Microfluorometric measurements of cytoplasmic calcium in chief and oxyphil parathyroid cells of adenomatous and hyperplastic glands and of normal-sized glands associated with adenomas

The effects of extracellular calcium on the cytoplasmic Ca2+ concentration (Ca2+i) were studied by dual-wavelength microfluorometry in individual human parathyroid cells obtained from adenomatous glands and normal-sized glands associated with adenomas in hypercalcemic hyperparathyroidism (HPT), as well as from enlarged glands of patients with uremia with HPT. In comparison with the normal parathyroid tissue, chief cells of the adenomatous and hyperplastic glands showed significantly lower Ca2+, and also right-shifted responses of Ca2+i to increases in the extracellular calcium concentration within the 0.5 to 3.0 mmol/L range. This pathophysiologic disturbance apparently was independent of the cell size. Oxyphil cells of nodules from the hyperplastic glands had lower Ca2+i and responded less to increments in extracellular Ca2+ than the chief cells from the surrounding parts of the same glands. Also the chief cells from the normal-sized glands associated with single adenomas exhibited a disturbance of the regulation of Ca2+i, which was less pronounced than that in the cells of the adenomas. These findings support the presence of relative calcium insensitivity of Ca2+i in chief and oxyphil parathyroid cells from adenomatous and hyperplastic glands. This derangement may also be found in all parathyroid glands of individuals with adenomatous HPT.     

Parathyroid pathology in hyperparathyroidism secondary to chronic renal failure

Weights and histopathological changes in parathyroid glands were evaluated in relation to clinical and biochemical parameters in 42 patients who underwent parathyroidectomy for hyperparathyroidism (HPT) secondary to chronic renal failure. There was a positive relation (r = 0.71, p less than 0.01) between duration of renal insufficiency and total parathyroid glandular weight. The glandular weight was also closely related to the serum levels of parathyroid hormone (r = 0.67, p less than 0.01). No correlation was found between total parathyroid glandular weight or histopathological findings and clinical symptoms, serum levels of calcium, phosphate, alkaline phosphatases, calcium X phosphorus product or radiological evidence of bone disease. The enlargement of the glands was mostly uniform in the individual patient and all patients showed multiple gland involvement. This indicates that when parathyroid surgery is performed in patients with uraemia and secondary HPT, a radical approach, i.e. total parathyroidectomy with autotransplantation or subtotal parathyroidectomy, should always be used. In smaller glands only diffuse hyperplasia of parenchymal cells was generally found; fat cells were present in near-normal amounts. With increasing glandular weight, fat cells were more sparse and nodularity was common. In general, the proportion of oxyphil cells increased parallel with the total glandular weight, suggesting that this cell type is sensitive to stimulation. As a group, patients undergoing conservative renal treatment had suffered longer with renal disease, had larger parathyroid glands with more nodularity, and had more oxyphil cells than those undergoing parathyroidectomy while on haemodialysis.     

高磷通过局部环氧化酶2途径刺激尿毒症患者甲状旁腺细胞增生

目的 探讨尿毒症时高磷是否通过局部环氧化酶2( COX2)途径刺激人甲状旁腺细胞增生和功能亢进.方法 收集19例行甲状旁腺切除术的尿毒症患者甲状旁腺组织,通过免疫组化和免疫共染法观察COX2和增殖细胞核抗原(PCNA)的表达和分布.进行人甲状旁腺细胞原代培养,分别予高磷和正常磷干预,48 h后检测两组细胞上清液甲状旁腺激素(iPTH)水平;应用Western印迹和实时PCR方法观察细胞中COX2及PCNA的表达.结果 在获取的62枚尿毒症甲状旁腺结节中43枚为结节性增生,19枚为弥漫性增生,均观察到大量PCNA阳性细胞和COX2高表达.在弥漫性和结节性增生的甲状旁腺组织中,分别有80.60％及85.20％的COX2阳性细胞同时表达PCNA.在体外原代培养的尿毒症患者甲状旁腺细胞中,高磷能显著增加iPTH分泌,同时显著上调COX2及PCNA蛋白和基因表达.结论 高磷可能通过局部COX2表达和代谢途径参与尿毒症甲状旁腺细胞增生和功能亢进.     

