Selective GSK3ß Inhibition Mediates an Nrf2-Independent Anti-inflammatory Microglial Response.

Glycogen synthase kinase 3 (GSK3) is associated with the proinflammatory phenotype of microglia and has been shown to act in concert with nuclear factor kappa B (NF-κB). GSK3 is also a suppressor of nuclear factor erythroid 2-related factor 2 (Nrf2), the principal regulator of redox homeostasis. Agreeing with the oxidative paradigm of aging, Nrf2 is often deregulated in parainflammatory and neurodegenerative diseases. In this study, we aimed to explore a multimodal disease-modifying utility of GSK3 inhibition, beyond neuronal proteopathologies. Furthermore, we aimed to underscore the difference in therapeutic value between the two GSK3 paralogs by isoform-selective chemical inhibition. The anti-inflammatory effects of paralog-selective GSK3 inhibitors were evaluated as a function of the reductive capacity of each to mitigate LPS-induced activation of SIM-A9 microglia. The Griess method was employed to detect the nitrate-lowering capacity of selective GSK3 inhibition. Real-time PCR was used to assess post-treatment expression levels of pro-inflammatory markers and antioxidant genes; pro-inflammatory cytokines were assayed by ELISA. Nuclear lysates of treated cells were examined for Nrf2 and NF-κB accumulation by immunoblotting. Finally, to infer whether the counter-inflammatory activity of GSK3 inhibition was Nrf2-dependent, DsiRNA-mediated knockdown of Nrf2 was attempted. Results from our experiments reveal a superior anti-inflammatory and anti-oxidative efficacy for GSK3ß-selective inhibition, compared to GSK3α-selective and non-selective pan-inhibition; hence, use of selective GSK3ß inhibitors is likely to be more propitious than non-selective dual inhibitors administered at comparable doses. Moreover, our results suggest that the anti-inflammatory effects of GSK3 inhibition are not Nrf2 dependent.

Effects of Metformin Combined With Antifolates on HepG2 Cell Metabolism and Cellular Proliferation.

Hepatocellular carcinoma (HCC), one of the most prevalent types of cancers worldwide, continues to maintain high levels of resistance to standard therapy. As clinical data revealed poor response rates, the need for developing new methods has increased to improve the overall wellbeing of patients with HCC. Furthermore, a growing body of evidence shows that cancer metabolic changes are a key feature of many types of human malignancies. Metabolic reprogramming refers to cancer cells' ability to change their metabolism in order to meet the increased energy demand caused by continuous growth, rapid proliferation, and other neoplastic cell characteristics. For these reasons, metabolic pathways may become new therapeutic and chemopreventive targets. The aim of this study was to investigate the metabolic alterations associated with metformin (MET), an anti-diabetic agent when combined with two antifolate drugs: trimethoprim (TMP) or methotrexate (MTX), and how metabolic changes within the cancer cell may be used to increase cellular death. In this study, single drugs and combinations were investigated using in vitro assays including cytotoxicity assay (MTT), RT-qPCR, annexin V/PI apoptosis assay, scratch wound assay and Seahorse XF analysis, on a human HCC cell line, HepG2. The cytotoxicity assay showed that the IC50 of MET as single therapy was 44.08 mM that was reduced to 22.73 mM and 29.29 mM when combined with TMP and MTX, respectively. The co-treatment of both drugs increased p53 and Bax apoptotic markers, while decreased the anti-apoptotic marker; Bcl-2. Both combinations increased the percentage of apoptotic cells and halted cancer cell migration when compared to MET alone. Furthermore, both combinations decreased the MET-induced increase in glycolysis, while also inducing mitochondrial damage, altering cancer cell bioenergetics. These findings provide an exciting insight into the anti-proliferative and apoptotic effects of MET and anti-folates on HepG2 cells, and how in combination, may potentially combat the aggressiveness of HCC.

Bioinformatics Analysis of Allele Frequencies and Expression Patterns of ACE2, TMPRSS2 and FURIN in Different Populations and Susceptibility to SARS-CoV-2.

