The first report on human cases serologically diagnosed as Japanese encephalitis in Indonesia

Although Japanese encephalitis (JE) virus was isolated from mosquitos in 1974, human JE cases have never been reported in Indonesia in spite of the prevalence of anti-JE antibodies among human and pig populations as well as abundant JE vector mosquitos. In this report, we describe serological diagnosis of JE cases in Bali. Indonesia. using IgM-capture ELISA both on serum and cerebrospinal fluid (CSF) of the patients. In the first series of our investigation (Series 1), we examined serum specimens from 12 patients with clinical diagnosis of viral encephalitis, meningitis or dengue hemorrhagic fever (DHF), and found 2 possible JE cases. In the next series (Series 2), we examined both serum and CSF from encephalitis patients and gave laboratory diagnosis of JE. One of them was suspected to have concomitant or recent infection with dengue virus, probably type 3. These results strongly indicated that JE has been prevalent in Bali, Indonesia.

Infection of dengue 2 virus strains isolated from patients exhibiting different disease severities to human peripheral blood leukocytes and production of cytokines in the infected culture supernatant

Three strains of type 2 dengue virus (DV-2), which had been isolated from patients exhibiting different disease severity, were inoculated to primary culture of human peripheral blood leukocytes from 3 healthy donors. The percentage of dengue antigen positive cells was highest for the strain isolated from a case of dengue shock syndrome, followed by the strain isolated from a case of dengue hemorrhagic fever, and lowest for the strain isolated from a mild case of dengue fever (DF). Generally, similar trend was observed for the amount of some cytokines released into infected culture supernatant, such as interleukin 6, and tumor necrosis factor-alpha. However, such a trend was not observed for interleukin 1 beta.

Decrease in the ciliary neurotrophic factor of the spinal cord in amyotrophic lateral sclerosis

Ciliary neurotrophic factor (CNTF), a potent survival factor in spinal motoneurons of embryonic chick and rat, is currently being investigated in humans as a treatment for amyotrophic lateral sclerosis (ALS). However, its physiological and pathological activities in ALS remain unclear. We measured CNTF contents in the cervical enlargement of the spinal cord from 9 ALS patients and 12 age-matched control subjects using a sensitive enzyme-linked immunoassay. CNTF genotypes were determined by the polymerase chain reaction-restriction fragment length polymorphism method. In control subjects, there were 8 homozygotes and 4 heterozygotes, while in ALS patients there were 6 and 3, respectively. In both homozygotes and heterozygotes, CNTF expression in the spinal cord from ALS patients tended to decrease compared to control subjects. In homozygotes, the decrease was significant (p < 0.05). Concerning the regional concentrations of CNTF, in homozygotes, CNTF contents in the lateral corticospinal tract were markedly lower (p < 0.001) in ALS patients than in controls. The decrease in CNTF expression in the lateral corticospinal tract of the spinal cord from ALS patients may be a feature of ALS and could be related to motor neuron loss.

Role and interaction of connective tissue growth factor with transforming growth factor-beta in persistent fibrosis: A mouse fibrosis model

Skin fibrotic disorders are understood to develop under the influence of some growth factors, such as transforming growth factor-beta (TGF-beta), basic fibroblast growth factor (bFGF), or connective tissue growth factor (CTGF). To establish an appropriate animal model of skin fibrosis by exogenous application of growth factors, we investigated the in vivo effects of growth factors by injecting TGF-beta, CTGF, and bFGF into the subcutaneous tissue of newborn mice. A single application of TGF-beta or bFGF resulted in the formation of transient granulated tissue that disappeared despite 7 days of consecutive injections. A single CTGF injection also caused slight granulation. However, injecting TGF-beta plus CTGF produced long-term fibrotic tissue, which persisted for at least 14 days. Also, fibrotic tissue was observed when CTGF was injected from 4 to 7 days after TGF-beta injections for the first 1-3 days. In situ hybridization analysis revealed the expression of CTGF mRNA in the fibroblasts at least in a few fibrotic conditions. These findings suggest that either CTGF mRNA or an application of exogenous CTGF protein is required for the development of persistent fibrosis. From our study, it appears that interaction of several growth factors is required for persistent fibrotic tissue formation, with TGF-beta causing the induction and CTGF needed for maintenance of skin fibrosis. The animal model on skin fibrosis by exogenous application of growth factors developed in this study may prove useful for future studies on fibrotic disorders.

