Red and Blue Light Differently Influence Actinidia chinensis Performance and Its Interaction with Pseudomonas syringae pv. Actinidiae

Light composition modulates plant growth and defenses, thus influencing plant-pathogen interactions. We investigated the effects of different light-emitting diode (LED) red (R) (665 nm) and blue (B) (470 nm) light combinations on Actinidia chinensis performance by evaluating biometric parameters, chlorophyll a fluorescence, gas exchange and photosynthesis-related gene expression. Moreover, the influence of light on the infection by Pseudomonas syringae pv. actinidiae (Psa), the etiological agent of bacterial canker of kiwifruit, was investigated. Our study shows that 50%R-50%B (50R) and 25%R-75%B (25R) lead to the highest PSII efficiency and photosynthetic rate, but are the least effective in controlling the endophytic colonization of the host by Psa. Monochromatic red light severely reduced ΦPSII, ETR, Pn, TSS and photosynthesis-related genes expression, and both monochromatic lights lead to a reduction of DW and pigments content. Monochromatic blue light was the only treatment significantly reducing disease symptoms but did not reduce bacterial endophytic population. Our results suggest that monochromatic blue light reduces infection primarily by modulating Psa virulence more than host plant defenses.

Effects of simulated nitrogen deposition on the nutritional and physiological status of beech forests at two climatic contrasting sites in Italy

Anthropogenic activities have resulted in a significant increase of reactive nitrogen (N) compounds in the atmosphere and a rise in N deposition on forest ecosystems. Increasing N loads impact forest productivity and health, altering tree physiological status and nutrient balance with possible beneficial and detrimental consequences. The impact of N deposition has received considerable attention by scientific research, covering medium and high latitudes, while experimental studies in the Mediterranean area are almost absent. The present study used a manipulative approach, through replicated N additions (background deposition, 30, 60 kg N ha^-1yr^-1) to simulate the cumulative effects of N deposition in two beech (Fagus sylvaticaL.) forests located in contrasting climatic regions of Italy. Leaf nutrients and photosynthetic pigments were tested as monitoring indicators after four years of N fertilization. Foliar N and pigment concentrations indicated not limiting N conditions at both forest sites, although changes in chlorophylls and carotenoids showed an early response of the canopy to N additions. N-to-phosphorus (P) and sulfur (S) ratios increased under elevated N fertilization, which could be partly related to the relative enhancement of foliar N concentration, and partly associated with the reduction of foliar P and S. The two eutrophic beech forests monitored were not severely affected by chronic N addition, not showing critical nutritional and physiological impairments over the short to medium period. However, the modifications in leaf nutrient and pigment compositions showed an incipient stress response and accentuated the differences induced by climatic and soil characteristics at the two sites. The potential use of nutrients and photosynthetic pigments in monitoring forest N deposition under contrasting climatic conditions and the eventual limits of manipulative experiments are discussed.

Language and turn-taking in schizophrenia spectrum disorders

Introduction

Language and conversation are deeply interrelated: language is acquired, structured, practiced in social interactions and linguistic resources (specifically syntactic, prosodic and pragmatic aspects) contribute to finely tuning turn-taking. Nevertheless, most studies focused on verbal aspects of speech in schizophrenia, with scant attention to their relation to conversation, where language is experienced at most.

Objectives

The present study was aimed at investigating a possible association between language impairment and conversational characteristics in a sample of clinically stable patients diagnosed with schizophrenia (N = 35, ages 18-65).

Methods

A spontaneous speech sample was recorded. For the assessment of language skills, the Scale for the Assessment of Thought, Language and Communication (TLC) and the Clinical Language Disorder Rating Scale (CLANG) were used, while conversational variables were extracted with an innovative method of semi-automatic analysis. The possible associations were investigated through the Pearson Correlation.

Results

Figure 1 represents graphically the correlational matrix between conversational variables and linguistic scale scores. In the heatmap, blue means negative and red positive correlations, the stronger the colour, the larger the correlation magnitude. Moreover, the significant associations are indicated with stars.

Conclusions

The results suggest that in schizophrenia spectrum disorders the disturbances of language, at a syntactic, prosodic and pragmatic level, have significant impact on communicative interaction.

Thus, conversation analysis might be a promising method to quantify objectively communicative impairment with the benefit of representing an ecological assessment, examining the performance of patients in the real situation of language use, which is social interaction.

Disclosure

No significant relationships.

Peripersonal space plasticity in Schizophrenia: a motor training

Introduction

A primary disruption of the bodily self is considered a core feature of schizophrenia patients (SCZ). The “disembodied” self would be underpinned by an inefficient body-related multisensory integration mechanism occurring in the Peripersonal Space (PPS). PPS is a plastic sector of space surrounding our body, whose extent is altered in SCZ. Although PPS represents a malleable interface marking the perceptual border between self and others, no study has investigated the potential alteration of its plasticity in SCZ.

Objectives

We investigated the PPS extension and its plasticity in SCZ and their potential correlations with the clinical scales.

Methods

Thirty SCZ and thirty healthy controls (HC) underwent a multisensory task to estimate PPS boundary before and after a motor training. Patients were also administered the Positive And Negative Syndrome Scale (PANSS) and the Examination of Anomalous Self-Experience (EASE).

