatin-insensitive serine proteinase (s) . Differing from rat neutrophils, human neutrophils do not contain cathepsin E. The ratio of cathepsin D to the serine proteinase (s) in neutrophils was not changed in GCF from periodontitis patients and these enzymes were associated with development of the disease.
The quantity of cathepsin B in GCF of periodontitis patients determined by enzyme immunoassay was closely correlated with that by activity measurement, indicating that cathepsin B increases with the increase of severity of the disease and that its level in GCF can be inferred by activity measurement.

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The peripheral blood mononuclear cells (PBMC) from healthy volunteers and patients with rheumatoid arthritis (RA) at different stages were examined for their proliferation and growth factor production in response to 12-O-tetradecanoyl phorbol-13-acetate (TPA) .
The mitogenic response and the factor production supporting the growth of pokeweed mitogen (PWM) -stimulated lymphoblasts, which were induced independently upon IL-2 production, were significantly higher in RA-PBMC than those in PBMC from healthy volunteers. A RA drug, salazosulfapyridine (SASP) was examined for its suppressive effect on these IL-2-independent proliferation induced by TPA. The results showed that SASP at concentrations greater than 20-50μg/ml significantly suppressed the mitogenic response of PBMC to TPA. The drug also showed a suppressive effect on another IL-2-independent proliferation of PBMC induced by heat-killed Streptococcus pyogenes (OK-432), which was also a phenomenon mediated independently of IL-2 production.
The significance of this suppressive effect of SASP was proposed as an experimental model for studying the therapeutic effect of SASP on RA diseases.

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Lobenzarit disodium (CCA) is an immunomodulating anti-rheumatic drug, and is reported to show inhibitory effects on B-cell activation. To further analyze the direct effects of CCA on B cells, we examined the effects of CCA on Ig-production in vitro by murine B cells stimulated with murine T cell-derived B-cell stimulation factor, B 151-TRF 2 which induces a polyclonal differentiation into Ig-secreting cells including autoantibody production.
CCA inhibited Ig-production induced by B 151-TRF 2. This result suggests that the inhibitory effect of CCA on Ig-production is one of the mechanism of CCA action on autoimmune disease, because B 151-TRF 2 is reported to be closely associated with the onset of autoimmune disease. In contrast, CCA did not inhibit Ig-production induced by LPS.
These results demonstrate that the induction process of Ig-production by B 151-TRF 2 is differ from that of Ig-production by LPS, and that the effective point of CCA is associated with this difference.

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A glomerulonephritis was induced in mice by injection of subnephrotoxic dose of nephrotoxic serum (NTS) after preimmunization with rabbit IgG. In order to characterize this glomerulonephritis, light, electron and immunofluorescence microscopic studies were carried out 15 days after NTS injection, the time when increases in urinary protein and serum cholesterol and a decrease in serum albumin were apparent.
Characteristic changes were widespread thickening of capillary walls and narrowing of the capillary lumen owing to widening of mesangial areas. In those capillary walls, the mesangial interposition into subendothelial areas was often noted ultrastructurally and double track was confirmed on sections stained with PAM. Linear deposition of mouse IgG was detected in capillary walls by immunofluorescence. In severely affected glomeruli, PAS-positive hyaline nodular lesion was observed light microscopically and massive mesangial deposits ultrastructurally.
Visceral epithelial cells demonstrated fusion of the foot processes, microvilli formation, occasional proliferation and enlargement. Parietal epithelial cells proliferated, forming cellular or fibrocellular crescent.
Based on these characteristics, it appears this nephritic model shares a common pathology with human membranoproliferative glomerulonephritis type 1 and crescentic glomerulonephritis and can be considered an appropriate model for producing severe nephritis for short periods.

