Performance of three techniques for diagnosing equine tapeworm infection.

Tapeworm infection in horses can cause serious health concerns, and recent data have documented treatment failures in the most common species, Anoplocephala perfoliata. The threat of anthelmintic resistance in A. perfoliata is of particular concern because of poor diagnostic performance of standard egg counting techniques for detecting this parasite. This study compared the performance of three diagnostic techniques 1) Mini-FLOTAC, 2) Cornell-Wisconsin, and 3) Proudman and Edwards used to detect and quantify A. perfoliata eggs in naturally infected horses. Eighteen adult female horses from the University of Kentucky's historic parasitology herd were included in this study. Fecal samples were collected from all horses at five collection time points two weeks apart and analyzed with the three techniques. A total of 90 samples were collected and 270 counts determined in the study. The proportions of positive samples determined by the three techniques were significantly different from each other (p<0.05): Mini-FLOTAC (16%), Cornell-Wisconsin (47%), and Proudman and Edwards (70%). The Proudman and Edwards technique counted consistently higher numbers of tapeworm eggs compared to the other two techniques throughout the study [p < 0.05]. Total raw counts of tapeworm eggs across the study for each technique were 16, 88, and 410 for the Mini-FLOTAC, Cornell-Wisconsin, and Proudman and Edwards, respectively. This study demonstrated that the Proudman and Edwards technique was superior in diagnosing A. perfoliata infection. Future work needs to assess this technique's potential for Fecal Egg Count Reduction Testing (FECRT).

Chemobiosis reveals tardigrade tun formation is dependent on reversible cysteine oxidation.

Tardigrades, commonly known as 'waterbears', are eight-legged microscopic invertebrates renowned for their ability to withstand extreme stressors, including high osmotic pressure, freezing temperatures, and complete desiccation. Limb retraction and substantial decreases to their internal water stores results in the tun state, greatly increasing their ability to survive. Emergence from the tun state and/or activity regain follows stress removal, where resumption of life cycle occurs as if stasis never occurred. However, the mechanism(s) through which tardigrades initiate tun formation is yet to be uncovered. Herein, we use chemobiosis to demonstrate that tardigrade tun formation is mediated by reactive oxygen species (ROS). We further reveal that tuns are dependent on reversible cysteine oxidation, and that this reversible cysteine oxidation is facilitated by the release of intracellular reactive oxygen species (ROS). We provide the first empirical evidence of chemobiosis and map the initiation and survival of tardigrades via osmobiosis, chemobiosis, and cryobiosis. In vivo electron paramagnetic spectrometry suggests an intracellular release of reactive oxygen species following stress induction; when this release is quenched through the application of exogenous antioxidants, the tardigrades can no longer survive osmotic stress. Together, this work suggests a conserved dependence of reversible cysteine oxidation across distinct tardigrade cryptobioses.

Susceptibility-Weighted MRI Approximates Intraoperative Microelectrode Recording During Deep Brain Stimulation of the Subthalamic Nucleus for Parkinson's Disease.

BACKGROUND: Deep brain stimulation of the subthalamic nucleus (STN-DBS) for Parkinson's disease can be performed with intraoperative neurophysiological and radiographic guidance. Conventional T2-weighted magnetic resonance imaging sequences, however, often fail to provide definitive borders of the STN. Novel magnetic resonance imaging sequences, such as susceptibility-weighted imaging (SWI), might better localize the STN borders and facilitate radiographic targeting. We compared the radiographic location of the dorsal and ventral borders of the STN using SWI with intraoperative microelectrode recording (MER) during awake STN-DBS for Parkinson's disease. METHODS: Thirteen consecutive patients who underwent placement of 24 STN-DBS leads for Parkinson's disease were analyzed retrospectively. Preoperative targeting was performed with SWI, and MER data were obtained from intraoperative electrophysiology records. The boundaries of the STN on SWI were identified by a blinded investigator. RESULTS: The final electrode position differed significantly from the planned coordinates in depth but not in length or width, indicating that MER guided the final electrode depth. When we compared the boundaries of the STN by MER and SWI, SWI accurately predicted the entry into the STN but underestimated the length and ventral boundary of the STN by 1.2 mm. This extent of error approximates the span of a DBS contact and could affect the placement of directional contacts within the STN. CONCLUSIONS: MER might continue to have a role in STN-DBS. This could potentially be mitigated by further refinement of imaging protocols to better image the ventral boundary of the STN.

