Immunotactoid glomerulopathy with massive bone marrow deposits in a patient with IgM kappa monoclonal gammopathy and hypocomplementemia.

A case of immunotactoid glomerulopathy with an amyloid-like material in the glomeruli and bone marrow is described. Clinically the patient was diagnosed as having severe nephrotic syndrome, hypocomplementemia, and IgM kappa monoclonal gammopathy. Immunotactoid glomerulopathy is an unusual cause of glomerulonephritis, characterized by Congo red-negative, amyloid-like deposits in the glomeruli. This unusual case presentation shows that immunotactoid glomerulopathy may be a manifestation of systemic disease. This patient also presented with hypocomplementemia, an extremely rare associated finding that has been reported previously in only four cases of immunotactoid glomerulopathy.

Prenatal diagnosis of oculocutaneous albinism type I: review and personal experience.

Oculocutaneous albinism type I (OCA I) comprises autosomal recessive syndromes of hypopigmentation and low vision, caused by the lack of tyrosinase activity. Affected families seek genetic counseling and prenatal diagnosis as preventive measures. Until recently, prenatal diagnosis of OCA I was achieved by histologic and electron microscopic examination of fetal skin biopsies. Lately, a molecular genetic approach has become possible by the identification of the two mutated copies of the TYR gene, coding the tyrosinase, in which over 60 mutations have been identified. We report here our experience in prenatal diagnosis of OCA I using the two strategies. Thirty-four prenatal tests were performed in fetuses at risk for OCA I. In 31 cases the diagnosis was made in fetal scalp biopsies using the histological approach. The microscopic observations revealed normal melanogenesis in 26 biopsies. Five albino fetuses were diagnosed by the demonstration of arrest of melanogenesis in early stages I and II. In three pregnancies, molecular genetic tests were performed on DNA extracted from amniocytes, using direct mutation analysis (in one), and complemented by linkage analysis (in two). One albino and two normally pigmented fetuses were diagnosed. The prenatal molecular genetic test can be applied to families when at least one mutation is diagnosed in the albino patient. The histological approach is applicable in all families at risk for OCA I.

Prenatal sonographic appearance of congenital fibrosarcoma.

Congenital fibrosarcoma is a rare soft tissue sarcoma. A 22-year-old woman in the 22nd week of her first pregnancy underwent sonographic examination, which revealed a soft tissue swelling of the fetus's left thigh. The pregnancy was terminated, and congenital fibrosarcoma was diagnosed by pathologic examination. To our knowledge, this is the first published report of the intrauterine sonographic observation of this tumor in a fetal extremity.

Infantile hemangioendothelioma of the ovary: a monodermal teratoma or a neoplasm of ovarian somatic cells?

Vascular tumors of the female genital tract are uncommon, and only a few cases have been reported in the ovary. We describe herein, an unusual tumor of the ovary: infantile hemangioendothelioma (cellular hemangioma of infancy) in a newborn. The tumor consisted of well-formed blood vessels and proliferating endothelial cells that were arranged in solid cordlike structures. The tumor permeated the ovarian stroma and entrapped normal ovarian follicles. By immunohistochemistry the neoplastic cells expressed factor VIII, CD34, and alpha smooth-muscle actin, and ultrastructurally they had the features of endothelial cells that were focally associated with pericytes. We examined simple sequence repeat (SSR) polymorphic markers in the tumor tissue, as well as in the patient's and parents' blood. The informative SSR markers were found to be identical in the tumor and in the patient's somatic cells. We suggest that the tumor described herein is a congenital infantile hemangioendothelioma arising from ovarian parenchymal cells rather than a teratoma originating from germ cells. A similar morphologic lesion has been described recently in the ovary and interpreted as monodermal teratoma composed of vascular tissue.

Merkel cell carcinoma diagnosed by fine-needle aspiration.

Merkel cell carcinoma is a relatively rare neoplasm of the skin. The present study describes three cases of Merkel cell carcinoma diagnosed by fine-needle aspiration cytology and reviews their histologic, cytologic, and ultrastructural features. The advantages of using fine-needle aspiration to diagnose Merkel cell carcinoma (and other cutaneous neoplasms) are emphasized.

