Near-infrared irradiation of the thyroid area: effects on weight development and thyroid and parathyroid secretory patterns.

This study evaluates possible changes in weight and the secretory patterns of the thyroid and parathyroid glands irradiated with a 780-nm light-emitting diode (LED) source under conditions allowing their identification in an animal model. The use of near-infrared light sources to detect the parathyroid glands has been a subject of research due to the benefit provided to patients undergoing thyroid and parathyroid surgery. However, few studies have explored possible changes in weight and the secretory patterns of the glands when subjected to light stimulation. Thirty-two male Wistar rats were divided into two groups and subjected to cervical dissection and irradiation of the thyroid-parathyroid region under general anesthesia. The animals in group 1 (irradiated) were exposed to a 780-nm LED light beam for 180 s (dose 1.37 J/cm2), whereas the animals in group 2 (control) were not irradiated. Blood samples were collected pre-exposure, 7 min after exposure, and 30 and 60 days after exposure to measure calcium, parathyroid hormone (PTH), triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH) levels in both groups. Weight variations between the evaluation periods were also analyzed. Parametric statistics were used (Student's t test and ANOVA) after assuming normal distribution of continuous variables with the Shapiro-Wilk test. No significant variation was observed in any of the analyzed parameters pre- and postexposure. A significant increase in the calcium level was observed at 30 days in the irradiated group compared with that in the control group (11.156 ± 1.31 mg/dl vs 10.300 ± 0.30 mg/dl; df = 30 p < 0.03) but this change was no longer observed at 60 days (9.925 ± 0.23 mg/dl vs 10.014 ± 0.18 mg/dl; df = 14 p = 0.21). Irradiated rats gained less weight in the first 30 days after surgery (39.647 ± 32.39 vs 55.917 ± 22.61; df = 30 p = 0.146) and at 60 days (84.000 ± 27.36 vs 84.571 ± 5.62; df = 14 p = 0.957), no differences were observed between the two groups. No significant variations in weight development or changes in the secretory patterns of the thyroid and parathyroid glands exposed to near-infrared stimulation were observed, confirming the safety of this light source in the identification of the parathyroid glands.

Microwave ablation of hyperplastic parathyroid glands is a treatment option for end-stage renal disease patients ineligible for surgical resection.

BACKGROUND: Secondary hyperparathyroidism (SHPT) is a frequently encountered problem in patients with end-stage renal disease (ESRD). Some patients with severe SHPT could not be managed by medical treatment and are ineligible for surgical resection. PURPOSE: Our objective was to evaluate the efficacy, safety of microwave ablation (MWA) on these patients. MATERIALS AND METHODS: Between 1 April 2015 and 28 February 2017, 35 patients (M/F 19/16, age 49.8 ± 12.9 years) were enrolled. All patients were treated with MWA. Levels of intact parathyroid hormone (iPTH) and of serum calcium and phosphorus were compared pre- and post-ablation. Repeated-measures ANOVA was used to compare treatment outcomes pre- and post-ablation. RESULTS: Complete ablation was achieved in all 63 glands in the 35 patients with SHPT. The mean follow-up time was 15.9 ± 2.2 months. The maximum gland diameter was 6-31 mm (mean, 14.9 ± 5.5 mm). The trends of the changes in iPTH and calcium levels showed a curve: the level of iPTH and calcium at 6 months post-ablation were lower than those pre-ablation (both p < .0001); after then iPTH remained relatively stable and the end of follow up, with no rebound (p < .0001), while instead of calcium at the end of follow up was not significantly lower than pre-ablation (p = .462). The trend in the change in phosphate levels showed a straight line; the level of phosphate at 6 months post-ablation and at the end of follow up both were significantly lower than pre-MWA (p < .001). There was no major complication. CONCLUSIONS: In this series, MWA was used successfully to treat SHPT patients who are ineligible for surgical resection.

