Investigation on the association between thyroid tumorigeneses and herpesviruses

Herpesviruses have been associated with various human malignancies and with thyroid autoimmunity. Aiming to investigate the presence of these viruses in thyroid nodules, we analyzed serum and thyroid tissue from 183 patients (83 benign and 100 malignant thyroid nodules). We also obtained 104 normal thyroid tissues extracted from the contralateral lobe of these patients. We used ELISA to screen the serology of all patients and a real-time quantitative PCR to analyze thyroid tissue viral load in antibody-positive patients. In addition, the presence of herpesviruses was tested by histological analysis in 20 EBV-positive tissues using the expression of LMP-1 by immunohistochemistry (IHC) and EBER by in situ hybridization (ISH). There was no evidence of HSV-2 or CMV DNA, but we found EBV DNA sequences in 29 (16%) thyroid tissue samples. We also found 7 positive EBV cases out of 104 normal tissues. Viral load was higher in tumors than in their respective normal tissues (p = 0.0002). ISH analysis revealed EBER expression in 11 out of 20 (52%) EBV-positive tissues, mostly in malignant cases (8/11, 73%). The presence of high EBV copy numbers in thyroid tumors and the expression of EBER only in malignant cases suggest an association between EBV and thyroid malignancies. However, we did not find any association between the presence of EBV and/or its viral load and any clinical or pathological tumor feature. Further studies aiming to clarify the mechanisms of EBV infection in thyroid cells are necessary to support a possible role in the development of thyroid cancer.

Gene expression of thyroid-specific transcription factors may help diagnose thyroid lesions but are not determinants of tumor progression

PURPOSE

The role of thyroid-specific transcription factors in thyroid malignancy is still poorly understood, so we investigate thyroid-specific transcription factors gene expression both in benign and in malignant thyroid nodules, aiming to study a possible clinical utility of these molecules.

METHODS

We quantified TTF-1, FOXE1 and PAX8 mRNA levels, relating their expression to diagnostic and prognostic features of thyroid tumors. RNA was extracted from 4 normal thyroid tissues, 101 malignant [99 papillary thyroid carcinomas (PTC) and 2 anaplastic thyroid carcinomas] and 99 benign thyroid lesion tissues [49 goiter and 50 follicular adenomas (FA)].

RESULTS

Levels of mRNA of both FOXE1 (P < 0.0001) and PAX8 (P < 0.0001) genes, but not TTF-1 (P = 0.7056), were higher in benign than in malignant thyroid lesions. FOXE1 was able to identify malignant nodules with 75.8 % sensitivity, 76.1 % specificity, 75.8 % positive predictive value, 76.1 % negative predictive value and 75.9 % accuracy. PAX8 was able to identify malignancy with 60.6 % sensitivity, 81.1 % specificity, 76.9 % positive predictive value, 66.4 % negative predictive value and 70.6 % accuracy. Both FOXE1 and PAX8 gene expression patterns were also able to differentiate FA from the follicular variant of PTC-FVPTC. However, the investigated gene expression was neither associated with any clinical feature of tumor aggressiveness nor associated with recurrence or survival.

CONCLUSIONS

We suggest that FOXE1 and PAX8 gene expression patterns may help to diagnose thyroid nodules, identifying malignancy and characterizing follicular-patterned thyroid lesions, but are not determinants of thyroid tumor progression.

TSHR intronic polymorphisms (rs179247 and rs12885526) and their role in the susceptibility of the Brazilian population to Graves' disease and Graves' ophthalmopathy

PURPOSE

Intronic thyroid-stimulating hormone receptor polymorphisms have been associated with the risk for both Graves' disease and Graves' ophthalmopathy, but results have been inconsistent among different populations. We aimed to investigate the influence of thyroid-stimulating hormone receptor intronic polymorphisms in a large well-characterized population of GD patients.

METHODS

We studied 279 Graves' disease patients (231 females and 48 males, 39.80 ± 11.69 years old), including 144 with Graves' ophthalmopathy, matched to 296 healthy control individuals. Thyroid-stimulating hormone receptor genotypes of rs179247 and rs12885526 were determined by Real Time PCR TaqMan(®) SNP Genotyping.

RESULTS

A multivariate analysis showed that the inheritance of the thyroid-stimulating hormone receptor AA genotype for rs179247 increased the risk for Graves' disease (OR = 2.821; 95 % CI 1.595-4.990; p = 0.0004), whereas the thyroid-stimulating hormone receptor GG genotype for rs12885526 increased the risk for Graves' ophthalmopathy (OR = 2.940; 95 % CI 1.320-6.548; p = 0.0083). Individuals with Graves' ophthalmopathy also presented lower mean thyrotropin receptor antibodies levels (96.3 ± 143.9 U/L) than individuals without Graves' ophthalmopathy (98.3 ± 201.9 U/L). We did not find any association between the investigated polymorphisms and patients clinical features or outcome.

