Summary Background: Thyroid hormone resistance (RTH) is a rare cause of thyroid dysfunction. High TSH levels, as described in RTH syndrome, are known to be associated with an increased risk of ...developing thyroid nodules with subsequent growth and malignancy. Patient findings: In 2006, a 29-year-old Caucasian man presented with a palpable mass in the neck. Increased free thyroxine and triiodothyronine levels were found in the context of unsuppressed TSH levels, despite no signs or symptoms of hyperthyroidism. Ultrasonography revealed a multinodular and enlarged goitre, and fine-needle aspiration cytology revealed suspicious features of malignancy. After excluding pituitary tumour and levothyroxine (l-T4) treatment, the patient was diagnosed with generalized RTH. Screening for all the known mutations in thyroid hormone receptor-β (TR β (THRB)) was negative. Thyroidectomy disclosed five Hürthle adenomas and three hyperplasic nodules. Euthyroidism was achieved after surgery with 6.1 μg/kg per day of l-T4. Conclusion: RTH may be a risk factor that predisposes to the development of multiple Hürthle cell adenomas. To our knowledge, this is the first case of multiple Hürthle cell adenomas in a patient with RTH. Learning points High TSH levels, as described in RTH syndrome, are known to be associated with an increased risk of developing thyroid nodules, with subsequent growth and malignancy. The exact role of TR β mutants in thyroid carcinogenesis is still undefined. We report the first case of multiple Hürthle cell adenomas associated with RTH.
Gastric perforations from abdominal trauma Rodríguez-Hermosa, José Ignacio; Roig, Josep; Sirvent, Josep Maria ...
Digestive surgery,
01/2008, Letnik:
25, Številka:
2
Journal Article
Recenzirano
Gastric rupture due to abdominal trauma is rare (0.02-1.7%); it is usually caused by traffic accidents. Delayed diagnosis, abdominal contamination and associated lesions cause morbidity and ...mortality.
Retrospective review of 2,083 patients with abdominal traumatism treated at our center over 20 years. We reviewed recent ingestion of a meal, etiology, time to surgery, site, Stomach Injury Scale, abdominal contamination, treatment, associated injuries, complications and mortality.
Gastric perforation occurred in 25 patients (1.2%), median age 35 years. Stomachs were distended from recent meals in 16 (64%). The commonest causes were traffic accidents (n = 13) and blunt weapon injury (n = 7). The median time to surgery was 1 h. Gastric lesions occurred predominantly in the anterior wall (n = 12) followed by the greater curvature (n = 7). Type II lesions repaired with simple suturing were the most usual. Abdominal contamination occurred in all cases. Associated lesions were present in 22 patients; the most commonly affected intra-abdominal organ was the liver, and the lungs were the most affected extra-abdominal organ. The morbidity rate was 60% (n = 15) and the mortality rate 4% (n = 1).
Early diagnosis and surgical treatment are important for reducing the morbidity and mortality in these patients.
Label-free monitoring of biomolecular interactions has become of key importance for the emerging proteomics field. Monitoring real time interaction kinetics and high throughput screening of complex ...samples is of major importance for a variety of applications. We previously reported the use of Silicon-on-Insulator photonics microring resonators for cheap disposable biosensors on chip. Silicon photonics is a platform for micro- and nanoscale integrated devices that can be fabricated at extremely low cost, with standard CMOS processing facilities. Incorporation of a hydrophilic heterobifunctional polymer coating on the silicon chips largely improved the system's response to non-specific binding. We report the chemical coating procedure, the chemical surface characterization and optical measurements for both specific and non-specific interactions. Two heterobifunctional polymer coatings were investigated, α-sulfanyl-ω-carboxy-poly(ethylene glycol) and monoprotected diamino-poly(ethylene glycol). Homogenous coatings with thicknesses of 2.3 and 2.5nm were obtained, corresponding to a surface loading of 99pm/cm2 carboxy- and 97pm/cm2 aminogroups, respectively. The polymer coated sensor with covalently bound biotin receptor molecules showed very low response to Bovine Serum Albumin (BSA) up to 1mg/ml in contrast to a high response to avidin with much lower concentrations (2, 10, 87.5 and 175μg/ml). By extrapolation the detection limit is about 10ng/ml or 0.37fg avidin mass. Comparison with the values reported for standard silanization confirms the polymer coating does not deteriorate the system's limit of detection. This makes the optical biosensor chip suitable to be integrated in a microflow system for commercial label-free biosensors and for lab-on-a-chip applications.