Results

Data confirm a narrower PPS extent in SCZ than in HC, whereas no differences in PPS expansion was found in the two groups after the motor training (Figure 1). Positive symptoms were associated directly with PPS extent and inversely with PPS plasticity. No associations were found between PPS and EASE domains. Figure1: Graphical representation of PPS expansion in SCZ and HC. Both panels show individual normalized sigmoid fits

Conclusions

The present study suggests a narrower PPS extent and a preserved PPS plasticity in SCZ with respect to HC. Both PPS extent and plasticity are related to the severity of positive symptoms. These results highlight the potential role of rehabilitation interventions in order to improve patients’ weakened body boundary.

Disclosure

No significant relationships.

SAT0557 RESIDUAL DISEASE ACTIVITY IN ADULT-ONSET STILL’S DISEASE: QUALITATIVE AND QUANTITATIVE ANALYSIS OF A SERIES OF 18F FDG-PET/MR

Background:

Adult-onset Still’s disease (AOSD) is a systemic autoinflammatory disorder characterized by episodes of spiking fever, the presence of an evanescent pink-salmon rash, arthritis/arthralgias, sore throat and increased inflammatory serum markers. The diagnosis is clinical and needs the exclusion of potential mimickers such as infections and lymphoproliferative disorders. Currently, a specific diagnostic test to assess the disease activity is not available.

Objectives:

To define the residual disease activity in AOSD and establish a possible response to therapy through18F-FDG PET/MR imaging technique.

Methods:

23 patients affected by AOSD and 24 controls underwent18F-FDG PET/MR between 2014 and 2018. A total of 5418F-FDG PET/MR were analysed. AOSD patients were diagnosed according to the Yamaguchi’s criteria and were in follow-up at the Rheumatology Unit of Padova University Hospital. The controls were chosen among non-AOSD patients with a previous diagnosis of solid tumors (lymphomas excluded). Aqualitative analysisof PET/RM carried out by a Nuclear Medicine Specialist and asemiquantitative analysiscarried out by measuring SUVs-to-liver (Standardized Uptake Value) for spleen, bone marrow (BM), lymph nodes and pharynx were performed. A SUVmax BM/SUVmean liver higher than 2.09 was set up as significant area of uptake for each organ considered. This threshold was calculated by adding the standard deviation multiplied by 2 at the mean ratio between SUVmax BM and SUVmean liver of the control group. The Pouchot score for disease activity was calculated for each subject. The distribution of the variables was investigated by Shapiro-Wilk test. The analysis of the association between the variables was carried out using the Mann-Whitney U test.

Results:

AOSD patients present areas of focal18F-FDG uptake mainly in BM, lymph nodes, pharynx, spleen and salivary glands. Sites of uptake in spleen were found in 3.3% of PET/MR, in BM in 23.3%, in lymph nodes in 23.3% and in pharynx in 36.6% of PET/RM respectively. Eleven/thirty (47.8%) patients were defined as “positive” since the uptake was higher than liver, and twelve/thirty (52.2%) were defined as “negative” since the uptake was lower than liver, regardless of SUVs and clinical manifestations. A semi-quantitative analysis assessed whether the values of the SUVmax BM/liver were higher than the cut-off of 2.09 in “positive” PET/MR and lower in the “negative” ones and if the clinical manifestations were present or absent in agreement with the evaluation of SUVs for each patient. BM was found to be active (SUVmax ratio > of 2.09) in 7 out of 11 patients when the PET/MR was defined “positive”, while only in 1 case out of 12 BM SUVmax was >2.09 when the exam was “negative”. Clinical manifestations were present in 10 out of 11 AOSD with a “positive” scan and in 7 out of 11 with both a “positive” scan and a SUV max BM/liver >2.09. Clinical manifestations were present in 1 out of 12 patients with a “negative” scan, while in 10 out of 12 cases with both a negative scan and a SUV max BM/liver <2.09 were absent. Six patients repeated PET/MR during follow-up. The values of the SUVmax BM/liver significantly decreased after anti IL-1β treatment with anakinra. In two cases in which anakinra was deferred, the BM SUVmax values exceeded the cut-off of 2.09 despite the patients did not complain any symptom or inflammation markers increase.

Conclusion:

18F FGD-PET/MR could be able to evaluate the disease activity in AOSD when clinical manifestations and serum markers are not sufficient to establish it. The uptake on BM seems quite sensitive in pointing out the disease severity and in assessing the response to anti IL-1β therapy.18F PET/MR is an accurate and repeatable method, however further studies are required to validate its applicability in routinary clinical practice.

