GWAS with principal component analysis identify QTLs associated with main peanut flavor-related traits.

Peanut flavor is a complex and important trait affected by raw material and processing technology owing to its significant impact on consumer preference. In this research, principal component analysis (PCA) on 33 representative traits associated with flavor revealed that total sugars, sucrose, and total tocopherols provided more information related to peanut flavor. Genome-wide association studies (GWAS) using 102 U.S. peanut mini-core accessions were performed to study associations between 12,526 single nucleotide polymorphic (SNP) markers and the three traits. A total of 7 and 22 significant quantitative trait loci (QTLs) were identified to be significantly associated with total sugars and sucrose, respectively. Among these QTLs, four and eight candidate genes for the two traits were mined. In addition, two and five stable QTLs were identified for total sugars and sucrose in both years separately. No significant QTLs were detected for total tocopherols. The results from this research provide useful knowledge about the genetic control of peanut flavor, which will aid in clarifying the molecular mechanisms of flavor research in peanuts.

A Decrease in Effective Renal Perfusion Pressure Is Associated With Increased Acute Kidney Injury in Patients Undergoing Cardiac Surgery.

PURPOSE: This study aimed to evaluate the relationship between intra-abdominal pressure (IAP), renal perfusion indices, and postoperative acute kidney injury (AKI) in cardiac patients. METHODS: In a prospective cohort study conducted at a single academic institution, we collected data from adult patients undergoing open-heart operations with cardiopulmonary bypass (CPB) at our institution from February 2022 to April 2022 using the Accuryn SmartFoley system® (Potrero Medical, Hayward, CA). Patients on mechanical support devices, pregnant patients, and patients on hemodialysis were excluded. Demographics, hemodynamics, and mean airway pressure (mAir) were measured at the beginning of the cardiac operations and during the first four hours of ICU. Renal perfusion indices were then calculated (mean perfusion pressure (MPP) = mean arterial pressure (MAP) - central venous pressure (CVP); abdominal perfusion pressure (APP) = MAP - IAP; and effective renal perfusion pressure (eRPP) = MAP - (CVP + mAir + IAP)). Length of stay (LOS) was measured from the day of surgery to ICU discharge (ICU LOS) and hospital discharge (hospital LOS). RESULTS: During the first four hours of ICU stay, the non-AKI group had lower IAP and higher renal perfusion indices (MPP, APP, and eRPP). Logistic regression showed high perfusion pressures correlated with lower postoperative AKI (all OR <1, p<0.05). The postoperative AKI group also had significantly longer ICU LOS (7.33 vs. 4.57 days) and hospital LOS (17.0 vs. 10.2 days). CONCLUSION: Renal perfusion indices are a promising tool to predict postoperative AKI in cardiac surgery patients.

GWAS and bulked segregant analysis reveal the Loci controlling growth habit-related traits in cultivated Peanut (Arachis hypogaea L.).

BACKGROUND: Peanut (Arachis hypogaea L.) is a grain legume crop that originated from South America and is now grown around the world. Peanut growth habit affects the variety's adaptability, planting patterns, mechanized harvesting, disease resistance, and yield. The objective of this study was to map the quantitative trait locus (QTL) associated with peanut growth habit-related traits by combining the genome-wide association analysis (GWAS) and bulked segregant analysis sequencing (BSA-seq) methods. RESULTS: GWAS was performed with 17,223 single nucleotide polymorphisms (SNPs) in 103 accessions of the U.S. mini core collection genotyped using an Affymetrix version 2.0 SNP array. With a total of 12,342 high-quality polymorphic SNPs, the 90 suggestive and significant SNPs associated with lateral branch angle (LBA), main stem height (MSH), lateral branch height (LBL), extent radius (ER), and the index of plant type (IOPT) were identified. These SNPs were distributed among 15 chromosomes. A total of 597 associated candidate genes may have important roles in biological processes, hormone signaling, growth, and development. BSA-seq coupled with specific length amplified fragment sequencing (SLAF-seq) method was used to find the association with LBA, an important trait of the peanut growth habit. A 4.08 Mb genomic region on B05 was associated with LBA. Based on the linkage disequilibrium (LD) decay distance, we narrowed down and confirmed the region within the 160 kb region (144,193,467-144,513,467) on B05. Four candidate genes in this region were involved in plant growth. The expression levels of Araip.E64SW detected by qRT-PCR showed significant difference between 'Jihua 5' and 'M130'. CONCLUSIONS: In this study, the SNP (AX-147,251,085 and AX-144,353,467) associated with LBA by GWAS was overlapped with the results in BSA-seq through combined analysis of GWAS and BSA-seq. Based on LD decay distance, the genome range related to LBA on B05 was shortened to 144,193,467-144,513,467. Three candidate genes related to F-box family proteins (Araip.E64SW, Araip.YG1LK, and Araip.JJ6RA) and one candidate gene related to PPP family proteins (Araip.YU281) may be involved in plant growth and development in this genome region. The expression analysis revealed that Araip.E64SW was involved in peanut growth habits. These candidate genes will provide molecular targets in marker-assisted selection for peanut growth habits.

