Structural alterations in the amygdala and impaired social incentive learning in a mouse model of a genetic variant associated with neurodevelopmental disorders

Copy number variants (CNVs) are robustly associated with psychiatric disorders and their dimensions and changes in brain structures and behavior. However, as CNVs contain many genes, the precise gene-phenotype relationship remains unclear. Although various volumetric alterations in the brains of 22q11.2 CNV carriers have been identified in humans and mouse models, it is unknown how the genes in the 22q11.2 region individually contribute to structural alterations and associated mental illnesses and their dimensions. Our previous studies have identified Tbx1, a T-box family transcription factor encoded in 22q11.2 CNV, as a driver gene for social interaction and communication, spatial and working memory, and cognitive flexibility. However, it remains unclear how TBX1 impacts the volumes of various brain regions and their functionally linked behavioral dimensions. In this study, we used volumetric magnetic resonance imaging analysis to comprehensively evaluate brain region volumes in congenic Tbx1 heterozygous mice. Our data show that the volumes of anterior and posterior portions of the amygdaloid complex and its surrounding cortical regions were reduced in Tbx1 heterozygous mice. Moreover, we examined the behavioral consequences of an altered volume of the amygdala. Tbx1 heterozygous mice were impaired for their ability to detect the incentive value of a social partner in a task that depends on the amygdala. Our findings identify the structural basis for a specific social dimension associated with loss-of-function variants of TBX1 and 22q11.2 CNV.

Structural alterations in the amygdala and impaired social incentive learning in a mouse model of a genetic variant associated with neurodevelopmental disorders

Copy number variants (CNVs) are robustly associated with psychiatric disorders and their dimensions and changes in brain structures and behavior. However, as CNVs contain many genes, the precise gene-phenotype relationship remains unclear. Although various volumetric alterations in the brains of 22q11.2 CNV carriers have been identified in humans and mouse models, it is unknown how the genes in the 22q11.2 region individually contribute to structural alterations and associated mental illnesses and their dimensions. Our previous studies have identified Tbx1 , a T-box family transcription factor encoded in 22q11.2 CNV, as a driver gene for social interaction and communication, spatial and working memory, and cognitive flexibility. However, it remains unclear how TBX1 impacts the volumes of various brain regions and their functionally linked behavioral dimensions. In this study, we used volumetric magnetic resonance imaging analysis to comprehensively evaluate brain region volumes in congenic Tbx1 heterozygous mice. Our data show that the volumes of anterior and posterior portions of the amygdaloid complex and its surrounding cortical regions were reduced in Tbx1 heterozygous mice. Moreover, we examined the behavioral consequences of an altered volume of the amygdala. Tbx1 heterozygous mice were impaired for their ability to detect the incentive value of a social partner in a task that depends on the amygdala. Our findings identify the structural basis for a specific social dimension associated with loss-of-function variants of TBX1 and 22q11.2 CNV.

Maternal approach behaviors toward neonatal calls are impaired by mother's experiences of raising pups with a risk gene variant for autism

How the intrinsic sequence structure of neonatal mouse pup ultrasonic vocalization (USV) and maternal experiences determine maternal behaviors in mice is poorly understood. Our previous work showed that pups with a Tbx1 heterozygous (HT) mutation, a genetic risk for autism spectrum disorder (ASD), emit altered call sequences that do not induce maternal approach behaviors in C57BL6/J mothers. Here, we tested how maternal approach behaviors induced by wild-type and HT USVs are influenced by the mother's experience in raising pups of these two genotypes. The results showed that wild-type USVs were effective in inducing maternal approach behaviors when mothers raised wild-type but not HT pups. The USVs of HT pups were ineffective regardless of whether mothers raised HT or wild-type pups. However, the sequence structure of pup USVs had no effect on the general, non-directional incentive motivation of maternal behaviors. Our data show how the mother's experience with a pup with a genetic risk for ASD alters the intrinsic incentive values of USV sequences in maternal approach behaviors.

Erratum: Structural and Valence Changes of Europium Hydride Induced by Application of High-Pressure H_{2} [Phys. Rev. Lett. 107, 025501 (2011)]

This corrects the article DOI: 10.1103/PhysRevLett.107.025501.

Maximizing T c by tuning nematicity and magnetism in FeSe1-x S x superconductors

A fundamental issue concerning iron-based superconductivity is the roles of electronic nematicity and magnetism in realising high transition temperature (T c). To address this issue, FeSe is a key material, as it exhibits a unique pressure phase diagram involving non-magnetic nematic and pressure-induced antiferromagnetic ordered phases. However, as these two phases in FeSe have considerable overlap, how each order affects superconductivity remains perplexing. Here we construct the three-dimensional electronic phase diagram, temperature (T) against pressure (P) and isovalent S-substitution (x), for FeSe1-x S x . By simultaneously tuning chemical and physical pressures, against which the chalcogen height shows a contrasting variation, we achieve a complete separation of nematic and antiferromagnetic phases. In between, an extended non-magnetic tetragonal phase emerges, where T c shows a striking enhancement. The completed phase diagram uncovers that high-T c superconductivity lies near both ends of the dome-shaped antiferromagnetic phase, whereas T c remains low near the nematic critical point.

