Prevalence and barriers of reporting needle-stick injures amongst government pharmacists working in Perak, Malaysia

INTRODUCTION

Needle-stick injuries (NSIs) are common amongst healthcare workers including pharmacists. Studies have reported a range of 0-5.65 per 1,000 pharmacists handling vaccinations that suffered at least one incident of NSI. The objective of this study was to determine the prevalence of NSI and the barriers encountered in reporting it amongst government pharmacists working in Perak.

MATERIALS AND METHODS

This was a cross-sectional study conducted amongst all government pharmacists in Perak. We excluded those who did not consent or were unreachable electronically. The researchers provided an online link that was forwarded to all heads of departments in Perak via social media. The respondents answered their demographic details, questions assessing their knowledge of NSI transmissible diseases, needle-stick handling practices, detail experiences of them suffering an NSI (all self-developed questionnaires), and their barriers in reporting an NSI (validated questionnaire). All responses were auto-tabulated in an excel sheet. A sample size of 516 pharmacists was needed for this study. A respondent was deemed to have inadequate knowledge when they answered any question wrongly about NSI knowledge-related questions and inappropriate practice in needle handling when respondents answered any questions wrongly for questions assessing practices.

RESULTS

A total of 524 pharmacists participated. The overall prevalence of NSI was 23.1% (n=121), of which, those with contaminated NSI were 10.3% (n=54, 95%CI: 7.9-13.30). Twothirds of the participants (66.6%) had inadequate knowledge and nearly all of them were unable to describe the appropriate needle-handling practices (94.7%). Amongst the reported barriers were "not knowing whose duty it was to report an NSI" (45.5%) and "busy schedules" (44.7%).

CONCLUSION

One in every five pharmacists in the state of Perak had a history of NSI, and 1 in every 10 had sustained a contaminated NSI. The barriers to reporting a NSI were mainly due to uncertainty about whose responsibility to report the incident and being too busy to report it.

Field-resolved high-order sub-cycle nonlinearities in a terahertz semiconductor laser

The exploitation of ultrafast electron dynamics in quantum cascade lasers (QCLs) holds enormous potential for intense, compact mode-locked terahertz (THz) sources, squeezed THz light, frequency mixers, and comb-based metrology systems. Yet the important sub-cycle dynamics have been notoriously difficult to access in operational THz QCLs. Here, we employ high-field THz pulses to perform the first ultrafast two-dimensional spectroscopy of a free-running THz QCL. Strong incoherent and coherent nonlinearities up to eight-wave mixing are detected below and above the laser threshold. These data not only reveal extremely short gain recovery times of 2 ps at the laser threshold, they also reflect the nonlinear polarization dynamics of the QCL laser transition for the first time, where we quantify the corresponding dephasing times between 0.9 and 1.5 ps with increasing bias currents. A density-matrix approach reproducing the emergence of all nonlinearities and their ultrafast evolution, simultaneously, allows us to map the coherently induced trajectory of the Bloch vector. The observed high-order multi-wave mixing nonlinearities benefit from resonant enhancement in the absence of absorption losses and bear potential for a number of future applications, ranging from efficient intracavity frequency conversion, mode proliferation to passive mode locking.

Nurse-Delivered Brief Behavioral Treatment for Insomnia in Lung Cancer Survivors: A Pilot RCT

Objective/Background: Insomnia occurs in 50 to 80% of lung cancer survivors. Cognitive behavioral therapy is the standard treatment for insomnia (CBTI); however, treatment length and lack of psychologists trained in CBTI limits access. Brief Behavioral Treatment for Insomnia (BBTI), a nurse-delivered modified CBTI, is proposed. This feasibility pilot study sought to compare the BBTI intervention to attention control Healthy Eating Program (HEP) for insomnia in lung cancer survivors. Participants: The participants comprised adults, 21 years of age or older with insomnia and stage I/II non-small cell lung cancer, more than 6 weeks from surgery and living in Western NY. Methods: Participants (n = 40) were randomly assigned to an experimental (BBTI) or attention control condition (Healthy Eating Program). Thirty participants completed the study. Results: Participants were 66 years of age (± 7.6; range 53-82), 40% (n = 16) male, 87.5% (n = 35) Caucasian, 50% (n = 20) married, BMI 27.7 (± 5.8), and 12% (n = 5) never smokers. Baseline sleep diary sleep efficiency, ISI and other baseline covariates were balanced between the groups. Sleep efficiency improved ≥85% in BBTI group (p = .02), but not in HEP control group (p = 1.00). Mean ISI for BBTI and attention control were 6.40 ± 4.98 and 14.10 ± 4.48 (p = .001) respectively. In addition, BBTI group mean total FACT-L score improved by 6.66 points from baseline while HEP group score worsened (p = .049). Conclusions: BBTI is a practical, evidence-based, clinically relevant intervention that improved sleep and quality of life in lung cancer survivors with insomnia. Additional research to evaluate efficacy, duration, and implementation strategies are essential.

Molecular subtyping reveals immune alterations associated with progression of bronchial premalignant lesions

Bronchial premalignant lesions (PMLs) are precursors of lung squamous cell carcinoma, but have variable outcome, and we lack tools to identify and treat PMLs at risk for progression to cancer. Here we report the identification of four molecular subtypes of PMLs with distinct differences in epithelial and immune processes based on RNA-Seq profiling of endobronchial biopsies from high-risk smokers. The Proliferative subtype is enriched with bronchial dysplasia and exhibits up-regulation of metabolic and cell cycle pathways. A Proliferative subtype-associated gene signature identifies subjects with Proliferative PMLs from normal-appearing uninvolved large airway brushings with high specificity. In progressive/persistent Proliferative lesions expression of interferon signaling and antigen processing/presentation pathways decrease and immunofluorescence indicates a depletion of innate and adaptive immune cells compared with regressive lesions. Molecular biomarkers measured in PMLs or the uninvolved airway can enhance histopathological grading and suggest immunoprevention strategies for intercepting the progression of PMLs to lung cancer.

High-speed THz spectroscopic imaging at ten kilohertz pixel rate with amplitude and phase contrast

By combining the advantages of the high-speed ASOPS technology and efficient THz generation, we have realized a high-speed laser-based spectroscopic THz imaging system with more than 10,000 pixels per second acquisition speed and an excellent signal-to-noise ratio of more than 100. Unlike THz line cameras or mm-wave intensity detectors, the present device allows for a much higher spatial resolution and attributes each imaging pixel with phase and amplitude information up to several THz while simultaneously maintaining a very high scanning speed unmatched by any other technique presented so far. The high-speed acquisition allows for samples to be scanned even at sample velocities of 5 m/s or higher while preserving the fundamental resolution limit of the THz radiation, which is on the order of 500 µm in the present case.

