The hippocampus is crucial for forming non-hippocampal long-term memory during sleep.

There is a long-standing division in memory research between hippocampus-dependent memory and non-hippocampus-dependent memory, as only the latter can be acquired and retrieved in the absence of normal hippocampal function1,2. Consolidation of hippocampus-dependent memory, in particular, is strongly supported by sleep3-5. Here we show that the formation of long-term representations in a rat model of non-hippocampus-dependent memory depends not only on sleep but also on activation of a hippocampus-dependent mechanism during sleep. Rats encoded non-hippocampus-dependent (novel-object recognition6-8) and hippocampus-dependent (object-place recognition) memories before a two-hour period of sleep or wakefulness. Memory was tested either immediately thereafter or remotely (after one or three weeks). Whereas object-place recognition memory was stronger for rats that had slept after encoding (rather than being awake) at both immediate and remote testing, novel-object recognition memory profited from sleep only three weeks after encoding, at which point it was preserved in rats that had slept after encoding but not in those that had been awake. Notably, inactivation of the hippocampus during post-encoding sleep by intrahippocampal injection of muscimol abolished the sleep-induced enhancement of remote novel-object recognition memory. By contrast, muscimol injection before remote retrieval or memory encoding had no effect on test performance, confirming that the encoding and retrieval of novel-object recognition memory are hippocampus-independent. Remote novel-object recognition memory was associated with spindle activity during post-encoding slow-wave sleep, consistent with the view that neuronal memory replay during slow-wave sleep contributes to long-term memory formation. Our results indicate that the hippocampus has an important role in long-term consolidation during sleep even for memories that have previously been considered hippocampus-independent.

Clinical and cone beam computed tomography outcomes of maxillary anterior implant restorations after immediate implant placement with interim restorations: A 1- to 14-year retrospective analysis.

STATEMENT OF PROBLEM: Achieving and maintaining optimal tissue health and esthetics when immediately placing maxillary anterior implants with interim restorations has been challenging and the clinical outcomes heterogenous. PURPOSE: The purpose of this retrospective study was to evaluate the clinical outcomes of immediate placement of maxillary anterior implants with interim restorations and compare the tomographic and clinical results before and after implant placement in participants followed for 1 to 14 years. MATERIAL AND METHODS: Twenty participants receiving 25 postextraction single implants in the anterior maxilla were studied. Clinical parameters included pink esthetic score (PES) and white esthetic score (WES), peri-implant phenotype, implant probing, plaque index, and cone beam computed tomography (CBCT) to compare initial and at least 1 year after crown placement (postoperative). For qualitative variables, a descriptive analysis was carried out. The PES and WES results were analyzed by using nonparametric statistics, the median (ME) and the interquartile range (IQR) were used as summary measures, and the Wilcoxon sum of signs test was used to compare the total scores between the intervention area and the contralateral tooth. To compare pre- and postoperative data points, the paired t test was used (α=.05). RESULTS: Mean ±standard deviation (SD) time of follow-up was 7.6 ±4.2 years. Twenty participants with a mean ±SD age of 62.4 ±11.0 years old received 25 implants. Mean ±SD initial torque value at implant placement was 38.6 ±9.63 Ncm. Bone height at the top of the alveolar ridge (BH) and bone width at the middle of the alveolar ridge (BW2) showed a statistically significant decrease between the initial and subsequent CBCT measurements (both P<.001). Likewise, the bone width at the alveolar crest (BW1) showed a statistically significant decrease between the initial and post-CBCT measurements (P=.006). Facial bone integrity (FBI) revealed a statistically significant increase between the initial and postoperative time periods (P<.001). The PES index showed a median of 9.0 IQR (8-10), statistically lower than the contralateral tooth (P=.032). No significant differences were found for the WES index or for FBI, regardless of the peri-implant phenotype. CONCLUSIONS: Immediate implant placement in the maxillary anterior sextant was found to be a predictable procedure with good esthetic results when the protocol described was used. Labial bone loss is inevitable after tooth extraction but can be compensated for by filling the space with a xenograft material. Long-term gingival tissue integrity was maintained, regardless of phenotype, in periodontally healthy participants.

