Home About us Contact
|
Home About us Contact | ||
|
|
||
PTC
Kinds of PTC Selected AbstractsPapillary thyroid carcinoma with atypical histiocytoid cells on fine-needle aspirationDIAGNOSTIC CYTOPATHOLOGY, Issue 4 2009Manju Harshan M.D. Abstract Although papillary thyroid carcinoma (PTC) usually has classic cytological characteristics on fine-needle aspiration (FNA), it can present rarely with aberrant features resembling those of histiocytes in a cystic nodule. The aim of the current study was to describe PTC with atypical histiocytoid cells and distinguish it from benign histiocytes. A retrospective computerized search for FNAs with atypical features suggestive of PTC and cystic degeneration was performed, and if available, the corresponding resection specimens were compared. Four cases met the criteria for FNAs and three had surgical pathology follow-up, which showed PTC. One aspirate had some features typical of PTC, but the remaining FNAs had atypical histiocytoid cells, which had traits intermediate between those of PTC and histiocytes. Large cell size, pseudoinclusions, nuclear grooves, and multiple well-defined vacuoles in atypical histiocytoid cells favor PTC over benign histiocytes. Ancillary immunocytochemical studies can also be useful in confirming the diagnosis. Histiocytic cells are frequently present in thyroid aspirates, and occasionally, they have atypical features that represent an unusual presentation of PTC. Closer examination of these cells can provide diagnostic clues for preventing false-negative diagnosis of PTC. Diagn. Cytopathol. 2009. © 2009 Wiley-Liss, Inc. [source] Cytologic features of mixed papillary carcinoma and chronic lymphocytic leukemia/small lymphocytic lymphoma of the thyroid glandDIAGNOSTIC CYTOPATHOLOGY, Issue 11 2008Michelle Reid-Nicholson M.D. Abstract We report a case of papillary thyroid carcinoma (PTC) and chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma of the thyroid gland. To the best of our knowledge, this is the first such case to be reported in the cytology literature. An 81-year-old male with known CLL presented for routine physical examination and was found to have a left-sided thyroid nodule. Thyroid ultrasound showed a calcified nodule. Fine-needle aspiration biopsy (FNAB) was performed and revealed PTC and an atypical lymphoid infiltrate that was suspicious for lymphoma. A partial thyroidectomy was performed and confirmed PTC with concurrent gland involvement by chronic lymphocytic leukemia/small lymphocytic lymphoma (SLL). Diagn. Cytopathol. 2008;36:813,817. © 2008 Wiley-Liss, Inc. [source] Cytopathology proficiency testing: Where do we go from here?,DIAGNOSTIC CYTOPATHOLOGY, Issue 4 2006George K. Nagy M.D. Abstract With the recent introduction of nationwide proficiency testing in cytopathology (PTC), reconsideration of several aspects of this controversial quality assurance method becomes justified. This paper discusses various merits and demerits of the PTC system currently prescribed by federal regulations, points out perceived deficiencies, and suggests methods for improvement. Diagn. Cytopathol. 2006;34:257,264. © 2006 Wiley-Liss, Inc. [source] Intranuclear cytoplasmic inclusions in fine-needle aspiration smears of papillary thyroid carcinoma: A study of its morphological forms, association with nuclear grooves, and mode of formationDIAGNOSTIC CYTOPATHOLOGY, Issue 5 2005D.SC., Dilip K. Das M.B.B.S., Ph.D. Abstract Intranuclear cytoplasmic inclusion (INCI) and nuclear grooves in fine-needle aspiration (FNA) smears of papillary thyroid carcinoma (PTC) represent cytoplasmic invaginations into the nucleus. Although formation of INCIs is linked to nuclear grooves, they seldom exist together. This study was undertaken to find out the various morphological forms of INCIs, their relation to nuclear grooves, and mode of formation. FNA smears of 54 PTC cases were studied for various forms of INCI, nuclear chromatin pattern, nuclear grooves, and nuclear notches. A differential count of INCIs was made in 19 cases having ,10 INCIs per 200 neoplastic cells. INCIs were present in 48 (88.9%) of 54 PTC cases. Round INCIs were present in 46 (85.2%) cases, followed by oval (48.1%), tear drop/flask-shaped (18.5%), irregular (14.8%), planoconvex/semicircular (13%), rectangular (9.3%), spindle-shaped (3.7%), and bilobed (3.7%). A differential count of INCIs also showed that the round form was the commonest (76.3%). The oval and other forms constituted 19.5 and 4.2%, respectively. INCIs and nuclear grooves were present together in a cell in 15 (27.8%) cases. The formation of INCIs as a cytoplasmic invagination into the nucleus was shown cytomorphologically in rare cells. For the first time in this study, the various morphological forms of INCIs, and the extent of their coexistence with nuclear grooves, (have been highlighted) and showed their mode of formation shown at a light microscopic level. Diagn. Cytopathol. 