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At least 199 records · Page 11Linked to original sources

PubMed1993

Intraoperative identification of parathyroid glands with methylene blue infusion.

Intraoperative staining of parathyroid glands with methylene blue was used in 120 cervical explorations for hyperparathyroidism. The dye clearly stained 66 of 67 adenomas (98%) and 194 of 198 hyperplastic glands (98%). No recurrences were observed in 66 patients undergoing surgery for an adenoma. Six of 48 patients (12%) had recurrences of hyperplasia of the parathyroid glands. We found methylene blue to be an effective, safe, and easy applicable method to quickly identify abnormal parathyroid glands, thereby considerably shortening the operating time.

Adenoma↗

PubMed1975

Avian parathyroid glands in organ culture: secretion of parathyroid hormone and calcitonin.

Parathyroid (PT) glands from 20-day-old embryonic chicks cultured in a chemically defined medium secreted a stimulator of in vitro bone resorption. This stimulator was presumed to be parathyroid hormone (PTH) because: 1) the in vitro dose response curve was parallel to that obtained with bovine PTH; 2) the activity was eluted on Sephadex G-1-- chromatography at a position similar to that for PTH; and 3) the material produced hypercalcemia in vivo in chicks. The amount of PTH-activity secreted was inversely proportional to the calcium concentration of the medium over the range of 0.75-2.25 mM. The chick PT glands also secreted an inhibitor of PTH-stimulated bone resorption in vitro. This inhibitor was presumed to be calcitonin (CT) because: 1) the in vitro dose-response curve was parallel to that obtained with synthetic salmon CT; 2) the activity was eluted on Sephadex G-50 chromatography at a position similar to that for salmon CT; and 3) the material produced hypocalcemia in vivo in rats. In contrast to what would be expected for CT secretion, the CT-activity was secreted by the PT glands in response to a low, not high calcium concentration. The data suggest that the secretion of avian PTH is similar to that of the mammalian hormone, and that the ultimobranchialectomized chick with an intact parathyroid gland may not be deficient in CT.

Animals↗

PubMed1993

[Clinical utility of thallium-201 chloride in the diagnosis of parathyroid glands in patients with hyperparathyroidism].

Clinical utility for detection of hyperfunctioning parathyroid glands in patients with primary and secondary hyperparathyroidism (PHPT, SHPT) using 201TlCl and 99mTcO4-images was estimated in 50 patients including 18 PHPT and 32 SHPT (male; n = 31, female; n = 19, 51.5 +/- 11.1 yr). Detection of 94 hyperfunctioning parathyroid glands in 34 cases were achieved correctly by 201TlCl and 99mTcO4- images in agreement with surgical findings. Detectability of hyperfunctioning parathyroid glands was 100% in more than 1.0 g, 62.0% in more than 0.5 g and 41.5% in less than 0.5 g respectively. Ectopic parathyroid glands in two cases and a metastasis to pretracheal lymph node in one case were clearly demonstrated. Our results show that parathyroid scintigraphy using 201TlCl and 99mTcO4- as well as 131I or 123I is useful and safe method for preoperative detection of hyperfunctioning parathyroid glands.

Adult↗

PubMed1998

The parathyroid glands of two species of dolphin--Risso's dolphin, Grampus griseus, and bottlenose dolphin, Tursiops truncatus.

Although there have been many reports regarding the structure of the parathyroid glands of various terrestrial mammals, little is known about the parathyroid glands of marine mammals including Cetacea. The morphology of the parathyroid glands of three Risso's dolphins, Grampus griseus (about 3 m in length and 300 kg in weight), and three bottlenose dolphins, Tursiops truncatus (about 3 m in length and 300 kg in weight), was examined macroscopically and microscopically. The dolphins examined in the present study had two or four parathyroid glands that varied in size and location on the thyroid gland. Each parathyroid gland was encapsulated by fibrous tissue on the dorsal surface of the thyroid gland, and was divided into several lobules by interlobular connective tissue which contained numerous capillaries. The parenchymal cells consisted of pale staining chief cells. Each cell was polygonal and about 15 microm in diameter, and had one round or oval nucleus. Oxyphil cells were not found. Considering their greater body size, the parathyroid glands were rather small. By electron microscopic observation, the parathyroid gland of the bottlenose dolphin had sparse granular endoplasmic reticulum, poorly developed Golgi complexes, and abundant secretory granules in the cytoplasm of the chief cells. These results support a possibility that the activity of the parathyroid gland is suppressed to adapt to a sea habitat.

Animals↗

PubMed1975

Effect of calcium and magnesium on deoxyribonucleic acid synthesis in rat parathyroid glands in vitro.

