Differentiation of brown adipose cells in three-dimensional collagen gel culture

Brown adipose cells are heat-producing cells through non-shivering thermogenesis by intramitochondrial "thermogenin". This specific protein is a marker for their cellular differentiation. It has long been known that cultured brown adipose cells in monolayer rapidly lose the thermogenin bioactivity. In this study, we cultured brown adipose cells in three-dimensional type I collagen gel matrix. Under this culture condition, they were able to survive, and differentiated morphologically and functionally for a long period of time, especially exhibited the characteristic immunohistochemical activity of thermogenin. These findings suggest that brown adipose cells differentiate in type I collagen gel. In this condition, cholera toxin or BRL 37344, one of beta 3-adrenoceptor agonists, specifically stimulated the brown adipose cells.

Intravascular immunoglobulin crystalloids in monoclonal cryoglubulinemia-associated dermatitis: ultrastructural findings

A 46-year-old woman developed polyarthritis, purpuric skin rashes, nasal septal perforation and marginal furrowing of corneas in 1980. Monoclonal IgG, kappa cryoglobulinemia was found in the patient's serum. No underlying lymphoproliferative disorder has been found in ten years since her original diagnosis. In 1991, she developed palpable purpura on both lower extremities with subsequent necrosis and ulceration. A skin biopsy revealed fibrin thrombi within capillaries in the papillary dermis, and immunofluorescence studies showed IgG and light chain kappa within the fibrin thrombi. An electron microscopy study showed intravascular immunoglobulin crystalloid structures with a mean diameter of 80.3A degrees (8.03 nm), mixed with fibrin and red blood cells. The exclusive vascular location of these crystalloids may have implication in the pathogenesis of skin lesions.

Parathyroid glands in primary hyperparathyroidism: an ultrastructural morphometric study of 25 cases

In parathyroid glands removed from patients with primary hyperparathyroidism (pHPT), hyperplasias and adenomas cannot be distinguished from one another by light microscopy when only one gland is available for examination. When a second gland is available, it is necessary to establish whether it is normal, suppressed, or hyperplastic. This distinction may be difficult, and the main criterion is the amount of cytoplasmic lipid in the parenchymal cells. If the lipid is abundant, the gland is considered normal or suppressed, and if it is scanty, the gland is interpreted as hyperplastic. We have performed a morphometric ultrastructural study to test the reliability of this criterion. Twenty-five adenomatous glands removed from patients with pHPT, when compared with glands of normal size from euparathyroid patients, showed a significant increase in the parameters indicative of metabolic activity, namely the size of the Golgi apparatus, the amount of rough endoplasmic reticulum, and the length of plasmalemmas. In addition, the amount of cytoplasmic lipid was significantly reduced. Furthermore, 25 glands of normal size removed from the same patients with pHPT showed an amount of lipid similar to that of normal glands from euparathyroid patients. However, all the parameters indicative of metabolic activity were significantly higher than those in glands from euparathyroid patients and comparable to those found in adenomatous glands. These results suggest that in pHPT, normal-size glands are as active as adenomatous glands, regardless of a higher lipid content.

Malignant fibrous histiocytoma of the brain in a six-year-old girl

We have prepared karyotypes from a malignant fibrous histiocytoma (MFH) of the brain of a 6-year-old girl. Sporadic cases of MFH in the central nervous system have been reported. However, to our knowledge, this is the first central nervous system tumor to be subjected to cytogenetic analysis. The tumor demonstrated a complex karyotype, with a variety of numerical and structural abnormalities. Although no specific cytogenetic abnormality was observed, the karyotype of this case was similar to those reported for adult MFH of soft tissues.

Comment to Shinohara et al. (1991) FEBS Letters 293, 173-174. The uncoupling protein is not expressed in rat liver

Using Northern blot analysis, immunoblotting with purified antibodies and Polymerase Chain Reaction analysis, we were unable to detect the Uncoupling Protein-UCP or its mRNA in liver of control, cold-exposed or newborn rats. The unique expression of this protein in brown adipocytes was confirmed. These data refute the surprising recent report on UCP expression in rat liver (Shinohara (1991) FEBS Lett. 293, 173-174). Moreover we report that the hybridization signal obtained by these authors is probably non-specific and due to the 3' non-coding domain of the UCP cDNA probe.

