Weak coupling between energetic status and the timing of reproduction in an Arctic ungulate.

Bioenergetic constraints are the ultimate determinant of the timing of reproduction, and seasonal breeding is consequently a widely observed trait. Consistent with this, attention has focused on plasticity in reproductive phenology conceptualized as a response to concomitant advances in the phenology of the environmental energy supply caused by climate change. Few studies, however, have directly compared timing of reproduction with energetic status in free-living wild animals. Here we demonstrate that neither body mass nor adiposity are strong proximate predictors of date of conception in wild reindeer (Rangifer tarandus). Weak coupling between energetic status and the phenology of reproduction accounts for the increasing discrepancy between the phenology of forage (energy supply) and the phenology of reproduction (energy demand) observed across the last 2-4 decades in two populations of this species. The results emphasise that phenological plasticity is not a passive response to changes in energy supply but derives from the way in which environmental factors interact with the core control mechanisms that govern timing. Central in this respect is integration, within the rheostatic centres of the hypothalamus, of information on nutritional status with the circannual life-history calendar.

Development of a stick-on hip protector: A multiple methods study to improve hip protector design for older adults in the acute care environment.

INTRODUCTION: Over 90% of hip fractures in older adults result from falls, and hospital patients are at especially high risk. Specific types of wearable hip protectors have been shown to reduce hip fracture risk during a fall by up to 80%, but user compliance has averaged less than 50%. We describe the development and evaluation of a "stick-on" hip protector (secured over the hip with a skin-friendly adhesive) for older patients in acute care. METHODS: An initial version of the product was evaluated with six female patients (aged 76-91) in a hospital ward, who were asked to wear it for one week. We subsequently refined the product through biomechanical testing and solicited feedback from 43 health professionals on a second prototype. RESULTS: The first prototype was worn by five of six patients for the full week or duration of their hospital stay. The second prototype (20 mm thick, surface area 19 × 15.5 cm) provided 36% force attenuation, more than common garment-based models (20-21%). Feedback from patients and health professionals highlighted usability, comfort, cost, and appearance. CONCLUSIONS: Our results from biomechanical and user testing support the need for further work to determine the value of stick-on hip protectors in acute care.

The antifibrotic potential of a sustained release formulation of a PDGFß-receptor targeted rho kinase inhibitor.

Rho kinase activity in hepatic stellate cells (HSCs) is associated with activation, transformation and contraction of these cells, leading to extracellular matrix production and portal hypertension in liver cirrhosis. Inhibition of rho kinase activity can reduce these activities, but may also lead to side effects, for instance systemic hypotension. This can be circumvented by liver-specific delivery of a rho kinase inhibitor to effector cells. Therefore, we targeted the rho kinase inhibitor Y27632 to the key pathogenic cells in liver fibrosis, i.e. myofibroblasts including activated HSCs that highly express the PDGFß-receptor, using the drug carrier pPB-MSA. This carrier consists of mouse serum albumin (MSA) covalently coupled to several PDGFßR-recognizing moieties (pPB). We aimed to create a prolonged release system of such a targeted construct, by encapsulating pPB-MSA-Y27632 in biodegradable polymeric microspheres, thereby reducing short-lasting peak concentrations and the need for frequent administrations. Firstly, we confirmed the vasodilating potency of PDGFß-receptor targeted Y27632 in vitro in a contraction assay using HSCs seeded on a collagen gel. We subsequently demonstrated the in vivo antifibrotic efficacy of pPB-MSA-Y27632-loaded microspheres in the Mdr2-/- mouse model of progressive biliary liver fibrosis. A single subcutaneous microsphere administration followed by organ harvest one week later clearly attenuated liver fibrosis progression and significantly suppressed the expression of fibrosis related genes, such as several collagens, profibrotic cytokines and matrix metalloproteinases. In conclusion, we demonstrate that polymeric microspheres are suitable as drug delivery system for the sustained systemic delivery of targeted protein constructs with antifibrotic potential, such as pPB-MSA-Y27632. This formulation appears suitable for the sustained treatment of liver fibrosis and possibly other chronic diseases.

Pharmacokinetics of a sustained release formulation of PDGFß-receptor directed carrier proteins to target the fibrotic liver.

