Identification of reference genes for RT-qPCR analysis in peach genotypes with contrasting chilling requirements.

Selecting and validating reference genes are the first steps in studying gene expression by reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR). The present study aimed to evaluate the stability of five reference genes for the purpose of normalization when studying gene expression in various cultivars of Prunus persica with different chilling requirements. Flower bud tissues of nine peach genotypes from Embrapa's peach breeding program with different chilling requirements were used, and five candidate reference genes based on the RT-qPCR that were useful for studying the relative quantitative gene expression and stability were evaluated using geNorm, NormFinder, and bestKeeper software packages. The results indicated that among the genes tested, the most stable genes to be used as reference genes are Act and UBQ10. This study is the first survey of the stability of reference genes in peaches under chilling stress and provides guidelines for more accurate RT-qPCR results.

Temperature-dependent production of various PlcR-controlled virulence factors in Bacillus weihenstephanensis strain KBAB4.

The Bacillus cereus sensu lato complex has recently been divided into several phylogenetic groups with clear differences in growth temperature range. However, only a few studies have investigated the actual pathogenic potential of the psychrotolerant strains of the B. cereus group at low temperature, and little information is available concerning gene expression at low temperature. We found that vegetative cells of the psychrotolerant B. weihenstephanensis strain KBAB4 were pathogenic against the model insect Galleria mellonella at 15°C but not at 30°C. A similar temperature-dependent difference also was observed for the supernatant, which was cytotoxic to Vero epithelial cell lines and to murine macrophage J774 cells at 15°C but not at 30°C. We therefore determined the effect of low temperature on the production of various proteins putatively involved in virulence using two-dimensional protein gel electrophoresis, and we showed that the production of the Hbl enterotoxin and of two proteases, NprB and NprP2, was greater at a growth temperature of 15°C than at 30°C. The quantification of the mRNA levels for these virulence genes by real-time quantitative PCR at both temperatures showed that there was also more mRNA present at 15°C than at 30°C. We also found that at 15°C, hbl mRNA levels were maximal in the mid- to late exponential growth phase. In conclusion, we found that the higher virulence of the B. cereus KBAB4 strain at low temperature was accompanied by higher levels of the production of various known PlcR-controlled virulence factors and by a higher transcriptional activity of the corresponding genes.

Validation of RNA isolated from milk fat globules to profile mammary epithelial cell expression during lactation and transcriptional response to a bacterial infection.

Mastitis, an inflammation of the mammary gland, is the most costly infectious disease of dairy ruminants worldwide. Although it receives considerable attention, the early steps of the host response remain poorly defined. Here, we report a noninvasive method using milk fat globules (MFG) as a source of mammary RNA to follow the dynamics of the global transcriptional response of mammary epithelial cells (MEC) during the course of a bacterial infection. We first assessed that RNA isolated from MFG were representative of MEC RNA; we then evaluated whether MFG RNA could be used to monitor the MEC response to infection. Sufficiently high yields of good-quality RNA (RNA integrity numbers ranging between 6.7 and 8.7) were obtained from goat MFG for subsequent analyses. Contamination of MFG by macrophages and neutrophils, which can be trapped during creaming, was assessed and when using quantitative real-time PCR for cell-type specific markers, was shown to be weak enough (<8%) to affect MFG gene expression profiling. Using microarrays, we showed that RNA extracted from MFG and from mammary alveolar parenchyma shared approximately 90% of the highlighted probes corresponding in particular to genes encoding milk proteins (CSN, BLG, LALBA) and enzymes involved in milk fat synthesis and secretion (FASN, XDH, ADRP, SCD, and DGAT1). In addition, a gene involved in the acute-phase reaction, coding for the serum amyloid A3 (SAA3) protein, was found within the first 50 most highly expressed genes in a noninfectious context in both mammary alveolar parenchyma and MFG, strongly suggesting that SAA3 is expressed in MEC. We took advantage of this noninvasive RNA sampling to follow the early proinflammatory response of MEC during the course of a bacterial infection and showed that the levels of mRNA encoding SAA3 sharply increased at 24h postinfection. Taken together, our results demonstrate that MFG represent a unique source of MEC RNA to noninvasively sample sufficient amounts of high-quality RNA to assess the dynamics of MEC gene expression in vivo, especially during the first steps of infection, thereby paving the way for the discovery of early biomarkers for the control of intramammary infections. Furthermore, this noninvasive technique could be used to provide mammary transcriptomic data on a large scale, thus filling the gap between genomic and phenotypic data.

