Small Thyroid Research Articles

Effects Study of Some Common Food Additives on Histological and Functional Thyroid Gland in Young Male Albino Rats

The current study was conducted in the animal house / Department of biology / Al- University of Qadisiyah from November to February This is for the purpose of studying the effect of some food additives on the histological structure and function of the thyroid gland, as well as some oxidative indicators. The current study included 32 young male albino rats randomly distributed into four equal groups The control dosed 1 ml of normal drinking water during the 30-day trial period, the first treatment group (T1) Tetrazine was dosed at a concentration of 25 mg/kg body weight for the duration of the 30-day trial period, The second treatment group (T2) received a chocolate brown dye at a concentration of 200 mg/kg body weight for the duration of the 30-day trial, The third treatment group (T3) dosed the preservative sodium benzoate at a concentration of 50 mg/kg body weight for the duration of the 30-day trial. The results of the statistical analysis showed a significant decrease in the concentration of Thyroxine T4, Thyroid Stimulating Hormone(TSH), enzyme concentration level Superoxide dismutases )SOD(, and Significant increase in the level of concentration of malondidehyde (MDA) In the first group ) T1( and the second group (T2) Compared with the control group. The results also showed a significant increase in (MDA) A significant decrease in the level of (SOD) in a group (T3) Compared with the control group, there was no significant difference in the concentration of T4 & TSH in a group (T3) compared to the control group. The histological study also showed that pathological histological changes occurred in (T1) (T2) )T3) Represented by changing the diameter of the thyroid gland's follicles and colloids Where there are many small irregular thyroid follicles, as well as bubbles in the colloidal substance And the occurrence of hyperplasia and an increase in the thickness of the lining layer of the vesicles. We conclude from the current study that eating food additives causes some negative on the histological structure and function of the thyroid gland. Keywords: Thyroid gland ,Tartrazine, Chocolate Brown HT E155, Benzoat sodium.

Association of Helicobacter pylori Infection with Papillary Thyroid Carcinoma: A Case-control Study

Background: The thyroid nodules incidence has risen worldwide. Although factors such as increasing the use of imaging techniques and more rapid detection of small thyroid nodules have been implicated in the recent rise in thyroid cancer incidence, some environmental parameters such as infectious agents may be involved. Helicobacter pylori infection is an environmental risk factor, which may mimic the antigenic properties of membranes of thyrocytes. Objectives: This study aimed at evaluating the association of H. pylori infection with benign and malignant thyroid nodules in comparison with the control group. Methods: Patients with benign thyroid nodules, papillary thyroid cancer (PTC), and euthyroid healthy controls without thyroid nodules that had just been diagnosed were included in the study. All participants underwent clinical examination. Various biochemical parameters such as serum H. pylori Ab (IgG) and thyroid function tests were measured. Comparisons were made between groups. Results: Finally, 370 patients with benign thyroid nodules, 364 patients with PTC, and 360 healthy subjects without nodules participated as a control group. In the patients with PTC, the prevalence of H. pylori infection was 89.6%, while in the group of patients with benign thyroid nodules and the control group was 81.1% and 75%, respectively (P < 0.001). Helicobacter pylori antibody (Ab) titer was not significantly associated with any of the anthropometric and biochemical variables. Conclusions: Helicobacter pylori infection was significantly higher in patients with benign thyroid nodules and PTC than in the control group. Also, the rate of infection was significantly higher in the malignant nodule group than in the benign thyroid nodules group.

Molecular Testing for Indeterminate Thyroid Nodules: Association of Negative Predictive Value With Nodule Size.

