Improving ethanol yields in sugarcane molasses fermentation by engineering the high osmolarity glycerol pathway while maintaining osmotolerance in Saccharomyces cerevisiae.

The ever-increasing demand of energy has made it imperative to increase the production of renewable fuels like ethanol. Many studies have reported increase in ethanol production by reducing fermentation by-products like glycerol. Deletion of structural genes like gpd1and gpd2 leads to an increase in ethanol by reducing glycerol; however, it makes the yeast osmosensitive that is not desirable for industrial strains. In this study, genes in the HOG pathway which regulates glycerol synthesis in Saccharomyces cerevisiae were targeted for improving ethanol yields in fermentation of sugarcane molasses. Deletion strains of ssk1, hot1, and smp1 were tested and they did not show osmosensitivity. Δssk1 and Δsmp1 recombinant strains showed consistent improved ethanol yields. As a result, a double-deletion strain, Δssk1Δsmp1, was also constructed, which showed a synergistic effect leading to 6% increase in ethanol yield and 35% decrease in glycerol yield. It was also observed that there was a significant decrease in acetic acid yields of all the recombinant strains. Overall, the study demonstrates an industrially viable technique of engineering the HOG pathway resulting in decrease of glycerol and no loss of osmotolerance. These S. cerevisiae strains showed a significant increase in ethanol yields.

Triaxial accelerometer-measured physical activity and functional behaviours among people with High Grade Glioma: The BrainWear Study.

BACKGROUND: High-grade gliomas (HGG) account for 60-75% of all adult gliomas. The complexity of treatment, recovery and survivorship creates a need for novel monitoring approaches. Accurate assessment of physical function plays a vital role in clinical evaluation. Digital wearable tools could help us address unmet needs by offering unique advantages such as scale, cost and continuous real-world objective data. We present data from 42 patients enrolled into the BrainWear study. METHODS: An AX3 accelerometer was worn by patients from diagnosis or at recurrence. Age-, sex-matched UK Biobank control groups were chosen for comparison. RESULTS: 80% of data were categorised as high-quality demonstrating acceptability. Remote, passive monitoring identifies moderate activity reduces both during a course of radiotherapy (69 to 16 minutes/day) and at the time of progressive disease assessed by MRI (72 to 52 minutes/day). Mean acceleration (mg) and time spent walking daily (h/day) correlated positively with the global health quality of life and physical functioning scores and inversely with the fatigue score. Healthy controls walked on average 2.91h/day compared to 1.32h/day for the HGG group on weekdays and 0.91h/day on the weekend. The HGG cohort slept for longer on weekends (11.6h/day) than weekdays (11.2h/day) compared to healthy controls (8.9h/day). CONCLUSION: Wrist-worn accelerometers are acceptable and longitudinal studies feasible. HGG patients receiving a course of radiotherapy reduce their moderate activity by 4-fold and are at least half as active as healthy controls at baseline. Remote monitoring can provide a more informed and objective understanding of patient activity levels to help optimise health related quality of life (HRQoL) among a patient cohort with an extremely limited lifespan.

Swine flu: a Birmingham experience.

By the beginning of July 2009 the West Midlands had seen more cases of novel H1N1 influenza (swine flu) than any other region in the U.K. Over a three-week period almost 850 people presented to Heartlands Hospital with flu-like symptoms. Of those admitted 52 adults were subsequently confirmed as having H1N1 infection. Most were younger than 30 and not from traditional influenza risk groups. The main risk factor for severe disease was asthma, and to a lesser extent pregnancy and obesity. Seven patients were admitted to intensive care and five developed an acute lung injury requiring prolonged admission. Two patients required extra corporeal membrane oxygenation and one died. Despite increased workload normal clinical services were unaffected. The hospital was not closed to admissions nor was it paralysed by staff absence. With a predicted second wave expected at the end of 2009, efforts to maintain effective community assessment remain crucial.

Pharmacological regulation of adult stem cells: chondrogenesis can be induced using a synthetic inhibitor of the retinoic acid receptor.