Metabolic engineering of Caldicellulosiruptor bescii for 2,3-butanediol production from unpretreated lignocellulosic biomass and metabolic strategies for improving yields and titers.

The platform chemical 2,3-butanediol (2,3-BDO) is used to derive products, such as 1,3-butadiene and methyl ethyl ketone, for the chemical and fuel production industries. Efficient microbial 2,3-BDO production at industrial scales has not been achieved yet for various reasons, including product inhibition to host organisms, mixed stereospecificity in product formation, and dependence on expensive substrates (i.e., glucose). In this study, we explore engineering of a 2,3-BDO pathway in Caldicellulosiruptor bescii, an extremely thermophilic (optimal growth temperature = 78°C) and anaerobic bacterium that can break down crystalline cellulose and hemicellulose into fermentable C5 and C6 sugars. In addition, C. bescii grows on unpretreated plant biomass, such as switchgrass. Biosynthesis of 2,3-BDO involves three steps: two molecules of pyruvate are condensed into acetolactate; acetolactate is decarboxylated to acetoin, and finally, acetoin is reduced to 2,3-BDO. C. bescii natively produces acetoin; therefore, in order to complete the 2,3-BDO biosynthetic pathway, C. bescii was engineered to produce a secondary alcohol dehydrogenase (sADH) to catalyze the final step. Two previously characterized, thermostable sADH enzymes with high affinity for acetoin, one from a bacterium and one from an archaeon, were tested independently. When either sADH was present in C. bescii, the recombinant strains were able to produce up to 2.5-mM 2,3-BDO from crystalline cellulose and xylan and 0.2-mM 2,3-BDO directly from unpretreated switchgrass. This serves as the basis for higher yields and productivities, and to this end, limiting factors and potential genetic targets for further optimization were assessed using the genome-scale metabolic model of C. bescii.IMPORTANCELignocellulosic plant biomass as the substrate for microbial synthesis of 2,3-butanediol is one of the major keys toward cost-effective bio-based production of this chemical at an industrial scale. However, deconstruction of biomass to release the sugars for microbial growth currently requires expensive thermochemical and enzymatic pretreatments. In this study, the thermo-cellulolytic bacterium Caldicellulosiruptor bescii was successfully engineered to produce 2,3-butanediol from cellulose, xylan, and directly from unpretreated switchgrass. Genome-scale metabolic modeling of C. bescii was applied to adjust carbon and redox fluxes to maximize productivity of 2,3-butanediol, thereby revealing bottlenecks that require genetic modifications.

Optimizing Strategies for Bio-Based Ethanol Production Using Genome-Scale Metabolic Modeling of the Hyperthermophilic Archaeon, Pyrococcus furiosus.

