Prevention and treatment of cardiovascular instability during spinal anaesthesia for caesarean section

Spinal anaesthesia is the method of choice for caesarean section. There is however a significant associated morbidity and mortality in South Africa, particularly in inexperienced hands. This review provides recommendations for safe practice for anaesthetists at all levels of expertise, with particular reference to the management of haemodynamic instability. S Afr Med J 2004; 94: 367-372

Inhibisie van osteoklastvorming en beenresorpsie deur poli-onversadigde vetsure in RAW 264.7 muismonosiete

Inhibition of osteoclast differentiation and bone resorption by polyunsaturated fatty acids in RAW 264.7 murine macrophages. This study investigated the effects of polyunsaturated fatty acids on osteoclast formation and bone resorption in RAW 264.7 murine pre-osteoclasts. Data obtained suggests an inhibitory effect of these compounds on osteoclastogenesis and bone resorption in the cell line tested. Beenhermodellering in volwassenes is ‘n fisiologiese proses wat die sintese van beenmatriks deur osteoblaste en die resorpsie (afbraak) van been deur osteoklaste behels. Osteoklaste ontstaan deur die samesmelting van hematopoïetiese selle van monosiet-makrofaagafkoms en speel ‘n deurslaggewende rol in beenhermodellering. Osteoklast-ooraktiwiteit kan die afbraak van been in verskeie patologiese toestande tot gevolg hê. Kliniese- en dierestudies het aangedui dat sommige poli-onversadigde vetsure ‘n voordelige effek op been kan hê. Die doel van hierdie proefstudie was om te bepaal of omega-3 en omega-6 poli-onversadigde vetsure osteoklastvorming vanaf RAW 264.7 monosiete moduleer en daardeur die aantal volwasse resorberende osteoklaste kan beïnvloed. Monosiet/makrofaag-muisselle (RAW 264.7 pre-osteoklaste) is teen 1.5x104 selle/putjie in steriele 24-put plaatjies in die aanwesigheid van 15 ng/ml muisreseptor-aktiveerder van NFκBligand (RANKL) gesaai. RANKL is noodsaaklik vir osteoklastvorming vanaf voorgangerselle. Etanol (oplosmiddelkontrole), die omega-6 poli-onversadigde vetsure aragidoonsuur en gammalinoleensuur asook die omega-3 poli-onversadigde vetsure eikosapentaënöesuur en dokosaheksaënöesuur is by die selkulture teen konsentrasies van 5–20 μg/ml gevoeg. Palmitiensuur, ‘n versadigde vetsuur, teen ‘n konsentrasie van 20 μg/ml is as positiewe kontrole vir inhibisie van osteoklastvorming gebruik. Na vyf dae inkubasie is osteoklastvorming geëvalueer deur van tartraat-weerstandigesuurfosfatase (TRAP)-kleuring gebruik te maak. TRAP-positiewe selle met vyf of meer kerne word as veelkernige osteoklaste beskou. Soortgelyke eksperimente is uitgevoer op plaatjies wat bedek is met ‘n sintetiese anorganiese beenoppervlak. Na sewe dae inkubasie is die selle afgewas en resorpsie van die oppervlak met behulp van mikroskoopfoto’s waargeneem. Die persentasie resorpsie-oppervlak is daarna met behulp van toepaslike rekenaarsagteware bepaal. Verder is RAW 264.7 selle op beenskyfies gesaai om die effek van poli-onversadigde vetsure op die degradering van organiese en anorganiese beenkomponente te evalueer. Na nege dae is die gekondisioneerde media afgetrek en die hoeveelheid Ca2+ en kollageenfragmente, beendegraderingsprodukte onderskeidelik afkomstig vanaf die anorganiese en organiese komponente van beenafbraak, deur gepaste kolorimetriese metodes bepaal. Resultate van hierdie studie het getoon dat die vorming van veelkernige osteoklaste deur die blootstelling aan poli-onversadigde vetsure by konsentrasies van 5–20 μg/ml geïnhibeer word. Blootstelling aan al die vetsure het tot inhibering van osteoklastvorming gelei met die grootste effek by die hoogste vetsuurkonsentrasies. Dokosaheksaënöesuur (omega-3) het die mees betekenisvolle inhiberende effek oor al die konsentrasies getoon en eikosapentaënöesuur die minste. Resorpsieholtes op die gesimuleerde beenplaatjies was kleiner waar die selle aan aragidoonsuur en dokosaheksaënöesuur blootgestel was in vergelyking met dié van die oplosmiddelkontrole, wat moontlik aan die laer voorkoms van volwasse veelkernige osteoklaste toegeskryf kan word. ‘n Afname in die beendegraderingsprodukte is ook waargeneem waar selle blootgestel is aan aragidoonsuur en dokosaheksaënöesuur in vergelyking met die oplosmiddelkontrole. Die resultate ondersteun die vermoede dat poli-onversadigde vetsure die vorming van volwasse osteoklaste inhibeer en daardeur ‘n beenbeskermende effek tot gevolg mag hê. Verdere navorsing is nodig om duidelikheid oor die meganismes wat hier betrokke is, te verkry. Hierdie navorsing is deur die Mediese Navorsingsraad en die Navorsings-ontwikkelingsprogram (Universiteit van Pretoria) befonds.falsefalsefalsePublishedPublishedPublishedSouth AfricaSouth AfricaSouth Afric

