AB0186 IMPROVEMENT OF RADIOGRAPHIC JOINT DESTRUCTION IN PATIENTS WITH EARLY RHEUMATOID ARTHRITIS IN THE LAST DECADE

Background

The paradigm shift has caused in the treatment for rheumatoid arthritis (RA) before the last decade [1]. The advent of high-dose MTX and biologics has maked it possible to treat RA with early and aggressive therapy, and prevent the joint destruction [2].

Objectives

To aim of this study, we investigated the joint destruction and clinical outcomes in patients with early RA every 5 years in the last decade.

Methods

81 patients with early RA (within 1 year from their onset of RA) enrolled retrospectively in this study. The number of patients with early RA were 21 in 2009, 23 in 2014, and 37 in 2019, respectively. They had 17 males and 64 females. Mean age was 59 years (19-92) at the first visit to our department. The following items were investigated: age, disease duration from onset to consultation, anti-cyclic citrullinated peptide antibody (ACPA) positivity (positivity was defined as >4.5 U/ml), CRP, DAS28CRP4, medications, and modified total sharp score (mTSS) at the time of initial consultation and 1 year later. Kruskal-Wallis test was used for statistics (PASW 25 software, SPSS Institute Inc., Chicago, IL, USA, p<0.05).

Results

The ACPA positivity rates were 71.4% (15/21) in 2009, 78.3% (18/21) in 2014, and 78.4% (29/37) in 2019, respectively. The mean value of DAS28CRP4 was 4.7 (2.4-6.8) in 2009, 4.2 (1.2-6.2) in 2014, and 4.2 (2.1-6.7) in 2019 at the time of the first visit to our department respectively. DAS28CRP4 under 2.6 was 29% (6/21) in 2009, 61% (14/23) in 2014, and 54% (20/37) in 2019 1 year after the first visit. The mean improvement of DAS28CRP4 (ΔDAS28CRP4) was -1.2 (-3.9 - 2.1) in 2009, -1.5 (-4.0 - 1.7) in 2014, and -1.7 (-4.1 - 0.4) in 2019, respectively. It had tended to improve gradually, however, it was not significantly different (p= 0.20, Figure 1).

Figure 1.

Mean value of improvement of mTSS and DAS28CRP4 (ΔmTSS and ΔDAS28CRP4) from initial visit to 1 year later at 2009, 2014 and 2019.

The changing of mTSS for a year (ΔmTSS) was 4.2 (0-17) in 2009, 0.9 (0-10) in 2014, and 0.6 (0-4) in 2019, respectivly. ΔmTSS in 2014 and 2019 was significantly lower compared to that in 2009 (p<0.05, Figure 1).

One year after the first visit to our department, the mean dose of MTX increased to 9.2 mg/week (2-14) in 2014 and 8.7 mg/week (4-16) in 2019 compared to 6.6 mg/week (2-8) in 2009 (p=0.19). The mean dose of PSL decreased 4.2 mg/day (1-8) in 2014, and 3.8 mg/day (1-10) in 2019 compared to 4.9 mg/day (2-10) in 2009, respectively (p=0.11). On the other hand, biological DMARDs were introduced in 24% (5/21) in 2009, 13% (3/23) in 2014, and 13% (1/37) in 2019, respectively.

Conclusion

Jonit destruction has been already reported to begin in patients with early-stage of RA [1, 2]. Based on the results of this study, joint desctruction in early RA was decreased in the last decade, because of more early and aggressive therapy for early RA with increasing mean dose of MTX gradually, not biologic DMARDs in real world. In addition, the mean dose of PSL in 2014 and 2019 decreased compared to that in 2009. The intensive therapy for early RA at our hospital has shown the improvement of joint destruction in the last decade.

References

[1]Emery P, Breedveld FC, Dougados M, et al. Early referral recommendation for newly diagnosed rheumatoid arthritis: evidence based development of a clinical guide. Ann Rheum Dis 2002;61:290–297.

[2]Smolen JS, Landewé RBM, Bijlsma JWJ, et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2019 update. Ann Rheum Dis 2020;79:685-699.

Disclosure of Interests

None declared

Application of cytochrome P450 reactivity on the characterization of chemical compounds and its association with repeated-dose toxicity

Repeated-dose toxicity (RDT) studies are one of the critical studies to assess chemical safety. There have been some studies attempting to predict RDT endpoints based on chemical substructures, but it remains very difficult to establish such a method, and a more detailed characterization of chemical compounds seems necessary. Cytochrome P450s (P450s) comprise multiple forms with different substrate specificities and play important roles in both the detoxification and metabolic activation of xenobiotics. In this study, we investigated possible use of P450 reactivity of chemical compounds to classify the compounds. A total of 148 compounds with available rat RDT test data were used as test compounds and subjected to inhibition assays against 18 human and rat P450s. Among the tested compounds, 82 compounds inhibited at least one P450 form. Hierarchical clustering analyses using the P450 inhibitory profiles divided the 82 compounds into nine groups, some of which showed characteristic chemical and biological properties. Principal component analyses of the P450 inhibition data in combination with the calculated chemical descriptors demonstrated that P450 inhibition data were plotted differently than most chemical descriptors in the loading plots. Finally, association analyses between P450 inhibition and RDT endpoints showed that some endpoints related to the liver, kidney and hematology were significantly associated with the inhibition of some P450s. Our present results suggest that the P450 reactivity profiles can be used as novel descriptors for characterizing chemical compounds for the investigation of the toxicity mechanism and/or the establishment of a toxicity prediction model.

