Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MTC”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources
PubMed1991

[Reactivities of various mycobacteria species against DNA probes (Gen-Probe Rapid Diagnostic System) specific to Mycobacterium tuberculosis complex, Mycobacterium avium and Mycobacterium intracellulare].

Various mycobacterial species (22 species, 178 strains) were studied for their reactivity to DNA probe specific for Mycobacterium tuberculosis complex (MTC), M. avium or M. intracellulare, using Gen-Probe Rapid Diagnostic System (Gen-Probe Inc., San Diego, Calif., U.S.A.). All the MTC strains, including M. tuberculosis, M. africanum, M. bovis and M. microti reacted with MTC-DNA probe at the % hybridization value of 42.8-51.9% (values higher than 10% are regarded as positive), but their reactivity to MAC-DNA probes (0.8-2.5%) was under the cut off value (10%). The test strains (28 strains) of M. avium complex (MAC) segregated into two groups on the basis of reactivity to DNA probes specific for M. avium and M. intracellulare, that is, one group (16 strains) positively reacted with M. avium-probe but not with M. intracellulare-probe, and the other group (12 strains) showed the converse reactivity. The two groups did not show a reactivity with MTC-probe higher than the cut off value. Nontuberculous mycobacteria other than MAC, including M. kansasii, M. marinum, M. simiae, M. asiaticum, M. scrofulaceum, M. gordonae, M. szulgai, M. malmoense, M. xenopi, M. gastri, M. nonchromogenicum, M. terrae, M. triviale, M. fortuitum, and M. chelonae (subsp. abscessus and chelonae) reacted with neither MTC- nor MAC-probe and values for % hybridization (0.6-3.6%) were lower than the cut off value. These findings indicate extremely superior specificity of the DNA probes (Gen-Probe) for MTC, M. avium and M. intracellulare, thereby indicating the usefulness of Gen-Probe Rapid Diagnostic System for the MTC and MAC in clinical use.

Animals↗
PubMed1989

Surgical treatment of medullary thyroid carcinoma in a thirteen-year-old girl with MEN 2B.

Patients with palpable medullary thyroid carcinoma (MTC) have lymph node metastases in 90% of cases. In most series such patients continue to have elevated serum calcitonin (CT) levels after surgery indicating residual tumor tissue. We attempted a microdissection technique for the treatment of MTC. "Micro" refers not to a small incision or a limited exploration but to a more safe operation associated with good lighting and magnification and minimal bleeding. This technique was used in a 13-year-old girl with multiple endocrine neoplasia type 2B (MEN 2B). The prognosis for MTC in MEN 2B is worse than for sporadic MTC and the MTC of MEN 2A. Every possible effort should be made to remove all tumor tissue in MEN 2B patients with MTC. In this case the pathologist found bilateral MTC and metastases in eight of 129 lymph nodes removed. The preoperative stimulated CT levels, which were markedly elevated, decreased to near normal postoperatively.

Adolescent↗
PubMed1980

Inotropic effects of non-depolarizing muscle relaxants in isolated canine heart muscle.

The inotropic effects of five non-depolarizing muscle relaxants were examined using an isolated canine heart muscle preparation. Except for fazadinium, all drugs were studied in their commercially available forms. d-Tubocurarine chloride (dTc) and metocurine iodide (MTC) produced dose-dependent decreases in isometric force (F) and the maximum velocity of force development (dF/dt) at concentrations greater than 22.5 x 10(-3) g/L for dTc and greater than 15.0 x 10(-3) g/L for MTC, concentrations which are 3 and 6 times higher than estimated clinical serum concentrations, respectively. Myocardial depression was about 3 times less with MTC than with dTc at equipotent concentrations. The degree of depression in F and dF/dt produced by MTC was almost identical with that produced by phenol, a preservative of MTC, indicating that MTC-induced myocardial depression may be due to the effect of the preservative. Pancuronium bromide (PC) produced a dose-dependent increase in F and dF/dt and decrease in the time to peak force. PC-induced changes in F, dF/dt, and time to peak force were inhibited by administration of propranolol 10(-6) M. The results indicate that PC possesses a positive inotropic effect mediated by beta-adrenergic stimulation. Alcuronium chloride did not change F or dF/dt at concentrations from 5.0 x 10(-3) to 60.0 x 10(-3) g/L. Frazadinium bromide increased F and dF/ dt slightly at a low concentration (1.875 x 10(-2) g/L), but further increases in its concentration returned the values of F and dF/dt to control levels. F and dF/dt were not altered in vitro by concentrations of relaxants that would be anticipated in plasma in vivo in patients given clinically effective doses of 0.3 mg/kg of dTc, 0.1 mg/kg of MTC or PC, 0.2 mg/kg of alcuronium chloride, or 0.75 mg/kg of fazadinium bromide.