2005;32:264,268. © 2005 Wiley-Liss, Inc. [source] Illness perceptions and quality of life amongst women with pseudotumor cerebriEUROPEAN JOURNAL OF NEUROLOGY, Issue 8 2009A. Kesler Background and purpose:, Pseudotumor cerebri (PTC) is a disorder of increased intracranial pressure without evidence of a space occupying lesion. The purpose of this study was to assess the subjective perception of PTC and its association with stress, anxiety and global quality of life (QOL). Methods:, Fifty-eight women diagnosed with PTC completed questionnaires measuring their subjective appraisal of PTC and specific perceptions of the symptoms, causes, consequences, timeline, controllability and their anxiety, perceived stress, and QOL. Results:, Appraisals of the condition were mostly of loss or threat and those were related to greater anxiety, stress and poorer QOL. Negative perceptions of PTC were related to greater anxiety, stress and poorer QOL. Most of the women attributed their condition to their weight, but adjustment for body mass index ruled out weight as accounting for the findings. Women attributed to the condition symptoms likely to be related to PTC as well as others that seem unrelated. Conclusions:, Our findings underscore the importance of assessing women's subjective perceptions of their condition as a factor related to their levels of anxiety and stress as well as to their QOL. Accurate symptom diagnosis and treatment as well as psychosocial support could assist women who are coping with the burden of this condition and possibly improve their QOL. [source] Detectable BRAF mutation in serum DNA samples from patients with papillary thyroid carcinomasHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 2 2010Tony C. Y. Chuang MD Abstract Background. An activating point mutation of the BRAF oncogene results in a V600E amino acid missense mutation found in a majority of papillary thyroid carcinomas (PTC). Methods. In this study, 28 matched tumor and serum samples obtained from patients with both benign and malignant thyroid disorders were analyzed for BRAF mutation using a gap-ligase chain reaction technique. Results. The BRAF mutation was absent in tumor DNA samples obtained from patients with benign adenomas, follicular neoplasms or carcinoma, and thyroid lymphoma. In contrast, 5 of 14 PTC tumors were positive for the BRAF mutation. Moreover, 3 of 14 patients with PTC were positive for BRAF mutation in serum and tumor. Of these 3 patients, 2 had lymph node metastasis and 2 had PTC in background of the Hashimoto's thyroiditis. Conclusions. The detection of free circulating mutant BRAF in patients with PTC is possible and future studies are warranted to determine its clinical significance. © 2009 Wiley Periodicals, Inc. Head Neck, 2010 [source] Small molecule c-MET inhibitor PHA665752: Effect on cell growth and motility in papillary thyroid carcinomaHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 8 2008Chandrani Chattopadhyay PhD Abstract Background c-Met is upregulated in papillary thyroid carcinoma (PTC) and can be an attractive therapeutic target. We tested the effects of the small molecule c-met inhibitor PHA665752 in blocking c-met,dependent phenotypic effects in PTC cell lines. Methods PTC patient tissues and cell lines were evaluated for c-met expression. The effect of PHA665752 on c-met phosphorylation, downstream signaling, hepatocyte growth factor (HGF),dependent cell growth, and induction of apoptosis was studied. The IC50 of PHA665752 in c-met,expressing PTC cells was determined, and growth curves at 0.1×, 1×, and 10× IC50 concentrations were obtained. Poly(ADP-ribose) polymerase (PARP) and caspase-9-processing post-PHA665752 treatment were studied as markers of apoptosis, and assays analyzing HGF-dependent cell invasion and migration in the presence and absence of PHA665752 were done. Results c-Met was upregulated in most of the patient tissues with PTC and in many PTC cell lines. PHA665752 specifically inhibited c-met phosphorylation, c-met,dependent cell growth, signal transduction, cell survival, cell invasion, and migration in PTC cells with high c-met. Conclusions PHA665752 is an effective and specific inhibitor of c-met in PTC cells with high levels of c-met expression. © 2008 Wiley Periodicals, Inc. Head Neck, 2008 [source] Is central neck dissection necessary for the treatment of lateral cervical nodal recurrence of papillary thyroid carcinoma?HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 10 2007Jong-Lyel Roh MD Abstract Background: Although the pattern of cervical lymph node metastases from papillary thyroid carcinoma (PTC) has been described, little is known about the pattern of lateral cervical nodal recurrence. The aim of this study was to establish the optimal strategy for neck dissection in patients who underwent reoperation for lateral cervical recurrence of PTC. Methods: We reviewed the records of 22 patients who underwent neck dissection for lateral nodal recurrence of thyroid cancer between 2002 and 2004. Eight patients had thyroid remnants or recurrent tumors in the bed and 6 had undergone lateral neck dissection prior to referral. Patients underwent comprehensive dissection of the posterolateral and ipsilateral (n = 10) or bilateral (n = 12) central neck. The pattern of nodal recurrence and postoperative morbidity were analyzed. Results: All patients had lateral compartment involvement, 91% at mid-lower, 45% at upper, and 18% at posterior sites. Central nodes were involved in 86% of patients: 82% at ipsilateral paratracheal, 32% at pretracheal, 27% at superior mediastinal, and 2 patients at contralateral sites. Skip lateral recurrence with no positive central nodes was rarely observed (14%). Postoperative vocal cord palsy (n = 1) and hypoparathyroidism (n = 5) developed only in patients undergoing bilateral central compartment dissection. Conclusions: The inclusion of comprehensive ipsilateral central and lateral neck dissection in the reoperation for patients with lateral neck recurrence of PTC is an optimal surgical strategy. © 2007 Wiley Periodicals, Inc. Head Neck, 2007 [source] Hyalinizing trabecular tumour