Leaf-level coordination principles propagate to the ecosystem scale

Fundamental axes of variation in plant traits result from trade-offs between costs and benefits of resource-use strategies at the leaf scale. However, it is unclear whether similar trade-offs propagate to the ecosystem level. Here, we test whether trait correlation patterns predicted by three well-known leaf- and plant-level coordination theories - the leaf economics spectrum, the global spectrum of plant form and function, and the least-cost hypothesis - are also observed between community mean traits and ecosystem processes. We combined ecosystem functional properties from FLUXNET sites, vegetation properties, and community mean plant traits into three corresponding principal component analyses. We find that the leaf economics spectrum (90 sites), the global spectrum of plant form and function (89 sites), and the least-cost hypothesis (82 sites) all propagate at the ecosystem level. However, we also find evidence of additional scale-emergent properties. Evaluating the coordination of ecosystem functional properties may aid the development of more realistic global dynamic vegetation models with critical empirical data, reducing the uncertainty of climate change projections.

Heatwave breaks down the linearity between sun-induced fluorescence and gross primary production

Sun-induced fluorescence in the far-red region (SIF) is increasingly used as a remote and proximal-sensing tool capable of tracking vegetation gross primary production (GPP). However, the use of SIF to probe changes in GPP is challenged during extreme climatic events, such as heatwaves. Here, we examined how the 2018 European heatwave (HW) affected the GPP-SIF relationship in evergreen broadleaved trees with a relatively invariant canopy structure. To do so, we combined canopy-scale SIF measurements, GPP estimated from an eddy covariance tower, and active pulse amplitude modulation fluorescence. The HW caused an inversion of the photosynthesis-fluorescence relationship at both the canopy and leaf scales. The highly nonlinear relationship was strongly shaped by nonphotochemical quenching (NPQ), that is, a dissipation mechanism to protect from the adverse effects of high light intensity. During the extreme heat stress, plants experienced a saturation of NPQ, causing a change in the allocation of energy dissipation pathways towards SIF. Our results show the complex modulation of the NPQ-SIF-GPP relationship at an extreme level of heat stress, which is not completely represented in state-of-the-art coupled radiative transfer and photosynthesis models.

The three major axes of terrestrial ecosystem function

The leaf economics spectrum^1,2 and the global spectrum of plant forms and functions³ revealed fundamental axes of variation in plant traits, which represent different ecological strategies that are shaped by the evolutionary development of plant species². Ecosystem functions depend on environmental conditions and the traits of species that comprise the ecological communities⁴. However, the axes of variation of ecosystem functions are largely unknown, which limits our understanding of how ecosystems respond as a whole to anthropogenic drivers, climate and environmental variability^4,5. Here we derive a set of ecosystem functions⁶ from a dataset of surface gas exchange measurements across major terrestrial biomes. We find that most of the variability within ecosystem functions (71.8%) is captured by three key axes. The first axis reflects maximum ecosystem productivity and is mostly explained by vegetation structure. The second axis reflects ecosystem water-use strategies and is jointly explained by variation in vegetation height and climate. The third axis, which represents ecosystem carbon-use efficiency, features a gradient related to aridity, and is explained primarily by variation in vegetation structure. We show that two state-of-the-art land surface models reproduce the first and most important axis of ecosystem functions. However, the models tend to simulate more strongly correlated functions than those observed, which limits their ability to accurately predict the full range of responses to environmental changes in carbon, water and energy cycling in terrestrial ecosystems^7,8.

On the importance of root traits in seedlings of tropical tree species

Plant biomass allocation may be optimized to acquire and conserve resources. How trade-offs in the allocation of tropical tree seedlings depend on different stressors remains poorly understood. Here we test whether above- and below-ground traits of tropical tree seedlings could explain observed occurrence along gradients of resources (light, water) and defoliation (fire, herbivory). We grew 24 tree species occurring in five African vegetation types, varying from dry savanna to moist forest, in a glasshouse for 6 months, and measured traits associated with biomass allocation. Classification based on above-ground traits resulted in clusters representing savanna and forest species, with low and high shoot investment, respectively. Classification based on root traits resulted in four clusters representing dry savanna, humid savanna, dry forest and moist forest, characterized by a deep mean rooting depth, root starch investment, high specific root length in deeper soil layers, and high specific root length in the top soil layer, respectively. In conclusion, tree seedlings in this study show root trait syndromes, which vary along gradients of resources and defoliation: seedlings from dry areas invest in deep roots, seedlings from shaded environments optimize shoot investment, and seedlings experiencing frequent defoliation store resources in the roots.

Beam and installation improvements of the NIO1 ion source

The NIO1 (Negative Ion Optimization phase 1) source can provide continuous beam operation, which is convenient for systematic parameter and equipment studies. Even in the pure volume production regime, the source yield was found to depend on conditioning procedures. Magnetic configuration tests continued adding magnets to the existing setup; the filter field component B_x has been progressively extended to span the -12 to 5 mT range, and as a trend, source performances improved with |B_x|. The progress of camera beam diagnostics and of the quality of the volume-produced H^- beam is also shown. The status, off-line results, and reliability of a first NIO1 cesium oven are discussed; other upgrades in preparation (cavity ring down spectrometer, the end calorimeter, and conceptual tests of the energy recovery system) are also listed.