Alcuronium↗
PubMed1993

Preoperative localization of occult medullary carcinoma of the thyroid gland with single-photon emission tomography dimercaptosuccinic acid.

BACKGROUND: Patients who undergo thyroidectomy for medullary carcinoma of the thyroid gland (MTC) often have elevations of postoperative serum calcitonin levels, which are indicative of metastatic or residual disease. It has been extremely difficult to localize tumor in these patients with standard diagnostic studies such as ultrasonography, computed tomography, or magnetic resonance imaging scans. Previous studies have suggested that planar technetium 99m (V) dimercaptosuccinic acid (DMSA) scintigraphic scans can localize MTC in these patients. We have recently increased the sensitivity of planar scintigraphic images by using single-photon emission tomography (SPECT). This study was performed to compare the sensitivity of planar DMSA scans with that of SPECT DMSA scans. METHODS: Two normal volunteers and three patients with occult MTC after previous total thyroidectomy underwent planar and SPECT DMSA scans. Each patient subsequently underwent surgical exploration based on the DMSA scans. RESULTS: Physiologic DMSA uptake was noted in the nasopharynx, axial skeleton, breast, liver, spleen, heart, kidneys, urinary bladder, great vessels, and skeletal muscles in both normal volunteers and patients with occult MTC. Planar DMSA scans and dynamic computed tomographic scans failed to localize MTC in any of these patients who had minimal disease. SPECT DMSA scans correctly localized cervical MTC in two of three patients, as proved by subsequent surgical resection. One patient who had a negative cervical exploration is presumed to have had a false-positive SPECT DMSA scan. CONCLUSIONS: SPECT DMSA scans appear to be a sensitive, safe, and noninvasive localization technique for patients with occult MTC who have undergone previous thyroidectomy.

Adult↗
PubMedDate not supplied

Determination of the optimal pulses in MR imaging with magnetization transfer contrast at 7 Tesla.

OBJECTIVE: The magnetization transfer contrast (MTC) effect depends on the shape, duration, amplitude, and offset frequency of the saturation pulse. In the present study, we investigated optimal combinations of these four parameters in vitro. METHODS: All experiments were performed with a 7.05 Tesla MR system, and the spin echo technique (TR 500/TE 30) was adopted. We used a simple phantom composed of 1% agar and water, representing restricted and free proton pools, respectively. Signal intensity changes were measured in the agar (Ma) and water (Mw), when the shape, duration, magnitude, and offset frequency of the saturation pulses were varied. The MTC effect was examined with the Mw/Ma ratio. RESULTS: The suppression of Mw was less with the gauss pulse than with the square and sinc pulses. The gauss pulse had the best MTC effect. The suppression of both Ma and Mw was greatest with a saturating duration of 60 msec. The MTC effect was greatest with a longer saturation pulse. The larger the amplitude, the stronger the MTC effect obtained. Mw was suppressed with an offset frequency of less than 3 kHz, and the MTC effect was greatest with an offset frequency closer to the spectrum of the free proton pool. CONCLUSION: In the present study the optimal MTC pulse at 7 Tesla is the gauss pulse with longer duration, maximal amplitude, and approximately 3 kHz off resonance.

