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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
411

PHENOTYPIC EFFECTS AND TRANSMISSION RATES OF CUCURBITA PALMATA CHROMOSOMES IN CUCURBITA MOSCHATA ANEUPLOIDS.

GRAHAM, JOHN DANA. January 1984 (has links)
Phenotypic effects and transmission rates of the extra chromosome in interspecific trisomics of Cucurbita moschata cv. Butternut (2n C. moschata + 1 C. palmata chromosome) were compared with those of a primary trisomic of C. moschata. Based on gross morphological similarities, 17 interspecific trisomic lines were placed in six phenotypic groups, suggesting that six different C. palmata chromosomes were recovered. Fruit from one of the interspecific trisomics exhibited the hard rind of C. palmata, indicating that this is a dominant trait carried on one chromosome. Some phenotypic effects of the extra chromosome were similar in both the interspecific and primary trisomics, showing a chromosomal effect due to genic imbalance. Transmission of the extra chromosome through the female ranged from 15% to 32% for the C. palmata chromosomes, and was 44% in the primary trisomic. None of the extra chromosomes were transmitted through the male parent.
412

Cytologic studies of the fallopian tube in patients undergoing salpingo-oophorectomy

Chen, Hao, Klein, Robert, Arnold, Stacy, Chambers, Setsuko, Zheng, Wenxin 01 October 2016 (has links)
Background: Mounting evidence suggests the fallopian tube as the origin for ovarian high grade serous carcinoma (HGSC). We attempted to identify the tubal cytological features that allow us to distinguish malignant from benign conditions. Methods: Tubal specimens (n = 56) were collected from patients who underwent bilateral salpingo-oophorectomy (BSO) due to various clinical indications. A standard procedure to collect fallopian tube brushings from freshly received surgical specimens was developed. Cytological diagnoses were classified into three categories: benign, atypical, and suspicious for malignancy/malignant. Cytological variables of individual cells and epithelia were subjected to statistical analysis. The fallopian tube histology was used as diagnostic reference for confirmation of cytology diagnosis. Results: Among the 56 fallopian tube specimens, 2 (3.7 %) showed inadequate cellularity preventing further evaluation, 11 (20.4 %) were diagnosed as malignant or suspicious of malignancy, 7 were atypical, and 36 were benign. The presence of three dimensional clusters (p < 0.0001, Fisher's Exact Test), or prominent nucleoli (p = 0.0252, Fisher Exact test) was highly correlated with the diagnosis of malignancy. The suspicious malignant/malignant cytological diagnosis was also highly correlated with presence of HGSC with or without serous tubal intraepithelial carcinoma (STIC). Conclusions: Tubal cytology may be useful for ovarian cancer screening and early detection.
413

Distributed hierarchical automata with applications to genetics in procaryotes.

Kohn, Wolf January 1978 (has links)
Thesis. 1978. Ph.D.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / Ph.D.
414

Targeting mechanisms of secretory carrier membrane protein 1 in tobacco BY-2 cells. / CUHK electronic theses & dissertations collection

January 2010 (has links)
Brefeldin A (BFA) has been a useful tool for studying organelle dynamics and protein trafficking in plant cells. Using several Golgi (MAN1 and GONST1) and TGN (SCAMP1 and SYP61) fluorescent protein markers as tools, I have showed that BFA-induced aggregates from Golgi apparatus and TGN are morphologically distinct in the same plant cells. In addition, the internalized endosomal marker FM4-64 colocalized with the TGN-derived aggregates but separated from the Golgi aggregates. In the presence of the endocytosis inhibitor tyrphostin A23, SCAMP1 and FM4-64 are largely excluded from the TGN SYP61-positive BFA-induced aggregates, indicating homotypic fusion of TGN rather than de novo endocytic trafficking is important for the formation of TGN/EE-derived BFA-induced aggregates. Since the TGN also serves as an EE receiving materials from plasma membrane continuously, these data therefore support the notion that the secretory Golgi organelle is distinct from the endocytic TGN/EE in response to BFA treatment in plant cells. / Little is known about the trafficking mechanism of plasma membrane (PM) proteins in the endomembrane system of plant cells that contain several membrane-bound organelles including the endoplasmic reticulum (ER), Golgi, trans-Golgi network (TGN) of early endosome (EE), prevacuolar compartment (PVC) or late endosome (LE). Here, I study the transport pathway and sorting signals of secretory carrier membrane protein 1 (SCAMP1) by following its transient expression in tobacco BY-2 protoplasts and show that SCAMP1 reaches the PM via an ER-Golgi-TGN-PM pathway. Loss-of-function and gain-of-function analysis of various GFP fusions with SCAMP1 mutations further demonstrates that: (1) the cytosolic N terminus of SCAMP1 contains an ER export signal; (2) the transmembrane domain 2 (TMD2) and TMD3 of SCAMP1 are essential for Golgi export; and (3) SCAMP1 TMD1 is essential for TGN-to-PM targeting. Therefore, both the cytosolic N-terminus and TMD sequences of SCAMP1 play integral roles in mediating its transport to the PM via an ER-Golgi-TGN pathway. / Cai, Yi. / Adviser: Liwen Jiang. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 93-102). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
415