Structure and function of neonatal social communication in a genetic mouse model of autism

A critical step toward understanding autism spectrum disorder (ASD) is to identify both genetic and environmental risk factors. A number of rare copy number variants (CNVs) have emerged as robust genetic risk factors for ASD, but not all CNV carriers exhibit ASD and the severity of ASD symptoms varies among CNV carriers. Although evidence exists that various environmental factors modulate symptomatic severity, the precise mechanisms by which these factors determine the ultimate severity of ASD are still poorly understood. Here, using a mouse heterozygous for Tbx1 (a gene encoded in 22q11.2 CNV), we demonstrate that a genetically triggered neonatal phenotype in vocalization generates a negative environmental loop in pup-mother social communication. Wild-type pups used individually diverse sequences of simple and complicated call types, but heterozygous pups used individually invariable call sequences with less complicated call types. When played back, representative wild-type call sequences elicited maternal approach, but heterozygous call sequences were ineffective. When the representative wild-type call sequences were randomized, they were ineffective in eliciting vigorous maternal approach behavior. These data demonstrate that an ASD risk gene alters the neonatal call sequence of its carriers and this pup phenotype in turn diminishes maternal care through atypical social communication. Thus, an ASD risk gene induces, through atypical neonatal call sequences, less than optimal maternal care as a negative neonatal environmental factor.

Formation of NaCl-type monodeuteride LaD by the disproportionation reaction of LaD2

Previous x-ray diffraction measurements revealed the pressure-induced decomposition of an fcc LaH2.3 into H-rich and H-poor fcc phases around 11 GPa. The present neutron diffraction measurements on LaD2 confirm the formation of NaCl-type LaD as a counterpart of the D-rich LaD2+δ by disproportionation. First-principles enthalpy and lattice dynamic calculations demonstrate that the NaCl-type LaH is stabilized at high pressures and can be recovered at ambient conditions. Finding the NaCl-type LaH will pave the way for investigations on the site-dependent nature of hydrogen-metal interactions.

Structural and valence changes of europium hydride induced by application of high-pressure H₂

Europium hydride EuH(x), when exposed to high-pressure H₂, has been found to exhibit the following structural and valence changes: Pnma(x = 2, divalent) → P6₃/mmc(x = 2, 7.2-8.7 GPa) → I4/m(x > 2, 8.7-9.7 GPa) → I4/mmm(x > 2, 9.7 GPa-,trivalent). With a trivalent character and a distorted cubic fcc structure, the I4/mmm structure is the β phase commonly observed for other rare-earth metal hydrides. Our study clearly demonstrates that EuH(x) is no longer an irregular member of the rare-earth metal hydrides.

Preparation and Properties of ferroelectric Bi2SrTa2O9 thin films for FeRAM using Flash-MOCVD

Ferroelectric Bi2 SrTa2 O9 thin films were successfully prepared by liquid delivery MOCVD, and structural and electrical properties were investigated. As-deposited films showed sharp distinct peaks, which were indexed assuming a fluorite-type structure. These precursors were transformed to bismuth-layered structures by annealing at 800 °C in flowing oxygen. Reasonable ferroelectric properties were observed in a film with 170 nm-thickness. Remanent polarization and coercive field were estimated to be 5.2 μC/cm2 and 52 kV/cm, respectively, at 5V.

Charge ordering and spin frustration in AlV2-x CrxO4

The relationship between charge and spin degrees of freedom in a geometrically frustrated system, AlV2-xCrxO4 spinel, is investigated. Upon Cr doping, the charge-ordered phase of AlV2O4 is rapidly suppressed and a charge-disordered phase grows up instead. It is found that the magnetic ground state is a spin-glass state dominated by geometrical frustration for both phases, but larger spin entropy remains down to low temperatures in the charge-ordered phase, possibly owing to its two-dimensional character.

Evaluation of three-dimensional glenoid structure using MRI

The tilting angle and the shape of the glenoid cavity are considered to relate closely to shoulder stability. They are also important when planning arthroplasty and developing new designs. This study examines the glenoid cavity using 3-dimensional MRI. Forty volunteers (20 men, 20 women; average age 21.4; range 18-35 y) were enrolled in the study. The tilting angles of the glenoid bone were measured in 5 consecutive axial planes perpendicular to the glenoidal long axis. Cross sections were divided into 3 types (concave, flat, convex) according to the shape on each plane. The average tilting angles for the 5 planes from the bottom to the top were 3.3+/-4.1, 1.4+/-3.8. -0.6+/-1.9, -1.4+/-3.3, and -6.2+/-3.3 degrees anteriorly, indicating that the 3-dimensional bony structure of the glenoid was twisted anteriorly to posteriorly. Images on the bottom plane consisted of 82.5 % concave type, 15% flat type and 2.5% convex type, while only 3 cases (7.5%) showed concave at the top plane. The shape of the glenoid cavity is thought to be conducive to glenohumeral motion and stability.

Differential expression of mRNAs for sialyltransferase isoenzymes induced in the hippocampus of mouse following kindled seizures

Sialic acids play important roles in various biological functions. In the brain, evidence suggests that sialylation of glycoproteins and glycolipids affects neural plasticity. While the 18 sialyltransferase isoenzymes (STs) identified to date synthesize individual sialyl-oligosaccharide structures, they each exhibit activity toward more than one substrate and can overlap in their specificity. Therefore, the distribution of STs is a secondary factor in the study of specific sialylation. Here, seven STs; ST3Gal I-IV, ST8Sia IV, ST6Gal I and ST6GalNAc II, the expressions of which were identified in the adult hippocampus by RT-PCR, showed diverse localization patterns in the hippocampus on in situ hybridization, suggesting that the individual cells expressed relevant STS: Furthermore, to assay activity-related changes in ST expression, we used amygdaloid-kindling among models of neural plasticity. Differential expression of the STs participating in the kindling, notably, up-regulation of ST3Gal IV and ST6GalNAc II mRNAs, and down-regulation of ST3Gal I and ST8Sia IV mRNAs, were observed in the hippocampus following kindled seizures. These results indicate that ST expressions are regulated by physiological activity and may play a role in neural plasticity.

