Nutritional status and out-of-hospital mortality in vascular surgery patients.

BACKGROUND: Malnutrition is often present in vascular surgery patient during hospital admission. The present evidence of the consequence malnutrition has on morbidity and mortality is limited. AIM: The purpose of this study was to determine the effect of nutritional status on out-of-hospital mortality in vascular surgery patients. METHODS: An observational cohort study was performed, studying non-cardiac vascular surgery patients surviving hospital admission 18 years or older treated in Boston, Massachusetts, USA. The exposure of interest was nutritional status categorized as well nourished, at-risk for malnutrition, nonspecific malnutrition or protein-energy malnutrition. The all cause 90-day mortality following hospital discharge was the primary outcome. Adjusted odds ratios were estimated by multivariable logistic regression models. RESULTS: This cohort included 4432 patients comprised of 48% women and a mean age 61.7 years. After evaluation by a registered dietitian, 3819 patients were determined to be well nourished, 215 patients were at-risk for malnutrition, 351 had non-specific malnutrition and 47 patients had protein-energy malnutrition. After adjustment for age, sex, ethnicity, medical versus surgical Diagnosis Related Group type, Deyo-Charlson index, length of stay, and vascular Current Procedural Terminology code category, the 90-day post-discharge mortality odds ratio for patients with non-specific malnutrition OR 1.96 (95%CI 1.21, 3.17) and for protein-energy malnutrition OR 3.58 (95%CI 1.59, 8.06), all relative to patients without malnutrition. DISCUSSION: Nutritional status is a strong predictor of out-of-hospital mortality. This suggests that patient with vascular disease suffering from malnutrition could benefit from more intensified In-hospital and out-of-hospital dietary guidance and interventions.

GLIM criteria for the diagnosis of malnutrition - A consensus report from the global clinical nutrition community.

RATIONALE: This initiative is focused on building a global consensus around core diagnostic criteria for malnutrition in adults in clinical settings. METHODS: In January 2016, the Global Leadership Initiative on Malnutrition (GLIM) was convened by several of the major global clinical nutrition societies. GLIM appointed a core leadership committee and a supporting working group with representatives bringing additional global diversity and expertise. Empirical consensus was reached through a series of face-to-face meetings, telephone conferences, and e-mail communications. RESULTS: A two-step approach for the malnutrition diagnosis was selected, i.e., first screening to identify "at risk" status by the use of any validated screening tool, and second, assessment for diagnosis and grading the severity of malnutrition. The malnutrition criteria for consideration were retrieved from existing approaches for screening and assessment. Potential criteria were subjected to a ballot among the GLIM core and supporting working group members. The top five ranked criteria included three phenotypic criteria (weight loss, low body mass index, and reduced muscle mass) and two etiologic criteria (reduced food intake or assimilation, and inflammation or disease burden). To diagnose malnutrition at least one phenotypic criterion and one etiologic criterion should be present. Phenotypic metrics for grading severity as Stage 1 (moderate) and Stage 2 (severe) malnutrition are proposed. It is recommended that the etiologic criteria be used to guide intervention and anticipated outcomes. The recommended approach supports classification of malnutrition into four etiology-related diagnosis categories. CONCLUSION: A consensus scheme for diagnosing malnutrition in adults in clinical settings on a global scale is proposed. Next steps are to secure further collaboration and endorsements from leading nutrition professional societies, to identify overlaps with syndromes like cachexia and sarcopenia, and to promote dissemination, validation studies, and feedback. The diagnostic construct should be re-considered every 3-5 years.

GLIM criteria for the diagnosis of malnutrition - A consensus report from the global clinical nutrition community.

