Follicular Colloid Research Articles

Diagnostic, Theranostic and Prognostic Value of Thyroglobulin in Thyroid Cancer.

Thyroglobulin (Tg) is an iodinated glycoprotein, which is normally stored in the follicular colloid of the thyroid, being a substrate for thyroid hormone production. Since it is produced by well-differentiated thyroid cells, it is considered a reliable tumor marker for patients with differentiated thyroid carcinoma (DTC) during their follow-up after total thyroidectomy and radioiodine ablation. It is used to monitor residual disease and to detect recurrent disease. After total thyroid ablation, unstimulated highly sensitive Tg measurements are sufficiently accurate to avoid exogenous or endogenous thyrotropin (TSH) stimulation and provide accurate diagnostic and prognostic information in the great majority of DTC patients. Adopting sophisticated statistical analysis, i.e., decision tree models, the use of Tg before radioiodine theranostic administration was demonstrated to be useful in refining conventional, pathology-based risk stratification and providing personalized adjuvant or therapeutic radioiodine administrations. The follow-up of DTC patients aims to promptly identify patients with residual or recurrent disease following primary treatment. Our review paper covers the diagnostic, theranostic and prognostic value of thyroglobulin in DTC patients.

Benin Goitre in the General Surgery Department at Teaching Hospital Gabriel Tour&#233

Introduction: Goitre is an increase in the volume of the thyroid gland. Goiters may be congenital or acquired, diffuse or nodular, functional or non-functional, benign or malignant. Purpose: The objectives of this work were to study and determine the frequency of benign goitre in the general surgery department of CHU Gabriel Touré, and to study epidemiological, clinical and therapeutic aspects. Patients and Method: This was a retrospective and prospective study conducted in the general surgery department of CHU Gabriel Touré, from January 1999 to December 2019. Included in the study were all patients with benign goiter confirmed in histology, hospitalized and treated in the service. Patients with thyroid malignant tumours, strumite, thyroid tract cyst, cervical abscess and neck trauma were not retained. Socio-demographic, clinical, para-clinical, therapeutic and post-operative aspects were the study parameters. Word processing and tables were done with Microsoft Word and Excel 2016 software. Data analysis was performed with Epi info7 software, the statistical test used was the Khi2 test and a value of P 0.05 was considered statistically significant. Results: A total of 253 patient files were collected. Thyroidectomy represented 5.02% (253/5036) of surgical procedures. The average age was 42.5 years with a standard deviation of 15.6 and extremes of 13.9 and 76 years. The sex ratio was 8.7 in favour of the female sex. Anterior cervical swelling was the most common reason for consultation with 90.0% (230/253). There were 118/253 cases of euthyroid goiter (46.6%), 132/253 cases of hyperthyroid goiter (52.2%) and 3/253 cases of Basedow’s disease (1.2%). Histology revealed (178/253) cases of micro and macro follicular colloid adenoma (70.3%), (27/253) cases of micro and macro follicular vesicular adenoma (10.7%) and (48/253) cases of micro and macro vesicular hyperplasia. The most performed surgical techniques were subtotal thyroidectomy with a rate of 138/253 (54.5%) isthmo-lobectomy with a rate of 102/253 (40.3%), lobectomy with a rate of 11/253 (4.3%) and isthmectomy 1/253 (0.4%). One-month follow-up was marked by 4 cases of surgical site infection (1.6%), 2 cases of transient hypocalcemia (0.8%). One-year follow-up was simple in 98.4% of cases, we noted 4 cases of keloid. The average length of hospitalization was 3.31 ± 0.1 days. Conclusion: Goiter surgery is relatively common in the general surgery department of CHU Gabriel Touré. Good preparation and better post-operative monitoring could help minimize post-operative complications.

