Early stage reactivity and in vitro behavior of silica-based bioactive glasses and glass-ceramics

The surface reactivity of different sets of glasses and glass-ceramics belonging to the SiO(2)-P(2)O(5)-CaO-MgO-K(2)O-Na(2)O system have been investigated. The attention was focused on the role of their composition on the bioactivity kinetics, in terms of pH modifications, silica-gel formation and its evolution toward hydroxycarbonatoapatite, after different times of soaking in simulated body fluid. Glasses and glass ceramics have been characterized by thermal analysis, SEM-EDS observations and phase analysis (XRD). XPS measurements have been carried out on the most representative set of sample in order to evaluate the evolution of the surface species during the growth of silica-gel and hydroxycarbonatoapatite. The response of murine fibroblast 3T3 to the material before and after a conditioning pre-treatment (immersion in SBF) has been investigated on the same set of samples in order to point out the role of the bioactivity mechanism on cell viability. The main differences among the various glasses have been related to the modifier oxides ratio and to the MgO content, which seems to have an influence on the glass stability, both in terms of thermal properties and surface reactivity. The surface characterization and in vitro tests revealed few variations in the reactivity of the different glasses and glass-ceramics in their pristine form. On the contrary, the different surface properties before and after the pre-treatment in SBF seem to play a role on the biocompatibility of both glass and glass-ceramics, due to the different ion release and hydrophilicity of the surfaces, affecting both cell viability and protein adsorption.

Treatment with alpha-melanocyte stimulating hormone preserves calcium regulatory proteins in rat heart allografts

Prevention of graft dysfunction is a major objective in transplantation medicine. Previous research on experimental heart transplantation indicated that treatment with the immunomodulatory peptide alpha-melanocyte stimulating hormone (alpha-MSH) improves histopathology, prolongs allograft survival, and reduces expression of the main tissue injury mediators. Because calcium-handling is critical in heart graft function, we determined the effects of transplantation injury and influences of alpha-MSH treatment on representative calcium regulatory proteins in rat heart allografts. Hearts from Brown Norway rats were transplanted heterotopically into MHC incompatible Lewis rats. Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), protein kinase C epsilon (PKC epsilon), sarcoplasmic/endoplasmic reticulum calcium-ATPase 2 (SERCA2a), arrestin-beta1 (Arrb1), cholinergic receptor M2 (Chrm2), and inositol 1,4,5-triphosphate receptor 1 (InsP(3)R1) were examined in: (1) non-transplanted donor hearts; (2) allografts from saline-treated rats; and (3) allografts from rats treated with the synthetic alpha-MSH analog Nle4-DPhe7-alpha-MSH (NDP-alpha-MSH) (100 microg i.p. every 12h). Transplantation injury was associated with severe reduction in calcium regulatory protein transcription and expression level. NDP-alpha-MSH administration partly reversed inhibition of protein transcription and almost completely prevented protein loss. Finally, because certain effects of cyclic 3'-5'-adenosine monophosphate (cAMP) signaling on calcium handling in cardiac myocytes depend on activation of exchange protein directly activated by cAMP 1 (Epac1), we determined Epac1 mRNA and protein expression in heart allografts. Transplantation injury markedly reduced Epac1. NDP-alpha-MSH treatment significantly preserved both Epac1 protein and mRNA in the allografts. Administration of alpha-MSH or related melanocortins could reduce transplantation-induced dysfunction through protection of heart calcium regulatory proteins.

