Delayed Postnatal Growth and Anterior Pituitary Development in Growth-Retarded (grt) Female Mice.

Growth-retarded (grt) mice display primary congenital hypothyroidism due to the hyporesponsiveness of their thyroid glands to thyroid-stimulating hormone (TSH). We examined somatic growth, anterior pituitary development, and hormonal profiles in female grt mice and normal ones. Although growth in grt females was suppressed 2 weeks after birth, the measured growth parameters and organ weights gradually increased and finally reached close to the normal levels. Grt mice exhibited delayed eye and vaginal openings and remained in a state of persistent diestrus thereafter, plasma estrogen levels being lower than those in normal mice. Grt mice that received normal-donor thyroids showed accelerated growth and their body weights increased up to the sham-normal levels, indicating the importance of early thyroid hormone supplementation. In the anterior pituitary, there were fewer growth hormone (GH) and prolactin (PRL) cells in grt mice than in normal mice as examined at 12 weeks after birth, but the numbers of these cells did not differ from those in normal mice after 24 weeks. Grt mice had more TSH cells than normal mice until 48 weeks. Plasma GH levels in grt mice were lower than those in normal mice at 2 weeks, but did not differ substantially after 5 weeks. Compared with normal mice, grt mice had significantly lower plasma PRL and thyroxine levels, but notably higher TSH levels until 48 weeks. These findings indicate that thyroid hormone deficiency in grt mice causes delayed development and growth, and inappropriate development of GH, PRL and TSH cells, followed by the abnormal secretion of hormones by these pituitary cells.

Free thyroid transfer to anterolateral thigh for prevention of radiation induced hypothyroidism: An initial experience.

AIM: Radiation induced hypothyroidism (RIHT) is one of the commonest late side effects of radiation therapy and is seen in more than half of patients and affects quality of life significantly. We report our initial experience on feasibility of free microvascular transfer of thyroid gland out of radiation field to prevent development of RIHT. MATERIAL AND METHODS: A prospective pilot study was undertaken during August 2017 to May 2018. Six Patients with stage III/IV patients of oral cavity cancers who required wide excision/composite resections with microvascular free flap (ALT) reconstruction and adjuvant radiation therapy were enrolled. A written informed consent was obtained from all patients prior to the procedure. RESULTS: The mean age of cohort was 51 years with tongue most common site of primary cancer. The free transfer of thyroid gland to anterolateral thigh was done using microvascular technique. The mean additional time for procedure was 51 min. All patients had successful transfer with no associated immediate complications. Patients were followed up with Tc99 scan, USG Doppler and biochemical assay at routine intervals in peri and postoperative period to assess the anatomical and physiological function of the transferred gland. At median follow up of 8 months, 5 patients were euthyroid and remaining one had biochemical hypothyroidism. All patients had functional thyroid gland in anetrolateral thigh. Five patient were alive, one patient died due to disease. CONCLUSION: This is a small and early feasibility study for free thyroid gland transfer and validates the previously published data. The selected group of patients who have high chances of developing RIHT may benefit from this strategy. Further validation of the technique may be explored in a larger cohort.

Generation of functional thyroid from embryonic stem cells.

The primary function of the thyroid gland is to metabolize iodide by synthesizing thyroid hormones, which are critical regulators of growth, development and metabolism in almost all tissues. So far, research on thyroid morphogenesis has been missing an efficient stem-cell model system that allows for the in vitro recapitulation of the molecular and morphogenic events regulating thyroid follicular-cell differentiation and subsequent assembly into functional thyroid follicles. Here we report that a transient overexpression of the transcription factors NKX2-1 and PAX8 is sufficient to direct mouse embryonic stem-cell differentiation into thyroid follicular cells that organize into three-dimensional follicular structures when treated with thyrotropin. These in vitro-derived follicles showed appreciable iodide organification activity. Importantly, when grafted in vivo into athyroid mice, these follicles rescued thyroid hormone plasma levels and promoted subsequent symptomatic recovery. Thus, mouse embryonic stem cells can be induced to differentiate into thyroid follicular cells in vitro and generate functional thyroid tissue.

[Long-term oucomes of tracheal transplantation: success and unsolved problems]. / Otdalennyi rezul'tat transplantatsii trakhei: uspekh i nereshennye problemy.