Claimed effects, outcome variables and methods of measurement for health claims proposed under regulation (EC) 1924/2006 and related to cognitive function in adults

Some food/food components have been the object of request of authorization to the use of health claims related to cognitive function in adults and compliant with the Regulation (EC) 1924/2006. Most of the requests have received a negative opinion by the European Food Safety Authority (EFSA) also because of the choice of not appropriate outcome variables (OVs) and methods of measurement (MMs) selected in the trials used to substantiate the claim. This manuscript referes to the collection, collation and critical analysis of OVs and MMs related to cognitive function in adults. OVs and MMs were collected from the EFSA Guidance document and the applications for authorization of health claims pursuant to the Articles 13(5). The critical analysis of OVs and MMs, performed by a literature review, was aimed at defining their appropriateness in the context of a specific claimed effect. The results highlight the importance of an adequate choice of OVs and MMs for an effective substantiation of the claims related to cognitive functioning. The information provided in this document may serve to EFSA for updating the guidance on the scientific requirements for health claims related to cognitive functions, but also for a better design of randomized controlled trials aimed at substantiating such health claims.

Claimed effects, outcome variables and methods of measurement for health claims proposed under European Community Regulation 1924/2006 in the framework of protection against oxidative damage and cardiovascular health

BACKGROUND AND AIMS

The high number of negative opinions from the European Food Safety Authority (EFSA) to the requests for authorization of health claims is largely due to the design of human intervention studies, including the inappropriate choice of outcome variables (OVs) and of their methods of measurement (MMs). The present manuscript reports the results of an investigation aimed to collect, collate and critically analyse the information in relation to claimed effects, OVs and MMs, in the context of protection against oxidative damage and cardiovascular health compliant with Regulation 1924/2006.

METHODS AND RESULTS

Claimed effects, OVs and the related MMs were collected from EFSA Guidance documents and applications for authorization of health claims under Articles 13.5 and 14. The OVs and their MMs were evaluated only if the claimed effect was sufficiently defined and was considered beneficial by EFSA. The collection, collation and critical analysis of the relevant scientific literature consisted in the definition of the keywords, the PubMed search strategies and the creation of databases of references. The critical analysis of the OVs and their MMs was performed on the basis of the literature review and was aimed at defining the appropriateness of OVs and MMs in the context of the specific claimed effects.

CONCLUSIONS

The information provided in this document could serve to EFSA for the development of further guidance on the scientific requirements for health claims, as well as to the stakeholders for the proper design of human intervention studies aimed to substantiate such health claims.

Application of the Ta liner technique to produce Ca beams at INFN-Legnaro National Laboratories (INFN-LNL)

The ECR ion sources are able to produce a wide variety of highly charged metallic ion beams thanks to the development of different techniques (ovens, sputtering, direct insertion, metal ions from volatile compounds (MIVOC)). In the case of the ovens, the sticking of the hot vapors on the surface of the plasma chamber leads to high material consumption rates. For elements like Ca, a tantalum liner inserted inside the chamber can be used to limit this phenomenon. The modeling of temperature distribution inside the chamber with and without the liner was carried out with COMSOL-multiphysics code. Results of simulation and the comparison with experiments performed at INFN-Legnaro National Laboratories with Ca beams are discussed.

Dentin matrix protein 1 and dentin sialophosphoprotein in human sound and carious teeth: an immunohistochemical and colorimetric assay

Dentin matrix protein 1 (DMP1) and dentin sialophosphoprotein (DSPP) are extracellular matrix proteins produced by odontoblasts involved in the dentin mineralization. The aim this study was to compare the distribution of DMP1 and DSPP in human sound dentin vs human sclerotic dentin. Sixteen sound and sixteen carious human molars were selected, fixed in paraformaldehyde and processed for immunohistochemical detection of DMP1 and DSPP by means of light microscopy, transmission electron microscopy (TEM) and high-resolution field emission in-lens scanning electron microscopy (FEI-SEM). Specimens were submitted to a pre-embedding or a post-embedding immunolabeling technique using primary antibodies anti DMP1 and anti-DSPP and gold-conjugated secondary antibodies. Other samples were processed for the detection of DMP1 and DSPP levels. Dentin from these samples was mechanically fractured to powder, then a protein extraction and a protein level detection assay were performed. DMP1 and DSPP were more abundant in carious than in sound samples. Immunohistochemical analyses in sclerotic dentin disclosed a high expression of DMP1 and DSPP inside the tubules, suggesting an active biomineralization of dentin by odontoblasts. Furthermore, the detection of small amounts of these proteins inside the tubules far from the carious lesion, as shown in the present study, is consistent with the hypothesis of a preventive defense of all dentin after a noxious stimulus has undermined the tooth.

Delta-6-desaturase activity and arachidonic acid synthesis are increased in human breast cancer tissue

Omega-6 (n-6) arachidonic acid (AA) and its pro-inflammatory metabolites, including prostaglandin E2 (PGE(2)), are known to promote tumorigenesis. Delta-6 desaturase (D6D) is the rate-limiting enzyme for converting n-6 linoleic acid (LA) to AA. Our objective was to determine if AA synthesis, specifically D6D activity, and PGE(2) levels are increased in cancerous breast tissue, and whether these variables differ between estrogen receptor positive (ER+) and negative (ER-) breast cancers. Gas chromatography was performed on surgical breast tissue samples collected from 69 women with breast cancer. Fifty-four had ER+ breast cancer, and 15 had ER- breast cancer. Liquid chromatography-mass spectrometry was used to determine PGE(2) levels. Lipid analysis revealed higher levels of LA metabolites (C18:3 n-6, C20:3 n-6, and AA) in cancerous tissue than in adjacent noncancerous tissue (P < 0.01). The ratio of LA metabolites to LA, a measure of D6D activity, was increased in cancerous tissue, suggesting greater conversion of LA to AA (P < 0.001), and was higher in ER- than in ER+ patients, indicating genotype-related trends. Similarly, PGE(2) levels were increased in cancerous tissue, particularly in ER- patients. The results showed that the endogenous AA synthetic pathway, D6D activity, and PGE(2) levels are increased in breast tumors, particularly those of the ER- genotype. These findings suggest that the AA synthetic pathway and the D6D enzyme in particular may be involved in the pathogenesis of breast cancer. The development of drugs and nutritional interventions to alter this pathway may provide new strategies for breast cancer prevention and treatment.