Molecular testing helps stratify risk of malignancy in indeterminate thyroid nodules, but it may be limited in its ability to rule out malignancy in large nodules. We compared small thyroid nodules (<4cm) to large thyroid nodules (4cm or greater) in a retrospective, single center, cohort study of indeterminate thyroid nodules analyzed with ThyroSeq from 10/2015 through 4/2020. Our primary outcome was negative predictive value. A total of 204 thyroid nodules were analyzed with ThyroSeq and 62 underwent resection allowing comparison to final pathology for 48 small nodules and 14 large nodules. A greater proportion of large nodules were observed in men (50.0% vs 18.8% in small nodules, P = .02), but median age was similar between the groups (49.0 vs 52.5years, P = .95). False negative results comprised a higher proportion of tests for large nodules (14.3%) than small nodules (0%, P = .01). The negative predictive value of ThyroSeq in small nodules was 1 indicating a negative test reliably predicted a benign nodule, compared to .5 in large nodules indicating a negative test in this cohort was reliable in predicting benignity. Applying the same negative predictive value to the cohort of large nodules that did not undergo resection after negative molecular testing (n = 16), it is possible that 8 large thyroid malignancies were missed at our institution during the study period. Large thyroid nodules are associated with a higher rate of false negative results and a lower negative predictive value during molecular analysis of indeterminate thyroid nodules.

Malignancy risk stratification of thyroid nodules smaller than 10 mm with ACR-TIRADS, K-TIRADS, and ATA-2015 guidelines: a prospective study

BackgroundSmall thyroid nodules (≤ 10 mm) are common findings in thyroid ultrasonography. The first purpose of this study was to compare the performance of three guidelines in the diagnosis of malignancy for small thyroid nodules. The second aim was to find the ultrasonographic characteristics potentially associated with the risk of malignancy. This prospective cross-sectional study was performed on the patients with a diagnosis of small thyroid nodules (≤ 10 mm), who were rereferred to the radiologists for sonography and FNA. Sonographic features were recorded and scored according to the American College of Radiology-Thyroid Imaging Reporting and Data System (ACR-TIRADS), American Thyroid Association (ATA-2015), and Korean-TIRADS (K-TIRADS). Finally, FNA was conducted and cytological findings were reported.ResultsIn total, 287 thyroid nodules from 256 subjects (64 men and 192 women) were finally included in the study. The accuracy of ACR-TIRADS categories TR5 and TR4/5 was 88.9% and 72.1%, respectively. This rate for ATA-2015 classes high suspicion and intermediate suspicion/high suspicion was 88.9% and 82.6%, respectively. For K-TIRADS classes 5 and 4/5, the diagnostic accuracy was 89.6% and 82.9%, respectively. Significant direct associations were found between malignancy and punctate echogenic foci (odds ratio [OR] = 6.46), hypoechogenicity (OR = 6.39), ill-defined margin (OR = 4.38), and irregular margin (OR = 7.33).ConclusionThe differences in the strength of the three guidelines in the prediction of the malignancy should be considered by clinicians and radiologists in the management of thyroid nodules smaller than 10 mm.

Incidentally discovered papillary thyroid microcarcinoma in patients undergoing thyroid surgery for benign disease.

The incidence of thyroid carcinoma has grown significantly over the last few decades. A possible explanation is the increased diagnosis of small thyroid microcarcinoma (TMc). TMc reach a maximum diameter of ≤1 cm, identified during histopathology examination following a thyroidectomy performed for reasons not pertaining to malignancy. This study aims to investigate the prevalence of papillary thyroid microcarcinoma (PTMc) according to the benign pathology that refers patients to surgery and its trend evolution. Retrospective cohort analysis of 1815 patients who underwent total thyroidectomy for non-malignant diseases in the 2005-2020 period. The mean age of the subjects was 53.5 years, with a higher proportion of women (1481, 82.1%). A total of 167 PTMc (9.3%) were incidentally discovered. A multivariate logistic regression analysis was performed, showing no differences in prevalence according to sex or age in patients with PTMc compared to final benign histology. Multinodular goiter increases the risk of PTMc with an odds ratio of 2.2 (p = 0.001) compared to Hashimoto's thyroiditis and Graves' disease (GD). There is a statistically significant increase in the incidence of PTMc in the group operated in the 2017-2020 vs. 2005-2008 period (p = 0.005). The overall prevalence of PTMc in patients who underwent thyroid surgery for the benign disease was 9.3%. Thyroid nodular hyperplasia was the most frequent benign pathology associated with PTMc compared to Hashimoto's or GD. Gender and age were not correlated with the prevalence of TMc. Over the years, surgical findings of PTMc have grown, particularly in the 2017-2020 period.

