Transcriptional activation of the human c-myc gene by simian virus 40 large T antigen without binding to p53 and RB proteins in the transient expression system

Transcriptional activation of the human c-myc gene by SV40 large T antigen was examined using HepG2 cells by co-transfecting a T antigen expression plasmid with a myc-CAT construct containing the 2.3-kb upstream region from the P1 promoter and the P2 promoter region fused to the CAT gene. T antigen increased the basal activity of the P2 promoter region containing the E2F binding site, but both the P2 promoter region and the upstream region from the P1 promoter were important for overall activation by T antigen. CAT assay using mutated T antigen lacking p53 or the RB binding site indicated that p53 or RB was not mainly involved in transcriptional activation of the c-myc gene. It appears that activation of the c-myc gene by T antigen is probably dependent upon E2F and a cellular factor through a mechanism which is independent of binding of T antigen to p53 and RB.

The Chlamydomonas reinhardtii ODA3 gene encodes a protein of the outer dynein arm docking complex

We have used an insertional mutagenesis/ gene tagging technique to generate new Chlamydomonas reinhardtii mutants that are defective in assembly of the uter ynein rm. Among 39 insertional oda mutants characterized, two are alleles of the previously uncloned ODA3 gene, one is an allele of the uncloned ODA10 gene, and one represents a novel ODA gene (termed ODA12). ODA3 is of particular interest because it is essential for assembly of both the outer dynein arm and the outer dynein arm docking complex (ODA-DC) onto flagellar doublet microtubules (Takada, S., and R. Kamiya. 1994. J. Cell Biol. 126:737- 745). Beginning with the inserted DNA as a tag, the ODA3 gene and a full-length cDNA were cloned. The cloned gene rescues the phenotype of oda3 mutants. The cDNA sequence predicts a novel 83. 4-kD protein with extensive coiled-coil domains. The ODA-DC contains three polypeptides; direct amino acid sequencing indicates that the largest of these polypeptides corresponds to ODA3. This protein is likely to have an important role in the precise positioning of the outer dynein arms on the flagellar axoneme.

Decreased expression of full-length mRNA for cBCD541 does not correlate with spinal muscular atrophy phenotype severity

Spinal muscular atrophy (SMA) is characterized by degeneration of spinal cord anterior horn cells and muscular atrophy and has three phenotypes based on clinical severity and age of onset. One of the responsible genes for SMA is the survival motor neuron (SMN) gene, which is homozygously absent or interrupted in more than 90% of SMA patients. The cBCD541 (BCD) gene is a highly homologous copy of the SMN gene, which has a single synonymous transition in the coding region and may compensate for the loss of the SMN gene. To evaluate the effects of the BCD gene expression on the phenotypes of SMA, we examined lymphocyte mRNA from 9 SMA patients lacking the SMN gene, 10 asymptomatic parents, and 15 control subjects. We amplified mRNA fragments containing exon 7 of the SMN or BCD genes using reverse transcription-polymerase chain reaction since the transcript lacking exon 7 encodes a putative protein with a different C-terminal end. We used glyceraldehyde-3-phosphate dehydrogenase (GAPDH) transcript as an internal control, and the relative expression level of the SMN or BCD gene was shown as the ratio of SMN or BCD transcript to GAPDH transcript (S/G ratio). The mean S/G ratios of the patients were significantly lower than that of the parents and controls. However, among the patients examined in this study, there was no relationship between the S/G ratios and phenotypes of SMA. The results showed that the BCD gene expression was not related to the phenotypes of SMA. Furthermore, there was an overlap between the S/G ratios in patients and controls. As our discrimination study showed that the S/G ratio reflected the expression of the BCD transcripts in patients and the SMN transcripts in controls, this finding suggested that the BCD gene expression per se does not compensate for the loss of the SMN gene.

Isolation and analysis of cellular DNA fragments directly binding to c-Myc protein

c-Myc protein, the product of cellular oncogene c-myc, is thought to play an important role in the control of cell cycle progression by binding to the E-box sequence (CACGTG) of cellular DNA, but only a few target genes are known. We cloned two small human DNA fragments (n16 and r37) that bound to c-Myc protein in vitro by random screening. Both clones contained the E-box sequence, to which c-Myc protein bound directly in vitro. Northern blot analysis showed that a low molecular-weight RNA was transcribed from the region near the n16 c-Myc binding site. The function of this low molecular-weight RNA and the regulatory role of c-Myc protein in related transcription are now under investigation.

An elementary mode coupling theory of random heteropolymer dynamics

The Langevin dynamics of a random heteropolymer and its dynamic glass transition are studied using elementary mode coupling theory. Contrary to recent reports using a similar framework, a discontinuous ergodic-nonergodic phase transition is predicted for all Rouse modes at a finite temperature T(A). For sufficiently long chains, T(A) is almost independent of chain length and is in good agreement with the value previously estimated by a static replica theory.

Evidence that absence of Wnt-3a signaling promotes neuralization instead of paraxial mesoderm development in the mouse

Wnt-3a mutant embryos show defects caudal to the forelimb level; somites are absent, the notochord is disrupted, and the central nervous system has a pronounced dysmorphology. Previous studies revealed that the primary defects of the mutant embryos are likely to be in the process of paraxial mesoderm formation. In this study, we analyzed the phenotype of Wnt-3a mutant embryos at early somite stages (8.0 days post coitum), when somite formation is initiated. In Wnt-3a mutants, cells which have ingressed through the primitive streak do not migrate laterally but remain under the streak and form an ectopic tubular structure. Several neural-specific molecular markers, but no paraxial mesoderm markers, are expressed in this structure, suggesting that the ectopic tube is an additional neural tube. In normal embryos, Wnt-3a is expressed in the primitive ectoderm, including the cells which are fated to give rise to the paraxial mesoderm and neurectoderm, but expression is absent in migrating mesoderm cells. These results suggest that Wnt-3a signaling may play a role in regulating paraxial mesodermal fates, at the expense of neurectodermal fates, within the primitive ectoderm of the gastrulating mouse embryo.