of the thyroid,differential expression of distinct miRNAs compared with papillary thyroid carcinomaHISTOPATHOLOGY, Issue 5 2010Sien-Yi Sheu Sheu S-Y, Vogel E, Worm K, Grabellus F, Schwertheim S & Schmid K W (2010) Histopathology56, 632,640 Hyalinizing trabecular tumour of the thyroid,differential expression of distinct miRNAs compared with papillary thyroid carcinoma Aims:, To compare the expression pattern of five microRNAs (miRNAs) (146b, -181b, -21, -221, -222) of papillary thyroid carcinoma (PTC) and hyalinizing trabecular tumour of the thyroid (HTT). Methods and results:, The expression pattern of five miRNAs known to be up-regulated in PTC was retrospectively analysed in 18 HTTs, adjacent normal thyroid tissue, 10 PTCs, 10 follicular adenomas and 10 non-toxic multinodular goitres (MNG) by reverse transcriptase-polymerase chain reaction using the TaqMan miRNA assay. Furthermore, the two common genetic alterations characteristic for PTC, the V600E mutation of the BRAF gene and RET/PTC 1 and 3 rearrangements, were determined in all HTTs. All miRNAs were significantly up-regulated in PTCs, whereas all miRNAs in HTT, normal thyroid tissue, adenomas, and MNGs were down-regulated. Calculating relative changes in gene expression, a 510-fold change of miRNA 146b between PTC and HTT could be observed followed by fold changes between 6.4 and 29 in the remaining miRNAs (P < 0.001). All HTTs lacked BRAF mutations and RET/PTC rearrangements. Conclusions:, Our findings do not support the concept that a high proportion of HTT represents a variant of PTC. It is suggested that HTTs lacking both a miRNA expression pattern characteristic for PTC and RET/PTC rearrangements are re-designated as ,hyalinizing trabecular adenomas'. [source] Nonoperative imaging techniques in suspected biliary tract obstructionHPB, Issue 6 2006Frances Tse Abstract Evaluation of suspected biliary tract obstruction is a common clinical problem. Clinical data such as history, physical examination, and laboratory tests can accurately identify up to 90% of patients whose jaundice is caused by extrahepatic obstruction. However, complete assessment of extrahepatic obstruction often requires the use of various imaging modalities to confirm the presence, level, and cause of obstruction, and to aid in treatment plan. In the present summary, the literature on competing technologies including endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiopancreatography (PTC), endoscopic ultrasound (EUS), intraductal ultrasonography (IDUS), magnetic resonance cholangiopancreatography (MRCP), helical CT (hCT) and helical CT cholangiography (hCTC) with regards to diagnostic performance characteristics, technical success, safety, and cost-effectiveness is reviewed. Patients with obstructive jaundice secondary to choledocholithiasis or pancreaticobiliary malignancies are the primary focus of this review. Algorithms for the management of suspected obstructive jaundice are put forward based on current evidence. Published data suggest an increasing role for EUS and other noninvasive imaging techniques such as MRCP, and hCT following an initial transabdominal ultrasound in the assessment of patients with suspected biliary obstruction to select candidates for surgery or therapeutic ERCP. The management of patients with a suspected pancreaticobiliary condition ultimately is dependent on local expertise, availability, cost, and the multidisciplinary collaboration between radiologists, surgeons, and gastroenterologists. [source] Molecular characterization of novel progranulin (GRN) mutations in frontotemporal dementia,HUMAN MUTATION, Issue 4 2008Odity Mukherjee Abstract Frontotemporal dementia (FTD) is a clinical term encompassing dementia characterized by the presence of two major phenotypes: 1) behavioral and personality disorder, and 2) language disorder, which includes primary progressive aphasia and semantic dementia. Recently, the gene for familial frontotemporal lobar degeneration (FTLD) with ubiquitin-positive, tau-negative inclusions (FTLD-U) linked to chromosome 17 was cloned. In the present study, 62 unrelated patients from the Washington University Alzheimer's Disease Research Center and the Midwest Consortium for FTD with clinically diagnosed FTD and/or neuropathologically characterized cases of FTLD-U with or without motor neuron disease (MND) were screened for mutations in the progranulin gene (GRN; also PGRN). We discovered two pathogenic mutations in four families: 1) a single-base substitution within the 3, splice acceptor site of intron 6/exon 7 (g.5913A>G [IVS6,2A>G]) causing skipping of exon 7 and premature termination of the coding sequence (PTC); and 2) a missense mutation in exon 1 (g.4068C>A) introducing a charged amino acid in the hydrophobic core of the signal peptide at residue 9 (p.A9D). Functional analysis in mutation carriers for the splice acceptor site mutation revealed a 50% decrease in GRN mRNA and protein levels, supporting haploinsufficiency. In contrast, there was no significant difference in the total GRN mRNA between cases and controls carrying the p.A9D mutation. Further, subcellular fractionation and confocal microscopy indicate that although the mutant protein is expressed, it is not secreted, and appears to be trapped within an intracellular compartment, possibly resulting in a functional haploinsufficiency. Hum Mutat 29(4), 512,521, 2008. © 2008 Wiley-Liss, Inc. [source] Mutation analysis in nephronophthisis using a combined approach of homozygosity mapping, CEL I endonuclease cleavage, and direct sequencing,HUMAN MUTATION, Issue 3 2008Edgar A. Otto Abstract Nephronophthisis (NPHP), an autosomal recessive kidney disease, is the most frequent genetic cause of chronic renal failure in the first three decades of life. Mutations in eight genes (NPHP1,8) have been identified. We here describe a combined approach for mutation screening of NPHP1, NPHP2, NPHP3, NPHP4, and NPHP5 in a worldwide cohort of 470 unrelated patients with NPHP. First, homozygous NPHP1 deletions were detected in 97 patients (21%) by multiplex PCR. Second, 25 patients with infantile NPHP were screened for mutations in inversin (NPHP2/INVS). We detected a novel compound heterozygous frameshift mutation (p.