Early Effects on T lymphocyte Response to Iron Deficiency in Mice. Short Communication

Iron deficiency is a common nutritional disorder, affecting about 30% of the world population. Deficits in iron functional compartments have suppressive effects on the immune system. Environmental problems, age, and other nutrient deficiencies are some of the situations which make human studies difficult and warrant the use of animal models. This study aimed to investigate alterations in the immune system by inducing iron deficiency and promoting recuperation in a mouse model. Hemoglobin concentration, hematocrit, liver iron store, and flow cytometry analyses of cell-surface transferrin receptor (CD71) on peripheral blood and spleen CD4+ and CD8+ T lymphocyte were performed in the control (C) and the iron-deficient (ID) groups of animals at the beginning and end of the experiment. Hematological indices of C and ID mice were not different but the iron stores of ID mice were significantly reduced. Although T cell subsets were not altered, the percentage of T cells expressing CD71 was significantly increased by ID. The results suggest that iron deficiency induced by our experimental model would mimic the early events in the onset of anemia, where thymus atrophy is not enough to influence subset composition of T cells, which can still respond to iron deficiency by upregulating the expression of transferrin receptor.

Governing coordination: Behavioural principles and neural correlates

The coordination of movement is governed by a coalition of constraints. The expression of these constraints ranges from the concrete—the restricted range of motion offered by the mechanical configuration of our muscles and joints; to the abstract—the difficulty that we experience in combining simple movements into complex rhythms. We seek to illustrate that the various constraints on coordination are complementary and inclusive, and the means by which their expression and interaction are mediated systematically by the integrative action of the central nervous system (CNS). Beyond identifying the general principles at the behavioural level that govern the mutual interplay of constraints, we attempt to demonstrate that these principles have as their foundation specific functional properties of the cortical motor systems. We propose that regions of the brain upstream of the motor cortex may play a significant role in mediating interactions between the functional representations of muscles engaged in sensorimotor coordination tasks. We also argue that activity in these ldquosupramotorrdquo regions may mediate the stabilising role of augmented sensory feedback.

Diagnostics of A Range of Highly Superorbital Carbon Dioxide Flows

Expansion tubes are impulse facilities capable of generating highly energetic hyper-sonic flows. This work surveys a broad range of flow conditions produced in the facility X1 with carbon dioxide test gas, for simulation of spacecraft entry into the Martian atmosphere. Conditions with nominal flow speeds of 7, 9, 11 and 13 km/s were tested. The freestream conditions were calibrated using static/Pitot pressure measurements and advanced optical diagnostics. An extensive set of holographic interferometry experiments was performed on flows over wedges for quantitative study of freestream and post-shock densities, and post-shock ionisation. A one-dimensional code with frozen and equilibrium chemistry capabilities was used to estimate the freestream conditions. An equilibrium chemistry model produced a good match to measured freestream quantities at the high enthalpy conditions which are a major aim of this facility's operation. The freestream in the lower enthalpy conditions was found to be heavily influenced by chemical non-equilibrium. Non-equilibrium in the final unsteady expansion process of flow generation was accounted for by switching from equilibrium to frozen chemistry at a predetermined point. Comparison between the freestream density results of holographic interferometry, pressure measurements and computations shows good agreement.

Short-term spatial diffusion in sigma o+ o- optical molasses

We have measured the spatial diffusion of atoms in a three-dimensional sigma(+)-sigma(-) optical molasses over twenty milliseconds timescale, starting from the initial interaction of the atoms with the molasses. We find that the diffusion constants agree well with a linear model for these short time scales and also compare favourably to other studies of diffusion made over longer time scales. These measurements enable us to quantify the detection method known as freezing molasses. We discuss this method, for detecting and measuring the momentum distribution of cold atoms, which relies on the slow diffusion of atoms in optical molasses to produce a freeze-frame of the spatial distribution of the atoms. This method enables a longer interrogation interval, providing a greatly increased signal-to-noise ratio. (C) 1998 Elsevier Science B.V.

