Development of Neonatal Airway Management Simulator for Evaluation of Tracheal Intubation

The long-term goal of this study is a training system that can simulate medical cases and advise physicians based on quantitative evaluation of neonatal resuscitation. In this paper, we designed and manufactured a neonatal airway management simulator for quantitative evaluation of tracheal intubation. This robotic simulator is equipped with 25 sensors of 6 types, which detect motions that lead to complications, inside the manikin replicated a neonate. A performance experiment of the developed sensor and an evaluation experiment with physicians were conducted. We observed that an erroneous operation in the laryngoscopy can be detected by the sensors in our simulator.

DNA vaccine-encapsulated virus-like particles derived from an orally transmissible virus stimulate mucosal and systemic immune responses by oral administration

Delivery of foreign genes to the digestive tract mucosa by oral administration of nonreplicating gene transfer vectors would be a very useful method for vaccination and gene therapy. However, there have been few reports on suitable vectors. In the present study, we found that plasmid DNA can be packaged in vitro into a virus-like particle (VLP) composed of open reading frame 2 of hepatitis E virus, which is an orally transmissible virus, and that these VLPs can deliver this foreign DNA to the intestinal mucosa in vivo. The delivery of plasmid DNA to the mucosa of the small intestine was confirmed by the results of immunohistochemical analyses using an expression plasmid encoding human immunodeficiency virus env (HIV env) gp120. After oral administration of VLPs loaded with HIV env cDNA, significant levels of specific IgG and IgA to HIV env in fecal extracts and sera were found. Moreover, mice used in this study exhibited cytotoxic T-lymphocyte responses specific to HIV env in the spleen, Payer's patches and mesenteric lymph nodes. These findings suggest that VLPs derived from orally transmissible viruses can be used as vectors for delivery of genes to mucosal tissue by oral administration for the purpose of DNA vaccination and gene therapy.

Infection of macaques with an R5-tropic SHIV bearing a chimeric envelope carrying subtype E V3 loop among subtype B framework

To establish simian/human immunodeficiency virus (SHIV) clones bearing a chimeric envelope carrying subtype E V3 loop among subtype B envelope, four subtype E V3 sequences were substituted into SHIV(MD14), a SHIV clone bearing an envelope derived from a CXCR4 (X4)/CCR5 (R5)-dual tropic subtype B HIV-1 strain. SHIV-TH09V3, an only V3-chimera clone capable of replicating in human and macaque peripheral blood mononuclear cells (PBMCs), was propagated in pig-tailed macaque PBMCs and in cynomolgus macaque splenic mononuclear cells. The propagated virus stocks were intravenously inoculated into respective macaque species. SHIV-TH09V3 infected both macaque species as shown by plasma RNA viremia, isolated viruses from PBMCs and plasma, and antibody production against viral proteins. To assess how the substituted V3 sequence affected coreceptor usage, SHIV-TH09V3 stocks propagated in vitro and after isolation from macaques were verified for their corecepor usage by GHOST cells assay. SHIV-TH09V3 maintained R5-tropic phenotype both in vitro and after isolation from macaques, in contrast to the X4/R5-dual tropic SHIV(MD14). This indicates the substituted V3 sequence among the backbone of SHIV(MD14) governs coreceptor usage. Future study of infecting macaques with SHIV-TH09V3 and SHIV(MD14) will focus on differences of the outcome caused by the different V3 sequences in connection with coreceptor usage.

Induction of effective antitumor immune responses in a mouse bladder tumor model by using DNA of an alpha antigen from mycobacteria

One of the main objectives of cancer immunotherapy is the activation and increase in number of antitumor effector cells. Recently, genetically modified tumor cell vaccines have been proposed for elicitation of antitumor effector cells. Native alpha antigen (alpha Ag) (also known as MPT59 and antigen 85B) of mycobacteria, which cross-reacts among mycobacteria species, may play an important biological role in host-pathogen interaction because it elicits various helper T-cell type 1 immune responses. To assess the induction of antitumor immune responses by alpha Ag, mouse tumor cell lines transfected with cDNA of alpha Ag from Mycobacterium kansasii were established, and the possibility of producing a tumor cell vaccine for induction of antitumor effects was explored. Transfection of tumor cell lines with an alpha Ag gene lead to primary tumor rejection and the establishment of protective immunity to nontransfected original tumor cell lines in Mycobacterium bovis bacillus Calmette-Gurin (BCG)-primed and unprimed mice. Mice immunized with tumor cell lines transfected with the alpha Ag gene showed delayed-type hypersensitivity responses in vivo and proliferative responses together with induction of interferon-gamma of spleen cells against nontransfected wild-type tumor cell lines in in vitro experiments. Moreover, immunization of mice with alpha Ag-expressing tumor cells elicited tumor-specific and cytotoxic T lymphocyte (CTL) epitope peptide-specific CD8+ CTLs. The results of this study provided evidence of the potential usefulness of alpha Ag in tumor cell vaccines.

Augmentation of human immunodeficiency virus type 1 subtype E (CRF01_AE) multiple-drug resistance by insertion of a foreign 11-amino-acid fragment into the reverse transcriptase

A human immunodeficiency virus type 1 (HIV-1) subtype E (CRF01_AE) variant (99JP-NH3-II) possessing an in-frame 33-nucleotide insertion mutation in the beta3-beta4 loop coding region of the reverse transcriptase (RT) gene was isolated from a patient who had not responded to nucleoside analogue RT inhibitors. This virus exhibited an extremely high level of multiple nucleoside analog resistance (MNR). Neighbor-joining tree analysis of the pol sequences indicated that the 99JP-NH3-II variant had originated from the swarm of drug-sensitive predecessors in the patient. Population-based sequence analyses of 82 independently cloned RT segments from the patient suggested that the variants with the insertion, three or four 3'-azido-3'-deoxythymidine resistance mutations, and a T69I mutation in combination had strong selective advantages during chemotherapy. Consistently, in vitro mutagenesis of a drug-sensitive predecessor virus clone demonstrated that this mutation set functions cooperatively to confer a high level of MNR without deleterious effects on viral replication capability. Homology modeling of the parental RT and its MNR mutant showed that extension of the beta3-beta4 loop by an insertion caused reductions in the distances between the loop and the other subdomains, narrowing the template-primer binding cleft and deoxynucleoside triphosphate-binding pocket in a highly flexible manner. The origin of the insert is elusive, as every effort to find a homologue has been unsuccessful. Taken together, these data suggest that (i) HIV-1 tolerates in vivo insertions as long as 33 nucleotides into the highly conserved enzyme gene to survive multiple anti-HIV-1 inhibitors and (ii) the insertion mutation augments multiple-drug resistance, possibly by reducing the biochemical inaccuracy of substrate-enzyme interactions in the active center.

