La dermatoscopia como herramienta para inferir el Breslow del melanoma / Dermoscopy as a Tool for Estimating Breslow Thickness in Melanoma

Antecedentes y objetivo: La incidencia del melanoma se ha incrementado significativamente y la forma más efectiva para disminuir su mortalidad es el diagnóstico precoz. La dermatoscopia aumenta la sensibilidad en el diagnóstico del melanoma, y por medio del análisis de las estructuras dermatoscópicas es posible estimar su grosor. Nuestro objetivo fue analizar la influencia del Breslow en las características dermatoscópicas del melanoma. Materiales y métodos: Estudio observacional de corte transversal. Se incluyeron pacientes con melanoma confirmado histológicamente y una imagen dermatoscópica del mismo. Se dividieron en tres grupos, melanoma in situ, melanoma fino (< 1 mm de Breslow) y melanoma grueso (≥ 1 mm de Breslow), y se analizaron el sexo, la edad, la localización, las características histológicas y las características dermatoscópicas. Resultados: Se analizaron 215 pacientes, 88 con melanoma in situ, 73 con melanoma fino y 54 con melanoma grueso. Las estructuras dermatoscópicas que incrementaron su frecuencia a medida que aumentó el Breslow del melanoma fueron el velo azul blanquecino (p < 0,001), las estructuras blanco brillantes (p < 0,001) y las áreas rojo lechosas (p < 0,003). Por otro lado, las líneas anguladas disminuyeron su frecuencia a medida que se incrementó el Breslow (p < 0,002). Conclusiones: La evaluación dermatoscópica tiene un importante rol, no solo en la precisión diagnóstica de las lesiones pigmentadas, sino también en ayudarnos a estimar el grosor preoperatorio del melanoma (AU)

Background and objective: The incidence of melanoma has increased significantly, and early diagnosis is the most effective way to reduce associated deaths. Dermoscopy increases diagnostic accuracy in melanoma and analysis of dermoscopic structures can help in the estimation of tumor thickness. The aim of this study was to analyze the influence of Breslow thickness on the dermoscopic characteristics of melanoma. Material and methods: Observational, cross-sectional study of patients with histologically confirmed melanoma and dermoscopic images of the tumor. The patients were divided into three groups: melanoma in situ, thin melanoma (≥ 1 mm Breslow thickness), and thick melanoma (≥ 1 mm Breslow thickness). Age, sex, tumor location, and histologic and dermoscopic characteristics were analyzed in all cases. Results: We studied 215 patients: 88 with melanoma in situ, 73 with thin melanoma, and 54 with thick melanoma. The frequency of the following dermoscopic features increased with increasing Breslow thickness: the blue-white veil (p < 0.001), white shiny structures (p < 0.001), and milky-red areas (p < 0.003). Angulated lines, by contrast, became less common with increasing thickness (p < 0.002). Conclusions: Dermoscopy not only improves diagnostic accuracy for pigmented lesions but also helps in the preoperative assessment of Breslow thickness in melanoma (AU)

Dermoscopy as a Tool for Estimating Breslow Thickness in Melanoma. / La dermatoscopia como herramienta para inferir el Breslow del melanoma.

BACKGROUND AND OBJECTIVE: The incidence of melanoma has increased significantly, and early diagnosis is the most effective way to reduce associated deaths. Dermoscopy increases diagnostic accuracy in melanoma and analysis of dermoscopic structures can help in the estimation of tumor thickness. The aim of this study was to analyze the influence of Breslow thickness on the dermoscopic characteristics of melanoma. MATERIAL AND METHODS: Observational, cross-sectional study of patients with histologically confirmed melanoma and dermoscopic images of the tumor. The patients were divided into three groups: melanoma in situ, thin melanoma (≥ 1 mm Breslow thickness), and thick melanoma (≥ 1 mm Breslow thickness). Age, sex, tumor location, and histologic and dermoscopic characteristics were analyzed in all cases. RESULTS: We studied 215 patients: 88 with melanoma in situ, 73 with thin melanoma, and 54 with thick melanoma. The frequency of the following dermoscopic features increased with increasing Breslow thickness: the blue-white veil (p < 0.001), white shiny structures (p < 0.001), and milky-red areas (p < 0.003). Angulated lines, by contrast, became less common with increasing thickness (p < 0.002). CONCLUSIONS: Dermoscopy not only improves diagnostic accuracy for pigmented lesions but also helps in the preoperative assessment of Breslow thickness in melanoma.

Forensic Engineering of Advanced Polymeric Materials-Part VII: Degradation of Biopolymer Welded Joints.