Insights into the Genomic Architecture of Seed and Pod Quality Traits in the U.S. Peanut Mini-Core Diversity Panel.

Traits such as seed weight, shelling percent, percent sound mature kernels, and seed dormancy determines the quality of peanut seed. Few QTL (quantitative trait loci) studies using biparental mapping populations have identified QTL for seed dormancy and seed grade traits. Here, we report a genome-wide association study (GWAS) to detect marker-trait associations for seed germination, dormancy, and seed grading traits in peanut. A total of 120 accessions from the U.S. peanut mini-core collection were evaluated for seed quality traits and genotyped using Axiom SNP (single nucleotide polymorphism) array for peanut. We observed significant variation in seed quality traits in different accessions and different botanical varieties. Through GWAS, we were able to identify multiple regions associated with sound mature kernels, seed weight, shelling percent, seed germination, and dormancy. Some of the genomic regions that were SNP associated with these traits aligned with previously known QTLs. For instance, QTL for seed dormancy has been reported on chromosome A05, and we also found SNP on the same chromosome associated with seed dormancy, explaining around 20% of phenotypic variation. In addition, we found novel genomic regions associated with seed grading, seed germination, and dormancy traits. SNP markers associated with seed quality and dormancy identified here can accelerate the selection process. Further, exploring the function of candidate genes identified in the vicinity of the associated marker will assist in understanding the complex genetic network that governs seed quality.

Transcriptome Profile Reveals Drought-Induced Genes Preferentially Expressed in Response to Water Deficit in Cultivated Peanut (Arachis hypogaea L.).

Cultivated peanut (Arachis hypogaea) is one of the most widely grown food legumes in the world, being valued for its high protein and unsaturated oil contents. Drought stress is one of the major constraints that limit peanut production. This study's objective was to identify the drought-responsive genes preferentially expressed under drought stress in different peanut genotypes. To accomplish this, four genotypes (drought tolerant: C76-16 and 587; drought susceptible: Tifrunner and 506) subjected to drought stress in a rainout shelter experiment were examined. Transcriptome sequencing analysis identified that all four genotypes shared a total of 2,457 differentially expressed genes (DEGs). A total of 139 enriched gene ontology terms consisting of 86 biological processes and 53 molecular functions, with defense response, reproductive process, and signaling pathways, were significantly enriched in the common DEGs. In addition, 3,576 DEGs were identified only in drought-tolerant lines in which a total of 74 gene ontology terms were identified, including 55 biological processes and 19 molecular functions, mainly related to protein modification process, pollination, and metabolic process. These terms were also found in shared genes in four genotypes, indicating that tolerant lines adjusted more related genes to respond to drought. Forty-three significantly enriched Kyoto Encyclopedia of Genes and Genomes pathways were also identified, and the most enriched pathways were those processes involved in metabolic pathways, biosynthesis of secondary metabolites, plant circadian rhythm, phenylpropanoid biosynthesis, and starch and sucrose metabolism. This research expands our current understanding of the mechanisms that facilitate peanut drought tolerance and shed light on breeding advanced peanut lines to combat drought stress.