A genome-scale metabolic model, encompassing a total of 623 genes, 727 reactions, and 865 metabolites, was developed for Pyrococcus furiosus, an archaeon that grows optimally at 100°C by carbohydrate and peptide fermentation. The model uses subsystem-based genome annotation, along with extensive manual curation of 237 gene-reaction associations including those involved in central carbon metabolism, amino acid metabolism, and energy metabolism. The redox and energy balance of P. furiosus was investigated through random sampling of flux distributions in the model during growth on disaccharides. The core energy balance of the model was shown to depend on high acetate production and the coupling of a sodium-dependent ATP synthase and membrane-bound hydrogenase, which generates a sodium gradient in a ferredoxin-dependent manner, aligning with existing understanding of P. furiosus metabolism. The model was utilized to inform genetic engineering designs that favor the production of ethanol over acetate by implementing an NADPH and CO-dependent energy economy. The P. furiosus model is a powerful tool for understanding the relationship between generation of end products and redox/energy balance at a systems-level that will aid in the design of optimal engineering strategies for production of bio-based chemicals and fuels. IMPORTANCE The bio-based production of organic chemicals provides a sustainable alternative to fossil-based production in the face of today's climate challenges. In this work, we present a genome-scale metabolic reconstruction of Pyrococcus furiosus, a well-established platform organism that has been engineered to produce a variety of chemicals and fuels. The metabolic model was used to design optimal engineering strategies to produce ethanol. The redox and energy balance of P. furiosus was examined in detail, which provided useful insights that will guide future engineering designs.

Elevated estradiol during a hormone simulated pseudopregnancy decreases sleep and increases hypothalamic activation in female Syrian hamsters.

Sleep disruptions are a common occurrence during the peripartum period. While physical and environmental factors associated with pregnancy and newborn care account for some sleep disruptions, there is evidence that peripartum fluctuations in estrogens may independently impact sleep. However, the impact of these large fluctuations in estrogens on peripartum sleep is unclear because it is difficult to tease apart the effects of estrogens on sleep from effects associated with the growth and development of the fetus or parental care. We therefore used a hormone-simulated pseudopregnancy (HSP) in female Syrian hamsters to test the hypothesis that pregnancy-like increases in estradiol decrease sleep in the absence of other factors. Adult female Syrian hamsters were ovariectomized and given daily hormone injections that simulate estradiol levels during early pregnancy, late pregnancy, and the postpartum period. Home cage video recordings were captured at seven timepoints and videos were analyzed for actigraphy. During "late pregnancy," total sleep time and sleep efficiency were decreased in hormone-treated animals during the white light period compared to pretest levels. Likewise, during "late pregnancy," locomotion was increased in the white light period for hormone-treated animals compared to pretest levels. These changes continued into the "postpartum period" for animals who continued to receive estradiol treatment, but not for animals who were withdrawn from estradiol. At the conclusion of the experiment, animals were euthanized and cFos expression was quantified in the ventral lateral preoptic area (VLPO) and lateral hypothalamus (LH). Animals who continued to receive high levels of estradiol during the "postpartum" period had significantly more cFos in the VLPO and LH than animals who were withdrawn from hormones or vehicle controls. Together, these data suggest that increased levels of estradiol during pregnancy are associated with sleep suppression, which may be mediated by increased activation of hypothalamic nuclei.

Manipulating Fermentation Pathways in the Hyperthermophilic Archaeon Pyrococcus furiosus for Ethanol Production up to 95°C Driven by Carbon Monoxide Oxidation.

Genetic engineering of hyperthermophilic organisms for the production of fuels and other useful chemicals is an emerging biotechnological opportunity. In particular, for volatile organic compounds such as ethanol, fermentation at high temperatures could allow for straightforward separation by direct distillation. Currently, the upper growth temperature limit for native ethanol producers is 72°C in the bacterium Thermoanaerobacter ethanolicus JW200, and the highest temperature for heterologously-engineered bioethanol production was recently demonstrated at 85°C in the archaeon Pyrococcus furiosus. Here, we describe an engineered strain of P. furiosus that synthesizes ethanol at 95°C, utilizing a homologously-expressed native alcohol dehydrogenase, termed AdhF. Ethanol biosynthesis was compared at 75°C and 95°C with various engineered strains. At lower temperatures, the acetaldehyde substrate for AdhF is most likely produced from acetate by aldehyde ferredoxin oxidoreductase (AOR). At higher temperatures, the effect of AOR on ethanol production is negligible, suggesting that acetaldehyde is produced by pyruvate ferredoxin oxidoreductase (POR) via oxidative decarboxylation of pyruvate, a reaction known to occur only at higher temperatures. Heterologous expression of a carbon monoxide dehydrogenase complex in the AdhF overexpression strain enabled it to use CO as a source of energy, leading to increased ethanol production. A genome reconstruction model for P. furiosus was developed to guide metabolic engineering strategies and understand outcomes. This work opens the door to the potential for 'bioreactive distillation' since fermentation can be performed well above the normal boiling point of ethanol. IMPORTANCE Previously, the highest temperature for biological ethanol production was 85°C. Here, we have engineered ethanol production at 95°C by the hyperthermophilic archaeon Pyrococcus furiosus. Using mutant strains, we showed that ethanol production occurs by different pathways at 75°C and 95°C. In addition, by heterologous expression of a carbon monoxide dehydrogenase complex, ethanol production by this organism was driven by the oxidation of carbon monoxide. A genome reconstruction model for P. furiosus was developed to guide metabolic engineering strategies and understand outcomes.