Liver fibrogenesis is associated with excessive production of extracellular matrix by myofibroblasts that often leads to cirrhosis and consequently liver dysfunction and death. Novel protein-based antifibrotic drugs show high specificity and efficacy, but their use in the treatment of fibrosis causes a high burden for patients, since repetitive and long-term parenteral administration is required as most proteins and peptides are rapidly cleared from the circulation. Therefore, we developed biodegradable polymeric microspheres for the sustained release of proteinaceous drugs. We encapsulated the drug carrier pPB-HSA, which specifically binds to the PDGFßR that is highly upregulated on activated myofibroblasts, into microspheres composed of hydrophilic multi-block copolymers composed of poly(l-lactide) and poly ethylene glycol/poly(ϵ-caprolactone), allowing diffusion-controlled release. Firstly, we estimated in mice with acute fibrogenesis induced by a single CCl4 injection the half-life of I125-labeled pPB-HSA at 40 min and confirmed the preferential accumulation in fibrotic tissue. Subsequently, we determined in the Mdr2 −/− mouse model of advanced biliary liver fibrosis how the subcutaneously injected microspheres released pPB-HSA into both plasma and fibrotic liver at 24 h after injection, which was maintained for six days. Although the microspheres still contained protein at day seven, pPB-HSA plasma and liver concentrations were decreased. This reduction was associated with an antibody response against the human albumin-based carrier protein, which was prevented by using a mouse albumin-based equivalent (pPB-MSA). In conclusion, this study shows that our polymeric microspheres are suitable as sustained release formulation for targeted protein constructs such as pPB-HSA. These formulations could be applied for the long-term treatment of chronic diseases such as liver fibrosis.

Polymeric microspheres for the sustained release of a protein-based drug carrier targeting the PDGFß-receptor in the fibrotic kidney.

Injectable sustained release drug delivery systems are an attractive alternative for the intravenous delivery of therapeutic proteins. In particular, for chronic diseases such as fibrosis, this approach could improve therapy by reducing the administration frequency while avoiding large variations in plasma levels. In fibrotic tissues the platelet-derived growth factor receptor beta (PDGFßR) is highly upregulated, which provides a target for site-specific delivery of drugs. Our aim was to develop an injectable sustained release formulation for the subcutaneous delivery of the PDGFßR-targeted drug carrier protein pPB-HSA, which is composed of multiple PDGFßR-recognizing moieties (pPB) attached to human serum albumin (HSA). We used blends of biodegradable multi-block copolymers with different swelling degree to optimize the release rate using the model protein HSA from microspheres produced via a water-in-oil-in-water double emulsion evaporation process. The optimized formulation containing pPB-HSA, showed complete release in vitro within 14days. After subcutaneous administration to mice suffering from renal fibrosis pPB-HSA was released from the microspheres and distributed into plasma for at least 7days after administration. Furthermore, we demonstrated an enhanced accumulation of pPB-HSA in the fibrotic kidney. Altogether, we show that subcutaneously administered polymeric microspheres present a suitable sustained release drug delivery system for the controlled systemic delivery for proteins such as pPB-HSA.

Milk production after preterm, late preterm and term delivery; effects of different breast pump suction patterns.

OBJECTIVE: This study aimed to compare the effectiveness of two different breast pump suction patterns (BPSP) during the initiation of lactation in mothers of term, late preterm and preterm infants. METHODS: Breast pump-dependent mothers (n=130) of term (n=19), late preterm (n=44) and preterm (n=67) infants were assigned to either a standard or irregular-BPSP after birth until the onset of secretory activation. Both groups used the same standard maintenance BPSP thereafter. Time to secretory activation, time to full milk production and daily milk output were compared between the standard and I-BPSP groups, and between the term, late preterm and preterm groups. RESULTS: Mothers using the irregular-BPSP demonstrated significantly greater daily milk output and established secretory activation significantly earlier. This effect was observed in mothers of term, late preterm and preterm infants. CONCLUSION: The irregular-BPSP mimicking sucking of healthy newborns is more effective at achieving secretory activation and an earlier adequate milk supply than the standard-BPSP. The irregular-BPSP can be used successfully for mothers of preterm up to term infants who are breast pump dependent during the establishment of lactation.

Clinical and genetic complexity of Mitchell-Riley/Martinez-Frias syndrome.