[Allergic bronchopulmonary aspergillosis successfully treated with itraconazole]

A 67-year-old man was admitted to our hospital because of coughing, a low-grade fever, and abnormal shadows on a chest X-ray film. He had had asthma as a child, but had no asthmatic symptoms on admission. A CT scan showed collapse of the right middle lobe and mucoid impactions in the lingula. Bronchoscopy revealed thick mucus obstructing the right middle-lobe bronchus and the left upper-lobe bronchus. The eosinophil count and the IgE level were abnormally high. Aspergillus fumigatus was detected in his sputum. Tests for immediate skin reaction and precipitating antibody to aspergillus antigen were positive. After treatment with itraconazole he became asymptomatic. Radiographic abnormalities had resolved by 1 month after the start of treatment; a high resolution CT scan obtained after clinical improvement revealed central bronchiectasis. In this patient with allergic bronchopulmonary aspergillosis, a course of itraconazole alone was followed by satisfactory improvement.

The expression of the mouse Zic1, Zic2, and Zic3 gene suggests an essential role for Zic genes in body pattern formation

We examined the expression of Zic1, Zic2, and Zic3 genes in the mouse embryo by means of in situ hybridization. Zic genes were found as a group of genes coding for zinc finger proteins that are expressed in a restricted manner in the adult mouse cerebellum. We showed that the genes are the vertebrate homologues of Drosophila odd-paired, which may play an essential role in parasegmental subdivision and in visceral mesoderm development. The expression of the three Zic genes was first detected at gastrulation in a spatially restricted manner. At neurulation, the expression became restricted to the dorsal neural ectoderm and dorsal paraxial mesoderm. During organogenesis, the three genes were expressed in specific regions of several developing organs, including dorsal areas of the brain, spinal cord, paraxial mesenchyme, and epidermis, the marginal zone of the neural retina and distal regions of the developing limb. For all stages, significant differences in the spatial expression of Zic1, Zic2, and Zic3 were observed. Furthermore, the expression of Zic genes in Pax3, Wnt-1, and Wnt-3a mutant embryos suggested that Zic genes are not primarily regulated by the three genes which were expressed in dorsal areas similar to Zic genes. However, in open brain, a mutant with severe neural tube defects, and in the Wnt-3a mutant mice, the expression of Zic genes was changed. The changed expression pattern in Wnt-3a mutant mice suggests that Zic genes in the neural tube are regulated by the factors from notochord. Our findings suggest that Zic genes are involved in many developmental processes. Furthermore, analysis of gene expression patterns in different mouse mutants indicated that Zic genes may act upstream of many known developmental regulatory genes.

Linkage map of Syrian hamster with restriction landmark genomic scanning

We have constructed the linkage map with precise genetic analysis of the Syrian hamster, Mesocricetus auratus, according to the restriction landmark genomic scanning (RLGS) spot mapping method. Although only 3.2-6.6% of the total RLGS spots between the two strains, ACN and BIO 14.6, showed genetic variance, 572 loci were found to be polymorphic. Out of 569 RLGS loci and 3 other loci, 531 were mapped with the backcross (ACN x BIO 14.6) F1 x BIO 14.6. The cumulative map was 1111.6 cM, indicating that the spots/loci are located throughout the genome at 1.94 cM intervals on average. Thus, RLGS provides us with a rapid tool to construct the genetic map of any species, even if it has less genetic variation.

Thromboxane inhibition potentiates antihypertensive effects of alpha 1 adrenoceptor antagonists in the rat

We investigated the influence of the vascular and renal thromboxane system on the antihypertensive effects of the alpha 1 adrenoceptor antagonist (alpha 1 blocker) bunazosin in spontaneously hypertensive rats (SHR). SHR were treated for 2 weeks with the alpha 1, blocker bunazosin (0.5 mg/kg body weight/day). The systolic blood pressure immediately declined with bunazosin treatment, and then rose toward the level observed in untreated SHR. This antihypertensive effect was accompanied by a decrease in the ratio of prostacyclin to thromboxane A2 in the vascular wall and the kidney. A subdepressor dose of the thromboxane synthase inhibitor OKY-046 lessened the thromboxane generation during bunazosin treatment, and synergistically potentiated the antihypertensive action of the alpha 1 blocker. Such synergy was also observed between OKY-046 and prazosin, an alternative alpha 1 blocker, but not with amosulalol, an alpha 1 blocker having no quinazoline moiety. alpha 1 blockers with a quinazoline moiety dose-dependently stimulate thromboxane generation in cultured smooth muscle cells from SHR. These data indicate that alpha 1 blockers enhance thromboxane generation in the arterial wall and kidney, thereby contributing to the lessening of the antihypertensive effects observed during alpha 1 blocker treatment.

Beat frequency difference between the two flagella of Chlamydomonas depends on the attachment site of outer dynein arms on the outer-doublet microtubules

The two flagella of Chlamydomonas, although similar to each other at first glance, differ in functional properties. A clear difference exists in the beat frequency: the trans-flagellum (the one farthest from the eyespot) beats with 30-40% higher frequency than the cis-flagellum (the one nearest to the eyespot) in demembranated and reactivated cell models. This difference is considered to be influenced by outer arm dynein, because the two flagella beat at almost the same frequency in cell models of oda mutants lacking the outer dynein arm. When a sample of outer arm dynein extracted and purified from the wild-type axoneme was mixed with the cell models of an oda mutant, oda1, an almost normal number of outer dynein arms became attached to the axonemes, and the wild-type level of beat frequency was recovered on reactivation with ATP addition. The frequency imbalance, however, was not restored. Unexpectedly, when a similar experiment was performed with the cell model of another oda mutant, oda6, the addition of outer arm dynein restored the cis-trans frequency imbalance in addition to the normal number of outer arms and the higher level of reactivated motility. Among other oda mutants, oda3 yielded results similar to those with oda1, whereas oda2, oda4, and oda5 yielded results similar to those with oda6. Because the only structural difference between the two groups of oda mutants is that the oda1 and oda3 axonemes lack the outer arm attachment site on the outer doublet A-tubule while the axonemes of the other mutants retain it, these findings suggest that the attachment site for the outer dynein arm is important in determining the flagellar beat frequency. This suggests that the basal portion of the outer arm dynein is important in regulating the flagellar activity and therefore the behavior of the cell.