[Q485fs]+[R687fs]), and a homozygous nonsense mutation (p.R899X). Third, 37 patients presenting with NPHP and retinitis pigmentosa (Senior-Løken syndrome [SLS]) were screened for NPHP5/IQCB1 mutations by direct sequencing. We discovered five different (three novel) homozygous premature termination codon (PTC) mutations (p.F142fsX; p.R461X; p.R489X; p.W444X; and c.488,1G>A). The remaining 366 patients were further investigated for mutations in NPHP1, NPHP3, and NPHP4. We applied a "homozygosity only" strategy and typed three highly polymorphic microsatellite markers at the respective loci. A total of 32, eight, and 14 patients showed homozygosity, and were screened by heteroduplex crude celery extract (CEL I) endonuclease digests. The sensitivity of CEL I was established as 92%, as it detected 73 out of 79 different known mutations simply on agarose gels. A total of 10 novel PTC mutations were found in NPHP1 (p.P186fs, p.R347X, p.V492fs, p.Y509X, and c.1884+1G>A), in NPHP3 (c.3812+2T>C and p.R1259X), and in NPHP4 (p.R59X, p.T1004fs, and p.V1091fs). The combined homozygosity mapping and CEL I endonuclease mutation analysis approach allowed us to identify rare mutations in a large cohort of patients at low cost. Hum Mutat 29(3), 418,426, 2008. © 2007 Wiley-Liss, Inc. [source] Expression of the muscle glycogen phosphorylase gene in patients with McArdle disease: the role of nonsense-mediated mRNA decay,HUMAN MUTATION, Issue 2 2008Gisela Nogales-Gadea Abstract Nearly 35% of all mutations identified in the muscle glycogen phosphorylase gene (PYGM) in patients with McArdle disease result in premature termination codons (PTCs), particularly the p.R50X mutation. The latter accounts for more than 50% of the mutated alleles in most Caucasian patient populations. Mutations resulting in PTC could trigger the degradation of mRNA through a mechanism known as nonsense mediated decay (NMD). To investigate if NMD affects the levels of transcripts containing PYGM mutations, 28 Spanish patients with McArdle disease, harboring 17 different mutations with PTCs in 77% of their alleles, were studied. Transcripts levels of PYGM were measured and sequenced. We assessed that 92% of patients showed NMD. The most frequent mutation (p.R50X) elicited decay in all the genotypes tested. Other PTC producing mutations resulting in NMD were: p.L5VfsX22, p.Q73HfsX7, p.E125X, p.N134KfsX161, p.W388SfsX34, p.R491AfsX7, and p.D534VfsX5. Located in the last exon, the mutation p.E797VfsX19 was not affected by NMD. Missense mutations did not appear to be affected by NMD. In the cDNA sequences they appeared as homozygous, despite being heterozygous in the genomic DNA sequences. Exceptions to the rules governing NMD were found in the mutations p.A704,V and p.K754NfsX49. Hum Mutat 29(2), 277,283, 2008. © 2007 Wiley-Liss, Inc. [source] Different structural components of conventional papillary thyroid carcinoma display mostly identical BRAF statusINTERNATIONAL JOURNAL OF CANCER, Issue 1 2007Alexander Abrosimov Abstract Activating BRAFT1799A mutation is closely associated with a papillary thyroid carcinoma (PTC) histotype. The transversion is frequently detected in the conventional type, Warthin-like and tall cell variants, but is rare in the follicular variant of PTC. Conventional PTC is often presented with tumors of mixed architecture, which besides the papillary structures also contain areas with follicular and solid morphology in which the details of BRAF mutational status are unknown. We set out to differentially investigate the presence of mutated BRAF in the individual structural components microdissected from 44 formalin-fixed, paraffin-embedded PTC tissues from 40 patients. The mutation was detected in at least 1 structural component in 23 tumors (52%). Different structural components of the same tumor had identical BRAF status in 41/44 tumors (93%). In 3 tumors the BRAFT1799A mutation was found only in the papillary, but not in the follicular component. Mutational patterns identical to those in the primary tumors were found in 11/12 lymph node metastases (92%, including both BRAFT1799A -positive and -negative cases). The high concordance of the BRAF mutational status in structurally distinct areas suggests a rather homogeneous distribution of neoplastic epithelial cells in a conventional PTC tumor in most cases. These results imply the reliability of preoperative molecular diagnosis of PTC regardless of the type of tumor component at the site of biopsy sampling and suggest that the majority of patients with BRAF mutation-positive PTC may benefit from the targeted pharmacotherapy. © 2006 Wiley-Liss, Inc. [source] Cyclin E expression in papillary thyroid carcinoma: Relation to stagingINTERNATIONAL JOURNAL OF CANCER, Issue 1 2004Jan Brzezi Abstract Cyclin E plays a pivotal role in the regulation of G1-S