Storage and degradation of secretory proteins in adenomatous and secondary hyperplastic parathyroid cells. An immunoelectron microscope study

Parathyroid hormone (PTH) and chromogranin A/secretory protein-I (SP-I) have been localized on immunoelectron microscopy in double-fixed tissues from adenomatous and secondary hyperplastic parathyroid glands. Storage organelles, identified on the basis of their consistent labelling, included tow morphologically distinct varieties of granules/vesicles; the mature granules and the progranules. The former consisted of dense, mostly rounded, medium to large-sized bodies which were strongly labelled and predominant in the proximity of the cell membrane. The other variety of body included a spectrum of small pale vesicles/granules which were mainly located in the Golgi area. Because their morphology and their labelling pattern varied other bodies were assumed to be engaged in degradation or cleavage of the secretory proteins. These bodies comprised crinophagic structures, that is to say multivesicular bodies and large Golgi-related vesicles, as well as a number of atypical solid bodies. Whereas most of the granulated cells stored a mature or a maturing population of vesicles/granules, the process of maturation appeared to be either absent or incomplete in a number of cells from some glands. The major defects were frequently associated with an unusual labelling pattern of the Golgi area and selectively affected groups of cells from all the transitional oxyphil cell adenomas. The minor defects concerned individual cells of different types present in both categories of glands. The present data suggest that in hyperfunctioning glands, the type of hormone processing depends on the capacity of each cell in progranule maturation and that the maturation capacity may decrease dramatically in adenomatous or chronically hyperstimulated cells of the transitional oxyphil type.

Ultrastructure of pituitary folliculo-stellate cells of lactating rat during treatment with 2-bromo-alpha-ergocriptine

Folliculo-stellate cells of adenohypophysis were studied by transmission electron microscopy in lactating rats during treatment with the dopaminergic agonist 2-bromo-alpha-ergocriptine. Folliculo-stellate cells showed marked activation in control lactating rats, were unaffected by a single injection of the drug (3 mg/kg), regressed to the morphology of those found in non-lactating animals upon 6 days of drug treatment (1 mg/kg/die) both in presence and in absence of the suckling stimulus. However, morphometric analysis showed a proportion of folliculo-stellate cells in the gland which was similar in the four experimental groups (range: 11.3-13.5%), despite the increasing reduction of prolactin cells (55, 44, 32, 30%). In chronically treated animals to which suckling had been denied, extruding and degenerating prolactin cells were found, as well as extracellular material in non follicular spaces; the latter were lined by both folliculo-stellate and endocrine cells. These data suggest a dual reactivity of folliculo-stellate cells in the adenohypophysis according to the functional status of the gland.

Pathology of dysproteinemia: light chain amyloidosis, non-amyloid immunoglobulin deposition disease, cryoglobulinemia syndromes, and macroglobulinemia of Waldenström

This review has dealt with four syndromes associated with dysproteinemia, and has emphasized studies of the tissue deposits and forms of tissue injury which occur in such patients. However, similar tissue deposits and tissue damage occasionally occur in the absence of a serum or urine paraprotein, in which case other clinical data are necessary to suggest the need for examination of tissue for Ig heavy and light chain determinants in order to provide a correct diagnosis of dysproteinemia. In such cases, one may speculate that there is a low rate of paraprotein production and secretion, in addition to tissue tropism. Some paraproteins are antibodies, in which case they may circulate and/or deposit as immune complexes, or bind to tissue antigens with immune complex formation in situ. Some paraproteins are also cryoproteins, and clues to this property can also be found in the tissue, particularly at the ultrastructural level. Thus, a wide spectrum of clinical manifestations of a B cell proliferative disorder may be associated with any of a variety of circulating paraproteins and a variety of forms of tissue deposit and injury. Consequently, the best understanding of an individual patient requires correlation of the clinical features of the disorder, the immunochemical characterization of the circulating and excreted paraproteins, and an immunohistochemical analysis of the tissue deposits and associated morphologic abnormalities. This should be correlated with histologic and immunohistologic assessment of bone marrow, looking for overt B cell neoplasia, the more difficult to define "lymphoproliferative disorders," or alterations in kappa to lambda plasma cell ratios which may correlate with the deposited material. Studies of the Ig synthesized by cultured bone marrow plasma cells, and biochemical analyses of the deposited material, have demonstrated structural abnormalities of paraproteins which may be responsible for their tissue deposition.