Contrast Media↗
PubMedDate not supplied

Age-dependent changes in magnetization transfer contrast of white matter in the pediatric brain.

BACKGROUND AND PURPOSE: It is unknown to what extent magnetization transfer contrast (MTC) in white matter of the brain changes during myelination. The goal of this study was to measure the age-dependent changes of MTC in different regions of the pediatric brain and to evaluate their relation to T2 relaxation times. METHODS: Seventy children aged 1 week to 80 months without evidence of organic brain disease underwent MR imaging of the brain. A double-echo spin-echo (SE) sequence and an SE sequence with and without an off-resonance pulse were performed in the axial orientation. Using paired images, we calculated MTC ratios in 13 predefined regions of the brain and compared them with the T2 relaxation times measured in the same areas. Regression analysis was performed for both parameters to evaluate age dependency. RESULTS: MTC in white matter increased during myelination from a range of 13% to 19% to a range of 34% to 37%. At the same time, T2 relaxation times decreased from a range of 115 to 160 milliseconds to a range of 60 to 70 milliseconds after myelination. For both MTC and T2 relaxation times, age dependency could be expressed by a monoexponential function. CONCLUSION: A strong positive correlation exists between MTC ratios and the degree of myelination in the pediatric brain, and an inverse correlation exists between MTC and T2 relaxation times. Fast proton relaxation within macromolecules in the myelinated white matter and subsequent MT may be the most important reason for the decreasing T2 relaxation time of white matter during brain myelination.

Aging↗
PubMed1994

Treatment of advanced medullary thyroid carcinoma with a combination of cyclophosphamide, vincristine, and dacarbazine.

BACKGROUND: Medullary thyroid carcinoma (MTC) is a neoplasm of the parafollicular C cells of the thyroid gland, which belongs to the diffuse neuroendocrine system. This cancer usually behaves in a relatively indolent manner for most patients. However, approximately 20% of patients have a more aggressive course that requires effective management. There are few reported clinical trials of chemotherapy for MTC. From the literature, the most active agent appears to be doxorubicin, with response rates of 30% reported. On the basis of the activity of cyclophosphamide, vincristine, and dacarbazine (CVD) in other advanced neuroendocrine neoplasms, the authors tested the combination in patients with advanced MTC. METHODS: Seven patients with advanced MTC were treated with cyclophosphamide (750 mg/m2), vincristine (1.4 mg/m2), and dacarbazine (600 mg/m2 daily for 2 days in each cycle) every 3 weeks. Assessments of measurable tumor and serum calcitonin and carcinoembryonic antigen were made before treatment and followed up until progressive disease was documented. RESULTS: Two patients had partial tumor and biochemical responses for a duration of 14 and 29 months, respectively. One patient had a partial biochemical response and stable tumor measurements for 9 months, and another patient had stable tumor size and markers for 14 months. Three patients had progressive disease. Diarrhea and flushing improved in two patients who had partial biochemical responses. CONCLUSION: Our experience suggests that CVD chemotherapy has moderate activity and is well tolerated in patients with advanced MTC. Additional prospective studies of this regimen for MTC are required.

Adult↗
PubMed2001

Radioisotope-guided surgery in patients with pheochromocytoma and recurrent medullary thyroid carcinoma: a comparison of preoperative and intraoperative tumor localization with histopathologic findings.