Regulation of androgen synthesis: the late steroidogenic pathway

Studies of the regulation of androgen synthesis in steroidogenic cells have focused on both transcriptional and post-translational regulation of the proteins that catalyze these reactions: the P450c17 that catalyzes the production of DHEA or androstenedione in consecutive hydroxylase and lyase activities, and the 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) that catalyzes the conversion of androstenedione to testosterone. Our studies of the regulation of the CYP17 lyase activity at the molecular level have utilized species- and tissue-specific differences to identify target regulatory sequences. Adenovirus infection of rat CYP17 promoter/luciferase reporter gene constructs in primary cultures of rat adrenal and rat Leydig cells revealed a rat-specific domain between-1 and -108 bp that cause inhibition of both basal and cAMP-induced CYP17 transcription in the adrenal, but not the Leydig cell. In contrast, similar promoter constructs from other species exhibited substantial cAMP-induced transcriptional activity in the rat adrenal. Mutagenesis of the conserved region of the rat and human proteins reveals significant differences in the amino acid domains required for hydroxylase and lyase activities within and between the two species, consistent with their differential regulation of lyase activity. The 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) reaction requires a viable glucose transporter system for optimal activity, and a high-energy phosphate was discovered to be the requisite product of glucose metabolism in 17 beta-HSD activation. These studies have provided insight into potential mechanisms of control of androgen synthesis in the late steroidogenic pathway, at the transcriptional and post-translational levels.

[The volume of white matter in cerebral palsy with MRI findings of periventricular leukomalacia]

The volume of the white matter in 5 cases of cerebral palsy (CP) of term delivery without hypoxic episodes with MRI findings of periventricular leukomalacia (PVL), was compared with that of 12 CP cases in preterm delivery manifesting typical MRI findings of PVL. It was significantly decreased in the latter. The volume for the full-term CP cases was the same as that for children born at term and developing normally. These findings suggest that the grade of perinatal brain damage is different between the full-term and pre-term CP cases, and that the intrauterine timing of fetal circulatory disturbance is different.

Degradation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans by the white rot fungus Phanerochaete sordida YK-624

A method for the degradation of dioxins by white rot fungi was developed. Degradation of a mixture of 10 kinds of tetra- to octachlorodibenzo-p-dioxins (polychlorinated dibenzo-p-dioxins [PCDDs]) and tetra- to octachlorodibenzofurans (polychlorinated dibenzofurans [PCDFs]), which were chlorinated at 2-, 3-, 7-, and 8-positions of the molecules, by the white rot fungus Phanerochaete sordida YK-624 was studied in a stationary low-nitrogen medium. The percent degradation values of PCDDs and PCDFs were approximately 40 (tetra-chloro-) to 76% (hexachloro-) and 45 (tetrachloro-) to 70% (hexachloro-), respectively. Metabolites of 2,3,7,8-tetra- and octaCDD formed by P. sordida YK-624 included 4,5-dichlorocatechol and tetrachlorocatechol, respectively. These results suggest that white rot fungus is able to substantially degrade both PCDDs and PCDFs. This is the first report of the degradation of highly chlorinated PCDDs and PCDFs by a microorganism.

A novel benzodiazepine inverse agonist, S-8510, as a cognitive enhancer

1. Pharmacological actions of a novel benzodiazepine receptor ligand, S-8510 (2-(3-isoxazolyl)-3,6,7,9-tetrahydroimidazo[4,5-d]pyrano+ ++[4,3-b] pyridine monophosphate monohydrate), were examined in in vitro and in vivo studies. 2. S-8510 was characterized as a partial inverse agonist with a modest GABA ratio and low efficacy. 3. S-8510 ameliorated memory impairment induced by cholinergic deficit in the water maze paradigm of Wistar rats. 4. S-8510 augmented LTP of the Schaffer collateral/commissural fiber-CA1 synapses in the hippocampal slice preparations of SD rat. 5. S-8510 increased the extracellular levels of acetylcholine and noradrenaline in the hippocampus of Wistar rat. 6. S-8510 selectively potentiated pentylenetetrazol-induced convulsion without affecting minimal electroconvulsive shock- or strychnine-induced convulsion in ddY mice. 7. S-8510 failed to induce any sign of anxiety in the Wistar rat pro-conflict test. 8. S-8510 showed antidepressant-like pharmacological actions in ddY mice. 9. These results suggest that S-8510 can be used as a therapeutic drug for senile dementia, including Alzheimer's disease with little risk for inducing anxiety or convulsion.

Five candidate genes for hamster cardiomyopathy did not map to the cardiomyopathy locus by FISH analysis

The Syrian cardiomyopathic hamster (BIO14.6), that develops both muscular dystrophy and progressive cardiomyopathy, is widely used as an animal model of autosomal recessive cardiomyopathy mimicking human hypertrophic cardiomyopathy, and five genes have been proposed as strong candidates for the cause of cardiomyopathy. We recently mapped the cardiomyopathy locus of the hamster to the centromeric region of chromosome 9qa2.1-b1 by construction of a genetic linkage map of the Syrian hamster. Thus, we analyzed the loci of the five candidate genes, alpha tropomyosin, cardiac troponin T, adhalin, calpain 3 and cardiac myosin binding protein-C, by the FISH method, and found that these genes were mapped on the distal portion of chromosome 12qa5 and 4pa2 and the proximal portion of chromosomes 9qb7, 1qc1.1 and 1qb3, respectively. These results provide strong evidence that the five candidate genes previously proposed are not related to the hamster cardiomyopathy.

Serum HGF levels in acute renal rejection after living related renal transplantation

Hepatocyte growth factor (HGF), a long sought-after hepatotrophic factor, has recently been shown to act as a renotrophic factor in regeneration of the kidney. We investigated serum HGF levels in 16 renal transplant patients. In patients with acute rejection, the serum HGF level was markedly increased (over 1 ng/ml), and its elevation was accompanied by an increase in serum creatinine and blood urea nitrogen (BUN). In contrast, serum HGF levels were continuously low in patients without rejection. We conclude that serum HGF may become a clinically useful marker for the assessment of acute renal rejection.

Synthesis and structure--activity relationships of fused imidazopyridines: a new series of benzodiazepine receptor ligands

2-Arylimidazo[4,5-c]quinolines and analogous fused imidazopyridines were synthesized and evaluated as benzodiazepine receptor ligands. Affinity to the receptors was greatly affected by the bulkiness of the aryl group at the 2-position, compared to the pyrazoloquinolines such as CGS-9896. Derivatives with an isoxazole moiety at the 2-position showed high binding affinity and in vivo activity. In the imidazo[4,5-c]quinoline series, substitution at the 6-position decreased or abolished activity. Most derivatives with an unsubstituted isoxazolyl group showed antagonist or inverse agonist activity except for the 7-halo analogues, which exhibited agonist activity. On the other hand, 5-methylisoxazol-3-yl or 3-methylisoxazol-5-yl derivatives generally exhibited agonist activity. A similar substitution effect on the isoxazole moiety was observed in the imidazopyridines fused with a nonaromatic ring. From the detailed pharmacological evaluation, S-8510, 2-(3-isoxazolyl)-3,6,7,9-tetrahydroimidazo[4,5-d]pyrano++ +[4,3-b]pyridine monophosphate, possessing weak inverse agonist activity was selected as a therapeutic candidate for the treatment of some symptoms of senile dementia.

