Association of intraosseous and intravenous access with patient outcome in out-of-hospital cardiac arrest.

Here we report the results of a study on the association between drug delivery via intravenous route or intraosseous route in out-of-hospital cardiac arrest. Intraosseous drug delivery is considered an alternative option in resuscitation if intravenous access is difficult or impossible. Intraosseous uptake of drugs may, however, be compromised. We have performed a retrospective cohort study of all Danish patients with out-of-hospital cardiac arrest in the years 2016-2020 to investigate whether mortality is associated with the route of drug delivery. Outcome was 30-day mortality, death at the scene, no prehospital return of spontaneous circulation, and 7- and 90-days mortality. 17,250 patients had out-of-hospital cardiac arrest. 6243 patients received no treatment and were excluded. 1908 patients had sustained return of spontaneous circulation before access to the vascular bed was obtained. 2061 patients were unidentified, and 286 cases were erroneously registered. Thus, this report consist of results from 6752 patients. Drug delivery by intraosseous route is associated with increased OR of: No spontaneous circulation at any time (OR 1.51), Death at 7 days (OR 1.94), 30 days (2.02), and 90 days (OR 2.29). Intraosseous drug delivery in out-of-hospital cardiac arrest is associated with overall poorer outcomes than intravenous drug delivery.

Prehospital tracheal intubations by anaesthetist-staffed critical care teams: a prospective observational multicentre study.

BACKGROUND: Prehospital tracheal intubation is a potentially lifesaving intervention, but is associated with prolonged time on-scene. Some services strongly advocate performing the procedure outside of the ambulance or aircraft, while others also perform the procedure inside the vehicle. This study was designed as a non-inferiority trial registering the rate of successful tracheal intubation and incidence of complications performed by a critical care team either inside or outside an ambulance or helicopter. METHODS: This observational multicentre study was performed between March 2020 and September 2021 and involved 12 anaesthetist-staffed critical care teams providing emergency medical services by helicopter in Denmark, Norway, and Sweden. The primary outcome was first-pass successful tracheal intubations. RESULTS: Of the 422 drug-assisted tracheal intubations examined, 240 (57%) took place in the cabin of the ambulance or helicopter. The rate of first-pass success was 89.2% for intubations in-cabin vs 86.3% outside. This difference of 2.9% (confidence interval -2.4% to 8.2%) (two sided 10%, including 0, but not the non-inferiority limit Δ=-4.5) fulfils our criteria for non-inferiority, but not significant superiority. These results withstand after performing a propensity score analysis. The mean on-scene time associated with the helicopter in-cabin procedures (27 min) was significantly shorter than for outside the cabin (32 min, P=0.004). CONCLUSIONS: Both in-cabin and outside the cabin, prehospital tracheal intubation by anaesthetists was performed with a high success rate. The mean on-scene time was shorter in the in-cabin helicopter cohort. CLINICAL TRIAL REGISTRATION: NCT04206566.

Percutaneous Renal Tumor Cryoablation Effect on Renal Function.

Background: Percutaneous cryoablation (PCA) of renal tumors is a well-established alternative to partial nephrectomy, but the effects on renal function after the procedure are not well-documented. The purpose of this study was to evaluate renal function after computed tomography-guided PCA. Materials and Methods: A retrospective cohort study including 259 patients treated with PCA at Odense University Hospital, Denmark from January 1, 2015 to December 31, 2019. Both patients with malignant (96%) and benign tumors (4%) were included. Mean age of patients was 66.5 years (standard deviation [SD] = 10.9, range: 27-91) and 174 (67%) patients were men. Baseline estimated glomerular filtration rate (eGFR) was recorded at baseline and 12 months after cryoablation. Results: Mean tumor size was 27.5 mm (SD = 10.0) distributed in seven different histopathological types, mainly clear cell renal-cell carcinoma (RCC) (64%) and papillary RCC (22%). Mean eGFR at baseline was 73.7 mL/min/1.73 m2 (SD = 23.2) with a follow-up mean eGFR of 69.7 (SD = 23.7) (p < 0.0001). At baseline before intervention 190 patients (73%) had eGFR matching chronic kidney disease (CKD) groups 1 and 2 (normal to mild CKD), 64 patients (24%) matching CKD group 3 (average CKD), and 1% in groups 4 and 5. At 12-month follow-up, 171 patients (66%) had eGFR matching CKD groups 1 and 2, 77 patients (30%) matching CKD group 3 and 11 patients (4%) matching CKD groups 4 and 5. In patients with skewed renography who had PCA in the kidney with better excretion, eGFR at baseline was 64.7 and 61.2 at follow-up (p = 0.703). Conclusions: This study showed minimal decline in renal function 12 months after PCA, even for patients with reduced renal function. PCA is therefore considered a safe and relevant intervention.

