Screening two biodegradable polymers in enhanced efficiency fertiliser formulations reveals the need to prioritise performance goals.

Enhanced efficiency fertilisers (EEF) may reduce nitrogen (N) losses and improve uptake efficiency through synchronising N release with in-season plant requirements. We hypothesised that EEF formed via matrix encapsulation in biodegradable polymers will improve N use efficiency when compared to conventional urea fertiliser. This hypothesis was investigated for two biodegradable polymer matrices: polyhydroxyalkanoate (PHA), containing 11.6% urea (by mass), and polybutylene-adipate-co-terephthalate (PBAT), containing either 19.4 or 32.7% urea; and two contrasting soil types: sand and clay. Nitrogen availability and form was investigated under leaching conditions (water) with a growth accelerator pot experiment involving a horticultural crop and novel non-destructive three-dimensional scanning to measure in-season biomass development. The PBAT 32.7% formulation enabled greater above ground biomass production at both 50 and 100 kg N ha-1 equivalent application rates compared to conventional urea. For the sandy soil, plant scanning indicated that improved uptake performance with PBAT 32.7% was probably the result of greater N availability after 25 days than for conventional urea. Two of the encapsulated formulations (PHA and PBAT 19.4%) tended to decrease nitrogen leaching losses relative to urea (P < 0.05 for the red clay soil). However, decreased N leaching loss was accompanied by poorer N uptake performance, indicative of N being less available in these biopolymer formulations. A snapshot of nitrous oxide emissions collected during peak nitrate concentration (prior to planting and leaching) suggested that the biopolymers promoted N loss via gaseous emission relative to urea in the sandy soil (P < 0.05), and carbon dioxide emissions data suggested that biopolymer-carbon increased microbial activity (P < 0.1). Controlled testing of N release in water was a poor predictor of biomass production and leaching losses. The diverse behaviours of the tested formulations present the potential to optimise biopolymers and their N loadings by taking into account soil and environmental factors that influence the efficient delivery of N to target crops. The greater N uptake efficiency demonstrated for the PBAT 32.7% formulation confirms our hypothesis that matrix encapsulation can enable better synchronisation of N release with crop requirements and decrease leaching losses.

A Metabolic Intravascular Platform to Study FDG Uptake in Vascular Injury.

PURPOSE: Metabolic alterations underlie many pathophysiological conditions, and their understanding is critical for the development of novel therapies. Although the assessment of metabolic changes in vivo has been historically challenging, recent developments in molecular imaging have allowed us to study novel metabolic research concepts directly in the living subject, bringing us closer to patients. However, in many instances, there is need for sensors that are in close proximity to the organ under investigation, for example to study vascular metabolism. METHODS: In this study, we developed and validated a metabolic detection platform directly in the living subject under an inflammatory condition. The signal collected by a scintillating fiber is amplified using a photomultiplier tube and decodified by an in-house tunable analysis platform. For in vivo testing, we based our experiments on the metabolic characteristics of macrophages, cells closely linked to inflammation and avid for glucose and its analog 18F-fluorodeoxyglucose (18F-FDG). The sensor was validated in New Zealand rabbits, in which inflammation was induced by either a) high cholesterol (HC) diet for 16 weeks or b) vascular balloon endothelial denudation followed by HC diet. RESULTS: There was no difference in weight, hemodynamics, blood pressure, or heart rate between the groups. Vascular inflammation was detected by the metabolic sensor (Inflammation: 0.60 ± 0.03 AU vs. control: 0.48 ± 0.03 AU, p = 0.01), even though no significant inflammation/atherosclerosis was detected by intravascular ultrasound, underscoring the high sensitivity of the system. These findings were confirmed by the presence of macrophages on ex vivo aortic tissue staining. CONCLUSION: In this study, we validated a tunable very sensitive metabolic sensor platform that can be used for the detection of vascular metabolism, such as inflammation. This sensor can be used not only for the detection of macrophage activity but, with alternative probes, it could allow the detection of other pathophysiological processes.

Improving survival of preterm babies in low- to middle-income countries ­ what can we do?

