Microrheological characterisation of Cyanoflan in human blood plasma.

Naturally occurring polysaccharidic biopolymers released by marine cyanobacteria are of great interest for numerous biomedical applications, such as wound healing and drug delivery. Such polymers generally exhibit high molecular weight and an entangled structure that impact the rheology of biological fluids. However, biocompatibility tests focus not so much on rheological properties as on immune response. In the present study, the rheological behaviour of native blood plasma as a function of the concentration of a cyanobacterium biopolymer is investigated via multiple particle tracking microrheology, which measures the Brownian motion of probes embedded in a sample, and cryogenic scanning electron microscope microstructural characterisation. We use Cyanoflan as the biopolymer of choice, and profit from our knowledge of its chemical structure and its exciting potential for biotechnological applications. A sol-gel transition is identified using time-concentration superposition and the power-law behaviour of the incipient network's viscoelastic response is observed in a variety of microrheological data. Our results point to rheology-based principles for blood compatibility tests by facilitating the assignment of quantitative values to specific properties, as opposed to more heuristic approaches.

Mixing and matching methylotrophic enzymes to design a novel methanol utilization pathway in E. coli.

One-carbon (C1) compounds, such as methanol, have recently gained attention as alternative low-cost and non-food feedstocks for microbial bioprocesses. Considerable research efforts are thus currently focused on the generation of synthetic methylotrophs by transferring methanol assimilation pathways into established bacterial production hosts. In this study, we used an iterative combination of dry and wet approaches to design, implement and optimize this metabolic trait in the most common chassis, E. coli. Through in silico modelling, we designed a new route that "mixed and matched" two methylotrophic enzymes: a bacterial methanol dehydrogenase (Mdh) and a dihydroxyacetone synthase (Das) from yeast. To identify the best combination of enzymes to introduce into E. coli, we built a library of 266 pathway variants containing different combinations of Mdh and Das homologues and screened it using high-throughput 13C-labeling experiments. The highest level of incorporation of methanol into central metabolism intermediates (e.g. 22% into the PEP), was obtained using a variant composed of a Mdh from A. gerneri and a codon-optimized version of P. angusta Das. Finally, the activity of this new synthetic pathway was further improved by engineering strategic metabolic targets identified using omics and modelling approaches. The final synthetic strain had 1.5 to 5.9 times higher methanol assimilation in intracellular metabolites and proteinogenic amino acids than the starting strain did. Broadening the repertoire of methanol assimilation pathways is one step further toward synthetic methylotrophy in E. coli.

CLINICAL PROGNOSTIC FACTORS IN PRE- AND POST-MENOPAUSAL WOMEN WITH OVARIAN CARCINOMA.

AIMS: To assess the impact of prognostic factors on the outcome of ovarian carcinoma (OC) and to determine the difference between pre and postmenopausal patients. DESIGN: Retrospective cohort, single centre study. SUBJECTS AND METHODS: One-hundred-sixty patients with stage IC-IV OC diagnosed between 2004-2016 were included. Treatment consisted in primary surgery followed by adjuvant chemotherapy (n=127, 79.4%), neoadjuvant chemotherapy followed by surgery (n=27, 16.9%) and chemotherapy alone (3.7%). RESULTS: At diagnosis 62 patients (38.8%) were premenopausal. Most patients presented with advanced OC (stage III/IV, 63.1%). After a median follow-up of 60 months, median progression free survival (PFS) for all stages was 36 months and median overall survival (OS) was 96 months. Postmenopausal patients had a poorer oncologic outcome compared with pre-menopausal women (PFS 24 vs. 72 months, p=0.0001, HR=2.32). Other clinical prognostic factors identified were performance status 1 vs. 0 (p=0.0001), ascites (p=0.027). Pathology prognostic factors were tumour grade (G1 vs. G2 and G3, p=0.0001) and endometrioid subtype compared to serous (p=0.008). Patients with residual disease after surgery had an increased risk of recurrence and death (HR=6.1, p=0.0001 and HR=4.2, p=0.0001). CONCLUSION: Premenopausal patients had a better oncologic long-term outcome and stage, ascites, grading, residual disease, were independent prognostic factors.

Outcome of urinary bladder cancer after combined therapies.

