Bitter-sweet symphony: defining the role of dendritic cell gp120 receptors in HIV infection

Background: Dendritic cells (DC) are believed to be one of the first cell types infected during HIV transmission. Recently a single C-type lectin receptor (CLR), DC-SIGN, has been reported to be the predominant receptor on monocyte derived DC (MDDC) rather than CD4. The role of other CLRs in HIV binding and HIV binding by CLRs on other types of DC in vivo is largely unknown. Objectives and study design: Review HIV binding to DC populations, both in vitro and in vivo, in light of the immense interest of a recently re-identified CLR called DC-SIGN. Results and conclusions: From recent work, it is clear that immature MDDC have a complex pattern of HIV gp120 binding. In contrast to other cell types gp120 has the potential to bind to several receptors on DC including CD4 and several types of C type lectin receptor, not just exclusively DC-SIGN. Given the diverse types of DC in vivo future work will need to focus on defining the receptors for HIV binding to these different cell types. Mucosal transmission of HIV in vivo targets immature sessile DCs, including Langerhans cells which lack DC-SIGN. The role of CLRs and DC-SIGN in such transmission remains to be defined. (C) 2001 Elsevier Science B.V. All rights reserved.

The effects of pregnancy on myelin basic protein-induced experimental autoimmune encephalomyelitis in Lewis rats: Suppression of clinical disease, modulation of cytokine expression in the spinal cord inflammatory infiltrate and suppression of lymphocyte p

Problem: The present study was performed to explore the effects of pregnancy on experimental autoimmune encephalomyelitis (EAE) induced in Lewis rats by inoculation with myelin basic protein (MBP) (MBP-EAE). Method of study: MBP-EAE was induced in pregnant and non-pregnant rats and severity of disease evaluated. Serum from pregnant and non-pregnant rats was used in standard lymphocyte proliferation assays. Real-time polymerase chain reaction (PCR) was used to investigate the expression of cytokine mRNA in the inflammatory cells obtained from the spinal cord of rats on day 15 after inoculation. Results: Pregnant rats developed less severe disease than non-pregnant rats. Serum from pregnant rats suppressed the proliferation of T lymphocytes in response to MBP. There was significantly increased expression of IL-4. IL-10 and TNF-alpha mRNA in the spinal cord infiltrate of pregnant rats. Conclusion: Circulating humoral factors and alteration in cytokine production by inflammatory cells may contribute to the suppression of EAE in pregnant rats.

The nutritive value of Rhodes grass (Chloris gayana) when treated with CaO, NaOH or a microbial inoculant and offered to dairy heifers as big-bale silage

A series of laboratory and animal studies examined the use of chemical and biological agents to enhance the digestibility of Rhodes grass (grass) cut at 60 (young) and 100 (mature) days of regrowth and ensiled as big round bales. The treatments included an untreated control (C), a microbial inoculant (I), NaOH, CaO and NaOH plus inoculant (NaOH + I). Inoculant was grown anaerobically, using a starter culture of rumen fluid from cattle given Rhodes grass. Treatments C, 1, NaOH, NaOH + I, were offered separately to twelve dairy heifers, in a 3 X 4 randomized complete block design, repeated twice for each grass silage. C and I had substantial mould growth, compared with no visible mould in NaOH or NaOH + 1. CaO treatment was effective in preventing mould growth, but had little effect on the chemical composition and in sacco digestibility of mature grass silage. NaOH reduced NDF content and increased in sacco digestibility (P < 0.05) but not the in vivo digestibility (P > 0.05) of both mature- and young-grass silage. The effects of other treatments on nutritive value were non-significant at both stages of maturity. NaOH increased the intake of mature-grass silage by 24-26% (P < 0.05), but had little effect on the intake of young-grass silage (P > 0.05). Treatment I consistently reduced grass silage intake (P < 005) for young-grass silage. The findings of these studies show that treating mature Rhodes grass with NaOH will improve its nutritive value and reduce mould growth in conserved herbage. However none of the treatments in this study had any consistently positive effects on the in vivo nutritive value or storage quality of young-grass silage.

Precursor scavenging of resistive grain-boundary phase in 8 mol % ytterbia-stabilized zirconia

The grain-boundary conduction of 8 mol % ytterbia-stabilized zirconia (8YbSZ) was improved markedly by precursor scavenging via the two-stage sintering process. The most significant increase in the grain-boundary conductivity was found when the sample, whose conductivity was higher than that via Al2O3-derived scavenging, was heat-treated at 1250degreesC for greater than or equal to 20 h. The formation of a stable Si-containing phase such as ZrSiO4 during the first-stage heat-treatment was suggested as one probable scavenging route from the optimal heat-treatment temperature (HTT), long duration time (>20 h) at HTT, and the stability of the formed phase up to sintering temperatures (1500degrees C). (C) 2002 The Electrochemical Society.