Lymphocytic Thyroiditis Transcriptomic Profiles Support the Role of Checkpoint Pathways and B Cells in Pathogenesis.

Background: Autoimmune thyroid diseases are the most common types of autoimmune diseases, but their physiopathology is still relatively unexplored. Genotype-tissue expression (GTEx) is a publicly available repository containing RNAseq data, including profiles from thyroid. Approximately 14.8% of these glands were affected by focal lymphocytic thyroiditis and 6.3% were annotated as Hashimoto. We interrogated these data to improve the characterization of infiltrating cells and to identify new molecular pathways active in autoimmune thyroiditis. Materials and Methods: Histological GTEx images of 336 thyroid samples were classified into three categories, that is, non-infiltrated thyroid, small focal infiltrated thyroid, and extensive lymphoid infiltrated thyroid. Differentially expressed genes among these categories were identified and subjected to in silico pathway enrichment analysis accordingly. CIBERSORTx deconvolution was used to characterize infiltrating cells. Results: As expected, most of the transcriptional changes were dependent on tissue infiltration. Upregulated genes in tissues include-in addition to lineage-specific B and T cell genes-a broad representation of inhibitory immune checkpoint receptors expressed by B and T lymphocytes. CIBERSORTx analysis identified 22 types of infiltrating cells showed that T cells predominate 3:1 over B cells in glands with small infiltrates, only by 1.7:1 in those with large infiltrates. Follicular helper and memory CD4 T cells were significantly more abundant in glands with large infiltrates (p < 0.0001), but the most prominent finding in these glands was an almost sixfold increase in the number of naive B cells (p < 0.0001). A predominance of M2 macrophages over M1 and M0 macrophages was observed in the three gland categories (p < 0.001). Conclusions: Analysis of transcriptomic RNA-seq profiles constitutes a rich source of information for the analysis of autoimmune tissues. High-resolution transcriptomic data analysis of thyroid glands indicates the following: (a) in all infiltrated glands, active autoimmune response coexists with suppressor counteracting mechanisms involving several inhibitory checkpoint receptor pairs, (b) glands with small infiltrates contain an unexpected relatively high proportion of B lymphocytes, and (c) in highly infiltrated glands, there is a distinct transcriptomic signature of active tertiary lymphoid organs. These results support the concept that the autoimmune response is amplified in the thyroid tissue.

Factors That Inform Individual Decision Making Between Active Surveillance, Hemithyroidectomy and Total Thyroidectomy for Low-Risk Thyroid Cancer: A Scoping Review.

Background: Due to the excellent prognosis and relatively high incidence of small low-risk thyroid cancers, more conservative management strategies such as active surveillance (AS) or hemithyroidectomy (HT) may be preferable to total thyroidectomy (TT) for patients seeking to balance long-term survival rates with the potential adverse effects of overtreatment. The aim of this review was to synthesize key factors or variables that inform patient decision making about treatment for low-risk thyroid cancer, from current primary investigations that presented participants with information facilitating this choice. Methods: Studies were identified from the Medline, Cochrane, and Embase databases up until March 2022. Study characteristics were extracted into a pre-piloted form. Factors were hypothesized to include treatment-related risks and possible outcomes and identified from a review of studies with consensus by discussion. Results: The search identified 444 unique studies: 397 were excluded on review of abstract and title with 47 studies undergoing a full text review and 6 studies identified to be eligible. Four were cross-sectional: one a prospective cohort study and one a mixed-methods study with both a prospective observational and qualitative component. The decisions addressed included: the choice between AS versus surgery (HT and/or TT) and HT versus TT and enrolled participants ranging from healthy volunteers to thyroid cancer patients. Treatment choice was the primary outcome in five studies. Across the studies, participants who were given the option of AS or surgery predominately chose the more conservative pathway, with a range of 70-84%. The major factors represented by information provision in the studies were risk of cancer recurrence or spread, need for hormone replacement therapy, and voice change. Conclusions: A framework of key factors informing patient treatment choice may be derived from current studies involving information provision for low-risk thyroid cancer management. Further research evaluating the efficacy and optimal timing for decision support interventions would help inform the design and clinical use of these tools to promote shared decision making.