Pituitary adenylate cyclase activating polypeptide (PACAP): discovery and current status of research

For last 2 years since PACAP was first discovered, many important findings on PACAP have been reported. cDNAs encoding the precursor proteins of PACAP in sheep, human and rat were cloned, and the precursor proteins characterized. PACAP was found in a high concentration in the central nervous system, adrenal medulla and testis. Immunohistochemical study indicated that PACAP containing neural fibers are present throughout the brain, including both internal and external zones of the median eminence. In the hypothalamus many PACAP positive cell bodies were demonstrated in the supraoptic nucleus and the paraventricular nucleus in various species. Four types of high affinity PACAP receptor were demonstrated. PACAP receptors in the central nervous system, pituitary, adrenal medulla and germ cells of the testis are highly specific for PACAP, and not shared with VIP. The PACAP receptor was solubilized and cross-linking of 125I-PACAP27 with the binding protein suggest that the molecular weight of the receptor is around 57,000. Various biological actions of PACAP were reported, but the physiological cellular events linked with PACAP-induced activation of adenylate cyclase remain to be investigated.

Intercellular communication within the rat anterior pituitary gland: IV. Changes in cell-to-cell communications during pregnancy

Cell-to-cell communication by gap junctions was investigated in the female rat anterior pituitary gland from 9 through 21 days of pregnancy and subsequently on days 2 and 20 of the lactational period. Compared with intact estrus females, the major morphological characteristics of the pituitary gland during pregnancy were remarkably developed prolactin cells and gonadotrophs. A close relationship of both cell types was clearly evident. Gap junctions were present at each of the time intervals studied; however, they were noted only between adjacent folliculo-stellate cells. No remarkable changes were noted in the number of gap junctions during the middle stage of pregnancy (day 9 through day 15), with the relative number resembling that found in intact, 90-day-old controls during estrus (0.47 +/- .01 junctions/follicle-control vs. 0.50 +/- 0.08--day 15 of pregnancy). In the later stages of pregnancy (day 17 through day 21), a demonstrable increase was observed (0.64 +/- 0.10--day 17, 0.79 +/- 0.11--day 19 and 0.72 +/- 0.12--day 21), whereas during the lactation, this pattern returned to that seen at midpregnancy. Since both prolactin and the gonadal steroid hormones dramatically fluctuate during pregnancy and lactation, it is postulated that they may have an active role in gap junction formation during these two phases of reproductive life.

Parathyroid hyperplasia in multiple endocrine neoplasia type 1: a pathological and immunohistochemical reappraisal

Twenty-nine parathyroid glands from nine patients with multiple endocrine neoplasia type 1 (MEN 1) syndrome were examined histopathologically and immunocytochemically to characterize better the nature of the accompanying parathyroid hyperplasia. The parathyroids showed varying degrees of nodular and diffuse (partial and total) hyperplastic involvement as well as apparently normal tissue. The nodules were usually multiple within any one gland and showed a varied cytoarchitectural pattern. All glands studied showed both cellular argyrophilia and parathyroid hormone immunoreactivity. The staining pattern for parathyroid hormone ranged from negative or weak to strong and from patchy to diffuse in hyperplastic tissue from different glands and within the same gland. Apparently normal areas usually showed the strongest positive reaction. Amyloid material was observed within glandular lumens from hyperplastic areas in over half of the studied cases and stained positively for parathyroid hormone. This suggests that the hormone could be the precursor molecule of parathyroid amyloid as occurs with hormone-derived amyloid from other endocrine tumours. The overall findings indicate that the most striking feature of the parathyroid glands in MEN 1 is their variability, both morphological and functional, as indicated by their parathyroid hormone immunoreactivity.

S-100 protein immunopositivity in human nontumorous hypophyses and pituitary adenomas