Discovery of DSP-1053, a novel benzylpiperidine derivative with potent serotonin transporter inhibitory activity and partial 5-HT1A receptor agonistic activity

We have previously shown that SMP-304, a serotonin uptake inhibitor with weak 5-HT_1A partial agonistic activity, may act under high serotonin levels as a 5-HT_1A antagonist that improves the onset of paroxetine in the rat swimming test. However, SMP-304 is mostly metabolized by CYP2D6, indicating limited efficacy among individuals and increased side effects. To reduce CYP2D6 metabolic contribution and enhance SERT/5-HT_1A binding affinity, we carried out a series of substitutions at the bromine atom in the left part of the benzene ring of SMP-304 and replaced the right part of SMP-304 with a chroman-4-one. This optimization work led to the identification of the antidepressant candidate DSP-1053 as a potent SERT inhibitor with partial 5-HT_1A receptor agonistic activity. DSP-1053 showed low CYP2D6 metabolic contribution and a robust increase in serotonin levels in the rat frontal cortex.

Role of innate immune sensors, TLRs, and NALP3 in rheumatoid arthritis and osteoarthritis

Innate immune sensors, Toll-like receptors (TLRs), and nucleotide-binding oligomerization domain-like receptors (NLRs) participate in the induction of innate inflammatory and adaptive immune responses in rheumatoid arthritis (RA) and osteoarthritis (OA). Danger signals, e.g., heat-shock proteins (HSPs) and high mobility group box-1 protein (HMGB-1), internal ligands of TLRs, have been reported in the patients with RA and OA. In RA, TLR1-9 have been implicated in the pathogenesis. Although the precise role of each receptor is still unknown, immunohistochemical analyses of RA tissues after treatment of biologic disease modifying antirheumatic drugs showed phenotypic changes of immune cell types and residual expression of some TLRs. This suggests the potential for modulation of moderate/severe local joint inflammation, composed in particular of and possibly driven by the "auto-inflammatory" TLR+ cells, still responding to internal ligands derived from destroyed tissues. In OA, systematic profiling of TLR using a histological grading system recently showed that TLR+ cells are greater in number in the surface zone of grades 3 and 4 OA, but interestingly not grade 5. NACHT, LRR, and PYD domains-containing protein (NALP) 3 and related molecules have been also demonstrated both in RA and OA. In addition, a cross talk mechanism of TLR and NALP responsible for increasing joint inflammation has been suggested. Taken together, although OA is not basically an inflammatory disease, and is different from that of RA, pattern recognition receptors-signaling pathways, TLRs and NALP3 may play a role in the pathogenesis of both these conditions, probably as driving forces of progression. Precise and intensive analyses of both receptors, signal pathways, and cross talk mechanisms may provide a new therapeutic approach as molecular targets.

A genome-wide scan for tying-up syndrome in Japanese Thoroughbreds

Tying-up syndrome, also known as recurrent exertional rhabdomyolysis in Thoroughbreds, is a common muscle disorder for racehorses. In this study, we performed a multipoint linkage analysis using LOKI based on the Bayesian Markov chain Monte Carlo method using 5 half-sib families (51 affected and 277 nonaffected horses in total), and a genome-wide association study (GWAS) using microsatellites (144 affected and 144 nonaffected horses) to map candidate regions for tying-up syndrome in Japanese Thoroughbreds. The linkage analysis identified one strong L-score (82.45) between the loci UCDEQ411 and COR058 (24.9-27.9 Mb) on ECA12. The GWAS identified two suggestive genomic regions on ECA12 (24.9-27.8 Mb) and ECA20 (29.3-33.5 Mb). Based on both results, the genomic region between UCDEQ411 and TKY499 (24.9-27.8 Mb) on ECA12 was the most significant and was considered as a candidate region for tying-up syndrome in Japanese Thoroughbreds.

Genetics of racing performance in the Japanese Thoroughbred horse:: I. Description of the data