CONCLUSION

We demonstrate that thyroid-stimulating hormone receptor intronic polymorphisms are associated with the susceptibility to Graves' disease and Graves' ophthalmopathy in the Brazilian population, but do not appear to influence the disease course.

Polymorphisms of cell cycle control genes influence the development of sporadic medullary thyroid carcinoma

BACKGROUND

The role of key cell cycle regulation genes such as, CDKN1B, CDKN2A, CDKN2B, and CDKN2C in sporadic medullary thyroid carcinoma (s-MTC) is still largely unknown.

METHODS

In order to evaluate the influence of inherited polymorphisms of these genes on the pathogenesis of s-MTC, we used TaqMan SNP genotyping to examine 45 s-MTC patients carefully matched with 98 controls.

RESULTS

A multivariate logistic regression analysis demonstrated that CDKN1B and CDKN2A genes were related to s-MTC susceptibility. The rs2066827*GT+GG CDKN1B genotype was more frequent in s-MTC patients (62.22%) than in controls (40.21%), increasing the susceptibility to s-MTC (OR=2.47; 95% CI=1.048-5.833; P=0.038). By contrast, the rs11515*CG+GG of CDKN2A gene was more frequent in the controls (32.65%) than in patients (15.56%), reducing the risk for s-MTC (OR=0.174; 95% CI=0.048-0.627; P=0.0075). A stepwise regression analysis indicated that two genotypes together could explain 11% of the total s-MTC risk. In addition, a relationship was found between disease progression and the presence of alterations in the CDKN1A (rs1801270), CDKN2C (rs12885), and CDKN2B (rs1063192) genes. WT rs1801270 CDKN1A patients presented extrathyroidal tumor extension more frequently (92%) than polymorphic CDKN1A rs1801270 patients (50%; P=0.0376). Patients with the WT CDKN2C gene (rs12885) presented larger tumors (2.9±1.8 cm) than polymorphic patients (1.5±0.7 cm; P=0.0324). On the other hand, patients with the polymorphic CDKN2B gene (rs1063192) presented distant metastases (36.3%; P=0.0261).

CONCLUSION

In summary, we demonstrated that CDKN1B and CDKN2A genes are associated with susceptibility, whereas the inherited genetic profile of CDKN1A, CDKN2B, and CDKN2C is associated with aggressive features of tumors. This study suggests that profiling cell cycle genes may help define the risk and characterize s-MTC aggressiveness.

The influence of the environment on the development of thyroid tumors: a new appraisal

Most epidemiological studies concerning differentiated thyroid cancers (DTC) indicate an increasing incidence over the last two decades. This increase might be partially explained by the better access to health services worldwide, but clinicopathological analyses do not fully support this hypothesis, indicating that there are carcinogenetic factors behind this noticeable increasing incidence. Although we have undoubtedly understood the biology and molecular pathways underlying thyroid carcinogenesis in a better way, we have made very little progresses in identifying a risk profile for DTC, and our knowledge of risk factors is very similar to what we knew 30-40 years ago. In addition to ionizing radiation exposure, the most documented and established risk factor for DTC, we also investigated the role of other factors, including eating habits, tobacco smoking, living in a volcanic area, xenobiotics, and viruses, which could be involved in thyroid carcinogenesis, thus, contributing to the increase in DTC incidence rates observed.

A putative OTU domain-containing protein 1 deubiquitinating enzyme is differentially expressed in thyroid cancer and identifies less-aggressive tumours

Background:

This study aimed to identify novel biomarkers for thyroid carcinoma diagnosis and prognosis.

Methods:

We have constructed a human single-chain variable fragment (scFv) antibody library that was selected against tumour thyroid cells using the BRASIL method (biopanning and rapid analysis of selective interactive ligands) and phage display technology.

Results:

One highly reactive clone, scFv-C1, with specific binding to papillary thyroid tumour proteins was confirmed by ELISA, which was further tested against a tissue microarray that comprised of 229 thyroid tissues, including: 110 carcinomas (38 papillary thyroid carcinomas (PTCs), 42 follicular carcinomas, 30 follicular variants of PTC), 18 normal thyroid tissues, 49 nodular goitres (NG) and 52 follicular adenomas. The scFv-C1 was able to distinguish carcinomas from benign lesions (P=0.0001) and reacted preferentially against T1 and T2 tumour stages (P=0.0108). We have further identified an OTU domain-containing protein 1, DUBA-7 deubiquitinating enzyme as the scFv-binding antigen using two-dimensional polyacrylamide gel electrophoresis and mass spectrometry.

Conclusions:

The strategy of screening and identifying a cell-surface-binding antibody against thyroid tissues was highly effective and resulted in a useful biomarker that recognises malignancy among thyroid nodules and may help identify lower-risk cases that can benefit from less-aggressive management.

