• Clinical and Experimental Pediatrics
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• v.60 no.2
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• pp.45-49
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• 2017

Purpose: Serum level of 25-hydroxyvitamin D (25-OHD) is considered as the most appropriate marker of vitamin D status. However, only a few studies have investigated the relationship between 25-OHD and parathyroid hormone (PTH) in children. To this end, this study was aimed at evaluating the lowest 25-OHD level that suppresses the production of parathyroid hormone in children. Methods: A retrospective record review was performed for children aged 0.2 to 18 years (n=193; 106 boys and 87 girls) who underwent simultaneous measurements of serum 25-OHD and PTH levels between January 2010 and June 2014. Results: The inflection point of serum 25-OHD level for maximal suppression of PTH was at 18.0 ng/mL (95% confidence interval, 14.3-21.7 ng/mL). The median PTH level of the children with 25-OHD levels of <18.0 ng/mL was higher than that of children with 25-OHD levels ${\geq}$ 18.0 ng/mL (P<0.0001). The median calcium level of children with 25-OHD levels<18.0 ng/mL was lower than that of children with 25-OHD levels${\geq}18.0ng/mL$ (P=0.0001). The frequency of hyperparathyroidism was higher in the children with 25-OHD levels<18.0 ng/mL than in the children with 25-OHD levels${\geq}18.0ng/mL$ (P<0.0001). Hypocalcemia was more prevalent in the children with 25-OHD levels<18.0 ng/mL than in the children with 25-OHD levels${\geq}18.0ng/mL$ (P<0.0001). Conclusion: These data suggest that a vitamin D level of 18.0 ng/mL could be the criterion for 25-OHD deficiency in children at the inflection point of the maximal suppression of PTH.

• Tuberculosis and Respiratory Diseases
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• v.47 no.4
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• pp.525-532
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• 1999

The parathyroid hormone related protein (PTHrP) is the most common causative peptide of humoral hypercalcemia of malignancy. In contrast, the serum level of parathyroid hormone (PTH) is low to undetectable in the majority of patients with malignancy associated hypercalcemia. Few cases exist in which the production and secretion of PTH by malignant nonparathyroid tumors have been authenticated. To our knowledge, there is very rare case in which a nonparathyroid tumor expressed simultaneously both the PTH and PTHrP. We report a case of squamous cell carcinoma of the lung with hypercalcemia which presented with simultaneous elevation of serum PTH and PTHrP. Severe hypercalcemia (serum calcium, 7.5 mEq/L) was found in a 65-year-old man who had a squamous cell carcinoma of the lung without any bony metastasis and detectable parathyroid abnormalities on isotope scintigraphy. The serum level of intact parathyroid hormone (PTH) con centration was markedly elevated as measured in two site radioimmunoreactive PTH assays (intact PTH 150 pg/mL ; normal 9~55). The serum level of a PTHrP was also increased as measured in C-terminal region specific radioimmunoassay (PTHrP 99.1 pmol/L; normal 13.8~55.3). There are no evidences of coincidental primary hyperparathyroidism in parathyroid MIBI scan and other imaging studies including neck ultrasonography and computed tomography. These results suggest that simultaneous elevation of serum PTH and PTHrP in this patient can be caused by production of both PTHrP and PTH in other nonparathyroid lesions such as squamous cell carcinoma.

• Molecules and Cells
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• v.27 no.5
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• pp.547-556
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• 2009

Parathyroid hormone is the most important endocrine regulator of calcium concentration. Its N-terminal fragment (1-34) has sufficient activity for biological function. Recently, site-directed mutagenesis studies demonstrated that substitutions at several positions within shorter analogues (1-14) can enhance the bioactivity to greater than that of PTH (1-34). However, designing the optimal sequence combination is not simple due to complex combinatorial problems. In this study, support vector machines were introduced to predict the biological activity of modified PTH (1-14) analogues using mono-substituted experimental data and to analyze the key physicochemical properties at each position that correlated with bioactivity. This systematic approach can reduce the time and effort needed to obtain desirable molecules by bench experiments and provide useful information in the design of simpler activating molecules.

• Korean Journal of Head & Neck Oncology
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• v.10 no.1
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• pp.31-37
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• 1994

Primary hyperparathyroidism is rare disease entity which secretes parathyroid hormone in excessively resulting in hypercalcemia. It involves skeletal system, urinary tract, gastrointestinal tract, and central nervous system. Recently the determination of the serum calcium and parathyroid hormone level has become a routine laboratory test and the localization of involved gland by neck ultrasonogram and parathyroid gland substraction scan has reduced operative complications. For the purpose of improvement of diagnosis and treatment, the authors analyzed the clinical characteristics of 6 cases of primary hyperparathyroidism(adenoma 5 cases, carcinoma 1 case) during 10 years and report with literatures.

• The Korean Journal of Nuclear Medicine
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• v.21 no.1
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• pp.75-78
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• 1987

A 57 year old female patient was diagnosed as primary hyperparathyroidism after incidental finding of hypercalcemia. She was treated with radioiodine for Graves disease twenty years ago. Preoperative localization procedures with sonography and CT were unrevealing but 201 thallium scintiscan clearly demonstrated ectopic parathyroid adenoma which was confirmed by surgery. Brief review of the preoperative parathyroid localization procedure was done and the relationship between radioiodine therapy and hyperparathyroidism was discussed.

