Exploring the synthetic potential of a marine transaminase including discrimination at a remote stereocentre.

The marine transaminase, P-ω-TA, can be employed for the transamination from 1-aminotetralins and 1-aminoindanes with differentiation of stereochemistry at both the site of reaction and at a remote stereocentre resulting in formation of ketone products with up to 93% ee. While 4-substituents are tolerated on the tetralin core, the presence of 3- or 8-substituents is not tolerated by the transaminase. In general P-ω-TA shows capacity for remote diastereoselectivity, although both the stereoselectivity and efficiency are dependent on the specific substrate structure. Optimum efficiency and selectivity are seen with 4-haloaryl-1-aminotetralins and 3-haloaryl-1-aminoindanes, which may be associated with the marine origin of this enzyme.

Health care provider's responses to children's resistance to peripheral vein cannulation: A qualitative observational study.

AIMS AND OBJECTIVES: Health care and treatment should be voluntary, but restraint is often used during treatment of children. Knowledge about how health care providers respond to preschool children's resistance is lacking and can help understand current paediatric care in hospitals. The aim of the present article was to provide knowledge about how healthcare providers respond to preschool children's resistance during the clinical procedure of peripheral vein cannulation. DESIGN: An explorative qualitative research design was developed for this study. METHODS: Observations with video recording were used to collect data. Eight nurses and seven physicians participated in the study (n = 15). Their responses to preschool children's (n = 6) resistance were studied during 14 attempts of peripheral vein cannulation. Consolidated criteria for reporting qualitative research (COREQ) were used. RESULTS: The healthcare providers made 380 responses to children's resistive expressions, interpreted within four main types, responses to acknowledge the child, responses to distract the child, responses to persuade the child and responses to reject the child. All main types of responses were used by both nurses and physicians. Regardless of the amount of resistance the children expressed, all children received distracting and acknowledging responses. Rejecting responses were used approximately twice as much in the implementation phase as in the preparation phase. Distraction, persuasion and rejection began in the preparation phase and increased in the implementation phase. CONCLUSIONS: The main types and sub-types of responses showed how healthcare providers use a wide array of responses to meet children's resistance during peripheral vein cannulation. RELEVANCE TO CLINICAL PRACTICE: The results can enable health care providers to become aware of their own practices during peripheral vein cannulation and other clinical procedures and to elaborate on their use of responses that can be considered intrinsically less child-friendly.

Monitoring plasmon coupling and SERS enhancement through in situ nanoparticle spacing modulation.

Self-assembled nanoparticle (NP) arrays at liquid interfaces provide a unique optical response which has opened the door to new tuneable metamaterials for sensing and optical applications. NPs can spontaneously assemble at a liquid-liquid interface, forming an ordered, self-healing, low-defect 2D film. The close proximity of the NPs at the interface results in collective plasmonic modes with a spectral response dependent on the distance between the NPs and induces large field enhancements within the gaps. In this study, we assembled spherical and rod-shaped gold NPs with the aim of improving our understanding of NP assembly processes at liquid interfaces, working towards finely controlling their structure and producing tailored optical and enhanced Raman signals. We systematically tuned the assembly and spacing between NPs through increasing or decreasing the degree of electrostatic screening with the addition of electrolyte or pH adjustment. The in situ modulation of the nanoparticle position on the same sample allowed us to monitor plasmon coupling and the resulting SERS enhancement processes in real time, with sub-nm precision.

Healthcare personnel self-assessed competence and knowledge following implementation of a new guideline on maternal resuscitation in Norway. A repeated measure study.

Introduction: Cardiac arrest in pregnancy is a rare, yet extremely challenging condition to manage for all healthcare personnel involved. Knowledge deficits and poor resuscitation skills can affect outcomes in cardiac arrest in pregnancy, but research exploring healthcare personnel competence and knowledge about maternal resuscitation is limited. Aims: The aim of this study was to explore (1) healthcare personnel self-assessed competence and knowledge about cardiopulmonary resuscitation (CPR) in pregnancy as well as perimortem caesarean section, before and after implementation of a new guideline, (2) whether there were any interprofessional differences in knowledge about maternal resuscitation, and (3) potential differences between different implementation strategies. Research Methodology: The study had a prospective repeated measure implementation design, utilizing a questionnaire before and after implementation of a new guideline on maternal resuscitation after cardiac arrest. Setting: All healthcare personnel potentially involved in CPR in six hospital wards, were invited to participate (n = 527). The guideline was implemented through either simulation, table-top discussions and/or an electronical learning course. Results: In total, 251 (48%) participants responded to the pre-questionnaire, and 182 (35%) to the postquestionnaire. The need for education and training/simulation concerning maternal resuscitation were significantly lowered after implementation of the guideline, yet still the majority of respondents reported a high to medium need for education and training/simulation. Participants' self-assessed overall competence in maternal resuscitation increased significantly postimplementation. Regardless of professional background, knowledge about CPR and perimortem caesarean section increased significantly in most items in the questionnaire after implementation. Differences in level of knowledge based on implementation strategy was identified, but varied between items, and was therefore inconclusive. Conclusion: This study adds knowledge about healthcare personnel self-assessed competence and knowledge about maternal resuscitation and perimortem caesarean section in pregnancy. Our findings indicate that there is still a need for more education and training in this rare incident.