Isolation and characterization of a full-length molecular DNA clone of Ghanaian HIV type 1 intersubtype A/G recombinant CRF02_AG, which is replication competent in a restricted host range

We have isolated a replication-competent, full-length molecular clone of HIV-1 CRF02_AG, designated p97GH-AG1, by reconstituting two separately amplified genomic regions of an HIV-1 provirus of a 1997 Ghanaian isolate. The phylogenetic and recombination breakpoint analyses revealed that 97GH-AG1 had an A/G recombinant structure similar to that of prototype Nigerian isolate IbNG. The 17-nucleotide insertion downstream of the primer-binding site appeared to be a common sequence signature specific to most CRF02_AG strains, including 97GH-AG1. 97GH-AG1 showed an R5 phenotype and exerted productive infection in both HOS and NP2 cell infectivity assays, whereas it failed to show a detectable level of progeny production in peripheral blood mononuclear cells (PBMCs). The data may suggest the presence of unknown determinant(s) that dictate efficient replication in PBMCs, but that are not required for replication in immortalized cell lines.

Induction of virus-specific cytotoxic T lymphocytes by in vivo electric administration of peptides

Generally, major histocompatibility complex (MHC) class I presentation of peptide antigens only occur for proteins' which are actively synthesized and processed intracellularly, so that immunization with a cytotoxic T lymphocyte (CTL) target peptide does not usually elicit effective CTL responses. In the present study, we explored the use of epitope peptides by in vivo electroporation to introduce directly into the cytoplasm for the vaccine elicitation of virus-specific CTLs in a mouse system. BALB/c mice were immunized with human immunodeficiency virus (HIV) env (P18, residues 311-320) or hepatitis C virus (HCV) NS5 (P17, residues 2423-2434) with or without electric pulses. Effector cells against peptide-labeled target cells were elicited in mice immunized with peptides with electric administration but not without electric administration. Moreover, cytolytic activities of CTL against peptide-labeled target cells were enhanced by the addition of plasmid having the immunostimulatory sequence (ISS) or cDNA of the B7-1 molecule in electric administration of peptides. The results of the present study suggest that a peptide vaccine against a virus using electric administration is effective in eliciting virus specific CTLs.

Closely related HIV-1 CRF01_AE variant among injecting drug users in northern Vietnam: evidence of HIV spread across the Vietnam-China border

To investigate the nature of recent HIV outbreaks among injecting drug users (IDUs) near the Vietnam-China border, we genetically analyzed 24 HIV-positive blood specimens from 2 northern provinces of Vietnam (Lang Son and quang Ninh) adjacent to the China border, where HIV outbreaks among IDUs were first detected in late 1996. Genetic subtyping based on gag (p17) and env (C2/V3) sequences revealed that CRF01_AE is a principal strain circulating throughout Vietnam, including the provinces near the China border. The majority of CRF01_AE sequences among IDUs in Quang Ninh and Lang Son showed significant clustering with those found in nearby Pingxiang City of China's Guangxi Province, sharing a unique valine substitution 12 amino acids downstream of the V3 loop. This particular subtype E variant, uniquely found among IDUs in northern Vietnam and southeastern China, is designated E(v). The genetic diversity of CRF01_AE distributed in Quang Ninh (1.5 +/- 0.6%) and Pingxiang City (1.9 +/- 1.2%) was remarkably low, indicating the emerging nature of HIV spread in these areas. It is also noted that the genetic diversity of CRF01_AE among IDUs was consistently lower than that in persons infected sexually, suggesting that fewer closely related CRF01_AE variants were introduced into IDUs and, conversely, that multiple strains of CRF01_AE had been introduced via the sexual route. The data in the present study provide additional evidence that HIV outbreaks among IDUs in northern Vietnam were caused by the recent introduction of a highly homogeneous CRF01_AE variant (E(v)) closely related to that prevailing in nearby southern China.

Emergence of new forms of human immunodeficiency virus type 1 intersubtype recombinants in central Myanmar

We have previously shown that HIV-1 env subtypes B' (a Thai-B cluster within subtype B) and E (CRF01_AE) are distributed in Yangon, the capital city of Myanmar. However, HIV strains from the rest of country have not yet been genetically characterized. In the present study, we determined env (C2/V3) and gag (p17) subtypes of 25 specimens from central Myanmar (Mandalay). Phylogenetic analyses identified 5 subtype C (20%), in addition to 10 CRF01_AE (40%) and 4 subtype B' (16%). Interestingly, the remaining six specimens (24%) showed discordance between gag and env subtypes; three gag subtype B'/env subtype C, one gag subtype B'/env subtype E, one gag subtype C/env subtype B', and one gag subtype C/env subtype E. These discordant specimens were found frequently among injecting drug users (4 of 12, 33%) and female commercial sex workers (2 of 8, 25%) engaging in high-risk behaviors. The recombinant nature of these HIV-1 strains was verified in three specimens, indicating the presence of new forms of HIV-1 intersubtype C/B' and C/B'/E recombinants with different recombination breakpoints. The data suggest that multiple subtypes of B', C, and CRF01_AE are cocirculating in central Myanmar, leading to the evolution of new forms of intersubtype recombinants among the risk populations exhibiting one of the highest HIV infection rates in the region.

Lipase-catalyzed asymmetric desymmetrization of prochiral 2,2-disubstituted 1,3-propanediols using 1-ethoxyvinyl benzoate

The lipase-catalyzed asymmetric desymmetrization of the prochiral 2,2-disubstituted 1,3-propanediols was studied using various types of 1-ethoxyvinyl esters (1a-i). Although 1a-e with aliphatic acyl groups were not sufficient, use of the benzoate (1f) in combination with Candida rugosa lipases converted acyclic diols (2, 6) and cyclic diols (11-14) to the optically active compounds (3f, 7f, 15f-18f), bearing a quaternary carbon center, with moderate-to-high optical yields. These products were fairly stable against racemization under acidic conditions.