SUMMARY

The Japan Racing Association (JRA) operates 10 national racecourses with both turf and dirt tracks. JRA formulates the rules for horseracing; registers owners, colors, and horses using foal registration; and licenses all JRA trainers and jockeys. In 1990, at the 10 racecourses there were 288 racing days, 3,353 races, and some 38,397 horses. Horse breeding is concentrated in 7 locations with 93% of the Thoroughbreds foaled each year coming from Hokkaido. Thoroughbred flat racing comprise 92% of all races held. Two year olds race together and nearly 40% of their races are run at 1200 m. Some 39% of the three year olds races are at 1800 m. For 3 (and 4) year olds, the range in distances is from 1000 m to 3600 m. The average, over years, of the number of race records per race for 2 year olds is 10.0 and for 3 year olds and up is 11.3. The average for race records per horse for 2 year olds is 3.5 and for 3 year olds and up is 6.7. This average for horses raced per year for 2 year olds is 1,164 and 4,240 for 3 year olds and up. Horses raced per sire averaged over years was 4.6 for 2 year olds and 10.5 for the older ages. The linear regression of seconds per 100 m fit the average seconds reported for the several distances run almost perfectly with R(2) values greater than .99 for all horse ages on either turf or dirt. There is selection practiced as indicated by horse numbers registered and their numbers over ages for stallions and mares. Less than .2% of the horses raced are geldings. A high degree of control exists by JRA in horse stabling and distribution of racing by horses over racecourses. Jockeys are trained by JRA, ride at several race courses, and ride for many trainers. ZUSAMMENFASSUNG: Genetik der Rennleistung beim Japanischen Vollblut: I. Beschreibung der Daten Die "Japan Racing Association" (JRA) betreibt in ganz Japan zehn Pferderennbahnen sowohl mit Rasen- als auch mit Sandkursen. JRA legt die Regeln für Pferderennen fest, registriert die Eigentümer, Farben und Pferde mittels Fohlenregistrierung und vergibt die Lizenzen für alle JRA-Trainer und -Jockeys. Im Jahre 1990 verzeichneten die zehn Pferderennbahnen 288 Renntage, 3353 Rennen mit 38 397 Pferden; Pferdezucht ist an sieben Orten konzentriert, wobei 93% der Vollblutfohlen aus Hokkaido stammen. Bei 92% der veranstalteten Rennen handelt es sich um Nichthindernisrennen von Vollblutpferden. Dabei stehen die Zweijährigen im Wettbewerb, und fast 40% der Rennen gehen über 1200 m. Etwa 39% der Dreijährigen nehmen an Rennen über 1800 m teil. Bei den Dreijährigen (und Vierjährigen) liegen die Distanzen zwischen 1000 bis 3600 m. Der Durchschnitt der Zahl der Rennmeldungen über mehrere Jahre für die Zweijährigen beträgt 10,0 und für die dreijährigen und älteren Pferde 11,3. Der Durchschnitt der Rennmeldungen pro Pferd bei den Zweijährigen beträgt 3,5 und den dreijährigen und älteren Pferden 6,7. Durchschnittlich nehmen jährlich an Rennen 1164 zweijährige und 4240 dreijährige und ältere Pferde teil. Die durchschnittliche Zahl der Pferde über mehrere Jahre war 4,6 pro Vatertier für die Zweijährigen und 10,5 für ältere Pferde. Die lineare Regression von Sekunden pro 100 m paßte sich mit R(2) -Werten über 0,99 fast genau den Durchschnittssekunden an, die für die verschiedenen Renndistanzen angegeben wurden, für die Pferde aller Altersgruppen sowohl auf Rasen- als auch Sandbahn. Selektion bei Hengsten und Stuten ergibt sich aus Zahl der registrierten Pferde mit verschiedenem Lebensalter. Unter den an Rennen beteiligten Pferden sind weniger als 0,2% Wallache. Bei JRA herrscht ein hoher Grad an Kontrolle in bezug auf Ställe und die Verteilung über die Pferderennbahnen. Die von JRA ausgebildeten Jockeys reiten auf verschiedenen Pferderennbahnen und für mehrere Trainer.

Estimation of genetic correlations between racing times recorded at different racing distances by restricted maximum likelihood in Thoroughbred racehorses

SUMMARY

Genetic correlations between racing times on track type (turf and dirt), and at racing distances on turf (1200 m, 1400 m, 1600 m, 1800 m, and/or 2000 m) and dirt (1000 m, 1200 m, 1400 m, 1600 m, 1700 m, and/or 1800 m) tracks, were estimated in Thoroughbred horses. (Co)variance components were estimated using multiple-trait derivative-free restricted maximum likelihood (MTDFREML). The data used were collected by the Japan Racing Association from 1992 to 1993. The generation 2 pedigree information was preferable for (co)variance estimates. The genetic correlations between racing times on turf and dirt tracks ranged from 0.69 to 0.31 (average 0.51). The genetic correlations between racing distances ranged from 0.68 to 1.00 (average 0.85) and from 0.53 to 1.00 (average 0.88) on turf and dirt tracks, respectively. These results suggest that the racing time per 100 m can be used for horse genetic evaluation within one track type. ZUSAMMENFASSUNG: Schätzung genetischer Korrelationen zwischen Rennzeiten von Vollblüternüber verschiednen Distanzen mittels restringierter Genetische Korrelationen zwischen Rennzeiten auf Rasen- und Erdbahnen, Renndistanzen auf Rasen- (1200, 1400, 1600, 1800 und 2000 m) und Erdbahnen (1000, 1200, 1400, 1600, 1700 und 2000 m) wurden für Vollblüter geschätzt. (Co)Varianzkomponenten wurden mittels Mehr-Merkmal Ableitungsfreier Restringierter Maximum Likelihood (MTDFREML) geschätzt. Die Unterlagen wurden von der Japanischen Renn Vereinigung 1992 und 1993 gesammelt. Generation 2 Abstammungsinformation war für die Co-Varianzschätzung günstig. Genetische Korrelationen zwischen Rennzeiten auf Rasen und auf Erdbahnen waren zwischen 0.69 und 0.31 (Durchschnitt 0.51), jene zwischen Distanzen zwischen 0.68 und 1.00 (Durchschnitt 0.85) und zwischen 0.53 und 1.00 (Durchschnitt 0.88) auf Rasen und Erdbahnen. Die Ergebnisse zeigen, daß Rennzeit per 100 m zur Bewertung der Pferde geeignet ist.

The use of arthrography in the diagnosis of temporomandibular joint synovial chondromatosis

Synovial chondromatosis (SC) involving the temporomandibular joint (TMJ) is very rare and can occur in either or both cavities. Differentiation of the affected cavity in SC is therefore as important as making the diagnosis. This report presents a case of SC in which both cavities were thought to be affected, but arthrography using cone beam CT (CBCT) allowed us to see that involvement was limited to the superior joint cavity. In addition, we describe the usefulness of arthrographic CBCT for diagnosis and treatment planning in SC of the TMJ.