Increased Detection of Carbapenemase-Producing Enterobacterales Bacteria in Latin America and the Caribbean during the COVID-19 Pandemic.

During 2020-2021, countries in Latin America and the Caribbean reported clinical emergence of carbapenemase-producing Enterobacterales that had not been previously characterized locally, increased prevalence of carbapenemases that had previously been detected, and co-production of multiple carbapenemases in some isolates. These increases were likely fueled by changes related to the COVID-19 pandemic, including empirical antibiotic use for potential COVID-19-related bacterial infections and healthcare limitations resulting from the rapid rise in COVID-19 cases. Strengthening antimicrobial resistance surveillance, epidemiologic research, and infection prevention and control programs and antimicrobial stewardship in clinical settings can help prevent emergence and transmission of carbapenemase-producing Enterobacterales.

A custom screw-retained implant-supported prosthesis for a patient with amelogenesis imperfecta: An 8-year clinical follow-up.

This clinical report with an 8-year follow-up describes the multidisciplinary management of a patient diagnosed with amelogenesis imperfecta. The rehabilitation included horizontal-guided bone regeneration, implant placement, use of a fixed interim prosthesis to preview the correction of occlusal disharmonies, and placement of a custom screw-retained definitive implant-supported restoration with a design that was retrievable and minimized maintenance problems.

Epistasis Between Two Gene Variants of Leptin and Vascular Endothelial Growth Factor Genes in the Development of Primary Knee Osteoarthritis.

BACKGROUND: The association of leptin (LEP) and vascular endothelial growth factor A (VEGFA) genes with the susceptibility to knee osteoarthritis (OA) has been analyzed; however, the epistasis between them has not been investigated. OBJECTIVE: The objective of the study was to analyze the association of LEP and VEGFA variants and their interaction with primary knee OA in a Mexican Mestizo population. METHODS: A case-control study was developed. Cases were ≥40 years, BMI ≤27 kg/m2, with primary knee OA and radiologic Grade ≥2. Controls were participants with no knee OA and a radiologic Grade < 2. The rs2167270 of LEP and rs2010963 of VEGFA were genotyped. Genotypic association was tested under codominant, dominant, and recessive models. Uni- and multi-variate analyses were developed through non-conditional logistic regression. The multifactor dimensionality reduction algorithm was developed to detect epistasis. RESULTS: Participants comprised 103 cases and 179 controls. Allelic and genotypic distributions did not show differences between the groups. Notwithstanding, a statistically significant interaction was observed between the LEP and VEGFA genes (p = 0.02) with a testing accuracy of 0.5199 and cross-validation consistency of 10/10. This interaction model confers an increased risk to knee OA (OR [95% CI] = 1.8 [1.1-2.9]). CONCLUSION: Interaction between LEP and VEGFA is related with genetic susceptibility to developing primary knee OA.

Refined cut-off for TP53 immunohistochemistry improves prediction of TP53 mutation status in ovarian mucinous tumors: implications for outcome analyses.

