Design and synthesis of 6-methylpyridin-2-one derivatives as novel and potent GluN2A positive allosteric modulators for the treatment of cognitive impairment

N-Methyl-D-aspartate receptors (NMDARs) are key regulators of synaptic plasticity in the central nervous system. Potentiation of NMDARs containing GluN2A subunit has been recently recognized as a promising therapeutic approach for neurological disorders. We identified a novel series of GluN2A positive allosteric modulator (PAM) with a pyridin-2-one scaffold. Initial lead compound 1 was discovered through in silico-based screening of virtual ligands with various monocyclic scaffolds. GluN2A PAM activity was increased by introduction of a methyl group at the 6-position of the pyridin-2-one ring and a cyano group in the side chain. Modification of the aromatic ring led to the identification of potent and brain-penetrant 6-methylpyridin-2-one 17 with a negligible binding activity for α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs). Oral administration of 17 significantly enhanced rat hippocampal long-term potentiation (LTP). Thus, 17 would be a useful in vivo pharmacological tool to investigate complex NMDAR functions for the discovery of therapeutics toward diseases associated with NMDAR dysfunction.

Structure-Activity Relationship Studies of Antimalarial Plasmodium Proteasome Inhibitors─Part II

With increasing reports of resistance to artemisinins and artemisinin-combination therapies, targeting the Plasmodium proteasome is a promising strategy for antimalarial development. We recently reported a highly selective Plasmodium falciparum proteasome inhibitor with anti-malarial activity in the humanized mouse model. To balance the permeability of the series of macrocycles with other drug-like properties, we conducted further structure-activity relationship studies on a biphenyl ether-tethered macrocyclic scaffold. Extensive SAR studies around the P1, P3, and P5 groups and peptide backbone identified compound TDI-8414. TDI-8414 showed nanomolar antiparasitic activity, no toxicity to HepG2 cells, high selectivity against the Plasmodium proteasome over the human constitutive proteasome and immunoproteasome, improved solubility and PAMPA permeability, and enhanced metabolic stability in microsomes and plasma of both humans and mice.

Design, Synthesis, and Optimization of Macrocyclic Peptides as Species-Selective Antimalaria Proteasome Inhibitors

With over 200 million cases and close to half a million deaths each year, malaria is a threat to global health, particularly in developing countries. Plasmodium falciparum, the parasite that causes the most severe form of the disease, has developed resistance to all antimalarial drugs. Resistance to the first-line antimalarial artemisinin and to artemisinin combination therapies is widespread in Southeast Asia and is emerging in sub-Saharan Africa. The P. falciparum proteasome is an attractive antimalarial target because its inhibition kills the parasite at multiple stages of its life cycle and restores artemisinin sensitivity in parasites that have become resistant through mutation in Kelch K13. Here, we detail our efforts to develop noncovalent, macrocyclic peptide malaria proteasome inhibitors, guided by structural analysis and pharmacokinetic properties, leading to a potent, species-selective, metabolically stable inhibitor.

Macrocyclic Peptides that Selectively Inhibit the Mycobacterium tuberculosis Proteasome

Treatment of tuberculosis (TB) currently takes at least 6 months. Latent Mycobacterium tuberculosis (Mtb) is phenotypically tolerant to most anti-TB drugs. A key hypothesis is that drugs that kill nonreplicating (NR) Mtb may shorten treatment when used in combination with conventional drugs. The Mtb proteasome (Mtb20S) could be such a target because its pharmacological inhibition kills NR Mtb and its genetic deletion renders Mtb unable to persist in mice. Here, we report a series of macrocyclic peptides that potently and selectively target the Mtb20S over human proteasomes, including macrocycle 6. The cocrystal structure of macrocycle 6 with Mtb20S revealed structural bases for the species selectivity. Inhibition of 20S within Mtb by 6 dose dependently led to the accumulation of Pup-tagged GFP that is degradable but resistant to depupylation and death of nonreplicating Mtb under nitrosative stress. These results suggest that compounds of this class have the potential to develop as anti-TB therapeutics.

Development of a Highly Selective Plasmodium falciparum Proteasome Inhibitor with Anti-malaria Activity in Humanized Mice

Plasmodium falciparum proteasome (Pf20S) inhibitors are active against Plasmodium at multiple stages-erythrocytic, gametocyte, liver, and gamete activation stages-indicating that selective Pf20S inhibitors possess the potential to be therapeutic, prophylactic, and transmission-blocking antimalarials. Starting from a reported compound, we developed a noncovalent, macrocyclic peptide inhibitor of the malarial proteasome with high species selectivity and improved pharmacokinetic properties. The compound demonstrates specific, time-dependent inhibition of the β5 subunit of the Pf20S, kills artemisinin-sensitive and artemisinin-resistant P. falciparum isolates in vitro and reduces parasitemia in humanized, P. falciparum-infected mice.

Effect of wearing fingers rings on the behavioral and psychological symptoms of dementia: An exploratory study

Objective:

This study was conducted to examine the effects of an approach that wears finger rings on elderly females with behavioral and psychological symptoms of dementia.

Method:

The subjects were seven Japanese dementia patients living in elderly nursing homes. A single-case experimental design was adopted for the study. Each study subject was asked to put rings on her finger (from 9:00 to 19:00) for 7 days. The Neuropsychiatric Inventory, scenes of behavioral and psychological symptoms of dementia, interest in wearing rings, self-awareness, and overall profile were determined to assess the effect on the patients of wearing rings.