Pharmacological profile of lurasidone, a novel antipsychotic agent with potent 5-hydroxytryptamine 7 (5-HT7) and 5-HT1A receptor activity

Lurasidone [(3aR,4S,7R,7aS)-2-[(1R,2R)-2-[4-(1,2-benzisothiazol-3-yl)piperazin-1-ylmethyl]cyclohexylmethyl]hexahydro-4,7-methano-2H-isoindole-1,3-dione hydrochloride; SM-13496] is an azapirone derivative and a novel antipsychotic candidate. The objective of the current studies was to investigate the in vitro and in vivo pharmacological properties of lurasidone. Receptor binding affinities of lurasidone and several antipsychotic drugs were tested under comparable assay conditions using cloned human receptors or membrane fractions prepared from animal tissue. Lurasidone was found to have potent binding affinity for dopamine D(2), 5-hydroxytryptamine 2A (5-HT(2A)), 5-HT(7), 5-HT(1A), and noradrenaline alpha(2C) receptors. Affinity for noradrenaline alpha(1), alpha(2A), and 5-HT(2C) receptors was weak, whereas affinity for histamine H(1) and muscarinic acetylcholine receptors was negligible. In vitro functional assays demonstrated that lurasidone acts as an antagonist at D(2) and 5-HT(7) receptors and as a partial agonist at the 5-HT(1A) receptor subtype. Lurasidone showed potent effects predictive of antipsychotic activity, such as inhibition of methamphetamine-induced hyperactivity and apomorphine-induced stereotyped behavior in rats, similar to other antipsychotics. Furthermore, lurasidone had only weak extrapyramidal effects in rodent models. In animal models of anxiety disorders and depression, treatment with lurasidone was associated with significant improvement. Lurasidone showed a preferential effect on the frontal cortex (versus striatum) in increasing dopamine turnover. Anti-alpha(1)-noradrenergic, anticholinergic, and central nervous system (CNS) depressant actions of lurasidone were also very weak. These results demonstrate that lurasidone possesses antipsychotic activity and antidepressant- or anxiolytic-like effects with potentially reduced liability for extrapyramidal and CNS depressant side effects.

Estimation of heritability and genetic correlation for behavioural responses by Gibbs sampling in the Thoroughbred racehorse

Genetic variation of the behaviour of racehorses is one of the major concerns for racehorse breeders. In this study, the heritabilities of behavioural responses to the inspections of conjunctiva, auscultation and blood sampling and the genetic correlations among them were estimated in the Thoroughbred racehorse. The estimation was done with Bayesian analysis with Gibbs sampling based on the univariate or bivariate threshold animal models. The behavioural responses were scored with four categories at the first entrance quarantine in Miho Training Center of Japan Racing Association from 1993 to 1995. The behavioural responses were treated as categorical or binary traits, with both showing similar results. The estimated heritabilities were in the range of 0.23-0.28, suggesting a genetic component in the variation on these traits. The estimated genetic correlations among the traits were very high (approximately 0.9), suggesting that these behavioural responses may be measures of the same trait. Because of the high genetic correlations, repeatability threshold model was applied assuming the responses to be a genetically identical trait measured with three different tests. The estimated heritabilities (approximately 0.23) were at the lower bound of the former estimates. The revealed high repeatabilities (0.97-0.98) suggest a strong contribution of the individual temperament on the behaviour of racehorses.

Estimation of heritability for Tying-up syndrome in the Thoroughbred racehorse by Gibbs sampling

Tying-up is a condition that primarily affects the muscles of horses. In this study, the heritability of the Tying-up syndrome in the Thoroughbred racehorse was estimated by Bayesian analysis with Gibbs sampling based on the threshold model for binary traits. The data used were the clinical data in racehorses diagnosed by veterinarians of the Racehorse Clinics of Japan Racing Association from 2000 to 2003. The health status of the Tying-up was treated as a binary trait. In the genetic analysis, the effect of changing the amount of the pedigree or inbreeding information on the estimation of heritability was investigated, too. The heritability estimates with non-zero probability in the posterior densities were approximately 0.16-0.18 in minimum, suggesting that the heritability of the Tying-up is not zero at least. The posterior density distributions of the heritability estimates were generally more pointed and sharp with using inbreeding coefficients than without using it, suggesting that more stable estimations were obtained when inbreeding coefficients were used. Among the different amounts of pedigree and inbreeding information, the heritabilities obtained with three or four generations of pedigree using inbreeding coefficients seems to be preferable, i.e. heritability of 0.42 or 0.43 for Tying-up.

Crystallization and preliminary X-ray analysis of methionine aminopeptidase from the hyperthermophilic bacterium Pyrococcus furiosus

Methionine aminopeptidase (MAP) from Pyrococcus furiosus (Pfu) has been crystallized in four different forms (A, B, C and D). Form A crystals belong to space group P2(1) with unit-cell dimensions a = 54.18, b = 85.72, c = 72.84 A, beta = 108.34 degrees. Forms B, C and D belong to space group P6(2(4)) with unit-cell dimensions a = 139.1, c = 63.7 A for form B, a = 198.6, c = 243.8 A for form C, and a = 111.0, c = 125.0 A for form D. Forms A and D diffract to 2.9 A, form B diffracts to 3.5 A, and form C crystals diffract to 4.5 A. Form A contains two molecules of MAP-Pfu per asymmetric unit. The binuclear metal center positions and a non-crystallographic twofold symmetry matrix has been determined for the form A crystals.