Goat α(s1)-casein genotype affects milk fat globule physicochemical properties and the composition of the milk fat globule membrane.

Milk fat secretion is a complex process that initiates in the endoplasmic reticulum of the mammary epithelial cell by the budding of lipid droplets. Lipid droplets are finally released as fat globules in milk enveloped by the apical plasma membrane of the mammary epithelial cell. The milk fat globule membrane (MFGM) thus comprises membrane-specific proteins and polar lipids (glycerophospholipids and sphingolipids) surrounding a core of neutral lipids (mainly triacylglycerols and cholesterol esters). We have recently described major proteins of the MFGM in the goat and we have highlighted prominent differences between goats and bovine species, especially regarding lactadherin, a major MFGM protein. Here, we show that, in the goat species, the well-documented genetic polymorphism at the α(s1)-casein (CSN1S1) locus affects both structure and composition of milk fat globules. We first evidenced that both milk fat globule size and ζ-potential are related to the α(s1)-casein genotype. At midlactation, goats displaying strong genotypes for α(s1)-casein (A/A goats) produce larger fat globules than goats with a null genotype at the CSN1S1 locus (O/O goats). A linear relationship (R(2)=0.75) between fat content (g/kg) in the milk and diameter of fat globules (µm) was established. Moreover, we found significant differences with regard to MFGM composition (including both polar lipids and MFGM proteins) from goats with extreme genotype at the CSN1S1 locus. At midlactation, the amount of polar lipids is significantly higher in the MFGM from goats with null genotypes for α(s1)-casein (O/O goats; 5.97±0.11mg/g of fat; mean ± standard deviation) than in the MFGM from goats with strong genotypes for α(s1)-casein (A/A goats; 3.96±0.12mg/g of fat; mean ± standard deviation). Two MFGM-associated proteins, namely lactadherin and stomatin, are also significantly upregulated in the MFGM from goats with null genotype for α(s1)-casein at early lactation. Our findings are discussed with regard to techno-functional properties and nutritional value of goat milk. In addition, the genetic polymorphism in the goat species appears to be a tool to provide clues to the lipid secretion pathways in the mammary epithelial cell.

Impaired wound healing in diabetes: the rationale for clinical use of hyaluronic acid plus silver sulfadiazine.

Diabetes-related chronic cutaneous lesions are a serious and common problem, as well as a major cause for hospital admissions, although no general consensus has been reached on the best available treatment for this frequent pathological condition. The primary objective of this review is to analyze the most recent evidence supporting the clinical use of a formulation containing hyaluronic acid (HA) and silver sulfadiazine (SSD) in the diabetic patient. This formulation has been widely used in cutaneous lesions of various etiology, both acute and chronic. The mechanisms underlying tissue repair are altered in the diabetic patient with respect to a healthy individual, namely for a diminished response of the keratinocytes and a reduced capacity of the endothelial cells to form new vessels (neoangiogenesis). Since HA favours the tissue repair process through various mechanisms, among these an increased angiogenic response and an activation of the keratinocytes, its application in diabetic lesions is a rational choice. SSD has been widely used in acute cutaneous lesions, particularly in burns, where it is considered the "gold standard" by which other treatments are measured. The efficacy of SSD in terms of antibacterial activity spectrum on various types of microorganisms, with a favourable safety profile, supports the potential use of SSD in diabetic lesions, where the presence of infection caused by bacteria resistant to most available antibiotics, but not to SSD, is rather frequent. In conclusion, the combined use of HA and SSD in the diabetic patient proves a rational choice and is potentially capable of improving the general clinical situation, on the basis of the synergic effect to control infection and accelerate the tissue repair process.

MICI-MINOTS: Linguistic and metric validation of a pediatric questionnaire on knowledge about inflammatory bowel disease.

