Conductive Skin Warming and Hypothermia: An Observational Study

Most surgical patients receiving regional or general anesthesia experience perioperative hypothermia unless effective preventive measures are used. Patient positioning poses a challenge for clinicians using existing technology. The purpose of this study is to describe outcomes of hypothermia after a combination of preoperative and intraoperative conductive skin warming (CSW). This retrospective observational study included 972 adult surgical patients receiving general or neuraxial anesthesia. Clinicians were provided an alternative for perioperative warming, an underbody conductive warming mattress using resistive ink technology (VitaHEAT UB3, VitaHEAT Medical), or the option to use current practice, forced air warming (FAW). The primary study endpoint was temperature on arrival in the postanesthesia care unit. Active warming was provided preoperatively with CSW (81.5%) or FAW (0.6%) and intraoperatively with CSW (61.1%), FAW (21.8%), or both (12.1%). Hypothermia occurred in 3.5% of patients overall and in 16.7% of patients when active warming was not used. When CSW was used preoperatively and intraoperatively, 4.1% of patients became hypothermic. When CSW was used preoperatively and FAW was used intraoperatively, 2.3% of patients became hypothermic. When clinicians used active warming methods based on individual patient needs, nearly all patients (96.5%) remained normothermic.

A somatic GNA11 mutation is associated with extremity capillary malformation and overgrowth

BACKGROUND

Capillary malformation is a cutaneous vascular anomaly that is present at birth, darkens over time, and can cause overgrowth of tissues beneath the stain. The lesion is caused by a somatic activating mutation in GNAQ. In a previous study, we were unable to identify a GNAQ mutation in patients with a capillary malformation involving an overgrown lower extremity. We hypothesized that mutations in GNA11 or GNA14, genes closely related to GNAQ, also may cause capillary malformations.

METHODS

Human capillary malformation tissue obtained from 8 patients that had tested negative for GNAQ mutations were studied. Lesions involved an extremity (n = 7) or trunk (n = 1). Droplet digital PCR (ddPCR) was used to detect GNA11 or GNA14 mutant cells (p.Arg183) in the specimens. Single molecule molecular inversion probe sequencing (smMIP-seq) was performed to search for other mutations in GNA11. Mutations were validated by subcloning and sequencing amplimers.

RESULTS

We found a somatic GNA11 missense mutation (c.547C > T; p.Arg183Cys) in 3 patients with a diffuse capillary malformation of an extremity. Mutant allelic frequencies ranged from 0.3 to 5.0%. GNA11 or GNA14 mutations were not found in 5 affected tissues or in unaffected tissues (white blood cell DNA).

CONCULSIONS

GNA11 mutations are associated with extremity capillary malformations causing overgrowth. Pharmacotherapy that affects GNA11 signaling may prevent the progression of capillary malformations.

Degradation of oil by fungi isolated from Gulf of Mexico beaches

Fungi of the Ascomycota phylum were isolated from oil-soaked sand patties collected from beaches following the Deepwater Horizon oil spill. To examine their ability to degrade oil, fungal isolates were grown on oiled quartz at 20°C, 30°C and 40°C. Consistent trends in oil degradation were not related to fungal species or temperature and all isolates degraded variable quantities of oil (32-65%). Fungal isolates preferentially degraded short (<C18; 90-99%) as opposed to long (C19-C36; 7-87%) chain n-alkanes and straight chain C17- and C18-n-alkanes (91-99%) compared to their branched counterparts, pristane and phytane (70-98%). Polycyclic aromatic hydrocarbon (PAH) compounds were also degraded by the fungal isolates (42-84% total degraded), with a preference for low molecular weight over high molecular weight PAHs. Overall, these findings contribute to our understanding of the capacity of fungi to degrade oil in the coastal marine environment.

SLP-76 couples Syk to the osteoclast cytoskeleton

The capacity of the osteoclast (OC) to resorb bone is dictated by cytoskeletal organization, which in turn emanates from signals derived from the alpha(v)beta(3) integrin and c-Fms. Syk is key to these signals and, in other cells, this tyrosine kinase exerts its effects via intermediaries including the SLP adaptors, SLP-76 and BLNK (B cell linker). Thus, we asked whether these two SLP proteins regulate OC function. We find BLNK-deficient OCs are normal, whereas cytoskeletal organization of those lacking SLP-76 is delayed, thus modestly reducing bone resorption in vitro. Cytoskeletal organization and bone resorption are more profoundly arrested in cultured OCs deficient in BLNK and SLP-76 double knockout (DKO) phenotypes. In contrast, stimulated bone resorption in vivo is inhibited approximately 40% in either SLP-76(-/-) or DKO mice. This observation, taken with the fact that DKO OCs are rescued by retroviral transduction of only SLP-76, indicates that SLP-76 is the dominant SLP family member in the resorptive process. We also find SLP-76 is phosphorylated in a Syk-dependent manner. Furthermore, in the absence of the adaptor protein, integrin-mediated phosphorylation of Vav3, the OC cytoskeleton-organizing guanine nucleotide exchange factor, is abrogated. In keeping with a central role of SLP-76/Vav3 association in osteoclastic resorption, retroviral transduction of SLP-76, in which the Vav binding site is disrupted (3YF), fails to normalize the cytoskeleton of DKO OCs and the resorptive capacity of the cells. Finally, c-Fms-activated Syk also exerts its OC cytoskeleton-organizing effect in a SLP-76/Vav3-dependent manner.