The virus responsible for the COVID-19 global health crisis, SARS-CoV-2, has been shown to utilize the ACE2 protein as an entry point to its target cells. The virus has been shown to rely on the actions of TMPRSS2 (a serine protease), as well as FURIN (a peptidase), for the critical priming of its spike protein. It has been postulated that variations in the sequence and expression of SARS-CoV-2's receptor (ACE2) and the two priming proteases (TMPRSS2 and FURIN) may be critical in contributing to SARS-CoV-2 infectivity. This study aims to examine the different expression levels of FURIN in various tissues and age ranges in light of ACE2 and TMPRSS2 expression levels using the LungMAP database. Furthermore, we retrieved expression quantitative trait loci (eQTLs) of the three genes and their annotation. We analyzed the frequency of the retrieved variants in data from various populations and compared it to the Egyptian population. We highlight FURIN's potential interplay with the immune response to SARS-CoV-2 and showcase a myriad of variants of the three genes that are differentially expressed across populations. Our findings provide insights into potential genetic factors that impact SARS-CoV-2 infectivity in different populations and shed light on the varying expression patterns of FURIN.

Mercury and Alzheimer's disease: a look at the links and evidence.

This review paper investigates a specific environmental-disease interaction between mercury exposure and Alzheimer's disease hallmarks. Alzheimer's disease is a neurodegenerative disorder affecting predominantly the memory of the affected individual. It prevails mostly in the elderly, rendering many factors as possible causative agents, which potentially contribute to the disease pathogenicity cumulatively. Alzheimer's disease affects nearly 50 million people worldwide and is considered one the most devastating diseases not only for the patient, but also for their families and caregivers. Mercury is a common environmental toxin, found in the atmosphere mostly due to human activity, such as coal burning for heating and cooking. Natural release of mercury into the atmosphere occurs by volcanic eruptions, in the form of vapor, or weathering rocks. The most toxic form of mercury to humans is methylmercury, to which humans are exposed to by ingestion of fish. Methylmercury was found to exert its toxic effects on different parts of the human body, with predominance on the brain. There is no safe concentration for mercury in the atmosphere, even trace amounts can elicit harm to humans in the long term. Mercury's effect on Alzheimer's disease hallmarks formation, extracellular senile plaques and intracellular neurofibrillary tangles, has been widely studied. This review demonstrates the involvement of mercury, in its different forms, in the pathway of amyloid beta deposition and tau tangles formation. It aims to understand the link between mercury exposure and Alzheimer's disease so that, in the future, prevention strategies can be applied to halt the progression of this disease.

Biocompatible PCL-nanofibers scaffold with immobilized fibronectin and laminin for neuronal tissue regeneration.

Recent advances in regenerative medicine have given hope in overcoming and rehabilitating complex medical conditions. In this regard, the biopolymer poly-ε-caprolactone (PCL) may be a promising candidate for tissue regeneration, despite lacking the essential bioactivity. The present study used PCL nanofibers (NFs) scaffold decorated with the extracellular matrix proteins fibronectin and laminin combined for neuronal regeneration. The potential for the dual proteins to support neuronal cells and promote axonal growth was investigated. Two NFs scaffolds were produced with PLC concentrations of 12% or 15%. Under scanning electron microscopy, both scaffolds evidenced uniform diameter distribution in the range of 358 nm and 887 nm, respectively, with >80% porosity. The Brunauer-Emmett-Teller (BET) test confirmed that the fabricated NFs mats had a high surface area, especially for the 12% NFs with 652 m2/g compared to 254 m2/g for the 15% NFs. The proteins of interest were successfully conjugated to the 12% PCL scaffold through chemical carbodiimide reaction as confirmed by Fourier-transform infrared spectroscopy. The addition of fibronectin and laminin together was shown to be the most favorable for cellular attachment and elongation of neuroblastoma SH-SY5Y cells compared to other formulations. Light microscopy revealed longer neurite outgrowth, higher cellular projected area, and lower shape index for the cells cultured on the combined proteins conjugated fibers, indicating enhanced cellular spread on the scaffold. This preliminary study suggests that PCL nanoscaffolding conjugated with matrix proteins can support neuronal cell viability and neurite growth.