Genetic analysis of global faba bean diversity, agronomic traits and selection signatures.

KEY MESSAGE: We identified marker-trait associations for key faba bean agronomic traits and genomic signatures of selection within a global germplasm collection. Faba bean (Vicia faba L.) is a high-protein grain legume crop with great potential for sustainable protein production. However, little is known about the genetics underlying trait diversity. In this study, we used 21,345 high-quality SNP markers to genetically characterize 2678 faba bean genotypes. We performed genome-wide association studies of key agronomic traits using a seven-parent-MAGIC population and detected 238 significant marker-trait associations linked to 12 traits of agronomic importance. Sixty-five of these were stable across multiple environments. Using a non-redundant diversity panel of 685 accessions from 52 countries, we identified three subpopulations differentiated by geographical origin and 33 genomic regions subjected to strong diversifying selection between subpopulations. We found that SNP markers associated with the differentiation of northern and southern accessions explained a significant proportion of agronomic trait variance in the seven-parent-MAGIC population, suggesting that some of these traits were targets of selection during breeding. Our findings point to genomic regions associated with important agronomic traits and selection, facilitating faba bean genomics-based breeding.

[Neonatal death due to congenital transmesenteric hernia].

Transmesenteric hernia (TMH) is a rare cause of small bowel obstruction. If left untreated, mortality rates are high. In this case report, the authors describe a case of TMH in a preterm neonate born at gestational age 36 + 1 with abdominal distention, subumbilical discolouration and difficulty breathing at birth. The neonate died shortly post-partum due to respiratory failure. Subsequent autopsy showed TMH with small bowel obstruction, distention, and necrosis. High-standing diaphragm with small lungs was the cause of death.

Expression of acyl-CoA-binding protein 5 from Rhodnius prolixus and its inhibition by RNA interference.

The acyl-CoA-binding proteins (ACBP) act by regulating the availability of acyl-CoA in the cytoplasm and must have essential functions in lipid metabolism. The genome of the kissing-bug Rhodnius prolixus encodes five proteins of this family, but little is known about them. In this study we investigated the expression and function of RpACBP-5. Feeding induced RpACBP-5 gene expression in the posterior midgut, and an increase of about four times was observed two days after the blood meal. However, the amount of protein, which was only detected in this organ, did not change during digestion. The RpACBP-5 gene was also highly expressed in pre-vitellogenic and vitellogenic oocytes. Recombinant RpACBP-5 was shown to bind to acyl-CoA of different lengths, and it exhibited nanomolar affinity to lauroyl-CoA in an isothermal titration assay, indicating that RpACBP-5 is a functional ACBP. RpACBP-5 knockdown by RNA interference did not affect digestion, egg laying and hatching, survival, or accumulation of triacylglycerol in the fat body and oocytes. Similarly, double knockdown of RpACBP-1 and RpACBP-5 did not alter egg laying and hatching, survival, accumulation of triacylglycerol in the fat body and oocytes, or the neutral lipid composition of the posterior midgut or hemolymph. These results show that RpACBP-5 is a functional ACBP but indicate that the lack of a detectable phenotype in the knockdown insects may be a consequence of functional overlap of the proteins of the ACBP family found in the insect.