Retrieval of precursors for white-type adipose conversion in brown adipose tissue

A cellular compartment from brown adipose tissue (BAT) of newborn rats was isolated by Percoll-density-gradient centrifugation and was shown to proliferate and to undergo adipose conversion in vitro in primary culture. The features of the effector requirement for adipose conversion as well as the differentiated morphological and biochemical phenotype are almost identical with that of a compartment designated HCF, from white adipose tissue (WAT). A possible role for these precursors from BAT and WAT in the involution of BAT into WAT, on the one hand, and in the development of brown adipose cells among typical WAT deposits, on the other, is discussed.

The laminate capillary and its wall of multiple basement membranes

Cutaneous telangiectatic vessels from two cases of unilateral dermatomal superficial telangiectasia were shown under electron microscopy to be venular capillaries with thick walls composed of multiple basement membranes. We suggest that this special capillary structure, seen in a variety of telangiectatic and disease states, should be called the 'laminate capillary'.

Gangliocytic paraganglioma of the duodenum: report of cytologic, histologic, immunohistochemical, and ultrastructural features of a case

A case of gangliocytic paraganglioma of the duodenum is reported, including light microscopic, ultrastructural, and immunohistochemical characteristics. The cytologic appearance, as might be seen in fine-needle aspiration smears, indicates a neoplasm with three cellular components (epithelioid, ganglion, and spindle cells) seen histologically by light and electron microscopy.

Dedifferentiated liposarcoma of the liver

Among the rare occurrences of primary malignant mesenchymal tumors of the liver, the development of liposarcoma has been only theoretically listed--there is no proven example in the literature. This article documents a case of primary liposarcoma of the liver in a 30-year-old woman who presented with a huge intrahepatic tumor in the left lobe measuring 14 X 10 X 6 cm. It was composed of two distinct macroscopic and histologic features--the well-differentiated liposarcoma and the cellular, nonlipogenic pleomorphic sarcoma. The former was a mature, lipomatous tumor with various stages of lipoblasts. The latter was much more cellular, made up of pleomorphic cells admixed with a few areas of spindle cells with many mitotic figures, resembling a pleomorphic variant of malignant fibrous histiocytoma. Oil red O stain revealed multifocal, but a scanty amount, of fat-storing tumor cells in both compartments aside from large fat globules in the differentiated area. This is the first reported case of primary liposarcoma of the liver.

Spindle cell lipoma: a clinicopathological study with some original observations

Forty-one cases of spindle cell lipoma, an entity first described in 1975, are presented. Of these, 38 were identified in a systematic review of 2478 tumours of adipose tissue diagnosed and treated in one hospital over a 25 year period. This lesion, therefore, accounts for about 1.5% of adipocytic neoplasms and is outnumbered by conventional benign lipomas by approximately 60 to 1. The remaining three were referred cases. Seventy-five per cent of the lesions arose, as expected, on the back of the neck, upper back or shoulder, almost exclusively in males between 40 and 70 years of age. Ten lesions were identified at unusual sites: six in the limbs, three on the face and one on the trunk. One lesion arose within skeletal muscle, a previously unreported phenomenon, and this case showed both cartilaginous and osseous metaplasia. Only one of the 41 tumours has recurred locally. The range of histological features in spindle cell lipoma is described and the differential diagnosis is discussed.

Hibernomas of the head and neck

Hibernomas are rare tumors derived from brown adipose tissue, a specialized form of fat tissue found in hibernating and nonhibernating animals. Only a minority of reported hibernomas have occurred in the head and neck region. This report describes two cases of cervical hibernomas, one of which was preoperatively diagnosed by the use of fine-needle aspiration biopsy. The clinical and pathologic characteristics of this neoplasm are reviewed. In general, hibernomas are slow-growing tumors with inconclusive evidence for the existence of a malignant variant. A review of the literature supports the conclusion that excision, sparing vital structures, appears to be curative.

Fine needle aspiration biopsy and the otolaryngologist

A survey of the diagnostic value of fine needle aspiration cytology in ENT practice was carried out over a 3-year period. The 119 aspirates were taken from a variety of head and neck sites and examined by an experienced cytopathologist. Cytology was accurate in 111 (93 per cent), with two false negative aspirates (1.7 per cent) and no false positive results. There were no complications and the technique was found to be a rapid, safe and cost-effective diagnostic tool.