Determination of Fifty Trace Element Contents in Macro and Micro Follicular Colloid Nodular Goiter

Determination of Fifty Trace Element Contents in Macro and Micro Follicular Colloid Nodular Goiter

The morphofunctional state of the fetal thyroid gland in maternal-fetal infections caused by Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae

Aim – experimental modelling and determination of the morphofunctional state of the thyroid gland of a rat fetus in maternal-fetal infections caused by E. coli, S. aureus and K. pneumoniae. Material and methods. We conducted a controlled experimental study with block randomization on 85 female Wistar Albino Glaxo rats, which, depending on the group assigned randomly, were infected or not with E. coli, S. aureus and K. pneumoniae before pregnancy with subsequent pathomorphological examination of 37 thyroid glands obtained from rats’ fetuses. The set of methods was applied: histological – HE and Mallory staining; indirect immunofluorescence: moAb to T4, types I and III collagen, IL-6, and TNF; histomorphometry using ImageJ software. Statistical analysis was performed with the R environment and packages “ggplot”, “dplyr”, “pastecs”, “graphics” for Shapiro–Wilk test, Bartlett’s test, Box-Cox method, ANOVA, and plotting. The null hypothesis was rejected in cases when an error probability (P) did not exceed the type I error set at 0.001 (P < 0.001). Results. In the thyroid glands of fetuses obtained from mothers infected with E. coli, S. aureus and K. pneumoniae, in comparison with the control group, a statistically significant increase in the following morphofunctional parameters was determined: the diameter and area of the follicle, the area of the colloid, the height and area of the thyrocyte, the intensity and area of the fluorescence of the follicular thyrocytes and colloid, in samples labeled MoAb to T4, the intensity of the fluorescence of collagen types I and III; a decrease in the area of the nucleus in relation to the area of the cytoplasm, which was reflected in a decrease in the NCR index. The most pronounced differences in morphological and functional parameters from the norm were found in the thyroid gland of fetuses from mothers infected with S. aureus. Conclusions. The revealed changes in the morphofunctional parameters of the thyroid gland of a rat fetus, which experienced the influence of maternal-fetal infections caused by E. coli, S. aureus and K. pneumoniae, are unidirectional and statistically significantly different from those recorded during physiological organogenesis. They correspond to an increase in the gland’s secretory activity and indicate the acceleration of organ’s maturation.

Effect of the Noninvasive Follicular Thyroid Neoplasm With Papillary-Like Nuclear Features (NIFTP) Nomenclature Revision on Indian Thyroid Fine-Needle Aspiration Practice.

To analyze risk of malignancy (ROM) in Bethesda categories (BCs) and the impact of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) reclassification on malignancy risk and surgical outcome. In this retrospective study based on fine-needle aspiration samples with histologic follow-up, ROM was analyzed in BCs. Possible cases of NIFTP were reviewed, followed by the analysis of impact of this reclassification on ROM in BCs. The incidence of NIFTP was 6.9% among excised thyroid nodules and 16.8% among all resected neoplastic lesions. ROM for BCs I to VI was 37.5%, 9.6%, 40.0%, 46.5%, 88.8%, and 96.8%, respectively. Risk of neoplasia was 50.0%, 13.8%, 55.0%, 71.2%, 88.8%, and 96.8% respectively. When NIFTPs were considered nonmalignant lesions, ROM decreased by 6.3%, 4.3%, 20%, 19.1%, 22.5%, and 1.5% in each Bethesda category (I-VI), respectively. Inability to diagnose NIFTP preoperatively led to overtreatment in 16.2%. Prevalence of NIFTP in Asian countries may be higher than expected. Substantial cases of NIFTP have a benign preoperative cytology; hence, cases of follicular adenoma and adenomatous colloid nodule should be included in the review. NIFTP reclassification has significantly reduced the ROM in indeterminate BCs, suggesting diagnostic lobectomy rather than total thyroidectomy. Countries should establish their own malignancy risk range and parameters.

Thyroid Function Changes in a Rat Model of Vitamin D Deficiency and Effect of Vitamin D and Metformin Treatment