Hepigenetics: A Review of Epigenetic Modulators and Potential Therapies in Hepatocellular Carcinoma.

Hepatocellular carcinoma is the fifth most common cancer worldwide and the second most lethal, following lung cancer. Currently applied therapeutic practices rely on surgical resection, chemotherapy and radiotherapy, or a combination thereof. These treatment options are associated with extreme adversities, and risk/benefit ratios do not always work in patients' favor. Anomalies of the epigenome lie at the epicenter of aberrant molecular mechanisms by which the disease develops and progresses. Modulation of these anomalous events poses a promising prospect for alternative treatment options, with an abundance of felicitous results reported in recent years. Herein, the most recent epigenetic modulators in hepatocellular carcinoma are recapitulated on.

The ability of spore formers to degrade milk proteins, fat, phospholipids, common stabilizers, and exopolysaccharides.

Spore formers are common spoilage-causing microorganisms in dairy products; however, their modes of spoilage (proteolysis, lipolysis, etc.) have not been described in detail for cultured dairy products such as sour cream and yogurt. The objective of the present study was to test the ability of spore-forming strains isolated from dairy environments for their spoilage-causing activities at typical sour cream (24°C) and yogurt (42°C) fermentation temperatures. A total of 25 spore-forming strains were isolated from different sources, including raw milk, pasteurizer balance tank, biofilms formed on heat exchangers, and milk powder. These strains were tested for proteolytic and lipolytic activities and for their ability to degrade phospholipids, common stabilizers (starch, gelatin, xanthan gum, pectin), and exopolysaccharides (EPS) at sour cream and yogurt fermentation temperatures. A higher percentage of positive strains was observed for selected activities at yogurt fermentation temperature compared with sour cream fermentation temperature. Identified proteolytic spore-forming strains, based on a skim milk agar method, were subsequently quantified for their level of proteolysis using non-casein nitrogen (NCN) content and sodium dodecyl sulfate-PAGE (SDS-PAGE). The proteolytic strains that showed the highest levels of proteolysis (highest percentages of NCN content) at 24°C were Bacillus mojavensis BC, Bacillus cereus DBC, Bacillus subtilis DBC, B. mojavensis DBC1, and Paenibacillus polymyxa DBC1. At 42°C the strains with the highest levels of proteolysis (highest percentages of NCN content) were B. subtilis DBC, B. mojavensis BC, B. mojavensis DBC1, B. cereus DBC, and Bacillus licheniformis DBC6. Results of SDS-PAGE demonstrated that proteolytic strains had primarily hydrolyzed ß- and κ-CN. A viscometric method was used to evaluate the susceptibility of exopolysaccharides (EPS) to degradation by selected spore formers. This method helped to determine that EPS produced by commercial yogurt and sour cream cultures is susceptible to degradation by spore formers present in dairy environments.

Dengue virus specific Immunoglobulin G antibodies among patients with febrile conditions in Osogbo, Southwestern Nigeria.

Dengue fever is becoming one of the major public health problems in the world and its distribution has been premised on the migration of people from infected regions. This study was carried out to determine the prevalence of dengue virus IgG antibody among the patients with febrile conditions attending health facilities in Osogbo metropolis, Southwestern Nigeria. The blood samples collected between July and September, 2014 were tested for Plasmodium falciparum and the sera were subsequently subjected to Enzyme Linked Immunosorbent Assay (ELISA) to detect the dengue virus IgG antibody. Of the hundred consented participants screened, 77% were sero-positive for dengue virus IgG antibody while 41% were positive for P. falciparum. Thirty-three (33%) of the participants were positive for both dengue virus IgG antibody and P. falciparum. No significant difference was found in the prevalence of dengue virus IgG antibody and malaria among the participants (P>0.05). The high prevalence of dengue virus IgG and malaria signifies the need by the government of Osun State to sensitize residents and institute urgent measures to mitigate the resultant effects of morbidity and mortality due to dengue fever and dengue hemorrhagic fever which has hitherto appeared to be alien to the area.

