Assessment of a 3D neural spheroid model to detect pharmaceutical-induced neurotoxicity

Drug-induced neurotoxicity is a leading cause of safety-related attrition for therapeutics in clinical trials, often driven by poor predictivity of preclinical in vitro and in vivo models of neurotoxicity. Over a dozen different iPSC-derived 3D spheroids have been described in recent years, but their ability to predict neurotoxicity in patients has not been evaluated nor compared with the predictive power of nonclinical species. To assess the predictive capabilities of human iPSC-derived neural spheroids (microBrains), we used 84 structurally diverse pharmaceuticals with robust clinical and pre-clinical datasets with varying degrees of seizurogenic and neurodegenerative liability. Drug-induced changes in neural viability and phenotypic calcium bursts were assessed using 7 endpoints based on calcium oscillation profiles and cel-lular ATP levels. These endpoints, normalized by therapeutic exposure, were used to build logistic regression models to establish endpoint cutoffs and evaluate probability for clinical neurotoxicity. The neurotoxicity score calculated from the logistic regression model could distinguish neurotoxic from non-neurotoxic clinical molecules with a specificity as high as 93.33% and a sensitivity of 53.49%, demonstrating a very low false positive rate for the prediction of seizures, convulsions, and neurodegeneration. In contrast, nonclinical species showed a higher sensitivity (75%) but much lower specificity (30.4%). The neural spheroids demonstrated higher likelihood ratio positive and inverse likelihood ratio neg-ative values compared with nonclinical safety studies. This assay has the potential to be used as a predictive assay to detect neurotoxicity in early drug discovery, aiding in the early identification of compounds that eventually may fail due to neurotoxicity.

Cell-based high-throughput screening for the evaluation of reactive metabolite formation potential

Here, we established a high-throughput in vitro assay system to predict reactive metabolite (RM) formation. First, we performed the glutathione (GSH) consumption assay to monitor GSH levels as an index of RM formation potential using HepaRG cells pretreated with 500 μM D,L-buthionine-(S,R)-sulfoximine (BSO) and then treated with ticlopidine and diclofenac. Both drugs, under GSH-reduced conditions, significantly decreased relative cellular GSH content by 70% and 34%, respectively, compared with that in cells not pretreated with BSO. Next, we examined the correlation between GSH consumption and covalent binding assays; the results showed good correlation (correlation coefficient = 0.818). We then optimized the test compound concentration for evaluating RM formation potential using 76 validation compound sets, and the highest sensitivity (53%) was observed at 100 μM. Finally, using HepG2 cells, PXB-cells, and human primary hepatocytes, we examined the cell types suitable for evaluating RM formation potential. The expression of CYP3A4 was highest in HepaRG cells, suggesting the highest sensitivity (56.4%) of the GSH consumption assay. Moreover, a co-culture model of PXB-cells and HepaRG cells showed high sensitivity (72.7%) with sufficient specificity (85.7%). Thus, the GSH consumption assay can be used to effectively evaluate RM formation potential in the early stages of drug discovery.

Freshly isolated primary human proximal tubule cells as an in vitro model for the detection of renal tubular toxicity

Drug induced kidney injury (DIKI) is a common reason for compound attrition in drug development pipelines with proximal tubule epithelial cells (PTECs) most commonly associated with DIKI. Here, we investigated freshly isolated human (hPTECs) as an in vitro model for assessing renal tubular toxicity. The freshly isolated hPTECs were first characterized to confirm gene expression of important renal transporters involved in drug handling which was further corroborated by confirming the functional activity of organic cation transporter 2 and organic anion transporter 1 by using transporter specific inhibitors. Additionally, functionality of megalin/cubilin endocytic receptors was also confirmed. A training set of 36 compounds was used to test the ability of the model to classify them using six different endpoints which included three biomarkers (Kidney Injury Molecule-1, Neutrophil gelatinase-associated lipocalin, and Clusterin) and three non-specific injury endpoints (ATP depletion, LDH leakage, and barrier permeability via transepithelial electrical resistance) in a dose-dependent manner across two independent kidney donors. In general, biomarkers showed higher predictivity than non-specific endpoints, with Clusterin showing the highest predictivity (Sensitivity/Specificity - 65.0/93.8 %). By using the thresholds generated from the training set, nine candidate internal Takeda compounds were screened where PTEC toxicity was identified as one of the findings in preclinical animal studies. The model correctly classified four of six true positives and two of three true negatives, showing validation of the in vitro model for detection of tubular toxicants. This work thus shows the potential application of freshly isolated primary hPTECs using translational biomarkers in assessment of tubular toxicity within the drug discovery pipeline.