Abstract Background: Previous studies showed controversies about the association of vitamin D deficiency and thyroid dysfunction and up to our knowledge there was no study that were con-ducted to study the effect of vitamin D deficiency on thyroid function. Metformin is an antidiabetic drug that is widely used and also there was contradictory data about its effect on thyroid function. Aim of Study: To identify whether vitamin D deficiency is considered a cause for hypothyroidism or not. Also, to investigate the effect of metformin treatment on thyroid function in a rat model of vitamin D deficiency. Material and Methods: 40 Adult male albino rats of local strains were divided randomly into 5 equal groups; control, control metformin treated (control + metformin), vitamin D deficient, vitamin D deficient metformin treated (vitamin D deficient + metformin) and vitamin D deficient vitamin D treated (vitamin D deficient + vitamin D). Results: Vitamin D deficiency model significantly in-creased final Body Mass Index (BMI), relative thyroid weight, serum Thyroid Stimulating Hormone (TSH), serum reverse triiodothyronine (rT3) and hepatic deiodinase 3 activity but significantly declined serum levels of each of triiodothyronine (T3), thyroxin (T4), 25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)2D) when compared to control group. Metformin treatment of vitamin D deficient rats significantly reduced relative thyroid weight with a significant decreased in TSH level when compared with vitamin D deficient group. A significant negative correlation was reported between serum 25(OH)D and each of final BMI, serum TSH, relative thyroid weight, hepatic deiodinase activity and serum rT3 but it was positively correlated to serum level of both T3 and T4. Histopathology and histomorphometric studies of the thyroid gland in vitamin D deficient rats showed a large number of follicles with increased dimensions, the follicular colloid showed no vacuolation, the amount of colloid increased and the follicles were found to be lined by simple cuboidal epithelial cells with basal nuclei. Conclusion: As vitamin D deficiency decreased thyroid function through affecting hepatic deiodinase 3 activity and this change was deteriorated with vitamin D supplementation, thus, monitoring of vitamin D levels and its supplementation may play a role in management of hypothyroidism. Also, metformin exerted an anti-proliferative activity, improved thyroid structure and lowered TSH without affecting serum levels of T4 or T3, thus it could provide a rationale for an innovative therapy of thyroid proliferative diseases.

A Rationale for Using Sonoelastography in Thyroid Nodular Pathology

Objective. To provide a rationale for using sonoelastography (SEG) in the differential diagnosis of thyroid cancer (TC).Material and methods. Thirty patients with thyroid nodules of various morphological structures were examined. The authors studied the data of SEG and immunohistochemistry (IHC) with monoclonal antibodies against types III and IV collagen (they evaluated the degree of the expressed collagen fibers). Analysis of variance, ROC analysis, and logistic regression were used (by comparing with the expression of collagens) to assess the predictive ability of ultrasound.Results. The study showed that irregular and uneven contours, microcalcifications, and “the height greater than the width” were most significant among the ultrasound signs in the diagnosis of TC. Cool colors prevailed when performing SEG in the pattern of thyroid cancer. Purple-blue hues were predominantly recorded (p<0.05 with regard to benign nodules), green ones were less frequently. ROC analysis of compression elastography showed that the area under the curve was 0.785 (95% CI 0.740-0.826), sensitivity 78.1%, specificity 79.0%. Comparison of the data of IHC and SEG revealed a direct correlation of tissue elasticity with the degree of a stromal component and with the presence of collagen-containing structures.Conclusion. SEG may suppose the probable nature of thyroid nodules on the basis of their morphological features. The low degree of the stromal component and the low content of types III and IV collagen make follicular colloid goiter and adenoma soft, which is recorded at SEG. TC is characterized by a high collagen level attributable to the characteristics of the metabolism of cancer cells, which makes them solid in the mode of SEG.

MORPHOLOGICAL CHARACTERISTICS OF TISSUE MICROREGION OF THE THYROID GLAND AT EXPERIMENTAL HYPOTHYROIDISM

Research purpose was to study the structures of the tissue microregion of the thyroid gland at an experimental hypothyroidism. Material and methods . The hypothyroidism model was created by mercazolilum intake at a dose of 5 mg/100 g of body mass for a month. The structure of tissue area (follicle, thyrocyte, interfollicular space) with morphometry and calculation of the integral indicators of the thyroid gland functional activity have been investigated by the light-optical and ultrastructural methods. Results and discussion . The morphophysiological structure of the thyroid gland is a tissue microregion. It unites a group of follicles and interfollicular space. The structure of the tissue miroregion have features of structural response to merkazolilum intake. The thyrostatic remedy changes the follicular organization of the thyroid gland to the predominance of small and medium follicles with signs of alteration. Thyrocytes have expansion and deformation of the granular endoplasmic reticulum cisterns, formation of intracellular colloid, reduction in the number of lysosomes and mitochondrions with their disorganization. The ratio of the area of the follicular epithelium, colloid and stroma changes at hypothyroidism. The portion of interstitial increases, there is an accumulation of tissue fluid because of weakening of a lymphatic drainage. Blood and lymphatic microvessels react by reducing the volume density to mercazolilum intake. Conclusion . The merkazolilum thyreostatics effects on morphology and metabolic and transport processes in tissue microregion. It testifies to decrease of thyroid function and the creation of hypothyroidism adequate model.