Dengue virus specific Immunoglobulin G antibodies among

Dengue fever is becoming one of the major public health problems in the world and its distribution has been premised on the migration of people from infected regions. This study was carried out to determine the prevalence of dengue virus IgG antibody among the patients with febrile conditions attending health facilities in Osogbo metropolis, Southwestern Nigeria. The blood samples collected between July and September, 2014 were tested for Plasmodium falciparum and the sera were subsequently subjected to Enzyme Linked Immunosorbent Assay (ELISA) to detect the dengue virus IgG antibody. Of the hundred consented participants screened, 77% were sero-positive for dengue virus IgG antibody while 41% were positive for P. falciparum. Thirty-three (33%) of the participants were positive for both dengue virus IgG antibody and P. falciparum. No significant difference was found in the prevalence of dengue virus IgG antibody and malaria among the participants (P>0.05). The high prevalence of dengue virus IgG and malaria signifies the need by the government of Osun State to sensitize residents and institute urgent measures to mitigate the resultant effects of morbidity and mortality due to dengue fever and dengue hemorrhagic fever which has hitherto appeared to be alien to the area.

Date (Phoenix dactylifera) Polyphenolics and Other Bioactive Compounds: A Traditional Islamic Remedy's Potential in Prevention of Cell Damage, Cancer Therapeutics and Beyond.

This review analyzes current studies of the therapeutic effects of Phoenix dactylifera, or date palm fruit, on the physiologic system. Specifically, we sought to summarize the effects of its application in preventing cell damage, improving cancer therapeutics and reducing damage caused by conventional chemotherapy. Phoenix dactylifera exhibits potent anti-oxidative properties both in vitro and in vivo. This allows the fruit to prevent depletion of intrinsic protection from oxidative cell damage and assist these defense systems in reducing cell damage. Macroscopically, this mechanism may be relevant to the prevention of various adverse drug events common to chemotherapy including hepatotoxicity, nephrotoxicity, gastrotoxicity, and peripheral neuropathy. While such effects have only been studied in small animal systems, research suggests a potential application to more complex mammalian systems and perhaps a solution to some problems of chemotherapy in hepato-compromised and nephro-compromised patients.

Effect of Vitamin D Supplementation on Glucose Control and Inflammatory Response in Type II Diabetes: A Double Blind, Randomized Clinical Trial.

BACKGROUND: Diabetes mellitus (DM) and vitamin D deficiency are major health concerns around the world. Evidence suggests a possible role of vitamin D in improvement of insulin secretion and sensitivity. OBJECTIVES: We assessed whether vitamin D supplementation could be used in vitamin D deficient-type II diabetes to improve glucose metabolism, components of metabolic syndrome (MetS) and specific inflammatory biomarkers. PATIENTS AND METHODS: A double blind, randomized clinical trial was conducted in King Khalid University Hospital, Saudi Arabia to evaluate the effect of cholecalciferol supplementation on glycemic control, MetS components and specific inflammatory biomarkers including tumor necrosis factor-alpha (TNF-α), Interleukin (IL-6), leptin, adiponectin and vascular cell adhesion molecule-1 (VCAM-1). Twenty-two patients with type II diabetes with insulin resistance, glycated hemoglobin (HbA1c) ≥ 6 (42 mmol/mol) and serum 25(OH)D < 50 nmol/L were randomized using a computer program to receive either supplementation with cholecalciferol (5000 IU/day) or placebo for 12 weeks. The primary outcome was change in HbA1c levels from baseline. RESULTS: Median [IQR] 25(OH)D levels increased significantly in the vitamin D group as 58.1 [48, 67.3] nmol/L (P = 0.002). There was no significant difference in the change of HbA1c between the groups (P = 0.5) with a decrease of -0.1% [-1, 0.5] in the vitamin D group and an increase of 0.15% [0.1, 0.2] in the placebo group. A significant improvement was observed in the homeostasis model of assessment of ß-cell activity (HOMA-%B) (P = 0.03) with vitamin D supplementation compared to baseline. CONCLUSIONS: Vitamin D repletion for 12 weeks increased serum vitamin D concentrations and improved ß-cell activity in vitamin D-deficient type II diabetes with no significant changes in HbA1c or insulin sensitivity.