Feasibility and Acceptability of a Complex Telerehabilitation Intervention for Pediatric Acquired Brain Injury: The Child in Context Intervention (CICI).

The current study is a feasibility study of a randomized controlled trial (RCT): the Child in Context Intervention (CICI). The CICI study is an individualized, goal-oriented and home-based intervention conducted mainly through videoconference. It targets children with ongoing challenges (physical, cognitive, behavioral, social and/or psychological) after acquired brain injury (ABI) and their families at least one year post injury. The CICI feasibility study included six children aged 11-16 years with verified ABI-diagnosis, their families and their schools. The aim was to evaluate the feasibility of the intervention components, child and parent perceptions of usefulness and relevance of the intervention as well as the assessment protocol through a priori defined criteria. Overall, the families and therapists rated the intervention as feasible and acceptable, including the videoconference treatment delivery. However, the burden of assessment was too high. The SMART-goal approach was rated as useful, and goal attainment was high. The parents' ratings of acceptability of the intervention were somewhat higher than the children's. In conclusion, the CICI protocol proved feasible and acceptable to families, schools and therapists. The assessment burden was reduced, and adjustments in primary outcomes were made for the definitive RCT.

Metabolic fate of ultratrace levels of GeCl(4) in the rat and in vitro studies on its basal cytotoxicity and carcinogenic potential in Balb/3T3 and HaCaT cell linesdagger.

The use of germanium (Ge) and the possibility of exposure to trace and ultratrace amounts of this element is increasing. Germanium is widely used in the industrial field as a semiconductor and also as a dietary supplement, an elixir to 'promote health and cure disease' (e.g. cancer and AIDS). More recently, germanium nanoparticles, ranging in size from 60 to 80 nm, have been developed as a potential spleen imaging agent. Like other metal-based nanoparticles used in nanomedicine, Ge nanoparticles may release trace and ultratrace amounts of Ge ions when injected. The metabolic fate and toxicity of these ions still needs to be evaluated. In this study the metabolic fate of a cationic tetravalent Ge species was studied in vivo by injecting rats i.p. with ultratrace amounts of Ge (80 ng kg(-1)) as [(68)Ge]GeCl(4). The cytotoxicity and carcinogenic potential was assessed in vitro using immortalised human skin keratinocytes and mouse fibroblasts (HaCaT and Balb/c 3T3 cell lines, respectively). At 24 h post-exposure Ge was poorly retained in rat tissues (kidney, liver, intestine, femur, spleen and the heart were the organs with the highest Ge concentration). In the blood, Ge was rapidly cleared, being almost equally distributed between plasma and red blood cells. The excretion was mainly via the urine. The hepatic and renal intracellular distribution showed the highest recovery of Ge in the cytosol and the nuclear fractions. Chromatographic separation and ultrafiltration experiments on kidney and liver cytosols showed that the bulk of Ge was associated with low molecular weight components, representing a 'mobile pool' of the element in the body. However, a significant part of the element was able to interact with biological macromolecules which could be responsible for the presence of Ge in the liver and kidney after 7 days. The in vitro experiments confirmed the low degree of cytotoxicity of GeCl(4) both in HaCaT and Balb/3T3. The latter model was more sensitive to the toxic effects induced by Ge as shown by a colony forming efficiency (CFE) greater than 70% at 700 microm of exposure. At the highest exposure concentration tested (700 microm) GeCl(4) failed to induce morphological neoplastic transformation of the cells, suggesting for the first time that a cationic form of Ge ions has no carcinogenic potential. This supports the results of the only study reported in mice, treated orally long-term to an anionic species of Ge such as sodium germanate (Kanisawa and Schroeder, 1967).

Development and validation of a questionnaire to assess healthcare personnel competence in cardiac arrest and resuscitation in pregnancy.