Gross Cystic Disease Fluid Protein-15(GCDFP-15)/Prolactin-Inducible Protein (PIP) as Functional Salivary Biomarker for Primary Sjögren's Syndrome

Background

Gross cystic disease fluid protein-15(GCDFP-15)/prolactin-inducible protein (PIP) is a secretory acinar glycoprotein of 14 KDa which we have recently described as significantly lower in salivary samples of patients with primary Sjögren’s syndrome (pSS) in comparison to healthy volunteers by proteomic analysis.

Aims of the study

(1) to validate our previous data on the decrease of GCDFP-15/PIP protein in a larger number of subjects with pSS (2) to integrate the proteomic results with complementary immunoassays in order better clarify the pathophysiological relevance of GCDFP-15/PIP in pSS exocrinopathy (3) to assess both the glandular expression of the GCDFP-15/PIP and the levels of glandular GCDFP-15/PIP mRNA in the patients’ minor salivary gland (MSG) biopsies in order to verify whether the observed reduction of GCDFP-15/PIP in saliva may be related to a decrease in the protein production.

Patients and methods

A total of 123 salivary samples from patients affected by pSS, no-SS sicca syndrome and sex- age-matched healthy volunteers were analyzed by different proteomic techniques (SELDI-TOF-MS, 2DE, MALDI-TOF-MS). The expression of GCDFP-15/PIP was then validated by western blot analysis. Real Time PCR and immunohistochemistry for GCDFP-15/PIP in the minor salivary glands (MSG) biopsies were then carried out.

Results

By using complementary proteomic analysis we found that a putative peak of 16547 m/z was among the best independent biomarkers for pSS able to discriminate between patients and healthy controls with a sensitivity of 96 % and a specificity of 70%, with a global cross validated error of 29%. We identified the peak as the GCDFP-15/PIP protein and verified that the intensity of GCDFP-15/PIP was significantly lower in pSS patients when compared to both no-SS sicca subjects and healthy controls (p<0.0001). GCDFP-15/PIP expression also correlated with both the salivary flow rate (r=0.312, p=0.023) and MSG biopsies focus score (r=−0.377, p=0.04). Finally, immunohistochemistry confirmed that GCDFP-15/PIP staining was faint in mucus acini and Real Time PCR showed that GCDFP-15/PIP mRNA was significantly lower in pSS patients when compared to both no-SS sicca subjects and healthy controls (p=0.023) thus supporting the hypothesis that the observed reduction of GCDFP-15/PIP in pSS saliva may be related to a decrease in the protein production.

Conclusion

In this study by different complementary-omic techniques we confirmed the potential role of GCDFP-15/PIP as a novel biomarker for pSS. This finding might also be functionally important as GCDFP-15/PIP has previously been shown to bind to Aquaporin 5 (AQP5), a salivary gland water channel, critical to saliva formation that is known to be downregulated in pSS. It is likely that exploring the GCDFP-15/PIP/AQP5 axis will help better understand the mechanism of salivary gland dysfunction in pSS.

Gene expression profile of human colon cancer cells treated with cross-reacting material 197, a diphtheria toxin non-toxic mutant

Cross-Reacting Material 197 (CRM197) is a diphtheria toxin non-toxic mutant that has shown antitumor activity in mice and humans. It is still unclear whether this anti-tumorigenic effect depends on its strong inflammatory-immunological property, its ability to inhibit heparin-binding epidermal growth factor (HB-EGF), or even its possible weak toxicity. CRM197 is utilized as a specific inhibitor of HB-EGF that competes for the epidermal growth factor receptor (EGFR), overexpressed in colorectal cancer and implicated in its progression. In this study we evaluate the effects of CRM197 on HT-29 human colon cancer cell line behaviour and, for CRM197 recognized ability to inhibit HB-EGF, its possible influence on EGFR activation. In particular, while HT-29 does not show any reduction of viability after CRM197 treatment (MTT modified assay), or changes in cell cycle distribution (flow cytometry), in EGFR localization, phospho-EGFR detected signals (immunohistochemistry) or in morphology (scanning electron microscopy, SEM) they show a change in the gene expression profile by microarray analysis (cDNA microarray SS-H19k8). The overexpression of genes like protein phosphatase 2, catalytic subunit, alpha isozyme (PPP2CA), guanine nucleotide-binding protein G subunit alpha-1(GNAI1) and butyrophilin, subfamily 2, member A1 (BTN2A1) has been confirmed with real-time-qPCR. This is the first study where the CRM197 treatment on HT-29 shows a possible scarce implication of endogenous HB-EGF on EGFR expression and cancer cell development. At the same time, our results show the alteration of a specific and selected number of genes.

Evidence that muscle cells do not express the histidine-rich glycoprotein associated with AMP deaminase but can internalise the plasma protein

Histidine-rich glycoprotein (HRG) is synthesized by liver and is present at relatively high concentration in the plasma of vertebrates. We have previously described the association of a HRG-like molecule to purified rabbit skeletal muscle AMP deaminase (AMPD). We also provided the first evidence for the presence of a HRG-like protein in human skeletal muscle where a positive correlation between HRG content and total determined AMPD activity has been shown. In the present paper we investigate the origin of skeletal muscle HRG. The screening of a human skeletal muscle cDNA expression library using an anti-HRG antibody failed to reveal any positive clone. The RT-PCR analysis, performed on human skeletal muscle RNA as well as on RNA from the rhabdomyosarcoma (RD) cell line, failed to show any mRNA specific for the plasma HRG or for the putative muscle variant. When the RD cells were incubated with human plasma HRG, a time-dependent increase of the HRG immunoreactivity was detected both at the plasma membrane level and intracellularly. The internalisation of HRG was inhibited by the addition of heparin. The above data strongly suggest that skeletal muscle cells do not synthesize the muscle variant of HRG but instead can actively internalise it from plasma.