Conventional methods for regulating the differentiation of stem cells are largely based on the use of biological agents such as growth factors. We hypothesize that stem cell differentiation could be driven by specific synthetic molecules. If true, this would offer the possibility of screening chemical libraries to develop pharmacological agents with improved efficacy. To test our hypothesis, we have determined which, if any, of the nuclear receptor superfamily might be involved in chondrogenesis. We used fluorescence-activated cell sorting, as well as quantitative polymerase chain reaction, to study expression of a range of nuclear receptors in the undifferentiated mesenchymal population and after growth factor-driven differentiation of these cells to chondrocytes. In this way, we identified retinoic acid receptor beta (RAR beta) as a potential pharmacological target. A low molecular weight synthetic inhibitor of the RAR alpha and RAR beta receptors was able to induce chondrogenic differentiation of mesenchymal stem cells derived from osteoarthritis patients, in the absence of serum and growth factors. Furthermore, the pathway is independent of SOX9 upregulation and does not lead to hypertrophy. When mesenchymal cells were seeded on to polyglycolic acid scaffolds and cultured with LE135, there was a dose-dependent formation of cartilage, demonstrated both histologically and by biochemical analysis of the collagen component of the extracellular matrix. These results demonstrate the feasibility of a pharmacological approach to the regulation of stem cell function. Disclosure of potential conflicts of interest is found at the end of this article.

Intraoperative Assessment of Tumor Resection Margins in Breast-Conserving Surgery Using 18F-FDG Cerenkov Luminescence Imaging: A First-in-Human Feasibility Study.

In early-stage breast cancer, the primary treatment option for most women is breast-conserving surgery (BCS). There is a clear need for more accurate techniques to assess resection margins intraoperatively, because on average 20% of patients require further surgery to achieve clear margins. Cerenkov luminescence imaging (CLI) combines optical and molecular imaging by detecting light emitted by 18F-FDG. Its high-resolution and small size imaging equipment make CLI a promising technology for intraoperative margin assessment. A first-in-human study was conducted to evaluate the feasibility of 18F-FDG CLI for intraoperative assessment of tumor margins in BCS. Methods: Twenty-two patients with invasive breast cancer received 18F-FDG (5 MBq/kg) 45-60 min before surgery. Sentinel lymph node biopsy was performed using an increased 99mTc-nanocolloid activity of 150 MBq to facilitate nodal detection against the γ-probe background signal (cross-talk) from 18F-FDG. The cross-talk and 99mTc dose required was evaluated in 2 lead-in studies. Immediately after excision, specimens were imaged intraoperatively in an investigational CLI system. The first 10 patients were used to optimize the imaging protocol; the remaining 12 patients were included in the analysis dataset. Cerenkov luminescence images from incised BCS specimens were analyzed postoperatively by 2 surgeons blinded to the histopathology results, and mean radiance and margin distance were measured. The agreement between margin distance on CLI and histopathology was assessed. Radiation doses to staff were measured. Results: Ten of the 12 patients had an elevated tumor radiance on CLI. Mean radiance and tumor-to-background ratio were 560 ± 160 photons/s/cm2/sr and 2.41 ± 0.54, respectively. All 15 assessable margins were clear on CLI and histopathology. The agreement in margin distance and interrater agreement was good (κ = 0.81 and 0.912, respectively). Sentinel lymph nodes were successfully detected in all patients. The radiation dose to staff was low; surgeons received a mean dose of 34 ± 15 µSv per procedure. Conclusion: Intraoperative 18F-FDG CLI is a promising, low-risk technique for intraoperative assessment of tumor margins in BCS. A randomized controlled trial will evaluate the impact of this technique on reexcision rates.

The 'intestinal-renal' arginine biosynthetic axis in the aging rat.