Welding technology may be considered as a promising processing method for the formation of packaging products from biopolymers. However, the welding processes used can change the properties of the polymer materials, especially in the region of the weld. In this contribution, the impact of the welding process on the structure and properties of biopolymer welds and their ability to undergo hydrolytic degradation will be discussed. Samples for the study were made from polylactide (PLA) and poly(3-hydroxyalkanoate) (PHA) biopolymers which were welded using two methods: ultrasonic and heated tool welding. Differential scanning calorimetry (DSC) analysis showed slight changes in the thermal properties of the samples resulting from the processing and welding method used. The results of hydrolytic degradation indicated that welds of selected biopolymers started to degrade faster than unwelded parts of the samples. The structure of degradation products at the molecular level was confirmed using mass spectrometry. It was found that hydrolysis of the PLA and PHA welds occurs via the random ester bond cleavage and leads to the formation of PLA and PHA oligomers terminated by hydroxyl and carboxyl end groups, similarly to as previously observed for unwelded PLA and PHA-based materials.

Prediction studies of environment-friendly biodegradable polymeric packaging based on PLA. Influence of specimens' thickness on the hydrolytic degradation profile.

Application of new biodegradable polymer packaging based on polylactide (PLA), susceptible to organic recycling, can help in the waste reduction in landfills. In this paper, the results of the study on abiotic degradation of PLA and its blend containing 15 mol% of poly[(R,S)-3-hydroxybutyrate], as a model for the first step of organic recycling were presented. The samples used for this study have different shapes and thicknesses: rigid films and cuboid-bars. Particular emphasis was placed on determining the pattern of degradation products released into the medium. Originally, the results of present study revealed that the application of electrospray ionization mass spectrometry supported by high performance liquid chromatography allowed envisaging the differences in the degradation products pattern released from the studied PLA-based samples differing in thickness. The significant differences in degradation products pattern were predominately observed in the first steps of incubation process and are caused by an autocatalytic effect, which occurs mainly during degradation of the large size PLA samples. Although, the thickness of PLA-based packaging changes the degradation product patterns, however this does not increase the total amounts of acids released to the medium. Thus, it may be concluded that thickness should not affect significantly organic recycling of the packaging.

Hip arthroscopy in the setting of hip dysplasia: A systematic review.

OBJECTIVE: Hip arthroscopy in the setting of hip dysplasia is controversial in the orthopaedic community, as the outcome literature has been variable and inconclusive. We hypothesise that outcomes of hip arthroscopy may be diminished in the setting of hip dysplasia, but outcomes may be acceptable in milder or borderline cases of hip dysplasia. METHODS: A systematic search was performed in duplicate for studies investigating the outcome of hip arthroscopy in the setting of hip dysplasia up to July 2015. Study parameters including sample size, definition of dysplasia, outcomes measures, and re-operation rates were obtained. Furthermore, the levels of evidence of studies were collected and quality assessment was performed. RESULTS: The systematic review identified 18 studies investigating hip arthroscopy in the setting of hip dysplasia, with 889 included patients. Criteria used by the studies to diagnose hip dysplasia and borderline hip dysplasia included centre edge angle in 72% of studies but the range of angles were quite variable. Although 89% of studies reported improved post-operative outcome scores in the setting of hip dysplasia, revision rates were considerable (14.1%), with 9.6% requiring conversion to total hip arthroplasty. CONCLUSION: The available orthopaedic literature suggests that although improved outcomes are seen in hip arthroscopy in the setting of hip dysplasia, there is a high rate of re-operation and conversion to total hip arthroplasty. Furthermore, the criteria used to define hip dysplasia vary considerably among published studies.Cite this article: M. Yeung, M. Kowalczuk, N. Simunovic, O. R. Ayeni. Hip arthroscopy in the setting of hip dysplasia: A systematic review. Bone Joint Res 2016;5:225-231. DOI: 10.1302/2046-3758.56.2000533.

Degradability in vitro of polyurethanes based on synthetic atactic poly[(R,S)-3-hydroxybutyrate].