Characterizing the T cell repertoire in lung squamous cell premalignancy and its association with lesion outcome

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Background: The immune response to frank malignancy has been the focus of published work, but little is known about the adaptive immune response to bronchial premalignant lesions (PMLs), precursors of lung squamous cell carcinoma. This study was designed to characterize the T cell receptor (TCR) repertoire in PMLs and its association with clinical, pathological and molecular features. Methods: Endobronchial biopsies (n=294) and brushings (n=137) from high-risk subjects (n=50), undergoing lung cancer screening at approximately 1-year intervals via auto fluorescence bronchoscopy and CT, were profiled by RNA-Seq as part of the Pre-Cancer Genome Atlas (PCGA). We applied the TCR Repertoire Utilities for Solid Tissue/Tumor (TRUST) tool to identify TCR CDR3 sequences in the RNA-Seq data. We quantified the ratio of private (i.e., found in one patient only) and public (i.e. found in two or more patients) TCRs that are found in curated databases with known antigen specificities. We measured the correlation of TCR diversity with previously derived PML transcriptional signatures and molecular subtypes; and with mutational burden among a subset of biopsies (n=115) also profiled with whole exome sequencing. Results: We detected 40,421 unique TCR sequences, of which 3,396 (8.4%) were found in more than one sample and 1,057 (2.6%) were found in two or more patients (i.e. Public). TCRs with known antigen specificities were enriched among public TCRs (p < 0.001). In PMLs with a proliferative molecular subtype reflective of dysplasia (n=80), TCR diversity was decreased in PMLs that regressed versus PMLs that progressed (p=0.045). TCR diversity was negatively associated with a transcriptional signature of T-cell mediated immune activation (Spearman’s rho -0.26, p < 0.001) but was not associated with mutational burden. Conclusions: To our knowledge, this is the first characterization of the TCR repertoire associated with bronchial premalignant lesions. TCR diversity may help predict the efficacy of the host immune response to PMLs but it is not associated with mutational burden. Further studies are needed to leverage these findings and explore the potential for immunoprevention of PMLs.

Abstract 3248: Genomic characterization of premalignant lung squamous cell carcinoma lesions

Background: Lung squamous cell carcinoma (SqCC) arises in the epithelial layer of the bronchial airway and is often preceded by the development of premalignant lesions. However, not all premalignant lesions progress to lung SqCC and many will regress spontaneously. Understanding the somatic alterations and molecular subtypes associated with progression will allow us to identify biomarkers for early detection and develop therapeutic strategies for disease prevention and interception. Methods: Biopsies were obtained from high-risk smokers undergoing lung cancer screening by auto-fluorescence bronchoscopy and CT at the Roswell Park Cancer Institute. For each subject, multiple sites were sampled repeatedly over time. One biopsy from each region was sent for pathological review while another biopsy was taken for molecular studies. Whole-exome sequencing (WES) was performed at Uniform Services University to 120x coverage and RNA-seq was performed at Boston University School of Medicine. Results: The median number of somatic mutations across all premalignant lesions that underwent DNA-seq (150 biopsies from 20 subjects) was 0.45 per megabase and displayed a modest association with histological grade (p=0.05). The most frequently mutated known lung cancer genes included NOTCH1 (14%), TP53 (6%), FAT1 (3%), PIK3CA (2%), KRAS (&lt;1%), and CDKN2A (&lt;1%). One patient had a moderate dysplastic lesion without any detectable arm-level copy number changes or known cancer mutations. Six months later, this lesion had progressed to severe dysplasia and obtained many genomic alterations commonly observed in squamous cell carcinoma including 3q gain, 3p loss, and mutations in TP53, NOTCH1, and CDKN2A. Using RNA-seq, we identified 4 distinct molecular subtypes using 197 biopsies from 29 subjects. One subtype was enriched for samples with dysplasia histology, high basal cell content, and the “Classical” SqCC tumor gene expression subtype (p&lt;0.001). These associations replicated in an independent set of 111 biopsies from 20 subjects. Genes associated with IFN-gamma signaling and T cell mediated immunity were down-regulated among lesions that persisted or progressed vs. those that regressed within the high-grade subtype. Staining of adjacent biopsies revealed that decreased expression of these immune pathways was associated with decreased numbers of CD4+ and CD8+ T cells within the lesions and surrounding tissue. Conclusions: The somatic alterations observed in known cancer genes may be among the earliest events in lung SqCC development and may be useful as biomarkers for early detection. Molecular classification of these lesions into molecular subtypes may lead to biomarkers of disease progression that could be used to identify at-risk patients for aggressive surveillance or for prevention trials.

Citation Format: Joshua D. Campbell, Xijun Zhang, Catalina Perdomo, Sarah Mazzilli, Yaron Geshalter, Samjot S. Dhillon, Gang Liu, Sherry Zhang, Hanqiao Liu, Jessica Vick, Christopher Moy, Stefano Monti, Evan Johnson, Matthew Meyerson, Matthew Wilkerson, Clifton Dalgard, Suso Platero, Chris Stevenson, Marc Lenburg, Mary Reid, Jennifer Beane, Avrum Spira. Genomic characterization of premalignant lung squamous cell carcinoma lesions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3248.

Abstract 3259: The genomic landscape of premalignant lung squamous cell carcinoma lesions

Background: Lung squamous cell carcinoma (SqCC) arises in the epithelial layer of the bronchial airway and is often preceded by the development of premalignant lesions. However, not all premalignant lesions progress to lung SqCC and many regress without therapeutic intervention. Understanding the somatic alterations that contribute to progression of premalignant lesions in the airway will allow us to identify biomarkers for early detection and develop therapeutic strategies for early intervention.

Methods: Airway biopsies were obtained from high-risk smokers undergoing lung cancer screening by auto-fluorescence bronchoscopy and chest CT at the Roswell Park Cancer Institute. For each subject (n=30), multiple premalignant lesions were sampled repeatedly over time (n=144 samples). One biopsy from each region was sent for pathological review while another biopsy was taken for molecular studies. DNA was also isolated from the blood or cytologically normal bronchial brushings to serve as a matched normal control. Exome capture was performed using the Illumina TruSeq Rapid Exome kit and sequenced to a mean depth of coverage of 120x at Uniform Services University and Walter Reed National Military Medical Center.

Results: The median number of somatic mutations across all premalignant lesions was 0.73 per megabase (range: 0.10 - 9.8 per Mb) and displayed a modest association with histological grade (p=0.07). The most frequently mutated lung cancer genes included KMT2C (12%), NOTCH1 (11%), FAT1 (6%), TP53 (5%), and CDKN2A (&lt;1%). Known oncogenic hotspot mutations were observed in PIK3CA (1%) and KRAS (&lt;1%). The majority of lesions did not have overlapping sets of mutations with other samples from the same patient, indicating that most of these lesions arose from clonally distinct populations. The two lesions with the relatively high mutation rates (&gt;7/Mb) were taken from adjacent sites over two time points in the same individual with a prior history of lung squamous cell carcinoma. These lesions had a significantly overlapping set of mutations including FAT1 indicating a common evolutionary ancestor.