MOK, a pharmacopuncture medicine, regulates thyroid dysfunction in L-thyroxin-induced hyperthyroidism in rats through the regulation of oxidation and the TRPV1 ion channel

BackgroundIn this study, we evaluated the therapeutic effect of MOK, a pharmacopuncture medicine, on thyroid dysfunction in L-thyroxin (LT4)-induced hyperthyroidism rats.MethodsThe experimental hyperthyroidism model was prepared by the intraperitoneal injection of LT4 (0.5 mg/kg) once daily for 2 weeks in SD rats. MOK extract was injected at doses of 0.3 or 3 mg/kg on acupuncture points in the thyroid glands of LT4-induced hypothyroidism rats once a day for 2 weeks. The body temperature, body weight, and food/water intake were measured once a week for 2 weeks. The levels of thyroid hormones, total cholesterol, LDL-cholesterol, GOT, and GPT were measured in the sera of rats using ELISA and an automatic blood analyzer. The histological changes of thyroid tissues were observed by H&E staining. The expression of thermo-regulating protein, TRPV1 was determined by western blot in dorsal root ganglion (DRG) and brain tissues. We also measured the contents of GSH in the liver and antioxidant enzymes, SOD, and catalase in the liver, heart, and brain tissues by enzyme-based assay and Western blot, respectively.ResultsThe acupuncture of MOK extract on the thyroid gland of LT4-induced hyperthyroidism rats significantly decreased the body temperature, and did not change body weight and food and water intakes. MOK acupuncture significantly increased the level of TSH, and decreased the levels of T3 and T4 in hyperthyroidism rats. The expression of TRPV1 was inhibited in both DRG and brain tissues after MOK acupuncture, and the levels of GOT, GPT, total cholesterol, and LDL-cholesterol were also decreased. MOK acupuncture also inhibited the pathological feature with follicular lining epithelial thicknesses and increased follicular colloid depositions in the thyroid glands of hypothyroidism. MOK acupuncture significantly increased hepatic GSH levels and decreased the expression of SOD and catalase in the liver, heart, and brain tissues of hyperthyroidism rats.ConclusionsThese results suggest that the pharmacopuncture with MOK extract in hyperthyroidism can improve the pathophysiological changes through regulating the body temperature, thyroid hormones imbalance, lipid accumulation, and oxidation. This anti-hyperthyroidism effect of MOK pharmacopuncture is thought to be related to the control of thermo-regulating protein TRPV1 in DRG and brain.

Follicular thyroglobulin induces cathepsin H expression and activity in thyrocytes

Thyroglobulin (Tg) stored in thyroid follicles exerts a potent negative-feedback effect on each step of pre-hormone biosynthesis, including Tg gene transcription and iodine uptake and organification, by suppressing the expression of specific transcription factors that regulate these steps. Pre-hormones are stored in the follicular colloid before being reabsorbed. Following lysosomal proteolysis of its precursor, thyroid hormone (TH) is released from thyroid follicles. Although the suppressive effects of follicular Tg on each step of pre-hormone biosynthesis have been extensively characterized, whether follicular Tg accumulation also affects hormone reabsorption, proteolysis, and secretion is unclear. In this study we explored whether follicular Tg can regulate the expression and function of the lysosomal endopeptidases cathepsins. We found that in the rat thyroid cell line FRTL-5 follicular Tg induced cathepsin H mRNA and protein expression, as well as cathepsin H enzyme activity. Double immunofluorescence staining showed that Tg endocytosis promoted cathepsin H translocalization into lysosomes where it co-localized with internalized Tg. These results suggest that cathepsin H is an active participant in lysosome-mediated pre-hormone degradation, and that follicular Tg stimulates mobilization of pre-hormones by activating cathepsin H-associated proteolysis pathways.

