Evaluation of Integrated Anaerobic Digestion and Hydrothermal Carbonization for Bioenergy Production

Lignocellulosic biomass is one of the most abundant yet underutilized renewable energy resources. Both anaerobic digestion (AD) and hydrothermal carbonization (HTC) are promising technologies for bioenergy production from biomass in terms of biogas and HTC biochar, respectively. In this study, the combination of AD and HTC is proposed to increase overall bioenergy production. Wheat straw was anaerobically digested in a novel upflow anaerobic solid state reactor (UASS) in both mesophilic (37 °C) and thermophilic (55 °C) conditions. Wet digested from thermophilic AD was hydrothermally carbonized at 230 °C for 6 hr for HTC biochar production. At thermophilic temperature, the UASS system yields an average of 165 L_CH4/kg_VS (VS: volatile solids) and 121 L _CH4/kg_VS at mesophilic AD over the continuous operation of 200 days. Meanwhile, 43.4 g of HTC biochar with 29.6 MJ/kg_{dry_biochar} was obtained from HTC of 1 kg digestate (dry basis) from mesophilic AD. The combination of AD and HTC, in this particular set of experiment yield 13.2 MJ of energy per 1 kg of dry wheat straw, which is at least 20% higher than HTC alone and 60.2% higher than AD only.     

Specular microscopy in glaucoma patients

The endothelial cells are one of the most important structures in a donor cornea. Morphology and concentration of endothelial cells must be carefully evaluated with a specular microscope before transplantation. The aim of this study is to evaluate the status of corneal endothelium in glaucoma patients. Prospective study included 50 patients suffering from glaucoma and 50 patients in control group. Patients had no corneal disease, ocular inflammation, previous trauma or ocular surgery. Patients were not contact lens wearers. They were also analyzed in groups according to type of glaucoma. Specular microscopy was performed on central corneas. This study showed that patients with glaucoma have lower central corneal endothelial cell density than those without glaucoma of the same age group. Also, patients with pseudoexfoliative glaucoma had lower values of central endothelial cell density comparing to patients with open angle or angle closure glaucoma.     

Limitation of the Ellman method: cholinesterase activity measurement in the presence of oximes

The Ellman method for assaying thiols is widely used for cholinesterase activity measurement. Cholinesterase activity is measured indirectly by quantifying the concentration of 5-thio-2-nitrobenzoic acid (TNB) ion formed in the reaction between the thiol reagent 5,5'-dithiobis-2-nitrobenzoic acid (DTNB) and thiocholine, a product of substrate (i.e., acetylthiocholine [ATCh]) hydrolysis by the cholinesterase. Oximes, reactivators of inhibited cholinesterase, are nucleophiles that also react with ATCh (oximolysis), producing thiocholine and (indirectly) TNB ion. The aim of this study was to characterize ATCh oximolysis. Therefore, we measured the oximolysis between oximes (K027 and HI-6) and ATCh in the presence of DTNB at different pH values, taking into account the final concentration of a product that is thiocholine. To confirm oximate ion involvement in the nucleophilic attack, we also determined the reaction rate between the oximes and ATCh, without DTNB, at different pH values by measuring the decrease in oximate ion absorption over time. The oximate ion of K027 reacted 14 times faster with ATCh (306M(-1)min(-1)) than the oximate ion of HI-6 (22M(-1)min(-1)). However, the rate constants obtained with the Ellman method were 84M(-1)min(-1) for K027 and 22M(-1)min(-1) for HI-6. Our results confirmed that the rate obtained with K027 using the Ellman method is actually the rate of the Ellman reaction itself. This suggests that the Ellman method cannot be used uncritically to evaluate oxime reaction with choline esters, in particular when oximolysis is faster than the Ellman reaction itself at a given pH.     

The metabolic role of isoleucine in detoxification of ammonia in cultured mouse neurons and astrocytes