AIM: To analyze long-term outcomes of tracheal transplantation. MATERIAL AND METHODS: There were 1128 patients with cicatricial tracheal stenosis who have been operated at the Petrovsky Russian Research Center for Surgery and the Sechenov First Moscow State Medical University for the period 1963-2015. RESULTS: Operations have become safer. Postoperative morbidity and mortality reduced from 41.4% (1963-1980) to 5.6% (2001-2015) and from 21.9% (1963-1980) to 0.5% (2001-2015), respectively. Tracheal transplantation was performed in 2 cases and fundamentally different tracheal structures were applied. Donor thyreotracheal complex with restored blood supply through thyroid vessels was used in the first case (2006). Perennial experimental trials preceded clinical application of this technique. In the second case (2010) we applied scientific results of foreign colleagues (cellular technologies and methods of regenerative medicine to create artificial trachea). Patients are still alive after 12 and 8 years, respectively. Restoration of blood supply of donor trachea is possible through thyroid collaterals. This technique is successful in long-term period. Tissue-engineered trachea cannot be considered true trachea due to no all tracheal components. However, such trachea provides air-conducting, evacuation and protective functions. Tracheomalacia requires further researches as one of the main problems of tracheal transplantation.

First Complex Allotransplantation of Neck Organs: Larynx, Trachea, Pharynx, Esophagus, Thyroid, Parathyroid Glands, and Anterior Cervical Wall: A Case Report.

OBJECTIVE: Evaluate the possibility of performing a complex vascular allotransplant of all neck organs including skin. SUMMARY BACKGROUND DATA: There are 2 previous attempts described in the literature, none of them being that complex. The first one is nonfunctional due to chronic rejection, the second one is viable yet considerably limited in complexity (no parathyroids, no skin). METHODS: The allotransplantation was performed simultaneously on 2 adjacent operating rooms, using microsurgical techniques. RESULTS: The patient's voice, breathing through mouth, swallowing, and endocrinal functions have been fully restored. CONCLUSIONS: Achieved results show clearly that such operations performed in selected patients can nearly fully restore functional and aesthetic effects in 1 single procedure.

[Proteasomes on thyroid tissue allotransplantation under induction of donor specific tolerance in rats].

The proteasomes in the liver of August rats (RT1C) were investigated 30 days after the allotransplantation of Wistar rat (RT1u) thyroid tissue under renal capsule with/without induction of donor specific tolerance by donor splenocyte intraportal administration. The level of the total proteasome pool, immune proteasomes containing the LMP2 and/or LMP7 subunits, proteasome 19S- and 11S-regulators was defined. The intact and sham-operated August rats were used as control groups. The level of all immune proteasome forms and 11S regulator increased while the level of the total proteasome pool and 19S regulator decreased in the liver of experimental animals compared to the control groups that indicated changes of liver functional state after transplantation. The 19S/11S ratio increased in the liver of non-tolerated rats compared to tolerated animals. In the liver of tolerated rats with survived transplants, the quantity of mononuclear cells, expressing the immune subunit LMP2, greatly increased in comparison with control and non-tolerated animals. Study of the survived transplants showed the increase of the ratio of LMP2/LMP7 immune subunits and 19S/11S regulators in them compared to the tissue replacing the rejected transplants. In the control intact thyroid tissue, the immune proteasomes were almost not revealed, while 19S/11S ratio was maximal. Thus, the development of the immune reaction or its suppression is accompanied by change of the balance between different proteasome forms. The immune subunit LMP7 and 11S regulator are connected with the response against donor tissue. On the contrary, the immune subunit LMP2 and 19S regulator are likely to be important for the immune tolerance development and survived tissue functioning. The low content of the immune proteasomes in the follicle cells was found by immunofluorescence assay. The formation of antigens for major histocompatibility complex class I molecules was impaired by low immune proteasome content that led to immunological tolerance to hormone-producing follicle cells.

[The transplantation of revascularized thyroid-trachea-lung complex: the experimental study].

The osteoplastic tracheobronchopathy affects the trachea, main, lobar and smaller bronchi, causing their stenosis. Nowadays the mainstay of the treatment of such patients is the cryodestruction, laser destruction and the endoscopic buginage of the trachea and bronchi. The palliative nature and low efficacy of these procedures forces to search new ways of treatment. The traditional lung transplantation or separate trachea and lung transplantation is inappropriate because of the complex affection of both trachea and bronchi. The experimental study aimed the possibility of thyreotracheolung revascularized donor complex transplantation.