Mesenchymal stem cells delivered at the subcapsule of the kidney ameliorate renal disease in the rat remnant kidney model

Stem cells (SC) are potential therapeutic tools in the treatment of chronic renal diseases. Number and engraftment of SC in the injured sites are important for possible differentiation into renal cells and paracrine effect. The aim of this study was to analyze the effect of subcapsular injection of mesenchymal stem cells (MSC) in the 5/6 nephrectomy model (5/6 Nx). MSC obtained from Wistar rats were isolated by their capacity to adhere to plastic surfaces, characterized by flow cytometry, and analyzed by their differentiation potential into osteoblasts. MSC (2 x 10(5)) were injected into the subcapsule of the remnant kidney of male Wistar rats, and were followed for 15 or 30 days. 5/6 Nx rats showed significant hypertension at 15 and 30 days, which was reduced by MSC at 30 days. Increased albuminuria and serum creatinine at 15 and 30 days in 5/6 Nx rats were also reduced by subcapsular injection of MSC. We also observed a significant reduction of glomerulosclerosis index 30 days after injection of MSC. 4-6 diamidino-2-phenylindole dihydrochloride (DAPI)-stained MSC showed a migration of these cells into renal parenchyma 5, 15, and 30 days after subcapsular injection. In conclusion, our data demonstrated that subcapsular injection of MSC in 5/6 Nx rats is associated with renoprotective effects. These results suggest that locally implanted MSC in the kidney allow a large number of cells to migrate into the injured sites and demonstrate that subcapsular injection represent an effective route for MSC delivery.

Histomorphometric evaluation of implant design as a key factor in peri-implant bone response: a preliminary study in a dog model

AIM

Primary implant stability as the establishment of a direct bone-to-implant contact (BIC) plays a major role in long-term successful implant osseointegration. Numerous factors influencing this initial stability have been studied. This preliminary in vivo study on a dog lower jaw aimed to investigate the hypothesis that primary implant stability in low density bone may be influenced by implant design.

METHODS

The authors compared two different implant designs with regard to their immediate quantitative relation to host bone (BIC% and gap area, GA%). The screw-shaped implants, manufactured by Or-Vit (Castelmaggiore-Bologna, Italy), exhibited similar microroughness surface and two different thread pitches: ''narrow-pitch'' implants (NP) and ''wide-pitch'' implants (WP) with a 0.5 mm and 1.5 mm thread pitch respectively. Implants were placed in dog jaw after complete osseous healing of the extractive sockets, according to a delayed implantation procedure. Five hours after surgery the animal was sacrificed. Radiographic, histological, morphometric and ultrastructural analysis were performed.

RESULTS

An inverse relation existed among the two parameters BIC and GA: GA, as a region with high osteogenetic potentiality, appeared wider in WP implants; BIC, as the expression of primary mechanical stability, was higher in NP implants.

CONCLUSION

Based on this results, we could assume that NP implants might be the clinical choice in case of immediate loading.This single case study might be considered a starting point for further long term in vivo investigations aiming to establish the implant design that best favours osseointegration at different bone quality sites.

Destination of titanium particles detached from titanium plasma sprayed implants

Small titanium particles may detach from titanium plasma sprayed (TPS) implants during implant insertion, when no preliminary tapping is used, probably for the frictional force between titanium coating and host bone. Aim of this study was to investigate the destination of these titanium particles observed in the peri-implant environment. Twenty-four TPS screws were implanted in tibiae of two sheep. Fourteen and 90 days after implantation the implants with the surrounding bone were removed and processed to be analyzed by light microscope and scanning electron microscope (secondary electron and back-scattered electron probes). Small titanium particles detached from the unloaded TPS implants were observed both in the newly-formed bone matrix and in marrow tissue. Histomorphometric analysis showed that both at 14 and 90 days after implantation the titanium particles appeared more concentrated in marrow tissue than in calcified bone matrix, decreasing by 66.4% over time. In particular, smaller particles (<250 microm(2)) decreased by 81.5%, whereas the larger ones (250-2000 microm(2)) did not show any significant variations over time, suggesting that most of the smaller particles may undergo to ionic dissolution, probably migrating into the peri-implant marrow lacunae. A slight migration of titanium particles from the implant surface towards the more distant peri-implant tissues was also demonstrated over time.

Detection of B lymphocytes (CD20+) in renal allograft biopsy specimens

Acute allograft rejection represents an important complication after transplantation with significant impact on long-term graft survival. The involvement and relevance of B lymphocytes in this process is still not clear. The aim of this study was to quantify in renal allograft biopsy specimens the number of cells positive for CD20, a specific marker for B lymphocytes. Immunohistochemical techniques using monoclonal anti-CD20 antibody was used on paraffin sections from 38 renal allograft biopsy specimens. The biopsy specimens were classified into 3 groups, according to clinical and histological criteria: normal kidney, acute rejection, and chronic allograft nephropathy (CAN). In the normal kidney, no CD20(+) cells were detected. In contrast, in all cases of acute rejection and CAN, there were CD20(+) cells. The CD20(+) cells occurred in the infiltrate in 2 distinct patterns: scattered or nodular. In cases of acute rejection, the number of CD20(+) cells was significantly higher than in CAN cases (137.0 +/- 57.2 vs 45.4 +/- 9.8 cells/mm(2); P < 0.05). The nodular pattern was observed in 4 of 11 cases (36%) in the acute rejection group, and in 4 of 20 cases (20%) in the CAN cohort. In the acute rejection group, the presence of B-cell clusters tender to be associated with a higher level of serum creatinine (3.7 +/- 1.8 mg/dL vs 2.8 +/- 0.1 mg/dL in the scattered pattern group; not significant [ns]). In conclusion, these preliminary results demonstrated B lymphocytes in cases of renal allograft dysfunction, which were more pronounced in acute allograft rejection. Further analyses are required to determine whether the detection of CD20(+) cells in renal allograft biopsy specimens can be used as a prognostic marker.