Bone grafting in cementless total hip replacement for congenital dysplasia of the hip

We reviewed 27 cementless primary total hip replacements in patients with osteoarthrosis secondary to congenital dysplasia of the hip. Autogenous bone grafting was used as augmentation. On average the follow-up period was 9 years. Two hips were revised and three acetabular components were considered loose. In hips with loose cups the average graft coverage was significantly greater than in stable hips. The use of a cementless acetabular component is encouraging for reconstruction, although extensive grafting should be avoided. Our study suggests that cementless reconstruction in dysplastic hips yields a satisfactory outcome.

Serial measurement of polyethylene wear of well-fixed cementless metal-backed acetabular component in total hip arthroplasty: an over 10 year follow-up study

Serial radiographic measurements of polyethylene wear were performed in 38 hips (33 patients) with primary cementless total hip arthroplasty (THA). The average follow-up period was 131.8 months. All prostheses were assessed as radiographically stable at the latest follow-up. A two-dimensional method was used to calculate the relative migration of the femoral head center to the cup center. The average total linear wear and wear rate were 1.22 mm and 0.11 mm/year, respectively. The degree of wear in the first 2 postoperative years accounted for nearly 40% of the total wear at the end of the study (average follow up: 131.8 +/- 10.0 months, +/-SD). The migration of the femoral head at an average period of 3. 4 months after operation accounted for 56% of the amount of wear in the first 2 years. Wear rate decreased gradually with time and stabilized after the fourth year. However, in 2 patients, a progressive increase in the wear rate was associated with severe osteolysis and failure of THA. Both creep and wear contributed to the femoral penetration into the polyethylene liner. The influence of creep cannot be ruled out, especially in the early period after operation. Polyethylene wear is a multifactorial process, and the study of individual wear patterns might be useful in identifying patients who are at risk of late failure of THA.

Use of an instrument sandwiched between the hoof and shoe to measure vertical ground reaction forces and three-dimensional acceleration at the walk, trot, and canter in horses

OBJECTIVE

To develop an instrument that could be sandwiched between the hoof and shoe of horses and that would reliably measure vertical ground reaction forces and three-dimensional acceleration at the walk, trot, and canter.

ANIMALS

5 clinically sound Thoroughbreds.

PROCEDURES

The recording instrument (weight, 350 g) consisted of 2 metal plates, 2 bolts, 4 load cells, and 3 accelerometers. It was mounted to the hoof with a glue-on shoe and devised to support as much load exerted by a limb as possible. The load cells and accelerometers were wired to a 16-channel transmitter, and transmitted signals were received and amplified with a telemetry receiver.

RESULTS

The recording instrument could measure in real time the 4 components of the ground reaction force or their resultant force along with acceleration in 3 dimensions as horses walked, trotted, or cantered on a treadmill. Patterns of force-time curves recorded for consecutive strides were similar to each other and to those previously reported, using a force plate.

CONCLUSIONS AND CLINICAL RELEVANCE

The recording instrument developed for use in the present study allowed us to record vertical ground reaction force and acceleration in 3 dimensions in horses at the walk, trot, and canter.

Influence of rough track surfaces on components of vertical forces in cantering thoroughbred horses

No kinetic data are available to indicate the influence of a rough track surface and the resultant loss of footing on the components of hoof vertical forces. The aim of the present study was to evaluate the influence of rough track surfaces on the components of hoof vertical forces. Seven clinically sound 2-year-old Thoroughbred horses had instrumented shoes attached to both of the fore hooves to obtain the magnitudes of consecutive forces exerted in the hoof. All horses were cantered at approximately 10 m/s on straight tracks of smooth and rough surfaces of woodchip and dirt. The instrumented shoe indicated in real time 4 component forces acting on the hoof via 4 transducers positioned on the lateral and medial sides of the toe (LT, MT) and the heel (LH, MH). The peak vertical component forces of the heel were about twice that of the toe. The variances of the 4 components of peak vertical forces significantly increased on the rough track surface of both the woodchip (Leading: LH, MH and MT; Trailing: MH and LT) and dirt (Leading: LH and LT; Trailing: MH and MT) tracks. The trajectories of the position of the resultant force acting on the hoof also tended to increase the variance on rough track surfaces. Therefore, running on a rough track changes the vertical hoof forces and the balance of the resultant hoof forces. These results suggest a mechanism by which the rough track surfaces may influence the soundness of the horse.

EMG activity of the muscles of the neck and forelimbs during different forms of locomotion

We recorded the electromyographic (EMG) activity of 7 skeletal muscles in the forequarters and 1 in the hindquarters of 6 Thoroughbred horses during overground walking, swimming in a circular pool, and walking and trotting in a water treadmill. Bipolar fine wire electrodes were inserted into the muscles and the EMG signals were recorded using a telemetric system. The splenius exhibited tonic EMG activity during swimming. The brachiocephalicus showed its highest intensity during swimming followed by the walk and trot in the water treadmill and then walking overground. The triceps brachii caput longum had a similar activity pattern to the brachiocephalicus. The brachialis showed only weak EMG activity in all 3 types of locomotion. The extensor digitorum communis had higher intensity of EMG activity in the walk in the water treadmill than in other kinds of locomotion. The flexor digitorum profundus exhibited the most intense EMG activity during swimming. These results indicated that swimming evoked strong EMG activity in the antigravity muscles in spite of reduced gravitational force. Walking in the water treadmill may require more intensified EMG activity of the forelimb than the trot in the same treadmill.