Parathyroid Changes After RAI in Patients With Differentiated Thyroid Carcinoma.

Objective: The purpose of this study was to investigate parathyroid hormone (PTH), serum calcium, phosphorus, and 25-hydroxyvitamin D (25-OH-VD) changes before and after radioactive iodine (RAI) in differentiated thyroid carcinoma (DTC) patients at different time points. Methods: A total of 259 DTC patients who received RAI were prospectively enrolled. We evaluated PTH, serum calcium, phosphorus, and 25-OH-VD levels at baseline pre-RAI, five days, six weeks, and six months post-RAI, respectively. We analyzed the risk factors of hypocalcemia at five days post-RAI. Results: The mean PTH, serum calcium and phosphorus values decreased five days post-RAI compared with pre-RAI (PTH 4.18 ± 1.23 pmol/L vs. 3.95 ± 1.41 pmol/L; calcium 2.27 ± 0.09 mmol/L vs. 2.20 ± 0.11 mmol/L; phosphorus 1.25 ± 0.17 vs. 0.98 ± 0.20 mmol/L, P < 0.05), and the differences were statistically significant. The mean 25-OH-VD levels did not significantly decrease at five days post-RAI. 21.2% (55/259) of patients had hypocalcemia at five days post-RAI, and all of them were given oral calcium supplements. At six weeks post-RAI, all of the above parameters were higher than those at five days post-RAI. Multivariate regression analysis showed that baseline pre-RAI serum calcium < 2.27 mmol/L, PTH < 4.18 pmol/L and negative 99mTcO4- thyroid imaging were risk factors for hypocalcemia at five days post-RAI. Conclusion: For DTC patients with normal PTH and serum calcium levels at pre-RAI, their PTH, serum calcium, and phosphorus levels decreased at five days post-RAI. About one-fifth of patients could have hypocalcemia at five days post-RAI. Lower baseline pre-RAI serum calcium and PTH levels and negative 99mTcO4- thyroid imaging were risk factors for hypocalcemia five days post-RAI.

Clinical Study on Safety and Efficacy of Microwave Ablation for Primary Hyperparathyroidism.

OBJECTIVE: To evaluate the safety, feasibility, and efficacy of microwave ablation (MWA) for the treatment of primary hyperparathyroidism (PHPT). MATERIALS AND METHODS: This study enrolled 67 PHPT patients (22 men, 45 women; mean age, 56.0 ± 16.3 years; range, 18-83 years) from January 2015 to December 2018. The laboratory data, including the serum intact parathyroid hormone (iPTH), calcium, phosphorus, and alkaline phosphatase (ALP) levels, were evaluated before MWA and again 2 hours, 1 day, 7 days, 1 month, 3 months, 6 months, 12 months, 18 months, and 24 months after. RESULTS: Complete ablation was achieved with all 72 hyperplastic parathyroid glands found on the 67 patients enrolled, 64 of whom were treated in one session and 3 were treated over two sessions. The technical success rate was 100%. The median follow-up time was 13.6 months (range, 10.0-31.1 months). The clinical success rate was 89.4%. The volume reduction rate was 79.4% at 6 months. Compared to pre-MWA, the serum iPTH, calcium, phosphorus, and ALP levels had significantly improved 6 months post-MWA (iPTH, 157.3 pg/mL vs. 39.2 pg/mL; calcium, 2.75 ± 0.25 mmol/L vs. 2.34 ± 0.15 mmol/L; phosphorus, 0.86 ± 0.20 mmol/L vs. 1.12 ± 0.22 mmol/L; ALP, 79 U/L vs. 54 U/L, respectively; all, p < 0.01). Hoarseness was a major complication in 4 patients (6.0%), but it improved spontaneously within 2-3 months. CONCLUSION: MWA is safe, feasible, and effective for the treatment of PHPT.