Conclusions: The somatic alterations observed in known cancer genes such as TP53, KMT2C, NOTCH1, and FAT1 may be among the earliest driver events in lung SqCC development and may be useful as biomarkers for early detection as well as targets for lung cancer interception.

Citation Format: Joshua Campbell, Xijun Zhang, Samjot S. Dhillon, Catalina Perdomo, Sarah Mazzilli, Yaron Geshalter, Gang Liu, Sherry Zhang, Hanqiao Lin, Jessica Vick, Christopher Moy, Stefano Monti, Evan Johnson, Matthew Meyerson, Steven Dubinett, Suso Platero, Matthew Wilkerson, Clifton Dalgard, Marc Lenburg, Mary Reid, Jennifer Beane, Avrum Spira. The genomic landscape of premalignant lung squamous cell carcinoma lesions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3259. doi:10.1158/1538-7445.AM2017-3259

Abstract 5002: Premalignant squamous cell lung carcinoma lesions have distinct molecular subtypes associated with histologic progression

Background: Squamous cell carcinoma (SCC) of the lung is a leading cause of cancer mortality in the US due to late stage diagnosis and lack of effective treatments. Lung SCC arises in the epithelial layer of the bronchial airways and is often preceded by the development of premalignant lesions (PMLs). The molecular events involved in the progression of PMLs to lung SCC are not clearly understood, and not all PMLs go on to form carcinoma. By molecularly characterizing PMLs and non-lesion areas in the airway of individuals with PMLs, we hypothesize that we will be able to identify subgroups of PMLs that are more likely to progress.

Methods: We used mRNA sequencing to profile biopsies obtained from high-risk smokers undergoing lung cancer screening by auto-fluorescence bronchoscopy and CT at the Roswell Park Cancer Institute in Buffalo, NY. For each subject (n=30), we sampled bronchial biopsies repeatedly over time (394 +/- 170 days) with serial bronchoscopies (6 +/- 5 biopsies/subject) as the biopsied area progressed towards or regressed away from frank malignancy. mRNA-Seq (n=197 biopsies) data was aligned to hg19 using STAR, and gene/transcript levels were summarized using RNA-Seq using RSEM and Ensembl 74 annotation. Immune, stromal, and epithelial cells content were inferred using the ESTIMATE algorithm and pathway activity of in vitro derived oncogenic signatures was estimated using GSVA for each sample. Molecular subtypes were derived using non-negative matrix factorization (NMF) and consensus clustering. Linear modeling was used to associate PML outcome metrics and pathway activity scores with subtype membership.

Results: We identified six distinct molecular subtypes of bronchial biopsies using NMF across the 10% most variable genes (n=2,322 gene). One subtype contained samples with stable high-grade histology (p&lt;0.01). This subtype was also enriched for basal epithelial cell content and oncogenic pathway activity including AKT and EGFR (p&lt;0.01). Another subtype was enriched for immune cell content and had elevated expression of immune-related pathways including chemokine, cytokine, and T-cell receptor signaling. Increased immune infiltrate was also observed in H&E stains from biopsies taken adjacent to the sequenced biopsy.

Conclusions: Molecular classification of premalignant lesions may lead to biomarkers of disease progression that could be used to stratify patients into prevention trials and to monitor efficacy of the treatment. Additionally, the results suggest that personalized interventions targeting specific cancer-related pathways or the immune system may be have potential therapeutic benefits.

Citation Format: Jennifer E. Beane, Sarah Mazzilli, Joshua Campbell, Christopher Moy, Michael Schaffer, Catalina Perdomo, David Jenkins, Gang Liu, Sherry Zhang, Hanqiao Liu, Jessica Vick, Evan Johnson, Suso Platero, Marc Lenburg, Mary Reid, Samjot S. Dhillon, Avrum Spira. Premalignant squamous cell lung carcinoma lesions have distinct molecular subtypes associated with histologic progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5002. doi:10.1158/1538-7445.AM2017-5002

Detecting the Presence and Progression of Premalignant Lung Lesions via Airway Gene Expression

Purpose: Lung cancer is the leading cause of cancer-related death in the United States. The molecular events preceding the onset of disease are poorly understood, and no effective tools exist to identify smokers with premalignant lesions (PMLs) that will progress to invasive cancer. Prior work identified molecular alterations in the smoke-exposed airway field of injury associated with lung cancer. Here, we focus on an earlier stage in the disease process leveraging the airway field of injury to study PMLs and its utility in lung cancer chemoprevention.Experimental Design: Bronchial epithelial cells from normal appearing bronchial mucosa were profiled by mRNA-Seq from subjects with (n = 50) and without (n = 25) PMLs. Using surrogate variable and gene set enrichment analysis, we identified genes, pathways, and lung cancer-related gene sets differentially expressed between subjects with and without PMLs. A computational pipeline was developed to build and test a chemoprevention-relevant biomarker.Results: We identified 280 genes in the airway field associated with the presence of PMLs. Among the upregulated genes, oxidative phosphorylation was strongly enriched, and IHC and bioenergetics studies confirmed pathway findings in PMLs. The relationship between PMLs and squamous cell carcinomas (SCC) was also confirmed using published lung cancer datasets. The biomarker performed well predicting the presence of PMLs (AUC = 0.92, n = 17), and changes in the biomarker score associated with progression/stability versus regression of PMLs (AUC = 0.75, n = 51).Conclusions: Transcriptomic alterations in the airway field of smokers with PMLs reflect metabolic and early lung SCC alterations and may be leveraged to stratify smokers at high risk for PML progression and monitor outcome in chemoprevention trials. Clin Cancer Res; 23(17); 5091-100. ©2017 AACR.

Abstract 895: Genomic characterization of premalignant lung squamous cell carcinoma lesions

Background: Lung squamous cell carcinoma (SqCC) arises in the epithelial layer of the bronchial airways and is often preceded by the development of premalignant lesions. However, not all premalignant lesions will progress to lung SqCC and many of these lesions will regress without therapeutic intervention. Understanding the molecular events that contribute to progression of premalignant lesions in the airway will allow us to identify biomarkers for early detection and develop therapeutic strategies for early intervention.

Methods: Bronchial brushings and biopsies were obtained from high-risk smokers undergoing lung cancer screening by auto-fluorescence bronchoscopy and CT at the Roswell Park Cancer Institute. For each subject (n = 30), both premalignant lesions (PMLs) and the cytologically normal mainstem bronchus were sampled repeatedly over time (n = 288 samples). DNA and RNA were isolated from a total of 197 bronchial biopsies of PML (average of 5 per subject) and 91 bronchial brushings. DNA was also isolated from the blood to serve as a matched normal. Exome capture was performed using the Agilent SureSelect Human All Exon+UTR 70MB kit and sequenced to a mean depth of coverage of 75x (n = 85 samples from 22 subjects). RNA libraries were prepared with Illumina TruSeq (mRNA-Seq: n = 288 samples from 30 subjects and miRNA-Seq: n = 183 samples from 26 subjects).