Surviving prematurity poses the greatest challenge in neonatal care in low- to middle-income countries (LMICs). South Africa has not made much progress in improving the survival of preterm babies. Neonatal survival of preterm infants has become a national priority since the serious failure to reach the Millennium Development Goal targets in 2015. High rates of prevention are particularly relevant in LMICs, where the neonatal mortality rate is at its highest owing to a lack of simple and effective measures. Preventing prematurity and related complications begins with a healthy pregnancy. Antenatal care and maternal corticosteroids are antenatal interventions that could improve the survival of preterm babies. Postnatal interventions include: the management of neonatal sepsis, meningitis and pneumonia;prevention of hypothermia after delivery, for example, the plastic bag/wrap and cap, which has been extensively researched and is found to be an effective, low-cost method for reducing hypothermia in preterm infants; the use of continuous positive airway pressure (CPAP),including the low-cost CPAP device, which is a cost-effective strategy for providing respiratory support for premature neonates with respiratory distress syndrome; exogenous surfactant; early feeding with breastmilk; and kangaroo mother care. The use of cost-effective,evidence-based interventions can be implemented in LMICs to reduce neonatal mortality

Enhanced photocurrent from Photosystem I upon in vitro truncation of the antennae chlorophyll.

Current effects on climate change and dwindling fossil fuel reserves require new materials and methods to convert solar energy into a viable clean energy source. Recent progress in the direct conversion of light into photocurrent has been well documented using Photosystem I. In plants, PSI consists of a core complex and multiple light-harvesting complexes, denoted LHCI and LHCII. Most of the methods for isolating PSI from plants involve a selective, detergent solubilization from thylakoids followed by sucrose gradient density centrifugation. These processes isolate one variant of PSI with a specific ratio of Chl:P700. In this study, we have developed a simple and potentially scalable method for isolating multiple PSI variants using Hydroxyapatite chromatography, which has been well documented in other Photosystem I isolation protocols. By varying the wash conditions, we show that it is possible to change the Chl:P700 ratios. These different PSI complexes were cast into a PSI-Nafion-osmium polymer film that enabled their photoactivity to be measured. Photocurrent increases nearly 400% between highly washed and untreated solutions based on equal chlorophyll content. Importantly, the mild washing conditions remove peripheral Chl and some LHCI without inhibiting the photochemical activity of PSI as suggested by SDS-PAGE analysis. This result could indicate that more P700 could be loaded per surface area for biohybrid devices. Compared with other PSI isolations, this protocol also allows isolation of multiple PSI variants without loss of photochemical activity.

Nectar sugar composition of European Caryophylloideae (Caryophyllaceae) in relation to flower length, pollination biology and phylogeny.

Floral nectar composition has been explained as an adaptation to factors that are either directly or indirectly related to pollinator attraction. However, it is often unclear whether the sugar composition is a direct adaptation to pollinator preferences. Firstly, the lower osmolality of sucrose solutions means that they evaporate more rapidly than hexose solutions, which might be one reason why sucrose-rich nectar is typically found in flowers with long tubes (adapted to long-tongued pollinators), where it is better protected from evaporation than in open or short-tubed flowers. Secondly, it can be assumed that temperature-dependent evaporation is generally lower during the night than during the day so that selection pressure to secrete nectar with high osmolality (i.e. hexose-rich solutions) is relaxed for night-active flowers pollinated at night. Thirdly, the breeding system may affect selection pressure on nectar traits; that is, for pollinator-independent, self-pollinated plants, a lower selective pressure on nectar traits can be assumed, leading to a higher variability of nectar sugar composition independent of pollinator preferences, nectar accessibility and nectar protection. To analyse the relations between flower tube length, day vs. night pollination and self-pollination, the nectar sugar composition was investigated in 78 European Caryophylloideae (Caryophyllaceae) with different pollination modes (diurnal, nocturnal, self-pollination) using high-performance liquid chromatography (HPLC). All Caryophylleae species (Dianthus and relatives) were found to have nectar with more than 50% sucrose, whereas the sugar composition of Sileneae species (Silene and relatives) ranged from 0% to 98.2%. In the genus Silene, a clear dichotomous distribution of sucrose- and hexose-dominant nectars is evident. We found a positive correlation between the flower tube length and sucrose content in Caryophylloideae, particularly in day-flowering species, using both conventional analyses and phylogenetically independent contrasts.

[Angiographic moyamoya in a female with glycogenosis type IA - a case report focusing therapeutic management: bilateral encephalo-duro-arterio-myo-synangiosis (EDAMS)]. / Angiografisches Moyamoya bei Glykogenose Typ IA - Management bei einer erwachsenen Patientin: Fallbericht mit Schwerpunkt auf der Behandlung: beidseitige Encephalo-Duro-Arterio-Myo-Synangiose (EDAMS).