transition and relates to malignant transformation of the cells. However, the clinical significance of cyclin E expression in patients with papillary thyroid carcinoma (PTC) remains unknown. We examined by immunohistochemistry the expression of cyclin E in 41 resected PTCs in pathologic stages from pT1a to pT4 and analyzed its relation to clinicohistopathologic factors. The positive staining was divided into 3 grades: no expression if less than 10%, expression if 11,50% and overexpression if more than 50% of the nuclei of tumor cells were stained positively. Cylin E expressions were observed in 75.6% of analyzed PTCs but only 60% of papillary microcarcinomas (PMCs) were immunopositive for cyclin E expression. However, cyclin E staining was observed in 90.4% of PTCs in a group with TNM higher than pT1a. The staining index was significantly different between the PMCs and the rest of the cancers investigated (14.91% ± 14.4% vs. 34.03% ± 23.44%, respectively; p < 0.005) and we observed positive relation between the staining index and factor T of staging of PTCs. All the lymph node metastases coexisted with cyclin E expression and most, but not all, of them coexisted with cyclin E overexpression. These findings indicate that cyclin E may play a key role for the oncogenesis and biologic behavior of PTC. If our results are confirmed in a larger study, a high level of cyclin E expression may become a new prognostic marker for PTCs. © 2003 Wiley-Liss, Inc. [source] Kinetics of synthesis of bis-(benzoxazolyl-2-methyl) sulfide under phase-transfer catalysis conditionsINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 5 2009Zuo-Xiang Zeng Kinetics of synthesis of bis-(benzoxazolyl-2-methyl) sulfide (BBMS) is investigated under phase-transfer catalysis conditions. Thus, the reaction of 2-chloromethylbenzoxazole and sodium sulfide is carried out in a two-phase (organic/water) medium, and quaternary ammonium salt and quaternary phosphonium salt are used as phase-transfer catalyst (PTC) in the reaction. The conversion of 2-chloromethylbenzoxazole is dramatically enhanced by adding a small quantity of PTC and is also greatly affected by the reaction conditions. The effects of various reaction variables on the kinetics are investigated, including the amount of catalyst, the temperature, the kinds of catalysts, the kinds of solvents, and the agitation speed. An interfacial reaction mechanism is proposed to explain the characteristics of the reaction. A pseudo-first-order rate model is established to describe the relationship between the fractional conversion and the reaction time. The kinetics data demonstrate that the model is suitable to the reaction of synthesis of BBMS. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 296,302, 2009 [source] Eco-friendly methodologies for the synthesis of some aromatic esters, well-known cosmetic ingredientsINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 1 2005C. Villa Synopsis Solid,liquid solvent-free phase transfer catalysis (PTC) and acidic catalysis in dry media were applied, with noticeable improvement and simplification over classical procedures in a Green Chemistry context, to the synthesis of some aromatic esters useful as cosmetic ingredients: 3-methylbutyl 4-methoxycinnamate, 2-ethylhexyl 4-methoxycinnamate, 2-ethylhexyl 4-(dimethylamino)benzoate and 2-ethylhexyl salicylate, well-known ultraviolet B sunscreen filters; 4-isopropylbenzyl salicylate, UV absorber and cutaneous antilipoperoxidant; propyl 4-hydroxybenzoate and butyl 4-hydroxybenzoate (parabens), antimicrobial agents. The reactions were performed under microwave (MW) activation and conventional heating. The best results for the synthesis of cinnamic, salicylic and 4-(dimethylamino)benzoic esters were achieved by in situ preformed carboxylates alkylation with alkyl bromides using PTC. The 4-hydroxybenzoates were obtained in good yields by classical esterification of the acid with alcohols using a simple heterogeneous mixture of reagents with catalytic amounts of p -toluenesulfonic acid (PTSA). The comparisons of yields and thermal profiles under either MW or conventional heating were studied and reported. Résumé La catalyse par transfert de phase (CTP) solide-liquide sans solvant et l'estérification acido-catalysée en ,,milieu sec'' ont été appliquées, dans le cadre de la ,,chimie verte'', avec des nettes améliorations et simplifications par rapport aux méthodes classiques, à la synthèse de certains esters aromatiques, ingrédients cosmétiques: 3-methylbutyl 4-méthoxycinnamate, 2-éthylhéxyl 4-méthoxycinnamate, 2-éthylhéxyl 4-(diméthylamino) benzoate et 2-éthylhéxyl salicylate, filtres solaires UVB bien connus; 4-isopropylbenzyl salicylate, filtre UV et antilipopéroxydant cutané; propyl 4-hydroxybenzoate et butyl 4-hydroxybenzoate (parabens), agents antimicrobien. Les réactions ont été procédées sous irradiation micro-onde et par chauffage classique. Pour la synthèse des esters dérivés de l'acide cinnamique, salicylique et 4-(diméthylamino)benzoïque les meilleurs résultats ont été obtenus grâce à la CTP par alkylation des carboxylates (préformés in situ) avec des bromures d'alkyle. Les esters de l'acide 4-hydroxybenzoique ont été obtenus avec de bons rendements par simple mélange hétérogène des réactifs et d'acide p-toluènesulfonique (PTSA) comme catalyseur. Les rendements et les profils de montée en température sous micro-ondes et par chauffage classique ont été comparés. [source] A novel mutation in the ATP2C1 gene is associated with Hailey,Hailey disease in