[HYPERPARATHYROIDISM AND PARATHYROID LESIONS IN THE ChNPP ACCIDENT SURVIVORS]. / GIPERPARATYREOZ TA URAZhENNIa PRYShchYTOPODIBNYKh ZALOZ U OSIB, OPROMINENYKh VNASLIDOK AVARIÏ NA ChAES.

OBJECTIVE: Study of the status of parathyroid glands in individuals exposed to ionizing radiation as a result of the ChNPP accident and comparison with the general population of Ukraine. MATERIALS AND METHODS: Subjects exposed as a result of the ChNPP accident (n = 1,348) and people from the general population of Ukraine (n=655) were examined. Diagnostic ultrasound scan of thyroid and parathyroid glands (PTG) was conducted in all study subjects. The technique of parathyroid ultrasound screening was developed, which led to an increase in the efficiency of their imaging. Additionally, the 25-hydroxyvitamin D (25(OH)D), parathyroid hor- mone, ionized calcium and some other parameters were selectively assayed in serum. RESULTS: High incidence of parathyroid hyperplasia was detected 27-32 years after the irradiation in persons ex- posed as a result of the ChNPP accident, especially in evacuees from the 30-km exclusion zone (71.4%; χ2Yates' = 24.1; р = 0) and residents of radilogically contaminated territories (41.7%; χ2Yates' = 6.45; p < 0.01) having no primary hyperparathyroidism. High prevalence of vitamin D insufficiency and deficiency was revealed in all study subgroups, namely in 83.1 % of the general population of Ukraine along with a bit better vitamin D status in the ChNPP acci- dent survivors i.e. the vitamin insufficiency and deficiency was found in 78.7 % of them. Incidence of hyperparathy- roidism, predominantly of the secondary (normocalcemic) one, was 33.8 % among persons exposed as a result of the ChNPP accident (p > 0.3) being somewhat higher than in the general population of Ukraine (26.1%), despite above- mentioned better supply of vitamin D. CONCLUSIONS: There is a widespread insufficiency or deficiency of vitamin D (over 78.7%) in the population of Ukraine in general providing an unfavorable background for the higher prevalence of health disorders associated with calcium and phosphorus metabolism. The latter features parathyroid hyperplasia and musculosceletal, immune, cardiovascular, and endocrine system comorbidities. Such disorders should exacerbate with a secondary increase in parathyroid hormone secretion (26.1 %). Higher incidence of normocalcemic hyperparathyroidism (33.8% versus 26.1%) against a background of better vitamin D status among irradiated individuals indicates the existence of other factors, where the past combined effects of Chornobyl radioactive fallout and external parathyroid exposure are most likely to be involved. This could explain the greater number of cases of parathyroid hyperplasia and hyper- parathyroidism among the exposed subjects. However the additional precise studies are required here with clarifi- cation of the personal data in population groups of the ChNPP accident survivors. Participants of the ChNPP acci- dent clean-up work in the «iodine period¼ of 1986 are of especial concern here. Besides that, the study population should be expanded with inclusion of subjects exposed in prenatal period.

Pilot study of parathyroid glands in adult and pediatric subjects exposed to ionizing radiation after the ChNPP accident, methodology of parathyroid diagnostic ultrasound. / PILOTNE DOSLIDZhENNIa STANU PRYShchYTOPODIBNYKh ZALOZ OSIB, OPROMINENYKh VNASLIDOK AVARIÏ NA ChAES DOROSLOGO TA DYTIaChOGO VIKU, METODOLOGIIa ÏKh UL'TRAZVUKOVOGO DOSLIDZhENNIa.