Serine proteinase inhibitor 3 and murinoglobulin I are potent inhibitors of neuropsin in adult mouse brain

Extracellular serine protease neuropsin (NP) is expressed in the forebrain limbic area of adult brain and is implicated in synaptic plasticity. We screened for endogenous NP inhibitors with recombinant NP (r-NP) from extracts of the hippocampus and the cerebral cortex in adult mouse brain. Two SDS-stable complexes were detected, and after their purification, peptide sequences were determined by amino acid sequencing and mass spectrometry, revealing that target molecules were serine proteinase inhibitor-3 (SPI3) and murinoglobulin I (MUG I). The addition of the recombinant SPI3 to r-NP resulted in an SDS-stable complex, and the complex formation followed bimolecular kinetics with an association rate constant of 3.4 +/- 0.22 x 10(6) M(-1) s(-1), showing that SPI3 was a slow, tight binding inhibitor of NP. In situ hybridization histochemistry showed that SPI3 mRNA was expressed in pyramidal neurons in the hippocampal CA1-CA3 subfields, as was NP mRNA. Alternatively, the addition of purified plasma MUG I to r-NP resulted in an SDS-stable complex, and MUG I inhibited degradation of fibronectin by r-NP to 24% at a r-NP/MUG I molar ratio of 1:2. Immunofluorescence histochemistry showed that MUG I localized in the hippocampal neurons. These findings indicate that SPI3 and MUG I serve to inactivate NP and control the level of NP in adult brain, respectively.

Interleukin-16 in synovial fluids from cases of various types of arthritis

OBJECTIVES

To examine the characteristic relationship between interleukin-16 (IL-16) and clinical data in various types of arthritis.

METHODS

We measured IL-16 levels of the synovial fluids (SF) of patients with various types of arthritis, which included rheumatoid arthritis, traumatic arthritis, pseudogouty arthritis, gouty arthritis, and osteoarthritis, by an enzyme immunosorbent assay, and examined their correlations with clinical parameters.

RESULTS AND CONCLUSIONS

Higher levels of IL-16 in synovial fluid from patients with rheumatoid arthritis, traumatic arthritis, and pseudogouty arthritis, compared to those with osteoarthritis, and gouty arthritis were indicated. Also, synovial IL-16 levels in patients with rheumatoid arthritis correlated significantly, especially with synovial matrix metalloproteinase-3 levels. But the IL-16 levels of both synovial fluid and peripheral blood did not correlate with conventional inflammatory parameters such as C-reactive protein, erythrocyte sedimentation rate, or rheumatoid factor. Although the function of IL-16 in inflammatory arthritis has not yet been defined, these data indicated some essential features of IL-16.

Sacral perineurial cyst with ossification of the arachnoid membrane

A case of sacral perineurial cyst with ossification of the arachnoid membrane discovered intraoperatively is reported. We are not aware of any similar cases in the literature.

A monoclonal antibody against a hepatitis B e antigen epitope borne by six amino acids encoded by the precore region

Hepatitis B e antigen (HBeAg) polypeptide in the circulation (p17e) is composed of ten amino acids (aa) coded for by the precore region and 149 aa by the core gene of hepatitis B virus. A monoclonal antibody (Y0583A) was raised against the N-terminal ten amino acids (SKLCLGWLWG) encoded by the precore region. The binding of Y0583A with a panel of 203 decapeptides on multipins, which covered the precursor of HBeAg polypeptide made of 212 aa shifting by one aa, recognized an epitope sequenced LGWLWG representing the C-terminal six aa coded for by the precore region. This HBeAg epitope was not readily accessible on HBeAg in serum, but it became exposed and bound with Y0583A by treatment with 0.2 N NaOH. Using Y0583A, an enzyme-linked immunosorbent assay was developed for specific determination of HBeAg. The test sample was incubated with the monoclonal antibody to an HBeAg determinant encoded by the core gene (904) that had been immobilized on a solid support. Captured HBeAg was treated with 0.2 N NaOH, neutralized and released into the fluid phase. The reactant was then tested for a sandwich between monoclonal antibody (C33) to the C-terminus of the HBeAg polypeptide immobilized on a solid support and Y0583A labeled with horseradish peroxidase.

Hyaluronan, cartilage destruction and hydrarthrosis in traumatic arthritis

The concentrations of hyaluronan (HA) and chondroitin sulfate (CS) in synovial fluids from patients with traumatic arthritis (TA) with and without hydrarthrosis were measured. The CS in synovial fluids was determined as a marker of cartilage destruction by high performance liquid chromotography. The concentration of HA in synovial fluids was lower in patients with hydrarthrosis than in healthy volunteers and patients with TA without hydrarthrosis, whereas the total amounts of HA and CS and the concentration of CS were higher in patients with hydrarthrosis. To investigate the relation between hydrarthrosis and production of HA in synovial tissues, TA synovial tissue biopsies were stained for HA with biotinylated HA binding region. The intensity of HA staining was higher in specimens from patients with hydrarthrosis than in normal and TA without hydrarthrosis specimens. Thus, there may be a correlation between hyperproduction of HA, cartilage destruction and increase in fluid volume in TA.

