Ultrasonic locating devices for central venous cannulation: meta-analysis

Objectives To assess the evidence for the clinical effectiveness of ultrasound guided central venous cannulation.Data sources 15 electronic bibliographic databases, covering biomedical, science, social science, health economics, and grey literature.Design Systematic review and meta-analysis of randomised controlled trials.Populations Patients scheduled for central venous access.Intervention reviewed Guidance using real time two dimensional ultrasonography or Doppler needles and probes compared with the anatomical landmark method of cannulation.Data extraction Risk of failed catheter placement (primary outcome), risk of complications from placement, risk of failure on first attempt at placement, number of attempts to successful catheterisation, and time (seconds) to successful catheterisation.Data synthesis 18 trials (1646 participants) were identified. Compared with the landmark method, real time two dimensional ultrasound guidance for cannulating the internal jugular vein in adults was associated with a significantly lower failure rate both overall (relative risk 0.14, 95% confidence interval 0.06 to 0.33) and on the first attempt (0.59, 0.39 to 0.88). Limited evidence favoured two dimensional ultrasound guidance for subclavian vein and femoral vein procedures in adults (0.14, 0.04 to 0.57 and 0.29, 0.07 to 1.21, respectively). Three studies in infants confirmed a higher success rate with two dimensional ultrasonography for internal jugular procedures (0.15, 0.03 to 0.64). Doppler guided cannulation of the internal jugular vein in adults was more successful than the landmark method (0.39, 0.17 to 0.92), but the landmark method was more successful for subclavian vein procedures (1.48, 1.03 to 2.14). No significant difference was found between these techniques for cannulation of the internal jugular vein in infants. An indirect comparison of relative risks suggested that two dimensional ultrasonography would be more successful than Doppler guidance for subclavian vein procedures in adults (0.09, 0.02 to 0.38).Conclusions Evidence supports the use of two dimensional ultrasonography for central venous cannulation.     

Angiotensin II utilizes Janus kinase 2 in hypertension, but not in the physiological control of blood pressure, during low-salt intake

Janus kinase (JAK) 2 is activated by ANG II in vitro and in vivo, and chronic blockade of JAK2 by the JAK2 inhibitor AG-490 has been shown recently to attenuate ANG II hypertension in mice. In this study, AG-490 was infused intravenously in chronically instrumented rats to determine if the blunted hypertension was linked to attenuation of the renal actions of ANG II. In male Sprague-Dawley rats, after a control period, ANG II at 10 ng·kg(-1)·min(-1) was infused intravenously with or without AG-490 at 10 ng·kg(-1)·min(-1) iv for 11 days. ANG II infusion (18 h/day) increased mean arterial pressure from 91 ± 3 to 168 ± 7 mmHg by day 11. That response was attenuated significantly in the ANG II + AG-490 group, with mean arterial pressure increasing only from 92 ± 5 to 127 ± 3 mmHg. ANG II infusion markedly decreased urinary sodium excretion, caused a rapid and sustained decrease in glomerular filtration rate to ～60% of control, and increased renal JAK2 phosphorylation; all these responses were blocked by AG-490. However, chronic AG-490 treatment had no effect on the ability of a separate group of normal rats to maintain normal blood pressure when they were switched rapidly to a low-sodium diet, whereas blood pressure fell dramatically in losartan-treated rats on a low-sodium diet. These data suggest that activation of the JAK/STAT pathway is critical for the development of ANG II-induced hypertension by mediating its effects on renal sodium excretory capability, but the physiological control of blood pressure by ANG II with a low-salt diet does not require JAK2 activation.     

Serum Nutritional Biomarkers and Their Associations with Sleep among US Adults in Recent National Surveys

Background

The associations between nutritional biomarkers and measures of sleep quantity and quality remain unclear.

Methods

Cross-sectional data from the National Health and Nutrition Examination Surveys (NHANES) 2005–2006 were used. We selected 2,459 adults aged 20–85, with complete data on key variables. Five sleep measures were constructed as primary outcomes: (A) Sleep duration; (B) Sleep disorder; (C) Three factors obtained from factor analysis of 15 items and labeled as “Poor sleep-related daytime dysfunction” (Factor 1), “Sleepiness” (Factor 2) and “Sleep disturbance” (Factor 3). Main exposures were serum concentrations of key nutrients, namely retinol, retinyl esters, carotenoids (α-carotene, β-carotene, β-cryptoxanthin, lutein+zeaxanthin, lycopene), folate, vitamin B-12, total homocysteine (tHcy), vitamin C, 25-hydroxyvitamin D (25(OH)D) and vitamin E. Main analyses consisted of multiple linear, logistic and multinomial logit models.