BACKGROUND: The objective of this study was to appraise the detection of metastases of medullary thyroid carcinoma (MTC) and pheochromocytoma using radioguided surgery (RGS) and to compare the results with external imaging modalities, surgical palpation, and histopathologic findings. METHODS: Twenty-five patients with recurrent MTC underwent preoperative scintigraphic imaging with 500 megabecquerels (MBq) of technetium 99m(V)-dimercaptosuccinic acid [(99m)Tc(V)-DMSA] and 222 MBq of indium 111 ((111)In)-pentetreotide. The radiopharmaceutical that showed the greatest preoperative tumor uptake was selected for intraoperative RGS. Surgery was performed 24 hours after the administration of (111)In-pentetreotide or 4 hours after the injection of (99m)Tc(V)-DMSA. Furthermore, three male patients underwent surgery who suffered from recurrent pheochromocytoma (injection of 180 MBq iodine 123-labeled metaiodobenzylguanidine [(123)I-MIBG] 4--5 hours before surgery). RESULTS: Overall, lesion detection sensitivities in patients with MTC for computed tomography, (111)In-pentetreotide, and (99m)Tc(V)-DMSA were 32%, 34%, and 65%, respectively. Surgical palpation identified lymph node metastases of recurrent MTC with a sensitivity of 65%, whereas RGS localized 64 malignant lesions (sensitivity, 97%). Altogether, 71 lesions could be excised, 5 of which were adjudged false positive with respect to MTC metastases. Both surgical palpation and RGS localized all paravertebral subdiaphragmatic lesions (size > or = 2 cm) of recurrent pheochromocytoma seen in the preoperative MIBG scan. CONCLUSIONS: RGS was capable of localizing more and smaller metastases of MTC compared with conventional imaging modalities and surgical palpation. However, the relatively high radioligand accumulation in the kidneys ((111)In-pentetreotide) and the dense hepatic and biliary signals using MIBG limited their use for intraoperative detection of tumors in the area of the adrenal gland.

Adult↗
PubMed1986

Familial medullary thyroid carcinoma without associated endocrinopathies: a distinct clinical entity.

In an evaluation of 213 patients from 15 kindreds with familial medullary thyroid carcinoma (MTC), we detected 41 subjects from two kindreds (L and O) who had MTC but no extra-thyroidal manifestations (hyperparathyroidism, phaeochromocytomas or mucosal neuromas) of multiple endocrine neoplasia (MEN) type IIa or IIb. In screening 178 members of the L and O kindreds, we found no evidence that any of them had died from MTC. To assess whether the malignancy was relatively indolent in these families, 20 selected subjects from the two kindreds were compared with 33 MEN IIa subjects. Both groups had clinically occult disease which was diagnosed biochemically by documenting elevated plasma calcitonin (CT) levels following stimulation with intravenous calcium and pentagastrin. There were no differences in the peak stimulated plasma CT levels at the time of diagnosis (1055 +/- 236 pg/ml versus 1096 +/- 191 pg/ml) or the incidence of regional lymph node metastases (0/20 versus 1/33) in the two groups. The mean age at diagnosis, however, was significantly higher in patients of the L and O kindreds than in patients with MEN IIa (43.1 +/- 3.4 years versus 21.1 +/- 2.2 years; P less than 0.001) indicating that in the two kindreds the MTC either developed at a later age or grew more slowly. This study demonstrates that MTC may occur in a familial pattern distinct from its presentation as MEN IIa or MEN IIb. In this setting it appears to be the least aggressive form of MTC yet described.

Adolescent↗
PubMed1995

Comparative study of the colchicine binding site and the assembly of fish and mammalian microtubule proteins.

Isolated microtubules from cod (Gadus morhua) are apparently more stable to colchicine than bovine microtubules. In order to further characterize this difference, the effect of the colchicine analogue 2-methoxy-5-(2,3,4-trimethoxyphenyl)-2,4,6-cyclo heptatrien-1-one (MTC) was studied on assembly, as measured by turbidity and sedimentation analysis, and on polymer morphology. MTC has the advantage to bind fast and reversible to the colchicine binding site of tubulin even at low temperatures. It was found to bind to one site in cod brain tubulin, with affinity (6.5 +/- 1.5) x 10(5)M-1 at both low or high temperature, similarly to bovine brain tubulin. However, the effect of the binding differed. At substoichiometric concentrations of MTC bovine brain microtubule assembly was almost completely inhibited, while less effect was seen on the mass of polymerized cod microtubule proteins. A preformed bovine tubulin-colchicine complex inhibited the assembly of both cod and bovine microtubules at substoichiometric concentrations, but the effect on the assembly of cod microtubules was less. At higher concentrations (5 x 10(-5) to 1 x 10(-3) M), MTC induced a large amount of cold-stable spirals of cod proteins, whereas abnormal polymers without any defined structure were formed from bovine proteins. Spirals of cod microtubule proteins were only formed in the presence of microtubule associated proteins (MAPs), indicating that the morphological effect of MTC can be modulated by MAPs. The effects of colchicine and MTC differed. At 10(-5) M colchicine no spirals were formed, while at 10(-4) M and 10(-3) M, a mixture of spirals and aggregates was found. The morphology of the spirals differed both from vinblastine spirals and from the spirals previously found when cod microtubule proteins polymerize in the presence of high Ca2+ concentrations. The present data show that even if the colchicine binding site is conserved between many different species, the bindings have different effects which seem to depend on intrinsic properties of the different tubulins.