TP53 mutations are implicated in the progression of mucinous borderline tumors (MBOT) to mucinous ovarian carcinomas (MOC). Optimized immunohistochemistry (IHC) for TP53 has been established as a proxy for the TP53 mutation status in other ovarian tumor types. We aimed to confirm the ability of TP53 IHC to predict TP53 mutation status in ovarian mucinous tumors and to evaluate the association of TP53 mutation status with survival among patients with MBOT and MOC. Tumor tissue from an initial cohort of 113 women with MBOT/MOC was stained with optimized IHC for TP53 using tissue microarrays (75.2%) or full sections (24.8%) and interpreted using established criteria as normal or abnormal (overexpression, complete absence, or cytoplasmic). Cases were considered concordant if abnormal IHC staining predicted deleterious TP53 mutations. Discordant tissue microarray cases were re-evaluated on full sections and interpretational criteria were refined. The initial cohort was expanded to a total of 165 MBOT and 424 MOC for the examination of the association of survival with TP53 mutation status, assessed either by TP53 IHC and/or sequencing. Initially, 82/113 (72.6%) cases were concordant using the established criteria. Refined criteria for overexpression to account for intratumoral heterogeneity and terminal differentiation improved concordance to 93.8% (106/113). In the expanded cohort, 19.4% (32/165) of MBOT showed evidence for TP53 mutation and this was associated with a higher risk of recurrence, disease-specific death, and all-cause mortality (overall survival: HR = 4.6, 95% CI 1.5-14.3, p = 0.0087). Within MOC, 61.1% (259/424) harbored a TP53 mutation, but this was not associated with survival (overall survival, p = 0.77). TP53 IHC is an accurate proxy for TP53 mutation status with refined interpretation criteria accounting for intratumoral heterogeneity and terminal differentiation in ovarian mucinous tumors. TP53 mutation status is an important biomarker to identify MBOT with a higher risk of mortality.

Options for the Treatment of Mucinous Ovarian Carcinoma.

OPINION STATEMENT: Complete surgical resection is the gold-standard treatment for all mucinous ovarian carcinoma (MOC) cases. Advanced-stage disease is often additionally treated with adjuvant platinum-based chemotherapy; however, these were developed largely against the more common high-grade serous ovarian carcinoma and have low efficacy in treating MOC. More effective therapeutics are needed to treat late-stage and platinum-resistant tumors; however, traditional drug development and clinical trial paradigms are a major challenge for such a rare disease. New approaches to support evidence-based treatment decisions are required, such as registry trials. Recently, a number of targeted therapies have emerged as viable treatment options in other cancer types, and for some of these, the actionable tumor mutations are also seen in MOC. Thus, a promising alternative approach to provide benefit to current MOC patients involves DNA sequencing to identify a tumor's unique mutational profile and allow matching to available targeted agents. Such a pipeline can involve special approval to administer a drug already approved for clinical use in other cancer types to a given MOC patient, or their inclusion in existing ongoing clinical trials, such as basket trials encompassing patients with tumors from a range of anatomical sites. Implementation of such personalized medicine can be boosted using improved pre-clinical models, where through a clinical research collaboration a patient's own tumor cells can be used to a test a range of putative therapies prior to administration in the clinic, enabling selection of the available pharmaceutical/s that give any given patient the best possible chance of cancer remission.

Therapeutic options for mucinous ovarian carcinoma.

OBJECTIVE: Mucinous ovarian carcinoma (MOC) is an uncommon ovarian cancer histotype that responds poorly to conventional chemotherapy regimens. Although long overall survival outcomes can occur with early detection and optimal surgical resection, recurrent and advanced disease are associated with extremely poor survival. There are no current guidelines specifically for the systemic management of recurrent MOC. We analyzed data from a large cohort of women with MOC to evaluate the potential for clinical utility from a range of systemic agents. METHODS: We analyzed gene copy number (n = 191) and DNA sequencing data (n = 184) from primary MOC to evaluate signatures of mismatch repair deficiency and homologous recombination deficiency, and other genetic events. Immunohistochemistry data were collated for ER, CK7, CK20, CDX2, HER2, PAX8 and p16 (n = 117-166). RESULTS: Molecular aberrations noted in MOC that suggest a match with current targeted therapies include amplification of ERBB2 (26.7%) and BRAF mutation (9%). Observed genetic events that suggest potential efficacy for agents currently in clinical trials include: KRAS/NRAS mutations (66%), TP53 missense mutation (49%), RNF43 mutation (11%), ARID1A mutation (10%), and PIK3CA/PTEN mutation (9%). Therapies exploiting homologous recombination deficiency (HRD) may not be effective in MOC, as only 1/191 had a high HRD score. Mismatch repair deficiency was similarly rare (1/184). CONCLUSIONS: Although genetically diverse, MOC has several potential therapeutic targets. Importantly, the lack of response to platinum-based therapy observed clinically corresponds to the lack of a genomic signature associated with HRD, and MOC are thus also unlikely to respond to PARP inhibition.

