Analysis of RET proto-oncogene abnormalities in patients with MEN 2A, MEN 2B, familial or sporadic medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) may occur either as a sporadic or familial (FMTC) disease. Multiple endocrine neoplasia (MEN) type 2, inherited as an autosomal dominant disease, is characterized by coexistence of MTC with other endocrine neoplasia. Activating mutations of the RET proto-oncogene, involving the somatic or the germinal cell lineage, are found in both inherited and acquired forms. In this study, RET mutations were screened in 47 individuals either affected by MTC or belonging to families with hereditary MTC. Exons 10, 11, 13, 14, 15 and 16 of the RET gene were amplified by polymerase chain reaction and examined by DNA sequence and/or restriction enzyme analysis to detect mutations in purified amplicons. Six MEN 2A families with a germline mutation at codon 634, one FMTC family carrying a mutation at codon 618 and two MEN 2B families with a mutation at codon 918 were identified. In affected members of a MEN 2A family no known RET mutations were observed. Besides, we identified a germline mutation in a patient with apparently sporadic MTC and in two out of three sons, indicating the presence of a sporadic misclassified familial disease. In all of the families examined we were able to distinguish the affected vs unaffected (not at risk) members. A somatic mutation of codon 918 was detected in three out of ten patients with apparently sporadic MTC.     

TFF1 gene expression in human medullary thyroid carcinoma

This epidemiological study investigated the reasons why children in Northern Ireland who need orthodontic treatment do not receive treatment even when it is provided free by the state. A total of 1584 15- and 16-year-olds were examined in 23 high schools with the Index of Orthodontic Treatment Need. The characteristics of the adolescents who had received orthodontic treatment were compared with those who had a definite need for treatment and yet did not receive treatment or advice. One in 10 of the adolescents examined had an unmet need for orthodontic treatment. Logistic regression analysis was used to assess the influence of 11 variables including socioeconomic status, religion, and standard of dental health on the uptake of orthodontic care. This analysis revealed that the only significant predictors of whether an adolescent received orthodontic treatment was the dental attendance pattern of the adolescent, the adolescent's dental health, and the dental attendance pattern of the adolescent's mother. Those adolescents who had good dental health, who regularly attended a dentist, and whose mother regularly attended a dentist were more likely to receive orthodontic treatment.     

Metastatic parathyroid carcinoma in the MEN2A syndrome

We report a patient with a metastatic parathyroid carcinoma and medullary carcinoma of the thyroid. This patient represents a variation of the multiple endocrine neoplasia syndrome (MEN) type 2A. There was no evidence of a phaeochromocytoma. The case illustrates the difficulties that may be encountered in localising the source of PTH secretion; the patient underwent four unsuccessful exploratory operations of the neck and mediastinum before further investigations revealed a single metastatic deposit of parathyroid carcinoma involving the first thoracic vertebra. PCR amplification and sequencing of the RET oncogene from the metastatic parathyroid carcinoma and genomic DNA revealed a heterozygous mutation (Cys634Tyr) in exon 11, as has previously been described to occur in MEN 2A. In addition, loss of tumour heterozygosity was demonstrated at loci from chromosomes 1, 2, 3p, 13q and 16p. This represents the first report of a parathyroid carcinoma in a MEN2A patient, in which the multiple allelic deletions are consistent with the generalised losses observed in aggressive tumours.     

Mutations of ret-proto-oncogene in thyroid medullary carcinoma

OBJECTIVE: To determine the importance of the molecular-genetic demonstration of germ-line mutation in the ret protooncogene for therapeutic measures in sporadic and hereditary medullary thyroid carcinoma (MTC). PATIENTS AND METHODS: Several molecular-genetic tests were performed on DNA of 35 families with hereditary and 81 patients with the sporadic form of MTC (isolation of genomic DNA; PCR amplification; DNA sequencing: demonstration of mutation in codon 918 with restriction enzyme FOK 1). RESULTS: A disease risk was demonstrated in 178 individuals among the 35 families, 159 of whom were investigated by molecular-genetic tests: 84 family members were found to be gene carriers. Germ-line mutation had already been suspected on clinical grounds in 76% of the carriers, 24% being discovered in a presymptomatic stage. Six children among the latter were treated prophylactically by thyroidectomy, histological evidence of C-cell hyperplasia being found in all of them, microcarcinomas in three of the older children. There were four patients among the non-carriers on whom thyroidectomy had been performed previously because of a false-positive pentagastrin-test; but germ-line mutation was now excluded. In one family, with familial MTC in two brothers, no mutation in ret-proto-oncogene has been demonstrated. The members of this family must now, as used to be routine, undergo a pentagastrin-test. Three of the 81 patients with "sporadic" MTC had a germ-line mutation, presumably a new one. CONCLUSION: Molecular-genetic tests have further improved the management of families with hereditary MTC and they thus take first place among essential diagnostic procedures. The diagnosis of sporadic MTC can be confirmed by excluding germ-line mutation in the ret-proto-oncogene.     