Results

Among key findings, independent inverse associations were found between serum vitamin B-12 and sleep duration, 25(OH)D and sleepiness (as well as insomnia), and between folate and sleep disturbance. Serum total carotenoids concentration was linked to higher odds of short sleep duration (i.e. 5–6 h per night) compared to normal sleep duration (7–8 h per night).

Conclusions

A few of the selected serum nutritional biomarkers were associated with sleep quantity and quality. Longitudinal studies are needed to ascertain temporality and assess putative causal relationships.     

On the mechanism and stoichiometry of the oxidation of hydrazine by illuminated chloroplasts

Hydrazine can support a rapid oxygen uptake in illuminated chloroplasts. The oxygen uptake rate is inhibited by 3-(3,4-dichlorophenyl)-1, 1-dimethylurea but is only slightly increased by added methyl viologen, and little H₂O₂ is produced. The pH optimum for hydrazine-dependent oxygen uptake is much higher than that of the Hill reaction. Addition of Mn (II) increases the rate of oxygen uptake in the light and causes the reaction to continue in the dark, the dark rate being dependent on the duration of the preceding light period. Flash yield experiments show that at least six electrons are transferred from hydrazine per flash compared to one electron per flash when water is the electron donor.     

The ferredoxin-NADP+ oxidoreductase-binding protein is not the 17-kDa component of the cytochrome b/f complex

The complex between ferredoxin-NADP+ oxidoreductase and its proposed membrane-binding protein (Vallejos, R. H., Ceccarelli, E., and Chan, R. (1984) J. Biol. Chem. 259, 8048-8051) was isolated from spinach thylakoids and compared with isolated cytochrome b/f complex containing associated ferredoxin NADP+ oxidoreductase (Clark, R. D., and Hind, G. (1983) J. Biol. Chem. 258, 10348-10354). There was no immunological cross-reactivity between the 17.5-kDa binding protein and an antiserum raised against the 17-kDa polypeptide of the cytochrome complex. Association of ferredoxin-NADP+ oxidoreductase with the binding protein or with the thylakoid membrane gave an allotopic shift in the pH profile of diaphorase activity, as compared to the free enzyme. This effect was not seen in enzyme associated with the cytochrome b/f complex. Identification of the 17.5-kDa binding protein as the 17-kDa component of the cytochrome b/f complex is ruled out by these results.     

Human serum amyloid P component, a circulating lectin with specificity for the cyclic 4,6-pyruvate acetal of galactose. Interactions with various bacteria.

Serum amyloid P component (SAP), a normal plasma glycoprotein, has recently been shown to have Ca2+-dependent binding specificity for methyl 4,6-O-(1-carboxyethylidene)-beta-D-galactopyranoside (MO beta DG) [Hind, Collins, Renn, Cook, Caspi, Baltz & Pepys (1984) J. Exp. Med. 159, 1058-1069]. SAP was found to bind in vitro to Klebsiella rhinoscleromatis, the cell wall of which is known to contain this particular cyclic pyruvate acetal of galactose. SAP also bound in similar amounts (approx. 6000 molecules per organism) to group A Streptococcus pyogenes, but very much less was taken up on Xanthomonas campestris, which contains the 4,6-cyclic pyruvate acetal of mannose. No SAP bound to Escherichia coli, which contains the 4,6-cyclic pyruvate acetal of glucose, or to Streptococcus pneumoniae type 4, which contains the 2,3-cyclic pyruvate acetal of alpha- rather than beta-galactopyranoside, or to other organisms (Streptococcus agalactiae, Staphylococcus aureus and Staphylococcus epidermidis), the carbohydrate structures of which are less well characterized. Binding of SAP to those organisms which it did recognize was completely inhibited or reversed by millimolar concentrations of free MO beta DG. SAP, a human plasma protein, thus behaves as a lectin and may be a useful probe for its particular specific ligand in the cell walls of bacteria and other organisms.     

872. COCHEMIEA PONDII subsp. MARITIMA

Cochemiea pondii subsp. maritima is illustrated, the species and all three subspecies described, each provided with a full synonymy, statements on distribution, habitat and ecology, etymology, phenology, and conservation status. A commentary is given on the re‐acceptance of Cochemiea, separated from Mammillaria. Cultivation notes are provided; the species, and in particular subspecies maritima, is far from common in cultivation and not widely available. The discussion covers aspects of recognition of the subspecies, type collections, related taxa, and comments on the addition of several more species to the genus by Doweld.