Results:

The majority of nursing care providers stated, based on their assessment, that the “irritability/lability” that was noted during the baseline period disappeared during the ring-wearing intervention period in the three patients who displayed an interest in rings. In the assessment of the self-awareness ability, these three women were aware themselves of their intellect collapsing and were capable of conjecturing their own and others’ minds. It was commonly seen that the nursing staff, even though they had not been asked to do so by the researchers, told the patients, “Mrs. XX, you look so beautiful” when they found a patient wearing rings.

Discussion/conclusion:

Individuals with low self-esteem are inclined to get angry and display aggression. In subjects with low self-esteem, anger and aggression readily arise when they are slighted by others. Self-esteem is low in those women who are aware of their own status of collapsing intellect. It is concluded that the words of conjuration, “you look so beautiful,” which the wearing of the ring per se by the patient elicited from the caregivers heightened the self-esteem and alleviated “irritability/lability” in the study subjects.

Discovery and optimization of 1,7-disubstituted-2,2-dimethyl-2,3-dihydroquinazolin-4(1H)-ones as potent and selective PKCθ inhibitors

A high-throughput screening campaign helped us to identify an initial lead compound (1) as a protein kinase C-θ (PKCθ) inhibitor. Using the docking model of compound 1 bound to PKCθ as a model, structure-based drug design was employed and two regions were identified that could be explored for further optimization, i.e., (a) a hydrophilic region around Thr442, unique to PKC family, in the inner part of the hinge region, and (b) a lipophilic region at the forefront of the ethyl moiety. Optimization of the hinge binder led us to find 1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one as a potent and selective hinge binder, which resulted in the discovery of compound 5. Filling the lipophilic region with a suitable lipophilic substituent boosted PKCθ inhibitory activity and led to the identification of compound 10. The co-crystal structure of compound 10 bound to PKCθ confirmed that both the hydrophilic and lipophilic regions were fully utilized. Further optimization of compound 10 led us to compound 14, which demonstrated an improved pharmacokinetic profile and inhibition of IL-2 production in a mouse.

Recent advance in investigation of gene polymorphisms in Japanese patients with aspirin-exacerbated respiratory disease

Aspirin-exacerbated respiratory disease (AERD) is a complex clinical syndrome characterised by severe asthmatic attack upon treatment with aspirin and/or non-steroidal anti-inflammatory drugs (NSAIDs). Genetic predisposition has been considered as a crucial determinant and candidate genes have concentrated especially on cysteinyl leukotrienes (LTs)-related genes as the inhibitory action of aspirin and NSAIDs on cyclooxygenase activity may cause overproduction of cysteinyl LTs. However, conflicting results have been reported, in parallel with replication studies in different ethnic groups. Thus, future areas of investigations need to focus on comprehensive approaches towards the discovery of other genetic biomarkers. Unfortunately, few papers have been reported about gene polymorphisms in Japanese patients with AERD. Here, we described on our recent genetic investigations on B2ADR, IL-13, IL-17A, CYP2C19, TBXA2R, CRTH2 and HSP70. This review indicates potential genetic biomarkers contributing to the early diagnosis of AERD, which may include CYP2C19 and HSP70 gene polymorphisms, and future validation studies in independent population are required to provide reassurance about our findings.

Transient neonatal diabetes mellitus in an extremely preterm infant

The present report concerns transient neonatal diabetes mellitus in an extremely preterm infant (gestational age 27 weeks, birth weight 718 g). The patient had intrauterine growth retardation and developed hyperglycaemia on the first day of life. Insulin administration was discontinued on the 89th day of life, which was 1 day before the original due date. This case suggests that (a) insufficient insulin secretion started at least from the second trimester of the pregnancy, and (b) the duration needed for recovery of insulin secretion was not dependent on the maturity.

Transient neonatal diabetes mellitus in extremely preterm infant

A report of transient neonatal diabetes mellitus in an extremely preterm infant (gestational age 27 weeks, birth weight 718 g). The patient had intrauterine growth retardation and developed hyperglycaemia on the first day of life. Insulin administration was discontinued on the 89th day of life, which was 1 day before the original due date. This case suggests that (a) insufficient insulin secretion started at least from the second trimester of the pregnancy; (b) the duration needed for recovery of insulin secretion was not dependent on the maturity.

The occurrence of crassulacean acid metabolism in Cymbidium (Orchidaceae) and its ecological and evolutionary implications

Crassulacean acid metabolism (CAM) is one of the photosynthetic pathways regarded as adaptations to water stress in land plants. Little is known about correlations among the level of CAM activity, environment of habitat, life form, and phylogenetic relationship of a plant group from an evolutionary perspective. We examined these relationships in 18 species of Cymbidium (Orchidaceae) because the genus shows distinctive diversification of habitats and life forms. The photosynthetic type was classed into three categories, strong CAM, weak CAM, and C(3) on the basis of CAM activity. CAM expression in Cymbidium was confined to the epiphytic and lithophytic species. Especially, all of these species from tropical to subtropical rainforest exhibited CAM activity. On the other hand, the terrestrial species always exhibited C(3) metabolism irrespective of their varied habitats. Regarding the evolution of photosynthetic characters, weak CAM was the ancestral state in Cymbidium and strong CAM and C(3) metabolism occurred subsequently. The evolution of strong CAM likely enabled Cymbidium to extend to exposed sites in tropical lowland where marked water stress exists. Further, different levels of CAM activity characterized each species and such potential plasticity of CAM may realize the radiation of Cymbidium into sites with different environmental conditions.