Role and interaction of connective tissue growth factor with transforming growth factor-beta in persistent fibrosis: A mouse fibrosis model

Skin fibrotic disorders are understood to develop under the influence of some growth factors, such as transforming growth factor-beta (TGF-beta), basic fibroblast growth factor (bFGF), or connective tissue growth factor (CTGF). To establish an appropriate animal model of skin fibrosis by exogenous application of growth factors, we investigated the in vivo effects of growth factors by injecting TGF-beta, CTGF, and bFGF into the subcutaneous tissue of newborn mice. A single application of TGF-beta or bFGF resulted in the formation of transient granulated tissue that disappeared despite 7 days of consecutive injections. A single CTGF injection also caused slight granulation. However, injecting TGF-beta plus CTGF produced long-term fibrotic tissue, which persisted for at least 14 days. Also, fibrotic tissue was observed when CTGF was injected from 4 to 7 days after TGF-beta injections for the first 1-3 days. In situ hybridization analysis revealed the expression of CTGF mRNA in the fibroblasts at least in a few fibrotic conditions. These findings suggest that either CTGF mRNA or an application of exogenous CTGF protein is required for the development of persistent fibrosis. From our study, it appears that interaction of several growth factors is required for persistent fibrotic tissue formation, with TGF-beta causing the induction and CTGF needed for maintenance of skin fibrosis. The animal model on skin fibrosis by exogenous application of growth factors developed in this study may prove useful for future studies on fibrotic disorders.

Role and interaction of connective tissue growth factor with transforming growth factor-beta in persistent fibrosis: A mouse fibrosis model

Skin fibrotic disorders are understood to develop under the influence of some growth factors, such as transforming growth factor-beta (TGF-beta), basic fibroblast growth factor (bFGF), or connective tissue growth factor (CTGF). To establish an appropriate animal model of skin fibrosis by exogenous application of growth factors, we investigated the in vivo effects of growth factors by injecting TGF-beta, CTGF, and bFGF into the subcutaneous tissue of newborn mice. A single application of TGF-beta or bFGF resulted in the formation of transient granulated tissue that disappeared despite 7 days of consecutive injections. A single CTGF injection also caused slight granulation. However, injecting TGF-beta plus CTGF produced long-term fibrotic tissue, which persisted for at least 14 days. Also, fibrotic tissue was observed when CTGF was injected from 4 to 7 days after TGF-beta injections for the first 1-3 days. In situ hybridization analysis revealed the expression of CTGF mRNA in the fibroblasts at least in a few fibrotic conditions. These findings suggest that either CTGF mRNA or an application of exogenous CTGF protein is required for the development of persistent fibrosis. From our study, it appears that interaction of several growth factors is required for persistent fibrotic tissue formation, with TGF-beta causing the induction and CTGF needed for maintenance of skin fibrosis. The animal model on skin fibrosis by exogenous application of growth factors developed in this study may prove useful for future studies on fibrotic disorders.

The marked inhibition of the bitter taste of Polymyxin B sulfate and trimethoprim x sulfamethoxazole by flavored BMI-60 in pediatric patients

Taste acceptability of ground Polymyxin B sulfate and Bactramin C tablets was examined when flavored BMI-60, a food additive, was added. Both adult and child volunteers found the bitter taste of the two drugs markedly inhibited, making it clinically useful. Noncompliance, due to this bitterness, was improved using flavored BMI-60. The most striking characteristic of flavored BMI-60 is the ease of preparation compared with the manufacture of other hospital pharmaceuticals such as jelly, gummi and candy done to mask bitterness.