Angiographic Moyamoya is a rare cerebrovascular disease most frequent in asia. Its characateristics are recurrent ischemic attacks due to progressive occlusion of ICA branches. Angiography reveals fine arterial collateralisation reminding of ascending smoke ("moyamoya" in japanese). Neurosurgical treatment strategies include direct and indirect reanastomosation procedures. Randomised trials for comparison of clinical outcome and long term survival remain missing. A 23 years old female with glycogenosis type IA was first diagnosed bilateral angiographic moyamoya with bilateral proximal stenosis of ICA after transient ischemic attack (TIA). Coincidence of both rare diseases moyamoya and glycogenosis has previously been reported in three cases, so that this metabolic dysfunction presumably is a true risk factor for moyamoya. In our case, excellent angiographic and functional results were achieved by bilateral, consecutive Enzephalo-Duro-Arterio-Myo-Synangiosis (EDAMS).

[Clinical and diagnostic characteristics of T1 root syndrome]. / Klinische und diagnostische Charakteristika des Wurzelsyndroms Th1.

BACKGROUND: Among radicular lesions, those affecting the T1 root are rare. Together with the similarity of symptoms to C8 syndrome, which is more common, this makes the diagnosis of T1 radiculopathy complicated. The clinical and diagnostic specifics of T1 syndrome are shown here based on three cases. MATERIALS AND RESULTS: We report on three patients with T1 syndrome. Clinical diagnostics (clinical investigation, electrophysiology, MRI) showed in two cases lateral intraforaminal disc herniae at the T1-2 level, and the third patient had metastasis of a cervix carcinoma being responsible for the radiculopathy. In all cases surgery was performed. The patients with disc herniae were immediately pain-free after surgery; in the third patient the neurological symptoms and pain clearly improved. CONCLUSIONS: These three cases show that by thorough analysis of clinical symptoms and functional (electrophysiology) and morphological (MRI) diagnostics, T1 radiculopathy can be differentiated from C8 lesions. All of the patients benefited from decompressive surgery.

Efficacy of phenazone in the treatment of acute migraine attacks: a double-blind, placebo-controlled, randomized study.

In this study we compared the efficacy of 1000 mg phenazone with that of placebo in the treatment of acute migraine attacks in a randomized double-blind, placebo-controlled study of 208 patients. The main target criterion was the number of patients with a pain reduction from severe or moderate to slight or no pain 2 h after taking the pain medication. The percentage of patients satisfying the main target criterion was 48.6% for phenazone and 27.2% (P < 0.05) for placebo. Freedom from pain after 2 h was reported by 27.6% with phenazone treatment and 13.6% (P < 0.05) with placebo. Compared with placebo, the phenazone treatment also resulted in a significant improvement in the associated migraine symptoms of nausea, phonophobia and photophobia. Of patients treated with phenazone 11.4%, and 5.8% of those treated with placebo reported adverse events. There was no significant difference between the groups with regard to numbers of patients with adverse events. No serious adverse events occurred. The results show that phenazone at a dosage of 1000 mg is effective and well tolerated in the treatment of acute migraine attacks.

A direct mechanical method for accurate and efficient adenoviral vector delivery to tissues.

We describe a mechanical method for delivery of adenoviral vector to the adventitial surface of arteries and to other tissues. Our goal was to characterize, principally in intact carotid artery, the morphological, biochemical, and functional effects of mechanical delivery of a recombinant beta-galactosidase-expressing adenoviral vector following its direct application using a small paintbrush. Our ex vivo and in vivo data demonstrate efficient, accurate, and rapid transduction of arteries without compromise of their morphological, biochemical, and functional integrity. We also demonstrate the general applicability of this technique in vivo via transduction of skeletal muscle, fibrotendinous tissue, peritoneum, serosal surface of bowel, and wounded skin. We conclude that direct mechanical delivery of an adenoviral vector to tissues using a suitable paintbrush represents an intuitive, accurate, and effective means of augmenting gene transfer efficiency, and may be a useful adjunct to other delivery methods.

Role of the E45K-reduced folate carrier gene mutation in methotrexate resistance in human leukemia cells.