[Effect of rush immunotherapy (RIT) on Hymenoptera allergy]

In our country approximately forty people die every year from anaphylaxis caused by hymenoptera stings. Between 1988 and 1996, 48 patients, who had experienced a systemic reaction to hymenoptera sting and were proved to have specific IgE antibodies to wasp, yellow or both (RAST score > or = 2), received rush immunotherapy (RIT) using venom extracts in our hospital. Fifteen patients had re-sting after RIT. Fourteen out of the 15 patients showed only local reaction to the hymenoptera re-sting and one patient had mild generalized symptoms. Although one patient showed mild generalized uriticaria during RIT, no adverse reaction occurred during and after RIT in the other subjects. Follow-up studies on the titers of serum total IgE antibodies and hymenoptera specific IgE and IgG4 antibodies revealed that total and specific IgE antibodies transiently increased one month after RIT and returned to their baseline values by 6 months after RIT, while specific IgG4 antibodies continued to gradually increase up to al least 3 years after RIT. These results demonstrates that RIT is effective in prevention of a systemic reaction to hymenoptera re-sting and an increase in the titer of hymenoptera specific IgG4 antibodies may at least partly explain the efficacy of RIT.

A phylogenetic analysis of the Orchidaceae: evidence from rbcL nucleotide

Cladistic parsimony analyses of rbcL nucleotide sequence data from 171 taxa representing nearly all tribes and subtribes of Orchidaceae are presented here. These analyses divide the family into five primary monophyletic clades: apostasioid, cypripedioid, vanilloid, orchidoid, and epidendroid orchids, arranged in that order. These clades, with the exception of the vanilloids, essentially correspond to currently recognized subfamilies. A distinct subfamily, based upon tribe Vanilleae, is supported for Vanilla and its allies. The general tree topology is, for the most part, congruent with previously published hypotheses of intrafamilial relationships; however, there is no evidence supporting the previously recognized subfamilies Spiranthoideae, Neottioideae, or Vandoideae. Subfamily Spiranthoideae is embedded within a single clade containing members of Orchidoideae and sister to tribe Diurideae. Genera representing tribe Tropideae are placed within the epidendroid clade. Most traditional subtribal units are supported within each clade, but few tribes, as currently circumscribed, are monophyletic. Although powerful in assessing monophyly of clades within the family, in this case rbcL fails to provide strong support for the interrelationships of the subfamilies (i.e., along the spine of the tree). The cladograms presented here should serve as a standard to which future morphological and molecular studies can be compared.

Pharmacokinetics of a novel benzodiazepine partial inverse agonist in the F344 rat, SD rat and B6C3F1 mouse

1. The pharmacokinetics of a novel benzodiazepine partial inverse agonist (S-8510) were studied in the Fischer 344 (F344) rat and B6C3F1 mouse to obtain information for the planning of carcinogenicity studies. Sprague-Dawley (SD) rats were also included for comparison. 2. Clear non-linear elimination of S-8510 was observed after single oral administration of S-8510 in all animals tested (F344 rat, 1-50 mg/kg; SD rat and B6C3F1 mouse, 1-150 mg/kg). 3. Exposure of S-8510 after single oral administration was in the order F344 rat > B6C3F1 mouse > SD rat. 4. Multiple oral administration to F344 rat and B6C3F1 mouse decreased the exposure to S-8510. 5. These results indicate that it is very important to evaluate pharmacological and toxicological studies based on exposure and to be careful in selecting the species and strains of animal used in toxicology studies.

Stereoselective uptake of an organic anion across the renal basolateral membrane in isolated perfused rat kidney

To clarify which process in renal secretion is responsible for the stereoselective renal secretion of organic anions, the renal handling of enantiomers of 5-monomethylsulfamoyl-6,7-dichloro-2, 3-dihydrobenzofuran-2-carboxylic acid (MBCA) was studied by the multiple-indicator dilution method, using isolated perfused rat kidney. After bolus injection of (R)-(+)-[14C]MBCA or (S)-(-)-[14C]MBCA into the renal artery, the outflow patterns for the perfusate and the urinary excretion rate profiles were estimated by statistical moment analysis. AUC values and mean transit times in kidney for the MBCA enantiomers indicated that (R)-(+)-MBCA was excreted much more extensively in urine and that it had a higher affinity for renal tissue than did (S)-(-)-MBCA. A significantly larger intrinsic clearance of secretion for (R)-(+)-MBCA attested to the R-(+)-preferential renal secretion. The uptake rate constant across the basolateral membrane, the ratio of the uptake rate constant to the free fraction in the perfusate, and the intracellular distribution volume were significantly larger for (R)-(+)-MBCA than for (S)-(-)-MBCA, indicating that uptake across the basolateral membrane and intracellular distribution were R-(+)-preferential. However, the mean time across renal epithelial cells for secreted molecules, the single-pass mean residence time in renal epithelial cells, and the rate constant for secretion across the brush-border membrane were not significantly different between enantiomers. The simultaneous presence of (R)-(+)-MBCA decreased the intrinsic clearance of secretion, the ratio of the uptake rate constant to the free fraction in the perfusate, and the intracellular distribution volume for (S)-(-)-[14C]MBCA, although the secretion rate constant, the mean time across renal epithelial cells for secreted molecules, and the single-pass mean residence time in renal epithelial cells were not influenced by (R)-(+)-MBCA, confirming that uptake across the basolateral membrane and intracellular distribution were stereoselective processes.