In vitro antibacterial activity of LJC 11,036, an active metabolite of L-084, a new oral carbapenem antibiotic with potent antipneumococcal activity

LJC 11,036 is the active metabolite of L-084, a novel oral carbapenem that exhibits potent broad-spectrum activity. Antibacterial activities of LJC 11,036 against clinical isolates from respiratory infections, such as Streptococcus pneumoniae (n = 52), Streptococcus pyogenes (n = 19), Haemophilus influenzae (n = 50), Klebsiella pneumoniae (n = 53), and Moraxella catarrhalis (n = 53), and from urinary-tract infections, such as Escherichia coli (n = 53) (MICs at which 90% of the isolates were inhibited [MIC(90)s], 0.1, </=0.006, 0.39, 0.05, 0.05, and 0.05 microg/ml, respectively), were 2- to 64-fold higher than those of imipenem, cefdinir, and faropenem. Moreover, against these bacterial species, except for H. influenzae, the MIC(90)s of LJC 11,036 were 4- to 512-fold lower than those of levofloxacin. LJC 11,036 showed bactericidal activity equal or superior to that of imipenem. Bactericidal activity against penicillin-resistant S. pneumoniae (PRSP) did not vary with the phase of growth. LJC 11,036 had potent activity against various beta-lactamase-producing strains, excluding carbapenemase producers. Against renal dehydropeptidase-I, LJC 11,036 was more stable than imipenem. Furthermore, LJC 11,036 produced in vitro postantibiotic sub-MIC effects against PRSP HSC-3 (6.0 h at one-fourth the MIC) and H. influenzae LJ5 (9.2 h at one-half the MIC). LJC 11,036 showed high binding affinities for PBP1A, -1B, -2A/2X, -2B, and -3 of PRSP and for PBP1B, -2, -3A, and -3B of H. influenzae.

Production of viral antigens in culture fluid of C6/36 mosquito cell line infected with dengue type 4 virus strains isolated from patients with different clinical severities

Viral antigen production was examined in the culture fluid of Aedes albopictus clone C6/36 cell line incubated at 28 degrees C and 37 degrees C after infection with four strains of dengue type 4 (DEN-4) virus which were isolated from patients with different clinical severities. During the observation period from day 1 to day 18, the number of infected cells at each day for all four strains did not show any significant difference (P >0.05). Antigen production as determined by the hemagglutination (HA) test and sandwich enzyme linked immunosorbent assay (ELISA) was higher at 28 degrees C than at 37 degrees C for all four DEN-4 virus strains examined. The amount of viral antigen produced was highest for CT93-74 strain (dengue hemorrhagic fever syndrome (DHF) grade II) and was significantly different in comparison to other strains (P <0.001). This strain was followed by CT93-158 and CT93-129 strains (both of DHF grade I), and CT93-77 strain (dengue fever (DF)). The viral antigen production was apparently proportional to the clinical severity of the patient from whom the virus was isolated. These results show that CT93-74 strain could be used to produce DEN-4 virus antigen of sufficiently high titer in the C6/36 cell culture instead of classical extraction of this antigen from suckling mouse brains.

An emergency balloon occlusion system for a rotary blood pump left ventricular assist system

A fatal outcome is expected in a left ventricular assist system (LVAS) utilizing a rotary blood pump if there is no mechanism to prevent the backflow from the aorta to the heart in the case of acute pump failure. To solve this problem, a passive mechanical clamping system at the outflow graft of a rotary blood pump was developed together with Fuji Systems, Inc., Yokohama, Japan. The system consisted of an emergency clamp port and an occlusion balloon. The balloon was fixed around the outlet graft of the LVAS. In an in vitro study, a fail-safe clamping operation with 2 ml saline injection under 7 L/min flow against 140 mm Hg pressure reduced the flow to 0.5 L/min while the pressure in the system increased to 190 mm Hg. The systems were also applied to 2 in vivo LVAD studies. When the pumps were stopped, there were approximately 3.0 L/min regurgitant flows. The balloon occluder prevented this regurgitant flow effectively against a 100/80 mm Hg arterial pressure. In conclusion, this emergency balloon occlusion system is relatively easy to operate and will work efficiently in all possible clinically encountered malfunctions of the rotary blood pump LVAS.