The presence, distribution, and morphological appearance of S-100 protein-immunoreactive cells in the human hypophysis were studied by immunocytochemistry. One hundred and twelve nonadenomatous pituitaries from fetuses to adults and pituitaries affected by several lesions including metastases, acute infarcts, and lymphocytic hypophysitis, as well as 115 pituitary adenomas were examined.S-100 protein immunoreactivity was detected in neurohy-pophyseal pituicytes and stellate cells of the pars distalis from 5 months following birth. In adults, S-100 protein-immunopositive cells displayed a preferential topographical association with growth hormone-, follicle-stimulating hormone-, luteinizing hormone-, and alpha-sub-unit-immunoreactive cells and with capillary walls. Colloid-containing follicles were mainly lined by hormone-containing cells, although scattered S-100 protein-immunoreactive processes or cell bodies were also observed forming their walls.No major changes in S-100 protein-immunoreactive cells were observed in the pituitary parenchyma bordering metastatic, inflammatory, necrotic, or adenomatous tissues. Eighteen of 115 pituitary adenomas contained a variable number of S-100 protein-immunoreactive cells. No preferential association of these cells with any type of pituitary adenoma was found.We propose that S-100 protein expression in the nontumorous adenohypophysis and pituitary adenomas may constitute a dynamic process and that S-100 protein-positive cells may constitute a heterogeneous cell population composed of pure, fully differentiated stellate cells and of transdifferentiated follicular cells.

Bone abnormalities and severe arthritis in pachydermoperiostosis

Two patients with pachydermoperiostosis were studied in whom the predominant features at presentation were severe and disabling knee and ankle joint pain in association with distal long bone pain. Analysis of synovial fluid from the knee joints showed non-inflammatory changes. In one patient a bicortical iliac crest bone biopsy specimen, taken after labelling with demeclocycline, showed appositional rates which were increased in cortical bone but reduced in trabecular bone. This mismatching resulted in trabecular osteoporosis, which occurred in association with increased numbers of osteoclasts, findings which suggest differential functional changes affecting the two bony envelopes.

Cancer family syndrome associated with multiple malignant melanomas and a malignant fibrous histiocytoma

A 64-year-old female with the cancer family syndrome suffered from multiple malignant melanomas and a malignant fibrous histiocytoma. She has shown unusually long survival which is a feature of these patients.

Intercellular communication within the rat anterior pituitary gland. III. Postnatal development and periodic changes of cell-to-cell communications in female rats

Cell-to-cell communication by gap junctions was investigated in the female rat anterior pituitary gland from 10 through 45 days of postnatal development and in 60-day-old animals. Gap junctions initially appeared between adjacent folliculo-stellate cells on day 25. Their appearance in female rats was 5 days later than that observed in males (Soji et al., 1990). Gap junction number increased until the animals became 40 days of age, when they reached a level that resembled that found in adults. In addition, a correlation was evident between the frequency of gap junctions and stages of the estrous cycle, where they were most numerous during either proestrus or estrus. These results along with those previously published suggest that gap junction formation within the female rat hypophysis is in part modulated by both gonadal steroid hormones as well as prolactin.

Response to autoimmune enteropathy to cyclosporin A therapy

Small bowel enteropathies that are associated with an autoimmune process are often resistant to treatment. Two children with autoimmune enteropathy were treated with cyclosporin A for eight months. Both improved, as assessed by growth, small intestinal mucosal morphology, and carbohydrate absorption. Cyclosporin A is useful in the treatment of autoimmune enteropathy. This report also suggests that T cell activation (which is suppressed by cyclosporin A) is important in the pathogenesis of this condition.

Gastrointestinal manifestations of type 1 neurofibromatosis (von Recklinghausen's disease)

Gastrointestinal involvement in von Recklinghausen's disease occurs in three principal forms: hyperplasia of the submucosal and myenteric nerve plexuses and mucosal ganglioneuromatosis which leads to disordered gut motility; gastrointestinal stromal tumours showing varying degrees of neural or smooth muscle differentiation; and a distinctive glandular, somatostatin-rich carcinoid of the periampullary region of the duodenum that contains psammoma bodies and which may be associated with phaeochromocytoma. This review describes the histopathological features of these lesions and discusses potential pitfalls in their differential diagnosis. Their accurate identification has significant implications for clinical management and may even provide the first pointer to the diagnosis of neurofibromatosis.

Lipid-rich rhabdomyosarcoma--a potential source of diagnostic confusion

Rhabdomyosarcoma is an often primitive tumor capable of diverse morphologic manifestations. The article describes three cases of childhood rhabdomyosarcoma in which a significant population of lipid-rich tumor cells was present. The lack of specificity and potentially confusing nature of this feature are discussed, and the ultrastructural diagnosis of rhabdomyosarcoma is briefly reviewed.