Effects of heat deproteinate bone and polynucleotides on bone regeneration: an experimental study on rat

This experimental study evaluated the effects of polynucleotides on bone regeneration on rats. Defects with a diameter of 2mm were prepared in the thickness of cortical bone of 32 rat tibiae and filled with different compounds: polynucleotide gel (PDRN), deproteinated porcine cortical bone (HDB) obtained by high temperature heating in the form of granules and a paste made of HDB granules and PDRN gel. Bone regeneration of the gaps was histologically analysed after a treatment time ranging from 1 to 12 weeks. Both PDRN and HDB stimulated bone growth and repair, but the paste prepared combining HDB granules and PDRN showed the best performance with faster filling, better osteconductive and biocompatible properties and easier handling. This study suggests that the paste prepared combining HDB and PDRN gel induces rapid bone regeneration in different clinical situations.

Proteinuria in Transplant Patients Associated With Sirolimus

Sirolimus (SRL) is a potent immunosuppressive drug used in organ transplantation for prophylaxis of acute allograft rejection. Conversion from calcineurin inhibitors to SRL has become an important alternative in patients with chronic allograft nephropathy. Recently, some reports have described the appearance of proteinuria after the use of SRL. The aim of the present study was to describe the incidence of proteinuria in transplant recipients receiving SRL in our transplant center. We studied 78 patients receiving SRL either de novo or after conversion. Eighteen transplant recipients (23.1%) developed proteinuria after SRL treatment. Proteinuria was diagnosed at 11.2 +/- 2.1 months after the initiation of SRL; in eight patients (44.4%) it occurred in the first 6 months. The mean value of proteinuria was 2.6 +/- 0.6 g/24 hours. In 5 patients (27.8%), proteinuria reached nephrotic levels, and in 13 patients (72.2%) was associated with edema. Renal allograft biopsies were performed before conversion to SRL, and a new biopsy, after the appearance of proteinuria. The light microscopy of biopsies performed after the onset of proteinuria showed no specific glomerular changes, except in 2 cases wherein the diagnosis was focal segmental glomerulosclerosis. Immunofluorescence was negative in all cases. In conclusion, in this study proteinuria was observed in 21.3% of patients receiving SRL therapy either as de novo protocol or after conversion to SRL. Proteinuria occurred early after the initiation of SRL therapy and in these cases, withdrawal of SRL was associated with reversion of proteinuria.

Cytotoxic effects and apoptotic signalling mechanisms of the sesquiterpenoid euplotin C, a secondary metabolite of the marine ciliate Euplotes crassus, in tumour cells

Most antitumour agents with cytotoxic properties induce apoptosis. The lipophilic compound euplotin C, isolated from the ciliate Euplotes crassus, is toxic to a number of different opportunistic or pathogenic microorganisms, although its mechanism of action is currently unknown. We report here that euplotin C is a powerful cytotoxic and pro-apoptotic agent in mouse AtT-20 and rat PC12 tumour-derived cell lines. In addition, we provide evidence that euplotin C treatment results in rapid activation of ryanodine receptors, depletion of Ca2+ stores in the endoplasmic reticulum (ER), the release of cytochrome c from the mitochondria, activation of caspase-12, and activation of caspase-3, leading to apoptosis. Intracellular Ca2+ overload is an early event which induces apoptosis and is parallelled by ER stress and the release of cytochrome c, whereas caspase-12 may be activated by euplotin C at a later stage in the apoptosis pathway. These events, either independently or concomitantly, lead to the activation of the caspase-3 and its downstream effectors, triggering the cell to undergo apoptosis. These results demonstrate that euplotin C may be considered for the design of cytotoxic and pro-apoptotic new drugs.

Hyperspectral imaging: a new approach to the diagnosis of hemorrhagic shock

BACKGROUND

Skin color changes and mottling are frequently described signs of hemorrhagic shock (HEM). Based on this, we developed a noninvasive, noncontact hyperspectral imaging system (HSI), which quantifies and depicts the surface tissue saturation of oxygen (SHSIO2) for each pixel in a region of interest (ROI). Our purpose was to assess HSI in a porcine HEM model. We hypothesized that HEM would cause decreases in SHSIO2 of the skin.

METHODS

The HyperMed HSI system employs a spectral separator to vary the wavelength of light admitted to a digital camera. During image acquisition, a "hypercube" of images, each at a separate wavelength, is generated (at 5-nm intervals, from 500 to 600 nm). Then, the visible light spectrum for each pixel in the hypercube is compared by linear regression to standard spectra for oxyhemoglobin (OxyHb) and deoxyhemoglobin (DeoxyHb). The resulting fit coefficients for OxyHb and DeoxyHb are used to calculate SHSIO2 values for each pixel in the ROI. The mean values for OxyHb, DeoxyHb, and SHSIO2 across the ROI are calculated. Grayscale SHSIO2 pictures of the ROI are also generated, in which the brightness of each pixel is proportional to its value. Seventeen pigs, 36.4 +/- 0.11 kg, underwent standard preparation, and were maintained on ketamine and isoflurane. Normothermia was maintained (37 degrees C to 39 degrees C). The hemorrhage group (HEM, n = 9) underwent three blood withdrawals, each 10 mL/kg, with 15 minutes between withdrawals. After the third withdrawal, animals were resuscitated with lactated Ringer's and then shed blood. The control group (CTRL, n = 8) received intravenous fluids at 100 mL/h. HSI images were obtained of the inner hindlimb throughout.

RESULTS

All HEM animals showed linear decreases in both mean SHSIO2 and OxyHb values with blood loss, which were reversed by resuscitation. These changes were evident on the grayscale SHSIO2 pictures, but not to the naked eye, and paralleled those of invasively obtained arterial base excess and mixed venous oxygen saturation.