Refined structure of orthorhombic lysozyme crystallized at high temperature: correlation between morphology and intermolecular contacts

The structure of orthorhombic hen egg-white lysozyme (HEWL) crystallized at 310 K has been refined at 1.7 A resolution. Large displacements of the side-chain atoms with respect to the tetragonal structure were observed in many places, in contrast to small displacements of the main-chain atoms. A chloride-ion binding site was observed at an interface of two molecules, but at a different position to the binding site in the tetragonal form. The analysis of intermolecular contacts in the crystal has shown the presence of three independent intermolecular contacts which are called macrobonds A, B and C. Arginine side chains are frequently involved in these macrobonds, suggesting that the high frequency of this residue in HEWL may be a possible reason for the multiple polymorphs of this protein. The crystal forms were determined using a light-reflecting device on a four-circle diffractometer. Correlations between crystal forms and the three-dimensional macrobond networks were interpreted in terms of their components in various crystallographic planes, making use of approximate strengths of hydrogen-bond and van der Waals interatomic forces.

Crystal structure of methionine aminopeptidase from hyperthermophile, Pyrococcus furiosus

The structure of methionine aminopeptidase from hyperthermophile Pyrococcus furiosus (PfMAP) with an optimal growth temperature of 100 degreesC was determined by the multiple isomorphous replacement method and refined in three different crystal forms, one monoclinic and two hexagonal, at resolutions of 2.8, 2.9, and 3.5 A. The resolution of the monoclinic crystal form was extended to 1.75 A by water-mediated transformation to a low-humidity form, and the obtained diffraction data used for high-resolution structure refinement. This is the first description of a eukaryotic type methionine aminopeptidase structure. The PfMAP molecule is composed of two domains, a catalytic domain and an insertion domain, connected via two antiparallel beta-strands. The catalytic domain, which possesses an internal 2-fold symmetry and contains two cobalt ions in the active site, resembles the structure of a prokaryotic type MAP from Escherichia coli (EcMAP), while the structure of the insertion domain containing three helices has a novel fold and accounts for a major difference between the eukaryotic and prokaryotic types of methionine aminopeptidase. Analysis of the PfMAP structure in comparison with EcMAP and other mesophile proteins reveals several factors which may contribute to the hyperthermostability of PfMAP: (1) a significantly high number of hydrogen bonds and ion-pairs between side-chains of oppositely charged residues involved in the stabilization of helices; (2) an increased number of hydrogen bonds between the positively charged side-chain and neutral oxygen; (3) a larger number of buried water molecules involved in crosslinking the backbone atoms of sequentially separate segments; (4) stabilization of two antiparallel beta-strands connecting the two domains of the molecule by proline residues; (5) shortening of N and C-terminal tails and stabilization of the loop c3E by deletion of three residues.

High-resolution crystals of methionine aminopeptidase from Pyrococcus furiosus obtained by water-mediated transformation

The monoclinic crystal form of methionine amino-peptidase from Pyrococcus furiosus (MAP-Pfu) has been crystallized from four different conditions. Native crystals belong to space group P2(1) with typical unit-cell dimensions a = 53.4, b = 85.1, c = 72.7 A, beta = 107.7 degrees and diffract to 2.9-4.5 A resolution. However, there is a problem of nonisomorphism among the crystals. Water-mediated transformation to low-humidity form occurs by reduction of the relative humidity of crystal environment to 79%. The unit-cell dimensions of transformed crystals are a = 51.9, b = 83.3, c = 70.3 A, beta = 105.9 degrees, and the calculated solvent content is 3.9% less than in original crystals. Transformation to low-humidity form is accompanied by 1.7 times reduction of overall temperature factors, extension of diffraction resolution up to 1.75 A, without change or reduction of crystal mosaicity, and improvement in stability to X-ray radiation. The water-mediated transformation also appears to relieve the problem of nonisomorphism among the original MAP-Pfu crystals.

Pituitary stalk meningioma: case report

We report a 45-year-old woman with a meningioma which was in contact with only the pituitary stalk on MRI. As the pituitary stalk has no dura mater, we suggest this tumour may have originated from the arachnoid membrane of the pituitary stalk. Though some reports have shown that meningiomas can arise from sites lacking a dural component, this is the first report of a meningioma originating from the pituitary stalk.

Assessment of autonomic nervous function by power spectral analysis of heart rate variability in the horse

We studied power spectral analysis of heart rate (HR) variability in the horse, with the hypothesis that the quantitative information provided by the spectral analysis of HR variability reflects the interaction between sympathetic and parasympathetic regulatory activities. For this purpose, electrocardiogram, blood pressure (BP) and respiratory (Resp) waveform were simultaneously recorded from Thoroughbred horses (3-5 years old) and analyzed by power spectrum. There were two major spectral components at low-frequency (LF) and high-frequency (HF) bands for HR variability. The peak of Resp variability clearly occurred at the HF range. In contrast to Resp variability, the power spectra of BP variability occurred at lower frequencies. The maximum coherence between HR and Resp variabilities and HR and BP variabilities occurred at approximately 0.15 and approximately 0.03 Hz, respectively. These relationships were similar to the ensemble spectra. On the basis of these data, we have defined two frequency bands of interest: LF (0.01-0.07 Hz) and HF (0.07-0.6 Hz). Therefore, we believe that power spectral analysis of HR variability provides a very powerful technique for assessing autonomic nervous activity in the horse.