Cerebral hyperammonemia is a hallmark of hepatic encephalopathy, a debilitating condition arising secondary to liver disease. Pyruvate oxidation including tricarboxylic acid (TCA) cycle metabolism has been suggested to be inhibited by hyperammonemia at the pyruvate and -ketoglutarate dehydrogenase steps. Catabolism of the branched-chain amino acid isoleucine provides both acetyl-CoA and succinyl-CoA, thus by-passing both the pyruvate dehydrogenase and the -ketoglutarate dehydrogenase steps. Potentially, this will enable the TCA cycle to work in the face of ammonium-induced inhibition. In addition, this will provide the -ketoglutarate carbon skeleton for glutamate and glutamine synthesis by glutamate dehydrogenase and glutamine synthetase (astrocytes only), respectively, both reactions fixing ammonium. Cultured cerebellar neurons (primarily glutamatergic) or astrocytes were incubated in the presence of either [U-¹³C]glucose (2.5 mM) and isoleucine (1 mM) or [U-¹³C]isoleucine and glucose. Cell cultures were treated with an acute ammonium chloride load of 2 (astrocytes) or 5 mM (neurons and astrocytes) and incorporation of ¹³C-label into glutamate, aspartate, glutamine and alanine was determined employing mass spectrometry. Labeling from [U-¹³C]glucose in glutamate and aspartate increased as a result of ammonium-treatment in both neurons and astrocytes, suggesting that the TCA cycle was not inhibited. Labeling in alanine increased in neurons but not in astrocytes, indicating elevated glycolysis in neurons. For both neurons and astrocytes, labeling from [U-¹³C]isoleucine entered glutamate and aspartate albeit to a lower extent than from [U-¹³C]glucose. Labeling in glutamate and aspartate from [U-¹³C]isoleucine was decreased by ammonium treatment in neurons but not in astrocytes, the former probably reflecting increased metabolism of unlabeled glucose. In astrocytes, ammonia treatment resulted in glutamine production and release to the medium, partially supported by catabolism of [U-¹³C]isoleucine. In conclusion, i) neuronal and astrocytic TCA cycle metabolism was not inhibited by ammonium and ii) isoleucine may provide the carbon skeleton for synthesis of glutamate/glutamine in the detoxification of ammonium.     

Expression of 25 human ABC transporters in the yeast Pichia pastoris and characterization of the purified ABCC3 ATPase activity

Human ATP-binding cassette (ABC) transporters comprise a family of 48 membrane-spanning transport proteins, many of which are associated with genetic diseases or multidrug resistance of cancers. In this study, we present a comprehensive approach for the cloning, expression, and purification of human ABC transporters in the yeast Pichia pastoris. We analyzed the expression of 25 proteins and demonstrate that 11 transporters, including ABCC3, ABCB6, ABCD1, ABCG1, ABCG4, ABCG5, ABCG8, ABCE1, ABCF1, ABCF2, and ABCF3, were expressed at high levels comparable to that of ABCB1 (P-glycoprotein). As an example of the purification strategy via tandem affinity chromatography, we purified ABCC3 (MRP3) whose role in the transport of anticancer drugs, bile acids, and glucuronides has been controversial. The yield of ABCC3 was 3.5 mg/100 g of cells in six independent purifications. Purified ABCC3, activated with PC lipids, exhibited significant ATPase activity with a Vmax of 82 +/- 32 nmol min-1 mg-1. The ATPase activity was stimulated by bile acids and glucuronide conjugates, reaching 170 +/- 28 nmol min-1 mg-1, but was not stimulated by a variety of anticancer drugs. The glucuronide conjugates ethinylestradiol-3-glucuronide and 17beta-estradiol-17-glucuronide stimulated the ATPase with relatively high affinities (apparent Km values of 2 and 3 microM, respectively) in contrast to bile acids (apparent Km values of >130 microM), suggesting that glucuronides are the preferred substrates for this transporter. Overall, the availability of a purification system for the production of large quantities of active transporters presents a major step not only toward understanding the role of ABCC3 but also toward future structure-function analysis of other human ABC transporters.     

Distribution of human papillomavirus types in different histological subtypes of cervical adenocarcinoma