Nitrification in a Vertisol subsoil and its relationship to the accumulation of ammonium-nitrogen at depth

Unusually high concentrations of ammonium have been observed in a Vertisol below 1 m depth in southeast Queensland. This study investigated the possibility that an absence of nitrification is allowing this ammonium to accumulate and persist over time, and examined the soil environmental characteristics that may be responsible for limiting nitrifying organisms. The possibility that anaerobiosis, soil acidity, soil salinity, low organic carbon concentrations, and/or an absence of active nitrifying microorganisms were responsible for limiting nitrification was examined in laboratory and field studies. The presence/absence of anaerobic conditions was determined qualitatively using a field test to give an indication of electron lability. In addition, an incubation study was conducted and soil environmental conditions were improved for nitrifying organisms by adjusting the pH from 4.4 to 7, adjusting the electrical conductivity from 1.6 to 0.5 dS/m, amending with a soluble carbon substrate at a rate of 500 mg/kg, and using microorganisms from the surface horizon to inoculate to the subsoil. Over a 180-day period no nitrification was detected in the control samples from the incubation study, indicating that an extremely low rate of nitrification is likely to be responsible for allowing ammonium to accumulate in this soil. Analysis of the effect of soil environmental conditions on nitrification revealed that anaerobic conditions did not exist at depth and that pH, EC, organic carbon, and inoculation treatments added in isolation had no effect on nitrification. However, when inoculum was added to the soil in combination with pH, a significant increase in nitrification was observed, and the greatest amount of nitrification was observed when inoculum, pH, and EC treatments were added in combination. It was concluded that the reason for the low rate of nitrification in this soil is primarily the absence of a significant population of active nitrifying microorganisms, which may have been unable to colonise the subsoil environment due to its acidic, and to a lesser extent, its saline environment.

Genotoxicity investigation of a cyanobacterial toxin, cylindrospermopsin

Cylindrospermopsin (CYN), a potent cyanobacterial hepatotoxin produced by Cylindrospermopsis raciborskii and other cyanobacteria, is regularly found in water supplies in many parts of the world, and has been associated with the intoxication of humans and livestock. In this study, Balb/c mice were injected via the intraperitoneal (IP) route with a single dose of 0.2 mg/kg CYN. Animals were sacrificed at 6, 12, 24, 48 and 72 It. DNA was isolated from the mouse livers, and examined for strand breakage by alkaline gel electrophoresis (pH 12). Significant DNA strand breakage was observed in the mouse liver exposed to CYN, suggesting that induction of DNA strand breakage is probably one of the key mechanisms for CYN genotoxicity. (C) 2002 Elsevier Science Ltd. All rights reserved.

Carpogenic germination of Sclerotinia minor and potential distribution in Australia

This study confirms that Australian isolates of Sclerotinia minor can produce fertile apothecia and further demonstrates that ascospores collected from these apothecia are pathogenic to sunflower (Helianthus annuus). Sunflower is a known host of the related fungus Sclerotinia sclerotiorum and is grown in some regions where S. minor is known to occur. Head rot symptoms were produced following inoculation with S. minor ascospores. Predictive modeling using CLIMEX software suggested that conditions suitable for carpogenic germination of S. minor probably occur in Australia particularly in southern regions. Carpogenic germination is probably a rare event in northern regions and, if it does occur, probably does not coincide with anthesis in sunflower crops, therefore allowing disease escape.

Protection of mice from group A streptococcal infection by intranasal immunisation with a peptide vaccine that contains a conserved M protein B cell epitope and lacks a T cell autoepitope

Infection with group A streptococci (GAS) can lead to rheumatic fever (RF) and rheumatic heart disease (RHD) which are a major health concern particularly in indigenous populations worldwide, and especially in Australian Aboriginals. A primary route of GAS infection is via the upper respiratory tract, and therefore, a major goal of research is the development of a mucosal-based GAS vaccine, The majority of the research to date has focused on the GAS M protein since immunity to GAS is mediated by M protein type-specific opsonic antibodies. There are two major impediments to the development of a vaccine-the variability in M proteins and the potential for the induction of an autoimmune response. To develop a safe and broad-based vaccine, we have therefore focused on the GAS M protein conserved C-region, and have identified peptides, J8 and the closely related J8 peptide (J14), which may be important in protective immunity to GAS infection. Using a mucosal animal model system, our data have shown a high degree of throat GAS colonisation in B10.BR mice 24 h following intranasal immunisation with the mucosal adjuvant, cholera toxin B subunit (CTB), and/or diptheria toxoid (dT) carrier, or PBS alone, and challenge with the M1 GAS strain. However, GAS colonisation of the throat was significantly reduced following intranasal immunisation of mice with the vaccine candidate J8 conjugated to dT or J14-dT when administered with CTB. Moreover, J8-dT/CTB and J14-dT/CTB-immunised mice had a significantly higher survival when compared to CTB and PBS-immunised control mice. These data indicate that immunity to GAS infection can be evoked by intranasal immunisation with a GAS M protein C-region peptide vaccine that contains a protective B cell epitope and lacks a T cell autoepitope. (C) 2002 Published by Elsevier Science Ltd.

