Routine Clinical-Pathologic Correlation of Pigmented Skin Tumors Can Influence Patient Management

Background

Several studies have demonstrated the benefit of integrating clinical with pathologic information, to obtain a confident diagnosis for melanocytic tumors. However, all those studies were conducted retrospectively and no data are currently available about the role of a clinical-pathologic correlation approach on a daily basis in clinical practice.

Aim of the Study

In our study, we evaluated the impact of a routine clinical-pathologic correlation approach for difficult skin tumors seen over 3 years in a tertiary referral center.

Results

Interestingly, a re-appraisal was requested for 158 out of 2015 (7.7%) excised lesions because clinical-pathologic correlation was missing. Of note, in 0.6% of them (13 out of 2045) the first histologic diagnosis was revised in the light of clinical information that assisted the Pathologist to re-evaluate the histopathologic findings that might be bland or inconspicuous per se.

Conclusion

In conclusion, our study demonstrated that an integrated approach involving clinicians and pathologists allows improving management of selected patients by shifting from a simply disease-focused management (melanoma versus nevus) to a patient-centered approach.     

Cytotype stability, facultative apomixis and geographical parthenogenesis in Ranunculus kuepferi (Ranunculaceae)

Background and Aims

Asexual organisms are more widespread in previously glaciated areas than their sexual relatives (‘geographical parthenogenesis’). In plants, this pattern is probably dependent on reproductive isolation and stability of cytotypes within their respective distribution areas. Both partial apomixis and introgressive hybridization potentially destabilize the spatial separation of sexual and apomictic populations. The wide distribution of apomicts may be further enhanced by uniparental reproduction which is advantageous for colonization. These factors are studied in the alpine species Ranunculus kuepferi.

Methods

Geographical distribution, diversity and mode of reproduction of cytotypes were assessed using flow cytometry and flow cytometric seed screening on samples from 59 natural populations of Ranunculus kuepferi. Seed set of cytotypes was compared in the wild.

Key Results

Diploid sexuals are confined to the south-western parts of the Alps, while tetraploid apomicts dominate in previously glaciated and in geographically isolated areas despite a significantly lower fertility. Other cytotypes (3x, 5x and 6x) occur mainly in the sympatric zone, but without establishing populations. The tetraploids are predominantly apomictic, but also show a partial apomixis via an uncoupling of apomeiosis and parthenogenesis in the seed material. Both pseudogamy and autonomous endosperm formation are observed which may enhance uniparental reproduction.

Conclusions

Diploids occupy a glacial relic area and resist introgression of apomixis, probably because of a significantly higher seed set. Among the polyploids, only apomictic tetraploids form stable populations; the other cytotypes arising from partial apomixis fail to establish, probably because of minority cytotype disadvantages. Tetraploid apomicts colonize previously devastated and also distant areas via long-distance dispersal, confirming Baker''s law of an advantage of uniparental reproduction. It is concluded that stability of cytotypes and of modes of reproduction are important factors for establishing a pattern of geographical parthenogenesis.     

Oxidized LDL and its correlation with lipid profile and oxidative stress biomarkers in young healthy Spanish subjects

The biological effects of oxidized LDL (oxLDL) may contribute to initiation and progression of the atherosclerotic process, and the association between cardiovascular disease and oxidation of LDL has been largely demonstrated. The objectives of this study were to establish the reference values of oxidative stress biomarkers in a young healthy Spanish population to determine the concentration of oxLDL and its relationship with lipid profile and with these biomarkers. oxLDL, F₂-isoprostanes, protein carbonyls (PC), and 8-hydroxy-2′-deoxyguanosine (8-OHdG) were determinate by ELISA in 72 healthy subjects. Antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GR) were carried out on a Hitachi 912 analyzer; lipid profile were assayed using automated systems (Cobas 711, Roche Diagnostics). All statistics were analyzed by using SPSS for Windows 15.0. SPSS Inc, Chicago, IL, USA. (Normal mean reference values): oxLDL (63.23 ± 16.23 U/L), (Male/Female 68.06 ± 17.69/58.39 ± 13.6 U/L), F₂-isoprostanes (2.26 ± 0.9 μg/g creatinine), PC (0.34 ± 0.15 nmol/mg), 8-OHdG (23.27 ± 10.58 ng/ml), SOD (931.97 ± 271.09 U/g Hb), GR (46.56 ± 11.68 U/L), GPx (27.58 ± 6.89 U/gHb (Male/Female 25.91 ± 5.03/29.2 ± 8.07 U/L)). OxLDL (63.23 U/L) was significantly (p < 0.05) positively correlated with BMI (22.53 Kg/m²), total cholesterol (175.79 mg/dl), triglycerides (87.58 mg/dl), LDL cholesterol (96.25 mg/dl), and uric acid (4.78 mg/dl), while negatively correlated with HDL-cholesterol (62.25 mg/dl). We have found different correlation between oxLDL and isoprostanes by gender with the rest of parameters. Normal reference values have been found significantly different for oxLDL and GPx by gender. Oxidized LDL is correlated with lipid profile but not with the oxidative stress biomarkers. Urinary isoprostanes are positively correlated with triglycerides and negatively with GR and GPx.     