Autoantibodies associated with prenatal and childhood exposure to environmental chemicals in Faroese children.

Methylmercury, polychlorinated biphenyls (PCBs), and perfluorinated compounds (PFCs) are ubiquitous and persistent environmental chemicals with known or suspected toxic effects on the nervous system and the immune system. Animal studies have shown that tissue damage can elicit production of autoantibodies. However, it is not known if autoantibodies similarly will be generated and detectable in humans following toxicant exposures. Therefore, we conducted a pilot study to investigate if autoantibodies specific for neural and non-neural antigens could be detected in children at age 7 years who have been exposed to environmental chemicals. Both prenatal and age-7 exposures to mercury, PCBs, and PFCs were measured in 38 children in the Faroe Islands who were exposed to widely different levels of these chemicals due to their seafood-based diet. Concentrations of IgM and IgG autoantibodies specific to both neural (neurofilaments, cholineacetyltransferase, astrocyte glial fibrillary acidic protein, and myelin basic protein) and non-neural (actin, desmin, and keratin) antigens were measured and the associations of these autoantibody concentrations with chemical exposures were assessed using linear regression. Age-7 blood-mercury concentrations were positively associated with titers of multiple neural- and non-neural-specific antibodies, mostly of the IgM isotype. Additionally, prenatal blood-mercury and -PCBs were negatively associated with anti-keratin IgG and prenatal PFOS was negatively associated with anti-actin IgG. These exploratory findings demonstrate that autoantibodies can be detected in the peripheral blood following exposure to environmental chemicals. The unexpected association of exposures with antibodies specific for non-neural antigens suggests that these chemicals may have toxicities that have not yet been recognized.

Neuroantibody biomarkers: links and challenges in environmental neurodegeneration and autoimmunity.

The majority of neurodegenerative (ND) and autoimmune diseases (AID) remain idiopathic. The contribution of environmental chemicals to the development of these disorders has become of great interest in recent years. A convergence of mechanism between of ND and AID development has also emerged. In the case of ND, including neurotoxicity, the focus of this review, work over the last two decade in the realm of biomarker development, indicates that the immune response provides a venue whereby humoral immunity, in the form of autoantibodies to nervous system specific proteins, or neuroantibodies (NAb), may provide, once validated, a sensitive high throughput surrogate biomarker of effect with the potential of predicting outcome in absence of overt neurotoxicity/neurodegeneration. In addition, NAb may prove to be a contributor to the progression of the nervous system pathology, as well as biomarker of stage and therapeutic efficacy. There is a compelling need for biomarkers of effect in light of the introduction of new chemicals, such as nanoengineered material, where potential neurotoxicity remains to be defined. Furthermore, the convergence of mechanisms associated with ND and AID draws attention to the neglected arena of angiogenesis in defining the link between environment, ND, and AID.

Starter cultures and cattle feed manipulation enhance conjugated linoleic acid concentrations in Cheddar cheese.