The production of ligno-cellulosic biomass-based composites requires the development of new methodologies to evaluate the reinforcement potential of a given biomass, such as miscanthus studied in the ...work. Miscanthus stems from thirteen genotypes were broken into elongated fragments and mixed with polypropylene composites in an internal mixer. The aim is to find the best protocol able to discriminate miscanthus genotypes for their reinforcement capability. The following process parameters were optimized in order to maximize the reinforcement effect of the stem fragment filler: mixing parameters (mixing time, rotor speed and chamber temperature), temperature, fragment content, size and length distributions and coupling agent. The relationship between the process parameters and the mechanical properties of composites were analyzed to evaluate the influence of genotype on reinforcement performance, showing the robustness of the protocol in effectively discriminating genotypes according to their reinforcing capacity.
Miscanthus biomass can be used to produce lightweight concrete. However, cell wall polymers leached in the alkaline cementitious medium can disturb cement setting. This is the case for grass lignin ...and grass arabinoxylan due to their specific alkali solubility. The main objective of this paper was to study the impact of lignin and of arabinoxylan from miscanthus biomass on the hydration of Portland cement and by electrical conductivity. To this end, dioxan lignin (DL) and arabinoxylan (AX) were extracted from miscanthus by methods preserving the main structural specificities of the native polymers. These DL and AX fractions were added to Portland cement (1–5% w/w in cement) and their impact on the electrical conductivity of cement/water mixtures was time-monitored. The novelty of this study lies in using polymers structurally similar to those of miscanthus fibers rather than commercially available ones, such as kraft lignin (KL). The addition of DL or of KL to cement/water mixture differently affected the electrical conductivity, which is most likely assignable to the severe structural degradation of KL during kraft process. The conductivity curves suggested that cement hydration was substantially delayed when DL % in cement was 3% or more while lower values had no impact. The results support the hypothesis that the access of water to cement grains was impeded by the adsorption of ionized lignin entities at their surface. When co-added to the cement (1.6 wt% each), the DL and AX fraction delayed cement hydration more substantially than when the same amounts were separately added. This unexpected synergy suggests that the miscanthus lignin and arabinoxylan polymers form lignin-carbohydrate complexes efficiently adsorbed on cement grains.
•Realistic plant lignins used for the first time to study cement hydration.•Conductimetry shows that miscanthus lignins are delaying cement hydration above 3%.•Kraft lignin has a different influence on cement hydration than miscanthus lignin.•Miscanthus arabinoxylan and lignin fractions synergistically delay cement hydration.
The hydroesterification of acenaphthylene with carbon monoxide and methanol, catalyzed by Pd
II/PR
3 systems has been studied. The activities and chemoselectivities of the catalytic systems were ...highly affected by the electronic and steric properties of the auxiliary ligands. The effect of reaction conditions, methanol concentration, catalyst precursor and excess of added auxiliary ligands and/or
p-toluenesulfonic acid were also studied.
The hydroesterification of acenaphthylene with carbon monoxide and methanol, catalyzed by Pd
II/PR
3 systems (PR
3=PPh
3, P(
o-MeC
6H
4)
3, P(
p-MeC
6H
4)
3, P(
p-FC
6H
4)
3, P(
i
Bu
)
3, PEt
3, PCy
3, P(OEt)Ph
2, P(OPh)
3, P(O-
o-MeC
6H
4)
3, P(O-
o-
t
BuPh
)
3, dppm, dppe, dppp, dppb, 1,1′-bis(diphenylphosphino)ferrocene (dppf), rac-BINAP) has been studied, the reaction yields a mixture of acenaphthene-1-carboxylic acid methyl ester
1, 1-methoxyacenaphthene
2 and polyacenaphthylene
3. For Pd/monophosphine/
p-TsOH precursors, only ligands with intermediate electronic and steric properties formed active catalytic systems with satisfactory chemoselectivities. These systems are highly influenced by the reaction conditions, as the methanol concentration and the Pd/
p-TsOH ratio, yielding conversions up to 85% with a chemoselectivity in ester
1 of 93%. When diphosphines were used as auxiliary ligands, less efficient catalytic systems were produced and their characteristics can be attributed to the electronic properties of the ligands, yielding conversions up to 60% and chemoselectivities in ester
1 of 85%.