Polymorphism in the interleukin-4 promoter affects acquisition of human immunodeficiency virus type 1 syncytium-inducing phenotype

The emergence of syncytium-inducing (SI) variants of human immunodeficiency virus type 1 (HIV-1) in infected individuals is an indicator of poor prognosis and is often correlated with faster CD4(+) cell depletion and rapid disease progression. Interleukin-4 (IL-4) is a pleiotropic cytokine with various immune-modulating functions including induction of immunoglobulin E (IgE) production in B cells, down-regulation of CCR5 (a coreceptor for HIV-1 non-SI [NSI] strains), and up-regulation of CXCR4 (a coreceptor for HIV-1 SI variants). Here we show that homozygosity of a polymorphism in the IL-4 promoter region, IL-4 -589T, is correlated with increased rates of SI variant acquisition in HIV-1-infected individuals in Japan. This mutation was also shown to be associated with elevated serum IgE levels in HIV-1-infected individuals, especially in those at advanced stages of disease. In contrast, neither a triallele polymorphism in IL-10, another Th2 cytokine, nor a biallele polymorphism in the RANTES promoter affected acquisition of the SI phenotype. This finding suggested that IL-4-589T increases IL-4 production in the human body and thus accelerates the phenotypic switch of HIV-1 from NSI to SI and possibly disease progression of AIDS.

Convergent evolution of reverse transcriptase (RT) genes of human immunodeficiency virus type 1 subtypes E and B following nucleoside analogue RT inhibitor therapies

Changes in the drug susceptibility, gene lineage, and deduced amino acid sequences of the reverse transcriptase (RT) of human immunodeficiency virus type 1 (HIV-1) subtype E following 3'-azido-3'-deoxythymidine (AZT) monotherapy or AZT-2', 3'-dideoxyinosine combination therapy were examined with sequential virus isolates from a single family. The changes were compared to those reported for HIV-1 subtype B, revealing striking similarities in selected phenotype and amino acids independent of differences in the RT backbone sequences that constantly distinguish the two subtypes. Particularly, identical amino acid substitutions were present simultaneously at four different positions (D67N, K70R, T215F, and K219Q) for high-level AZT resistance. These data suggest that HIV-1 subtypes E and B evolve convergently at the phenotypic and amino acid levels when the nucleoside analogue RT inhibitors act as selective forces.

Inhibition of immunoglobulin E response to Japanese cedar pollen allergen (Cry j 1) in mice by DNA immunization: different outcomes dependent on the plasmid DNA inoculation method

To develop a new immunotherapy for Japanese cedar (Cryptomeria japonica; CJ) pollinosis, we evaluated the use of DNA immunization by inoculating mice with plasmid DNA encoding Cry j 1 as a CJ pollen major allergen (pCACJ1). Repeated intramuscular (i.m.) inoculation of BALB/c mice with pCACJ1 produced anti-Cry j 1 antibody responses, which were predominately of the immunoglobulin G2a (IgG2a) type. Furthermore, this inoculation suppressed immunoglobulin E (IgE) and IgG1 antibody responses to subsequent alum-precipitated Cry j 1 injections. Splenic T cells isolated from mice inoculated with pCACJ1 i.m. secreted interferon-gamma (IFN-gamma), but not interleukin (IL)-4, in vitro upon stimulation with Cry j 1 as well as with p277-288, a peptide corresponding to the T-cell epitope of Cry j 1. In contrast, inoculation of BALB/c mice with pCACJ1 by gene gun injection caused response predominantly of the IgG1 type, and enhanced production of anti-Cry j 1 IgE antibodies to subsequent alum-precipitated Cry j 1 injections. Splenic T cells isolated from pCACJ1-innoculated mice by gene gun injection secreted both IFN-gamma and IL-4 in vitro, upon stimulation with Cry j 1 as well as with p277-288. These findings suggest that i.m. inoculation with pCACJ1 effectively elicits Cry j 1-specific T helper 1 (Th1)-type immune responses, resulting in inhibition of the IgE response to Cry j 1.

A group of V3 sequences from human immunodeficiency virus type 1 subtype E non-syncytium-inducing, CCR5-using variants are resistant to positive selection pressure

In a human immunodeficiency virus type 1 (HIV-1)-infected individual, immune-pressure-mediated positive selection operates to maintain the antigenic polymorphism on the gp120 third variable (V3) loop. Recently, we suggested on the basis of sequencing C2/V3 segments from an HIV-1 subtype E-infected family that a V3 sequence lineage group of the non-syncytium-inducing (NSI) variants (group 1) was relatively resistant to positive selection pressure (35). To better understand the relationship between the intensity of positive selection pressure and cell tropism of the virus, we determined the linkage between each V3 genotype and its function of directing coreceptor preference and MT2 cell tropism. The biological characterization of a panel of V3 recombinant viruses showed that all of the group 1 V3 sequences could confer an NSI/CCR5-using (NSI/R5) phenotype on HIV-1(LAI), whereas the group 2 V3 sequence, which was more positively charged than the group 1 sequence, dictated mainly a syncytium-inducing, CXCR4-using (SI/X4) phenotype. Phylogenetic analysis of C2/V3 sequences encoding group 1 or 2 V3 suggested that the variants carrying group 1 V3 are the ancestors of the intrafamilial infection and persisted in the family, while the variants carrying group 2 V3 evolved convergently from the group 1 V3 variants during disease progression in the individuals. Finally, a statistical test showed that the V3 sequence that could dictate an NSI/R5 phenotype had a synonymous substitution rate significantly higher than the nonsynonymous substitution rate. These data suggest that V3 sequences of the subtype E NSI/R5 variants are more resistant to positive selection pressure than those of the SI/X4 variants.