Switch in the expression of mGlu1 and mGlu5 metabotropic glutamate receptors in the cerebellum of mice developing experimental autoimmune encephalomyelitis and in autoptic cerebellar samples from patients with multiple sclerosis

Recent evidence suggests that changes in the expression of membrane receptors/ion channels in cerebellar Purkinje cells contribute to the onset of cerebellar motor symptoms in patients with multiple sclerosis (MS). We examined the expression of group-I metabotropic glutamate receptors (mGlu1 and mGlu5 receptors) in the cerebellum of mice developing experimental autoimmune encephalomyelitis (EAE) and in autoptic cerebellar samples of MS patients. EAE was induced in mice by immunization with the 35-55 fragment of MOG (myelin oligodendrocyte glycoprotein). EAE mice showed a progressive loss of mGlu1a receptors in the cerebellum, associated with an increased expression of mGlu5 receptors. These changes were restricted to Purkinje cells and their dendritic arborization, as shown by immunohistochemistry. A reduced expression of mGlu1a receptors in cerebellar Purkinje cells was also found in 7 of 9 MS patients. In addition, a light/moderate to very strong mGlu5 receptor immunoreactivity was detected in Purkinje cells of 8 MS patients, but was always absent in non-MS control patients. In EAE mice, an acute treatment with the mGlu1 receptor enhancer, 9H-xanthene-9-carboxylic acid (4-trifluoromethyl-oxazol-2-yl)-amide (RO0711401), significantly improved motor coordination, whereas treatment with the mGlu5 receptor antagonists, 2-methyl-6-(phenylethynyl)-pyridine (MPEP) and 6-methyl-2-(phenylazo)-3-pyridinol (SIB-1757), had no effect. We conclude that mGlu1 receptor enhancers improve motor symptoms associated with EAE and might be helpful as symptomatic drugs in patients with MS.

Myiasis of the scalp due to Dermatobia hominis in a traveler returning from Brazil

This article describes a case of myiasis by Dermatobia hominis diagnosed in a young Italian man returning from a vacation through Brazil. Considering the increasing number of travels to tropical and subtropical areas, clinicians in nonendemic areas must think about the possibility of imported unusual infestations during their daily practice.

Iron depletion by deferoxamine up-regulates glucose uptake and insulin signaling in hepatoma cells and in rat liver

Iron depletion improves insulin resistance in patients with nonalcoholic fatty liver disease and diabetes and also stabilizes the hypoxia-inducible factor (HIF)-1, resulting in increased glucose uptake in vitro. This study investigated the effect of iron depletion by deferoxamine on insulin signaling and glucose uptake in HepG2 hepatocytes and in rat liver. In HepG2 cells, deferoxamine stabilized HIF-1alpha and induced the constitutive glucose transporter Glut1 and the insulin receptor. Up-regulation of insulin receptor by deferoxamine was mimicked by the intracellular iron chelator deferasirox and the hypoxia inducer CoCl2 and required the HIF-1 obligate partner ARNT/HIF-1beta. Iron depletion increased insulin receptor activity, whereas iron supplementation had the opposite effect. Deferoxamine consistently increased the phosphorylation status of Akt/PKB and its targets FoxO1 and Gsk3beta, which mediate the effect of insulin on gluconeogenesis and glycogen synthesis, and up-regulated genes involved in glucose uptake and utilization. Iron depletion of Sprague-Dawley rats increased HIF-1alpha expression, improved glucose clearance, and was associated with up-regulation of insulin receptor and Akt/PKB levels and of glucose transport in hepatic tissue. Conversely, gluconeogenic genes were not affected. In rats with fatty liver because of a high-calorie and high-fat diet, glucose clearance was increased by iron depletion and decreased by iron supplementation. Thus, iron depletion by deferoxamine up-regulates glucose uptake, and increases insulin receptor activity and signaling in hepatocytes in vitro and in vivo.