Neighborhood environment, self-rated health and quality of life in Latin America.

To conduct a systematic review examining the associations between neighborhood environments and self-rated health (SRH) and health-related quality of life (HR-QOL) in the urban context of Latin America. We conducted a structured search of quantitative studies in three bibliographic databases published in Spanish, English, Portuguese and French from January 1990 to December 2015. We restricted the search to studies conducted in Latin-American cities with one million and more inhabitants. Eleven studies were finally included in the analysis. Ten were cross-sectional studies and one was a cohort follow-up study. Two studies found positive associations between accessibility to parks and HR-QOL. One study found that high neighborhood social capital was positively associated with SRH. Neighborhood socioeconomic status was positively associated with both HR-QOL and SRH in two studies. A walkable neighborhood was positively associated with SRH in two studies. Three studies included attributes related with neighborhood security perception and road safety, with higher scores of HR-QOL, both in the physical and mental dimensions, while high levels of street noise were negatively associated. Narrowness and slope of streets were negatively associated with SRH. No association was found between the perception of neighborhood security and SRH. The results of this systematic review show that several studies conducted in Latin America have found significant associations between neighborhood environment and SRH and HRQOL. However, the relatively small number of studies and the heterogeneity among them require further studies to better understand this topic in the region.

Involvement of selected cellular miRNAs in the in vitro and in vivo infection of infectious salmon anemia virus (ISAV).

Infectious salmon anemia virus (ISAV) is the causative agent of infectious salmon anemia (ISA), a relatively novel disease primarily affecting farmed salmon species, primarily in Salmo salar specimens, causing severe outbreaks in most producer countries. Although ISAV has been extensively studied at the molecular level, not much is known about the host/cell interaction at the small RNA level. MicroRNAs (miRNAs) are small, non-coding RNA that regulate mRNA expression at the post-transcriptional level. In recent years, the putative role of these molecules in host-pathogen interactions has drawn particular attention because of their pivotal involvement as regulatory elements in a number of eukaryotic organisms. Given the importance of the salmon industry in Chile, a deep understanding of the interaction between ISAV and its hosts is of importance. In the present work, we studied the kinetic expression of selected miRNAs during ISAV infection, both in vitro and in vivo. Based on initial experimental data derived from a small RNA-Seq analysis, a group of miRNAs that were differentially expressed in infected cells were selected for analysis. As a result, two miRNAs, miR-462a-5p and miR-125 b-5p, showed increased and decreased expression, respectively, during ISAV infection.

Constitutive and Companion Cell-Specific Overexpression of AVP1, Encoding a Proton-Pumping Pyrophosphatase, Enhances Biomass Accumulation, Phloem Loading, and Long-Distance Transport.

Plant productivity is determined in large part by the partitioning of assimilates between the sites of production and the sites of utilization. Proton-pumping pyrophosphatases (H(+)-PPases) are shown to participate in many energetic plant processes, including general growth and biomass accumulation, CO2 fixation, nutrient acquisition, and stress responses. H(+)-PPases have a well-documented role in hydrolyzing pyrophosphate (PPi) and capturing the released energy to pump H(+) across the tonoplast and endomembranes to create proton motive force (pmf). Recently, an additional role for H(+)-PPases in phloem loading and biomass partitioning was proposed. In companion cells (CCs) of the phloem, H(+)-PPases localize to the plasma membrane rather than endomembranes, and rather than hydrolyzing PPi to create pmf, pmf is utilized to synthesize PPi. Additional PPi in the CCs promotes sucrose oxidation and ATP synthesis, which the plasma membrane P-type ATPase in turn uses to create more pmf for phloem loading of sucrose via sucrose-H(+) symporters. To test this model, transgenic Arabidopsis (Arabidopsis thaliana) plants were generated with constitutive and CC-specific overexpression of AVP1, encoding type 1 ARABIDOPSIS VACUOLAR PYROPHOSPHATASE1. Plants with both constitutive and CC-specific overexpression accumulated more biomass in shoot and root systems. (14)C-labeling experiments showed enhanced photosynthesis, phloem loading, phloem transport, and delivery to sink organs. The results obtained with constitutive and CC-specific promoters were very similar, such that the growth enhancement mediated by AVP1 overexpression can be attributed to its role in phloem CCs. This supports the model for H(+)-PPases functioning as PPi synthases in the phloem by arguing that the increases in biomass observed with AVP1 overexpression stem from improved phloem loading and transport.