Results of the calcitonin stimulation test in normal volunteers compared with genetically unaffected members of MEN 2A and familial medullary thyroid carcinoma families

SETTING: Sample survey based on pulmonary tuberculosis (TB) patients registered in 264 health centres in Korea, compared with data obtained from nationwide TB prevalence surveys conducted since 1965. OBJECTIVE: To determine the level of antituberculosis drug resistance (DR) and to assess its impact on treatment outcome and its relationship with cure rates in the National TB Programme (NTP). DESIGN: Mycobacterium tuberculosis isolates from 2,486 new patients and 189 previously treated patients were subjected to susceptibility testing against 10 antituberculosis drugs. Treatment outcome was assessed. The DR levels were compared with those observed in the national TB prevalence surveys, and the trend was correlated with the cure rate of patients treated in the NTP. RESULTS: Resistance to any drug was 11.3% in new cases and 54.0% in previously treated cases. Initial resistance to isoniazid (INH) or rifampicin (RMP) was 7.7% or 2.2%, and to INH and RMP (+/- other drugs) 1.6%. Compared with previous data, initial drug resistance (IDR) has decreased significantly and is inversely related to improvement of cure rates in the NTP. The treatment outcome of patients with single drug resistance was satisfactory. CONCLUSION: Drug-resistant TB has decreased remarkably during the last decades in Korea as a result of improved efficiency in the treatment programme of the NTP.     

Immunotherapy for medullary thyroid carcinoma by a replication-defective adenovirus transducing murine interleukin-2

We have evaluated the feasibility of gene transduction using replication-defective adenovirus vector as a novel therapy for medullary thyroid carcinoma (MTC), a thyroid C cell neoplasm. Replication-defective adenoviruses were constructed to express murine interleukin-2 (mIL-2) gene and Escherichia coli beta-galactosidase (beta-gal; lacZ) gene under the control of the human cytomegalovirus (CMV) promoter (AdCMVmIL2, AdCMVbeta-gal) by homologous recombination. The efficiency of transduction was evaluated using AdCMVbeta-gal at different conditions. The gene transduction efficiency was dependent on multiplicity of infection, duration of exposure to the virus, and viral concentration. The expression of functional mIL-2 in transduced tumor cells was verified both in vitro and in vivo. Two cell lines (rat MTC and mMTC) secreted large amounts of functional mIL-2 after transduction, as tested in cytotoxic T lymphocyte (CTL) L-2 cells. When AdCMVmIL2-infected mMTC cells were injected s.c. into their host animals, tumors developed in 2 of 10 animals, in contrast to 9 of 10 animals injected with AdCMVbeta-gal-infected mMTC cells and all 10 animals injected with parental mMTC cells. Moreover protected animals developed a long lasting immunity against mMTC tumor cells and their splenocytes, showing cytotoxicity to parental tumor cells, and active natural killer (NK) cell activity. BALB/c-SCID (severe combined immune deficiency) mice were also used to evaluate the function of NK cells in antitumor activities. No tumor developed in SCID mice injected with AdCMVmIL2-infected cells, whereas all animals injected with either AdCMVbeta-gal-infected or parental mMTC cells developed tumors. Our data indicate that IL-2 production by MTC cells leads to rejection in syngeneic animals and suggest that both cytotoxic T cells and NK cells may play an important role. In addition, transduction of adenoviral vectors into tumor cells produces some nonspecific antitumor effects.     