Differential bone adaptation to mechanical unloading and reloading in young, old, and osteocyte deficient mice.

Mechanical unloading causes rapid loss of bone structure and strength, which gradually recovers after resuming normal loading. However, it is not well established how this adaptation to unloading and reloading changes with age. Clinically, elderly patients are more prone to musculoskeletal injury and longer periods of bedrest, therefore it is important to understand how periods of disuse will affect overall skeletal health of aged subjects. Bone also undergoes an age-related decrease in osteocyte density, which may impair mechanoresponsiveness. In this study, we examined bone adaptation during unloading and subsequent reloading in mice. Specifically, we examined the differences in bone adaptation between young mice (3-month-old), old mice (18-month-old), and transgenic mice that exhibit diminished osteocyte density at a young age (3-month-old BCL-2 transgenic mice). Mice underwent 14 days of hindlimb unloading followed by up to 14 days of reloading. We analyzed trabecular and cortical bone structure in the femur, mechanical properties of the femoral cortical diaphysis, osteocyte density and cell death in cortical bone, and serum levels of inflammatory cytokines. We found that young mice lost ~10% cortical bone volume and 27-42% trabecular bone volume during unloading and early reloading, with modest recovery of metaphyseal trabecular bone and near total recovery of epiphyseal trabecular bone, but no recovery of cortical bone after 14 days of reloading. Old mice lost 12-14% cortical bone volume and 35-50% trabecular bone volume during unloading and early reloading but had diminished recovery of trabecular bone during reloading and no recovery of cortical bone. In BCL-2 transgenic mice, no cortical bone loss was observed during unloading or reloading, but 28-31% trabecular bone loss occurred during unloading and early reloading, with little to no recovery during reloading. No significant differences in circulating inflammatory cytokine levels were observed due to unloading and reloading in any of the experimental groups. These results illustrate important differences in bone adaptation in older and osteocyte deficient mice, suggesting a possible period of vulnerability in skeletal health in older subjects during and following a period of disuse that may affect skeletal health in elderly patients.

Thermal Damage Estimate Artifact Following Antecedent Biopsy: A Case Report.

MR-guided laser interstitial therapy (MRgLITT) is becoming more commonly used for minimal access approaches to intracranial lesions of all etiologies. The short-term safety profile of MRgLITT is favorable compared with sweeping incisions and open craniotomies, especially for lesions located in deep, periventricular, and highly eloquent areas. The Visualase software (Medtronic Inc., Minneapolis, MN, USA) has multiple adaptations to assist with this safety margin, including the thermal damage estimate (TDE), which applies predictive mathematical modeling to a two-dimensional (2D) graphical representation. TDE has been shown to highly correlate with actual tissue destruction in a priori MRgLITT cases and to anecdotally be imprecise when MRgLITT is combined with biopsy. We present a case regarding a 17-year-old male patient with intractable focal epilepsy. He underwent stereotactic biopsy and then ablation where it was shown that TDE is ~35% larger in the coronal plane than in the actual ablation zone. Air may have caused this artifact in the biopsy cavity, which affected the proton resonance frequency (PRF) and caused TDE pigment deposition. We believe in the need for a more comprehensive understanding and investigation regarding this TDE artifact. Future prospective studies into MRgLITT should attend carefully in cases where it is combined with biopsy.

