Giant extraordinary transmission of acoustic waves through a nanowire.

Wave concentration beyond the diffraction limit by transmission through subwavelength structures has proved to be a milestone in high-resolution imaging. Here, we show that a sound wave incident inside a solid over a diameter of 110 nm can be squeezed through a resonant meta-atom consisting of a nanowire with a diameter of 5 nm equal to λ/23, where λ is the incident acoustic wavelength, corresponding to a transmission efficiency of 500 or an energy densification of ~14,000. This remarkable level of extraordinary acoustic transmission is achieved in the absence of ultrasonic attenuation by connecting a tungsten nanowire between two tungsten blocks, the block on the input side being furnished with concentric grooves. We also demonstrate that these "solid organ pipes" exhibit Rayleigh end corrections to their effective longitudinal resonant lengths notably larger than their in-air analogs. Grooves on the output side lead to in-solid directed acoustic beams, important for nanosensing.

Molecular cloning and characterization of a novel glycoprotein, gp34, that is specifically induced by the human T-cell leukemia virus type I transactivator p40tax.

We have cloned and sequenced a cDNA encoding gp34, a novel glycoprotein expressed in cells bearing human T-cell leukemia virus type I (HTLV-I). HTLV-I has a trans-acting transcriptional activator, p40tax, that is thought to be implicated in leukemogenesis through the activation of cellular enhancers. With a subline (JPX-9) of the human T-cell line Jurkat, in which p40tax is inducible, gp34 was shown to be of cellular origin and to be transcriptionally activated by p40tax. It was also demonstrated that two species of mRNA are generated from one copy of the gp34 gene and that these mRNAs encode the identical gp34 product and differ in the 3' untranslated region. Analysis of the deduced amino acid sequence of gp34 showed that it lacks typical signal peptides; however, it has a hydrophobic stretch for membrane anchoring and four possible N-linked glycosylation sites at the carboxy-terminal portion, indicating that it belongs to the family of membrane proteins whose carboxy-terminal portion protrudes out of the cell. The gp34 gene displayed relatively delayed induction compared with other genes activated by p40tax. Taken together with the observation of the dependence of gp34 expression on HTLV-I p40tax, unlike other p40tax-dependent genes such as those for the interleukin-2 receptor alpha chain and c-fos, which are expressed or induced under physiological conditions, we predict that the mechanism involved in the induction of gp34 expression by p40tax is distinct from and more intricate than those for the previously characterized genes.

Two distinct regions form a functional activation domain of the HTLV-1 trans-activator Tax1.

Tax1 of human T-cell leukemia virus type 1 (HTLV-1) is an enigmatic viral transactivator that regulates expression of the viral gene and also several cellular genes normally controlled by various mitogenic signals. However, previous studies have failed to define the functional domains of Tax1 for enhancer specificities and for transcriptional activation (95% of the protein portion was indispensable for the activation function). This complexity has hampered understanding of the molecular basis of Tax1 action. In this study, we analysed the activation function of a Tax1 fused to the heterologous DNA-binding domain of the yeast transcription factor GAL4 and dissected the domain required for the activation function by using derivatives of a Tax1 mutant with an insertion between amino acids (a.a.) 170 and 171. Analysis of the derivatives of the mutant fusion protein having various partial overlaps encompassing the interrupted site suggested that two contiguous stretches, AD-I (2-255 a.a.) and AD-II (227-337 a.a.), should be both intact for the activation function of Tax1 and that they form a functional activation domain.

Viral RNA-binding activity of HIV-2 nucleocapsid protein is inhibited by a synthetic peptide containing the first zinc finger motif of HIV-2.