An infectious DNA clone of HIV type 1 subtype C

Among the 10 subtypes of the M group of human immunodeficiency virus type 1, subtype C is the most prevalent in India and may dominate worldwide in the near future; however, there has been no report on the infectious DNA clone of this subtype. We have isolated an infectious DNA clone of the 93IN101 strain of HIV-1 subtype C, which was isolated in India in 1993. MAGIC5 cells, which are derived from HeLa-CD4-LTR-beta-gal (MAGI) cells and express CCR5, were inoculated with the 93IN101 strain of HIV-1 subtype C. The genomic DNA of the infected cells was used as a template for amplification of the HIV-1 genome. The genome DNA obtained was subcloned into pBR322, and the resulting plasmid was designated as pIndie-C1. The insert of pIndie-C1 was 9680 bp in length and had an intact genomic organization with open reading frames of all structural, regulatory, and accessory proteins. Phylogenetic analysis confirmed that the nucleotide sequence of pIndie-C1 is closely related to those of HIV-1 subtype C isolated in India. Transfection of pIndie-C1 into 293T cells yielded as much virus as did pNL432, one of the most widely used HIV DNA clones. The recovered Indie-C1 virus infected MAGIC5 but not the parent MAGI cells, indicating that Indie-C1 is CCR5 tropic. Expressed Env protein was reacted efficiently with the sera of HIV-1-infected patients of India, but not of Japan. Expression of Nef and Vpr was also confirmed by immunoblotting.

Genetic similarity of HIV type 1 subtype E in a recent outbreak among injecting drug users in northern Vietnam to strains in Guangxi Province of southern China

To investigate the molecular epidemiology of a recent HIV-1 outbreak in northern Vietnam and its relation to the epidemic in surrounding areas, we analyzed 17 HIV-positive blood specimens from 3 heterosexuals, 2 sexually transmitted disease patients, and 12 injecting drug users (IDUs), collected in 4 provinces near Hanoi in 1998. These were compared with the specimens from Ho Chi Minh City (n = 10) and An Giang Province (n = 10) in southern Vietnam and with published sequences from neighboring countries. Genetic subtyping based on the env C2/V3 sequences revealed that HIV-1 subtype E predominated throughout Vietnam in all risk populations; the exception was one typical United States-European-type HIV-1 subtype B detected in a patient in Ho Chi Minh City, the first case of HIV infection identified in Vietnam in 1990. The HIV-1 subtype E sequences identified in 9 of the 12 IDUs from northern provinces were closely related phylogenetically to those in IDUs in nearby Guangxi Province of China, and also shared a common amino acid signature downstream of the env V3 loop region. The low interperson nucleotide diversity among IDUs in northern Vietnam supports the view that HIV-1 subtype E was introduced recently among IDUs in northern Vietnam. These data indicate a linkage between HIV-1 circulating among IDUs in northern Vietnam and southern China, and suggest recent transborder introductions as the likely source of HIV-1 subtype E in northern Vietnam.

Sendai virus-based production of HIV type 1 subtype B and subtype E envelope glycoprotein 120 antigens and their use for highly sensitive detection of subtype-specific serum antibodies

We previously described a Sendai virus (SeV)-based expression system for the recombinant gp120 of HIV-1 subtype B (rgp120-B), which has permitted the production of antigenetically and functionally authentic gp120 at a concentration as high as 6 microg/ml of culture supernatant (Yu D et al.: Genes Cells 1997;2:457-466). Here the same procedure was successfully applied to the production of HIV-1 subtype E gp120 (rgp120-E). The remarkable production of the proteins by the SeV expression system enabled us to use crude culture supernatants for serological and functional studies of gp120s. The immunological authenticity of rgp120-E was verified by patient sera and anti-V3 loop monoclonal antibodies specific for HIV-1 subtypes B and E. CD4-binding properties were corroborated by FACS analyses. The rgp120s were then used in an enzyme immunoassay (rgp120-EIA) to detect antibodies in the sera of HIV-1-infected individuals, and the performance was assessed in comparison with a conventional V3 loop peptide EIA (V3-EIA). The initial evaluation of a serum panel (n = 164) consisting of 76 subtype E and 88 subtype B sera revealed that the rgp120-EIA was nearly 1000-fold more sensitive than the V3-EIA and was able to detect subtype-specific antibody with 100% sensitivity and with a complete correlation with the genotypes, whereas the V3-EIA failed to detect 9 and 24% of the same subtype E and B sera, respectively. Furthermore, a study employing a panel of 28 international sera with known genotypes (HIV-1 subtypes A through F) confirmed the remarkable specificity of this method. An EIA reactivity higher than 1.0 was an unambiguous predictor of HIV-1 subtype E and B infections. The data imply the presence of strong subtype-specific epitopes for antibody bindings to these rgp120s.

TT virus infection is widespread in the general populations from different geographic regions

By PCR screening, we found an extremely high prevalence of TT virus (TTV) in the general populations from different geographic regions. This suggests that TTV may be a common DNA virus with no clear disease association in humans. TTV genotyping by phylogenetic analysis was also performed.

Role of naturally occurring basic amino acid substitutions in the human immunodeficiency virus type 1 subtype E envelope V3 loop on viral coreceptor usage and cell tropism

To assess the role of naturally occurring basic amino acid substitutions in the V3 loop of human immunodeficiency virus type 1 (HIV-1) subtype E on viral coreceptor usage and cell tropism, we have constructed a panel of chimeric viruses with mutant V3 loops of HIV-1 subtype E in the genetic background of HIV-1LAI. The arginine substitutions naturally occurring at positions 8, 11, and 18 of the V3 loop in an HIV-1 subtype E X4 strain were systematically introduced into that of an R5 strain to generate a series of V3 loop mutant chimera. These chimeric viruses were employed in virus infectivity assays using HOS-CD4 cells expressing either CCR5 or CXCR4, peripheral blood mononuclear cells, T-cell lines, or macrophages. The arginine substitution at position 11 of the V3 loop uniformly caused the loss of infectivity in HOS-CD4-CCR5 cells, indicating that position 11 is critical for utilization of CCR5. CXCR4 usage was conferred by a minimum of two arginine substitutions, regardless of combination, whereas arginine substitutions at position 8 and 11 were required for T-cell line tropism. Nonetheless, macrophage tropism was not conferred by the V3 loop of subtype E R5 strain per se. We found that the specific combinations of amino acid changes in HIV-1 subtype E env V3 loop are critical for determining viral coreceptor usage and cell tropism. However, the ability to infect HOS-CD4 cells through either CXCR4 or CCR5 is not necessarily correlated with T-cell or macrophage tropism, suggesting that cellular tropism is not dictated solely by viral coreceptor utilization.