One-month oral toxicity study of the new quinolone antibacterial agent (S)-10-[(S)-(8-amino-6-azaspiro[3,4]octan-6-yl)-9-fluoro-2,3-dihydro-3- methyl-7-oxo-7H-pyrido [1,2,3-de] [1,4] benzoxazine-6-carboxylic acid hemihydrate in rats and cynomolgus monkeys

One-month oral toxicity of (S)-10-[(S)-(8-amino-6-azaspiro[3,4] octan-6-yl)]-9-fluoro-2,3-dihydro-3-methyl-7-oxo-7H-pyrido[1,2,3-de] [1,4]benzoxazine-6-carboxylic acid hemihydrate (CAS 151390-79-3, DV-7751a) a new quinolone antibacterial agent was investigated in Sprague-Dawley rats at doses of 12.5, 50, 200 and 800 mg/kg/d and in cynomolgus monkeys at 10, 30 and 100 mg/kg/d. Rats receiving 200 mg/ kg showed abnormal urine crystals, enhanced deposition of lipid in hepatocytes and exacerbation of osteochondrotic lesions in the femoral condyle. In addition, dosing at 800 mg/kg induced decrease in body weight gain and increased levels of serum alkaline phosphatase (ALP), cholinesterase, leucine aminopeptidase and total cholesterol. Monkeys receiving 100 mg/kg showed abnormal urine crystals and increases in serum glutamic oxaloacetic transaminase, glutamic pyruvic transaminase and ALP levels. The non-toxic doses of DV-7751a in rats and monkeys were 50 and 30 mg/kg, respectively, under the present experimental conditions.

[Cognitive function and MRI findings in very low birth weight infants]

Twenty-two very low birth weight infants at preschool ages of 5-6 years were studied to clarify the correlation between cognitive function and MRI findings. Cognitive function was evaluated by the Wechsler Intelligence Scale for Children-Revised (WISC-R) and the Frostig developmental test of visual perception. Ventricular enlargement, assessed by the bioccipital index (B. I.) measured on MRI, was correlated to cognitive disorders. Children with periventricular high intensity areas (T2-weighted images) extending from the posterior periventricular region to the parietal lobe tend to highly suffer from cerebral palsy and visuo-perceptual impairment. These results indicate that the disorders of cognitive function in very low birth weight infants were caused by a damage of association fibers in periventricular areas which was detectable by MRI.

A genetic linkage map of the Syrian hamster and localization of cardiomyopathy locus on chromosome 9qa2.1-b1 using RLGS spot-mapping

The Syrian cardiomyopathic hamster (BIO14.6) has an inherited form of progressive myocardial necrosis and congestive heart failure. Although widely studied as an animal model for human hypertrophic cardiomyopathy, further genetic analysis has been limited by a scarcity of DNA markers. Until now, only six autosomal linkage groups have been described and the number of polymorphic loci was extremely limited. In this study, we applied the restriction landmark genome scanning (RLGS) spot-mapping method to construct a genetic map of the Syrian hamster (Mesocricetus auratus) using 72 back-cross progeny. Although the polymorphic rate is very low (3-7%) between the strains, 531 polymorphic spots/loci were mapped, showing the power of this approach and reasonable applicability to other organisms lacking a well-defined genetic map. Further, the spot markers which flank the cardiomyopathy (cm) locus were cloned to determine the chromosomal location of cm by fluorescent in situ hybridization (FISH) analysis, resulting in the assignment of the locus to the centromeric region of hamster chromosome 9qa2.1-b1. Several candidate genes responsible for hypertrophic cardiomyopathy in humans have been excluded.

Activation of the inactive X chromosome induced by cell fusion between a murine EC and female somatic cell accompanies reproducible changes in the methylation pattern of the Xist gene

Mouse embryonal carcinoma (EC) cell lines are divided into two classes with or without the capability of reactivating the inactive X chromosome from a fusion partner of female lymphocyte. The 5' region of Xist was partially methylated in reactivating-competent EC cells but was fully methylated in reactivating-incompetent EC cells having a single X chromosome. Partial or heterogeneous methylation implies methylation of each CpG site in about half of the cell independently of methylation status of neighboring CpG sites. Fusion of the reactivating-competent EC cells with female lymphocytes induced not only de novo methylation in the 5' region of Xist allele on the hitherto inactivated X chromosome, but also demethylation of the same region of Xist on the other X chromosome from the female somatic cell. In contrast, no such changes occurred in hybrid cells involving reactivating-incompetent EC cells. Thus, partial methylation of the 5' region of Xist most probably maintained by low maintenance and high de novo methylation efficiency is correlated with reactivation potential of the EC cell. It is possible that this unique methylation pattern is implicated in random X inactivation in EC-hybrid cells in vitro and in epiblast cells in vivo.

Serum HGF levels in acute renal rejection after living related renal transplantation

Hepatocyte growth factor (HGF), a long sought-after hepatotrophic factor, has recently been shown to act as a renotrophic factor in regeneration of the kidney. We investigated serum HGF levels in 16 renal transplant patients. In patients with acute rejection, the serum HGF level was markedly increased (over 1 ng/ml), and its elevation was accompanied by an increase in serum creatinine and blood urea nitrogen (BUN). In contrast, serum HGF levels were continuously low in patients without rejection. We conclude that serum HGF may become a clinically useful marker for the assessment of acute renal rejection.

Severe neonatal nemaline myopathy with delayed maturation of muscle

A Japanese infant with a severe neonatal form of nemaline myopathy showed features of muscle immaturity as well as rods in the biopsied quadriceps femoris muscle, and involvement of diaphragm was first confirmed at autopsy. The biopsied muscle showed numerous rods in 80% of muscle fibers, and an increased number of type 2C fibers (23.2%). Electron microscopic findings were characterized by the presence of many small, immature round fibers with central nuclei and sparse myofibrils, and an increased number of satellite cells in close association with the small muscle fibers, as well as numerous rod structures. These microscopic and electron microscopic findings are interpreted as immature muscle fibers. Maturational delay or arrest implies deprivation of a development promoting factor such as a neuronal signal. Severe involvement with numerous rods was demonstrated in both diaphragm and intercostal muscles at the time of the postmortem examination, compatible with the patient's respiratory failure.