Ptosis caused by pachydermoperiostosis

Pachydermoperiostosis is a rare inherited disorder which presents with finger clubbing, facial enlargement, and periostitis. A case is described in which surgery for ptosis was performed and the differential diagnosis of the condition is discussed. The histological and ultrastructural appearances of the eyelids show sebaceous gland hyperplasia and excessive deposition of mucin in the dermis and would suggest that pachydermoperiostosis may be an example of a cutaneous mucinosis.

Histopathology, hormone products, and clinicopathological profile of endocrine tumors of the upper small intestine: A study of 44 cases

Forty-two duodenal and 3 upper jejunum tumors from 44 patients were investigated. All tumors were tested immunohistochemically for gastroenteropancreatic hormones and general endocrine cell markers. Twenty-eight of the 45 tumors (62%) proved to be gastrin cell tumors, with (12 cases) or without (16 cases) associated Zollinger-Ellison syndrome. Zollinger-Ellison syndrome was part of type 1 multiple endocrine neoplasia syndrome in 3 cases. Twenty-three of the 28 gastrin cell tumors (82%) were from proximal duodenum, 2 were from the second part of the duodenum, and 3 were from the upper jejunum. Seven cases were somatostatin cell tumors, 6 of which were from the ampullary region; 5 cases were associated with biliary tract disease and 2 with associated cutaneous neurofibromatosis. Four ganglioneuromatous paragangliomas, from the ampullary region or nearby duodenum, showed somatostatin cells, coupled with pancreatic polypeptide cells in 2 cases. Two serotonin-producing argentaffin carcinoids were also identified. In addition to the main cell type, 30 tumors showed one or more, usually minor, cell populations producing somatostatin, serotonin, cholecystokinin, pancreatic polypeptide, insulin, neurotensin, or the alpha chain of human chorionic gonadotropin. Only 3 tumors lacked hormone immunoreactivity. Some correlation has been noted between histological structure and hormone content of tumor cells, with prevalence of broad gyriform trabeculae and vascular pseudorosettes among gastrin cell tumors, tubuloacinar patterns among somatostatin cell tumors, thin parallel trabeculae among PP cell growths, and a solid nest pattern among argentaffin carcinoids. Deep infiltration of the intestinal wall was observed in 22 tumors, 6 of which also had metastases to local lymph nodes. All metastatic cases were among ZES tumors or ampullary somatostatin cell tumors. Ganglioneuromatous paragangliomas and nonfunctioning gastrin cell tumors had essentially benign behavior, even when involving deep strata of the intestinal wall. Post operative follow-up study of 36 cases, including all metastatic tumors, showed no evidence of tumor-related death or progressive tumor disease.

Ultrastructural morphology of folliculo-stellate cells in human pituitary adenomas

Fifty-six pituitary adenomas were studied by electron microscopy in a search for the presence of folliculo-stellate cells (FSCs) with the aim of evaluating their prevalence and ultrastructural morphology. FSCs were scattered in two adenomas (one oncocytoma and one densely granulated GH cell adenoma) and were numerous in a sparsely granulated GH cell adenoma; their overall prevalence was 5.4%. Ultrastructural examination of the three neoplasms revealed that FSCs were hypertrophic element with abundant cytoplasm and organelles (in contrast to FSCs of the normal pituitary) and no obvious signs of neoplastic transformation. Junctional complexes between FSCs were similar to those described in the normal gland. Numerous follicular structures were lined by FSCs. FSCs in pituitary adenomas are probably nonneoplastic, reactive cells showing signs of hyperactivity, similar to FSCs found during pituitary hypersecretion and in estrogen-induced tumor.

Lack of binding between cryoimmunoglobulins, immunoglobulins and fibronectin: implications for immune complex vasculitis

Immune-complex-mediated vasculitis is a frequent complication of rheumatoid arthritis and systemic lupus erythematosus. The mechanism of deposition of immune complexes within the vessel wall in these diseases remains unknown, but probably involves other proteins. Fibronectin is a likely candidate since it possesses the ability to bind to collagen, endothelial cells, and possibly immunoglobulins and immune complexes. In this study, the binding of fibronectin to IgG and IgM cryoglobulins, cold soluble IgM, IgG, IgG subclasses and IgG fragments was investigated in the solution phase. Static light scattering, fluorescence anisotropy, fluorescence intensity, and PEG precipitation studies were used to investigate binding under different conditions of temperature and ionic strength. These studies failed to demonstrate significant binding between fibronectin and IgM, IgG, IgG subclasses and IgG fragments under the conditions studied. These findings argue against solution phase binding of fibronectin and immunoglobulins contributing to immune complex vasculitis. The possibility of important surface interactions between these proteins has not been ruled out.