Association of differentially expressed R-gene candidates with leaf spot resistance in peanut (Arachis hypogaea L.).

Early leaf spot (ELS) and late leaf spot (LLS) are major fungal diseases of peanut that can severely reduce yield and quality. Development of acceptable genetic resistance has been difficult due to a strong environmental component and many major and minor QTLs. Resistance genes (R-genes) are an important component of plant immune system and have been identified in peanut. Association of specific R-genes to leaf spot resistance will provide molecular targets for marker-assisted breeding strategies. In this study, advanced breeding lines from different pedigrees were evaluated for leaf spot resistance and 76 candidate R-genes expression study was applied to susceptible and resistant lines. Thirty-six R-genes were differentially expressed and significantly correlated with resistant lines, of which a majority are receptor like kinases (RLKs) and receptor like proteins (RLPs) that sense the presence of pathogen at the cell surface and initiate protection response. The largest group was receptor-like cytoplasmic kinases (RLCKs) VII that are involved in pattern-triggered kinase signaling resulting in the production reactive oxygen species (ROS). Four R-genes were homologous to TMV resistant protein N which has shown to confer resistance against tobacco mosaic virus (TMV). When mapped to peanut genomes, 36 R-genes were represented in most chromosomes except for A09 and B09. Low levels of gene-expression in resistant lines suggest expression is tightly controlled to balance the cost of R-gene expression to plant productively. Identification and association of R-genes involved in leaf spot resistance will facilitate genetic selection of leaf spot resistant lines with good agronomic traits.

Identification of potential QTLs and genes associated with seed composition traits in peanut (Arachis hypogaea L.) using GWAS and RNA-Seq analysis.

Cultivated peanut (Arachis hypogaea L.) is a major oilseed crop providing edible oil and protein. Oil quality is determined by fatty acid composition including the ratio of oleic acid (C18:1) and linoleic acid (C18:2). A genome-wide association study with 13,382 single nucleotide polymorphisms (SNPs) was conducted to investigate the genetics basis of oil, protein, eight fatty acid concentrations, and O/L ratio (ratio of oleic and linoleic acid) using a diverse panel of 120 genotypes mainly selected from the U.S. peanut mini core collection grown in two years. A total of 178 significant quantitative trait loci (QTLs) associated with those seed composition traits were identified with phenotypic variation explained (PVE) from 18.35% to 27.56%. RNA-Seq analysis identified 282 DEGs (differentially expressed genes) within the 1 Mb of the significant QTLs for seed composition traits. Among those 282 genes, sixteen candidate genes for seed fatty acid metabolism and protein synthesis were screened according to the gene functions.

Identification of QTLs for resistance to leaf spots in cultivated peanut (Arachis hypogaea L.) through GWAS analysis.

KEY MESSAGE: Two QTLs on ChrB09 significantly associated with both early and late leaf spots were identified by genome-wide association study in the US peanut mini-core collection. Early leaf spot (ELS) and late leaf spot (LLS) are two serious peanut diseases in the USA, causing tens of millions of dollars of annual economic losses. However, the genetic factors underlying resistance to those diseases in peanuts have not been well-studied. We conducted a genome-wide association study for the two peanut diseases using Affymetrix version 2.0 SNP array with 120 genotypes mainly coming from the US peanut mini-core collection. A total of 46 quantitative trait loci (QTLs) were identified with phenotypic variation explained (PVE) from 10.19 to 24.11%, in which eighteen QTLs are for resistance to ELS and 28 QTLs for LLS. Among the 46 QTLs, there were four and two major QTLs with PVE higher than 16.99% for resistance ELS and LLS, respectively. Of the six major QTLs, five were located on the B sub-genome and only one was on the A sub-genome, which suggested that the B sub-genome has more potential resistance genomic regions than the A sub-genome. In addition, two genomic regions on chromosome B09 were found to provide significant resistance to both ELS and LLS. A total of 74 non-redundant genes were identified as resistance genes, among which, twelve candidate genes were in significant genomic regions including two candidate genes for both ELS and LLS, and other ten candidate genes for ELS. The QTLs and candidate genes obtained from this study will be useful to breed peanuts for resistances to the diseases.