Disclosure of Interests:

None declared

Nitrogen deposition outweighs climatic variability in driving annual growth rate of canopy beech trees: Evidence from long-term growth reconstruction across a geographic gradient

In this study, we investigated the role of climatic variability and atmospheric nitrogen deposition in driving long-term tree growth in canopy beech trees along a geographic gradient in the montane belt of the Italian peninsula, from the Alps to the southern Apennines. We sampled dominant trees at different developmental stages (from young to mature tree cohorts, with tree ages spanning from 35 to 160 years) and used stem analysis to infer historic reconstruction of tree volume and dominant height. Annual growth volume (G_V ) and height (G_H ) variability were related to annual variability in model simulated atmospheric nitrogen deposition and site-specific climatic variables, (i.e. mean annual temperature, total annual precipitation, mean growing period temperature, total growing period precipitation, and standard precipitation evapotranspiration index) and atmospheric CO₂ concentration, including tree cambial age among growth predictors. Generalized additive models (GAM), linear mixed-effects models (LMM), and Bayesian regression models (BRM) were independently employed to assess explanatory variables. The main results from our study were as follows: (i) tree age was the main explanatory variable for long-term growth variability; (ii) GAM, LMM, and BRM results consistently indicated climatic variables and CO₂ effects on G_V and G_H were weak, therefore evidence of recent climatic variability influence on beech annual growth rates was limited in the montane belt of the Italian peninsula; (iii) instead, significant positive nitrogen deposition (N_dep ) effects were repeatedly observed in G_V and G_H ; the positive effects of N_dep on canopy height growth rates, which tended to level off at N_dep values greater than approximately 1.0 g m^-2  y^-1 , were interpreted as positive impacts on forest stand above-ground net productivity at the selected study sites.

A global assessment of forest surface albedo and its relationships with climate and atmospheric nitrogen deposition

We present a global assessment of the relationships between the short-wave surface albedo of forests, derived from the MODIS satellite instrument product at 0.5° spatial resolution, with simulated atmospheric nitrogen deposition rates (Ndep ), and climatic variables (mean annual temperature Tm and total annual precipitation P), compiled at the same spatial resolution. The analysis was performed on the following five forest plant functional types (PFTs): evergreen needle-leaf forests (ENF); evergreen broad-leaf forests (EBF); deciduous needle-leaf forests (DNF); deciduous broad-leaf forests (DBF); and mixed-forests (MF). Generalized additive models (GAMs) were applied in the exploratory analysis to assess the functional nature of short-wave surface albedo relations to environmental variables. The analysis showed evident correlations of albedo with environmental predictors when data were pooled across PFTs: Tm and Ndep displayed a positive relationship with forest albedo, while a negative relationship was detected with P. These correlations are primarily due to surface albedo differences between conifer and broad-leaf species, and different species geographical distributions. However, the analysis performed within individual PFTs, strengthened by attempts to select 'pure' pixels in terms of species composition, showed significant correlations with annual precipitation and nitrogen deposition, pointing toward the potential effect of environmental variables on forest surface albedo at the ecosystem level. Overall, our global assessment emphasizes the importance of elucidating the ecological mechanisms that link environmental conditions and forest canopy properties for an improved parameterization of surface albedo in climate models.

Structure, function and control of complement C5 and its proteolytic fragments

As part of the innate immune system, the complement system recognises a wide range of non-self structures present on pathogens or altered self cells. Its activation elicits proteolytic cascades which eventually results in the cleavage of the C5 protein into two fragments, C5a and C5b. The small anaphylatoxin C5a induces a variety of biological responses upon binding to the 7TM receptors C5aR and the C5L2, while the large C5b fragment nucleates formation of the membrane attack complex capable of killing susceptible pathogens by the formation of a pore structure in association with complement components C6, C7, C8, and C9. A number of regulatory molecules help to control C5 mediated immune responses towards host cells, but in several major inflammatory conditions including sepsis and arthritis, C5a is believed to contribute significantly to disease etiology. Inhibition of membrane attack complex assembly is already approved for treatment of paroxysmal nocturnal haemoglobinuria and atypical hemolytic uremic syndrome. A number of recent crystal structures have provided a comprehensive insight into the architecture and properties of intact C5 and its fragments, and how pathogens interfere with their function. Here we review the functional and structural aspects of C5 and its fragments, the pathological conditions associated with them, and strategies employed by pathogens to interfere with the biological function of C5. Structural insight and elucidation of evasion strategies employed by pathogens present a unique opportunity for promoting the development of novel selective C5 inhibitors with therapeutic applications.

Assessing the effects of nitrogen deposition and climate on carbon isotope discrimination and intrinsic water-use efficiency of angiosperm and conifer trees under rising CO2 conditions

The objective of this study is to globally assess the effects of atmospheric nitrogen deposition and climate, associated with rising levels of atmospheric CO2 , on the variability of carbon isotope discrimination (Δ(13) C), and intrinsic water-use efficiency (iWUE) of angiosperm and conifer tree species. Eighty-nine long-term isotope tree-ring chronologies, representing 23 conifer and 13 angiosperm species for 53 sites worldwide, were extracted from the literature, and used to obtain long-term time series of Δ(13) C and iWUE. Δ(13) C and iWUE were related to the increasing concentration of atmospheric CO2 over the industrial period (1850-2000) and to the variation of simulated atmospheric nitrogen deposition and climatic variables over the period 1950-2000. We applied generalized additive models and linear mixed-effects models to predict the effects of climatic variables and nitrogen deposition on Δ(13) C and iWUE. Results showed a declining Δ(13) C trend in the angiosperm and conifer species over the industrial period and a 16.1% increase of iWUE between 1850 and 2000, with no evidence that the increased rate was reduced at higher ambient CO2 values. The temporal variation in Δ(13) C supported the hypothesis of an active plant mechanism that maintains a constant ratio between intercellular and ambient CO2 concentrations. We defined linear mixed-effects models that were effective to describe the variation of Δ(13) C and iWUE as a function of a set of environmental predictors, alternatively including annual rate (Nrate ) and long-term cumulative (Ncum ) nitrogen deposition. No single climatic or atmospheric variable had a clearly predominant effect, however, Δ(13) C and iWUE showed complex dependent interactions between different covariates. A significant association of Nrate with iWUE and Δ(13) C was observed in conifers and in the angiosperms, and Ncum was the only independent term with a significant positive association with iWUE, although a multi-factorial control was evident in conifers.