Results: We identified gene and miRNA expression changes associated with histological grade as well as progressive/stable disease. The Hippo pathway, Wnt signaling, p53 signaling, and immune-related pathways are modulated with histological grade and disease progression. Genes associated with histological grade in the cytologically normal airway and in the biopsies were significantly concordantly enriched (FDR&lt;0.05) demonstrating a strong relationship between the PMLs and the field of injury. The somatic mutation rate of PMLs displayed no significant association with histological grade (p = 0.65). Mutations in previously characterized lung cancer genes included TP53 (3%), CREBBP (3%), FAT1 (3%), and NOTCH1 (9%). Examining copy number alterations revealed a single metaplastic lesion with an arm-level amplification on chr5p containing TERT. The two lesions with the highest mutation rates (&gt;3/Mb) were taken from adjacent sites over two time points in the same individual with a history of lung squamous cell carcinoma. These lesions had a significantly overlapping set of mutations (p = 2.2 × 10−17) indicating a common evolutionary ancestor, and contained mutations in CREBBP and FAT1, suggesting they are at increased risk for progressing to frank malignancy.

Conclusions: We performed genomic profiling of PMLs in the airways of high-risk smokers. The gene expression and somatic alterations that were observed in known cancer genes may be among the earliest events in cancer development.

Citation Format: Joshua D. Campbell, Catalina Perdomo, Sarah Mazzilli, Yaron Geshalter, Samjot S. Dhillon, Gang Liu, Sherry Zhang, Hangqio Lin, Jessica Vick, Christopher Moy, Evan Johnson, Matthew Meyerson, Suso Platero, Marc Lenburg, Mary Reid, Avrum Spira, Jennifer Beane. Genomic characterization of premalignant lung squamous cell carcinoma lesions. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 895.

Aspirin use and the risk of bleeding complications after therapeutic bronchoscopy

BACKGROUND

Aspirin use has been shown to be safe for patients undergoing certain diagnostic bronchoscopy procedures such as transbronchial biopsies and endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration. However, there are no studies documenting the safety of aspirin in patients undergoing therapeutic bronchoscopy. The aim of this study is to evaluate whether aspirin increases the risk of bleeding following therapeutic bronchoscopy.

METHODS

This was a retrospective study to determine if there was a higher risk of bleeding in patients on aspirin undergoing therapeutic bronchoscopy compared with those not on aspirin. Patient characteristics were reported by cohort using the mean, median, and standard deviation for continuous variables, and using frequencies and relative frequencies for categorical variables.

RESULTS

Of the 108 patients who had multimodality therapeutic bronchoscopy, 17 (15.7%) were taking aspirin and 91 (84.3%) were not on aspirin. Patients in the aspirin group were older than those in the no aspirin group (median age: 66 versus 60 years, p = 0.007). The treatment modalities were similar in both groups except that more patients in the no aspirin group were treated with argon plasma coagulation (APC) compared to the aspirin group (60.4% versus 29.4%, p = 0.031). The estimated blood loss (EBL) between the aspirin and no aspirin groups was not significantly different (mean: 6.0 versus 6.7 ml; median: 5.0 versus 5.0, p = 0.36). Overall, there was no difference in complications between both groups.

CONCLUSION

Aspirin use was not associated with increased risk of bleeding or procedure-related complications after therapeutic bronchoscopy.

Vitamin D3 intake modulates diaphragm but not peripheral muscle force in young mice

Recent data support an important role for vitamin D in respiratory health. We tested the hypothesis that dietary vitamin D3 (VD3) intake modulates diaphragm (DIA) strength. Four-week-old female A/J mice (n = 10/group) were randomized to receive diets containing 100 IU VD3/kg (low), 1,000 IU VD3/kg (reference), or 10,000 IU VD3/kg (pharmacologic). After 6 wk of dietary intervention, plasma 25-hydroxyvitamin D3 (25D3) levels, DIA and extensor digitorum longus (EDL) in vitro contractile properties, and fiber cross-sectional area (CSA) were measured. Myosin heavy chain (MHC) composition and Akt/Foxo3A growth signaling were studied in the DIA and tibialis anterior. Mice fed the low, reference, and pharmacologic diets had average 25D3 levels of 7, 21, and 59 ng/ml, respectively. Maximal DIA force, twitch force, and fiber CSA were reduced 26%, 28%, and 10% (P < 0.01), respectively, in mice receiving the low-VD3 diet compared with the reference and pharmacologic diets. EDL force parameters were unaltered by diet. Effects of VD3 intake on DIA force were not observed in mice that began dietary intervention at 12 wk of age. VD3 intake did not alter the MHC composition of the DIA, indicating that decreases in force and CSA in young mice were not due to a switch in fiber type. Paradoxically, low VD3 intake was associated with activation of anabolic signaling in muscle (hyperphosphorylation of Akt and Foxo3A and decreased expression of autophagy marker LC3). These studies identify a potential role of dietary VD3 in regulating DIA development and insulin sensitivity.

Engineered far-fields of metal-metal terahertz quantum cascade lasers with integrated planar horn structures

The far-field emission profile of terahertz quantum cascade lasers (QCLs) in metal-metal waveguides is controlled in directionality and form through planar horn-type shape structures, whilst conserving a broad spectral response. The structures produce a gradual change in the high modal confinement of the waveguides and permit an improved far-field emission profile and resulting in a four-fold increase in the emitted output power. The two-dimensional far-field patterns are measured at 77 K and are agreement in with 3D modal simulations. The influence of parasitic high-order transverse modes is shown to be controlled by engineering the horn structure (ridge and horn widths), allowing only the fundamental mode to be coupled out.

The Case for a Pre-Cancer Genome Atlas (PCGA)

Understanding the earliest molecular and cellular events associated with cancer initiation remains a key bottleneck to transforming our approach to cancer prevention and detection. While TCGA has provided unprecedented insights into the genomic events associated with advanced stage cancer, there have been few studies comprehensively profiling premalignant and early-stage disease or elucidating the role of the microenvironment in premalignancy and tumor initiation. In this article, we make a call for development of a "Pre-Cancer Genome Atlas (PCGA)," a concerted initiative to characterize the molecular alterations in premalignant lesions and the corresponding changes in the microenvironment associated with progression to invasive carcinoma. This initiative will require a multicenter coordinated effort to comprehensively profile (cellular and molecular) premalignant lesions and their corresponding "field of injury" collected longitudinally as the lesion progresses towards or regresses from frank malignancy across multiple tumor types. Genomic characterization of alterations in premalignant lesions and their microenvironment, for both bulk tissue and single cells, will enable development of biomarkers for early detection and risk stratification as well as allow for the development of novel targeted cancer interception strategies. The multi-institutional and multidisciplinary collaborative "big-data" effort underlying the PCGA will help usher in a new era of precision medicine for cancer detection and prevention.