Inflammatory cytokine production induced by an analogue of muramyl dipeptide MDP-Lys(L18) in rat macrophage cultures and dog synovial fluid

To examine the involvement of cytokines in the mechanisms of N2-[(N-acetylmuramoyl)-L-alanyl-D-isoglutaminyl]-N6-stearoyl-L-lysine, MDP-Lys(L18)-induced arthritis, we analyzed interleukin-1 (IL-1), tumor necrosis factor (TNF), colony-stimulating factor (CSF), and neutrophil chemotactic factor (NCF) by bioassays in the rat macrophage-conditioned medium (Mluminal diameter-CM) stimulated by MDP-Lys(L18) in vitro and the synovial fluid from dogs treated subcutaneously with MDP-Lys(L18) for 14 days in vivo. The dog showed arthritis characterized by swelling of the knee joint, increased synovial fluid and thickened synovial membrane, and a single subcutaneous injection of MDP-Lys(L18) was previously shown to induced synovitis in rat tarsal joint. IL-1, TNF, CSF, and NCF activities in Mluminal diameter-CM were increased by MDP-Lys(L18), while only NCF activity was detected in the dog synovial fluid. Partial purification procedures revealed that NCF in Mluminal diameter-CM was not leukotriene B4 but a protein having heparin-affinity, and, in addition, immuno-reactive IL-8 was evident to be in Mluminal diameter-CM. The NCF activity in the dog synovial fluid was not inhibited by dialysis, showing that NCF is a protein substance, possibly a chemokine. These results suggest that MDP-Lys(L18) produces a chemokine, such as IL-8, which recruits neutrophils to the synovial membrane for subsequent development of synovitis in rats and dogs.

Hepatitis B virus X gene expression is activated by X protein but repressed by p53 tumor suppressor gene product in the transient expression system

Hepatitis B virus (HBV) X gene is known to exhibit a transcriptional activation function and is considered to play a major role in hepatocarcinogenesis. We determined a 20-bp promoter element for the HBV X gene transcription and found a binding protein to this promoter element, designated as an X-PBP. We then examined the effects of HBV X protein and p53 tumor suppressor gene product on X gene transcription from the 20-bp promoter element using the transient expression technique. Activity of the X gene promoter was stimulated by X protein expression, but, in contrast, was repressed by transfected normal p53 gene. On the other hand, mutant p53 gene product exhibited no repression. Moreover, the p53 repression of X gene transcription was canceled by X protein coexpression. Thus, the effects of X protein and normal p53 product appear to be mutually antagonistic in the regulation of X gene expression. However, mutated promoter elements which failed to bind to X-PBP still responded to X protein or p53, indicating that the process of X transactivation or p53 repression may be independent of X-PBP binding to the promoter element. Our data suggest that X protein could disrupt function of normal p53 protein in X gene-transfected cells.

Analysis of the vestigial tail mutation demonstrates that Wnt-3a gene dosage regulates mouse axial development

Mice homozygous for the recessive mutation vestigial tail (vt), which arose spontaneously on Chromosome 11, exhibit vertebral abnormalities, including loss of caudal vertebrae leading to shortening of the tail. Wnt-3a, a member of the wingless family of secreted glycoproteins, maps to the same chromosome. Embryos homozygous for a null mutation in Wnt-3a (Wnt-3a(neo)) have a complete absence of tail bud development and are truncated rostral to the hindlimbs. Several lines of evidence reveal that vt is a hypomorphic allele of Wnt-3a. We show that Wnt-3a and vt cosegregate in a high-resolution backcross and fail to complement, suggesting that Wnt-3a(neo) and vt are allelic. Embryos heterozygous for both alleles have a phenotype intermediate between that of Wnt-3a(neo) and vt homozygotes, lacking a tail, but developing thoracic and a variable number of lumbar vertebrae. Although no gross alteration in the Wnt-3a gene was detected in vt mice and the Wnt-3a coding region was normal, Wnt-3a expression was markedly reduced in vt/vt embryos consistent with a regulatory mutation in Wnt-3a. Furthermore, the analysis of allelic combinations indicates that Wnt-3a is required throughout the period of tail bud development for caudal somitogenesis. Interestingly, increasing levels of Wnt-3a activity appear to be necessary for the formation of more posterior derivatives of the paraxial mesoderm.

Effects of fusogenic and DNA-binding amphiphilic compounds on the receptor-mediated gene transfer into hepatic cells by asialofetuin-labeled liposomes

Effects of fusogenic and DNA-binding amphiphilic compounds on the receptor-mediated gene transfer using asialofetuin-labeled liposomes (AF-liposomes) were examined with HepG2 cells and rat hepatocytes in primary culture. AF-liposomes were sufficiently taken up by both types of cells through the asialoglycoprotein receptor-mediated endocytosis. In HepG2 cells, bacterial beta-galactosidase (beta-Gal) gene expression was observed by transfection using AF-liposomes encapsulating plasmid pCMV beta DNA (AF-liposome-pCMV beta). By addition of dioleoylphosphatidylethanolamine (DOPE) to the liposomal lipid composition (AF-liposome(DOPE)-pCMV beta), the transfection efficiency was clearly increased. The effects of DOPE were more conspicuous in the presence of chloroquine in the medium throughout the transfection. When pCMV beta complexed with gramicidin S (pCMV beta (GrS)) was encapsulated (AF-liposome(DOPE)-pCMV beta (GrS) and was transfected to HepG2 cells, an significantly high beta-Gal activity in the cells was observed as compared with that in the cells transfected with AF-liposome(DOPE)-pCMV beta. No effects of GrS were found in the transfection using AF-non-labeled control liposomes. In primary culture of rat hepatocytes, no beta-Gal gene expression was observed even though AF-liposome(DOPE)-pCMV beta was introduced into the cells prepared from adult rats. However, following the transfection with AF-liposome(DOPE)-pCMV beta, the beta-Gal activity was expressed in the cells from immature rats cultured in the medium supplemented with epidermal growth factor and insulin, and the transfection efficiency was 2-fold higher than that transfected with pCMV beta encapsulated in AF-non-labeled control liposomes. By the complex formation of pCMV beta with GrS, the transfection efficiency of AF-liposome(DOPE)-pCMV beta (GrS) increased according to the increase of GrS in the complex. It was shown that AF-liposome(DOPE)-pCMV beta (GrS) did efficiently introduce and express beta-Gal gene in both HepG2 cells and primary hepatocytes in the receptor mediated manner.