Fine needle aspiration cytology of thyroid lesions with histopathological correlation

Introduction: FNAC of thyroid lesions is a simple, rapid, patient friendly and inexpensive procedure, which can be repeated in cases of inadequate samples. It has the best predictive value of all currently available diagnostic procedures. Along with FNAC, other diagnostic modalities such as thyroid scanning, ultrasonography, thyroid hormone and antibody level measurements enhance the diagnostic accuracy of the technique.Material and Methods: The present study was a prospective and interventional type of study done from January 2013 to December 2013. The study was undertaken in 50 patients to evaluate the cytology of the palpable thyroid lesions and compared them with histopathology to determine its diagnostic accuracy at Department of Pathology, Dhiraj general hospital, Piparia.Result: Among the non-neoplastic lesions, benign follicular lesion (51.16%) and colloid and nodular goitre was commonly encountered (41.86%). Hashimotos thyroiditis was diagnosed in 3 cases (6.98%). Among the neoplastic lesions (14%), papillary carcinoma was the commonly encountered lesion (56.14%). Histopathological examination was confirmatory in all cases.Conclusion: The diagnostic accuracy of FNAC on palpable thyroid lesions with histopathologic correlation is 100%.

Inhaling Benzene, Toluene, Nitrogen Dioxide, and Sulfur Dioxide, Disrupts Thyroid Function in Captive American Kestrels (Falco sparverius).

Research investigating the effects of air contaminants on biota has been limited to date. Captive adult female American kestrels (Falco sparverius) were exposed to a mixture of benzene (0.6 ppm), toluene (1 ppm), nitrogen dioxide (NO2; 2 ppm) and sulfur dioxide (SO2; 5.6 ppm), in a whole-body inhalation chamber. Thyroid axis responses to meet metabolic demands were examined through thyroid histology, plasma thyroxine (T4), and triiodothyronine (T3), and hepatic outer ring deiodination (T4-ORD). Plasma free (F) T3 and T4 were measured at baseline, and at 9 days and 18 days of exposure, whereas total (T) T3 and TT4, thyroid histology and hepatic T4-ORD were determined at the final 18 day exposure. Inhalation of these contaminants significantly suppressed plasma FT4 and TT4, and depleted follicular colloid and increased epithelial cell height at 18 days, and significantly altered the temporal pattern of plasma FT4. Significant histological changes in the follicular colloid:epithelial cell height ratio indicated sustained T4 production and release by the thyroid glands. There was no effect on plasma FT3, TT3, or hepatic T4-ORD. We hypothesize that contaminant-related activation of the hypothalamus-pituitary-thyroid axis in the kestrels increased elimination of plasma T4 through Phase II enzymes. Further research is required to test this hypothesis in wild birds.

Histological study of the thyroid tissue in carp fish (Cyprinus Carpio) in Summer and Winter

This study is designed to investigate the effect of temperature on thyroid gland of 24 adult healthy female carp fish (12/ season). Neutral buffered formalin solution10% was used for fixation and routine histological techniques. Hemotoxline and Eosine and PAS stains were, also used. The results revealed that the thyroid tissue in carp fish was closely associated with the renal and sub pharyngeal tissue. Spleen and liver did not show any thyroid follicles. The thyroid tissue of carp fish consisted of disseminate thyroid follicles not surrounded by apparent capsule. Different sizes and shapes of thyroid follicles were observed. The follicular cells form tight epithelium. Para follicular cells were distributed among the follicles. The seasonal thyroid follicles were often filled with colloid summer and winter. In conclusion the study was classified glands units of the thyroid tissue into two states: The first stat of the low activity in winter its cells were epithelial flat to squamous and follicles almost filled with homogeneous, while the state of activity in the Summer, follicular homogenous colloid cells were cuboidal follicular and sessile to high contain homogeneous diluted colloid.