BACKGROUND: Cardiac arrest is rare in pregnancy, and up-to date competence can be difficult to assess and maintain. The objective of this study was to develop and validate a questionnaire to assess healthcare personnel experiences, self-assessed competence and perception of role and resposibility related to cardiac arrest and cardio-pulmonary resuscitation (CPR) in pregnancy. METHODS: The study had a cross-sectional design, developing and validating a questionnaire: the Competence in cardiac arrest and CPR in pregnancy (ComCA-P). Development and validation of the ComCA-P was conducted in three stages: 1) Literature review and expert group panel inputs, 2) a pilot study and 3) a cross-sectional questionnaire study. In stage one, the ComCA-P was developed over several iterations between the researchers, including inputs from an expert group panel consisting of highly competent professionals (n = 11). In stage two, the questionnaire was piloted in a group of healthcare personnel with relevant competence (n = 16). The ComCA-P was then used in a baseline study including healthcare personnel potentially involved in CPR in pregnancy (n = 527) in six hospital wards. Based on these data, internal consistency, intra-class correlations, and confirmatory factor analysis were utilized to validate the questionnaire. RESULTS: The expert group and pilot study participants evaluated the appropriateness, relevance and accuracy to be high. Formulation of the items was considered appropriate, with no difficulties identified related to content- or face validity. Cronbach's alpha was 0.8 on the thematic area self-assessment, and 0.73 on the theoretical knowledge area of the ComCA-P. On both the self-assessed competence items and the teoretical knowledge items, Kaiser-Meyer-Olkin was 0.8. Moreover, the Bertletts' test of sphericity was greater than the critical value for chi-square, and significant (p < .0001). CONCLUSIONS: Findings indicate that the ComCA-P is a valid questionnaire that can be used to assess healthcare personnel competence in cardiac arrest and resuscitation in pregnancy.

Quantitative detection of protein expression in single cells using droplet microfluidics.

We demonstrate that single cells can be controllably compartmentalized within aqueous microdroplets; using such an approach we perform high-throughput screening by detecting the expression of a fluorescent protein in individual cells with simultaneous measurement of droplet size and cell occupancy.

Inverse dose- and time-dependent effect of basic fibroblast growth factor on the gene expression of collagen type I and matrix metalloproteinase-1 by periodontal ligament cells in culture.

BACKGROUND: Growth factors are known to play a major role in the regeneration of the periodontium. Basic fibroblast growth factor (bFGF) is a polypeptide growth factor considered to have a role in chemotaxis and mitogenesis of periodontal ligament cells (PLC). The aim of this study was to assess the dose-dependent effect of bFGF administration on the levels of gene expression of collagen type I (a1) (col I), collagen type III (col III), and collagenase-1 (MMP-1) in PLC. METHODS: PLC were cultured in different concentrations of bFGF (0.1 to 10 ng of bFGF) for 14 and 21 days. At each time point, the gene expression of the examined molecules was assessed semi-quantitatively by reverse transcription-polymerase chain reaction (RT-PCR) assay. RESULTS: The results indicated that bFGF exhibits an inverse time- and dose-dependent effect on the gene expression of col I and MMP-1: it simultaneously downregulates the gene expression of col I and upregulates the gene expression of MMP-1. On the other hand, bFGF had no dose-dependent effect on col III gene expression. The effect of bFGF on the expression of the three genes was modulated by the time of incubation with bFGF. CONCLUSIONS: These results suggest that bFGF is one of the important regulators involved in the active remodeling of col I in the periodontal ligament and possibly in other connective tissues.

Cobalt speciation in urine of hard metal workers. A study carried out by nuclear and radioanalytical techniques.

A method for the determination of inorganic and organically-bound cobalt in human urine has been developed and applied to the urine of hard metal workers. The development was based on the use of the radionuclides 57Co, 58Co and 60Co-labelled Co compounds such as Co-Vitamin B12 and CO2+ ions which allowed the study of their biotransformations in human and rat urine. The proposed procedure is based on the use of Chelex 100 resin which retains quantitatively the inorganic Co from the urine while the organic complexed form of the element is eluted. Cobalt is detected in both column and eluate by neutron activation analysis (NAA). The method has been applied to speciate inorganic and organically-bound Co in the urine of hard metal workers. There is a significant increase (P < 0.02) of the ratio inorganic/organic Co (2.3) in the urine of workers compared with controls (1.01), showing an increase of the inorganic fraction of Co in the urine of workers. The ratio was constant for the wide range of urinary Co analyzed (from 180 micrograms to 1254 micrograms Co/l). Therefore, the discrimination between inorganic and organic Co in urine should not represent progress in the biological monitoring of Co compared with the determination of total urinary Co. However, a large amount of organically-complexed Co is formed in the body of hard metal workers and excreted in urine, thus, investigations of the nature of the organo-cobalt compounds are of fundamental importance in establishing their possible clinical significance.