Animals↗
PubMed2003

Enhancement of lymph node metastasis and distant metastasis of thyroid carcinoma.

BACKGROUND: The mechanisms of local and distant metastases are imperfectly understood. The goal of the current study was to add to the body of knowledge regarding local and distant metastases of thyroid malignancies. METHODS: The authors performed multivariate analysis of 573 patients who underwent surgery between November 1994 and May 2002 for follicular (FTC; n = 100), papillary (PTC; n = 236), or medullary thyroid carcinoma (MTC; n = 237) at a university hospital. RESULTS: In multivariate analysis, extrathyroidal extension consistently evolved as the key risk factor for both lymph node metastasis and distant metastasis. This correlation was most pronounced in MTC and least pronounced in FTC. The risk of lymph node metastasis also increased with reoperative status in patients with MTC and with primary tumor diameter in patients with MTC (tumor diameter > 10 mm) and patients with PTC (tumor diameter > 20 mm). In the PTC group, lymph node metastasis was more common among patients younger than age 45. In the MTC group, extrathyroidal growth and distant metastasis were associated exclusively with lymph node metastasis. Lymph node metastasis was the only secondary risk factor for distant metastasis. In the analysis of risk factors for distant metastasis in the FTC and PTC groups, no interaction was found between extrathyroidal growth and lymph node metastasis. This finding suggests that extrathyroidal growth and lymph node metastasis of FTC and PTC, and presumably also MTC, represent separate mechanisms and routes of distant metastasis. CONCLUSIONS: Screening for both local residual disease and distant metastases should be intensified in the high-risk population of patients whose primary tumors exhibit large diameters, extrathyroidal growth, or lymph node metastasis.

Adenocarcinoma, Follicular↗
PubMed2006

Prognosis of medullary thyroid carcinoma: demographic, clinical, and pathologic predictors of survival in 1252 cases.

BACKGROUND: Medullary thyroid cancer (MTC) is a rare cancer. There is a relative paucity of data over the last decade with regard to the prognosis of these patients. Therefore, the authors used the population-based Surveillance, Epidemiology, and End Results (SEER) registry to update what to their knowledge is one of the largest series of patients with MTC reported to date. METHODS: All patients with a diagnosis of MTC with active follow-up in the SEER database from 1973 to 2002 were included. Univariate and multivariate regression analyses were used to assess the associations between demographic, clinical, and pathologic characteristics of patients and survival. RESULTS: A total of 1252 patients with MTC were identified over 29 years of follow-up. In all, 87% of patients were white and 60% were female, with a mean age of 50 years. Although many variables were significant on univariate analysis, SEER stage and age at diagnosis were found to be the strongest predictors of survival in the multivariate analysis. Prognosis was poor in patients with advanced disease (hazards ratio [HR], 4.47), or those age >65 years (HR, 6.55). Patients who underwent surgery fared better than those who did not. Overall, 51% of patients had less than the currently recommended treatment guidelines for MTC. Adjuvant radiation therapy was found to be independently associated with a decreased survival (HR, 1.65). CONCLUSIONS: Stage of disease and age at diagnosis were found to be the strongest predictors of survival for patients with MTC. To the authors' knowledge there has been no change in stage at diagnosis or a significant improvement in survival noted over the last 30 years. Many patients underwent surgery that was deemed less than optimal for stage of disease.