RATIONALE: This initiative is focused on building a global consensus around core diagnostic criteria for malnutrition in adults in clinical settings. METHODS: In January 2016, the Global Leadership Initiative on Malnutrition (GLIM) was convened by several of the major global clinical nutrition societies. GLIM appointed a core leadership committee and a supporting working group with representatives bringing additional global diversity and expertise. Empirical consensus was reached through a series of face-to-face meetings, telephone conferences, and e-mail communications. RESULTS: A two-step approach for the malnutrition diagnosis was selected, i.e., first screening to identify "at risk" status by the use of any validated screening tool, and second, assessment for diagnosis and grading the severity of malnutrition. The malnutrition criteria for consideration were retrieved from existing approaches for screening and assessment. Potential criteria were subjected to a ballot among the GLIM core and supporting working group members. The top five ranked criteria included three phenotypic criteria (non-volitional weight loss, low body mass index, and reduced muscle mass) and two etiologic criteria (reduced food intake or assimilation, and inflammation or disease burden). To diagnose malnutrition at least one phenotypic criterion and one etiologic criterion should be present. Phenotypic metrics for grading severity as Stage 1 (moderate) and Stage 2 (severe) malnutrition are proposed. It is recommended that the etiologic criteria be used to guide intervention and anticipated outcomes. The recommended approach supports classification of malnutrition into four etiology-related diagnosis categories. CONCLUSION: A consensus scheme for diagnosing malnutrition in adults in clinical settings on a global scale is proposed. Next steps are to secure further collaboration and endorsements from leading nutrition professional societies, to identify overlaps with syndromes like cachexia and sarcopenia, and to promote dissemination, validation studies, and feedback. The diagnostic construct should be re-considered every 3-5 years.

Real-time direct cell concentration and viability determination using a fully automated microfluidic platform for standalone process monitoring.

The industrial production of cells has a large unmet need for greater process monitoring, in addition to the standard temperature, pH and oxygen concentration determination. Monitoring the cell health by a vast range of fluorescence cell-based assays can greatly improve the feedback control and thereby ensure optimal cell production, by prolonging the fermentation cycle and increasing the bioreactor output. In this work, we report on the development of a fully automated microfluidic system capable of extracting samples directly from a bioreactor, diluting the sample, staining the cells, and determining the total cell and dead cells concentrations, within a time frame of 10.3 min. The platform consists of custom made stepper motor actuated peristaltic pumps and valves, fluidic interconnections, sample to waste liquid management and image cytometry-based detection. The total concentration of cells is determined by brightfield microscopy, while fluorescence detection is used to detect propidium iodide stained non-viable cells. This method can be incorporated into facilities with bioreactors to monitor the cell concentration and viability during the cultivation process. Here, we demonstrate the microfluidic system performance by monitoring in real time the cell concentration and viability of yeast extracted directly from an in-house made bioreactor. This is the first demonstration of using the Dean drag force, generated due to the implementation of a curved microchannel geometry in conjunction with high flow rates, to promote passive mixing of cell samples and thus homogenization of the diluted cell plug. The autonomous operation of the fluidics furthermore allows implementation of intelligent protocols for administering air bubbles from the bioreactor in the microfluidic system, so that these will be guided away from the imaging region, thereby significantly improving both the robustness of the system and the quality of the data.

Carbon nanotube-based separation columns for microchip electrochromatography.

Fabrication of the stationary phase for microchip chromatography is most often done by packing of the individual separation channel after fabrication of the microfluidic chip, which is a very time-consuming and costly process (Kutter. J Chromatogr A 1221:72-82, 2012). Here, we describe in detail the fabrication and operation protocols for devices with microfabricated carbon nanotube stationary phases for reverse-phase chromatography. In this protocol, the lithographically defined stationary phase is fabricated in the channel before bonding of a lid, thereby circumventing the difficult packaging procedures used in more conventional protocols.

Carbon nanotubes integrated in electrically insulated channels for lab-on-a-chip applications.

A fabrication process for monolithic integration of vertically aligned carbon nanotubes in electrically insulated microfluidic channels is presented. A 150 nm thick amorphous silicon layer could be used both for anodic bonding of a glass lid to hermetically seal the microfluidic glass channels and for de-charging of the wafer during plasma enhanced chemical vapor deposition of the carbon nanotubes. The possibility of operating the device with electroosmotic flow was shown by performing standard electrophoretic separations of 50 microM fluorescein and 50 microM 5-carboxyfluorescein in a 25 mm long column containing vertical aligned carbon nanotubes. This is the first demonstration of electroosmotic pumping and electrokinetic separations in microfluidic channels with a monolithically integrated carbon nanotube forest.