A comparison of three diagnostic techniques for malaria: a rapid diagnostic test (NOW Malaria), PCR and microscopy

Malaria is a common, life-threatening infection in endemic tropical areas and one that presents a diagnostic challenge to laboratories in most non-endemic countries. A rapid and accurate diagnosis is a prerequisite for effective treatment, especially for the potentially fatal cases of Plasmodium falciparum infection. In the present, multi-centre study, the performances of a rapid diagnostic test (NOW) Malaria) and several, commercial, PCR-based assays (AMS61, AMS42, AMS43, AMS4 and AMS45) were compared against the results of microscopical examination of bloodsmears (the current 'gold standard'). The subjects were either non-European immigrants (N=135) or international travellers (N=171). There was good concordance between the results of all the detection methods, with kappa values of >0.8. Although the NOW Malaria rapid test was both sensitive (100%) and specific (100%) in detecting P. falciparum infections, it was less specific (93.1%) and sensitive (90.7%) in identifying the other Plasmodium species. The results from the AMS61 assay, designed to detect any malarial infection, generally parallelled those of the microscopy (kappa = 0.89), giving a specificity of 98.2% and a sensitivity of 91.0%. Although the use of species-specific molecular primers to identify pure infections with P. falciparum and P. vivax gave results that were in good agreement with those of the microscopy, the subjects who had apparently pure infections with P. ovale or P. malariae were always found PCR-negative. Compared with the standard microscopy, both the NOW Malaria test and the PCR-based assays were therefore poor at identifying mixed infections. The NOW Malaria test and the PCR-based assays clearly need to be improved, particularly for the correct identification of infections with Plasmodium spp. other than P. falciparum, including mixed infections. For now, expert microscopy must remain the mainstay of the laboratory diagnosis of malaria.

Role of lamivudine in the posttransplant prophylaxis of chronic hepatitis B virus and hepatitis delta virus coinfection

BACKGROUND

Posttransplant combined lamivudine (LAM) and immunoglobulin (HBIg) prophylaxis is the gold standard in the case of single hepatitis B virus (HBV), but is still not recommended in the case of patients coinfected with hepatitis delta virus (HDV).

METHODS

We compared two consecutive groups of chronic HDV carriers who survived >6 months after liver transplantation of the risk of recurrence, survival and HBIg requirements: 21 received passive prophylaxis (HBIg group) and 25 were treated with combined prophylaxis (LAM+HBIg group). The immunoprophylaxis schedule was the same in both groups: intramuscular HBIg targeted to maintain anti-HBs levels of >500 IU/L during the first 6 posttransplant months and >200 IU/L thereafter.

RESULTS

The mean length of follow-up in the two groups was significantly different (133 vs. 40 months; P<0.001). None of the patients in either group developed recurrent hepatitis, and the 3-year actuarial survival rate was 100% in both groups. During the first 6 months, HBIg requirement was 38% lower in the LAM+HBIg group although similar anti-HBs target levels were maintained, leading to significantly lower costs (5,000 Euros in the first year and 500 Euros in the second).

CONCLUSIONS

This is the first study of large and homogeneous cohort of long-term HDV coinfected liver transplant survivors showing the absence of HBV recurrence under combined prophylaxis. Although retrospective, our results suggest that combined anti-HBV prophylaxis should also be preferred to single immunoprophylaxis in patients with HDV coinfection because it allows significant cost savings in the first two posttransplant years.

Dynamic fibroblast cultures: response to mechanical stretching

Mechanical forces play an important role in the organization, growth and function of tissues. Dynamic extracellular environment affects cellular behavior modifying their orientation and their cytoskeleton. In this work, human fibroblasts have been subjected for three hours to increasing substrate deformations (1-25%) applied as cyclic uniaxial stretching at different frequencies (from 0.25 Hz to 3 Hz). Our objective was to identify whether and in which ranges the different deformations magnitude and rate were the factors responsible of the cell alignment and if actin cytoskeleton modification was involved in these responses. After three hours of cyclically stretched substrate, results evidenced that fibroblasts aligned perpendicularly to the stretch direction at 1% substrate deformation and reached statistically higher orientation at 2% substrate deformation with unmodified values at 5-20%, while 25% substrate deformation induced cellular death. It was also shown that a percentage of cells oriented perpendicularly to the deformation were not influenced by increased frequency of cyclical three hours deformations (0.25%3 Hz). Cyclic substrate deformation was shown also to involve actin fibers which orient perpendicularly to the stress direction as well. Thus, we argue that a substrate deformation induces a dynamic change in cytoskeleton able to modify the entire morphology of the cells.