Characterization and functional studies of a testis-specific transcription factor, NYD-SP24. / CUHK electronic theses & dissertations collection

January 2005 (has links)
Further investigation of possible regulatory pathway of NYD-SP24 demonstrated that the cell cycle of NYD-SP24 overexpressing cells was incompletely blocked at G2/M phase, and one of cell cycle-related genes, p21, shown to be an inducer of differentiation in different types of cell system, was found upregulated in a p53-independent manner, consistent with a role of NYD-SP24 in differentiation. (Abstract shortened by UMI.) / Spermatogenesis is a unique cell differentiation process consisting of three main phrases, namely mitosis, meiosis and postmeiosis. The differentiation of germ cells in the process involves distinct transcriptional programs, each under control of different transcription factor network. Many testis-specific transcription factors have been reported previously, however, few detailed studies have been done. This thesis describes the characterization and functional studies of a newly discovered testis-specific transcription factor, NYD-SP24, and the investigation of the possible regulatory pathway of NYD-SP24 in spermatogenesis. / The results demonstrated that in normal human tissues, NYD-SP24 was specifically and highly expressed in the testis but not in other somatic tissues, indicating its possible role in spermatogenesis. In the mouse model, mRNA and protein of NYD-SP24 mouse homolog gene (mNYD-SP24) were increased in the first wave of spermatogenesis. During the differentiation of germ cells, mNYD-SP24 mRNA and protein were confined to spermatocyte, round spermatid and spermatozoa. In hyperthermic mouse model, expression of mNYD-SP24 was decreased following the damage to germ cells by heat shock, but returned to normal level upon recovery of spermatogenesis. These results suggest the involvement of NYD-SP24 in spermatogenesis. / To identify the possible downstream targets of NYD-SP24, microarray and two-dimension gel technologies were performed in NYD-SP24 overexpressing cells and control cells. The results of microarray showed that 16 genes were upregulated and 4 genes were downregulated in NYD-SP24 overexpressing cells. In the two-dimension gel analysis, 12 protein spots were found to be altered significantly, with 8 increased and 4 decreased. Among these proteins, 3 were successfully identified by mass spectrometry. The nuclei localization in germ cells and the ability of NYD-SP24 to alter gene expression profile suggest that NYD-SP24 may be a testis-specific transcription factor, involved in gene regulation in spermatogenesis. / Zhu Hu. / "June 2005." / Adviser: Chan Hsiao Chang. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3607. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 136-146). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.
416

The effect of growth factors on the corneal stroma extracellular matrix production by keratocytes

Etheredge, LaTia Shaquan. January 2009 (has links)
Dissertation (Ph.D.)--University of South Florida, 2009. / Title from PDF of title page. Document formatted into pages; contains 91 pages. Includes vita. Includes bibliographical references.
417

Examining potential cellular alterations within the anterior cingulate cortex in major depression and suicide

Hercher, Christa. January 2008 (has links)
Representing a major public health concern, suicide is a leading cause of death worldwide. Generally regarded as a behavior with a multitude of state and trait dependent risk factors (e.g. psychiatric disorders, substance abuse, genetics), explanations as to why certain individuals commit suicide while others do not are complex. Of interest is in studying potential trait dependent variables involved in the neurobiology of suicide, particularly at the cellular level. Knowledge of the cellular integrity may aid in explaining the observed macroscopic alterations and ultimately the behavioral correlates associated with suicidality. Therefore we set out to summarize extant knowledge of the cellular alterations occurring in the brains of major depressive and suicide individuals. Following this, we conducted our own cellular investigation in a region known to be altered in major depression and suicide, a supracallosal area of BA24a. Neuronal and glial cell densities as well as neuronal cell sizes were assessed in upper and lower cortical layers between sudden-death controls and MDD suicide subjects. Secondary analyses were also conducted to examine the effect of alcohol on depressed suicides. Analyses of cell densities and neuronal soma sizes between controls and MDD suicide subjects did not reveal any significant differences. Further analyses showed increased glial cell densities in alcoholic depressed suicides. Future studies are necessary to examine explicit changes in the cellular compositions occurring in alcoholic dependent individuals. Staining techniques aimed at targeting specific subtypes of neurons and glial cells will help determine if these cell populations do in fact have an influential role in suicide and MDD.
418