Variability of stomatal conductance in a small and isolated population of silver fir (Abies alba Mill.)

We analyzed the response to drought of 420 individuals from eight half-sib families from a small and isolated population of silver fir (Abies alba Mill.): 105 of them were kept in well-watered conditions as control while the remaining 315 were exposed to drought for 27 days. A model describing stomatal behavior derived from Monteith and developed in beech by Leonardi et al. was fitted to experimental transpiration data obtained simply from the difference between two daily pot weighings. The estimated parameters were maximum stomatal conductance, maximum transpiration in well-watered conditions and sensitivity to soil water deficit. The model worked well: convergence for all but four individuals and concordance between experimental and fitted data were good (R(2)=0.86). Inter-individual variability for all three estimated parameters was high and two of them (maximum stomatal conductance and sensitivity to soil water deficit) were significantly different among families, suggesting genetic control. Our results validate the simplified method used to evaluate individual stomatal parameters. We also show that in the small and isolated population of our study substantial adaptive variability remains, a crucial prerequisite to endure environmental conditions determined by climatic change foreseen for the next decades.

Effectiveness of the photochemical reflectance index to track photosynthetic activity over a range of forest tree species and plant water statuses

In this study, we investigated the potential of the photochemical resistance index (PRI) to track photosynthetic activity under water stress conditions by measuring PRI, leaf fluorescence, the xanthophyll cycle and photosynthetic activity in different forest tree species subjected to progressive drought. The PRI declined with pre-dawn water potential and a significant relationship between PRI and the xanthophyll de-epoxidation state (DEPS) was observed, although with large interspecific variability in the sensitivity of PRI to changes in DEPS. For single tree species, a strong relationship was observed on either PRI light saturated photosynthesis or PRI maximum photochemical efficiency of PSII (ΔF/Fm'); a larger variability in both relationships was apparent when data from different species were pooled together. However, an improved correlation was shown only in the former relationship by plotting the ΔPRI (dawn PRI minus the midday PRI values). Thus, we conclude that PRI is able to provide a good estimate of maximum CO2 assimilation at saturating light and ΔF/Fm' for single tree species, despite the severe drought conditions applied. PRI should be applied more cautiously when dealing with multispecific forests because of confounding factors such as the strong interspecific differences in the initial value of PRI and in the sensitivity of PRI to changes in DEPS in response to drought.

Sanio?s laws revisited. Size-dependent changes in the xylem architecture of trees

Early observations led Sanio [Wissen. Bot., 8, (1872) 401] to state that xylem conduit diameters and lengths in a coniferous tree increase from the apex down to a height below which they begin to decrease towards the tree base. Sanio's law of vertical tapering has been repeatedly tested with contradictory results and the debate over the scaling of conduit diameters with distance from the apex has not been settled. The debate has recently acquired new vigour, as an accurate knowledge of the vertical changes in wood anatomy has been shown to be crucial to scaling metabolic properties to plant and ecosystem levels. Contrary to Sanio's hypothesis, a well known model (MST, metabolic scaling theory) assumes that xylem conduits monotonically increase in diameter with distance from the apex following a power law. This has been proposed to explain the three-fourth power scaling between size and metabolism seen across plants. Here, we (i) summarized available data on conduit tapering in trees and (ii) propose a new numerical model that could explain the observed patterns. Data from 101 datasets grouped into 48 independent profiles supported the notions that phylogenetic group (angiosperms versus gymnosperms) and tree size strongly affected the vertical tapering of conduit diameter. For both angiosperms and gymnosperms, within-tree tapering also varied with distance from the apex. The model (based on the concept that optimal conduit tapering occurs when the difference between photosynthetic gains and wall construction costs is maximal) successfully predicted all three major empirical patterns. Our results are consistent with Sanio's law only for large trees and reject the MST assumptions that vertical tapering in conduit diameter is universal and independent of rank number.