Properties of Zinc Releasing Surfaces for Clinical Applications

Two series of glasses of general formula (2-p) SiO2·1.1Na 2O·CaO·pP2O5·xZnO (p=0.10, 0.20; x=0.0, 0.16, 0.35, and 0.78) have been analyzed for physico-chemical surface features before and after contact with simulated body fluid, morphological characteristics, and osteoblast-like cells behavior when cultured on them. The resulted good cell adhesion and growth, along with nonsignificant changes of the focal contacts, allow the authors to indicate HZ5 and HP5Z5 glasses as the ones having optimal ratio of Zn/P to maintain acceptable cell behavior, comparable to the bioactive glass (Bioglass®) used as a control; results are also rationalized by means of three-dimensional models derived by molecular dynamic simulations, with decomposition and conversion rates optimized with respect to the parent Hench's Bioglass®.

[Low incidence of hip fractures among the elderly in Guadeloupe: a spared Caribbean island population]

PURPOSE OF THE STUDY

The purpose of this study was to determine the incidence of hip fractures among the elderly population in Guadeloupe, a French Caribbean archipelago with 440,000 inhabitants who present two rarely associated characteristics: 90% of the population is of African descent and life expectancy is similar to that of European populations.

MATERIAL AND METHODS

Using the recent census report, we established that in 2002, 61,000 persons aged 60 years or more (27,000 men and 34,000 women) lived in Guadeloupe. All new cases of hip fracture among the population aged 60 years or more were recorded in 2002, 2003, and 2004 in the seven islands that compose Guadeloupe. For each case, we noted patient age and gender, type of hip fracture, and treatment administered. We excluded open and pathologic fractures. Overall and age-specific incidence of hip fractures were determined and compared with rates reported for other countries.

RESULTS

Three hundred and two new cases of hip fracture were recorded from 2002 to 2005 in 211 women (70%) and 91 men (30%). The age of patients was 82 years on average (range 60-102). There were 134 neck fractures and 168 intertrochanteric fractures which were treated by osteosynthesis for 193 and arthroplasty for 108. Only one orthopedic treatment was noted. The incidence of hip fracture for people aged over 60 years was 16.9/10,000; for the population aged 65 years or more, it was 22.2/10,000.

DISCUSSION

Osteoporotic fracture is a pandemic problem. Incidence is increasing worldwide. Our findings demonstrate that Guadeloupeans are spared from this pathology. This population offers an interesting field for research into the causal mechanisms of osteoporotic fractures and potential means of prevention or screening.

CONCLUSION

The incidence of hip fractures among the elderly population in Guadeloupe is the lowest recorded in the world. We suggest that an environmental and genetic study in this spared population could provide interesting insight into the cause of hip fractures and appropriate means of prevention and screening among the elderly. The geographic and environmental characteristics of Guadeloupe make this area a unique zone of research and should enable new insight into the genetic and environmental factors involved in hip fractures.