BACKGROUND: Therapeutic education is an essential part of the treatment of chronic diseases, such as inflammatory bowel disease (IBD). The IBD-KID, developed in Canada in English, assesses children's and adolescents' acquired knowledge about their condition and has been validated in Canadian and Australian populations. However, there is no pediatric questionnaire in French to assess patients' knowledge about IBD. OBJECTIVE: To report the linguistic validation process and metric validity of the MICI-MINOTS, the French version of the IBD-KID. METHOD: The translation process consisted of three consecutive steps: forward-backward translation, acceptability testing, and cognitive interviews. The IBD-KID consists of 23 questions, but a 24th question about immunomodulatory therapy was added in the MICI-MINOTS. Psychometric testing was conducted with five groups: children with IBD, their parents, children in a control group, their parents, and health workers recruited from the Timone Pediatric Hospital and the Saint-Sébastien Maternal and Child Protection Center, Marseille, France. A total of 15 individuals completed the tool twice, with a 15-day interval. Internal consistency, reliability, external validity, reproducibility, and sensitivity to change were tested. RESULTS: A total of 38 children with IBD (sex: 20 boys, 18 girls; age: 13.90 [±2.88] years; 25 with Crohn's disease), 20 children in the control group, 58 parents (every child was included with one parent), and 62 health workers were included in the analysis. Intraclass correlation was 0.94 (95% confidence interval 0.83-0.98) for test-retest assessment. Readability using the Scolarius score corresponded to elementary school level. Among the children with IBD, 89.5% answered all 24 questions. For 23 questions, the mean score of children with IBD was higher than among children in the control group: 9.58 (±3.01) versus 5.47 (±3.56), respectively (P<0.01). Parents of children with IBD scored higher than parents of children in the control group: 10.63 (±3.16) versus 8.4 (±3.07), respectively (P=0.012). In the health workers' group, pediatric residents (17.82±3.46) scored higher than nurses 11.75 (±3.4) and ward clerks (8.67±2.40; P<0.01). Patients' knowledge score was significantly related to their parents' knowledge score (r=0.402, P=0.012) for 23 questions. CONCLUSION: The French version of the IBD-KID showed satisfactory psychometric properties to assess knowledge about the disease in French-speaking children.

Terminal differentiation of goat mammary tissue during pregnancy requires the expression of genes involved in immune functions.

Terminal differentiation of mammary tissue into a functional epithelium that synthesizes and secretes milk occurs during pregnancy. The molecular mechanisms underlying this complex process are poorly understood, especially in ruminants. To obtain an overview of the ruminant mammary gland's final differentiation process, we conducted time-course gene expression analysis of five physiological stages: four during pregnancy (P46, P70, P90, and P110) and one after 40 days of lactation (L40). An appropriate loop experimental design was used to follow gene expression profiles. Using three nulliparous (pregnancy) or primiparous (lactation) goats per stage, we performed a comparison starting from nine dye-swaps and using a 22K bovine oligoarray. Statistical analysis revealed that the expression of 1,696 genes varied significantly at least once in the study. These genes fell into 19 clusters based on their expression profiles. Identification of biological functions with Ingenuity Pathway Analysis software revealed several similarities, in keeping with physiological stages described in mice. As in mice, expression of milk protein genes began at midpregnancy, and genes regulating lipid biosynthesis were induced at the onset of lactation. During the first half of pregnancy, the molecular signature of goat mammary tissue was characterized by the expression of genes associated with tissue remodeling and differentiation, while the second half was mainly characterized by the presence of messengers encoding genes involved in cell proliferation. A large number of immune-related genes were also induced, supporting recent speculation that mammary tissue has an original immune function, and the recruitment of migrating hematopoietic cells possibly involved in the branching morphogenesis of the mammary gland. These data hint that the induction of differentiation occurs early in pregnancy, very likely before P46. This period is therefore crucial for obtaining a healthy and productive mammary gland.

Phylogeography Approach of Diloboderus abderus (Coleoptera: Melolonthidae) in the Southern Cone of America.