Surgical treatment of disabling conditions caused by anogenital lichen sclerosus in women: An account of surgical procedures and results, including patient satisfaction, benefits, and improvements in health-related quality of life.

BACKGROUND: Anogenital lichen sclerosus (LS), a chronic dermatitis that causes scarring and introital stenosis, may prevent sexual intercourse and reduce health-related quality of life (QoL). Surgery can restore the anatomy, allowing patients to resume their sexual lives. This study investigates outcomes in women treated with local skin flaps. METHODS: Thirty-eight consecutive LS-verified patients, surgically treated for debilitating conditions between 1990 and 2013, were retrospectively evaluated. A survey measured patient satisfaction, benefits, and health-related QoL, and the patients were also evaluated by a long-term clinical follow-up. RESULTS: In total, 33 patients (87%) experienced dyspareunia, 24 of whom could not perform coitus. At mean short-term follow-up (10.0 months), only five patients (15%) reported dyspareunia; for seven patients, the outcome was unknown. The survey response rate was 87%, and the mean time from treatment to response was 7.6 years. Twenty of 24 patients reported dyspareunia. Seventy-five percent of patients with preoperative dyspareunia reported a surgical benefit, 74% were satisfied/very satisfied with the cosmetic and overall results, respectively, and 58% reported that surgery had improved their sexual lives. The mean long-term clinical follow-up was 8.4 years. The follow-up rate was 78%. The main reason for recurrent dyspareunia was minor LS relapse (50%); these patients were still able to have coitus, and dyspareunia was reported as considerably minor compared to before surgery; 38% had more severe LS relapse, resulting in apareunia. CONCLUSIONS: Surgery for LS sequelae provides acceptable short-term functional results, enabling patients to resume coitus, with high patient satisfaction reported. However, the chronic relapsing nature of LS consequently provides varying and often short-term coital improvements following surgery.

The ACBP gene family in Rhodnius prolixus: Expression, characterization and function of RpACBP-1.

The acyl-CoA-binding proteins (ACBP) constitute a family of conserved proteins that bind acyl-CoA with high affinity and protect it from hydrolysis. Thus, ACBPs may have essential roles in basal cellular lipid metabolism. The genome of the insect Rhodnius prolixus encodes five ACBP genes similar to those described for other insect species. The qPCR analysis revealed that these genes have characteristic expression profiles in insect organs, suggesting that they have specific roles in insect physiology. Recombinant RpACBP-1 was able to bind acyl-CoA in an in vitro gel-shift assay. Moreover, heterologous RpACBP-1 expression in acb1Δ mutant yeast rescued the multi-lobed vacuole phenotype, indicating that RpACBP-1 acts as a bona fide acyl-CoA-binding protein. RpACBP-1 knockdown using RNAi caused triacylglycerol accumulation in the insect posterior midgut and a reduction in the number of deposited eggs. The amount of stored triacylglycerol was reduced in flight muscle, and the incorporation of fatty acids in cholesteryl esters was increased in the fat body. These results showed that RpACBP-1 participates in several lipid metabolism steps in R. prolixus.

Characterization of yeast mutants lacking alkaline ceramidases YPC1 and YDC1.

Humans and yeast possess alkaline ceramidases located in the early secretory pathway. Single deletions of the highly homologous yeast alkaline ceramidases YPC1 and YDC1 have very little genetic interactions or phenotypes. Here, we performed chemical-genetic screens to find deletions/conditions that would alter the growth of ypc1∆ydc1∆ double mutants. These screens were essentially negative, demonstrating that ceramidase activity is not required for cell growth even under genetic stresses. A previously reported protein targeting defect of ypc1∆ could not be reproduced and reported abnormalities in sphingolipid biosynthesis detected by metabolic labeling do not alter the mass spectrometric lipid profile of ypc1∆ydc1∆ cells. Ceramides of ypc1∆ydc1∆ remained normal even in presence of aureobasidin A, an inhibitor of inositolphosphorylceramide synthase. Moreover, in caloric restriction conditions Ypc1p reduces chronological life span. A novel finding is that, when working backwards as a ceramide synthase in vivo, Ypc1p prefers C24 and C26 fatty acids as substrates, whereas it prefers C16:0, when solubilized in detergent and working in vitro. Therefore, its physiological activity may not only concern the minor ceramides containing C14 and C16. Intriguingly, so far the sole discernable benefit of conserving YPC1 for yeast resides with its ability to convey relative resistance toward H2O2.