Benign convulsions with mild gastroenteritis: a report of 10 recent cases detailing clinical varieties

To better define the characteristic clinical features of benign convulsions with mild gastroenteritis, recently recognized as a new entity in Japan, we reviewed all the 10 patients we have seen from 1992 to 1994. The clinical features have been previously reported in the literature to be afebrile generalized tonic-clonic seizures occurring between the first and the fifth sick day of mild gastroenteritis. In our series, four of 10 patients had convulsions before the onset of gastroenteritis. Overall, seizures were mostly brief and often repetitive occurring in cluster (19 seizures/10 episodes). Among these, a prolonged or partial seizure was frequently observed. In six of the 10 patients, the seizure type changed during an episode: from generalized to partial seizures (n = 2), from partial to generalized seizures (n = 2), or from partial to another type of partial seizures (n = 2). None in our series experienced a recurrence episode of afebrile convulsion during follow-up. These findings suggest that benign convulsions with mild gastroenteritis exhibit some variations in their clinical manifestation.

Cardiac sympathetic innervation in patients with dilated cardiomyopathy--immunohistochemical study using anti-tyrosine hydroxylase antibody

Depletion of norepinephrine in the left ventricular myocardium in cases of dilated cardiomyopathy (DCM) has been suggested. However, there have been few histological studies of the sympathetic nerves, in which myocardial norepinephrine is believed to exist. We performed an immunohistological study of the density of tyrosine hydroxylase (TH, a marker of sympathetic nerves)-positive nerve fiber in endomyocardial biopsy specimens in cases of DCM using antibody against TH. TH-positive nerves were stained brown along with the myocardium, and they were more dense in the right ventricle than in the left ventricle in both the DCM and control groups. The density of TH-positive nerves in cases of DCM was significantly less than that in the control group in the subendocardial myocardium of the right and left ventricles, but especially in the left ventricle. A correlation was observed in the DCM group between the density of TH-positive nerves and the ejection fraction in the right ventricle, but not in the left ventricle. In the failing human heart, a decrease in subendocardial sympathetic nerve density may be one of the causes of myocardial norepinephrine depletion.

[The study of continuous local arterial-infusion chemotherapy with 5-FU + CDDP for patients with severely advanced HCC--for the elongation of the life-span and the improvement of QOL]

We tried continuous local arterial-infusion chemotherapy using 5-FU + CDDP with an implanted reservoir, for patients with severely advanced hepatocellular carcinoma (HCC), who had no indications for operation, PEIT or TAE. Arterial-infusion was continued for one week, followed by a one-week no-infusion period, and this treatment was repeated 1-32 times, and patients were observed for 36-549 days. Until the end of April 1993, the one-year survival rate was 61.1%. There were 3 partial remission (PR) cases, 3 progressive disease (PD) cases and the other cases showed no change (NC). Only one patient had any side effects, and all could continue as outpatients for 94.0% of the entire therapy. The patients' evaluation of QOL revealed no differences of QOL according to the length of the whole therapy, the history of rehospitalization during therapy, response to therapy, etc. But PR cases tended to show improved QOL. Therefore we considered this as effective therapy for the elongation of the life-span and the improvement of QOL.

Sequence in DNA synthetic phase ratio of spontaneous hypertensive rat (SHR) myocardium--study on development of cardiomegaly

We studied the relative synthetic phase (S-phase) ratio of cardiac myocytes of spontaneously hypertensive rats (SHR) utilizing monoclonal antibody to 5-bromo 2'-deoxyuridine (BrdU), a halogen derivative of thymidine. BrdU was administered intraperitoneally to SHR and Wistar Kyoto rats at 66.7 mg/kg/day for 3 consecutive days. The rats were sacrificed 1 week after the first injection of BrdU. Using anti-BrdU antibody, myocardial tissue was stained by the avidin biotinylated peroxidase complex method. We assessed the ability of the nuclei to synthesize DNA. The percentage of BrdU-labeled myocytes was higher in SHR than in control rats at 9 weeks. The hyperplastic phase of heart growth in rats was presumed to occur about 3 weeks after birth. From these results, the ability of the myocardial cell to synthesize DNA is probably enhanced under the load of high blood pressure in the early hypertrophic phase following hyperplasia.

Phosphorus-31 NMR spectra by the linear prediction z-transform method

The linear prediction z-transform method (LPZAR) was applied to estimate 31P NMR spectra of perfused rat hearts. The spectra obtained by the LPZAR method showed sharper peaks with less noise for phosphate concentrations than those obtained by conventional fast Fourier transform. The LPZAR method provided a better estimation of intracellular phosphate concentrations in short acquisition time experiments in which condition Fourier transform spectra are not suitable for the quantification due to the poor resolution of FFT spectra. Utilizing the LPZAR method, rapid changes in phosphoric metabolites of the heart can be monitored during ischemia followed by reperfusion.