Development and application of sub-2-µm particle CO2 -based chromatography coupled to mass spectrometry for comprehensive analysis of lipids in cottonseed extracts.

RATIONALE: Refined cottonseed oil has widespread applications in the food and chemical industries. Although the major lipids comprising cottonseed oil (triacylglycerols) are well known, there are many diverse lipid species in cotton seeds that occur at much lower levels and have important nutritional or anti-nutritional properties. METHODS: The lipid technical samples were prepared in chloroform. The biological samples were extracted using a mixture of isopropanol/chloroform/H2 O (2:1:0.45). The data were collected using high and low collision energy with simultaneous data collection on a time-of-flight (TOF) mass spectrometer which allowed the characterization of lipids by precursor and product ion alignment. The supercritical fluid chromatography methodology is flexible and can be altered to provide greater retention and separation. The comprehensive method was used to screen seed lipid extracts from several cotton genotypes using multivariate statistical analysis. RESULTS: Method variables influencing the peak integrity and chromatographic separation for a mixture of lipids with different degrees of polarity were explored. The experiments were designed to understand the chromatographic behavior of lipids in a controlled setting using a variety of lipid extracts. Influences of acyl chain length and numbers of double bonds were investigated using single moiety standards. CONCLUSIONS: The methodology parameters were examined using single moiety lipid standards and standard mixtures. The method conditions were applied to biological lipid extracts, and adjustments were investigated to manipulate the chromatography. Insights from these method variable manipulations will help to frame the development of targeted lipid profiling and screening protocols. Copyright © 2017 John Wiley & Sons, Ltd.

Non-Criteria or Seronegative Obstetric Antiphospholipid Syndrome?

BACKGROUND: Obstetric antiphospholipid syndrome (Obs-APS) is one of the most commonly identified causes of recurrent pregnancy loss and its accurate diagnosis is a requirement for optimal treatment. Some patients do not fulfill the revised Sapporo classification criteria, the original APS classification criteria, and are considered to be non-criteria Obs-APS. In these patients with non-criteria, there is controversy about their inclusion within the spectrum of APS and eventually their treatment as having Obs-APS. A subset of patients may also have clinical characteristics of Obs-APS even though lupus anticoagulant (LA), anticardiolipin antibodies, and anti-ß2-glycoprotein I (aß2GPI) antibodies are consistently negative. These patients are recognized as seronegative Obs-APS. We reviewed evidence of non-criteria Obs-APS and discuss a case of a woman with a diagnosis of active systemic lupus erythematosus (SLE) and non-criteria Obs-APS with four consecutive pregnancy losses. After an accurate diagnosis the patient received prenatal counseling and benefited from the optimal treatment of Obs-APS that led to a successful pregnancy. The applicability of this successful experience about outcomes in women with non-criteria, or seronegative, Obs-APS is also evaluated.

Temporal-spatial interaction between reactive oxygen species and abscisic acid regulates rapid systemic acclimation in plants.