Unsaturated glycerophospholipids mediate heme crystallization: biological implications for hemozoin formation in the kissing bug Rhodnius prolixus.

Hemozoin (Hz) is a heme crystal produced by some blood-feeding organisms, as an efficient way to detoxify heme derived from hemoglobin digestion. In the triatomine insect Rhodnius prolixus, Hz is essentially produced by midgut extracellular phospholipid membranes known as perimicrovillar membranes (PMVM). Here, we investigated the role of commercial glycerophospholipids containing serine, choline and ethanolamine as headgroups and R. prolixus midgut lipids (RML) in heme crystallization. All commercial unsaturated forms of phospholipids, as well as RML, mediated fast and efficient ß-hematin formation by means of two kinetically distinct mechanisms: an early and fast component, followed by a late and slow one. The fastest reactions observed were induced by unsaturated forms of phosphatidylethanolamine (uPE) and phosphatidylcholine (uPC), with half-lives of 0.04 and 0.7 minutes, respectively. ß-hematin crystal morphologies were strikingly distinct among groups, with uPE producing homogeneous regular brick-shaped crystals. Interestingly, uPC-mediated reactions resulted in two morphologically distinct crystal populations: one less representative group of regular crystals, resembling those induced by uPE, and the other largely represented by crystals with numerous sharp edges and tapered ends. Heme crystallization reactions induced by RML were efficient, with a heme to ß-hematin conversion rate higher than 70%, but clearly slower (t1/2 of 9.9-17.7 minutes) than those induced by uPC and uPE. Interestingly, crystals produced by RML were homogeneous in shape and quite similar to those mediated by uPE. Thus, ß-hematin formation can be rapidly and efficiently induced by unsaturated glycerophospholipids, particularly uPE and uPC, and may play a role on biological heme crystallization in R. prolixus midgut.

Profiling of lipid species by normal-phase liquid chromatography, nanoelectrospray ionization, and ion trap-orbitrap mass spectrometry.

Detailed analysis of lipid species can be challenging due to their structural diversity and wide concentration range in cells, tissues, and biofluids. To address these analytical challenges, we devised a reproducible, sensitive, and integrated lipidomics workflow based on normal-phase liquid chromatography-Fourier transform mass spectrometry (LC-FTMS) and LC-ITMS(2) (ion trap tandem mass spectrometry) for profiling and structural analysis of lipid species. The workflow uses a normal-phase LC system for efficient separation of apolar and polar lipid species combined with sensitive and specific analysis powered by a chip-based nanoelectrospray ion source and a hybrid ion trap-orbitrap mass spectrometer. The workflow was executed using a primary LC-FTMS survey routine for identification and profiling of lipid species based on high-mass accuracy and retention time followed by a targeted LC-ITMS(2) routine for characterizing the fatty acid moieties of identified lipid species. We benchmarked the performance of the workflow by characterizing the chromatographic properties of the LC-MS system for general lipid analysis. In addition, we demonstrate the efficacy of the workflow by reporting a study of low-abundant triacylglycerol and ceramide species in mouse brain cerebellum and 3T3-L1 adipocytes, respectively. The workflow described here is generic and can be extended for detailed lipid analysis of sample matrices having a wide range of lipid compositions.

Compositional and structural characterization of monolayers and bilayers composed of native pulmonary surfactant from wild type mice.