OBJECTIVE: To analyze the antigenic structure and viral RNA-binding activity of HIV-2GH-1 nucleocapsid protein (NC). METHODS: Five synthetic peptides corresponding to hydrophilic regions of HIV-2GH-1 NC were prepared. The reactivity of rabbit antisera directed against these synthetic peptides was examined by Western blot (WB) assay, using lysates of purified HIV-2GH-1 virus and HIV-2GH-1-infected cells as antigen. The binding activity of NC to viral RNA synthesized in vitro, was assessed by Northwestern blot (NWB) assay using 32P-labeled RNA as a probe. RESULTS: One of five antisera against the peptides reacted with a protein of 8 kD (p8) of HIV-2GH-1 in WB. p8 was analyzed for the amino-terminal amino-acid sequence and identified as a portion of NC including two zinc finger motifs (ZFM), comprising the DNA-binding region in the molecule. The binding of the RNA probe to p8 was observed by NWB and did not always depend on zinc. In competition experiments, the reactivity of p8 with the RNA probe ceased to be evident following preincubation of the probe with a peptide containing the first ZFM in the molecule. CONCLUSION: p8 of HIV-2GH-1 NC binds to viral RNA in vitro. The first ZFM in the p8 molecule appears to be essential to binding activity. Functional analysis of synthetic peptides corresponding to ZFM of HIV p8 may provide important information on the development of antiviral agents.

Fluorescence sandwich enzyme-linked immunosorbent assay for detecting human interleukin-2 receptors.

A very sensitive fluorescence sandwich enzyme-linked immunosorbent assay (FS-ELISA) for the detection of soluble and cell-associated human interleukin-2 receptors (IL-2R) has been developed. For use in this assay system, two anti-human IL-2R monoclonal antibodies, H 48 and biotinylated HA 26, were selected from six monoclonal antibodies directed against different epitopes on the IL-2R molecule. The FS-ELISA specifically detected human IL-2R in both the culture supernatants and cell lysates of human IL-2R-bearing cells and the assay displayed a 10(3)-fold increase in sensitivity over the usual colorimetric IL-2R ELISA. The IL-2R molecules in supernatants and lysates of the PHA-stimulated mononuclear cells were of 50,000 and 60,000 molecular weight, respectively, as estimated by size exclusion high performance liquid chromatography.

Response of human glioblastoma cells to recombinant interleukin-2.

We investigated the ability of glioma cells to respond to T cell-derived lymphokines. The growth of astrocytoma and mixed glioblastoma cell lines, as assessed by DNA synthesis, was inhibited in the presence of supernatants derived from mitogen-stimulated human T cells, an HTLV-II-transformed human T cell line, Mo, and human interleukin-2 (IL-2). The mixed glioblastoma cell line, 138-MG-C, was subjected to limiting dilution analysis, and two cell lines (5D7, 5C5) were derived which were homogeneous with respect to staining for galactocerebroside (GalC) (100%). These two GalC+ glioblastoma cell lines proliferated in the presence of high concentrations of recombinant human interleukin-2 (RIL-2). Additionally, these cell lines bear receptors for the IL-2 molecule as determined by immunofluorescent staining with various anti-IL-2 receptor antibodies.

Multiple antigenic epitopes expressed on gag proteins, p26 and p15, of a human immunodeficiency virus (HIV) type 2 as defined with a library of monoclonal antibodies.

Thirty-two hybridoma clones producing monoclonal antibody (MAb) against HIV-2[GH-1] were established from mice immunized with NP-40-disrupted purified whole virus of a Ghanaian isolate of human immunodeficiency virus type 2 (HIV-2), strain HIV-2[GH-1]. Of these 32 MAbs, 20 reacted with p26 and the other MAbs recognized p15 of the HIV-2[GH-1] isolate. From the results of serological characterization by these MAbs, p26 and p15 were identified as capsid proteins and matrix protein, respectively, of HIV-2[GH-1] gag products. In addition to two gag proteins, a 55-kD protein corresponding to the primary translational product of gag gene and 39-kD protein corresponding to an intermediate product of cleavage of p55 were recognized by these MAbs in the lysate of HIV-2[GH-1]-infected cells. Moreover, these MAbs were used to analyze the number of antigenic epitopes on p26 and p15 of HIV-2[GH-1] isolate. The results of cross-reactivity with different HIV-1, HIV-2, and simian immunodeficiency virus (SIV) isolates and competitive binding assay suggest that there are at least four and five antigenic epitopes in p26 and p15, respectively, of the HIV-2[GH-1] isolate. The biological activity of MAbs was studied by performing syncytium inhibition assay and infection inhibition assays. However, our MAbs could not inhibit syncytium formation and infection by cell-free virus.