Diloboderus abderus (Sturm, 1826) (Coleoptera: Melolonthidae) is a serious soil pest of corn, wheat, oat, and natural and cultivated pastures in Argentina, Paraguay, Uruguay, and southern Brazil. Despite its economic importance, the genetic diversity and population structure of D. abderus remain unknown. We sequenced a fragment of the mitochondrial gene cytochrome oxidase I region (COI), of six populations of D. abderus from the Southern Cone of America. The mtDNA marker revealed a high haplotype diversity, high pairwise FST values, and significant genetic variations among populations. No correlation was found between genetic and geographical distances, yet the most common haplotype (Dab01) was present in four out of the six populations. Analysis of molecular variance showed that most of the variation was within populations of D. abderus. Tajima's D and Fu's FS tests indicated no evidence that D. abderus populations are under recent expansion. Our results indicate that genetic-based traits will likely remain localized or spread slowly, and management strategies need to be undertaken on a small scale.

Adult mesenchymal stem cells for bone and cartilage engineering: effect of scaffold materials.

Bone marrow is a useful cell source for skeletal tissue engineering approaches. In vitro differentiation of marrow mesenchymal stem cells (MSCs) to chondrocytes or osteoblasts can be induced by the addition of specific growth factors to the medium. The present study evaluated the behaviour of human MSCs cultured on various scaffolds to determine whether their differentiation can be induced by cell-matrix interactions. MSCs from bone marrow collected from the acetabulum during hip arthroplasty procedures were isolated by cell sorting, expanded and characterised by a flow cytometry system. Cells were grown on three different scaffolds (type I collagen, type I + II collagen and type I collagen + hydroxyapatite membranes) and analysed by histochemistry, immunohistochemistry and spectrophotometry (cell proliferation, alkaline phosphatase activity) at 15 and 30 days. Widely variable cell adhesion and proliferation was observed on the three scaffolds. MSCs grown on type I+II collagen differentiated to cells expressing chondrocyte markers, while those grown on type I collagen + hydroxyapatite differentiated into osteoblast-like cells. The study highlighted that human MSCs grown on different scaffold matrices may display different behaviours in terms of cell proliferation and phenotype expression without growth factor supplementation.

Protective role of heparin on in vitro functional aortic response in Watanabe heritable hyperlipidemic rabbits.

The effects of prolonged in vivo heparin treatment upon vasomotor responses and content of cholesterol and energy related compounds were studied in isolated thoracic and abdominal aortas from Watanabe heritable hyperlipidemic (WHHL) rabbits. Unfractionated heparin was administered subcutaneously (2 mg/kg twice a day) to 3-month-old WHHL rabbits for a period of 6 months. A group of WHHL rabbits was treated with saline solution and considered as control. Aortic cholesterol infiltration and serum cholesterol were not significantly decreased by the prolonged heparin treatment. In heparin-treated WHHL rabbits, the in vitro aortic endothelium-dependent relaxation produced by acetylcholine or calcimycin (A 23187) was greater than in saline-treated WHHL group. ATP-induced aorta relaxation (endothelium-dependent and endothelium-independent) did not vary significantly in the two groups of WHHL rabbits, even after mechanical removal of endothelium. Also the noradrenaline-induced aorta contraction did not vary between the two groups of WHHL rabbits. No significant variation in energy-related compounds (except for ADP) was found in the aortic arch. These results suggest that heparin produces a protective effect on aortic tissue by acting mainly at endothelial level.

In K562 leukemia cells treated with doxorubicin and hemin, a decrease in c-myc mRNA expression correlates with loss of self-renewal capability but not with erythroid differentiation.

The decrease in c-myc mRNA expression occurring in leukemia cell lines induced to differentiate is supposed to be an early event of the commitment to the differentiation program. Alternatively, the decrease in c-myc mRNA expression could be simply a consequence of loss of the self-renewal capability characteristic of the terminal differentiated phenotypes. In an attempt to clarify these hypotheses, we analysed comparatively the kinetics of variations in c-myc mRNA expression, hemoglobin synthesis, DNA and RNA syntheses, cell cycle kinetics and self-renewal capability in normal and hemin-treated K562 leukemia cells exposed for different periods of time to the antitumoral antibiotic doxorubicin. Times of exposure to doxorubicin were either 2 h, which resulted in reversible induction of hemoglobin synthesis without significant cytostatic effects, or continuously for more than 5 days, which resulted in an irreversible induction of hemoglobin synthesis and in the complete and irreversible loss of self-renewal activity. Comparative analysis of the experimental data indicated that the decrease in c-myc mRNA expression correlated with the loss of replicative activity, possibly due to an irreversible cytostatic effect of the long exposure to doxorubicin, but not with the commitment to the differentiation programs.