Resistance to the antifolate methotrexate (MTX) can cause treatment failure in childhood acute lymphoblastic leukemia (ALL). This may result from defective MTX accumulation due to alterations in the human reduced folate carrier (hRFC) gene. We have identified an hRFC gene point mutation in a transport-defective CCRF-CEM human T-ALL cell line resulting in a lysine to glutamic acid substitution at codon 45 (E45K), which has been identified in other antifolate-resistant sublines (JBC 273:30 189, 1998; JBC 275:30 855, 2000). To characterize the role of this mutation in MTX resistance, transfection experiments were performed using hRFC-null CCRF-CEM cells. E45K transfectants demonstrated an initial rate of MTX influx that was approximately 0.5-fold that of CCRF-CEM cells, despite marked protein overexpression. Cytotoxicity studies revealed partial reversal of MTX and raltitrexed resistance in E45K transfectants, while trimetrexate resistance was significantly increased. Kinetic analysis indicated only minor differences in MTX kinetics between wild-type and E45K hRFCs, however, K(i)s for folic acid and 5-formyltetrahydrofolate were markedly reduced for E45K hRFC. This was paralleled by increased folic acid transport and reduced synthesis of MTX polyglutamates. Collectively, the results demonstrate that expression of E45K hRFC leads to increased MTX resistance due to decreased membrane transport and, secondarily, from alterations in binding affinities and transport of folate substrates. However, despite these findings, we could find no evidence of this mutation in 121 childhood ALL samples, suggesting that it does not contribute to clinical MTX resistance in this disease.

The impact of a new educational strategy on acquiring neonatology skills.

OVERVIEW: A shortage of staff for teaching neonatology skills to large numbers of students, in small groups and following a new curriculum, necessitated an innovative educational strategy. This entailed the development and implementation of an interactive multimedia program (CD-ROM) to deliver information about skills and to demonstrate them. METHODS: Students had to study a specific skill using the CD-ROM and then practise in the Skills Laboratory, supported by lecturers who provided formative evaluation. OBJECTIVES: The aims of this study were to assess the students' perspectives on the new strategy, and to compare the skills of students following the new curriculum to those of students following the traditional curriculum, who do not follow structured programmes on practical skills but experience a practical neonatology rotation. RESULTS: The evaluation of the CD-ROM program was very favourable. The majority of students still preferred live demonstrations but found the CD-ROM useful for revision purposes. With the exception of one skill, endotracheal intubation, the new curriculum students were found to be as competent as the students following the traditional curriculum and performed mask ventilation and cardiac massage significantly better than them.

Single nucleotide polymorphisms in the human reduced folate carrier: characterization of a high-frequency G/A variant at position 80 and transport properties of the His(27) and Arg(27) carriers.

The presence of sequence variants in the human reduced folate carrier (hRFC) was assessed in leukemia blasts from children with acute lymphoblastic leukemia (ALL) and in normal peripheral blood specimens. A CATG frame shift insertion at position 191 was detected in 10-60% of hRFC transcripts from 10 of 16 ALL specimens, by RFLP analysis and direct sequencing of hRFC cDNAs. In genomic DNAs prepared from 105 leukemia (n = 54) and non-leukemia (n = 51) specimens, PCR amplifications and direct sequencing of exon 3 identified a high-frequency G to A single nucleotide polymorphism at position 80 that resulted in a change of arginine-27 to histidine-27. The allelic frequencies of G/A80 were nearly identical for the non-leukemia (42.2% CGC and 57.8% CAC) and leukemia (40.7% CGC and 59.3% CAC) genomic DNAs. In cDNAs prepared from 10 of these ALL patients, identical allelic frequencies (40 and 60%, respectively) were recorded. In up to 62 genomic DNAs, hRFC-coding exons 4-7 were PCR-amplified and sequenced. A high-abundance C/T696 polymorphism was detected with nearly identical frequencies for both alleles, and a heterozygous C/A1242 sequence variant was identified in two ALL specimens. Both C/T696 and C/A1242 were phenotypically silent. In transport assays with [(3)H]methotrexate and [(3)H]5-formyl tetrahydrofolate, nearly identical uptake rates were measured for the arginine-27- and histidine-27-hRFC proteins expressed in transport-impaired K562 cells. Although there were no significant differences between the kinetic parameters for methotrexate transport for the hRFC forms, minor (approximately 2-fold) differences were measured in the K(i)s for other substrates including Tomudex, 5,10-dideazatetrahydrofolate, GW1843U89, and 10-ethyl-10-deazaaminopterin and for 5-formyl tetrahydrofolate.

Role for tissue factor pathway in murine model of vascular remodeling.