Genes of detoxification are important modulators of hereditary medullary thyroid carcinoma risk

CONTEXT

Different inherited profiles of genes involved in cellular mechanisms of activation and detoxification of carcinogenic products can provide specific protection or determine the risk for cancer. Low-penetrance polymorphic genes related to the biotransformation of environmental toxins have been associated with susceptibility to and the phenotype of, human tumours.

OBJECTIVE

To investigate the role of germline inheritance of polymorphisms in CYP1A2*F, CYP1A1 m1, GSTP1, NAT2 and TP53 genes in hereditary medullary thyroid carcinoma (HMTC) patients.

DESIGN

This study was developed in University of Campinas (Unicamp).

PATIENTS

We studied 132 patients with HMTC, 88 first-degree relatives of HMTC patients and 575 control individuals.

MEASUREMENTS

All patients with MTC and their relatives were sequenced for the RET gene and five genes were genotyped using TaqMan(®) system.

RESULTS

We observed that the inheritance of CYP1A2*F (OR = 2·10; 95% CI = 1·11-3·97; P = 0·022), GSTP1 (OR = 4·41; 95% CI = 2·47-7·88; P < 0·001) and NAT2 (OR = 2·54; 95% CI = 1·16-5·58; P = 0·020) variants increased the risk for HMTC. In addition, multiple regression analysis showed that the inheritance of GSTP1 polymorphisms was associated with the diagnosis in older patients (B = 8·0229; 95% IC = ± 5·5735; P = 0·0054). Concerning the group of HTMC relatives, CYP1A2*F (OR = 2:40; 95% CI = 1·19-4·86; P = 0·015), CYP1A1 m1 (OR = 2·79; 95% CI = 1:04-7·51; P = 0·042), GSTP1 (OR = 2·86; 95% IC = 1·53-5·32; P < 0·001) and NAT2 (OR = 2·25; 95% IC = 1·20-4·22; P = 0·012) were associated with HMTC risk.

CONCLUSIONS

We have demonstrated that the inheritance of specific genes determining the individual response to environmental toxins may contribute to the risk and phenotypic variability that exists in patients with HMTC. Moreover, we identified a group at risk in relatives of HMTC patients.

How good is the levothyroxine replacement in primary hypothyroidism patients in Brazil? Data of a multicentre study

BACKGROUND

Studies from every continent have shown that only around 50% of the patients subjected to thyroid hormone replacement have TSH in the normal range. However, to date, there are no consistent data about Brazil.

OBJECTIVES

To evaluate levothyroxine (LT4) replacement treatment in patients with primary hypothyroidism followed in referral centers in Brazil.

METHODS

Patients with primary hypothyroidism followed in referral centers (University Hospitals from Universidade Federal do Rio de Janeiro - UFRJ, Unicamp, Universidade Federal do Paraná - UFPR and Universidade Federal do Ceará-UFC) answered a questionnaire that inquired about clinical and biochemical conditions, social- economic status, life quality and clinicians' orientations as well as their understanding about the information given. Serum TSH was checked close to the interview.

RESULTS

2292 consecutive patients met the inclusion criteria. Mean age 51.2 yr and TSH values between 0.4 and 4.0 mUI/l were considered to be within the reference range. Among all patients taking thyroid medication, 42.7% had an abnormal serum TSH (28.3% were undertreated and 14.4% were overtreated). Approximately all patients (99%) took LT4 in the morning but less than 30 min before breakfast (85.4%). Regarding the clinicians' orientations: 97.5% of the patients were instructed to take the medication daily, and 92.6% to take 30 min before breakfast (92.6%). However, only 52.1% were told not to take LT4 along with other medication.

CONCLUSIONS

Our study found that a significant number of patients taking thyroid hormones were not in the therapeutic range. Clinicians should, therefore, consider monitoring patients on thyroid replacement more frequently and being more precise on giving recommendations about the correct use of LT4.

Chromatin changes in papillary thyroid carcinomas may predict patient outcome

PURPOSE

New insights in prognostic predictions are urgently needed for papillary thyroid carcinoma (PTC). The present study aimed to investigate whether computerized analysis of chromatin texture allows the identification of PTC patients with a poor prognosis.

METHODS

We randomnly selected paraffin-embedded blocks from surgical specimens of 103 classic cases of PTC. During follow-up, 68 of the patients were classified as free of disease, whereas 35 presented with recurrences. Characteristics of chromatin were obtained from digitized images of at least 100 randomly selected tumor nuclei per patient. An independent series of 30 goiters was used to validate our observations.

RESULTS

Stage, age and distant metastases were found to serve as independent prognostic factors for survival. In addition, multivariate Cox regression confirmed variable cluster prominence as an independent prognostic factor. By comparing malignant and benign nodules, we found that the PTC lesions presented with higher nuclear perimeters, nuclear areas, Minkowski fractal dimensions, optical densities and nuclear longest chords.

