Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 10 de 10
Filter
Add more filters










Publication year range
1.
Med Mol Morphol ; 46(2): 86-91, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23381602

ABSTRACT

The aim of the present study was to develop a novel transfection method for short interfering RNA (siRNA). A nanotube with surfactant activity, A6K, consisting of six alanine residues and a hydrophilic head, lysine, was compared to the conventional cationic transfectant reagents siFECTOR and Lipofectamine 2000. Cytotoxicity for the human glioblastoma cell lines U87MG, A172, and T98G was examined with the MTS assay. Transfection efficiency was analyzed with FITC-labeled siRNA targeting matrix metalloproteinase (MMP)-2 mRNA by fluorescent activity on microscopy. The ultrastructure of A6K was evaluated by electron microscopy. The level of cytotoxicity associated with A6K in the U87MG cells was significantly lower than with siFECTOR and Lipofectamine 2000. Transfection efficiency for siRNA was increased in a dose- and time-dependent fashion. The relative expression of MMP-2 mRNA to ß-actin was reduced in a dose-dependent manner by real-time RT-PCR analysis. The ultrastructure of the A6K was transformed to micelle formation when mixed with the siRNA. The lipid-like self-assembling peptide, A6K, has genes in the micelle associated with the hydrophilic tail. This transfection method is a novel and stable technique with lower cytotoxicity than the current standard methods.


Subject(s)
Nanotubes/chemistry , RNA, Small Interfering/genetics , Transfection/methods , Actins/genetics , Cell Line , Humans , Lipids/chemistry , Matrix Metalloproteinase 2/genetics , Peptides/chemistry , Peptides/genetics , RNA, Messenger/genetics
3.
Acta Neurochir (Wien) ; 147(11): 1189-92; discussion 1192, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16155804

ABSTRACT

We report a rare intracisternal C1 posterior root neurinoma in a 35-year-old man without neurofibromatosis who presented with headache, nuchal pain, bilateral motor weakness of the upper extremities, and numbness in the right distal upper extremity. CT and MRI study showed a 20-mm intracisternal lesion at the foramen magnum. At surgery, there was an anastomosis between the C1 posterior root and a spinal accessory nerve at the site of the tumor; the root from the collateral sulcus of this C1 root was absent. Postoperatively, the patient remains free of symptoms. Foramen magnum neurinomas have been described as accessory nerve tumors. We present new anatomical consideration regarding this lesion.


Subject(s)
Cisterna Magna/pathology , Foramen Magnum/pathology , Neurilemmoma/diagnosis , Spinal Neoplasms/diagnosis , Spinal Nerve Roots/pathology , Accessory Nerve/pathology , Adult , Cervical Atlas/anatomy & histology , Cervical Atlas/surgery , Cisterna Magna/diagnostic imaging , Cisterna Magna/surgery , Foramen Magnum/diagnostic imaging , Foramen Magnum/surgery , Humans , Magnetic Resonance Imaging , Male , Medulla Oblongata/anatomy & histology , Medulla Oblongata/surgery , Muscle Weakness/etiology , Muscle Weakness/physiopathology , Neck Pain/etiology , Neck Pain/physiopathology , Neurilemmoma/blood supply , Neurilemmoma/surgery , Neurosurgical Procedures , Paraplegia/etiology , Paraplegia/physiopathology , Radiography , Spinal Neoplasms/blood supply , Spinal Neoplasms/surgery , Spinal Nerve Roots/physiopathology , Subarachnoid Space/diagnostic imaging , Subarachnoid Space/pathology , Subarachnoid Space/surgery , Treatment Outcome , Vertebral Artery/anatomy & histology , Vertebral Artery/surgery
5.
Mod Pathol ; 13(10): 1097-108, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11048804

ABSTRACT

We investigated the localization of pituitary homeo box 1 (Ptx1) protein in five human non-neoplastic pituitaries and 73 of all types of pituitary adenomas using immunohistochemistry, and the expression of Ptx1 messenger RNA (mRNA) in 18 representative pituitary adenomas using the reverse transcriptase polymerase chain reaction (RT-PCR) technique. By immunohistochemical analysis, Ptx1 protein was extensively detected in the nuclei of normal human pituitary cells. Ptx1 was detected in 10/14 (71.4%) of growth hormone (GH)-secreting adenomas, 12/12 (100%) of prolactin (PRL)-secreting adenomas, 18/20 (90%) of adrenocorticotropic hormone (ACTH)-secreting adenomas, 6/7 (85.7%) of thyroid-stimulating hormone (TSH)-secreting adenomas, and 17/20 (85%) of clinically non-functioning adenomas, including 9/10 (90%) of gonadotropin-subunit-positive adenomas. Thus, there was no relationship between Ptx1 expression and a particular type of pituitary adenomas. By RT-PCR analysis, Ptx1 mRNA was expressed in all 18 cases of pituitary adenomas, including two cases negative for Ptx1 protein by immunohistochemistry. These results suggested that Ptx1 may be an universal transcription factor in both neoplastic and non-neoplastic conditions in human pituitaries. The synergistic action with other transcription factors may be speculated to determine the specific production of the anterior pituitary hormones.