Type-3 dengue viruses responsible for the dengue epidemic in Malaysia during 1993-1994

To characterize the dengue epidemic that recently occurred in Malaysia, we sequenced cDNAs from nine 1993-1994 dengue virus type-3 (DEN-3) isolates in Malaysia (DEN-3 was the most common type in Malaysia during this period). Nucleic acid sequences (720 nucleotides in length) from the nine isolates, encompassing the precursor of membrane protein (preM) and membrane (M) protein genes and part of the envelope (E) protein gene were aligned with various reference DEN-3 sequences to generate a neighbor-joining phylogenetic tree. According to the constructed tree, the nine Malaysian isolates were grouped into subtype II, which comprises Thai isolates from 1962 to 1987. Five earlier DEN-3 virus Malaysian isolates from 1974 to 1981 belonged to subtype I. The present data indicate that the recent dengue epidemic in Malaysia was due to the introduction of DEN-3 viruses previously endemic to Thailand.

Evidence for stanniocalcin gene expression in mammalian bone

Stanniocalcin (STC) acts as a regulator of calcium and phosphate homeostasis in an endocrine manner in bony fish. Recently, complementary DNAs encoding human and mouse STC have been characterized, and the messenger RNA (mRNA) expression was identified in various tissues, such as kidney, small intestine, prostate, thyroid, and ovary. Because previous studies concerning the effects of fish STC on mammalian bone have been discussed, there is a good possibility that mammalian STC is a local factor in bone. Here, we demonstrated STC mRNA expression in neonatal mouse calvaria, the primary cultured mouse osteoblast-rich fractions, and human and mouse osteoblastic cell lines. We also mapped the cellular distribution of the STC mRNA in femur and calvaria in developing mice. Several transcripts with a major 4-kb band were detected in all samples. The cellular distribution of the mRNA expression corresponded closely to osteoblasts in both femur and calvaria. Significant labeling of the STC mRNA was also identified in chondrocytes but not in osteoclasts and other bone marrow elements. These results are the first evidence that hormone may be actually expressed in osteoblasts and chondrocytes, and they strongly implicate the involvement of local STC in both endochondral and membrane bone as an autocrine/paracrine factor.

Stimulatory effect of zinc acexamate administration on fracture healing of the femoral-diaphyseal tissues in rats

The effect of zinc acexamate on fracture healing of the femoral-diaphyseal tissues in rats was investigated in vivo. Zinc acexamate (0.3 and 10.0 mg Zn/100 g body weight per day) was orally administered to rats (4 weeks old) surgically fractured the femoral diaphysis for 14 to 28 days. Calcium content and alkaline phosphatase activity in the femoral-diaphyseal tissues were significantly decreased in rats with fracture healing, while bone acid phosphatase activity and protein content were markedly increased. The administration of zinc acexamate (10.0 mg Zn/100 g) for 28 days caused a significant increase in calcium content, alkaline and acid phosphatases activities, protein and deoxyribonucleic acid (DNA) contents in the femoral-diaphyseal tissues of rats with fracture healing. With the lower dose (3.0 mg Zn/100 g), zinc compound had a partial effect on bone components. Femoral mineral density in rats with fracture healing was significantly increased by the administration of zinc acexamate (10.0 mg Zn/100 g) for 28 days. Femoral-diaphyseal zinc content was significantly decreased in rats with fracture healing. This decrease was completely restored by the administration of zinc acexamate (10.0 mg Zn/100 g) for 28 days. The present study suggests that the supplement of zinc compound stimulates fracture healing of the femoral-diaphyseal tissues in rats.