CONCLUSION

From our results we conclude that, in conjunction with clinical and histopathological data, morphometric data may provide relevant prognostic information in PTC patients.

Current recommendations for levothyroxine treatment of differentiated thyroid cancer patients are not properly implemented in clinical practice

BACKGROUND

Levothyroxine (L-T4) treatment aims to minimize the risk of differentiated thyroid cancer (DTC) recurrence and should be tailored to patient risk stratification and potential morbidity from adverse effects.

AIM

To evaluate the effectiveness of current recommendations on L-T4 treatment of DTC patients in clinical practice.

MATERIAL AND METHODS

We submitted to in-person interviews and revised the charts of 139 low-risk (LR) and 57 not-low-risk (NLR) DTC patients. A second evaluation made 24-60 months after surgery reclassified 131 patients who maintained (thyroglobulin) Tg≤2 ng/dl with no evidence of relapse/recurrence as LR, whereas the remaining 65 cases were considered NLR.

RESULTS

Only 27% LR patients were appropriately controlled; 18% were kept suppressed; 49% maintained serum TSH levels between 0.11-0.4 mU/l; 21% had TSH=2.5- 4.5 mU/l; and 12% TSH>4.5 mU/l. Among the NLR patients, 24 (37%) of the patients presented serum TSH levels above goal, including 13 (20%) patients with TSH>4.5 mU/l. There were 4 NLR elders whose TSH levels were kept between 0.41 and 4.5 for medical reasons; likewise, 28 NLR patients maintained with low but not undetectable serum TSH levels had cardiovascular and/or bone risk factors, but all the remaining 24 NLR patients were not adequately controlled because of poor treatment compliance. On the other hand, 45% of 152 inappropriately controlled patients presented risks for bone fractures, including 33 patients kept with low serum TSH levels without medical indication.

CONCLUSION

We concluded that guidelines are not adequately applied and alternative strategies aiming to increase adherence are urgently needed for DTC patients.

Evidence that polymorphisms in detoxification genes modulate the susceptibility for sporadic medullary thyroid carcinoma

AIM

Polymorphic low-penetrance genes have been consistently associated with the susceptibility to a series of human tumors, including differentiated thyroid cancer.

METHODS

To determine their role in medullary thyroid cancer (MTC), we used TaqMan SNP method to genotype 47 sporadic MTC (s-MTC) and a control group of 578 healthy individuals for CYP1A2*F, CYP1A1m1, GSTP1, NAT2 and 72TP53. A logistic regression analysis showed that NAT2C/C (OR=3.87; 95% CI=2.11-7.10; P=2.2×10(-5)) and TP53C/C genotypes (OR=3.87; 95% CI=1.78-6.10; P=2.8×10(-4)) inheritance increased the risk of s-MTC. A stepwise regression analysis indicated that TP53C/C genotype contributes with 8.07% of the s-MTC risk.

RESULTS

We were unable to identify any relationship between NAT2 and TP53 polymorphisms suggesting they are independent factors of risk to s-MTC. In addition, there was no association between the investigated genes and clinical or pathological features of aggressiveness of the tumors or the outcome of MTC patients.

CONCLUSION

In conclusion, we demonstrated that detoxification genes and apoptotic and cell cycle control genes are involved in the susceptibility of s-MTC and may modulate the susceptibility to the disease.

Clinical and pathological implications of concurrent autoimmune thyroid disorders and papillary thyroid cancer

Cooccurrences of chronic lymphocytic thyroiditis (CLT) and thyroid cancer (DTC) have been repeatedly reported. Both CLT and DTC, mainly papillary thyroid carcinoma (PTC), share some epidemiological and molecular features. In fact, thyroid lymphocytic inflammatory reaction has been observed in association with PTC at variable frequency, although the precise relationship between the two diseases is still debated. It also remains a matter of debate whether the association with a CLT or even an autoimmune disorder could influence the prognosis of PTC. A better understanding about clinical implications of autoimmunity in concurrent thyroid cancer could raise new insights of thyroid cancer immunotherapy. In addition, elucidating the molecular mechanisms involved in autoimmune disease and concurrent cancer allowed us to identify new therapeutic strategies against thyroid cancer. The objective of this article was to review recent literature on the association of these disorders and its potential significance.

Bacteriophage therapy of venous leg ulcers in humans: results of a phase I safety trial

OBJECTIVE

This phase 1 trial set out to examine the safety of a bacteriophage-based preparation for difficult-to-treat wounds.

METHOD

The intention-to-treat sample comprised 42 patients with chronic venous leg ulcers (VLUs); 39 patients completed the trial. The ulcers were treated for 12 weeks with either a saline control or bacteriophages targeted against Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. Follow-up continued until week 24.