Subcutaneous transplantation of human thyroid tissue into a pre-vascularized Cell Pouch™ device in a Mus musculus model: Evidence of viability and function for thyroid transplantation.

This study aimed to investigate the survival and efficacy indicators of human thyroid tissue transplantation into a retrievable, prevascularized implanted Sernova Corp Cell Pouch™ (CP) device. Thyroid tissue from human donors was transplanted subcutaneously into the pre-implanted CP device or into the subcutaneous (SC) space alone as a control in a nude Mus musculus model. Transplanted M. musculus were monitored for human serum thyroglobulin (TG) levels for 3 months until the transplants were removed for histological assessment. Human thyroid tissue survived and continued to produce TG in transplanted nude M. musculus in the CP, with no adverse events. CP transplants exhibited more persistent and robust production of human TG than tissue placed in the SC space alone from 3 to 13 weeks post transplantation. Fresh thyroid transplants had better survival and function compared to cryopreserved transplants. Thyroid transplant viability correlated with TG levels at 3 months post-transplant (p = 0.03). Immunofluorescence staining of transplants for TG and TPO localized in thyroid follicles. Human thyroid tissue transplanted into the subcutaneously implanted pre-vascularized CP in nude M. musculus survived and continued to produce robust and persistent human TG and warrants further investigation as a treatment for postoperative hypothyroidism.

Cryopreserved Rat Thyroid Autotransplantation in the Treatment of Postoperative Hypothyroidism.

To verify the viability and functionality of cryopreserved thyroid autotransplantation in rats who underwent total thyroidectomy in the treatment of postoperative hypothyroidism. Thirty-two Wistar rats were randomly assigned into groups (G) with eight animals each: control (CG); simulation (SG); hypothyroidism (HTG) and transplanted (TG). At the beginning and in the 13th week of the experiment, serum levels of total T3, free T4, TSH and calcium were determined. In both the first and 14th weeks, scintigraphic examinations, 99m-Tc pertechnetate radioisotope biodistribution and histopathology were performed. In the 14th week, the expression of proliferating cell nuclear antigen (PCNA) and cellular apoptosis (caspase-3) were also evaluated. In the 13th week, the transplanted animals had normal serum levels of total T3 and free T4. TSH levels showed a tendency towards normality. In the 14th week, scintigraphic exams displayed graft isotopic uptake in all animals in the TG group. Histological examinations 13 weeks after transplantation showed the viability and functionality of thyroid follicles. PCNA revealed significant immunoreactivity of the graft (p < 0.001) when the TG was compared to the CG. There was no difference between CG and TG considering the expression of activated caspase-3. The experimental study confirmed the viability and functionality of thyroid autotransplantation implanted in skeletal muscle with evidence of cell proliferation without cellular apoptosis. This surgical strategy was effective in the treatment of postoperative hypothyroidism.

Influence of culturing on the survival of major histocompatibility complex-compatible and -incompatible thyroid grafts in rats.

Culturing Fischer thyroid fragments promotes their survival in major histocompatibility complex (MHC) -incompatible ACI rats but not in MHC- compatible Lewis animals.

H-2 I-region encoded targets in allograft rejection.

Fresh thyroids transplanted to I-region disparate recipients are, in most cases, rejected; in some instances fresh thyroids undergo periods of crisis followed by functional recovery. Cultured thyroids that are taken from donor animals pretreated with lymphocytotoxic drugs, gamma radiation and cultured for 10 d in vitro are not rejected by any normal allogenic recipient. If the recipient is sensitized with lymphoid cells syngeneic with an I-region disparate cultured thyroid donor, the cultured thyroid is rejected if I-A-subregion differences are included. We interpret these data to indicate that there exist I-region encoded perenchymal cell target determinants which are not, by themselves, immunogenic.

The failure of a major histocompatibility antigen to stimulate a thyroid allograft reaction after culture in oxygen.