Diarrhea as initial manifestation of medullary thyroid carcinoma

HISTORY AND CLINICAL FINDINGS: For 15 months a 52-year-old business man had been suffering from chronic diarrhoea which had persisted even after exophthalmic hyperthyroidism (Grave's disease) had been diagnosed and adequately treated. Physical examination on admission revealed no abnormalities, in particular no sign of hyperthyroidism. INVESTIGATIONS AND DIAGNOSIS: Repeated stool examinations failed to demonstrate any infectious organisms. Upper gastrointestinal endoscopy and ileaocoloscopy were normal, as were biopsies. Persistence of the diarrhoea during a fasting test and the bulky stools suggested a secretory cause. Among various hormonal tests the calcitonin concentration was found to be greatly raised (4572 ng/l, normal 10 < ng/l). Ultrasound demonstrated a thyroid tumour and cytological examination of a fine-needle biopsy revealed a medullary carcinoma. TREATMENT AND COURSE: After total thyroidectomy with bilateral neck dissection the patient was free of any symptoms: the diarrhoea ceased immediately after the operation and the calcitonin concentration became nearly normal. CONCLUSIONS: Signs of chronic secretory diarrhoea suggest the possibility of an endocrinally active tumour. Search for a medullary carcinoma of the thyroid with measurement of the serum calcitonin level should be among the diagnostic procedures.     

Differential display in primary and metastatic medullary thyroid carcinoma

Platelet-activating factor (PAF) is a mediator produced in human airways during acute and chronic inflammatory lung diseases. The levels of PAF are regulated by acetylhydrolase (AH), the enzyme that converts PAF to lyso-PAF. To determine whether AH was present in human bronchoalveolar lavage (BAL) fluid, BAL was obtained from normal donors (n = 18) and from adult patients with mild bronchial asthma (n = 15) or with lung fibrosis (n = 15). AH activity was consistently found in the cell-free BAL fluid. BAL-AH is an enzyme different from secretory phospholipase A2 and from plasma AH and erythrocyte AH. Furthermore, BAL-AH is inhibited as much as 95% by exposure to an oxygen radical-generating system (xanthine/xanthine oxidase). BAL-AH is significantly correlated with the number of BAL macrophages (rs = 0.63; p < 0.02). In addition, BAL macrophages release AH both spontaneously and after stimulation with tumor necrosis factor-alpha (TNF-alpha) (100 ng/ml). BAL-AH activity in patients with bronchial asthma (1.32 +/- 0.18 pmol of PAF converted to lyso-PAF/min) is significantly lower than that in normal donors (2.25 +/- 0.26 pmol/min; p < 0.001). In contrast, BAL-AH activity in patients with lung fibrosis (6.13 +/- 0.81 pmol/min) is higher than that found in normal donors (p < 0.01). The variations in BAL-AH activity in patients with bronchial asthma or lung fibrosis are due to a reduction and to an increase, respectively, in the number of active molecules rather than to changes in enzyme affinity. These data demonstrate that human BAL fluid contains an extracellular AH activity that inactivates PAF released in the airways. BAL-AH is secreted by alveolar macrophages and is highly sensitive to oxygen radical-induced damage. The secretion and inactivation of BAL-AH may influence the levels of this enzyme in BAL fluid during acute and chronic inflammatory lung diseases and, ultimately, regulate the proinflammatory activities of PAF in these disorders.     

Histopathological and immunohistochemical studies on medullary thyroid carcinoma

In order to study the multidifferentiation of medullary carcinoma of the thyroid gland (MCT), 24 cases of MCT were examined for the presence of immunoreactive calcitonin (CT), thyroglobulin (Tg), chromogranin A (CgA), somatostatin (SS), serotonin (5-HT), S-100 protein (S-100), neuron-specific enolase (NSE), vasoactive intestinal polypeptide (VIP), adrenocorticotrophin (ACTH) and neurofilament protein (NF) by using immunohistochemical ABC methods. Results showed that CT-immunoreactive cells were present in all tumors. Tg was present in three tumors. 23 cases contained CgA-immunoreactive cells. 14 tumors contained 5-HT-immunoreactive cells, 10 cases were immunoreactive to NSE and SS. 4 tumors contained VIP-immunoreactive cells and only one cases was positive for S-100. The demonstration of immunoreactivity for multiple antigens in 24 cases suggests that the origin of medullary thyroid carcinoma may originate from neuroectoderm cells potentially capable of producing numerous hormone substances. In addition, as the neoplastic cells in 12% of the tumors containing hormone substances as well as thyroglobulin, it is suggested that follicular epithelial differentiation and mixed medullary thyroid carcinoma may be more common than previously suspected. Recent studies indicate that mixed carcinoma of the thyroid may be derived from common stem cells in posterior branchia capable of differentiating into both follicular and parafollicular tumor cells.     