Spermatic cord liposarcoma: ultrasound for diagnosis and follow-up. Case report

A case of spermatic cord liposarcoma is described in a 48-year-old man. Following local excision, the tumour recurred after 3 years, leading to funiculoorchiectomy. The case is presented, the literature reviewed and the role of ultrasound in the diagnosis discussed.

The pituitary gland in pregnancy: a clinicopathologic and immunohistochemical study of 69 cases

A histologic and immunocytochemical study of 69 autopsy-obtained pituitaries from women who died during pregnancy, after abortion, or in the postpartum period revealed an accumulation of large chromophobic to slightly acidophilic and periodic acid-Schiff-negative pregnancy cells that were immunoreactive for prolactin but not for other pituitary hormones. This increase in the number of prolactin cells was confirmed by cell counts. Thus, pregnancy cells are capable of prolactin production. The finding of mitotic figures in such cells supports the view that they arise by multiplication from preexisting prolactin cells. With use of "mirror section" techniques, no mammosomatotrophs (cells immunoreactive for growth hormone and prolactin) were identified. Hyperplasia of prolactin cells was evident at 1 month of pregnancy and gradually disappeared within several months after delivery or abortion; the process of involution seemed to be retarded in the one lactating patient investigated. In some pituitaries, the accumulation of prolactin cells was so extensive that the hyperplastic foci resembled microadenomas. Another striking change in the pituitaries of pregnant women was appreciable reduction of immunostaining of gonadotropic cells, a process that was reversible as soon as 1 month after delivery. Among the 69 pituitaries studied, 8 noninvasive microadenomas (12%) were encountered (7 contained prolactin only and 1 was plurihormonal). Prolactin-producing adenomas were no more numerous or larger than were similar tumors encountered in nonpregnant women or normal men; thus, pregnancy neither initiates formation of pituitary adenomas nor accelerates their growth. In the pituitaries that harbored prolactin-producing adenomas, massive pregnancy cell hyperplasia was evident outside the tumor; thus, prolactin production by adenoma cells did not seem to suppress the proliferation of prolactin-containing pregnancy cells.

Limited joint mobility in insulin dependent childhood diabetes

Limited joint mobility (LJM), beginning typically in the fifth finger and moving radially, affecting interphalangeal, metacarpal-phalangeal, and large joints, is the earliest clinically apparent complication of diabetes in childhood and adolescence. It is painless and not disabling. Approximately 50% of post-adolescent patients with more than 5 years duration of diabetes are affected, with age being more important than duration of diabetes, as is the case with other complications. Growth failure is more frequent in the presence of LJM, although correlations with diabetic control have not been found. Variations in frequency in various reports, including high prevalence in controls or relatives, appear to be related to the quality of the examination; simple inspection with hands pressed flat on the table top or together in the prayer position is inadequate; passive extension must be performed. Although differential diagnosis from other conditions causing limitation of the fingers in diabetes would appear simple, LJM has been confused with other conditions which can be distinguished by the presence of pain or paresthesias, neurologic findings, disability, finger-locking, swelling, muscle atrophy, palmar skin or fascial thickening, absence of typical distribution, calcification of the vessels and, particularly, the age group affected. That the periarticular thickening found on examination and demonstrated on roentgenograms reflects generalized abnormalities is suggested by association with thick tight waxy skin, decreased pulmonary function, and association with retinopathy, nephropathy, and neuropathy, independently of duration of diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Allo-activated CD4+ and CD8+ lymphocyte subsets: new ultrastructural findings based on computer-assisted image analysis

Primary allo-stimulation induces substantial and differentiated modifications in the development of cytoplasmic organelles of peripheral T-lymphocyte subsets. The present computer-assisted image analysis provides evidence that the CD4+ subset undergoes significant increase in organelle density after stimulation, while the CD8+ subset exhibits a post-stimulation organelle development proportional to the cell size. Each immunological subset contains two distinct patterns of cytoplasmic organization, here defined as type I (containing a few cytoplasmic organelles) and type II (with well-developed synthesis and storage organelles). On the basis of these findings cytologic parameters could be ascribed to a heterogeneous proliferation of functionally distinct T-cell clones in CD4+ and CD8+ subsets.