a Chinese familyINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 1 2009Zhou Jiang Liu MD Background, A three-generation Chinese family with Hailey,Hailey disease (HHD) was identified and characterized. The proband developed HHD with severe recurrent blisters and crusted erosions involving the body folds. Skin biopsy studies showed epidermal hyperkeratosis and defects in cell-to-cell adhesion. Three other members in the family were also affected with HHD and had the same clinical manifestations. The purpose of this study was to identify the pathogenic gene or mutation in the family. Methods, All exons and exon,intron boundaries of ATP2C1 were polymerase chain reaction (PCR) amplified and sequenced with DNA samples from the proband. Restriction fragment length polymorphism (RFLP) analysis for the intron 23,exon 24 boundary of ATP2C1 was performed in all family members and in 100 normal control subjects. Results, A novel 2-bp deletion (c.2251delGT) was detected in exon 24 of the ATP2C1 gene. The mutation was present in the three other affected family members and in two asymptomatic young carriers, but not in the other normal family members or the 100 normal controls. The mutation resulted in a frameshift change and led to the formation of a premature termination codon (PTC) four amino acid residues downstream from the sixth transmembrane domain. Conclusions, Our results indicate that the novel c.2251delGT (p.V751fs) mutation in the ATP2C1 gene is responsible for HHD in this Chinese family. This study expands the spectrum of ATP2C1 mutations associated with HHD. [source] Compound heterozygosity in sibling patients with recessive dystrophic epidermolysis bullosa associated with a mild phenotypeINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 3 2006Y. Shibusawa MD We describe two cases of a 3-year-old Japanese boy and his 1-year-old sister presenting recessive dystrophic epidermolysis bullosa; a relatively mild phenotype. Blistering and scarring were limited to the acral region, and some fingernails and toenails were lost. PCR-RFLP and DNA sequencing analyses revealed compound heterozygotes for a splice-site mutation (6573 +1GtoC) and a nonsense mutation (E2857X) in the type VII collagen gene (COL7A1). Both mutations caused a premature termination codon (PTC). The mutation E2857X was located behind the candidate cleavage site within the NC-2 domain required for the assembly of anchoring fibrils. This PTC position may explain their mild phenotype. [source] Phase-Transfer-Catalyzed Intramolecular Cyclization of ortho -Alkynyl Phenyl Ether Derivatives for Synthesis of 2,3-Disubstituted Benzo[b]furansADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 2-3 2010Jie Hu Abstract A variety of substituted benzo[b]furans are readily prepared in good to excellent yields under the mild reaction conditions from o -(1-alkynylphenoxy)-1-phenylethanone under phase-transfer catalysis (PTC). This methodology accommodates simple experimental operations, inexpensive and environmentally benign catalysts, metal catalyst-free conditions, facile reagents and the possibility to conduct large-scale preparations. The development of carbon-carbon bond formation processes via an overall structural isomerization represents the most atom-economical approach. [source] Cover Picture: The Proto-Ribosome: An Ancient Nano-machine for Peptide Bond Formation (Isr. J. Chem.ISRAEL JOURNAL OF CHEMISTRY, Issue 1 20101/2010) The cover picture shows the ribosome 50S subunit on a fungal background. Represented fungi, Clitopilus scyphoides, produce antibiotics of the pleuromutilin family. Pleuromutilins ,moving" into the ribosome Peptidyl Binding Centre (PTC) are also shown. The figure was contributed by Anat Bashan and Ada Yonath (see The Proto-Ribosome: An Ancient Nano-machine for Peptide Bond Formation, Davidovich et al., p. 29 in this issue). [source] Liquid-Liquid-Liquid Phase Transfer Catalysis: A Novel and Green Concept for Selective Reduction of Substituted NitroaromaticsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2005Ganapati Abstract The selective reduction of nitroaromatics to the corresponding amines is an important transformation since many aromatic amines exhibit biological activities and find a multitude of industrial applications, being intermediates for the synthesis of dyes, pharmaceuticals and agrochemicals. A variety of nitroaromatics dissolved in organic solvents was reduced by using aqueous sodium sulfide, and tetrabutylammonium bromide (TBAB) as the phase transfer catalyst by choosing appropriate concentrations which resulted in three immiscible liquid phases. Compared to L-L PTC, the L-L-L PTC offers much higher rates of reaction, better selectivities and repeated use of catalyst. The selectivities for the desired products were 100%. [source] Functional aspects of ribosomal architecture: symmetry, chirality and regulationJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 11 2004Raz Zarivach Abstract High-resolution structures of both ribosomal subunits revealed that most stages of protein biosynthesis, including decoding of genetic information, are navigated and controlled by the elaborate ribosomal architectural-design. Remote interactions govern accurate substrate alignment within a flexible active-site pocket [peptidyl transferase center (PTC)], and spatial considerations, due mainly to a universal mobile nucleotide, U2585, ensure proper chirality by interfering with D -amino-acids incorporation. tRNA translocation involves two correlated motions: overall