CONCLUSIONS

HSI is a promising noninvasive and noncontact tool for quantifying changes in skin oxygenation during HEM and resuscitation.

Poly-epsilon-caprolactone/hydroxyapatite composites for bone regeneration: in vitro characterization and human osteoblast response

Polycaprolactone (PCL), a semicrystalline linear resorbable aliphatic polyester, is a good candidate as a scaffold for bone tissue engineering, due to its biocompatibility and biodegradability. However, the poor mechanical properties of PCL impair its use as scaffold for hard tissue regeneration, unless mechanical reinforcement is provided. To enhance mechanical properties and promote osteoconductivity, hydroxyapatite (HA) particles were added to the PCL matrix: three PCL-based composites with different volume ratio of HA (13%, 20%, and 32%) were studied. Mechanical properties and structure were analysed, along with biocompatibility and osteoconductivity. The addition of HA particles (in particular in the range of 20% and 32%) led to a significant improvement in mechanical performance (e.g., elastic modulus) of scaffold. Saos-2 cells and osteoblasts from human trabecular bone (hOB) retrieved during total hip replacement surgery were seeded onto 3D PCL samples for 1-4 weeks. Following the assessment of cell viability, proliferation, morphology, and ALP release, HA-loaded PCL was found to improve osteoconduction compared to the PCL alone. The results indicated that PCL represents a potential candidate as an efficient substrate for bone substitution through an accurate balance between structural/ mechanical properties of polymer and biological activities.

Biological fixation of endosseous implants

Primary implant stability is ensured by a mechanical fixation of implants. However, during implant healing a biological anchorage is necessary to achieve final osseointegration. Aim of this study was to investigate the histological aspects of biological fixation around titanium screws. Forty-eight titanium screws with different surfaces (smooth, plasma sprayed, sand blasted) were inserted in tibiae and femura of sheep and analyzed by light microscope and SEM 1 hour, 14 and 90 days after implantation. One hour after implantation the implant-bone gap was filled with a blood clot and host bone chips arising from burr surgical preparation or friction during implant insertion. Fourteen days after implantation new trabecular bone and enveloped bone chips were observed in the gap: no osteogenesis developed where implant threads were in contact with host bone. Ninety days after surgery all trabecular bone and most of the bone chips were substituted by a mature lamellar bone with few marrow spaces. Our results suggest that the trabecular bone and bone chips represent a three-dimensional network ensuring a biological implant fixation in all different implant surfaces 2 weeks after surgery. Host bone chips could favour the peri-implant osteogenesis. Inter-trabecular and implant-trabecular marrow spaces of both trabecular and lamellar bone may favour the peri-implant bone turnover.

Quality of life in patients with Charcot-Marie-Tooth disease

The authors evaluated quality of life in Charcot-Marie-Tooth disease by administering the Medical Outcome Study Short Form-36 (SF-36) questionnaire to 121 Italian patients. Patients scored lower on all of the SF-36 scales compared with Italian normative data. Scores were lower in nonworking vs working patients, women vs men, and older vs younger patients, but not between patients with demyelinating vs axonal forms or between patients who had undergone orthopedic foot surgery vs those who had not.

Handgrip impairment in Charcot-Marie-Tooth disease

AIM

Charcot-Marie-Tooth disease (CMT) is a genetic neuropathy causing muscle weakening in the feet, legs and hands, with consequent impairment of ambulation and handgrip. For fast clinical evaluation and rehabilitation management of handgrip deficits, a functional classification in 4 stages or levels of clinical severity, based on the loss of handgrip types from the finest to the roughest, has been recently proposed. The aim of this study is to evaluate the prevalence of each level of handgrip impairment in a wide population of patients affected with demyelinating and axonal CMT.

METHODS

Two-hundred and forty-eight non-operated hands were examined to evaluate if and how the pinch between the pulp of the thumb and the pulp of the second or third finger was made, starting from the palm-up position with the fingers abducted or, in case of impossibility to do so, if a lateral pinch or only a grasp was possible. Following to this observation, each hand was fitted in 1 of the 4 stages described in the above-mentioned classification and then the frequency of each stage was determined.

RESULTS

As a whole, 75.4% hands were at stage 1; 9.7 were at stage 2; 10.9% at stage 3; 4% at stage 4.

CONCLUSIONS

The results of this survey reveal that, in the majority of the CMT cases, handgrip is affected mildly so that only simple recommendations to prevent further muscle and joint damage are required; however, in more than 1 out 5 cases, the handrip impairment is quite severe and requires a detailed rehabilitative program with daily exercises, and, in a small number of cases, is so severe that independence in the daily living activities is lost or very reduced.

A calpain-like proteolytic activity produces the limited cleavage at the N-terminal regulatory domain of rabbit skeletal muscle AMP deaminase: evidence of a protective molecular mechanism

On storage at 4 degrees C, rabbit skeletal muscle AMP deaminase undergoes limited proteolysis with the conversion of the native 85-kDa enzyme subunit to a 75-kDa core that is resistant to further proteolysis. Further studies have shown that limited proteolysis of AMP deaminase with trypsin, removing the 95-residue N-terminal fragment, converts the native enzyme to a species that exhibits hyperbolic kinetics even at low K+ concentration. The results of this report show that a 21-residue synthetic peptide, when incubated with the purified enzyme, is cleaved with a specificity identical to that reported for ubiquitous calpains. In addition, the cleavage of a specific fluorogenic peptide substrate by rabbit m-calpain is inhibited by a synthetic peptide that corresponds to residues 10-17 of rabbit skeletal muscle AMP deaminase; this peptide contains a sequence (K-E-L-D-D-A) that is present in the fourth subdomain A of rabbit calpastatin, suggesting that the N-terminus of AMP deaminase shares with calpastatin a regulatory sequence that might exert a protective role against the fragmentation-induced activation of AMP deaminase. These observations suggest that a calpain-like proteinase present in muscle removes from AMP deaminase a domain that holds the enzyme in an inactive conformation and which also contains a regulatory region that protects against unregulated proteolysis. We conclude that proteolysis of AMP deaminase is the basis of the large ammonia accumulation that occurs in skeletal muscle subjected to strong tetanic contraction or passing into rigor mortis.