Ultrastructural characteristics of cytotrophoblast cells during stages of differentiation.

Isolated cytotrophoblast cells from term human placenta were separated into eleven fractions according to cell size, by centrifugal elutriation. Each fraction isolated was examined by electron microscopy to elucidate ultrastructural features consistent with differences in stages of cellular differentiation. As a rule, increasing cell size correlated with evidence of progressive intracellular differentiation. This was represented by the appearance of specialization structures in later fractions, and by changes in the density of organelles and other cellular constituents. Progressive development and maturation of the rough endoplasmic reticulum was also evident. These data are the first to demonstrate successful subfractionation of the heterogeneous cytotrophoblast cell population into distinct groups, each representing different levels of cellular differentiation. These morphologic features of differentiation correlate closely with established biochemical parameters associated with various stages of intermediate cytotrophoblast cell differentiation.

Structural and functional evaluation of modifications in the composite skin graft: cryopreserved dermis and cultured keratinocytes.

Structural and functional aspects of modifications in the composite skin graft consisting of cultured keratinocytes and cryopreserved dermis were determined. Cryopreserved human cadaveric dermis separated from skin by short and mild trypsinization was compared with dermis obtained by prolonged incubation in medium and with fresh dermis obtained by the same methods. All types of dermis were shown to retain normal ultrastructure and topographic organization, as detected by scanning and transmission electron microscope and immunofluorescence analysis. However, in fresh skin, the layers were more firmly attached, mechanical separation was more difficult, and residual epidermis often remained attached to the dermis. Keratinocytes attached better, began replication earlier, and generally reached higher cell numbers when cultured on trypsinized dermis than on medium-treated dermis. The performance of several modifications in the reconstitution and grafting procedures of the composite skin graft after transplantation to athymic mice was examined. Cultured epidermis combined onto trypsinized or medium-treated whole and meshed dermis, dermis pregrafted and allowed to take before transplanting epidermis on top, and keratinocytes grown into multiple epithelia on top of trypsinized meshed or whole dermis prior to grafting. The best grafting results were obtained with an "instant" reconstituted skin model: multiple epithelia grown in vitro combined immediately before grafting onto meshed trypsinized dermis. The transplantation results of this modification were significantly better than those of all the other modifications, including initial growth of keratinocytes into multiple epithelia on top of trypsinized dermis prior to grafting.

Oxygen and extracellular fluid restriction in cultured heart cells: electron microscopy studies.

STUDY OBJECTIVE: To evaluate the effects of "simulated ischaemia" on the structure of cultured heart cells. DESIGN: Cultured heart cells were subjected for 2 h either to anoxia or to anoxia with simultaneous extracellular volume restriction ("simulated ischaemia"). Cells maintained under normoxic conditions served as controls. The cells were then fixed in situ in Petri dishes with formaldehyde-glutaraldehyde. EXPERIMENTAL MATERIALS: Heart cells from one day old rats on day 5 in culture were used. MEASUREMENTS AND RESULTS: Electron microscope studies were carried out on control and injured cells. "Mildly ischaemic" cells featured raffled and invaginated cell surfaces, reduced matrix density, disorientated mitochondrial cristae due to swelling, and giant mitochondria. Dilatation of rough endoplasmic reticulum and electron dense membrane bound vesicles were observed in the cytoplasm. CONCLUSIONS: The model of simulated ischaemia is in keeping with the classical picture of irreversible cell damage caused by ischaemic injury.

Muscle carnitine deficiency presenting as familial fatal cardiomyopathy.

Three siblings presented with fatal cardiomyopathy confirmed by electron microscopy, and normal serum but low muscle carnitine concentrations. A fourth had similar signs but remained asymptomatic. He was treated with carnitine orally which increased the concentration in muscle, though it remained below normal. Electron microscopic features were unchanged.

Localization of glycogen in the placenta of diabetic rats: a light and electron microscopic study.

The ultrastructure of the placentae on day 20 of gestation was studied in rats made diabetic by streptozotocin injection on day 13 of gestation. In the placentae of control rats most of the glycogen was found in the glycogen cells, while some of it was localized to the labyrinth trophoblastic layers. In the diabetic rats a marked increase in glycogen content, together with higher numbers of glycogen cells in the junctional zone, was seen. Glycogen was also stored in other cell types of this zone, as well as in all cell types of the placental labyrinth of the diabetic animals.