mRNA/tRNA (messenger and transfer RNA) shift, and a rotation of the tRNA single-stranded aminoacylated-3, end around the bond connecting it with the tRNA helical-regions. This bond coincides with an axis passing through a sizable symmetry-related region, identified around the PTC in all large-subunit crystal structures. Propelled by a bulged universal nucleotide, A2602, positioned at the two-fold symmetry axis, and guided by a ribosomal-RNA scaffold along an exact pattern, the rotatory motion results in stereochemistry optimal for peptide-bond formation and in geometry ensuring nascent proteins entrance into their exit tunnel. Hence, confirming that ribosomes contribute positional rather than chemical catalysis, and that peptide bond formation is concurrent with A- to P-site tRNA passage. Connecting between the PTC, the decoding center, the tRNA entrance and exit points, the symmetry-related region can transfer intra-ribosomal signals between remote functional locations, guaranteeing smooth processivity of amino acids polymerization. Ribosomal proteins are involved in accurate substrate placement (L16), discrimination and signal transmission (L22) and protein biosynthesis regulation (CTC). Residing on the exit tunnel walls near its entrance, and stretching to its opening, protein-L22 can mediate ribosome response to cellular regulatory signals, since it can swing across the tunnel, causing gating and elongation arrest. Each of the protein CTC domains has a defined task. The N -terminal domain stabilizes the intersubunit-bridge confining the A-site-tRNA entrance. The middle domain protects the bridge conformation at elevated temperatures. The C -terminal domain can undergo substantial conformational rearrangements upon substrate binding, indicating CTC participation in biosynthesis-control under stressful conditions. Copyright © 2004 John Wiley & Sons, Ltd. [source] Polyrotaxanes based on polyethers and ,-cyclodextrinJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 17 2009Saloua Chelli Abstract A polyrotaxane in which ,-cyclodextrins (,-CDs) are threaded onto a polyether chain was prepared by polycondensation of a ,-CD/bisphenol A (BPA) inclusion complex with aromatic dihalides. Two dihalides, with and without a side chain, were used. This polycondensation results in a polyrotaxane (or pseudopolyrotaxane for polymers without stoppers) with a 1:1 threading ratio when the side chain is present and 2:3 when there is none. The long side chain prevents dethreading of the macrocycles. The best yield and a good threading ratio were obtained when the polycondensation was performed by liquid,solid phase transfer catalysis without solvent (L/S PTC) using 2,5-bi(iodomethyl)-4-methoxy-(1-octyloxy)benzene as dihalide. The 1H NMR and FTIR spectra show that the products consist of ,-CD and polyether. The 2D NOESY NMR spectrum shows that the polyether chains are included in the ,-CD cavity. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4391,4399, 2009 [source] Isolation, propagation and characterization of primary tubule cell culture from human kidney (Methods in Renal Research)NEPHROLOGY, Issue 2 2007WEIER QI SUMMARY: Proximal tubule cells (PTC) are the major cell type in the cortical tubulointerstitium. Because PTC play a central role in tubulointerstitial pathophysiology, it is essential to prepare pure PTC from kidney tissue to explore the mechanisms of tubulointerstitial pathology. The authors have successfully refined and characterized primary cultures of human PTC using Percoll density gradient centrifugation as a key PTC enrichment step. The cells obtained by this method retain morphological and functional properties of PTC and are minimally contaminated by other renal cells. In particular, the primary isolates have characteristics of epithelial cells with uniform polarized morphology, tight junction and well-formed apical microvilli. Cytokeratin is uniformly and strongly expressed in the isolates. Brush border enzyme activities and PTC transport properties are retained in the isolates. This method therefore provides an excellent in vitro model for the physiologic study of the human proximal tubule. [source] MRCP in the diagnosis of iatrogenic bile duct injuryNMR IN BIOMEDICINE, Issue 8 2003Luis Bujanda Abstract Postoperative biliary tract lesions are becoming increasingly common. The diagnosis is made by direct cholangiography via endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous transhepatic cholangiography (PTC). The present comparative study evaluates the diagnostic efficacy of magnetic resonance cholangiopancreatography (MRCP) in application to iatrogenic bile duct injury. A prospective blind study was performed, contrasting MRCP and ERCP in 10 patients with suspected postoperative biliary tract lesions. MRCP was performed less than 72,h before ERCP. Final diagnosis was made on the basis of findings at surgery and ERCP. The presence of biliary dilatation, excision injury, stricture, fluid collection and free fluid was analyzed. The mean patient age was 66.5 years. There were three males and seven females. The type of postoperative lesion (Bergman classification) are five patients type C, three type D, one type B and one type A. Diagnostic failure was recorded in two cases with ERCP, while in five patients it was unable to define a therapeutic approach. In contrast, MRCP correctly diagnosed all patients. MRCP is effective in diagnosing postoperative biliary tract lesions, and can help decide the best therapeutic approach. Copyright © 2003 