Antibody responses and protective immunity to recombinant vaccinia virus-expressed bluetongue virus antigens

The role of individual viral proteins in the immune response to bluetongue virus (BTV) is not clearly understood. To investigate the contributions of the outer capsid proteins, VP2 and VP5, and possible interactions between them, these proteins were expressed from recombinant vaccinia viruses either as individual proteins or together in double recombinants, or with the core protein VP7 in a triple recombinant. Comparison of the immunogenicity of the vaccinia expressed proteins with BTV expressed proteins was carried out by inoculation of rabbits and sheep. Each of the recombinants was capable of stimulating an anti-BTV antibody response, although there was a wide range in the level of response between animals and species. Vaccinia-expressed VP2 was poorly immunogenic, particularly in rabbits. VP5, on the whole, stimulated higher ELISA titers in rabbits and sheep and in some animals in both species was able to stimulate virus neutralizing antibodies. When the protective efficacy of VP2 and VP5 was tested in sheep, vaccinia-expressed VP2, VP5 and VP2 + VP5 were protective, with the most consistent protection being in groups immunized with both proteins. (C) 1997 Elsevier Science B.V.

The effects of prepulse-blink reflex trial repetition and prepulse change on blink reflex modification at short and long lead intervals

Prepulse inhibition and facilitation of the blink reflex are said to reflect different responses elicited by the lead stimulus, transient detection and orienting response respectively. Two experiments investigated the effects of trial repetition and lead stimulus change on blink modification. It was hypothesized that these manipulations will affect orienting and thus blink facilitation to a greater extent than they will affect transient detection and thus blink inhibition. In Experiment 1 (N = 64), subjects were trained with a sequence of 12 lead stimulus and 12 blink stimulus alone presentations, and 24 lead stimulus-blink stimulus pairings. Lead interval was 120 ms for 12 of the trials and 2000 ms for the other 12. For half the subjects this sequence was followed by a change in pitch of the lead stimulus. In Experiment 2 (N = 64), subjects were trained with a sequence of 36 blink alone stimuli and 36 lead stimulus-blink stimulus pairings. The lead interval was 120 ms for half the subjects and 2000 ms for the other half. The pitch of the lead stimulus on prestimulus trials 31-33 was changed for half the subjects in each group. In both experiments, the amount of blink inhibition decreased during training whereas the amount of blink facilitation remained unchanged. Lead stimulus change had no effect on blink modification in either experiment although it resulted in enhanced skin conductance responses and greater heart rate deceleration in Experiment 2. The present results are not consistent with the notion that blink facilitation is linked to orienting whereas blink inhibition reflects a transient detection mechanism. (C) 1998 Elsevier Science B.V.

Vaccine-induced Th1-type responses are dominant over Th2-type responses in the short term whereas pre-existing Th2 responses are dominant in the longer term

The effect of adjuvant on induction of human papillomavirus type 16 E7 protein-specific cytotoxic T lymphocytes (CTL) and immunoglobulin G (IgG)(2a) antibody was studied in C57BL/6 J mice immunized with various adjuvants and E7 protein. Quil-A adjuvant, but not complete Freund's adjuvant (CFA) or Algammulin, induced a T-helper 1 (Th1)-type response to E7, which was characterized by CTL activity against a tumour cell line transfected with E7 protein and by E7-specific IgG(2a). All tested adjuvants elicited comparable levels of E7-specific IgG(1). The longest duration and greatest magnitude of CTL response was seen following two immunizations with the highest dose of E7 and Quil-A. Simultaneous immunization with a Th1 and a T helper 2 (Th2)-promoting adjuvant gave a Th1-type response. However, E7 and Quil-A were unable to induce a Th1-type response (as measured by the inability to generate anti-E7 IgG(2a) antibody) in animals with a pre-existing Th2-type response to E7. These results suggest that saponin adjuvants may be suitable for immunotherapy in humans where a Th1-type response is sought, provided that there is no pre existing Th2-type response to the antigen.