This work comprises a structural and dynamical study of monolayers and bilayers composed of native pulmonary surfactant from mice. Spatially resolved information was obtained using fluorescence (confocal, wide field and two photon excitation) and atomic force microscopy methods. Lipid mass spectrometry experiments were also performed in order to obtain relevant information on the lipid composition of this material. Bilayers composed of mice pulmonary surfactant showed coexistence of distinct domains at room temperature, with morphologies and lateral packing resembling the coexistence of liquid ordered (lo)/liquid disordered (ld)-like phases reported previously in porcine lung surfactant. Interestingly, the molar ratio of saturated (mostly DPPC)/non-saturated phospholipid species and cholesterol measured in the innate material corresponds with that of a DOPC/DPPC/cholesterol mixture showing lo/ld phase coexistence at a similar temperature. This suggests that at quasi-equilibrium conditions, key lipid classes in this complex biological material are still able to produce the same scaffold observed in relevant but simpler model lipid mixtures. Also, robust structural and dynamical similarities between mono- and bi-layers composed of mice pulmonary surfactant were observed when the monolayers reach a surface pressure of 30mN/m. This value is in line with theoretically predicted and recently measured surface pressures, where the monolayer-bilayer equivalence occurs in samples composed of single phospholipids. Finally, squeezed out material attached to pulmonary surfactant monolayers was observed at surface pressures near the beginning of the monolayer reversible exclusion plateau (~40mN/m). Under these conditions this material adopts elongated tubular shapes and displays ordered lateral packing as indicated by spatially resolved LAURDAN GP measurements.

Compromised mitochondrial fatty acid synthesis in transgenic mice results in defective protein lipoylation and energy disequilibrium.

A mouse model with compromised mitochondrial fatty acid synthesis has been engineered in order to assess the role of this pathway in mitochondrial function and overall health. Reduction in the expression of mitochondrial malonyl CoA-acyl carrier protein transacylase, a key enzyme in the pathway encoded by the nuclear Mcat gene, was achieved to varying extents in all examined tissues employing tamoxifen-inducible Cre-lox technology. Although affected mice consumed more food than control animals, they failed to gain weight, were less physically active, suffered from loss of white adipose tissue, reduced muscle strength, kyphosis, alopecia, hypothermia and shortened lifespan. The Mcat-deficient phenotype is attributed primarily to reduced synthesis, in several tissues, of the octanoyl precursors required for the posttranslational lipoylation of pyruvate and α-ketoglutarate dehydrogenase complexes, resulting in diminished capacity of the citric acid cycle and disruption of energy metabolism. The presence of an alternative lipoylation pathway that utilizes exogenous free lipoate appears restricted to liver and alone is insufficient for preservation of normal energy metabolism. Thus, de novo synthesis of precursors for the protein lipoylation pathway plays a vital role in maintenance of mitochondrial function and overall vigor.

The acyl-CoA binding protein is required for normal epidermal barrier function in mice.

The acyl-CoA binding protein (ACBP) is a 10 kDa intracellular protein expressed in all eukaryotic species. Mice with targeted disruption of Acbp (ACBP(-/-) mice) are viable and fertile but present a visible skin and fur phenotype characterized by greasy fur and development of alopecia and scaling with age. Morphology and development of skin and appendages are normal in ACBP(-/-) mice; however, the stratum corneum display altered biophysical properties with reduced proton activity and decreased water content. Mass spectrometry analyses of lipids from epidermis and stratum corneum of ACBP(+/+) and ACBP(-/-) mice showed very similar composition, except for a significant and specific decrease in the very long chain free fatty acids (VLC-FFA) in stratum corneum of ACBP(-/-) mice. This finding indicates that ACBP is critically involved in the processes that lead to production of stratum corneum VLC-FFAs via complex phospholipids in the lamellar bodies. Importantly, we show that ACBP(-/-) mice display a ∼50% increased transepidermal water loss compared with ACBP(+/+) mice. Furthermore, skin and fur sebum monoalkyl diacylglycerol (MADAG) levels are significantly increased, suggesting that ACBP limits MADAG synthesis in sebaceous glands. In summary, our study shows that ACBP is required for production of VLC-FFA for stratum corneum and for maintaining normal epidermal barrier function.