New phenotypic cytotoxicity assay for ROS-inducing compounds using rat renal epithelial cells

An important mechanism of chemical toxicity is the induction of oxidative stress through the production of excess reactive oxygen species (ROS). In this study, we show that the level of drug-induced ROS production between NRK52E and HepG2 cells is significantly different for several marketed drugs and a number of Takeda's internal proprietary compounds. Nifedipine, a calcium channel blocker and the initial focus of the study, was demonstrated to promote in vitro ROS production and a decrease in cell viability in NRK52E cells but not HepG2 cells. ROS production after nifedipine treatment was inhibited by a NOX inhibitor (GKT136901) but not the mitochondrial NADH dehydrogenase inhibitor, rotenone, suggesting that nifedipine decreases NRK52E cell viability primarily through a NOX-mediated pathway. To understand the breadth of NOX-mediated ROS production, 12 commercially available compounds that are structurally and/or pharmacologically related to nifedipine as well as 172 internal Takeda candidate drugs, were also evaluated against these two cell types. Over 15 % of compounds not cytotoxic to HepG2 cells (below 50 μM) were cytotoxic to NRK52E cells. Our results suggest that a combination of cell viability data from both NRK52E and HepG2 cells was superior for the prediction of in vivo toxicity findings when compared to use of only one cell line. Further, the NRK52E cell viability assay is a good predictor of NOX-mediated ROS production and can be used as a follow up assay following a negative HepG2 response to aid in the selection of suitable compounds for in vivo toxicity studies.

Utility of Physicochemical Properties for the Prediction of Toxicological Outcomes: Takeda Perspective

The role that physicochemical properties play toward increasing the likelihood of toxicity findings in in vivo studies has been well reported, albeit sometimes with different conclusions. We decided to understand the role that physicochemical properties play toward the prediction of in vivo toxicological outcomes for Takeda chemistry using 284 internal compounds. In support of the previously reported "3/75 rule", reducing lipophilicity of molecules decreases toxicity odds noticeably; however, we also found that the trend of toxicity odds is different between compounds classified by their ionization state. For basic molecules, the odds of in vivo toxicity outcomes were significantly impacted by both lipophilicity and polar surface area, whereas neutral molecules were impacted less so. Through an analysis of several project-related compounds, we herein demonstrate that the utilization of the 3/75 rule coupled with consideration of ionization state is a rational strategy for medicinal chemistry design of safer drugs.

Small-Scale Panel Comprising Diverse Gene Family Targets To Evaluate Compound Promiscuity

Despite the recent advances in the life sciences and the remarkable investment in drug discovery research, the success rate of small-molecule drug development remains low. Safety is the second most influential factor of drug attrition in clinical studies; thus, the selection of compounds with fewer toxicity concerns is crucial to increase the success rate of drug discovery. Compounds that promiscuously bind to multiple targets are likely to cause unexpected pharmacological activity that may lead to adverse effects. Therefore, avoiding such compounds during early research stages would contribute to identifying compounds with a higher chance of success in the clinic. To evaluate the interaction profile against a wide variety of targets, we constructed a small-scale promiscuity panel (PP) consisting of eight targets (ROCK1, PDE4D2, GR, PPARγ, 5-HT_2B, adenosine A₃, M1, and GABA_A) that were selected from diverse gene families. The validity of this panel was confirmed by comparison with the promiscuity index evaluated from larger-scale panels. Analysis of data from the PP revealed that both lipophilicity and basicity are likely to increase promiscuity, while the molecular weight does not significantly contribute. Additionally, the promiscuity assessed using our PP correlated with the occurrence of both in vitro cytotoxicity and in vivo toxicity, suggesting that the PP is useful to identify compounds with fewer toxicity concerns. In summary, this small-scale and cost-effective PP can contribute to the identification of safer compounds that would lead to a reduction in drug attrition due to safety issues.