The aim of the present study was to determine the degradability of aliphatic polyurethanes, based on a different amount of synthetic, atactic poly[(R,S)-3-hydroxybutyrate] (a-PHB), in hydrolytic (phosphate buffer) and oxidative (H2O2/CoCl2) solutions. The soft segments were built with atactic poly[(R,S)-3-hydroxybutyrate] and polycaprolactone or polyoxytetramethylenediols, whereas hard segments were the reaction product of 4,4'-methylenedicyclohexyl diisocyanate and 1,4-butanediol.The selected properties - density and morphology of polymer surfaces - which could influence the sensitivity of polymers to degradation processes - were analyzed.The analysis of molecular mass (GPC), thermal properties (DSC) and the sample weight changes were undertaken to estimate the degree of degradability of polymer samples after incubation in environments studied.Investigated polyurethanes were amorphous with the very low amount of crystalline phases of hard segments.The polyurethane synthesized with a poly[(R,S)-3-hydroxybutyrate] and polyoxytetramethylenediol at a molar ratio of NCO:OH=3.7:1 (prepolymer step) appeared as the most sensitive for both degradative solutions. Its weight and molecular mass losses were the highest in comparison to other investigated polyurethanes.It could be expected that playing with the amount of poly[(R,S)-3-hydroxybutyrate] in polyurethane synthesis the rate of polyurethane degradation after immersion in living body would be modeled.

Radiographic prevalence of CAM-type femoroacetabular impingement after open reduction and internal fixation of femoral neck fractures.

PURPOSE: The purpose of this study was to estimate the radiographic prevalence of CAM-type femoroacetabular impingement (FAI) in elderly patients (≥ 50 years) who have undergone internal fixation for femoral neck fracture. METHODS: A total of 187 frog-leg lateral radiographs of elderly patients who underwent internal fixation for a femoral neck fracture were reviewed by two independent reviewers. The alpha angle, beta angle, and femoral head-neck offset ratio were calculated. The presence of two abnormal radiographic parameters was deemed to be diagnostic of radiographic CAM-type impingement. RESULTS: Radiographic CAM-type FAI was identified in 157 out of 187 (84 %) patients who underwent internal fixation for fractures of the femoral neck. Moderate-to-good inter-observer reliability was achieved in the measurement of radiographic parameters. With reference to fracture subtypes and prevalence of radiographic features of CAM-type morphology, 97 (72 %) out of 134 patients were positive for CAM in Garden subtypes I and II, whereas 49 (85.9 %) out of 57 patients had radiographic CAM in Garden III and IV subtypes. CONCLUSION: There was a high prevalence of CAM-type FAI in patients that underwent surgical fixation of femoral neck fractures. This is significantly higher than the reported prevalence in non-fracture patient populations. The high prevalence of CAM morphology could be related to several factors, including age, fracture morphology, quality of reduction, type of fixation, and fracture healing.

Complications following hip arthroscopy: a systematic review and meta-analysis.

PURPOSE: The use of hip arthroscopy to address injuries and conditions about the hip is becoming more widespread. There are several narrative reviews regarding complications of hip arthroscopy but a systematic review is currently lacking. The primary goal of this study is to determine the complication rate associated with hip arthroscopy in the literature. METHODS: A search of the EMBASE and Ovid Medline databases was performed to identify articles published between 1 January 2000 and 25 November 2011 that reported a complication rate after hip arthroscopy. Appropriate inclusion and exclusion criteria were applied to identify articles, and a meta-analysis was performed to determine an overall complication rate. Complications were divided into major and minor. RESULTS: A total of 66 papers (n = 6,962 hip arthroscopies) were identified and deemed appropriate for analysis. The overall complication rate was found to be 4.0 % (95 % CI 2.9-5.2 %). Of the 287 complications identified in the literature, 20 were deemed major constituting a rate of 0.3 %. CONCLUSIONS: Hip arthroscopy appears to be safe. The vast majority of complications are minor in nature. Prospective trials looking at the complications of hip arthroscopy would aid in identifying prognostic factors. LEVEL OF EVIDENCE: Systematic review and meta-analysis, Level III.

Synthesis of poly(2-methyl-3-hydroxyoctanoate) via anionic polymerization of alpha-methyl-beta-pentyl-beta-propiolactone.

Synthesis of an alpha,beta-alkyl branched polyester, i.e., poly(2-methyl-3-hydroxyoctanoate), has been accomplished via anionic polymerization of alpha-methyl-beta-pentyl-beta-propiolactone mediated by supramolecular complexes of potassium methoxide or potassium hydroxide, respectively. The structure of resulting polymers has been established by electrospray ionization multistage mass spectrometry (ESI-MSn), FT-IR, NMR, and GPC analyses. Previously proposed addition-elimination mechanism of the polymerization of beta-lactones containing alpha-hydrogen by alkoxide anion has been confirmed to operate also in the case of beta-lactone having alkyl substituents in both alpha and beta positions.

The differential killing of genes by inversions in prokaryotic genomes.