Hachimi-jio-gan extract protects the kidney from hypertensive injury in Dahl salt-sensitive rat

We investigated whether the Chinese herbal remedy, Hachimi-jio-gan extract, attenuates the renal injury seen in salt-induced hypertension in Dahl salt-sensitive (Dahl S) rats. Administration of this extract for 5 weeks dose-dependently decreased systolic blood pressure in Dahl S rats fed with a high-salt (2% NaCl) diet. This blood pressure reduction was associated with a decrease in cardiac mass and in thickness of the aortic wall. Urinary excretion of prostaglandin E2 was increased and glomerular filtration rate was improved with this treatment. Glomerulosclerosis and arterial injury in the kidney were morphologically improved. These data suggest that Hachimi-jio-gan extract exhibits an antihypertensive effect, which is associated with partial resolution of renal injury in salt-induced hypertension.

Expression of CD44 splice variants in human transitional cell carcinoma

The CD44 cell adhesion molecule is a surface glycoprotein mainly expressed in lymphoid tissues. Recently, abnormal variants of CD44 including alternatively-spliced large molecular variants, have been reported in many neoplastic tissues. We studied the variation in the size of CD44 molecules in 25 transitional cell carcinomas and 11 normal transitional epithelial tissues, using the reverse transcriptase-polymerase chain reaction (RT-PCR) followed by electrophoresis and Southern blot hybridization. Whereas 23 of 25 (92.0%) tumor tissues expressed CD44 splice variants with large molecular size, only 1 of 11 (9.1%) normal tissues expressed the abnormal variants. Urine sediments from 5 of 7 (71.4%) patients also was positive for the CD44 splice variants. CD44 splice variants are increased markedly in human transitional cell carcinoma. In conclusion, detection of CD44 splice variants using the RT-PCR, which is a convenient molecular biological technique, may be useful in combination with other diagnostic methods such as cytology, flow cytometry, and tumor antigens.

Impairment of regional fatty acid uptake in relation to wall motion and thallium-201 uptake in ischaemic but viable myocardium: assessment with iodine-123-labelled beta-methyl-branched fatty acid

In coronary artery disease, discrepancy in the uptake of thallium-201 and of methyl-branched fatty acid at rest has been described. The purpose of this study was to evaluate iodine-123 labelled beta-methyl-branched fatty acid (BMIPP) myocardial uptake and wall motion at rest in segments with stress-induced ischaemia identified by stress 201Tl tomography in patients with chronic coronary artery disease. 123I-BMIPP myocardial tomography was performed at rest and was compared with the findings of exercise-reinjection 201Tl tomography in 45 patients with chronic coronary artery disease. Regional wall motion was evaluated by contrast left ventriculography in 36 patients. Among 237 segments with reversible 201Tl defects, equally decreased uptake on both reinjection 201Tl and BMIPP images was observed in 93 (39%), more severely decreased uptake of BMIPP in 118 (50%) and more severely decreased uptake of reinjection 201Tl in 26 (11%). On the other hand, among 90 segments with non-reversible 201Tl defects, each pattern was observed in 71 (79%), 6 (7%) and 13 (14%) segments, respectively. When comparing the ischaemic segments with and without more severely reduced uptake of BMIPP than of reinjection 201Tl, wall motion was impaired to a greater extent in the segments with more severely reduced uptake of BMIPP than of reinjection 201Tl [severe hypo- or dyskinesis was present in 64 (70%) of 91 segments and in 24 (22%) of 110 segments, respectively, P<0.005]. In patients with chronic coronary artery disease, resting fatty acid uptake was frequently more reduced than reinjection 201Tl in the segments with stress-induced ischaemia, while in most of the fixed perfusion defects BMIPP and reinjection 201Tl uptake decreased concordantly. In ischaemic myocardium, wall motion was impaired to a greater extent in those segments which showed more severely reduced uptake of BMIPP than of reinjection 201Tl. In ischaemic but viable myocardium, discordant BMIPP uptake less than reinjection 201Tl uptake may indicate metabolic alterations and wall motion abnormality at rest independent of perfusion abnormalities. In conclusion, the combination of resting BMIPP and stress-reinjection 201Tl imaging may provide information on metabolic alterations and wall motion abnormality at rest independent of perfusion abnormalities.

Receptor-mediated transfer of pSV2CAT DNA to mouse liver cells using asialofetuin-labeled liposomes

Asialofetuin-labeled liposomes (AF-liposomes) were developed as a nonviral vector having high transfection activity for receptor-mediated gene transfer to hepatocytes by systemic administration. Initially, the majority of pSV2CAT, a chloramphenicol acetyltransferase (CAT) gene expression plasmid, was associated with AF-liposomes (AF-liposome-pSV2CAT), and they were injected into the portal vein of an adult mouse. Significantly high CAT activity was observed in the liver. The CAT activity in the liver was further increased two-fold by using AF-liposomes completely encapsulating pSV2CAT. Nonlabeled control liposomes, on the other hand, showed lower CAT activity in the liver than in the spleen or lung. The level of CAT mRNA reflected the CAT activity obtained by each liposome preparation in each tissue. Immunohistochemical staining showed that CAT was produced in a large number of parenchymal cells localizing in the periportal area. The plasmid encapsulated in the internal aqueous layer of the liposomes was effectively protected from environmental degradation. Thus, by administration into the blood circulation, AF-liposomes would be successfully incorporated into hepatocytes through receptor-mediated endocytosis, and the encapsulated plasmid would be transferred to the intracellular pathway.

Difficulties of families with handicapped children after the Hanshin-Awaji earthquake

In order to clarify the difficulties which handicapped people experienced in the Hanshin-Awaji earthquake disaster, 678 families with handicapped children were studied 1.5 months after the earthquake. All the students who were enrolled in this study were going to some type of school or training classes for handicapped children in January 1995. The study was completed between 1 and 10 March. The questionnaires which were designed for this study consisted of three parts: the difficulties which the families were faced with, their requirements for social and medical services and the symptoms and reactions of their children after the earthquake. A total of 466 answers were obtained from their parents. The kinds of difficulties differed between the families of mentally retarded children and those of the physically handicapped. While many parents with physically handicapped children desired better medical information or materials, many parents with mentally retarded children wanted better care services for their children. Physical and psychological effects of the earthquake were only temporary in most cases. However, some of the handicapped children were still suffering from such reactions as of 10 March. From the results of our study it became evident that a systematic relief program for these handicapped people should be established. The relief program should include the distribution of information regarding medical and social services. Psychological reactions such as panic, excitement and suppression of mental activity were still observed in some handicapped children on 10 March. Further observation will therefore be necessary.