Production and characterization of mouse monoclonal antibodies against the transmembrane protein of a human immunodeficiency virus type 2.

We established seven hybridoma clones producing monoclonal antibodies (MAbs) against the envelope transmembrane protein (TMP) of a Ghanian isolate of human immunodeficiency virus type 2 (HIV-2[GH-1]) from mice immunized with the detergent-disrupted purified whole virus. The MAbs were found to react with 35 kilodalton (kD) TMP of the HIV-2[GH-1] virus in a Western blot assay (WB). Two of these MAbs recognized 135 kD proteins in addition to TMP in the lysate of HIV-2[GH-1]-infected cells. Two other MAbs cross-reacted with viral components corresponding to TMPs of HIV-2ROD and SIVMAC isolates in a Western blot. Results of competitive binding assay suggest that there are at least three epitopes on a TMP molecule of the HIV-2[GH-1] isolate. The MAbs did not inhibit syncytium formation between HIV-2[GH-1]-infected MOLT-4 cells and MOLT-4 clone 8 cells, nor virus infection to MOLT-4 clone 8 cells.

An antigenic structure of the trans-activator protein encoded by human T-cell leukemia virus type-I (HTLV-I), as defined by a panel of monoclonal antibodies.

In order to study an antigenic structure of the trans-activator protein encoded by human T-cell leukemia virus type-I (HTLV-I), tax1 antigen, we generated and characterized a panel of rat anti-tax1 monoclonal antibodies (MAbs) designated WATM-1, WATM-2, WATM-3, and WATM-4. These MAbs were derived from WKA rats immunized with HTLV-I-transformed (HTLV-I+) syngeneic T cells. Immunoblot assays showed that: (1) All the MAbs reacted with the tax1 antigen in HTLV-I+ cell lines and a recombinant tax1 antigen, PX141 (containing entire tax1 polypeptide); (2) WATM-3 and WATM-4, but not WATM-1 or WATM-2, reacted with a truncated tax1 antigen, XD59 (tax1 amino acids 180-338); (3) None of them reacted with another truncated tax1 antigen, XD128 (tax1 amino acids 1-47 and 286-353); and (4) each of the four MAbs had different reactivity with tax1-related antigens in the range 38-41 kDa expressed in simian cell lines infected with various HTLV-I-related simian retroviruses (STLV-I). None of the MAbs reacted with HTLV-II tax antigen. Human sera containing anti-tax1 antibodies interfered specifically with the antigen-specific binding of all the MAbs. These results suggest that the present rat MAbs are directed against various epitopes on the tax1 antigen. An antigenic structure of the tax1 antigen deduced from reactivity of a panel of anti-tax1 MAbs including the present rat MAbs is discussed.

Monitoring follicular maturation through measurement of urinary estrogen excretion by latex agglutination inhibition reaction.

We evaluated the clinical utility of the MS 8601 kit, which is a new method of measurement of estrogens in urine. Changes in daily urinary estrogen excretion measured with the kit were highly correlated with that in daily serum E2. This kit was sensitive enough to detect the rises in estrogens in the follicular phase not only in women with normal menstrual cycle, but also in hMG-hCG treated patients.

Expression of human T-cell lymphotropic virus type-1 gene products in the short-term cultured skin tissues of an adult T-cell leukemia/lymphoma patient with cutaneous manifestations.