We have elaborated a method which has allowed us to estimate the direction of translocation of orthologs which have changed, during the phylogeny, their positions on chromosome in respect to the leading or lagging role of DNA strands. We have shown that the relative number of translocations which have switched positions of genes from the leading to the lagging DNA strand is lower than the number of translocations which have transferred genes from the lagging strand to the leading strand of prokaryotic genomes. This paradox could be explained by assuming that the stronger mutation pressure and selection after inversion preferentially eliminate genes transferred from the leading to the lagging DNA strand.

Water-soluble L-alanine and related oligopeptide conjugates with poly[(R,S)-3-hydroxybutanoic acid] oligomers, synthesis and structural studies by means of electrospray ionization multistage mass spectrometry.

The reactions of (R,S) beta-butyrolactone with L-alanine and related oligopeptides (Ala-Ala-Ala) were investigated. The resulting water-soluble oligomers were composed of poly[(R,S)-3-hydroxybutanoic acid] (a-PHB) covalently conjugated to L-alanine and Ala-Ala-Ala oligopeptide. The other chain end was of the carboxylic acid type. The structure of the obtained oligomers was assessed by electrospray ionization multistage mass spectrometry (ESI-MSn) and the respective structural information was completed by IR, NMR, and GPC analyses. The molecular weight and structure of the products could be controlled through reaction conditions. Using this new synthetic approach. a-PHB oligomers with well-defined end groups, as well as respective block copolymers, can be prepared via regioselective ring-opening oligomerization of (R,S) beta-butyrolactone induced by amino acids under their zwitterionic form.

Evolution rates of genes on leading and lagging DNA strands.

One of the main causes of bacterial chromosome asymmetry is replication-associated mutational pressure. Different rates of nucleotide substitution accumulation on leading and lagging strands implicate qualitative and quantitative differences in the accumulation of mutations in protein coding sequences lying on different DNA strands. We show that the divergence rate of orthologs situated on leading strands is lower than the divergence rate of those situated on lagging strands. The ratio of the mutation accumulation rate for sequences lying on lagging strands to that of sequences lying on leading strands is rather stable and time-independent. The divergence rate of sequences which changed their positions, with respect to the direction of replication fork movement, is not stable-sequences which have recently changed their positions are the most prone to mutation accumulation. This effect may influence estimations of evolutionary distances between species and the topology of phylogenetic trees.

A new type of thermoalkalophilic hydrolase of Paucimonas lemoignei with high specificity for amorphous polyesters of short chain-length hydroxyalkanoic acids.

A novel type of hydrolase was purified from culture fluid of Paucimonas (formerly Pseudomonas) lemoignei. Biochemical characterization revealed an unusual substrate specificity of the purified enzyme for amorphous poly((R)-3-hydroxyalkanoates) (PHA) such as native granules of natural poly((R)-3-hydroxybutyrate) (PHB) or poly((R)-3-hydroxyvalerate) (PHV), artificial cholate-coated granules of natural PHB or PHV, atactic poly((R,S)-3-hydroxybutyrate), and oligomers of (R)-3-hydroxybutyrate (3HB) with six or more 3HB units. The enzyme has the unique property to recognize the physical state of the polymeric substrate by discrimination between amorphous PHA (good substrate) and denatured, partially crystalline PHA (no substrate). The pentamers of 3HB or 3HV were identified as the main products of enzymatic hydrolysis of native PHB or PHV, respectively. No activity was found with any denatured PHA, oligomers of (R)-3HB with five or less 3HB units, poly(6-hydroxyhexanoate), substrates of lipases such as tributyrin or triolein, substrates for amidases/nitrilases, DNA, RNA, casein, N-alpha-benzoyl-l-arginine-4-nitranilide, or starch. The purified enzyme (M(r) 36,209) was remarkably stable and active at high temperature (60 degrees C), high pH (up to 12.0), low ionic strength (distilled water), and in solvents (e.g. n-propyl alcohol). The depolymerase contained no essential SH groups or essential disulfide bridges and was insensitive to high concentrations of ionic (SDS) and nonionic (Triton and Tween) detergents. Characterization of the cloned structural gene (phaZ7) and the DNA-deduced amino acid sequence revealed no homologies to any PHB depolymerase or any other sequence of data banks except for a short sequence related to the active site serine of serine hydrolases. A classification of the enzyme into a new family (family 9) of carboxyesterases (Arpigny, J. L., and Jaeger, K.-E. (1999) Biochem. J. 343, 177-183) is suggested.

DNA asymmetry and the replicational mutational pressure.