Fast neutron mutagenesis of soybean (Glycine soja L.) produces a supernodulating mutant containing a large deletion in linkage group H

We describe for the first time the application of fast neutron mutagenesis to the genetic dissection of root nodulation in legumes. We demonstrate the utility of chromosomal deletion mutations through production of a soybean supernodulation mutant FN37 that lacks the internal autoregulation of nodulation mechanism. After inoculation with microsymbiont Bradyrhizobium japonicum, FN37 forms at least 10 times more nodules than the wild type G. soja parent and has a phenotype identical to that of chemically induced allelic mutants nts382 and nts1007 (NTS-1 locus). Reciprocal grafting of shoots and roots confirmed systemic shoot control of the FN37 nodulation phenotype. RFLP/PCR marker pUTG132a and AFLP marker UQC-IS1 which are tightly linked to NTS-1 allowed the isolation of BAC contigs delineating both ends of the deletion. The genetic/physical distance ratio in the NTS-1 region is 279 kb/cM. The deletion is estimated to be about 460 kb based on the absence of markers and bacterial artificial chromosomes (BAC) ends as well as genetic and physical mapping. Deletion break points were determined physically and placed within flanking BAC contigs.

Hand-assisted laparoscopic adrenalectomy: An alternative minimal invasive surgical technique for the adrenal gland

Background: Presently the surgical approach to the adrenal gland is in a state of flux. While the traditional approach to the adrenal gland has been the open transabdominal technique, more recently laparoscopic approaches, particularly via the transabdominal route, have increasingly been utilized. However, laparoscopic intervention for the adrenal gland can be problematic in certain circumstances, particularly for large adrenal masses and in instances of adrenal malignancies. Methods: In this report we describe the use of hand-assisted laparoscopic adrenalectomy as an alternative minimal invasive surgical approach to the adrenal gland. Hand-assisted laparoscopic adrenalectomy using the HandPort system (Smith & Nephew, Sydney, Australia) was undertaken in three patients requiring adrenalectomy for mass lesions including one patient with Conn's syndrome. Results: In all three cases, surgery proceeded promptly and uneventfully. In the present paper, the details of the technique of hand-assisted adrenalectomy are described. This is the first report in the world literature of this new technique for the adrenal gland. Conclusions: Hand-assisted laparoscopic adrenalectomy is an easily performed technique, which can be completed within a short operative time span and which has the advantage of providing intraoperative tactile localization for the adrenal gland. It may be particularly applicable for large adrenal tumours, yet only involves the performance of a small abdominal incision. Postoperative recovery is comparable with that reported for the laparoscopic-only technique. Hand-assisted adrenalectomy is a new technique which has great potential and which warrants further evaluation.

Dietary supplementation with vitamin E modulates avian intestinal immunity

The effect of dietary vitamin E on immunoglobulin A (IgA) antibody production, which acts as the first line of defence at the intestinal mucosa, has not been evaluated in chickens. In the present study the impact of the inclusion of supplementary levels of vitamin E to the diet, on total and antigen-specific IgA antibody titres, T-cell subsets and Ia+ cells, was assessed. From hatching, chickens received a maize-based diet which was supplemented with either 25, 250, 2500 or 5000 mg dl-alpha-tocopherol acetate/kg. Primary immunisation with tetanus toxoid (T. toxoid) emulsified in a vegetable oil-in-water adjuvant was administered by the intraperitoneal route at 21 d of age. At 35 d of age all birds received an oral booster vaccination of T. toxoid. Significantly higher total IgA antibody titres were present in the day 42 intestinal scrapings of birds receiving the 5000 mg/kg vitamin E-supplemented diet (VESD) (P=0.05) and a notable increase was observed in birds receiving the 250 mg/kg VESD (P=0.06). At days 21 and 42 total serum IgA antibody titres of birds receiving the 250 mg/kg VESD was significantly higher (P