It has been suggested that L-arginine availability declines with advanced age, which could contribute to the endothelial dysfunction and decreased nitric oxide (NO) production that are features of aging. L-Arginine is made in the kidney and since the aging kidney develops progressive injury there may be decreased synthesis limiting availability. In this study we investigated the impact of aging on the regulation, at the gene level, of the various enzymes that synthesize L-arginine in the kidney (argininosuccinate synthetase and argininosuccinate lyase) and citrulline, the precursor of L-arginine made in the small intestine (phosphate-dependent glutaminase, carbamyl phosphate synthetase-1 and ornithine transcarbamylase). Studies were in young (3-5 months), middle-aged (11-13 months) and old (18-22 months) male and female Sprague-Dawley rats aged under barrier conditions. The plasma, renal cortical and brain cerebellar levels of L-arginine are unchanged in the old male rat, and expression of the genes involved in renal arginine synthesis and small intestinal citrulline synthesis is unchanged or upregulated with age in both males and females. This study shows that the synthesis of L-arginine is maintained with aging despite developing kidney damage. Therefore, the reduced NO generating capacity that occurs in aging must be due to downstream changes in the NO biosynthesis pathway, such as reduced abundance of NO biosynthetic enzymes.

Repair of meniscal cartilage white zone tears using a stem cell/collagen-scaffold implant.

Injuries to the avascular region of knee meniscal cartilage do not heal spontaneously. To address this problem we have developed a new stem cell/collagen-scaffold implant system in which human adult bone marrow mesenchymal stem cells are seeded onto a biodegradable scaffold that allows controlled delivery of actively dividing cells to the meniscus surface. Sandwich constructs of two white zone ovine meniscus discs with stem cell/collagen-scaffold implant in between were cultured in vitro for 40 days. Histomorphometric analysis revealed superior integration in the stem cell/collagen-scaffold groups compared to the cell-free collagen membrane or untreated controls. The addition of TGF-beta1 to differentiate stem cells to chondrocytes inhibited integration. Biomechanical testing demonstrated a significant 2-fold increase in tensile strength in all constructs using the stem cell/collagen-scaffold compared to control groups after 40 days in culture. Integration was significantly higher when collagen membranes were used that had a more open/spongy structure adjacent to both meniscal cartilage surfaces, whereas a collagen scaffold designed for osteoinduction failed to induce any integration of meniscus. In conclusion, the stem cell/collagen-scaffold implant is a potential therapeutic treatment for the repair of white zone meniscal cartilage tears.

Three-dimensional cartilage tissue engineering using adult stem cells from osteoarthritis patients.

OBJECTIVE: To determine whether it is possible to engineer 3-dimensional hyaline cartilage using mesenchymal stem cells derived from the bone marrow (BMSCs) of patients with osteoarthritis (OA). METHODS: Expanded BMSCs derived from patients with hip OA were seeded onto polyglycolic acid scaffolds and differentiated using transforming growth factor beta3 in the presence or absence of parathyroid hormone-related protein (PTHrP) to regulate hypertrophy. Micromass pellet cultures were established using the same cells for comparison. At the end of culture, the constructs or pellets were processed for messenger RNA (mRNA) analysis by quantitative real-time reverse transcription-polymerase chain reaction. Matrix proteins were analyzed using specific assays. RESULTS: Cartilage constructs engineered from BMSCs were at least 5 times the weight of equivalent pellet cultures. Histologic, mRNA, and biochemical analyses of the constructs showed extensive synthesis of proteoglycan and type II collagen but only low levels of type I collagen. The protein content was almost identical to that of cartilage engineered from bovine nasal chondrocytes. Analysis of type X collagen mRNA revealed a high level of mRNA in chondrogenic constructs compared with that in undifferentiated BMSCs, indicating an increased risk of hypertrophy in the tissue-engineered cells. However, the inclusion of PTHrP at a dose of 1 microM or 10 microM during the culture period resulted in significant suppression of type X collagen mRNA expression and a significant decrease in alkaline phosphatase activity, without any loss of the cartilage-specific matrix proteins. CONCLUSION: Three-dimensional hyaline cartilage can be engineered using BMSCs from patients with OA. This method could thus be used for the repair of cartilage lesions.