Cloricromene, a semi-synthetic coumarin derivative, inhibits tumor necrosis factor-alpha production at a pre-transcriptional level.

Cloricromene decreases myocardial infarct size after ischemic-reperfusion injury in vivo, and it has been suggested that this is due to inhibition of tumor necrosis factor-alpha (TNF-alpha). The purpose of this work was to characterize the mechanism of cloricromene-induced inhibition of TNF-alpha in rat macrophages. Cloricromene inhibited lipopolysaccharide-induced TNF-alpha release in a dose-dependent manner (IC(50)=5.9 +/- 0.8 microM). This was not due to cytotoxicity, as cloricromene was well tolerated up to 500 microM. Cloricromene inhibited lipopolysaccharide-induced expression of TNF-alpha mRNA, which suggests a pre-transcriptional effect. We then investigated the early signal transduction pathway triggered by lipopolysaccharide. The binding of lipopolysaccharide to its receptor CD14 activates protein kinase C and nuclear factor-kappaB (NF-kappaB). Cloricromene inhibited NF-kappaB activation in a dose-dependent manner, but affected protein kinase C translocation only slightly. We then established that cloricromene inhibited lipopolysaccharide-induced cellular oxidative activity, which is important for NF-kappaB activation. Our results show that cloricromene interferes with the early signal transduction pathway triggered by lipopolysaccharide.

Acute carotid artery occlusive thrombosis and its pharmacological prevention in the rabbit.

A simple and reproducible method to induce an occlusive thrombus in rabbit carotid artery is reported. Rabbits were anesthetized and prepared to record arterial pressure, heart rate, and carotid blood flow. A critical stenosis of a damaged carotid artery was obtained using an external plastic cylinder. Complete occlusion occurred within 6 to 12 minutes, as measured by the decrease in blood flow. Both stenosis of the vessel and deliberate damage (clamping by surgical forceps) were found essential to occlusion. Occlusion was prevented by administration of heparin (200 IU/kg), tissue plasminogen activator (300 micrograms/kg), iloprost (10 micrograms/kg) or the synthetic thrombin inhibitor, FPRCH2Cl (0.5 mg/kg), while ASA (100 mg/kg) was uneffective. The procedure permits an easy and rapid evaluation of thrombus formation and of anti-thrombotic drugs affecting the hemostatic process.

In vitro effects of elastase on periosteum of long bones: an histochemical, immunohistochemical and morphometric study.

The aim of the study was to determine the in vitro effects of porcine pancreatic elastase on the periosteum of long bones and to what extent the effects are selective for the elastic fibres of the tissue. Twenty-eight new-born chicks' tibiae were incubated for 1 or 3 hours in different experimental conditions (PBS, 30 or 60 units (U)/ml of porcine pancreatic elastase) or immediately formalin fixed. The tibiae were then processed for histo-chemical (Verhoeff and van Gieson stain), immunohistochemical (anti-elastin antibody) and histomorphometric analysis. A decrease of periosteal elastic fibres in all the specimens incubated with elastase in comparison with non incubated specimens was evident. The effect of elastase was easily detectable even at the lower concentration (30 U/ml) and at the shorter time of incubation (1 h). The amount of elastic fibres decreased in accordance with the rise of enzyme levels and incubation time, while periosteal collagen fibre content was not substantially modified by elastase activity. Present data are a prerequisite to evaluate the in vitro and in vivo effects of experimental destruction of periosteal elastic fibres by elastase and to assess the role of these fibres in the growth process of long bones.

Expression of NGF, Trka and p75 in human cartilage.

Nerve growth factor (NGF) exerts its action through two types of receptor: high-affinity tyrosine kinase A receptor (trkA) and low-affinity p75 receptor. NGF has a neurotrophic role in central and peripheral nervous system development, but there is also clear evidence of its involvement in the developing skeleton. The aim of the present immunohistochemical study was to investigate the expression and distribution of NGF, trkA, and p75 in normal cartilaginous tissues from adult subjects: articular and meniscal cartilage of the knee, cartilage from the epiglottis, and intervertebral disc tissue. Detection of NGF mRNA was also performed by in situ hybridization. Immunoreaction for NGF and the two receptors in articular chondrocytes, chondrocyte-like cells of meniscus and annulus fibrosus, and chondrocytes of the epiglottis demonstrated that they are all expressed in hyaline, fibrous and elastic cartilaginous tissues, suggesting that they could be involved in cartilage physio-pathology.