What is a healthy weight for middle aged women?

OBJECTIVE: To explore associations between body mass index (BMI) and selected indicators of health and well-being and to suggest a healthy weight range (based on BMI) for middle aged Australian women. DESIGN: population based longitudinal study (cross-sectional baseline data). SUBJECTS: 13431 women aged 45-49 y who participated in the baseline survey for the Australian Longitudinal Study on Women's Health. RESULTS: Forty-eight percent of women had a BMI>25kg/m(2). Prevalence of medical problems (for example, hypertension, diabetes), surgical procedures (cholescystectomy, hysterectomy) and symptoms (for example, back pain) increased monotonically with BMI, while indicators of health care use (for example, visits to doctors) showed a 'J' shaped relationship with BMI. Scores for several sub-scales of the MOS short form health survey (SF36) (for example, general health, role limitations due to emotional difficulties, social function, mental health and vitality) were optimal when BMI was around 19-24 kg/m(2). After adjustment for area of residence, education, smoking, exercise and menopausal status, low BMI was associated with fewer physical health problems than mid-level or higher BMI, and the nationally recommended BMI range of 20-25 was associated with optimum mental health, lower prevalence of tiredness and lowest use of health services. CONCLUSIONS: Acknowledging the limitations of the cross-sectional nature of these data, the results firmly support the benefits of leanness in terms of reducing the risk of cardiovascular disease, diabetes and gall bladder disease. The findings are moderated, however, by the observation that both low and high BMI are associated with decreased vitality and poorer mental health. The optimal range for BMI appears to be about 19-24 kg/m(2). From a public health perspective this study provides strong support for the recommended BMI range of 20-25 as an appropriate target for the promotion of healthy weight in middle aged Australian women.

Folding, calcium binding, and structural characterization of a concatemer of the first and second ligand-binding modules of the low-density lipoprotein receptor

The ligand-binding domain of the low-density lipoprotein (LDL) receptor is comprised of seven tandemly repeated ligand-binding modules, each being approximately 40 amino acids long and containing six conserved cysteine residues. We have expressed and characterized a concatemer of the first two modules (LB1 and LB2) of the human LDL receptor. Oxidative folding of the recombinant concatemer (rLB(1-2)), in the presence of calcium ions, gave a single dominant isomer with six disulfide bonds. Peptic cleavage of the short Linker region that connects the last cysteine residue of LB1 and the first cysteine residue of LB2 yielded two discrete fragments, thus excluding the presence of intermodule disulfide bonds. The N-terminal module, LB1, reacted with a conformation-specific monoclonal antibody (IgG-C7) made to LB1 in the native LDL receptor. From this, we concluded that the first module was correctly folded, with the same set of disulfide bonds as LB1 of the LDL receptor. The disulfide bond connections of LB2 were identified from mass spectral analysis of fragments formed by digestion of the C-terminal peptic fragment with elastase. These data showed that the disulfide bonds of LB2 connected Cys(I) and Cys(III), Cys(II) and Cys(V), and Cys(IV) and Cys(VI). This pattern is identical to that found for recombinant LB1 and LB2. The concatemer has two high-affinity calcium-binding sites, one per module. An analysis of the secondary chemical shifts of C alpha protons shows that the conformations of LB1 and LB2 in the concatemer are very similar to those of the individual modules, with no evidence for strong interactions between the two modules.

Off-diagonal long-range order in a supersymmetric integrable model of correlated electrons

A new model for correlated electrons is presented which is integrable in one-dimension. The symmetry algebra of the model is the Lie superalgebra gl(2\1) which depends on a continuous free parameter. This symmetry algebra contains the eta pairing algebra as a subalgebra which is used to show that the model exhibits Off-Diagonal Long-Range Order in any number of dimensions.