Heterogeneous expression of receptor mRNAs in parathyroid glands of secondary hyperparathyroidism.

BACKGROUND: Secondary hyperparathyroidism (HPT) is characterized by inappropriate control of parathyroid hormone (PTH) secretion and asymmetric hyperplasia of the parathyroid glands. Receptors for calcium and vitamin D are involved in the control of secretion, as well as parathyroid cell proliferation. Defective receptor mechanisms therefore may play a role in the pathogenensis of secondary HPT. Previous studies have shown that the expression of calcium receptor (CaR), calcium-sensing receptor (CAS) and vitamin D receptor (VDR) protein, and mRNA is decreased in hyperplastic parathyroid glands of secondary HPT when compared with normal parathyroid glands. METHODS: Thirty-six hyperplastic glands from 18 patients with secondary hyperparathyroidism were analyzed with in situ hybridization in order to investigate the expression of CaR, CAS, VDR, and PTH mRNAs in the same specimens. In nine nodular parathyroid glands, it was possible to make a comparison between the expression of these mRNAs in nodular and internodular areas. RESULTS: The level of CaR was in the same order of magnitude in the hyperplastic glands and in the biopsies of normal parathyroid, whereas the levels of CAS, VDR and PTH were clearly reduced in the hyperplastic glands. There was a positive correlation between the expression of CaR and CAS (P = 0.02). Otherwise, no correlations between CaR, CAS, VDR, and PTH mRNAs were found. The expression of all four genes was highly variable as well between different glands as within individual glands. CONCLUSION: The expression of mRNAs for receptors of importance in the control of PTH secretion and parathyroid cell proliferation is heterogeneously decreased in parathyroid glands of secondary HPT. The expression pattern corroborates earlier studies in which it has been assumed that each nodule in secondary HPT is of monoclonal origin, but that the monoclonal origin of each nodule is independent.     

Ultrasound scanning for preoperative location of parathyroid tumours

Ultrasonic examination of the parathyroid glands has been used in 50 consecutive patients with surgically verified hyperparathyroidism. It revealed 21 of 32 parathyroid adenomas located in the neck. In 16 patients with primary or secondary (uraemic) hyperplasia, 11 out of 48 hyperplastic glands in the neck were identified by ultrasound. A parathyroid adenoma was revealed in all (3) patients with hypercalcaemic crisis. Enlarged parathyroid glands were correctly located in all (5) patients with adenomas and previous explorations of the neck, whereas two out of three glands were visualized by ultrasound prior to secondary explorations in 3 patients with hyperplasia associated with the multiple endocrine neoplasia syndrome type 1. Undetected parathyroid glands were generally smaller than those visualized by ultrasonic examination. It was often difficult to unequivocally establish that identified lesions represented parathyroid glands. Irregular noduli and cysts of the thyroid as well as lymph nodes could be misinterpreted as parathyroid lesions. A nodular thyroid goitre was present in almost half of the patients with a negative ultrasonic examination of the parathyroid glands.     

Functioning oxyphil cell adenomas of the parathyroid gland. A study of 15 cases

Parathyroid adenomas composed predominantly of chief cells are the most frequent cause of primary hyperparathyroidism. Until as recently as 1978, the rare oxyphil cell parathyroid adenoma was generally considered nonfunctioning. A retrospective review of 500 consecutive patients at the Massachusetts General Hospital with a diagnosis of hyperparathyroidism associated with parathyroid adenoma during the years 1979-1987 yielded 15 (3.0%) oxyphil cell adenomas. A total of 65 case reports of hyperparathyroidism associated with a diagnosis of oxyphil cell adenomas were reviewed, applying the same diagnostic criteria used in case selection for the present series. These criteria include: (a) at least 90% composition of the adenoma by oxyphil cells; (b) biopsy or excision of a second histologically normal parathyroid gland to help rule out hyperplasia; and (c) postoperative alleviation of hypercalcemia. More than 50% of the previously reported cases did not conform to these criteria. The findings in the present study further document the entity of hyperparathyroidism caused by oxyphil cell parathyroid adenomas and suggest criteria guidelines for this rare diagnosis.     

Influence of 1,25-dihydroxycholecalciferol on parathyroid activity in patients with primary hyperparathyroidism.