OBJECTIVE: Estimation of the parathyroid hyperplasia prevalence after the ChNPP accident in adults exposed to ion izing radiation and their descendants using the diagnostic ultrasound and its methodology elaboration. MATERIALS AND METHODS: The pilot prospective study of the prevalence of parathyroid hyperplasia among the Chornobyl Nuclear Power Plant (ChNPP) accident adult survivors (n=686) and their descendants (54 children) was performed using diagnostic ultrasound examination of thyroid and parathyroids. Among the study subjects there were 339 ChNPP accident clean up workers (ACUW), 32 persons were evacuated from the 30 km exclusion zone and 224 ones were included to the control group. Diagnostic ultrasound of thyroid and parathyroids was performed according to the standard method. Additionally, in children with parathyroid hyperplasia an additional assay of 25 hydroxyvitamin D levels in serum was performed. In calculating the statistical significance, its level p < 0.05 was considered statistically significant. RESULTS: Parathyroids are a few small but critically important endocrine glands that synthesize parathyroid hormone, regulating mainly phosphoric calcium metabolism. Insufficient (hypoparathyroidism) or excessive (hyperparathy roidism) function of parathyroids is harmful to the patients affecting the state of nervous and cardiovascular sys tem. Parathyroidss can accumulate isotopes of cesium, strontium and radioactive iodine. The available data testify to an increased incidence of clinically significant hyperplasia of parthyroids (more than 9 mm in adults and more than 5 mm in children) among persons exposed toionizng radiation as a result of the accident at the ChNPP (28.64%) and their descendants (23.8-70.6%). First of all are concerned those adults who live in contaminated areas in comparison with the control group (24.15% in not irradiated). Evacuees from the 30 km exclusion zone being the category of people who were exposed to the absorbed iodine isotopes in the first days of the Chernobyl accident are the another risk group. These data demonstrate sensitivity of parathyroidss to the impact of incorpo rated isotopes (iodine, cesium and strontium), which in the long term exposure create conditions for structural and functional changes in regulation of phosphorous calcium metabolism being the basis for a significant prevalence of osteopenia and osteoporosis in irradiated individuals and their descendants. A number of further studies are required to clarify the findings and to disclose the hormonal mechanisms of radiation effects on parathyroids. CONCLUSIONS: Parathyroid glands are radiosensitive and susceptible to effects of strontium, cesium and iodine iso topes, which cause parathyroid irradiation and subsequent structural and functional changes, being a prerequisite for development of osteopenia and osteoporosis in the ChNPP accident survivors and their descendants. High inci dence of parathyroid hypertrophy is found in the inhabitants of the radiation contaminated territories (long term irradiation by cesium isotopes), as well as in evacuated from the 30 km exclusion zone (irradiation by iodine iso topes in the early days of the accident).

Experimental induction of parathyroid adenomas in the rat.

Neonatal inbred Wistar albino rats were given either 5 or 10 microCi radioiodine (131I) within 24 hours of birth. After weaning, animals were placed on diets high, normal, or deficient in vitamin D3 (cholecalciferol) for periods up to 2 years. In animals aged 12 months and older, adenomas were found in 0 of 67 unirradiated controls, in 22 of 67 given 5 microCi 131I, and in 25 of 67 given to microCi 131I. The incidence of tumors in irradiated animals was highest (55%) in those on a low-vitamin D diet and lowest (20%) in those on a high-vitamin D diet. Plasma calcium levels were significantly increased by the high-vitamin D diet, but the low-vitamin D diet did not lead to any significant decrease as compared to the calcium levels of the normal vitamin D diet group. Small but significant calcium increases were found in tumor-bearing animals. These findings indicate that parathyroid tumors in the rat can be induced by radiation and that their incidence is strongly influenced by dietary vitamin D content. The possibility that metabolites of vitamin D3 may influence parathyroid growth and tumor formation directly is discussed.

Long-term parathyroid- and c-cell function after radioiodine for benign thyroid diseases.