C-cell hyperplasia and medullary thyroid carcinoma in patients routinely screened for serum calcitonin

To elucidate the differential reactivity of pulmonary microvessels in the acini to hypoxia, excessive CO2, and increased H+, we investigated changes in the diameter of precapillary arterioles, postcapillary venules, and capillaries in isolated rat lungs on exposure to normocapnic hypoxia (2% O2), normoxic hypercapnia (15% CO2), and isocapnic acidosis (0.01 mol/L HCl). Microvascular diameters were precisely examined using a real-time confocal laser scanning luminescence microscope coupled to a high-sensitivity camera with an image intensifier. Measurements were made under conditions with and without indomethacin or N(omega)-nitro-L-arginine methyl ester to assess the importance of vasoactive substances produced by cyclooxygenase (COX) or NO synthase (NOS) as it relates to the reactivity of pulmonary microvessels to physiological stimuli. We found that acute hypoxia contracted precapillary arterioles that had diameters of 20 to 30 microm but did not constrict postcapillary venules of similar size. COX- and NOS-related vasoactive substances did not modulate hypoxia-elicited arteriolar constriction. Hypercapnia induced a distinct venular dilatation closely associated with vasodilators produced by COX but not by NOS. Arterioles were appreciably constricted in isocapnic acidosis when NOS, but not COX, was suppressed, whereas venules showed no constrictive response even when both enzymes were inhibited. Capillaries were neither constricted nor dilated under any experimental conditions. These findings suggest that reactivity to hypoxia, CO2, and H+ is not qualitatively similar among intra-acinar microvessels, in which COX- and NOS-associated vasoactive substances function differently.     

The prognostic importance of calcitonin screening in familial medullary thyroid carcinoma

A prospective study of 20 patients with traumatic amputations of the fingers and a thumb was carried out during a six week period at Mpilo Central Hospital, Bulawayo. Most of the adult injuries (17 patients) resulted from industrial accidents (76.5 pc) while two out the three children sustained their injury from domestic accidents. Inadequate safety precaution, ignorance and human error contributed significantly to the injuries. Safety education and preventive measures both at home and in industry should be inoculated into the daily life of individuals.     

Elevated CEA in breast cancer patients with overlooked medullary thyroid carcinoma

After mastectomy and radiation for breast cancer, two patients were found to have persistent elevated CEA in their serum. This finding was erroneously attributed to occult metastases for the first patient and to local recurrence for the second. Overlooked medullary thyroid carcinoma (MTC) was the causal disease in both patients. A review of the literature stresses the frequency of CEA elevation in serum of MTC patients. A thorough search for any possible cause of elevated levels of CEA is advocated, particularly by thyroid sonogram with a needle aspiration biopsy when a nodule is discovered and by calcitonin assay in the serum.     

Papillary thyroid carcinoma: justification for total thyroidectomy and management of lymph node metastases

Papillary thyroid carcinoma (PTC) is the most common epithelial thyroid tumor and comprises approximately 80% of all thyroid cancers. In this article, the authors discuss the data showing that total thyroidectomy is the treatment of choice of clinically significant PTC, and review an algorithm for the management of lymph node metastases. Although the prognosis for patients with PTC is generally good, appropriate surgical management (total thyroidectomy plus 131I and life-long TSH suppression) can further reduce recurrence and cancer death rates significantly.     

Presence of atrial natriuretic peptide in rat thyroid medullary carcinoma cell line

In 1923, Masson described a neoplastic process consisting of papillary hyperplasia of the endothelial cells, with a consequent obliteration of the vascular lumen, followed later by degenerative changes. Masson coined the term vegetant intravascular haemangioendothelioma, however, these days it is more commonly known as papillary endothelial hyperplasia (PEH), or by the pseudonym, Masson's tumour. Although relatively rare, there are numerous accounts of PEH in the literature, describing its predilection for the head and neck region. Our case report describes the finding of a PEH within the paranasal sinuses, a site not previously mentioned even in the largest of series found on literature search. We will then discuss the relevant histological features of the lesion, and its natural history.     

Multiple endocrine neoplasia-type medullary thyroid carcinoma in three generations of a family

The familial accumulation of a multiple endocrine neoplasia (MEN) type 2a medullary thyroid carcinoma, is described based on the retrospective analysis of a family history. The proband was characterized by medullary carcinoma (MC) combined with phaeochromocytoma, her child had been shown to suffer from MC. In the third generation of the family C-cell hyperplasia and bilateral adrenal hyperplasia occurred. It is shown that in order to arrive at a correct decision as regards the therapy to be used, modern laboratory tests (serum calcitonin, CEA-analysis) and diagnostic imaging methods (ultrasound, computer tomography, magnetic resonance imaging, positron emission tomography, metaiodobenzylguanidine scintigraphy) should be used. It is emphasized that the available therapeutic means (surgery, radiotherapy, nuclear medicine) have to be carefully selected and, if necessary, combined. In medullary thyroid carcinoma associated tumours in other endocrine organs should be expected to occur. Family screening using blood chemical and genetic tests are recommended in asymptomatic cases, since their surgical treatment can in this way lead to complete recovery.     