The human footprint in the carbon cycle of temperate and boreal forests

Temperate and boreal forests in the Northern Hemisphere cover an area of about 2 x 10(7) square kilometres and act as a substantial carbon sink (0.6-0.7 petagrams of carbon per year). Although forest expansion following agricultural abandonment is certainly responsible for an important fraction of this carbon sink activity, the additional effects on the carbon balance of established forests of increased atmospheric carbon dioxide, increasing temperatures, changes in management practices and nitrogen deposition are difficult to disentangle, despite an extensive network of measurement stations. The relevance of this measurement effort has also been questioned, because spot measurements fail to take into account the role of disturbances, either natural (fire, pests, windstorms) or anthropogenic (forest harvesting). Here we show that the temporal dynamics following stand-replacing disturbances do indeed account for a very large fraction of the overall variability in forest carbon sequestration. After the confounding effects of disturbance have been factored out, however, forest net carbon sequestration is found to be overwhelmingly driven by nitrogen deposition, largely the result of anthropogenic activities. The effect is always positive over the range of nitrogen deposition covered by currently available data sets, casting doubts on the risk of widespread ecosystem nitrogen saturation under natural conditions. The results demonstrate that mankind is ultimately controlling the carbon balance of temperate and boreal forests, either directly (through forest management) or indirectly (through nitrogen deposition).

A simple general method to evaluate intra-specific transpiration parameters within and among seedling families

A method to evaluate the genetic control of plant response to increasing soil water deficit is proposed. A description of single tree transpiration behavior was obtained considering parameters independent from air and soil conditions. We removed environmental effects by using two approaches: the normalization of drought data to control (watered) plants and the fitting of a process model. We analyzed the transpiration of 475 4-year-old European beech seedlings, belonging to eight full-sib families. Approximately, one-third of the seedlings were kept in well-watered conditions while the others were exposed to drought for 14 days. Daily plant transpiration was estimated as the difference between two subsequent gravimetric measurements. A mechanistic model was fitted to transpiration data separately for each tree. In the model, the relationship of transpiration with vapor pressure deficit and soil water deficit of each tree is modulated by three parameters: maximum leaf conductance (gM1), maximum transpiration in well-watered soil conditions E(M0)1 and a parameter describing stomatal sensitivity to soil water deficit (c). The model successfully fitted most single tree data and a distribution of estimates for the three parameters (gM1, E(M0)1 and c) was obtained. Predicted transpiration values were in good agreement with observed data (R (2) = 0.86). The model approach produced parameters significantly correlated with those of the "normalization to control" approach. Estimated parameters vary considerably among trees, suggesting the presence of individual differences in stomatal behavior and response to drought. In spite of a large among tree (within family) variation, the among families component for gM1, E(M0)1 and c explained 9.5, 3.3 and 0.1% of total parameters variation suggesting a significant genetic control of transpiration processes.

Seasonal and interannual variability of photosynthetic capacity in relation to leaf nitrogen in a deciduous forest plantation in northern Italy

Gas exchange was measured in a forest plantation dominated by Fraxinus angustifolia Vahl. and Quercus robur L. in northern Italy, over three growing seasons that differed in water availability (2001, 2002 and 2003). The objectives were to: (1) determine variability in the photosynthetic parameters V(cmax) (maximum carboxylation capacity) and J(max) (maximum rate of electron transport) in relation to species, leaf ontogeny and drought; and (2) assess the potential of the photosynthesis-nitrogen relationship for estimating leaf photosynthetic capacity. Marked seasonal and interannual variability in photosynthetic capacity was observed, primarily caused by changes in leaf ontogeny and water stress. Relatively small differences were apparent between species. In the absence of water stress (year 2002), the seasonal patterns of V(cmax) and J(max) were characterized by a rapid increase during spring, a relatively steady state during summer and a rapid decline during autumn. In years with a moderate (year 2001) or a severe (year 2003) water stress, photosynthetic capacity decreased during the summer in proportion to drought intensity, without a parallel decline in leaf nitrogen content. The V(cmax)-nitrogen relationship was significantly affected by both leaf ontogeny and drought. As a consequence, the use of a single annual regression to predict V(cmax) from leaf nitrogen yielded good estimates only during the summer and in the absence of water stress. Irrespective of the mechanisms by which photosynthetic capacity is affected by water stress, its large seasonal and interannual variability is of great relevance for modeling the forest carbon cycle.

Maternal body composition at term gestation and birth weight: is there a link?

To assess the relative influence of maternal body composition at late gestation on birth weight, we examined maternal body composition near term (36.50+/-2.67 weeks gestation) in a group of 29 women, aged 20-39 years. The women came to the laboratory after an overnight fast. After anthropometric measurements, bioelectrical impedance analysis (BIA) was performed, determining resistance (R) and reactance (Xc), with a Tefal scale at 50 kHz. Fat mass (FM, kg) and fat-free mass (FFM, kg) were determined with the total body water (TBW) equation of Siri. The correlation between BIA parameters and birth weights was examined by linear regression analysis. All subjects delivered between 37 and 41 weeks' gestation. The mean+/-SD values of the studied parameters were: Xc=490.00+/-77.34 ohm, R=55.71+/-8.71 ohm, FM=24.18+/-6.51 kg, FFM=45.82+/-2.65 kg, maternal weight gain=9.51+/-6.43 kg, birth weight=3.43+/-0.36 kg. A direct significant correlation was found between FFM, maternal weight gain, and birth weight. It is known that in late pregnancy, maternal weight gain over gestation is linked to birth weight. We observed that FFM was the most important maternal body component associated with the newborn weight at term gestation, and we believe that this finding might be elucidated by fluid retention. In fact, resistance seemed to be inversely related to birth weight and we do not overlook the link between resistance and TBW. The implementation of our study could shed more light on the influence of maternal body composition on birth weight.