Conjugated linoleic acid (CLA) is a fatty acid (FA) that provides several health benefits to humans. The feeding of fish oil-supplemented diets to dairy cows has been extensively studied as a means to improve the CLA content in milk. Several studies have also been conducted on the ability of many microorganisms to produce CLA by utilizing substrates containing linoleic acid. In the present study, the dietary manipulated milk was used in combination with the CLA-producing culture to manufacture Cheddar cheese. The two diets fed to cattle were control and treatment diets to obtain control and treatment milk, respectively. The treatment diet containing fish oil (0.75% of dry matter) was fed to 32 dairy cows grouped in a pen for 18 d to increase the total CLA content in milk. Treatment milk had a CLA content of 1.60 g/100g of FA compared with 0.58 g/100g of FA in control milk obtained by feeding the control diet. A 2 × 2 factorial design with 3 replicates was used to test the combined effect of the CLA-producing starter culture of Lactococcus lactis (CI4b) versus a commercial CLA nonproducing cheese starter as the control culture, and type of milk (control vs. treatment milk) on CLA content in Cheddar cheese. Chemical composition (moisture, salt, fat, and protein) was not affected by the type of culture used. However, the age of the cheese affected the sensory properties and microbiological counts in the different treatments. Ripening with the CI4b culture was found to be effective in further enhancing the CLA content. The CI4b cheeses made from control milk and treatment milk contained 1.09 and 2.41 (±0.18) g of total CLA/100g of FA after 1 mo of ripening, which increased to 1.44 and 2.61 (±0.18) g of total CLA/100g of FA after 6 mo of ripening, respectively. The use of treatment milk resulted in an increase in the CLA isomers (trans-7,cis-9+cis-9,trans-11, trans-9,cis-11+cis-10,trans-12, trans-10,cis-12, cis-9,cis-11, trans-11,cis-13, cis-11,cis-13, trans-11,trans-13, and trans-9,trans-11). The CI4b culture specifically increased cis-11,cis-13 and trans-10,cis-12 isomers in cheese. The total CLA content in cheese was significantly higher when the CI4b culture was used compared with CLA nonproducing culture cheeses made from control milk and treatment milk after 1 mo [1.09 and 2.14 (±0.18) g of total CLA/100g of FA] and 6 mo [0.99 and 2.05 (±0.18) g of total CLA/100g of FA] of ripening, respectively. The results indicated that the combination of a CLA-producing starter culture and milk from cattle fed fish oil-supplemented diets (0.99 g of CLA/100g of FA) could enhance levels of total CLA in Cheddar cheese by up to 2.6 times compared with cheese made from control milk with CLA nonproducing starter culture (2.61 g of CLA/100g of FA) after 6 mo.

Nervous system autoantibodies and vitamin D receptor gene polymorphisms in hemodialysis patients.

Cognitive deficits are prevalent in hemodialysis (HD) patients. Vitamin D deficiency and vitamin D receptor (VDR) gene single nucleotide polymorphism (SNPs) have been linked to both neurodegeneration (ND) and neuroprotection, respectively. Autoantibodies (Ab) to myelin basic protein (MBP), glial fibrillary acidic protein (GFAP), and neurofilament (NF) triplet proteins arise secondary to nervous system (NS) damage providing a means to assess neurological injury. Characterization of Ab biomarkers of NS damage in HD patients, their association with VDR SNPs, and nutritional vitamin D (NVD) therapy was performed. VDR genotypes, cytokines, and Ab biomarkers to NS proteins in HD subjects receiving ergocalciferol (n = 40) were compared with nonusers (n = 71). Interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and immunoglobulin G (IgG) titers against NFs, GFAP, and MBP were measured by immunoassay. Subjects were genotyped for VDR SNPs BsmI (rs1544410) and FokI (rs2228570). Subjects (age 63.3 ± 16.1 years, 66% male) who were C allele carriers of BsmI had higher values of NF-68 antibody titers (p = 0.027). Ergocalciferol users (n = 40) compared with nonusers (n = 71) had lower Ab titers to NS proteins; however, only anti-NF-160 and anti-MBP titers were significantly (p < 0.05) higher. IgG against NS proteins in HD patients suggests neuronal and glial insult and a relationship with VDR alleles. NVD may provide some neuroprotection, indicated by anti-NF-160 and anti-MBP, which was markedly lowered in ergocalciferol patients. This preliminary study suggests that Ab detection may be useful in monitoring ND and the potential of NVD for neuroprotection in HD patients.

Effects of obesity and sex on antimicrobial pharmacokinetics and acute kidney injury: validation of a preclinical model.