Dose-dependent suppression of toluene metabolism by isopropyl alcohol and methyl ethyl ketone after experimental exposure of rats

In order to examine possible suppression of toluene metabolism due to coexposure to other solvents, female Wistar rats were exposed for 8 h to toluene alone (at 50 or 100 ppm), or in combination with either methyl ethyl ketone (at 50, 100, 200 or 400 ppm) or isopropyl alcohol (at 50, 100, 200, 400, 800 or 1600 ppm). Urine samples were collected for 24 h after initiation of each exposure, and subjected to analysis for two toluene metabolites, hippuric acid and o-cresol, both by HPLC. The excretion of hippuric acid, a major metabolite, was not modified when the concentrations of methyl ethyl ketone or isopropyl alcohol were low, i.e. 100 ppm or below, whereas it was reduced when methyl ethyl ketone or isopropyl alcohol concentrations were twice or more times higher than that of toluene. There were no changes in any cases in excretion of o-cresol, a minor metabolite. The observation after coexposure to methyl ethyl ketone or isopropyl alcohol at low concentration is in line with the negative interaction between toluene and methyl ethyl ketone as well as between toluene and isopropyl alcohol after occupational exposures at low concentrations. Metabolic interaction may take place when the exposure intensity is high, as observed in the present study and also after experimental exposure of volunteers to toluene and m-xylene, or occupational exposure to benzene and toluene.

Effect of levofloxacin on glycosaminoglycan and DNA synthesis of cultured rabbit chondrocytes at concentrations inducing cartilage lesions in vivo

We investigated the toxic effect of levofloxacin (LVFX), a quinolone antibacterial agent, on cartilage by examining aspects of its in vivo toxicokinetics and effect on the function of cultured chondrocytes of the femoral articular cartilage from juvenile New Zealand White rabbits. Repeated administration of LVFX (100 mg/kg) orally for 7 days induced focal necrosis and superficial erosion in the articular cartilage of the femoral condyle, but 30 mg/kg did not. Concentrations of LVFX in the cartilage were highest at the first sampling point (30 min) after a single administration, being 4.93 and 12.2 micrograms/g in the 30- and 100-mg/kg groups, respectively. The arthropathic concentration of LVFX in the cartilage was then shown to be 12.2 micrograms/g or more. For an in vitro study, chondrocytes were separated from the articular cartilage of the rabbit femoral condyle and cultured for 7 days until confluence. 35SO4 uptake by cultured chondrocyte sheets was most susceptible to LVFX, decreasing at drug concentrations of 5 micrograms/ml or more in 24- and 48-h cultures but not in a 72-h culture. Furthermore, 3H-thymidine uptake was decreased at concentrations of 10 micrograms/ml or more in a 48-h culture but not in 24- and 72-h cultures. Rhodamine 123 accumulation was susceptible to inhibition in cultured chondrocytes at an LVFX concentration of 10 micrograms/ml or more. These results suggest that LVFX inhibits glycosaminoglycan synthesis initially and DNA synthesis and mitochondrial function secondarily at actual arthropathic concentrations in cultured rabbit chondrocytes but that these changes are reversible and not enough to kill the cells.

Disruption of the function of tumor-suppressor gene p53 by the hepatitis B virus X protein and hepatocarcinogenesis

The X gene of the hepatitis B virus codes for a small basic protein and is able to transactivate viral and cellular genes, although the X protein exhibits no DNA-binding activity. The mechanism of transactivation by X protein has been suggested to be via protein-protein interaction(s). We first demonstrated that X protein had amino acid sequences homologous to the functionally essential domain of Kunitz-type serine protease inhibitors and that those sequences were indispensable for the transactivation function. We demonstrated that X protein exhibited an inhibitor activity against hepatic serine proteases, and subsequently found that the protein activated X gene transcription in HepG2 cells and that the X responsive element was localized in the minimal promoter of the X gene. In contrast, the tumor-suppressor gene p53, but not mutant p53, remarkably reduced transcription from the minimal promoter. This p53 repression on the X gene promoter was cancelled by X gene co-expression, probably indicating that the X protein disrupts the p53 tumor suppressor function in the nucleus. All data suggest that X protein leads to transactivation of cellular oncogenes by preventing an interaction between p53 and cellular transcription factor(s) consisting of the basal transcriptional machinery.

[A case of remission of recurrent carcinosarcoma of the uterus with massive ascites by carboplatin]

A case of remission of recurrent carcinosarcoma of the uterus with massive ascites by chemotherapy using carboplatin (CBDCA) is reported. A 75-year-old female was diagnosed with cancer of the uterine body. She underwent abdominal total hysterectomy with bilateral salpingo-oophorectomy, which revealed carcinosarcoma of the uterus penetrating the myometrium and reaching the serosa of the uterus. Eight weeks after, she developed abdominal distension, obstruction of bilateral ureters and bleeding tumor measuring 5 cm in diameter at the vaginal cuff ending. Acute retention of bloody ascites of more than 2500 ml was demonstrated. Abdominal centesis, aspiration of ascites and intraperitoneal administration of 600 mg of CBDCA were performed. Two weeks after single use of CBDCA, the ascites completely disappeared and there was recovery from anuria. The remission has lasted more than 4 months, which has suggested the efficacy of CBDCA for uterine carcinosarcoma.

Detection of aberrations in androgen receptor gene by analysis of single-stranded conformation polymorphisms in polymerase chain reaction products

Analysis of single-stranded conformation polymorphisms in polymerase chain reaction (PCR) products (PCR-SSCP) is a sensitive method for detecting point mutations in genomic DNA. To investigate its utility in examining the androgen receptor gene, we analyzed data on a patient with the testicular feminization syndrome (TFS) with a known point mutation in exon C. We detected mobility shifts of fragments of the corresponding region. Since examination of the subject's brother (legally sister), who also has TFS, revealed an identical shift pattern, we sequenced the exon C of the sibling and detected a mutation identical to that in the former. We conclude that PCR-SSCP is available for screening mutations of the androgen receptor gene.