Postpartum thyroiditis is associated with fluctuations in transforming growth factor-beta1 serum levels

Postpartum thyroiditis (PPT) is characterized by a rapid evolution and recovery of euthyroidism. Therefore, it can represent a good model to study early cytokine fluctuations in autoimmune thyroid diseases. TGFbeta1 is an immunosuppressive cytokine, as it inhibits T and B cell proliferation, natural killer cell cytotoxic activity, and the generation of T cell cytotoxicity. The aim of this study was to assess serum concentrations of TGFbeta1 during pregnancy and to study possible serum fluctuations of this cytokine during the different phases of PPT. Thyroid biochemical pattern, antithyroid autoantibodies (ATA), and total and active TGFbeta1 (aTGFbeta1) serum concentrations were evaluated in 63 pregnant women. Thirty-four of them were ATA(+), and 29 were ATA(-). Twenty of the 34 ATA(+) women were followed in the postpartum year. Nine of these 20 women developed PPT; 11 remained euthyroid. All of the PPT women became euthyroid during the follow-up. Our results showed 1) detectable serum levels of aTGFbeta1 in 50% of ATA(+) pregnant women, suggesting that the presence of autoantibodies may characterize a favorable condition for TGFbeta1 activation; and 2) decreased total TGFbeta1 and increased aTGFbeta1 serum levels during the active phase of PPT in ATA(+) women. This seems to suggest that inflammation may be responsible for TGFbeta1 activation and autoantibody increase because of antigen release. Although further studies of women with persistent hypothyroidism after the postpartum year are needed, the possibility that the enhanced activation of TGFbeta1 may contribute to resolution of thyroid inflammation postpartum cannot be excluded.

Response of a mature Pinus laricio plantation to a three-year restriction of water supply: structural and functional acclimation to drought

The response of mature forest stands to a reduction in water availability has received little attention. In particular, the extent to which a short-term reduction in gas exchange can be alleviated in the long-term by acclimation processes is not well understood. We studied the impact of a severe reduction in water availability on the water relations and growth of 35-year-old Pinus laricio Poiret. trees in a replicated experiment. Sapwood and needle increments, soil and tree water status, stand transpiration, xylem embolism and plant hydraulic architecture were monitored over a 3-year period in control and drought-treated plots. Needle length was reduced in drought-treated trees by 30, 19 and 29%, and sapwood increments by 50, 27 and 24% over the 3 years. Drought did not result in tree mortality or in extensive xylem embolism or foliage dieback. On the contrary, a conservative water-use strategy was observed, because minimum leaf water potentials did not differ between treatments or over the season. Plant hydraulic resistance was also unaffected by restricted water availability. Stand transpiration was strongly reduced by drought treatment over the summer, but not during the winter, despite significant differences in leaf area between control and drought-treated trees, implying higher transpiration rates per unit leaf area in the droughted plants. This suggests that water transport capacity, rather than the amount of leaf area, controlled stand transpiration, which is at variance with expectations based on experiments with seedlings and short-term experiments with mature trees.

Regulation of the serotonin transporter by interacting proteins

The serotonin transporter (SERT) plays a critical role in the maintenance of normal neurotransmission by serotonin [5-hydroxytryptamine (5-HT)]. Recent evidence suggests that SERT and other neurotransmitter transporters are tightly regulated. Activation of protein kinase C results in a decrease in SERT-mediated 5-HT uptake, which is due to an internalization of the transporter. However, to date little is known about the mechanism and proteins involved in the down-regulation of the transporter. One candidate SERT-regulatory protein is the SNARE (soluble N-ethylmaleimide-sensitive factor-attachment protein receptor) protein, syntaxin 1A (Syn1A), which has recently been implicated in the regulation of ion channels as well as the SERT-related gamma-aminobutyric acid- and glycine-transporters. Using 5-HT uptake assays, confocal microscopy and glutathione S-transferase (GST) pull-down assays we showed that Syn1A also interacts with SERT and alters the subcellular localization of the transporter, resulting in a reduction of 5-HT transport. In addition, we have used the yeast two-hybrid system to search for novel regulatory proteins that interact with the cytoplasmic N-terminal domain of SERT. By screening rat brain cDNA library we have identified six potential SERT-binding proteins. Here we also present progress towards the elucidation of the biological relevance of these proteins and their potential role for the regulation of the serotonin transporter.

High frequency of antithyroid autoantibodies in pregnant women at increased risk of gestational diabetes mellitus

BACKGROUND

Thyroid autoantibodies (ThyAb) and subclinical hypothyroidism occur more frequently in pregnant women with insulin-dependent diabetes mellitus than in healthy pregnant women. Few studies have investigated the presence of ThyAb in women with gestational diabetes mellitus (GDM), and no significant association between diabetes in pregnancy and thyroid function has been reported.