Localization of hyaluronic acid in human articular cartilage

To demonstrate localization of hyaluronic acid (HA) in articular cartilage of the human femur, biotinylated HA-binding region, which specifically binds HA molecules, was applied to the tissue. In sections fixed by 2% paraformaldehyde-2% glutaraldehyde, HA staining was detected in lamina splendens and chondrocytes in the middle zone. By pretreatment with trypsin, intense HA staining appeared in the extracellular matrix of the deep zone and weak staining in the superficial and middle zones. Moreover, pre-treatment with chondroitinase ABC (CHase ABC) intensely enhanced the stainability for HA in the superficial and middle zones and weakly in the deeper zone. Combined pre-treatment of trypsin with CHase ABC abolished intra- and extracellular staining for HA in all zones. By microbiochemical study, the concentrations of HA and dermatan sulfate were high in the middle zone, whereas those of chondroitin sulfate and keratan sulfate were high in the deep zone. These results suggest that HA is abundantly synthesized in and secreted from the chondrocytes, particularly in the middle zone, whereas it is largely masked by proteoglycan constituents in the extracellular matrix.

Simultaneous determination of the migration coefficient of each base in heterogeneous oligo-DNA by gel filled capillary electrophoresis

The direct determination of migration coefficients was achieved by analysing the migration time of heterogeneous oligo-DNA with a gel filled capillary using the Gauss least-squares method for the observation functions, assuming that the migration time of oligo-DNA is dependent on its base composition and chain length. By using the coefficients obtained, the migration time of oligo-DNA of any known sequence that does not have a secondary structure can be estimated with an accuracy of less than 0.5-mer of cytidine. In addition, from the deviation of the actual migration time from the calculated migration time in certain specially designed base sequences, the existence of a secondary structure such as a hairpin structure was strongly suggested even in the presence of 7 M urea. From the investigation of the effects of secondary structure on migration time, it was concluded that this approach will give qualitative information on secondary structure, which may be applicable in work such as single strand conformational polymorphism (SSCP) analysis or antisense DNA analysis, in which secondary structure plays an important role in accelerating or decelerating migration times. The results of the analysis also predict the apparent chain length reversal from short to long together with a reduction in the actual chain length in DNA sequencing using capillary electrophoresis.

Chimeric hepatitis B virus core particles with parts or copies of the hepatitis C virus core protein

Either parts or multiple copies of the core gene of hepatitis C virus (HCV) were fused to the 3' terminus of the hepatitis B virus (HBV) core gene with 34 codons removed. As many as four copies of HCV core protein (720 amino acids) were fused to the carboxy terminus of truncated HBV core protein (149 amino acids) without preventing the assembly of HBV core particles. Chimeric core particles were sandwiched between monoclonal antibody to HBV core and that to HCV core, thereby indicating that antigenic determinants of both HBV and HCV cores were accessible on them. Proteolytic digestion deprived chimeric core particles of the antigenicity for the HCV core without affecting that of the HBV core, confirming the surface exposure of HCV core determinants. The density of HCV core determinants on chimeric core particles increased as copies of fused HCV core protein were increased. Hybrid core particles with multiple HCV core determinants would be instrumental as an antigen probe for detecting class-specific antibodies to the HCV core in patients with acute and chronic hepatitis C and for simultaneous detection of antibodies to HBV core and those to HCV core in donated blood.

Alterations of proteoglycan synthesis in rabbit articular cartilage induced by intra-articular injection of papain

In order to investigate the biochemical alteration of proteoglycan (PG) synthesis during cartilage repair, reversible destruction was induced by injecting papain into the knee joint cavity of rabbits. The PG synthesis in the cartilage was examined using Na2 35SO4 and high performance liquid chromatography (HPLC). PGs labeled with 35SO4(2-) (35S-PGs) were extracted from normal and papain-treated cartilage, and the amount of synthesis, ability to aggregate with hyaluronan (HA), and the composition of glycosaminoglycan and chondroitin sulfate isomer labeled with 35SO4(2-) (35S-GAG and 35S-CS isomer) were analyzed. Synthesis of 35S-PGs, especially those that were unable to aggregate with HA (nonaggregating 35S-PGs), increased in papain-treated cartilage compared with that in normal cartilage. The acceleration and qualitative change in PG synthesis in the papain-treated cartilage are considered to be responses to the supplementation of the loss of cartilage PGs induced by papain. The compositions of 35S-GAG and 35S-CS isomer of the nonaggregating 35S-PGs differed from those of 35S-PGs which were able to aggregate with HA (aggregating 35S-PGs) in the papain-treated cartilage as well as in the normal cartilage. However, the compositions of both nonaggregating and aggregating 35S-PGs in the papain-treated and normal cartilage were similar. These results indicate that most of the nonaggregating 35S-PGs in papain-treated cartilage have properties similar to those in normal cartilage and are not simple degradation products of aggregating 35S-PGs; they also suggest that the supplementary reaction for PG content in the cartilage during its repair process is not simple acceleration in PG turn-over but the enhancement of PG synthesis accompanied by alterations in aggregating ability and the compositions of GAG and CS isomer.