Radiofrequency thermal ablation for a small papillary thyroid carcinoma: a case report

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Not All Patients with Small Papillary Thyroid Carcinomas Are Appropriate Candidates for Active Surveillance

Not All Patients with Small Papillary Thyroid Carcinomas Are Appropriate Candidates for Active Surveillance

Predictors of radiation-induced hypothyroidism in nasopharyngeal carcinoma survivors after intensity-modulated radiotherapy

BackgroundThe aim of the study is to identify clinical and dosimetric factors that could predict the risk of hypothyroidism in nasopharyngeal carcinoma (NPC) patients following intensity-modulated radiotherapy (IMRT).MethodsA total of 404 non-metastatic NPC patients were included in our study. All patients were treated with IMRT. The thyroid function were performed for all patients before and after radiation at regular intervals. The time onset for developing hypothyroidism was defined as the time interval between the completion of RT and the first recorded abnormal thyroid hormone test. The cumulative incidence rates of hypothyroidism were estimated using Kaplan–Meier method. Univariate and multivariate Cox regression analyses were performed to detect the most promising factors that were associated with hypothyroidism.ResultsMedian follow up was 60.6 months. The 3-, 5- and 7- year cumulative incidence rate of hypothyroidism was 39.4%, 49.1% and 54.7%, respectively. The median time to primary hypothyroidism and central hypothyroidism were 15.4 months (range 2.9–83.8 months) and 29.9 months (range 19.8–93.6 months), respectively. Univariate and multivariate analyses revealed that younger age, female gender and small thyroid volume were the most important factors in predicting the risk of hypothyroidism. Dtmean (mean dose of thyroid), V30-V50 (percentage of thyroid volume receiving a certain dose level) and VS45-VS60 (the absolute volumes of thyroid spared from various dose levels) remained statistically significant in multivariate analyses. Cutoff points of 45 Gy (Dtmean), 80% (Vt40) and 5 cm3 (VS45Gy) were identified to classify patients as high-risk or low-risk group.ConclusionThyroid Vt40 highly predicted the risk of hypothyroidism after IMRT for NPC patients. We recommended plan optimization objectives to reduce thyroid Vt40 to 80%.Trial registration: Retrospectively registered.

The Treatment of Thyroid Cancer With Radiofrequency Ablation

In the past decade, there has seen been a shift from treating all thyroid cancer surgically, to favoring less aggressive approaches for low-risk thyroid cancer. Surgery was historically the treatment of choice for most thyroid cancer. Active surveillance has emerged as an alternative for low-risk thyroid cancer in select patients. This approach has been accepted worldwide, and sound evidence supports its oncological safety in carefully selected patients. However, not all patients want to undergo lifelong monitoring, and some patients may wish to treat their cancer in a minimally invasive manner. Thermal ablation has developed as a minimally invasive alternative to surgery and active surveillance for well selected patients with thyroid malignancy. Herein, we review the role of thermally ablative techniques, specifically radiofrequency ablation, for the treatment of small primary thyroid cancers, recurrent thyroid cancer, and lymph node metastases.

Morphological, histological and ultra-structural studies on the ultimobranchial body of goat (Capra hircus).