Age of Onset↗
PubMed1979

The time of origin of the mesencephalic trigeminal neurons in Xenopus.

Time of origin of the mesencephalic trigeminal cells (MTC) in Xenopus 'has been studied with 3H-thymidine autoradiography. The first MTC's were formed at stage 20, and they continued to arise up to stage 58. The mitotic rate of MTC's was found to be ten per cent at any time from stages 20--50, with a slow decrease thereafter. MTC's in the tectum were distributed in a spatio-temporal manner. Cells generated earliest were located in the rostral pole of the tectum and were followed in caudomedial sequence by cells formed later. The generation times of MTC and the neurons of the sensory trigeminal ganglion (TGC) were strikingly dissimilar, indicating that they probably do not represent a common cell lineage, that is, the former may not arise from the mesencephalic neural crest. It is proposed that the majority of MTC's generated from stage 30 onward, derive through proliferative activity of precursor cells in the di-mesencephalic junction and in the tectal neuroepithelium.

Age Factors↗
PubMed1981

Phenotypic drift of metastatic and cell-surface properties of mammary adenocarcinoma cell clones during growth in vitro.

We have examined cell clones obtained from a 13762 mammary adenocarcinoma tumor and its spontaneous lung metastasis for phenotypic stability during serial culture passage in vitro. Two clones that varied markedly in their metastatic properties were chosen for further examination. One of these clones (MTC) obtained from the parental transplanted tumor initially failed to metastasize within 23 days post-injection s.c. but gained the ability to form spontaneous pulmonary metastases after several serial passages in vitro. Another clone (MTLn3) derived from a spontaneous lung metastasis was initially higher metastatic from short-term culture, but lost the potential to form large numbers of spontaneous lung metastases with long-term culture. In contrast to MTA, clone MTLn3 displayed lymph-node metastasis, and the frequency of lymph-node involvement increased when late-passage cultures of MTLn3 cells were assayed in vivo. Both clones from late-passage cultures produced larger tumor sizes at the primary (mammary fat pad) injection sites compared to early passage cells. The morphologies of MTC cells changed with serial tissue culture passage, while the morphologies of MTLn3 cells did not change. The display of fibronectin on MTC cells by immunofluorescence did not change with culture passage; fibronectin was not detected in cultures of clone MTLn3. Fibronectin was also found on MTC cells by cell surface labelling using lactoperoxidase-catalyzed iodination-sodium dodecylsulfate polyacrylamide gel electrophoresis-autoradiography. Iodination of fibronectin on MTC cells did not vary with culture passage, and as in immunofluorescence experiments it was not detected on MTLn3 cells. There was a decrease in exposure of certain cell surface proteins on MTC cells with culture passage, but we did not detect modifications with this procedure that correlated with culture passage of MTLn3 cells. We conclude that prolonged culture in vitro can result in modifications fo metastatic and cell-surface properties of tumor cell clones.

Adenocarcinoma↗
PubMed2003

Estrogenic endocrine disruptive components interfere with calcium handling and differentiation of human trophoblast cells.

During development, calcium (Ca) is actively transported by placental trophoblasts to meet fetal nutritional and the skeletal mineralization needs. Maternal exposure to estrogenic pesticides, such as 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT) and methoxychlor (MTC), has been shown to result in reproductive disorders and/or abnormal fetal development. In this study, we have examined the effects of exposure of trophoblastic cells to MTC and DTT, in comparison to 17beta-estradiol (E2) and diethylstilbestrol (DES), to test the hypothesis that cellular Ca handling is a target for these endocrine disruptive components. Treatment with DDT, MTC, DES, or E2 increased cellular Ca uptake, and the expression of trophoblast-specific human Ca binding protein (HCaBP) was down-regulated by both MTC and DDT. Treatment with MTC, DDT, and DES inhibited cell proliferation, induced apoptosis, and suppressed expression of several trophoblast differentiation marker genes. These effects were reversed by overexpression of metallothionein IIa, a gene highly responsive to cadmium and other metals. These results strongly suggest that trophoblast Ca handling functions are endocrinally modulated, and that their alteration by candidate endocrine disruptors, such as MTC and DDT, constitutes a possible pathway of the harmful effects of these components on fetal development.