GWAS and Coexpression Network Reveal Ionomic Variation in Cultivated Peanut.

Peanut is an important legume providing products with nutrient dense including mineral nutrition. However, the genetic basis underlying the variations in the mineral composition in peanut is still unknown. Genome-wide association studies (GWAS) of the concentrations of 13 mineral elements combined with coexpression network were performed using a diverse panel of 120 genotypes mainly selected from the U.S. peanut mini core collection. A total of 36 significant quantitative trait loci (QTLs) associated with five elemental concentrations were identified with phenotypic variation explained (PVE) from 18.35% to 27.56%, in which 24 QTLs were for boron (B), 2 QTLs for copper (Cu), 6 QTLs for sodium (Na), 3 QTLs for sulfur (S), and 1 QTL for zinc (Zn). A total of 110 nonredundant candidate causal genes identified were significantly associated with elemental accumulation, which included one high-priority overlap (HPO) candidate gene arahy.KQD4NT, an important elemental/metal transporter gene located on LGB04 with position 5,413,913-5,417,353.

Identification of expressed R-genes associated with leaf spot diseases in cultivated peanut.

Peanut (Arachis hypogaea L.) is an important food and oilseed crop worldwide. Yield and quality can be significantly reduced by foliar fungal diseases, such as early and late leaf spot diseases. Acceptable levels of leaf spot resistance in cultivated peanut have been elusive due to environmental interactions and the proper combination of QTLs in any particular peanut genotype. Resistance gene analogs, as potential resistance (R)-genes, have unique roles in the recognition and activation of disease resistance responses. Novel R-genes can be identified by searches for conserved domains such as nucleotide binding site, leucine rich repeat, receptor like kinase, and receptor like protein from expressed genes or through genomic sequences. Expressed R-genes represent necessary plant signals in a disease response. The goals of this research are to identify expressed R-genes from cultivated peanuts that are naturally infected by early and late spot pathogens, compare these to the closest diploid progenitors, and evaluate specific gene expression in cultivated peanuts. Putative peanut R-genes (381) were available from a public database (NCBI). Primers were designed and PCR products were sequenced. A total of 214 sequences were produced which matched to proteins with the corresponding R-gene motifs. These R-genes were mapped to the genome sequences of Arachis duranensis and Arachis ipaensis, which are the closest diploid progenitors for tetraploid cultivated peanut, A. hypogaea. Identification and association of specific gene-expression will elucidate potential disease resistance mechanism in peanut and may facilitate the selection of breeding lines with high levels of leaf spot resistance.

Refining a major QTL controlling spotted wilt disease resistance in cultivated peanut (Arachis hypogaea L.) and evaluating its contribution to the resistance variations in peanut germplasm.

BACKGROUND: Spotted wilt, caused by tomato spotted wilt virus (TSWV), has been one of major diseases in cultivated peanut grown in the southeastern United States (US) since 1990. Previously a major quantitative trait locus (QTL) controlling spotted wilt disease resistance was mapped to an interval of 2.55 cM genetic distance corresponding to a physical distance of 14.4 Mb on chromosome A01 of peanut by using a segregating F2 population. The current study focuses on refining this major QTL region and evaluating its contributions in the US peanut mini-core germplasm. RESULTS: Two simple sequence repeat (SSR) markers associated with the major QTL were used to genotype F5 individuals, and 25 heterozygous individuals were selected and developed into an F6 segregating population. Based on visual evaluation in the field, a total of 194 susceptible F6 individuals were selected and planted into F7 generation for phenotyping. Nine SSR markers were used to genotype the 194 F6 individuals, and QTL analysis revealed that a confidence interval of 15.2 Mb region had the QTL with 22.8% phenotypic variation explained (PVE). This QTL interval was further genotyped using the Amplicon-seq method. A total of 81 non-redundant single nucleotide polymorphism (SNP) and eight InDel markers were detected. No recombinant was detected among the F6 individuals. Two InDel markers were integrated into the linkage group and helped to refine the confidence interval of this QTL into a 0.8 Mb region. To test the QTL contributes to the resistance variance in US peanut mini-core germplasm, two flanking SSR markers were used to genotype 107 mini-core germplasm accessions. No statistically significant association was observed between the genotype at the QTL region and spotted wilt resistance in the mini-core germplasm, which indicated that the resistance allelic region at this QTL didn't contribute to the resistance variance in the US peanut mini-core germplasm, thus was a unique resistance source. CONCLUSION: A major QTL related to spotted wilt disease resistance in peanut was refined to a 0.8 Mb region on A01 chromosome, which didn't relate to spotted wilt disease resistance in the US peanut mini-core germplasm and might be a unique genetic source.