(1aR,5aR)1a,3,5,5a-Tetrahydro-1H-2,3-diaza-cyclopropa[a]pentalene-4-carboxylic acid (MK-1903): a potent GPR109a agonist that lowers free fatty acids in humans.

G-protein coupled receptor (GPCR) GPR109a is a molecular target for nicotinic acid and is expressed in adipocytes, spleen, and immune cells. Nicotinic acid has long been used for the treatment of dyslipidemia due to its capacity to positively affect serum lipids to a greater extent than other currently marketed drugs. We report a series of tricyclic pyrazole carboxylic acids that are potent and selective agonists of GPR109a. Compound R,R-19a (MK-1903) was advanced through preclinical studies, was well tolerated, and presented no apparent safety concerns. Compound R,R-19a was advanced into a phase 1 clinical trial and produced a robust decrease in plasma free fatty acids. On the basis of these results, R,R-19a was evaluated in a phase 2 study in humans. Because R,R-19a produced only a weak effect on serum lipids as compared with niacin, we conclude that the beneficial effects of niacin are most likely the result of an undefined GPR109a independent pathway.

Distinct roles of two ceramide synthases, CaLag1p and CaLac1p, in the morphogenesis of Candida albicans.

Lag1p and Lac1p catalyse ceramide synthesis in Saccharomyces cerevisiae. This study shows that Lag1 family proteins are generally required for polarized growth in hemiascomycetous yeast. However, in contrast to S. cerevisiae where these proteins are functionally redundant, C. albicans Lag1p (CaLag1p) and Lac1p (CaLac1p) are functionally distinct. Lack of CaLag1p, but not CaLac1p, caused severe defects in the growth and hyphal morphogenesis of C. albicans. Deletion of CaLAG1 decreased expression of the hypha-specific HWP1 and ECE1 genes. Moreover, overexpression of CaLAG1 induced pseudohyphal growth in this organism under non-hypha-inducing conditions, suggesting that CaLag1p is necessary for relaying signals to induce hypha-specific gene expression. Analysis of ceramide and sphingolipid composition revealed that CaLag1p predominantly synthesizes ceramides with C24:0/C26:0 fatty acid moieties, which are involved in generating inositol-containing sphingolipids, whereas CaLac1p produces ceramides with C18:0 fatty acid moieties, which are precursors for glucosylsphingolipids. Thus, our study demonstrates that CaLag1p and CaLac1p have distinct substrate specificities and physiological roles in C. albicans.

Quantitative profiling of PE, MMPE, DMPE, and PC lipid species by multiple precursor ion scanning: a tool for monitoring PE metabolism.

We report a method for the simultaneous identification and quantification of phosphatidylethanolamine (PE), monomethyl-phosphatidylethanolamine (MMPE), dimethyl-phosphatidylethanolamine (DMPE), and phosphatidylcholine (PC) species in lipid extracts. The method employs a specific "mass-tag" strategy where DMPE, MMPE, and PE species are chemically methylated with deuterated methyliodide (CD(3)I) to produce PC molecules having class-specific mass offsets of 3, 6 and 9Da, respectively. The derivatized aminoglycerophospholipids release characteristic phosphorylcholine-like fragment ions having specific mass offsets that powers sensitive and quantitative analysis by multiple precursor ion scanning on a hybrid quadrupole time-of-flight mass spectrometer. Using the mass-tag strategy, we could for the first time determine the stoichiometric relationship between the biosynthetic intermediates MMPE and DMPE, and abundant PE and PC species in a single mass spectrometric analysis. We demonstrated the efficacy of the methodology by conducting a series of biochemical experiments using stable isotope labeled ethanolamine to survey the activities and substrate specificities of enzymes involved in PE metabolism in Saccharomyces cerevisiae. Finally, we benchmarked the mass-tag strategy by specific and sensitive profiling of intermediate MMPE and DMPE species in liver.