Little information is available regarding distribution of HPV types in different histological subtypes of adenocarcinoma (AC). Thus, in this study we examined the frequency of high-risk (hr) HPV types in AC, adenocarcinoma in situ (AIS) and adenosquamous carcinoma (ADSQ). A total of 102 cases of primary cervical adenocarcinoma (26 AIS and 76 invasive AC) obtained from pathology files from 1995-2006 were histologically subtyped. Our results demonstrated that endocervical type occupied the major subtype of AC (22/66) followed by ADSQ (17/66) where as in the group of AIS endocervical type (12/23) was followed by intestinal type of AIS (7/23). Successful DNA extraction was obtained in 89 samples; 81 out of 89 (91.0%) tested positive for HPV DNA. The prevalence of HPV DNA in AIS, AC and ADSQ was 91.3% (21/23), 90.9% (60/66) and 94.1% (16/17), respectively. We found HPV 18 type to be the most predominant type in AIS (11/21) and AC (17/60) followed by HPVof undeternmined type in AIS (3/21) and HPV 16 in AC (9/60) as the sole viral type. HPV 18 was most frequently detected type in all histological subtypes of AIS and AC. We have detected HPV DNA in all 5 samples of clear cell carcinoma (CCC), although other studies have reported a highly variable prevalence of HPVDNA in CCC. The most prevalent HPV type in ADSQ was HPV-16 followed by HPV 33 as single type. The observed overall predominance of HPV 18 in AIS (chi(2) = 6.109, p< or = 0.025) and AC (chi(2) = 8.927, p< or =0.01) as well as of HPV 16 in ADSQ (chi(2) = 10.164, p < or = 0.01) was statistically significant. Our data revealed statistically significant predominance of single hrHPV infections in AIS (16/21; chi(2) = 11.523, p < 0.001) and AC (37/60; X2 = 6.533, p < 0.025) whereas multiple hrHPV infections were more abundant in AC comparing to AIS (23/81and 5/81, respectively; chi(2) = 13.989, p< or =0.001).     

Psychological status and coping with illness in patients with malignant melanoma

Melanoma patients are subject to different degrees of psychosocial distress. The emotional impact of malignant melanoma can be long lasting and profound, with the most common reactions to melanoma being depression, anxiety and deterioration in quality of life. Coping styles have been shown to have a significant influence on patients' quality of life and their emotional reaction to the illness. The aim of this paper was to investigate the quality of life, emotional status and coping styles in patients with melanoma. 31 patients suffering from malignant melanoma were included in the study. Results of this study show that melanoma has a medium influence on patients' psychological status and quality of life. The most "constructive" coping style--problem focused coping is the mostly used style by the patients, which might be one of the reasons why the illness didn't have a more severe influence on patients' psychological status.     

A single-centre experience with octreotide in the treatment of different hypersecretory syndromes in patients with functional gastroenteropancreatic neuroendocrine tumors

The aim of this research was to assess the clinical and biochemical efficacy of the octreotide in the treatment of patients with various functional gastroenteropancreatic neuroendocrine tumors (GEP-NETs). The study included 14 patients treated with octreotide for 6 months. They were diagnosed with VIPoma, glucagonoma, gastrinoma, medullary thyroid carcinoma (solitary and as a part of MEN-II syndrome), pancreatic carcinoids (solitary and as a part of multiple endocrine neoplasia type-1 syndrome-MEN-1 syndrome) and midgut carcinoids. The patients presented with Verner-Morrison, glucagonoma, Zollinger Ellison and carcinoid syndrome respectively. All had a metastatic disease at the time of diagnosis and a positive octreoscan finding. Initially elevated chromogranin A (CgA) levels were detected in 11 (78.6%) and elevated 5-hydroxyindolacetic acid (5-HIAA) levels in 8 (57.1%) patients. Symptomatic efficacy assessments were made by diarrhea reductions during treatment course, and laboratory efficacy was assessed through changes in 5-HIAA and CgA levels. Assessments were made initially and following 6 months of therapy. Median urinary 5-HIAA and the number of stools decreased significantly (p = 0.016 and p = 0.009 respectively, p < 0.05) while CgA levels had the decreasing tendency but not statistically significant (p = 0.14). There was a positive correlation between the 5-HIAA reduction and the decrease in stool number at baseline and during treatment course (p < 0.05). No correlation was observed between 5-HIAA and CgA levels and also there was no correlation between CgA reduction and symptomatic improvement. The results prove octreotide to be effective in reducing symptoms and biochemical markers associated with hypersecretory syndromes of GEP-NETs.     

Deletion polymorphism of the angiotensin I-converting enzyme gene in elderly patients with coronary heart disease

Controversy exists as to whether the deletion/deletion (DD) genotype of angiotensin l-converting enzyme (ACE) gene polymorphism is associated with coronary heart disease (CHD). There are only a few studies dealing with this issue in the elderly, also with controversial results. The aim of this study was the assessment of correlation between genetic markers and the risk of CHD in the elderly. The results indicated DD genotype importance for CHD in the elderly as proven by discriminant analysis (chi2 = 25.77; df = 16; p = 0.0620). However, the use of univariate method demonstrated no correlation between DD genotype of ACE gene polymorphism and coronary artery disease. D allele of ACE gene was associated with higher activities of ACE plasma. A weak, but increased risk of MI is associated with high frequency of DD genotype in the elderly. Strong correlation between ACE polymorphism and ACE plasma activities was demonstrated.