Effects of noradrenaline exposure on rat brown adipocytes in cultures. An ultrastructural study

Adipocytes in intact brown adipose tissue show multivacuolar lipid deposit and mitochondria of 'typical' morphology. Cultured brown adipocytes retain the multivacuolar lipid deposit, while 'typical' mitochondria degenerate and 'atypical' organelles appear instead of the former. Since evidence exists that catecholamines deeply influence brown adipose tissue morphology and function in vivo, we undertook the present ultrastructural investigation to assess whether exposure of cultured brown fat cell to noradrenaline could prevent (or induce regression of) the in vitro morphological modifications of brown adipocytes. Brown adipocytes cultured for 8 h in the presence of noradrenaline (5 X 10(-5) M) had a larger mitochondrial area (i.e. a larger percentage of cytoplasm occupied by non-degenerating mitochondria) in comparison with control cells, as assessed by morphometry; this was due to larger number of mitochondria in noradrenaline-treated cells. Moreover, a number of cells with mitochondria strictly resembling those of the intact tissue were visible in noradrenaline-treated cultured after 8 hr, while 'typical' mitochondria were no longer observed in parallel control cultures. After 5 days of culture without hormone addition, exposure to noradrenaline (5 X 10(-5) M) did not induce quantitative modifications of 'atypical' mitochondria or changes of their ultrastructure up to 12 hr. However, reduction in size of the lipid deposit and activation of both rough endoplasmic reticulum and Golgi apparatus were evident in noradrenaline-treated adipocytes in comparison with non-treated cells.

Parathyroid cell variants may be provoked during immersion fixation

Parathyroid glands of cattle, dogs, cats, mice and rats were immersed in glutaraldehyde or mixtures consisting of glutaraldehyde, formaldehyde and acrolein in either Na-phosphate, Na/K-phosphate or Na-cacodylate buffer, and postfixed with OsO4 in the same buffers or, alternatively, in s-collidine. Excellent preservation of bovine, feline and murine parathyroid glands was achieved with fixation mixtures containing 1% glutaraldehyde, 1.5-2% formaldehyde and 2.5-5% acrolein in 0.1 M Na-cacodylate with or without Ca2+ and Mg2+, Na-phosphate or Na/K-phosphate at 4 degrees C followed by postfixation with 1% OsO4 in the same buffers or in s-collidine containing sucrose, Ca2+ and Mg2+. This procedure largely abolished the occurrence of parathyroid cell variants. Bovine parathyroid glands were also satisfactorily preserved with 1% glutaraldehyde and 2% formaldehyde whereas 1% glutaraldehyde and 2.5 or 5% acrolein, lower or higher buffer osmolarity, or immersion at room temperature led to vacuolization of RER and to breakdown of membranes. In contrast, all fixation protocols led to the formation of dark and light cell variants and to multinucleated syncytial cells in dog and rat parathyroids. The results thus show that parathyroid cell variants arise during immersion fixation and that aldehydes, buffers and temperature are important factors for provoking parathyroid cell variants.

A preadipocyte clonal line from mouse brown adipose tissue. Short- and long-term responses to insulin and beta-adrenergics

A clonal cell line has been established from the interscapular brown adipose tissue (BAT) of the C57 BL/6J +/+ mouse. The line, designated BFC-1, is aneuploid and exhibits both morphological and biochemical properties characteristics of mature adipocytes. Adipose conversion begins after confluence and is accompanied by an early emergence of lipoprotein lipase; a later emergence of glycerol-3-phosphate dehydrogenase and acid: CoA ligase; an increase in the average triglyceride content. Adipose conversion, estimated by activities of enzyme markers, is enhanced at any given time by the continuous presence in the culture medium of insulin and triiodothyronine, both within their physiological range of concentrations. In addition to both hormones, chronic exposure of confluent cells to beta-adrenergics brings similar long-term effects on adipose conversion. The uptake of labelled 2-deoxyglucose by differentiated BFC-1 cells is stimulated by insulin; the half-maximum effect is observed at 1 nM insulin. Differentiated BFC-1 cells, in which endogenous triglycerides have been prelabelled on the fatty acid moiety, do respond to beta-adrenergics by releasing radioactive fatty acids. The agonist potency order and the EC50 value for each agonist are BRL 37344 (0.5 nM) greater than isoproterenol (1.5 nM) greater than norepinephrine (3 nM) greater than epinephrine (7 nM) greater than salbutamol (15 nM). The half-maximally and maximally effective concentrations of corticotropin to stimulate lipolysis are found to be 4 and 100 nM, respectively. The lipolytic response to isoproterenol is counteracted by prior addition of insulin or simultaneous addition of propranolol. Parallel studies performed on Ob17 cells, a clonal line established from mouse white adipose tissue (Négrel et al., Proc natl acad sci US 75 (1978) 6054), show that the agonist potency order and the EC50 value for each agonist are BRL 37344 (3 nM) greater than isoproterenol (10 nM) greater than norepinephrine (20 nM) greater than epinephrine (40 nM). Thus both BFC-1 cells and Ob17 cells show an atypical beta-adrenoreceptor similar to that described in rat adipocytes (Arch et al., Nature 309 (1984) 163), but the sensitivity of BFC-1 cells toward beta-agonists is found to be 6-fold higher than that of Ob17 cells. Thus the BFC-1 line represents a useful model for the study of short- and long-term responses to beta-adrenergics.