Ultimobranchial body (UBB) remnant was considered as an enigma till the last few years, then it was recognized as a necessary organ where it is the origin of the parafollicular cells. The samples were fixed and processed for the histological and electron microscopic examination. Macroscopically, the UBB remnant appeared as a white mass at the end of the cranial one-third of the thyroid lobe. It was composed of solid cell nest, cluster of cells and small thyroid follicles. Transmission electron microscope showed some round cells containing euchromatic nuclei, numerous parafollicular cells with darkly stained granules and paler ones. It also showed some mast cells with heterochromatic nuclei and large darkly stained granules. The parafollicular cells were distributed throughout the thyroid gland but concentrated within the UBB remnant. To our knowledge, our findings represent very unique histological manifestations specially the ultra-structural ones which revealed an original finding about the new clear type of cells suggested to be a UBB remnant and ensure those of the light microscope.

Development of hypothyroidism over 13 years of follow-up of patients with hyperthyroidism after radioiodine therapy.

To analyze the incidence and associated factors of hypothyroidism after radioiodine treatment for hyperthyroidism during a 13-year follow-up period. This was a retrospective study of consecutive patients with hyperthyroidism who were treated using a single dose of radioactive iodine (RAI) with a calculated dose regimen from 07/2005 to 12/2012. Univariate and multivariate Cox regression models were used to examine the factors that are associated with the occurrence of hypothyroidism after RAI therapy. Kaplan-Meier analysis was used for confirming associations between these models. A total of 182 patients were included during a 7.5-year median follow-up (range: 6-13 years). They were 36.4±11.1 years. The mean radioactive iodine dosage was 308.2±104.3 (range: 129.5-740.0) MBq. The rates of euthyroidism, early hypothyroidism, improvement, and ineffective treatment at 6 months were 48.4%, 37.9%, 8.8%, and 4.9%, respectively. The cumulative incidence of hypothyroidism in all patients with hyperthyroidism was 45.6% at 1 year, 48.9% at 5 years, and 52.3% at 10 years. Thyroid weight >46g (HR=0.643, 95%CI: 0.422-0.981, P=0.040) and a course of disease of 0.5-3 years (HR=0.592, 95%CI: 0.358-0.981, P=0.042) were identified as independent factors associated with an increased risk of hypothyroidism after radioactive iodine therapy. Radioactive iodine treatment with a calculated dose has a high cure rate for hyperthyroidism and has a low annual increase of hypothyroidism. Hypothyroidism after radioactive iodine treatment is more likely to occur in patients with small thyroid and a short disease course.

Thyroidectomy for Papillary Thyroid Carcinoma.

Papillary thyroid carcinoma is the most common endocrine malignancy and accounts for the overwhelming majority of thyroid carcinoma. Thisrecent dramatic increase in incidence is almost exclusively attributed to the incidental detection of small papillary thyroid carcinoma or microcarcinoma. Surgical management of thyroid carcinoma has been evolving to avoid overtreating patients by adopting the appropriate risk-based approach including the recommendation of hemithyroidectomy for low-risk carcinoma, the avoidance of routine prophylactic central nodal dissections, a higher threshold in using postoperative radioiodine ablation after total thyroidectomy, and the active observation or surveillance of papillary microcarcinoma as a viable alternative option instead of immediate surgical treatment.

Are sputum autoantibodies more clinically relevant in idiopathic pulmonary fibrosis than serum autoantibodies?