Initial daily interferon administration can gain more eradication of HCV-RNA in patients with chronic hepatitis C, especially with serum intermediate viral load

BACKGROUND/AIMS

We studied the effect of initial daily administration of interferon for the treatment of chronic hepatitis C, especially in patients with intermediate viral load.

METHODOLOGY

Consecutive patients who met the inclusion criteria were randomly enrolled into two groups in this study. All patients analyzed could be treated with interferon-alpha for 6 months. Patients in group A were administered 6 million units of interferon-alpha subcutaneously daily initially for 2 weeks and then thrice weekly. Patients in group B were treated with the same dose of interferon-alpha thrice weekly from the first administration. We decided the criteria of complete remission as the absence of serum HCV-RNA at both points of the end of interferon treatment and 6 months later.

RESULTS

Due to the relationship between the efficacy and serum viral load, we decided the criteria of the intermediate load as the quantitative value of serum HCV-RNA to be not lower than 10(5.0) and not higher than 10(6.5) copies/ml. Seventy-six and 78 patients, whose genotype and quantitative value of serum HCV-RNA could be measured before treatment, were analyzed in group A and B, respectively. The rate of complete remission in group A (40.8%) was higher than that in group B (25.6%), significantly (p = 0.046). In the intermediate viral load group, the rate of complete remission in group A (52.3%) was significantly higher than that in group B (29.3%) (p = 0.045). In the patients with genotype 1 b virus, the rate of complete remission had a tendency to be higher in group A (33.3%) than in group B (17.4%) (not significant). In the patients with genotype 2, the rate of complete remission was higher in group A (77.8%) than in group B (41.2%) (significant, p = 0.041).

CONCLUSIONS

These results suggest that the initial daily interferon administration is necessary to gain a higher rate of serum HCV-RNA eradication in patients with intermediate viral load in chronic hepatitis C.

Identification of a flavivirus isolated from mosquitos in Chiang Mai Thailand

A virus isolate, ThCAr105/92, from a pool of mosquitos, Culex tritaeniorhynchus, collected in Chiang Mai, Thailand in 1992, appeared to be a member of the genus Flavivirus of the family Flaviviridae, based on the reverse transcription polymerase chain reaction (RT-PCR) using flavivirus cross-reacting primer pairs, electron microscopic examination, and serological tests. However, RT-PCR using Japanese encephalitis (JE) virus-specific primers showed that the isolate was different from JE virus. Sucrose density gradient sedimentation of the virus replicated in C6/36 cells indicated that the virus is relatively unstable in the infected culture fluids at 37 degrees C. Antibody prepared against this virus and a virus seed for the isolate were tested by cross neutralization against a panel of flaviviruses and the results showed that the new isolate was a distinct subtype of Tembusu virus.

Effect of vitamin K2 (menaquinone-7) in fermented soybean (natto) on bone loss in ovariectomized rats

The effect of dietary vitamin K2 (menaquinone-7) on bone loss in ovariectomized (OVX) rats was investigated. OVX rats were freely given experimental diets containing menaquinone-4 (MK-4; 12mg/100g diet) or menaquinone-7 (MK-7; 18.1mg/100g diet) for 24 days; MK-4 and MK-7 were equal in molar concentrations. This feeding caused a remarkable increase of MK-4 and MK-7 concentrations in the serum and femur of OVX rats. OVX-induced decrease in the femoral dry weight and femoral calcium content was prevented by the feeding of dietary MK-4 or NK-7. In separate experiments, OVX rats were freely given experimental diets containing the fermented soybean (natto; including 9.4 microg MK-7/100g diet) without or with added MK-7 (37.6 microg/100g diet) for 77 days. Feeding produced a significant elevation of MK-4 and MK-7 concentrations in the serum of OVX rats. In this case, a significant increase in the femoral MK-4 content was observed but MK-7 was not detected in the femoral tissues. OVX-induced decreases in the femoral dry weight and femoral calcium content were significantly prevented by the feeding of diets containing natto with MK-7 added (37.6 microg/100g diets). This study demonstrates that the intake of dietary MK-7 has a preventive effect on bone loss caused by OVX. This effect may be partly caused by MK-4, which is formed by degradation of MK-7.