Functional complementation of the envelope hypervariable V3 loop of human immunodeficiency virus type 1 subtype B by the subtype E V3 loop

The hypervariable V3 loop within gp120 of human immunodeficiency virus type 1 (HIV-1) is the major determinant of cell tropism and the entry coreceptor usage of the virus. However, the information obtained thus far has been from only subtype B from North America and Europe, and little is known about other subtypes whose V3 amino acids differ by as much as 50% from subtype B V3. In this study, we examined the functional potential of the V3 element of the HIV-1 subtype E, the most crucial variant causing the AIDS epidemic throughout southeast Asia. A panel of HIV-1LAI recombinants was constructed by the overlap extension method, by which the LAI V3 loop was precisely replaced by that of the subtype E nonsyncytium-inducing (NSI) or syncytium-inducing (SI) variant. All of the recombinant viruses infected peripheral blood mononuclear cells, whereas only those with SI V3 infected MT2 cells, a CD4(+) T cell line. Consistently, the SI V3 recombinants used CXCR4, while the NSI V3 recombinants used CCR5 for infection of HOS-CD4(+) cells. Finally, only the NSI V3 sequence conferred CC-chemokine sensitivity on the parental virus. The data support the notion that the HIV-1 V3 loop consists of a relatively independent domain in gp120 and suggest that the subtype E V3 loop indeed contains the functional element to dictate the cell tropism, coreceptor preference, and chemokine sensitivity of the virus. These findings are of immediate importance in understanding V3 structure-function relationship and for examining phenotypic evolution of HIV-1 subtype E.

Evolution and biological characterization of human immunodeficiency virus type 1 subtype E gp120 V3 sequences following horizontal and vertical virus transmission in a single family

It has been suggested that immune-pressure-mediated positive selection operates to maintain the antigenic polymorphism on the third variable (V3) loop of the gp120 of human immunodeficiency virus type 1 (HIV-1). Here we present evidence, on the basis of sequencing 147 independently cloned env C2/V3 segments from a single family (father, mother, and their child), that the intensity of positive selection is related to the V3 lineage. Phylogenetic analysis and amino acid comparison of env C2/V3 and gag p17/24 regions indicated that a single HIV-1 subtype E source had infected the family. The analyses of unique env C2/V3 clones revealed that two V3 lineage groups had evolved in the parents. Group 1 was maintained with low variation in all three family members regardless of the clinical state or the length of infection, whereas group 2 was only present in symptomatic individuals and was more positively charged and diverse than group 1. Only virus isolates carrying the group 2 V3 sequences infected and induced syncytia in MT2 cells, a transformed CD4(+)-T-cell line. A statistically significant excess of nonsynonymous substitutions versus synonymous substitutions was demonstrated only for the group 2 V3 region. The data suggest that HIV-1 variants, possessing the more homogeneous group 1 V3 element and exhibiting the non-syncytium-inducing phenotype, persist in infected individuals independent of clinical status and appear to be more resistant to positive selection pressure.

Polymorphism in RANTES chemokine promoter affects HIV-1 disease progression

RANTES (regulated on activation normal T cell expressed and secreted) is one of the natural ligands for the chemokine receptor CCR5 and potently suppresses in vitro replication of the R5 strains of HIV-1, which use CCR5 as a coreceptor. Previous studies showed that peripheral blood mononuclear cells or CD4(+) lymphocytes obtained from different individuals had wide variations in their ability to secrete RANTES. These findings prompted us to analyze the upstream noncoding region of the RANTES gene, which contains cis-acting elements involved in RANTES promoter activity, in 272 HIV-1-infected and 193 non-HIV-1-infected individuals in Japan. Our results showed that there were two polymorphic positions, one of which was associated with reduced CD4(+) lymphocyte depletion rates during untreated periods in HIV-1-infected individuals. This mutation, RANTES-28G, occurred at an allele frequency of approximately 17% in the non-HIV-1-infected Japanese population and exerted no influence on the incidence of HIV-1 infection. Functional analyses of RANTES promoter activity indicated that the RANTES-28G mutation increases transcription of the RANTES gene. Taken together, these data suggest that the RANTES-28G mutation increases RANTES expression in HIV-1-infected individuals and thus delays the progression of the HIV-1 disease.

Genetic and serologic characterization of HIV type 1 prevailing in Myanmar (Burma)

To study the molecular epidemiology of HIV-1 spread in Myanmar and the interplay with the epidemic in surrounding Southeast Asian countries, we determined the HIV-1 subtypes prevailing in Myanmar. Thirty HIV-positive blood specimens were sampled in the capital city, Yangon, and an additional 459 sera were collected nationwide in 1995. Genetic subtyping based on the env C2/V3 sequence and serologic data, using a V3 peptide enzyme immunoassay (PEIA), revealed three patterns of HIV spread in different geographic regions in Myanmar: (1) in the capital city, Yangon, HIV-1 subtype B' ("Thai-B" cluster within subtype B) predominated both in IDUs and heterosexuals; (2) in the cities near the border with Thailand, including Tachelaik and Kawthaung, where heterosexual transmission is a major pathway of HIV-1 spread, HIV-1 subtype E was predominantly distributed among the commercial sex workers and heterosexuals; (3) in central and northeast Myanmar, both HIV-1 subtypes B' and E occurred in a mixed distribution, without showing any significant segregation by risk group. In addition, the PEIA data implied the occurrence of other subtype(s) in these areas. The interperson nucleotide sequence variations in env C2/V3 regions of B' and E, prevailing in Yangon, were 6.7 +/- 2.1 and 7.1 +/- 0.7%, respectively. They were similar to those levels observed in Thailand. These findings are consistent with the view that HIV spread in Myanmar might have taken place at about the same time as that in Thailand, and that multiple entries and exchanges of HIV-1 with neighboring countries are important factors contributing to the current distribution of subtypes in Myanmar.