Adenosine Triphosphatases↗
PubMedDate not supplied

Use of three-dimensional segmented FLASH sequence with magnetization transfer contrast to improve Gd-DTPA-enhanced intrahepatic MR portography.

Twenty healthy volunteers underwent gadopentetate dimeglumine (gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA))-enhanced MR angiography (MRA) using three-dimensional-segmented fast low angle shot images (FLASH) with magnetization transfer contrast (MTC) pulses. MRA was obtained at 75 seconds (early phase) and 135 seconds (late phase) after bolus injection of Gd-DTPA (MTC+ group) during one period of breath-holding. Within 1 week. MRA without MTC was performed under the same scanning conditions. Visualization of intrahepatic portal branches with these methods was compared in both phases. Portal vein-liver contrast-to-noise ratios were significantly higher in the MTC+ group in both phases. For third- and fourth-order portal branches, visualization was significantly better in the MTC+ group in both phases. Use of three-dimensional-segmented FLASH shortened acquisition time and facilitated imaging during breath-holding and also reduced whole-body average specific absorption rate values. Visualization of intrahepatic portal vein branches was improved by MTC pulses, and effective imaging time was prolonged.

Adult↗
PubMed1990

Calcitonin gene-related peptide in patients with endocrine tumors.

The plasma level of calcitonin gene-related peptide (CGRP) was measured by RIA in 41 patients with endocrine tumors [22 medullary thyroid carcinomas (MTC), seven parathyroid adenomas, four benign insulinomas, five carcinoids, and three pheochromocytomas]. Of the 22 patients with MTC, all five preoperative patients had elevated CGRP levels. The correlation between CGRP and calcitonin levels was significant (P less than .001) in 22 patients with MTC. Six of 19 patients with endocrine tumors other than MTC showed elevated CGRP levels. Immunohistochemical study showed that tumor tissues from all 22 cases of MTC and seven from other endocrine tumors contained immunoreactive CGRP. CGRP reactivity was found in only small numbers of tumor cells. Thus, although CGRP appeared to be a useful additional marker for MTC, the role of CGRP in the pathophysiology of endocrine tumors was not elucidated.

Adenoma↗
PubMed1997

Differential display in primary and metastatic medullary thyroid carcinoma.

Despite recent advances in the understanding of the role of the RET proto-oncogene in the development of familial and approximately 30% of sporadic medullary thyroid carcinomas (MTC), little is known about other genetic events that modify the course and outcome of the disease. We compared the expression of genes in intrathyroidal MTCs to autologous local lymph node metastases by means of mRNA differential display (DDRT-PCR). This is the first report of differential display using surgical specimens of a primary cancer and its metastases. Total RNA was extracted from tumor tissue of two patients with MTC associated with multiple endocrine neoplasia (MEN 2B) and sporadic MTC, respectively. Following reverse transcription (RT), the products were PCR-amplified and separated on a denaturating polyacrylamide gel. RT-PCR products demonstrating differential expression were reamplified and used as probes for Northern blot analysis. Six fragments for which differential expression was confirmed were cloned and sequenced. Resultant sequences were tested for homology to sequences in public data bases, and two novel MTC-derived fragments (MDF-1, MDF-2) were identified. Sensitivity of the method was confirmed by identification of a sequence encoding the calcitonin precursor flanking peptide which is expressed almost exclusively in MTC and normal thyroid C cells. Overexpression of the ribosomal genes S3a and P0 was found in the metastases. Recent reports suggest that components of the translational apparatus act as regulatory mediators of growth, proliferation, and neoplastic change. The altered expression of ribosomal proteins and gene products encoded by MDF-1 or MDF-2 may play an important role in the progression and metastatic spread of MTC.

Blotting, Northern↗