Background:The adaptive immune system plays a role in the pathogenesis of idiopathic pulmonary fibrosis (IPF) has been reported previously. However, the association between airway and circulating autoantibodies (AAbs) levels is unclear. The aim of this study is to investigate the link between the AAb levels in airway and circulation in stable patients with IPF.Materials and Methods:From June 2016 to March 2017, 21 stable IPF patients and 22 healthy volunteers were recruited. We established Luminex interacting AAbs with bead-antigen complex to detect the immunoglobulin G antibodies levels of ten autoantigens which were matched serum (Se) and sputum (Sp) samples collected from recruited subjects, including Smith (Sm), Anti-ribosomal P antibody (P0), Sjögren syndrome type A antigen (SSA), La/Sjögren syndrome type B antigen (SSB), DNA topoisomerase (Scl-70), histidyl-tRNA synthetase (Jo-1), U1 small nuclear ribonucleoprotein (U1-SnRNP), thyroid peroxidase, Proteinase 3, and Myeloperoxidase. Spearman's rank correlation matrix was applied to explore the associations of Ab profiles between Se and Sp.Results:For IPF patients, Spearman's correlation matrix showed multiple intercorrelations among Sp-AAbs and Sp-AAbs (P < 0.05), while only the levels of AAb against Sm and anti-La in Se were correlated with those Sp-AAb counterparts (P < 0.05). For healthy individuals, only anti-La in Se was associated with those Sp-AAb counterparts (P < 0.05). For IPF patients, there was a positive correlation between carbon monoxide diffusing capacity (DLCO)% predicted and Sp-anti-P0 level (r = 0.464, P = 0.034). Forced vital capacity% predicted was positively correlated with Sp-anti-Scl-70 level (r = 0.466, P = 0.033).Conclusion:Comparing to Se-AAbs, Sp-AAbs are more associated with clinical parameters in the patients with IPF. In order to better understand the role of autoimmunity in the pathogenesis of IPF, detection of Sp-AAbs for local autoimmune responses may be a good choice.

Efficacy and Safety of Different Thermal Ablation Modalities for Papillary Thyroid Microcarcinoma: A Network Meta-Analysis.

Small thyroid-like carcinoma (PTMC) is one of the most common subtypes of thyroid cancer. The main treatment options include surgery and radiofrequency ablation (RFA), microwave ablation (MWA), and laser ablation (LA). Thermal ablation has the advantage of being less invasive and has fewer complications than traditional surgical treatment. The objective is to explore the efficacy and safety of PTMC by different thermal ablation modalities through a network meta-analysis. From the database establishment to October 2021, a computerized search of the Chinese Knowledge Infrastructure (CKNI), VIP Chinese Science and Technology Journal Full-Text Database (VP-CSJFD), WanFang Data journal article resource (WangFang), PubMed, the Cochrane Library, and Embase were performed to include the different methods of thermal ablation for small thyroid carcinoma. A retrospective study of different methods of thermal ablation of small thyroid carcinoma was included. A total of 12 retrospective studies involving 1,926 patients with PTMC were included, all of which were of high quality. This study mainly involved RFA, MWA, LA, and ethanol combined with radiofrequency ablation (EA + RFA). Network meta-analysis showed no significant difference between interventions (p > 0.05) in terms of recurrence rate. Surgical resection may be the measure with the lowest recurrence rate after treatment of PTMC, LA may be the measure with the lowest incidence of complications after treatment, and RFA may be the measure with the least length of hospital stay, operation time, and postoperative lymph node metastasis rate. However, due to the limitations of network meta-analysis, this result still needs to be treated with caution, and more high-quality, large-sample clinical studies are recommended for further verification.

Radiofrequency Ablation for Thyroid Nodules and Cancer in the United States: Balancing a Transformation of Thyroid Care With Risk for Misuse

Radiofrequency ablation (RFA), the most commonly used image-guided thermal ablation technique for thyroid nodules and cancers, has the potential to dramatically change the landscape of thyroid tumor management. Pioneered in Asia and Europe, RFA is now used in the United States to noninvasively decrease the size of a subgroup of benign solid thyroid nodules when there are compressive symptoms and/or cosmetic concerns and, less frequently, to treat small thyroid cancers and isolated lymph node metastases.

Invasion of a Recurrent Laryngeal Nerve from Small Well-Differentiated Papillary Thyroid Cancers: Patient Selection Implications for Active Surveillance.