The study examined static and dynamic parathyroid hormone and calcitonin secretion after radioiodine, and was a retrospective study of patients having received radioiodine for benign conditions 8-12 years earlier. In one group of patients parathyroid hormone and calcium were measured as single blood tests, in a second group of patients parathyroid hormone and calcitonin secretion capacity were measured during a hypocalcaemic citrate-clamp and a hypercalcaemic stimulation test. Baseline calcium and parathyroid hormone were normal within expected ranges 8-12 years after radioiodine. Stimulated parathyroid hormone or calcitonin secretion did not differ from an age- and gender-matched control group. Radioiodine in doses used for benign thyroid diseases appears safe with regard to parathyroid hormone and calcitonin secretion.

Therapeutic radiation and hyperparathyroidism. A case-control study in Rochester, Minn.

A case-control study was conducted among residents of Rochester, Minn, to assess the influence of prior therapeutic radiation on the risk of primary hyperparathyroidism. Fifty-one cases of surgically proven primary hyperparathyroidism diagnosed from 1975 through 1983 were each matched by age and gender to two control subjects, with radiation exposure documented through preexisting medical records. The overall odds ratio for any prior therapeutic radiation therapy was 1.9 (95% confidence interval, 0.9 to 4.4) and it was 2.3 (95% confidence interval, 0.9 to 5.7) when limited to those with prior head and neck radiation. Among women, the figures were 2.9 (95% confidence interval, 1.1 to 7.5) for any prior therapeutic radiation and 3.4 (95% confidence interval, 1.2 to 10.2) for head and neck exposure. This study confirms the association between primary hyperparathyroidism and prior therapeutic radiation exposure, at least for women in this population.

Dose-response relationships for radiation-induced hyperparathyroidism.

It has been hard to establish with certainty that radiation exposure is a risk factor for developing hyperparathyroidism. In part this is because many cases of hyperparathyroidism remain asymptomatic and escape clinical detection. We present results from a study of 2555 subjects who received external beam radiotherapy to the head and neck area for benign conditions before their 16th birthday between 1939 and 1962. The average length of follow-up was 36.6 yr. There were 36 confirmed cases of hyperparathyroidism. Based on a relative risk model, the excess relative risk increased significantly by 0.11/centigray; however, the confidence interval was wide (95% confidence interval, 0.0-17.2). The hyperparathyroidism rates and dose-response relationships were not affected by gender or age at first radiation treatment. The demonstration of a dose-response relationship within an irradiated cohort supports an association between radiation exposure and hyperparathyroidism and suggests that the calcium levels of individuals irradiated to the head and neck area should be monitored.

Thyroid, parathyroid, and salivary gland evaluations in patients exposed to multiple fluoroscopic examinations during tuberculosis therapy: a pilot study.

The prevalence of thyroid, parathyroid, and salivary abnormalities was determined in 91 women who received an average of 112 fluoroscopic chest examinations during pneumothorax treatment for tuberculosis more than 40 yr previously and in 72 women treated for tuberculosis by other modalities. Thyroid abnormalities were determined by physical examination, scintiscans, and measurements of serum free T4 index, TSH, and thyroid microsomal antibodies. Thyroid nodules were diagnosed in 7.7% of the exposed and 4.2% of the comparison group (prevalence ratio, 1.8; 90% confidence interval 0.6-5.7). Autoimmune thyroid disease was diagnosed in 15.2% of the exposed and 6.9% of the comparison group (prevalence ratio, 2.2; 95% confidence interval, 0.8-6.2). No salivary tumors were detected. Two exposed women and 1 comparison woman had primary hyperparathyroidism. Although absorbed dose to the thyroid could not be precisely determined, approximately 60 rads would be expected to yield the observed excess of thyroid nodules. While the prevalence ratios were not significantly increased in the exposed group, the results suggest that susceptibility of the thyroid to nodules from cumulative radiation doses of this magnitude could be increased even when the doses are accumulated over years and that such x-ray exposure of the thyroid gland may predispose the patient to the development of autoimmune disease.

Parathyroid ultrastructure after aldehyde fixation, high-pressure freezing, or microwave irradiation.