Rationale:Urinary bladder cancer is the fourth most common cancer in men and the eighth in women, being an important public health issue. Methods:: Medical files of 155 patients (132M/ 23F) with urinary bladder cancer treated between 2006 and 2012 were retrospectively analyzed. The median age at diagnosis was 65 years (range: 19-85 years). Disease free survival (DFS) for patients with complete tumor resection receiving adjuvant treatment and progression free survival (PFS) for patients with post-operative residual disease was estimated. Results:The distribution of the stage disease was: 50 patients (32.2%) stage II, 47 (30.3%) stage III, 58 (37.4%) stage IV. Radical cystectomy was performed in 56 patients (36.1%), while 99 patients (63.9%) underwent repeated transurethral resection of the urinary bladder tumor (TURBT). Postoperative treatment included multimodal therapy in 47 patients (30.3%) (chemotherapy and external beam radiation), external beam radiation alone in 57 patients (36.8%) and chemotherapy alone (methotrexate, vinblastine, doxorubicin, and cisplatin-MVAC or gemcitabine+platinum) in 51 patients (32.9%). After a median follow-up of 31 months (range: 3-79 months), 51 patients (32.9%) presented local recurrence, 32 patients (21%) distant recurrence (metastases), 10 patients (6.4%) both local and distant recurrence, and 62 patients (40%) were free of disease. The median duration until progression was 27 months. Discussion:Despite the combined therapy approaches, urinary bladder carcinoma remains an aggressive disease, with a high relapse rate. Earlier diagnosis, aggressive radical surgery in intention to cure (cystectomy), and adjuvant multimodal treatment (radiotherapy and chemotherapy) are needed for survival improvement.

Outcome of urinary bladder cancer after combined therapies.

RATIONALE: Urinary bladder cancer is the fourth most common cancer in men and the eighth in women, being an important public health issue. OBJECTIVE: to assess the outcome of patients with urinary bladder cancer treated in an oncologic center. METHODS: Medical files of 155 patients (132M/ 23F) with urinary bladder cancer treated between 2006 and 2012 were retrospectively analyzed. The median age at diagnosis was 65 years (range: 19-85 years). Disease free survival (DFS) for patients with complete tumor resection receiving adjuvant treatment and progression free survival (PFS) for patients with post-operative residual disease was estimated. RESULTS: Stage disease's distribution was: 50 patients (32.2%) stage II, 47 (30.3%) stage III, 58 (37.4%) stage IV. Radical cystectomy was performed in 56 patients (36.1%), while 99 patients (63.9%) underwent repeated transurethral resection of the urinary bladder tumor (TURBT). The postoperative treatment included multimodal therapy in 47 patients (30.3%) (chemotherapy and external beam radiation), external beam radiation alone in 57 patients (36.8%) and chemotherapy alone (methotrexate, vinblastine, doxorubicin, and cisplatin-MVAC or gemcitabine + platinum) in 51 patients (32.9%). After a median follow-up of 31 months (range: 3-79 months), 51 patients (32.9%) presented local recurrence, 32 patients (21%) distant recurrence (metastases), 10 patients (6.4%) both local and distant recurrence, and 62 patients (40%) were free of disease. The median duration until progression was of 27 months. DISCUSSION: Despite combined therapy approaches, urinary bladder carcinoma remains an aggressive disease, with high relapse rate. Earlier diagnosis and an aggressive radical surgery with the intention to cure (cystectomy), and adjuvant multimodal treatment (radiotherapy and chemotherapy) are needed for survival improvement.

Hydrophobic dipeptide crystals: a promising Ag-free class of ultramicroporous materials showing argon/oxygen adsorption selectivity.

The adsorption isotherms of nitrogen, oxygen and argon in four VA-class hydrophobic dipeptides are presented. Isotherms were determined at 5, 20 and 35 °C, for a pressure range of 0-6 bar. Under these conditions, adsorption is still in the Henry region. For all materials and temperatures, the sequence of preferential adsorption is Ar > O2 > N2, a highly abnormal result. At 5 °C, the dipeptide with the smallest pores, VI, has Ar/O2 adsorption equilibrium selectivities up to 1.30, the highest ever measured in Ag-free adsorbents. Gas uptakes, at 1 bar and 20 °C, are ∼0.05 mol kg(-1), very low relative values that are partially explained by the low porosity of the solids (<10%). The significance of these results for the development of new materials for the process of O2 generation by pressure swing adsorption (PSA) is discussed. The results indicate some of the structural and chemical properties that prospective Ag-free adsorbents should have in order to have Ar/O2 selectivity, hydrophobic pores, less than 0.5 nm-wide, and porosity of, at least, 20%.