Metabolic and toxicological studies on cobalt.

In this study, the following in vitro and in vivo experiments were carried out: (a) Rats were exposed to the radionuclide 57Co2+ ions in single intraperitoneal or intravenous doses (from 10 ng to 1 mg Co/rat) or to 50 ng Co/rat/day through drinking water for 109 days. The target tissue for cobalt depended on the dosage and route of administration (e.g. lung, kidney or bone). Excretion took place mainly through urine (i.p. and i.v. administration) or feces. At 24 h, testis of rats i.v. injected with 10 ng Co/rat contained 0.056% of the dose, with approximately 0.036% in the epididymus, and 0.08% in the deferens. No radioactivity was found in the germinal cells. (b) In vitro incorporation of cobalt in rat sperm. Cobalt enters the germinal cells suggesting that in vivo barriers against the incorporation of the element in sperms may occur. (c) Dose-effect relationships in BALB/3T3 cell cultures exposed to concentrations of cobalt from 1000 to 1 microM of Co2+. Cobalt induced a dose dependent cytotoxic response. At 10 microM, cell growth was reduced to about 30%. No inhibition was found at 1 microM. Morphological transformation assays gave negative results when the cells were exposed to 1000 microM of cobalt.

Intracellular interaction and biotransformation of arsenite in rats and rabbits.

The accumulation of arsenic with time in tissues of rats and rabbits was determined by neutron activation analysis (NAA). Rats showed a steady increase in the As-concentrations with age, whereas in rabbits it was nearly the same for adults and in young animals. The metabolism of arsenic was studied in both animal species after i.p. injection of 50/micrograms As/kg b.w. as 74As labelled arsenite. Eight tissues, as well as blood and urine, were analysed for 74As content after 16 and 48 hours. The binding of 74As to hematic and intracellular components and the chemical forms of arsenic in tissues and urine were investigated. In the plasma and the RBC-fraction of the rabbit, the As concentration decreased during the first two days, while in the rats it only disappeared from the plasma, but was retained in the RBC-fraction. Liver, kidney and lung of rabbits with the highest As concentrations at 16 and 48 hours showed a rapid clearance of As in the first 48 hours. In the corresponding tissues of the rats, the rate of decline was significantly lower, due to the higher binding of 74As to tissue constituents. Poor binding of As to plasma proteins was seen in rabbits while in rats it was totally bound to this fraction. In the RBC, liver and kidney cytosols, however, the affinity of As for intracellular proteins was higher in both animal species but characterized by a rate of binding different between the two animal species. The amount of dimethylarsinic acid (DMA) in the tissues was significantly lower in the rat than in the rabbit, reflecting the total amount of diffusible arsenic, which was also much lower in the tissues of rats than in rabbits.

Trace metal lung disease: in vitro interaction of hard metals with human lung and plasma components.

Hard metal pneumoconiosis is an occupational pulmonary disease caused by long-term exposure to dust produced in the hard metal industry. In vitro experiments have been carried out to study the solubility and metabolic behaviour in human lung tissue and plasma of hard metal alloy constituents such as cobalt, tungsten, tantalum, titanium and niobium. The experiments were carried out using 60Co, 187W, 182Ta, 44Ti and 95Nb radiotracers in combination with neutron activation, radio-release tests and gel filtration techniques. Leaching experiments from neutron-irradiated hard metal dust showed that cobalt was highly soluble, especially in the lung cytosol and plasma, in comparison with tantalum and tungsten. The gel filtration experiments showed three biochemical pools of cobalt in both lung and plasma components, in accordance with the hypothesis that cobalt represents the allergic factor in the development of hard metal disease. High affinity for proteins was observed for Nb, Ta and Ti, but not for W, in agreement with the dissimilar biological half-lives of these elements in the body. The different ability of the metals to interact with biochemical components and to be solubilized in biological media may explain the various degrees of retention in the lung, which would influence the metabolic pathways. This would explain the presence of Co, Ta and W in body fluids, as well as in the public hair and toenails of hard metal workers.

Vanadium transport across placenta and milk of rats to the fetus and newborn.