Changes of Seed Weight, Fatty Acid Composition, and Oil and Protein Contents from Different Peanut FAD2 Genotypes at Different Seed Developmental and Maturation Stages.

The level of oleic acid in peanut seed is one of the most important factors in determining seed quality and is controlled by two pairs of homeologous genes ( FAD2A and FAD2B). The genotypes of eight F8 breeding lines were determined as AABB, aaBB, AAbb, and aabb by real-time polymerase chain reaction and sequencing. Fresh seeds were collected from five seed developmental stages and, after drying, were used for chemical analysis. Our results showed that (1) as seeds developed, seed weight, oil content, and oleic acid level significantly increased, whereas four other fatty acid levels decreased, but protein content and another four fatty acid levels did not significantly change, (2) FAD2A/ FAD2B significantly affected fatty acid profiles but not oil and protein contents, and (3) the data were consistent across 2 years. The variability of seed quality traits revealed here will be useful for peanut breeders, farmers, processers, and consumers.

Conducting Prolonged General Anesthesia without Intravenous Access in a Child with Hypoplastic Left Heart Syndrome.

Children with chronic medical conditions often need multiple intravenous (IV) access instances during their hospitalizations, both peripheral and central. Obtaining a working IV in this patient population undergoing general anesthesia can be challenging. In our case report, we describe a method of administering general anesthesia in an infant with partially repaired hypoplastic left heart syndrome without IV access.

Lymph Node Yield in Therapeutic Neck Dissection: Impact of Dissection Levels and Prior Radiotherapy.

OBJECTIVE: Lymph node yield in therapeutic neck dissection is clinically significant and incompletely studied. We quantified node yield based on extent of neck dissection and presence of preoperative radiation. We also evaluated factors affecting incidence of extracapsular spread (ECS). METHODS: Retrospective review of 499 patients undergoing therapeutic neck dissection; 414 patients met inclusion criteria and were divided into 2 groups: neck dissection alone or before radiation (surgery first: 280 patients; 385 dissections) and primary radiation before surgery (radiation first: 134 patients; 157 dissections). Node yield relative to levels dissected and incidence of ECS were examined. RESULTS: Dissection-specific node yield was greater in the surgery first group for dissection of levels I-V (31.1 ± 16.7 vs 24.0 ± 14.7, P < .001) and levels II-V (26.7 ± 14.4 vs 21.1 ± 10.7). Extracapsular spread incidence was 32.1% (98/305) in the surgery first group and 15.4% (23/149) in the radiation first group ( P < .001). CONCLUSION: This study clarifies anticipated node yield based on number of levels dissected and presence of preoperative radiation. Node yield and incidence of ECS are lower in patients undergoing preoperative radiation.

Characterization of small RNA populations in non-transgenic and aflatoxin-reducing-transformed peanut.

Aflatoxin contamination is a major constraint in food production worldwide. In peanut (Arachis hypogaea L.), these toxic and carcinogenic aflatoxins are mainly produced by Aspergillus flavus Link and A. parasiticus Speare. The use of RNA interference (RNAi) is a promising method to reduce or prevent the accumulation of aflatoxin in peanut seed. In this study, we performed high-throughput sequencing of small RNA populations in a control line and in two transformed peanut lines that expressed an inverted repeat targeting five genes involved in the aflatoxin-biosynthesis pathway and that showed up to 100% less aflatoxin B1 than the controls. The objective was to determine the putative involvement of the small RNA populations in aflatoxin reduction. In total, 41 known microRNA (miRNA) families and many novel miRNAs were identified. Among those, 89 known and 10 novel miRNAs were differentially expressed in the transformed lines. We furthermore found two small interfering RNAs derived from the inverted repeat, and 39 sRNAs that mapped without mismatches to the genome of A. flavus and were present only in the transformed lines. This information will increase our understanding of the effectiveness of RNAi and enable the possible improvement of the RNAi technology for the control of aflatoxins.