자음강화탕(滋陰降火湯)이 Propylthiouracil(PTU)로 유발된 Rat의 갑상선기능저하증에 미치는 영향

Objectives: This study was to evaluate the effect of Jaeumkanghwa-tang (JEKHT) on the propylthiouracil (PTU)-induced rat hypothyroidism. Methods: Six groups, each of 8 rats per group were used in the present study - intact vehicle control, PTU control, Levothyroxine (<TEX>$LT_4$</TEX>), JEKHT 500, 250 and 125 mg/kg treated groups. JEKHT were administered once a day for 42 days as an oral dose of 500, 250 and 125 mg/kg, and hypothyroidism was induced by daily subcutaneous treatment of PTU 10 mg/kg for 28 days. The changes on the body and organ weight, serum hormone and lipid profiles, liver and testis antioxidant defense factors were observed with histopathology of organs. Results were compared with <TEX>$LT_4$</TEX> 0.5 mg/kg intraperitoneally treated rats in this experiment. Results: PTU treatment, marked decrease of body weight, increases of thyroid weight, decreases of liver, testis, epididymis and prostate weights, decreases of serum Tri-iodothyronine (<TEX>$T_3$</TEX>), and Thyroxine (<TEX>$T_4$</TEX>) level with increase of serum Thyroid-stimulating hormone (TSH) level, decreases of serum testosterone and dihydrotestosterone (DHT) level with increases of serum Follicular stimulating hormone (FSH) level, increases of serum High density lipoprotein (HDL), decrease of triglyceride content, increase of serum Aspartate aminotransferase (AST) level, decreases of liver and testis antioxidant defense factors were observed. In addition, marked hyperplasia of follicular cells with decreases of follicular colloid contents and diameters was additionally demonstrated with the decrease of hepatocyte numbers per unit area due to hypertrophy of hepatocytes related to lipid droplet depositions, increase of a/oligospermatic epididymal tubules with epididymal atrophic changes, seminiferous tubular atrophy with decrease of stage I~II seminiferous tubules in testis, prostate tubular atrophic changes at histopathological inspections. However, these PTU induced hypothyroidism and related hepatic and male reproductive organ damages were favorably and dose-dependently inhibited by treatment of JEKHT 500, 250 and 125 mg/kg, and JEKHT also effectively regulated the PTU-induced abnormal antioxidant defense factor changes in the both liver and testis. Conclusions: JEKHT 500, 250 and 125 mg/kg dose-dependently inhibited PTU-induced hypothyroidism and related liver and male reproductive organ damages in rats.

Immunohistochemical and morphometric study of pituitary pars distalis folliculostellate cells of nonpregnant and pregnant viscachas

Pituitary folliculostellate cells (FSC) have several functions. Morphological, immunohistochemical and physiological characteristics of these cells have been reported for many mammalian species. There is little information, however, about the effect of pregnancy on FSC, particularly in wild animals. We conducted an immunohistochemical and morphometric study of the effect of pregnancy on FSC in viscacha, a seasonal breeder with a long gestation period. Immunohistochemistry and image analysis were used to measure the percentages of S-100-positive total, cellular, and colloidal areas and the number of FSC. In all groups studied, FSC were either isolated or arranged in small groups. These cells exhibited irregular nuclei, stellate shape, and cytoplasmic processes that delimited the follicles or contacted blood vessels. They expressed S-100 protein, which was localized both intracellularly (FSC) and extracellularly (follicular colloid). Some FSC were immunostained by anti-GFAP or anti-vimentin in the cytoplasm surrounding the nucleus and in the cytoplasmic processes, respectively. Morphometric parameters showed variation between nonpregnant and pregnant females. These variations were greatest during mid-pregnancy. We demonstrated that distribution of the FSC in pituitary pars distalis and expression of S-100 protein differ in nonpregnant and pregnant viscachas. Our findings suggest that FSC are involved in intrapituitary regulation of the hormone-secreting cells during pregnancy, probably by a paracrine mechanism.