Photonic crystal resonator integrated in a microfluidic system.

We report on a novel optofluidic system consisting of a silica-based 1D photonic crystal, integrated planar waveguides, and electrically insulated fluidic channels. An array of pillars in a microfluidic channel designed for electrochromatography is used as a resonator for on-column label-free refractive index detection. The resonator was fabricated in a silicon oxynitride platform, to support electro-osmotic flow, and operated at lambda=1.55 microm. Different aqueous solutions of ethanol with refractive indices ranging from n=1.3330 to 1.3616 were pumped into the column/resonator, and the transmission spectra were recorded. Linear shifts of the resonant wavelengths yielded a maximum sensitivity of Deltalambda/Deltan=480 nm/RIU (refractive index unit), and a minimum difference of Deltan=0.007 RIU was measured.

Lab-on-a-chip with integrated optical transducers.

Taking the next step from individual functional components to higher integrated devices, we present a feasibility study of a lab-on-a-chip system with five different components monolithically integrated on one substrate. These five components represent three main domains of microchip technology: optics, fluidics and electronics. In particular, this device includes an on-chip optically pumped liquid dye laser, waveguides and fluidic channels with passive diffusive mixers, all defined in one layer of SU-8 polymer, as well as embedded photodiodes in the silicon substrate. The dye laser emits light at 576 nm, which is directly coupled into five waveguides that bring the light to five different locations along a fluidic channel for absorbance measurements. The transmitted portion of the light is collected at the other side of this cuvette, again by waveguides, and finally detected by the photodiodes. Electrical read-out is accomplished by integrated metal connectors. To our knowledge, this is the first time that integration of all these components has been demonstrated.

Measurements of scattered light on a microchip flow cytometer with integrated polymer based optical elements.

Flow cytometry is widely used for analyzing microparticles, such as cells and bacteria. In this paper, we report an innovative microsystem, in which several different optical elements (waveguides, lens and fiber-to-waveguide couplers) are integrated with microfluidic channels to form a complete microchip flow cytometer. All the optical elements, the microfluidic system, and the fiber-to-waveguide couplers were defined in one layer of polymer (SU-8, negative photoresist) by standard photolithography. With only a single mask procedure required, all the fabrication and packaging processes can be finished in one day. Polystyrene beads were measured in the microchip flow cytometer, and three signals (forward scattering, large angle scattering and extinction) were measured simultaneously for each bead. To our knowledge this is the first time forward scattered light and incident light extinction were measured in a microsystem using integrated optics. The microsystem can be applied for analyzing different kinds of particles and cells, and can easily be integrated with other microfluidic components.

The unique mutation in ace-1 giving high insecticide resistance is easily detectable in mosquito vectors.

High insecticide resistance resulting from insensitive acetylcholinesterase (AChE) has emerged in mosquitoes. A single mutation (G119S of the ace-1 gene) explains this high resistance in Culex pipiens and in Anopheles gambiae. In order to provide better documentation of the ace-1 gene and the effect of the G119S mutation, we present a three-dimension structure model of AChE, showing that this unique substitution is localized in the oxyanion hole, explaining the insecticide insensitivity and its interference with the enzyme catalytic functions. As the G119S creates a restriction site, a simple PCR test was devised to detect its presence in both A. gambiae and C. pipiens, two mosquito species belonging to different subfamilies (Culicinae and Anophelinae). It is possibile that this mutation also explains the high resistance found in other mosquitoes, and the present results indicate that the PCR test detects the G119S mutation in the malaria vector A. albimanus. The G119S has thus occurred independently at least four times in mosquitoes and this PCR test is probably of broad applicability within the Culicidae family.

Monolithic integration of optical waveguides for absorbance detection in microfabricated electrophoresis devices.