Alveolar soft-part sarcoma of the female genital tract. Case report with ultrastructural findings.

An alveolar soft-part sarcoma of the uterine cervix observed in a 26-year-old woman is described. One year after extended radical hysterectomy there was no evidence of tumor recurrence. To the best of our knowledge, this is the second reported case of alveolar soft-part sarcoma arising in the female genital tract and the first description of this tumor in the uterine cervix.

Incorporation and modification of exogenous phosphatidylcholines by mycoplasmas.

The uptake and modification of exogenous phosphatidylcholine (PC) by several Mycoplasma and Spiroplasma species was investigated. While in most Mycoplasma species and in all Spiroplasma species tested the PC appears to be incorporated unchanged from the growth medium, the PC of M. gallisepticum, M. pulmonis, and M. pneumoniae was disaturated PC, apparently formed by modification of 1-saturated-2-unsaturated PC from the growth medium. The modification of the exogenous PC by M. gallisepticum was inhibited by chloramphenicol under conditions that did not affect de novo synthesis of phosphatidylglycerol. A low activity of an endogenous phospholipase A was detected in native M. gallisepticum membranes. The activity was markedly stimulated by treating the membranes with low concentrations of the nonionic detergents. The PC modification was affected by the fatty acid composition of the exogenous PC species. Diunsaturated, 1-saturated-2-unsaturated, and 1-unsaturated-2-saturated PCs were modified to various extents, whereas the disaturated dipalmitoyl PC (DPPC) was not. Both modified and unmodified PCs were incorporated by the cells, but the unmodified DPPC was incorporated at a lower rate and to a lesser extent. The possibility that the incorporation of DPPC into M. gallisepticum cells is associated with the formation of intracytoplasmic membranes is discussed.

Nonfunctional paraganglioma of the pancreas.

A patient with nonfunctional paraganglioma situated adjacent to the pancreas is presented. The clinical picture, the laboratory studies, as well as the gross appearance of the tumor and a frozen section at operation were not diagnostic. Internal drainage of the cystic tumor, assumed to be a pseudocyst of the pancreas, was done. Excision was performed when the diagnosis was histologically and ultrastructurally established. The microscopic and the electron microscopic features of this rare neoplasm are discussed. Excision of the tumor is recommended as the treatment of choice because of the malignant potential that does not correlate well with the histological appearance.

Uptake and transbilayer distribution of phosphatidylcholines in Mycoplasma gallisepticum and their effect on cell morphology.

Mycoplasma gallisepticum cells grown in a serum-free medium incorporated large amounts of egg-phosphatidylcholine (Egg-PC), dioleoylphosphatidylcholine (DOPC) or dipalmitoylphosphatidylcholine (DPPC) added to the growth medium. Egg-PC and DOPC were incorporated at a high rate and to a large extent and were modified by the organisms, whereas DPPC was incorporated at a lower rate and to a lesser extent and was not modified by the cells. The lactoperoxidase-mediated radioiodination applied to study the transbilayer distribution of phosphatidylcholine (PC) in the membranes revealed that the PC in cells grown with DOPC is almost equally distributed in the outer and inner leaflets of M. gallisepticum membranes, while the PC in DPPC-grown cells is preferentially located in the outer leaflet and that in Egg-PC-grown cells is found in the inner leaflet. Thus, in Egg-PC- or DPPC-grown cells the equilibrium in structure and properties between the inner and outer leaflets is disturbed, resulting in dramatic effects on the morphology of M. gallisepticum cells.

Tubular cell emboli in the glomerulus--a needle biopsy artifact.

In a needle biopsy specimen of the kidney, epithelial cells were found within the capillaries of a single glomerulus. These proved to be proximal tubular epithelial cells with their typical nuclei, mitochondria, lysosomes, junctional complexes, and brush border. Similar cells were also found in Bowman's space. This is an artifact of the needle biopsy in which tubular cells or cell fragments had been detached from the tubule by the needle and then pushed through the cut end of an arteriole into the glomerular capillaries and to Bowman's space.