Reporting of central airway obstruction on radiology reports and impact on bronchoscopic airway interventions and patient outcomes

BACKGROUND

Central airway obstruction (CAO) is a serious condition that affects patients with both benign and malignant diseases. Timely recognition of CAO is crucial for prompt intervention aimed at improving the symptoms and quality of life of these patients. The aim of this study is to evaluate the formal radiology reporting of CAO and its impact on patients' outcomes.

METHODS

The medical records of patients who underwent advanced therapeutic bronchoscopy for CAO from August 2013 to September 2014 were retrospectively reviewed. Three researchers each reviewed 14 of the 42 formal radiology reports that were performed at 16 different medical and radiology centers.Patient characteristics were reported as means, medians, and standard deviations for continuous variables, and as frequencies and relative frequencies for categorical variables.

RESULTS

Out of 42 patients who underwent advanced bronchoscopy for planned therapeutic intervention, only 30 had radiology and pulmonology concordance about the airway findings of CAO. This is an agreement rate of 71.4% [95% confidence interval (CI): 56.7-83.3%] or a disagreement rate of 28.6% (95% CI: 16.7-43.3%). The radiology reports did not mention 31% of CAO on CT scans. The median time from CT imaging to bronchoscopy was significantly longer in patients with CAO not reported by the radiologists (21 versus 10 days; p = 0.011). Most patients improved postoperatively with no significant difference between the two groups.

CONCLUSIONS

Findings of CAOs were not described in a significant proportion of radiology reports. This results in significant delay in bronchoscopic airway management.

Adequacy of Malignant Pleural Effusion for Epidermal Growth Factor Receptor Mutation Analysis Using the Pyrosequencing Method

Background:

Epidermal growth factor receptor (EGFR) mutation analysis is a standard approach for initial therapeutic decision in patients with metastatic adenocarcinoma of the lung (MAL). The feasibility of performing EGFR mutation testing using pleural fluid specimen is not well characterized.

Objectives:

The aim of this study is to report the percentage of patients eligible for EGFR mutation testing based on the percentage of malignant cells (PMCs) in the pleural fluid using the pyrosequencing method.

Methods:

From our database, we reviewed the clinical data of 61 patients with malignant pleural effusion (MPE) secondary to MAL. The PMCs were divided into 2 categories with a cutoff point of 10% (PMC1 is defined as ≤10% and PMC2 is defined as >10%). For the pyrosequencing method, only patients in the PMC2 group were eligible for EGFR mutation testing.

Results:

Of 61 patients with MPE secondary to MAL, 38 (62.3%) were in the PMC2 group, which represents the percentage of patients eligible for EGFR mutation testing. Of these 38 patients, 15 patients had the testing done on the MPE. Quantity was not sufficient for testing only in 1 patient. Therefore, in PMC2 patients group, the rate of successful EGFR mutation testing was 93% (14 of 15). The thoracentesis volume was not significantly different between PMC1 and PMC2.

Conclusion:

Performing EGFR mutation analysis on the MPE in patients with MAL is feasible in 62% of patients. The rate of successful testing on the eligible samples is 93%.

MiR-205 and MiR-375 microRNA assays to distinguish squamous cell carcinoma from adenocarcinoma in lung cancer biopsies

INTRODUCTION

Identification of adenocarcinoma (AC) and squamous cell carcinoma (SCC) histology of non-small-cell lung cancer (NSCLC) in biopsies is clinically important but can be inaccurate by routine histopathologic examination. We quantify this inaccuracy at a cancer center, and evaluate the utility of a microRNA-based method to histotype AC/SCC in biopsies.

METHODS

RNA was extracted from tissue sections with greater than 90% tumor content that were macro- or micro-dissected from formalin-fixed, paraffin-embedded biopsy specimens. MicroRNAs in RNA from the biopsies and from resected tumors were quantified by TaqMan reverse transcription-polymerase chain reaction assays and normalized against the RNU6B housekeeping RNA. Publicly available microRNA expression datasets were examined.

RESULTS

NSCLC subtyping of small biopsy specimens by routine histopathologic examination either failed or mistyped the histology of 21% of 190 cases. Using 77 resectates, an reverse transcription-polymerase chain reaction-based assay of microRNAs miR-21, miR-205, and miR-375 was developed to identify AC and SCC subtypes of NSCLC. This method identified the AC/SCC histotypes of 25 biopsies with an accuracy of 96%, and correctly histotyped all 12 cases for which the histology had been mistyped by routine histopathologic examination of the biopsy. Examination of publicly available datasets identified miR-205 and miR-375 as microRNAs with the best ability to histotype AC and SCC, and that levels of the two microRNAs in AC or SCC are unaffected by the pathologic stage of the tumor or the age or race of the patient.

CONCLUSIONS

Histotypic microRNA assays can aid the subtyping of NSCLC biopsies as AC or SCC by standard histopathologic methods.

Optical sideband generation up to room temperature with mid-infrared quantum cascade lasers

Mid-infrared (MIR) sideband generation on a near infrared (NIR) optical carrier is demonstrated within a quantum cascade laser (QCL). By employing an externally injected NIR beam, E(NIR), that is resonant with the interband transitions of the quantum wells in the QCL, the nonlinear susceptibility is enhanced, leading to both frequency mixing and sideband generation. A GaAs-based MIR QCL (E(QCL) = 135 meV) with an aluminum-reinforced waveguide was utilized to overlap the NIR and MIR modes with the optical nonlinearity of the active region. The resulting difference sideband (E(NIR) - E(QCL)) shows a resonant behavior as a function of NIR pump wavelength and a maximum second order nonlinear susceptibility, χ((2)), of ~1 nm/V was obtained. Further, the sideband intensity showed little dependence with the operating temperature of the QCL, allowing sideband generation to be realized at room temperature.

Substernal thyroid biopsy using Endobronchial Ultrasound-guided Transbronchial Needle Aspiration

Substernal thyroid goiter (STG) represents about 5.8% of all mediastinal lesions(1). There is a wide variation in the published incidence rates due to the lack of a standardized definition for STG. Biopsy is often required to differentiate benign from malignant lesions. Unlike cervical thyroid, the overlying sternum precludes ultrasound-guided percutaneous fine needle aspiration of STG. Consequently, surgical mediastinoscopy is performed in the majority of cases, causing significant procedure related morbidity and cost to healthcare. Endobronchial Ultrasound-guided Transbronchial Needle Aspiration (EBUS-TBNA) is a frequently used procedure for diagnosis and staging of non-small cell lung cancer (NSCLC). Minimally invasive needle biopsy for lesions adjacent to the airways can be performed under real-time ultrasound guidance using EBUS. Its safety and efficacy is well established with over 90% sensitivity and specificity. The ability to perform EBUS as an outpatient procedure with same-day discharges offers distinct morbidity and financial advantages over surgery. As physicians performing EBUS gained procedural expertise, they have attempted to diversify its role in the diagnosis of non-lymph node thoracic pathologies. We propose here a role for EBUS-TBNA in the diagnosis of substernal thyroid lesions, along with a step-by-step protocol for the procedure.