The lymphocytic infiltration found in multiple cultured BALB/c thyroids placed in the same C57BL/6 recipient was found to be highly correlated and the high variability between animals was not influenced by the number of lobes. It was concluded that the variable infiltration was largely due to host factors. Because a similar correlation was found between BALB/c and C3H grafts, the response to a minor antigen common to these two strains was suggested as a cause of the infiltration. When the response of C57BL/6 mice to cultured B6.C (H-2d) and BALB.B (H-2b) grafts was compared, a synergism between major and minor antigens was suggested. However, when the time of culture was increased from 48 to 60 h and the response of BALB/c and C57BL/6 mice were compared with identically cultured B6.C (H-2d) grafts, a striking difference between major and minor antigens was observed. None of 10 such grafts in C57BL/6 recipients (major antigens only) showed any infiltration, whereas 8 out of the 9 grafts in BALB/c recipients (minor antigens only) were infiltrated.

Observations on tissue grafts established in rabbit ear chambers. A combined light and electron microscopic study.

An in vivo microscopic and ultrastructural study of tissues transferred to the transparent rabbit ear chamber is presented. Fragments of liver, kidney, thyroid, and myometrium were successfully auto- or allografted into the chamber from donors of all ages and allowed continuous in vivo observation of parenchymal structure and function, as well as of the graft vasculature which plays such an active role during rejection. Circulation was quickly reestablished by anastomosis of graft vessels to those of the ear chamber membrane and only minor reversible parenchymal changes occurred. Both vessels and parenchyma retained the characteristics of the organs of origin on both light and electron microscopy and were observed functioning in vivo for periods up to 1 yr in the case of autografts, and until rejection occurred in allografts. In the latter case, rejection did not occur in tissues obtained from adult and neonatal donors for nearly 3 months, while tissues of fetal origin were generally rejected much earlier. The kidney grafts provide a unique opportunity for a close comparative study of mammalian fetal and adult glomerular blood flow under varying rates of perfusion, and the tubular epithelium could be observed regenerating after initial acute tubular necrosis. Renal tubules from fetal, neonatal, and adult donors were all capable of metaplastic change to form a highly ciliated epithelium. Grafts of these tissues will allow the fine detail of the processes of rejection to be studied continuously in vivo.

Effects of fission neutrons on human thyroid tissues maintained in SCID mice.

Morphology and function (secretion of thyroid hormone) of human thyroid tissues from Graves' disease patients are well maintained in C57BL/6J-scid mice. Serum level of thyroid hormone was reduced by fission neutrons from the nuclear reactor UTR-KINKI, and changes in thyroid hormone by fission neutrons were bigger than those by low LET radiations, X-rays and (137)Cs gamma-rays, suggesting high relative biological effectiveness (RBE; 6.5) of fission neutrons. Microarray analyses revealed that about 3% of genes showed more than 4-fold change in gene expression in the unexposed thyroid tissues against surgically resected thyroid tissues from the same patient, probably due to the difficult oxygen and nutrient supply shortly after transplantation. Dose-dependent changes in gene expression against unexposed concurrent controls were observed with increasing doses of fission neutrons (0.2-0.6Gy) and (137)Cs gamma-rays (1.0-3.0Gy) and showed high RBE (4.2). Furthermore, there were some specific genes which showed more than 4-fold change in gene expression in all the thyroid tissues exposed to higher doses of radiation, especially neutrons (0.4 and 0.6Gy), but none at lower doses (0.2Gy of neutrons and 1.0 and 2.0Gy of gamma-rays). These genes related to degeneration, regeneration, apoptosis, and transcription, respond specifically and very sensitively to neutron injury in human thyroid tissues. This is the first experimental report that fission neutrons can induce some morphological and functional disorders in human tissues, showing high RBE against gamma-ray exposure. These results are useful to evaluate the risks of fission neutrons and cosmic rays to humans.

Thyroid gland flap minimizes mucosal defects at supracricoid partial laryngectomy with cricohyoidoepiglottopexy.

Wound infection is a major complication after supracricoid partial laryngectomy with cricohyoidoepiglottopexy (CHEP) for radiation therapy failure. A 60-year-old man received chemoradiotherapy for a glottic carcinoma. CHEP, reusing the thyroid gland flap (TF), was performed because the cancer recurred after a salvage vertical partial laryngectomy following radiation therapy failure. The TF was sutured to the supraglottis and cricoid cartilage mucosa to minimize mucosal defects before the hyoid bone and cricoid cartilage were sutured. Wound healing after CHEP was good without infection. After decannulation, oral food intake was possible without aspiration, and speech function was comparable to that of other patients who had supracricoid partial laryngectomies. Histopathological examination revealed a close connection between the TF and its surrounding tissues without fibrous scarring. TF may improve wound healing after CHEP for radiation failure by minimizing mucosal defects.