Predictors of Seizure Freedom in Pediatric Low-Grade Gliomas.

OBJECTIVE: Pediatric low-grade gliomas (LGGs) are found in approximately one to three percent of patients with childhood epilepsy. Epilepsy in these patients is often medically refractory and therefore represents a unique cohort with significant morbidity from concomitant pathology. Similar studies in adult patients with low-grade gliomas have identified predictors of seizure freedom including gross-total resection, preoperative seizure control on antiepileptic medication and duration of seizures of less than one year. This study aims to identify similar predictors of seizure freedom in operatively managed pediatric LGGs. METHODS: A retrospective chart review was performed for patients diagnosed with World Health Organization (WHO) Grade I and II gliomas in patients ≤18 years old at a single institution (Indiana University School of Medicine at Riley Hospital for Children in Indianapolis, IN) from 2007-2017. Infratentorial and purely intraventricular lesions were excluded. WHO classification and histologic diagnosis were based on surgical pathology. Tumor grade, location, laterality, seizure status at presentation, and AED requirements pre- and post-operatively were recorded. Chi-squared analyses for independence were performed controlling for age at presentation, resection extent, seizure type, and Engel Class for seizure freedom post-operatively. RESULTS: Forty-two patients met the inclusion criteria. Preoperative seizures were observed in 23 patients (55%). Presentation with preoperative seizures was highly associated with continued seizure burden post-operatively, independent of the extent of surgical resection. Supratentorial location and the administration of prophylactic pre- and post-operative AEDs were associated with Engel Class I seizure freedom. Temporal location was not significantly associated with medically refractory epilepsy compared with extra-temporal locations. CONCLUSIONS: In our cohort of pediatric LGGs, we find that patients that did not initially present with seizures and those who were treated with prophylactic pre- and post-operative AEDs, were more likely to achieve Engel Class I seizure freedom post-operatively. Tumors located in the temporal location were not significantly associated with a higher seizure burden than other supratentorial, extra-temporal tumors. Neither extent of resection nor electrocorticography-guided resection correlated with improved seizure freedom outcomes during glioma resection.

"Reduced to My Race Once Again": Perceptions about Underrepresented Minority Medical School Applicants in Canada and the United States.

Phenomenon: To increase racial diversity in medical school classes, many institutions have created underrepresented minority (URM) application streams. However, many URM students experience overt and passive marginalization throughout their training and this may be related to how matriculants from URM streams are perceived by their peers. Approach: We conducted a discourse analysis of online discussion forums to explore how URM streams across Canada and the United States are perceived. We analyzed 850 posts from 13 discussion threads published between 2015 and 2020. We used inductive content analysis to develop a data-driven coding scheme from which we identified common themes. Findings: Despite an overall appreciation of the benefits of a diverse workforce, participants engaged in prominent discussions surrounding the merits of URM streams. We identified perceptions that students admitted from URM streams are less academically and clinically competent, with URM applicants reporting feeling unworthy for admission in the eyes of non-URM applicants. Users felt that the influence of socioeconomic status was under-appreciated, and that admissions officers inadequately addressed this barrier. There were some applicants who perceived the admissions process as "broken" with non-URMs displaying a fear of social change, and URMs fearing that the system defines them by their racialized status. Insights: Online discussion forums provide unique insight into perceptions surrounding URM streams. We identified potentially harmful misconceptions about URM students applying to these streams and highlight that actionable measures to reduce marginalization against URM matriculants must begin before medical school.

Sex differences in systemic bone and muscle loss following femur fracture in mice.