[Cytomegalovirus infection and its possible treatment with herbal medicines]

Medicinal herbs, Geum japonicum, Syzygium aromaticum, Terminalia chebula, and Rhus javanica, with anti-herpes simplex virus therapeutic activity, inhibited replication of human cytomegalovirus(CMV) and murine CMV(MCMV) in vitro. These anti-CMV activities were examined in an MCMV infection model using immunosuppressed mice. Geum japonicum, Syzygium aromaticum, and Terminalia chebula significantly suppressed MCMV yields in lungs of treated mice compared with water treatment. Efficacy of oral treatment with 750 mg/kg/day of Geum japonicum-extract was similar to that of the intraperitoneal administration with 2 mg/kg/day of ganciclovir in increasing the body weight of infected mice and reducing the virus yield in the lungs. These herbs may be beneficial for the prophylaxis of CMV diseases in immunocompromized patients.

Lipogenic and lipolytic activities in isolated adipocytes from cattle with fat necrosis

The metabolic activity and cellularity of adipocytes isolated from the abdominal adipose tissue of normal heifers and heifers with fat necrosis were compared. The basal rate of U-14C glucose incorporation into total lipids in adipocytes from the periphery of the necrotic mass was higher than that in the colonic mesentery of both the affected and normal heifers. In the affected animals. adipocytes from the mesentery of the spiral colon and adipocytes from the periphery of the necrotic mass failed significantly to increase the incorporation of labelled acetate and glucose, respectively, in response to insulin. In the presence of adrenalin, adipocytes from the colonic mesentery and the periphery of the necrotic mass of the affected heifers released more glycerol than adipocytes from the colonic mesentery of normal animals. In addition, the mean diameters of adipocytes from the colonic mesentery and the periphery of the necrotic mass of the affected heifers were significantly greater than those from the colonic mesentery of normal animals. These results indicate that excessive fattiness in abdominal adipose tissue may predispose cattle to fat necrosis.

Infection with GB virus C in leprous patients in Japan

The detection of hepatitis C virus (HCV) in blood donors and patients with acute and chronic hepatitis has brought to the fore another virus or viruses which can be transmitted parenterally and induce liver disease. The RNA of a candidate virus designated GB virus C (GBV-C) was determined by the polymerase chain reaction with primers deduced from a helicase-like region in 229 leprous patients in Japan. GBV-C RNA was detected in 12 (5.2%) patients, and HCV RNA in 41 (18%). Three patients were coinfected with GBV-C and HCV. The nine patients infected with GBV-C alone had aminotransferase levels lower than the three patients with the mixed infection or the 38 patients infected with HCV only (P < 0.001). Sequence comparison within 100 base pairs in the helicase-like region suggested that two, three and three patients, respectively, would have been infected with three distinct strains of GBV-C. These results indicate that patients with leprosy are at increased risk for infection not only with HCV, but also with GBV-C, and that the infection with GBV-C alone would not induce hepatic injuries as severe as HCV infection.

Hepatitis C virus antibody, viral RNA and genotypes in leprous patients in Japan

BACKGROUND/METHODS

Markers of hepatitis C virus infection were tested for in 229 patients with leprosy (male 154, female 75) in Japan.

RESULTS

Antibody to hepatitis C virus by a second-generation enzyme immunoassay was detected in 68 patients (30%), and RNA of hepatitis C virus in 41 (18%), in prevalence rates much higher (p < 0.001) than those in matched controls (11/923 or 1.2% and 9/923 or 1.0%, respectively). Hepatitis C virus genotypes were II/1b in 37 (90%), III/2a in three (7%) and IV/2b in one (2%), in which II/1b was more frequently (p < 0.003) represented than in hepatitis C virus carriers without leprosy in Japan (520/767 or 68%). The 41 patients with hepatitis C virus viremia had serum transaminase levels significantly higher than those in the other 188 patients without viremia (p < 0.01).

CONCLUSIONS

These results indicate that leprous patients confined in institutions are at high risk of hepatitis C virus infection, and that patients infected with hepatitis C virus should be monitored for liver function and placed on interferon therapy whenever required.

Restoration and analysis of standing-up in complete paraplegia utilizing functional electrical stimulation

OBJECTIVE

Restoration of stand-up motion in patients with complete paraplegia utilizing multichannel functional electrical stimulation, and analysis of the restored motion.

DESIGN

Nonrandomized control trial.

SETTING

General community, a referral center, institutional practice, and ambulatory care:

PATIENTS

Twelve volunteer samples were used for the collection of normal data. Two complete paraplegics received treatment for the restoration of stand-up motion.

MAIN OUTCOME MEASURES

The electromyogram, joint angle, and floor reaction force were investigated during standing-up with arms crossed in front of the chest, and hands-assisted standing-up using parallel bars. The maximum knee joint torque during standing-up without hands-assists was calculated using a three-segment link model. Standing-up motion in complete paraplegics was restored, and then analyzed using the three-dimensional floor reaction force and the hip, knee, and ankle angles.

RESULTS

Main muscles used to stand up were the quadriceps, tibialis anterior, and paraspinal muscles. Hands-assists reduced the muscle activity and the vertical floor reaction force. Peak muscle activity was less during hands-assisted standing-up, except for the rectus femoris and the iliopsoas muscle. The maximum knee joint torque during standing-up was 1.6Nm/kg for both knees. Two complete paraplegics were able to stand up smoothly from a wheelchair based on stimulation data obtained from normal subjects. The characteristic pattern during standing-up was knee flexion preceding extension.

CONCLUSION

Stand-up motion was restored utilizing electromyogram data and knee joint torque data from normal subjects.