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Hydroperoxyeicosatetraenoic acids (HPETEs), hydroperoxy intermediates of arachidonic acid, have been recently reported to play an important role in regulating and modulating various cell functions such as secretion of hormones.
As for neutrophils, 5-HPETE produced by various stimuli is known to enhance the function of primary stimulus such as FMLP. In the present study, we firstly confirmed that 5-HPETE enhanced FMLP-stimulated superoxide generation, which was chosen as one of neutrophil functions. In order to clarify the possible mechanism of the enhancing effect of 5-HPETE, we measured the increase in cytosolic free calcium, which is thought to be necessary for FMLP-stimulated neutrophil activation, using fura-2-loaded human neutrophils. We have shown that 5-HPETE dose-dependently augumented FMLP-stimulated increase in cytosolic free calcium without converting to LTB₄. 5-HPETE had no effect on ³H-FMLP binding to human neutrophils.
The present data suggested that 5-HPETE by itself would enhance FMLP-stimulated increase in cytosolic free calcium, which resulted in neutrophil activation.

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We studied a case of systemic lupus erythematosus with massive pleural effusion accompanying neutrophil predominant infiltration. The presence of immune complexes and the low complement level in the effusion suggested an activation of the complement system in the pleural cavity. The effusion contained strong neutrophil chemotactic activity in the morphological polarization assay and the Boyden's chamber. From the molecular size and heat stability of the chemotactic activity, the neutrophil chemotactic factors were suggested to be C5a and the related moleules. The effusion also contained trypsin-like amidase activities against chromogenic peptide substrates. One of them was identified to be plasmin.
These results suggested that the marked effusion of the lupus pleuritis might be resulted from the neutrophil dependent vascular permeability enhancement mechanism with participation of the complement system and probably other plasma cascades.

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To investigate the mechanism of OK-432 induced pleurodesis in carcinomatous pleuritis, we studied procoagulant activity (PCA) of mononuclear cells in pleural fluids. Five patients with primary lung cancer and carcinomatous pleuritis were studied. Before intrapleral administration of OK-432, pleural fluids and peripheral blood were taken and separated into mononuclear cells using Ficoll-Paque Method. Monouclear cells were incubated with several concentrations of OK-432 for twenty hours. PCA was measured using a one-stage coagulation assay. Mononuclear cells both in pleural fluids and in peripheral blood showed markedly increased PCA in a dose dependent manner. In two of five patients, PCA of mononuclear cells in pleural fluids after intrapleural administration of OK-432 was measured. Compared with PCA before intrapleural administration of OK-432, PCA after treatment was clearly augmented.
It was shown that OK-432 could augment PCA of mononuclear cells in pleural fluids both in vitro and in vivo. It was suspected that augmented PCA of mononuclear cells in pleural fluid might lead to fibrosis and adhesion of pleura.

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The effect of D-penicillamine (D-P) on proliferation of human endothelial cells (ECs) and synovial fibroblastic cells (SFCs) was examined. D-P inhibited DNA synthesis of both ECs and SFCs in the presence of copper sulfate. Inhibition of DNA synthesis occurred in a dose-dependent fashion and a significant inhibition was attained at 60 μM D-P, a level which is attained in the serum of treated patients. Similar inhibition was observed by other thiols but not by disulfides. D-P, in vitro, produced hydrogen peroxide in the presence of copper sulfate. As the inhibition observed by D-P and copper sulfate was reversed almost to the control level by simultaneous addition of catalase and horseradish peroxide, it is suggested that inhibition of EC and SFC DNA synthesis is due to the action of hydrogen peroxide produced by D-P and cupric ion.
D-P, therefore, may suppress the growth of pannus and synovial fibrosis by inhibition of synovial vessel growth and SFC proliferation and in this way, may reduce rheumatoid inflammation.

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To confirm that platelet activating factor (PAF) plays an important role as a mediator in acute inflammation and allergic reacton, it is necessary to develop a more sensitive and stable method, capable of measuring trace amounts of PAF in various biological samples.
For that reason, we have improved gas chromatography/negative ion chemical ionization mass spectrometry (GC/NICI-MS), (established by Ramesha and Pickett in 1985) by employing SPB-1 column and isobutane as the reagent gas. Furthermore, by using this method, we investigated the time course of hexadecyl-PAF production and release from human polymorphonuclear leukocytes (PMNs) stimulated by Ca-ionophore A23187 in this experiment. PMNs were obtained from venous blood from a human donor by centrifugation and were stimulated by 5 μM of Ca-ionophore A23187. PAF was purified by SEP-PAK silica column and thin layer chromatography, and then it was hydrolyzed by phospholipase C. The extract was treatd with pentafluorobenzoyl chloride. We obtained the following results: the production of hexadecyl-PAF in cell pellet reached peak (8.1 ng/10⁷ cells) at 2 minutes after stimulation and that in the supernatant reached peak (6.3 ng/10⁷ cells) at about 7.5 minutes after stimulation.
We conclude that the procedure of GC/NICI-MS improved by us will be useful for the structural identification of trace amounts of unknown PAF synthesized by cells.

