Raman hyperspectral imaging as an effective and highly informative tool to study the diagenetic alteration of fossil bones.

Retrieving the pristine chemical or isotopic composition of archaeological bones is of great interest for many studies aiming to reconstruct the past life of ancient populations (i.e. diet, mobility, palaeoenvironment, age). However, from the death of the individual onwards, bones undergo several taphonomic and diagenetic processes that cause the alteration of their microstructure and composition. A detailed study on bone diagenesis has the double purpose to assess the preservation state of archaeological bones and to understand the alteration pathways, thus providing evidence that may contribute to evaluate the reliability of the retrieved information. On these bases, this research aims to explore the effectiveness of Raman hyperspectral imaging to detect types, extent and spatial distribution of diagenetic alteration at the micro-scale level. An early-Holocene bone sample from the Al Khiday cemetery (Khartoum, Sudan) was here analysed. Parameters related to the collagen content, bioapatite crystallinity and structural carbonate content, and to the occurrence of secondary mineral phases were calculated from Raman spectra. The acquired data provided spatially-resolved information on both the preservation state of bone constituents and the diagenetic processes occurring during burial. Given the minimal sample preparation, the easy and fast data acquisition and the improvement of system configurations, micro-Raman spectroscopy can be extensively applied as a screening method on a large set of samples in order to characterise the preservation state of archaeological bones. This technique can be effectively applied to identify suitable and well preserved portions of the analysed sample on which perform further analyses.

Evidence of preserved collagen in an Early Jurassic sauropodomorph dinosaur revealed by synchrotron FTIR microspectroscopy.

Fossilized organic remains are important sources of information because they provide a unique form of biological and evolutionary information, and have the long-term potential for genomic explorations. Here we report evidence of protein preservation in a terrestrial vertebrate found inside the vascular canals of a rib of a 195-million-year-old sauropodomorph dinosaur, where blood vessels and nerves would normally have been present in the living organism. The in situ synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectra exhibit the characteristic infrared absorption bands for amide A and B, amide I, II and III of collagen. Aggregated haematite particles (α-Fe2O3) about 6∼8 µm in diameter are also identified inside the vascular canals using confocal Raman microscopy, where the organic remains were preserved. We propose that these particles likely had a crucial role in the preservation of the proteins, and may be remnants partially contributed from haemoglobin and other iron-rich proteins from the original blood.

Extracellular Matrix Invasion in Metastases and Angiogenesis: Commentary on the Matrigel "Chemoinvasion Assay".

Invasive and metastatic cells must cross the basement membrane's extracellular matrix to disseminate to distant sites. Although in the eighties the concept was well established, no easy in vitro functional assay was available. Working in Hynda Kleinman's and George Martin's laboratory at NIH (Bethesda, MD), where the reconstituted basement membrane Matrigel was discovered, I had the intuition that Matrigel coating of migration filters could represent a valid tool to mimic in vitro biological matrix barriers. The "chemoinvasion assay" using Matrigel in Boyden blind-well chambers was developed in 1985-1986 and published in Cancer Research in 1987. It was a rapid and easy tool for studying invasion, a crucial step in cancer metastasis. Since its conception, the assay has been employed for studies on the metastatic process, angiogenesis, and for the screening of drugs that are potentially able to decrease cell invasion. It was adapted to be easily employed as a routine assay and commercialized. In that historical article, we also described the use of thick layers of Matrigel for the study of morphogenesis of invasive cells, a simple and visual assay, adaptable to reproduce collective cell migration in vitro To date, in its diverse optimized variants, the chemoinvasion assay is still widely used, contributing to novel data production. In the era of precision medicine and next-generation sequencing, the cheap, fast, and reproducible chemoinvasion assay may have further developments, including possible applications in the investigations on cancer stem cells, immunity and immune modulators, applications with siRNA silencing, selection of aggressive cell populations, and phenotypes and genetic evaluations. Cancer Res; 76(16); 4595-7. ©2016 AACR.See related article by Albini A et al., Cancer Res 1987;47:3239-45Visit the Cancer Research 75(th) Anniversary timeline.

Identification of the earliest collagen- and plant-based coatings from Neolithic artefacts (Nahal Hemar cave, Israel).