Mitchell-Riley syndrome/Martinez-Frias syndrome (MRS/MFS) is a rare, autosomal recessive disorder with multisystem involvement and poor prognosis. Most reported cases have been associated with homozygous or compound heterozygous mutations in the RFX6 gene, a transcriptional regulatory factor for pancreatic morphogenesis. Given the limited number of reported cases, the syndrome may be under-recognized. When the particular phenotype of MFS includes a mutation on the RFX6 gene and neonatal diabetes, it has been called Mitchell-Riley syndrome. Because of this, we propose that MFS/MRS is a symptom continuum or an RFX6 malformation complex. We report an infant with all of the key clinical features of MRS/MFS without a definable mutation in RFX6 gene, supporting the consideration of these features as a symptom complex, and raising the question of genetic heterogeneity.

Rapid comprehensive characterization of crude oils by thermogravimetry coupled to fast modulated gas chromatography-single photon ionization time-of-flight mass spectrometry.

Comprehensive multi-dimensional hyphenation of a thermogravimetry device (i.e. a thermobalance) to gas chromatography and single photon ionization-time-of-flight mass spectrometry (TG-GC×SPI-MS) has been used to investigate two crude oil samples of different geographical origin. The source of the applied vacuum ultraviolet radiation is an electron beam pumped rare gas excimer lamp (EBEL). The soft photoionization favors the formation of molecular ions. Introduction of a fast, rapidly modulated gas chromatographic separation step in comparison with solely TG-SPI-MS enables strongly enhanced detection especially with such highly complex organic matrices as crude oil. In contrast with former TG-SPI-MS measurements, separation and identification of overlying substances is possible because of different GC retention times. The specific contribution of isobaric compounds to one mass signal is determined for alkanes, naphthalenes, alkylated benzenes, and other compounds.

Reduction of fibrogenesis by selective delivery of a Rho kinase inhibitor to hepatic stellate cells in mice.

One of the pathways activated during liver fibrosis is the Rho kinase pathway, which regulates activation, migration, and contraction of hepatic stellate cells (HSC). Inhibition of this kinase by the Rho kinase inhibitor Y27632 [(+)-(R)-trans- 4-(1-aminoethyl)-N-(4-pyridyl)cyclohexanecarboxamide dihydrochloride] has been shown to reduce fibrosis in animal models. However, kinase expression is ubiquitous, so any inhibitor may affect many cell types. We hypothesize that cell-specific delivery of a kinase inhibitor will be beneficial. Therefore, we conjugated Y27632 to the carrier mannose-6-phosphate (M6P) human serum albumin (HSA), which is taken up specifically in activated HSC through the M6P/insulin-like growth factor II receptor. This conjugate decreased protein expression of phosphorylated myosin light chain 2 (pMLC2) and vinculin, downstream of Rho kinase, in activated primary HSC and decreased the migration and contraction of HSC. In an ex vivo model, free Y27632 decreased contractility of rat aortas, whereas the Y27-conjugate did not, showing that the Y27-conjugate does not affect nontarget tissue. In chronic CCl(4)-induced liver fibrosis, both free drug and conjugate reduced HSC activation; however, only the Y27-conjugate significantly reduced collagen deposition. Treatment with the Y27-conjugate, but not with free drug, reduced pMLC2 expression in livers 24 h after injection, demonstrating prolonged inhibition of the Rho kinase pathway. The Rho kinase inhibitor Y27632 can be specifically targeted to HSC using M6PHSA, decreasing its effects in nontarget tissues. The targeted drug effectively reduced fibrotic parameters in vivo via the inhibition of the Rho kinase pathway.

Real-time cancellation of temperature induced resonance shifts in SOI wire waveguide ring resonator label-free biosensor arrays.

A comprehensive investigation of real-time temperature-induced resonance shift cancellation for silicon wire based biosensor arrays is reported for the first time. A reference resonator, protected by either a SU8 or SiO(2) cladding layer, is used to track temperature changes. The temperature dependence of resonators in aqueous solutions, pertinent to biosensing applications, is measured under steady-state conditions and the operating parameters influencing these properties are discussed. Real-time measurements show that the reference resonator resonances reflect the temperature changes without noticeable time delay, enabling effective cancellation of temperature-induced shifts. Binding between complementary IgG protein pairs is monitored over 4 orders of magnitude dynamic range down to a concentration of 20 pM, demonstrating a resolvable mass of 40 attograms. Reactions are measured over time periods as long as 3 hours with high stability, showing a scatter corresponding to a fluid refractive index fluctuation of ± 4 × 10(-6) in the baseline data. Sensor arrays with a SU8 protective cladding are easy to fabricate, while oxide cladding is found to provide superior stability for measurements involving long time scales.

