T cell-mediated and non-specific inflammatory mechanisms contribute to the skin pathology of HPV 16 E6E7 transgenic mice

One of three lines of mice transgenic for the E6 and E7 genes of human papillomavirus type 16 (HPV16) expressed from an alpha A-crystallin promoter also expresses the transgene ectopically in the skin. This line, designated alpha ACE6E7#19, develops skin disease from 3 months of age, characterised by epidermal hyperplasia and eventual skin loss. Administration of complete Freund's adjuvant (CFA) to alpha ACE6E7#19 mice, but not to nontransgenic littermate controls, induced local epidermal hyperplasia which was histologically similar to the spontaneously arising skin pathology. Local application of 2,4-dinitrochlorobenzene (DNCB) to DNCB-sensitised aACE6E7#19 mice, but not DNCB-sensitised controls, also induced hyperplasia. Treatment with cyclosporin A (CsA) or systemic depletion of CD4+ cells significantly reduced the incidence of skin disease. These data suggest that local inflammation, and cytokines produced by T helper cells, contribute to the induction of hyperplastic skin disease in alpha ACE6E7#19 mice. Spontaneous skin disease with similar histological appearance, frequency, age of onset and severity in alpha ACE6E7#19 mice was observed in scid-/- aACE6E7#19 mice, despite immune paresis. Antigen-specific immune responses and T-cell cytokines a re therefore not necessary for the induction of skin disease. We propose that epidermal hyperplasia associated with HPV16 E6 and E7 expression in skin is accelerated by local secretion of pro-inflammatory cytokines, whose production can be enhanced by activated CD4+ T cells.

Both CD4(+) and CD8(+) lymphocytes reduce the severity of tissue lesions in murine systemic candidiasis, and CD4(+) cells also demonstrate strain-specific immunopathological effects

The role of T lymphocytes in host responses to sublethal systemic infection with Candida albicans was evaluated by mAb depletion of CD4(+) and CD8(+) cells from BALB/c and CBA/CaH mice, which develop mild and severe tissue damage, respectively. Depletion of CD4(+) lymphocytes from BALB/c mice markedly increased tissue damage, but did not alter the course of infection. In CBA/CaH mice, depletion of CD4+ cells abrogated tissue destruction in both brain and kidney at day 4 after infection, and significantly decreased fungal colonization in the brain. However, the severity of tissue lesions increased relative to controls from day 8 onwards. A small increase in tissue damage was evident in both mouse strains after depletion of CD8(+) cells. There were no major differences between days 4 end 8 after infection in cDNA cytokine profiles of CD4(+) lymphocytes from either BALB/c or CBA/CaH mice. After passive transfer into infected syngeneic recipients, spleen cells from infected CBA/CaH mice markedly increased tissue damage when compared to controls, and also caused a significant increase in fungal colonization in the brain. A similar transfer in BALB/c mice increased the number of inflammatory cells in and around the lesions, but had no effect on the fungal burden in brain and kidney. The data demonstrate that both CD4(+) and CD8(+) lymphocytes contribute to the reduction of tissue damage after systemic infection with C. albicans, and that the development and expression of CD4(+) lymphocyte effector function is influenced by the genetic background of the mouse.

Miscibility and specific interactions in blends of poly(4-vinylphenol) and poly(2-ethoxyethyl methacrylate)

The properties of the hydrogen-bonded polymer blends of poly(4-vinylphenol) and poly(2-ethoxyethyl methacrylate) are presented. Spectroscopic techniques such as C-13 solid-state NMR and FT-IR are used to probe specific interactions of the blends at various compositions. Spectral features from both techniques revealed that site-specific interactions are present, consistent with a significant degree of mixing of the blend components. Changes in chemical shift and line shape of the phenolic carbon and carbonyl resonances in the C-13 CPMAS spectra of the blends as a function of composition are interpreted as resulting from changes in the relative intensities of two closely overlapped signals. A quantitative measure of hydrogen-bonded carbonyl groups using C-13 NMR has been obtained which agreed well with the results from FT-IR analyses. It is also shown that C-13 NMR can be used to measure the fraction of hydroxyl groups associated with carbonyl groups, which was not possible previously using FT-IR due to extensive overlapping of bands in the hydroxyl stretching region. The results of measurements of H-1 T-1 and 1H T-1 rho indicate that PVPh and PEEMA are intimately mixed on a scale less than 2-3 nm.