Mortuary practices in human evolution record cognitive, social changes and technological innovations. The Neolithic Revolution in the Levant was a watershed in this domain that has long fascinated the archaeological community. Plaster modelled skulls are well known at Jericho and several other Neolithic sites, and in Nahal Hemar cave (Israel, ca. 8200 -7300 cal. BC) excavations yielded six unique human skulls covered with a black organic coating applied in a net pattern evoking a headdress. This small cave was used as storage for paraphernalia in the semi-arid area of the Judean desert and the dry conditions preserved other artefacts such as baskets coated with a similar dark substance. While previous analysis had revealed the presence of amino acids consistent with a collagen signature, in the present report, specific biomarkers were characterised using combined proteomic and lipid approaches. Basket samples yielded collagen and blood proteins of bovine origin (Bos genus) and a large sequence coverage of a plant protein charybdin (Charybdis genus). The skull residue samples were dominated by benzoate and cinnamate derivatives and triterpenes consistent with a styrax-type resin (Styrax officinalis), thus providing the earliest known evidence of an odoriferous plant resin used in combination with an animal product.

Preenchimentos faciais - parte um / Dermal fillers - part one

Nos últimos anos, presenciamos o aparecimento de grande variedade de preenchimentos dérmicos. Eles permitiram que aumentasse nossa variedade de escolha, nunca tida antes. Neste artigo abordaremos algumas novas opções de preenchedores.

The history of injectable facial fillers.

In an attempt to maintain a youthful appearance or to reconstruct facial deformities, physicians have greeted new technologies with excitement. In the late 1800 s, shortly after the invention of the syringe, chemical agents were used for facial augmentation. Unfortunately, history has taught us that new technologies must be used with care, because complications can occur, sometimes many years after initial treatment. The first injectable filling agent was paraffin, whose use was abandoned after complications of migration, embolization, and granuloma formation were described. More recently, silicone use was banned by the U.S. Food and Drug Administration (FDA) because of similar complications. In 1981, bovine collagen was the first agent to be approved by the FDA for cosmetic injection. Since its approval, dozens of injectable filling agents have been developed, and many are already FDA approved for cosmetic use. This article will review the highlights of the evolution of facial filling agents.

[The Maillard reaction: physiopathological role and pharmacological approach]. / La réaction de Maillard. Rôle physiopathologique et approche pharmacologique.

In this review, we shall first present a short summary of Maillard's carrier, his pioneering work for the introduction of chemistry in medicine and a short description of the reaction he described in 1912 between reducing sugars and amino groups on proteins, part of his PhD thesis. This reaction was rediscovered several decades later by biochemists. Nowadays an increasing number of teams specialise in the study of the Maillard reaction, because of its importance in aging and age-related pathologies. After a short description of this reaction, we report the importance of receptors recognising a variety of AGE-s and mediating their effect on cells and tissues. The importance of glycoxidation is mentioned, mediating the release of free radicals (ROS-s) directly involved in a number of noxious effects of AGE-s, such as crosslinking and even mutagenesis. All these - in his time - unforeseen consequences of this reaction have made Maillard the best known French scientist in international scientific circles.

An original approach to aging: an appreciation of Fritz Verzár's contribution in the light of the last 50 years of gerontological facts and thinking.

The motivation of this review is the 120th anniversary of the birth of Fritz Verzár, founder of experimental gerontology. His major contributions to aging research are shortly reviewed and re-evaluated in the light of modern gerontological research. Verzár undertook aging research after his retirement from the Chair of Physiology at the Medical Faculty of Basel. His first experiments on aging of the rat tail tendon revealed an important mechanism of aging: an exponential increase of cross-linking of collagen fibres. This observation, correctly interpreted by Verzár as a new age-dependent mechanism, was shown later to be attributed to the Maillard reaction, the non-enzymatic glycosylation of protein (and nucleotide bases) amino groups followed by evolution of the reaction to advanced glycation end products (AGEs) involved in a number of harmful reactions. Many of these reactions were shown to be mediated by receptors recognizing AGE products (RAGEs). This was the first example of a post-synthetic (post-translational) reaction involved in the aging of biological macromolecules, especially those of the extracellular matrix. Verzár extended the research activity of his team to several other aspects of aging research, such as loss of muscular strength, nutritional requirements at high altitude, cell loss with aging, and ultrastructural studies, and started also the first longitudinal clinical study of aging in a Basel population. Modern gerontological research confirmed and extended Verzár's observations. His work on collagen cross-linking by glycation became of paramount importance in recent times because of the rapid increase of diabetes type II, combined with the metabolic syndrome, one of the major pathologies of modern times.