Parathyroid morphology and blood chemistry were studied in five patients with primary hyperparathyroidism treated with 1,25-dihydroxycholecalciferol (1,25-DHCC) for 2 to 11 days before planned operation. Before the institution of treatment all patients were hypercalcemic, whereas the serum immunoreactive parathyroid hormone (iPTH) concentration either was elevated or normal. During the treatment the urinary phosphate excretion was significantly increased, whereas the calcium excretion and the serum concentrations of calcium and phosphate were unaffected or only slightly changed. Serum iPTH decreased during the first days of treatment, but returned then to increased levels close to the pretreatment ones. The treatment was tolerated well by the patients. Light and electron microscopy of the removed parathyroid glands disclosed one adenoma in each of the five patients, the other glands exhibiting either a slight hyperplasia or a normal appearance. Both the adenomatous and the non-adenomatous parathyroid tissue showed a predominance of dark chief cells and three of the adenomas exhibited a varying number of atrophic and oxyphil cells. The non-adenomatous glands were composed of atrophic and dark chief cells. Signs of low functional activity were ultrastructurally observed in the parathyroid parenchymal cells. It is suggested that 1,25-DHCC treatment of patients with primary hyperparathyroidism inhibits parathyroid hormone secretion.     

Value of high resolution real-time ultrasonography in secondary hyperparathyroidism

Thirty-two patients were treated surgically for symptomatic secondary or tertiary hyperparathyroidism, and 27 of these patients had high resolution (10 mHz) real-time ultrasonography before parathyroidectomy. This preoperative localization study identified one or more enlarged hyperplastic parathyroid glands in all but one patient who had not had a previous parathyroid operation, and in five of six patients who did have previous parathyroid operations. In both of the patients in whom no parathyroid glands were identified by ultrasonography the only abnormal enlarged parathyroid glands were those situated within the superior mediastinum. When large glands are not observed by ultrasonography in patients with severe secondary hyperparathyroidism, the glands are usually situated in the superior mediastinum, behind the trachea or esophagus, or deeply within the neck. The size of the parathyroid glands correlated positively with the serum parathyroid hormone level and with the severity of the secondary hyperparathyroidism. Thus, the preoperative identification of parathyroid glands by ultrasonography not only localizes the site of most hyperplastic parathyroid glands (70 percent of patients), but also detects those patients who have enlarged parathyroid glands, elevated serum parathyroid hormone levels, and severe secondary hyperparathyroidism. These are the patients who are thus unlikely to respond to further medical therapy.     

Apoptosis in parathyroid hyperplasia of patients with primary or secondary uremic hyperparathyroidism

BACKGROUND: Chronic oversecretion of parathyroid hormone (PTH) is associated with parathyroid hyperplasia, reflecting a disturbed balance between cell proliferation and apoptosis. This study addressed the unsolved issue of apoptosis in hyperparathyroidism. METHODS: Parathyroid glands from 19 patients with primary (1 degrees ) and 11 patients with secondary (2 degrees ) uremic hyperparathyroidism, as well as 13 normal parathyroid glands, were examined. Apoptosis was evaluated by terminal deoxynucleotidyl transferase (Tdt)-mediated dUTP nick end-labeling assay (TUNEL). Because the apoptotic process is regulated by several oncoproteins, the expression of Bcl-2 and Bax was analyzed by immunohistochemistry. RESULTS: The numbers of apoptotic cells in 1 degrees parathyroid adenoma (0.99 +/- 0.03 per 1000 cells, mean +/- SE, P < 0.009) and 2 degrees parathyroid hyperplasia (1.20 +/- 0.54 per 1000 cells, P < 0.005) were significantly higher than in normal parathyroid tissue (0.13 +/- 0. 06 per 1000 cells). Light microscopy examination of hyperplastic parathyroid tissue from a uremic patient showed the presence of nuclei with dense chromatin characteristic of apoptosis. Bcl-2 staining was strong in normal tissues but weak or negative in several sections of 1 degrees and 2 degrees hyperparathyroid tissues, mostly in nodular areas. Bax staining was homogeneous in normal tissue but patchy in several hyperplastic tissues. CONCLUSION: These results suggest that hyperparathyroidism is associated with a compensatory increase in apoptosis, possibly favored by a diminished Bcl-2/Bax ratio. This renders highly improbable the hypothesis that parathyroid hyperplasia is due to a decreased rate of apoptosis.     