Effect of YM264 on the airway hyperresponsiveness and the late asthmatic response in a guinea pig model of asthma

We investigated the effects of YM264, a specific platelet-activating factor (PAF) antagonist, on the airway hyperresponsiveness (AH) and the late asthmatic response (LAR) of guinea pigs that were sensitized by exposure to aerosolized ovalbumin (OA). Respiratory resistance (Rrs) was determined by the oscillation technique. Airway responsiveness was evaluated by administering a dose of histamine at which the Rrs reached 200% of the baseline value (H200). Animals were administered 1 or 3 mg/kg of YM264 orally 30 min before and again at 3 h after exposure to OA. YM264 significantly suppressed AH 24 h after and 5 days after the exposure. YM264 also suppressed the development of the LAR and accumulation of eosinophils and neutrophils in the tracheal mucosa of guinea pigs. These observations suggest that PAF is involved in the AH and the development of the LAR in asthma. PAF antagonists may play a beneficial role in the treatment of asthma.

[Effect of BAY u3405-thromboxane A2 receptor antagonist, on biphasic airway responses induced by platelet-activating factor in actively sensitized guinea pigs]

Our previous study in activity sensitized guinea pigs demonstrated an LAR-like increase in respiratory resistance (Rrs) at 3 to 9 hr after PAF inhalation. The result suggested possible involvement of the priming effect of active sensitization and PAF. Mean while, thromboxane A2 (TXA2) is known to be induced by PAF. The present study investigated the involvement of TXA2 in the guinea pig LAR model with a new TXA2 receptor antagonist, BAY u3405. One hr after BAY u3405 administration to guinea pigs sensitized by ovalbumin, the Rrs following inhalation of PAF was subsequently determined. Infiltration of inflammatory cells in the airway tissue 9 hr after PAF inhalation was also observed. While a re-increase in Rrs was found in all the cases in the control group, the re-increase in Rrs was inhibited significantly in the BAY u3405 administration group, 4 to 9 hr after PAF inhalation. The numbers of eosinophils and lymphocytes in the airway tissue were significantly decreased in the BAY u3405 administration group, as compared with the control group. From these results, the possibility is suggested that TXA2 and its direct effect on the airway and the migration-enhancing effect on eosinophils and T lymphocytes, as well as PFA, are involved in the development of LAR by PAF.

Ocular absorption, distribution, and systemic absorption of a novel antiglaucoma medication, prostaglandin derivative, in male white rabbits

A prostaglandin derivative, (5Z,9 alpha,11 alpha,13E)-9,11-dihydroxyprosta- 5,13-dienoic acid sodium salt (S-1033), that lowers intraocular pressure with little adverse effect, may have clinical value in the treatment of glaucoma. After [14C]S-1033 (0.2% solution) was instilled into the eye of a white rabbit, radioactivity and S-1033 appeared in systemic plasma so rapidly (tmax, 5 min) and S-1033 was eliminated very rapidly with half-lives of 2.8 and 11.0 min at alpha- and beta-phases, respectively. The metabolite, M-1, [1R-[1 alpha,2 beta-(1E),3 alpha,5 alpha]]-3,5-dihydroxy-2-(1- octenyl)-cyclopentanepropanoic acid (tetranor-S-1033), appeared in plasma very rapidly (tmax, 5 min), suggesting that a fast metabolism was a major factor in the rapid elimination of S-1033 from plasma. The values for the ratios of the area under the curve of ocular instillation to intravenous administration for radioactivity and S-1033 were 1.01 and 0.52, respectively, indicating that more than half of the S-1033 instilled was transported into the systemic circulation. To clarify the contributing pathway of the massive and rapid systemic absorption of S-1033 after topical dosing, plasma levels of S-1033 were investigated after instillation to rabbits in which the nasolacrimal ducts were occluded. Plasma concentrations of S-1033 were slightly higher than those in intact rabbits, suggesting that conjunctiva would be as important as nasal mucosae for the systemic absorption under the physiological condition. As for the intraocular distribution, the highest levels of radioactivity were found in the cornea, conjunctiva, and anterior sclera.(ABSTRACT TRUNCATED AT 250 WORDS)

Suppression of tumor cell growth by anthocyanins in vitro

Bioflavonoids, extracted from flower petals, were examined for their growth inhibitory effect on cells in culture. They were found to significantly suppress the growth of the cultured cells. Anthocyanins tended to show greater inhibitory effect than other flavonoids. Commercially synthesized or purified aglycones of flavonoids were also studied for their suppression of tumor cells. The anthocyanins were more effective than other flavonoid aglycones, although the aglycones were easily inactivated under the culture conditions.

Effect of inhaled cyclosporin A on the allergen-induced late asthmatic response and increased in airway hyperresponsiveness in a guinea pig model of asthma

Oral administration of cyclosporin (CsA), a potent inhibitor of helper T cell function, prevents the allergen-induced late asthmatic response (LAR) and the increase in airway hyperresponsiveness (AH) seen in actively sensitized guinea pigs. The systemic administration of this agent in humans has been associated with serious side effect, therefore, the effects of inhaled CsA were therefore examined in guinea pigs that were actively sensitized by repeated exposure to nebulized ovalbumin. Respiratory resistance (Rrs) of the animals was measured by an oscillation method and the extent of AH was inferred from the inhaled concentration of histamine required to increase Rrs by 200%. The magnitude of ovalbumin-induced immediate bronchoconstriction after sensitization was similar in CsA-treated and nontreated control animals. However, a LAR was observed in 4/5 control animals but in 0/5 CsA-treated animals. The increase in AH observed 24 hours after antigen exposure in control animals was significantly inhibited by prior CsA inhalation. Significant CsA concentrations were detected by radioimmunoassay in the lungs of CsA-treated animals. Thus, inhaled CsA should be further investigated because it may be useful treating asthma while avoiding side effects.