20 THz broadband generation using semi-insulating GaAs interdigitated photoconductive antennas

We demonstrate broadband (20 THz), high electric field, terahertz generation using large area interdigitated antennas fabricated on semi-insulating GaAs. The bandwidth is characterized as a function of incident pulse duration (15-35 fs) and pump energy (2-30 nJ). Broadband spectroscopy of PTFE is shown. Numerical Drude-Lorentz simulations of the generated THz pulses are performed as a function of the excitation pulse duration, showing good agreement with the experimental data.

Mode-locking of a terahertz laser by direct phase synchronization

A novel scheme to achieve mode-locking of a multimode laser is demonstrated. Traditional methods to produce ultrashort laser pulses are based on modulating the cavity gain or losses at the cavity roundtrip frequency, favoring the pulsed emission. Here, we rather directly act on the phases of the modes, resulting in constructive interference for the appropriated phase relationship. This was performed on a terahertz quantum cascade laser by multimode injection seeding with an external terahertz pulse, resulting in phase mode-locked terahertz laser pulses of 9 ps duration, characterized unambiguously in the time domain.

Detection of a possible case of pulmonary tumour thromboembolism by endobronchial ultrasound

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Integrated injection seeded terahertz source and amplifier for time-domain spectroscopy

We used a terahertz (THz) quantum cascade laser (QCL) as an integrated injection seeded source and amplifier for THz time-domain spectroscopy. A THz input pulse is generated inside a QCL by illuminating the laser facet with a near-IR pulse from a femtosecond laser and amplified using gain switching. The THz output from the QCL is found to saturate upon increasing the amplitude of the THz input power, which indicates that the QCL is operating in an injection seeded regime.

The "silver-nitrate-oma"

This case report demonstrates and emphasises the unusual radiographic appearance of silver nitrate treatment in a 30-year-old patient, who subsequently underwent excision biopsy of a presumed potentially malignant lesion.

Estrogen inhibits NPY secretion through membrane-associated estrogen receptor (ER)-α in clonal, immortalized hypothalamic neurons

OBJECTIVE

Estrogen (E(2)) has an inhibitory effect on food intake by acting centrally in the hypothalamus, although it is not clear which hypothalamic neurons are involved in this process. Earlier studies from our lab and others have implicated neuropeptide Y (NPY) as an important central anorexigenic target of E(2). This study was designed to investigate whether E(2) can directly regulate NPY secretion and examine the cellular mechanisms and receptors responsible for this anorexigenic action of E(2).

DESIGN

Clonal, murine, hypothalamic neuronal cell models, mHypoE-42 and mHypoA-2/12, were investigated for NPY secretory responses to 17β-estradiol (E(2)) in the presence or absence of pharmacological inhibitors directed against the phosphatidylinositol-3-kinase (PI3K), mitogen-activated protein kinase (MAPK) and AMP-activated kinase (AMPK) pathways or to estrogen receptor (ER) specific agonists/antagonists.

MEASUREMENTS

The presence of hypothalamic markers and characterization of neuronal cell lines was completed with polymerase chain reaction. NPY levels were measured using an enzyme immunoassay (EIA). The expression of ER-α and caveolin-1 was analyzed using immunocytochemistry.

RESULTS

E(2) significantly decreased NPY secretion in both the mHypoE-42 and mHypoA-2/12 neurons. The E(2)-mediated repression of NPY secretion in the mHypoE-42 and mHypoA-2/12 neurons required ER-α, but not ER-β, as shown by studies using an ER-specific agonist/antagonists. Additionally, using immunocytochemistry we detected colocalization of ER-α and the membrane-associated signaling protein caveolin-1. Importantly, using E(2)-conjugated bovine serum albumin (E(2)-BSA) and ER antagonists, we were able to show that the E(2)-mediated decrease in NPY secretion occurred through membrane-bound ER-α. Finally, using a combination of pharmacological inhibitors, we found that inhibition of the PI3K or AMPK pathway blocked the E(2)-mediated decrease in NPY secretion.

CONCLUSION

These findings indicate that the central anorexigenic action of E(2) occurs at least partially through hypothalamic NPY-synthesizing neurons. This regulation of NPY secretion occurs through rapid signaling mechanisms through membrane bound ER-α.

Simulating the influence of vernalization, photoperiod and optimum temperature on wheat developmental rates

BACKGROUND AND AIMS

Accurately representing development is essential for applying crop simulations to investigate the effects of climate, genotypes or crop management. Development in wheat (Triticum aestivum, T. durum) is primarily driven by temperature, but affected by vernalization and photoperiod, and is often simulated by reducing thermal-time accumulation using vernalization or photoperiod factors or limiting accumulation when a lower optimum temperature (T(optl)) is exceeded. In this study T(optl) and methods for representing effects of vernalization and photoperiod on anthesis were examined using a range of planting dates and genotypes.

METHODS

An examination was made of T(optl) values of 15, 20, 25 and 50 degrees C, and either the most limiting or the multiplicative value of the vernalization and photoperiod development rate factors for simulating anthesis. Field data were from replicated trials at Ludhiana, Punjab, India with July through to December planting dates and seven cultivars varying in vernalization response.

KEY RESULTS

Simulations of anthesis were similar for T(optl) values of 20, 25 and 50 degrees C, but a T(optl) of 15 degrees C resulted in a consistent bias towards predicting anthesis late for early planting dates. Results for T(optl) above 15 degrees C may have occurred because mean temperatures rarely exceeded 20 degrees C before anthesis for many planting dates. For cultivars having a strong vernalization response, anthesis was more accurately simulated when vernalization and photoperiod factors were multiplied rather than using the most limiting of the two factors.

CONCLUSIONS

Setting T(optl) to a high value (30 degrees C) and multiplying the vernalization and photoperiod factors resulted in accurately simulating anthesis for a wide range of planting dates and genotypes. However, for environments where average temperatures exceed 20 degrees C for much of the pre-anthesis period, a lower T(optl) (23 degrees C) might be appropriate. These results highlight the value of testing a model over a wide range of environments.

Anatomical study comparing the thickness of the volar and dorsal cortex of cadaveric adult distal radii using digital photography

INTRODUCTION

Dorsally displaced fractures of the distal radius fractures are one of the commonest in day-to-day practice. There is still no consensus among surgeons regarding the suitability of using volar or the dorsal cortex as basis for internal fixation for dorsally displaced fractures.

BACKGROUND

We report an anatomical study, which compares the thickness of the volar and dorsal cortices of cadaveric adult radii using digital photography.

RESULTS

Results of this study show that the volar cortex was statistically, significantly thicker than the dorsal cortex. We believe that the volar cortex may behave as the calcar of the distal radius and hence internal fixation devices applied to the volar cortex may provide a more stable internal fixation compared to those based on the dorsal cortex.