Parathyroid cell variants, commonly observed in parathyroid glands fixed by immersion in glutaraldehyde, are believed to be the result of cyclic changes in the course of parathyroid hormone secretion. Immersion of bovine parathyroid glands in a mixture consisting of 1% glutaraldehyde, 1.5% formaldehyde, and 2.5% acrolein, followed by post-fixation in 1% osmium tetroxide, resulted in high uniformity with only one cell variant, whereas the same fixation procedure led to disruption of cell membranes and formation of cell variants in rat parathyroids. Parathyroid glands of both cattle and rats prepared by high-pressure quick-freezing and subsequent freeze-substitution contained only one cell variant. Excellent preservation of the ultrastructure of bovine and rat parathyroids, also exhibiting only one cell variant, was achieved by microwave irradiation in the presence of 2.5% glutaraldehyde in Na-cacodylate followed by post-fixation with OsO4 in Na-cacodylate or s-collidine, both containing Ca2+ and Mg2+. Use of the appropriate buffer, as well as osmication, is essential for successful fixation utilizing microwave energy. The main effects are considered to be heating specimens within sufficient short periods and enhancement of subsequent osmium fixation. The results support the idea, arising after examination of perfusion-fixed parathyroid tissue, that parathyroid cell variants occur during improper aldehyde fixation rather than that they express functional diversity.

Subtotal parathyroidectomy for primary hyperparathyroidism. Long-term results in 292 patients.

Subtotal parathyroidectomy was performed in a consecutive series of 292 patients with primary hyperparathyroidism. We evaluated the long-term postoperative results during a period of 16 years. Patients ranged in age from 14 to 83 years and included 176 women and 116 men. Of these, 16% had a history of exposure to radiation in childhood or adolescence, while thyroid disease requiring some form of thyroidectomy coexisted in 91 (31%) of the patients. Histologic information on three or more parathyroid glands was obtained in 73% of the cases. We considered 285 patients (97.6%) cured after their first operation. The remaining seven patients (2.4%) had persistent hyperparathyroidism. However, five were cured after a sternum-splitting mediastinal exploration and one after a second neck exploration. The seventh remains hypercalcemic despite a subsequent mediastinal exploration. Temporary postoperative hypoparathyroidism occurred in 10% of our cases and permanent hypoparathyroidism in 1%. There have been no instances of recurrent hyperparathyroidism.

Effect of decicurie doses of radioactive iodine 131 on parathyroid function.

Although parathyroid deficiency has been reported after administration of relatively small doses of iodine 131, reports of such deficiency after the much larger doses given in the management of thyroid cancer are notable by their absence in the literature. We observed one such patient, then instituted a prospective study. We observed a 58 percent incidence of apparently diminished parathyroid reserve among 53 patients given high doses of I 131. Susceptibility does not appear to be related to age, sex, extent of thyroid operation, operative technique, the amount of thyroidal I 131 uptake, the use of external radiation to the neck, or to the presence of parathyroid glands or of Hashimoto's disease in the operative specimen; however, susceptibility may be related to the anatomic location of the parathyroid glands in relation to the thyroid gland. The administered dose of I 131 almost reached significant levels (p = 0.1) in the present study. The initial pretreatment serum calcium levels were consistently lower among affected patients (p = 0.01), suggesting the presence of a preexisting latent impairment of parathyroid reserve which was subsequently unmasked after the administration of I 131. Thyroid cancer is compatible with very long-term survival, and therefore, there is a considerable risk of delayed chronic hypocalcemia among patients who have received large doses of I 131, particularly female patients in the premenopausal age group. These patients deserve special management surveillance.

Primary hyperparathyroidism and nonmedullary thyroid cancer.