Practical application of 3-substituted-2,6-difluoropyridines in drug discovery: Facile synthesis of novel protein kinase C theta inhibitors

We previously reported a facile preparation method of 3-substituted-2,6-difluoropyridines, which were easily converted to 2,3,6-trisubstituted pyridines by nucleophilic aromatic substitution with good regioselectivity and yield. In this study, we demonstrate the synthetic utility of 3-substituted-2,6-difluoropyridines in drug discovery via their application in the synthesis of various 2,3,6-trisubstituted pyridines, including macrocyclic derivatives, as novel protein kinase C theta inhibitors in a moderate to good yield. This synthetic approach is useful for the preparation of 2,3,6-trisubstituted pyridines, which are a popular scaffold for drug candidates and biologically attractive compounds.

Design, synthesis, and biological evaluation of a novel series of peripheral-selective noradrenaline reuptake inhibitors - Part 3

Peripheral-selective inhibition of noradrenaline reuptake is a novel mechanism for the treatment of stress urinary incontinence to overcome adverse effects associated with central action. Here, we describe our medicinal chemistry approach to discover a novel series of highly potent, peripheral-selective, and orally available noradrenaline reuptake inhibitors with a low multidrug resistance protein 1 (MDR1) efflux ratio by cyclization of an amide moiety and introduction of an acidic group. We observed that the MDR1 efflux ratio was correlated with the pKa value of the acidic moiety. The resulting compound 9 exhibited favorable PK profiles, probably because of the effect of intramolecular hydrogen bond, which was supported by a its single-crystal structure. The compound 9, 1-{[(6S,7R)-7-(4-chloro-3-fluorophenyl)-1,4-oxazepan-6-yl]methyl}-2-oxo-1,2-dihydropyridine-3-carboxylic acid hydrochloride, which exhibited peripheral NET-selective inhibition at tested doses in rats by oral administration, increased urethral resistance in a dose-dependent manner.

Design, synthesis, and biological evaluation of a novel series of peripheral-selective noradrenaline reuptake inhibitors-Part 2

Peripherally selective inhibition of noradrenaline reuptake is a novel mechanism for the treatment of stress urinary incontinence to overcome adverse effects associated with central action. Herein, we describe our medicinal chemistry approach to discover peripheral-selective noradrenaline reuptake inhibitors to avert the risk of P-gp-mediated DDI at the blood-brain barrier. We observed that steric shielding of the hydrogen-bond acceptors and donors (HBA and HBD) of compound 1 reduced the multidrug resistance protein 1 (MDR1) efflux ratio; however, the resulting compound 6, a methoxyacetamide derivative, was mainly metabolized by CYP2D6 and CYP2C19 in the in vitro phenotyping study, implying the risk of PK variability based on the genetic polymorphism of the CYPs. Replacement of the hydrogen atom with a deuterium atom in a strategic, metabolically hot spot led to compound 13, which was mainly metabolized by CYP3A4. To our knowledge, this study represents the first report of the effect of deuterium replacement for a major metabolic enzyme. The compound 13, N-{[(6S,7R)-7-(4-chloro-3-fluorophenyl)-1,4-oxazepan-6-yl]methyl}-2-[(2H(3))methyloxy]acetamide hydrochloride, which exhibited peripheral NET selective inhibition at tested doses in rats, increased urethral resistance in a dose-dependent manner.

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.

Allylcyanation of Alkynes: Regio- and Stereoselective Access to Functionalized Di- or Trisubstituted Acrylonitriles

Allyl cyanides are found to add across alkynes in the presence of a nickel catalyst prepared from Ni(cod)2 and P(4-CF3-C6H4)3 in situ to give variously functionalized di- or trisubstituted acrylonitriles in highly stereoselective manners possibly via a pi-allylnickel species as an intermediate. alpha-Siloxyallyl cyanides also react at the gamma-position of a cyano group with both internal and terminal alkynes having various functional groups to give silyl enol ethers, which give the corresponding aldehydes or ketones upon hydrolysis.

Stannylative Cycloaddition of Enynes Catalyzed by Palladium−Iminophosphine

Palladium-iminophosphine complex catalyzes stannylative cycloaddition of conjugated enynes using hexabutyldistannoxane as a stannylating agent to afford highly substituted 3-alkenylphenylstannanes regioselectively. Stannylative cross-cycloaddition reactions between different enynes or between enynes and diynes are also achieved. The reaction is successfully applied to a concise synthesis of alcyopterosin N, which has been isolated recently from sub-Antarctic soft coral, Alcyonium paessleri.

[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.