DNA synthesis in rat parathyroid glands in organ culture is significantly affected by the calcium concentration of the medium. 3-H-thymidine incorporation over a 46-hour period was more than 100 per cent greater at 1.3 mM calcium than at 3.0 mM calcium. Thymidine incorporation was greatest at 0.9 to 1.3 mM, and fell off sharply between 1.3 and 1.8 mM calcium. Variation of magnesium concentration between 0.3 and 1.5 mM had no appreciable effect on DNA synthesis at either 1.3 or 1.8 mM calcium. No effect on DNA synthesis in rat liver explants or mouse L cells was observed over these ranges of calcium concentration, but in cultured rat kidney fragments, an opposite effect of calcium was observed, i.e., DNA synthesis was more active at 3.0 mM calcium than at 1.3 mM calcium. Time course experiments showed that a significant difference between DNA synthesis rates in high and low calcium media was observable in parathyroid glands during the first 3 hours in culture, and persisted for at least 108 hours. The calcium effect on DNA synthesis was not mediated by any direct effect on the rate of thymidine uptake by the tissue. These results suggest that a small drop in ambient calcium concentration in vivo could significantly increase the rate of DNA synthesis in the parathyroid glands, and thus provide experimental support for the concept that parathyroid hyperplasia in chronic renal insufficiency is caused by lowered serum calcium levels.

Animals↗

PubMed1997

[Recent progress in radionuclide imaging of parathyroid glands].

Scintigraphic imaging of parathyroid glands has been the subject of new developments. Efficiency of the technique has been improved by the use of a new agent Tc-99m sestamibi (MIBI). A meta-analysis study of the literature confirmed the superiority of this agent toward the conventional Tc/T1201. Various protocols have been proposed for parathyroid imaging with MIBI they are described with a comparison of their advantages and drawbacks. The superiority of a two isotopes protocol using Tc-99m sestamibi with Iodine 123 and a subtraction processing seems proven. Moreover, this latter protocol allows the use of lateral views resulting in a higher accuracy. The visualization of hyperplasic glands is also improved by this technique. Comparison of ultrasonography versus Tc-99m sestamibi scintigraphy is discussed in the light of recent published materials. The scintigraphy appears more sensitive than ultrasonography and specially in the detection of mediastinal ectopic glands. Finally the exact role of radionuclid imaging of the parathyroids in the management of primary hyperparathyroidism is described.

Humans↗

PubMed2003

Potential role for intraoperative gamma probe identification of normal parathyroid glands.

BACKGROUND: Patients undergoing central neck surgery are at risk for hypoparathyroidism. We hypothesized that gamma probe identification of sestamibi-labeled parathyroid glands might help maximize parathyroid preservation. METHODS: Records of 351 patients who underwent central neck surgery were reviewed. A subgroup of patients underwent sestamibi injection followed by gamma probe-directed parathyroid gland identification. RESULTS: Operation was performed for malignancy in 73% of patients and represented a reoperation in 34%. Persistent hypoparathyroidism was more common in patients who underwent reoperation versus a primary operation (6.8% versus 1.7%; P = 0.02). Thirteen patients underwent gamma probe-directed identification of sestamibi-labeled parathyroid glands; in 6 of these patients, sestamibi-labeled parathyroid glands were salvaged from the resected specimens and autografted. None of these 13 patients developed persistent hypoparathyroidism. CONCLUSIONS: Patients undergoing reoperative central neck surgery are at increased risk for postoperative hypoparathyroidism. Gamma probe-directed salvage of sestamibi-labeled parathyroid glands may help maximize parathyroid preservation, especially in complex or reoperative central neck surgery.

Gamma Cameras↗

PubMed1999

Macrophages in the hamster parathyroid gland: immunohistochemical and ultrastructural investigations.

The distribution and morphology of the parathyroid macrophages in golden hamsters from neonatal to senile periods were investigated using the monoclonal antibody to ED2 and electron microscopy. The results showed that definite ED2-positive cells were hardly detectable in the parathyroid gland of 1-day-old hamsters. A few ED2-positive cells could be identified in the parathyroid gland of 10-day-old hamsters. The ED2-positive cells were more densely and became conspicuous in 1-, 3-, and 12-month-old hamsters. The number of the cells seems to be increased with aging. Ultrastructurally, we did not find any macrophages in parathyroid glands of 1-day-old hamsters. In the 10-day-old hamster parathyroid gland, a few macrophages existed only in the interstitial tissues. In the parathyroid gland of 1-, 3-, and 12-month-old hamsters, many macrophages were found in the perivascular regions, some cells located among the parenchymal chief cells with no obvious vascular association. These cells showed some physical contacts with chief cells. These results suggest that the parathyroid macrophages exhibit dramatical changes in their distribution and morphology from neonatal to senile periods.