RNAi-mediated Control of Aflatoxins in Peanut: Method to Analyze Mycotoxin Production and Transgene Expression in the Peanut/Aspergillus Pathosystem.

The Food and Agriculture Organization of the United Nations estimates that 25% of the food crops in the world are contaminated with aflatoxins. That represents 100 million tons of food being destroyed or diverted to non-human consumption each year. Aflatoxins are powerful carcinogens normally accumulated by the fungi Aspergillus flavus and A. parasiticus in cereals, nuts, root crops and other agricultural products. Silencing of five aflatoxin-synthesis genes by RNA interference (RNAi) in peanut plants was used to control aflatoxin accumulation following inoculation with A. flavus. Previously, no method existed to analyze the effectiveness of RNAi in individual peanut transgenic events, as these usually produce few seeds, and traditional methods of large field experiments under aflatoxin-conducive conditions were not an option. In the field, the probability of finding naturally contaminated seeds is often 1/100 to 1/1,000. In addition, aflatoxin contamination is not uniformly distributed. Our method uses few seeds per transgenic event, with small pieces processed for real-time PCR (RT-PCR) or small RNA sequencing, and for analysis of aflatoxin accumulation by ultra-performance liquid chromatography (UPLC). RNAi-expressing peanut lines 288-72 and 288-74, showed up to 100% reduction (p ≤ 0.01) in aflatoxin B1 and B2 compared to the control that accumulated up to 14,000 ng · g(-1) of aflatoxin B1 when inoculated with aflatoxigenic A. flavus. As reference, the maximum total of aflatoxins allowable for human consumption in the United States is 20 ng · g(-1). This protocol describes the application of RNAi-mediated control of aflatoxins in transgenic peanut seeds and methods for its evaluation. We believe that its application in breeding of peanut and other crops will bring rapid advancement in this important area of science, medicine and human nutrition, and will significantly contribute to the international effort to control aflatoxins, and potentially other mycotoxins in major food crops.

Development and Utilization of InDel Markers to Identify Peanut (Arachis hypogaea) Disease Resistance.

Peanut diseases, such as leaf spot and spotted wilt caused by Tomato Spotted Wilt Virus, can significantly reduce yield and quality. Application of marker assisted plant breeding requires the development and validation of different types of DNA molecular markers. Nearly 10,000 SSR-based molecular markers have been identified by various research groups around the world, but less than 14.5% showed polymorphism in peanut and only 6.4% have been mapped. Low levels of polymorphism limit the application of marker assisted selection (MAS) in peanut breeding programs. Insertion/deletion (InDel) markers have been reported to be more polymorphic than SSRs in some crops. The goals of this study were to identify novel InDel markers and to evaluate the potential use in peanut breeding. Forty-eight InDel markers were developed from conserved sequences of functional genes and tested in a diverse panel of 118 accessions covering six botanical types of cultivated peanut, of which 104 were from the U.S. mini-core. Results showed that 16 InDel markers were polymorphic with polymorphic information content (PIC) among InDels ranged from 0.017 to 0.660. With respect to botanical types, PICs varied from 0.176 for fastigiata var., 0.181 for hypogaea var., 0.306 for vulgaris var., 0.534 for aequatoriana var., 0.556 for peruviana var., to 0.660 for hirsuta var., implying that aequatoriana var., peruviana var., and hirsuta var. have higher genetic diversity than the other types and provide a basis for gene functional studies. Single marker analysis was conducted to associate specific marker to disease resistant traits. Five InDels from functional genes were identified to be significantly correlated to tomato spotted wilt virus (TSWV) infection and leaf spot, and these novel markers will be utilized to identify disease resistant genotype in breeding populations.

In-office biopsy of upper airway lesions: safety, tolerance, and effect on time to treatment.