To protect peptide pharmaceuticals against peptidases.

INTRODUCTION: The major hurdle in the application and delivery of peptide pharmaceuticals is their rapid in vivo breakdown. METHODS: We here combined two approaches to stabilize peptide pharmaceuticals, introduction of D-amino acids and cyclization, by applying an innovative enzymatic method. This method yields peptides with thioether bridges between a D-amino acid and an L-amino acid. On the basis of guidelines concerning the flanking residues of serines/threonines and cysteines, a peptide of interest is designed with serine/threonine and cysteine at appropriate positions to allow their effective participation in cyclization. In Lactococcus lactis the peptide of interest is directly or via a spacer genetically fused to a lantibiotic leader peptide which induces enzyme-catalysed synthesis of a thioether-bridged peptide. The peptide is translocated via a lantibiotic transporter, analysed by mass spectrometry and the leader peptide is removed. Because of its therapeutic relevance and terminal modifications we chose the decapeptide Luteïnizing Hormone Release Hormone (LHRH) as a test case for thioether bridge introduction. The N-terminal pyroglutamate protects against aminopeptidase activity; the amidated C-terminus, which occurs in 50% of all therapeutic peptides, precludes carboxypeptidase action and is essential for optimal receptor interaction. We had Lactococcus posttranslationally introduce a thioether bridge between residues 4 and 7 of the Leu7Cys-LHRH analog QHWSYGCRPG. The N-terminal glutamine of the thioether-bridged peptide could be converted in pyroglutamate. The introduction of the thioether bridge proved to be compatible with subsequent chemical and enzymatic amidation methods. In this way biologically produced thioether LHRH was compared with LHRH isomers obtained by base-assisted sulfur extrusion. RESULTS: Biologically produced thioether LHRH is the most stable thioether LHRH isomer with strongly enhanced proteolytic resistance compared to natural LHRH. DISCUSSION: The data convincingly demonstrate the broad perspective of stereo- and regiospecifically generating cyclized peptide pharmaceuticals with significantly enhanced therapeutic potential.

Interferometric sensing platform with dielectric nanostructured thin films.

A new interferometer-based optical sensing platform with nanostructured thin films of ZrO2 or TiO2 as sensing environment has been developed. With the application of an IC compatible Si(3)N(4) waveguide technology, Mach-Zehnder interferometer devices have been fabricated. The application of the glancing angle deposition technique allowed fabrication of nanostructured thin films as the optical sensing environment. Sensing ability of fabricated devices has been demonstrated through the refractive index measurement of a known gas. The transmission spectra and time response measurements have demonstrated a maximum phase shift of Delta phi=pi/10 and a |Delta P(out)|=0.65 dBm. Devices with TiO2 film on the sensing region performed much better than devices with ZrO2, with sensitivity twice as high.

Extracting coupling and loss coefficients from a ring resonator.

A method is developed for extracting the coupling and loss coefficients of ring resonators from the peak widths, depths, and spacings of the resonances of a single resonator. Although the formulas used do not distinguish which coefficient is coupling and which is loss, it is shown how these coefficients can be disentangled based on how they vary with wavelength or device parameters.

Folded cavity SOI microring sensors for high sensitivity and real time measurement of biomolecular binding.

We demonstrate folded waveguide ring resonators for biomolecular sensing. We show that extending the ring cavity length increases the resonator quality factor, and thereby enhances the sensor resolution and minimum level of detection, while at the same time relaxing the tolerance on the coupling conditions to provide stable and large resonance contrast. The folded spiral path geometry allows a 1.2 mm long ring waveguide to be enclosed in a 150 microm diameter sensor area. The spiral cavity resonator is used to monitor the streptavidin protein binding with a detection limit of approximately 3 pg/mm(2), or a total mass of approximately 5 fg. The real time measurements are used to analyze the kinetics of biotin-streptavidin binding.

Where do tuberculosis patients go for treatment before reporting to DOTS clinics in southern Nigeria?

