• 대한치과의사협회지
• /
• 제48권5호
• /
• pp.365-370
• /
• 2010

Herpes virus family is highly infectious to patients, their families and dentists. The diagnosis of herpes infection is based on the characteristic clinical appearance and the location of the lesions. Herpes Simplex Virus(HSV) usually acquired through direct contact with infected lesions or body fluids, and the prevalence of HSV infection increases progressively from childhood. Primary infections provoke herpetic gingivostomatis typically affects the tongue, lips, gingival, buccal mucosa and palate. Recurrent infections give rise to vesiculo-ulcerative lesions at vermilion border of lip(herpes labialis). In the form of chickenpox, Varicella Zoster Virus(VZV) usually is infected in childhood. VZV spreads in the affected primary afferent nerve to the skin and produces a vesicular rash and pain. Epstein-Barr Virus(EBV) infects B cells and cause infectious mononucleosis. Latent EBV infection has also been implicated in Burkitt lymphoma, nasopharyngeal carcinoma. Cytomegalovirus(CMV) is associated with immune-compromised patient such as organ transplantation and AIDS patients.

• 한국가축번식학회지
• /
• 제21권3호
• /
• pp.311-319
• /
• 1997

This study was carried out to investigate the ultrastructural changes of spermatozoa obtained from 20 of 3-year-old male chum salmon(Oncorhynchus keta) collected and analysed in middle October in 1995. The ultrastructural changes of gonad of fingerlings were examined to describe the sex differentiation of this species. The results obtained in this study were as follows : In spermatozoa, the nucleus is dense and homogeneous. Two spheroidal mitochondria(about 350nm long) are situated in parallel between the nucleus and the axoneme. Spermatozoa mitochondria are assembled into an organized sheath surrounding the outer dense fibres and axoneme of the flagellar midpiece. The sheath flagellum is situated beneath the base of the sperm head. The primordial germ cells of 6.8~7.2${\mu}{\textrm}{m}$ in size, which were buried under fibrous mesenchymal tissue between gut duct and notochord of larva with a total length of 2.4cm at 50 days after hatching. In juvenile of 10.5cm in total length at 70 days after hatching, the gonad was occupied by bundles of oogonia. The dense drumstick bodies(large arrows) are observed in the nuclei of the primordial gonad and surrounding tissue cells of fingerling at 70 days after hatching. The oval Barr bodies(asterisk) are observed in the nuclei of the primordial germ cells under the mitosis(2n). Note the large mitochondria, ribosomes and rough endoplasmic reticulum in the cytoplasm. Accordingly, the fingerlings at 70 days after hatching are identified as the female(xx). In result, the gonadal sex differentiation begins from the 70 days after hatching in chum salmon.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제45권4호
• /
• pp.225-229
• /
• 2019

Individuals with human immunodeficiency virus (HIV) infection present with unique intraoral manifestations of various neoplasms. Intraoral HIV-associated Burkitt's lymphoma is a rare presentation, especially in patients of Indian origin and may present as an initial sign of HIV. The objective of this paper is to report a rare case of Burkitt's lymphoma in an HIV-positive Indian patient along with a special emphasis on differential diagnosis. A 30-year-old Indian female presented with a solitary, well-defined, exophytic mass extending anteroposteriorly and buccolingually from the 35th to 38th regions with no evidence of intraosseous extension. An incisional biopsy was performed, and histopathology showed sheets of neoplastic lymphoid cells with numerous tingible body macrophages with clear cytoplasm, presenting a starry sky appearance, suggesting a diagnosis of BL. The tumor cells were positive for CD10, CD20, c-myc, and Epstein-Barr virus, with a nearly 100% Ki-67 proliferative index. The patient tested positive for HIV. This report indicates the importance of immunohistochemical analysis to differentiate Burkitt's lymphoma from other similar lesions like diffuse large B-cell lymphoma. Thorough knowledge of the clinical presentation, etiopathogenesis, histopathology, and immunoprofile of intraoral HIV-associated Burkitt's lymphoma is essential among clinicians and pathologists.