RESULTS

No adverse events were attributed to the study product. No significant difference (p>0.05) was determined between the test and control groups for frequency of adverse events, rate of healing, or frequency of healing.

CONCLUSION

This study found no safety concerns with the bacteriophage treatment. Efficacy of the preparation will need to be evaluated in a phase II efficacy study.

DECLARATION OF INTEREST

One of the authors (AS) holds an equity interest in Intralytix. The other authors do not have any interest in commercial activities.

Lack of association of GSTT1, GSTM1, GSTO1, GSTP1 and CYP1A1 polymorphisms for susceptibility and outcome in Brazilian prostate cancer patients

The polymorphic inheritance of human drug-metabolizing enzymes, such as those encoded by the GST and CYP systems, has been implicated in both cancer risk and prognostic. In an effort to increase our understanding of the interaction between potential environmental exposure, lifestyle, and genetic factors in the predisposition and response to radiotherapy of prostate cancer patients, we examined GSTT1, GSTM1, GSTO1, GSTP1 and CYP1A1 genotypes in a Brazilian population. We studied 125 prostate cancer patients and 100 benign prostatic hyperplasia patients paired for ethnic and lifestyle characteristics. Lifetime occupational history, dietary patterns, cigarette-smoking, and other anamnestic data were obtained through interviews. Outcome was evaluated in 42 stage <or= T2a patients presenting a Gleason score <or= 6, PSA <or= 10 ng/ml, treated with radiotherapy and followed up for 12 to 34 months (15 +/- 8 months). None of the studied polymorphisms was found associated to prostate cancer risk either considered separately or in combination, in uni- or multivariate regression logistic analysis. Also, there was no association between genotypes and possible clinical factors of risk or any parameter of tumour aggressiveness at diagnosis or during follow-up. Patients' response to radiotherapy treatment was not associated to any genotype. In conclusion, our data suggest that GST and CYP1A1 genotypes are not associated with the susceptibility to prostate cancer or its outcome in the Brazilian population.

Usefulness of HBME-1, cytokeratin 19 and galectin-3 immunostaining in the diagnosis of thyroid malignancy

AIMS

To investigate the usefulness of immunohistochemical expression and immunolocalization of a panel of thyroid malignancy markers including HBME-1, cytokeratin (CK) 19 and galectin-3.

METHODS AND RESULTS

We evaluated 170 thyroid lesions including 148 neoplastic lesions [84 papillary carcinomas (PC), 38 follicular carcinomas (FC), 18 follicular adenomas, one hyalinizing trabecular tumour, five medullary carcinomas, two anaplastic carcinomas] and 22 non-neoplastic lesions (12 adenomatous nodules and 10 Hashimoto's thyroiditis). HBME-1, galectin-3 and CK 19 were expressed in 94%, 72.6%, 72.6% of PCs and in 63%, 21%, 21% of FCs. The three markers were mostly negative in all normal tissues. Although the most helpful marker in terms of sensitivity and specificity for the follicular variant of PC and for FC diagnosis was HBME-1, when we consider the differentiation between cases of follicular variant of papillary carcinoma (FVPC) and FC or adenoma, in terms of percentage of positive cells, galectin-3 and CK 19 were more relevant.

CONCLUSIONS

HBME-1 is the most sensitive marker for thyroid malignancy but the three markers may be useful in specific cases. This panel of markers is useful to differentiate the follicular patterned lesions, with special reference to the FVPC.

GSTO polymorphism analysis in thyroid nodules suggest that GSTO1 variants do not influence the risk for malignancy

A new class of glutathione S-transferase enzymes named omega (GSTO) has been recently identified and shown to be expressed in a wide range of human tissues. A genetic polymorphism of the GSTO1 gene causing an alanine-to-aspartate (A140D) substitution in amino acid 140 produces a variant with lowered enzyme activities in the biotransformation of inorganic arsenic, a common contaminant of drinking water in many regions of the world and a well-known carcinogen. In order to investigate the role of GSTO1 inheritance pattern on thyroid cancer risk we used a polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP)-sequencing approach to compare the genotypes of 173 (87 women, 86 men; 18-81 years old; 47+/-18 years old) healthy control individuals with those of 145 patients with thyroid nodules (84 women, 61 men; 17-81 years old; 49+/-14 years old) including 17 follicular carcinomas, 76 papillary carcinomas, 21 follicular adenomas and 31 multinodular goiters. The incidence of GSTO1 variants was similar in the control population and population with the benign and malignant nodules. There was no association between genotype and the patients' clinical features, tumour parameters of aggressiveness at diagnosis or behaviour during follow-up. We conclude that GSTO1 variants do not influence the risk for thyroid nodules or their pathologic and clinical characteristics.