Fracture induces systemic bone loss in mice and humans, and a first (index) fracture increases the risk of future fracture at any skeletal site more in men than women. The etiology of this sex difference is unknown, but fracture may induces a greater systemic bone loss response in men. Also sex differences in systemic muscle loss after fracture have not been examined. We investigated sex differences in systemic bone and muscle loss after transverse femur fracture in 3-month-old male and female C57BL/6 J mice. Whole-body and regional bone mineral content and density (BMC and BMD), trabecular and cortical bone microstructure, muscle contractile force, muscle mass, and muscle fiber size were quantified at multiple time points postfracture. Serum concentrations of inflammatory cytokines (IL-1ß, IL-6, and TNF-α) were measured 1-day postfracture. One day postfracture, IL-6 and Il-1B were elevated in fracture mice of both sexes, but TNF-α was only elevated in male fracture mice. Fracture reduced BMC, BMD, and trabecular bone microstructural properties in both sexes 2 weeks postfracture, but declines were greater in males. Muscle contractile force, mass, and fiber size decreased primarily in the fractured limb at 2 weeks postfracture and females showed a trend toward greater muscle loss. Bone and muscle properties recovered by 6 weeks postfracture. Overall, postfracture systemic bone loss is greater in men, which may contribute to sex differences in subsequent fracture risk. In both sexes, muscle loss is primarily confined to the injured limb and fracture may induce greater inflammation in males.

An Unexpected Finding of Hepatosplenomegaly in a Pediatric Patient.

Gaucher disease (GD) is a rare autosomal recessive metabolic disorder. It is characterized by a deficiency of lysosomal glucocerebrosidase, which results in the accumulation of glycosphingolipid substrates, primarily glucosylceramide, in the phagocyte system. In GD Type 1, the liver, spleen, and bone marrow are typically affected. We report the case of a 7-year-old female with GD Type 1 who presented with hepatosplenomegaly detected incidentally following a motor vehicle accident. She was found to have concomitant thrombocytopenia and Erlenmeyer flask deformities of her lower limbs. Diagnosis was made on the basis of very low leukocyte ß-glucocerebrosidase activity and elevated plasma chitotriosidase. DNA mutation studies revealed both c.1226A>G and c.116_1505 deletion (exons 3-11). The patient is currently managed with biweekly intravenous imiglucerase (Cerezyme) replacement therapy. She demonstrated resolution of thrombocytopenia and hepatosplenomegaly at 2-year follow-up. Physicians must consider this rare diagnosis in children presenting with hepatosplenomegaly to prompt timely management.

GammaTile for Gliomas: A Single-Center Case Series.

GammaTile® (GT Medical Technologies, Tempe, Arizona) is a surgically targeted radiation source, approved by FDA for brachytherapy in primary and secondary brain neoplasms. Each GammaTile is composed of a collagen sponge with four seeds of cesium 131 and is particularly useful in recurrent tumors. We report our early experience in seven patients with recurrent gliomas to assess this type of brachytherapy with particular attention to ease of use, complication, and surgical planning. This study represents a retrospective chart review of surgical use and early clinical outcomes of GammaTile in recurrent gliomas. The number of tiles was planned using pre-operative imaging and dosimetry was planned based on post-operative imaging. Patients were followed during their hospital stay and were followed up after discharge. Parameters such as case length, resection extent, complication, ICU length of stay (LOS), hospital LOS, pre-operative Glasgow Coma Scale (GCS), immediate post-operative GCS, post-operative imaging findings, recurrence at follow-up, length of follow-up, and dosimetry were collected in a retrospective manner. Seven patients were identified that met the inclusion criteria. Two patients were diagnosed with recurrent glioblastoma multiforme (GBM), one lower-grade glioma that recurred as a GBM, one GBM that recurred as a gliosarcoma, and two recurrent oligodendrogliomas. We found that operation time, ICU LOS, hospital LOS, pre- and post-operative GCS, and post-operative complications were within the expected ranges for tumor resection patients. Further, dosimetry data suggests that six out of seven patients received adequate radiation coverage, with the seventh having implantation limitations due to nearby organs at risk. We report no postoperative complications that can be attributed to the GammaTiles themselves. In our cohort, we report seven cases where GammaTiles were implanted in recurrent gliomas. No implant-related post-operative complications were identified. This early data suggests that GammaTile can be a safe form of brachytherapy in recurrent gliomas.

