No description available.

Abstract¡G Activating point mutations of the BRAF gene have been recently reported to be restricted to papillary thyroid carcinomas (PTCs) and anaplastic thyroid carcinomas (ATCs) arising from PTCs among various benign and malignant thyroid tumors. A thymine-to-adenine transversion at nucleotide 1799 (T1799A), formerly designated as T1796A, in exon 15 resulting in a valine to glutamate substitution at residue 600 (V600E), formerly designated as V599E, was the only mutational site reported in thyroid cancer. We have previously shown that BRAFV600E mutations were detected in 49 of 105 (47%) PTCs but not in 5 follicular thyroid carcinomas (FTCs), 10 follicular adenomas, 3 Hürthle cell adenomas and 10 nodular goiters. In contrast to PTC, to date only few studies have been published concerning the frequency of BRAFV600E in ATCs and their coexisting differentiated thyroid carcinomas. In addition, there is no report concerning the BRAF status in multiple PTCs. In this study, paraffin-embedded tumor tissues of 25 patients with thyroid cancer (15 ATCs and 10 PTCs) were obtained from the Department of Pathology of Chang Gung Memorial Hospital-Kaohsiung. Nine ATCs were found to contain a coexisting differentiated carcinoma, including three follicular and six papillary carcinomas. Ten cases of PTC with multiple tumor foci were selected from a cohort of 105 PTCs as previously reported. Paraffin blocks containing tumor were sectioned followed by microdissection to obtain tissue for DNA extraction. Mutational hot spot in exon 15 (codon 600) of the BRAF gene were amplified by PCR and sequenced with an automatic sequencer. BRAFV600E mutations were detected in 3 of 15 (20%) ATCs. In the 9 coexisting differentiated carcinomas, 2 out of 6 PTCs harbored BRAF mutations but not in the three follicular carcinomas. In none of 3 ATCs with coexisting PTCs were mutations detectable in both tumor types. Among the ten cases of PTCs with multiple tumor foci, 5 cases demonstrated the same BRAF status in each tumor foci whereas 5 cases showed distinct BRAF status in different tumor foci. We conclude that the distinct BRAF status in anaplastic carcinoma and its coexisting differentiated carcinoma suggests that anaplastic carcinoma might not arise from differentiated carcinoma.The distinct BRAF status in different tumor foci of multiple papillary carcinomas suggests that multifocal tumors might not be formed through intrathyroidal lymphatic metastasis.

A 71-year-old white woman presented to her primary care physician for a routine visit and was found to have a new, previously undocumented cardiac murmur. A subsequent transthoracic echocardiogram revealed a 1 cm mobile mass arising from the lateral free wall of the left ventricle. Transesophageal echocardiography later confirmed these findings. The patient underwent a left ventriculotomy and excision of a .7 cm friable mass, which was later identified as a papillary fibroelastoma (PFE) by routine histopathologic studies. We present this unique case with a review of the literature.

No description available.

Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 4 uppsatser.

Intraductal papillary mucinous neoplasms (IPMN) are pancreatic lesions with uncertain biologic behavior. This study sought objective, accurate prediction tools, through the use of quantitative histopathological signatures of nuclear images, for classifying lesions as chronic pancreatitis (CP), IPMN, or pancreatic carcinoma (PC). Forty-four pancreatic resection patients were retrospectively identified for this study (12 CP; 16 IPMN; 16 PC). Regularized multinomial regression quantitatively classified each specimen as CP, IPMN, or PC in an automated, blinded fashion. Classification certainty was determined by subtracting the smallest classification probability from the largest probability (of the three groups). The certainty function varied from 1.0 (perfectly classified) to 0.0 (random). From each lesion, 180 +/- 22 nuclei were imaged. Overall classification accuracy was 89.6% with six unique nuclear features. No CP cases were misclassified, 1/16 IPMN cases were misclassified, and 4/16 PC cases were misclassified. Certainty function was 0.75 +/- 0.16 for correctly classified lesions and 0.47 +/- 0.10 for incorrectly classified lesions (P = 0.0005). Uncertainty was identified in four of the five misclassified lesions. Quantitative histopathology provides a robust, novel method to distinguish among CP, IPMN, and PC with a quantitative measure of uncertainty. This may be useful when there is uncertainty in diagnosis.

by Ka-chun Yiu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1989. / Bibliography: leaves 162-192.

The overall aim of this Thesis was to characterise the energetic properties of the mouse papillary muscle as this preparation could become a useful model to study alterations of energetic aspects of cardiac pathologies and heart-focussed genetic changes. Measurements of resting and active metabolism of the papillary muscles were made in vitro using the myothermic technique. In the first study the mechanism underlying impaired contractility of post-ischaemic rat papillary muscle was investigated. The rat preparation is well established and was used to develop protocols and approaches that could later be used as the basis for studies with mouse papillary muscle. The muscles were exposed to simulated ischaemia for 60 min and change in energetics was studied 30 min into the reperfusion phase. The work output was reduced to 66 ± 3% of the pre-ischaemia value and the enthalpy output decreased to 71 ± 3% of pre-ischaemia value. However, there was no change in either initial, 19 ± 3%, or net mechanical efficiency, 9.0 ± 0.9%. These data, in combination with studies of Ca2+ handling, suggests that the reduced work output was caused by attachment of fewer cross-bridges in each twitch, but with no change in work generated by each cross-bridge. The following two studies involved characterisation of the energetics of the mouse papillary muscle and included measurements of resting and active metabolism. The resting metabolic rate varied with muscle size but the mean initial value was tilda 25 mW g-1 and the estimated steady value tilda 5 mW g-1 . The resting metabolic rate declined exponentially with time towards a steady value, with a time constant of 18 ± 2 min. There was no alteration in isometric force output during this time. The magnitude of resting metabolism depended inversely on muscle mass, more than doubled following a change in substrate from glucose to pyruvate and was increased 2.5-fold when the osmolarity of the bathing solution was increased by addition of 300 mM sucrose. Addition of 30 mM BDM affected neither the time course of the decline in metabolic rate nor the eventual steady value. The energy requirements associated with contractile activity were tilda7 mJ g-1 twitch-1 at a contraction frequency of 1 Hz. The enthalpy output was not affected by changing substrate from glucose to pyruvate but did decrease with an increase in temperature. The enthalpy output was partitioned into force-dependent and force-independent components using BDM to selectively inhibit cross-bridge cycling. The force-independent enthalpy output was 18.6 ± 1.9% of the initial enthalpy output. Muscle initial efficiency was &tilda32% and net efficiency tilda 17% when shortening at a realistic velocity. The enthalpy output decreased with increased contraction frequency but was independent of shortening velocity. On the basis of these values, it was calculated that the twitch energetics were consistent with ATP splitting by half the cross-bridges and the pumping of one Ca 2+ into the SR for every three cross-bridge cycles. The lack of influence of shortening velocity on energy cost supports the idea that the amount of energy to be used is determined early in a twitch and is not greatly influenced by events that occur during the contraction. The suitability of the mouse papillary muscle as a model to study ischaemia and reperfusion damage was also assessed. This preparation is excellent for studying muscle specific changes in work and enthalpy output; however, due to the long-term instability and variability amongst preparations, the suitability of this preparation in prolonged experiments remains uncertain.

No description available.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.