No evidence for mutations in exons 1, 8 and 18 of the patched gene in sporadic skin lesions of Brazilian patients

There is strong evidence that the patched (PTCH) gene is a gene for susceptibility to the nevoid basal cell carcinoma syndrome. PTCH has also been shown to mutate in both familial and sporadic basal cell carcinomas. However, mutations of the gene seem to be rare in squamous cell carcinomas. In order to characterize the role of the gene in the broader spectrum of sporadic skin malignant and pre-malignant lesions, we performed a polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis of genomic DNA extracted from 105 adult patients (46 females and 59 males). There were 66 patients with basal cell carcinomas, 30 with squamous cell carcinomas, 2 with malignant melanomas and 7 patients with precancerous lesions. Two tissue samples were collected from each patient, one from the central portion of the tumor and another from normal skin. Using primers that encompass the entire exon 1, exon 8 and exon 18, where most of the mutations have been detected, we were unable to demonstrate any band shift. Three samples suspected to present aberrant migrating bands were excised from the gel and sequenced directly. In addition, we sequenced 12 other cases, including tumors and corresponding normal samples. A wild-type sequence was found in all 15 cases. Although our results do not exclude the presence of clonal alterations of the PTCH gene in skin cancers or mutations in other exons that were not screened, the present data do not support the presence of frequent mutations reported for non-melanoma skin cancer of other populations.

Lack of mutations of exon 2 of the MEN1 gene in endocrine and nonendocrine sporadic tumors

In addition to the mutations that underlie most cases of the multiple endocrine neoplasia type 1 (MEN1) syndrome, somatic mutations of the MEN1 gene have also been described in sporadic tumors like gastrinomas, insulinomas and bronchial carcinoid neoplasm. We examined exon 2 of this gene, where most of the mutations have been described, in 148 endocrine and nonendocrine sporadic tumors. DNA was obtained by phenol/chloroform extraction and ethanol precipitation from 92 formalin-fixed, paraffin-embedded samples, and from 40 fresh tumor tissue samples. We used 5 pairs of primers to encompass the complete coding sequence of exon 2 of the MEN1 gene that was screened by the polymerase chain reaction-single-stranded conformation polymorphism (PCR-SSCP) technique in 78 sporadic thyroid cancers: 28 follicular adenomas, 35 papillary carcinomas, 14 follicular carcinomas, and 1 anaplastic thyroid carcinoma. We also examined 46 adrenal lesions (3 hyperplasias, 3 adenomas and 35 adrenocortical carcinomas, 2 pheochromocytomas, 2 ganglioneuroblastomas, and 1 lymphoma) and 24 breast cancers (6 noninvasive, 16 infiltrating ductal, and 2 invasive lobular tumors). The PCR product of 5 tumors suspected to present band shifts by SSCP was cloned. Direct sense and antisense sequencing did not identify mutations. These results suggest that the MEN1 gene is not important in breast, thyroid or adrenal sporadic tumorigenesis. Because the frequency of mutations varies significantly among tumor subgroups and allelic deletions are frequently observed at 11q13 in thyroid and adrenal cancers, another tumor suppressor gene residing in this region is likely to be involved in the tumorigenesis of these neoplasms.

Thyroid stimulating hormone levels in cord blood are not influenced by non-thyroidal mothers' diseases

CONTEXT

Screening programs not only offer the opportunity to trace and treat almost all cases of congenital hypothyroidism but also mean large savings to the health system. However, carefully planned strategies are necessary to extend their benefits and reduce costs.

OBJECTIVE

To determine the possible influence of maternal diseases that affect maternal-fetal placenta dynamics on primary thyroid stimulating hormone (TSH) screening for congenital hypothyroidism.

DESIGN

Prospective non-randomized clinical trial with at least 3 months of follow-up.

SETTING

A public university referral center [CAISM/Hospital das Clínicas, Faculty of Medicine, University of Campinas, Campinas, SP].

PARTICIPANTS

415 neonates divided into 5 groups: eighty-three infants born from cardiac mothers; 98 from mothers that had toxemia; 54 of the mothers had diabetes mellitus; 40 were HIV positive and 140 had no diseases.

INTERVENTION

All newborns had cord blood samples collected on filter paper at birth.

MAIN MEASUREMENTS

TSH was measured from dried blood spots using a homemade immunofluorescence assay (sensitivity in dried blood spots = 0.1 mU/L).

RESULTS

There was no significant difference in the mean TSH levels among the 5 groups. Moreover, TSH levels were around 5 mU/L in 48% of the newborns, indicating that our region is severely deficient in iodine.

CONCLUSIONS

Our results indicate that primary TSH screening programs using cord blood are not affected by maternal diseases. We suggest that, besides its technical advantages over heel punctures with T4 primary approaches, neonatal screening using primary cord blood TSH may also be used as a monitoring tool for evaluation and control of iodine deficiency disorders (IDD).