Severe Generalized Bullous Fixed Drug Eruption Treated with Cyclosporine: A Case Report and Literature Review.

Generalized bullous fixed drug eruptions (GBFDEs) are rare in the paediatric population. We present the case of a 7-year-old girl with GBFDE believed to be secondary to oral ibuprofen, who experienced rapid resolution of lesions and cessation of blistering with a 3-week course of oral cyclosporine. To the best of our knowledge, this is the first report of a paediatric case of GBFDE treated with cyclosporine. In our report, we review published cases of GBFDE in children, and all adult cases managed with cyclosporine.

Symptomatic Cerebral Vasospasm After Transsphenoidal Tumor Resection: Two Case Reports and Systematic Literature Review.

Cerebral vasospasm is a rare life-threatening complication of transsphenoidal surgery (TSS). We report our experience with two cases of symptomatic vasospasm after endoscopic TSS, alongside a systematic review of published cases. Two patients who underwent endoscopic TSS for resection of a tuberculum sella meningioma (case 1) and pituitary adenoma (case 2) developed symptomatic vasospasm. Clinical variables, including demographics, histopathology, the extent of subarachnoid hemorrhage (SAH), diabetes insipidus (DI), day of vasospasm, vasospasm symptoms, vessels involved, management, and clinical outcome, were retrospectively extracted. We subsequently reviewed published cases of symptomatic post-TSS vasospasm. Including our two cases, we identified 34 reported cases of TSS complicated by symptomatic vasospasm. Female patients accounted for 20 (58.8%) of 34 cases. The average age was 48.1 ± 12.9 years. The majority of patients exhibited postoperative SAH (70.6%). The average delay to vasospasm presentation was 8.5 ± 3.6 days. The majority of patients exhibited vasospasm in multiple vessels, typically involving the anterior circulation. Hemodynamic augmentation with hemodilution, hypertension, and hypervolemia was the most common treatment. Death occurred in six (17.6%) of 34 patients. Common deficits included residual extremity weakness (17.6%), pituitary insufficiency (8.8%), and cognitive deficits (8.8%). Symptomatic vasospasm is a rare, potentially fatal complication of TSS. The most consistent risk factor is SAH. Early diagnosis requires a high index of suspicion when confronted with intractable DI, acute mental status change, or focal deficits in the days after TSS. Morbidity and death are significant risks in patients with this complication.

Photosynthetic Metabolism and Nitrogen Reshuffling Are Regulated by Reversible Cysteine Thiol Oxidation Following Nitrogen Deprivation in Chlamydomonas.

As global temperatures climb to historic highs, the far-reaching effects of climate change have impacted agricultural nutrient availability. This has extended to low latitude oceans, where a deficit in both nitrogen and phosphorus stores has led to dramatic decreases in carbon sequestration in oceanic phytoplankton. Although Chlamydomonas reinhardtii, a freshwater model green alga, has shown drastic systems-level alterations following nitrogen deprivation, the mechanisms through which these alterations are triggered and regulated are not fully understood. This study examined the role of reversible oxidative signaling in the nitrogen stress response of C. reinhardtii. Using oxidized cysteine resin-assisted capture enrichment coupled with label-free quantitative proteomics, 7889 unique oxidized cysteine thiol identifiers were quantified, with 231 significantly changing peptides from 184 proteins following 2 h of nitrogen deprivation. These results demonstrate that the cellular response to nitrogen assimilation, photosynthesis, pigment biosynthesis, and lipid metabolism are regulated by reversible oxidation. An enhanced role of non-damaging oxidative pathways is observed throughout the photosynthetic apparatus that provides a framework for further analysis in phototrophs.