H syndrome: recently defined genodermatosis with distinct histologic features. A morphological, histochemical, immunohistochemical, and ultrastructural study of 10 cases.

This study analyzes the histopathological findings in H syndrome, a recently recognized autosomal recessive genodermatosis characterized by indurated, hyperpigmented, and hypertrichotic skin in well-defined anatomical areas accompanied by various systemic manifestations. So far, descriptions of the histopathological skin changes in this disorder, as reported in a few small case series, were inconsistent, leading to diverse clinical interpretations. In an attempt to define standardized, diagnostic, morphological criteria that will distinguish this disorder from other fibrosing conditions, we studied skin biopsies from 10 patients with H syndrome.

Angiokeratoma corporis diffusum in human beta-mannosidosis: Report of a new case and a novel mutation.

Background: Human beta-mannosidosis, a rare disorder of oligosaccharide catabolism, results from a deficiency of beta-mannosidase activity. So far, mutational analysis has been performed in only seven families and revealed 11 mutations in the MANBA gene which encodes the enzyme beta-mannosidase.

Objectives: We report here a 36-year-old Arab female with beta-mannosidosis who presented with mental retardation and multiple angiokeratomas.

Osteoporosis in the Cohen diabetic rat: correlation between histomorphometric changes in bone and microangiopathy.

Osteoporosis is well documented in type I diabetes, but its occurrence is controversial in type II diabetes. Microangiopathy is a major complication of type I and type II diabetes. We studied bone and microvascular changes in the Cohen diabetic rat, a unique nonobese model of noninsulin-dependent diabetes mellitus.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Isolation, chemical composition, and ultrastructural features of the cell membrane of the mycoplasma-like organism Spiroplasma citri.

Thin sections of Spiroplasma citri, a mycoplasma-like organism isolated from citrus infected with "Stubborn" disease, showed the organisms to be limited by a single trilaminar plasma membrane. An additional outer layer could, however, be frequently seen in freeze-etched preparations of unwashed cells. The organisms were found to be extremely sensitive to lysis by osmotic shock.