Suicide in urban New South Wales, Australia 1985-1994: Socio-economic and migrant interactions

Variation of suicide with socio-economic status (SES) in urban NSW (Australia) during 1985-1994, by sex and country or region of birth, was examined using Poisson regression analysis of vital statistics and population data (age greater than or similar to 15 yr). Quintiles of SES were defined by municipality of residence and comparisons of suicide by SES were adjusted for age and country (or region) of birth (COB), and examined by COB. Risk of suicide in females was 28% that of males for all adults and 21% for youth (age 15-24 yr). Suicide risk was lower in males from southern Europe, Middle East and Asia, and higher in northern and eastern European males, compared to the Australian-born. Risks for suicide increased significantly with decreasing SES in males, but not in females. The relationship of male suicide and SES was stronger when controlled for COB. For males, the relative risk of suicide, adjusted for age and COB, was 66% higher in the lowest SES quintile compared to the highest quintile, and 39% higher for youth (age 15-24 yr). For male suicide, the population attributable fraction for SES (less than the highest quintile) was 27%. Analysis of SES differentials in male suicide according to COB indicated a significant inverse suicide gradient in relation to SES for the Australian-born and those burn in New Zealand and the United Kingdom or fire. but not in non-English speaking COB groups, except for Asia. For Australian-born males, suicide risk was 71% higher in the lowest SES group (compared to the highest), adjusted for age. These findings indicate that SES plays an important role in male suicide rates among the Australian-born and migrants from English-speaking countries and Asia, and among youth; but not in female suicide, nor suicide in most non-English speaking migrant groups. Reduction in SES differentials through economic and social policies may reduce male suicide in lower SES groups and should be seen to be at least as important as individual level interventions. (C) 1998 Elsevier Science Ltd. All rights reserved.

Behavior and interactions of children in cooperative groups in lower and middle elementary grades

The study investigated the behaviors and interactions of children in structured and unstructured groups as they worked together on a 6-week social studies activity each term for 3 school terms. Two hundred and twelve children in Grade 1 and 184 children in Grade 3 participated in the study. Stratified random assignment occurred so that each gender-balanced group consisted of 1 high-, 2 medium-, and 1 low-ability student. The results show that the children in the structured groups were consistently more cooperative and they provided more elaborated and nonelaborated help than did their peers in the unstructured groups. The children in the structured groups in Grade 3 obtained higher reading and learning outcome scores than their peers in the unstructured groups.

Volatile solvent use among western Australian adolescents

Semistructured interviews were conducted with 40 adolescents who reported inhaling volatile solvents. Their average age was 14.2 years, and they used a range of substances. All were aware of the short-term health risks involved in volatile solvent use, and most reported experiencing ill effects, such as headaches and vomiting. Users were found to be organized into groups and peer networks, which often were involved in theft, prostitution, and other risk-taking behaviors. More chronic users had higher status within the group. Suggestions pertaining to intervention were obtained, and these are discussed in light of the findings.

In vitro human epidermal and polyethylene membrane penetration and retention of the sunscreen benzophenone-3 from a range of solvents

Purpose. To study epidermal and polyethylene membrane penetration and retention of the sunscreen benzophenone-3 (BP) from a range of single solvent vehicles and evaluate solvent effects on permeability parameters. Methods. The solubility of BP was measured in a number of solvents. Penetration of BP across human epidermis and high density polyethylene (HDPE) membranes was studied from 50% saturated solutions in each solvent. Results. Maximal BP fluxes from the solvents across the two membranes varied widely. Highest fluxes were observed from 90% ethanol (EtOH) for epidermis and from isopropyl myristate (IPM) and C12-15 benzoate alcohols (C12-15 BA) for HDPE membrane. Both the flux and estimated permeability coefficient and skin-vehicle partitioning of BP appeared to be related to the vehicle solubility parameter (delta(v)). The major effects of solvents on BP flux appear to be via changes in BP diffusivity through the membranes. Conclusions. Minimal penetration of sunscreens such as BP is best achieved by choosing vehicles with a delta(v) substantially different to the solubility parameter of the membrane.