Accommodation and vergence response gains to different near cues characterize specific esotropias

Aim. To describe preliminary findings of how the profile of the use of blur, disparity and proximal cues varies between non-strabismic groups and those with different types of esotropia. Design. Case control study Methodology. A remote haploscopic photorefractor measured simultaneous convergence and accommodation to a range of targets containing all combinations of binocular disparity, blur and proximal (looming) cues. 13 constant esotropes, 16 fully accommodative esotropes, and 8 convergence excess esotropes were compared with age and refractive error matched controls, and 27 young adult emmetropic controls. All wore full refractive correction if not emmetropic. Response AC/A and CA/C ratios were also assessed. Results. Cue use differed between the groups. Even esotropes with constant suppression and no binocular vision (BV) responded to disparity in cues. The constant esotropes with weak BV showed trends for more stable responses and better vergence and accommodation than those without any BV. The accommodative esotropes made less use of disparity cues to drive accommodation (p=0.04) and more use of blur to drive vergence (p=0.008) than controls. All esotropic groups failed to show the strong bias for better responses to disparity cues found in the controls, with convergence excess esotropes favoring blur cues. AC/A and CA/C ratios existed in an inverse relationship in the different groups. Accommodative lag of >1.0D at 33cm was common (46%) in the pooled esotropia groups compared with 11% in typical children (p=0.05). Conclusion. Esotropic children use near cues differently from matched non-esotropic children in ways characteristic to their deviations. Relatively higher weighting for blur cues was found in accommodative esotropia compared to matched controls

Two-step stabilization of orbital order and the dynamical frustration of spin in the model charge-transfer insulator KCuF3

We report a combined experimental and theoretical study of KCuF3, which offers - because of this material's relatively simple lattice structure and valence configuration (d9, i.e., one hole in the d-shell) - a particularly clear view of the essential role of the orbital degree of freedom in governing the dynamical coupling between the spin and lattice degrees of freedom. We present Raman and x-ray scattering evidence that the phase behaviour of KCuF3 is dominated above the Neel temperature (T_N = 40 K) by coupled orbital/lattice fluctuations that are likely associated with rotations of the CuF6 octahedra, and we show that these orbital fluctuations are interrupted by a static structural distortion that occurs just above T_N. A detailed model of the orbital and magnetic phases of KCuF3 reveals that these orbital fluctuations - and the related frustration of in-plane spin-order-are associated with the presence of nearly degenerate low-energy spin-orbital states that are highly susceptible to thermal fluctuations over a wide range of temperatures. A striking implication of these results is that the ground state of KCuF3 at ambient pressure lies near a quantum critical point associated with an orbital/spin liquid phase that is obscured by emergent Neel ordering of the spins; this exotic liquid phase might be accessible via pressure studies.Comment: 13 pages, 3 figure

Mycobacterium tuberculosis ClpP Proteases Are Co-transcribed but Exhibit Different Substrate Specificities

PMCID: PMC3613350This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Platelets Boost Recruitment of CD133+ Bone Marrow Stem Cells to Endothelium and the Rodent Liver-The Role of P-Selectin/PSGL-1 Interactions