Cryodamage of the vessel wall accelerates the development of atherosclerotic lesions in arterial vessels of Watanabe hyperlipidemic rabbits.

In the present study we developed an experimental model, resembling human atherosclerosis, by removing the endothelial layer in Watanabe heritable hyperlipidemic (WHHL) rabbits (10 months old) by application of cryodamage on the external surface of arterial vessels. In age-matched New Zealand white (NZW) rabbits, used as control, after two months following cryodamage, carotid artery and infrarenal segments of abdominal aorta did not show any particular change in the ultrastructure of vessel wall. In WHHL rabbits, two months after cryodamage, atherosclerotic lesions (fatty streaks and fibrous plaques) were observed in both arteries. Many lipid-laden endothelial cells, subendothelial foam cells and smooth muscle cells were found in cryodamaged areas. In some areas, the cap of plaques appeared to be thinned and ruptured. Increased number of collagen and elastic fibrils was also observed in atherosclerotic regions. We conclude that this simple technique on WHHL rabbits provides a model of atherosclerosis with a high degree of morphological similarity between the artificially-induced plaque and human atherosclerotic plaque.

[Geriatric department]. / Il dipartimento dell'anziano

The medicolegal, health and organisational aspects of the department introduced by law into the Italian hospital structure are examined. A comparison is made with the proposals made in the single national contract for hospital workers. An account is given of the Senior Citizen's Department set up at Trieste, in the light of the city's demographic and socioeconomic situation.

[Prevention of viral hepatitis B with specific gamma globulin. Results of 2 years' experience in a hemodialysis center]. / Profilassi dell'epatite virale B con gamma globuline specifiche. Risultati di due aunni di esperienza in un Centro di Emodialisi.

Prophylaxis with gamma globulins specific for virus hepatitis B was carried out at the Trieste Haemodialysis Centre from December 1979 to December 1981. Since no clear distinction could be drawn between HBsAg-positive dialysed subjects, all staff and patients at the Centre were regarded as constantly at risk for contagion, and hence in the post-exposure state. Those who refused prophylaxis were excluded, together with surface antigen carriers and subjects with antibodies. Specific gamma globulins (Uman-Big) were given at a dose of 0.06 cc/kg at intervals of 90-105 days, together with 0.02 cc/kg standard gamma globulins for conjectured protection against non-A and non-B hepatitis. No allergic reactions worthy of not were observed. Only one patient positivised of all those who underwent continuous prophylaxis. New carriers of HBsAg gradually decreased in number from 1976 to 1981, initially due to the adoption of disposable filters, subsequently owing to partial separation of Au-positives, and finally, in a significant manner, with the introduction of prophylaxis with specific gamma globulins.

Exogenous hyaluronic acid and wound healing: an updated vision.

Hyaluronic acid (HA), an endogenous substance whose concentration increases during the process of wound repair, can be manufactured in order to use it as an exogenous intervention able to reduce the time to wound repair and improve the quality of the scar. The role of HA as a key component of the extracellular matrix structure has been recognized for many decades, while its actions on cells involved in the process of tissue repair has been partly clarified only in the last few years. Fibroblasts, endothelial cells and macrophages are key players in the tissue repair process and a concerted activation of specific functions of these cells may substantially improve the process of wound closure. Hyaluronan, as well as its degradation products that are generated in the wounds, are capable to activate specific responses in all the cells involved in the process; in particular, fibroblast proliferation and new vessel formation have been extensively studied. The molecular patterns leading to cell activation have been substantially clarified and it is now widely accepted that cellular actions of hyaluronic acid are mediated by specific surface receptors, including CD44, RHAMM and toll like receptors. Elucidation of the mechanisms of cellular activation will allow an optimal use of exogenous hyaluronan and its derivatives in the wound care setting.