Regulation of skeletal muscle satellite cell proliferation by NADPH oxidase

Mofarrahi, Mahroo. January 2007 (has links)
Skeletal satellite cells are adult stem cells located among muscle fibers. Proliferation, migration and subsequent differentiation of these cells are critical steps in the repair of muscle injury. We document in this study the roles and mechanisms through which the NAPDH oxidase complex regulates skeletal satellite cell proliferation. The NADPH oxidase subunits Nox2, Nox4, p22phox, p47phox and p67 phox were detected in primary human and murine skeletal muscle satellite cells. In human satellite cells, NADPH oxidase-fusion proteins were localized in the cytosolic and membrane compartments of the cell, except for p47 phox, which was detected in the nucleus. In proliferating subconfluent satellite cells, both Nox2 and Nox4 contributed to O2- production. However, Nox4 expression was significantly attenuated in confluent cells and in differentiated myotubes. Proliferation of satellite cells was significantly reduced by antioxidants (N-acetylcysteine and apocynin), inhibition of p22phox expression using siRNA oligonucleotides, and reduction of Nox4 and p47phox activities with dominant-negative vectors resulted in attenuation of activities of the Erk1/2, PI-3 kinase/AKT and NFkappaB pathways and significant reduction in cyclin D1 levels. We conclude that NADPH oxidase is expressed in skeletal satellite cells and that its activity plays an important role in promoting proliferation of these cells.
419

Papers submitted by H.C. Gurney for the degree of M.Sc

Gurney, H. C. January 1935 (has links) (PDF)
Title from handwritten title supplied by author, on folder cover sheet. Includes bibliographical references A classification of South Australian wheat varieties. Reprinted from: Bulletin / Dept. of Agriculture of South Australia. no. 266 (1932), pp. 1-19 -- Cytology of wheat x rye hybrids of the 5th and 6th generation. Reprinted from: The Australian journal of experimental biology and medical science, vol. xi (1933), pp. [123]-137 -- Cytology of rye (work carried out under the Ernest Ayers Research Scholarship in Botany at the University of Adelaide, 1931). Original typescript. 15 leaves + 4 leaves of plates
420

Evaluation of second-generation liquid-based cytology system for the detection of cervical abnormality

Shah, Bijal Nigam January 2011 (has links)
Liquid-based cytology (LBC) has replaced conventional smears in the UK. The National Institute for Health and Clinical Excellence (NICE) recommended the use of LBC in 2003. ThinPrepTM (TP) and SurePathTM (SP) LBC systems were adopted for use in the National Health Service Cervical Screening Programme (NHSCSP) in the UK. NICE recommended further review of any other technologies or other liquid-based cytology systems in the future. For any second-generation LBC systems to be considered for cervical screening in the NHSCSP, there must be an evaluation of technical requirements and clinical data relating to their sensitivity, specificity and the percentage of inadequate samples.The objective of the work undertaken for this thesis was to provide evidence to enable an informed decision on the use of second-generation liquid-based cytology systems for cervical screening in the UK. The decision to accept the second-generation LBC system in the NHSCSP is based on its reliability, clinical effectiveness and cost implications. This work will determine the reliability, microscopic quality and reproducibility of slides of the second-generation LBC system, and the results of this work will form the platform for progression to the clinical evaluation of the system.Initially, four second-generation LBC systems were considered suitable for evaluation. They were Seroa CYTO-screen, Shandon Papspin, LGM Liqui-PREP and CellSolution 120. However, the specifications of only one system (CellSolution 120TM) met NHSCSP technical requirements to start the evaluation. One hundred random, electronically generated colposcopy patient samples were used to assess the technical reliability of the CellSolution 120TM system. The technical evaluation consisted of pre-phase I and phase I. The results of these phases will decide whether the CS 120TM liquid-based cytology system could be carried further for clinical evaluation (phase II) or not.This study was sponsored by the NHS Purchasing and Supply Agency (PASA), the Centre for Evidence based Purchasing (CEP) on behalf of the NHSCSP. The Manchester Cytology Centre (MCC) was selected as the site for evaluation of CellSolution 120™ and the project was managed by Guildford Medical Device Evaluation Centre (GMEC) on behalf of CEP.

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