Trans-complementation among naturally occurring deletion mutants of hepatitis B virus and integrated viral DNA for the production of viral particles with mutant genomes in hepatoma cell lines

Cultured hepatoma cells (HepG2) were cotransfected with two different plasmids carrying a head-to-tail dimer of recombinant hepatitis B virus (HBV) DNA cloned from deletion mutants isolated from the circulation of persistently infected hosts. They were tested for the secretion of viral particles with mutant genome encapsidation. A recombinant plasmid defective in the S gene and one defective in both the C and P genes complemented in trans for the production of viral particles. Mutant genomes from either of the recombinants were encapsidated. Similarly, a recombinant defective in the C gene and another defective in the P gene trans-complemented for the production of viral particles containing mutant genomes. A hepatoma cell line with integrated HBV DNA sequences defective in the C and P genes (PLC/PRF/5) when transfected with a recombinant defective in the S gene produced viral particles with the HBV genome from the transfecting recombinants. These results confirm the expected trans-complementation among the S, C and P genes of HBV, when either episomal or integrated into chromosomes, for the maintenance of defective HBV mutants in persistently infected hosts.

Allelic subtypic determinants of hepatitis B surface antigen (i and t) that are distinct from d/y or w/r

A monoclonal antibody (I-18) was raised against an enneapeptide representing amino acids 125 to 133 of the product of the S gene of hepatitis B virus DNA [S(125-133) segment] with a sequence of Thr-Ile-126-Pro-Ala-Gln-Gly-Thr-Ser-Met. Another monoclonal antibody (T-7) was raised against an S(125-133) segment in which Ile-126 was replaced by Thr-126. In a panel of 16 samples of hepatitis B surface antigen (HBsAg) with known S gene sequences, I-18 reacted with 5 with Ile-126. T-7 reacted with 10 HBsAg samples with Thr-126; it did not, however, react with the remaining one of subtype ayw with Thr-126 flanked by Met-125 and Thr-127. The two allelic subtypic determinants, specified by Ile-126 and Thr-126 and distinct from d/y or w/r, were named i and t after isoleucine and threonine, which regulate them. They were expressed in a mutually exclusive fashion in 216 (83%) of 260 HBsAg samples from asymptomatic carriers. They were not detected in 36 (14%) samples; the failure to detect an i or t determinant was particularly common in HBsAg samples of subtype ayw (26 [79%] of 33). A part of the S gene sequence was determined for eight HBsAg samples without a detectable i or t determinant. They had an Ile-126 or Thr-126 residue that was flanked by Thr-127, not the Pro-127 commonly possessed by HBsAg samples displaying an i or t determinant. Expression of the i/t allele, therefore, would require Pro-127. In eight (3%) of the samples, both i and t determinants were detected; the presence of i and t on the selfsame HBsAg particles was verified by sandwiching the particles between I-18 and T-7. A point mutation from thymine to cytosine at nucleotide 377 in the S gene, contributing different second letters to codon 126 (ATT for Ile and ACT for Thr), would have been responsible for the assembly of HBsAg particles with both i and t determinants by means of phenotypic mixing.

Exercise therapy for osteoporosis

Our experimental and clinical studies lead to the following conclusions: 1. The amount of exercise that has a favorable effect on bone tissue differs between males and females among individuals. 2. An appropriate amount of exercise has a favorable influence not only on weight-bearing bone but also on non-weight-bearing bone, provided there is a sufficient intake of calcium. 3. Exercise may prevent the bone loss in osteoporosis, but an increase in bone mass cannot be expected. The major aim is to increase bone mass before the achievement of peak bone mass in order to prevent osteoporosis. However, suitable weight-bearing exercise in osteoporosis is useful for the prevention of falls which may result in fractures, to increase muscle strength, to improve walking balance and coordination, and to prevent orthostatic hypotension.

Intra- and extracellular localization of hyaluronic acid and proteoglycan constituents (chondroitin sulfate, keratan sulfate, and protein core) in articular cartilage of rabbit tibia

To demonstrate the intra- and extracellular localization of hyaluronic acid (HA) in articular cartilage of the rabbit tibia, biotinylated HA binding region, which specifically binds to the HA molecule, was applied to the tissue. In comparison with the localization of HA, that of chondroitin sulfate (CS), keratan sulfate (KS), and the protein core (PC) of the proteoglycan was examined by immunohistochemistry. Strong positive staining for HA was detected in chondrocytes located in the transition between the superficial and middle zones of the tissue. Pre-treatment with chondroitinase ABC, keratanase II, or trypsin enhanced the stainability for HA in peri- and intercellular matrices. Immunohistochemistry with or without enzymatic pre-treatment demonstrated that immunoreactivity for CS, KS, and PC was distinctly discerned in chondrocytes and in the extracellular matrix located in the middle and deep zones. In particular, the immunoreactivity for KS and PC was augmented by pre-treatment with chondroitinase ABC not only in chondrocytes but in the extracellular matrix located in the middle and deep zones. Microbiochemical analysis corresponded well with histochemical and immunohistochemical results. These results suggest that HA is abundantly synthesized and secreted in chondrocytes located in the transition between the superficial and middle zones.