Aging↗

PubMed1976

Hyperparathyroidism: ectopic parathyroid glands.

A patient with a parathyroid adenoma located beneath the throid capsule and within a benign thyroid adenoma is reported on. To the best of our knowledge, this lesion has not previously been reported. This case points out the difficulties that may be encountered when it is necessary to locate a missing parathyroid gland in a patient with multinocular goiter. In this clinical setting there may be a role for use of the various technics recommended for preoperative localization of a parathyroid adenoma.

Adenoma↗

PubMed1980

Immunofluorescent staining experiments in parathyroid glands.

An antiserum against bovine parathyroid hormones was raised and applied for demonstration of parathormone-containing cells. Parathyroid glands of frog, fowl, dog, cattle and rat were used with different tissue preparation procedures. The best results were obtained in rats stimulated by previous intraperitoneal injection of sodium glycerophosphate. Bovine parathyroids were also positive after glutaraldehyde fixation and paraffin embedding.

Animals↗

PubMed1990

Immunohistochemical identification of calcitonin gene-related peptide and substance P in nerves of the bovine parathyroid gland.

Although peptide neurotransmitters have been shown to modulate hormone secretion in many glands, there are very few studies of neurotransmitters in the parathyroid gland. Bovine parathyroid glands were collected at a local abattoir, fixed with paraformaldehyde, sectioned using a cryostat, and stained by indirect immunohistochemistry for calcitonin gene-related peptide and substance P. We were able to positively identify both neuropeptides. Nerve fibres containing calcitonin gene-related peptide and substance P were identified in contact with the tunica media of arteries and arterioles and dispersed throughout the stroma of the gland. While many of the fibres encircled parenchymal lobules, no intimate contact with the peripheral chief cells was observed. All immunoreactive fibres were found to contain both neuropeptides. Since calcitonin gene-related peptide and substance P are vasodilators, they may increase blood flow within the gland. In addition, the neuropeptides may diffuse from perilobular nerve fibres into the parenchyma, thereby modulating secretion of parathyroid hormone.

Animals↗

PubMed1979

Effects of cadmium on the ultrastructure of the mouse parathyroid gland.

Electron-microscopic studies were made on the parathyroid gland of cadmium-treated mice. Most chief cells in treated mice were rich in free ribosomes and secretory granules compared to the control mice. In the parathyroid gland after 3 and 4 weeks of administration of cadmium, interdigitations between adjacent chief cells became more complex than in the control mice. In most chief cells of the parathyroid gland after 2, 3 and 4 weeks of administration of cadmium, the Golgi complexes associated with numerous prosecretory granules were better developed than in the control mice. These ultrastructural appearances suggest that parathyroid gland cellular activity was stimulated in response to cadmium treatment.

Animals↗

PubMed1989

Different responses between the upper and the lower parathyroid gland in a state of secondary hyperfunction. A study on chronic renal failure by morphometry and nuclear DNA analysis.

The size of the parathyroid gland and the size, the numerical density and nuclear DNA-content of the parathyroid gland cells were evaluated in chronic renal failure (CRF) and revealed a difference between the upper and the lower glands in the manner of adaptation to a state of long-term hyperfunction, secondary to CRF. The parathyroid gland enlarged as a whole in CRF, an effect more marked in the lower gland, whereas individual parathyroid gland cell enlargement in CRF was mainly seen in the upper gland cells. The numerical density of the lower parathyroid gland cells was higher than that of the upper gland. Nuclear DNA-content of the parathyroid gland cells were increased in CRF and the lower gland tended to show hyperdiploid aneuploidy. These findings are probably related to the fact that parathyroid adenomas occur most often in the lower gland. The higher proliferative activity of the lower parathyroid gland in long-term hyperfunction may explain the higher risk for the lower gland in the occurrence of adenomas.

Autopsy↗

PubMed1987

S-100 protein and neuron-specific enolase in parathyroid glands and C-cells of the thyroid.

Normal parathyroid glands and parafollicular cells (C-cells) of man, rat and rabbit, and also human parathyroid adenomas and medullary carcinomas were investigated for the presence of S-100 protein and neuron-specific enolase (NSE). For determination of the proteins immunoperoxidase methods were applied, i.e., the PAP method and the avidin-biotin system. The antisera, of polyclonal origin, were specifically directed against cow S-100 protein and rat or bovine NSE. The respective antisera are known to crossreact with S-100 protein from man, rat, and rabbit, as well as with NSE from man and rat. Surprisingly, the test for S-100 protein was found to be strongly positive in the parathyroid glands of rat and rabbit and was focally positive in normal and adenomatous human parathyroid glands, but completely negative in C-cells and medullary carcinoma cells. NSE was present in C-cells of rat and man, and in medullary carcinoma cells, but was absent in normal and adenomatous parathyroid cells. The results support data that indicate that both parathyroid cells and C-cells are derived from elements of the neural crest, but undergo different maturation processes during embryological development.