Health-seeking patterns of persons with tuberculosis (TB) before reporting at the Directly Observed Treatment Short-course (DOTS) clinic for diagnosis and treatment were analysed. A total of 221 persons registered in the DOTS programme in 12 randomly selected rural and urban Local Government Areas in southern Nigeria were interviewed using a semi-structured questionnaire. Perceived causes of TB influenced first choice of treatment. Patients re-evaluated initial choices and shop for alternatives in persistent TB. Chemists were the first port of call for most patients. Those with unscientific causative theories of tuberculosis such as witchcraft engaged more in multiple health-seeking than those who indicated bacterial infection (P < 0.0001). The respondents had a median diagnostic-delay of 90 days. Delay in commencement of DOTS treatment was attributable to ignorance among patients and poor attitude of health workers. In conclusion, delay exists between recognition of symptoms and initiation of treatment in DOTS clinics partly because of ignorance among patients. Health workers' attitude to patients reporting at health clinics also discouraged the use of DOTS facilities. Consequently, it is recommended to address such delay through social mobilization of communities and through engaging Chemists in TB service delivery in this area.

Gradient-index antireflective subwavelength structures for planar waveguide facets.

We demonstrate the use of subwavelength gratings etched into the facets of silicon-on-insulator ridge waveguides as a means of reducing facet reflectivity by the gradient-index effect. Reflectivities as low as 2.0% and 2.4% for the fundamental TE and TM modes, respectively, are demonstrated experimentally for light of 1.55 microm wavelength, in agreement with both effective medium theory and finite-difference time domain calculations. Simulations show that facet reflectivites can be further reduced to less than 1% by increasing the grating modulation depth.

A high-resolution silicon-on-insulator arrayed waveguide grating microspectrometer with sub-micrometer aperture waveguides.

We demonstrate a 50-channel high-resolution arrayed waveguide grating microspectrometer with a 0.2 nm channel spacing on a silicon-on-insulator (SOI) platform. The chip size is 8 mm x 8 mm. High channel density and spectral resolution are achieved using high aspect ratio 0.6 mum x 1.5 mum waveguide apertures to inject the light into the input combiner and to intercept different spectral channels at the output combiner focal region. The measured crosstalk is <-10 dB, the 3 dB channel bandwidth is 0.15 nm, and the insertion loss is -17 dB near the central wavelength of lambda = 1.545 mum.

Retrospective study of 24 cases of septic calcaneal bursitis in the horse.

REASONS FOR PERFORMING STUDY: Wounds to the plantar aspect of the tarsus present a diagnostic and treatment challenge. This study was undertaken to describe specific features of traumatic wounds involving the calcaneal bursa, with a view to determining which clinical examination findings and diagnostic tests results could provide reliable indicators of prognosis. OBJECTIVES: To report clinical presentation, diagnostic findings, treatment and outcome of 24 cases of septic calcaneal bursitis; and to determine the importance of the involvement of specific anatomical structures in relation to the prognosis for survival and return to athletic function. METHODS: Records of 24 horses that had suffered traumatic wounds involving the calcaneal bursae were reviewed and divided into 3 groups, based on the bursa involved and presence or absence of involvement of the tuber calcanei. Clinical, diagnostic imaging and surgical findings were recorded for each case. Differences between groups and outcome were examined for significance with Chi-squared, Fisher's Exact or Kruskal-Wallis tests, as appropriate. RESULTS: Wounds involving only the subcutaneous bursa had an excellent prognosis for survival. Seventy-five percent of horses with wounds involving the intertendinous calcaneal bursa survived. Involvement of the tuber calcanei presented a fair to guarded prognosis, with only 44% of horses with involvement of this structure surviving. CONCLUSIONS: In contrast to other studies of septic synovial structures, the time between initial injury and referral did not affect the outcome. Correct identification of invasion of the calcaneal bursa(e) and/or tuber calcanei in wounds to the plantar aspect of the tarsus allows for more accurate pronostication. Damage to the tuber calcanei presents a poorer prognosis than for cases that involve only the soft tissue structures in the region. POTENTIAL RELEVANCE: This study demonstrates the importance of correct anatomical identification of structures involved in wounds in the region of the calcaneal bursa. The use of radiography, ultrasonography and synoviocentesis are essential in these cases to provide the most appropriate treatment for the horse and accurate prognosis for the owner.