Ultrastructural characterization of platelet-activating factor-stimulated human eosinophils from patients with asthma

1. Purified human eosinophils from asthmatic patients were stimulated with platelet-activating factor in vitro and examined for morphological changes by transmission electron and light microscopy. Changes were also evaluated by morphometric analysis and were related to the platelet-activating factor-stimulated release of granular eosinophil cationic protein. 2. Stimulation of eosinophils with platelet-activating factor induced a dose-dependent shape change, including the elongation of cells, loss of microvilli and the formation of lamellipodia. This effect was maximal at 25 min and was reversible. 3. Stimulation with platelet-activating factor also induced granule movement to the cell periphery and fusion of adjacent granules. Granules became swollen and vesiculated, whereas both the matrix and core showed evidence of solubilization. 4. There was a time-dependent secretion of eosinophilic cationic protein from human eosinophils upon stimulation with platelet-activating factor which occurred without significant lactate dehydrogenase release. 5. Morphometric analysis of the transmission electron micrographs indicated a significant reduction in cytoplasmic area after 10 min of incubation with platelet-activating factor from 39.0 +/- 1.7 microns 2 for untreated eosinophils to 33.2 +/- 2.3 microns 2 (P < 0.02) for platelet-activating factor-treated cells, underscoring the observation that the cells change from spherical to ellipsoidal. No significant increase in the perimeter of the cells was found. 6. The number of granule-profiles in platelet-activating factor-stimulated eosinophils was slightly reduced when compared with control, and an increase in granule area was observed 10 min after platelet-activating factor challenge (0.215 +/- 0.011 microns 2 versus 0.246 +/- 0.016 microns 2).(ABSTRACT TRUNCATED AT 250 WORDS)

[Eosinophil-derived collagenase (metalloproteinase)]

Collagenase is a highly specific neutral protease which acts by cleaving the collagen molecule into fragments, at a site three-quarters of the distance from the amino terminus. Collagenase has been assumed to be connected with the destruction of the pathological connective tissue which accompanies inflammatory conditions such as rheumatoid arthritis and interstitial lung disease. Despite the association of eosinophils with wound-healing and fibrotic processes, their collagenolytic ability has been poorly defined and it was not until 1984 that human eosinophils were shown to contain an enzymatic activity which degrades collagen. Eosinophils contain a metalloprotein that degrades types I and III collagens and no collagenolytic activity against types IV and V collagens is detected. Some experiments suggested that the eosinophil collagenase was different from neutrophil collagenase which cleaves type I collagen preferentially. Eosinophils may play a role in the alterations in connective-tissue matrices seen in physiological and pathological states.

[Effect of capsaicin on the migration of eosinophils into the bronchi of guinea pigs]

Substance P (SP), a potent neuropeptide, which is localized in the sensory nerves and released by many physiological stimuli has been implicated in airway neurogenic inflammation. We have studied the effects of capsaicin (CAP), which releases tachykinins (TK) from the sensory nerves, on eosinophil (EOS) recruitment in the airway in guinea pigs in vivo. Male guinea pigs were used. The respiratory resistance (Rrs) of the guinea pigs were measured by an oscillation technique and histological studies of the right main bronchus were carried out. Exposure to inhaled CAP resulted in a significant increase in Rrs with PC200 CAP of 0.97 +/- 0.25 (x 10(-6) M) (n = 5). This stimulation also provoked striking eosinophilia in the right bronchus in a dose-dependent manner. A neutral endopeptidase (NEP) inhibitor, phosphoramidon, potentiated CAP-induced EOS infiltration. By contrast, pretreatment with [D-Pro2, D-Trp7,9]-SP, an analogue of SP and its receptor antagonist, diminished the response. We conclude that CAP-induced tachykinin release is capable of causing striking eosinophilia in the lung in vivo. This mechanism may contribute to airway inflammation in patients with asthma. This would provide further support for a link between tachykinin and bronchial eosinophilia in asthma.

Sensitization primes platelet-activating factor (PAF)-induced accumulation of eosinophils in mouse skin lesions: contribution of cytokines to the response

We have examined the hypothesis that cytokines mediate the enhanced responsiveness of eosinophils to PAF in sensitized mouse skin. PAF (10 ng per site) resulted in a considerable degree of eosinophil accumulation in ovalbumin (OA)-sensitized mice but not in non-sensitized mice. Intradermal preadministration of cytokines (IL-5, IL-3 and GM-CSF) also significantly enhanced PAF-induced migration of eosinophils in a dose-dependent manner. The relative potency with which these cytokines primed cell migration was IL-5 greater than IL-3 greater than GM-CSF, however, each cytokine alone showed no direct effect. We conclude that the sensitization or the exogenous application of cytokines is capable of augmenting PAF-induced eosinophil migration in mice in vivo, and the cytokines thus elicited by sensitization may contribute to the extensive recruitment of inflammatory cells in allergic diseases.