Adult T-cell leukemia/lymphoma (ATLL) is recognized as a disease etiologically associated with human T lymphotropic virus type-1 (HTLV-1) infection, but, neither viral replication nor specific virus antigen expression have been detected on ATLL cells distributed in organs, including skin. To examine the latent expression of HTLV-1 in the cutaneous lesions of ATLL patients, we cultured the lesional skin tissues in vitro and applied immunofluorescence staining with mouse monoclonal antibodies Lt-4, GIN-14, and F10, which react with p40tax, p19 and gp21, respectively. We recognized HTLV-1 specific antigens on clustered ATLL cells only in the deeper dermis of the skin after 24 hrs cultivation of the lesional skin tissue from an ATLL patient in RPMI-1640 medium supplemented with 20% fetal calf serum. In the electron microscope, we observed HTLV-1 like particles, 80-140 nm in diameter with envelope and core structures, in the same tissue specimen. These findings suggest that HTLV-1 gene products may be expressed in the skin lesions of ATLL patients and involved in the pathogenesis of skin eruptions in cutaneous type ATLLs. To our knowledge, this is the first report that envisages the potency of intracutaneous HTLV-1 expression in vivo.

Effects of alkali and oxygen on nitrosation in dimethylamine-nitrite mixtures with and without reductants.

Two types of 'alkali effect', i.e., the formation of NDMA by alkylization of nitrite-DMA mixtures with and without reductants, were investigated. In the reductant-free system, the 'alkali effect' was found to increase with decreasing pH of the initial system. 'Cofactors' (some buffering agents or metallic ions) were essential for the 'alkali effect' in the presence of ascorbate, but were not necessary when tannic acid was the reductant. It may be concluded that free NO is released from nitrite by the action of reductants, with or without 'cofactors', and that N2O3 and/or N2O4, the nitrosating agents, are derived from NO via NO2 by air oxidation. Dinitrogen trioxide, generated from HNO2 in an acidic solution, and N2O4, derived from N2O3, are considered to be the main nitrosating agents producing the 'alkali effect' in the reductant-free system, but the presence of O2 also showed a remarkable enhancing effect on NDMA formation in this system.

[The role of prolactin on sexual maturation of female rat].

The role of prolactin (PRL) in sexual maturation of immature female rats was examined in drug induced hyper-or hypoprolactinemic models. 1. In order to examine the role of PRL before the third week after birth, at which the serum PRL level of female rats is known to be low under physiological conditions, hyperprolactinemia was induced by daily subcutaneous injections of sulpiride from day 10 to day 20. Ovarian and uterine weights, serum hormone levels and in vitro estradiol (E2) release from removed ovary were evaluated on day 15 and day 20. The inhibition of uterine growth on both days a low serum E2 concentration on day 20 and inhibition of in vitro ovarian E2 release were demonstrated as the result of sulpiride treatment. 2. In order to examine the role of PRL after the fourth week, when the serum PRL level is known to become high, hyper- or hypoprolactinemia was induced from day 22 by per os administration of sulpiride or bromocriptine. Timing of the onset of puberty weights of the ovary, uterus and adrenal gland and serum hormone levels at the onset of puberty were evaluated. In the sulpiride treated group the timing of the onset of puberty was not affected and lower adrenal gland weight and a low serum FSH concentration were observed. In the bromocriptine treated group the timing of the onset of puberty was delayed and greater adrenal gland weight was observed. Serum hormone levels were not affected. These results suggest that (i) prolactin could have an inhibitory effect on sexual maturation before the 3rd week.(ABSTRACT TRUNCATED AT 250 WORDS)

Adsorption of LLCMK2 cell-grown Sendai virus onto human red blood cells and its release from the virus adsorbed cells.

An early stage of virus adsorption was studied in a system of Sendai virus metabolically labeled with [3H]leucine in LLCMK2 cells and of human red blood cells (RBCs). The efficiency of viral release from the virus-bound RBCs by incubation at 37 C depended on the number of virus particles which had been used for adsorption onto the RBC at 4 C. When 7.8 x 10(2) virus particles were previously adsorbed onto the RBC at 4 C, most of the viruses were dissociated from the RBC at 37 C. In the case of adsorption of 3 to 12 virus particles per RBC, however, most of the viruses were not dissociated from the RBC by incubation at 37 C. Such RBC-bound viruses were released by incubation with various bacterial neuraminidases (Clostridium perfringens, etc.) or with a large number of LLCMK2 cell-grown Sendai virus (LLCMK2-Sendai) particles, but not released by treatment with hemagglutinin-neuraminidase protein (Sendai-gp) isolated from egg-grown Sendai virus.