A simple assay system for examination of the inhibitory potential in vivo of decoy RNAs, ribozymes and other drugs by measuring the Tat-mediated transcription of a fusion gene composed of the long terminal repeat of HIV-1 and a gene for luciferase

Nucleic acid-based drugs, including antisense RNA and DNA, ribozymes and decoys appear to have potential for the suppression of the expression of specific genes. To allow the examination of the potential of such agents in vivo as anti-HIV drugs in standard laboratories, where facilities for handling live virions are not available, we constructed a simple assay system (HIV-1 model) that allows measurement of the extent of inhibition of Tat-mediated transcription of HIV-1 by nucleic acid-based drugs and other agents. In cells that harbor a stable chimeric long terminal repeat (LTR)-Luc construct (a fusion gene consisting of the LTR of HIV-1 and the gene for luciferase), total luciferase activity in an aliquot of cell lysate is dose- and promoter-dependent on transfection with a Tat expression plasmid, reflecting the character of the LTR promoter of HIV. When HeLa cells were co-transfected with the Tat expression plasmid and another plasmid that encoded the U6 promoter or the promoter of the gene for tRNA(Val) linked to the trans-activating response (TAR) sequence, total luciferase activity was inhibited by 60 or 40%, respectively. The inhibition was also dependent on the dose of the TAR expression plasmid. These results demonstrate the usefulness of this simple assay system for detection of the efficacy of a decoy RNA or a ribozyme in vivo, without a requirement for HIV-infected cells, by measurement of luciferase activity in vitro.

Identification and molecular characterization of human T lymphotropic virus type II infections in intravenous drug abusers in the former South Vietnam

Previous serological studies have demonstrated that some 60% of intravenous drug abusers (IVDAs) in urban areas of the former South Vietnam are infected with HTLV-II. In the present report we have attempted to characterize the viruses using restriction fragment length polymorphism (RFLP) and nucleotide sequence analysis of the provirus long terminal repeat (LTR) region. RFLP analysis of nine samples demonstrated that all were infected with the HTLV-IIb subtype. The HTLV-IIa subtype was not detected. Phylogenetic analysis of the nucleotide sequences demonstrated that the viruses clustered closely with HTLV-IIb isolates present in IVDAs from the New York City area. The present molecular analysis together with the previously reported absence of HTLV-II infection in North Vietnam supports the view that HTLV-II may have been introduced from the United States to this part of Asia by military personnel during the Vietnam conflict.

[Predictability of EC/IC bypass function: a retrospective study]

Although the efficacy of extracranial/intracranial bypass for reduction of risk of ischemic stroke has been denied, we have encountered patients in whom bypass operation seems to have improved his or her clinical course. The efficacy of bypass should be evaluated not by the patency of the bypass but by the extent of collateral circulation brought about by the bypass. We retrospectively analyzed our patients to determine whether the extent of bypass flow could be predicted from the results of preoperative studies. In 18 hemispheres of 18 consecutive patients who underwent extracranial/intracranial bypass surgery, correlation between the extent of bypass flow and the multiple preoperative factors including the angiographic findings were investigated. The bypass function was highly predictable in the light of preoperative studies. In all of 10 hemispheres in patients under 70 years of age and with occlusive lesions in the proximal portion of the middle cerebral artery, collateral circulation through the bypass developed to an extensive or a moderate degree. In 9 of 10 hemispheres in which an interval between the latest attack and the diagnosis of hemodynamic failure was 4 weeks or longer, collateral circulation through the bypass was shown to have developed to an extensive or a moderate degree. Our results indicate that extensive or moderate collateral circulation through the bypass can be expected only in patients under 70 years of age, with lesions in the proximal portion of the middle cerebral artery, and in whom an interval between the latest attack and diagnosis of hemodynamic failure was 4 weeks or more.

Large quantity production with extreme convenience of human SDF-1alpha and SDF-1beta by a Sendai virus vector

We describe a robust expression of human stromal cell-derived factor-1alpha (SDF-1alpha) and SDF-1beta, the members of CXC-chemokine family, with a novel vector system based upon Sendai virus, a non-segmented negative strand RNA virus. Recombinant SDF-1alpha and SDF-1beta were detected as a major protein species in culture supernatants, reached as high as 10 microg/ ml. This remarkable enrichment of the products allowed us to use even the crude supernatants as the source for biological and antiviral assays without further concentration nor purification and will thus greatly facilitate to screen their genetically engineered derivatives.

[Treatment of tuberculous meningitis: marker of cure]

A 49-year-old male with tuberculous meningitis was reported. When admitted to our hospital with mild right hemiparesis, he was alert but he developed disorientation 7 days later. A diagnosis of tuberculous meningitis was reached because of elevated levels of adenosine-deaminase at 19.6U/liter in the cerebrospinal fluid. MRI showed a marked enhancement in the basal cisterns and an enhanced intraparenchymal lesion in the brainstem. Chronological changes of MRI findings did not closely correlate with the clinical course. Slight meningeal enhancement on MRI seems to remain for a long time without active tuberculous meningitis, and absence of the meningeal enhancement on MRI is not necessarily appropriate as a marker of cure of tuberculous meningitis.

[Localization of the pyramidal tract in the internal capsule: relationship between CT classification of thalamic hemorrhage and motor weakness]

To better understand the pyramidal tract of the internal capsule, we evaluated the relationship between the localization of thalamic hemorrhage and motor weakness. On an axial CT scan at the level of the pineal body, two lines were drawn as follows: line-a between the lateral edge of the anterior horn and the lateral edge of the trigone, line-b vertical to the sagittal line and passing the midpoint of the third ventricle. The location of the hematoma was classified into three types according to localization of the center of the hematoma and lateral extension beyond line-a as follows: type A (anterior), type P (posterior) and type PL (postero-lateral). Discrepancy of motor weakness between upper extremities and lower extremities was higher in patients with hematoma of type P and type PL (p < 0.05) than in those with hematoma of type A. Improvement of motor weakness on discharge was higher in patients with type P (p < 0.01) than in those with type A. We concluded that most of the pyramidal tract fibers were located in the third quarter of the posterior limb of the internal capsule but a small number of pyramidal tract fibers were located in the anterior two-thirds of it. A greater number of cortico-spinal fibers to the upper extremities than to the lower extremities occupy the third quarter of the posterior limb of the internal capsule.

Nucleotide sequence variation of human T-lymphotropic virus type II in Vietnam

A high rate of human T-lymphotropic virus type II (HTLV-II) infection has been documented in intravenous drug abusers (IVDAs) in South Vietnam. We have investigated the molecular characteristics of the virus and have shown that one HTLV-II subtype is predominant in Ho Chi Minh City. This molecular subtype, HTLV-IIb, was identified in a number of South Vietnamese by nucleotide sequence analysis of the long terminal repeat (LTR) region. HTLV-IIa was not found. These findings suggest that HTLV-IIb is endemic in IVDAs in South Vietnam, although IVDAs in urban areas in North America are predominantly infected with HTLV-IIa.