Belowground materials from two miscanthus species were ground into fragments for preparing polyethylene composites. Both species show a lot of similarities in terms of polysaccharides, lignin and ...cell wall-linked p-coumaric and ferulic acids contents. The structures of polysaccharides and of lignins are markedly different in the miscanthus belowground and aboveground biomass. The non-cellulosic fraction of the samples comprises a high level of xylose, with the arabinose to xylose ratio about twice as high as that observed for analogous stem samples, suggesting that belowground arabinoxylans are more substituted than stem ones. The mechanical properties of the belowground miscanthus-polyethylene composites correlate with several of their compositional traits, with similar trends as for plant stem-polyethylene composites with positive correlations for lignin and p-coumaric acid contents and negative correlations for most non-cellulosic sugars.
•Identifying of specific maize biochemical traits for improving composite properties.•p-coumaric acids is favorable for better composite performances.•Cellulose is the component dominating the ...mechanical properties of maize fragments.•Correlations between histology and mechanical properties of the composites is complex.
This study was devoted to identifying specific biochemical traits that may be addressed in maize breeding programs for improving lignocellulosic composition for biomass utilization in the composites. To this aim, six maize contrasted genotypes were cultivated, harvested and compared in term of their capability to reinforce a low-density polyethylene (LDPE) matrix. Stem biochemical composition and histological pattern of a given internode were evaluated to determine the traits that impacted the mechanical properties of the maize-LDPE composites. Across genotypes, maize stems with higher concentrations of total cell wall residue, lignin, p-coumaric acids and cellulose in conjunction with lower concentrations of ferulic acids and hemicellulose yielded better composite performances. This strong influence of hydroxycinnamic acids is a new finding. Cellulose is found to be the component dominating the mechanical properties of the fragments since the effects of cell wall residue and cellulose are following the same pattern towards composite properties. Contrary to expectations, the correlations between the histological structure of stems and the mechanical properties of the composites prepared with stem fragments is complex and cannot be interpreted in a simple manner. The two most contrasted genotypes in terms of mechanical performances (Cm484 and F2bm3) have the most contrasted biochemical and histological parameters.
Objective
To investigate key enzymes of heme biosynthesis in human adipocytes and adipose tissue (AT).
Methods
Heme biosynthesis‐related gene expression (ALAS1, ALAD, HMBS) was investigated in whole ...AT from humans (n = 178 and n = 75) and rats according to obesity status and during adipogenesis of human preadipocytes. The effects of aminotriazole (an ALAD inhibitor) and of ALAD knockdown were also studied.
Results
Consistent heme biosynthesis‐related gene expression was detected in both subcutaneous AT (SAT) and visceral AT (VAT) and was significantly increased in SAT. ALAS1, ALAD, and HMBS mRNAs were positively associated with adipogenic gene expression in human AT and significantly decreased in subjects with obesity. These results were replicated in an independent cohort. Both SAT and VAT heme levels were positively correlated with ALAS1, ALAD, and HMBS mRNAs. ALAD and HMBS were mainly expressed in adipocytes and increased during differentiation of human adipocytes in parallel to adipogenic genes. In rats, high‐fat diet‐induced weight gain resulted in decreased Alad and Hmbs mRNAs in a similar way to what was observed with Adipoq. Aminotriazole administration or ALAD knockdown attenuated adipogenesis in parallel with decreased glucose uptake and impaired mitochondrial respiratory function during human adipocyte differentiation.
Conclusions
Current data suggest a possible role of heme biosynthesis in human adipogenesis.
•There is a variation of composite mechanical properties between sorghum genotypes.•Best mechanical properties correlated with largest blending energy dissipation.•Weak correlation between tensile ...mechanical properties and resistance to impact.
Composites prepared with whole sorghum stem fragments reinforcing a polyethylene matrix were studied using ten different sorghum genotypes. Using a robust processing protocol, it is shown that for a given sorghum genotype, the composition of the stem fragments varies depending on the size of the sieved fragments but with the genotype effect being larger than the sieving effect. There is a variation of mechanical properties between the genotypes (from 0.6 to 1GPa for modulus, from 7.2 to 11.5MPa for tensile strength and from 4.4 to 6.2kJ/m2 for impact strength). The genotypes giving the best tensile mechanical properties are the ones which have the highest viscosity, which show during blending the largest energy dissipation and which have the less decrease of size after processing. There is a weak correlation between tensile mechanical properties and resistance to impact suggesting that it is not the same tissues or physical properties which contribute to these two tests.
PDF