A Japanese case of dengue fever with lymphocytic vasculitis: diagnosis by polymerase chain reaction

A 37-year-old Japanese male was admitted to Nagasaki University Hospital with abrupt onset of biphasic fever, general malaise and myalgia 9 days after coming back to Japan from Manila. He developed a rubella like erythematous rash 3 days after admission and purpuric eruption one week after admission. A biopsied specimen from the purpura revealed lymphocytic vasculitis with T cell dominance and without immunoglobulin or complement deposition around the blood vessels. RT-PCR analysis on peripheral blood mononuclear cells using dengue virus specific primers confirmed the diagnosis of type 3 dengue fever. PCR analysis using virus specific primers is a rapid and valuable method for making a correct diagnosis of dengue fever.

Preparation of a monoclonal antibody specific for human stanniocalcin

Stanniocalcin (STC) is a glycoprotein hormone that was first identified in fish, where it regulates the calcium level in the body fluid. The cDNA which encodes human STC has recently been reported but the function has not been completely elucidated. We have prepared a monoclonal antibody against human STC using an analogous peptide of the putative antigenic domain in human STC; it was conjugated with keyhole limpet hemocyanin (KLH). The monoclonal antibody specifically stained the distal convoluted tubules in human kidney which is a putative target organ of STC. The ELISA was established using the monoclonal antibody and recombinant human STC as a standard antigen. The monoclonal antibody prepared in this study provides a useful tool for clinical studies of STC in human.

Relationship between spontaneous aminoglycoside resistance in Escherichia coli and a decrease in oligopeptide binding protein

Changes in the amount of oligopeptide binding protein (OppA) in spontaneous kanamycin-resistant mutants of Escherichia coli were investigated. Among 20 colonies obtained from 10(8) cells cultured in the presence of 20 microgram of kanamycin/ml, 1 colony had no detectable OppA and 7 colonies were mutants with reduced amounts of OppA. Sensitivity of wild-type cells to kanamycin increased slightly by transformation of the oppA gene, but the sensitivity of the mutants increased greatly by the transformation. A mutant with no OppA was found to be a nonsense mutant of the oppA gene at amino acid position 166. In a mutant having a reduced level of OppA, the reduction was due to the decrease in OppA synthesis at the translational level. These mutants were also resistant to other aminoglycoside antibiotics, including streptomycin, neomycin, and isepamicin. Isepamicin uptake activities decreased greatly in these two kinds of mutants. The results support the proposition that aminoglycoside antibiotics are transported into cells by the oligopeptide transport system, and that transport is an important factor for spontaneous resistance to aminoglycoside antibiotics.

Dengue virus infection among children with undifferentiated fever in Karachi

Sera were collected from a total of 122 children, comprising 117 cases with undifferentiated fever and 5 cases with dengue hemorrhagic fever (DHF), during June to September 1994 in Karachi, Pakistan. Sera were tested by the IgM-capture ELISA using dengue type 1 (D1), dengue type 2 (D2), West Nile (WN), and Japanese encephalitis (JE) viral antigens. Among 92 single sera from undifferentiated fever cases, IgM antibodies were detected in 5 cases by D1, 8 cases by D2, and 5 cases by WN antigens, respectively. Corresponding number of positives among 25 paired sera from undifferentiated fever cases were 3 by D1, 6 by D2, and 1 by WN antigen. Four out of 5 DHF cases possessed anti-D1 as well as anti-D2 IgM antibodies. Only a single DHF case was positive for anti-WN IgM antibodies. Anti-JE IgM antibodies were not detected in any of the tested serum specimens. Clinical manifestations of undifferentiated fever patients were generally non specific, but the percentage of children with anemia, hepatomegaly and splenomegaly was higher in patients possessing anti-dengue IgM antibodies than those without. Among the groups with anti-dengue IgM antibodies, those possessing only anti-D2 but not anti-D1 IgM antibodies showed higher percentages with cough, edema, and splenomegaly. The results indicated that up to 26% of the undifferentiated fever cases were caused by dengue virus infection in Karachi, Pakistan.