Subject(s)
Adenoma/metabolism , Homeodomain Proteins/metabolism , Pituitary Gland/metabolism , Pituitary Neoplasms/metabolism , Transcription Factors/metabolism , Adenoma/pathology , Adolescent , Adult , Aged , Aged, 80 and over , Blotting, Western , DNA Primers/chemistry , Female , Homeodomain Proteins/genetics , Humans , Immunohistochemistry , Male , Middle Aged , Paired Box Transcription Factors , Pituitary Gland/pathology , Pituitary Hormones/metabolism , Pituitary Neoplasms/pathology , RNA, Messenger/metabolism , RNA, Neoplasm/analysis , Reverse Transcriptase Polymerase Chain Reaction , Transcription Factors/genetics
6.
Neurol Med Chir (Tokyo) ; 40(7): 383-6, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10927908

ABSTRACT

A 50-year-old male with acromegalic features presented with a pituitary stone in a growth hormone-secreting adenoma. Endocrinological examination showed "low growth hormone acromegaly." The serum growth hormone level responded to the thyrotropin-releasing hormone test and was not suppressed by oral glucose loading. Neuroimaging revealed an adenoma including a large calcification (pituitary stone) located in the right lateral wing. The adenoma with stone was totally removed by transsphenoidal surgery. The patient regained almost normal response of serum growth hormone. Histological examination showed the stone was composed of thick calcification surrounded by necrotic adenoma tissue and chronic hemorrhage. Large intratumoral pituitary stone is very rare, although calcification is sometimes observed in the adenoma capsule. The long history of this disease and previous apoplexy within the tumor may have caused the pituitary stone in this patient.


Subject(s)
Acromegaly/pathology , Adenoma/pathology , Calcinosis/pathology , Human Growth Hormone/metabolism , Pituitary Neoplasms/pathology , Adenoma/metabolism , Humans , Male , Middle Aged , Pituitary Gland/pathology , Pituitary Neoplasms/metabolism
9.
Horm Res ; 50(1): 11-7, 1998.
Article in English | MEDLINE | ID: mdl-9691207

ABSTRACT

The pituitary-specific transcriptional factor Pit-1 is known to play a role in the development and differentiation of pituitary cells. Recent investigations have suggested a role for this transcriptional factor in pituitary adenomas, especially growth hormone (GH)- and prolactin (PRL)-secreting pituitary adenomas. In this study we analyzed the expression of Pit-1 mRNA and its protein in 24 clinically nonfunctioning pituitary adenomas in comparison with normal pituitary glands using in situ hybridization (ISH) and immunohistochemistry (IHC). The interaction between inhibin/activin, a member of the transforming growth factor-beta family, and Pit-1 was also studied. Immunohistochemically, Pit-1 protein was detected in 9 of 24 adenomas (37.5 %), and 8 of these 9 were also positive for the alpha subunit of glycoprotein (alphaSU). The expression of Pit-1 mRNA was detected in 14 of 24 (58.3%) clinically nonfunctioning adenomas, and it was found in all cases which expressed the Pit-1 protein. By the combined ISH and IHC method, Pit-1 mRNA was frequently observed in alphaSU-immunopositive cells in adenomas. The inhibin/activin alpha subunit was detected in all 24 adenomas and the betaA subunit was detected in 13 of 24 adenomas. The inhibin/activin betaA subunit was detected frequently with Pit-1 mRNA. From our observations, the inhibin/activin betaA subunit in nonfunctioning adenomas may have related the expression of Pit- mRNA in these adenomas.


Subject(s)
Adenoma/chemistry , DNA-Binding Proteins/genetics , Gene Expression , Inhibins/analysis , Pituitary Neoplasms/chemistry , Transcription Factors/genetics , Activins , Adenoma/genetics , Adult , Aged , Female , Follicle Stimulating Hormone/analysis , Follicle Stimulating Hormone, beta Subunit , Humans , Immunohistochemistry , In Situ Hybridization , Luteinizing Hormone/analysis , Male , Middle Aged , Pituitary Neoplasms/genetics , RNA, Messenger/analysis , Transcription Factor Pit-1
10.
Mod Pathol ; 11(3): 232-8, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9521468

ABSTRACT

Prohormone convertase (PC) 1/3 and PC2 are involved in post-translational processing of endocrine tissues, including the pancreatic islets and pituitary glands. Our immunohistochemical studies disclosed the presence of PC1/3 and PC2 in non-neoplastic pituitary glands, especially in corticotrophs, gonadotrophs, and thyrotrophs. Among 58 pituitary adenomas obtained by trans-sphenoidal surgery, adrenocorticotropin (ACTH)-secreting adenomas showed a high incidence of the presence of PC1/3 and PC2, i.e., nine of nine cases were positive for ACTH. Five of nine cases showed consistency between PC2 localization and alpha-melanocyte stimulating hormone immunoreactivity, which suggests the functional correlation between PC2 and the processing of ACTH. In four cases, we observed inconsistency in immunolocalization, which suggested the possibility of inactive PC2 and abnormal processing of alpha-melanocyte stimulating hormone. The high incidence of PC1/3 and PC2 in nonfunctioning adenomas might be related to the processing of chromogranin A.


Subject(s)
Adenoma/enzymology , Aspartic Acid Endopeptidases/analysis , Pituitary Gland, Anterior/enzymology , Pituitary Neoplasms/enzymology , Subtilisins/analysis , Adenoma/chemistry , Adenoma/ultrastructure , Adrenocorticotropic Hormone/analysis , Adult , Cytoplasmic Granules/chemistry , Female , Follicle Stimulating Hormone/analysis , Humans , Immunohistochemistry , Male , Melanocyte-Stimulating Hormones/analysis , Microscopy, Confocal , Microscopy, Immunoelectron , Middle Aged , Pituitary Gland, Anterior/chemistry , Pituitary Gland, Anterior/ultrastructure , Pituitary Neoplasms/chemistry , Pituitary Neoplasms/ultrastructure , Proprotein Convertase 2 , Proprotein Convertases , Thyrotropin/analysis
SELECTION OF CITATIONS
SEARCH DETAIL
...