Parathyroid glands in primary hyperparathyroidism: an ultrastructural study of 50 cases

Parathyroid glands from 50 cases of primary hyperparathyroidism were examined by light and electron microscopy in an attempt to elucidate the diagnostic role of electron microscopy in this disease. In the cases in which only one gland was removed at surgery, a final diagnosis by light microscopy was not possible. The electron microscopic findings for some of these single glands (e.g., ribosomal-lamellar complexes and groups of centrioles) suggested that they were adenomas. In cases in which two or more enlarged glands were removed, a correct final diagnosis could be made on the basis of the light microscopic findings alone, and electron microscopy provided no further significant information. Where one enlarged gland and one normally sized gland were removed, electron microscopy disclosed important findings in the normally sized glands. Specifically, light microscopic examination of normally sized glands suggested endocrine suppression, while electron microscopy showed chief cell activity, thereby changing the final diagnosis from adenoma to hyperplasia. The clinical follow-up assessment in some of these patients confirmed the electron microscopic findings. Therefore, the incidence of adenoma in patients with primary hyperparathyroidism should be critically re-evaluated by ultrastructural studies of the normal glands that should be removed with the enlarged ones.

Asymmetrical lipomatosis: report of two cases

We report on two patients with an asymmetrical expansion of fat tissue. At computed tomography, lipomatous tissue proved to be superficially located in one patient and both subcutaneously and deeply located in the second. Signs and symptoms of a peripheral neuropathy were observed in both patients, who were otherwise asymptomatic. The lipolytic activity in post-heparin plasma was normal in both patients. The fat cell size of lipomatous tissue, obtained in one patient by percutaneous needle biopsy, was higher than that of contralateral, uninvolved adipose tissue. The adipose tissue lipoprotein lipase activity in lipomatous tissue was higher than that in normal tissue. High density lipoprotein (HDL), HDL2 and HDL3 cholesterol values were elevated in both patients but not exceeding 1 standard deviation the values of age and sex matched controls. Isoprenaline-stimulated lipid mobilization was similar in lipomatous and in control tissue.

Nailfold computed videomicroscopy in morpho-functional assessment of diabetic microangiopathy

Although careful measurement of the size of capillary loops is mandatory in the evaluation of diabetic microangiopathy, no current technique allows rapid and careful morphometric analysis of capillaroscopic findings. In an attempt to solve this problem, assembling readily available instruments, the authors have set up an original apparatus for computed videomicroscopy. The apparatus ensures detailed morphological assessment of single loops at high magnification. Each single frame stored on videocassettes can be digitalized for morphometric analysis, saved on floppy disk or printed by means of a graphic printer.

Functional alpha 1 protease inhibitor produced by a human hepatoma cell line

Alpha 1 protease inhibitor antigen was identified in the culture medium of the human ascites hepatoma cell line SK-HEP-1. Trypsin inhibitory activity and alpha 1 Pl antigen accumulated in serum-free medium concomitantly over a period of several days. Radioactive alpha 1 Pl antigen was detected in conditioned medium from cultures supplemented with 35S-L-methionine, indicating a synthesis and release of the protein. Alpha 1 Pl antigen in conditioned medium appeared to be antigenically identical to that in human plasma, and the newly synthesized (radiolabeled) antigen co-migrated with plasma, alpha 1 Pl after immunoelectrophoresis or SDS-polyacrylamide gel electrophoresis. Moreover, evidence is presented that the synthesized inhibitor exhibits functional activity, since the 35S-labeled alpha 1 Pl in conditioned medium complexes with trypsin. We conclude that SK-HEP-1 cells in culture produce functionally active alpha 1 Pl which may be identical to that in plasma.

Mixed chemodectoma-ganglioneuroma of the conus medullaris region

Report of a 33-year-old man with a year-long history of low-back pain radiating into the left leg. Neurologic examination upon admission to the hospital revealed a spinal compression syndrome at the level L5. Laminectomy at L 4/5 revealed an encapsulated intradural tumor measuring 4 X 2.5 X 2.5 cm. The tumor was attached to the dorsal root L 4 and extended downward to the conus region. Light and electron microscopy revealed features mostly consistent with a mixed chemodectoma and ganglioneuroma.