Relationship between parathyroid oxyphil cell proportion and clinical characteristics of patients with chronic kidney disease

International Urology and Nephrology - Parathyroid glands consist of chief cells and oxyphil cells. The parathyroid oxyphil cell proportion increased dramatically in patients with chronic kidney...     

An evaluation of the intraoperative staining technique using methylene blue for the detection of hyperplastic parathyroid glands

Intraoperative staining with methylene blue was employed during parathyroid surgery on 50 glands from 13 patients, 5 with primary and 8 with secondary hyperparathyroidism. Forty-seven out of the 50 glands (94 per cent) were visualized by the staining and 2 out of the 13 patients were revealed to have supernumerary parathyroid glands. Since we started using this technique, there have been no cases of persistent hypercalcemia. The results of this study support the clinical usefulness of this staining procedure for detecting hyperplastic parathyroid glands in both primary and secondary hyperparathyroidism.     

Sestamibi/iodine subtraction single photon emission computed tomography in reoperative secondary hyperparathyroidism

BACKGROUND: Sestamibi/iodine subtraction single photon emission computed tomography (SPECT) has been used successfully for the preoperative localization of adenomatous and hyperplastic parathyroid tissue in primary hyperparathyroidism, but the clinical usefulness of this technique in secondary hyperparathyroidism remains uncertain. The purpose of this study was to evaluate parathyroid localization that uses sestamibi/iodine subtraction SPECT in patients with secondary hyperparathyroidism before reoperative parathyroid surgery. METHODS: Fourteen consecutive patients with chronic renal failure and secondary hyperparathyroidism who had previously undergone total parathyroidectomy combined with parathyroid autotransplantation in a sternocleidomastoid muscle were studied. Before reoperation, each patient received 400 microCi of sodium iodide I 123 orally and 20 to 25 mCi of technetium Tc 99m ((99m)Tc)-sestamibi intravenously, followed by sestamibi/iodine subtraction SPECT of the neck and chest. At surgery, the location, weight, and histopathologic results of all identified parathyroid tissue were recorded. RESULTS: At surgery, 1 hyperplastic parathyroid gland was resected from each of 13 patients; including 1 undescended gland, 6 parathyroid autotransplants, and 5 mediastinal glands. The mean weight of the resected parathyroid glands was 1707 mg (range, 85-5300 mg). Sestamibi/iodine subtraction SPECT correctly identified and localized all 13 parathyroid glands (100% sensitivity) and was negative in the 1 patient whose surgery was unsuccessful. CONCLUSIONS: The (99m)Tc-sestamibi/(123)I subtraction SPECT is able to correctly localize hyperplastic parathyroid tissue in patients with secondary hyperparathyroidism who have previously undergone parathyroid surgery and is a clinically useful study before reoperation.     

Relation of biochemical, cytologic, and morphologic parameters to the result of gammagraphy with technetium 99m sestamibi in primary hyperparathyroidism

The aim of this study was to analyze the possible relation of biochemical, cytologic, and morphologic parameters to the results of parathyroid gammagraphy with Tc 99m sestamibi in primary hyperparathyroidism. We studied 46 consecutive patients with primary hyperparathyroidism who were undergoing surgery. All the patients were given a preoperative parathyroid gammagraphy with Tc 99m sestamibi and a complete preoperative biochemical study. During the surgical intervention we recorded the weight and size of the pathologic glands to calculate the volume of each. We also determined the percentage of the chief and oxyphil cells in the pathologic glands. Tc 99m sestamibi sensitivity is higher in adenomas (91%) than in hyperplasia (67%) or double adenomas (50%). No relation was found between biochemical or cytologic parameters and gammagraphic results. Weight and gland volume were significantly greater for adenomas than for hyperplasia (P < 0.0014 and P < 0.0004, respectively), and statistically significant differences in both of them were observed between the glands with positive and negative sestamibi.     