OBJECTIVE

To assess the thyroid biochemical profile and estimate the prevalence of ThyAb in a group of pregnant women at increased risk of GDM due to family and personal risk factors, and to investigate the relationship between a positive family history of diabetes or thyroid diseases and the eventual presence of ThyAb during pregnancy.

METHODS

Oral glucose tolerance, serum ThyAb and thyroid function were evaluated in 181 pregnant women with increased risk for GDM (study group). Seventeen healthy pregnant women without risk factors for GDM and with a normal glucose tolerance were recruited as controls.

RESULTS

The women who developed GDM showed a mean free thyroxine concentration significantly lower than that observed in the healthy pregnant women and in those with impaired gestational glucose tolerance and normal glucose tolerance. Twenty-nine of the 181 women in the study group (16%) were ThyAb positive. However, the risk of being ThyAb positive during pregnancy was three times greater in the women with positive family history of both diabetes mellitus and thyroid disease than in those with no family history of these conditions.

CONCLUSIONS

This study showed that women with increased risk of GDM, mostly those with family history of diabetes mellitus and thyroid disease, also have an increased risk of being ThyAb positive during pregnancy. It also highlighted the importance of evaluating thyroid function in pregnant women with impaired glucose tolerance, in view of their increased risk of subclinical hypothyroidism.

Multifrequency bioelectrical impedance analysis in women with a normal and hypertensive pregnancy

BACKGROUND

An increase in total body water is common in normal pregnancy. It is thought to be an important mechanism of maternal adaptation to pregnancy.

OBJECTIVE

The aim of the present study was to assess longitudinal changes in body water compartments in pregnant women and to correlate these measurements with the course of pregnancy.

DESIGN

One hundred seventy-three pregnant women with apparently normal, single pregnancies participated in this longitudinal study. Anthropometric measurements and multifrequency bioelectrical impedance were performed during the first, second, and third trimesters of pregnancy.

RESULTS

One hundred three of the women completed all of the measurements; 50 of the women had a normal pregnancy and 13 had gestational hypertension. Total body water, extracellular water, and intracellular water values in normal pregnancies showed a significant, progressive increase throughout pregnancy. In women with gestational hypertension, total body water, extracellular water, and intracellular water values showed an opposite trend, suggesting a lack of plasma volume expansion through fluid-retention mechanisms.

CONCLUSIONS

Our results show that multifrequency bioelectrical impedance analysis can be used to monitor variations in body water compartments in normal pregnancy and detect gestational hypertension.

Is neuronal nitric oxide involved in adjuvant-induced joint inflammation?

Several reports have described a role of macrophagic, endothelial and synoviocytal nitric oxide (NO) in inflammation, immunity and sensory processes in joint diseases. In view of the role of the peripheral nervous system in arthritis and owing to the presence of NO-producing neurons in primary sensory neurons, we have investigated the possible role of neuronal NO during adjuvant-induced joint inflammation in rats. Neural nitric oxide synthase production in sensory ganglia and the spinal cord was investigated by in situ hybridization and immunocytochemistry. Neuronal NO synthase mRNA expression and neuronal NO synthase immunoreactivity increased in lumbar dorsal root ganglia in arthritic rats compared to those of normal rats, whereas neuronal NO synthase mRNA expression decreased in lamina X and lamina I-II of the lumbar spinal cord. The administration of the selective neuronal NO synthase inhibitor 7-nitro indazole, reduced the joint inflammation, whereas the administration of the inducible NO synthase selective inhibitor, aminoguanidine, had no effect on inflammation when administered daily from the third day after adjuvant. These findings could indicate a role for neural NO in adjuvant arthritis.

The response of Pinus sylvestris to drought: stomatal control of transpiration and hydraulic conductance

We investigated the impact of drought on the physiology of 41-year-old Scots pine (Pinus sylvestris L.) in central Scotland. Measurements were made of the seasonal course of transpiration, canopy stomatal conductance, needle water potential, xylem water content, soil-to-needle hydraulic resistance, and growth. Comparison was made between drought-treated plots and those receiving average precipitation. In response to drought, transpiration rate declined once volumetric water content (VWC) over the top 20 cm of soil reached a threshold value of 12%. Thereafter, transpiration was a near linear function of soil water content. As the soil water deficit developed, the hydraulic resistance between soil and needles increased by a factor of three as predawn needle water potential declined from -0.54 to -0.71 MPa. A small but significant increase in xylem embolism was detected in 1-year-old shoots. Stomatal control of transpiration prevented needle water potential from declining below -1.5 MPa. Basal area, and shoot and needle growth were significantly reduced in the drought treatment. In the year following the drought, canopy stomatal conductance and soil-to-needle hydraulic resistance recovered. Current-year needle extension recovered, but a significant reduction in basal area increment was evident one year after the drought. The results suggest that, in response to soil water deficit, mature Scots pine closes its stomata sufficiently to prevent the development of substantial xylem embolism. Reduced growth in the year after a severe soil water deficit is most likely to be the result of reduced assimilation in the year of the drought, rather than to any residual embolism carried over from one year to the next.