Postnatal appearance of uncoupling protein and formation of thermogenic mitochondria in hamster brown adipose tissue

Brown adipose tissue of developing hamster was characterized by western blotting, enzyme activity measurements and immunoelectron microscopy. During the first postnatal week the tissue contained significant amounts of differentiating mitochondria and comparable quantities of active cytochrome oxidase and ATP synthase. The uncoupling protein appeared on the 7/8th day and its specific content increased 80-times between day 8 and day 17. In parallel, the specific content and activity of cytochrome oxidase increased 3-times but ATP synthase decreased 2-times. The total content of uncoupling protein and of cytochrome oxidase in interscapular brown adipose tissue increased 360- and 11-times, respectively. Analysis of isolated mitochondria showed that the observed differences result mainly from changes of the enzymic equipment of the mitochondrial membrane. During the same interval, propylthiouracil-insensitive "type II' thyroxine 5'-deiodinase activity in brown adipose tissue increased 10-times. It was concluded that the thermogenic function of the hamster brown adipose tissue develops after the first postnatal week due to highly differentiated synthesis of mitochondrial proteins leading to replacement of preexisting, uncoupling protein-lacking nonthermogenic mitochondria by thermogenic ones, similarly as shown in brown adipose tissue of the embryonic mouse and rat (Houstĕk, J., et al. (1988) Biochim. Biophys. Acta 935, 19-25).

Morphometric evaluation of intracytoplasmic lipid in normal and pathological parathyroid glands

The chief morphological criterion for classifying parathyroid glands as 'normal', 'suppressed', or 'activated' is the lipid content of the cytoplasm. In particular, cytoplasm lipid deposit is scanty in the active parathyroid cell, according to many authors. In this paper we present the results of a morphometrical study of ten normal parathyroid glands from patients undergoing thyroidectomy, 20 enlarged 'adenomatous' glands from patients with primary hyperparathyroidism, and 20 glands of normal size from the same hyperparathyroid patients. We aimed at assessing the content of intracytoplasmic lipid of secretory cells in all these conditions. The results show that secretory cells of adenomatous glands have less lipid than those from normal glands; however, there was considerable overlapping of the data in the two groups. The mean lipid content of cells in glands of normal size taken from hyperparathyroid patients was not significantly different from the mean value of normal cells, even when ultrastructural evidence of activation was present in the former. These data suggest that caution has to be exercised in assessing the functional status of parathyroid glands on the basis of lipid content of secretory cells, mainly when differentiating between adenoma and hyperplasia.

Isolation of a novel 38 residue-hypothalamic polypeptide which stimulates adenylate cyclase in pituitary cells

A novel neuropeptide which stimulates adenylate cyclase in rat anterior pituitary cell cultures was isolated from ovine hypothalamic tissues. Its amino acid sequence was revealed as: His-Ser-Asp-Gly-Ile-Phe-Thr-Asp-Ser-Tyr-Ser-Arg-Tyr-Arg-Lys-Gln- Met-Ala- Val-Lys-Lys-Tyr-Leu-Ala-Ala-Val-Leu-Gly-Lys-Arg-Tyr-Lys-Gln-Arg-Val-Lys-Asn-Lys - NH2. The N-terminal sequence shows 68% homology with vasoactive intestinal polypeptide (VIP) but its adenylate cyclase stimulating activity was at least 1000 times greater than that of VIP. It increased release of growth hormone (GH), prolactin (PRL), corticotropin (ACTH) and luteinizing hormone (LH) from superfused rat pituitary cells at as small a dose as 10(-10)M (GH, PRL, ACTH) or 10(-9)M (LH). Whether these hypophysiotropic effects are the primary actions of the peptide or what physiological action in the pituitary is linked with the stimulation of adenylate cyclase by this peptide remains to be determined.

Intracerebral malignant fibrous histiocytoma at site of a previously excised low grade glioma

The case of a 42-year-old patient is reported who developed an intracerebral malignant fibrous histiocytoma at the site of an oligoastrocytic mixed glioma which had been excised 2 1/2 years previously. Reasons for the extreme rarity of intracranial malignant fibrous histiocytomas, the probability of a traumatic aetiology of this particular tumour, and the possible significance of intratumoural cells positive for glial fibrillary acidic protein (GFAP) are discussed.