Obese patients may be at a greater risk for acute kidney injury (AKI) with the use of certain antimicrobial agents that are dosed by weight. Current preclinical models of AKI utilize the male rat within a narrow weight range that limits extrapolation of the generated results. We evaluated the pharmacokinetics and AKI potential of gentamicin in 14-week-old diet-induced obesity-prone (n = 40) and obesity-resistant (n = 40) rats of both sexes. Single daily doses of gentamicin (12.5, 18.75, or 25 mg/kg of body weight) or saline (control) were administered intraperitoneally for 14 doses. Blood samples were collected after doses 1, 7, and 14, assayed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and analyzed using a nonparametric population pharmacokinetic approach for gentamicin. Urine was collected after doses 1, 3, and 5 and assayed for kidney injury molecule 1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) and normalized to creatinine (Cr) values. Histology was performed on all animals, and the degree of proximal tubular injury was graded. The mean (minimum, maximum) weight of the rats was 330 (136, 580) g. NGAL/Cr predicted AKI better than did KIM-1/Cr and was detectable in male rats after dose 1 and in obesity-prone female rats after dose 5. Proximal tubular injury by histology was significantly higher in male than in female rats. A significant relationship between the gentamicin area under the curve from zero to 24 hours (AUC(0-24)) estimates and the maximum NGAL/Cr ratio was observed. This preclinical model has the potential to aid with dose extrapolation for body size and improve assessment of the toxicology potential of antimicrobials in development.

Exopolysaccharides modify functional properties of whey protein concentrate.

The objective of this research was to produce whey protein concentrate (WPC) with modified functionality using exopolysaccharide- (EPS) producing cultures. Two different EPS-producing cultures, Lactococcus lactis ssp. cremoris JFR and Streptococcus thermophilus, producing EPS1 and EPS2 respectively, were used in this study. One EPS-nonproducing commercial cheese culture (DVS 850; Chr. Hansen, Milwaukee, WI) was used as the control. Reconstituted sweet whey powder was used in this study to eliminate variations from fresh whey. Cultures grown overnight in reconstituted WPC (10% wt/vol) were added, directly or after overnight cooling (cooled EPS), at 2% (wt/vol) to 6% (wt/wt) solution of reconstituted whey. Whey was then high-temperature, short-time pasteurized at 75 °C for 35s and ultrafiltered to a volume reduction factor of 5. Ultrafiltered whey (retentate) was spray dried at inlet and outlet air temperatures of 200 and 90 °C, respectively, to obtain WPC. In general, the solubility of WPC was higher at pH 7 than at pH 3. Whey protein concentrate containing EPS2 exhibited higher protein solubility than did WPC containing no EPS. Also, the presence of EPS in WPC decreased protein denaturation. The emulsifying ability of WPC containing EPS was higher than that in control. Addition of EPS to WPC significantly enhanced its gelling ability. Foam overrun and hydrophobicity of WPC were not affected by addition of EPS. In conclusion, data obtained from this study show that EPS modify WPC functionality. The extent of modification depends on the type of EPS. Cooling of culture containing EPS before its addition to whey further reduced WPC protein denaturation and increased its solubility at pH 7 and gel hardness.

Invited review: anaerobic fermentation of dairy food wastewater.

Dairy food wastewater disposal represents a major environmental problem. This review discusses microorganisms associated with anaerobic digestion of dairy food wastewater, biochemistry of the process, factors affecting anaerobic digestion, and efforts to develop defined cultures. Anaerobic digestion of dairy food wastewater offers many advantages over other treatments in that a high level of waste stabilization is achieved with much lower levels of sludge. In addition, the process produces readily usable methane with low nutrient requirements and no oxygen. Anaerobic digestion is a series of complex reactions that broadly involve 2 groups of anaerobic or facultative anaerobic microorganisms: acidogens and methanogens. The first group of microorganisms breaks down organic compounds into CO(2) and volatile fatty acids. Some of these organisms are acetogenic, which convert long-chain fatty acids to acetate, CO(2), and hydrogen. Methanogens convert the acidogens' products to methane. The imbalance among the different microbial groups can lead not only to less methane production, but also to process failure. This is due to accumulation of intermediate compounds, such as volatile fatty acids, that inhibit methanogens. The criteria used for evaluation of the anaerobic digestion include levels of hydrogen and volatile fatty acids, methane:carbon ratio, and the gas production rate. A steady state is achieved in an anaerobic digester when the pH, chemical oxygen demand of the effluent, the suspended solids of the effluent, and the daily gas production remain constant. Factors affecting efficiency and stability of the process are types of microorganisms, feed C:N ratio, hydraulic retention time, reactor design, temperature, pH control, hydrogen pressure, and additives such as manure and surfactants. As anaerobic digesters become increasingly used in dairy plants, more research should be directed toward selecting the best cultures that maximize methane production from dairy food waste.