Nested-PCR using MPB64 fragment improves the diagnosis of pleural and meningeal tuberculosis

Fluids in which Mycobacterium tuberculosis are seldom found, such as pleural and cerebrospinal liquids, are good candidates to be studied using PCR techniques. We detail our experience with a PCR assay applied to pleural and cerebrospinal fluids using the primer MPB64. Seventy three specimens were analyzed: 30 pleural fluids (PF), 26 pleural biopsies (PB) and 17 cerebrospinal fluids (CSF). The gold standard for the diagnosis of tuberculous meningitis was the positive culture for M. tuberculosis in CSF. Tuberculous pleural effusion was diagnosed when cultures of PF and/or PB were positive for M. tuberculosis, or the PB histology showed granulomas. Our results, compared to the gold standards employed, showed a sensitivity of 70%, specificity of 88%, positive predictive value of 82% and negative predictive value of 80%. The high specificity of the MPB64 fragment while still retaining a good sensitivity makes it very well suited for pleural and cerebrospinal tuberculosis diagnosis.

Serum cytokine levels in autoimmune and non-autoimmune hyperthyroid states

Although the role of interleukin-2 (IL-2) and interferon gamma (gammaIFN) is still poorly understood in hyperthyroid diseases, it is reasonable to assume that these cytokines may be present at higher levels in Graves' disease (GD) than in other primarily non-autoimmune thyroid diseases. In order to look for an easy method to distinguish GD from primarily non-autoimmune causes of hyperthyroidism, we compared 13 healthy individuals with 21 treated and untreated hyperthyroid GD patients and with 19 patients with hyperthyroidism due to other etiologies: 7 cases of multinodular goiter, 5 cases of excessive hormone replacement and 7 cases of amiodarone-associated hyperthyroidism. All patients presented low TSH levels and a dubious clinical thyroid state. We found a good correlation between TSH and serum IL-2 levels (r = 0.56; P<0.01). Serum IL-2 (P<0.01) and gammaIFN (P<0.01) levels were lower in the hyperthyroid group of patients than in control subjects, suggesting a depressed TH1 pattern in the T-cell subset of hyperthyroid patients. GD had normal IL-2 levels, while patients with other forms of thyrotoxicosis presented decreased IL-2 levels (P<0.05). There was no difference between treated and untreated GD patients. We suggest that the direct measurement of serum IL-2 level may help to confirm hyperthyroidism caused by GD.

Serum cytokines in chronic Chagas' disease

We studied the serum levels of IL-2, IFN-gamma and TNF in different clinical forms of Chagas' disease and in patients clinically compensated and decompensated. Cytokines measured in 91 patients with the chronic form of the disease did not differ from those of 13 normal individuals, suggesting the absence of activation of the TH1 pattern of lymphocyte response. There were no statistical differences among the 17 patients in the indeterminate form of the disease, the patients presenting either early (n = 4) or well-developed signs of cardiomyopathy (n = 62), the digestive (n = 4) or the mixed (n = 4) forms of the disease. Serum TNF was undetectable and IFN-gamma levels did not differ between clinical forms and severities of Chagas' disease. However, we found IL-2 higher levels in the 25 non-controlled patients than in the 66 controlled individuals (p < 0.001). We suggest that IL-2 dosage may be useful as an indicator of the need for more aggressive procedures.

[Comparison of two strategies for the early detection of congenital hypothyroidism]

OBJECTIVE

Compare two different strategies in newborn screening for congenital hypothyroidism, primary TSH in the umbilical cord blood (method 1) and primary T4 in blood collected from the heel in the 2nd day of life (method 2).

METHODS

We compared both strategies in 10,000 newborns, measuring TSH by a sensitive immunofluorimetric assay and T4 by a radioimmunoassay.

RESULTS

Both strategies detected all cases of hypothyroidism (4 cases, 1/2,500 newborns). The recalling index owing to insufficient amount of blood to perform the assays was zero in method 1 and 8.5% (850 newborns) in method 2. The recalling index for confirmation of the results was 0.06% (6 newborns) in method 1 and 2.25% (225 newborns) in method 2; when method 2 included supplementary TSH, the recalling index was reduced to 1.63% (163 newborns).

CONCLUSION

Our data indicate the technical superiority of the umbilical cord blood compared to heel and primary TSH compared to primary T4 in the neonatal thyroid screening for congenital hypothyroidism.