A six-year longitudinal study of the relationship of physical activity to bone mineral accrual in growing children: The University of Saskatchewan bone mineral accrual study

To investigate the influence of physical activity on bone mineral accrual during the adolescent years, we analyzed 6 years of data from 53 girls and 60 boys. Physical activity, dietary intakes, and anthropometry were measured every 6 months and dual-energy X-ray absorptiometry scans of the total body (TB), lumbar spine (LS), and proximal femur (Hologic 2000, array mode) were collected annually. Distance and velocity curves for height and bone mineral content (BMC) were fitted for each child at several skeletal sites using a cubic spline procedure, from which ages at peak height velocity (PHV) and peak BMC velocity (PBMCV) were identified. A mean age- and gender-specific standardized activity (Z) score was calculated for each subject based on multiple yearly activity assessments collected up until age of PHV. This score was used to identify active (top quartile), average (middle 2 quartiles), or inactive (bottom quartile) groups. Two-way analysis of covariance, with height and weight at PHV controlled for, demonstrated significant physical activity and gender main effects (but no interaction) for PBMCV, for BMC accrued for 2 years around peak velocity, and for BMC at 1 year post-PBMCV for the TB and femoral neck and for physical activity but not gender at the LS (all p < 0.05). Controlling for maturational and size differences between groups, we noted a 9% and 17% greater TB BMC for active boys and girls, respectively, over their inactive peers 1 year after the age of PBMCV. We also estimated that, on average, 26% of adult TB bone mineral was accrued during the 2 years around PBMCV.

Description of Gluconacetobacter sacchari sp. nov., a new species of acetic acid bacterium isolated from the leaf sheath of sugar cane and from the pink sugar-cane mealy bug

A new species of the genus Gluconacetobacter, for which the name Gluconacetobacter sacchari sp. nov. is proposed, was isolated from the leaf sheath of sugar cane and from the pink sugar-cane mealy bug, Saccharicoccus sacchari, found on sugar cane growing in Queensland and northern New South Wales, Australia, The nearest phylogenetic relatives in the alpha-subclass of the Proteobacteria are Gluconacetobacter liquefaciens and Gluconacetobacter diazotrophicus, which have 98.8-99.3% and 97.9-98.5% 16S rDNA sequence similarity, respectively, to members of Gluconacetobacter sacchari. On the basis of the phylogenetic positioning of the strains, DNA reassociation studies, phenotypic tests and the presence of the Q10 ubiquinone, this new species was assigned to the genus Gluconacetobacter. No single phenotypic characteristic is unique to the species, but the species can be differentiated phenotypically from closely related members of the acetic acid bacteria by growth in the presence of 0.01% malachite green, growth on 30% glucose, an inability to fix nitrogen and an inability to grow with the L-amino acids asparagine, glycine, glutamine, threonine and tryptophan when D-mannitol was supplied as the sole carbon and energy source. The type strain of this species is strain SRI 1794(T) (= DSM 12717(T)).