Effect of iodine deficiency in pregnant rats on doublecortin and synaptophysin (p38) expressions of fetal brain

Objective To investigate the effects of maternal thyroid dysfunction during pregnancy caused by iodine deficiency of different degrees on doublecortin ( DCX ) and synaptophysin ( p38 ) expressions in fetal brain.Methods Wistar female rats were randomly divided into four groups:adequate iodine ( AI),mild iodine deficiency ( MiID ),moderate iodine deficiency ( MoID ),and severe iodine deficiency ( SID ),according to the total daily iodine supply( fed on an iodine deficient diet with different dosages of KI added in drinking water).Three months later the rats were mated.Serum TSH and thyroid hormones were determined in maternal rats on gestational day 20 using chemiluminescent immunoassay.The iodine contents in urine and histological changes of thyroid gland were observed in pregnant rats.The mRNA and protein levels of DCX and synaptophysin ( p38 ) were analyzed in fetal brain by using real time quantitative RT-PCR and western blotting respectively.Results ( 1 ) Iodine contents in urine of pregnant rats were reduced with the decrease of their iodine supply.Compared with group AI,serum TSH was significantly increased [ ( 2.95 ± 1.70 vs 1.31 ± 0.55 ) mU/L,P ＜ 0.05 ],and both TT4 and FT4 were significantly decreased [ ( 14.3±4.1 vs 28.4±19.3 ) nmol/L,P＜0.05 ] and [ ( 10.8±3.6 vs 20.2±8.0) pmol/L,P＜0.01 ] in pregnant rats of SID group.Whereas,a slight rise in TSH,and a mild decline in both TT4and FT4 were found in MoID and MiID groups.However,there were no significant changes in TT3 and FT3 levels among these four groups.( 2 )Histological characteristics of thyroid gland in pregnant rats showed a typical goiter with small follicular hyperplasia and lack of colloid in SID group,moderate follicular hyperplasia with decreased colloid in MoID group; but mild cellular hyperplasia without decrease in follicular size and colloid in MiID group.( 3 ) The mRNA levels of DCX were increased in fetal brains of three iodine deficiency groups compared with AI group,but a statistical significance was found in MoID group.The protein levels of DCX in all experiment groups were significantly increased.Both mRNA and protein expressions of synaptophysin ( p38 ) were significantly down-regulated in three iodine deficiency groups.Conclusions Maternal thyroid dysfunction caused by iodine deficiency,even by mild or moderate iodine deficiency,may lead to retardation of fetal neuronal and synaptic growth. Key words: Iodine deficiency; Pregnancy; Thyroid function; Doublecortin; Synaptophysin

Effect of the photoperiod and administration of melatonin on folliculostellate cells of the pituitary pars distalis of adult male viscacha ( Lagostomus maximus maximus)

Numerous reports have shown the effect of photoperiod and melatonin administration on the different hormone secreting cell types in the pituitary pars distalis. The viscacha ( Lagostomus maximus maximus) is a rodent with photoperiod-dependent seasonal reproduction. The aim of this study was to examine the effect of photoperiod seasonal variations and melatonin administration on the folliculostellate cells in pituitary pars distalis of viscacha. Immunohistochemistry and image analysis were used to measure the percentage of S-100-positive area (total, cellular and colloidal) and the number of folliculostellate cells. The S-100 protein was immunolocalized at intracellular (folliculostellate cells) and extracellular (follicular colloid) levels. The morphometric parameters analyzed exhibited seasonal variations with highest values in the summer (long photoperiod) and lowest values in the winter (short photoperiod). The administration of melatonin caused a significant decrease of immunostaining. Results suggest that the natural photoperiod might be the most important environmental signal causing the decrease in folliculostellate cells immunostaining observed in the winter. These findings agree with seasonal changes previously reported in endocrine cells and suggest that folliculostellate cells may be involved in the paracrine regulation of the secretory activity of pituitary pars distalis through S-100 protein production.

Effects of Ginseng Radix on the Rat Hypothyroidism Induced by PTU (6-n-propyl-2-thiouracil)