Studies of allelic loss in thyroid tumors reveal major differences in chromosomal instability between papillary and follicular carcinomas

Loss of heterozygosity (LOH) studies have been used to identify sites harboring tumor suppressor genes involved in tumor initiation or progression. Previous reports have suggested that regions within chromosomes 3p, 11q, 2p, 2q, 10q, and 1p may be frequently deleted in human follicular thyroid cell tumors. We have extended the analysis of these and other selected regions to 65 paired thyroid tumor tissues. Twenty-four were follicular adenomas, 30 were papillary carcinomas, 10 were follicular carcinomas, and 1 was an anaplastic carcinoma. Sixty percent of the follicular carcinomas, 33% of the follicular adenomas, and 23% of the papillary carcinomas presented LOH at least at 1 site. Fifty percent of the follicular carcinomas showed 2 or more chromosome arms affected by deletions, whereas just 1 of the 24 follicular adenomas and none of the papillary carcinomas presented this feature. However, none of the specific loci examined had a rate of LOH greater than 33%, even in follicular carcinomas. This prompted us to place our findings into a broader context, and we, therefore, performed a meta analysis of all published studies of LOH in follicular thyroid neoplasms. There was a phenotype dependency in the overall rate of LOH, with no specific region displaying a particularly high prevalence. Most notably, by contrast to follicular carcinomas, papillary carcinomas had exceedingly low rates of LOH. Thus, there is a sharp distinction between the two major forms of differentiated thyroid cancer in their tendency to lose genetic material. This probably results from a fundamental difference in mechanisms controlling chromosomal stability in these two forms of cancers that in all likelihood has implications for tumor behavior and prognosis.

Isolation and Identification of beta-Casein A(1)-4P and beta-Casein A(2)-4P in Commercial Caseinates

Caseinate contained two modified beta-casein (beta-CN) fractions that together represented from 5 to 27% of the total beta-CN depending on the type of caseinate analyzed (sodium, calcium, or potassium). Mass spectroscopy showed that the modified beta-CN fractions had molecular weights of 23 940 +/- 3 and 23 904 +/- 2, approximately 80 (or the mass of one phosphate group) less than that of the native beta-CN fractions found in milk, beta-CN A(1)-5P (24 028) and beta-CN A(2)-5P (23 988). (31)P NMR verified mass spectroscopy results showing that the modified fractions contained four instead of five phosphorylated serine residues. Molecular weight differences between the modified and unmodified fractions also indicated that the dephosphorylation was a result of enzyme, acid, or alkali hydrolysis and not alkali hydrolysis that proceeds through beta-elimination. The two modified fractions identified as beta-CN A(1)-4P and beta-CN A(2)-4P are probably present in caseinate as a result of the dephosphorylation of the main beta-CN gene products beta-CN A(1)-5P and beta-CN A(2)-5P, respectively.

[Predictive value of the measurement of iodothyronines in the prognosis of patients with severe nonthyroidal illness]

PURPOSE

In order to find prognostic parameters in patients with severe diseases, we analyzed sequentially the levels of thyroid hormones.

METHODS

We measured iodothyronines (T3, T4 and rT3) in 42 patients before the admission and after the discharge in an intensive care unit. In addition, we also measured the iodothyronines in other 17 patients after the discharge.

RESULTS

Comparing the group of good outcome with the patients who died, we observed in the former group initial normal T4 levels in 76% of the patients, which were maintained in 65% of them during hospitalization and in 70% of them at the time of delivery from the intensive care unit. Patients who died, however, presented initial low T4 levels in 56% of them, decreasing values in 95% of them during hospitalization and low levels in 81% of patients at the last dosage. The combined profile of T3 and T4 also differentiated good and bad outcome.

CONCLUSION

We suggest that serial analysis of serum levels of thyroid hormones may help the evaluation of critical care patients.

A method for isolating beta-casein

A new method was developed for obtaining pure beta-CN. Calcium caseinate (3%) was reconstituted, renneted to form a gel, cooled (4 degrees C) to allow beta-CN dissociation from the caseinate gel, and centrifuged. The supernatant was warmed to 30 degrees C, precipitating pure beta-CN from solution. Large quantities of beta-CN were recovered by scaling-up this procedure, but these beta-CN preparations were less pure than the beta-CN that was prepared on a smaller scale. Chromatography (FPLC) and urea-PAGE showed beta-CN to be the main component in the precipitate. Chymosin, used to form the caseinate gel, did not extensively hydrolyze beta-CN under the conditions of these experiments. Calcium concentration, cooling time, and caseinate concentration influenced the recovery of beta-CN. Maximum recovery of beta-CN, under the experimental conditions used, occurred at 10 mM calcium, 48 h of cooling, and 3% caseinate concentration.

Determination of glucose levels using dried filter paper blood spots: new perspective in home monitoring

We present a method for the determination of blood glucose using dried filter paper blood spots. To validate this method, we compared our results using filter paper and simultaneously collected venous blood. We demonstrated that there is a linear relationship between the filter paper glucose levels and those determined in whole blood (r = 0.98). There was no significant difference between the results of the two methods (p > 0.05). This method is a cheap alternative which may improve the control of diabetes mellitus, and may also be very useful in the diagnosis of postprandial hypoglycemia and other special situations.