Being sessile organisms, plants evolved sophisticated acclimation mechanisms to cope with abiotic challenges in their environment. These are activated at the initial site of exposure to stress, as well as in systemic tissues that have not been subjected to stress (termed systemic acquired acclimation [SAA]). Although SAA is thought to play a key role in plant survival during stress, little is known about the signaling mechanisms underlying it. Here, we report that SAA in plants requires at least two different signals: an autopropagating wave of reactive oxygen species (ROS) that rapidly spreads from the initial site of exposure to the entire plant and a stress-specific signal that conveys abiotic stress specificity. We further demonstrate that SAA is stress specific and that a temporal-spatial interaction between ROS and abscisic acid regulates rapid SAA to heat stress in plants. In addition, we demonstrate that the rapid ROS signal is associated with the propagation of electric signals in Arabidopsis thaliana. Our findings unravel some of the basic signaling mechanisms underlying SAA in plants and reveal that signaling events and transcriptome and metabolome reprogramming of systemic tissues in response to abiotic stress occur at a much faster rate than previously envisioned.

Polymyalgia Rheumatica Post-SARS-CoV-2 Infection.

There is growing evidence that infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can lead to dysregulation of the immune system and, consequently, the development of autoimmune phenomena. Here, we describe the case of a 75-year-old woman with rheumatic manifestations characterized by intense musculoskeletal pain and stiffness in the neck and shoulders, with sudden onset and with the inability to raise her arms. The patient was admitted with severe pain located in the neck and shoulders. Previously, she had oropharyngeal pain, severe fatigue, and fever; a real-time polymerase chain reaction test for COVID-19 was positive. Two weeks later, the patient presented localized musculoskeletal pain in the neck and shoulders. Relevant laboratory results included an erythrocyte sedimentation rate of 46 mm/hr and a negative rheumatoid factor test; ultrasound findings with bilateral subacromial-subdeltoid bursitis were observed. A diagnosis of polymyalgia rheumatica (PMR) was initially made according to the EULAR/ACR provisional classification criteria for PMR; however, due to C-reactive protein negativity, the diagnosis was established based on symptoms. Management was with prednisone at the dose of 25 mg/day for 4 weeks and progressive reduction until prednisone suspension. The patient showed complete recovery at 6 months of follow-up. In this case, COVID-19 was implicated in the development of autoimmune and inflammatory rheumatic manifestations. PMR is a rare rheumatic condition that should be included in the wide range of rheumatologic manifestations expressed post-SARS-CoV-2 infection.

Functional assessment of the Medicago truncatula NIP/LATD protein demonstrates that it is a high-affinity nitrate transporter.

The Medicago truncatula NIP/LATD (for Numerous Infections and Polyphenolics/Lateral root-organ Defective) gene encodes a protein found in a clade of nitrate transporters within the large NRT1(PTR) family that also encodes transporters of dipeptides and tripeptides, dicarboxylates, auxin, and abscisic acid. Of the NRT1(PTR) members known to transport nitrate, most are low-affinity transporters. Here, we show that M. truncatula nip/latd mutants are more defective in their lateral root responses to nitrate provided at low (250 µm) concentrations than at higher (5 mm) concentrations; however, nitrate uptake experiments showed no discernible differences in uptake in the mutants. Heterologous expression experiments showed that MtNIP/LATD encodes a nitrate transporter: expression in Xenopus laevis oocytes conferred upon the oocytes the ability to take up nitrate from the medium with high affinity, and expression of MtNIP/LATD in an Arabidopsis chl1(nrt1.1) mutant rescued the chlorate susceptibility phenotype. X. laevis oocytes expressing mutant Mtnip-1 and Mtlatd were unable to take up nitrate from the medium, but oocytes expressing the less severe Mtnip-3 allele were proficient in nitrate transport. M. truncatula nip/latd mutants have pleiotropic defects in nodulation and root architecture. Expression of the Arabidopsis NRT1.1 gene in mutant Mtnip-1 roots partially rescued Mtnip-1 for root architecture defects but not for nodulation defects. This suggests that the spectrum of activities inherent in AtNRT1.1 is different from that possessed by MtNIP/LATD, but it could also reflect stability differences of each protein in M. truncatula. Collectively, the data show that MtNIP/LATD is a high-affinity nitrate transporter and suggest that it could have another function.