Quantitation of chondroitin 4-sulfate and chondroitin 6-sulfate in pathologic joint fluid

OBJECTIVE

To investigate the correlation between joint disease and the composition of chondroitin sulfate in the joint fluid, unsaturated disaccharide isomers of chondroitin 4-sulfate (delta di-4S) and chondroitin 6-sulfate (delta di-6S) were measured in joint fluids obtained from patients with osteoarthritis (OA), rheumatoid arthritis (RA), or traumatic arthritis (TA).

METHODS

These pathologic joint fluids were digested with chondroitinase ABC, and the delta di-4S and delta di-6S produced were determined by high performance liquid chromatography combined with fluorometry.

RESULTS

Total content of delta di-4S plus delta di-6S was 71.8 +/- 30.0 nmoles/ml (mean +/- SD) in OA, 55.4 +/- 29.3 nmoles/ml in RA, and 211 +/- 149 nmoles/ml in TA joint fluids. The ratio of delta di-6S to delta di-4S was 3.81 +/- 0.992 in OA, 1.13 +/- 0.527 in RA, and 5.75 +/- 2.46 in TA joint fluids. Differences between groups were statistically significant.

CONCLUSION

These results strongly suggest that the levels of chondroitin sulfate isomers and the delta di-6S: delta di-4S ratio in joint fluid reflect the proteoglycan metabolism of joint tissues, particularly of articular cartilage; hence, they could be used to diagnose joint diseases and to predict articular cartilage destruction from such joint diseases.

Two distinct subtypes of hepatitis C virus defined by antibodies directed to the putative core protein

Four distinct genotypes of hepatitis C virus types I, II, III and IV have been identified by comparison of nucleotide sequences of isolates from different areas of the world. We examined the possibility that hepatitis C virus may have serologically definable subtypes. Enzyme-linked immunosorbent assay systems were prepared by use of two synthetic peptides deduced from the putative core protein of hepatitis C virus. The following are the two peptides that were used: (a) IPKARRPEGRTWAQPGY (subtype-1) conserved in hepatitis C virus isolates with type I and type II genotypes; and (b) IPKDRRSTGKSWGKPGY (subtype-2) conserved in type III and type IV genotypes. With the enzyme-linked immunosorbent assays, the subtype-1 antibodies were detected in 26 (68%) of 38 subjects whose hepatitis C virus RNA had been genotyped as type I or type II, whereas subtype-2 antibodies were not detected. Inversely, the subtype-2 antibodies were detected in 10 (56%) of 18 subjects with hepatitis C virus RNA genotypes III or IV, whereas subtype-1 antibodies were detected in none of them. These results suggest that hepatitis C virus has two serologically distinguishable core antigen subtypes, corresponding to either genotype I/II or genotype III/IV. Subtyping of HCV by serological methods would contribute to tracking transmission routes of the virus, especially in cases where serum samples were not stored under conditions to preserve RNA or in infected hosts who have cleared the virus and therefore have only antibodies remaining to identify the infection.

Mutations within the S gene of hepatitis B virus transmitted from mothers to babies immunized with hepatitis B immune globulin and vaccine

A variant of hepatitis B virus (HBV) having a specific mutation within the S gene has been found to infect vaccinees. To know whether similar variants were involved in Japan, we analyzed two cases of maternal transmission of HBV in infants immunized with hepatitis B immune globulin and hepatitis B vaccine. DNA clones of HBV S genes were propagated from patients and family members and sequenced. In one family, the DNA clones from the baby patient had a Gly-to-Arg mutation at the 145th codon of the S gene, whereas those from her mother had no such mutations. In the other family, all the DNA clones obtained from the two infected children had the 145th codon intact, but they had a missense mutation at the 126th codon of the S gene, causing an amino acid substitution of Asn for Thr or Ile. This same mutation was observed in 12 of 17 clones of DNA obtained from their mother. In comparison with the wild type HBV-derived hepatitis B surface antigen, the two types of S gene mutations, either at the 145th or the 126th codon, were associated with a significant decrease in the antigenicity of some determinants on the hepatitis B surface antigen, measured by MAb. Amino acid substitution at these sites, therefore, would have induced the escape from conventional vaccines that were S gene products of wild type HBV and also from hepatitis B immune globulin, whose main components were probably also antibodies against the S gene products expressed by wild type HBV.

Hepatitis B surface antigen particles of subtypes adw and adr, and compound subtype (adwr) in symptom-free carriers in Japan

Of sera from 1,878 Japanese blood donors who carried hepatitis B surface antigen (HBsAg), 420 were subtyped as adw (22.4%) and 1,443 as adr (76.8%); only 15 (0.8%) contained HBsAg of subtype ayw or ayr. Sera with HBsAg/adr had higher HBsAg titres than those with HBsAg/adw (geometric mean of haemagglutination titre: 10.1 +/- 2.4 vs. 9.7 +/- 2.4, p less than 0.01), and a higher prevalence of hepatitis B e antigen (24% vs. 13%, p less than 0.001). Carriers of HBsAg/adr progressively predominated over those of HBsAg/adw with increasing age. Of sera from 1,863 carriers of HBsAg/adw or HBsAg/adr, 182 (9.8%) contained HBsAg particles with both subtypic determinants in the w/r allele. The presence of w and r determinants on the same particles was ascertained by sandwiching them between monoclonal antibody with the specificity for w and that with the specificity for r. HBsAg particles of compound subtype (adwr) were found more often in sera with hepatitis B e antigen than those without it (145/403 [36.0%] vs. 37/1,460 [2.5%], p less than 0.001). Sera with HBsAg/adwr particles had HBsAg titres higher than those without them (12.4 +/- 1.9 vs. 9.7 +/- 2.3, p less than 0.001). HBsAg/adwr particles arise from phenotypic mixing of the S-gene product of wild-type virus and that of mutants with point mutations for subtypic changes. The results obtained indicated that HBV strains of subtype adr have a higher replicative activity than those of adw, and suggested that mutations in the S gene for subtypic changes would be associated with an active replication of hepatitis B virus.