John Wiley & Sons, Ltd. [source] Lack of association between BRAF V600E mutation and mitogen-activated protein kinase activation in papillary thyroid carcinomaPATHOLOGY INTERNATIONAL, Issue 1 2007Hui Zuo The BRAF V600E mutation has been identified in a high proportion of papillary thyroid carcinoma (PTC). In cell lines and a transgenic mouse model it has been demonstrated that the mutation constitutively activates the mitogen-activated protein kinase (MAPK) pathway but in human PTC samples its effects remain unexamined. Herein the correlation of BRAF mutation and MAPK activation was examined in 42 human PTC samples. Activating mutations of the BRAF gene and all three RAS genes were detected by polymerase chain reaction-direct sequencing, and RET/PTC1 rearrangements were screened by nested reverse transcription,polymerase chain reaction. MAPK activation was assessed by immunohistochemistry and western blot analysis. Twenty-eight cases (66.7%) of BRAF V600E mutation, three cases (7.1%) of RET/PTC1 rearrangement but no cases of RAS genes mutation were identified. Activated MAPK was found in six cases (14.3%) with only two cases of mutant BRAF. In total 7.1% of PTC with BRAF mutation had activated MAPK. Furthermore, BRAF mutations were more prevalent in patients 0e;45 years, but did not correlate with aggressive clinical behaviors. Absence of association between BRAF mutation and activation of MAPK pathway in PTC suggests the presence of mechanisms that downregulate MAPK activation. [source] Mutations of the BRAF gene in papillary thyroid carcinoma and in Hashimoto's thyroiditisPATHOLOGY INTERNATIONAL, Issue 9 2005Kyung-Hee Kim The purpose of the present study was to investigate the frequency of BRAF mutations in human papillary thyroid carcinoma (PTC) and Hashimoto's thyroiditis (HT) and to evaluate the association of the BRAF mutation with the clinicopathological features of both of these thyroid disorders. A total of 51 PTC with no HT, 28 PTC with HT and 27 HT with no PTC were evaluated using DNA extracted from paraffin-embedded specimens. BRAF mutations were analyzed by direct DNA sequencing of the polymerase chain reaction (PCR)-amplified exon 15. The BRAF missense mutation at codon 599 (T1796A) was present in 46 of 51 PTC (90%) with no HT, 18 of 28 PTC (64%) with HT, four of 28 HT (14%) with PTC, and zero of 27 HT with no PTC. The BRAF mutation at codon 600 (A1798G) was not detected in any case. Clinicopathological examination of 106 patients with either PTC or HT showed that the BRAF mutation was significantly correlated with patient age. These data indicate that the BRAF mutation is associated with a valuable biological property of PTC and may participate in the pathogenesis of PTC arising in HT. These results indicate that the detection of the BRAF mutation in HT can be helpful for prediction of progress to PTC. [source] Differentiation, proliferation and retinoid receptor status of papillary carcinoma of the thyroidPATHOLOGY INTERNATIONAL, Issue 4 2003Weihua Tang Messenger RNA expression of retinoic acid receptors (RAR,, RAR, and RAR,) and retinoid X receptors (RXR,, RXR, and RXR,) was examined using reverse transcription-polymerase chain reaction in 42 papillary thyroid carcinomas (PTCs). A loss of mRNA expression was observed in 18 cases of the 42 PTCs, including three cases for RAR,, 14 cases for RAR,, six cases for RXR, and five cases for RXR,. The expressions of RAR, and RXR, were found in all 42 PTCs. Based on Ki 67/MIB1 labeling index (LI), the 42 PTCs were classified into Group A (20 cases; LI = 0,2%), Group B (17 cases; LI = 2,5%) and Group C (5 cases; LI > 5%). The PTCs of groups B and C showed solid, trabecular or scirrhous arrangements, infiltrative growth, loss of cellular polarity and cohesiveness more frequently, but capsulated growth pattern less frequently, when compared with PTCs of Group A. They also showed more frequent extrathyroidal extension than Group A. However, no significant differences were identified in sex, age, nodal status and tumor size. Loss of expression for one or more retinoid receptors frequently occurred in groups B and C. These results suggest that the loss of retinoid receptors might occur during the loss of differentiation and tumor progression of PTC. [source] Arterial-venous fistulas following pediatric liver transplant case studiesPEDIATRIC TRANSPLANTATION, Issue 6 2007Kathleen Falkenstein Abstract:, AV fistula is a rare but serious complication following pediatric liver transplant and may lead to graft loss. Our aim was to describe two pediatric centers' experience with the diagnosis, treatment and outcomes of children who presented with AV fistulas post-liver transplantation We report five cases of late arterio-portal fistula following liver transplantation. Four children were successfully treated with coil embolization. All of the children in this series had liver biopsies within 2,6 months of their AV fistula diagnosis. All biopsies were performed using a Bard Monopty 18 gauge needle with no ultrasound guidance and only one pass per biopsy. Two children also had PTC 4,8 months prior to their diagnosis of AV fistula. Three of the five children in this series had GI bleeds requiring banding or sclerotherapy. The other two had varices found on CT scan. All five cases in this series had ascites on their initial presentation. Four out of the five children had a history of non-compliance and the other child had a history of malabsorption and chronic diarrhea. [source] | |||||||||||||||||||||||||||||||||||||||||||