Background: The success of an active surveillance management approach to low-risk papillary thyroid cancer (PTC) is heavily dependent on proper patient selection. For example, primary tumors located in a subcapsular position immediately adjacent to the trachea or a recurrent laryngeal nerve (RLN) are considered to be inappropriate for active surveillance. Since preoperative imaging cannot reliably rule out extrathyroidal extension or reveal the full course of the RLN relative to the thyroid gland, it is important for clinicians to understand subcapsular tumor locations and minimum tumor sizes that are most likely to be associated with gross invasion of the RLNs. Methods: We assessed the medical records of 123 patients treated at Memorial Sloan Kettering Cancer Center (MSK) between 1986 and 2015 who had a primary PTC tumor demonstrating gross extrathyroidal extension to either the right or left RLN. Thirty patients with a primary tumor ≤2 cm in diameter demonstrating extrathyroidal extension into an RLN were included in the analysis. Results: Gross invasion of an RLN by tumors ≤2 cm is a rare event that was seen in only 0.8% (35/4334) of patients with PTC who underwent initial thyroid surgery at MSK between 1986 and 2015. Gross RLN invasion was associated with subcapsular PTC tumors located in either the right paratracheal area (60%), left paratracheal area (36.7%), or right lateral posterior lobe area not adjacent to the trachea (3.3%). Only a quarter of the patients had imaging findings suggestive of extrathyroidal extension and only 30% had clinically apparent vocal paresis/paralysis on preoperative examination. Invasion of the RLN was not observed for primary tumors <0.9 cm in diameter, regardless of tumor location. Conclusions: Well-differentiated PTC tumors ≥0.9 cm in maximal diameter that are located in the right paratracheal, left paratracheal, and right lateral posterior lobe subcapsular positions are usually not appropriate for active surveillance even in the absence of definitive evidence for nerve invasion on preoperative imaging or vocal cord examination. Patient selection for active surveillance management should take into account not only the size and growth rate of a tumor but also its location in relation to the expected course of RLNs.

Good News for Active Surveillance: Recurrent Laryngeal Nerve Invasion by Small Papillary Thyroid Carcinomas Is Rare and May Only Occur in Subcapsular Tumors

Good News for Active Surveillance: Recurrent Laryngeal Nerve Invasion by Small Papillary Thyroid Carcinomas Is Rare and May Only Occur in Subcapsular Tumors

Protective Effect of Zinc Sulfate on Hypo-and Hyperthyroidism Induced in Adult Male Rabbits

The present study was conducted to investigate the effect of co-administration of zincsulfate with Carbimazole (CBZ) and, Levothyroxine (L-T4) on thyroid gland function inadult male rabbits. Fifty adult male rabbits, were divided randomly into five equal groups (6rabbits/group) as follows: The first group (control group): Rabbits were given oral doses ofdistilled water daily by gavage; second group (Hypothyroidism): Rabbits were given oraldoses of carbimazole (5 mg/kg. bw) daily by gavage; the third group; Rabbits were givenoral doses of carbimazole (5 mg/kg. bw) + zinc sulfate (20 mg/kg.bw); fourth group(Hyperthyroidism): Rabbits were given oral doses of L-T4 (100µg/kg.bw) daily by gavage;Fifth group: Rabbits were given oral doses of L-T4(100µg/kg.bw) + Zinc sulfate(20mg/kg.bw) daily by gavage. The treatment continued for 30 days. The results revealedthe following: A significant elevation in serum TSH level and a significant reduction inserum T4, T3 and, FT3 levels in CBZ treated rabbits group compared with the control group,while a significant reduction in serum TSH level and a significant elevation in serum levelsof T4, FT4 and FT3 in animals group treated with the L-T4 compared with the control groupHistopathological changes of hypothyroidism were observed in CBZ treated groupcharacterized by small thyroid follicles, increase the height of thyrocytes hyperplasia, andvacuolation of colloid. L-T4 and L-T4-Zinc treated groups showed large follicles distendedwith homogenous acidophilic colloid. No significant changes in thyroid architecture wereobserved in CBZ-Zinc treated group compared with the control group.