281 research outputs found

    Role of the Digestive Gland in Ink Production in Four Species of Sea Hares: An Ultrastructural Comparison

    Get PDF
    The ultrastructure of the digestive gland of several sea hare species that produce different colored ink (Aplysia californica produces purple ink, A. juliana white ink, A. parvula both white and purple ink, while Dolabrifera dolabrifera produces no ink at all) was compared to determine the digestive gland’s role in the diet-derived ink production process. Rhodoplast digestive cells and their digestive vacuoles, the site of digestion of red algal chloroplast (i.e., rhodoplast) in A. californica, were present and had a similar ultrastructure in all four species. Rhodoplast digestive cell vacuoles either contained a whole rhodoplast or fragments of one or were empty. These results suggest that the inability to produce colored ink in some sea hare species is not due to either an absence of appropriate digestive machinery, that is, rhodoplast digestive cells, or an apparent failure of rhodoplast digestive cells to function. These results also propose that the digestive gland structure described herein occurred early in sea hare evolution, at least in the common ancestor to the genera Aplysia and Dolabrifera. Our data, however, do not support the hypothesis that the loss of purple inking is a synapomorphy of the white-ink-producing subgenus Aplysia

    Ultrastructural Comparison of Processing of Protein and Pigment in the Ink Gland of Four Species of Sea Hares

    Get PDF
    The ink glands of four sea hare species (Aplysia californica, A. parvula, A. juliana, and Dolabrifera dolabrifera) were compared to determine where ink protein is synthesized, how it is incorporated into protein storage vesicles, and the degree of variation in the structure of the ink gland. Ink protein was synthesized in RER cells and stored in amber and white vesicles. Lack of competent RER cells in the ink gland of D. dolabrifera was correlated with the absence of ink protein. Ink protein had similar characteristics in all three Aplysia species but, again, it was absent in D. dolabrifera. Its uptake involved pinocytosis by protein vesicle cell membranes. Granulate cells showed little variation in structure among the four species, the opposite was the case for RER cells. The conversion of the red algal pigment, phycoerythrin, to phycoerythrobilin (PEB) occurs in the digestive gland but the change of PEB to aplysioviolin (APV), the form of pigment released by the ink gland, occurs in the ink gland itself by both granulate cells and pigment vesicles. The literature describes five types of vesicles based upon color and contents in the ink gland of these four species. We report only three types of vesicle: colored (purple), protein (white and amber), and transparent (includes clear vesicles)

    Chemotherapy alone for organ preservation in advanced laryngeal cancer

    Full text link
    Background. For patients with advanced laryngeal cancer, a trial was designed to determine if chemotherapy alone, in patients achieving a complete histologic complete response after a single neoadjuvant cycle, was an effective treatment with less morbidity than concurrent chemoradiotherapy. Methods. Thirty-two patients with advanced laryngeal or hypopharyngeal cancer received 1 cycle of induction chemotherapy, and subsequent treatment was decided based on response. Results. A histologic complete response was achieved in 4 patients and were treated with chemotherapy alone. All 4 patients' cancer relapsed in the neck and required surgery and postoperative radiotherapy (RT). Twenty-five patients were treated with concomitant chemoradiation. Three patients were treated with surgery. Overall survival and disease-specific survival at 3 years were 68% and 78%, respectively. Conclusion. Chemotherapy alone is not feasible for long-term control of regional disease in patients with advanced laryngeal cancer even when they achieve a histologic complete response at the primary site. © 2009 Wiley Periodicals, Inc. Head Neck, 2010Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77508/1/21285_ftp.pd

    Prevalence and predictive role of p16 and epidermal growth factor receptor in surgically treated oropharyngeal and oral cavity cancer

    Full text link
    Background The purpose of this study was to describe the relationship of p16 and epidermal growth factor receptor (EGFR) expression with survival in surgically treated patients who had oropharyngeal or oral cavity squamous cell carcinoma (SCC). Methods Tissue from 36 patients with oropharyngeal SCC and 49 patients with oral cavity SCC treated between 1997 and 2001 was imbedded and immunostained using a tissue microarray. Results The p16 was positive in 57% and 13% of patients with oropharyngeal SCC and oral cavity SCC, respectively. EGFR was positive in 60% and 63% of patients with oropharyngeal SCC and oral cavity SCC, respectively. In patients with oropharyngeal SCC, p16 expression was associated with improved disease‐specific survival (DSS), overall survival (OS), and time to recurrence (TTR) ( p < .01, < .01, and <.01, respectively). EGFR expression was associated with poorer DSS, OS, and TTR ( p < .01, = .01, and < .01, respectively). For oropharyngeal SCC, when examining both p16 and EGFR expression as combined biomarkers, high p16 expression coupled with low EGFR expression was associated with improved DSS ( p p16 = .01; p EGFR = .01). Patients with oral cavity SCC showed no association between biomarker and outcome. Conclusions For patients with oropharyngeal SCC, high p16 and low EGFR were associated with improved outcome, suggesting a predictive role in surgically treated patients. © 2012 Wiley Periodicals, Inc. Head Neck, 2013Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99017/1/23087_ftp.pd

