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1.
Arch Microbiol ; 185(1): 63-8, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16362286

ABSTRACT

Electron microscopy examinations of thin sections and freeze-fracture replicas revealed the specific ultrastructural features of Alicyclobacillus tolerans strain K1(T). In particular, the cell wall displayed an ultrastructure typical of gram-positive bacteria and consisted of a thin murein layer (50-60 A in thickness); cells exhibited a surface S-layer constituted by large hexagonally packed (p6-symmetry) rod-shaped subunits of 150-160 A in diameter and 200 A in height. In the cytoplasmic membrane, there were intramembrane vesicular structures that sometimes appeared as large leaflets in the central part. The cytoplasm contained numerous vesicular inclusions covered with a monolayered wall, dissimilar to bilamellar lipid membranes. Endospore coats displayed an intricate structure and consisted of three thick layers; the outer layer had an unusual fine structure; the exosporium was also found.


Subject(s)
Gram-Positive Endospore-Forming Rods/ultrastructure , Cell Wall/ultrastructure , Cytoplasm/ultrastructure , Endospore-Forming Bacteria/cytology , Endospore-Forming Bacteria/ultrastructure , Membranes/ultrastructure
2.
J Clin Endocrinol Metab ; 89(9): 4280-4, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15356022

ABSTRACT

A high prevalence of the activating BRAF mutation, BRAF(T1796A), is observed in adult papillary thyroid carcinomas (PTCs). The prognosis of childhood PTCs is generally fairly good despite the fact that distant metastases are often documented in these cases. To investigate the differences between the characteristics of childhood and adult PTCs, we analyzed both BRAF(T1796A) and RAS mutations in 31 Japanese and 48 post-Chernobyl Ukrainian thyroid carcinomas. In the 31 Japanese childhood cases, BRAF(T1796A) was found in only one instance (3.2%), and no RAS mutations were detected. In the Ukrainian subjects, of the 15 childhood and the 33 adolescent and young adult PTCs examined, the BRAF(T1796A) mutation was found in zero and eight cases, respectively, and RAS mutations were found in two of the young adult cases. In addition, 17 of the 48 Ukrainian cases showed expression of the RET tyrosine kinase region, indicating the existence of RET/PTC rearrangements. Unlike adult PTCs, we could detect no positive association between BRAF(T1796A) mutations and clinical parameters in the childhood carcinomas, suggesting that a low prevalence of BRAF(T1796A) is a common feature of PTCs in children regardless of radiation exposure levels. The differences in the prevalence of BRAF(T1796A) mutations between childhood and adult cases of PTC may well reflect inherent differences in the clinical features of these cancers between the two age groups.


Subject(s)
Mutation , Proto-Oncogene Proteins c-raf/genetics , Thyroid Neoplasms/genetics , Adolescent , Carcinoma, Papillary/genetics , Child , Child, Preschool , Female , Gene Rearrangement , Humans , Infant , Male , Oncogene Proteins/genetics , Power Plants , Proto-Oncogene Proteins B-raf , Proto-Oncogene Proteins c-ret , Radioactive Hazard Release , Receptor Protein-Tyrosine Kinases/genetics , Ukraine
3.
Cancer Lett ; 209(1): 1-6, 2004 Jun 08.
Article in English | MEDLINE | ID: mdl-15145515

ABSTRACT

Point mutations of the BRAF gene have been recently described with high prevalence in papillary thyroid carcinomas. However, this molecular alteration has not been studied in radiation-induced thyroid tumors. We analyzed the prevalence of BRAF point mutations and RET/PTC rearrangements in 55 post-Chernobyl papillary carcinomas, compared with 82 sporadic papillary carcinomas. Radiation-induced tumors demonstrated a low prevalence (4%) of BRAF point mutations and high prevalence (58%) of RET/PTC rearrangements. Sporadic papillary carcinomas revealed a clearly distinct pattern, with 37% of tumors harboring BRAF mutations and 20% RET/PTC rearrangements. These results demonstrate a significant difference in the molecular genetic profile of sporadic and radiation-induced thyroid tumors.


Subject(s)
Carcinoma, Papillary/genetics , Neoplasms, Radiation-Induced/genetics , Point Mutation , Proto-Oncogene Proteins c-raf/biosynthesis , Proto-Oncogene Proteins c-raf/genetics , Thyroid Neoplasms/etiology , Thyroid Neoplasms/genetics , Adolescent , Adult , Carcinoma, Papillary/metabolism , Child , Humans , Mutation , Neoplasms, Radiation-Induced/metabolism , Polymerase Chain Reaction , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins B-raf , Proto-Oncogene Proteins c-ret , Receptor Protein-Tyrosine Kinases/genetics , Temperature , Thyroid Neoplasms/metabolism
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