Volatile N-nitrosamines in fish meal, with special reference to the mechanism of formation of N-nitrosothiazolidine.

Volatile N-nitrosamines in 32 commercial Japanese fish meal samples were analysed, and three compounds, N-nitrosodimethylamine, N-nitrosopyrrolidine and N-nitrosothiazolidine (NT), were detected. We also examined the mechanism of formation of NT during fish meal production. Both cysteamine and thiazolidine were found to be precursors of NT. The cysteamine content decreased during boiling and drying of the fish; but that of thiazolidine increased during boiling. N-Nitrosothiazolidine 4-carboxylic acid (NTCA) was formed in sardine meal after treatment with nitrogen dioxide gas, and the rate of formation of NT from NTCA added to sardine meal was as high as 10% when the meal was heated at 160 degrees C for 60 min. We propose two pathways for NT formation during fish meal manufacture: (1) cysteamine----thiazolidine----NT; and (2) cysteine----(thiazolidine 4-carboxylic acid)----NTCA----NT.

Neutralization of sendai virus by the IgG subclass antibodies of the guinea pig.

A comparative study was made of the neutralizing activities of IgG subclasses IgG1 and IgG2, fractionated from guinea pig antisera against Sendai virus. The yields of IgG2 from the antisera were about 16 times as much as those of IgG1. The neutralizing activity of IgG2 per unit weight was four times as high as that of IgG1. This neutralizing activity of both IgG subclasses was enhanced about 10 times by addition of antibodies to the L-chain of guinea pig immunoglobulin. It is suggested that, in the complement-dependent neutralization of the virus, IgG1 and IgG2 activate the complement through the alternative and the classical pathway, respectively.

Viral RNA binding properties of human immunodeficiency virus type-2 (HIV-2) nucleocapsid protein-derived synthetic peptides.

The nucleocapsid (NC) protein of HIV-2 (NCp8) contains two Cys-His arrays which function as zinc finger motifs (ZFMs). In this study, we analyzed the viral RNA-binding properties of NCp8-derived synthetic peptides using ultraviolet (UV) cross-linking assay. Several synthetic peptides containing ZFM(s) interacted pH-dependently with in vitro-synthesized HIV-2 RNA. Although the peptides corresponding to the 1st and 2nd ZFMs, respectively, failed to interact with the viral RNA, the corresponding peptides flanked by basic amino acid clusters interacted tightly. Furthermore, basic amino acid residues within a cluster adjacent to ZFMs contributed to the RNA-binding of NCp8 more than Cys and His residues within the ZFM in vitro. In competitive UV cross-linking assay using non-specific RNA as a competitor, the peptides corresponding to the 1st and 2nd ZFMs flanked by basic amino acid clusters interacted specifically with viral RNA. These findings suggest that both ZFM regions of HIV-2 may be concerned with the specificity of packaging of genomic viral RNA into the virion.

Monoclonal antibody defining tax protein of human T-cell leukemia virus type-I.

We prepared a monoclonal antibody (MAb), Lt-4, which recognizes a tax protein expressed in HTLV-I-infected cells. Indirect immunofluorescence staining showed that the antigen recognized by Lt-4 MAb located mainly in the nuclei of HTLV-I-infected T cell lines such as HUT102, TCL-As2, MT-1 and MT-2, and also weakly in the cytoplasm of MT-2 cell line. Lt-4 MAb did not react with two HTLV-I-uninfected T cell lines tested and fresh and PHA-activated peripheral blood lymphocytes (PBL) of several normal donors. Furthermore, Lt-4 MAb stained the nuclei of HeLa cells infected with a recombinant vaccinia virus encoding the tax but not with a wild type vaccinia virus. In Western blot (WB) and radioimmunoprecipitation analyses, Lt-4 MAb detected a 40 kDa molecule (p40) in HUT102 and TCL-As2 cells, and p40 and p68 in MT-2 cells. These results show that Lt-4 MAb is highly specific for the tax protein.