The fabrication and performance of an electrophoretic separation chip with integrated optical waveguides for absorption detection is presented. The device was fabricated on a silicon substrate by standard microfabrication techniques with the use of two photolithographic mask steps. The waveguides on the device were connected to optical fibers, which enabled alignment free operation due to the absence of free-space optics. A 750 microm long U-shaped detection cell was used to facilitate longitudinal absorption detection. To minimize geometrically induced band broadening at the turn in the U-cell, tapering of the separation channel from a width of 120 down to 30 microm was employed. Electrical insulation was achieved by a 13 microm thermally grown silicon dioxide between the silicon substrate and the channels. The breakdown voltage during operation of the chip was measured to 10.6 kV. A separation of 3.2 microM rhodamine 110, 8 microM 2,7-dichlorofluorescein, 10 microM fluorescein and 18 microM 5-carboxyfluorescein was demonstrated on the device using the detection cell for absorption measurements at 488 nm.

Ultraviolet transparent silicon oxynitride waveguides for biochemical microsystems.

The UV wavelength region is of great interest in absorption spectroscopy, which is employed for chemical analysis, since many organic compounds absorb in only this region. Germanium-doped silica, which is often preferred as the waveguide core material in optical devices for telecommunication, cannot accommodate guidance below 400 nm, owing to the presence of UV-absorbing centers. We show that silicon oxynitride (SiO(x) N(y)) waveguides exhibit very good UV performance. The propagation loss for 24-microm -wide SiO(x)N (y) waveguides was found to be ~1.0dB/cm in the wavelength range 220-550 nm. The applicability of these waveguides was demonstrated in a biochemical microsystem consisting of multimode buried-channel SiO(x)N (y) waveguides that were monolithically integrated with microfluidic channels. Absorption measurements of a beta -blocking agent, propranolol, at 212-215 nm were performed. The detection limit was reached at a concentration of 13microM , with an optical path length of 500microm (signal/noise ratio, 2).

Monolithic integration of microfluidic channels and optical waveguides in silica on silicon.

Sealing of the flow channel is an important aspect during integration of microfluidic channels and optical waveguides. The uneven topography of many waveguide-fabrication techniques will lead to leakage of the fluid channels. Planarization methods such as chemical mechanical polishing or the etch-back technique are possible, but troublesome. We present a simple but efficient alternative: By means of changing the waveguide layout, bonding pads are formed along the microfluidic channels. With the same height as the waveguide, they effectively prevent leakage and hermetically seal the channels during bonding. Negligible influence on light propagation is found when 10-mum-wide bonding pads are used. Fabricated microsystems with application in absorbance measurements and flow cytometry are presented.

Development of ARI case management at primary and secondary level in southern Vietnam.

In southern Vietnam it is not uncommon that children under 5 years of age die from pneumonia. Reduction of severity and mortality has to rely on proper case management by mothers and health workers on both grass root level and referral level. The responsibility of training of clinical skills of ARI case management in the southern provinces of Vietnam has been delegated to Pediatric Hospital N1 (PHN1) Ho Chi Minh City (HCMC) by Ministry of Health. A pilot project was carried out by the Danish-Vietnamese Study Group. The immediate objects were: to provide basic epidemiological information about ARI in southern Vietnam, to develop training modules and case management intervention modules at primary and secondary level in order to enable mothers, village workers, health post staff and district hospital emergency department staff to treat moderate and severe pneumonia and acute bronchitis in accordance with the WHO management guide for ARI and to evaluate the effect of those modules after implementation in a limited number of communes. The modules were developed at PHN1. Ten commune health stations were carefully selected. The purpose of the project and the conditions for taking part had been explained to the health workers. The doctors and other commune health workers from the 10 commune health stations and doctors from the connected district hospitals attended the training courses at PHN1, HCMC and also at the belonging provincial hospitals. Essential equipment was provided and a pharmacy with essential drugs established. The registered health statistics was collected yearly during on site visits. The local doctors and commune health workers gave seminars for mothers in the villages of the 10 project communes. The mothers' knowledge, attitude and practice (KAP) was tested in interviews before and two months after the seminars had taken place. The spread of KAP was measured by random interviews of mothers six month later. In the interviews information on social conditions was obtained. The mothers' KAP had risen by 25% two months after attending the seminars. A further increase of KAP by 5-10% within the untrained group appeared in a survey 4-6 months later. It was not possible to obtain reliable statistics on morbidity or mortality of ARI in the project area.