A female patient with Lesch-Nyhan syndrome

The authors report the second case of a female with typical Lesch-Nyhan syndrome. She exhibited athetoid movement, self-multilation, mental retardation and spasticity. Laboratory investigations revealed hyperuricaemia, hyperuricosuria and decreased erythrocyte hypoxanthine guanine phosphoribosyl transferase activity. She has normal female external genitalia and karyotype. Her parents are non-consanguineous and there is no family member with gout, nephropathy or any psychoneurological disorder. To prevent self-stimulation, it was necessary to fix the patient's upper extremities to the backrest of her wheelchair. The authors also describe an apparatus that limits elbow flexion.

[Platelet activating factor (PAF)-induced late asthmatic response in sensitized but not in non-sensitized guinea pigs]

We have recently demonstrated that pretreatment with WEB 2086, a specific PAF antagonist or cyclosporine A (CsA), a potent helper T cell suppressant, resulted in preventing the development of late asthmatic response (LAR) and increase of airway hyperreactivity (AH) in guinea pig experimental models of asthma. We have now examined whether exogenously applied PAF causes LAR in these models in vivo. The respiratory resistance (Rrs) of guinea pigs was measured by an oscillation technique and histological studies of the bronchi were also made. Guinea pigs, actively sensitized by repeated antigen (ovalbumin; OA) inhalation, showed a leftward shift of the inhaled PAF dose response curve of Rrs compared with that in control animals, indicating that the sensitized animals were more sensitive to inhaled, PAF. PC200 PAF, which indicate provocative concentrations of PAF aerosols causing a 200% increase in the baseline Rrs, were 3800 +/- 604.9 micrograms/ml and 780 +/- 94.3 micrograms/ml, in the control and sensitized animals, respectively. The same magnitude of immediate bronchoconstriction after 780 and 3800 micrograms/ml of PAF exposure was observed in the actively sensitized and non-sensitized control animals, respectively. However, LAR developed 4 out of 6 animals only in the sensitized guinea pigs. We conclude that both exogenously applied PAF by inhalation and antigen exposure are capable of inducing LAR in sensitized guinea pigs, and thus the priming effect of immunization and PAF may contribute to the development of LAR observed in asthma.

[Cyclosporine A inhibits allergen-induced late asthmatic response and increase of airway hyperresponsiveness in guinea pigs]

Considerable interest has recently focused on the role of T-cell function in the pathogenesis of asthma. We have previously demonstrated that repeated inhaled antigen (ovalbumin; OA) exposure resulted in an appearance of late phase airway obstruction (LAR) in more than 50% and significant increase of airway hyperresponsiveness (AH) in guinea pig experimental models. We have studied the effect of cyclosporine A (CsA), a potent helper T-cell suppressant, on these models in vivo. Respiratory resistance (Rrs) of sensitized guinea pigs by repeated OA inhalation was measured by the oscillation method and AH estimated as an inhaled concentration of histamine, causing a 200% increase in the baseline Rrs (PC200 Hist). The magnitude of immediate OA (10 mg/ml/min) inhalation-induced bronchoconstriction was not significantly different in CsA-treated (25 mg/kg/day, 7-day oral administration) and non-treated groups. However, the development of LAR was markedly inhibited in CsA treatment groups (n = 5). Antigen-induced increase of AH at 24 hr and 5 days was also significantly inhibited by CsA pretreatment. We conclude that CsA is capable of inhibiting the development of LAR and increase of AH, and thus the regulation of T-cell function may contribute to the treatment of asthma.

[Involvement of platelet activating factor (PAF) in ovalbumin antigen-induced late asthmatic response and increase of airway hyperresponsiveness in a guinea pig experimental model of asthma]

Platelet activating factor, a potent chemical mediator, has been implicated in the pathogenesis of asthma in terms of inflammatory cell recruitment and activation. We have recently demonstrated that repeated antigen (ovalbumin; OA) exposure by inhalation to guinea pigs results in a development of late asthmatic response (LAR) in more than 50% of the animals and significant increase in airway hyperresponsiveness (AH). We have studied the effect of WEB 2086, a specific PAF receptor-antagonist, on this model. Respiratoly resistance (Res) of guinea pigs was measured by a oscillation technique and AH was evaluated by the provocative concentration of aerosols of histamine causing 200% increase of Rrs over the baseline Rrs (PC200 Hist). Four out of 5 actively sensitized and diphenhydramine-pretreated animals developed LAR 3 to 9 hr after allergen (20 mg/ml OA, 10 min inhalation)-induced immediate bronchoconstriction (LAR). Treatment with WEB 2086 (3 mg/kg intravenously) 30 min before and 3 hr after the exposure suppressed LAR clearly without affecting the IAR. Significant increase in AH from 2.80 +/- 0.03 to 2.51 +/- 0.01 and 2.60 +/- 0.08 (p less than 0.05, n = 8) of PC200 Hist (mg/ml, log) was observed 24 hr and 5 day after the OA exposure, respectively. The WEB 2086 treatment also prevented the increase of AH after the OA exposure (PC200 Hist; 2.82 +/- 0.09 before the challenge 2.80 +/- 0.07 and 2.75 +/- 0.09 24 hr and 5 days after, respectively. n = 8). Administration of WEB 2086 did not affect baseline Rrs and PC200 Hist in normal guinea pigs without any antigen challenge. We conclude that WEB 2086 is capable of preventing the development of LAR and increase in AH, and thus PAF may play an important causal role in LAR and increased AH observed in asthma.