Application of salt whey in process cheese food made from Cheddar cheese containing exopolysaccharides.

The objective of this work was to use salt whey in making process cheese food (PCF) from young (3-wk-old) Cheddar cheese. To maximize the level of salt whey in process cheese, low salt (0.6%) Cheddar cheese was used. Because salt reduction causes undesirable physiochemical changes during extended cheese ripening, young Cheddar cheese was used in making process cheese. An exopolysaccharide (EPS)-producing strain (JFR) and a non-EPS-producing culture (DVS) were applied in making Cheddar cheese. To obtain similar composition and pH in the EPS-positive and EPS-negative Cheddar cheeses, the cheese making protocol was modified in the latter cheese to increase its moisture content. No differences were seen in the proteolysis between EPS-positive and EPS-negative Cheddar cheeses. Cheddar cheese made with the EPS-producing strain was softer, and less gummy and chewy than that made with the EPS-negative culture. Three-week-old Cheddar cheese was shredded and stored frozen until used for PCF manufacture. Composition of Cheddar cheese was determined and used to formulate the corresponding PCF (EPS-positive PCF and EPS-negative PCF). The utilization of low salt Cheddar cheese allowed up to 13% of salt whey containing 9.1% salt to be used in process cheese making. The preblend was mixed in the rapid visco analyzer at 1,000 rpm and heated at 95°C for 3 min; then, the process cheese was transferred into copper cylinders, sealed, and kept at 4°C. Process cheese foods contained 43.28% moisture, 23.7% fat, 18.9% protein, and 2% salt. No difference in composition was seen between the EPS-positive and EPS-negative PCF. The texture profile analysis showed that EPS-positive PCF was softer, and less gummy and chewy than EPS-negative PCF. The end apparent viscosity and meltability were higher in EPS-positive PCF than in EPS-negative PCF, whereas emulsification time was shorter in the former cheese. Sensory evaluation indicated that salt whey at the level used in this study did not affect cheese flavor. In conclusion, process cheese, containing almost 13% salt whey, with improved textural and melting properties could be made from young EPS-positive Cheddar cheese.

Nutritional vitamin D supplementation in haemodialysis: A potential vascular benefit?

AIM: Vitamin D deficiency is highly prevalent in end-stage renal disease and has been associated with atherosclerosis, endothelial dysfunction and left ventricular hypertrophy. Although activated vitamin D has shown to be cardioprotective, the cardiovascular benefits of nutritional vitamin D (i.e. ergocalciferol or cholecalciferol) have not been explored in the dialysis population. The aim of this investigation was to evaluate the effect of ergocalciferol therapy on vascular adhesion molecules, markers of inflammation and atherosclerosis among haemodialysis patients. METHODS: This was a pilot study of matched haemodialysis patients. For every patient enrolled taking ergocalciferol, an age and race matched control was recruited. Predialysis blood samples were collected and assayed for adhesion molecules (soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), E-selectin and P-selectin), inflammatory cytokines (interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α)), oxLDL-ß(2) GPI and IgG anticardiolipin. RESULTS: A total of 40 haemodialysis patients were studied (20 on ergocalciferol therapy, 20 not receiving ergocalciferol therapy). Patients taking ergocalciferol had higher 25-hydroxyvitamin D levels compared with those not taking ergocalciferol. Even though doxercalciferol usage and dosing was similar between groups, plasma sVCAM-1, sICAM-1 and P-selectin concentrations were lower among ergocalciferol treated patients. No significant differences in E-selectin, IL-6, TNF-α, oxLDL-ß(2) GPI or anticardiolipin antibody levels were observed. CONCLUSION: Patients receiving ergocalciferol had lower plasma levels of vascular adhesion molecules despite equivalent use of activated vitamin D therapy. Future investigations should confirm the role of nutritional vitamin D therapy, in addition to activated D therapy, in haemodialysis patients and the potential vascular benefits of these agents.