Keratins and lipids in ethnic hair.

Human hair has an important and undeniable relevance in society due to its important role in visual appearance and social communication. Hair is mainly composed of structural proteins, mainly keratin and keratin associated proteins and lipids. Herein, we report a comprehensive study of the content and distribution of the lipids among ethnic hair, African, Asian and Caucasian hair. More interestingly, we also report the study of the interaction between those two main components of hair, specifically, the influence of the hair internal lipids in the structure of the hair keratin. This was achieved by the use of a complete set of analytical tools, such as thin layer chromatography-flame ionization detector, X-ray analysis, molecular dynamics simulation and confocal microscopy. The experimental results indicated different amounts of lipids on ethnic hair compositions and higher percentage of hair internal lipids in African hair. In this type of hair, the axial diffraction of keratin was not observed in X-ray analysis, but after hair lipids removal, the keratin returned to its typical packing arrangement. In molecular dynamic simulation, lipids were shown to intercalate dimers of keratin, changing its structure. From those results, we assume that keratin structure may be influenced by higher concentration of lipids in African hair.

Small transthyretin (TTR) ligands as possible therapeutic agents in TTR amyloidoses.

In transthyretin (TTR) amyloidosis TTR variants deposit as amyloid fibrils giving origin, in most cases, to peripheral polyneuropathy, cardiomyopathy, carpal tunnel syndrome and/or amyloid deposition in the eye. More than eighty TTR variants are known, most of them being pathogenic. The mechanism of TTR fibril formation is still not completely elucidated. However it is widely accepted that the amino acid substitutions in the TTR variants contribute to a destabilizing effect on the TTR tetramer molecule, which in particular conditions dissociate into non native monomeric intermediates that aggregate and polymerize in amyloid fibrils that further elongate. Since this is a multi-step process there is the possibility to impair TTR amyloid fibril formation at different stages of the process namely by tetramer stabilization, inhibition of fibril formation or fibril disruption. Till now the only efficient therapy available is liver transplant when performed in an early phase of the onset of the disease symptoms. Since this is a very invasive therapy alternatives are desirable. In that sense, several compounds have been proposed to impair amyloid formation or disruption. Based on the proposed mechanism for TTR amyloid fibril formation we discuss the action of some of the proposed TTR stabilizers such as derivatives of some NSAIDs (diflunisal, diclofenac, flufenamic acid, and derivatives) and the action of amyloid disrupters such as 4'-iodo-4'-deoxydoxorubicin (I-DOX) and tetracyclines. Among all these compounds, TTR stabilizers seem to be the most interesting since they would impair very early the process of amyloid formation and could also have a prophylactic effect.

Xanthones--a structural perspective.

Xanthones, synthesized or isolated from a natural source, display a wide range of biological and pharmacological activities. In a few cases, their chemical characterization has involved the structure elucidation by single crystal X-ray diffraction. The purpose of this review is to assess in detail this three-dimensional structural data, and thus contribute to a better understanding of the molecular mechanisms involved in the different biological activities presented by xanthones.

Naturally occurring 1,2,8-trimethoxyxanthone and biphenyl ether intermediates leading to 1,2-dimethoxyxanthone.

In order to study structure-activity relationships, a series of mono-, di- and trioxygenated xanthones has been synthesized and the structures of methyl 2-(3,4-dimethoxyphenoxy)benzoate, C(16)H(16)O(5), 2-(3,4-dimethoxyphenoxy)benzoic acid, C(15)H(14)O(5), 1,2-dimethoxy-9H-xanthen-9-one, C(15)H(12)O(4), and 1,2,8-trimethoxy-9H-xanthen-9-one, C(16)H(14)O(5), have been determined. The first two compounds both assume skew conformations, the dihedral angles between the two phenyl rings being 80.04 (8) and 83.0 (1) degrees, respectively. The latter two compounds are essentially planar and their methoxy substituents assume orientations consistent with minimum steric interactions.

Tetillapyrone and nortetillapyrone, two unusual hydroxypyran-2-ones from the marine sponge Tetilla japonica.

Extraction of the marine sponge Tetilla japonica from the Bay of Thailand furnished tetillapyrone and nortetillapyrone, two unusual tetrahydrofurylhydroxypyran-2-ones, whose structures were established by NMR spectrometry and an X-ray analysis of tetillapyrone.