OBJECTIVES/HYPOTHESIS: Definitive tissue diagnosis for lesions warranting biopsy is shifting from the operating room to the office. Safety, tolerance, factors related to successful biopsy, and time to treatment are not well-defined. METHODS: Retrospective review of 116 patients undergoing in-office biopsy of oropharynx, larynx, or hypopharynx were included. Logistic regression determined if demographics, site, T-stage, or approach (transoral/transnasal) were related to success. Time to definitive treatment was also analyzed. RESULTS: Ninety-two transnasal and 24 transoral biopsies were performed on 73 laryngeal, 35 oropharyngeal, and 8 hypopharyngeal lesions. Of those, 97 of 116 diagnoses were made in-office. There were no complications; two patients did not tolerate the procedure. Success was not related to age (P = 0.374), site (P = 0.527), T-stage (P = 0.587), or approach (P = 0.566). Time to treatment was 24.2 ± 13.9 days with successful office biopsy and 48.8 ± 49.4 days without. CONCLUSIONS: High procedural completion rate was observed across patients, sites, and approaches. All patients should be considered for in-office biopsy, a more time- and cost-effective option leading to earlier treatment.

Care of pediatric tracheostomy in the immediate postoperative period and timing of first tube change.

OBJECTIVE: To analyze the safety of a standardized pediatric tracheostomy care protocol in the immediate postoperative period and its impact on tracheostomy related complications. STUDY DESIGN: Retrospective case series. SUBJECTS: Pediatric patients undergoing tracheotomy from February 2010-February 2014. METHODS: In 2012, a standardized protocol was established regarding postoperative pediatric tracheostomy care. This protocol included securing newly placed tracheostomy tubes using a foam strap with hook and loop fastener rather than twill ties, placing a fresh drain sponge around the tracheostomy tube daily, and performing the first tracheostomy tube change on postoperative day 3 or 4. Outcome measures included rate of skin breakdown and presence of a mature stoma allowing for a safe first tracheostomy tube change. Two types of tracheotomy were performed based on patient age: standard pediatric tracheotomy and adult-style tracheotomy with a Bjork flap. Patients were analyzed separately based on age and the type of tracheotomy performed. RESULTS: Thirty-seven patients in the pre-protocol group and 35 in the post-protocol group were analyzed. The rate of skin breakdown was significantly lower in the post-protocol group (standard: p=0.0048; Bjork flap: p=0.0003). In the post-protocol group, all tube changes were safely accomplished on postoperative day three or four, and the stomas were deemed to be adequately matured to do so in all cases. CONCLUSION: A standardized postoperative pediatric tracheostomy care protocol resulted in decreased rates of skin breakdown and demonstrated that pediatric tracheostomy tubes can be safely changed as early as 3 days postoperatively.

Unimodal primary sensory cortices are directly connected by long-range horizontal projections in the rat sensory cortex.

Research based on functional imaging and neuronal recordings in the barrel cortex subdivision of primary somatosensory cortex (SI) of the adult rat has revealed novel aspects of structure-function relationships in this cortex. Specifically, it has demonstrated that single whisker stimulation evokes subthreshold neuronal activity that spreads symmetrically within gray matter from the appropriate barrel area, crosses cytoarchitectural borders of SI and reaches deeply into other unimodal primary cortices such as primary auditory (AI) and primary visual (VI). It was further demonstrated that this spread is supported by a spatially matching underlying diffuse network of border-crossing, long-range projections that could also reach deeply into AI and VI. Here we seek to determine whether such a network of border-crossing, long-range projections is unique to barrel cortex or characterizes also other primary, unimodal sensory cortices and therefore could directly connect them. Using anterograde (BDA) and retrograde (CTb) tract-tracing techniques, we demonstrate that such diffuse horizontal networks directly and mutually connect VI, AI and SI. These findings suggest that diffuse, border-crossing axonal projections connecting directly primary cortices are an important organizational motif common to all major primary sensory cortices in the rat. Potential implications of these findings for topics including cortical structure-function relationships, multisensory integration, functional imaging, and cortical parcellation are discussed.