Oxyphil parathyroid carcinomas: a clinicopathologic and immunohistochemical study of 10 cases

Oxyphil parathyroid carcinomas are uncommon neoplasms, and the clinicopathologic features of these tumors are largely unknown. We evaluated the clinicopathologic features of oxyphil parathyroid carcinomas and the expression of cytokeratin 14 (CK14), the high-affinity glucose transporter-4 (Glut-4), as well as the cell cycle proteins p27 and Ki67 and compared these with oxyphil parathyroid adenomas and chief cell parathyroid adenomas and carcinomas. Formalin-fixed, paraffin-embedded archival tissues from primary (n = 6) and recurrent (n = 4) oxyphil carcinomas were analyzed and compared with chief cell parathyroid carcinomas (n = 12), oxyphil parathyroid adenomas (n = 38), and chief cell parathyroid adenomas (n = 17) by immunohistochemistry for CK14, Glut-4, p27, and Ki67 using the avidin-biotin peroxidase system. Patients with primary oxyphil and chief cell carcinoma presented with high levels of serum calcium (n = 15.5 and 13.7 mg/dL, respectively). Approximately half the patients in each group died of disease. The Ki67 labeling index was higher (4.9 vs 1.9) and the p27 index lower (23 vs 66) in primary oxyphil carcinoma compared with primary oxyphil adenomas. CK14 was expressed in most oxyphil adenomas (35 of 38 cases) but not in oxyphil carcinomas (0 of 10 cases). Glut-4 was more commonly expressed in both groups of adenomas compared with carcinomas. These results show that oxyphil parathyroid carcinomas are functional malignancies similar to chief cell carcinomas and are associated with hypercalcemia, recurrence, and death. Expression of CK14 is very different in oxyphil adenomas compared with carcinomas. Although distinction between parathyroid adenomas and carcinomas can only be made by histopathologic and clinical findings, these results suggest that immunostaining for CK14, p27, and Ki67 may provide additional information to help distinguish between difficult cases of parathyroid adenomas and carcinomas. These findings also indicate that the same histopathologic features should be used to diagnose oxyphil and chief cell parathyroid carcinomas.     

Secondary hyperparathyroidism: Pathophysiology, histopathology, and medical and surgical management

It is generally accepted that morphological changes of the parathyroid glands appear early in renal failure. When diffuse hyperplasia develops into a nodular type, the cells grow monoclonally and proliferate aggressively, with abnormal suppression of parathyroid hormone (PTH) secretion under high extracellular calcium. Based on histopathological and pathophysiological findings, patients with nodular hyperplasia in renal hyperparathyroidism might be refractory to medical treatment, including calcitriol pulse therapy. Thus, parathyroid surgery is indicated for individuals developing hypercalcemia, elevated PTH levels, and/or bone disease, who cannot be effectively treated medically. The detection of enlarged parathyroid glands by image diagnosis is another criterion for surgery. In our experience, parathyroidectomy is an effective treatment; however, the timing of the operation is important, because skeletal deformity and vessel calcification cannot be expected to diminish even after successful surgery. Technically, it is important to identify all parathyroid glands and, in autotransplantation, to use an adequate amount of suitable, tissue, namely, a diffuse type of hyperplastic tissue, to guarantee satisfactory postoperative function.     

An evaluation of the intraoperative staining technique using methylene blue for the detection of hyperplastic parathyroid glands

Intraoperative staining with methylene blue was employed during parathyroid surgery on 50 glands from 13 patients, 5 with primary and 8 with secondary hyperparathyroidism. Forty-seven out of the 50 glands (94 per cent) were visualized by the staining and 2 out of the 13 patients were revealed to have supernumerary parathyroid glands. Since we started using this technique, there have been no cases of persistent hypercalcemia. The results of this study support the clinical usefulness of this staining procedure for detecting hyperplastic parathyroid glands in both primary and secondary hyperparathyroidism. This paper was presented at the 19th Annual Meeting of the Japanese Society of Thyroid Surgery held in Beppu, Ohita on November 27th and 28th, 1986.     

Nuclear DNA analysis of hyperplastic parathyroid glands in multiple endocrine neoplasia type I.