The type I interferon receptor: structure, function, and evolution of a family business.

Recent results indicate that coherent models of how multiple interferons (IFN) are recognized and signal selectively through a common receptor are now feasible. A proposal is made that the IFN receptor, with its subunits IFNAR-1 and IFNAR-2, presents two separate ligand binding sites, and this double structure is both necessary and sufficient to ensure that the different IFN are recognized and can act selectively. The key feature is the duplication of the extracellular domain of the IFNAR-1 subunit and the configurational geometry that this imposes on the intracellular domains of the receptor subunits and their associated tyrosine kinases.

Shared receptor components but distinct complexes for alpha and beta interferons.

The type I interferon family includes 13 alpha, one omega and one beta subtypes recognized by a complex containing the receptor subunits ifnar1 and ifnar2 and their associated Janus tyrosine kinases, Tyk2 and Jak1. To investigate the reported differences in the way that alpha and beta interferons signal through the receptor, we introduced alanine-substitutions in the ifnar2 extracellular domain, and expressed the mutants in U5A cells, lacking endogenous ifnar2. A selection, designed to recover mutants that responded preferentially to alpha or beta interferon yielded three groups: I, neutral; II, sensitive to alpha interferon, partially resistant to beta interferon; III, resistant to alpha interferon, partially sensitive to beta interferon. A mutant clone, TMK, fully resistant to alpha interferon with good sensitivity to beta interferon, was characterized in detail and compared with U5A cells complemented with wild-type ifnar2 and also with Tyk2-deficient 11.1 cells, which exhibit a similar alpha-unresponsive phenotype with a partial beta interferon response. Using anti-receptor antibodies and mutant forms of beta interferon, three distinct modes of ligand interaction could be discerned: (i) alpha interferon with ifnar1 and ifnar2; (ii) beta interferon with ifnar1 and ifnar2; (iii) beta interferon with ifnar2 alone. We conclude that alpha and beta interferons signal differently through their receptors because the two ligand subtypes interact with the receptor subunits ifnar 1 and ifnar2 in entirely different ways.

Differences in activity between alpha and beta type I interferons explored by mutational analysis.

Type I interferon (IFN) subtypes alpha and beta share a common multicomponent, cell surface receptor and elicit a similar range of biological responses, including antiviral, antiproliferative, and immunomodulatory activities. However, alpha and beta IFNs exhibit key differences in several biological properties. For example, IFN-beta, but not IFN-alpha, induces the association of tyrosine-phosphorylated receptor components ifnar1 and ifnar2, and has activity in cells lacking the IFN receptor-associated, Janus kinase tyk2. To define the structural basis for these functional differences we produced human IFN-beta with point mutations and compared them to wild-type IFN-beta in assays that distinguish alpha and beta IFN subtypes. IFN-beta mutants with charged residues (N86K, N86E, or Y92D) introduced at two positions in the C helix lost the ability to induce the association of tyrosine-phosphorylated receptor chains and had reduced activity on tyk2-deficient cells. The combination of negatively charged residues N86E and Y92D (homologous with IFN-alpha8) increased the cross-species activity of the mutant IFN-betas on bovine cells to a level comparable to that of human IFN-alphas. In contrast, point mutations in the AB loop and D helix had no significant effect on these subtype-specific activities. A subset of these latter mutations did, however, reduce activity in a manner analogous to IFN-alpha mutations. The effects of these mutations on IFN-beta activity are discussed in the context of a family of related ligands acting through a common receptor and signaling pathway.

Establishment of drug chests in commune health stations in Vietnam, Bamako Initiative.