Thyroid autoimmunity in pregnant women at risk for GDM

Presence of antithyroid autoantibodies (ThyAb) during pregnancy is strictly related to the risk of developing post partum thyroiditis (PPT) and this risk is increased in IDDM pregnant women. Gestational diabetes mellitus (GDM) is defined as carbohydrate intolerance of variable severity that begins, or is first diagnosed, during pregnancy. GDM is considered a risk factor for both type 1 and type 2 diabetes and various non-organ specific autoantibodies have been found to be associated with GDM, although there is little information on the association of GDM with thyroid autoimmunity. In this study oral glucose tolerance and prevalence of ThyAb were evaluated in a group of 41 pregnant women at increased risk of developing GDM and in a healthy control group. Our results showed that 22% of GDM risk group had impaired glucose gestational tolerance (IGGT) or GDM at the time of oral glucose tolerance test (OGTT). Moreover, ThyAb prevalence found in the women at increased risk of GDM (14.6%) was similar to that observed in healthy pregnant controls (12.5%). Nevertheless ThyAb frequency was higher in those GDM risk women with family history of diabetes (30.7%).

Occupational genotoxicity assessment by mutagenicity assays

Mutagenic activity measured by Ames test and by gene conversion, point mutation and mitochondrial mutability in Saccharomyces cerevisiae D7 strain was determined in the indoor environment of a glass factory. The results suggest that the increase in mutagenicity of air sample collected near the machinery is due to the thermal decomposition of oils. Modified assays were therefore compared for their ability to detect mutagens contained in urinary concentrates of exposed workers. The bacterial tests were performed by microsuspension assay in TA98, TA100 strains and in YG1024, YG1029 strains which overproduce O-acetyltransferase. Significant differences are evidenced both in the eukaryotic and prokaryotic systems.

[Nose disease caused by occupational exposure to chromium in the electroplating industry: cytomorphological aspects]

Twenty-six workers were studied (9 chrome-platers exposed to chromium dioxide and 17 workers exposed to metallic chromium dust) in order to investigate the macroscopic and cytological changes of the nasal mucosa due to exposure to water-soluble hexavalent chromium or to metallic chromium dust in the electroplating industry and the role of different valencies in the onset of nasal disease. Experimental and epidemiological data have shown that hexavalent chromium, which has strong oxidative power, induces more noticeable toxic effects on tissues and mucous membranes than other compounds. The correlation between the degree of local toxic effects and the chemical state of chromium was demonstrated in both the macro- and the microscopic investigations and in particular in the cytological examinations: cases of atypia were found only in workers exposed to hexavalent chromium. Evidence of atypia raises the question of whether hexavalent chromium may act as a carcinogenic agent on the rhinosinusal mucosa. For this reason, the introduction of cytological nasal examination in health surveillance programmes for this category of workers acquires considerable importance. Sample collection from the nasal mucosa by brushing is the method of choice since it is simple, non-invasive and gives good diagnostic results.

Phase II double-blind randomized study of lonidamine and radiotherapy in epidermoid carcinoma of the lung

Patients with non metastatic squamous cell lung cancer were treated with radiotherapy (RT) plus lonidamine (LND) or placebo (PLAC), according to a randomized double-blind study design. Treatment with lonidamine 150 mg t.i.d. (27 patients) or placebo (23 patients) started 3 days before RT, lasted up to 7 months. Partial responses were observed in 14 and 6 patients respectively in the LND + RT and PLAC + RT groups. Statistical analysis of the survival curves showed no significant difference between the LND + RT (median 311 days) and PLAC + RT (median 193 days) groups. Stage III patients survived significantly longer (p less than 0.05) when treated with LND + RT (median 318 days) than with PLAC + RT (median 163 days). No synergistic toxic effects between radiation and LND were noted. To confirm these data a new and larger multicentric study is now in progress.

[Medical docimology in radiology]

The authors report the experience of computerized integrated didactics on trial at the Institute of Radiology of the University of Catania. Students majoring in Medicine undergo a propaedeutic written test, consisting in a number of multiple choice questions, before proceeding to the oral examination in radiology. The procedures preceding the test and those following it are accomplished with the aid of a computer. The authors discuss the docimological motivations, the specifications of the system and the results obtained after a trial period.

Mortality experience among chromeplating workers. Initial findings

A retrospective cohort study was conducted in nine chromeplating plants to examine the mortality of workers employed for at least one year during the period January 1951-December 1981. The study group totaled 178 individuals, 116 of whom were from "hard" and 62 from "bright" chromeplating plants. Vital status ascertainment was 97% complete. The total number of deaths was fairly close to the expected figure (15 observed, 15.2 expected), whereas deaths from tumors exceeded the expected number (8 observed, 4.2 expected). Individuals were distinguished into two subcohorts depending on the exposure intensity, which was much higher in hard than in bright chromeplating. Most deaths from cancer occurred among hard chromium platers, the excess against the expected rate being statistically significant (7 observed, 2.7 expected, p = 0.02). All deaths from lung cancer occurred in this subcohort (3 observed, 0.7 expected, p = 0.03). The increased mortality from cancer among chromium platers seems to be related to exposure intensity and strongly suggests the need for further studies on larger cohorts to confirm the carcinogenicity of chromic acid in man.