Syk tyrosine 317 negatively regulates osteoclast function via the ubiquitin-protein isopeptide ligase activity of Cbl

Cytoskeletal organization of the osteoclast (OC), which is central to the capacity of the cell to resorb bone, is induced by occupancy of the alphavbeta3 integrin or the macrophage colony-stimulating factor (M-CSF) receptor c-Fms. In both circumstances, the tyrosine kinase Syk is an essential signaling intermediary. We demonstrate that Cbl negatively regulates OC function by interacting with Syk(Y317). Expression of nonphosphorylatable Syk(Y317F) in primary Syk(-/-) OCs enhances M-CSF- and alphavbeta3-induced phosphorylation of the cytoskeleton-organizing molecules, SLP76, Vav3, and PLCgamma2, to levels greater than wild type, thereby accelerating the resorptive capacity of the cell. Syk(Y317) suppresses cytoskeletal organization and function while binding the ubiquitin-protein isopeptide ligase Cbl. Consequently, Syk(Y317F) abolishes M-CSF- and integrin-stimulated Syk ubiquitination. Thus, Cbl/Syk(Y317) association negatively regulates OC function and therefore is essential for maintenance of skeletal homeostasis.

Revisiting depression in palliative care settings: the need to focus on clinical utility over validity

OBJECTIVE

To review the literature on depression in palliative care patients to identify implications for development of clinical practice and individual patient care.

METHOD

A qualitative review of depression prevalence studies in palliative care settings. We explore the utility of existing prevalence studies for clinical practice through testing two hypotheses: that high prevalence rates are associated with increased risk factors in study samples, and that poor methodological quality of the studies artefactually inflate prevalence estimates. Eighteen studies were identified in the search and included in this review.

RESULTS

Risk factors may contribute to depression prevalence but through a complex interaction of factors making individual risk levels hard to determine. Measurement artefact cannot, alone, account for elevated levels of depression in this population but may contribute to imprecision. The importance of organic decline as a potential confounding variable is highlighted.

CONCLUSION

Future research into the causes and prevalence of depression should adopt longitudinal approaches using large samples, and consider the impact of organic disorder as an important confounding factor. Clinical practice and care of individual patients may be better supported by development of a prognostic index considering the predictive power of depressive symptoms and risk factors on well-being.

Macrovascular thrombosis is driven by tissue factor derived primarily from the blood vessel wall

Leukocytes and leukocyte-derived microparticles contain low levels of tissue factor (TF) and incorporate into forming thrombi. Although this circulating pool of TF has been proposed to play a key role in thrombosis, its functional significance relative to that of vascular wall TF is poorly defined. We tested the hypothesis that leukocyte-derived TF contributes to thrombus formation in vivo. Compared to wild-type mice, mice with severe TF deficiency (ie, TF–/–, hTF-Tg+, or “low-TF”) demonstrated markedly impaired thrombus formation after carotid artery injury or inferior vena cava ligation. A bone marrow transplantation strategy was used to modulate levels of leukocyte-derived TF. Transplantation of low-TF marrow into wild-type mice did not suppress arterial or venous thrombus formation. Similarly, transplantation of wild-type marrow into low-TF mice did not accelerate thrombosis. In vitro analyses revealed that TF activity in the blood was very low and was markedly exceeded by that present in the vessel wall. Therefore, our results suggest that thrombus formation in the arterial and venous macrovasculature is driven primarily by TF derived from the blood vessel wall as opposed to leukocytes.

Murine thrombosis models

Due to exciting advances in molecular biology, the laboratory mouse has become an important and frequently used model for studying thrombosis. This article reviews several experimental approaches that have been used to study arterial, venous, and microvascular thrombosis in mice. The advantages and limitations of different models are examined. Related topics of mouse anesthesia, phlebotomy, and in vitro hemostasis testing are also reviewed.