O desenvolvimento do corpo vertebral em aves é modulado pela matriz extracelular / Vertebral body developmente

A distribuição dis colágenos tipos I e II foi estudada no desenvolvimento do corpo vertebral, ao nível dos membros superiores, de embriões de Gallus gallus domesticus, L no período de dois a 21 dias (estádio 14 a estádio 46 de Hamburger e Hamilton) de incubação e de animais pós-eclosão, utilizando o método avidina-biotina marcada com enzima peroxidase (método Lab)em espécimes fixados e inclídos em parafina. Inicialmente (estádios 17-22), as reações com os anticorpos anticolágeno tipo I e antifibronectina foram muito intensas na matriz extracelular do esclerotoma em migração, e fraca com anticorpo anticolágeno tipo II, a qual foi intensa na membrana basal do notocórdio e do tubo neural. Mais adiante (estádios 25-27) foram obtidas fortes reações com os anticorpos anticolágeno tipo I e antifibronectina bem como positividade muito intensa com o anticorpo anticolágeno tipo II. Pelo estádio 32, as reações com os anticorpos anticolágeno tipo I e antifibronectina diminuíram, excetuando-se no pericõndrio, onde o colágeno tipo II apresentou reação intensa, com o anticorpo específico, em áreas de condrificação. Ao final (estádios 40-46), foi observada positiviade muito intensa, para todos os anticorpos estudados, as áreas de hipertrofia dos condrócitos (começando pelo estádio 36). Nas trabéculas ósseas (começando polo estádio 41), a positividade restringiu-se aos anti-corpos anticolágeno tipo I e antibronectina. Este mesmo padrão foi observado nos espécimes pós-eclosão. Esses resultados sugerem um papel ativo para as macromeléculs da matriz extracelular nos processos de migração, condrogênese e osteogênese. As células notocordais e o epitélio do tubo neural induzem a migração das células mesenquimais, que sintetizamcolágeno tipo I e fibronectina durante os processos de migração e condogênese precose e colágeno tipo II na diferenciação ondrogênica. A particiapçaõ dos colágenos tipos I e II mais a fibronectina é essencial na etapa de condro-apoptose da osteogênese

Isotopic biogeochemistry as a marker of Neandertal diet.

Natural abundances in 13C and 15N of bone collagen are linked to those of the diet. This isotopic signal can thus be linked to the dietary parameters of a given individual, such as the plants at the beginning of his food web and his position in the trophic web. In order to use this approach to study the diet of ancient humans, it is crucial to be sure that the original isotopic abundances of fossil collagen are preserved. This is done by controlling the biochemical purity of the organic matter extracted from fossil bones, and by checking that the isotopic differences observed in modern environments between herbivorous and carnivorous species are indeed measured in the fossil samples. Upper Pleistocene sites with a good isotopic preservation of collagen have been recognized in temperate and arctic environments. The isotopic signatures measured in such sites highlight particularities of the "mammoth steppe" fauna, and improve our knowledge of the diet of Neandertals.

Molecular preservation and isotopy of Mesolithic human finds from the Ofnet cave (Bavaria, Germany).

Favourable burial conditions and self-limiting decomposition processes led to an extraordinarily well molecular preservation of the Mesolithic human skull finds from the Ofnet cave (district Nördlingen, Bavaria). Beyond the extraction of bone collagen, a selection of serum proteins from bone was identified immunologically. Stable carbon and nitrogen isotope ratios from collagen gave clues to dietary behaviour including nursing practices. Diverging results after the application of biochemical protocols (for protein cleaning) and biophysical methods (for stable isotope analysis) are of particular interest: while the first approach failed to quantitatively eliminate anorganic contaminations, the second left some organic, exogenous residues in the samples. Thus, methods for protein extraction must vary according to problem solution and ultimate aim of the study. Taking this into account, application of invasive methods is also encouraged to rare and valuable skeletal finds.

[Biogenic decomposition of bone collagens]. / Zum biogenen Abbau menschlicher Knochenkollagene.

Soil bacteria, which are an always present component of all burial conditions, substantially contribute to the decomposition of bone collagen, i.e. even modifications of preserved bone collagen. Archaeometric data, which were derived from collagen remnants, therefore may always contain diagenetic components which disturb the biological signals and must subsequently be eliminated. To adequately assess probable diagenetic influences one should refer to our model of the biogenic steps of decomposition. The taphonomic experiments and their verifications of archaeological human bones, which were gathered from different origins and of different historical times, were done with histological, biochemical and biophysical methods. Experimentally, as well as through archaeological bone analysis, we were able to identify a "high" molecular product of decomposition, which contains (1) changes in the amino acid composition caused by specific soil conditions and (2) significant deviations of stable nitrogen and carbon isotopes. Due to decomposition procedures, isotope analysis of isolated amino acids indicate rearrangements of collagen fragments.