Season-specific directional movement in migratory Australian butterflies

Large numbers of adults of certain species of butterfly flying in an apparently 'purposeful' manner are often noted by entomologists and the general public. Occasionally, these are recorded in the literature. Using these records we summarise information regarding the direction of movement in Australian butterflies and test whether there are consistent patterns that could account for known seasonal shifts in geographical range. The data were analysed using contingency tables and directionality statistics. Vanessa itea, Vanessa kershawi, Danaus plexippus, Danaus chrysippus and Badamia exclamationis flew predominately south in the spring-summer and north in the autumn-winter. Tirumala hamata has a strong southern component to its flight in spring but, as in Euploea core, appears non-directional in the autumn. For many supposedly known migratory species, the number of literature records are few, particularly in one season (mainly autumn). Thus, for Appias paulina, four of seven records were south in the spring-summer, as were six of nine records for Catopsilia pomona, and three of five for Zizina labradus. For Belenois java, flight records were only available for the spring and these showed geographical differences; predominantly north-west in northern Australia (Queensland) and south-west in southern Australia (Victoria, New South Wales). There were too few records for Papilio demoleus in the literature (four only) to draw any conclusions. Major exceptions to the seasonal trend of south in the spring and north in the autumn were Junonia villida, which showed a predominant north-westward direction in both seasons, and Eurema smilax, with a predominant southern or western flight in both seasons. We discuss these species specific trends in migration direction in relation to seasonal shifts in suitable habitat conditions, possible cues used in orientation and in timing changes in direction.

Molecular characterization of the toxic cyanobacterium Cylindrospermopsis raciborskii and design of a species-specific PCR

Cylindrospermopsis raciborskii is a toxic-bloom-forming cyanobacterium that is commonly found in tropical to subtropical climatic regions worldwide, but it is also recognized as a common component of cyanobacterial communities in temperate climates. Genetic profiles of C. raciborskii were examined in 19 cultured isolates originating from geographically diverse regions of Australia and represented by two distinct morphotypes. A 609-bp region of rpoC1, a DNA-dependent RNA polymerase gene, was amplified by PCR from these isolates with cyanobacterium-specific primers. Sequence analysis revealed that all isolates belonged to the same species, including morphotypes with straight or coiled trichomes. Additional rpoC1 gene sequences obtained for a range of cyanobacteria highlighted clustering of C. raciborskii with other heterocyst-producing cyanobacteria (orders Nostocales and Stigonematales). In contrast, randomly amplified polymorphic DNA and short tandemly repeated repetitive sequence profiles revealed a greater level of genetic heterogeneity among C. raciborskii isolates than did rpoC1 gene analysis, and unique band profiles were also found among each of the cyanobacterial genera examined. A PCR test targeting a region of the rpoC1 gene unique to C. raciborskii was developed for the specific identification of C. raciborskii from both purified genomic DNA and environmental samples. The PCR was evaluated with a number of cyanobacterial isolates, but a PCR-positive result was only achieved with C, raciborskii. This method provides an accurate alternative to traditional morphological identification of C. raciborskii.

The influence of supra-optimal root-zone temperatures on growth and stomatal conductance in Capsicum annuum L.

Pepper (Capsicum annuum L.) plants were grown aeroponically in a Singapore greenhouse under natural diurnally fluctuating ambient shoot temperatures, but at two different root-zone temperatures (RZTs): a constant 20 +/- 2 degrees C RZT and a diurnally fluctuating ambient (A) (25-40 degrees C) RZT, Plants grown at 20-RZT had more leaves, greater leaf area and dry weight than A-RZT plants. Reciprocal transfer experiments were conducted between RZTs to investigate the effect on plant growth, stomatal conductance (g(s)) and water relations. Transfer of plants from A-RZT to 20-RZT increased plant dry weight, leaf area, number of leaves, shoot water potential (Psi(shoot)), and g(s); while transfer of plants from 20-RZT to A-RZT decreased these parameters. Root hydraulic conductivity was measured in the latter transfer and decreased by 80% after 23 d at A-RZT. Transfer of plants from 20-RZT to A-RZT had no effect on xylem ABA concentration or xylem nitrate concentration, but reduced xylem sap pH by 0.2 units. At both RZTs, g(s) measured in the youngest fully expanded leaves increased with plant development. In plants with the same number of leaves, A-RZT plants had a higher g(s) than 20-RZT plants, but only under high atmospheric vapour pressure deficit. The roles of chemical signals and hydraulic factors in controlling g(s) of aeroponically grown Capsicum plants at different RZTs are discussed.