Antibodies against synthetic oligopeptides deduced from the putative core gene for the diagnosis of hepatitis virus infection

Immunoassays were developed to detect antibodies against oligopeptides deduced from the putative core gene of hepatitis C virus, and their performances were compared with that of the commercial immunoassay for antibodies against the product of nonstructural regions of hepatitis C virus (anti-C100-3). A 19-mer oligopeptide (CP10) and a 36-mer oligopeptide (CP9) were chemically synthesized, which represented hydrophilic regions of the product of the hepatitis C virus core gene. They were used to capture corresponding antibodies, anti-CP10 and anti-CP9, by enzyme-linked immunosorbent assay in sera from patients with acute or chronic non-A, non-B liver disease and in blood donations. At the onset of acute non-A, non-B hepatitis, anti-CP10 was detected in 15 of 20 patients (75%), and anti-CP9 was detected in 14 patients (70%). This was more frequent than anti-C100-3, which was found in only 9 patients (45%). In 186 patients with chronic non-A, non-B liver disease, anti-CP9, anti-CP10 or both were detected in 170 patients (91%). This was more frequent than anti-C100-3, which was found in 138 patients (74%). Blood with anti-CP10 as the single serological marker for hepatitis C virus infection transmitted non-A, non-B hepatitis by needlestick exposure. In sera from 558 apparently healthy blood donors, anti-CP10 was detected in 55 donors (9.9%), anti-CP9 was detected in 26 donors (4.7%) and anti-C100-3 was detected in 7 donors (1.3%).(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular heterogeneity of e antigen polypeptides in sera from carriers of hepatitis B virus

Hepatitis B e Ag (HBeAg) was isolated from pooled sera of carriers, without abnormalities in liver function, by affinity column chromatography with mAb against HBeAg. HBeAg polypeptide with an estimated molecular size of 20,000 Da (p20e) was detected, in addition to regular HBeAg polypeptides (p17e/p18e). p20e, as well as p17e/p18e, did not bind with mAb against the carboxyl-terminal domain of the C-gene product. p20e disclosed an N-terminal sequence of MQLFHLXLII- (X unknown), whereas p17e had that of SKLXLGXLXGMDIDPXKEFG- (X's unknown). By comparing them with the amino acid sequence encoded by the precore region and C gene of hepatitis B virus DNA, p20e was deduced to possess amino acids 1 to 19 of the precore-region product at the N-terminus, which contains signal sequence and usually removed before the secretion of HBeAg. p17e had amino acids 20 to 29 of the precore-region product that continued to the C-gene product. Inasmuch as p20e was invariably detected in HBeAg preparations from carriers without evidence for liver disease, it would not have been released into the circulation from destructed hepatocytes. HBeAg polypeptide bearing an uncleaved signal sequence would help in further understanding the mechanism of HBeAg secretion.

Nucleotide sequence of the genomic RNA of hepatitis C virus isolated from a human carrier: comparison with reported isolates for conserved and divergent regions

The complete nucleotide sequence of a hepatitis C virus derived from plasma of a human carrier in Japan was determined. The cDNA of the isolate (HC-J6) contained 9481 nucleotides and an additional T stretch of 30 to 108 nucleotides at the 3' end, and had one large open reading frame coding for a polyprotein of 3033 amino acids. It differed by 31.8 to 32.1% in the nucleotide sequence and by 27.4 to 27.7% in the amino acid sequence from an American isolate and two Japanese isolates previously reported. Among these four isolates, the 5' non-coding region of 329 to 341 nucleotides was well conserved (greater than 93% identity), whereas the 3' non-coding region of 39 to 45 nucleotides (T stretches not included) was more variable (greater than 30% identity). An excellent degree of conservation of the 5' non-coding region would reflect its pivotal role in replication, and primers deduced from this region could be applied for the sensitive and specific detection of viral RNA by polymerase chain reaction. Due to a high degree of similarity in the amino acid sequence of the putative core protein (greater than 90%), antigen probes deduced from it would be suitable for the serological diagnosis of HCV infection. Low sequence similarity in the putative envelope protein (greater than 53% identity), however, would have to be taken into account in considering the immunoprophylaxis of HCV infection.