S-100 protein in white preadipocytes: an immunoelectronmicroscopic study

Differentiation of adipocytes from their precursor cells (preadipocytes) is an important problem in the study of the pathogenesis of obesity. Unfortunately, among the immature stages of adipocytes, only relatively differentiated forms can be identified by their fine structure; because early preadipocytes cannot be distinguished from fibroblasts solely on the basis of their morphology, it is impossible to assess the size of the preadipocyte population. S-100 protein has been identified in various mammalian tissues and recently mature adipocytes have been shown to be positive for this protein. Because fibroblasts are negative for S-100 protein, the present study tested the S-100 immunoreactivity of preadipocytes by the peroxidase-antiperoxidase (PAP) preembedding method at the ultrastructural level both in vivo and in culture. Mature adipocytes and early preadipocytes, including fibroblast-like cells devoid of lipid droplets, were positive both in vivo and in culture. Endothelial cells and pericytes were negative; but flattened, lipid-free, fibroblast-like cells surrounding the pericytes were positive. True fibroblasts both in vivo and in culture were negative. Therefore, S-100 protein can be a useful biochemical marker in distinguishing fibroblasts from early preadipocytes.

Spindle cell and pleomorphic lipoma: an immunohistochemical study and histogenetic analysis

Twenty-two spindle cell lipomas and seven pleomorphic lipomas were investigated immunohistochemically in order to study the differentiation of the non-adipocytic elements. In all cases, neither spindle cells nor pleomorphic cells reacted with antibodies to a monocyte/macrophage antigen (MAC-387), fibronectin, laminin or type IV collagen. The absence of demonstrable basement membrane material argues against the possible prelipoblastic nature of these cells. With the antibody to S-100 protein, spindle cells were immunonegative, whereas pleomorphic cells sometimes revealed an intracytoplasmic weak to moderate staining reaction. In the light of what is known about the development of adipose tissue, our results would support the hypothesis of Bolen and Thorning (Am J Surg Pathol 1981; 5: 435-441) that spindle cell lipoma is composed of adipocytes and non-fat storing immature mesenchymal cells. It would appear that pleomorphic lipoma is similarly derived but that in some cases adipocytic differentiation is also abnormal. The characteristic clinical distribution of these two types of tumour may be of relevance in determining the cause of these unusual benign patterns of differentiation.

Brown adipocytes differentiated in vitro can express the gene for the uncoupling protein thermogenin: effects of hypothyroidism and norepinephrine

Expression of the gene for the brown-fat specific uncoupling protein thermogenin was investigated in cell cultures by hybridization of isolated RNA with a cDNA clone corresponding to mouse thermogenin. The RNA was isolated 3-4 days after confluence from cells differentiated in culture from precursors isolated from the interscapular brown adipose tissue of 5-week-old mice. Very low thermogenin mRNA levels were found in cells derived from untreated mice, and there was only little effect of added norepinephrine on thermogenin gene expression in these cells. However, in cells derived from hypothyroid (methimazole-treated) mice there was a higher expression of thermogenin, and norepinephrine had a marked augmenting effect on the thermogenin mRNA level in these cells. These effects of thermogenin mRNA levels were specific, in that they contrasted with the effects of hypothyroidism and norepinephrine on the level of other mRNA species in these cells (coding for beta-actin, lipoprotein lipase, cytochrome-c oxidase, and glycerol-3-phosphate dehydrogenase). It was concluded that brown-fat cells in culture can reach a differentiated state, sufficiently advanced that the unique properties of these cells can be expressed, and that thermogenin gene expression (i.e., the level of thermogenin mRNA) is under direct control of norepinephrine.

Ectopic endocrine pancreatic tumour simulating splenic angiosarcoma

A case of ectopic endocrine pancreatic tumour that had developed within the spleen of a 46-year-old man is reported. The tumour was highly vascularized through the splenic artery, angiographically simulating an angiosarcoma. The histological pattern was typical of an endocrine tumour, and its nature was confirmed by a positivity for keratin, chromogranin A and somatostatin. Foci of atrophic pancreatic tissue were detected in the tumour capsule.

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.