Clinical measures of obesity and weight loss in men

OBJECTIVES: (?) To determine the relationship between waist circumference and body weight in overweight men both before and after participation in a weight loss program; and (2) to make recommendations for the appropriate use of these measures at various stages of weight toss. DESIGN: Weight and waist circumference measures were taken in two diverse groups of men both before and 1-2y after commencing a men's 'waist loss' program. Regression analyses were used to assess the relationship between weight and waist measures. SUBJECTS: One group of 42 retired Caucasian men from New South Wales, and one group of 45 indigenous men from the Torres Strait region of Northern Australia. RESULTS: There were differences in the relationships of weight and waist circumference before the program and change in weight and change in waist circumference after weight loss. These differences were similar in both groups of men (indigenous men and retired Caucasian men), with a 1 cm waist loss being on average equivalent to about 3/4 kg, but with wide variability, suggesting inter-individual variation in fat losses from different depots. This variation suggests that neither weight nor waist alone is a sufficient measure of fat loss for men. CONCLUSIONS: Weight and waist circumference should both be used at various stages in the clinical situation to assess change in body fat in men involved in obesity reduction.

Level-one highest weight representations of U-q[g1(1 vertical bar 1)] and associated vertex operators

We study the level-one irreducible highest weight representations of U-q[gl(1\1)] and associated q-vertex operators. We obtain the exchange relations satisfied by these vertex operators. The characters and supercharacters associated with these irreducible representations are calculated'. (C) 2000 Published by Elsevier Science B.V. All rights reserved.

Comparison of trends in method-specific suicide rates in Australia and England & Wales, 1968-97

Objective: To compare secular trends in method-specific suicide rates among young people in Australia and England & Wales between 1968 and 1997. Methods: Australian data were obtained from the Australian Bureau of Statistics, and for England & Wales from the Office for National Statistics. Overall and method-specific suicide rates for 15-34 year old males and females were calculated using ICD codes E950-9 and E980-9 except E988.8. Results: In both settings, suicide rates have almost doubled in young males over the past 30 years (from 16.8 to 32.9 per 100,000 in Australia and from 10.1 to 19.0 in England & Wales). Overall rates have changed little in young females. In both sexes and in both settings there have been substantial increases in suicide by hanging (5-7 fold increase in Australia and four-fold increase in England & Wales). There have also been smaller increases in gassing in the 1980s and '90s. In females, the impact of these increases on overall rates has been offset by a decline in drug overdose, the most common method in females. Conclusions: Rates of male suicide have increased substantially in both settings in recent years, and hanging has become an increasingly common method of suicide. The similarity in observed trends in both settings supports the view that such changes may have common causes. Research should focus on understanding why hanging has increased in popularity and what measures may be taken to diminish it.

Induction of an antigen-specific CTL response by a conformationally biased agonist of human C5a anaphylatoxin as a molecular adjuvant