PRODUCTION AND EFFECTS OF α-MELANOCYTE-STIMULATING HORMONE DURING ACUTE LUNG INJURY

Alpha-melanocyte-stimulating hormone (alpha-MSH) is a peptide with broad anti-inflammatory effects. The present research was designed to determine production and effects of alpha-MSH in acute bleomycin-induced lung injury in rats. Intratracheal bleomycin instillation induced alpha-MSH expression in lung infiltrating cells and a marked peptide increase in the circulation. In experiments on the therapeutic potential of alpha-MSH on lung injury, we determined influences of the synthetic alpha-MSH analogue [Nle4-dPhe7]-alpha-MSH (NDP-alpha-MSH) on pulmonary edema, circulating nitric oxide, and gene expression profile in lungs 8 and 24 h after bleomycin instillation. Three main gene categories, known to be involved in the development of acute lung injury, were explored: stress response, inflammation, and fluid homeostasis. Peptide treatment was associated with a significant reduction in interstitial edema, with a virtually normal wet/dry weight ratio. Several stress-related genes, which were either upregulated or reduced by bleomycin, were only marginally altered during NDP-alpha-MSH treatment. NDP-alpha-MSH prevented bleomycin-related transcriptional alterations in genes involved in lung fluid homeostasis, including upregulation of Na/K-transporting ATPase and epithelial sodium channels and downregulation of cystic fibrosis transmembrane conductance regulator. Bleomycin-induced expression of proinflammatory and profibrotic factors (interleukin 6, tumor necrosis factor-alpha, transforming growth factor-beta1, and inducible nitric oxide synthase) and chemokines (chemokine [C-C motif] ligand 2 and chemokine [C-C motif] ligand 5) was likewise significantly reduced by NDP-alpha-MSH. In conclusion, treatment with the alpha-MSH analogue NDP-alpha-MSH greatly improved the clinical and molecular picture of bleomycin-induced lung injury. Treatment with alpha-MSH-related agents can exert beneficial effects in acute lung injury.

Animal model for liver cell banking from non-heart beating donors after prolonged ischaemia time

BACKGROUND AND AIM

Although there is a growing interest on the use of non-heart beating donors to enlarge the liver donor pool, livers with prolonged warm ischaemia time are not currently considered for organ transplantation. We hypothesised that these organs may represent a source of hepatocytes for cell transplantation and/or use in bioartificial liver devices. Thus, we investigated if prolonged ischaemia could influence the recovery and viability of functional hepatocytes dissociated from rat livers.

METHODS

Hepatocytes were isolated from the liver within 15 min after death (t=15 min) and after 4, 8 and 12h of ischaemia. Cells were either maintained in culture or cryopreserved. In all products, we evaluated cell recovery and viability, hepatocyte markers and cellular functions, including albumin and urea production.

RESULTS

The number of cells per gram of tissue was similar at 15 min, 4 and 8h, while it was significantly decreased at 12h. About 0.2 x 10(6) viable cells expressing hepatocyte markers and producing albumin and urea were isolated up to 8h of ischaemia per gram of tissue.

CONCLUSIONS

Recovery of viable and functional hepatocytes seems possible after prolonged ischaemia time. These data warrant the evaluation of hepatocyte isolation from human livers of non-heart beating donors.

Antimicrobial properties of alpha-MSH and related synthetic melanocortins

The natural antimicrobial peptides are ancient host defense effector molecules, present in organisms across the evolutionary spectrum. Several properties of α-melanocyte stimulating hormone (α-MSH) suggested that it could be a natural antimicrobial peptide. α-MSH is a primordial peptide that appeared during the Paleozoic era, long before adaptive immunity developed and, like natural antimicrobial molecules, is produced by barrier epithelia, immunocytes, and within the central nervous system. α-MSH was discovered to have antimicrobial activity against two representative pathogens, Staphylococcus aureus and Candida albicans. The candidacidal influences of α-MSH appeared to be mediated by increases in cell cyclic adenosine monophosphate (cAMP). The cAMP-inducing capacity of α-MSH likely interferes with the yeast's own regulatory mechanisms of this essential signaling pathway. It is remarkable that this mechanism of action in yeast mimics the influences of α-MSH in mammalian cells in which the peptide binds to G-protein-linked melanocortin receptors, activates adenylyl cyclase, and increases cAMP. When considering that most of the natural antimicrobial peptides enhance the local inflammatory reaction, the anti-inflammatory and antipyretic effects of α-MSH confer unique properties to this molecule relative to other natural antimicrobial molecules. Synthetic derivatives, chemically stable and resistant to enzymatic degradation, could form the basis for novel therapies that combine anti-inflammatory and antimicrobial properties.