Receptor-mediated transfer of pSV2CAT DNA to a human hepatoblastoma cell line HepG2 using asialofetuin-labeled cationic liposomes

Asialofetuin-labeled liposomes (AF-lps) were developed as a vector for gene transfer to hepatocytes. Plasmid pSV2CAT DNA which encodes bacterial chloramphenicol acetyltransferase (CAT) was associated with (meaning, in this report, the sum of 'to be adsorbed on the surface of' and 'to be encapsulated into the internal phase of') AF-lps (AF-lps-pSV2CAT) prepared by a tandem combination of the detergent removal and freeze-thaw methods. Ninety-six percent of input pSV2CAT was associated with AF-lps containing N-(alpha-trimethylammonioacetyl)-didodecyl-D-glutamate chloride, and approx. two-thirds of the associated DNA was encapsulated into the internal phase. The uptake of AF-lps by the cultured human hepatoblastoma cell line HepG2, having asialoglycoprotein receptors (AGPR) on their plasma membrane, was decreased by the addition of free AF and cytochalasin B. AF-lps bound to HepG2 cells through specific interaction with AGPR, and were internalized into the cells by the receptor-mediated endocytotic pathway. HepG2 cells transfected by AF-lps-pSV2CAT showed a significantly higher CAT activity than those transfected by pSV2CAT associated with non-labeled control lps (N-lps-pSV2CAT) or a mixture of pSV2CAT and empty AF-lps. Pretreatment with EDTA-encapsulated AF-lps increased the transfection efficiency of AF-lps-pSV2CAT. The CAT activity in A431 and Swiss/3T3 cells transfected with AF-lps-pSV2CAT was low and almost the same as those transfected with N-lps-pSV2CAT. Since DNA encapsulated in lps is likely to be protected against digestion by nucleases in the blood circulation, AF-lps could be used as a gene transfer vector targeting the hepatocytes in vivo.

[Ischemic cerebrovascular disease in patients with atrial fibrillation]

The purpose of this retrospective study was to elucidate 1) which subgroups are prone to have ischemic cerebrovascular disease (CVD) among patients with atrial fibrillation (Af), 2) vulnerable period of CVD after the diagnosis of chronic Af and 3) the clinical efficacy of antiplatelet therapy in chronic nonvalvular Af patients. During 9 years, a total of 479 patients included 124 cases with paroxysmal Af, 30 cases with paroxysmal Af initially which later changed to chronic Af and 325 cases with chronic Af were enrolled. Among these 355 cases with chronic Af, 57 cases had valvular heart disease (VHD). The results were as follows: 1) The high risk subgroups (incidence rate/100 person-years is more than 6) were chronic Af with VHD or hypertension. The low risk subgroups (less than 2) were paroxysmal Af under 60 years of age, chronic Af with mitral valve prolapse syndrome or with hyperthyroidism. 2) There was no vulnerable period for occurrence of CVD during 9 years' follow-up from the onset of Af. 3) No significant difference in the incidence of CVD was seen in the groups with antiplatelet therapy and without.

Application of a spray drying technique in the production of TRH-containing injectable sustained-release microparticles of biodegradable polymers

Copoly (dl-lactic/glycolic acid) microparticles for sustained release of a water-soluble drug (Thyrotropin releasing hormone: TRH) were prepared by a spray drying method. A higher entrapment ratio was achieved with the spray drying method with the in-water drying method. In order to avoid agglomeration of the microparticles, a double-nozzle spray drying method was designed using mannitol as an anti-adherent. The surface of the spray-dried microparticles was coated with mannitol, and the extent of agglomeration was decreased. Acetonitrile was the most suitable solvent for microencapsulation using the double-nozzle spray drying method because the initial burst of TRH from the microparticles during the first day was the smallest. When PLGA with a weight-average molecular weight of 14,000 was used, constant release of TRH continued for one month with a small initial burst. In conclusion, the production of biodegradable microparticles by the double-nozzle spray drying method appears to be an attractive alternative to conventional microencapsulation methods.

Different effect of cyclosporin A on arthritides induced by a muramyl dipeptide analogue or the complete adjuvant in rats

Muramyl dipeptide-Lys(L18) given by daily subcutaneous injection for 14 days induced arthritis in male Lewis, Fischer and nude rats, to a lesser degree in the last two than in the first strain. On the other hand, a single intradermal administration of Freund's complete adjuvant induced arthritis in Lewis and Fischer but not nude rats. Cyclosporin A (CsA) co-administered for 14 days markedly exacerbated the muramyl dipeptide-Lys(L18) induced arthritis (MIA) in rats of all three strains, but completely blocked the development of the adjuvant induced arthritis (AIA) in Lewis rats. Furthermore, AIA was transferred to recipient Lewis rats through spleen cells obtained from the donors with AIA, whereas MIA was not. Antibodies against type II collagen and DNA were not detected in sera from MIA or AIA rats. These data show a clear difference between MIA and AIA in the pattern of development of arthritis and suggest that delayed hypersensitivity reactions may be involved in the pathogenetic mechanisms of AIA, but not in MIA.

Histological examination on Achilles tendon lesions induced by quinolone antibacterial agents in juvenile rats

We examined the effects of the quinolone antibacterial agents pefloxacin (PFLX) and ofloxacin (OFLX) on the Achilles tendon of Sprague-Dawley rats. A single oral administration of PFLX 300 and 900 mg/kg or OFLX 900 mg/kg induced edema with mononuclear cell infiltration mainly in the inner sheath of the inner Achilles tendon just proximal to the tuber calcanei in rats killed on the next day. Cell infiltration was also seen in the adjacent synovial membrane and joint space. With progression of severity, the lesions extended to the surface tendon tissue, wherein irregularly arranged collagen bundles were detached from each other and nuclei of fibroblasts were pyknotic and fragmented. After 2-wk repeated administration, these lesions were replaced by fibrotic foci with regenerated tendon fibroblasts, and the incidence and severity were reduced in the OFLX but not PFLX groups. Coadministration of cyclosporin A with OFLX 300 mg/kg induced these lesions despite the fact that neither induced lesions alone. The tendon lesions were induced in juvenile rats (4 wk of age) but not in young adults (12 wk). The articular cartilage of juvenile rats showed focal degeneration and/or cavitation in the tarsal joints after a single and 2-wk administration of PFLX or OFLX. Hydrocortisone slightly increased the incidence of OFLX-induced lesions in both the tendon and cartilage after a 2-wk administration. The occurrence of the tendon lesions is different from that of the Achilles tendon disorders reported in older humans, but they are thought to be a useful model for them.