A conformationally biased decapeptide agonist of human C5a anaphylatoxin (YSPKPMPLaR) was used as a molecular adjuvant in stimulating an Ag-specific CTL response against murine P815S target cells expressing an Ld-restricted CTL epitope of the hepatitis B surface Ag (HBsAg), Groups of BALB/c mice (H-2(d)) were immunized with aqueous solutions of the HBsAg CTL epitopes (IPQSLDSWWTSL and IPQSLDSTaVTSLRR); the C5a agonist (YSFKPMPLaR); the C5a agonist and HBsAg CTL epitopes admired (IPQSLDSWWTSL and IPQSLDSWWTSLRR + YSFKPMPLaR); the C5a-active, HBsAg CTL epitope-C5a agonist constructs (IPQSLDSWWTSLYSFKPMPLaR, IPQSLDSWWTSLRRYSFKPMPLaR, and IPQSLDSWWTSLRVRRYSFPMPLaR); a C5a-inactive, reverse-moiety construct (YSFKPMPLaRRRIPQSLDSWWTSL); and a C5a-attenuated, carboxyl-terminal-blocked construct (IPQSLDSWWTSLRRYSFKPMPLaRG). Ag-specific CD8(+) CTL responses were observed after the secondary boost in the absence of any added adjuvant only in mice that were immunized with C5a-active contructs, IPQSLDSWWTSLRRYSFKPMPLaR and IPQSLDSWWTSLRVRRYSFKPMPLaR. These two C5a-active immunogens contained potential subtilisin-sensitive linker sequences between the HBsAg CTL epitope and the C5a agonist; i.e., a double-Arg (RR) and a furin protease sensitive sequence (RVRR), The introduction of these potentially cleavable sequences may be a method of increasing the likelihood of liberating the CTL epitope from the C5a agonist by intracellular proteases, thereby facilitating entry of the epitope into Ag-processing pathways via an exogenous route.

E2F-1 induces proliferation-specific genes and suppresses squamous differentiation-specific genes in human epidermal keratinocytes

Squamous differentiation of keratinocytes is associated with decreases in E2F-1 mRNA expression and E2F activity, and these processes are disrupted in squamous cell carcinoma cell lines. We now show that E2F-1 mRNA expression is increased in primary squamous cell carcinomas of the skin relative to normal epidermis, To explore the relationship between E2F-1 and squamous differentiation further, we examined the effect of altering E2F activity in primary human keratinocytes induced to differentiate. Promoter activity for the proliferation-associated genes, cdc2 and keratin 14, are inhibited during squamous differentiation. This inhibition can be inhibited by overexpression of E2F-1 in keratinocytes, Overexpression of E2F-1 also suppressed the expression of differentiation markers (transglutaminase type 1 and keratin 10) in differentiated keratinocytes, Blocking E2F activity by transfecting proliferating keratinocytes with dominant negative E2F-1 constructs inhibited the expression of cdc2 and E2F-1, but did not induce differentiation. Furthermore, expression of the dominant negative construct in epithelial carcinoma cell lines and normal keratinocytes decreased expression from the cdc2 promoter. These data indicate that E2F-1 promotes keratinocyte proliferation-specific marker genes and suppresses squamous differentiation-specific marker genes. Moreover, these data indicate that targeted disruption of E2F-1 activity may have therapeutic potential for the treatment of squamous carcinomas.

Assessment of intracellular water by whole body bioelectrical impedance and total body potassium in HIV-positive patients

.:Abstract-Objective: Bioelectrical impedance analysis (BIA) is widely used as bedside assessment of body composition. Body cell mass (BCM) and intracellular water (ICW) are clinically important body compartments. Estimates of ICW obtained from BIA by different calculation approaches were compared to a reference method in male HIV-infected patients. Patients: Representative subsample of clinically stable HIV-infected outpatients, consisting of 42 men with a body mass index of 22.4 +/- 3.8 kg/m(2) (range, 13-31 kg/m(2)). Methods: Total body potassium was assessed in a whole body counter, and compared to 50 kHz mono-frequency BIA and multifrequency bioelectrical impedance spectroscopy. Six different prediction equations for ICW from BIA data were applied. Methods were compared by the Bland-Altman method. Results: BIA-derived ICW estimates explained 58% to 73% of the observed variance in ICW (TBK), but limits of confidence were wide (-16.6 to +18.2% for the best method). BIA overestimated low ICW (TBK) and underestimated high ICW (TBK) when normalized for weight or height. Mono- and multifrequency BIA were not different in precision but population-specific equations tended to narrower confidence limits. Conclusion: BIA is an unreliable method to estimate ICW in this population, in contrast to the better established estimation of total body water and extracellular water. Potassium depletion in severe malnutrition may contribute to this finding but a major part of the residual between methods remains unexplained. (C) 2000 Harcourt Publishers Ltd.