Neutrophils, nitric oxide, and microvascular permeability in severe sepsis

STUDY OBJECTIVES

Alterations in microvascular permeability are prevalent in patients with sepsis; a recent study reported that patients with septic shock had increased capillary filtration coefficient (Kf), a noninvasive index of microvascular permeability. We aimed to determine whether patients with severe sepsis had increased Kf, and whether the magnitude of Kf correlated with indexes of nitric oxide activity and neutrophil activation.

DESIGN

Single-center, prospective study.

SETTING

Twenty-five-bed ICU of a medical college-affiliated teaching hospital.

PATIENTS

Fifteen ICU patients with severe sepsis based on the American College of Chest Physicians/Society of Critical Care Medicine consensus criteria of 1992, and 10 nonseptic ICU patients as control subjects.

INTERVENTIONS

Kf was measured by venous congestion plethysmography, plasma nitrate/nitrite (NOx) by chemiluminescence, and neutrophil expression of alpha4-integrin (an index of neutrophil activation) by flow cytometry.

MEASUREMENTS AND RESULTS

Septic patients had higher Kf than nonseptic control subjects. Kf of septic patients was 5.6 +/- 0.6 x 10(-3) mL.min(-1).100 mL tissue(-1).mm Hg(-1) (mean +/- SEM, mL.min(-1).100 mL tissue(-1).mm Hg(-1) = Kf units [KfU]) as compared to 3.9 +/- 0.5 x 10(-3) KfU in nonseptic ICU patients (p < 0.05). There was no correlation between plasma NOx and Kf, or between neutrophil alpha4-integrin expression and Kf in patients with sepsis. Septic patients with clinical evidence of edema had significantly higher Kf (p < 0.05) than nonedematous septic patients.

CONCLUSIONS

ICU patients with severe sepsis have increased Kf, a noninvasive index of microvascular water permeability. The magnitude of hyperpermeability did not correlate with NOx levels or one index of neutrophil activation (alpha4-integrin expression). Presence of peripheral edema in these patients was associated with increased Kf, and may represent a simple, clinical indicator of altered microvascular permeability in sepsis.

Patellar tendon ruptures in a pair of brothers

The patellar tendon does not easily rupture due to its considerable high tensile strength. Therefore, in normal individuals, ruptures of the patellar tendon are uncommon. We report three episodes of patellar tendon ruptures in two normally fit and healthy brothers; postulating the possibility of inherent weakness. The treatment options for these injuries are discussed.

Palmar cortical angle of the distal radius: a radiological study

Fifty lateral radiographs of normal wrists were viewed to determine the palmar cortical angle of the distal radius. The palmar cortical angle is different to its previously described palmar tilt or angulation. The mean value for the palmar cortical angle was 37 degrees (range, 26-50 degrees). This may be clinically important in the design of palmar plates for the distal radius.

Transitional cell carcinoma manifesting as acute cor pulmonale: cause of microscopic tumor embolism

Acute cor pulmonale is an uncommon manifestation of microscopic pulmonary tumor embolism. We describe the case of an 84-year-old man with a history of transitional cell carcinoma (TCC) of the urinary bladder who had acute cor pulmonale and died within a few hours after the onset of dyspnea. Autopsy showed that the right ventricle was dilated without hypertrophy. Microscopic examination of the lung showed that the small arteries, arterioles, and capillaries were filled with micrometastases of TCC. Microscopic pulmonary tumor embolism has rarely been reported with TCC, and to the best of our knowledge, such a fulminant course has not been previously described in the English language.

Lumbosacral plexopathy after dual kidney transplantation

A 58-year-old man underwent dual kidney transplantation. He was unable to move his right leg after surgery. This was caused by extensive lumbosacral plexopathy on the side of surgery. Lumbosacral plexopathy after kidney transplantation is uncommon, because the plexus has rich anastomotic blood supply, and ischemic injury is unlikely. However, isolated femoral neuropathy after renal transplantation has been reported, as the distal portion of this nerve is supplied by branches of internal iliac artery only and is more prone to ischemic injury during surgery. Dual-kidney transplantation involves a larger dissection, and the procedure takes 60 to 90 minutes longer than single-kidney transplantation. It involves more vascular reconstruction. This may predispose the lumbosacral plexus to ischemic injury. To the best of our knowledge, this is the first reported case of lumbosacral plexopathy after a dual kidney transplantation, and this may be seen more frequently because this procedure is becoming more common.

Pneumococcal bacteremia associated with an infected central venous catheter

Pneumococcus (Streptococcus pneumoniae) bacteremia is a serious infection. Pneumococcus has never been implicated as a cause of a central venous catheter-related bacteremia. It has been isolated from the catheter tip only twice before, and in one case caused the infection of an infusion port device. We report case of a 41-year-old woman who developed pneumococcal bacteremia after 6 days of an indwelling central venous catheter. The catheter tip grew > 300 cfu of S pneumoniae by the roll-plate method described by Maki and colleagues. No other focus of infection could be found in this patient. To the best of our knowledge, this is the first reported case of pneumococcal bacteremia associated with an infected central venous catheter.

Lady Windermere syndrome: middle lobe bronchiectasis and Mycobacterium avium complex infection due to voluntary cough suppression

An 81-year-old woman who presented with middle lobe bronchiectasis and Mycobacterium avium complex infection is described. She had a history of habitual suppression of cough, as in Lady Windermere syndrome. She was thin and had mild kyphoscoliosis but had no history of smoking or connective tissue disease. The middle lobe and lingula are predisposed to chronic inflammation because of their particular anatomic structures. Inability to clear the secretions from the airway due to voluntary cough suppression may predispose to bronchiectasis and M. avium complex infection.

Diffuse alveolar hemorrhage and pulmonary capillaritis due to propylthiouracil

Propylthiouracil (PTU) has recently been observed to be associated with antineutrophil cytoplasmic antibody (ANCA)-positive small vessel vasculitis, resulting in crescentic glomerulonephritis and, infrequently, diffuse alveolar hemorrhage (DAH). We describe a case of a 23-year-old pregnant woman who developed a perinuclear ANCA and antimyeloperoxidase-positive small vessel vasculitis manifesting as DAH and crescentic glomerulonephritis after she began taking PTU. An open lung biopsy was consistent with pulmonary capillaritis. She responded to corticosteroid therapy and discontinuation of PTU. DAH can be caused by pulmonary capillaritis, bland hemorrhage, or diffuse alveolar damage. To our knowledge, this represents the first documentation of an underlying pulmonary capillaritis in a case of PTU-induced DAH.