Phosphorylation in the carboxyl-terminal domain of the capsid protein of hepatitis B virus: evaluation with a monoclonal antibody

The capsid protein of hepatitis B virus (p21c) is made of 183 amino acids coded for by the C gene. By using p21c isolated from Dane particles (hepatitis B virus) as an immunogen, a monoclonal antibody (no. 2212) which recognized an epitope dependent on the phosphorylation of p21c was raised. The binding of no. 2212 antibody to authentic p21c was completely inhibited by a synthetic undecapeptide with a sequence of RRRSQSPRRRR, representing amino acids 165 to 175 of p21c, only when the peptide was phosphorylated. Either or both of Ser-168 and Ser-170 were phosphorylated in p21c in vivo, therefore, and contributed to the manifestation of the epitope. No. 2212 antibody bound to p21c from core particles derived from Dane particles or hepatocellular carcinoma tissues (PLC/342) propagated in nude mice but did not bind to p21c from core particles expressed in Escherichia coli or yeast cells, indicating different states of phosphorylation in them. Nonphosphorylated p21c showed a higher affinity for the viral DNA than did phosphorylated p21c. Since the serum from an asymptomatic carrier, with a high titer for antibody to hepatitis B core antigen, specifically bound to phosphorylated undecapeptide (amino acids 165 to 175), the epitope would stimulate humoral antibody responses in the human host.

Molecular heterogeneity of e antigen polypeptides in sera from carriers of hepatitis B virus

Hepatitis B e Ag (HBeAg) was isolated from pooled sera of carriers, without abnormalities in liver function, by affinity column chromatography with mAb against HBeAg. HBeAg polypeptide with an estimated molecular size of 20,000 Da (p20e) was detected, in addition to regular HBeAg polypeptides (p17e/p18e). p20e, as well as p17e/p18e, did not bind with mAb against the carboxyl-terminal domain of the C-gene product. p20e disclosed an N-terminal sequence of MQLFHLXLII- (X unknown), whereas p17e had that of SKLXLGXLXGMDIDPXKEFG- (X's unknown). By comparing them with the amino acid sequence encoded by the precore region and C gene of hepatitis B virus DNA, p20e was deduced to possess amino acids 1 to 19 of the precore-region product at the N-terminus, which contains signal sequence and usually removed before the secretion of HBeAg. p17e had amino acids 20 to 29 of the precore-region product that continued to the C-gene product. Inasmuch as p20e was invariably detected in HBeAg preparations from carriers without evidence for liver disease, it would not have been released into the circulation from destructed hepatocytes. HBeAg polypeptide bearing an uncleaved signal sequence would help in further understanding the mechanism of HBeAg secretion.

The effect of sodium hyaluronate on the migration of rabbit corneal epithelium. II. The effect of topical administration

The effect of topically administered sodium hyaluronate (Na-HA) on the healing of corneal epithelial defect was investigated using rabbit eyes. The corneal epithelium was removed surgically or with iodine vapor or n-heptanol, and saline was administered to one eye as the control, and 0.1% or 0.25% Na-HA with a molecular weight of 87.3 x 10(4) to the other eye once daily. The area of epithelial defect was measured once daily before a topical administration, and the healing rate of epithelial defect was calculated. When the corneal epithelium was removed with iodine vapor, a topical administration of 0.1% or 0.25% Na-HA did not significantly accelerate the epithelial healing. But when removed surgically or with n-heptanol, the healing rates of the corneas treated with 0.25% Na-HA significantly exceeded those of the control eyes. When the epithelium was removed surgically, treatment with 0.1% Na-HA also significantly accelerated the healing. To determine why the effect of Na-HA differed in these three models with the epithelial defect, the amount of fibronectin (FN) produced by the cornea were investigated. The amount of FN produced was determined from the concentration of FN in the medium obtained after incubation of the corneo-scleral section with corneal epithelial defect, and the amount of Na-HA retained on that cornea was estimated from radioactivity detected in tears and cornea after a topical administration of 14C-labeled Na-HA (14C-Na-HA). The corneo-scleral section whose corneal epithelium had been removed surgically, or with n-heptanol, produced a significantly larger amount of FN than that whose corneal epithelium had been removed with iodine vapor. In addition, the amount of 14C-Na-HA retained on the cornea of the first or second model also significantly exceeded that on the cornea of the third model. The topical administration of Na-HA would thus appear to accelerate the healing of the epithelial defect producing a larger amount of FN or retaining a larger amount of Na-HA.

Common and subtypic determinants of hepatitis B surface antigen particles: susceptibility to reduction and/or alkylation evaluated with monoclonal antibodies

The specificity of five monoclonal antibodies, three raised against hepatitis B surface antigen (HBsAg) particles and two against envelope polypeptides, was tested for on a panel of 366 sera containing HBsAg of various subtypes (131 adw, 146 adr, 39 ayw and 50 ayr). Three monoclonals bound to HBsAg irrespective of subtypes, and therefore, were directed to the common antigenic determinants of HBsAg. Of these, two raised against particles (No. 824 and No. 7922) did not bind with reduced HBsAg particles. The other raised against peptides (No. 5124) bound to reduced HBsAg particles. It did not, however, bind to reduced and alkylated HBsAg particles, thereby indicating that it was directed to an epitope involving cysteine residues not contributing to the conformation. The remaining two monoclonals were directed to subtypic determinants not identical to any of d, y, w and r determinants. The subtypic determinant detectable by one of them (No. 4403), raised against HBsAg polypeptides, markedly increased after reduction of HBsAg particles with or without alkylation. In contrast, the subtypic determinant, detectable by the other monoclonal (No. 2155) raised against particles, substantially decreased after reduction. Non-identity of common or subtypic determinants detectable by the five monoclonals were established by blocking tests in which labeled antibody was competed by non-labeled antibody, of a homologous or heterologous specificity, for the binding with HBsAg. These monoclonals would be useful in studies for immunochemical configuration of HBsAg particles and epidemiology of novel subtypic determinants.