Thyroid allograft immunogenicity is reduced after a period in organ culture.

The survival time of mouse thyroid, transplanted under the kidney capsule of an H-2 incompatible recipient, is extended by holding the thyroid in organ culture for 12 days prior to transplantation.

Activation of transplant immunity: effect of donor leukocytes on thyroid allograft rejection.

The survival of thyroid allografts in mice was prolonged by either holding the grafts in vitro culture for 20 to 27 days or by cobalt-60 irradiation of the donor 2 days before transplantation with or without the intravenous injection of colloidal carbon just before removing the thyroid from the donor. In both cases the rejection process was restored by an intravenous injection of recipients with living peritoneal exudate cells (50 to 80 percent macrophages) syngeneic to the thyroid donor.

Effect of oxygen pressure during culture on survival of mouse thyroid allografts.

A marked increase in the percentage of mouse thyroids that retained function 20 days after transplantation across a major histocompatibility barrier and the percentage that lacked generalized infiltration was observed when the grafts received hyperbaric oxygen during a 4-day culture period. Perfusion of the donor animal before thyroidotomy and the addition of fetal calf serum to the culture medium did not have a significant effect on graft survival, but the percentage of grafts lacking generalized infiltration was slightly increased by the addition of hydrocortisone to the culture medium.

Differential radiation sensitivity to morphological, functional and molecular changes of human thyroid tissues and bone marrow cells maintained in SCID mice.

Morphology and function of human organs and tissues are well maintained in the improved SCID (severe combined immunodeficient) mice for a long period (approximately 3 years). To study the radiation-induced damage on human thyroid gland, human thyroid tissues transplanted to SCID mice were consecutively exposed to X-rays or 137Cs gamma-rays at high and low dose rates for approximately 2 years. Consecutive irradiation resulted in the disappearance of follicles and significant decrease of thyroid hormone secretion. Mutations in p53 and c-kit genes were induced significantly in human thyroid tissues from old head and neck cancer patients (av. 56.8 years, 4 males) and a Graves' disease patient (20 years, male) over the dose of 24 Gy (44.7+/-5.9 Gy, mean+/-S.E) and 11 Gy (20.2+/-7.8 Gy), respectively, while mutations were not detected at lower doses nor in unexposed matched controls (p < 0.01). There were significant differences in mutation frequency in the transplanted human thyroid tissues (31 years, female) between high dose rate (1.19 Gy/min; 8 in 20 tissues) and low dose rate (0.00023 Gy/min; 0 in 14 tissues) exposures (p < 0.01). Mutations were not detected in RET, K-ras and beta-catenin genes. Expression analysis by GeneChip indicated that gene expression was also well maintained in the transplanted human thyroid tissues. However, lower doses (1 or 3 Gy) of 137Cs gamma-rays can induce changes in gene expression in the transplanted human thyroid tissues. Furthermore, fatally irradiated SCID mice could survive with human bone marrow cell transplantation. When about half of mouse bone marrows were replaced by human bone marrow cells, the human bone marrow cells showed high sensitivity to gamma-irradiation; 28.0% and 0.45% survival after 0.5 and 2.0 Gy exposures, respectively.

Autotransplantation of thyroid tissue in rats. An experimental study.

BACKGROUND: The aim of this study is to demonstrate the functional capacity of thyroid autografts after total thyroidectomy in a rat model. MATERIALS AND METHODS: 60 rats were divided into 6 groups of 10 rats each. Thyroid gland was cut into 0.5 mm pieces and was inserted intramuscularly into the left rectus abdominis muscle at different time intervals following total thyroidectomy. The animals were observed for 30 days. Blood samples were collected weekly for TSH, FT3 and FT4 measurements. This study was conducted in strict accordance with the provisions of the law concerning test procedures on animals, as per Legislative Decree n.116/92. RESULTS: Autologous transplantations were successful in 70% of the cases. Histopathological findings showed normal thyroid architecture. It was observed that thyroid function recovered was more rapidly if the implants were performed immediately after thyroidectomy than in implants performed at a later time. These results could be due to the thyroid tissue preserving procedure used which may have led to reduce the restored thyroid function in the groups of animals where the implantation was not immediate. CONCLUSIONS: Ectopically transplanted thyroid tissue is able to survive and recover its function completely if maintained vital in an adequate preserving medium.