The transport of vanadium across placenta and milk rats was studied by iv injection of low doses of 48V-labeled pentavanadate (0.1 micrograms V/rat) to pregnant and nursing rats. Significant concentrations of vanadium were found in the liver, intestine, and kidneys of the fetuses, showing that vanadium is capable to pass the placental barrier and, thus, being metabolized in the fetuses. Two days after injection of 0.1 micrograms V/rat as 48V-labeled vanadate to nursing rats, 34 ng V/g milk were found, decreasing to 4 ng V/g at the d 12 after dosing. The corresponding suckling rats showed a significant absorption of vanadium taken up by the milk, as suggested by the presence in their intestine, where 48V is easily absorbed in form of low molecular weight components. Vanadium in milk may be transported in the form of a biocomplex with lactoferrin, since at 12 d after injection, the 48V in the rat milk was mainly found in fractions corresponding to proteins. In weanling rats, 7 d postlactation and 18 d after administration of vanadium to the mother, only very small amounts of 48V were still present in the organs. Excretion studies on weanling rats for 7 d showed that vanadium is rapidly released mainly via feces when earlier taken up by the milk of iv injected mothers and having the same elimination pattern as the milk, which lost about 80% of its vanadium concentration after 12 d.

Environmental and biochemical trace-metal speciation studies by radiotracers and neutron activation analysis.

Although knowledge of the total concentrations of trace metals in the environment and living organisms is still the essential starting point for any toxicological evaluation, it is, however, not sufficient to explain the mechanisms responsible for retention and toxic effect of trace metals. Differentiation between their chemical and biochemical forms is necessary. The need to resolve the total concentration of trace metals into single chemical species poses great experimental difficulties and imposes the use of very sensitive analytical techniques for trace metal determinations after specific preseparation procedures of the different chemical species.Thus, once the chemical or biochemical metal species have been selectively isolated, the speciation becomes merely an analytical problem, which requires high sensitivity and accuracy, as well as the evaluation of matrix effects, blanks, contamination, loss, and sampling.This paper describes the use of nuclear and radiochemical techniques related to chemical and biochemical speciation problems at the Joint Research Centre, Ispra, with carrier-free radiotracers and radiochemical neutron activation analysis.

Biliary excretion of barium in the rat.

Biliary excretion of barium was studied in Sprague-Dawley bile-duct-cannulated rats injected intravenously with 1.8 micrograms Ba/rat as 133Ba-labeled barium chloride. Approximately 0.5% of the barium dose was excreted into bile within 2 h. The time-course profile of biliary excretion of the radiotracer closely reflected that of plasma concentrations. Biliary barium levels reached their peak in the first 15-min period after administration and rapidly declined thereafter. The plasma-to-bile barium-concentration ratio was approx 1 at 2 h after injection. There was no tendency of barium to concentrate in liver, and the 133Ba levels in stomach and small intestine largely exceeded hepatic levels. There is evidence indicating that barium is predominantly excreted with feces following parenteral administration in rats and humans. The results of this study suggest that biliary excretion is of little quantitative importance and that physiological routes other than bile contribute to elimination of barium by the digestive tract.

Blood coagulation studies in guineapigs (Cavia porcellus).

Blood coagulation studies were performed on 45 healthy, adult guinea pigs. Additionally thrombelastograms of 30 animals were recorded. Guineapigs revealed short partial thromboplastin times and euglobulin lysis times, but long prothrombin times and thrombin times. Fibrinogen values were within the range of human normal values. Biphasic ADP-induced aggregation of platelets, as occurs in man, was found in 29% of the animals. Short r (reaction time until the beginning of clot formation) and k times (time from the beginning of clot formation until an amplitude of 20 mm) of their thrombelastograms indicate, that whole blood clotting is enhanced in guineapigs. Higher maximum amplitudes in this species suggest a stronger clot stability than in man.

A microfluidic approach for high-throughput droplet interface bilayer (DIB) formation.

We present a simple, automated method for high-throughput formation of droplet interface bilayers (DIBs) in a microfluidic device. We can form complex DIB networks that are able to fill predefined three dimensional architectures. Moreover, we demonstrate the flexibility of the system by using a variety of lipids including 1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC).

Droplet-based compartmentalization of chemically separated components in two-dimensional separations.

We demonstrate that nanolitre-sized droplets are an effective tool in coupling two-dimensional separations in both time and space. Using a microfluidic droplet connector, chemically separated components can be segmented into nanolitre droplets. After oil filtering and droplet merging, these droplets are loaded into a second dimension for comprehensive separations.