Artificial neural networks for source localization in the human brain

Source localization in the brain remains an ill-posed problem unless further constraints about the type of sources and the head model are imposed. Human head is modeled in various ways depending critically on the computing power available and/or the required level of accuracy. Sophisticated and truly representative models may yield more accurate results in general, but at the cost of prohibitively long computer times and huge memory requirements. In conventional source localization techniques, solution source parameters are taken as those which minimize an index of performance, defined relative to the model-generated and clinically measured voltages. We propose the use of a neural network in the place of commonly employed minimization algorithms such as the Simplex Method and the Marquardt algorithm, which are iterative and time consuming. With the aid of the error-backpropagation technique, a neural network is trained to compute source parameters, starting from a voltage set measured on the scalp. Here we describe the methods of training the neural network and investigate its localization accuracy. Based on the results of extensive studies, we conclude that neural networks are highly feasible as source localizers. A trained neural network's independence of localization speed from the head model, and the rapid localization ability, makes it possible to employ the most complex head model with the ease of the simplest model. No initial parameters need to be guessed in order to start the calculation, implying a possible automation of the entire localization process. One may train the network on experimental data, if available, thereby possibly doing away with head models.

Repetitive intratumoral hemorrhage in medulloblastoma. A case report

An 8-year-old girl experienced five repeated hemorrhagic episodes around the cerebellar vermis. Surgical specimens histologically showed abnormal vascular components invaded by tumor cells. Autopsy disclosed medulloblastoma disseminating in the subependymal zone of the ventricles. An atypical clinical course is reported with special attention to the cause of hemorrhage.

Analysis of premovement components of movement-related cortical potentials in patients with Parkinson's disease or brain tumors

We have recorded movement-related cortical potentials (MRCPs) preceding voluntary finger extension in patients with Parkinson's disease and in patients with brain tumors that may involve the motor system. Three components of potential shifts preceding the voluntary movement were identified in all subjects. There were no differences between the healthy subjects and those with Parkinson's disease, or between pre- and postoperative recordings from the same parkinsonian patients in terms of onset latencies and gradients of these potential shifts. There was no evidence of MRCPs from the depth electroencephalogram recorded from the thalamic ventrolateral (VL) nucleus. After removal of the cerebellar dentate nucleus along with a tumor, MRCPs were still identified. After removal of tumors from the supplementary motor cortex and frontal association cortex, a part of the MRCPs preceding the voluntary movement was absent. The generation of MRCPs was considered not to be greatly affected by the cerebellar system because: (1) no MRCPs were detected from the thalamic VL nucleus, which is the relay nucleus of the dentato-rubro-thalamic pathway, believed to be related to voluntary movement; (2) destruction of the VL nucleus did not cause any changes in the MRCPs recorded at other sites, and (3) the MRCPs did not disappear when the dentate nucleus, an output system, was excised.

[MRI findings of locked-in syndrome--a case report]

We report a case of Locked-in syndrome caused by thrombus in basilar artery resulting in a brainstem infarction in the ventral pons, magnetic resonance imaging (MRI) shows abnormal signal intensity regions in the ventral pons and basilar artery clearly.

[A case of unruptured A1 aneurysm causing ischemic compression to the medial proximal striate artery]

A 58-year-old female was admitted to our hospital because of weakness of the right lower extremity and dysesthesia of the right upper extremity. From her clinical symptoms the patient was tentatively diagnosed as having a sort of cerebral infarction and treated with administration of urokinase and antiplatelet agents. However, angiographical examination revealed a unruptured aneurysm of the A1 portion of the left anterior cerebral artery. Preoperative angiogram showed that the dome of the aneurysm compressed one of the neighboring perforating artery which arose from adjacent to the neck of the aneurysm. The patient underwent neck clipping of aneurysm successfully. During the operation, the perforator was hardly adhered to the dome of the aneurysm. So, careful dissection was made only around the neck and the perforator was spared. Her symptoms were disappeared immediately after surgery. The perforator was demonstrated with better filling in the postoperative angiogram than that in the preoperative angiogram. The pathomechanisms of cerebral ischemia caused by unruptured aneurysm were reviewed on the literature. Most of the cases were caused by release of fragmental thrombi from a large aneurysm. There was a very exceptional case whose symptoms had seemed to be related to the direct compression of the neighboring perforator by the aneurysm. The compressed perforator in this case was seemed to be corresponded with the medial proximal striate artery stated by Yaşargil.

[Adult identical twins with moyamoya disease]

Adult identical twins with Moyamoya disease are reported. Laboratory examinations such as blood types, AB, Rh(+), HLA (human leucocytic antigen) analysis [AW26(9), A26(10), BW62(15), BW61(40), CW3], and finger prints, and hairs confirmed that two patients were identical twins. Both had normal serum immunoglobulin levels and no anti-DNA antibodies. Patient No. 1, a 39-year-old female, was admitted to our service with chief complaints of nausea, vomiting and left hemiparesis with sudden onset on Oct 31, 1981. The patient had an episode of tetraplegia that occurred suddenly at 4 years of her age and lasted about a week. Motor weakness had completely disappeared but moderate mental retardation remained. She had been employed just prior to this attack. CT and angiographic examinations revealed ventricular hemorrhage with Moyamoya disease, which had miliary aneurysm in the branch of the right posterior choroidal artery. The operation of encephalomyosynangiosis was performed on her left hemisphere. The postoperative course was uneventful. Patient No. 2, the twin sister of patient No. 1, was in good health and mental state until 19 years of her age, when she suddenly lost consciousness and developed hemiparesis. After this attack, her motor function had recovered well. However, mental ability gradually deteriorated and she was admitted to a psychiatric ward. CT examination and angiographic studies were performed on Oct 12, 1982, and she was diagnosed as having Moyamoya disease.(ABSTRACT TRUNCATED AT 250 WORDS)