Tissue factor (TF) is a low-molecular-weight glycoprotein that initiates the extrinsic clotting cascade and is considered a major regulator of arterial thrombogenicity. TF pathway inhibitor (TFPI) is a major physiological inhibitor of TF-initiated coagulation. The aim of this study was to define the complex interplay between TF and TFPI and the regulation of vascular thrombogenicity in a model of vascular remodeling. To determine the levels and pattern of vascular expression of TF and TFPI associated with vascular remodeling, a murine model of flow cessation was studied. TF activity of the arteries increased after ligation (P<0.05). Quantitative analysis of homogenates of remodeled carotid arteries revealed increased TF expression but unchanged TFPI expression compared with normal carotid arteries, resulting in enhanced TF activity. To determine the potential therapeutic role of TFPI in this thrombogenic state, mice were treated with intravascular adenoviral delivery of either murine TFPI (Ad-mTFPImyc) or a control adenovirus (Ad-DeltaE1). Overexpression of TFPI decreased vascular TF activity compared with viral control (P<0.01). Overexpression of TFPI inhibited neointimal formation (P=0.038), resulting in enhanced luminal area (P=0.001) 4 weeks after flow cessation. In this murine model of vascular remodeling, an imbalance between TF and TFPI expression is generated, resulting in increased TF activity. Overexpression of TFPI in this model inhibits vascular TF activity and results in attenuation of vascular remodeling associated with flow interruption.

Relationship of p15 and p16 gene alterations to elevated dihydrofolate reductase in childhood acute lymphoblastic leukaemia.

The downstream effects of p15 and p16 gene deletions and loss of transcripts on dihydrofolate reductase (DHFR) were examined in 63 B-precursor (BP) acute lymphoblastic leukaemia (ALL) samples. p15 and/or p16 gene deletions were seen in 6% and 8%, respectively, of BP-ALL samples; however, losses of p15 and/or p16 transcripts were seen in 26 out of 63 (41%) samples. Loss of p15 transcripts (36.5%) exceeded that for p16 (17.5%). For the 26 BP-ALLs that lacked p15 and/or p16 transcripts, only six (23%) exhibited low levels of DHFR by flow cytometry assay with Pt430, a fluorescent anti-folate. Conversely, 18 out of 37 (49%) BP-ALL samples with intact p15 and/or p16 genes and transcripts showed low levels of DHFR (P = 0.04). In p15- and p16-null K562 cells transfected with a tetracycline-inducible p15 cDNA construct, induction of p15 transcripts and protein was accompanied by decreased growth rates, decreased S-phase fraction, decreased retinoblastoma protein phosphorylation, and markedly reduced levels of DHFR transcripts and protein. Collectively, our results suggest that losses of p15 and/or p16 gene expression result in elevated levels of DHFR in BP-ALL in children. However, additional downstream factors undoubtedly also contribute to elevated levels of this enzyme target.

Association of deletions and translocation of the reduced folate carrier gene with profound loss of gene expression in methotrexate-resistant K562 human erythroleukemia cells.

Severe impairment of methotrexate membrane transport in methotrexate-resistant K562 (K500E) cells was characterized by a nearly complete loss of reduced folate carrier (RFC) transcripts and RFC protein. As determined by 5'-rapid amplification of cDNA ends (5'-RACE), approximately 93% of the RFC transcripts in wild-type cells contained the KS43 5'-untranslated region transcribed from the RFC-B promoter. KS43 transcripts decreased > 90% in K500E cells. The basal and full-length RFC-B promoters were more active (3- and 2-fold, respectively) in directing transcription of a luciferase reporter gene in K500E than in wild-type cells. Treatment with a demethylating agent, 5-aza-2'-deoxycytidine, or with a histone deacetylase inhibitor, trichostatin A, did not increase the levels of RFC transcripts in K500E cells. No differences in RFC gene structure were detected between the lines on Southern blots; however, the RFC signals were decreased approximately 60% in K500E cells. DNA sequences were identical between the lines for the RFC coding region and the two 5'-non-coding exons and their respective promoters. Spectral karyotype analysis and fluorescence in situ hybridization in wild-type cells showed two normal chromosome 21 copies and one or two marker chromosomes, each with an RFC signal. In K500E cells, the RFC gene locus was no longer localized to a normal chromosome 21 (at 21q22.2), and a single RFC signal was associated with a small metacentric chromosome, characterized by a 21/22 translocation. Our results suggest that loss of RFC transcripts in K500E cells is unrelated to changes in the levels of critical transcription factors, or to differences in the extent of RFC promoter methylation or core histone deacetylation. Rather, this phenotype is due to the loss of one or more RFC alleles, and to a translocation of the remaining RFC allele with the formation of a 21/22 fusion chromosome.