Early detachment of titanium particles from various different surfaces of endosseous dental implants

Titanium (Ti) endosseous dental screws with different surfaces (smooth titanium--STi, titanium plasma-sprayed-TPS, alumina oxide sandblasted and acid-etched--Al-SLA, zirconium oxide sandblasted and acid etched--Zr-SLA) were implanted in femura and tibiae of sheep to investigate the biological evolution of the peri-implant tissues and detachment of Ti debris from the implant surfaces in early healing. Implants were not loaded. Sections of the screws and the peri-implant tissues obtained by sawing and grinding were analysed by light microscopy immediately after implantation (time 0) and after 14 days. All samples showed new bone trabeculae and vascularised medullary spaces in those areas where gaps between the implants and host bone were visible. In contrast, no osteogenesis was induced in the areas where the implants were initially positioned in close contact with the host bone. Chips of the pre-existing bone inducing new peri-implant neo-osteogenesis were surrounded by new bone trabeculae. The threads of some screws appeared to be deformed where the host bone showed fractures. Ti granules of 3-60 microm were detectable only in the peri-implant tissues of TPS implants both immediately after surgery and after 14 days, thus suggesting that this phenomenon may be related to the friction of the TPS coating during surgical insertion.

Interactions of fibroblasts with soldered and laser-welded joints

Relatively little is known about the biocompatibility of the soldered or laser-welded joints of dental appliances. We investigated the reaction of human gingival fibroblasts cultured in vitro in direct contact with samples of soldered and laser-welded joints from orthodontic lingual arches. Contrast phase light microscopy was used to evaluate cell adhesion, morphology and proliferation after 6 and 24h and after 7 and 16 days. Scanning electron microscopy (SEM) was performed at 16 days. Our in vitro findings provide evidence that laser-welded orthodontic appliances have superior fibroblast biocompatibility.

Biomechanical and histomorphometric investigations on two morphologically differing titanium surfaces with and without fluorohydroxyapatite coating: an experimental study in sheep tibiae

The influence of fluorohydroxyapatite (FHA) coating and surface roughness of Ti6Al4V implants on bone response was investigated. Uncoated and FHA-coated screws with lower (LR and LR+FHA; Ra: 5.7+/-0.2 microm) and higher (HR and HR+FHA; Ra: 21.8+/-0.9 microm) surface roughness, were inserted into the diaphyses of 8 sheep tibiae. Twelve weeks after implantation, extraction torque and bone-to-implant contact were evaluated. The smoothest surfaces showed an improved extraction torque and significant differences were observed between LR and HR (-24.6%, p<0.0005), LR and HR+FHA (-30.7%, p<0.0005), LR+FHA and HR (-17.4%, p<0.005), and LR+FHA and HR+FHA (-24.0%, p<0.005). The bone-to-implant contact data paralleled the biomechanical data: the smoother the surface, the greater the bone-to-implant contact. Significant (p<0.0005) decreases in bone-to-implant contact were observed between LR+FHA and HR (-24.2%), and between LR+FHA and HR+FHA (-29.2%). The current findings suggest that LR surfaces significantly improve the osteointegration rate of implanted cortical screws independently of the FHA coating.

Detachment of titanium and fluorohydroxyapatite particles in unloaded endosseous implants

The shape, surface composition and morphology of orthopaedic and endosseous dental titanium implants are key factors to achieve post-surgical and long-term mechanical stability and enhance implant osteointegration. In this study a comparison was made between 12 titanium screws, plasma-spray-coated with titanium powders (TPS), and 12 screws with an additional coating of fluorohydroxyapatite (FHA-Ti). Screws were implanted in the femoral and tibial diaphyses of two mongrel sheep and removed with peri-implant tissues 12 weeks after surgery. The vibrational spectroscopic, ultrastructural and morphological analyses showed good osteointegration for both types of implants in host cortical bone. The portion of the FHA-Ti implants in contact with the medullary canal showed a wider area of newly formed peri-implant bone than that of the TPS implants. Morphological and EDAX analyses demonstrated the presence of small titanium debris in the bone medullary spaces near the TPS surface, presumably due to the friction between the host bone and the implant during insertion. Few traces of titanium were detected around FHA-Ti implants, even if smaller FHA debris were present. The present findings suggest that the FHA coating may act as a barrier against the detachment of titanium debris stored in the medullary spaces near the implant surface.

Hierarchical structures in fibrillar collagens

The collagen family includes several large transcripts, usually exceeding 1000 amino acid residues per single chain. As a group, they make up 1/3 of all the protein of the body and are responsible for modelling the framework of connective tissues; individually, they show both a wide variety and a complex hierarchy of mutual interactions, and form a range of functional aggregates including a variety of fibrils, microfibrils and basal membranes. Of the collagens, the fibril-forming types (i.e. the types I, II III, V and XI) are the most abundant and the most extensively studied. At the primary structure level, the amino acid sequence of all collagens is now known in detail and it shows a distinctive domain organization, its composition being dominated by the amino acid glycine (roughly 1/3 of all residues) and by post-translational hydroxylation of proline and lysine residues. Collagen secondary and tertiary structure, which together give origin to a classic triple helix, were painstakingly determined in the 1950s and 1960s. In contrast with the primary, secondary and tertiary structure, the supramolecular arrangement within collagen fibres seems to be far more elusive, and none of the models so far advanced can be said to be universally accepted. Half a century of research and debate spawned numerous mutually incompatible models, most of them focussing either on a quasi-crystalline supramolecular array or on several forms of microfibrillar aggregates, while radial fibrils, epitaxial fibrils and other structural models have almost been ignored. In many cases, data gained with a single technique from a single tissue were arbitrarily given a general legitimacy, whilst other well-documented morphological evidence went virtually unnoticed by the scientific community.Moreover, in recent years there has been a growing interest in the multiple interactions of collagens with the other macromolecules of the extra-cellular matrix, as their structure and their functional role become known. It is now indisputable that collagen interacts and forms functional entities with several other macromolecules of the extracellual matrix. This paper will succinctly review some current concepts on the structural biology of collagen higher-order structures.