Isolation and characterization of a stem cell population from adult human liver

Several studies suggested the presence of stem cells in the adult normal human liver; however, a population with stem cell properties has not yet been isolated. The purpose of the present study was to identify and characterize progenitor cells in normal adult human liver. By stringent conditions of liver cell cultures, we isolated and characterized a population of human liver stem cells (HLSCs). HLSCs expressed the mesenchymal stem cell markers CD29, CD73, CD44, and CD90 but not the hematopoietic stem cell markers CD34, CD45, CD117, and CD133. HLSCs were also positive for vimentin and nestin, a stem cell marker. The absence of staining for cytokeratin-19, CD117, and CD34 indicated that HLSCs were not oval stem cells. In addition, HLSCs expressed albumin, alpha-fetoprotein, and in a small percentage of cells, cytokeratin-8 and cytokeratin-18, indicating a partial commitment to hepatic cells. HLSCs differentiated in mature hepatocytes when cultured in the presence of hepatocyte growth factor and fibroblast growth factor 4, as indicated by the expression of functional cytochrome P450, albumin, and urea production. Under this condition, HLSCs downregulated alpha-fetoprotein and expressed cytokeratin-8 and cytokeratin-18. HLSCs were also able to undergo osteogenic and endothelial differentiation when cultured in the appropriated differentiation media, but they did not undergo lipogenic differentiation. Moreover, HLSCs differentiated in insulin-producing islet-like structures. In vivo, HLSCs contributed to regeneration of the liver parenchyma in severe-combined immunodeficient mice. In conclusion, we here identified a pluripotent progenitor population in adult human liver that could provide a basis for cell therapy strategies.

Alteration in the Transcriptional Profile of Livers from Brain-dead Organ Donors

BACKGROUND

There is evidence that brain death causes changes in peripheral organs. Marked inflammation is found in organs collected during experimental brain death and clinical studies indicate that, despite genetic mismatch, organs obtained from living donors show improved survival over those from brain-dead donors. The aim of the present clinical research was to explore changes in the transcriptional profile of livers from brain-dead organ donors.

METHODS

Using the cDNA macroarray technique, we compared gene expression in liver biopsies from 21 brain-dead organ donors and in normal liver tissue obtained during resection of benign focal lesions.

RESULTS

Analysis of gene expression showed significant differences in the mRNA levels of 117 genes. There was reduced expression of 93 genes whereas expression of 24 genes was enhanced. Downregulated pathways included transcripts related to morphogenesis, blood coagulation, complement cascade, amine metabolism, lipid metabolism, nucleic acid metabolism, biodegradation of xenobiotics, signal transduction, and transcription. Conversely, there was induction of genes related to acute phase response, damage-related response, electron transport, and energy metabolism.

CONCLUSIONS

The present research demonstrates major changes in the transcriptional profile of livers from brain-dead organ donors. The presence of both down- and upregulated gene families suggests that the alteration in transcriptional profile is not a consequence of death-associated organ failure, but rather, an active change in regulatory mechanisms.

Change in gene expression profile induced by alpha-melanocyte stimulating hormone in a malignant mesothelioma cell line

We have previously reported that the peptide a-melanocyte stimulating hormone (alpha-MSH) has antiproliferative effects in human malignant mesothelioma cells. To determine the molecular mechanisms underlying such effects, we investigated the changes in gene expression profile induced by the alpha-MSH analog [Nle4 -DPhe7 ]-alpha-MSH (NDP-alpha-MSH) in a human malignant mesothelioma cell line. The cDNA macroarray technique revealed changes in expression of genes involved in cell growth, adhesion, signal transduction, and transcription. In particular, NDP-alpha-MSH down-regulated expression of B-Myb and Myc, two oncogenes considered of paramount importance for cell proliferation and cancer. Further, NDP-alpha-MSH exerted a favorable transcriptional regulation of certain integrins and their signaling pathways. Finally, peptide treatment was associated with a prominent inhibition of IL-13, a cytokine with tumor-promoting effects. The data indicate that the influences of alpha-MSH extend beyond the established anti-inflammatory effects in normal cells to include cell cycle regulatory properties in malignant cells.