Lehwald N, Duhme C, Pinchuk I, et al. Platelets Boost Recruitment of CD133+ Bone Marrow Stem Cells to Endothelium and the Rodent Liver-The Role of P-Selectin/PSGL-1 Interactions. International journal of molecular sciences. 2020;21(17): 6431.We previously demonstrated that clinical administration of mobilized CD133+ bone marrow stem cells (BMSC) accelerates hepatic regeneration. Here, we investigated the potential of platelets to modulate CD133+BMSC homing to hepatic endothelial cells and sequestration to warm ischemic livers. Modulatory effects of platelets on the adhesion of CD133+BMSC to human and mouse liver-sinusoidal- and micro- endothelial cells (EC) respectively were evaluated in in vitro co-culture systems. CD133+BMSC adhesion to all types of EC were increased in the presence of platelets under shear stress. This platelet effect was mostly diminished by antagonization of P-selectin and its ligand P-Selectin-Glyco-Ligand-1 (PSGL-1). Inhibition of PECAM-1 as well as SDF-1 receptor CXCR4 had no such effect. In a model of the isolated reperfused rat liver subsequent to warm ischemia, the co-infusion of platelets augmented CD133+BMSC homing to the injured liver with heightened transmigration towards the extra sinusoidal space when compared to perfusion conditions without platelets. Extravascular co-localization of CD133+BMSC with hepatocytes was confirmed by confocal microscopy. We demonstrated an enhancing effect of platelets on CD133+BMSC homing to and transmigrating along hepatic EC putatively depending on PSGL-1 and P-selectin. Our insights suggest a new mechanism of platelets to augment stem cell dependent hepatic repair

The concentration of three anti-seizure medications in hair: the effects of hair color, controlling for dose and age

BACKGROUND: This paper assess the relationship between the quantity of three anti-seizure medications in hair and the color of the analyzed hair, while controlling for the effects of dose, dose duration, and patient age for 140 clinical patients undergoing anti-seizure therapy. Three drugs are assessed: carbamazepine (40 patients), valproic acid (40 patients), and phenytoin (60 patients). The relationship between hair assay results, hair color, dose, dose duration, and age is modeled using an analysis of covariance. The covariance model posits the hair assay results as the dependent variable, the hair color as the qualitative categorical independent variable, and dose, dose duration, and age as covariates. The null hypothesis assessed is that there is a no relationship between hair color and the quantity of analyte determined by hair assay such that darker colored hair will demonstrate higher concentrations of analyte than lighter colored hair. RESULTS: The analysis reveals that there is a significant relationship between dose and concentration for all hair color categories independent of the other covariates or the categorical independent variable. CONCLUSION: There does not appear to be any relationship between carbamazepine concentration and hair color. There is a weak relationship between hair color and valproic acid concentration, which the data suggest may be mediated by age. There is a significant, moderate relationship between phenytoin concentration and hair color such that darker colored hair has greater concentration values than lighter colored hair

Profiles of physical, emotional and psychosocial wellbeing in the Lothian birth cohort 1936

<p>Abstract</p> <p>Background</p> <p>Physical, emotional, and psychosocial wellbeing are important domains of function. The aims of this study were to explore the existence of separable groups among 70-year olds with scores representing physical function, perceived quality of life, and emotional wellbeing, and to characterise any resulting groups using demographic, personality, cognition, health and lifestyle variables.</p> <p>Methods</p> <p>We used latent class analysis (LCA) to identify possible groups.</p> <p>Results</p> <p>Results suggested there were 5 groups. These included High (n = 515, 47.2% of the sample), Average (n = 417, 38.3%), and Poor Wellbeing (n = 37, 3.4%) groups. The two other groups had contrasting patterns of wellbeing: one group scored relatively well on physical function, but low on emotional wellbeing (Good Fitness/ Low Spirits,n = 60, 5.5%), whereas the other group showed low physical function but relatively well emotional wellbeing (Low Fitness/Good Spirits, n = 62, 5.7%). Salient characteristics that distinguished all the groups included smoking and drinking behaviours, personality, and illness.</p> <p>Conclusions</p> <p>Despite there being some evidence of these groups, the results also support a largely one-dimensional construct of wellbeing in old age—for the domains assessed here—though with some evidence that some individuals have uneven profiles.</p

Attosecond nanoscale near-field sampling

The promise of ultrafast light-field-driven electronic nanocircuits has stimulated the development of the new research field of attosecond nanophysics. An essential prerequisite for advancing this new area is the ability to characterize optical near fields from light interaction with nanostructures, with sub-cycle resolution. Here we experimentally demonstrate attosecond near-field retrieval for a tapered gold nanowire. By comparison of the results to those obtained from noble gas experiments and trajectory simulations, the spectral response of the nanotaper near field arising from laser excitation can be extracted.113023Ysciescopu