Maculatic Acids-Sex Attractant Pheromone Components of Bald-Faced Hornets.

Yellowjackets in the genera Vespula and Dolichovespula are prevalent eusocial insects of great ecological and economic significance, but the chemical signals of their sexual communication systems have defied structural elucidation. Herein, we report the identification of sex attractant pheromone components of virgin bald-faced hornet queens (Dolichovespula maculata). We analyzed body surface extracts of queens by coupled gas chromatographic-electroantennographic detection (GC-EAD), isolated the compounds that elicited responses from male antennae by high-performance liquid chromatography (HPLC), and identified these components by GC mass spectrometry (MS), HPLC-MS, and NMR spectroscopy. In laboratory olfactometer experiments, synthetic (2Z,7E)-3,7-dimethyldeca-2,7-diendioic acid (termed here maculatic acid A) and (2Z,7E)-10-methoxy-3,7-dimethyldeca-10-oxo-deca-2,7-dienoic acid (termed here maculatic acid C) in binary combination significantly attracted bald-faced hornet males. These are the first sex attractant pheromone components identified in yellowjackets.

Detection of hypoxia by near-infrared spectroscopy and pulse oximetry: a comparative study.

SIGNIFICANCE: Pulse oximetry is widely used in clinical practice to monitor changes in arterial oxygen saturation (SpO2). However, decreases in SpO2 can be delayed relative to the actual clinical event, and near-infrared spectroscopy (NIRS) may detect alterations in oxygenation earlier than pulse oximetry, as shown in previous cerebral oxygenation monitoring studies. AIM: We aim to compare the response of transcutaneous muscle NIRS measures of the tissue saturation index with pulse oximetry SpO2 during hypoxia. APPROACH: Episodes of acute hypoxia were induced in nine anesthetized Yucatan miniature pigs. A standard pulse oximeter was attached to the ear of the animal, and a transcutaneous NIRS sensor was placed on the hind limb muscle. Hypoxia was induced by detaching the ventilator from the animal and reattaching it once the pulse oximeter reported 70% SpO2. RESULTS: Twenty-four episodes of acute hypoxia were analyzed. Upon the start of hypoxia, the transcutaneous NIRS measures changed in 5.3 ± 0.4 s, whereas the pulse oximetry measures changed in 14.9 ± 1.0 s (p < 0.0001). CONCLUSIONS: Transcutaneous muscle NIRS can detect the effects of hypoxia significantly sooner than pulse oximetry in the Yucatan miniature pig. A transcutaneous NIRS sensor may be used as an earlier detector of oxygen saturation changes in the clinical setting than the standard pulse oximeter.

Predicting heterogeneity in clone-specific therapeutic vulnerabilities using single-cell transcriptomic signatures.

While understanding molecular heterogeneity across patients underpins precision oncology, there is increasing appreciation for taking intra-tumor heterogeneity into account. Based on large-scale analysis of cancer omics datasets, we highlight the importance of intra-tumor transcriptomic heterogeneity (ITTH) for predicting clinical outcomes. Leveraging single-cell RNA-seq (scRNA-seq) with a recommender system (CaDRReS-Sc), we show that heterogeneous gene-expression signatures can predict drug response with high accuracy (80%). Using patient-proximal cell lines, we established the validity of CaDRReS-Sc's monotherapy (Pearson r>0.6) and combinatorial predictions targeting clone-specific vulnerabilities (>10% improvement). Applying CaDRReS-Sc to rapidly expanding scRNA-seq compendiums can serve as in silico screen to accelerate drug-repurposing studies. Availability: https://github.com/CSB5/CaDRReS-Sc .

The fly factor phenomenon is mediated by interkingdom signaling between bacterial symbionts and their blow fly hosts.

We tested the recent hypothesis that the "fly factor" phenomenon (food currently or previously fed on by flies attracts more flies than the same type of food kept inaccessible to flies) is mediated by bacterial symbionts deposited with feces or regurgitated by feeding flies. We allowed laboratory-reared black blow flies, Phormia regina (Meigen), to feed and defecate on bacterial Luria-Bertani medium solidified with agar, and isolated seven morphologically distinct bacterial colonies. We identified these using matrix-assisted laser desorption/ionization mass spectrometry and sequencing of the 16S rRNA gene. In two-choice laboratory experiments, traps baited with cultures of Proteus mirabilis Hauser, Morganella morganii subsp. sibonii Jensen, or Serratia marcescens Bizio, captured significantly more flies than corresponding control jars baited with tryptic soy agar only. A mixture of seven bacterial strains as a trap bait was more attractive to flies than a single bacterial isolate (M. m. sibonii). In a field experiment, traps baited with agar cultures of P. mirabilis and M. m. sibonii in combination captured significantly more flies than traps baited with either bacterial isolate alone or the agar control. As evident by gas chromatography-mass spectrometry, the odor profiles of bacterial isolates differ, which may explain the additive effect of bacteria to the attractiveness of bacterial trap baits. As "generalist bacteria," P. mirabilis and M. m. sibonii growing on animal protein (beef liver) or plant protein (tofu) are similarly effective in attracting flies. Bacteria-derived airborne semiochemicals appear to mediate foraging by flies and to inform their feeding and oviposition decisions.

Continuous Optical Monitoring of Spinal Cord Oxygenation and Hemodynamics during the First Seven Days Post-Injury in a Porcine Model of Acute Spinal Cord Injury.

One of the only currently available treatment options to potentially improve neurological recovery after acute spinal cord injury (SCI) is augmentation of mean arterial blood pressure (MAP) to promote blood flow and oxygen delivery to the injured cord. However, to optimize such hemodynamic management, clinicians require a method to monitor the physiological effects of these MAP alterations within the injured cord. Therefore, we investigated the feasibility and effectiveness of using a novel optical sensor, based on near-infrared spectroscopy (NIRS), to monitor real-time spinal cord oxygenation and hemodynamics during the first 7 days post-injury in a porcine model of acute SCI. Six Yucatan miniature pigs underwent a T10 vertebral level contusion-compression injury. Spinal cord oxygenation and hemodynamics were continuously monitored by a minimally invasive custom-made NIRS sensor, and by invasive intraparenchymal (IP) probes to validate the NIRS measures. Episodes of MAP alteration and hypoxia were performed acutely after injury, and at 2 and 7 days post-injury to simulate the types of hemodynamic changes SCI patients experience after injury. The NIRS sensor demonstrated the ability to provide oxygenation and hemodynamic measurements over the 7-day post-SCI period. NIRS measures showed statistically significant correlations with each of the invasive IP measures and MAP changes during episodes of MAP alteration and hypoxia throughout the first week post-injury (p < 0.05). These results indicate that this novel NIRS system can monitor real-time changes in spinal cord oxygenation and hemodynamics over the first 7 days post-injury, and has the ability to detect local tissue changes that are reflective of systemic hemodynamic changes.