Steps in reductive activation of the disulfide-generating enzyme Ero1p

Ero1p is the primary catalyst of disulfide bond formation in the yeast endoplasmic reticulum (ER). Ero1p contains a pair of essential disulfide bonds that participate directly in the electron transfer pathway from substrate thiol groups to oxygen. Remarkably, elimination of certain other Ero1p disulfides by mutation enhances enzyme activity. In particular, the C150A/C295A Ero1p mutant exhibits increased thiol oxidation in vitro and in vivo and interferes with redox homeostasis in yeast cells by hyperoxidizing the ER. Inhibitory disulfides of Ero1p are thus important for enzyme regulation. To visualize the differences between de-regulated and wild-type Ero1p, we determined the crystal structure of Ero1p C150A/C295A. The structure revealed local changes compared to the wild-type enzyme around the sites of mutation, but no conformational transitions within 25 Å of the active site were observed. To determine how the C150—C295 disulfide nonetheless participates in redox regulation of Ero1p, we analyzed using mass spectrometry the changes in Ero1p disulfide connectivity as a function of time after encounter with reducing substrates. We found that the C150—C295 disulfide sets a physiologically appropriate threshold for enzyme activation by guarding a key neighboring disulfide from reduction. This study illustrates the diverse and interconnected roles that disulfides can play in redox regulation of protein activity.     

Alternative Splicing at a NAGNAG Acceptor Site as a Novel Phenotype Modifier

Approximately 30% of alleles causing genetic disorders generate premature termination codons (PTCs), which are usually associated with severe phenotypes. However, bypassing the deleterious stop codon can lead to a mild disease outcome. Splicing at NAGNAG tandem splice sites has been reported to result in insertion or deletion (indel) of three nucleotides. We identified such a mechanism as the origin of the mild to asymptomatic phenotype observed in cystic fibrosis patients homozygous for the E831X mutation (2623G>T) in the CFTR gene. Analyses performed on nasal epithelial cell mRNA detected three distinct isoforms, a considerably more complex situation than expected for a single nucleotide substitution. Structure-function studies and in silico analyses provided the first experimental evidence of an indel of a stop codon by alternative splicing at a NAGNAG acceptor site. In addition to contributing to proteome plasticity, alternative splicing at a NAGNAG tandem site can thus remove a disease-causing UAG stop codon. This molecular study reveals a naturally occurring mechanism where the effect of either modifier genes or epigenetic factors could be suspected. This finding is of importance for genetic counseling as well as for deciding appropriate therapeutic strategies.     

Antiproliferative effect of D-glucuronyl C5-epimerase in human breast cancer cells

Background  

D-glucuronyl C5-epimerase (GLCE) is one of the key enzymes in the biosynthesis of heparansulfate proteoglycans. Down-regulation of GLCE expression in human breast tumours suggests a possible involvement of the gene in carcinogenesis. In this study, an effect of GLCE ectopic expression on cell proliferation and viability of breast carcinoma cells MCF7 in vitro and its potential molecular mechanisms were investigated.     