Human peripheral blood V alpha 24(+) V beta 11(+) NKT cells expand following administration of alpha-galactosylceramide-pulsed dendritic cells

Background and Objectives We have undertaken the first clinical trial involving the administration of alpha-GalactosylCeramine (alpha-GalCer)-pulsed dendritic cells (DCs) to human subjects, to determine safety, optimal dose, optimal administration route and immunological effects. Materials and Methods Subjects (n = 4) with metastatic malignancy received two infusions of alpha-GalCer-pulsed DCs intravenously, and two infusions intradermally. The percentages of Valpha24 Vbeta11 NKT cells in peripheral blood (PB) were determined by three-colour flow cytometry and the PB NKT cell numbers were calculated using the total number of PB lymphocytes/ml determined by automated full-blood counts. Results No serious treatment related adverse events were observed during the study period. Administration of alpha-GalCer-pulsed DCs in vivo can significantly (P < 0.03) increase PB Valpha24(+) Vbeta11(+) NKT cell numbers above pretreatment baseline levels after the transient fall in the NKT numbers within 48 h. Conclusions Administration of alpha-GalCer-pulsed DCs is well tolerated, modulates PB Valpha24(+) Vbeta11(+) NKT cells and may have a role in the therapy of malignancies sensitive to activities of Valpha24(+) Vbeta11(+) NKT cells, or for autoimmune diseases.

Parenteral and mucosal delivery of a novel multi-epitope M protein-based group A streptococcal vaccine construct: investigation of immunogenicity in mice

Primary vaccine strategies against group A streptococci (GAS) have focused on the M protein-the target of opsonic antibodies important for protective immunity. We have previously reported protection of mice against GAS infection following parenteral delivery of a multi-epitope vaccine construct, referred to as a heteropolymer. This current report has assessed mucosal (intranasal (i.n.) and oral) delivery of the heteropolymer in mice with regard to the induction and specificity of mucosal and systemic antibody responses, and compared this to parenteral delivery. GAS-specific IgA responses were detected in saliva and gut upon i.n. and oral delivery of the heteropolymer co-administered with cholera toxin B subunit, respectively. High titre serum IgG responses were elicited to the heteropolymer following all routes of delivery when administered with adjuvant. Moreover, as with parenteral delivery, serum IgG antibodies were detected to the individual heteropolymer peptides following i.n. but not oral delivery. These data support the potential of the i.n. route in the mucosal delivery of a GAS vaccine. (C) 2002 Elsevier Science Ltd. All rights reserved.

A suite of novel allenes from Australian melolonthine scarab beetles. Structure, synthesis, and stereochemistry

A suite of allenic hydrocarbons, previously unknown as a molecular class from insects, has been characterized from several Australian melolonthine scarab beetles. The allenes are represented by the formula CH3(CH2)nCH=.=CH(CH2)(7)CH3 with n being 11-15, 17 and 19, and thus, all have Delta(9,10)-unsaturation. These structures have been confirmed by syntheses and comparisons of spectral and chromatographic properties with those of the natural components. The enantiomers of (+/-)-Delta(9,10)-tricosadiene and Delta(9,10)-pentacosadiene were separable on a modified beta-cyclodextrin column (gas chromatography), and the natural Delta(9,10)-tricosadiene (n = 11) and Delta(9,10)-pentacosadiene (n = 13) were shown to be of >85% ee. Syntheses of nonracemic allenes of known predominating chirality were acquired using both organotin chemistry and sulfonylhydrazine intermediates, and comparisons then demonstrated that the natural allenes were predominantly (R)-configured.

Generation of CTL responses using Kunjin replicon RNA

The Kunjin replicon was used to express a polytope that consisted of seven hepatitis C virus cytotoxic T lymphocyte epitopes and one influenza cytotoxic T lymphocyte epitope for vaccination studies. The self-replicating nature of, and expression from, the ribonucleic acid was confirmed in vitro . Initial vaccinations with one dose of Kun-Poly ribonucleic acid showed that an influenza-specific cytotoxic T lymphocyte response was elicited more efficiently by intradermal inoculation compared with intramuscular delivery. Two micrograms of ribonucleic acid delivered in the ear pinnae of mice was sufficient to elicit a detectable cytotoxic T lymphocyte response 10 days post-vaccination. Further vaccination studies showed that four of the seven hepatitis C virus cytotoxic T lymphocyte epitopes were able to elicit weak cytotoxic T lymphocyte responses whereas the influenza epitope was able to elicit strong, specific cytotoxic T lymphocyte responses following three doses of Kun-Poly ribonucleic acid. These studies vindicate the use of the Kunjin replicon as a vector to deliver encoded proteins for the development of cell-mediated immune responses.