Animals↗

PubMed1988

Immunocytochemical localization of parathyroid hormone in hamster parathyroid gland.

The immunocytochemical localization of parathyroid hormone was examined in the hamster parathyroid gland by using the protein A-gold technique. Protein A-gold particles were concentrated over secretory granules, large secretory granules thought to be storage granules and Golgi vacuoles. No protein A-gold particles were detected over large vacuolar bodies and cisternae of the granular endoplasmic reticulum.

Animals↗

PubMed1985

[Parathyroid glands in long-term dialysis].

Parathyroid glands from 100 deceased persons treated by hemodialysis were compared with 84 bone lesions and with immunoreactive parathormon in serum of 59 cases. Parathyroid findings were in correlation with the type of bone lesion and parathormon rates. Increase of parathormon in hemodialysed patients reflected the hyperplasia of parathyroid glands.

Bone Diseases↗

PubMed1994

Blood supply of the parathyroid gland from the superior thyroid artery.

BACKGROUND: There is considerable controversy about the arterial supply to the superior parathyroid glands. Knowledge of this blood supply should be important for the surgeon performing thyroid and parathyroid operations. The purpose of this investigation was to document whether the superior parathyroid glands receive their blood supply from the superior thyroid artery. METHODS: We injected contrast material into the superior thyroid artery in 52 cadavers and determined the arterial blood supply to the parathyroid glands by using a dissecting microscope. RESULTS: The upper parathyroid gland was identified in 51 instances and the upper and lower glands in 26 instances on the side of injection. Of 92 parathyroid glands identified, 57 glands (62%) had a single artery, 26 (28%) had two, and 9 (10%) had three or more arteries. In 9 (45%) of the 20 cases specifically examined, a distinct anastomosing branch was identified between the inferior and the superior thyroid arteries, from which the upper parathyroid artery arose. CONCLUSIONS: Our study documented that the superior thyroid artery almost always supplies the upper parathyroid glands. Forty-five percent of the subjects had a distinct anastomosing branch between the superior and inferior thyroid arteries, which should be kept intact at operation to preserve the upper parathyroid function. One third of the parathyroid glands have two or more parathyroid arteries.

Arteries↗

PubMed1991

Ontogeny of parathyroid hormone-related protein in the ovine parathyroid gland.

PTH-related protein (PTHrP) has been implicated in calcium regulation during fetal life. In this study the ontogeny of PTHrP was examined in ovine parathyroid glands. Immunohistochemical techniques, Western blot analysis, and a RIA with antisera raised against synthetic fragments of human (h) PTHrP (i.e. 1-34, 1-40, 50-69, and 107-141) were used to detect the presence of immunoreactive PTHrP in parathyroid glands from fetal and neonatal lambs and maternal ewes. Positive immunostaining for PTHrP was observed in fetal (from 116 days of gestation) and lamb (up to 180 days post birth) but not maternal parathyroid glands with the PTHrP(50-69) antiserum. Fetal and lamb parathyroid glands consisted entirely of one cell type in which PTHrP immunoreactivity to PTHrP(50-69) antiserum was found. In contrast, immunoreactivity to PTHrP could not be detected in sections of fetal, lamb, or maternal parathyroid glands with antisera raised against PTHrP(1-34) or PTHrP(107-141). However, PTHrP immunoreactivity in urea/acid extracts of newborn lamb parathyroid glands could be detected by Western blot analysis and RIA with antisera raised against the N-terminal portion of PTHrP. Western blot analysis with the PTHrP(1-34) antisera revealed that urea/acid extracts of newborn lamb parathyroid glands contained a substance with a mol wt of 14.4K, which corresponded in size to that of hPTHrP(1-84). Newborn lamb parathyroid glands contained 0.35 ng PTHrP/micrograms extract, whereas maternal parathyroid glands contained only 0.035 ng PTHrP/micrograms extract when tested in a RIA employing recombinant hPTHrP(1-84) as standard and an antibody raised against hPTHrP(1-40). The detection of immunoreactive PTHrP in the developing ovine parathyroid gland provides further evidence to support the suggestion that PTHrP produced in the parathyroid gland is involved in the normal hormonal regulation of calcium metabolism in the mammalian fetus and neonate.

Animals↗