Advances and controversies in the diagnosis and management of medullary thyroid carcinoma

In tasks requiring sustained attention, human alertness varies on a minute time scale. This can have serious consequences in occupations ranging from air traffic control to monitoring of nuclear power plants. Changes in the electroencephalographic (EEG) power spectrum accompany these fluctuations in the level of alertness, as assessed by measuring simultaneous changes in EEG and performance on an auditory monitoring task. By combining power spectrum estimation, principal component analysis and artificial neural networks, we show that continuous, accurate, noninvasive, and near real-time estimation of an operator's global level of alertness is feasible using EEG measures recorded from as few as two central scalp sites. This demonstration could lead to a practical system for noninvasive monitoring of the cognitive state of human operators in attention-critical settings.     

Prophylactic antiemetic therapy with granisetron in women undergoing thyroidectomy

BACKGROUND: In an attempt to better understand and define the progression of amyotrophic lateral sclerosis (ALS), we developed a classification of 5 discrete health states that reflect patients' activities of daily living. These health states were used to determine whether patients with ALS who are treated with riluzole differed from those treated with placebo. SETTING: Clinics for patients with ALS. DESIGN: Placebo-controlled trial of riluzole treatment in 959 patients with ALS. Interventions: Treatment with riluzole or placebo. MAIN DEPENDENT MEASURES: A Cox model was used to assess whether, from the initial randomization to the end of an 18-month follow-up, there was a difference in the times of transition into subsequent health states between patients treated with riluzole and those treated with placebo. RESULTS: Our analysis showed a significant difference in the time to transit between the riluzole and the placebo groups in less severely affected cases, ie, state 2 and state A (the milder states) of ALS. CONCLUSION: Patients receiving riluzole remained in the milder health states longer (P<.05).     

Use of somatostatin analogue scintigraphy in the localization of recurrent medullary thyroid carcinoma

Detection of recurrence of medullary thyroid carcinoma (MTC) remains a diagnostic problem. Increased serum tumour marker levels frequently indicate recurrence while conventional imaging techniques (CIT) are non-diagnostic. In this study, we performed indium-111 octreotide scintigraphy and CIT in a series of 20 patients with MTC presenting with elevated serum tumour markers after surgery. 111In-octreotide whole-body studies detected 15 pathological uptake foci in 11 of the 20 patients studied and CIT detected 17 lesions in 11 of the 20 patients. Ten patients underwent reoperation, five of them with positive 111In-octreotide scintigraphy and CIT and two with positive isotopic exploration and negative CIT. Surgical findings demonstrated that the results of isotopic study and CIT had been false-positive for MTC in one case (sarcoidosis). The six patients with true-positive 111In-octreotide studies had significantly higher basal calcitonin (CT) and carcinoembryonic antigen (CEA) levels than the patients with negative isotopic studies. The expression of somatostatin receptor (SSTR) subtypes by PC-PCR could be investigated in four cases with a positive isotopic study. Among the three cases with a true-positive study, SSTR2, the SSTR subtype that preferentially binds to the somatostatin analogue octreotide, was detected in two, SSTR5 was demonstrated in the three, and SSTR3 was detected in one. No subtype of SSTR was detected in the case with a final diagnosis of sarcoidosis. We conclude that 111In-octreotide has limited sensitivity in detecting recurrence in patients with MTC, although its sensitivity may improve with high serum CT levels. This radionuclide imaging technique should be employed when conventional imaging techniques are negative or inconclusive or when the presence of somatostatin receptors may provide the basis for treatment with somatostatin analogues.     

The diagnosis of medullary carcinoma of the thyroid (author's transl)

The pentagastrin stimulation test was given to ten brothers and sisters of two patients who had previously undergone total thyroidectomy for medullary carcinoma of the thyroid. 5 microng pentagastrin/kg body-weight were injected as an intravenous bolus and calcitonin levels determined before and after. The test was positive in four members of the family and the presence of a medullary carcinoma was subsequently confirmed in them histologically.