In remote areas in Vietnam essential drugs are often not available. Some of the reasons are inadequate resources and failure of distribution. All activities at the health stations are very weak, partly because of inappropriate usage of drugs and lack of fund for buying drugs. The object of the project was to establish sustainable provision of essential drugs for commune health stations in rural areas, to teach the health personnel the importance of essential drugs and to create incentives for the staff and a certain surplus for other health activities. Four District Health Centers (DHC) and 10 Health Stations (HS), 2-4 in each DHC were selected. A pharmacist was made monitor of the project. The health personnel were trained in proper use of drugs, drug prescription, price setting, book keeping and management of pharmacy. Written guidelines were produced. One person was responsible for the drug chest at each HS. After recognizing the aim of the project and signing the contract by which the responsible person was bound, the initial capital was given free. The DHC was responsible for the supervision and advice to the HS. Reporting on prescribed drugs, buying and selling price, profit and fund left took place monthly. Monitoring of recovery of capital, turnover rate, rate of essential drugs and incentives for staff were monitored on forms and quarterly collected by the monitor on his visits. The HS were visited half-yearly by a steering group. All ten HS had been able to establish and maintain the pharmacy and to fully recover or even increase the capital and to create a surplus. Seven out of ten HSs had a turnover rate of more than one. The rate of essential drugs sold was more than 60% in seven pharmacies. The interest rate of 18% on average was used for incentives for staff, to provide drugs for those who cannot pay and for equipment for the HS. The cooperation between the DHC and the HS became closer. Establishment of drug chests seems to be a reasonable strategy of reinforcing primary health. Much attention should be paid on training of staff, monitoring, supervision and integration of health services.

Interferon-alpha-dependent activation of Tyk2 requires phosphorylation of positive regulatory tyrosines by another kinase.

Tyk2 and JAK1, members of the Janus kinase (JAK) family of protein tyrosine kinases, are required for interferon-alpha/beta binding and signaling. Both enzymes are associated with the interferon-alpha/beta receptor, and upon ligand binding, they undergo tyrosine phosphorylation and catalytic activation in an interdependent manner. To identify residues involved in Tyk2 regulation and to understand the basis of the interdependence of Tyk2 and JAK1, six mutated versions of Tyk2 bearing single or multiple point mutations in the tyrosine kinase domain were studied in a cell line lacking endogenous Tyk2. The Y1054F/Y1055F substitutions in the putative activation loop prevented ligand-dependent activation of Tyk2, without abolishing its catalytic potential. The K930R mutation in the ATP binding site generated a kinase-negative protein, which however, still became phosphorylated upon interferon-alpha treatment. The Y1054F/Y1055F substitutions in this kinase-negative Tyk2 abolished the induced phosphorylation. These results indicate that Tyk2 is activated by phosphorylation on Tyr-1054 and/or Tyr-1055 and that this phosphorylation requires another kinase, most likely JAK1. While the Tyk2 forms mutated on Tyr-1054 and Tyr-1055 or on Lys-930 allowed some inducible gene expression, the combination of the three point mutations totally abolished signaling.

Mutant U5A cells are complemented by an interferon-alpha beta receptor subunit generated by alternative processing of a new member of a cytokine receptor gene cluster.

The cellular receptor for the alpha/beta interferons contains at least two components that interact with interferon. The ifnar1 component is well characterized and a putative ifnar2 cDNA has recently been identified. We have cloned the gene for ifnar2 and show that it produces four different transcripts encoding three different polypeptides that are generated by exon skipping, alternative splicing and differential use of polyadenylation sites. One polypeptide is likely to be secreted and two are transmembrane proteins with identical extracellular and transmembrane domains but divergent cytoplasmic tails of 67 and 251 amino acids. A mutant cell line U5A, completely defective in IFN-alpha beta binding and response, has been isolated and characterized. Expression in U5A cells of the polypeptide with the long cytoplasmic domain reconstitutes a functional receptor that restores normal interferon binding, activation of the JAK/STAT signal transduction pathway, interferon-inducible gene expression and antiviral response. The IFNAR2 gene maps at 0.5 kb from the CRFB4 gene, establishing that together IFNAR2, CRFB4, IFNAR1 and AF1 form a cluster of class II cytokine receptor genes on human chromosome 21.