    Matted nodes: Poor prognostic marker in oropharyngeal squamous cell carcinoma independent of HPV and EGFR status

    Full text link
    Background Despite better prognosis, there is a group of oropharyngeal squamous cell carcinoma (SCC) human papillomavirus (HPV)+ patients who experience treatment failure and succumb to distant metastasis. Methods Seventy‐eight previously untreated patients nested in a concurrent chemoradiation protocol were reviewed to correlate patterns of local‐regional tumor extent to distant metastasis. Biomarker assessment was: HPV in situ hybridization and epidermal growth factor receptor (EGFR) immunointensity. Results The 3‐year disease‐specific survival (DSS) for patients presenting with and without matted nodes was 69% and 94%, respectively ( p = .003). Matted nodes were a poor prognostic factor independent of T classification, HPV, EGFR, and smoking status. For patients who were HPV+, 7 of 11 died of distant metastasis and 6 of 7 with distant metastasis had matted nodes. Conclusion Matted nodes are a novel marker of poor prognosis in oropharyngeal SCC independent of established prognostic factors. Matted nodes may identify patients at risk for the development of distant metastasis who could benefit from systemic therapy, whereas patients without matted nodes may be candidates for de‐escalation of therapy. © 2012 Wiley Periodicals, Inc. Head Neck , 2012Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94456/1/21997_ftp.pd

    A prospective study of hearing changes after beginning zidovudine or didanosine in HIV-1 treatment-naïve people

    Get PDF
    BACKGROUND: While hearing loss in HIV-infected people after beginning nucleoside reverse transcriptase inhibitors (NRTIs) has been reported, there have been no prospective studies that measured hearing changes longitudinally in treatment-naïve HIV-infected subjects following initiation of regimens containing NRTIs. The goal of this study was to conduct a prospective assessment of the contribution of zidovudine (ZDV) and didanosine (ddI) to hearing loss METHODS/DESIGN: A prospective observational pilot study to determine whether ZDV or ddI, alone or in combination, are associated with sensorineural hearing loss in HIV-infected persons. Changes in hearing levels at all frequencies and in low and high frequency pure tone averages were measured at baseline, 16, and 32 weeks after initiating antiretroviral therapy. DISCUSSION: Treatment with ZDV and ddI did not result in loss of hearing, even after taking into account noise exposure, immune status and age. The results of this prospective pilot study do not support the notion that treatment with nucleoside antiretrovirals damages hearing

    The Surgical Infection Society revised guidelines on the management of intra-abdominal infection

    Get PDF
    Background: Previous evidence-based guidelines on the management of intra-abdominal infection (IAI) were published by the Surgical Infection Society (SIS) in 1992, 2002, and 2010. At the time the most recent guideline was released, the plan was to update the guideline every five years to ensure the timeliness and appropriateness of the recommendations. Methods: Based on the previous guidelines, the task force outlined a number of topics related to the treatment of patients with IAI and then developed key questions on these various topics. All questions were approached using general and specific literature searches, focusing on articles and other information published since 2008. These publications and additional materials published before 2008 were reviewed by the task force as a whole or by individual subgroups as to relevance to individual questions. Recommendations were developed by a process of iterative consensus, with all task force members voting to accept or reject each recommendation. Grading was based on the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) system; the quality of the evidence was graded as high, moderate, or weak, and the strength of the recommendation was graded as strong or weak. Review of the document was performed by members of the SIS who were not on the task force. After responses were made to all critiques, the document was approved as an official guideline of the SIS by the Executive Council. Results: This guideline summarizes the current recommendations developed by the task force on the treatment of patients who have IAI. Evidence-based recommendations have been made regarding risk assessment in individual patients; source control; the timing, selection, and duration of antimicrobial therapy; and suggested approaches to patients who fail initial therapy. Additional recommendations related to the treatment of pediatric patients with IAI have been included. Summary: The current recommendations of the SIS regarding the treatment of patients with IAI are provided in this guideline

    Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

    Get PDF
    Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts
    corecore