Microfilaments associated with Paget's disease of bone: comparison with nucleocapsids of measles virus and respiratory syncytial virus.

The structural characteristics and intracellular disposition of microtubules present in osteoclasts in Paget's disease of bone were compared with those of nucleocapsids in cells infected with measles virus and respiratory syncytial virus (RSV). The distribution of microtubules in pagetic osteoclasts closely paralleled that of measles nucleocapsids in monkey kidney cells, but the dimensions of the pagetic microtubules were significantly different from those of measles virus. In contrast, pagetic microtubules were not distinguishable in dimensions from RSV nucleocapsids but were dissimilar in their conformation and location. The observations support the hypothesis tht Paget's disease of bone is a slow virus disease and suggest that the virus is a pneumovirus (RSV) rather than a morbillivirus (measles).

Colony formation by normal and malignant human B-lymphocytes.

A method is described that permits colony formation in culture by B lymphocytes from normal blood and from blood, marrow or lymph nodes of patients with myeloma or lymphoma. The method depends on: (1) exhaustively depleting cell suspensions of T lymphocytes, (2) a medium conditioned by T lymphocytes in the presence of phytohaemagglutinin (PHA-TCM), and (3) irradiated autologous or homologous T lymphocytes. Under these conditions the assay is linear. Cellular development of B lymphocytes can be followed; differentiation to plasma cells is seen in cultures of cells from normal individuals and myeloma patients, but not lymphoma patients. Malignant B lymphocytes in culture produced immunoglobulin of the class identified in the patient's blood, or in freshly obtained cells. We conclude that the assay is suitable for studying the growth, differentiation and regulation of normal and malignant B lymphocytes in culture.

Necrospermia or immotile cilia syndrome as a cause of male infertility.

A case of infertility secondary to necrospermia was reinvestigated and reclassified as the "immotile cilia syndrome". The immotile spermatozoa were viable but motionless owing to an ultrastructural defect of the tail characterized by absence of microtubular dynein sidearms. There is no therapy for this congenital disorder and artificial insemination was performed.

PIP: A 24-year-old man presented for infertility after his wife of 5 years had undergone a battery of fertility tests, ruling out her role in the inability to conceive. Repeated analyses of this man's semen showed normal volume, count, and morphology, but 100% of the spermatozoa were immotile. The man's medical history showed no exposure to toxins temperature extreme, or urinary tract infections. Genitalia were normal. By trypan blue dye exclusion, the case was reclassified as immotile cilia syndrome, rather than necrospermia, because the immotile sperm were viable but motionless due to an untrastructural defect of the tail detected by electron microscopy and characterized by absence of microtubular dynein sidearms. This is a congenital disorder; artificial insemination was successfully performed.

Acute myeloblastic leukemia considered as a clonal hemopathy.

Acute myeloblastic leukemia, like certain other hematologic disorders, originates in pluripotent stem cells. Two general biologic processes underlie development of the disease. Over long times, clonal progression leads from normal polyclonal hemopoiesis through clonal preleukemia to leukemia. Overt leukemia is characterized by the emergence of blast cell populations. Over shorter times, clonal expansion yields cellular diversity based upon randomizing events. The analysis indicates that that blast population is of crucial importance. Characteristics of a colony assay for blast cell progenitors are presented.

Identification of type C viruses by electron microscopy.

The cores of a small proportion of the particles in purified preparations of type C viruses are characterized by two concentric shells that have a "double-ring" appearance in specimens prepared for electron microscopy by negative staining or thin sectioning techniques. This distinctive feature allows such particles to be recognized as viral in impure preparations. Detectability of double-ring particles is considerably enhanced by treating the specimens with a non-ionic detergent before fixation and negative staining. The limit of detectablity of type C virus (identified by the double-ring feature) in the presence of a large excess of nonviral particulates of similar size and density was assessed.

Particles with characteristics of leukoviruses in cultures of marrow cells from leukemic patients in remission and relapse.

An enzyme activity with the characteristics of RNA-directed DNA polymerase (reverse transcriptase) was detected in marrow from patients with leukemia in relapse and in firm hematological remission. Material having the enzyme activity, when analyzed in sucrose gradients, appeared as two distinct homogeneous bands of particles with densities of about 1.17 and 1.23 g/ml. The enzyme activity was stimulated by exogenous template poly(rC).(dG)(12-18) but not by (dT)(12-18). The enzyme activities in these bands also increased (1.7- to 24-fold) after culture, and both bands with enzyme activity were obtained from the cultured cells and from the supernatant medium. Electron microscopic studies showed that the two bands contained particles resembling leukoviruses or their cores.