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We reported twelve patients, 11 females and 1 male aged from 33 to 57 years, who had been having a strong attachment for the diagnosis of Behçet's disease but had a part of the vexed diagnostic problem because of lacking stringent clinical features of genuine Behçet's disease. The chief complaint of the majority of those patients was usually a severe pain somewhere, such as abdominal pain, arthralgia or headache. However, examinations hardly furnished any evidence of inflammatory or organic lesions which could substantiate their complaints, in addition, symptoms were never progressive and no one showed positive skin prick test throughout the clinical course.
There may be some other causes for them and the underlying disease condition, although there was a high incidence of HLA-B51 among them, being comparable to that in patients with typical complete type. One must be cautious in making diagnosis of Behçet's disease when a patient shows only muco-cutaneous lesions and complaints not confirmed with objective signs.

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Cepharanthine was evaluated against ear inflammation produced in mice by arachidonic acid and the following results were obtained. (1) Cepharanthine supressed ear edema in mice on arachidonic acid inflammation by systemic administration. (2) When cepharanthine ointments and nordihydroguaiaretic acid aceton solution were used topically, these agents were more effective against ear edema. (3) The othe drugs contained cycloxigenase inhibitors except for glucocorticoids were not effective neither local nor systemic administration.
These results suggested that cepharanthine influenced 5-lipoxigenase system on arachidonic acid metabolism.

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Prostaglandin synthesis of glomeruli was studied in the control and aminonucleoside-induced nephrotic rats. Production of PGs (PGE₂, TXB₂, 6-keto-PGF_1α) was determined by radioimmunoassay after incubation of glomeruli under basal condition or in the presence of arachidonic acid. Protein excreton, and the contents of creatinine and PGs in urine were also measured.
PGs production in the glomeruli of the nephrotic rats was significantly (p<0.01) greater than that in the glomeruli of the control rats. Furthermore, in the nephrotic rats, the rate of increase of TXB₂ and 6-keto-PGF_1α production in the glomeruli was higher than that of the contents of TXB₂ and 6-keto-PGF_1α in urine. These results suggest that TXA₂ and PGI₂ may play an important role in protein leakage from the glomeruli in the nephrotic rats.

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The clinical usefulness of Mofezolac (N-22), a new non-steroidal anti inflammatory agent, was evaluated in comparison with Ibuprofen (IP) by a double-blind comparative study on patients with pharyngitis, laryngitis and tonsillitis.
Daily dose was 225 mg (3 times/day) in N-22 group and 600 mg (3 times/day) in IB group. The results are summarized as follows.
A total of 215 cases were subjected for the study, of which 108 were for N-22 group and 107 were for IP group. No significant difference in patient back-ground factors was recognized between N-22 and IP group.
Of a total of 183 efficacy evaluable cases (N-22; 89, IP; 94), 65.2% of N-22 group and 57.4% of IP group were rated “≥ moderately improved” in final global improvement rate, no significant difference between N-22 and IP groups.
In the rating “Significant improvement” with respect to the “Improvement by Symptom”, N-22 group showed an improvement higher than IB group in the categories of both analgesic effect (laryngitis and pharyngitis, etc) .
No significant difference between the two groups was recognized in Overall Safety rating. N-22 group caused side-effects in 8 cases (8.4%) and IP group in 9 cases (9.4%), most of which were observed an gastrointestinal symptoms found not clinically serious.
Of a total of 183 utility evaluable cases (N-22; 89, IP; 94), 62.9% of N-22 group and 54.3% of IP group were rated “≥moderately useful” in global utility rate, with no significant difference between N-22 and IP groups.
From the foregoing study, N-22 is found clinically useful to pharyngitis, laryngitis and tonsillitis with pain.

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