Cells isolated from umbilical cord tissue rescue photoreceptors and visual functions in a rodent model of retinal disease.

Progressive photoreceptor degeneration resulting from genetic and other factors is a leading and largely untreatable cause of blindness worldwide. The object of this study was to find a cell type that is effective in slowing the progress of such degeneration in an animal model of human retinal disease, is safe, and could be generated in sufficient numbers for clinical application. We have compared efficacy of four human-derived cell types in preserving photoreceptor integrity and visual functions after injection into the subretinal space of the Royal College of Surgeons rat early in the progress of degeneration. Umbilical tissue-derived cells, placenta-derived cells, and mesenchymal stem cells were studied; dermal fibroblasts served as cell controls. At various ages up to 100 days, electroretinogram responses, spatial acuity, and luminance threshold were measured. Both umbilical-derived and mesenchymal cells significantly reduced the degree of functional deterioration in each test. The effect of placental cells was not much better than controls. Umbilical tissue-derived cells gave large areas of photoreceptor rescue; mesenchymal stem cells gave only localized rescue. Fibroblasts gave sham levels of rescue. Donor cells were confined to the subretinal space. There was no evidence of cell differentiation into neurons, of tumor formation or other untoward pathology. Since the umbilical tissue-derived cells demonstrated the best photoreceptor rescue and, unlike mesenchymal stem cells, were capable of sustained population doublings without karyotypic changes, it is proposed that they may provide utility as a cell source for the treatment of retinal degenerative diseases such as retinitis pigmentosa.

Nucleostemin is a marker of proliferating stromal stem cells in adult human bone marrow.

The identification of stem cell-specific proteins and the elucidation of their novel regulatory pathways may help in the development of protocols for control of their self-renewal and differentiation for cell-based therapies. Nucleostemin is a recently discovered nucleolar protein predominantly associated with proliferating rat neural and embryonic stem cells, and some human cancer cell lines. A comprehensive study of nucleostemin in human adult bone marrow stem cells is lacking. The aim of the study was to determine if nucleostemin is synthesized by adult bone marrow stem cells and to analyze its expression during their expansion and differentiation. Using a multipotential adherent population of stem cells, nucleostemin was localized to the nucleoli and occurred in 43.3% of the cells. There was a high level of expression of nucleostemin mRNA in bone marrow stem cells and this remained unchanged over time during cell expansion in culture. When bone marrow stem cells were stimulated to proliferate by fibroblast growth factor (FGF)-2, nucleostemin expression increased in a dose-dependent manner. Small interfering RNA (siRNA) knockdown of nucleostemin abolished the proliferative effect of FGF-2. When bone marrow stem cells were differentiated into chondrocytes, adipocytes, or osteocytes, nucleostemin expression was 70%-90% lower than in the undifferentiated cells retained in monolayer culture. We conclude that nucleostemin is a marker of undifferentiated human adult bone marrow stem cells and that it is involved in the regulation of proliferation of these cells.

Differences in leukocyte phenotype and interferon-gamma expression in stroma and endothelium during corneal graft rejection.

Critical to the success of human corneal transplants is prevention of corneal endothelial rejection, yet little is known about the endothelial infiltrate. To examine the endothelium, a method for removal and processing this layer as a flat sheet was used and the infiltrate was compared with stroma and epithelium. LEW or PVG strain rat corneas were transplanted to PVG strain recipients. Clinical changes after transplantation were monitored by slit lamp and animals sacrificed at a range of time points during rejection. Clinically defined rejection, accompanied by an epithelial rejection line and endothelial cell infiltration, occurred between days 10 and 15. There was some infiltration of leukocytes in the stroma of isografts at these time points, but significantly more in allografts (p<0.003 for all subsets). There was no infiltration of isograft endothelium at any time and no infiltration of allograft endothelium on day 10. On day 15, there were similar numbers of all major subsets except B cells in the stroma, while on the endothelium macrophages, MHC class II(+) cells and CD8(+) cells predominated (p<0.001 CD4(+) vs CD8(+) cells). T cells and NK cells predominated in the epithelial rejection line. While TNF-alpha and IFN-gamma-producing cells were numerous in stroma and epithelium, no IFN-gamma-producing cells were found on endothelium. Distinct differences in infiltrative profile within layers of the cornea suggest that the mechanisms of rejection may also differ. The restricted endothelial cell profile and lack of IFN-gamma suggests that the anti-endothelial response may be modulated by the anterior chamber environment.