Isolation and characterisation of 8-hydroxy-3Z,5Z-tetradecadienoic acid, a putative intermediate in Pichia guilliermondii gamma-decalactone biosynthesis from ricinoleic acid

During a screening procedure for the discovery of a strong gamma-decalactone producer from ricinoleic acid, we observed that the yeast Pichia guilliermondii accumulated transiently 8-hydroxy-3Z,5Z-tetradecadienoic acid 1 during gamma-decalactone biosynthesis in the stationary phase of growth. The structural elucidation of 1 was based on nuclear magnetic resonance, infrared, ultraviolet and gas chromatography-mass spectrometry experiments. The occurrence of 1 is discussed in relation with previously proposed gamma-decalactone biosynthetic pathways.

Electromagnetic stimulation on the bone growth using backscattered electron imaging

The events at the hydroxyapatite implant material/tissue interface following electromagnetic stimulation were studied in the rabbit. Two kinds of hydroxyapatite were used: natural (NA) and synthetic (HA) both with a grain size of <50 microm. Bone defects, artificially created in rabbit tibiae, were filled with the material examined. One group of animals was exposed immediately after surgery and every 12h thereafter to 30-min treatments with electromagnetic fields (PEMFs). A second group was used as a control (untreated). Two and 4 weeks after implantation, animals were sacrificed and bone samples processed for LM, TEM and SEM using a backscatter electron detector for the evaluation of bone growth. This study indicates that HA has more osteoconductivity than NA, and shows that PEMF-treatment results in a benefit in accelerating bone formation at early time periods.

Regulation of skeletal muscle AMP deaminase: lysine residues are critical for the pH-dependent positive homotropic cooperativity behaviour of the rabbit enzyme

Reaction of rabbit skeletal muscle AMP deaminase with a low molar excess of trinitrobenzene sulfonic acid (TNBS) results in conversion of the enzyme into a species with about six trinitrophenylated lysine residues per molecule which no longer manifests positive homotropic cooperativity at pH 7.1 or at the optimal pH value of 6.5 in the presence of low K+ concentrations. Substitution of the reactive thiol groups with 5,5'-dithiobis-(2-nitrobenzoic acid) does not protect the enzyme from the TNBS-induced changes of the catalytic properties, indicating that cysteine residues modification is not at the basis of the effects of TNBS treatment on AMP deaminase and strongly suggesting the obligatory participation of lysine residues to the constitution of a regulatory anionic site to which AMP must bind to stimulate the enzyme at alkaline pH. The TNBS-treated enzyme is also completely desensitized to inhibition by ATP, but not to inhibition by GTP and stimulation by ADP. This observation suggests a connection between the operation of the hypothesized anionic activating site, responsible for positive homotropic cooperativity, and the inhibition exerted by anionic compounds that compete for the same site, among them the most efficient metabolite being probably ATP.

Qualitative assessment of natural apatite in vitro and in vivo

Among the natural and synthetic materials investigated as bone graft substitutes, much interest has been focused on natural apatite obtained from low temperature heat-deproteinated compact bone. Previous research demonstrates that, when treated at a temperature below 500 degrees C, this material maintains its characteristic ultrastructural features, with a high surface/volume ratio, while as an implant material, it offers the host tissue a large surface of interaction. In vitro and in vivo tests showed that natural apatite is well tolerated and is a good osteoconducing material. The present in vivo study in rabbits was carried out to first investigate the behavior and capacity of natural apatite implants to stimulate bone ingrowth, and then to analyze the cells located at the bone/material interface. Synthetic hydroxyapatite was used as a control material. In a parallel in vitro study, we investigated the activity of differentiated osteoblasts and periosteal cells obtained from rats and new-born rabbits, incubated with natural apatite and synthetic hydroxyapatite. The in vivo study showed that natural apatite allows osteoblasts to form new bone tissue, adhering to the implant with ingrowth into the implant structure. In the presence of synthetic hydroxyapatite, a less pronounced osteoblastic activity was observed. In agreement with these observations, the in vitro study showed that natural apatite is more effective in attracting cells, favoring their proliferation and stimulating alkaline phosphatase activity. These findings suggest that natural apatite is more suitable for bone filling or bone regeneration than synthetic hydroxyapatite.

Peri-implant medullary cisternae at the interface of bone-smooth surface titanium endosseous implant

A histological and ultrastructural study was carried out on the spongy bone response to smooth titanium oral implant surfaces. The samples obtained both from monkeys and from patients at various times from the implant insertion revealed that the bone-implant integration developed through different morphological aspects. The implant surface appeared in contact with medullary lacunae, as well as with osteoid tissue or directly with bone matrix. The complementary ultrastructural techniques employed have shown that the medullary lacunae appeared as wide and flattened cisternae delimited by a continuous single layer of flattened cells forming a thin lamina adhering to the implant and an endosteal lamina facing the bone surface. For their position and flattened shape we named them peri-implant medullary cisternae. The presence of blood vessels, reticular cells and myeloid cells in their lumen suggested that these peri-implant medullary cisternae were functional sites of new bone formation.