[Simple method for typing human immunodeficiency virus type I (B, E) by PCR and chronological change of distribution of subtype (B to E) in Japan]

We analyzed the clade distribution of B and E in HIV-1 isolates in Japan by a nested PCR method using 5'-CCCACAAGATTTAAATATG-3' of the gag gene as clade B primer and 5'-CCCACAAGATTTAAACTCC-3' of the gag gene as clade E primer. Seventy-two anti-HIV-1 confirmatory positive serum samples were collected during a period of 1991-1996 in two hospitals in Yokohama City. Peripheral blood mononuclear cells were obtained from the buffy coat of these samples and extracted DNA were used for nested PCR. The 72 cases comprised of 11 Japanese hemophiliacs, 14 Japanese male homosexuals, 19 Japanese male heterosexuals, 5 Japanese female heterosexuals and 23 Thai female heterosexuals. Of these 36 were clade B and 35 were clade E and one case showed positive PCR results for both B and E primers. Almost all male Japanese hemophiliacs and homosexuals in our sample have clade B, while the female Thai heterosexuals have clade E, irrespective of the year of isolation. As for Japanese male heterosexuals, through 1993, clade B was predominant but since 1994, the predominate clade switched to clade E. Although the number of Japanese female heterosexuals in our sample is small, clade B was isolated in 2 cases even after 1994.

In vivo sequence variability of human immunodeficiency virus type 1 envelope gp120: association of V2 extension with slow disease progression

According to the rate of depletion of CD4 cell counts, we grouped 12 cases of human immunodeficiency virus type 1 (HIV-1) infection as 6 rapid (21.0 to 33.8 cells per microl per month) and 6 slow (0.9 to 7.9 cells per microl per month) progressors and determined the individual viral quasispecies patterns by sequencing the genome region encoding the V1, V2, and V3 loops of envelope protein. Although the quasispecies structures varied widely from one individual to another, a strong correlation was observed between a low rate of disease progression and a high degree of genetic diversity of HIV-1. Furthermore, the V2 loop extension was observed specifically in individuals with slow or no disease progression, whereas basic amino acid substitutions in V3 characteristic of a viral phenotype shift from non-syncytium inducing to syncytium inducing were observed in patients with advanced stages of disease regardless of their rate of disease progression. Studies with recombinant viruses suggested that elongation of V2 potentially restricts the capacity of HIV-1 to replicate in macrophages. Thus, our results suggest the association of distinct sequence features of both V3 and V2 with particular patterns of disease progression. Elongation of the V2 loop may be a good predictor of slow disease progression, while basic substitutions of V3 without elongation of V2 are characteristic of rapid progression.

A polypeptide encoded within the murine AIDS defective virus stimulates primary proliferation of CD8+ T-cells

The murine AIDS (MAIDS) is a retrovirus-induced disease that shows severe immunodeficiency with abnormal lymphoproliferation in susceptible strains of mice. To clarify the antigenicity of gag gene products of the LP-BM5 defective virus, which is known as the causative virus of MAIDS, we expressed and purified the gag p12 gene product (P12) by using a baculovirus expression vector system. The P12 protein strongly stimulated the proliferation of normal C57BL/6 (B6) lymph node T-cells in vitro. Furthermore, a 25-mer synthetic polypeptide within the P12 sequence gave rise to the similar or even higher activation of T-cells. The phenotype of responding T-cells was found to be CD8+ CD44low, indicating that naive CD8+ T-cells respond against a peptide encoded within a MAIDS defective virus gag p12 gene. Finally, the expression of T-cell receptor (TcR) V beta on the responding CD8+ T-cells was analyzed. Although CD8+ T-cells with the particular V beta chains were expanded in response to the 25-mer peptide, this polypeptide does not seem to be a superantigen, since this response is MHC class I-restricted and the V beta preference is not striking. The presentation pathway of this highly antigenic polypeptide will be discussed.

Inclusion of Volatile Organic Compounds into Natural Cyclodextrins and Their Branched Cyclodextrins in the Gaseous Phase

The adsorption isotherms of water, the differential heat of adsorption, and the entropy of adsorbed water were investigated to elucidate the structure of stability of cyclodextrins (CyD) and branched CyD's. The amount adsorbed on branched CyD's increased with increasing relative humidity. The steep rise in the amount adsorbed at higher relative humidities indicated that the structure of branched CyD's was affected by the water molecules at these higher relative humidities. The bonding force between alpha-CyD's and water molecules was stronger than that between their branched CyD's and water, while that between beta-CyD's and water was weaker than that between their branched CyD's and water. We have used activated carbons for the recovery of organic solvents. There are polar groups on the activated carbon surface. Therefore, the recovered organic solvents were degraded by these groups. However, such polar groups are not expected for the hydroxyl groups of the CyD's. The amounts of 1,1,1-trichloroethane, benzene, and toluene included in natural CyD's and their branched CyD's were measured. The amounts of organic solvents included in the CyD's depended upon the cavity radii and the glucosyl and maltosyl functional groups of the CyD's and the radii of the organic solvent molecules.

Establishment of human granulocyte-macrophage colony stimulating factor producing transgenic SCID mice

Previous work has shown the usefulness of severe combined immunodeficient (SCID) mice as in vivo models for the growth of normal human haemopoietic cells and leukaemic cells. Many approaches have been made to improve the engraftment of human haemopoietic cells in SCID mice. We established transgenic mice producing human granulocyte-macrophage colony stimulating factor (hGM-CSF) with the homozygote of the scid gene. Endogenous serum hGM-CSF levels were detected by ELISA [mean 9585 pg/ml (line A, n = 4); mean 1610 pg/ml (line B, n = 4)]. Expression of hGM-CSF was observed in all organs tested including the heart, lung, liver, kidney, spleen, thymus, bone marrow and brain of hGM-CSF transgenic (hGMTg) mice. Morphological analysis of organs and peripheral blood cell counts showed no differences between hGMTg mice and their littermates. Murine Ba/F3 cells expressing functional hGM-CSF alpha beta receptor (BAF/alpha beta cells) could be successfully engrafted in hGMTg SCID mice. The cells invaded multiple organs and caused death within a few weeks of transplantation, although they infiltrated only the spleen of their littermates. These results showed that these hGM-CSF-producing SCID mice are useful as an in vivo assay system for investigating leukaemogenesis.