The mode of replication and organisation of bacterial genomes impose asymmetry on their nucleotide composition. The asymmetry is seen in coding and non-coding sequences and is reflected in the amino acid composition of proteins. The mechanisms generating asymmetry include: unequal mutation rates connected with replication and transcription, selection forces positioning genes and signal sequences nonrandomly in the genome, and protein coding constraints on coding sequences. There are different methods of visualising and measuring the asymmetry. Some of them can assess the contribution of individual mechanisms to the observed asymmetry and those have been described in greater detail. Asymmetric mutational and selection pressures differentiate the rates of evolution of genes on leading and lagging strands. The genes relocated to the opposite strand have to adapt to a different mutational pressure or are eliminated. Translocations from leading to lagging strands are more often selected against than from lagging to leading strands. Comparison of intergenic sequences that have lost the coding function to the original genes enables finding the frequencies of the twelve substitution rates in sequences free from selection. In the absence of selection, the half-time of substitution of a given type of nucleotide is linearly correlated with the fraction of that nucleotide in the sequence.

High correlation between the turnover of nucleotides under mutational pressure and the DNA composition.

BACKGROUND: Any DNA sequence is a result of compromise between the selection and mutation pressures exerted on it during evolution. It is difficult to estimate the relative influence of each of these pressures on the rate of accumulation of substitutions. However, it is important to discriminate between the effect of mutations, and the effect of selection, when studying the phylogenic relations between taxa. RESULTS: We have tested in computer simulations, and analytically, the available substitution matrices for many genomes, and we have found that DNA strands in equilibrium under mutational pressure have unique feature: the fraction of each type of nucleotide is linearly dependent on the time needed for substitution of half of nucleotides of a given type, with a correlation coefficient close to 1. Substitution matrices found for sequences under selection pressure do not have this property. A substitution matrix for the leading strand of the Borrelia burgdorferi genome, having reached equilibrium in computer simulation, gives a DNA sequence with nucleotide composition and asymmetry corresponding precisely to the third positions in codons of protein coding genes located on the leading strand. CONCLUSIONS: Parameters of mutational pressure allow us to count DNA composition in equilibrium with this mutational pressure. Comparing any real DNA sequence with the sequence in equilibrium it is possible to estimate the distance between these sequences, which could be used as a measure of the selection pressure. Furthermore, the parameters of the mutational pressure enable direct estimation of the relative mutation rates in any DNA sequence in the studied genome.

Electrospray multistep ion trap mass spectrometry for the structural characterisation of poly

Electrospray 'soft' ionisation (ESI) and multistep mass spectrometry (MS(n)) techniques enable characterisation of a bioactive polymer, poly[(R,S)-3-hydroxybutanoic acid] (a-PHB), containing covalently bonded benzylpenicillin. The chemical structures of individual mass-selected bioactive macromolecules have been determined, and their fragmentation mechanisms have been compared with those of pure penicillin G. Copyright 2000 John Wiley & Sons, Ltd.

Is there replication-associated mutational pressure in the Saccharomyces cerevisiae genome?

Compositional bias of yeast chromosomes was analysed using detrended DNA walks. Unlike eubacterial chromosomes, the yeast chromosomes did not show the specific asymmetry correlated with origin and terminus of replication. It is probably a result of a relative excess of autonomously replicating sequences (ARS) and of random choice of these sequences in each replication cycle. Nevertheless, the last ARS from both ends of chromosomes are responsible for unidirectional replication of subtelomeric sequences with pre-established leading/lagging roles of DNA strands. In these sequences a specific asymmetry is observed, resembling the asymmetry introduced by replication-associated mutational pressure into eubacterial chromosomes.

Electrospray ionisation tandem mass spectrometry of poly

Evaluation of polymer end-capping reactions with the aid of electrospray ionisation tandem mass spectrometry techniques (ESI-MS(n)) allows characterisation of novel poly[(R, S)-3-hydroxybutanoic acid]-(a-PHB) telechelics, containing primary hydroxyl groups at both polymer chain ends. The chemical structures of individual mass-selected macromolecules of the well-defined a-PHB telechelics have been defined in this way, and fragmentation mechanisms have been proposed. Copyright 1999 John Wiley & Sons, Ltd.

Total number of coding open reading frames in the yeast genome.

At the end of 1996 we approximated the total number of protein coding ORFs in the Saccharomyces cerevisiae genome, based on their properties, as 4700-4800. The number is much smaller than the 5800 which is widely accepted. According to our calculations, there remain about 200-300 orphans-ORFs without known function or homology to already discovered genes, which is only about 5% of the total number of genes. Our results would be questionable if the analysed set of known genes was not a statistically representative sample of the whole set of protein coding genes in the S. cerevisiae genome. Therefore, we repeated our estimation using recently updated databases. In the course of the last 18 months, previously unknown functions of about 500 genes have been found. We have used these to check our method, former results and conclusions. Our previous estimation of the total number of coding ORFs was confirmed.