• Tuberculosis and Respiratory Diseases
• /
• 제73권6호
• /
• pp.336-341
• /
• 2012

Primary effusion lymphoma (PEL) is a rare type of lymphoma that arises in the body cavity without detectable masses. It is associated with human herpes virus-8 (HHV-8), Epstein-Barr virus (EBV), and human immunodeficiency virus (HIV). Recently, PEL unrelated to viral infection has been reported and it has been termed HHV-8 unrelated primary effusion lymphoma-like lymphoma (HHV-8 unrelated PEL-like lymphoma). Here, we report a case of HHV-8 unrelated PEL-like lymphoma in an 80-year-old woman. Chest X-ray and computed tomography revealed left-sided pleural effusion. Pleural effusion analysis and mediastinoscopic biopsy showed atypical cells that had originated from the B cells. The cells were positive for CD20 and bcl-2, but negative for CD3, CD5, CD21, CD30, CD138, epithelial membrane antigen, and HHV-8. Serological tests for HIV and EBV were negative. Considering the patient's age, further treatments were not performed. She has shown good prognosis without chemotherapy for more than 18 months.

• 식물조직배양학회지
• /
• 제24권1호
• /
• pp.1-35
• /
• 1997

Fertilized egg, by successive cell divisions, differentiates into different tissues and organs with various structures and functions. Different cells and tissues contain different proteins, products of selective gene expression. Not all the genes in any genomes are equally active, temporal and spatial gene expression being the general rule. Present paper attempts to review the tanscriptional mechanisms or the initiations of transcription from several angles. In some of the organisms the genes in the process of transcription or the genes in the inactive state can be seen under the light microscope. Some bands of Drosophila polytene chromosomes may exhibit a swollen or puff appearance under certain conditions. A puff, unfolded or decondensed form of chromomere, represents sets of intense transcriptional activity or RNA synthesis. The heterochromatic X chromosome whose genes remain inactive in the female mammals can be visualized as a dark staining structure called Barr body, Configuration of chromatin differs between transcribed and nontranscribed chromatin. Modification to the chromatin facilitates RNA synthesis. The movement of large polymerase molecule along the DNA would probably be facilitated if some modifications of the chromatin configuration is effected. Methylation of cytosines in CG sequences is associated with inactive genes. Methylation can play a role in determination of mammalian cells during embryogenesis. Demethylation is necessary for the gene to be expressed during development A histone modification that is also known to be correlated with transcriptional capacity of chromatin is acetylation of the lysine residues of the core histones. Chromatin containing a high level of histone acetylation is very sensitive to DNase 1. For the transcription to occur TBP must first bind to the TATA box. Another TF, TF IIB, then binds to the promoter-TBP complex, facilitating the access of RNA polymerase to the transcription initiation site. As recently as eight years ago researchers assumed that histones were irrelevant to the regulation of gene expression. Histones combine with the DNA to form nucleosome of the chromatin. Histones are vital participant in gene regulation. Histone and basal factors compete for access to TATA box. When DNA is exposed to basal factors before histones are introduced, the basal factors assemble on TATA boxes preventing the access of histones, allowing transcription to occur, for transcription to begin, activator protein at the upstream activation sequence or enhancer must interact with the tail of histone H4 at TATA box and cause the histone role particle to dissociate from the TATA box leading to partial breakup of the histone core particle and allowing the basal factors to bind to the TATA box. New concept of genomic flux in contrast to the old concept of static genome has been developed based on the powerful new molecular techniques. Genomic changes such as repetitive DNAs and transposable elements, it is assumed but not yet proved, may affect some of the developmental patterns that characterize particular cells, tissues, organs, and organisms. In the last decade or so remarkable achievement have been made in the researches of the structures and functions of TFs and the specific target sequences located in promoters or enhancers where these TFs bind. TFs have independent domains that bind DNA and that activate transcription. DNA binding domain of TFs serves to bring the protein into the right location. There are many types of DNA binding domains. Common types of motifs can be found that are responsible for binding to DNA. The motifs are usually quite short and comprise only a small part of the protein structure. Steroid receptors have domains for hormone binding, DNA binding, and activating transcription. The zinc finger motif comprises a DNA binding domain. Leucine zipper consist of a stretch of amino acids with a leucine residue in every seventh position Two proteins form a dimer because they interact by means of leucine zippers on similar α-helical domain. This positions their DNA binding basic domains for interaction with the two halves of a DNA sequence with dyad symmetry of TGACTCA, ACTGAGT.