Ruptured aneurysm of the distal posterior inferior cerebellar artery in a neonate--case report

A 34-day-old male presented with a rare neonatal ruptured aneurysm of the distal posterior inferior cerebellar artery manifesting as a 10-day history of enlargement of head circumference. Magnetic resonance imaging revealed hydrocephalus and a round infratentorial enhanced lesion which compressed the medulla. Left vertebral angiography demonstrated an aneurysm on the telovelotonsillar segment of the left posterior inferior cerebellar artery. Ventriculoperitoneal shunt emplacement and proximal artery clipping were performed. The cerebrospinal fluid was bloody, suggesting aneurysm rupture had caused hydrocephalus. His postoperative course was uneventful, and neurological and developmental findings were normal 7 months later. Present neuroimaging, surgical, and neuro-anesthesiology techniques allow successful surgical intervention in cases of neonatal ruptured aneurysm.

Suppression of HIV replication in human monocyte-derived macrophages induced by granulocyte/macrophage colony-stimulating factor

Susceptibility to HIV infection was examined in macrophages differentiated from human monocytes by macrophage colony-stimulating factor (M-CSF) or granulocyte/macrophage colony-stimulating factor (GM-CSF). The replication of macrophage-tropic human immunodeficiency virus type-1 (HIV-1), which was determined by reverse transcriptase (RT) activity, was significantly suppressed in macrophages induced by GM-CSF (GM-type macrophages) but not in those induced by M-CSF (M-type macrophages). Multinucleated giant cells were formed only in M-type macrophages after HIV infection. However, the expression of CD4 molecules on the surface of both types of macrophages was similar and the proviral DNA was detectable in cell lysates of both macrophages, although the amount of proviral DNA in M-type macrophages was higher than that in GM-type macrophages. Many steps have been defined in HIV infection and replication, such as adsorption of HIV to the cell surface, internalization of the viral core into the cytoplasm, uncoating of viral RNA, reverse transcription and integration of proviral DNA into cellular DNA, transcription and translation of proviral DNA, assembly of viral components, and budding of virus particles. Our findings suggested that the suppression of HIV-1 replication in macrophages induced by GM-CSF is mainly due to a disturbance at certain steps of replication after synthesis of the proviral DNA. Thus, the suppression of HIV replication in GM-type macrophages may provide a model of the latency of HIV infection in vivo.

[A case of successful acute revascularization using a long vein graft]

We experienced a case of successful acute revascularization using a long vein graft. A 68-year-old man was admitted to our department due to transient ischemic attack of the left hemiparesis. CT scan showed no infarction, but PAO-SPECT revealed moderate hypoperfusion in the right ACA and MCA area. Cerebral angiography demonstrated right IC occlusion at its origin and moderate collateral circulation via leptomeningeal anastomosis from the PCA area, and via the external carotid system, especially directly from STA. But the STA was very narrow. Three days after admission, left hemiparesis appeared again and deteriorated severely. This time the hemiparesis persisted. Although MRI demonstrated little infarction in the right frontal lobe, we decided to carry out revascularization on the same day. Right saphenous vein was harvested for a graft because of the narrow STA. The facial artery and angular artery was selected as a donor and a recipient respectively, to avoid a clamp of the EC and a craniotomy of the STA running area. Finally we performed a facial artery-vein graft-angular artery (M4) bypass. The patient showed no complication and the left hemiparesis improved enough to allow the patient to walk by himself. Revascularization using vein graft is dangerous for acute ischemia due to the possibility of a complication such as brain edema and hemorrhagic infarction. The usual style of vein graft bypass is an EC-vein graft-M2 or M3 bypass. Using this style, high pressure inside the EC is carried intracranially.(ABSTRACT TRUNCATED AT 250 WORDS)

A naturally occurring single basic amino acid substitution in the V3 region of the human immunodeficiency virus type 1 env protein alters the cellular host range and antigenic structure of the virus

Human immunodeficiency virus type 1 circulates in vivo as a mixture of heterologous populations (quasispecies). We previously analyzed the quasispecies of the third hypervariable region (V3) in the viral envelope glycoprotein gp120 in an infected individual and found that the species with a basic amino acid substitution (lysine for aspartic acid) at a particular position evolved and became a distinct population within a short period, followed by progression to the typical immunodeficiency stage (S. Oka et al., AIDS Res. Hum. Retroviruses 10:271-277, 1994). In the present study, we examined the biological significance of this amino acid substitution by constructing recombinant viruses with specific point mutations and comparing their replication capabilities in different cell types. The results demonstrated that the single basic amino acid substitution was sufficient to render a virus fully capable of replicating in human T-cell lines under certain conditions. With an acidic amino acid at the position, the virus grew much less fast or did not grow at all in the T-cell lines. Viral neutralization assay and peptide enzyme-linked immunosorbent assays further showed that this amino acid substitution resulted in different recognition by several of the serum specimens from human immunodeficiency virus type 1-infected individuals and thus could alter the antigenic structure. An additional finding worthy of note was that at the terminal stage, the proviral sequences of peripheral blood mononuclear cells and the viral isolates from them were without exception of the late type with the basic amino acid substitution, whereas the early sequence without the substitution was retained as a major subset in the spleen. These results support the notion that basic amino acid substitutions in V3 are a strong predictor of virus tropism and may be relevant to disease progression.

[A case of early myoclonic encephalopathy accompanied with central respiratory dysfunction]

A case of unusual early myoclonic encephalopathy was reported. He showed massive and/or fragmentary myoclonic seizures soon after birth until 20 months before death. These seizures were resistant to various kinds of anti-epileptic drugs. The EEG pattern of suppression-burst was continuously seen in both waking and sleep states from 2 months to 19 months of age. He was supported with mechanical ventilator because of the central respiratory dysfunction since 4 days after birth until death. This case was electroclinically considered as that of early myoclonic encephalopathy. The central respiratory dysfunction has not been reported in early myoclonic encephalopathy.