Intrauterine hyperglycemia increases insulin binding sites but not glucose transporter expression in discrete brain areas in term rat fetuses.

Diabetic pregnancy results in several metabolic and hormonal disorders, both in the embryo and the fetus of different species, including humans. Insulin is a potent modulator of brain development and is suggested to promote the differentiation and maturation of hypothalamic or related extrahypothalamic structures, which are directly involved in neural inputs to the pancreas. Because these structures are known to be specifically responsive both to insulin and glucose, we examined the effects of 48-h hyperglycemic clamps in unrestrained pregnant rats on insulin binding and glucose transporter expression in hypothalamic and extrahypothalamic-related areas of their fetal offspring. The main result was an increase in insulin binding in the ventromedial hypothalamic nucleus (VMH), the arcuate nucleus (AN), and the lateral hypothalamus (LH), and in the nucleus of the tractus solitarius (NTS) for extrahypothalamic areas (+30% in the VMH, +37% in the AN, +25.8% in the LH, and +37.3% in the NTS). The deleterious effect of brain hyperinsulinism during the late gestational stage does not seem to act through glucose transporter (GLUT) expression, inasmuch as no relationship between GLUT level and hyperinsulinism in brain areas could be observed. The specific increase in insulin binding in areas involved in the nervous control of metabolism could be a factor in the increased glucose intolerance and impairment of insulin secretion that was previously observed in the adult rats from hyperglycemic mothers.

Cultured rat hippocampal neural progenitors generate spontaneously active neural networks.

We previously demonstrated that the neural cell adhesion molecule (N-CAM) inhibited the proliferation of cultured rat hippocampal progenitor cells and increased the number of neurons generated. We demonstrate here that the continued presence of fibroblast growth factor 2 along with N-CAM or brain-derived neurotrophic factor over 12 days of culture greatly increased the number of both progenitors and neurons. These progenitor-derived neurons expressed neurotransmitters, neurotransmitter receptors, and synaptic proteins in vitro consistent with those expressed in the mature hippocampus. Progenitor cells cultured on microelectrode plates formed elaborate neural networks that exhibited spontaneously generated action potentials after 21 days. This activity was observed only in cultures grown in the presence of fibroblast growth factor 2 and either N-CAM or brain-derived neurotrophic factor. Analysis of neuronal activity after various pharmacological treatments indicated that the networks formed functional GABAergic and glutamatergic synapses. We conclude that mitogenic growth factors can synergize with N-CAM or neurotrophins to generate spontaneously active neural networks from neural progenitors.

Cloning of human agmatinase. An alternate path for polyamine synthesis induced in liver by hepatitis B virus.

Agmatinase, which hydrolyzes agmatine to putrescine and urea, not only represents a potentially important mechanism for regulating the biological effects of agmatine in mammalian cells but also represents an alternative to ornithine decarboxylase for polyamine biosynthesis. We have isolated a full-length cDNA encoding human agmatinase whose function was confirmed by complementation in yeast. The single-copy human agmatinase gene located on chromosome 1 encodes a 352-residue protein with a putative mitochondrial targeting sequence at the NH(3)-terminus. Human agmatinase has about 30% identity to bacterial agmatinases and <20% identity to mammalian arginases. Residues required for binding of Mn(2+) at the active site in bacterial agmatinase and other members of the arginase superfamily are fully conserved in human agmatinase. Agmatinase mRNA is most abundant in human liver and kidney but also is expressed in several other tissues, including skeletal muscle and brain. Its expression in human liver is induced during hepatitis B virus infection, suggesting that agmatinase may play a role in the pathophysiology of this disease.