Functional suitability of commercially milled rice bran in India for use in different food products

The effect of blending of commercially available full fat and defatted rice brans in India from modern multistage rice mills with parboiling/stabilizing facilities in different food products in comparison to those obtained from laboratory milling of rice is reported. Bread volume and cookie spread decreased but muffin volume increased with the addition of different types of bran to wheat flour, however, the cookie spread factor was not affected by addition of full fat rice bran. The yields of the extrudate were increased by the blending of full fat rice bran but were decreased by the addition of defatted rice bran. Rice brans could be added to different food products to the extent of 5-10%. However, the full fat rice bran could not be used for production of extruded snack food.

A new approach to hysteroscopic cannulation of the fallopian tube

Hysteroscopic cannulation of the fallopian tube has become an essential part of the treatment of interstitial fallopian tube obstruction. This report describes the use of a flexible instrument that can be introduced through a rigid hysteroscope for the purpose of hysteroscopic tubal cannulation.

Genital tuberculosis: case report and literature review

A 64-year-old woman complained of abdominal pain and postmenopausal bleeding. A uterine curettage demonstrated acid fast bacilli and non caseating granulomas, indicating Mycobacterium tuberculosis. A chest roentgenogram revealed the presence of bilateral upper lobe calcific granulomas. The epidemiologic, diagnostic, and therapeutic implications of genital tuberculosis are discussed.

The effects of a few xenobiotics on certain phosphatases in the plasma of Clarias batrachus and Cirrhina mrigala

The effects of sublethal concentrations 1/2, 1/4 and 1/8 fractions of 96-h LC50 of aldrin and Swascofix CD-38 on alkaline, acid and glucose-6-phosphatases in the plasma of Clarias batrachus and Cirrhina mrigala were studied. These enzymes increased after exposure of fish to both xenobiotics. The increase was maximal after 20 days exposure to the highest concentrations. The enzyme increase was greatest in the fish exposed to aldrin.

DNA, RNA, protein and heterochromatin changes during embryo development and germination of soybean (Glycine max L.)

DNA, RNA, protein and heterochromatin were measured cytophotometrically in developing soybean (Glycine max) seeds. The average 2C DNA content for the soybean genome was 2.64 pg. The amounts of nuclear DNA in embryo axes showed no significant change during embryo development, whereas the DNA content in cotyledon nuclei increased significantly from 3.58 pg to 5.49 pg. The number of endopolyploid nuclei increased from 26% to 48% and the DNA content from 4.45 to 5.49 pg after cessation of cell division. The changes in RNA and protein content during embryo development were in general similar to those in DNA content. This can be interpreted that increased DNA levels in soybean cotyledons generated during embryogeny increase the protein synthesizing capacity. During the first 15 days of germination, the number of endopolyploid nuclei in cotyledons declined from 46% to 4%, and this decline is interpreted as DNA degradation providing a ready source of nucleosides and phosphates during early embryo growth. A later decline, however, between 15 and 20 days after germination, was age related similar to leaf senescence, because the percentage of endopolyploid nuclei remained unchanged while the number of non-viable cells increased. In senescing cotyledons, 73% and 80% of RNA and protein but only 20% of DNA were lost, as compared to dormant cotyledons. The heterochromatin (condensed chromatin) measurements indicated that nuclei of metabolically inactive dormant and senescent cotyledon nuclei contained an average of 33% more heterochromatin than nuclei from the green cotyledons of seedlings.

Reassociation Kinetics and Cytophotometric Characterization of Peanut (Arachis hypogaea L.) DNA

The base composition of peanut (var. NC-17) DNA determined from thermal denaturation profiles showed an average guanine plus cystosine content of 34% which was in close approximation to 36% guanine plus cytosine calculated from the buoyant density. Buoyant density also indicated the absence of satellite DNA. The genome size, 2.0 x 10(9) base pairs, as determined by reassociation kinetics of the single copy DNA was close to the genome size determined by cytophotometry, 2.1 x 10(9) base pairs. Peanut DNA averaging 450 to 600 base pairs long, reassociated in phosphate buffer and fractionated by hydroxylapatite, indicated a DNA genome composition of 36% nonrepetitive or single copy DNA; reassociation in formamide and followed by optical methods indicated the repetitive DNA possesses highly repeated, intermediately repeated and rarely repeated components of DNA with DNA sequences repeated on the average about 38,000, 6,700, and 200 times each. Different criteria of reassociation in formamide revealed further subdivisions of these four separate components of DNA. The DNA of above mentioned NC-17 variety compared to Florigiant variety showed no differences in thermal denaturation profiles, buoyant density, or in genome size.

Nonspecific light loss and intrinsic DNA variation problems associated with feulgen DNA cytophotometry

Nonspecific light loss by the cell-wall-plus-cytoplasm (CWC) can cause a 50% increase in Feulgen absorption units in peanut root-tip nuclei as determined by scanning at 450 nm, whereas this phenomenon is not evident with chicken erythrocytes. A two wavelength scanning method of subtracting nonspecific 450 nm absorption from 550 nm Feulgen absorption values eliminated the nonspecific light loss in CWC, However, the two wavelength scanning method is time consuming and somewhat impractical with a regular scanning microdensitometer such as Vickers M85. Elimination of the problem of nonspecific light loss is suggested by careful determination of background setting with the spot position close to the nucleus in CWC. The accuracy of the CWC background setting method was further tested by comparison with subtraction method. The use of plant nucleis as an internal standard in plant DNA measurements was also evaluated. Significant variation among the replicate slides due to the variation in pine nuclear DNA amounts was observed and plant nuclei generally are not reliable internal standards. Mature chicken erythrocytes are recommended as an internal standard because the cell type and metabolic state is known.

Feulgen cytophotometry of pine nuclei. II. Effect of pectinase used in cell separation

Pectinase used for cell separation prior to cytophotometry contains a DNase that is able to penetrate the cells of pine root tips and attack nuclear DNA. When pine root tips were exposed to 1% pectinase (pH 6.0), there was a decrease in nuclear DNA content at every sample point and a sharp drop between 16 and 20 hr. The effect of the DNase was eliminated by preparing the enzyme solution in 0.01 M sodium citrate or 0.001 M EDTA. It is suggested that heat denaturation of the DNase should also be effective and might be used in combination with the magnesium chelators.

Influence of Varied Phosphorus Supply on Growth and Xylem Sap Cytokinin Level of Sycamore (Platanus occidentalis L.) Seedlings

Effects of varying levels of phosphorus (P) on sycamore (Platanus occidentalis L.) growth and on the endogenous cytokinin levels in the xylem sap were tested. The seedlings were grown in aerated nutrient solutions in the greenhouse. Photoperiod was held constant at 16 hours. Four P concentrations, 0.02, 0.10, 0.50, and 2 mm, were used. There were no P deficiency symptoms even at the lowest P concentration. The maximum growth occurred in seedlings grown in 0.10 mm P. The greatest dry matter yield as well as stem height, stem diameter, and leaf area were produced at 0.10 or 0.50 mm P. The amount of cytokinin in xylem sap for each harvest during P nutrition followed closely the dry matter values, stem height, stem diameter, and leaf area.