Effect of stocking rate, time of lambing and inclusion of lucerne on prime lamb production in north-east Victoria

Results of a grazing study involving Border Leicester x Merino ewes and their progeny are reported for a 4-year period 1969 to 1972. The study was conducted at Rutherglen in north-east Victoria. The 1260 ewes observed throughout the study were allotted to 42 treatment plots with 30 ewes per plot. Thirty of the plots were located on annual pasture (subterranean clover, barley grass) involving three replicates of ewes stocked at 7.4,9.9 and 12.4 ewes ha-l for ewes joined over 7-week periods to commence lambing about May 5, June 23 or August 8. Additionally, an extra three plots with spring lambing were grazed at 14.8 ewes ha-1. A further 12 plots contained lucerne on one third of the plot area. The ewes on these plots also lambed for a 7-week period commencing August 8, and provided three replicates of 7.4 9.9, 12.4 and 14.8 ewes ha-1. First services were concentrated early in the joining period in the spring-lambing ewes, there were few returns to services and few ewes failed to mate. On the other hand, among ewes joined to lamb in autumn, first services were distributed over the entire joining period, and many ewes returned to service or failed to mate. The mating pattern of ewes joined to lamb in winter were intermediate between the autumn and spring lambing groups. Although the liveweight of spring-lambing ewes was lighter at mating, the number of lambs born per 100 ewes joined was greater than for winter lambing, and these in turn were greater than for autumn lambing ewes. The response to an additional 1 kg liveweight at mating was 1.7, 2.0 and 2.8 additional lambs born per 100 ewes joined for autumn, winter and spring lambing, respectively. Wool production per hectare increased linearly with increase in stocking rate; it was marginally affected by time of lambing and was greatest where lucerne was provided. The number of lambs reared per ha increased linearly with increase in stocking rate, albeit there was some decline in carcase weight and a small decline in numbers of lambs reared per ewe. Lambs born in autumn and winter were generally slaughtered in prime condition at 31 kg liveweight, except in the drought year of 1972, but more lambs were produced from a winter lambing than from autumn lambing. When lambing was in August-September there was a slight increase in the numbers of lambs reared above that of winter lambing, but the proportion of lambs marketed at less than 31 kg was greatly increased. Where lucerne was provided to spring-lambing ewes the greatest weight of meat per hectare was produced, and few lambs were less than 31 kg. In descending order of magnitude, the major factors affecting carrying capacity were season, year, stocking rate and time of lambing. Seasonal shortcomings in nutrition were alleviated by the provision of supplementary feed. At the lighter stocking rates of 7.4 and 9.9 ewes ha-1 the amounts of supplements fed were very low, even in the drought year of 1972. These two lowest stocking rates could be maintained indefinitely without excessive use of supplementary feed. Discernible changes in botanical composition with partial loss of productive grass and clover species, reduction in pasture growth rate, increased use of supplementary feed and lowered wool production of ewes, occurred with spring lambing without lucerne, particularly at 12.4 and 14.8 ewes ha-1. Pasture composition and growth details were very similar with either autumn or winter lambing.

Effect of different levels of the supplements lupin grain, lucerne, wheat, and wheat with urea and sulphur fed during mating in February to Border Leicester x Merino ewes in north-east Victoria

The use of supplements for four weeks beginning one week before joining from February 7 to April 1 was examined in an attempt to increase lambing rates. Four supplements (lupin grain, freshly cut lucerne, wheat, and wheat with 3% urea and sulphur) were fed at four rates (0, 0.1 7, 0.34, and 0.51 kg day-1/ewe) to a flock of 1200 maiden Border Leicester x Merino ewes grazing annual pasture at the Rutherglen Research Station in north-eastern Victoria. For every 0.2 kg of lupin fed per day the liveweights, ovulation rate and lambing rate of ewes increased by 1 kg, 0.06 and 0.03 per ewe joined, respectively. The mean increase in wool growth for ewes fed lupins, wheat, and wheat with urea and sulphur was 39, 26 and 37%, respectively. Feeding of lucerne did not affect any attributes measured. The intake of supplement by ewes fed wheat based supplements at the higher rates appeared to be more variable between ewes than the intake of the ewes on other treatments. This was indicated by the greater variability in liveweight gain of the ewes fed wheat at the higher rates. Results show that of the supplements used, lupins was the only one which if fed at mating in February, could be expected to substantially improve reproduction.

Effect of lupin grain and recently cut lucerne on intake and digestibility of mature weathered herbage by Border Leicester × Merino ewes

The effect of lupin grain and freshly cut lucerne supplements on the ad libitum intake of mature, weathered herbage (Lolium rigidum and Trifolium subterraneum) by fourteen Border Leicester x Merino ewes was examined. There were seven treatments: in six, each supplement was fed separately at three rates between 190 and 750 g ewe-1 day-1. and in one, no supplement was fed. There were two replicates : one of ewes with high, and the other with low, ad libitum intake. Treatments were imposed for three weeks, and for analysis, data for an individual ewe were related to data collected during two periods of three weeks before and after the experimental period. Apparent digestibilities of DM of herbage, lucerne, and lupins were 50, 60 and 88%, respectively, and were not affected by different rates of supplement fed. Ad libitum intake of herbage at 0 and 200 g ewe-l day-1 of supplement intake was similar. At supplements above 200 g ewe-1 day-1, intake of herbage decreased by 40 and 61 g DM for each 100 g DM increase in supplement consumed by high and low intake ewes, respectively. Liveweights increased by 100 g for every 250 g DM of supplement consumed. It was concluded that the effect of feeding ewes lupin grain on consumption and digestion of roughage was unlikely, by itself, to be responsible for improvements in reproduction observed in ewes fed a supplement of lupin grain.