Inhibitory Effects of the Peptide (CKPV)2 on Endotoxin-Induced Host Reactions

BACKGROUND

alpha-Melanocyte stimulating hormone (alpha-MSH) is an endogenous peptide that has remarkable anti-inflammatory and antimicrobial effects. These activities have been traced to the C-terminal tripeptide Lys-Pro-Val (KPV). A dimer composed of two KPV sequences connected with a Cys-Cys linker, (CKPV)2, is currently under clinical investigation for antimicrobial use. The present research was designed to evaluate effects of (CKPV)(2) on endotoxin-induced host reactions in vitro and in vivo.

MATERIALS AND METHODS

Effects of (CKPV)2, KPV, and [Nle4-dPhe7]-alpha-MSH (NDP-alpha-MSH) on tumor necrosis factor alpha (TNF-alpha) production were determined: 1) in human peripheral blood mononuclear cells (PBMC) stimulated with lipopolysaccharide (LPS) in vitro, and 2) in rats injected with LPS i.v. and sacrificed at 1 h. In additional experiments, dialysis peritonitis was induced in rats by adding LPS to dialysis fluid. Net ultrafiltrate was calculated and concentrations of nitrite (NO2-) and TNF-alpha were measured in blood and peritoneal fluid at 7 h.

RESULTS

(CKPV)2 inhibited TNF-alpha production by LPS-stimulated human PBMC. This small peptide was as effective as NDP-alpha-MSH and more potent than KPV. Similar effectiveness was observed in vivo: 1 h after LPS injection, the large increase in circulating TNF-alpha was markedly reduced by (CKPV)2 treatment. In LPS-induced peritonitis, (CKPV)2 restored net ultrafiltrate to control values and significantly inhibited concentrations of TNF-alpha and NO2- both in plasma and in dialysate.

CONCLUSIONS

The remarkable capacity of (CKPV)2 to inhibit endotoxin-induced host reactions suggests that it may be useful in treatment of inflammatory disorders.

Reduced expression of the melanocortin-1 receptor in human liver during brain death

OBJECTIVE

There is evidence that brain death has detrimental effects on peripheral organs. Clinical and experimental studies on organ donors showed marked inflammation in tissue samples of livers and kidneys collected during brain death. The inflammatory reaction is characterized by release of cytokines and inflammatory cell infiltration. Because melanocortins and their receptors are significant modulators of inflammation, we hypothesized that downregulation of melanocortin receptors during brain death could contribute to enhance inflammation.

METHODS

Using real-time polymerase chain reaction (PCR) analysis, we determined expression of melanocortin receptors in liver biopsies obtained from brain-dead organ donors before cold ischemia and in normal liver tissue during resection of benign focal lesions of the liver. Tissue biopsies were also analyzed for expression of intercellular adhesion molecule-1 (ICAM-1), which has a central function in inflammatory cell migration.

RESULTS

Expression of melanocortin-1 receptor (MC1R) mRNA was markedly reduced in liver samples obtained from brain-dead organ donors compared to hepatic tissue collected during resection of benign focal lesions of the liver. Conversely, expression of the adhesion molecule ICAM-1 was significantly increased in livers of brain-dead organ donors.

CONCLUSIONS

Disruption of the endogenous anti-inflammatory circuit based on MC1R could contribute to tissue damage during brain death.