Object : This study was to evaluate the effect of Ginseng Radix, aqueous extracts of the root part of Panax ginseng on the 6-n-propyl-2-thiouracil(PTU)-induced rat hypothyroidism. Methods : Aqueous extracts of Ginseng Radix(GR; yield = 11.70%) were administered, once day for 42 days from 2 weeks before start of PTU treatment as an oral dose of 300 and 150 mg/kg(body weight), and hypothyroidism was induced by daily subcutaneous treatment of PTU 10mg/kg for 28 days. The changes in the body weight, thyroid gland weights, serum levels of thyroid hormone-thyroid stimulating hormone(TSH), tri-iodothyronine(T3) and thyroxine(T4), total cholesterol, low density lipoprotein(LDL), high density lipoprotein(HDL) and triglyceride, liver antioxidant defense system-lipid peroxidation, , superoxide dismutase(SOD) and catalase(CAT) were observed with histopathology of thyroid glands. Results : Results were compared with LevoT4 0.5mg/kg treated rats. GR extracts suppressed the decreases in the body weight, thyroid gland weights, T3 and T4, TG, liver and SOD activities as results of PTU treatment. And GR extracts suppressed the increases of HDL contents, liver CAT activities, thyroid gland weight as results of PTU treatment. In addition, marked hyperplasia of follicular cells with decreases of follicular colloid contentsand sizes were demonstrated at histopathological inspections. However, these PTU-induced histopathological changes related to hypothyroidism were dramatically decreased by treatment of both different dosages of GR extract, respectively Conclusions : This study suggest that GR extracts have favorable effects on the thyroid hormone productions with beneficial effects on the hypothyroidism mediated by the modulatory effects on the antioxidant defense system.

Fetal and maternal lesions of cyanide dosing to pregnant goats

The present work evaluated the pathological effects in both dams and their fetuses of cyanide ingestion during pregnancy using goat as animal model. From the Day 24 of pregnancy, three pregnant goats were dosed by gavage with 3.0 mg KCN/kg bw/day, and two others received only tap water. All dams were euthanized and necropsied at Day 120 of pregnancy. The fetuses were examined carefully for gross abnormalities. Determinations of cyanide and thiocyanate were performed in maternal and fetal blood and in amniotic fluid. Samples of several organs were collected for histopathologic evaluation. No clinical changes were seen in any animal throughout the pregnancy. No malformations or dead fetuses were observed; however, placenta from one treated goat presented increased cotyledon surface area occupied by vascular lumina. Histological lesions in KCN-treated dams consisted of vacuolation of hepatocytes and thyroid follicular cells, increased number of vacuoles on thyroid follicular colloid, and spongiosis of cerebral, internal capsule, and cerebellar peduncles tracts. Fetuses from these mothers showed vacuolation of hepatocytes and thyroid follicular cells, and spheroids in the cerebellar white matter. Levels of cyanide and thiocyanate were higher in maternal than fetal blood, which suggests that these substances were largely but not freely transferred from mothers to fetuses.

Depletion and reaccumulation of follicular thyroglobulin (TG) in guinea-pig thyroid gland after short- and long-term administration of thyrotropin (TSH).

The relationships among the content and composition of soluble iodoproteins in thyroid gland, the serum Tg concentration and the morphological structure of gland were investigated in guinea-pigs during short-term and long-term TSH administration (2 I.U. per day for 1 to 28 days). A significant decrease in the content of Tg in the gland (from 6.50 mg to 1.32 mg/100 mg tissue), disappearance of 12 S iodoprotein, hypertrophy and hyperplasia of the follicular cells were observed in guinea-pigs treated with TSH up to 7 days. Later on, after depletion of follicular colloid, reaccumulation of colloid in the preexisting and newformed follicles (a marked increase of Tg and 12 S protein) and partial involution of the structural changes occurred. The serum Tg concentration increased during the whole period of TSH treatment (mean values from 100 to 500 micrograms/l). A marked positive correlation between serum Tg concentration and thyroid weight was found. Serum T3 and T4 concentrations increased transiently with maximal values on the 1st day (T3, from 0.86 to 3.26 nmol/l, T4, from 44 to 138 nmol/l) and decreased thereafter. The results imply that different regulatory mechanisms exist which control thyroid hormone secretion and transfer of Tg from the gland into blood circulation. The serum Tg level is directly dependent on the total bulk of thyroid tissue, but is considerably less dependent on the structure of the gland. The reaccumulation of colloid (Tg) in thyroid follicles of guinea-pigs treated with TSH is a result of the reduction of the stimulatory effect of TSH on the process of Tg degradation during chronic hormone application. Several different factors may be responsible for the appearance of refractoriness or desensitization of the thyroid to prolonged exogenous TSH stimulation.