Recombinant, activated factor VII for surgery in factor VII deficiency: a prospective evaluation - the surgical STER.

Excessive bleeding represents a major complication of surgical interventions and its control is especially relevant in patients with Congenital Bleeding Disorders (CBD). In factor VII (FVII) deficiency, scanty data on surgery is available to guide treatment strategies. The STER (Seven Treatment Evaluation Registry) is a multi-centre, prospective, observational, web-based study protocol providing the frame for a structured and detailed data collection. Inhibitor occurrence was checked in a centralized fashion. Forty-one surgical operations (24 'major' and 17 'minor') were performed in 34 subjects with a carefully characterized FVII deficiency under the coverage of recombinant activated Factor VII (rFVIIa). Bleeding occurred during three major interventions of orthopaedic surgery, but rFVIIa was given at very low dose in each case. An antibody to FVII was observed in one patient who underwent a multiple dental extraction. No thromboses were reported during the 30-d follow up period. Replacement therapy with rFVIIa proved effective when suitable doses were used, which, during the period of maximum bleeding risk (the day of operation), were calculated (Receiver Operated Characteristic analysis) to be of at least 13 µg/kg/body weight per single dose and no less than three administrations. This indication is important especially in the case of major surgery.

Yeast cells lacking all known ceramide synthases continue to make complex sphingolipids and to incorporate ceramides into glycosylphosphatidylinositol (GPI) anchors.

In yeast, the inositolphosphorylceramides mostly contain C26:0 fatty acids. Inositolphosphorylceramides were considered to be important for viability because the inositolphosphorylceramide synthase AUR1 is essential. However, lcb1Δ cells, unable to make sphingoid bases and inositolphosphorylceramides, are viable if they harbor SLC1-1, a gain of function mutation in the 1-acyl-glycerol-3-phosphate acyltransferase SLC1. SLC1-1 allows the incorporation of C26:0 fatty acids into phosphatidylinositol (PI), thus generating PI″, an abnormal, C26-containing PI, presumably acting as surrogate for inositolphosphorylceramide. Here we show that the lethality of the simultaneous deletion of the known ceramide synthases LAG1/LAC1/LIP1 and YPC1/YDC1 can be rescued by the expression of SLC1-1 or the overexpression of AUR1. Moreover, lag1Δ lac1Δ ypc1Δ ydc1Δ (4Δ) quadruple mutants have been reported to be viable in certain genetic backgrounds but to still make some abnormal uncharacterized inositol-containing sphingolipids. Indeed, we find that 4Δ quadruple mutants make substantial amounts of unphysiological inositolphosphorylphytosphingosines but that they also still make small amounts of normal inositolphosphorylceramides. Moreover, 4Δ strains incorporate exogenously added sphingoid bases into inositolphosphorylceramides, indicating that these cells still possess an unknown pathway allowing the synthesis of ceramides. 4Δ cells also still add quite normal amounts of ceramides to glycosylphosphatidylinositol anchors. Synthesis of inositolphosphorylceramides and inositolphosphorylphytosphingosines is operated by Aur1p and is essential for growth of all 4Δ cells unless they contain SLC1-1. PI″, however, is made without the help of Aur1p. Furthermore, mannosylation of PI″ is required for the survival of sphingolipid-deficient strains, which depend on SLC1-1. In contrast to lcb1Δ SLC1-1, 4Δ SLC1-1 cells grow at 37 °C but remain thermosensitive at 44 °C.

Potent tricyclic pyrazole tetrazole agonists of the nicotinic acid receptor (GPR109a).

Tricyclic pyrazole tetrazoles which are potent partial agonists of the high affinity niacin receptor, GPR109a, have been discovered and optimized. One of these compounds has proven to be effective at lowering free fatty acids in vitro and in vivo.