Twenty-four hyperplastic parathyroid glands from 11 patients with multiple endocrine neoplasia type I (MEN-I), and 36 hyperplastic parathyroid glands in 15 patients with sporadic primary hyperparathyroidism, ie, not associated with MEN, were analyzed for DNA by flow cytometry. Sixteen of 24 hyperplastic parathyroid glands from patients with MEN-I were DNA diploid, and eight were DNA aneuploid. Thirty-three of 36 hyperplastic parathyroid glands from patients without MEN were DNA diploid, and only three were DNA aneuploid. The mean percentage of 4c level (a measure of the G2M phase of the cell cycle) of DNA diploid hyperplastic parathyroid glands taken from patients with MEN-I was 8.1% +/- 4.5%, which is significantly higher than the 3.5% +/- 3.4% for those taken from patients without MEN. Our results show that there is a difference in nuclear DNA content between hyperplastic parathyroid glands in patients with MEN-I and those in patients without MEN.     

Morphologic and functional studies to prevent graft-dependent recurrence in renal osteodystrophy

The cross sections of hyperplastic glands removed during total parathyroidectomy in patients with renal osteodystrophy were classified on the basis of macroscopic and functional criteria. Diffuse (type 1) and nodular (type 2) glands could be distinguished macroscopically. Functional in vitro studies showed no significant difference in suppressibility and basal parathyroid hormone (PTH) secretion (61% and 74%, respectively). In both types of glands A, B, C, and D regions could be distinguished with use of a stereo magnifier (magnification, x10 to x16). In diffuse A regions containing stroma fat cells, PTH secretion could be suppressed optimally (more than 50% of maximum secretion) in more than 90% of all specimens in vitro. In diffuse B regions containing no fat cells, hormonal secretion could be suppressed in only 17% and 25%, respectively. Confined (oxyphilic or chief cell) nodules (C regions), only found in type 2 glands, could be suppressed in 18%. Nodules of "degenerating" oxyphilic cells (D regions), only found in type 2 glands, were suppressible, but the low PTH secretion indicated degenerative processes. Thus only fragments from A regions should be selected for autotransplantation.     

Two-phase scintigraphy with technetium 99m-sestamibi in patients with hyperparathyroidism due to chronic renal failure

BACKGROUND: The objective of the current study was to study different functional and anatomic features of the hyperplastic gland and clinical and biochemical characteristics of renal hyperparathyroidism (HPT) patients and their relationship with the scintigraphic detection of parathyroid glands. METHODS: A retrospective study was performed of 40 patients with chronic renal failure (CRF) who underwent cervical surgery for HPT. Weight, histology, and localization of hyperplastic glands were recorded. Parathyroid cell proliferation was assessed by percentage of S-phase cells. Double-phase scintigraphy with technetium 99m-sestamibi and serum parathyroid intact hormone (PTHi), creatinine, calcium, and phosphate levels were performed. RESULTS: Detection of hyperplastic parathyroid glands by 99mTc-sestamibi scintigraphy was associated with the weight and inferior localization of the glands. The functionality of the glands as reflected in serum PTHi and phosphorus levels was associated with the number of glands detected. CONCLUSION: Double-phase 99mTc-sestamibi scintigraphy is of limited usefulness in patients with renal HPT. Detection of hyperplastic parathyroid glands in patients with CRF depends on the weight and inferior localization of the glands. Serum PTHi, phosphorus and creatine levels are associated with the number of glands detected by means of 99mTc-sestamibi scintigraphy.     

Surgical treatment of secondary hyperparathyroidism

Secondary hyperparathyroidism is one of the most serious complications for long-term hemodialysis patients. In our department, we performed parathyroidectomies on 215 patients between July 1973 and June 1990. We found that parathyroidectomies on 215 patients between July 1973 and June 1990. We found that parathyroidectomy was an effective treatment for advanced renal hyperparathyroidism and that after total parathyroidectomy with forearm autograft, renal hyperparathyroidism was controllable, even when hyperparathyroidism was progressive. However, the timing of this operation was important, because skeletal deformity and vessel calcification did not improve after parathyroidectomy. There were two problems after parathyroidectomy for secondary hyperparathyroidism. One was persistent hyperparathyroidism due to supernumerary parathyroid glands, particularly those located in the mediastinum, and the other was recurrent hyperparathyroidism. From our clinical and pathohistological investigations, we suspected that the proliferation of parathyroid cells changed with the progress of renal hyperparathyroidism and we found that it was difficult to prevent enlargement of parathyroid glands and recurrence of this problem.