The importance of initial daily administration of interferon alpha for the eradication of hepatitis C virus in patients with chronic hepatitis C: a multicenter randomized trial

BACKGROUND/AIMS

We studied the effect of initial daily administration of interferon for the treatment of chronic hepatitis C, to clarify a more effective treatment protocol for the eradication of the hepatitis C virus.

METHODOLOGY

Consecutive patients who met the inclusion criteria were randomly enrolled in two groups in this study. One hundred and five patients were randomized and assigned to two groups. Patients, who enrolled in group A, were treated with 6 million units of natural interferon-alpha given subcutaneously daily for an initial two weeks and then thrice a week for 22 weeks. Patients, who were enrolled in group B, were treated with the same dose of interferon-alpha given for 26 weeks thrice a week from the first administration.

RESULTS

In groups A and B, 58 and 47 patients were analyzed, respectively. At the end of treatment, 37 patients in group A (63.8%) had negative serum HCV-RNA test, compared with 26 in group B (55.3%), but at 6 months after discontinuation of interferon administration, 27 patients in group A (46.6%), compared with 8 in group B (21.3%). The rate of complete remission in group A (46.6%) was higher than that in group B (21.3%) (P<0.01). In patients with genotype 1b virus, the rate of complete remission was higher in group A (31.3%) than in group B (12.5%) (not significantly), and the relapse rate was lower in group A (9.4%) than in group B (37.5%), significantly (p<0.05).

CONCLUSIONS

This study suggests that initial daily interferon administration is necessary to gain a higher rate of serum HCV-RNA eradication in patients with chronic hepatitis C.

Molecular and in vitro analysis of eight dengue type 2 viruses isolated from patients exhibiting different disease severities

Potential genetic determinants of dengue virulence were studied by sequencing the entire genomes of eight dengue 2 virus strains isolated from patients exhibiting different disease severities during an epidemic season in northeastern Thailand in 1993. The isolates came from one dengue shock syndrome (ThNH-7/93), three dengue hemorrhagic fever, and four dengue fever patients. Phylogenetic analysis showed that the isolates belonged to the Southeast Asian genotype. The 3' noncoding regions showed distinctive secondary structures, with one specific structure for the isolate ThNH-7/93. Analysis of the predicted polyprotein showed several amino acid (aa) changes scattered mostly in the nonstructural region. Of 30 positions with aa changes, 7 were unique to the isolate ThNH-7/93 and 3 of those led to radical alterations in aa character. Several aa changes coincided with previous studies relating genome sequence and virulence. Minimal changes in computer-predicted protein secondary structures were observed. Infective particles in the inoculum for all isolates were approximately equal as measured by focus formation on BHK-21 cells, but this did not correlate with the number of plaques formed on LLC-MK2 cells. Isolates from patients that experienced secondary infection were shown to have significantly larger plaques than the isolates from primary infection patients.