• The Korean Journal of Nuclear Medicine
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• v.37 no.4
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• pp.260-261
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• 2003

Tc-99m methoxyisobutylisonitrile (MIBI) and Tl-201/technetium subtraction scintigraphy have been used for localization of abnormal parathyroid gland. The uptake mechanism of tracers has been postulated to be increased cellular density and vascularity, or dependent on the presence of mitochondria-rich cells. However, the uptake of these tracers was not specific for abnormal parathyroid gland. The author report a case of thymic carcinoma that would have been mistaken for carcinoma of parathyroid because of Tc-99m MIBI and Tl-201 uptake.

• Korean Journal of Radiology
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• v.23 no.5
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• pp.555-565
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• 2022

Objective: To assess the efficacy and safety of ultrasound (US)-guided radiofrequency ablation (RFA) in patients with primary hyperparathyroidism (PHPT). Materials and Methods: This prospective study enrolled 39 participants (14 male, 25 female; mean age, 59.5 ± 15.3 [range, 18-87] years) between September 1, 2018, and January 31, 2021. All participants had parathyroid lesions causing PHPT, proven biochemically and through imaging. The imaging features of the PHPT nodules, including the shape, margin, size, composition, and location, were evaluated before treatment. Serum intact parathyroid hormone, calcium, and phosphorus levels; parathyroid nodule volume; and PHPT-related symptoms were recorded before and after treatment. We calculated the technical success, biochemical cure, and clinical cure rates for these patients. Complications were evaluated during and after the ablation. Results: Complete ablation was achieved in 38 of the 39 nodules in the 39 enrolled participants. All the patients were treated in one session. The technical success rate was 97.4% (38/39). The mean follow-up duration was 13.2 ± 4.6 (range, 6.0-24.9) months. At 6 and 12 months post-RFA, the biochemical cure rates were 82.1% (32/39) and 84.4% (27/32), respectively, and the clinical cure rates were 100% (39/39) and 96.9% (31/32), respectively. Only 2.6% (1/39) of the patients had recurrent PHPT. At 1, 3, 6, and 12 months after technically successful RFA, 44.7% (17/38), 34.3% (12/35), 15.8% (6/38), and 12.5% (4/32) of participants, respectively, had elevated eucalcemic parathyroid hormone levels. Recurrent laryngeal nerve paralysis occurred in 5.1% (2/39) of the patients, who recovered spontaneously within 1-3 months. Conclusion: US-guided RFA was effective and safe for PHPT patients. RFA may be an alternative treatment tool for patients who cannot tolerate or refuse to undergo surgery.

• The Korean Journal of Nuclear Medicine
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• v.35 no.4
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• pp.274-279
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• 2001

A large superior mediastinal mass was found incidentally by ultrasonography in a 60-year-old man. There was an abnormal accumulation of Tl-201 in the lower pole of left thyroid gland, extending into left superior mediastinum on Tc-99m pertechnetate/Tl-201 subtraction scan. Laboratory findings relating thyroid and parathyroid were all within normal range. We considered the mass as a non-functioning parathyroid adenoma tentatively. However, subsequent surgery and pathologic examination revealed the mass to be a benign mixed thymoma. We report a case of patient with thymoma showing unusual Tc-99m pertechnetate/Tl-201 subtraction imaging and laboratory findings, and suggest to consider the possibility of other mediastinal tumors rather than parathyroid adenoma.

• Korean Journal of Head & Neck Oncology
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• v.25 no.2
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• pp.174-177
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• 2009

Parathyroid cyst are rare lesion of the neck and superior mediastinum. They are classified as either functional or nonfunctional based on the presence or absence of hyperparathyroidism. They typically present as a palpable neck mass, or as an incidental finding during neck surgery. So, it must be included within the differential diagnosis of a neck lump. A 48-year old woman was admitted to our hospital for evaluation of left anterior neck mass. Physical finding showed soft, movable, non-tender mass on the lower left third of the neck. Laboratory findings revealed normal thyroid function and normal serum calcium level. On previous history, patient underwent two times sono-guided fine needle aspiration at local clinic, and about 10cc clear watery aspirate was noted. Computerized tomography findings showed non-enhancing hypodense cystic lesion on left thyroid area with tracheal deviation to right side. Preoperative diagnosis was thyroid cyst, and thyroidectomy was planed. Intra-operative finding showed huge cystic mass occupying the left thyroid area and smooth, shiny, semitransparent thin cyst wall was noted, which was loosely attached to the thyroid. The cyst was easily dissected free from the thyroid and surrounding tissues. After cyst removal, pathological study confirmed as a parathyroid cyst.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.3
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• pp.217-223
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• 2014

Plasma ionized calcium ($Ca^{2+}$) concentrations are tightly regulated in the body and maintained within a narrow range; thus it is challenging to quantify calcium absorption under normal physiologic conditions. This study aimed to develop a mechanistic model for the parathyroid hormone (PTH) response after calcium intake and indirectly compare the difference in oral calcium absorption from PTH responses. PTH and $Ca^{2+}$ concentrations were collected from 24 subjects from a clinical trial performed to evaluate the safety and calcium absorption of Geumjin Thermal Water in comparison with calcium carbonate tablets in healthy subjects. Indirect response models (NONMEM Ver. 7.2.0) were fitted to observed $Ca^{2+}$ and PTH data, respectively, in a manner that absorbed but unobserved $Ca^{2+}$ inhibits the secretion of PTH. Without notable changes in $Ca^{2+}$ levels, PTH responses were modeled and used as a marker for the extent of calcium absorption.