Whole genomes from bacteria collected at diagnostic units around the world 2020.

The Two Weeks in the World research project has resulted in a dataset of 3087 clinically relevant bacterial genomes with pertaining metadata, collected from 59 diagnostic units in 35 countries around the world during 2020. A relational database is available with metadata and summary data from selected bioinformatic analysis, such as species prediction and identification of acquired resistance genes.

Analysis of estrogen receptor alpha gene haplotype in Mexican mestizo patients with primary osteoarthritis of the knee.

The aim of this work was to test the association between estrogen receptor α gene (ERα) polymorphism and primary osteoarthritis (OA) of the knee in Mexican mestizo patients. A case-control study was conducted. Cases were patients >40 years of age, with a body mass index (BMI) ≤ 27 and radiologic score for OA of the knee of ≥2 according to Kellgren-Lawrence scale, and controls were subjects >40 years age with a radiologic score <2. Two restriction fragment length polymorphisms, PvuII (T/C; rs2234693), and XbaI (A/G; rs9340799), of the ERα were analyzed. Allelic haplotypes were constructed and non-conditional logistic regression was developed to evaluate risk magnitude through odds ratios (ORs) and 95% Confidence intervals (95% CI). Three different allelic haplotypes were identified: TA; CG, and CA. Unadjusted analysis of the haplotypes did not show significant associations; nonetheless, when data were adjusted for gender, age, and BMI, a significant decrease risk was observed for CG haplotype (OR [95% CI]) = 0.5 (0.3-0.9)] (P = 0.04). These results suggest that ERα gene CG haplotype could be associated with a reduced risk of primary knee OA in Mexican mestizo population.

Comprehensive Analysis of Plant Lipids Using Sub-2-µm Particle CO2-Based Chromatography Coupled to Mass Spectrometry.

Lipids play an essential role in plants, and historically manipulating their levels and composition has been an important target for metabolic engineering. A variety of analytical techniques, many based on mass spectrometry, have been utilized for lipid profiling, but the analysis of complex lipid mixtures still poses significant analytical challenges. Recent advances in technology have revived the supercritical fluid chromatography (SFC) as a promising separation technique for lipid analysis. Utilization of sub-2-µm particle columns improves the separation efficiency and robustness of the SFC systems. The combination of SFC with sub-2-µm particle separation, commonly referred as ultra-performance convergence chromatography, has been successfully used for separation of both polar and neutral lipids. In this chapter, we present a simple method for lipid class separation using Sub-2-µm particle CO2-based chromatography coupled to mass spectrometry. The supercritical fluid chromatography methodology is flexible and can be altered to provide greater retention and separation of lipid classes or individual lipids within class.

Critical Limb Ischemia as a Rare Presentation of Malignant Solitary Fibrous Tumor of the Pleura.

BACKGROUND Solitary fibrous tumor (SFT) of the pleura is a rare fibroblastic neoplasm. It is commonly found incidentally on imaging and is usually benign but has significant potential to recur as a malignant tumor. Patients present asymptomatically or with pulmonary symptoms such as cough or shortness of breath. Cardiac invasion of an SFT can create an avenue for peripheral tumor embolization and critical limb ischemia, as in this case report. There is no prior published report of recurring malignant SFT presenting as critical limb ischemia. CASE REPORT We report a rare presentation of malignant SFT recurrence in a 57-year-old woman with critical limb ischemia of both lower extremities secondary to bilateral tumor emboli. The patient's primary tumor was treated with surgical resection alone. Upon recurrence, the tumor growth was so extensive that it was no longer amenable to surgical resection at the time of her critical limb ischemia. The patient presented with bilateral numbness and tingling, without any pulmonary symptoms. CONCLUSIONS Although it is sporadic, clinicians should know that an aggressive malignant SFT can embolize and present as critical limb ischemia. The possibility of tumor emboli provides a pressing reason to surgically resect SFT masses in their early stages before any cardiac invasion.