Generation of oxygen free radicals from blood eosinophils from asthma patients after stimulation with PAF or phorbol ester

Eosinophils (EOS) may play an important role in the pathophysiology of bronchial asthma because they can release oxygen free radicals and several basic proteins which are cytotoxic to bronchial epithelium. We have studied the response of EOS isolated from the blood of atopic subjects with symptoms of asthma (AS, n = 7) or rhinitis (AR, n = 4) or without symptoms (AA, n = 5) and of subjects with the hypereosinophilic syndrome (HES, n = 5). EOS were separated using metrizamide density gradients and activated in vitro with platelet-activating factor (PAF, 100 nM) or phorbol 12-myristate-13-acetate (PMA, 100 nM). Oxygen free radical generation was assessed by a lucigenin-enhanced chemiluminescence (CL) assay. EOS purity was 83 +/- 1.7% (mean +/- SEM) with greater than 95% viability. Background CL responses of EOS from HES were significantly higher than those from AA (p less than 0.01) and AR (p less than 0.05). Normodense EOS from AS (PAF-induced CL = 90 +/- 27 mV) were more responsive to PAF than were those from AR (17 +/- 13 mV, p less than 0.01) and from AA (23 +/- 14 mV, p less than 0.01). Similar results were obtained with PMA. Hypodense EOS from HES subjects were as responsive as normodense EOS from AS to PMA and PFA. Thus, EOS from AS have an enhanced potential for activation, particularly by PAF; this may represent an important mechanism for the perpetuation of the inflammatory response in asthma, since EOS can also release PAF.

Generation of oxygen free radicals from blood eosinophils from asthma patients after stimulation with PAF or phorbol ester

Eosinophils (EOS) may play an important role in the pathophysiology of bronchial asthma because they can release oxygen free radicals and several basic proteins which are cytotoxic to bronchial epithelium. We have studied the response of EOS isolated from the blood of atopic subjects with symptoms of asthma (AS, n = 7) or rhinitis (AR, n = 4) or without symptoms (AA, n = 5) and of subjects with the hypereosinophilic syndrome (HES, n = 5). EOS were separated using metrizamide density gradients and activated in vitro with platelet-activating factor (PAF, 100 nM) or phorbol 12-myristate-13-acetate (PMA, 100 nM). Oxygen free radical generation was assessed by a lucigenin-enhanced chemiluminescence (CL) assay. EOS purity was 83 +/- 1.7% (mean +/- SEM) with greater than 95% viability. Background CL responses of EOS from HES were significantly higher than those from AA (p less than 0.01) and AR (p less than 0.05). Normodense EOS from AS (PAF-induced CL = 90 +/- 27 mV) were more responsive to PAF than were those from AR (17 +/- 13 mV, p less than 0.01) and from AA (23 +/- 14 mV, p less than 0.01). Similar results were obtained with PMA. Hypodense EOS from HES subjects were as responsive as normodense EOS from AS to PMA and PFA. Thus, EOS from AS have an enhanced potential for activation, particularly by PAF; this may represent an important mechanism for the perpetuation of the inflammatory response in asthma, since EOS can also release PAF.

Distribution and molecular form of immunoreactive big endothelin-1 in porcine tissue

In the present study a specific and sensitive radioimmunoassay for big endothelin-1 was developed. Half maximal inhibition of binding of radioiodinated big endothelin-1 was observed at 58 pg/tube and big endothelin-1 was detectable as low as 2 pg/tube. With this assay, the regional distribution of big endothelin-1 was determined in porcine tissue and compared to the distribution of an immunoreactive endothelin. Considerable amount of immunoreactive big endothelin-1 was observed in the aortic intima (0.84 +/- 0.094 pg/mg wet tissue; mean +/- S.D.) and the lung (0.47 +/- 0.055), but there was a low concentration in other tissue including the kidney inner medulla, which has been shown to be abundant in immunoreactive endothelin. Furthermore the molecular form of immunoreactive big endothelin-1 in aortic intima was found to be big ET-1[1-39], but the molecular form of major immunoreactive big endothelin-1 in the lung is big endothelin-1[22-39] with big endothelin-1[1-39] being minor.

Beta 2-adrenergic receptors on eosinophils. Binding and functional studies

We have studied the binding characteristics and functional effects of beta-adrenoceptors on human and guinea pig eosinophils. We determined the binding of the beta-antagonist radioligand [125I]pindolol (IPIN) to intact eosinophils obtained from the peritoneal cavity of guinea pigs and from blood of patients with eosinophilia. Specific binding was saturable, and Scatchard analysis showed a single binding site with a dissociation constant (Kd) of 24.6 pM and maximal number of binding sites (Bmax) of 7,166 per cell. ICI 118,551, a beta 2-selective antagonist, inhibited IPIN binding with a Ki value of 0.28 nM and was approximately 5,000-fold more effective than the beta 1-selective antagonist, atenolol. Isoproterenol increased cAMP levels about 5.5-fold above basal levels (EC50 = 25 microM); albuterol, a beta 2-agonist, behaved as a partial agonist with a maximal stimulation of 80%. Binding to human eosinophils gave similar results with a Kd of 25.3 pM and a Bmax corresponding to 4,333 sites per cell. Incubation of both human and guinea pig eosinophils with opsonized zymosan (2 mg/ml) or with phorbol myristate acetate (PMA) (10(-8) and 10(-6) M) resulted in superoxide anion generation and the release of eosinophil peroxidase; albuterol (10(-7) to 10(-5) M) had no inhibitory effect on the release of these products. Thus, eosinophils from patients with eosinophilia and from the peritoneal cavity of guinea pigs possess beta-receptors of the beta 2-subtype that are coupled to adenylate cyclase; however, these receptors do not modulate oxidative metabolism or degranulation. The possible therapeutic consequences of these observations to asthma are discussed.