Isolation of mycoplasma membranes by dicyclohexylcarbodiimide-induced lysis.

A simple procedure was devised to prepared membranes from Mycoplasma gallisepticum cells. The cells were lysed in an isosmotic NaCl solution by dicyclohexylcarbodiimide, which blocks ATPase activity and interferes with the regulation of cell volume. The procedure can be used to isolate membranes of other osmotically resistant mycoplasmas.

The occurrence of extracellular matrix vesicles in pulmonary alveolar microlithiasis.

Mineralization in pulmonary alveolar microlithiasis was studied by transmission electron microscopy. The disease is characterized by psammoma like calcifications composed of hydroxyapatite crystals. The calcifications were surrounded by typical forming cells and matrix composed of collagen fibers arranged in a longitudinal pattern. Abundant calcifying extracellular matrix vesicles were found between the cells and the calcified fronts. The type of calcification found in the present lesion is similar to ectopic primary mineralization in other diseases, embryonal ossification and bone wound healing.

Formation of gap and tight junctions between reaggregated blastomeres of the killifish, Fundulus.

Blastomeres from eggs of the killifish, Fundulus, were mechanically dissociated and reaggregated by pelleting in a simple saline solution. Formation of gap and tight junctions was followed by electron microscopy of freeze-fracture replicas. Five to eight min after pelleting, neither new nor old junctions were observed. After 10-15 min, small gap junctions were found, but these were not associated with distinct formation plaques. Larger gap junctions were observed after 45 min, and the images were consistent with growth by accretion of intramembrane particles. In aggregates, after 20 min or more, tight junctions were much more commonly found than in intact blastulae, and it seemed likely that they were being formed by cells that were not doing so in the intact embryo. Initial stages consisted of short strands that appeared to grow in length. Also, more elaborate junctions were seen than occur in situ. Particle-free membrane often occurred near incomplete junctions, and large junctions like those in situ separated particle-rich from particle-free membrane. In this system, the formation of both gap and tight junctions occurs with shorter latency, and is more precisely timed, than heretofore described.

Membrane polypeptides co-induced with the bacterial bioluminescent system.

Electrophoretic analysis of membrane proteins and electron microscopy of freeze-fracture replicas reveal that certain polypeptides and intramembrane particles are absent in Beneckea harveyi harvested prior to luminescence induction but present after induction. The polypeptides and particles are also absent in mutants which fail to synthesize the luminescent system. These correlations implicate membrane polypeptides in the bacterial bioluminescent system.

Characterization of the mycoplasma membrane proteins. V. Release and localization of membrane-bound enzymes in Acholeplasma laidlawii.

The peripheral membrane protein fraction released by washing Acholeplasma laidlawii membranes with low-ionic strength buffers contained about 50% of the total membrane-bound ribonuclease and deoxyribonuclease activities. The ATPase, NADH oxidase and p-nitrophenylphosphatase activities remained bound to the membrane even when EDTA was added to the wash fluids, and thus appear to belong to the integral membrane protein group. Serving as a marker for peripheral membrane proteins, the membrane-bound ribonuclease activity was solubilized by bile salts much more effectively than the integral membrane-bound enzymes. On the other hand, the solubilized ribonuclease showed a much lower capacity to reaggregate with other solubilized membrane components to membranous structures. Yet, most of the ribonuclease molecules which were bound to the reaggregated membranes could not be released by low-ionic strength buffer. The reaggregated membranes differed from the native membranes in the absence of particles on their fracture faces obtained by freeze cleaving, and by their much higher labeling by the [125-I]lactoperoxidase iodination system. These results suggest that most of the proteins are exposed on the reaggregated membrane surfaces, with very little, if any, protein embedded in its lipid bilayer core. Enzyme disposition in the A. laidlawii membrane was studied by comparing the activity of isolated membranes with that of membranes of intact cells after treatment with pronase or with an antiserum to membranes. The data indicate the asymmetrical disposition of these activities, the ATPase and NADH oxidase being localized on the inner membrane surface, while the nucleases are exposed on the external membrane surface.