Of 2,058 patients who had surgically proven primary hyperparathyroidism at the Mayo Clinic from 1965 through 1979, 51 or 2.5 percent had associated nonmedullary thyroid carcinoma. A history of radiation exposure to the head and neck was obtained in 14 of 43 patients questioned. Thyroid disease consisted of grade 1 papillary adenocarcinoma in 48 cases and pure follicular adenocarcinoma in 3 cases. The parathyroid disease included 41 single adenomas and 5 cases of parathyroid hyperplasia; 5 patients had 2 adenomas. At follow-up, none of the patients had evidence of metastatic thyroid carcinoma. Ten patients were receiving calcium or vitamin D supplementation for protracted hypocalcemia presumably due to the increased insult to the parathyroids from combined bilateral thyroidectomy and parathyroidectomy. More consecutive thyroidectomy, along with parathyroid autotransplantation when indicated, will provide definitive treatment of the thyroid cancer and at the same time minimize the risk of postoperative hypoparathyroidism.

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: appendix III. evaluation of viscera and other tissues.

Histopathological findings in the lungs, livers, bone marrows, small intestines, gonads, kidneys, and other tissues of the four pocket mice (Perognathus longimembris) that survived the Apollo XVII flight were evaluated in the light of their immediate environment and as targest of HZE cosmic ray particles. Results of this study failed to disclose changes that could be ascribed to the HZE particle radiation. Decreased numbers of erythropoietic cells in the bone marrow of the flight mice were probably related to the increased oxygen pressure. The small intestine showed no changes. Ovaries and tests appeared normal. Two of the three surviving male flight mice displayed early stages of spermatogenesis, just as ground-based controls did at the same season. Abnormalities were also not found in the thyroid, parathyroids, adrenals, or kidneys. The status of the juxtaglomerular apparatus could not be evaluated. The lungs exhibited nonspecific slight rections. A variety of incidental lesions were noted in the livers of both the flight mice and their controls. The heart muscle showed nothing that could be regarded as pathological. Sections of skeletal muscle examined were free from significant change.

[Study of the possibility of hyperparathyroidism development in rats exposed to internal irradiation by iodine radioisotope]. / Issledovanie vozmozhnosti razvitiia giperparatireoza u krys, perenesshikh vnutrennee obluchenie ot radioizotopa ioda.

The possibility of hyperparathyroidism development secondary to earlier internal irradiation with radioactive iodine was studied experimentally in Wistar rats. This report describes the parathyroid morphology and biochemical findings for animals irradiated with 131I at the doses of 4.5, 40, or 80 Gy. The interval between the radiation exposure of two-month-old rats and their examination for thyroid and parathyroid pathology was 14 months. Neither hypercalcemia nor hypophosphatemia was found. Moreover, the level of calcium in serum slightly decreased following 40 and 80 Gy irradiation. The increased incidence of parathyroid fibrosis and hypofunctional structure transformation were revealed.

[Morphological and ultrastructural characteristics of the epithelial cells of the parathyroid glands]. / Morfologicheskie i ul'trastrukturnye osobennosti épitelial'nykh kletok okoloshchitovidnykh zhelez

Histochemical and ultrastructural characteristics of the main, oxyphilic and C-cells of 50 parathyroid glands of man and 105 ones of animals (rats) is presented. Types of the structure of the structure of the parathyroid glands (compact, retiform, lobular) are identified and their morphological changes under conditions of impairment of the phosphorus-calcium metabolism are described.

[The correction of the subcellular postradiation changes in the hypothalamus and parathyroid gland by using low-intensity laser radiation (an experimental study)]. / Korrektsiia subkletochnykh postradiatsionnykh izmenenii v gipotalamuse i parashchitovidnoi zheleze pri ispol'zovanii nizkointensivnogo lazernogo izlucheniia (éksperimental'noe issledovanie).

The exposure of the rat adrenals 30 days after radiation (1 Gy) to low-intensity infrared laser radiation arrests development of ultrastructural disorders in the cells of hypothalamus and parathyroid gland, enhances subcellular manifestations of adaptation and rehabilitation processes.