Defective intracellular transport of tissue-nonspecific alkaline phosphatase with an Ala162-->Thr mutation associated with lethal hypophosphatasia

We have studied the biosynthesis and intracellular transport of tissue-nonspecific alkaline phosphatase (TNSALP) transiently expressed in COS-1 cells. Mutations were introduced into TNSALP to examine the effects of a single amino acid substitution on the activity and biosynthesis of TNSALP. The cells expressing wild-type TNSALP exhibited more than 200-fold higher alkaline phosphatase activity than untransfected ones. Pulse-chase experiments showed that TNSALP was synthesized as a 66-kDa endoglucosaminidase H (Endo H)-sensitive form and converted to EndoH-resistant forms with heterogenous molecular masses ( approximately 80 kDa), which finally appeared on the cell surface as judged by digestion with phosphatidylinositol-specific phospholipase C (PI-PLC). In contrast, a TNSALP with a Glu218-->Gly mutation exhibited no phosphatase activity at all and the 66-kDa Endo H-sensitive form was the only molecular species throughout the chase in the transfected cells. In accordance with this finding, digestion with PI-PLC and immunofluorescence observation confirmed that this mutant was never expressed on the cell surface. Another mutant with a Ala162-->Thr substitution, which naturally occurs in association with a lethal hypophosphatasia, exhibited a low activity and only a small fraction of the 66-kDa form acquired Endo-H resistance and reached the cell surface. Since the wild-type and the mutant TNSALPs were labeled with [3H]ethanolamine, a component of glycosylphosphatidylinositol (GPI), it is unlikely that the impaired intracellular transport of the two mutants is due to a failure in their modification by GPI. Interestingly, the 66-kDa Endo H-sensitive form of the TNSALP mutants but not that of the wild-type, was found to form an interchain disulfide-bonded high-molecular-mass aggregate within the cells. These results suggest that impaired intracellular transport of the TNSALP (Ala162-->Thr) molecule caused by its aggregation is the molecular basis for the lethal hypophosphatasia carrying this mutation.

Tazanolast inhibits ozone-induced airway hyperresponsiveness in guinea pigs

We studied the inhibitory effect of tazanolast, a selective mast-cell-stabilizing drug, on ozone-induced airway hyperresponsiveness in guinea pigs. Airway responsiveness to methacholine peaked at 2 h after ozone exposure (2.0 ppm for 2 h) and the number of neutrophils in bronchoalveolar lavage (BAL) fluid continued to increase until 6 h. Tazanolast administered before ozone exposure at doses of 30, 100, or 300 mg/kg inhibited ozone-induced airway hyperresponsiveness in a dose-dependent manner. However, tazanolast administered after ozone exposure did not inhibit the airway hyperresponsiveness. Tazanolast did not significantly change the cell distribution of BAL cells at 2 h after the exposure. We conclude that tazanolast significantly inhibits ozone-induced airway hyperresponsiveness in guinea pigs. This result suggests that mast cells may play an important role in its development.

Differential expression of connective tissue growth factor gene in cutaneous fibrohistiocytic and vascular tumors

Connective tissue growth factor (CTGF) is a member of a family of immediate early gene products that may play an important role during tissue regeneration, wound repair and skin fibrosis. In this study, CTGF gene expression in mesenchymal tumors was investigated by in situ hybridization and CD34 antigen expression was studied by means of immunohistochemical staining. CTGF mRNA was expressed in fibroblasts of all nine dermatofibromas examined, but five of seven dermatofibrosarcoma protuberans (DFSP) or two cases of malignant fibrous histiocytoma were negative for its expression. In contrast, CD34 antigen was expressed only in DFSP. In vascular tumors, CTGF mRNA was expressed in pyogenic granuloma but not in angiosarcoma. In addition, the endothelial cells in angiolipoma and angioleiomyoma, but not in venous lake, expressed CTGF mRNA. These vascular lesions were all positive for CD34 expression. Tumors of other origins were negative for CTGF mRNA. Our findings indicated that benign fibroblasts and/or vascular endothelial cells have the capability to express CTGF mRNA when activated, but these cells lose this ability when they achieve malignant potency. Thus, examination of CTGF gene expression may be useful for differentiating between benign and malignant mesenchymal tumors, or to determine the origin of the tumors in connective tissue.