Gene expression profiling reveals multiple protective influences of the peptide alpha-melanocyte-stimulating hormone in experimental heart transplantation

Novel therapies are sought to increase efficiency and survival of transplanted organs. Previous research on experimental heart transplantation showed that treatment with the anti-inflammatory peptide alpha-melanocyte-stimulating hormone (alpha-MSH) prolongs allograft survival. The aim of the present research was to determine the molecular mechanism of this protective activity. Gene expression profile was examined in heart grafts removed on postoperative days 1 and 4 from rats treated with saline or the synthetic alpha-MSH analog Nle4DPhe7 (NDP)-alpha-MSH. On postoperative day 1, the peptide induced expression of cytoskeleton proteins, intracellular kinases, transcription regulators, metallopeptidases, and protease inhibitors. Conversely, NDP-alpha-MSH repressed immune, inflammatory, cell cycle, and protein turnover mediators. Later effects of alpha-MSH treatment included down-regulation of oxidative stress response and up-regulation of ion channels, calcium regulation proteins, phosphatidylinositol signaling system, and glycolipidic metabolism. NDP-alpha-MSH exerted its effects on both Ag-dependent and -independent injury. The results indicate that NDP-alpha-MSH preserves heart function through a broad effect on multiple pathways and suggest that the peptide could improve the outcome of organ transplantation in combination with immunosuppressive treatments.

Three-dimensional structure of the alpha-MSH-derived candidacidal peptide [Ac-CKPV]2

Previous research has shown that the immunomodulatory peptide alpha-melanocyte-stimulating hormone (alpha-MSH) and its carboxy-terminal tripeptide KPV (Lys-Pro-Val alpha-MSH11-13) have antimicrobial influences. By inserting a Cys-Cys linker between two units of KPV, we designed the dimer [Ac-CKPV]2 that showed excellent candidacidal effects in pilot tests and was the subject of further investigations. [Ac-CKPV]2 was active against azole-resistant Candida spp. Therefore, the molecule appeared a promising candidate for therapy of fungal infections and was the subject of a structural study. 1H-NMR and restrained mechanic and dynamic calculations suggest that the peptide adopts an extended backbone structure with a beta-turn-like structure. These results open a pathway to development of additional novel compounds that have candidacidal effects potentially useful against clinical infections.

Giant basal cell carcinoma of the thoracic wall: a case report and review of the literature

Giant basal cell carcinoma is a rare skin tumour with aggressive biological behaviour, and deep invasion and metastasis have been reported. The authors describe a giant basal cell carcinoma involving the anterior chest wall. The lesion infiltrated the mediastinum, occluding the left brachiocephalic vein. Vascular invasion caused venous occlusion affecting the left upper limb. Neither surgical treatment nor radiotherapy were practicable.

Back-Table Arterial Reconstructions in Liver Transplantation: Single-Center Experience

Anatomic variations of the arterial supply to donor liver grafts often require complex hepatic artery reconstructions on the back table. Therefore, because of the additional anastomoses, there is a greater risk of arterial thrombosis and graft loss. Among the 620 orthotopic liver transplantations (OLT) in 549 adult and pediatric patients performed from June 1983 through August 2004, the rates and types of donor hepatic artery variations (HAV) and the type of reconstructions were reviewed as well as the 1- and 5-year grafts and patient survival rates after OLT. At least 1 HAV was present in 133 liver grafts (21.4%). The most frequent variations were as follows: right hepatic artery (RHA) from superior mesenteric artery (SMA) (44 cases); RHA from aorta (4 cases); and RHA from SMA, combined with a left hepatic artery (LHA) from left gastric artery (3 cases). No graft was discarded. Fifty-six of 133 (42%) HAV required arterial reconstructions, generally a termino-terminal (TT) anastomosis between RHA and splenic artery (26 cases, 46.4%). Less frequently performed anastomoses were the "fold-over" technique (15 cases, 26.8%) and the anastomosis between the RHA and the gastro-duodenal artery (6 cases, 10.6%); rare reconstructions were performed in 9 cases (16.0%). The rate of hepatic artery thrombosis was 5.4% (3 of 56 OLT) in complex hepatic artery reconstructions and 2.2% in other grafts. One- and 5-years graft and patient actuarial survival rates have been respectively 73.2%- 71.4% in hepatic artery reconstructions and 78.6%-76.8% in the absence of an artery reconstruction, respectively.