Thiocyanate transport in resting and IL-4-stimulated human bronchial epithelial cells: role of pendrin and anion channels

SCN(-) (thiocyanate) is an important physiological anion involved in innate defense of mucosal surfaces. SCN(-) is oxidized by H(2)O(2), a reaction catalyzed by lactoperoxidase, to produce OSCN(-) (hypothiocyanite), a molecule with antimicrobial activity. Given the importance of the availability of SCN(-) in the airway surface fluid, we studied transepithelial SCN(-) transport in the human bronchial epithelium. We found evidence for at least three mechanisms for basolateral to apical SCN(-) flux. cAMP and Ca(2+) regulatory pathways controlled SCN(-) transport through cystic fibrosis transmembrane conductance regulator and Ca(2+)-activated Cl(-) channels, respectively, the latter mechanism being significantly increased by treatment with IL-4. Stimulation with IL-4 also induced the strong up-regulation of an electroneutral SCN(-)/Cl(-) exchange. Global gene expression analysis with microarrays and functional studies indicated pendrin (SLC26A4) as the protein responsible for this SCN(-) transport. Measurements of H(2)O(2) production at the apical surface of bronchial cells indicated that the extent of SCN(-) transport is important to modulate the conversion of this oxidant molecule by the lactoperoxidase system. Our studies indicate that the human bronchial epithelium expresses various SCN(-) transport mechanisms under resting and stimulated conditions. Defects in SCN(-) transport in the airways may be responsible for susceptibility to infections and/or decreased ability to scavenge oxidants.     

Sexually mature and immature yearling male European ground squirrels: a comparison of behavioral and physiological parameters

Early puberty may increase lifetime reproductive success, but may also entail diverse costs. In male European ground squirrels (Spermophilus citellus), age at sexual maturity varies among individuals. We compared sexually active and inactive yearling males under standardized conditions in outdoor enclosures. Non-reproductive yearling males hibernated significantly longer than mature males and emerged when the mating period had already started. Testosterone concentrations peaked in the precocious males during premating and mating, and were depressed in the non-reproductive individuals throughout the study period. Emergence body mass was similar in both groups, although sexually immature males were significantly heavier at the end of the active season. Additionally, non-reproductive yearlings grew faster than precocious individuals. Male–male aggression peaked during mating and the following 4 weeks. Intense aggressive interactions like chases and fights were mostly initiated by reproductive males and were directed towards mature competitors. Aggressive behavior in immature males was mainly expressed as spatial displacements. Non-agonistic interactions with females were only observed in sexually active males. Concentrations of fecal cortisol metabolites did not differ between the two male groups and were elevated in the second half of the active season. Leucocyte numbers were reduced during mating in mature males, whereas in immature animals, cell numbers did not change significantly. Our results indicate that early puberty in European ground squirrels involves lower growth rates, high intrasexual aggression, lower prehibernatory body mass, and probably worse immunological condition during mating.     

Endothelin stimulates vascular hydroxyl radical formation: effect of obesity

Reactive oxygen species (ROS) and endothelin-1 (ET-1) contribute to vascular pathophysiology in obesity. In this context, whether ET-1 modulates hydroxyl radical (*OH) formation and the function of ROS/*OH in obesity is not known. In the present study, formation and function of ROS, including *OH, were investigated in the aorta of lean and leptin-deficient obese ob/ob mice. Hydroxyl radical formation was detected ex vivo using terephthalic acid in intact aortic rings and the involvement of ROS in ET-1-mediated vasoreactivity was analyzed using the antioxidant EPC-K1, a combination of alpha-tocopherol and ascorbic acid. Generation of either *OH, *O(2)(-), and H(2)O(2) was strongly inhibited by EPC-K1 (all P < 0.05). In obese mice, basal vascular *OH formation and ROS activity were reduced by 3-fold and 5-fold, respectively (P < 0.05 vs. lean). ET-1 markedly enhanced *OH formation in lean (6-fold, P < 0.05 vs. untreated) but not in obese mice. Obesity increased ET-1-induced contractions (P < 0.05 vs. lean), and ROS scavenging further enhanced the response (P < 0.05 vs. untreated). Exogenous ROS, including *OH caused stronger vasodilation in obese animals (P < 0.05 vs. lean), whereas endothelium-dependent relaxation was similar between lean and obese animals. In conclusion, we present a sensitive method allowing ex vivo measurement of vascular *OH generation and provide evidence that ET-1 regulates vascular *OH formation. The data indicate that in obesity, vascular formation of ROS, including *OH is lower, whereas the sensitivity to ROS is increased, suggesting a novel and important role of ROS, including *OH in the regulation of vascular tone in disease status associated with increased body weight.